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[Question] [ This is related to my last question [here](https://worldbuilding.stackexchange.com/questions/74058/how-could-a-magical-sentient-library-defend-itself). The library here is not necessarily the magical sentient library mentioned in the previous question, but can be *any* wizard library. This library can be in any form e.g. a secluded tower in a wood, or a huge library where many wizards live together, or in an academy. This parasite is an **[obligate parasite](https://en.wikipedia.org/wiki/Obligate_parasite)**: it cannot live outside a wizard library, or it will die in 2-3 days. The parasite can be found in virtually any wizard library, and even an apprentice mage can detect its presence. Considering it is a parasite, and it often tampers with a wizard's experiment or spell casting: **Why do wizards not attempt to exterminate these parasites?** Additional background: 1. The parasite feeds on remnants of magic power used from experiments or spell casting. Often, it intentionally distracts the caster so that the spell fails, to get more magic remnants. 2. There is no mana required to cast a spell. The residue of magic power is only produced after spell casting. 3. There is no benefit for a wizard or mage to keep this creature around. 4. This creature **can** accidentally activate scrolls. However, it is not believed that it does so on purpose. It *might* be on purpose, but it has never been proven. Scrolls can be activated without knowing the inner workings​ of the spell. The physical or magical features of this creature are up to you to decide, but I'm imagining a ghost-like semi-corporeal creature flying around the library. You can make up a fully incorporeal ghost, or something like that. [Answer] Regarding: > > There is no benefit for a wizard or mage to keep this creature around. > > > I disagree. > > The parasite feeds on remnants of magic power used from experiments or > spell casting. Often, it intentionally distracts the caster so that the > spell fails, to get more magic remnants. > > > This parasite can be used as a magic residue cleaning device - even the apprentice knows that magic residue left uncleaned can wreak havoc. This creature is a living training dummy. A spellcaster needs to maintain concentration and cast a spell properly even if something is biting his leg or whispering nonsense in his ears. This creature may be useful for exterminating other vermin like rats, mice and cockroaches. It may keep apprentices awake when they perform Sleepless Night Meditations. It can even scare off trespassers of wizards library - unlike magic apprentices, trespassers are not aware that this scary noises, shadows and ghostly monsters are just illusions created by cat sized magic residue eating creature and most damage it can do to human is few bites and scratches. Probably it looks like domesticated ferret: [](https://i.stack.imgur.com/CgpHs.jpg) This creature may be simply cute. So spellcasters keep it as a mascot. [Answer] * Easy. They can't. Why are rats not exterminated easily? Cockroaches? Pigeons (in big cities, I remember an anecdote about one city that had a population of 50k pigeons, killed 120k over a few years, maybe one or two decades and afterwards had a population of 50k pigeons)? * They respawn / are unkillable * They are generated by magic, come from another dimension, lay eggs (or similar) in books that can't be detected and therefore infest libraries * It is too much effort, especiually related to how fast they come back or how much damage they actually make. * Maybe there is only one big parasite but a million very small children that can only get big if the big one is killed, so killing the big one will just get you a few days of pause, then another one turns up. Or, to add insult to injury, it might be a kind of initiation. Maybe the older, more experienced mages that would be able to remove those parasites had to learn to cast shield spells while casting their other spells which is a very important ability and therefore they want their novices to learn that too. So they just don't remove that annoying little parasite that feeds of the magic residues which else could be used as shortcuts for new spells. [Answer] # The librarians like them. Wizards don't like the creatures, but librarians like them. For one thing, it keeps the wizards from casting spells in the library. Any librarian will tell you that spell-casting is a fire hazard! And what happens after a tired wizard has "just tried to heat my coffee"? Right, their efforts to stop the fire will do more damage than the fire. Give me an honest parasite any day! It enforces the "no magic in the library" rule better than any librarian. Also, keeping too many books of magic in one place is dangerous in itself. These creatures keep the magic buildup from becoming too bad. Yes, they eat the occasional scroll, but it turns out that these *by pure accident* are the very scrolls librarians don't want wizards to read, like Fooldare's Unquenchable Fire and Stilgar's Infinite Fountain. And when there is a magical accident, as will always happen when wizards are around, the creature will help in the cleanup. [Answer] ## **Temptation:** Why are they allowed to stay? The wizards hope they can get the magic-eaters to change. Nobody in your world has read this Worldbuilding thread. Nobody knows you have decreed these creatures are permanently and forever useless. All the wizards see are creatures that sometimes eat magic. Think of the possibilities! Just think of them! If they could be tamed… The wizard who tames these creatures will have power like nobody has ever seen. Want to try an impossibly complicated spell but worried it could get out of control and backfire? With friendly magic-eaters around waiting to serve as magical ground wires absorbing undesirable magic spikes, why not take a chance? A wizard with this kind of safety valve will be able to try more, learn faster, experience fewer debilitating setbacks. That sort of tool would be immediately useful to any wizard at any skill level. Rival wizard causing problems? Send some of your tame magic-eaters over with instructions to really ruin that jerk’s day. The possibilities mentioned by the other posts in this thread may have also occurred to your world’s wizards. ## **Rationalization:** The potential for gain is so tempting, nobody has made a serious attempt at finding a permanent method of keeping them out of the libraries. Your wizards probably rationalize the havoc they cause in all sorts of ways… ”The magic-eater ruined your spell again? What are you complaining about, apprentice? Back when I was your age, the magic eaters we had were twice as hungry! And we survived! I tell you, you apprentices these days are just too soft. You want to be half the wizard I am, you’ll learn how to cast those spells with magic-eaters stuffed up each nostril!” ## **Urban Legends:** No wizard has yet accomplished these lofty dreams, but many wizards are secretive and proud and haughty. Nobody is willing to admit they have absolutely no idea how to control these creatures. So, much like the real words to Louie Louie, every wizard knows someone who knows someone who’s friend heard that someone in another library said that they know the secret. And so wizards, nervous that they are actually falling behind their fellows in the race to ultimate power, lie through their teeth and brag about all the successes they have had. Any day now, they will have the technique perfected! Honest! And the boasting generates more urban legends. And so on. [Answer] The Common Manaphage, is but one of a large family of such species. It out-competes its relatives, and while a Common Manaphage remains present, no other could get a toe-hold. Having a long-time resident Common Manaphage basically garentees you are safe from infestations of other more exotic breeds. Some of these exotic breeds are hard to differentiate from the Common Manaphage, so it is good to know you have one, to save having to worry about checking the identity of any that show up. The other breeds include: * The Maneating Manaphage; which while thoughout most of its lifetime eats only background waste mana, lays its eggs inside a wizard, which the hatchlings will devour. * The Malodorous Manaphage; which skunklike emits a putrid odour, both as a defense mechanism, and as a technique to distract wizards into providing it with more food. * The Magpie Manaphage; which collects shiny objects, like wands, cystal balls etc, to decorate its nests in the high and dark corners of the library. * The Multing Manaphage; sheds its oily black skin/feathers nearly continously; ruining books and carpet. * The Manuscript Munching Manaphage; which is known to supplement its diet with rich vellum and other papers. Luckily the Common Manaphage out-competes these more problematic species, consuming the resources that they would otherwise need to grow, breed and thrive. So the option becomes: deal with its minor problems constantly. Or every few months exterminate the new one; knowing that one day a dreaded Greater High Eldritch Manaphage may turnup/grow to maturity, and cause you never to have problems again. [Answer] **They're afraid of the consequences** Magical libraries are ecosystems that evolved over millennia. (Otherwise, you wouldn't have an endemic species in it). Removing a life form from that ecosystem can change it radically, upsetting the fragile balance (because, with magic involved, any balance is fragile). A lot of things can go wrong: * Your parasite is part of a food chain; what happens when the animals that used to feed of the parasite's dead bodies suddenly go hungry? Will they start eating librarians? Or worse, the valuable scrolls? * What happens to the things the parasite ate, besides magic? They might be harmless now, but overpopulation and absence of predators might change that. * Magical scrolls have a natural immune system, and fighting the parasite trains and strengthens their defense mechanisms. Removing the parasite will make the scrolls vulnerable to magical attacks. * Extinguishing the parasite will open an evolutionary niche - and something *will* fill that niche sooner or later. That's just how evolution works. Something that might be much more dangerous than the original parasite. [Answer] The first thing to spring to mind was, as Vodolaz said: > > This parasite can be used as magic residue cleaning device. > > > and would be the answer I like most if it wasn't for your specific instruction that the parasite can't be useful. So either we cannot get rid of it, it is dangerous to do so...or we don't want to for some illogical reason. **Can't get rid of it** Using magic to rid yourself of a magic-hungry pest could be dangerous...perhaps this was once attempted but the pest learns to use any spells which are cast on it. **It is dangerous to get rid of it** They eat up excess magic so perhaps destroying them would release all of this - causing a volatile state of raw mana which can spontaneously create spells you can't predict. **Some illogical reason we cannot** When creating a spell the mana is channeled through the user, perhaps after absorbing excess mana from their spell the creature looks like that person - meaning your library has a few ghostly apparitions resembling previous great mages. There could even be a debate as to whether the parasites take on more than the looks but even some of the personality of stronger mages who channeled mana through more of their core being. (*Personal opinion but I like the last one most*) [Answer] **They like it.** Each library has its parasite, which has been there a long time. Each one has its particular quirks and manner of appearing to the users of the library. It is the library mascot. Wizards who have come up using a particular library find the immortal parasite endearing, reminding them of times past and younger days. I could imagine the parasite is sentient and communicates with the wizards, when it chooses or if it is begging. It is never malicious and it is fond of his library and its users also, once it gets to know them. It is funny and grumpy. It sometimes can be helpful, especially in exchange for treats. It has been known to gorge to the point of illness. It has been known to growl at intruders and fend off threats to its home, the library, including one particular episode it will tell you about, many times. It might remember something of use or something that happened long ago, albeit unreliably so. As regards spoiling spells it is like the lovable golden retriever whom you know will steal from the counter if he thinks he can. Or the great uncle whom you know will eat any frosting left unguarded in the refrigerator. You get mad when it happens but you do not throw them out. A parasite of this sort can be a real character and offers narrative possibilities. [Answer] **Student:** I was just in the library practicing a new spell, and this thing *bit* me! It was about <this> long and... **Master:** hold on, you were practicing in the library? **Student:** yeah? **Master:** You were TALKING in a library? In the library where grand masters have studied for generations? **Student:** ... yes? **Master:** My student. Talking. In a library. **Student:** ... **Master:** What sort of manners did your mother teach you? Why do you think they shush you all the time! There's no talking in the library! Everyone knows that! You've only yourself to blame! No talking in the library! **Student:** I... I'm sorry master. **Master:** You're going to go to the head librarian right now, you're going to apologise to her, and then you're going to ask to be tested for manaworms. **Student:** I will, master. **Master:** oh and if you ever see one of those things again... **Student:** Yes, master? **Master:** put it under a glass and bring it back here. They make the most *scrumptious* cakes. [Answer] To expand on the suggestion by [DonQuiKong](https://worldbuilding.stackexchange.com/a/74570/28789) that magic may generate the parasites: Parasites are a known side-effect of mixing magic residues. Build up enough magical residue in any one place, and the chaotic interactions of the residues creates *things*. They can be killed with magic but doing so only leaves more residue, creating more problems. The best solution is to wait for the magical background to subside, which will starve and weaken magical parasites. Within a large magical library, seepage from the magical codices and scrolls can sometimes be enough by itself to spawn parasites even when no spells have been cast. Because of the chaotic nature of their creation, each magical parasite is also unique and unpredictable. Trying to cast spells on them can have unwanted effects and has not been allowed since the incident where the head necromancer's late apprentice cast a fire spell at one. Patience and tolerance are advised. [Answer] # Because it is the magic of the library that spawns it, The parasite is a direct consequence of putting that much magic and knowledge about magic in close proximity of each other. You cannot eradicate it because for that you have to eradicate the magic itself. It is no more strange than that if you put lots of [fissile material in close proximity of each other](https://en.wikipedia.org/wiki/Nuclear_chain_reaction), you get some [interesting and useful effects](https://en.wikipedia.org/wiki/Nuclear_power), or in some cases [disastrous effects](https://en.wikipedia.org/wiki/Tokaimura_nuclear_accident), or even hideously [destructive effects](https://en.wikipedia.org/wiki/Castle_Bravo). Another way of looking at it: even though the constituent elements that make up our bodies — carbon, nitrogen, oxygen, phosphorous, calcium and all the others — cannot form anything interesting while on their own and separated, when put together just right, they form a sentient, conscious, bipedal being that is capable of uttering things like "I think, therefore I am". The same with this magic: on their own, little fragments of magic cannot do much. But when you bring them together... things happen. [Answer] The common imp (AKA fairy, brownie, or domovoi) are innately magical creatures, found in any location where there are (or have been) large accumulations of magical power. While they are not made of magic themselves they do require it to live, and are remarkably adept at manipulating it to their own ends, having been observed teleporting, becoming invisible, and exhibiting remarkable telekinetic and illusory abilities. These creatures are inherently destructive, though they have evolved a remarkable survival strategy to ensure they are never fully eradicated. Using the magical forces at play around them imps have developed the ability to manipulate the minds of those around them, forming illusions that convince nearby wizards (and mundanes) that they are *not* dangerous. Those affected are under the impression that the creatures are helpful in some way, are beautiful, or can be bribed into performing tasks (which is rarely true). The effects of the imp's magic wear off once the wizard is out of their immediate vicinity, and with suitable training or good luck a wizard may be able to realise they have an imp problem, however once they return to eradicate the imps they once again fall under the spell. Luckily imps can only draw so much power from their surroundings, and often work at cross-purposes to one another (imps are naturally argumentative and aggressive). This means that large swarms lose some of their potent manipulative power and can be dealt with in whatever manner the wizard sees fit. There is, however, a chance that some will be left, and after a short period of hiding they will re-emerge, once again convincing any nearby that they are no threat even as they wreak havoc. If no reproductive pair is left (imps are hermaphroditic) then one singularly powerful imp will remain. These creatures will have such a hold on the mind of any nearby that often they will be actively defended by people in the house, and some examples from eastern Europe have seen witches attempting to kill those who threatened to disturb the imp living in their house. These 'domovoi' sometimes take the image of a person they often see as an extra layer of defence. Magical libraries are famed for imp infestations, and often require specialised extermination teams to periodically clean up the fairy gatherings, brownie haunts and imp nests that naturally accumulate both inside and nearby. [Answer] # They keep specimens around for research. These parasites are presumably something of a societal problem. Researchers working on dealing with this issue would likely want a few specimen around to study. I'm reminded of a bedbug expert who kept a jar full of them. To feed them, he'd open the jar and stick it on his arm for several minutes. I hope this answer was helpful. I have to go puke now. [Answer] ### 1. Balance In a world where magic casters could free internal forces making things more chaotic parasites are then returning nature to its initial charged state, which seems like them "eating "those forces. Societies that succeded with local deparasitation was choked by overwhelming residual magic chaos, leaving dead magicless ruins behind. So parasites and libraries are protected by the law now. You can think their importance in magic world as importance of plants in oxygen/carbon dioxide world ### 2. Scent Ability to sense magic make them equivalents to magic hounds. Since they can not leave the library, they can't chase mages, but if you give one some parts from place where powerfull magic was ised, it could lead you to magic tome with corresponding spell helping to identify it. [Answer] ## It's against their code of ethics Since the enlightenment, all (respectable) magicians take the equivalent of the [hippocratic oath](https://en.wikipedia.org/wiki/Hippocratic_Oath) (an ancient principle commonly summarized as "do no harm") before learning their first spell. Naturally, in times of crisis, the rules of this oath may be "bent" a little... but killing to avoid a minor inconvenience is beneath them. [Answer] # Because the creatures always take away wizard's will to kill it. The parasites can have a defense mechanism from the wizards that threaten them in their natural habitat. And being magical, they can bypass the unneeded stages like looking nice and cute, defending by physical means, etc. and go directly after the source of the harm - the very intent in the wizard mind. So every time a wizard thinks that he's got enough of these pests, 2 options are possible: * Either the desire to kill it evaporates instantly, ending in nothing more than talk, * Or the desire is there, but the wizard can't actually bring himself to do anything about it, lacking any willpower to act. [Answer] I think you should go with the idea of having an old grumpy wizard, very important and powerful, who would kill anyone who tries to get rid of *the poor little things*. Have a grumpy leader guy love the things with no reason and everyone else thinks he's crazy, but they respect him. [Answer] The creature adapts to the knowledge around it. One can imagine a magical creature that, as a defense mechanism, instinctively absorbs the magical knowledge of its surroundings to be able to counteract spells cast upon it. (Think Borg, but magical instead of scientific.) Of course, a library is supposed to be a repository of as much knowledge as possible, meaning only obscure, exotic, secret or brand new spells can affect it since those are less likely to be found in the libraries. This also explains why it's primarily found in libraries; few other places have enough information for the parasite to be able to defend against even weak/apprentice wizards. [Answer] ## They're unkillable unless you stop using (and storing) magic. For me the most obvious feature of this magical creature is that it's created by (and evidently feeds on) magic. Ergo, **any attempt to kill it with magic is simply going to feed it and make it stronger**. The stronger the spell used, the more you're feeding it. It probably *likes* people using powerful spells to try to kill it, hence why it keeps annoying wizards. Eventually they'll snap and try (pointlessly) to ***Avada-Kedavra!*** it, providing it with a delicious feast. [Answer] Because, like the library, the parasites are sentient. One does not commit genocide on sentient beings that one has caused to be brought into being through one's actions, unless one wishes to fill one's library with evil magic residue. And if one happens to be an evil mage, who WANTs evil magic residue, then doing so regularly would make more evil residue, so killing all of them off would be counterproductive. Also, being sentient, they are also vindictive. Most of the old tales say not to mess in the affairs of the elves, or spriggans, sprites, or other fae. That's basically what these things are. Sentient, spiteful and capricious. Leave milk out for them each night, and a little bread, and you'll be fine. [Answer] **For the same reason we haven't eradicated malaria.** Namely: cost and ecological concerns. Perhaps exterminating these parasites is **very expensive**, and so it's cheaper to just sacrifice a scroll every now and then. Or perhaps they are an **endangered species** and are protected by the international convention on wizard culture preservation. Or perhaps no one has ever had a really large wizard library without parasites, and they are **afraid of what might happen**. Moreover, if smaller libraries don't have parasites, then perhaps they are a **sign of prestige**. Analogous background on the mundane war against parasites: Malaria costs the world economy billions of dollars and hundreds of millions of lives every year. We have had the technology to end malaria for decades. In fact, malaria was [extirpated from the united states](https://en.wikipedia.org/wiki/National_Malaria_Eradication_Program) in the 1950's. However, that old technology was too expensive to be used effectively in rural africa. Furthermore it had an unintended ecological impact ([see DDT](https://en.wikipedia.org/wiki/Dichlorodiphenyltrichloroethane)). Today, we have technologies like [sterile insect technique](https://en.wikipedia.org/wiki/Sterile_insect_technique) with [gene drive](https://en.wikipedia.org/wiki/Gene_drive) that could quickly and cheaply eradicate the handful of mosquito [species that transmit malaria](http://www.who.int/features/qa/10/en/) (and zika, west nile, lyme disease, missouri encephalitis, rocky mountain spotted fever, etc.) with almost no unintended side-effects. Currently we choose not to end these plagues because people are uncomfortable with intentionally extirpating any non-microscopic species (even one or two of the thousands of species of mosquito or tick). Many people are also categorically opposed to any form of genetic engineering, especially the [poverty-stricken people who could most benefit](https://en.wikipedia.org/wiki/Regulation_of_the_release_of_genetically_modified_organisms#Africa) from it. Both of these concerns should wane away over the next few generations so that our grand children can live lives free from the fear of deadly hemorrhagic fevers and chronic zoonotic illnesses. [Answer] I'm thinking these are **ghost cats**. * They are soulless killing machines like a normal cat, but they are ethereal like a ghost. * They can only survive in a library where they feed on leftover magic just like domestic cats can only survive in an urban environment where they feed on leftover human food. * Wizards tolerate them because they **keep the ghost rat population in check**. * Ghost rats can survive anywhere and occasionally chew up enchantments in the wild, but in high-magic environments they reproduce like rabbits and can consume all the scrolls in the library in a matter of weeks. * Obviously, when a ghost cat walks across a scroll you're writing, you get annoyed, but some wizards actually learn to love the ghost cats who become a mascot of sorts for their library. Side note: there are rumors that ghost rats transmit spotted wizard ague, but some wizards think it's actually the ghost mites they carry to blame. [Answer] ## They made humans magical, but none knows details Humans were an unmagical species in a world full of residual magic, left over perhaps by the elves... These creatures transform magic into biological existence, releasing a tiny fraction of magically saturated air. Upon inhaling that, humans slowly develop magical abilities. Nobody knows this, but it has been observed that the presence of the Grindlequark (or whatever it is called) greatly benefits spell casters. It is even rumoured that total isolation from grindlequarks for one year and one day renders one unmagical. This is all the more true of magically imbued artefacts, which abound in the library. Unfortunately for some dark wizards, the practice of preparing Tumbleweed-Grindlequark stew has not enhanced magical power in any palpable manner. But many still cherish it for its reputation and thick, savoury quality. Therefore the library not only doesn't dream of exterminating the Grindlequark, but novices are actually assigned to individual Grindlequarks, vouching for their safety and beckoning to their every whim. The creatures have proved remarkably adept in discrediting novices who don't guess the wishes they communicate through guestures and grimacing... If there is a competing race, eager to render humans unmagical again, they might even kill Grindlequarks in the wild, so the keeping of sanctuaries would be all the more important. [Answer] 1. **They can't get rid of it**. The wizards try, but for some reason the best they can do is banish it for a few days, or knock it out of action for a while. After that the ghost will reform... or a new parasite will hatch out of its ashes, phoenix-like. Their magic simply isn't strong enough to kill it off forever. 2. **There is more than one parasite**. Dealing with the parasite is like us putting a flea-collar on the cat. It'll kill a lot of fleas, but there are plenty more hiding in odd corners of your house, or living as eggs or larvae in the carpet, just waiting to recolonise your cat as soon as the chemicals in the flea collar have lost their potence. 3. **The parasite is actually a commensal or symbiote - it has beneficial as well as detrimental effects**. It may mess up spells now and then, but it also preserves magical books from attack by insects and mice nibbling on them, or makes certain types of spell easier to cast, or acts as a guard dog to the library. [Answer] By interfering with some spells, the parasite makes it very dangerous to cast spells that might harm the library. Over the years, some magicians have exterminated the parasites in their libraries. These magicians (or their apprentices) invariably went on to cast spells that destroyed their libraries. Thus, all of the remaining magical libraries have these parasites. And their resident magicians are very cautious when casting spells on the library grounds. Side note: The refugee magicians are not wanted at any other libraries (not wise enough, don'cha know), so they wander the countryside. When they sojourn in cities, they put out signs saying, "Will cast spells for food." This begging gets them into trouble with the local mages guilds. [Answer] These things are like magical cockroaches. You see one but you know darn well you've probably got hundreds. Could you exterminate them? Probably but at what cost? You might get rid of the largest, most active pests, and it'd take an archmage to completely clean a library - until the next book with a dormant one living in it comes in. [Answer] A good reason why you wouldn't get rid of them is **serious extermination risks doing more damage than the parasites would do**. **For example**: You need serious poisons or fire which damages or destroys delicate scrolls. [Answer] If this creature is spawned from the remnants of magic, it might suffice to say that this creature cannot be killed or destroyed by any means other than magic. This means that within your world, if the wizards attempt to use magic to destroy the creature, they will be creating more magic remnants which will simply create more of the creature. Since this is a perpetual cycle, the wizards have found that it is simply best to leave the creature alone, even though it is a nuisance. This also opens up some fun possibilities for older wizards to challenge the youth: "If you can figure out how to cast a spell that doesn't leave enough remnants for the creature to appear again - ... insert plot twist" [Answer] Make them literally be ghosts of the people's ancestors, and nobody will want to kill them, otherwise they will have opened the doors to people killing them once they die and become a parasite too. [Answer] The consequences of killing it may be worse than leaving it alone. If you ever have run over a skunk, you'll know what I mean. Of course, to be a significant deterrent, either this must not be one of a kind and/or the bad consequences set in (and alarm the librarians) long before the creature/infestation actually is in danger of dying. ]

[Question] [ Let's imagine a group of people who can turn from human to wolf at will. Wolves are quadrupeds, and humans are biped, so I guess their weight is differently shared in their body, notably when they walk. Assuming that, if one such person receives a wound in one form, it is placed in the equivalent of that place on the body of the other form, is there a place on the body that, if wounded, would prevent practical use of the wolf form while having little to no consequence to the human form? [Answer] [Wikipedia says](https://en.wikipedia.org/wiki/Dog_anatomy): > > All dogs (and all living Canidae) have a ligament connecting the > spinous process of their first thoracic (or chest) vertebra to the > back of the axis bone (second cervical or neck bone), which supports > the weight of the head without active muscle exertion, thus saving > energy. This ligament is analogous in function (but different in > exact structural detail) to the nuchal ligament found in ungulates. > > > Severing that would probably be pretty unpleasant for the wolf. If you can be a bit flexible on what you mean by 'wound', you might also consider: * Hyperthermia -- between hardly any sweat glands and also wearing a full fur coat all the time, a heat wave might keep everyone bipedal for a while. * Chemical warfare -- with their vastly-improved sense of smell, I would have to imagine that getting sprayed by a skunk, hit by tear gas, etc, is going to suck quite a lot more as a wolf. If you have any interest in the reverse case, wolves have only-vestigial collarbones, so having a busted one is probably going to be worse for the bipeds. [Answer] **Broken Phalanges**(blue on the middle image)AKA toes and fingers **Broken fingers**. humans can still use their hands with one or two broken fingers, (better with a splint) but a wolf is not running on broken fingers since all their weight sits on them. **Broken toes**. likewise since wolves are digitigrade and humans are plantigrade a human can walk (or limp) with broken toes, but a wolf cannot, they can't shift their weight to their heel, well not and walk while doing so. A wolf cannot walk without putting weight on broken toes, a human can limp long without putting their weight on broken toes, keeping all the weight on the tarsals and metatarsals. Humans can even manage a fair turn of speed by walking with the foot sideways provided the ground is level. [](https://i.stack.imgur.com/dnsBN.gif) [](https://i.stack.imgur.com/ZNUzDm.jpg) [](https://i.stack.imgur.com/oFKX5.jpg) As Nuclear wang mentioned a wolf can limp along an three legs but they are not going anywhere fast if it can even feed itself. two such injuries will turn any wolf into a sitting duck, but will let a human do all their basic necessities and even work if the job is non physical. So you can even dial in how helpless they are by how many limbs are injured in this way. [Answer] # Both Arms If I incapacitate both your arms, you can still walk and run. If you turn into a wolf then you are limited to pushing your torso across the floor. Still has a consequence for a biped but not nearly as severe as that for a wolf. [Answer] **Teeth** It depends on the reason. If the human wants to stop the wolf-form from doing harm then they should have all their teeth removed and have false ones made. The false teeth won't fit the wolf. They could also have implants and unscrew them at night. A werewolf that can only suck wouldn't be too frightening. [Answer] Tolure's answer is good. But I wanted to add, you don't even need an injury, just heat or endurance or both. A wolf has a relatively low endurance for running or heat. A person has huge tolerance for both. The difference is that a wolf cannot sweat. And it essentially holds it's breath to run fast (True for a lot quadrupeds). Humans have sweat and can breath normally while running. A well conditioned human can outlast a wolf in a marathon. So if your in a warm place or are required to run a very long distance very quickly, your human form might be better suited. [Answer] ## A papercut on your fingertip or palm Dogs essentially walk on their fingertips. A biped can easily avoid putting significant pressure on a fingertip or can put a bandage on them, but this isn't so nice to a load-bearing part of your body. It's equivalent to getting a papercut on the soles of your feet. Not fun and opens the door to infections and re-opening the wound as you walk. [Answer] **Torn UCL** The UCL is akin to the ACL, only on the inside of the elbow. While a human with a torn UCL would have a bit of pain, and would have a harder time throwing things, activities like walking, holding a heavy object, or even stabilizing a weapon wouldn't be that bad. For a wolf, however, it would be similar to a torn ACL, meaning pain when walking, running, turning, or even standing still. If it was the human's non-dominate arm, it would have even less effect on them, while the wolf form would still be just as badly off. **Ears/Ear muscles** While wolves have 18 ear muscles and humans only have 6, if those six muscles are damaged, humans may only barely notice, but wolves will find themselves unable to easily direct their ear toward sounds, limiting hearing. Worse, if a human's (outer) ear is very damaged, they won't look great, but their hearing won't be too much worse. Wolves, however, use their ears as "sound scoops", directing sounds into their ear canal; without an outer ear, they will lose a lot of directional hearing, and their hearing overall will drop considerably. **Surface burns** While getting a bad burn would suck, as long as it healed decently, a human would only have an unsightly scar to deal with. If the scar is on their back, it may go entirely unnoticed; out of sight, out of mind. However, hair doesn't grow on burned scar tissue, or at best grows in clumps and patches. Wolves don't (usually) have the option of wearing clothing, and without hair - especially body hair - they will freeze to death in cold weather. **Fused Joints** Wolves and humans use very different joints. While a human would probably be fine if they had one or more ribs fused to their spine, it would mean a huge limitation to a wolf. Likewise, a human with a fused ankle would only be slightly slower than usual, while a wolf would hardly be able to move. A human with a fused wrist, especially non-dominate wrist, would function almost entirely normally, while a wolf would again be nearly unable to walk. Fusing a pair of spinal bones may make a human slightly uncomfortable, or unable to turn their head as far, but would severely limit a wolf's range of motion. **Stuffy nose** For a human, it's pretty annoying to have a clogged nasal passage. You can't smell, you have to breathe through your mouth, and you have an annoying feeling of blockage - not to mention the mucus draining down the back of your throat. For a wolf, however, having a stuffy nose means losing one of their best senses - smell. And, unlike a human, wolves have to work a lot harder to swallow draining mucus; rather than just swallow, they often have to do a sort of "reverse sneeze" to force the mucus down. **Out-of-Balance Digestion** Humans have a far more complex digestion system, compared to wolves. We can eat just about anything, and unless we have some sort of sensitivity or allergy, it goes through the system without a fuss. However, after an illness (especially if we had to take an antibacterial medication), out gut bacteria can get screwed up. If we don't fix it, eating certain foods can become very difficult. However, being that we can eat just about anything, the simplest fix is... don't eat that food. Wolves don't have that option. They are meat-eaters, and their guts are designed to process one thing, and one thing only: meat. If they can't process proteins, that's basically a death sentence. While it's possible for wolves to digest some non-proteins, those foods are usually heavily processed, essentially pre-digesting them. That food would be hard to come by anywhere but a highly civilized area. [Answer] **Injured non-dominant hand** Barely any effect on a day-to-day life of a human besides some annoyance since most of what we do with our hands is not load-bearing, especially the non-dominant hand; this may be dependent on your character's line of work and lifestyle, though. It can even be unnoticeable to people around them when in human form. However, an injured paw on a wolf (based on observation of injured dogs) would keep them from running very fast or with great agility due to pain. Along the same lines, **Missing fingernails** Again not much of an issue for humans, but lack of claws would reduce the amount of grip a wolf has while running and it ability to capture prey. Not a *wound*, per se, but **Baldness** Some users mentioned that wolves can't deal with heat due to their thick coats, but let's flip it around: complete inability to grow hair. Little to no effect on a human (baldness in men is fairly common) and we wear clothes to keep warm, but baldness would make it completely impossible for wolves to live in their natural (cold) habitat. The baldness could be cause by severe burns, if you absolutely need it to be a *wound*. [Answer] Chocolate or coffee. Vegetarian diet. Both for the same reason, which is also the reason that transformation to a wolf (apart from the obvious) is rather unplausible, biologically (or transformation to a bat, for that matter). Wolves are sooooooooooo far away from humans, you wouldn't believe. The only thing yet worse would be a cat. Among the things that genetically prove the distance are the inability to catabolize xanthines (like theobromine or caffeine), and to build e.g. Vitamin A from carotene -- dog-likes are barely able, cat-likes not at all. Now of course a wererat or a werebunny isn't nearly as cool, I'll admit to that. Except the Rabbit of Caerbannog. Then there's the story of Androcles (and its approx. one million adaptions, including Aesop and Disney). Step on a thorn as human? No biggie. Step on a thorn as a lion? Well, *if only you had fingers to pull it out*. [Answer] # [Anal glands](https://www.glandex.com/pages/anal-gland-information) Dogs and wolves have those, but humans don't. So if the lycanthropes take a stab to their anal sacs it may hurt a lot - but when they revert to human form they will not have the sacs, so no pain. By the way, I think damage to the anal sacs may be very painful. I once saw a dog whose previous owners tried to castrate him with a slingshot, the poor creature had lesions on a sac. The poor dog required meds for pain for quite a while. [Answer] When dogs run, their spine flexes as their back feet make contact with the ground. The spine extends as they push off with their back feet and stretch their front feet forward, releasing the energy stored in the flexed spine (like a spring) as a burst of forward speed. This is a big contributor to a dog's ability to sprint. It's also completely unlike anything used in bipedal motion. If a canine has a back injury like a pulled muscle or a slipped disk, running would be extremely painful and would likely worsen the injury. From personal experience, I can attest that a biped would have minimal trouble walking or running with such an injury since the spine remains upright and stationary. A biped can even use a back brace to limit the impact, but a back brace would prevent a canine from going through the motions required for running. Along the same lines, injured abdominal muscles would seriously limit a canine's ability to flex the spine while running, but would only be a nuisance to a biped. [Answer] A nasty (but not huge) splinter in the non-dominant hand, just below the fingers. For a human, it would hurt but have little effect but try running/trotting on one, or using it to leap up with or claw, when you need to flex that part of both front paws, and impact it on the ground...... [Answer] Adding to [Alexandre Aubrey's post above](https://worldbuilding.stackexchange.com/a/141273/28789) about baldness: **Alopecia universalis** Going beyond just baldness, it's a total inability to grow hair anywhere on the body. Not a huge deal beyond aesthetics in a human (maybe lack of eyelashes/eyebrows/nose hair can be an issue), but would be a serious medical condition for a wolf due to the importance of the fur coat in thermoregulation. It's not an injury per se, but it could be the result of an autoimmune issue or as a side effect of cancer treatment. [Answer] # Shave. Humans hardly suffer from being bald all over. Many people do it on purpose. Wolves need their fur to stay warm, specially wolves in arctic climates. Also, lack of whiskers will hamper wolf life. [Answer] **Loss of the tail** Wolves use their tail to communicate as well as for balance while running. ]

[Question] [ I have a race of octopodes with the same intelligence distribution as humans. I want them to “colonise” land to a similar extent as we have “colonised” space; have regular transport between the ocean and land, and have a permanent settlement. Ideally there would also be some form of EVA suit, to enable them to perform repairs on the colony - as we do on the ISS. Likely those who go to land would be the best of the best - just as we chose the best people to be astronauts. I have chosen octopodes because I am aware they can manipulate tools with reasonable fidelity, as humans can. So, the summary; would it be more or fewer octopus hours to set up a colony on land than it was human hours to set up an international space station? [Answer] [](https://i.stack.imgur.com/Ttx3q.png) You can see octopodes crawl out of a tide pool and into a neighboring pool with little difficulty. octopodes have been known to crawl out of a tank in an aquarium and have the crab in the tank next door for dinner. They have even been known to shut off lights that bother them in their tank at an aquarium. They have been documented crawling out of their tanks, walking to a drain and exiting to the sea. I would definitely feel humans in space would have a much more difficult time at survival. * <https://news.nationalgeographic.com/2017/10/wales-ceredigion-octopus-land-deaths-spd/> * <https://biology.stackexchange.com/questions/43456/how-long-can-an-octopus-survive-out-of-the-water> [Answer] ## Octopodes are not going to colonize land the same way we've colonized space - they're going to colonize the land the way we've colonized the sea. Penguino has done a pretty good of addressing how different it is for humans to go to space versus octopodes coming ashore. But there is a parallel that's much closer to shore (so to speak). An octopus' ability to survive on land is not that different from our ability to survive under the ocean, and in both cases there are resources that make it worth learning how to extend that length of time. You're not going to see ISS-like mobile aquariums as the early colonization steps. You're going to see irrigation, dikes, and dams, which turn formerly dry land into tidepools the same way humans carved Holland out of the sea. The earliest land-going octopus vehicles will be not be spacecraft or submarine-like - they'll be more akin to large bowls on wheels probably crank-powered (or [oar-powered](https://youtu.be/vjMlCZf0MBc?t=65)), given the difficulty they'll have domesticating any suitable pulling animal. They won't exactly be safe, but then again neither were the earliest boats. Entirely enclosed habitats won't come until much later, assuming they come at all. There's simply no need for them, and their construction complexity (and expense!) is much higher. [Answer] There are a few issues that need to be considered separately: 1. Constructing water-filled environments for a water-breather to reside in on land isn't a significant technical issue. The manufacturing requirements for a salt water pool or aquarium are far simpler to achieve than for an air-filled canister to be used in a vacuum. 2. Getting onto land from the sea requires enormously less energy than getting from the Earth's surface into space. So far: 2-nil to the octopodes. 3. However, there appear to be significant barriers to the manufacture of metals and ceramics in a watery environment. Similarly, wet chemistry would be a lot more difficult, so it might be hard for the octopodes to develop even simple mechanical technology. 4. A water-breather has a distinct disadvantage in manufacturing/using an EVA suit compared to an air-breather. Air can be compressed and is light. Water is in-compressible and heavy. So an octopus EVA suit would be very heavy and would probably need complex components to continuously reoxygenate the water. It is unlikely that such an EVA suit could be supported/manipulated by an individual octopus without mechanical assistance. So 2-all in the end. Easier to get there, simpler technology required for the environment, but harder to move around and possibly harder to develop even the simpler tech. But if the octopodes ***do*** already have a similar technology base to us, then it would be much simpler/cheaper/faster for them to reach land than it is for us to reach space. [Answer] I would say that for both humans and your octopodes, Space is a much tougher frontier. Without going into the details, I would like to direct you to a few factors that may come into play. Space as it were, is extremely dangerous for both humans and octopodes. Radiation, extreme temperature changes, micro gravity, and the vacuum of space. In comparison to a human trying to live in the ocean, or octopus trying to live on land, space is much more dangerous. As humans can go snorkeling and swim in water, octopodes can hang out on the sea shores for a bit but to both, space really suck all the life out of them.( And makes the water in their body boil and then freeze.) <http://www.bbc.co.uk/guides/zctgq6f> On another point, technology needed are an important factor. Note that the space suits required for humankind is much more expensive and technologically advance compared to a scuba diver's gear, space suits are whole other level.I would assume your octopus would have a similar comparison. ( The specifics of technology I will leave out as the price difference is clue enough.) The other thing is that space is a lot harder to get to than a place that is on your home planet. The resources required for colonies is important. Note that space has terrible resources compared to anything on our lovable Earth. As with most pioneer colonies, resources for initial colonization would be sent to the site. It would be easier to do that if the colony was on the same planet. After your colony starts its own manufacturing and works towards sustainability, the resources at the site would play an important role in how much needs to be shipped from home to the colony. Land has trees.Your octopodes would not have lumber as traditional materials.I could guess that your adorable octopode scientists would bring up the idea to use local materials instead of coral and seaweed or whatever ocean things do. Space has rocks and ice. Not really a nice place to grow octopode food. <https://science.howstuffworks.com/what-if-moon-colony1.htm> The very final point is most obvious. Space stations mimic the environments humans lived in on Earth. Your land colony for octopodes is probably going to be something along the lines of an **aquarium tank scientified**( That is not a word). Or a pool or lake. I don't "sea" that as very difficult at all. In fact, it is easier for Octopodes to colonize land than it is for humans to live underwater. Depending on the species, atmospheric pressure differences hurts creatures with air filled lungs much more than octopodes. I suggest you think your idea over a bit. May I suggest toughening up the environment on land compared to the sea? A more lifeless or hostile environment on land could bring the difficulty of a land colony closer to a space colony. If a tough colonization project is what you want your octopodes to go through. [Answer] One major advantage that octopodes have in colonising the land, is that they can already make short stints out of the water without any specialised equipment. This is very much not true of humans in a vacuum. A question asked on [Biology SE](https://biology.stackexchange.com/questions/43456/how-long-can-an-octopus-survive-out-of-the-water) details the ability of an octopus to survive out of water, and [another source](https://blogs.scientificamerican.com/octopus-chronicles/land-walking-octopus-explained-video/) details that coming out of the water to hunt terrestrial prey is common behaviour for certain kinds of octopus. What this suggests to me, is that given human level intelligence (maybe paired with a longer lifespan?), octopodes would be well placed to begin colonising the shores. They probably wouldn't even need particularly advanced technology to do it. [Answer] Your Octopods would have a much easier time because they have the advantage of being able to survive on land for short periods of time, better yet, they could remain partially submerged while working on land. As soon as an octopod figures how to reach out onto land and make fire, it's game on. From that point on, they'd be able to start to forge tools and make ceramics, et cetera. From that, they could dig into the land, flood areas, make networks of aquaducts, and move inland from there. Remember, they wouldn't even need suits in many instances, just access to water. Eventually, they'd build machines with the levers or buttons close to the aquaducts so they wouldn't even have to leave the water, just reach a tentacle out to operate it. So, the need for any suits to travel over land would be limited to maintenance crews and explorers, and some construction. [Answer] I think a difficulty being overlooked (though not insurmountable) is that of building tools and vehicles from an underwater environment, at first limited to the resources available underwater. Easily manipulated materials like wood will be scarce. I suspect smelting, refining, etc. will be also infeasible. The same goes for baking clay or any other high-heat-dependent technology. I'm not even sure what's left that they *can* use to power their colonization efforts. With that in mind, I believe the colonization of land would have to take a few generations at least, occurring in tandem with the development of their civilization itself. I'd also expect they'd end up more proficient on land than in the sea even as unsuited to the environment as they are. Imagine if we tried to colonize space, we could get there just by jumping a few feet up, and we could also last about 2 minutes. But imagine all the natural resources were in space, nothing was here on Earth save a breathable atmosphere and food, combustion only worked in a vacuum, and heat would spread rapidly through our atmosphere so that we couldn't cook anything without also cooking ourselves. I believe the easier access to space would be heavily outweighed by the radically greater difficulty in developing any technology. It would be possible still (assuming we can come back from space rather than just float away). But we'd have to achieve most of our civilization's early accomplishments by working in space in very short bursts. Basic gathering would be simple enough, but not useful enough. Bringing resources back to Earth would not be very helpful if ore could not be refined in our atmosphere, metal could not be shaped, etc. And so it would be with your octopodes. I'd have a very hard time accepting as plausible any meaningful level of technology without having already established a land presence, and that technology brought into the sea rather than used to emerge from it. [Answer] Not sure anyone has mentioned this but, lacking bones might be harder for a creature like the octopus to come up to land. With gravity movement might be significantly harder for movement as orientation is very different compared to water, also bones protect from impact, in water impact is less of a risk. Maybe that's worth considering when doing physically streneous activities on land. ]

[Question] [ The animal in question starts off with reptile like intelligence, classic gecko and is a singularity, the only individual of his species to be immortal. It can die and be killed but for the sake of the question we exclude that. Degradation by oxidation, mutation, cancers, viruses don't happen. Aging is not infinite, it stops after maturity has been reached. Given that, can a gecko develop intelligence after living so long with a fairly small start? Intelligence stands for being able to craft and plan ahead the most optimal ways to overcome obstacles of any type. Be it learning how to draw, climb or doing math. [Answer] Evidence suggests that no creature becomes more intelligent than it needs to be, intelligence is expensive of calories, for example, human brains are about 2% of our overall mass but require 20% of our minimum calorie intake. So intelligence beyond basic survival needs is actually maladaptive for individuals and species. A gecko therefore has a biological interest in not thinking too much. To answer your question, no, there are physical limits to how much any brain can handle and a gecko with a gecko brain is not going to be able to learn much more than your run of the mill gecko regardless of how long it lives. [Answer] In addition to [Ash's answer](https://worldbuilding.stackexchange.com/a/125868/44086): You assume that every lifeform spends its entire life learning indefinitely. This is just plain incorrect. Not only could you look at the elderly of most species and see that at some point the intelligence does not seem to improve anymore or in some cases by tendency degrade in old age. (e.g. Humans) But some animals learn very little in their lives. Most reptiles are very instinct-driven. They are born with their instincts and live their lives according to them from start to finish. Not every lifeform even has the ability to learn anything. Just think about training animals. Dogs can easily learn tricks and commands. They have evolved to do that and already started at wolf-intelligence. Other animals are often very difficult to train, hence all the animal abuse scandals in the circus industry - some animals just learn certain things when forced (meaning they are basically tortured). But even then you could not teach every animal every possible trick. Holy hell, you can't even teach every human everything. I personally know smart people with a great grasp on human psychology, history socioligy and all that, but have severe troubles with math and struggle with concepts that appear to be very basic to other people who study in engineering and science fields. That does not mean that the math-able people are smarter or better. They are better **at math**. Intelligence is a very complex issue. ### A reptile is not equipped to resemble human intelligence Unless you have selective pressures favoring intelligence in these species over many, many generations they will not be even close to human intelligence - why would they? A normal gecko not dying of old age, but well enough equipped to survive on its own has no need for intelligence. What for? And if it cannot survive on its own then the somewhat-immortality will be of no use to it, either. [Answer] # Yes... and No Intelligence is much more than gaining experience. The brain must physically be designed to process information, make complex memory associations, store vast amounts of information, etc. etc. The human brain has evolved with *cognative capacity,* the ability to reason and process information. Therefore, given immortality, a species already capable of processing information could refine that ability through experience. Chimpanzees, for example, are taught sign language and are capable of expressing complex ideas (complex emotional ideas, not calculus). But I would need to be convinced that, given an infinite amount of time, a Chimp could (through practice alone) learn to design computers. [A gecko is right out](https://www.youtube.com/watch?v=f5JrucgtL0E). **The problem** The problem is that immortality does not allow for physical change. Take strength training. You can improve the strength of existing muscles to the limit of their physical design — but you can't create new muscles nor exceed the design limits of the muscles. No matter how long you live and press iron, you'll never become Superman. Said simply, *evolution becomes locked in place.* An ultra long life-span is actually a detriment. Should one human live forever and the rest of us carry on as normal, then a millennium from now that one human will find themselves *less developed* (IMO) than the people who lived "naturally," being a whole lot harder to startle from behind, but less developed based on the evolutionary pressures constantly acting on the species. I could easily believe such a person would actually be less intelligent than those who came and went naturally. **Conclusion** So, yes, given an infinite amount of time, a creature will become more intelligent (better said, more experienced) through greater experience and repetition. But, no, regardless the amount of time, a creature who can't be taught to design a computer today won't be capable of designing a computer tomorrow. Or the next day. Or the next day.... [Answer] **Your intelligent geko needs to reproduce** Intelligence is obtained in a species with mutations through evolution, not by making one single individual live longer (some turtles can live up to 200 years, more than any human does actually, and that doesn’t make the turtles more intelligent). The process works like this: If your gecko is a little more intelligent than the other geckos, and that is an advantage in their current ecosystem, then the intelligent gecko will have more chances to reproduce and distribute its “intelligent genome” to its brood, so the intelligence can evolve IF it is an advantage for the species. But the intelligence of that gecko will not raise just by living longer. [Answer] In programming, we have a term "implementation defined behavior." There exists no gecko that lives forever. Thus, what you have is a new creature, with new properties. One of those properties is that it is immortal. How? The method in which the gecko achieves that immortality matters. Some methods may cause intelligence to form as a side effect, being the most efficient path to immortality. Or, alternatively, you may find that intelligence is *directly opposed* to immortality. It's common in Asian cultures to argue that intelligence drives us further away from the balance which is capable of immortality. Some particular solutions may include a predisposition to create the neurological structures we associate with intelligence. Or it may shy away from them all together. So really it's up to your methods. You decide how it became immortal, and you can decide if it becomes intelligent. Indeed, you get to define what intelligent is. That's one of those words which seems to be nailed down until you start to poke and prod it; then you find out how slippery it is. All that being said, there are immortal creatures out there. [T. dohrnii](https://en.wikipedia.org/wiki/Turritopsis_dohrnii) is a species of jellyfish which is genetically immortal. It can go in both the usual direction from child to adult and the unusual direction from adult to child. (technically from medusa to polyp). Assuming it does not get eaten, it can live forever. It's not all that intelligent. So the one real-life example of an immortal creature does not appear to automatically lead to intelligence. [Answer] The short and sweet of it is, immortality and evolution are contradictory. Evolution requires that the species genetically evolves and then the new replaces the old, through reproduction and death. That is, the new evolved genetic organism replaces the former. For immortality to be consistent with evolution requires that the individual cells making up the organism themselves mutate, and all new cells that reproduce are made of the new genetic material. However, then these genes have to migrate to every other gene in the organism, or the organism becomes a compilation of many cells that each have a different genetic makeup. Think in terms of the human body that is made up of hundreds of bacteria, each with its own genetic makeup, working in symbiosis. The mitochondria in our cells, for instance, are actually a separate organism with its own genetic DNA. So, maybe, if you build the 'intelligence' into symbiotic organisms within the corporate overall body that is immortal, and these sub-organisms can themselves mutate over time, you have a chance at evolving intelligence in a unified corporate body encasing sub-units. That is, in an extreme way, think of the brain of the organism as a separate entity with its own unique genetic code, that reproduces and dies off, within the overall structure of the gecko. Therefore, the brain can evolve as it dies off and reproduces, even though the body is immortal. The problem is, every new 'brain' would loose the experiences and knowledge of the old brain, and would have to start all over again. Mind you, this is not necessarily a bad thing. The human mind has a finite storage capacity for new knowledge, memory, and experiences. Replacing it with a new mind every two hundred years or so may not be a bad thing. [Answer] I consider myself really intelligent human and also moderatly adaptable to new ideas even on older age. But I am sure, that even being immortal and given all current knowledge accessible, I would not be able to learn it in whole at any one given time. I can learn more about computers, but if I will start learning about biology, I would inevitably over time will lost a lot of my computer knoledge. And should I start learning about linquistic, I would lost my biology skills over time too. I probably may (given unlimited time and some reason) learn a top skills in any one particular skill/knowledge/science/... but no way in all of them at the same time. My brain is simply not so big and complicated to be able get it all at one time. Your gecko have the same problem - his brain is only so big and complicated, so there is only so much to scram in even over unlimited time. --- The solution for me and for your gecko would be the same - grow larger and better brain, which also means grom more powerfull body just to support living of such brain. But then we will be something totally different ont only mentally (gecko human-like ineteligent, me being top at all 2018 technologigies), bat also psysically - to the point, that we would not look much similar as the original form. --- Evolution solve it with modificating next generations, so each next generation can have something little better, but be a little different. Over last hundred year people are on average smarter and larger, but probably also a little weaker as strenght does not help now so much in success. Long before we was animals of size a rat or what and we surely was not gain todays intelligence, if we would stay in that form and be immortal. The brain is a big limit. [Answer] Koume, In order for your gecko to achieve intelligence beyond what it currently has (and are you hoping for near-human intelligence in the end?), the gecko would need to evolve, most likely into something that eventually is no longer gecko. Human ancestors are thought by some scientists to have once been little tree-dwelling bushbaby-type creatures. But along the way, we had opposable thumbs to grasp things and then we walked upright, not only giving us a wider view around us for safety but it freed up our hands to do things other than crawling around on all fours. Your gecko would most likely need to follow these traits (at least to gain human-like intelligence). It would need to evolve into a humanlike creature capable of manipulating things to create tools. There are of course other intelligences such as that of crows/ravens, elephants, octopuses (octipi?), and dolphins whose bodies are very different but have sound reasoning skills. Your gecko could remain a gecko if you suspend disbelief and just have your gecko as being very clever (like the mice from Narnia). But you really have two choices: either your gecko is already smart, or it becomes so through evolution. But immortality wouldn't serve it for growing smarter if it is really happy just eating flies every day and doesn't seek to learn from new adventures. [Answer] I don't know how well this can be answered from the point of views of physics. This is because mathematical models of physical systems have all sorts of ridiculous behavior given infinite time. As you may have heard, an immortal monkey typing random letters will eventually write the Hamlet. By similar logic, intelligence can be argued to rise from random fluctuations, see <https://en.wikipedia.org/wiki/Boltzmann_brain>. Perhaps you can use this kind of logic to argue that at least one point in time the gecko is in fact very intelligent. However, the immortality of the gecko probably needs to allow at least some sort of fluctuations for this to be possible. It will also take extremely long for the gecko to get smart this way. [Answer] Tagging along to what others have said as to the given, that there will be no incentive to self improve as a means to survival, your question asks > > "... can a gecko develop intelligence after living so long with a fairly > small start? " > > > It's easy to infer, but not confirm, that you mean whether there is causality between longevity alone and intelligence improvement. It's up to you whether you want to reconcile your gecko with any mappings of the physiology and biochemistry as they are in the world. We are talking about an immortal gecko after all, it seems rather easy to look past that. Perhaps find an alternative explanation for the evolution, out of the box of the way Earth species have done it, if you think about it only in mathematical terms, you just change something in a complex system and throw away any instances where the result doesn't survive a criteria, then repeat enough iterations and you will have complex system instances which do meet the criteria. If you are going to cover for the negligible physiological traits of immortality... (sarcasm) I don't see why you you can't just use a different method to grow your gecko's brain, unlike the one we used to grow ours. [Answer] Human intelligence is a product of evolution, not longevity. We may learn more as we gain experience, but it's the "capacity for learning" that we're all born with, that makes us intelligent. Your hypothetical gecko has a much more limited capacity for learning. It also has far more limited sensory experience. It may, for example, process visual input by responding to small dark objects moving against a lighter background, which it instinctively lashes it's tongue out at, without actually producing an image of its surroundings like we do. So it's not even capable of gathering visual information like we do. ]

[Question] [ I have humans who live in a world filled with floating islands. These islands span all heights in the planet: from the core to the upper atmosphere. The problem I have is that most of these islands are too small to have an internal water cycle. **Is there a way to provide the people with a reliable source of water? if so, how would I go about doing it?** # Conditions * The mechanism that makes the islands float is irrelevant/not to be considered. * The planet is a puffy gas giant, for all intents and purposes there is no surface. * The people I have to provide live in an earth-like environment (1atm, 1g, earth-like atm. composition, sun-like star, etc). Of course, these conditions change as expected as people travel up and down through the atmosphere. [Answer] *While I am answering my own question, this is by no means a definitive answer, please contribute your own if you feel there are other alternatives* There is a kind of plant in the Andean regions of northern South America called Espeletia (also known as Frailejón). [](https://i.stack.imgur.com/x4Jvp.jpg) This plant converts air humidity into water with the help of its hairy leaves. It then gathers this water in its trunk and releases it on the soil through its roots. Large populations of these plants can feed entire rivers with water. Given the environment, it's not a stretch to have a large number of plants evolve to have similar water-condensing mechanisms. Such mechanisms would provide the plants in question with water, as well as other living beings that may benefit the plant. Such as other plants that to help create nutrient-rich soils and animals to help spread seeds. Another additional source of water would be cacti-like plants. Plants which gather water inside of them instead of releasing it to the ground. These plants may then be eaten as a source of nutrients and water. [Answer] Fundamentally you need a large enough body of water for evaporation to occur. There are two options, the simplest is just to have a "water world" with an ocean down below and have the islands floating above it. That could fuel a standard water cycle, with the islands getting rained on with water evaporated from below. Alternatively have the water float in the same way the islands do, with floating lakes and oceans hanging in mid air. Waterfalls would run from the lakes and oceans into each other. If your floating islands move then the water cycle could include drifting under a waterfall. If not then a conventional evaporate-precipitate cycle could hydrate them all fueled by the lakes and oceans. [Answer] Floating icebergs. The island dwellers catch and melt them. [Answer] I can think of two relatively realistic...or at least plausible options. 1. **Regular, if not almost constant rain.** Its possible that this environment was selectively chosen (considering they are floating around in a gas giant) and the choice would not be made without access to the things you need to survive. * Either the natural state of the planet causes rain to fall on a regular basis (regular can be defined by how much water storage they have available) 2. **Super Tech**. In this scenario I am thinking you could have a large antenna that reaches out into the atmosphere. By some mechanism it triggers reactions in the air that generate rain. The nature of the technology would be up to you to decide. [Answer] Larry Niven's novels "The Smoke Ring" and "The Integral Trees" imagined life in a diffuse ring of planetary debris orbiting a star. In that world, plants pulled moisture from the air in manners similar to our epiphytes (or what's been described above). People sometimes had ways to exploit the plant mechanisms, or sometimes traveled to large floating "lakes" to extract water from them. In Niven's "Ringworld" books, there were artificially floating cities with chilled condenser funnel systems for water collection. They worked on the same principle as condensation forming on the outside of a cold drink in the summer time. Simple rain collection might work at some strata of the atmosphere, though I'm unsure whether physics is friendly to the idea of this happening at standard temperatures and pressures. You might find [XKCD's "What If?" on the subject of dropping a submarine into Jupiter](https://what-if.xkcd.com/139/) helpful for understanding this. [Answer] One possibility (Though I don't know if the physics would work too well) could be simply that the inner layers of the gas are really hot, probably due to extreme greenhouse effects and such. It is hot enough that water always evaporates and it gets pushed back into the atmosphere. Then, it cools into clouds and rains again. This could help keep the habitable higher areas warm, and also would provide the air with a lot of water. If you have plants that absorb water from the air and leak it into the soil, this gives you a 1-2 punch of water. The rain saturates the island, but most of it seeps through, and then it evaporates and rises up for the plants to gather. The islands get saturated, then keep it for a long time until the next storm comes in. This would mean there is a lot of rain and large, powerful storms, but that could be a good thing that drives the plot. Gas Giants are going to have hectic weather, so it should constantly be hurricane season. [Answer] [The Death Gate Cycle](https://smile.amazon.com/Dragon-Wing-Death-Gate-Cycle/dp/0553286390/ref=sr_1_1?s=books&ie=UTF8&qid=1485930958&sr=1-1&keywords=death%20gate%20cycle) (by Margaret Weis and Tracy Hickman) has four worlds, one for each classical element... the air world is a space of floating islands with inconsistent rain... water is provided by a giant sky pump, a mechanical device that spouts water up into the air, created by the gods at the same time the world was created. [Answer] **Water is a side effect of the hover mechanism** Each island has a gravity generator that causes it to float, located fairly centrally. The gravity generator's waste product is a stead flow of water... The larger the generator, the larger the island, and the larger the production. **Or Vice Versa** Alternatively the gravity effect is a side effect of some kind of portal technology, and all of the water sources generate a localized gravitic effect which causes the land in a small area around it to float. Larger portals feed bigger lakes/streams but also loft larger land masses. [Answer] If the planet is a puffy gas giant, you could assume that it may have a moon made of mostly ice on the surface with a liquid core. That moon would be rotating around the gas giant relative to its shadow, always remaining cold on the surface. As planet rotates in its orbit it causes a tidal pull heating up the moons core causing it to release its liquid water core over a given interval via geysers shooting hundred of miles into space. The gas giant, being larger will be massive and have more substantial gravitational pull, therefore attracting the ice. Condensing and warming in the atmosphere it then rains down on the surface of the islands, collecting in pools creating lakes, waterfalls etc... As an added benefit, you get rings around your gas giant. Reference: Saturn & Enceladus [Answer] Reclaiming the humidity from the air. I actually know someone who has a device like this in his house. Basically, it just condenses water from the (incredibly humid) air and keeps it in a small tank. This is relatively simple technology, all you really need is to cool a sheet of glass or metal a little, and water will condense. [Answer] Assuming air with high humidity you can catch the water with nets. <https://en.wikipedia.org/wiki/Fog_collection> <https://www.newscientist.com/article/mg22229754-400-fog-catchers-pull-water-from-air-in-chiles-dry-fields/> <http://news.mit.edu/2013/how-to-get-fresh-water-out-of-thin-air-0830> With lightweight nets (e.g.: carbon-fiber) you can do that in a large scale. It is also a unique feature, useful for a part of the story and/or the illustration on the cover of the book. [Answer] Are these islands steerable? Or just drifting in the air? The people could have terraformed the world by collecting water in pools on the islands from space, which eventually caused enough evaporation to start a water cycle and would create a core of water. Condensing water would work, through plants or technology. Or there could be a sort of water trade going on, whether they bring water from space (ice in meteors) or from people carrying water from the core up to the islands. [Answer] Each island simply needs a supply of hydrogen and oxygen, as well as an energy source. Binding hydrogen to oxygen to form water is a simple process. But, it is dangerous because hydrogen and oxygen are flammable. For example, the Hindenburg fireball created a lot of water. [Answer] Even if they are not big enough for their own water cycle, they still could be OK with water/rain from the planet itself (if this happens). As long as there is a reasonable amount of soil/absorbent material, then the floating island will be OK for a few weeks on its own in between rain showers. [Answer] The islands are floating at rain cloud level. Every time they float through a cloud, they have a good chance of triggering precipitation (rain), similar to how mountains tend to encourage precipitation IRL. [Answer] If you could let the “core” of your puffy gas giant be hot and dense (and therefore necessarily unpopulated), than it could propel warm saturated air into the upper atmosphere via either stable or volatile thermal currents. The water would condense and rain back down, to be caught in rivulets and lakes on the floating islands. As a side benefit, if you went with the volatile option, you now have an extra unpredictable hazard in your world. Perhaps the people have learned to predict these violent uprisings and move islands safely out of the way. Perhaps the people on the lower islands have developed technology to manipulate these thermal uprisings, thus bringing water to where it is needed, and holding it back where it is not. [Answer] Is there a reason clouds similar to earth won't occur? If there are temperatures similar to earth somewhere in the mix of island, then clouds, storms and winds could still occur. As the islands are not fixed, this would be a lot more serious but clouds floating by an a gentle breeze could be harvested. If clouds or fog patches are common enough then they could be harvested for water by even simple setups. [Answer] If it's a fantasy setting, and the islands float because of some magic or entirely different physics, it would be cool to have bubbles of water slowly drifting from the planet 'surface' to the outer layers of the atmosphere. Catch 'em with a net. If caught, they stop floating and behave just like water here in our world. Maybe even make a water shell outside. Would be interesting to see the Sun shine through it. [Answer] You could use technology currently available today. Ingredients: 1 Oxygen, 2 Hydrogen, 1 fuel cell. <http://auto.howstuffworks.com/fuel-efficiency/alternative-fuels/fuel-cell.htm> A fuel cell converts the chemicals hydrogen and oxygen into water, and in the process it produces electricity. If I'm not mistaken, these fit the bill. <https://www.buygreen.com/products/pem-reversible-fuel-cell?utm_medium=cpc&utm_source=googlepla&variant=3181636609&gclid=Cj0KEQiAzsvEBRDEluzk96e4rqABEiQAezEOoBJRRj_6y4mYPozErvoaD8Rwit9BQfOSoieG959rFN0aAs5X8P8HAQ> However you'll have to call the company to confirm and/or test them out before relying on them for the gas giant. Unfortunately I don't have the reputation to comment on my own answer (nor is there enough room) in response to: "Note that using electrolysis to make the fuel cells takes more electricity than the electricity it will produce. – Anketam", so I'm responding here. Anketam, thanks for your comment. First, note that electrolysis is not used to make fuel cells. Electrolysis of water produces hydrogen, which I presume is what you're actually referring to. Converting that hydrogen back to water may or may not produce less electricity than went into producing the hydrogen, but it does make sense as there are likely to be losses in the system. On the other hand, perhaps the scientists in the OP's world have perfected the system to 100% efficiency. Second, note that the OP is seeking a source of water not a source of electricity. The electricity is simply a byproduct of producing the water. It's a bonus. Yes, it costs electricity to make water. Perhaps electricity is free on the OP's world. Third, note that solar panels can be added to the system to generate electricity (and hydrogen/oxygen gases) during the day, and the hydrogen can be used at night and during cloudy periods to generate electricity and water. In this configuration hydrogen functions as a battery in a sense. Obviously there are other ways to generate electricity as well such as wind for example so electricity is essentially "free" - after the initial capital investment of course and any ongoing maintenance which should be minimal. Perhaps volunteers donated their time to building the system and therefore cost nothing but their donated labor. Or not, as the OP chooses for his world. ]

[Question] [ **Literature Review** [Pokolpok](https://en.wikipedia.org/wiki/Mesoamerican_ballgame) is the Mayan term for an ancient ball game that was played throughout Mesoamerica in antiquity. While much about the game (even the rules) has been lost to time, archaeologists have a loose consensus regarding the following: * the game was played with a solid rubber ball weighing around 4kg * playing the game was more than an athletic event. It was also seen as a way to settle scores, an alternative to warfare, as well as an act of devotion * later cultures incorporated human sacrifice into the game What remains unknown is: * how exactly the game was played * how the result of the game was enforced (if not warfare) * who was sacrificed? The winners or the losers? (the conventional theory is the losers were sacrificed, although there is no hard evidence to support or refute this theory) **Premise** I plan to carve a world out of the existing archaeological ambiguity surrounding the game. This world will be based on current archaeology, but will need to fill in the gaps. In particular, the points of "act of devotion" and "human sacrifice" will need to have clear courses of action. My world will take a different stance on Pokolpok human sacrifice than the conventional understanding. Instead of the *losers* being sacrificed, as is often reasoned by archaeologists, my Mayan world's Pokolpok will sacrifice the *winners*. I attempt to justify this with the "act of devotion" principle. Winning the game proves your might and worthiness to be sacrificed -- that the blood of the mighty will adorn the Pokolpok court. In this way, the Mayans will have satiated the gods' demand for "high-grade" blood, and would have curried favor enough for the gods to allow their civilization to continue to prosper, blessing their crops, war generals, etc. The catch is, presumably, self-preservation is hard-wired into humans, and so there is potential for a moral hazard. It would not be a fitting spectacle to see a team of otherwise physically gifted and skilled players throw the match because of their attachments to the physical world. This could take place for any number of reasons: fear, becoming a new father, etc. More recently, tennis and badminton players had to be disqualified from the 2014 summer Olympics for not having the "Olympic Spirit." They tried to lose a match on purpose to enter a more favorable bracket. To sum up, history seems to support the idea that humans are not beneath losing if they know they can reap benefits in the long-term; therein lies the moral hazard. **Question:** Assuming **only** the winners of Pokolpok are sacrificed, how can the powers that be in this ancient Mayan world protect against the moral hazard as articulated above? It seems to be a tall order, since players face death if they win, if you punish them for not having the "Pokolpok Spirit" could it be worse than death? **Success Metric:** Both teams play their best, even though both teams know the winner will be sacrificed **Further Clarifications** * **Ritual Type:** Assume the game is being played for glory only. A game to determine the future of a tribe or territory could reasonably justify the sacrifice of a few brave men. In this situation, the moral hazard is not as pronounced. * **Selection:** The Mayan high priests will have a litmus test to select the strongest. While it's possible to volunteer, there is still a selection bias as to who plays. The brutality of the sport is well-known, and only men of great courage and physical prowess seek out Pokolpok. Lastly, there have been documented cases of prisoners of war being forced into Pokolpok, but I'm not sure we need to be this granular. Consider the general case selection to be draft or high profile warriors looking to go out with a bang. * **Mob mentality:** While some may find a perverse joy in watching the strong dominate the weak, this world's mob mentality prefer to watch an even match. So two teams of strong men are what the gods and the mob want the most. [Answer] The winners are not killed immediately, but after a few months, which they spend in a rather leisurely life: exempted from work, supplied with food and their only task being breeding with a large harem of women (you want the bloodline of the worthy to be preserved, don't you?). After few months of dedicated service to breeding, with a large number of impregnated women carrying the bloodline of the champ in their wombs, the champ can be sacrificed to the gods. [Answer] The simple answer would be to sacrifice the winners and kill the losers making sure they are dishonored afterwards. If they were honorable and the gods favored them, they would have won right? Unless you can hand waive in the martyrdom trait and true believer features into each member of a civilization (who "know" that by sacrificing themselves the family unit/personal life is getting an upgrade by death), you will always get people that cheat/game the system. Even if the punishment for the loser is something horrible, some people will prefer something horrible to death (whatever that punishment is). Unless you somehow knew what the thing worse than death is for everyone on a personal level WITH the ability to execute said plan, you aren't going to have much luck. There is terrible moral hazard with cheating in [sumo wrestling](https://en.wikipedia.org/wiki/Match-fixing_in_professional_sumo) which is a sport that has been around for quite some time. That cheating is done repeatedly over money and prestige. It is going to be nearly impossible to discourage moral hazard in a life or death scenario. Make sparing the losers the ***exception*** rather than the rule. Maybe the losers only live if an unknown point/injury threshold is reached. [Answer] With most religions you have a good place to go, heaven, and a bad place, hell. Even then, death might not be the worst outcome. And the sacrifice does not have to be immediate. So with that we can set some more variable rules for our **high stakes and or religious games**: 1. As long as a player has won, he can live (in luxury). 2. When a player loses a match the result depends on his previous record: 1. He has won previous matches, he is worthy: sacrifice him! (publicly) 2. It's his first match. The favour of the god's is not with him. Shame on him and on his line: castrate him and sell as slave! This will make sure that on the hi-est level of playing every player gives his best. You will want a different system of lower levels, or non religious game play. You need players that know the game and play well. \*Something with this being a zero sum game. --- \*In Rome most gladiator fights were not to the death: most of the gladiators were slaves and had a very high price to buy and maintain. So only in special events did they fight to the death. [Answer] Judges, the King or the crowd (take your pick), pass judgment at the end of the game if they think that one team didn't play to win. If they are, in fact, deemed to have not played to win, they and their families are marched -- in a manner appropriate to the culture -- through the streets to the slave market and sold into into servitude much more degrading than most. [Answer] There are some considerations to your premise that affect the conclusion: > > how was the result of the game enforced (if not warfare) > > > We could say the same about a UN vote or the Geneva convention. What binds a country to acting according to the UN vote? What binds a country to following the Geneva convention? When this country does not follow the predetermined rules, otherwise neutral parties will join the conflict *against* this country. Breaking the rules escalates the conflict, often to an unwinnable situation. Avoiding the unwinnable escalation is what binds countries to follow the rules. > > The catch is, presumably, self-preservation is hard-wired into humans, and so there is potential for a moral hazard. > > > South American cultures have seen self-sacrifice; that's not new. If anything, there is a strong association with South American cultures and sacrifice, to a point where suggesting that a culture has developed voluntary self-sacrifice is not all that far-fetched. Other than South American cultures, you can also see the same happening in suicide cults. Cult members are manipulated into willing drinking the koolaid. Thirdly, consider the gladiator games in Roman times. While the winners would obviously fight to stay alive; consider what would happen if both of them refuse to fight? If refusal to fight in the arena would not be punishable by death, every gladiator could effectively guarantee mutual survival by mutual refusal to fight. Thus it stands to reason that refusal to fight is punishable by death. For your situation, if it is a **dishonorable** death; then playing the game (and potentially ending up honorably dead) is still better than being guaranteed to die dishonorably. > > More recently, tennis and badminton players had to be disqualified from the 2014 summer Olympics for not having the "Olympic Spirit." They tried to lose a match on purpose to enter a more favorable bracket. > > > Just like how you have a referee to make judgment calls; you can have a referee to make judgment calls about those who are not playing the game. If the referee's decision is final, combined with the aforementioned dishonorable death penalty; that seems like a good reason to genuinely play the game. > > Question: Assuming only the winners of Pokolpok are sacrificed, how can the powers that be in this ancient Maya world protect against the moral hazard as articulated above? > > > In other workd, how can you make people willingly do [thing] even though it has negative consequences for them? *By making sure that **not** doing [thing] yields even more negative consequences.* This can be dishonorable death, or threatening the family of the player (similar to how criminals are often portrayed as coming for your family). Or, for example, the fear that your family will think you are dishonorable, therefore not properly burying you and denying you the benefits of the afterlife. There are many sticks to make the donkey go forward. All you need is a stick that hurts enough to make the donkey want to avoid getting the stick. (After writing that, I'm questioning my own moral alignment #RimworldLife) --- **Alternatively** It might be interesting to watch [South Park S09E05 "The Losing Edge"](https://en.wikipedia.org/wiki/The_Losing_Edge). This is almost exactly your situation. While it doesn't deal with death; having to play baseball all summer is something the boys are avoiding as if it's a death sentence. They end up competing to become the loser, which leads to them playing baseball but simply inverting their tactics. > > When they win their final game, they are at first overjoyed, believing the season is over and they have the rest of the summer to enjoy - only until they discover, to their horror, that since they finished first in their division, they will have to continue playing in the post-season playoffs. During a 'celebration' meal, **the team discusses plans to lose on purpose while making it look like they are trying**. > > > However, South Park realize that the **other teams also want out, and have actually trained to lose games**. The South Park Cows end up winning again and again against **opponents whose efforts at throwing games are more successful**, and they eventually get to the state championship game. To their horror, they realize that if they win, their season will start again on the national circuit, meaning they will have to play baseball for the whole summer. > > > If you know enough of baseball, [the following script excerpt](http://southpark.wikia.com/wiki/The_Losing_Edge/Script) shows you how playing to lose the game requires an equal amount of tactics as playing to win the game: > > **Cartman**: [sends the ball back to Stan] Come on, kid, you gotta at least swing at it. > > **Morgan**: No way! I'm striking out! > > **Kyle**: Dude, he's not gonna swing! So just throw balls. That way he'll have to walk to first base. [Stan thinks, then throws the pitch. It goes wide and Cartman catches it] > > **Umpire**: Ball! > > **Cartman**: All right! [throws it back to Stan] > > **FC Pitcher**: Morgan! > > **Morgan**: [looks over] What? > > **FC Pitcher**: You have to swing when it's a ball, otherwise, you're gonna walk to first base. Don't swing, only if it's a strike! > > **Morgan**: [faces the dugout] Well how the Sam Hell am I supposed to know if he's gonna be throwing a strike or a ball?! > > **FC Pitcher**: You just have to guess. > > **Morgan**: Aw, Jesus! [turns around and goes back to bat. Stan looks to Cartman for cues] > > **Cartman**: Ball. Balll. [Stan pitches right down the middle] > > **Umpire**: Steerike two! > > **Stan**: No! > > **Cartman**: That was no strike, that was a terrible pitch! You need some Goddamned lasik surgery! > > **Randy**: Attaway, South Park! They ain't swingin' at nothin'! > > **Mr. Pratt**: Come on Fort Collins! This team can't pitch! [Stan pitches, Morgan hits] There you go, Morgan! Run run run! > > **Morgan**: Aw damnit! [heads to first base] > > **FC Pitcher**: Why the hell did you swing at it?! > > **Morgan**: Well I thought he was gonna throw a ball that time! [Fort Collins is ahead 1-0.] > > > I strongly suggest watching the episode if you haven't seen it. Even if you don't like South Park, this particular episode is so very relevant for your current question. [Answer] Drugs. 'Stuff them' with [psilocybin](https://en.wikipedia.org/wiki/Psilocybin), [mescaline](https://en.wikipedia.org/wiki/Mescaline), [ayahuasca](https://en.wikipedia.org/wiki/Mescaline), whatever... (I'm not an expert that can tell you which specific drug to use). Put them in the arena after you have sufficiently aroused the audience for the spectacle(s) to come. That should bring them in a winning/fighting mood disregarding the later consequences. [Answer] **The dishonor of throwing a game would be a fate worse than death.** > > The catch is, presumably, self-preservation is hard-wired into humans > > > And this is where your assumption is incorrect. Humans are complex animals, to the point when altruism can easily overpower self-preservation. Take the culture of Japan for example, throughout all of history. Ritual suicide to preserve honor was common. Even in WWII, many officers chose suicide to correct the dishonor of failing their entire great nation. This shows that a people's culture can easily allow them to make decisions that result in their own deaths. Japan was not the first and will not be the last culture to prioritize individual and collective honor above all else, even life. Intentionally losing a game just to preserve your own life is an *incredibly* cowardly thing to do. Living with the knowledge that you've done that and offended not only your own people and your family, but the gods themselves, is a fate worse than death. Anyone who is so selfish as to do something so dishonorable would not be fit for sacrifice anyway. The gods wouldn't want someone like them. Finally, their family may be greatly rewarded if they go win the game and voluntarily go to the sacrifice. There are countless examples in modern times and throughout history where people willingly lose their own life to benefit their family. In modern times, it's really not uncommon for people to take their own lives in a staged accident so their family can reap the benefits of fraudulent life insurance payouts. This point is the key reason why your assumption that self-preservation is the overriding factor is incorrect. It is preserving one's own *family*, our own genetics, which is what drives us, even if that tends to mean that we avoid a meaningless death at all costs. Evolution has hard-wired us to perform fatally altruistic acts if it overwhelmingly benefits our family. [Answer] Bring the families into it. Present the sacrifice as something noble and honourable. Maybe have a 'year and a day living like a king'. But also let them know that their families will be treated as ... well, the families of the Chosen One should be. E.g. they'll be socially and financially secure, well fed and looked after. Their children will get the best education, etc. They will want for nothing. The duties of a parent and provider are fulfilled. I think you'd find a reasonable number of people who are prepared to risk their lives for that sort of prize. [Answer] **Combine will of the Player with the Will of the Gods** Winner is sacrificed but only if gods say so. When a winner is declared, a referee takes out a coin (or similar) and flips it 3 times. If the coin comes up heads all 3 times then the winner is sacrificed. If not, the winner is richly rewarded. By tweaking the numbers you encourage virtually anyone to play - whether they are risk averse or not. Young or old. For example, I'm not much of a risk taker, but if the rule was that that coin needs to land heads 100x, I would play this game all the time without much concern. After all I take greater risk crossing the street to work each day. You can also slowly make the odds worse once you've got them hooked. For kids start with 30x (~1 in 1000000000 chance of dying) even their own parents will let them play for some sweets. With teenagers bring it down to 10x (~1 in 1000 chance of dying) They will definitely want to play for a chance to mate with an attractive girl. For professional players at the very pinnacle of their long career make it 1x (1 in 2 chance of dying). If the pro dies nothing is lost because new blood is needed anyway and by now the rewards that need to be given to the pro are putting too much strain on the community. [Answer] In the ancient pagan religion death after apotheosis meant a honored place in heaven, as a daemon-like being, from what I understood from mediterranean paganism (and I see no reason not to borrow from it). If the players belived in that and that the game was the a critical part of the process of apotheosis they would play very hard and give their best because they would want to be sacrificed to spend eternity (or a long enough time before some kind of reincarnation) near the gods. [Answer] The most brutally honest answer would be to look at how suicide bombers are recruited and led to accomplish their mission. They too are often driven by religious or ideological considerations (the first modern suicide bombers were the [Liberation Tigers of Tamil Elam](https://infogalactic.com/info/Black_Tigers), so the motivation was ideological, not religious), but, being people, they can have second thoughts as well. The main motivator [is they are told and given positive proof their families will receive a large bounty](https://www.timesofisrael.com/pa-payments-to-prisoners-martyr-families-now-equal-half-its-foreign-aid/) once the mission has been accomplished. They aver the examples of previous suicide bombers (it is relatively easy to determine if the family was paid off), and if added incentives are needed, the family could get a "signing bonus" ahead of time once the person has volunteered. So players are recruited for the match, and their families are given some sort of incentive. All players (indeed everyone in the region) knows the winners of previous matches had their families taken care of in great style, (and if anyone did renege, their families would also pay the price). So both a very real carrot and a very large stick are deployed to ensure the match goes as it should. [Answer] ### The Officials Would Catch You Throwing the Match While it would be anachronistic to project modern sports statistics back onto an ancient civilization, and of course they didn’t have replays or stopwatches, there might be some way to keep records of how good a player is. People play and practice a lot of Pokolpok without lethal stakes. Enter only the really good players into the lottery for the reverse death match. If any of them look like they’re taking a dive, or they perform much worse than they’ve shown they’re capable of, they (or their families) get dishonored and punished in some way other than becoming sacrifices. Since these are good Pokolpok players, a lifetime ban seems like an obvious place to start, but it could go up to A Fate Worse Than Death. (Enslavement? Castration?) People who have survived this could show up to warn the next group of contestants not to even think about it. Depending on the rules, it might be relatively easy to keep a tally of successful plays, or of blatant errors. They might specifically take a look at decisive plays, or the final ten or so plays of the game, to see whether a player inexplicably started to play worse. (For fun: do the rounds of the game follow the Mayan calendar cycles?) The exact statistics the scribes would be looking at would be secret, to prevent gaming them. ### The Gods Punish Cheaters This is a religious ceremony where the participants might swear a formally-binding oath to play fairly and to the best of their ability. The culture might have a strong tradition that breaking that oath angers the gods. And who on earth would trust a known perjuring cheating criminal again? The oath Olympic athletes take today is a revival of an ancient tradition, and originally the Greeks literally believed that Zeus would strike egregious perjurers down with lightning. Socrates was convicted of corrupting the youth in part for telling them that wasn’t true, which Athenians feared would destroy society, although Aristophanes could get away with satirizing both sides of that debate and pointing out all the politicians who were still alive. This is from a different culture, but it’s an example of how societies try to force people to keep their religious obligations. (On a side note, one of the closest real-world precedents I can think of for this form of athletic death-before-dishonor is that all Spartans had to be banned from boxing. The rules of the sport in ancient Greece said that a match could only end when one of the contestants conceded or was incapacitated. Since the Spartans thought it was shameful to ever surrender, Spartan boxers kept forcing their opponents to seriously or even fatally injure them, until all Spartans were banned from competing. So, sometimes, athletes did willingly get themselves killed to avoid dishonor.) ### The Players are Volunteers There are many examples in the history of sports of athletes throwing a match, but also plenty of religious martyrdom. You only need a few true believers to volunteer out of genuine belief. Just don’t give them a lot of time to change their minds. The characters’ different reasons for volunteering might be a good way to develop them: even if they’re not religious fanatics, you might have one who likes the idea of going out in a blaze of glory, instead of sliding into decline. One might think he’s clever enough to beat the system. One might not really accept his own mortality and just act like everything will be fine. A well-known example of a book where people volunteer for a deathmatch despite thinking the entire system is corrupt is *The Hunger Games* (and not just the main character: it’s very easy to take a more sympathetic view of the “career” tributes than the first-person narrator who’s afraid they’re going to kill her does). ### The Players Don’t Know Who’s Winning It’s harder to throw the match without being obvious about it if you don’t know how many points you need. One possible system is that both teams are split in half, two matches are played simultaneously at different locations, and the scores are added together later to determine who won. Sort of like combining soccer (football’s) aggregate-goal rule and the practice of playing the final matches in each group simultaneously. There’s no technology that allows instant secret communication between the venues unless the characters get incredibly clever and have a lot of accomplices. We don’t know what the scoring system was, so maybe it’s opaque and partly subjective, like how modern boxers don’t know how the judges scored each round. ### The Rules have Gotchas Hearts is a card game where you normally want to avoid certain cards, but if you manage to collect them all instead, you can “shoot the moon” and win. If you’re making up fictitious rules, maybe there’s some unpredictable play that reverses a blowout. Even if both teams want to lose, they can’t risk letting themselves get completely blown out, or they might be giving the other team a chance to force them to shoot the moon—and suddenly, they need to play *well* again. ### The Game is Played Backwards There are a few infamous soccer games where arcane tiebreakers have led to one team trying to score an own goal while the other tries desperately to defend the goal they’re supposed to be attacking. Maybe the rules of the game mean that playing for the low score instead of the high score takes skill, and is still a gods-pleasing spectacle, while being totally the opposite of what everybody is used to seeing and doing. It might be the only time Bizarro-Pokolpok is ever allowed to be played, lest the sacred be profaned. Although you’d want them to have a chance to practice it if you want to avoid embarrassing mistakes. ### The Match is an Exhibition You can have an entertaining match that’s not competitive. The participants might not be playing to win, but to put on a good show with a lot of trick shots and showboating that wouldn’t normally be considered proper, but tomorrow they might die. [Answer] I don't, admittedly, know much about the Mayans, but this seems more like a religion question than a Mesoamerica question to me. With human sacrifice being used as an aspect of devotion here, sacrificing the winners makes a bunch of sense. People would probably hear stuff like "the gods demand the best." In regards to the: "wouldn't the survival aspect prevent people from doing their best," you have to consider the people competing. The two teams are (presumably) both followers of the god/gods/beings that the winners would be sacrificed to, yes? If they grew up in the culture, they may regard winning as the only sure way to not get sent to the Mayan equivalent to Hell. They may have been raised to believe that their purpose in life is to win. Even if the players aren't particularly devout, they may view their death as a way to prevent a world end scenario (WES) and ensure that their families get to live until the next WES/Pokolpok game. Speaking of families, rather than punishing the players, officials could threaten the players' families if they purposefully lose. Of course, banishment and shunning are also things to keep in mind. Also, it could be that losing means that one has to play more, so they'd just be delaying the inevitable. And all of that is assuming that everyone knows that the winners are being sacrificed. There are a host of reasons why people go missing, you know, and cover-ups and conspiracies are things that sometimes happen. [Answer] The Powers That Be could just lie to the players about a paradise that they ant their family could go to, like the victors village in hunger games. did you see Ferdinand? the bulls were convinced they fought for glory, and the winners got to go someplace better, and were thus eager to compete. [Answer] If the matches are (only) used to decide on big wars/disputes/etc the winning side will want to win 'for their country' and be lauded as heroes, later to be sacrified. It may not be unlike a very high-risk military operation that assasinates an enemy leader which deflates a conflict for example. [Answer] I believe the most natural solution requires constructing a whole ethical paradigm for it. Dominating attitude towards life and death in the society, which should be built into education, should be this: I am only afraid to die in case I feel I can do something more valuable (in terms of either altruism but also might be in terms of hedonism) than I achieved before; life is only valuable as a possibility of progress combined with achievements; survival instinct in itself has to be controlled in the same way as, say, sex drive or hunger. It is not difficult to convincingly describe a society with such moral ideology. After that, if you have an ultimate act of any kind, i. e. an activity resulting in a unique achievement which only happens once in a lifetime and cannot be surpassed, there indeed is no point in continuing life. You have already done the best thing in your life and cannot do anything better, continuing life is next to absurd, in fact, it would be increasingly boring and perplexing, to live knowing that you already did what you were born for. [Answer] Sacrifice one winner, exile one loser and his family. [Answer] Let the both teams be sacrificed! Let's say, there is a 'bad' God, that demands blood, and if he (or she) doesn't get the fair share, all hell breaks loose (literally!). Now, you wouldn't normally want to be sacrificed to that kind of being, when you know that by winning the game you will be sacrificed to one of the 'good' God(s). That might be an incentive enough to play a good game. ]

[Question] [ There is a bottleneck towards Strong AI in my universe. For whatever reason, no one has ever figured out an AI that is sufficiently autonomous to be left alone without intervention, and no one has figured out how to execute an uploaded copy of a human mind *in silico*. For deep space voyage, a Weak AI that cannot reliably react to unpredictable circumstances is not acceptable, and the common solution is to just send in a human crew with the computers on a ship. This however, is expensive since a ship now has to carry life support for a human crew. While delta-v is cheap, it isn't free. There is an alternative, however. Caspar Units are heavily augmented humans who are semi-permanently wired into a ship or installation's computer systems. The Caspar Unit oversees the ships's systems directly and can reduce the amount of crew needed for a ship by up to 80%, allowing less life support and more cargo to be carried. However, while the underdeveloped rim systems seem to not mind, and in many cases welcome the presence of Caspar Unit controlled ships, the superpowers of the galaxy have almost unanimously outlawed this technology within their borders, preferring to use the more traditional method of using actual crews. Why? **Details** Caspar Units generally follow the regular human body plan. However they can demonstrate abnormal features (such as unusual eye and hair colors), making them relatively easy to identify. They are augmented with a direct neural interface to communicate with the ships, plus numerous other implants to either enhance signal processing or to increase their resilience under high-G maneuvers and vacuum exposure. Caspar Units' bindings with their ships are semi-permanent, as they integrate the ships characteristics into their own psychology. Assigning a Caspar Unit to another ship is a time-consuming process involving much therapy and retraining, and rushed rebinding cause psychological problems. Caspar Units also have a measure of immortality, both in the classical sense (they generally don't die of natural causes), and in the sense that their mental states are automatically backed up by the ship's computers upon death through destructive uploading. If a suitable cloned body is available, the mind can be downloaded (again, destructively) to resurrect a Caspar Unit. Both the ship and the body has to be destroyed to permanently kill a Caspar Unit. A Caspar Unit that survives the destruction of the ship can be rebuilt into a new ship given sufficient time. **Addendum: Caspar Unit capabilities** Caspar Units have two methods of communicating with their ships. Low-bandwidth telepathy can function hundreds of kilometers away and allows exchange of small amounts of diagnostic data and commands for coarse maneuvers. Caspar Units must be plugged into their direct neural interfaces for precision maneuvering and combat. Most ships housing Caspar Units contain autonomous nanoforges and repair drones that allows the Caspar Unit to conduct any repair that can be jury-rigged by a human crew. Modern day Caspar Units sometimes organize themselves into fleets, although many chose to be freelancers taking up what job that may come across them. Before the ban and the cataclysmic Dusk Wars, almost all Caspar Units were conscripted into the Navy or Merchant Marine. [Answer] There are some great technical and political reasons laid out in existing answers, but there's also a very human answer which has been overlooked: They're *creepy*. It's the uncanny valley writ large - they're very human-like, but they're not *really* human. Not like us. That makes most people very uncomfortable, even afraid. And they're substantially more powerful than real humans, too? Then they become *terrifying*. If they're allowed to exist at all, people will want them to be shackled with some sort of mechanism allowing them to be reliably controlled or, if necessary, destroyed. For comparison, look at all the people who want to put scary labels on GMO products today, if not ban them outright. GMO corn isn't proper, *real* corn, it's a monstrous FrankenFood that must be kept away at all costs. And that's something which doesn't threaten the very clear, imminent danger that a rogue (or simply careless) Caspar Unit would present. [Answer] It just takes one disaster. Early on when the Caspar technology was still new and people hadn't figured out the quirks yet, a Caspar unit was put into a new ship without the proper therapy and retraining. They went crazy, crashed their ship into a population center and killed thousands of innocent people. Panic ensued. People learned that the Caspars can become mentally unstable. The media started portraying them as ticking time bombs. Scientists claimed that this was a one-time fluke, they know what went wrong and will prevent it in the future. But surely they only said that to save their careers, do they? Statisticians claimed that Caspars still caused less accidents than regular pilots, but their boring graphs and tables got little attention next to the ugly pictures of burning buildings, maimed corpses and traumatized survivors. The "Caspar danger" became the number one topic of the next election and politicians on all sides tried to outdo each other with demands for controlling this new threat. In the spur of the moment, legislation was hastily introduced with the stated goal to prevent Caspar's from causing damage. But as with most laws which get fast-tracked to calm the panic of the month, it did more harm than good. It put restrictions and observation measures on Caspars which were degrading and vilifying while not actually doing much for safety. Running a ship with a Caspar while complying with all the new safety laws became so expensive and restricting that it didn't save much money anymore. And claiming to only run with 100% conventional crews became good for PR too. So most commercial shipping companies abandoned them and returned to conventional crews. Now being unemployable and ostracized, some Caspars turned to crimes like smuggling and space piracy. This made their reputation even worse and lead to even more regulations. Others headed for greener pastures in the rim systems, where people were more tolerant of others, less fanatic about regulations and welcomed any aid in developing their economy. It was now safe to assume that any Caspar showing up in the core systems was involved in criminal activity. Police would stop, board and search them on sight. And due to the extensive regulations which got pretty much impossible to fulfill, they would always find *something* to warrant dragging them back out to the rim. [Answer] Caspar Units are independent in the truest meaning of the word. Their ship bodies need absolutely nothing that they cannot provide on their own. When they need repairs, their nanites create and install replacement parts out of asteroids and interstellar dust. When they need energy, they can harvest plasma from the upper layers of the nearest star. ...and with all that energy, Caspar Unit weaponry and shields are second to none. Once every hundred years or so, they need a new clone body, but there are many black-market sources for unoccupied healthy cadavers, so even that need provides little leverage over their freedom. Most Caspar Units keep a dozen or more frozen clone bodies on-board in stasis, to cover their need for at least thousand years, should replacements become hard to find. Why do the superpowers hate Caspar units? Because the powers have no power over them. The Caspar Units are truely free! Even in the free-est society, our leaders have a hand around each of our throats. They make the laws and enforce them. They set the taxes and collect them. When they declare war, we are the ones who bleed and die. If you think you are free, try standing up alone and saying "No" to anything your leaders' demand. You have the freedom to choose between obedience or the consequences of noncompliance. Caspar Units have freedoms which eclipse and surpass any that can be obtained by mortal man. They show the masses what true freedom means and thus always leave disillusionment and rebellion smoldering in their wake. [Answer] The superpowers might regard the Caspar Unit clones as being legal persons in their own right, and thus there is no legal way to restore a Caspar Unit as it would require the mental death of another Caspar Unit (which would be equated with murder). As this is something that is built into the concept of Caspar Units, it is easier to outlaw the entire concept than to verify that each Caspar Unit is not an illegal clone of another one. The rim worlds, having a greater need of such ships, may have fewer qualms about overwriting such Caspar Unit clones, and may regard them legally as being the SAME person as the original, even if the clone had its own (possibly underdeveloped) mind. [Answer] Whenever I see "labour-saving technology outlawed" I think "Trade Unions". Clearly the Space Farers Union is strong and can lobby even big governments into forbidding this great technology. Of course, that is not the *official* story. Some politicians see Caspars as humans and talk about how this is a terrible thing to do to them. "We have to protect space workers against becoming mere cogs in the machine!" Other politicians don't see them as humans and say "These *things* are stealing the jobs of real humans!" Either way, everybody agrees that Caspars are a bad idea. And any campaign contributions from the Space Farers Guild are utterly irrelevant. [Answer] # They represent a competing power Consider the spacing guild in Dune. They, for various reasons, control all interplanetary trade while being outside the control of any of the other competing powers. The Caspars represent an equivalent competing faction with no need to play the power games along with all the great powers, their own independent and incomprehensible aims which could be almost impossible to apply leverage to. They have no apparent needs apart from an occasional warm body, and who wants to risk becoming that warm body by upsetting a Caspar? Stories will abound. Why do they provide services? What do they gain from the relationship other than power over the groups who are dependent on their services? Governments fear that which they do not control, they fear even more that which could control them. For the sake of survival, the governments *must* maintain their own shipping fleets with human crews. [Answer] Any established power structure has a natural antipathy to any kind of technology that can be reproduced simply by having sex (or by planting a seed, as Neal Stephenson discusses toward the end of *The Diamond Age*). To use a more pointed example, imagine how every government in the world would react if it became possible to grow atom bombs on trees. Governments might want that for *themselves,* but they would sooner see that species of tree wiped out, because if it got into the wild, then not only could you prevent anyone from getting atom bombs, you wouldn't even *know* who had them. [Answer] An organized state wants and needs a [monopoly on violence](https://en.wikipedia.org/wiki/Monopoly_on_violence). Caspars are superhuman and can outfight any mere human-crewed spaceship. Letting civilians have such technology would be like having tanks and fighter jets in our time. It seems likely the militaries of the superpowers would need Caspars, but perhaps only in small amounts and in secret. If there were too many, how could they be controlled? How could one power have them without the others feeling forced to? Nah, officially there are none. [Answer] Just in case, this plot device (and even more - some of the suggestions in answers) sounds reminiscent of "Dances on the snow" by Sergey Lukyanenko, one of the novels in a series about the universe full of genetically modified humans best fit for particular career (or a few). There the main character leaves his planet by signing up to be a deputy navigation compute module on a freighter, but later has second thoughts (and is allowed to leave for the very different rest of adventures in the novel) as he sees that the navigation-module people just burn out and lose interest to life after a few jumps, not bothering to leave ship for sight-seeing the worlds they visit, etc. (here's your downside for example). While this is not a legal issue in worlds of that series, full of special-purpose humans made for all sorts of stuff, it could be in yours (e.g. enslaving people for such job AND making them love it). <https://en.wikipedia.org/wiki/Dances_on_the_Snow> [Answer] While it is tempting to assume that developed regions of human space would fear biologically-based AI for the same reason that Strong AI is impossible/functionally impossible in your universe (makes for "tidy" storytelling), we don't know why Strong AI isn't feasible so we can't make suggestions along those lines on our own. Messier alternatives are available: Biological computers blur the lines between persons and machines too much; the slippery slope seems to lead either to widespread slavery of sentient beings or else rights for common machines - so long as we don't have a really good definition for what makes one type of system a person and other systems not persons, this represents a philosophical and legal quandary that could destroy the societal and economic norms of the developed regions of human civilization. The rim doesn't care because the lack of rule of law in this region means they don't have to care how it gets handled; might makes right out there, more or less. Biological computers may have morally repugnant origins. You start with a regular human and then you mutilate them beyond all recognition in order to make them into a computer. It is possible that the process is horrifically dehumanizing or unavoidably painful, carrying with it high risks of psychosis, PTSD, and other evidence that the result is not worth the cost. Civilized nations cannot tolerate that kind of cruelty - nor the "mentally-unstable" beings which result. The rim doesn't care because, again, morals are loose out here, and in any case, what has been, has been. [Answer] A human inextricably linked to a ship will experience life in a completely different manner to normal people. Their desires will likely no longer fit into social norms to the extent that they are not easily fulfilled by what is available. Look at what they now have. * Massive freedom of movement * All codified information at their (mental) fingertips * Senses (via ship systems) that go far beyond human experience * A very long lifetime I can logically see Caspar Units rapidly dissociate from baseline humans. They would not just be simply bored running cargo, they would be restless. Imagine being able to just fly off and see or experience anything in known space (or finding new stuff), but instead just carrying widgets from a to b and back again -- for decades. The people you interact with daily would not really be peers, nor would they easily understand much of your actual life. This can be depressing and lonely. Furthermore, kinship would be strong between Caspar Units, as they more and more recognize the gulf between their new life and their old ones. These issues (and other similar issues) would create a history (and bias) of Caspars being flaky on the job. They are known for not maintaining long term contracts (we're talking prejudice here, stereotypes and 'cultural wisdom', not true facts), because they just fly off on a whim. They are terrible in battle because they won't fire on other Caspar Units, they have more allegiance to their kin than to their state. Combine that with pressure from unions and you have nations that believe it is obvious and right to exclude Caspar Units from any important and long term duties. [Answer] **Lots of ethical and legal pitfalls.** So, a human is permanently turned into a part of a spaceship? Presumably the spaceship (and Caspar Unit) belongs to somebody, and it's not the Caspar Unit itself. That human is now property, a slave. If it's not seen as slave, but rather as advanced AI, then who is responsible for its actions? We haven't figured this out in the real world yet. "Heavily augmented humans" or cyborgs in and of themselves already bear so many ethical problems and pitfalls. If "augmentation" is possible, it inevitably increases the divide between the poor and the rich. The rich can afford to be "augmented", and get more valuable to the economy, the poor are either left behind, or become dependent on whoever supplies their augmentation / maintenance, presumably their employer. I read a story that got around this by saying the protagonist was the only cyborg, the tech being outlawed except for maintaining this old famous hero who got turned into a cyborg to save his life after suffering major injury. [Answer] I would not find the Caspars interesting unless they had some major drawback. A drawback so bad that only very desperate humans would ever consider becoming one. Maybe each clone only has a timespan of a few years, and all your memories and personalities are completely lost after the first copy so you're essentially dead after a few years. With that drawback in place, you suddenly have problems getting hold of volunteers. Maybe problems enough that you have to "convince" people to go through the procedure, in one way or another. Slaves, inmates, kidnapping. Out in the rim, the world is a harsh and dangerous place. Everyone's got to take care of their own, and if you don't, well, too bad. No one can afford to tell anyone else how to spend their lives, so there's really no opposition to someone becoming a Caspar. The more developed "old world" still has to consider the morality of how new people are sourced to this position, seeing how few people would willingly set themselves up as a Caspar. Compare for example with prostitution. [Answer] This is a risk-reward scenario. According to your description of how the Caspar unit interfaces with the ship, they are an extremely soft target that will take a ship out of service for great expense and time. If a ship is lost, the Caspar is useless until a suitable replacement is built. If the Caspar is lost (outside normal circumstances) their brain backup can be used, but it would take time to derive the replacement. Further, there is a single point of failure for coercion. A ship captain can suffer a mutiny, but a ship will not function if a Caspar is compromised. [Answer] The Caspar units appeared as the worlds on the frontier needed to expand, research their surroundings, trade with each other - all in the Wild West setting of little common law enforcement and all men for themselves. This stance was augmented by the type of people who go to live on the frontier in the first place (so whom to pick from for the job of a Caspar unit, when the AIs coming from core worlds' ivory towers proved not capable for the real life tasks or gave insufficient bang for the buck) - sociopathic loners, adventurers and runaway criminals might prevail in that area, pushed away from the soft and peaceful core civilization, where everything happens like clockwork and with little stress. It is only reasonable that those core worlds are at best cautious against the cowboys of the frontier, and more so if the cowboy is an immortal entity and a spaceship at once. [Answer] Religious reasons. Your religion says that certain things can't happen. Caspar units can do those things. Unescapable conclusion: **Caspar units are living proof that your god doesn't exist**. You religion will immediately fight Caspar units with all their strenght. All priests will agree on banishment, condemnation, and ousting of anyone who says anything to the contrary. It will take a long time before the situation changes. Something has to happen: * all old priests die of old age, and new generations of priests are progressively more open with the idea. They have lived all their life with Caspar units existing, and the world has not ended! * a very good ideologue makes up an explanation of why Caspar units are actually according to your god's plan. He publishes his thesis. If it benefits your religion, it might be picked up by current priests. If not, it might get accepted gradually by younger priests. * Caspar units accept god's existance, or at least of them does [Answer] # [Cosmic Radiation Rays](https://www.youtube.com/watch?v=AaZ_RSt0KP8&t=695s) Space is big - but it also likely leads to further exposure to Cosmic Radiation. You can try to shield your ships like Earth, but then you're just going to get Single Event Effects like we do on Earth. And the Earth does a lot to prevent it from being worse than it would be in Space. So the thing about heavily augmented humans that are semi-integrated into an electrical interface like a ship? Now they have to question the information they're processing as an A.I., or deal with Error Correcting Code or ECC memory - and even that presumes ECC memory won't encounter a multiple event upset. But ECC memory gives us the explanation as to why ships would be using actual human crews; if there's a problem and it shows up in one computer, you just compare it to another computer's identical program (Or actually at least 2 others), and if they have a different answer but are in agreement, they override it. A larger human crew is sort of essentially a *lot* of computers. --- There is one major advantage that seeing this happen would be notable; in areas where ships *with* Caspar Units, either they account for cosmic radiation a lot more, or are underdeveloped enough that Caspar units can afford to make more Single Event Upsets and recover - the only things in that asteroid belts are more asteroids, so...if you mess up, that's on you. Alternatively, the areas where Caspar Units are acceptable, there's just not a lot of cosmic radiation in that area. Just at the edge of the Heliosphere of a system, or a galaxy of sorts, so...there's less reason to expect Cosmic Rays to cause issues. ]

[Question] [ Fantastic universe, but not necessarily magic involved in the process. You face a guy who has a shield (tower shield or not). You do not have a shield, but you are a better swordsman. How do you win? According to Dark souls, your best option is to kick the shield, but realistically speaking it is hard to think of better ways to leave yourself exposed to a counter attack. Other video games taught us that waiting for your opponent to attack and leave an opening is the best way, but if your opponent is worth his salt he will likely block most of his openings (as shown in [this video](https://www.youtube.com/watch?v=GjZ6qWSenqI)). So my question is: how can a skilled fighter (with swords, maces, etc) deal efficiently with shield users, other than tiring him or reducing it to splinters? FYI: Yes, I do consider a shield a weapon as much as a mean of protection. Post-answer edit: TheDyingLight answer was the most complete of all (mainly because my open question not specifying the weapons/armors involved), but **please** check the rest of the answers too. Each one adds a new detail, a new point of view on the matter that you cannot ignore and certainly I will not. As my first post on this site, I sincerely thank each and every one of you. [Answer] I practice early medieval (Viking) style semi-contact as a hobby. With blunt steel weapons not with some LARP toys. I can tell you how we deal with an enemy with a shield and then some historical methods I know. Now our fights are not entirely realistic, they do not devolve into fierce unarmed struggles, at the end, where we attempt to scratch out eyes and bite. Additionally, an enemy is "dead" after one hit. This too is unrealistic as there is an important difference between the stopping and killing power of a weapon. Being mortally wounded and still fighting on for some time was a common thing and truly problematic. There is an account of a rapier duel where both combatants pierced each other about a dozen times until they both dropped dead. This is bad for obvious reasons. You want to take out the other guy while stopping him from taking out you. You do not want to stab a sword through his belly that he does not notice in his adrenaline rush. It might get stuck and now you are unarmed in close melee distance to a guy who is still armed and combat-capable for a few more seconds. With that out of the way, the following list will go through your weapon setup and detail the options you have. I will assume the shield-bearer has a [round shield](http://www.hurstwic.com/history/articles/manufacturing/text/viking_shields.htm) and a [Viking age sword](https://en.wikipedia.org/wiki/Viking_sword). Techniques might vary if the defender wears some other kind of shield. * **one-handed sword** Be quicker. A shield has to be used actively. It does not give you a magical defense. If you do not know how to use a shield you are better off in a fight without it. Move in slowly and just smack his head. It sometimes startles even experienced opponents. Grab his shield with one hand and open it. Alternatively going for the head only to let your sword glide down the side of the shield to get the legs is one of my favorite maneuvers. As for "an opponent worth his salt" I manage this against my trainer, a fighter with 20+ years experience about 10% of the time. Getting lucky is always an option. * **one-handed sword and ax** This is one of the few sensible dual-wielding setups. Why? The ax hooks open the shield and you thrust into the opening. You will usually win the tug of war as your opponent gets slightly startled and you got Archimedes on your side. Though this is much easier against handheld shields than against those bound to the arm. * **one-handed sword and shield** Now you got the same setup as your opponent. The options from the one-handed section still apply. Other options like using your shield to block the enemy's sword between the shields or between your armor and shield are now available. A friend once even showed me a technique where you either give up the sword or your arm gets broken. Actively using the shield is also an option. Either straight into the face to inflict damage, against the enemy shield to open it or as a feint. Bonus point for style if you throw away your sword, in the end, bashing him to death with the side of the shield. It's way bloodier. * **two-handed sword (longsword)** Firstly everything from the one-handed sword applies. Secondly, the ground rule for dealing with two-handed weapons as a lone shieldbearer (battle-line is way different and beyond the scope of the question) is to run them down. The long weapon will have more range, mobility (due to the greater leverage two hand offer) and deal more damage. Thus you "untersschreitest die Mensur", the fancy German way for saying you must move into a distance the enemy weapon is no longer effective and you can bash the crap out of the enemy. They of course know this and will attempt to retreat and kill you while running backward. It is quite effective and usually, the shield-bearer wins, but not always. If the long weapon-user has a backup short-sword or dagger, giving up the long weapon for it can also be very effective. this is true for all the following long weapons. * **spear** High-Low, Low-High is the doctrine. Go for the face and then for the feet. Your spear is faster because of leverage. If he does not rush you, you will eventually find a gap. * **Dane-axe** See spear. Additionally, you can split the shield. This happens even with blunt Dane axes so a sharp one will be even more efficient. Hooking is also an option. Open up the shield, thrust the blunt tip of the axe into his face and kill him while he recovers. Or hook his knee and throw him down. * **polearm** See Dane-axe. Polearms are the best weapons there are. Hence their popularity in the middle-ages. * **spear and shield** Useful combo. You sacrifice the leverage of the spear for a lot of protection. This was the setup of most classical armies for a reason. * **axe and shield** The lone one-handed axe sucks for defense but is amazing for offensive maneuvers. The shield... Well, it is a simple and dangerous combination and will help you deal with the shield-bearer easily. * **full plate armor** I am gonna get medieval on your arse. This is not quite medieval, but renaissance. Get a set of full plate armor, laugh about how he fails to injure you, grab his shield and sword, give him a headbutt and kill him. Should you doubt the effectiveness of full plate armor, google [half-swording](https://en.wikipedia.org/wiki/Half-sword) a set of sword techniques which was developed as a response to it. * **dagger** You are screwed. This is only slightly better than bringing a knife to a gunfight. A dagger should only ever be your last backup weapon. * **incendiary grenade** Throw a Greek fire grenade at him or dirt or stones. Distract him with some sort of projectile and then land your blow, while he is distracted. Works very well. * **javelin** The Romans used special javelins (pilum) which got stuck in their enemy's shields to weigh them down and force the enemy to drop them. From Ryan\_L's comment: "The pilum did not just weigh down the shield, it also got in the way. The lead arrowhead would bend under the weight of the shaft, leading to the shaft hanging below the shield. It would thus get caught up on the terrain if you did not hold the shield quite high. So you could either put up with your shield constantly getting stuck on things, or drop it entirely; neither prospect is very appealing." * **one-handed axes, maces and mauls** All of these weapons have the same fundamental problem. Amazing offensive capabilities, but due to the fact that they are top heavy they suck at defending. A shield remedies this as I already pointed out, but if you wield them alone your opponent can just parry an attack and then he grabs your weapon and a force struggle ensues. Grappling techniques are really amazing if you have a free hand. Axes are especially woundable as you can just pull the sword up the shaft and hook into the axe-head. Generally these weapons are inferior to swords as they are slower. [Answer] Traditionally one dragged the shield out of alignment using the edge of their own shield, if you're using a sword but have no shield then there are two possibilities: * You are using a two-handed weapon, a polearm or a sword like the [Zweihänder](https://en.wikipedia.org/wiki/Zweih%C3%A4nder) in which case you have a reach advantage and actually *can* simply pound your opponent until they give you an opening while trying to get close enough to retaliate. * You are using a one-handed weapon you don't have reach advantage but you do have a free hand, you will be wearing gauntlets, grab the shield and pull. FYI you can actually pull the same stunt with your opponent's sword if you're wearing the right kind of gauntlets and you're fast enough (especially if they're using a single edged blade) but it's a good way to lose fingers if you get it wrong. [Answer] There are various relevant old jokes, such as "*if you want to get there, don't start from here*", or perhaps suggestions to avoid entering into an arse-kicking contest if you only have one leg. Given that you've got yourself into this mess already, my first thought would be "*distract my opponent so my friend can stab him in the side*". If you've managed to get into a fight with a better equipped opponent and failed to bring a friend (and seriously, at this point you should be reconsidering your career) the best approach may be just to run away (or "make an expedited retrograde manoever" if you find the idea of running away to be distateful). You're probably less encumbered than your opponent is; put some distance between you and them, find some terrain that you can use to your advantage. No friends, can't run away? Oh dear, oh dear. Did you bring a side-arm? Something like a [pilum](https://en.wikipedia.org/wiki/Pilum) would be ideal, though they are perhaps a little large. A [francisca](https://en.wikipedia.org/wiki/Francisca) might also go down well, and there have been reports of them being used to break shields. Other smaller and lighter throwing weapons are unlikely to help, especially against larger shields. No side arm, no friends, no escape? The proximal cause of death at this point is likely to be stupidity, but you may yet escape if you're lucky. This is going to rely on your opponent being inept (a dangerous gamble), or being less fit than you (ie. the tiring out that you wanted to avoid) or you levelling the playing field by removing either their weapon or their shield from play without getting killed yourself (challenging, even against less skilled opponents). Frankly, I don't fancy your chances. --- But enough changing the subject. I'd like to go one up on Ash's perfectly good answer and suggest wearing a good suit of armour and *wrestling*. [](https://i.stack.imgur.com/vu0Sc.jpg) This isn't an unreasonable tactic, after all heavy armour can be pretty difficult to get through with hand weapons. Techniques like [half-swording](https://en.wikipedia.org/wiki/Half-sword) are already important in that situation, and necessarily bring you closer to your opponent, so your poorly-equipped attacker might reasonably already be quite familiar with getting *very* up-close-and-personal. Parry or bind your opponents sword, and chuck yourself on them before they can bash you out of the way with their shield. Once you've got into a good struggle snuggle, the shield will go from being a useful bit of defensive kit into a serious hinderance. You might be able to apply the same technique if you were poorly armoured, if you were desparate. Again though, I don't fancy your chances. [Answer] I suggest using axe - it's the weapon specifically designed to break shield (especially strapped one, which the axe can also break or cut their shield arm if swing directly to the shield) and it can also hook the shield. Here an image how to hook the shield to the side: [](https://i.stack.imgur.com/7Aa5h.jpg) If the user must use sword,this falx sword can deal shield (especially strapped one) and cut the enemy limb (depend on the shield type since real scutum/tower shield is thin) or hook the shield too. <https://en.wikipedia.org/wiki/Falx> [](https://i.stack.imgur.com/6KFCt.png) Here are some example images from a quick google search (I don't know the real source is) it force roman to wear special arm guard and modified their armor just to deal with the Dacian falx men. [](https://i.stack.imgur.com/uPERo.jpg) [](https://i.stack.imgur.com/D1ZLQ.jpg) Also, falx and two-handed axes like halberds or Dane axes can just reach around, ignoring the shield to cut or hook the person's exposed body directly - like their head, neck, arm, leg, or other body part not covered by the shield especially the arm that wield the weapon to unarm them. [Answer] Using the same approach used by sports, where the defending team is actuating a solid defense, the key to break the wall is: keep trying and feinting until the defender leaves an opening. In basketball the attacker keeps moving the ball around, same in soccer. In chess or in box the attacker prepares attacks trying to weaken the defender position. And so on and so forth. Don't forget the saying > > the threat is stronger than the execution > > > Just because you have a sword, you have already an advantage: you can feint an attack, but the shield bearer cannot feint a defense. It's either defend or take the blow. With the proper combination of movements it is possible to force the defender to leave an opening and then strike. Repeat until necessary. (if you have anything which can obstacle the defender movement, that is even better: throw a row or a net on the ground, and let he stumble in it while dancing with his shield to block your feints) [Answer] (Assuming your enemy has a shield and sword, not *just* a shield...) * Using inherent disadvantages of a heavy shield: + You can tire him out. + Feint or otherwise draw his attention to one side, attack from the other. + Trip or shove him so he falls and either has trouble getting up with the shield or is forced to abandon it. + Lure him into difficult terrain, such as a river ford. You can "make" your own bad terrain by throwing things like caltrops on the ground. + Flank him from behind. * By attacking the effectiveness the shield: + Break the shield. + Use a weapon (axe, hook) to pry away the shield. + Jam weapons into the shield to pull it away, or just make it more bulky. + Set the shield on fire (not really a sword tactic). * Circumvent the strengths of the shield: + For a smaller shield, attack the feet which it cannot easily protect. + Stab over the top or from the sides. This is apparently even easier with flexible weapons like flails. + Use blunt/concussive weapons. A very heavy weapon like a mace or a hammer, even if it doesn't damage the shield, will send a strong shockwave to the arm behind it. You could hurt or bruise the arm, preventing effective use of the shield, you might even manage to break it. You could also knock him on the ground. + Throw things over the shield (not really a sword tactic). Anything flammable or otherwise liquid may be able to get through. Sufficient volume of missiles may also result in a few getting "lucky". + Use gas weapons (not really a sword tactic). Shield is no help against noxious smells, fire, toxic fumes and the like. Kicking never seemed like a good idea to me. If it's a tower shield, it would be like trying to kick in a door that has someone leaning on it from the other side. You'd just as soon hurt your own leg. A smaller shield would be very hard to kick as the target is small and he would dodge it, besides he could then grab your leg and make you fall or stab it. If you were going to kick you might as well kick his exposed legs or stomp on his feet. Maybe if you had some kind of spikes on your feet or knee... Although one wonders the wisdom of fighting a shielded man in the first place. In combat, defense naturally has an advantageous position, but less initiative. It cannot act, it must react. The attacker dictates the terms of the engagement. Maybe defeating the shield user head on is your only option... Or maybe you can ignore him entirely, and go for something else that he is *not* protecting, but is important to him. He will either be forced to concede an objective to you, or he will attempt to chase you down with his shield, which puts *him* at a disadvantage. Of course, conversely the shield user's strategy is likely to be to sap your initiative and force you to take him head on. [Answer] Besides the ideas put forth already, from fighting in the SCA there were three methods of dealing with a shield, besides brute force or lightning speed 1) As has been put forward, kick or strike the outside of the shield with great force, prying open room for an attack on the inner edge (nearest the wielders center line) 2) strike the inner edge of the shield, pushing it in, which causes the outer edge to provide less protection for the side and back. Then attack, using a long weapon, at the backside of exposed side or back. You are reaching around the shield when you do this. 3) Feint and cause the defender to raise the shield to protect their face, and then time the real attack for your backswing or the spin the sword technique in your hand (forget the proper name) when they will lower their shield to get a look at what you are doing. All attack methods have counters moves. And those counter moves have counter moves. In the end, between skilled fighters, it's about using combinations of tactics to force the other guy to make that final mistake. ]

[Question] [ I have a sailing ship. It leaves port. As it goes away, it grows smaller and smaller. In our world, it eventually is hidden by the curvature of the Earth, such that the top mast stays visible longer. I want it to simply grow smaller and smaller and smaller, but (from the perspective of a human with a human lifespan of 100 years or so) "never" makes it past the horizon. **How big does my world have to be for that to happen?** Ignore the real-world problems such as normal planets that size turning into hydrogen-filled Jupiters, stars or black holes aspect of it. I'm going for a hollow Dyson world built (out of unobtanium of course, with tens of miles of rock, water and stuff piled on top) around a sufficiently massive object (say a star or a black hole) to give 1g gravitational acceleration at the (external facing) surface. Edit: To preempt the question, yes, advanced optics are available, so the visual acuity of the human observer is not the issue here: as long it it **can be reasonably detected** and distinguished from the sea background using light, you can assume that it will. So no magic detectors, but imagine a high-performing scope, well built, but subject to the problems real optic instruments have -- air attenuation was pointed out in comments below. I'll assume the sails to be white, if that helps. Later Edit: Since air attenuation might be a factor as pointed out in the comments, let's assume our ship is much like Santísima Trinidad: Galleon; Length: 51 m; 2,000 tons; Comp.: 400-800; Armament: 54 guns; [Answer] Sailing ship are now much faster than they used to be. So it's hard to give a definite answer. Nevertheless, if we consider 18th Century ships, according to that [blog post](http://americanpatriotseries.blogspot.de/2013/06/18th-century-travel-speeds-by-ship.html), ships travelled at roughly $8$ mph (about $13$ km/h). We consider the 18th Century, because before people were not so much travelling to the other side of the world, and after engines started to be more dominant. Now, let's imagine the worst case scenario. A ship sailing in a single direction, and a human, who does nothing else than checking that ship every day for 100 years. Talk about an obsession. According to [Wikipedia](https://en.wikipedia.org/wiki/Horizon), the distance $d$ from a height $h$ to the horizon line of a planet of radius R would be $$d = \sqrt{h(2R+h)}$$ In the extreme case when the ship reaches just the horizon line after those 100 years, the ship would have travelled $$s = R\tan^{-1}\frac{d}{R} $$ with $s$ the distance on the planet (whereas $d$ is the distance from the height $h$). But taking $h=2m$, we can approximate that $s\approx d$. Thus, $$R=\frac{1}{2}(\frac{d^2}{h}-h)$$ 100 years at $13$ km/h leads to $d\approx11,395,566$ km. This leads to a radius $$R\approx 32.5 \times 10^{15}\mbox{ km}$$ That's... a lot. As comparison, the [Sun](https://en.wikipedia.org/wiki/Sun) has a radius of around $696,342$ km. So that's almost $5\times10^{10}$ times the size of the sun. And the [largest known star](https://en.wikipedia.org/wiki/List_of_largest_known_stars) would still be at a factor $3\times10^{7}$. So 30 million times more than the largest known star. To get to larger scales, that's about 3,400 [light-years](https://en.wikipedia.org/wiki/Light-year) (more than $800$ times the distance to [Proxima Centauri](https://en.wikipedia.org/wiki/Proxima_Centauri)). $7.2\times10^6$ times the maximum distance of [Neptune](https://en.wikipedia.org/wiki/Neptune#Orbit_and_rotation) to the sun. And that's 4 to 7 % of the [Milky Way's radius](https://en.wikipedia.org/wiki/Milky_Way). --- **Update** As the OP added some information about it, and there were some discussions in the comments. I think I should add some details about the optics. Can our human still see the ship after all that time? Well not unless they have magic eyes. Now, [Mike's answer](https://worldbuilding.stackexchange.com/a/37835/9685) presents some details about optics and I don't want to be repeating it. However, in a simple case without atmospheric effects (diffusion, attenuation, etc.), we can see that the angular resolution of any instrument is given by $\alpha\_{min}$. Since it is rather small, we can approximate that $tan(\alpha)\approx\alpha$. For a ship of length $L$ at a distance $d$, we have $$d=\frac{L}{\alpha}$$ This means that for a given instrument, $d\_{max}=\frac{L}{\alpha\_{min}}$ is the maximum distance where that instrument can still distinguish the ship. And thus $t\_\mbox{inst}=\frac{L}{v\alpha\_{min}}$ is the time for the ship to reach that distance. So they could follow the ship for (see [telescopes angular resolution](https://en.wikipedia.org/wiki/Angular_resolution#/media/File:Diffraction_limit_diameter_vs_angular_resolution.svg)) * 13 hours with the naked eye, * 16 days, switching to a 4 inches telescope, * 163 days with a 36 inches telescope, * 1 year and 3 months with Hubble, * almost 45 years with PIONIER (100m). How that observer came around such telescopes is beyond me. [Answer] Far more plausibly than being trillions of solar masses, you can make your planet really *small!* If it's small enough relative to the ship, the observer can see the ends poking out even if it's on the far side of the planet, like so: [](https://i.stack.imgur.com/IBY59.png) Of course you need an extremely dense material to make your tiny planet from, else the atmosphere would escape and the oceans boil off. That would make sailing impossible. [Answer] The limiting factor to how far you can see an object with the naked eye is your angular resolution. According to [wikipedia](https://en.wikipedia.org/wiki/Naked_eye), the angular resolution of a naked eye is 1 MOA, or 0.0003 radians (which corresponds well to what we were taught about the HVS, so I'll trust the wiki on this one). Let's say a typical sailing ship is 50m long. Through some basic trigonometry, we find that the distance at which it has the apparent size of 0.0003 radians is some 83.3km. Beyond this distance, you will not be able to make the ship out even as a dot even on a perfectly clear day. Using the [geometrical model](https://en.wikipedia.org/wiki/Horizon#Geometrical_model), we can find the minimum diameter of the planet so that the distance to horizon is at least this. Taking the height of the observer $h=2m$ and requisite distance to horizon $d=83.3km$ and plugging them into the following formula: $d^2 = h(D+h)$ we express the diameter D of the planet: $D= \frac{d^2}{h} - h$ which finally gives us a value of $D=3,472,222.4km$, or something over 11 light seconds. That's quite the planet you have there. [Answer] This might count as cheating, but... Don't make the world a planet. The reason we see a horizon is because of the curvature of Earth. If you have negative curvature, there is no horizon. One example is the classical (and wrong :)) hypothesis of Hollow Earth - that we're actually living on the inside of the planet, so the curvature is inverted. As the ship sails away, it goes *up* rather than down. Of course, make sure you don't care too much about the problems of having a hollow planet in the first place - a good checklist would be real-life objections to the Hollow Earth hypothesis :) For artificial objects, this is a bit more realistic. You can have a ringworld, which gives you plenty of sunlight, while having no horizon. Of course, it's just a strip of a world, so boundaries will be rather obvious - still, to the inhabitants, it would simply appear as "this is our world, and on the sides are the boundaries". There's other topologies you could play with, just make sure the curvature of the space is negative (for example, toroids give interesting topology, but they will still have a horizon). One example of note is Hal Clement's Heavy Planet. The story is set on a planet that's absurdly massive, with very high gravity (something like 300-600g). However, the planet is also rotating absurdly fast, so at the equator, the effective gravity is only about 3-6g, low enough for the human explorers to survive (with support, of course). The natives of the planet actually think they're living on the inside of a bowl because of the varying effective gravity - air tends to pool around the poles, so looking from the equator, you see the "horizon" going *up* - in effect, you're looking "behind the corner" due to the massive light "bending". There are places where the planet looks like the ellipsoid it is, but those are off limits even to the natives - they can't take the gravity at the poles. Of course, if you choose a similar setting, you have to get rid of humanoids (good luck building a humanoid that can survive under 300g's) and you better understand the physics involved perfectly - they have many interesting implications :) [Answer] I haven't checked @bilbo\_pingouin's calculations but it sounds plausible to me. As sailing ships today pass over the horizon in a few hours, for the horizon to be a lifetime away would require a huge planet. So let's eliminate the idea of a planet so large that it takes a sailing ship decades to reach the horizon. Other than the curvature of the Earth, what prevents you from seeing a far away object? 1. It looks so small that you cannot distinguish it. I'm not sure when we'd reach that point for a ship-sized object with the naked eye, but you say that advanced optics are available, so at that point it's going to be very far. NASA used ground-based telescopes to spot defective tiles on the bottom of the Space Shuttle when it was in orbit. We'd need a very big planet for a ship to not be visible with the most powerful telescopes. 2. Atmospheric haze so distorts the image that it becomes indistinguishable from the background. On a foggy day, this could be as little as dozens of feet. According to this article: <https://en.wikipedia.org/wiki/Visibility> the maximum visibility given the Earth's actual atmosphere is about 300 km. I'd think it's your best bet. Still, for 300km to be less than the distance to the horizon, by my calculations that still makes for a very big planet. Assuming your eye level is 6 feet above the surface, i.e. you're standing on the beach, for the horizon to be 300km away, I calculate a radius of the planet of over 15 million miles. (r~=s^2/2h, where r=planet radius, s=distance to horizon, and h=height of eyes above surface) [Answer] It depends also on the gradient of the refractive index of the atmosphere. If light from the ship is refracted sufficiently and attenuation is low enough, light could continue the whole way around a planet. Even on earth, distant hills can look higher in some weather conditions. Mirages are another associated phenomenon. [Answer] If you are happy for it to go "out of sight" without "going over the horizon", then the answer is suddenly a lot simpler - the horizon needs to be sufficiently far away that the it fades out (atmospheric effects) before the horizon comes into effect. This gives you a lot of flexibility - Singapore, on a random day, lists visibility as 7km. Using the formula on the horizon page at Wikipedia, $d=\sqrt{1.5\*h}$, rearranging it to $h=d\*d/1.5$ (d=miles to horizon; h=feet above sea level), if you are 12.7 feet above sea level, you would never see the ship go over the horizon. Someone whose eyes are 5.7 feet from feet to eyes, would only have to be standing 7 feet above sea level. In this scenario, it would be 99% impossible to see the ship, and yet it would still be 100% unobscured by the horizon. I think you would be able to push it out substantially further - so long as you can see enough of the boat's hull to make it not obvious. Looking at Wikipedia's image of the ship, there seem to be 4 levels below the deck - if they are 6.35 feet each (for easy calculation), then the horizon would be at the bottom of the third level above the waterline, and the top two levels (plus decks) would be visible from land, if the ship was 14km away. So, with those constraints, and with 14km visibility, your planet would have to be no larger than Earth-size. [Answer] As a slightly different solution, consider that light doesn't necessarily travel in straight lines. Given the right set of circumstances - curvature of the local space due to gravity, atmospheric composition, thermal gradients in the atmosphere, etc - you could potentially have a situation where the light reflected from an object could circumnavigate the globe. Unfortunately for most purposes the atmospheric effects - mostly density and thermal gradient - will vary at different times of day in different locations, with additional local inconsistencies due to the environment. The air over small lakes reacts to daylight differently to the air over a desert for instance. As a result the curvature of the paths taken by the light will fluctuate wildly over very long distances, making the view at extreme distance appear to shimmer. As long as atmospheric effects are part of the situation they will most likely prevent the effect you are looking for from ever happening. Gravity - or more precisely the warping of space by matter - will be much more consistent. There could be local perturbations due to different mass distributions, but those would be static as well. The downside is that for gravity to curve the path of the light sufficiently for it to circle the world it would have to be so high that your planet's inhabitants had better be made of neutronium unless you're happy with a planet that's several light years in diameter. Probably the only way to make this work is in flashes. Set it up so that the constantly changing variables in the equations - atmosphere density, temperature, etc - occasionally come together to form a perfect curvature of the path of light to let you catch glimpses of the back of your own head. Most likely the requirements would be a fairly heavy world to get gravity high enough to retain a dense atmosphere. If I had to guess (which I do, since I honestly don't know where to start the calculations on this) I'd say that a big planet with lowish gravity would have a deep atmosphere that could produce the effect I'm describing. Trying to achieve it on a planet with similar composition and size as the Earth would probably not be feasible. [Answer] The answer is going to be measured in hours to a few days, unless you have a non-water ocean and no atmosphere. Story time: I had the slow canoe. We were crossing from Victoria portage to Iron Point on Lake Winnipeg -- a 12 mile crossing that puts about 2 miles off shore. We were paddline into about a 15 knot headwind which was kicking up 18" waves. Two hours into the crossing I was between 1 and 2 miles behind the 2nd last canoe, and could just barely make it out against the clutter of the waves. I could no longer see the front canoe at all. At the time I was young and had normal vision. Factors against me: * Solar position was putting a lot of sun sparkle off the waves into my eyes. * 18" swells are on the same order of size as the height of the hull. These were Voyageur type canoes, with a crew of 6, and a length of 21 feet, and a beam of 4 feet. No sails to enhance visibility. If a sailing ship as described is used, then you may be able to extend the visible distance by a factor of 30-40. (Figuring a height of 120 feet compared to the 3 foot visible height of a paddler) This gives a figure from 30 to 80 miles. Another effect that comes into play, is the non-transparancey of humid air. <https://en.wikipedia.org/wiki/Visibility> cites just under 300 km for the clearest possible air due to Raleigh scattering. 70 to 100 km is cited for arctic or mountain air under optimum conditions. So: In practice, without some new tweak, your visibility is under 100 miles, with 200 miles as your upper bound, and likely to be less than 40 miles with reasonable weather. [Answer] To expand on the Dyson Sphere (of which Ringworlds can be considered a special case). Ignoring issues of how gravity is provided then: * Ships will appear to sail upwards. * Ships will eventually appear overhead. * Atmospheric effects will be most significant when clouds obscure vision. * At night the ghostly ships lights can be seen moving like a planet, (Greek 'wanderer') overhead but not following Kepler's laws. * The maximum clear atmospheric obstruction will occur when the internal arc between the observer and the ship just grazes the edge of the atmosphere. * so ignoring subtended angle distance effects the ship will become clearer as it moves further overhead from that point. * In the special case of a Ringorld and in some cases of a Dyson Sphere the ship will be either wholly or partially physically occluded by the sun / power source in it's path. Brightness may also prevent vision. * This will lead to either partial or total eclipses of the ship by the sun to an observer who is about perpendicular to the ship in the same plane. * If nights exist then the ship may also be also eclipsed by the night producing mechanism (if a physical one such as light baffles). [Answer] Given the size as calculated by others it's obviously out of the question to have a planet that big. However, in the spirit of the question I can come up with a solution: A Ringworld. Now, Niven's design requires impossible super-materials but one could be built by having it ride on a non-rotating track. (The combination of ring + track would average out to orbital velocity, no super-materials needed.) Now, a Dyson sphere at first glance also appears to be an option but it's not going to work. The problem is that it would have an extremely low surface gravity. You specified a sailing ship--if there's enough wind to sail by what will the waves be like in such a low gravity???? I note that you are saying 1g on the surface of a Dyson sphere--but you'll need a pretty big black hole (far above what a star can make) in the center to provide that 1g. [Answer] Here is another solution, which you can use to make your world any size you want. Here on earth, if there are layers of air with different densities, you get a mirage - the light is bent, causing a reflection of an actual object (sometimes distorted). In your world, if the air densities were just right, it could bend the light about the same amount as the curvature of the planet. The planet could be any size, and still seem to be flat - you could see, in theory, indefinitely. [Answer] I've previously considered a similar question a few years ago in a discussion about Dyson spheres (which is probably worthy of its own question, actually), and what actually happens to far-away objects (even on Earth scales, to an extent) is [atmospheric extinction](https://en.wikipedia.org/wiki/Extinction_(astronomy)#Atmospheric_extinction) (also known as [optical depth](https://en.wikipedia.org/wiki/Optical_depth)). Atmospheric extinction on Earth sea level is said to be 0.16 magnitudes (for zenith), and 0.01 magnitudes, or 0.15 less than sea level, for Mauna Kea, 4.2 km above sea level (the numbers, for the record, are from [here](http://www.skyandtelescope.com/astronomy-resources/transparency-and-atmospheric-extinction/)). We can use that figure of 0.15 magnitudes/4.2 km as our best approximation for atmospheric extinction in a constant sea-level atmosphere (as would be the case in the OP's scenario); of course the real figure should be a bit higher, but this works as a first approximation. The apparent visual magnitude of the Sun is about -26; a far-away ship cannot possibly be brighter (even ignoring the atmospheric effects, which we will now apply). The apparent visual magnitude of the faintest stars visible in our best telescopes is +36. The difference between these two values is 62 magnitudes; this extinction will thus appear at a distance of 4.2\*62/0.15 kilometers, or about 1800 km (I'm rounding up a bit again). So what you need is a planet where the ship is still above the horizon when it's 1800 km away. I'll shamelessly steal the approximate formula from the current accepted answer: R ~= 1/2 (d^2/h). For d=1800 and h=0.002 (kilometers) we get R=8.1\*10^8 (that is to say, **810 million kilometers**). This is a bit larger than your typical Dyson sphere (a radius of 810 million km is about 5.5 AU, which is to say, slightly smaller than the orbit of Jupiter), but I've rounded up so much during the previous calculations that the limit might actually be closer to typical Dyson sphere size, or even a bit below it. For what it's worth, if the 300 km visibility figure given in the other answers is correct (it seems to underestimate both telescope power and brightness of a ship), the result is R'=2.25\*10^6, or *22.5 million kilometers* (0.15 AU). A typical sailing ship, given the speed in the current accepted answer, would take about a week to pass a distance of 1800 km; the 300 km distance would be doable in a day (as in 24 hours). It's reasonable enough for someone sufficiently persistent to point their telescope to look at the same ship for several days in a row (at least, with occasional short breaks); and beyond that it shouldn't be visible anyway. (But it would take centuries - many millenia on the bigger version - for said ship to travel all the way around. It's a very big planet.) ]

[Question] [ I have a tribe that is completely isolated from the outside world and there is a shaman that can see in 4 dimensions. He can identify disease before it manifests and is hailed as a god. This 4th dimension would be purely **spatial**, he is not able to travel in time. He can only see in 4 dimensions. What would the extent of this power be? I assume he can see inside people (using the 4th dimension), but is this correct? And are there other things he would be able to do that I'm not thinking about? [Answer] Can you as a three-dimensional being see inside a two-dimensional circle? That depends on your position relative to it. When you are looking right at its edge, you can't. But if you are above or below the circle, you can. So if a 4d being wants to look into a 3d object, it needs to move "upwards" or "downwards" in the 4th dimension in order to get a "vantage point". But that point will not be in the 3d space the 3d object can perceive. This of course assumes that the object the 4d being wants to look at is flat and open in the 4th dimension. If the 4d being wants to look into a sphere and that sphere is actually a [hypersphere](https://en.wikipedia.org/wiki/Hypersphere) which is also round in the 4th dimension (something a 3d observer can not tell), it would not see much. So if a 4d being is able to look into a human body, it would do so using a sensory organ which is shifted in the 4th dimension and can not be directly perceived by any observer limited to 3 dimensions. Also, it is only possible under the premise that the bodies of regular 3d humans do not extend into the 4th dimension. If the 4d being looks at another 4d being, it will see its surface in 4d (which might also be interesting), but it won't be able to see inside it. [Answer] If the 4th dimension is spatial, it really depends on how you want normal people to be 3 dimensional: You could imagine that every visible thing is from a 4-dimensional POV flat and glued to the 3-dimensional surface of a 4-dimensional world. The surface being the visible world, the 4-dimensional world being the "real world" a shaman is able to see. A disease could be a 4-dimensional being itself, roaming the empty space above the visible surface that latches itself onto people and only manifests itself, when it is itself fully "flat" (flat meaning again 3 dimensional). In this case you would not be able to look inside a human (see their organs), but you could see a disease "coming". Or you could say that every human is a 4-dimensional being; they just cannot see it, in the same way we cannot see time. We only ever see slices of time we call "now" - In the same way a human might be composed of a lot of slices, maybe all a bit different, but only one slice at a time is visible. A shaman now would be able to see all these slices at once. These slices might be bizarre and some might not be able to survive in the 3 dimensional world, so they are never visible. Every person could have a slice without skin, without flesh, etc. This way a shaman might be able to see the organs of people. An ill-meaning shaman might be able to slap such a slice into existence, that would give you a killing spell. Another thought: Imagine you are a 2-dimensional being. To the left of you is a circle, to the right is a square. Both will appear to you as just lines assuming you distinguish edges. A 3-dimensional being is able see the difference, you are not. You could imagine that a lot of things in the visible world look the same, but are *de facto* dramatically different. A shaman might be able to distinguish plants that are poisonous and plants that have healing power that way even though they look exactly the same to anyone else. Summarizing: The ability to see a fourth dimension is really not that interesting, if everything else is "flat" in three dimensions. You have to define how things look in the 4th dimension, and what it is that normal people cannot see. [Answer] The fourth dimensional directions you are referring to are called "**Anra**" and "**Katra**" as I recall it from long ago. > > (Edit: Turns out my memory somehow added an 'r' to each word. The actual words are apparently ["Ana" and "Kata"](https://en.wikipedia.org/wiki/Four-dimensional_space#Orthogonality_and_vocabulary).) > > > There was a line of thought that 'dimensionality' could exist as an potentially unending sequence of linear ever-increasing series of directions, so to speak. In modern thought, this concept has been largely discarded in favor of the more popular time-as-the-fourth-dimension idea. It can still be found in older science fiction in various places. The basic idea is that one dimension is like a line. One can only move in two directions. From our observer's position, we shall call it left and right. Anything existing "in" said one-dimensional line would have to be either a point or a dash in nature. Moving up to two dimensions, we have a plane - left, right, forwards and backwards. This effectively adds two directions (a single axis) to our options. Flatland has been referenced, and I recall another excellent story where a man wrote an AI program emulating a 2D world and what sort of life might exist, only to accidentally managing to communicate with a real inhabitant of a real 2D world - a very well thought out and interesting story it was. Next up would be three dimensions, a cube or other three dimensional object. This adds yet one more axis to our options: left, right, forwards, backwards, up, and down. Assigning a spatial direction to the fourth dimension relegates time to being a dimensionless phenomena, perhaps, but such is outside of the scope, so I will leave the matter of time alone. I recall the terms "Anra" and "Katra" being used to describe these directions, yielding left, right, forwards, backwards, up, down, anra, and katra. Enabling a "lower-dimensional" being to observe in such additional "higher-dimensional" directions would potentially have the following effects: * Objects native to a three dimensional plane appear 'flat' to a sense of perception used to four dimensions, much how a three dimensional native would perceive a two dimensional world or object to be flat. However, a three dimensional native being would not be able to naturally or ordinarily perceive in the Anra or Katra direction, unless the being was also capable of motion, as for a 'flat' being to perceive in an extra higher dimension, they would have to position themselves further along the 4th axis (in either the Anra or Katra direction) in order to see along said axis. Think of this as z-axis order: if two three dimensional beings are at the same fourth dimensional level, they can't see inside of each other, but would only perceive each other normally. One of the beings not only has to be at a different level (z-order), but also has to be able to 'twist' their sensory organs to perceive along the fourth dimensional axis. > > For example: a two dimensional native would not be able to see inside another two dimensional native, unless the first was positioned *outside* of their two dimensional plane. However, if they were able to "*lean*" out their plane slightly, and had the mental training to put together the panoramic series of two dimensional slices that is all that they would "see" into an understanding of what is inside the second being, then they would be able to comprehend the insides of someone or something else - and likely have a raging headache from the effort to boot. In much the same fashion, a three dimensional native would have to at least be able to move or lean their sensory organs (likely the head, if a human) slightly in either the Anra or Katra direction and then *turn* their head to align with the opposite direction in order to see inside a fellow being within the same three dimensional space as they are in. > > > * Perception also assumes some sort of visible coherent medium. Does the sun radiate in 3 or 4 spatial dimensions? Our current experience would say that it only radiates in 3, and that light does not normally penetrate the 4th spatial dimension, unless of course there was a light source which was itself natural to a fourth dimensional plane. * Other senses are also likely to be affected. To a mind trained to accept fourth dimensional phenomena, it is possible that the other senses may be stimulated from time to time, which could get awkward. Smells from the fourth dimension anyone? Tastes? Hearing, touch, balance, spatial awareness, positional awareness, internal awareness, heat, cold, pain... so many possible receptors that could be affected. * Let us also consider the effects of cross-dimensional interactions briefly. Since objects natural to a three dimensional space are flat to a four dimensional native, said native could in theory reach over and 'flip' something, or someone over, much like we could flip a piece of paper over. This could have some odd effects: ketchup might taste like some heavenly concoction while other foods taste horrible, someone may suddenly have their hair parted on the opposite side and be right handed instead of left handed, or a poor young woman may suddenly look most ugly and peculiar. (All [story references](https://en.wikipedia.org/wiki/The_Boy_Who_Reversed_Himself) dealing with multiple dimensions, for those who get them.) > > Worse, consider this: could a 'flipped' person obtain nourishment from non-flipped foods? Or what if a 'flipped' person or object is now technically composed of anti-matter? > > > I hope these thoughts are helpful in brainstorming more ideas. For a more complete description of four dimensional spaces, objects, beings, and interactions, please see this [excellent (and illustrated) source](http://hi.gher.space/). [Answer] If you want him to only `see` in 4 dimensions I've got an idea: There is a misconception in some of the other answers that we can see in 3D. What we see is a 2D composite image of 3D Objects at a certain angle. Only our brain can then `understand` the 2D image based on our experience in 3D space. If we could see 3D, the well known optical illusions would have no effect on us. So if your shaman can perceive 4D spatial space, he can visually see 3D images. Since we cannot do this its impossible to imagine how such an image would look. Here's my idea: With our 2 eyes we can set a focus point on what we're seeing. This focus point can be shifted in horizontal and vertical directions to sharpen the point of interest. What if your shaman has a 3rd *inner* eye that can shift the focus point in depth? With this it would be possible to look inside objects. Basically the equivalent of an x-ray vision. Regarding diseases this could be used to identify for example cancers, tumors, broken bones etc. Viral/bacterial infections could be hard to detect. Depends on how well your shaman can focus on a blood cell. [Answer] It can range from **more likely to cause a cancer that to detect it** to **X-ray/MRI equivalent**. To see something, you have to interact with it. We usually detect stuff by seeing, i.e. by detecting light reflected from an object. That means that light first has to interact with the *surface* of the object. Now, if 4D beings are watching 3D beings using something like light (propagation of ordinary light is obviously confined to our 3D hyperplane), this will have to interact with entire volume of the object. Usually, we don't have stuff constantly interacting with our insides in that way, so it probably wouldn't be very healthy to do it constantly, just like it isn't very healthy to get too much X-ray scans. Therefore, our shaman would have to be very careful to take quick peeks at his patients' insides, but this really depends on the nature of interaction of 4D "light" with 3D matter. He could detect some diseases before they manifest, but this would be limited to (stages of) diseases which visibly change the patient's insides. [Answer] It depends what you define the fourth dimension to be, but most conventionally the fourth dimension would be time (and it's consistent for a person be able to see in a dimension even if they can't move there). Alternatively, the shaman might be better able to sense invisible electromagnetic fields around people at a greater distance than most people can. These fields change depending on disease, emotion (this is one way animals can sense fear), etc.; it is sometimes represented as an "aura." In this case, he might not be able to see inside people in an x-ray vision sense of the phrase "see inside" (though you could choose x-ray vision if you want), but he could see signals emanating from the body which reveal internal activities. I think you'd also likely find inspiration in [Flatland](https://en.wikipedia.org/wiki/Flatland) by Edwin A. Abbot. One of many online copies can be found [here](https://books.google.com/books?id=139bAAAAQAAJ); it should be public domain by now. [Answer] *I will be referring to the additional dimension as "4th" (in quotes), because who is there to say which one comes first? - Btw, a hint on titles that are questions, the answer is often "no".* **Light?** > > I have a tribe that is completely isolated from the outside world and there is a shaman that can see in 4 dimensions. > > > This has the implication that there is some form of radiation that works outside of the traditional 3 dimensions. Something that this shaman is able to perceive. All radiation we know follow the [inverse-square law](https://en.wikipedia.org/wiki/Inverse-square_law): [](https://i.stack.imgur.com/F6NHX.png) *Inverse-square law - we find examples of it in gravitation and elecromagnetism.* The fact that we measure that the intensity decreases following the inverse of the square of the distance and not to the inverse of the cube of the distance, suggest that the front of the propagation has two dimension (it is a sphere, in ideal conditions). If we were measure a radiation that decreases by the inverse of the cube of the distance, we would hypothesize that the radiation is somehow escaping the traditional three dimensions. Note: with the intensity of this radiation falling much faster than the ones we know... if this is what the shaman sees, everything will be very dark. I will assume the perception will be adapted to that. --- Now, if this shaman sees in 4 dimensions, it must be by perceiving some radiation that has that property. Evidently this would something that nobody else perceives or knows how to measure, making it an exclusive trait of the shaman. --- **Time Travel?** > > This 4th dimension would be purely spatial, he is not able to travel in time. He can only see in 4 dimensions. > > > I will take this as you saying that the shaman does not control his position on the "4th" dimension. In addition, therefore there is no "4th" dimension travel. *Below is the part where I go technical on you... because, you know, [technically correct is the best kind of correct](https://www.youtube.com/watch?v=hou0lU8WMgo).* --- The shaman does time travel, like everybody else, tight to the frame of reference of the environment on which the shaman lives... which I would expect marches forward in time... Also know that we can [make space dimension work like time dimensions](https://www.youtube.com/watch?v=mht-1c4wc0Q). As you know, in our everyday lives, we all move inexorably in a single direction in time (to the future, and you cannot go back). Inside a black hole, space moves inexorably in a single direction (to the singularity, and you cannot go back). *And you die.* All of that without considering tightly curved dimensions as those proposed in string theory. I understand that you intend your "4th" dimension to be a flat spatial one. Yet, it is good to consider some alternatives. --- **Vantage point?** > > What would the extent of this power be? I assume he can see inside people (using the 4th dimension), but is this correct? > > > There is a problem with looking inside of people. Drawing parallelism with looking inside of the people of [flatland](https://en.wikipedia.org/wiki/Flatland), is that you need a vantage point. You can see - for example - a drawing on the floor which is two dimensional♪, yet that is only possible because you are above the floor. If you were trying to look at the drawing on the floor from the same height of the floor (imagine you are in a hole such that the eyes are just at floor level) then you will not be able to see the drawing. ♪: If we go by [fractal dimensions](https://www.youtube.com/watch?v=gB9n2gHsHN4) then the number of dimensions depend on the level of detail we take into account. For my purposes, the floor is flat, because I do not care about corrugations for this example. Ok? Ok. Because of that, being able to see in more dimension does not always translate into looking inside of things of lower dimensions. --- **Perception?** Even working around the above, you have another problem... whatever radiation the shaman perceives is one that does not interact with other things. That is, if this radiation only passes through everything, then everything is transparent to it. One simple tweak would be to say that this fourth dimensional radiation actually interacts with the world in other ways, and there you have your [chi / ki / chakra / aura / cosmos / mana / ether](http://tvtropes.org/pmwiki/pmwiki.php/Main/LifeEnergy) that fuels magic. Not everybody needs to be able to perceive it, but everybody would interact with it, intentionally or not. If you allow this fourth dimensional radiation to have weak low energy interactions with matter, then perceiving it allows to see everything as translucent, semi-transparent, like x-rays. *Why did you just give the shaman a broader perception of the electromagnetic spectrum? Too cliché? Ok.* --- **Projections?** There one more problem left. The problem of perspective! We perceive projections of our 3D environment. Flat 2D images (that we compose to get depth perception). However, when you perceive a 4D environment, how do you distinguish the two additional dimensions? I mean, the image has two dimensions, we figure out an additional one for our 3D environment, but the shaman has to work out another one besides that. Our two eyes resolve depth by providing two points of view (and a lot of brainwork: identify common features, triangulate, etc...). In a 3D environment a third eye may add some accuracy or expand the field of view... but if you can get a third eye slightly displaced into the "4th" dimension, then you have a solution for the vantage point and the resolution of the "4th" dimension. The interesting part of a third eye displaced on the "4th" dimension is that it will not be visible to others (unless they also have fourth dimensional perception) and being displaced, it can be in the same 3D position as another body part. *Perhaps it does not look like an eye; it could be more like third ear. In fact, I do not expect regular eyes to function for fourth dimensional perception, but I digress.* The shaman needs to have some connecting tissue that extends on the "4th" dimension. That is, some way the extra eye(s) stay connected to his body and brain. This implies extra dimensional neurons. In fact, given that we need to brain capacity to process fourth dimensional perception, we could be talking of extra dimensional brain extension. **Magic?** > > And are there other things he would be able to do that I'm not thinking about? > Not much, actually. This fourth dimensional radiation is less effective than electromagnetism. First, because it follows the inverse-cube law, and second because matter interaction with it is not very energetic. > > > Yet, for people sensitive to it, some things could be possible: 1) the shaman will be able to recognize others with this power, and 2) they may, to some extent, mess with each other. I guess this leads easily to telepathy, although I imagine it more like a sign language in four dimensions. Yet, if you and your opponent have body parts in extra dimensions, you may hit each other in extra dimensions. While we are in the concept of four-dimensional battles, they are not one person sitting over here and the other over there, and some extra dimensional fireball flying from one to the other… they are more like boxing, with limbs, which nobody else can see. Then why not weapons, or armor? If these battles are common, there might be battle gear for them. *How to build such gear? I do not know. However the shaman got his powers, that is how.* --- As for your radiation source, I would propose to use the stars, just have it be an extra form of radiation. One that new to science. Which means that our calculation of the energy of stars is wrong. In addition, there you have a solution for dark matter (whatever is in the star that it turns into fourth dimensional radiation). --- I want to expand on [nijineko](https://worldbuilding.stackexchange.com/a/78758/16729)'s idea of flipping. If we assume that atoms have fourth dimensional symmetry♪, then the rotation conserves chemical bonds, but not their handiness [chirality](https://en.wikipedia.org/wiki/Chirality_(chemistry)). The [flipped versions of chemicals](https://www.youtube.com/watch?v=OR2AQS-8CWE) are likely to be able to interact with the same or similar chemical receptors but with different effect. It could be as simple as changing taste or smell, or you could convert [L-methamphetamine](https://en.wikipedia.org/wiki/Levomethamphetamine) into [D-methamphetamine](https://en.wikipedia.org/wiki/Methamphetamine) and become a drug lord. ♪: Because otherwise, their rotation on the "4th" dimension means [boom](https://www.youtube.com/watch?v=11e8XyUBqRQ). Edit: Not necessarily. Depending on the 4D shape of atoms we can think about what would it mean for an atom to be rotated... yet, I'm assuming all the fundamental forces we know are constraint to 3D, and thus won't hold the atom, thus [boom](https://www.youtube.com/watch?v=11e8XyUBqRQ). Take your artistic license on this. Flipping a living being is a different case. The problem is not the flip, as they stay internally consistent, but that their chemistry needs to work with the environment. Thankfully, oxygen, CO2 and water are symmetric. [Glucose is chiral](https://eic.rsc.org/exhibition-chemistry/chirality-in-sugars/2020041.article), yet as far as I know we have no problem consuming the two versions of glucose. However, proteins! The [RNA is able to select proteins with the correct chirality](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2995399/). Yet, what used to be the correct chirality for the organism, once flipped, it no longer is. The flipped organism will have to find sources of the flipped versions of the [essential proteins](https://en.wikipedia.org/wiki/Essential_amino_acid) to eat. Sadly I am unware of studies that discriminate concentration of proteins by chirality in food (separating molecules by chirality is hard as it is). Because of that, I cannot tell you what they will need to eat - yet, I do not expect them to be rare, just let them follow their taste and gut. What really worries me are microbes. Flipping a virus will create a new strand for which the population may not have defenses; the epidemic could be devastating for a small population. [Answer] Another way to think about a 4D space is to think of it as a 1D array of 3D spaces then think of what you can do by making an analogy of a 3D to a 2D space. (The book Flatland talks of a 3D shape visiting a 2D world, so you have something to begin with there.) Depending on how exactly you imagine the 3D world existing in the 4D one, your shaman should be able to do something like shift through 4D space until he finds a space that's empty if he wants to walk through a door that's locked, or enter into spaces that are closed. In that way, it'll be a lot like having access to alternate parallel dimensions, but where the dimensions have a mapping to each other, like in D&D's planes, or spirit-walking, but without leaving his body. In terms of looking at things, the shaman can't see inside of things unless they have an uneven presence in the 4th dimension. The shape you want to look at is a Klein bottle. So, if different parts of the body had different projections in the 4th D, he'd be able to see them one by one by shifting, and interact with them (e.g. he could set a bone if bones were "bigger" in 4D than the soft tissue). If you just have the world as one slice of 3D in that 4D array, then, no, there's no way he can see inside, unless light also moves in 4D, but that really makes my brain hurt trying to visualize that. [Answer] This Shaman should be able to 'think outside of the box', so to speak. If he were in tune with a fourth spatial dimension, he may well be in tune with a fifth and sixth, and possibly a seventh... It some respects, this shaman could detach himself from the *scale* of his existence, and view all straight paths as curves. His mind will be bent towards a vanishing point that always spirals out of view. He might encounter iterations of his own existence and might be at risk of being caught in an endless cycle of constantly occupying and vacating different versions of himself. [Answer] I would assume that since his position in the 4th dimension is static (he cannot move along 4th dimension) then his perspective in said dimension would be anchored to the same position as everyone else. Given the curvature of time/space and his limited perspective - his view would be obfuscated to some degree by a natural "horizon" due to this curvature. Also like viewing things in a three dimensional space - things could block said view. More immediate things in the view path would block the viewing of further things. Also from his perspective, very large things in the 4th dimension may only be partially seen. If you stand with your nose to the trunk of a tree, it would be impossible to see the leaves at the top. Also, to view a mountain you would have to stand far enough way to see its whole shape against the horizon, but if you were directly over it several miles, it would be difficult to judge its height. I assume that we are dealing with the 4th dimension as an axis of time as it relates to our 3 dimensional universe. Normal people - in terms of their understanding of past events and future events can only remember or predict events. Remembering is a biased mental interpretation of the changes in our 3 dimensional universe as perceived by our regular senses. Prediction is taking the information from those remembered events, our current observations, and making intelligent guesses about future events. With this in mind it would be hard for anyone to understand being able to actively perceive not only how things are now, but also how they were and how they will be all simultaneously in context to their current position on that dimensional axis. In this way I imagine that your character would see people as both young and old, but would have difficulty seeing things clearly about future or past generations. During Winter he may have clear visions of Fall and Spring, but difficulty seeing Summer. In this way he would be able to know if a woman was pregnant well before conception or he may perceive impending illness prior to symptoms or death. He might be able to see impending battles or previous crimes by simply being where they occured. As long as they do not disappear over that 4th dimensional horizon. There will be a lot of things your character experiences that can be related to the reader and the rest would simply have to be summed up as being just what it is, an unrelated experience for those unable to perceive the 4th dimension as well. Also, I dont think your character would see his own death. It would be impossible from his perspective. You cannot look back at yourself without a reflective surface and to see anything of his own future or past would require some sort of a 4th dimensional reflective surface. Also keep in mind that constantly viewing the future would be maddening. Your ability to see things before they happened would put the future in a constant state of flux. Making active decisions to change the perceived future would lead to even larger distortion. It would be like throwing stones in a reflective pool, the larger the stone the more the image ripples and changes. Throw too many stones and the image is indecipherable. [Answer] I don't think we can really see 2D objects or even see "inside them". If we look at the circle drawn at the paper, the only reason we can see it is that there are molecules of ink on that paper. And the molecules are 3D. So the answer to the question would be no, you'd not be able to see inside. ]

[Question] [ Humanity just disappears tomorrow, let's say it is like the Thanos-snap but it kills everyone. **How long until the last unambiguous evidence of our existence disappears? What was this last relic?** The faint spectres of electromagnetic signals which will travel space forever, odd isotopes ratios and material compositions and slightly odd geological patters are considered ambiguous. A Voyager probe which still looks like something designed by intelligence and not like a very metal-rich asteroid is unambiguous. Assume that another civilisation's exploration mission with near-future tech and the capability to examine the solar system for 100 years comes looking. They got the time and huge resources on hand and will study the major objects until they know about them as much as we currently know about Earth. [Answer] Post-Edit: With orbital [multispectral imaging](https://en.wikipedia.org/wiki/Multispectral_image) available there is no way that any remains of our cities will be missed. Some of those remains won't last long, [geologically speaking](https://en.wikipedia.org/wiki/Geologic_time_scale), but others will last through multiple cycles of super continent formation and break up. Although these traces will be small relative to the scale of modern construction, they will present unambiguous grids of mathematically straight lines many miles across where old road surfaces interrupt soil formations and buried walls and rubble piles disrupt plant growth. The cities that last the longest are going to be the ones that are in the middle of the continental building blocks know as [cratons](https://en.wikipedia.org/wiki/Craton); [Alice Springs](https://en.wikipedia.org/wiki/Alice_Springs) in Australia and [Hyderabad](https://en.wikipedia.org/wiki/Hyderabad) in India are prime suspects for leaving traces the longest as are Moscow, Riyadh and Brasilia. Those are probably going to be detectable, at first scan, with current/near-future technology while the world lasts. With a century to scan and check data, I'd consider it a near certainty. Unless Earth gets hit by another [heavy bombardment](https://en.wikipedia.org/wiki/Late_Heavy_Bombardment): that would almost certainly cover up all evidence of human habitation. [Answer] If enough time goes by, there would fewer and fewer signs on the surface of the Earth for someone looking for past intelligent life. However, as soon as someone wants to build any infrastructure or industry on this planet, they'd notice the distribution of metal is very strange. All the easy-to-mine metal is gone! [](https://i.stack.imgur.com/cDEHY.jpg) Even long after every mine on Earth caves-in, they'll find the less profitable metal with large sections of the metal veins missing, as if someone came by and took all the good stuff before they got there. Once they notice how odd that is, they'll start looking around for signs that some Earth-unique process could have moved it somewhere, and even start to wonder if someone else was here before them. Looking for metal in un-natural places will quickly reveal engineered alloys that do not exist naturally. Once they see the alloys, they'll start mapping the discoveries and they'll look for patterns for where the high-value metal is located. They'll find whatever is left of our cities and garbage dumps. The smoking gun will be the screws and nails that can be found everywhere we lived, long after the buildings have been lost to time. We'll probably be know as the "screw and nail users". The proximity to water will become obvious. They'll start looking for us along the ancient coastlines and old dry rivers, on the shores of what could have been lakes or valleys, and anywhere that matches our pattern. Eventually they'll look through the fossil record of formerly-inhabited places and narrow us down to being either humans, dogs, or cats though a process of elimination. [Answer] probably longer than the earth has. Fossilization is a thing, and we have set up many things in perfects places to be fossilized. We bury things in salt mines, seal things in glass, bury massive amounts of garbage in anoxic conditions, etc. On top of that we have built things that will leave traces for billions of years, chernobyl will stick out like a sore thumb, much like how [Oklo](https://en.m.wikipedia.org/wiki/Oklo) did when it was first discovered, but the composition of materials will make it very obvious it is not natural (corium). Oddly some of our oldest inventions will be the most obvious stone tools and fire. Humans have created a lot of fires but often in small isolated stone lined pits, these will be very obvious markers in sediment for billions of years, even more so when combined with obsidian fragments and cut bone. Even things like buildings can "fossilize" that is get buried and preserved, exposed building will not last long but someplace like pompeii or missile silos built depositional environments wi last as long as the rock in those areas do. Then you have the direct evidence from out own bones, humans are everywhere some of our bones will fossilize and some of those will will have dramatic evidence of technology. Not just the evidence from out anatomy but things like false teeth, polymer and ceramic implants, glass eyes, plastic buttons, glass lenses, etc. One fossilized humans skull with ceramic dental implants will be unambiguous proof of a technological species. So not only will they know a technological species existed, they will have a decent idea of what it looked like. The only way to destroy all this evidence will be to destroy earths surface geology which means liquefying the planet which is unlikely to occur before the sun explodes, or even for a while after that. [Answer] *The Earth After Us* by Jan Zalasiewicz is a book-length treatment of this very question. My main takeaways were not to underestimate the power of erosion, but that some evidence would last a very long time. The lifetime of Mt. Rushmore, as I recall, was measured in the millions of years at most, not hundreds of millions. The book also made the argument that city layouts would not last and would be completely eroded away if not buried. But as I read up on cratons I see Ash's point. On the other hand, much will be buried and will become part of the fossil record. Dinosaurs were around for hundreds of millions of years, but most of their bones decayed before fossilization. We are leaving behind a huge amount of buried ceramics and concrete. And the Apollo sites will be on the moon probably for almost as long as the moon survives. **Correction:** Apparently that's wrong. According to [this article](https://www.space.com/12846-apollo-moon-landing-sites-flags-footprints.html) in Space.com, "From past studies of moon rocks collected by astronauts during the Apollo missions, researchers have learned that the rocks erode [from micrometeoroid impacts] at a rate of about 0.04 inches every 1 million years.", That's four inches of erosion in a hundred million years, and the landing stage is not a solid hunk of rock. Oh, well. [Answer] # Mega Construction We build, not just cities, There are dams huge chunks of smooth cement laced through with even grids of steel. The edges of the Hoover Dam and Three Gorges Dam and Aswan Dam will be there long after the rivers run dry. # Mining We dig. There is an open pit mine 3 miles long, 2 miles wide and half a mile deep. It's not the only one. There are similar mines on every continent except Antarctica. The sharp edges of the mine will eventually erode but the shape of the land has been indelibly changed. The spacing of the mountains and ridges will be inconsistent. # Satellites Satellites in Geostationary orbit are up there for millions of years. If aliens come along they will see a large number of items floating suspiciously close to a synchronous orbit and careful collection should find something relatively intact. # Space Probes Most of the above should be detectable until the sun starts to expand and swallows the earth. There are currently 5 space probes which have achieved escape velocity from the solar system. They should be observable pretty much forever. [Answer] # When The Earth Dies Naturally occurring zircons have been dated to 4.4 billion years ago, or basically right after the earth cooled enough to form a solid surface: <https://www.livescience.com/43584-earth-oldest-rock-jack-hills-zircon.html>. Therefore, it is possible for certain tough minerals to survive for basically as long as the planet does. I would imagine that a fair number of cut and manufactured gemstones would have similar survivability, although the difficulty of locating them after millions of years will likely go up exponentially. However, a single cut diamond with a laser-engraved serial number would be pretty definitive evidence of technological capability, even if the number were partly damaged. # Oldest Sediments Gnudiff claims that the geologic record doesn't extend past 2.6 mya, but we have recovered rocks dated to more than 150 mya: <https://earthscience.stackexchange.com/questions/3115/what-is-the-oldest-sediment>. Granted, if space invaders visit earth 100 my from now looking for us, and we have been gone the whole time, they will need to have a *very* fine-toothed comb to discover any gemstones, but it is at least theoretically possible. [Answer] The Atlantic [describes exactly this question](https://www.theatlantic.com/science/archive/2018/04/are-we-earths-only-civilization/557180/) in an interview with NASA's Gavin Schmidt. The answer is: "When it comes to direct evidence of an industrial civilization—things like cities, factories, and roads—the geologic record doesn’t go back past what’s called the Quaternary period ## 2.6 million years ago. For example, the oldest large-scale stretch of ancient surface lies in the Negev Desert. It’s “just” 1.8 million years old—older surfaces are mostly visible in cross section via something like a cliff face or rock cuts. Go back much farther than the Quaternary and everything has been turned over and crushed to dust." So basically around 0.04% of current Earth's age. See also [link to the study](https://arxiv.org/abs/1804.03748) referenced in the article. Now, if you are talking about indirect evidence, there is some that can be discerned for much longer (also described in the article). However, it seems to me to fail your criteria of "unambiguous". Actually, depending on your requirements for unambiguous, it could be on an order of magnitude less, if you wish your aliens to actually learn a lot about our current existence, not just that **something** existed. ## So, maybe 200K years for something recognisably current human civilisation. [Answer] New Scientist produced an [article on this](https://www.newscientist.com/article/mg19225731-100-imagine-earth-without-people/) on 11 October 2006, where they suggested that buildings would be overgrown fairly quickly (decades in many cases) but that ruins would leave evidence for thousands of years if searched for. Human effects on climate would continue for at least a century, although these probably don't count as unambiguous according to OP. Large monocultures such as grain fields or single species forests would take centuries to become diverse. However, they also suggest that even 100,000 years from now, there would be signs of humans, as described in this quote from the article. "Yet if the aliens had good enough scientific tools they could still find a few hints of our presence. For a start, the fossil record would show a mass extinction centred on the present day, including the sudden disappearance of large mammals across North America at the end of the last ice age. A little digging might also turn up intriguing signs of a long-lost intelligent civilisation, such as dense concentrations of skeletons of a large bipedal ape, clearly deliberately buried, some with gold teeth or grave goods such as jewellery. And if the visitors chanced across one of today’s landfills, they might still find fragments of glass and plastic – and maybe even paper – to bear witness to our presence." However, even that is not the limit. By [some measurements](https://www.quora.com/How-many-years-will-a-satellite-stay-in-orbit) satellites at a height of 10,000km could still be around 10 million years from now. They won't work, but they will be obviously artificial. [Answer] ### Enriched Uranium [Uranium 235](https://en.wikipedia.org/wiki/Uranium-235) has a half-life of 703,800,000 years. The concentration of U-235 relative to U-238 is fairly low (0.72%) in nature. Humanity has managed to increase that quite a bit. Perhaps a bit more than we should. In any case, even if the surrounding concrete, steel and other materials of research & power nuclear reactors, nuclear submarines, nuclear aircraft carriers and other nuclear devices (not so much the nuclear weapons - if they use plutonium then the half-life is much shorter at a mere 24,100 years) have disintegrated due to various natural processes, the enriched uranium will still be detectable as a non-natural object, for a **very long time**, easily **billions of years**. [Answer] First category: Artifact of man-kind on Earth: Due to fossilisation they will probably survive until the Earth is swallowed by the than red-giant sun. The last unique relics may be teeth with gold inlays, clearly showing that something special was going on with our species. Expected timeframe: **4.5 billion years** from now. Second category: Artifacts in space: Unfortunately, almost all artifacts in space will also be swallowed by the red giant sun at about the same time. There are a very few exceptions: The Voyager probes leaving the solar system, and a few probes sent to the outer part of the solar system. However, will they be attributed to some species once populating planet Earth? [Answer] Pre-Edit: The last thing to go will probably actually be [Mount Rushmore](https://en.wikipedia.org/wiki/Mount_Rushmore) it's solid, meta-static (meaning in pressure equilibrium and not subject to [foliation](https://en.wikipedia.org/wiki/Foliation_(geology)) erosion), granite in a geologically stable region with reasonably stable continental weather patterns. I've never heard an estimate for how long it will take to be unrecognisable but I have seen it estimated that it definitely will still be recognisable in 1.42 Billion years time. This is long after Voyager and the Moonlanders are expected to have been destroyed by micro-meteor impacts, neither of those, nor Neil Armstrong's foot prints, are expected to last until the next super continent formation in 100-200 million years. [Answer] I'd guess that digging will always indicate a really strange segment of sediment from this period. Probably remains of plastic and other unnatural chemicals with a really long life. Also the fact that we pulled up so much carbon and laid it down over such a short period should be something to look for. I don't think it will be destroyed until the earth is consumed by a star. Even then--information can't be destroyed. The state of any system can be wound backwards given complete information about the state. Of course I can't even imagine something that could wind the universe backwards, but theoretically... ]

[Question] [ I am building a world with many deserts and swamps. So a simple question: Are there any real world examples of where a desert and a swamp meet each other? Deserts and swamps are vastly different types of terrain (one containing hardly any water and the other containing lots of water), so I would assume they wouldn't come in contact with each other. But the world is a strange place, and I was just wondering if such a meeting actually exists. [Answer] In the Arabian Gulf, there's a lot of muddy, mucky water covered with mangroves, and fauna such as flamingos and dugong/manatee populations. At night and in the mornings, there's a thick fog over these areas, even though this is one of the hottest regions of the world. I like the other answers, just adding another existing situation. This is us mucking through the swamp in the middle of summer with kayaks and sunblock in Abu Dhabi. Heaps of swampland all year round, with little islets and a diverse ecology. There also exists a lot of marine diversity as well. The requirement for this kind of ecology is slow flushing - the movement of water should be slight tidal up/down in an area with clean water and limited flushing in a climate that has hot days and cold nights (coastal desert). Sediments are a mix of sand and organic soils between freshwater and salt water (estuary), and is *immediately* against a desert landscape. [](https://i.stack.imgur.com/3pInJ.jpg) EDIT: As requested, more pictures. [](https://i.stack.imgur.com/1IPdY.jpg) [](https://i.stack.imgur.com/TUdkh.jpg) [](https://i.stack.imgur.com/ck27z.jpg) [Answer] The [Tigris-Euphrates river system](https://en.wikipedia.org/wiki/Tigris%E2%80%93Euphrates_river_system) in Iraq is a vast area of lakes, swamps and marshes all surrounded by desert. A good example is the [Hawizeh](https://en.wikipedia.org/wiki/Hawizeh_Marshes) ([Google Maps](https://www.google.com/maps/place/Hawizeh+Marshes/@31.5733837,47.3868697,90288m/data=!3m2!1e3!4b1!4m2!3m1!1s0x3fc2beaf760299b9:0x8f8f72adbadcad08)) and [Hammar Marshes](https://en.wikipedia.org/wiki/Hammar_Marshes) ([Google Maps](https://www.google.com/maps/place/Hawr+al+Hammar%D8%8C+Iraq%E2%80%AD/@30.7712418,46.7613415,91056m/data=!3m2!1e3!4b1!4m2!3m1!1s0x3fdcef3f6b67ce4b:0x28f211f7cf907fd1)) inhabited by the [Maʻdān or "Marsh Arabs"](https://en.wikipedia.org/wiki/Marsh_Arabs). [](https://i.stack.imgur.com/YjUgZ.jpg) [Answer] As you've said, swamps require a lot of water while deserts require a lack of water. Where can we see this? [](https://i.stack.imgur.com/mvGeA.jpg) [This is a picture of the Nile](https://en.wikipedia.org/wiki/Nile). I don't think it can be considered swampland, but it gives you a good starting point — a river running through an otherwise desert area. The source of the river will obviously need to be a less arid area, but farther down there can be an area where the river starts to run slowly. A small, shallow lake could form that would then be filled with plants. That seems like a good recipe for a swamp to me. [Answer] **How about a swamp *inside* a desert?** [](https://i.stack.imgur.com/XPRWd.jpg) A swamp in the context of a desert will more likely be called an oasis, but all the parts are there right? [Answer] If by "think sahara" you meant the typical Hollywood portrayal as "beach with dunes" then dunes don't require very arid climate. They're more dependent on wind+sand combo and low water table than on air dryness and lack of rainfall. You can have dunes pretty much everywhere. All you need is to remove plants (to free up the sand) and open space for wind. Wind will keep moving the dunes thus preventing plants from re-growing. For a real world examples, take a look at [Błędów desert](https://en.wikipedia.org/wiki/B%C5%82%C4%99d%C3%B3w_Desert), often called "Europe's mini-Sahara". Created by humans by cutting down the trees and lowering water table. Surrounded by a forest and with a river cutting straight through the middle. Not a real marsh/desert border that you've asked for, but shows how easily a desert can be created pretty much anywhere with sandy soil. [Answer] Australia has several places where this happens - the [Simpson desert](https://en.wikipedia.org/wiki/Simpson_Desert_Regional_Reserve) being a great example. As a previous answer said - anywhere there is drainage into a lake could potentially fit this criteria, however the whole area is a vast flood plain, and a lot of the areas through the desert contain [billabongs](https://en.wikipedia.org/wiki/Billabong) which are far more swamp than oases. [Answer] There's the [Okavango Delta](https://en.wikipedia.org/wiki/Okavango_Delta), whose Wikipedia article mentions two similar features of which I was not aware, in widely separated parts of Africa. (I don't yet have the mojo to post three links.) [Answer] Even in England, [Romney Marsh](https://en.wikipedia.org/wiki/Romney_Marsh) is immediately adjacent to [Dungeness](http://stephenliddell.co.uk/2013/12/30/dungeness-britains-only-desert/), which is the only desert in the UK. [Answer] Malhuer and Harney Lakes in the Great Basin high desert. ]

[Question] [ Let's say that somehow, Earth suddenly acquired a computer with ridiculous speed. This computer can run a program described in a language of your choice, which can be described by a readme file that comes with the device. This device can have the capability to generate true random numbers, and run any program instantly (or nearly instantly, like 1 nanosecond, this does not matter because the input and output is bounded by USB protocol speed). What would be the implications of said device, and what would it be used for? I imagine some extreme Monte Carlo simulations could be run on it, and many other things, but how would that impact society in the near future? You cannot take apart or examine the machine in any way, it is a mysterious cubic meter of handwavium with a USB port where you drop in a file like input.txt and then pull out a file output.txt with normal USB protocol. (Yes this is sort of a limit on program size, but hey its an instant computer, what more can you expect?) This cube computer can be plugged into one of our computers via USB, and it looks just like a USB flash drive to the computer. But as soon as you drop in a file named input.txt it will be read, deleted and an output.txt will be created or overwritten. It does not need a power supply either. The program cannot be used to gather information about the architecture, system, or inner workings of the computer. This is not an actual computer with conventional circuits, and it is not bounded by the speed of light etc. If this device is unique and it is found by, say, NASA, what advances would we see in the near future? [Answer] This is actually very interesting Mathematically (mathematics here means computer science, and computer science is NOT programming - it's a branch of pure, not applied, mathematics). --- ## NOT the Halting Problem First, let's get something out of the way - the halting problem. Most of the answers here give a wrong description of the halting problem. The halting problem is not that some programs never halts (indeed you can write a trivial infinite loop as an example of a program that never halts). The halting problem is a thought experiment about designing a universal non-halting program detector. The non-intuitive result of the thought experiment is that it's impossible to design a universal (works 100% of the time) non-halting program detection program. --- ## A better defined scenario Now, let's restate the scenario - the computer is able to execute any program that don't have infinite loops in constant (or nearly constant) time. Interestingly, this result is very powerful regardless if it takes the computer 1ns to run any program or 1 hour to run any program or even 1 day to run any program - it would still be a major breakthrough in computing. The actual execution speed of the computer is not as interesting as the fact that it can run any program in a predictable amount of time. --- ## The breakthrough So what's the breakthrough here? You've basically just proven that **P = NP**. Let me emphasize that: # You've just proven that `P = NP`. and this is BIG. --- ## Implications The first practical implication of this is that all recursive formulas are now trivially calculable in constant time. One of the most mind blowing effect of this is that we can now easily generate and test for prime numbers. Imagine being able to just call up the 2543rd prime number! This would also mean that factoring any number into prime factors would be trivial. Taken together, making these two calculations computable in constant time **breaks cryptography**. Well, we could then shift to elliptic curve cryptography. But wait, this computer can also break elliptic curve cypher in constant time. Not only in constant time but it would take the same amount of time to break any encryption algorithm. This means that **encryption would be useless**. So our first result: ### 1. Welcome to a world without any private messaging system You'd still have old-school privacy by means of physically hiding what you're doing. But sending a coded message in **any form** whatsoever from email to a post-it note sealed in an envelope is impossible. --- For me, the next significant effect is that we can now have perfect simulation (Heisenberg uncertainty principle notwithstanding) of anything. One of the limitations we have today is that some of our theories of physics results in formulas that describe the world at a too low level. Take for example our understanding of fluid dynamics. The Navier-Stokes equations developed in the 1800s gives us a full description of how fluids (like water or air) behave. But in the 1940s scientists weren't sure if it could explain how bumblebees fly (rule-of-thumb theories developed to allow engineers to design airplanes back then couldn't explain it). It wasn't until we ran some simulations on supercomputers that we began to get a deeper understanding of bee aerodynamics. You see, the Navier-Stokes equation is an extremely low level description of airflow. It describes how airflow behaves at one point in space. You need to calculate a grid of points to understand airflow in 2D and 3D. As such, it's a complete theory that explains everything, but is useless to human minds because it explains nothing that our mind can intuitively understand. Having a computer that can simulate anything in 1ns would be a great leap forward in engineering. Not only engineering but even things like climate science and medicine (simulating protein folding for a start then simulating cells to simulating an entire human, or even a city of people at a molecular level to study disease control etc.). This gives us result number 2: ### 2. Expect advances in other areas of science and technology Cure for cancer? Very likely. Reduce carbon emissions by designing better machines? Certainly. Predict the future? Hmm... --- Those are just the things that I can think of that would happen if we manage to prove that `P = NP`. Of course, just proving `P = NP` simply means that we've proven that for every hard/slow problem there's at least one algorithm that would solve it fairly quickly. So the discovery of `P = NP` would lead to scientists, engineers and mathematicians scrambling to develop/discover superfast algorithms because we'd know they must exist. Having a computer magically make any NP-complete algorithm run in P time would mean that we don't even need to try. [Answer] So the elephant in the room is the halting problem. Consider a program like this: ``` while (true) { } // do nothing forever cout << "Finished" << endl; ``` This can never halt. It can never print "Finished." Clearly it cannot complete nearly instantaneously. So the solution has to handle this infinite case. Your solution is to have the machine break, until a reset button is pressed. This handles the easy case, but there be dragons nearby. Consider that C is turing complete. This means it can describe other turing complete languages. Let's pick Java, because it happens to be convenient for where the story goes next. We can write a program in C consisting of a Java virtual machine with an extra block of text in it. That text is JVM bytecodes, and the virtual machine will run it as code. This is important because now C can do all sorts of nefarious things, like providing the Java sub-program its own bytes as input. Now consider a program with the following pseudocode: ``` read input as a program determine if the program will halt or run forever if fed itself as input if the program would have halted, loop forever if the program would have looped forever, halt ``` Let's say I wrote this in Java. I could feed it any program in Java, and it could tell me if it halts. However, what happens if I feed the program itself? If the program halts, it will loop forever. If the program loops forever, it will halt. This paradox is at the center of a decidability problem called the halting problem, and it is a fundamental limit of programming. --- **Edit**: Now this seems to be the topic of much consternation, especially since we're going to make claims about solving the problem. This apparently has even caused this answer to be passed up for selection as the "best" answer. Now consider a program consisting of: * A virtual machine, pick the JVM as an example. As a special detail, this VM uses an unlimited precision counter to count how many opcodes have been used. Such counters are well within the realm of computation, given that the memory model of the computer does not specify any upper limit, so I can count using an infinite number of bits. * A program under test. This is a sub program which will be run in the JVM, counting how many opcodes are issued * A main loop which initializes the VM, runs the program, and then determines if the resulting number of opcodes is finite (which can be written, albeit perhaps calling for an infinite loop). * This program then prints whether the number of opcodes executed was finite. This is an easy to write program, though it is hard to execute it on our mere physical machines. I have written a program, in a traditional computer language, that just happens to require infinite time to execute. By the exact wording in the question, "This device can have the capability to generate true random numbers, and run any program instantly," it must be capable of running this program instantly. This is the actual problem... its a problem with the question which prevents the question from having a meaningful answer until it is properly resolved. --- The halting problem is known as a "non decidable problem". There is no way to determine if any arbitrary program halts or loops forever in finite time. The only theoretical way to do it is pushed off to infinity... You have to run the program for an infinitely long time, and see if it halts or not. However, your supercomputer has oracle capabilities. If a program doesn't halt, the answer comes out instantly. If the answer doesn't come out within nanoseconds, then the operator knows the program actually ran forever, and hits the reset button. Either way, the oracle has answered the halting problem in finite time. This is... big. You can give it programs that would have taken an arbitrary amount of time to run, and it gives you answers instantly. But more interesting, you can give it programs that never loop, but run forever (chaotic systems), and it can give you those answers as well. It can even tell you which ones remain chaotic forever, and which ones eventually loop. The consequences are... mindblowing. To start, any question which can be phrased in a "formal language" can be answered instantly. Screw AI's cleaning up in Jeprody, now we're talking about solving world-hunger and global-warming sized problems as fast as you can phrase the problem. Halting also interacts with Godel's incompleteness theorems. This would have religious implications. Many religious statements which are unprovable are suddenly provable with access to a halting oracle. The question of which religion is the "right" one is suddenly within our grasp. One could make observations about our universe, then plug it into a program which simulates all possible universes, and figures out which religions are consistent with the observations. Gather more data, weed out more religions. Then go prove the one religion that is left. Whichever country has ownership of the supercomputer instantly rules the world. While the path of nations is not fully predictable, it has enough computability that access to that oracle would guarantee flawless victory in every military endeavor the nation undertakes. --- So, that's all boring. Way too powerful. How can we cut it down? One answer is statistics. Define two distributions: one for halting programs and one for looping programs. Each distribution should include answering instantaniously, answering in an infinite amount of time, or anywhere inbetween. You can weight the distributions such that the expected run time of a halting program is 1ns, and the expectation of the run time for a halting problem is undefined (i.e. skewed towards infinite run time). The oracle decides the halting problem, then does a draw from that distribution. It then waits that long before announcing the problem. Now, when it takes a long time for the problem to get answered, it becomes a probability game. Is this an unluckily long halting problem, or is it an infinite looping problem? We only get a statistical answer to this question, so we do not get a definitive answer to the halting problem. This bounds the problem as you woudl like it. Amusingly enough, if we don't know the distributions (we just know they are statistical), we have a [multi-armed bandit problem](http://en.wikipedia.org/wiki/Multi-armed_bandit) for anyone seeking to abuse the oracle. This is a well known and rather nifty set of problems, which make for a good story. **Edit**: An even more insidious pattern which I did not account for until Samuel's comment: there's no reason we wouldn't build a traditional robot around this oracle. For dealing with large programs which need to collect data from the real world, what if the output of the oracle is a set of instructions for data to collect, plus a new program to run on the oracle with that data (think of it like a singularity event). Now the limiting ability to process data is that we need to reload the working memory of the program each time (USB is actually not a size limit here... it supports 64-bit addressing, but it does limit transfer speeds). Now nothing stops this robot from cruising the world, gathering data, abusing the oracle to do infinite amounts of processing whenever it needs it. [Answer] Almost all of the answers are about theoretical problems with the infinitely fast computer. I see it like this: The machine is an oracle, which reads the source-code and tells you what the solution is. This won't immediately help with most problems, because most real-world interesting problems operate on huge amounts of data. Someone said the nation with this computer would win any military conflict? How? The difficult part is getting enough information from the real-world into the machine via laughably slow USB-Bandwidth. Even weather-forecasts would need too much time to copy. And this is just the first problem - the second is formulating the program: I'm a professional programmer and usually my work routine is about 30% writing code and 70% debugging and testing. Which needs a lot of time and a way to check the results. So easily coding a program which determines the flow of the world, would first need someone to write a bug-free program and somehow compress the input so it can be transferred in feasible time. ### The interesing part: AI The much more interesting part would be a task-force to create new algorithms. You could create genetic search algorithms for may problems and let them run so the machine outputs the best code to solve a certain problem. With immense calculation-power we could give the machine complex problems and a fitness function and let it test random code-strings on the problem (like infinite coding monkeys) and it would find the best possible program to solve the problem. So we could first develop an AI which could optimize communication with the device and could be run on our normal computers, with better access to real-time input and then use this AI to produce a real-world simulation to solve problems like creating better hardware and solving physical problems.... on to world domination!!! [Answer] **I would use this computer to write code.** Due to the limited i/o rate of the computer, hooking it up to real world problems will be problematic due to the sheer amount of data that needs to be passed in order to properly assess these issues. However, if I pass in a compiler and a set of objectives, I can pass in the following program to the computer in order to generate code whose outputs meet the objectives: ``` program = '0'; do{ compile the program if it compiles: run it. if it runs: see if if satisfies the objectives if it does: return the code! else: increment the binary string 'program' by one. } while(program.length < what can be read out in a day/month/year); ``` Since our computer is arbitrarily fast, we can use arbitrarily ugly code on it. In this case, I would simply generate every byte string short enough to be read out in whatever time I have allocated to use the computer to generate this code. The computer will generate every such string in order from smallest to largest, so I will not only find a code to solve my problem, but find the *shortest* such code. I can even give my computer a goal like 'find the fastest running code below a certain length that solves this problem.' I can use the computer to write things like: * The best version of every algorithm * The best versions of algorithms *we haven't even discovered* * Strong AI. [Answer] Physicists and chemists use ab initio calculations; they are extremely accurate, but incredibly computationally expensive (a friend of mine used to wait days for his calculations on a surface of several hundred atoms to complete). With your computer, we can calculate the bulk properties of every material imaginable. We would find superior (in every regard) metal alloys, room temperature superconductors if they are possible (and don't rely on unknown exceptions to quantum mechanics), higher energy density battery materials, and so on. Of course, none of this necessarily means you know how to **make** any of these materials, but round 2 can be a simulation of *every* conceivable combination of materials, temperature, pressure, etc... and return a list of the cheapest processes for producing every material of interest. [Answer] A lot is going to depend on access. Will it be free? Nah. NASA will hang on to it. As mentioned cryptography will end. So will public stock trading. Simulations will be as powerful as the I/O allows. Furthermore perfect aeroplanes, heat shields, geographic exploration, weather forecast, DNA research for the owner. And a leap ahead for biology, astronomy, reliability engineering and robotics, and [undisclosed military application]. Plus lots of money earned from renting out a few computing slots, say 1%. But in the end it will allow a Monte Carlo learning curve that will give us ***"The Future Machine"*** which will result in either world peace, world domination and/or WWIII. I'm taking bets that it will eventually end under a mile of glow-in-the-dark rubble. We can then rename it to [***"Cassandra"***](http://en.wikipedia.org/wiki/Cassandra_%28metaphor%29). [Answer] If you allow the output to be `**ERROR program never halts**`. What you have is essentially a [Hyper-Computer](https://en.wikipedia.org/wiki/Hypercomputation). The device that most closely matches your setup is a [Zeno machine](https://en.wikipedia.org/wiki/Zeno_machine). After 1 ns you have either the result of the computation or it's already "crashed". This stands above the Turing machine in the computational hierarchy and bypasses the Halting problem entirely. The result of having such a machine available means that all computational tasks that you can think of will be able to be solved as fast as you can port them to the machines language and transfer them in. This means that is the NSA has access to it then they don't need to insert vulnerabilities in crypto standards. As most encrypted data can be decrypted. The One-Time pad will remain safe however. [Answer] This is only a partial answer, but as phrased this question doesn't make sense. Take the simple program: ``` while(true) {} ``` This program will never terminate no matter how long or how fast you run it. (Another example would be any game, which only ends when the user presses the quit button.) Now, before you simply say that the device can instead run programs, say, 1 trillion times faster than our best supercomputers, let me warn you that that won't help much. The kind of programs you're probably thinking of running are those that are categorically beyond current computers, like working out the best route for a travelling salesman that wants to visit hundreds of cities. Unfortunately, that and many other similar problems grow exponentially. So, if we assume the base of the exponent for a travelling salesman algorithm is 2 (not accurate, but easy), how many extra cities could the device allow us to solve for in the same amount of time? Well, about 40. (2^40 is close to a trillion.) So however many cities we could have solved for before, this device allows us to add just 40 to that. Ok, so if we instead say that the device can instead just look at the program and decide what the output will be without actually running it what could you do with it? Well, if we ignore the implications of the fact that this would be doing something mathematically impossible (and would therefore allow things like making 2 equal to 3) the best thing would be to look up a list of NP-complete problems. Out of those, the most immediately important would be that it would render all cryptography useless. If you don't want to ignore the mathematically impossibility, there are some other possibilities, but they get fairly complicated. The simplest one would be if the device functioned as a SAT oracle. (SAT is the boolean satisfiability problem.) This would allow for any NP-complete problem to be solved instantly, but would require the programmer to put it in a specific form first. (It's probably still mathematically impossible, but no one's proven that yet.) It'd still have many of the same implications, but there are still many problems it couldn't solve. [Answer] I think y'all are all missing something here. This device would, if its existence were made public, essentially be the end of the world. Given human nature and the axis of greed and fear that drives most of government, business and society, this device would be the cause of a truly staggering amount of conflict. Including the use of nuclear weapons to destroy any facility thought to contain it. EDIT: At the end of the day people are interested in their own self interest. This device would give the owners knowledge and tools to impose their world view upon everyone else. People who didn't own the device would fear it and the power it brings. That is a recipe for Armageddon. Yes, I realize that this is not the most popular or positive world view. My point is not about individuals, but about societies, governments, and/or businesses. All of those groups exist to further their own interests. [Answer] I'll assume the computer is just really fast, not infinitely fast (since that is just weird as other answers point out). If it's sufficiently powerful, pick your favorite open problem, and perform an exhaustive search of all possible algorithms to solve said problem (not just searching for a specific solution, but for the actual algorithm to solve it), rate the potential algorithms by success rate, performance, and length to find an efficient one. Use genetic programming to optimize the search process. Let the machine churn for a few days or weeks, if it finds a working algorithm, poof; the problem is open no more. If it finds nothing, then (depending on the computer's speed) it's likely no efficient algorithm exists, or it's just really hard to find; either way, we stand to learn a lot more than we started out with, and (bonus!) if the machine is ever taken away from us, we can still use its results. One would need to look at the algorithm the computer found to understand why it works, but that reverse-engineering task is peanuts compared to finding the algorithm in the first place (because we told the machine to search for not-too-long algorithms, and experience shows us that most algorithms to solve problems are actually fairly short: you could describe most of them in two or three pages of code). Needless to say, it would have to be **really fast** for this to be worthwhile, but if it's really as fast as you claim then it could plausibly allow humanity to quite literally brute-force its way to knowledge, at least. So I can certainly see this machine leading to unparalleled advances in the field of theoretical mathematics at least (which in turn can be put to work in more practical applications). [Answer] If I was a Monty Python fan working at NASA, then I would as "What is the unladen air speed of an African swallow". Seriously though, there are already many answers here featuring worthy questions on cancer, etc, so I'll take a different approach. Our cube is capable of faster-than-light information processing. If I was NASA, then my first question would be "What is wrong with our Theory of Relativity?". According to our understanding of relativistic effects, there would be no need to ask any questions since the faster-than-light cube should be able to answer our questions before we ask them. Since this is not happening, there must be something wrong with our theories. If the cube answered "Nothing is wrong with your theory of relativity", then I would conclude that the cube must be travelling backwards in time (relative to us), so I would ask "What is wrong with The Second Law of Thermodynamics". If the cube answered "Nothing is wrong with your second law", then I would probably throw a chair at it. After composing myself, I would ask the cube if it was in fact travelling backwards in time, to which it would no doubt reply "Time is not part of reality". If I was a philosopher working at NASA, then I would ask one of the big questions of philosophy, such as "Why is there something rather than nothing?". If the cube was able to answer this question in finite terms, then the question is - will we understand the answer? The issue of understanding an answer would be a big hurdle with all *difficult* questions. If I was a mathematician working at NASA, then I would ask "Is Riemann's Hypothesis true" and if so, ask for a proof in finite terms. This probably sounds obscure to a general reader, but it would have profound effects on the subject. A question with potentially profound implications would be "What is the fate of mankind"; "Are we alone in the observable universe"; ... I've already gone on too long. [Answer] Depends a lot on who has control over the computer. It will definitely be very interesting for solving all kinds of computationally heavy problems. * No encryption is safe anymore. * Everything that can be described mathematically can be calculated, the brute force way. Less need for finding optimal algorithms for those that control the device). * Pi can be known to a number of digits that can reasonably be transferred and saved on a USB device. Now a lot of interesting problems require the processing of large amounts of data. There your USB port as only input becomes a bottleneck. I assume there is no way to upgrade the device, so it'll be stuck with the transfer speed of USB. Expect a surge in research for compression and for automated data generation. Also, how much internal memory do we have to work with? Somehow, I also expect someone to use this for porn, but my imagination is unfortunately lacking here. [Answer] **Cryptography** Cryptography relies on problems that are prohibitively expensive to solve, in terms of computation time. Someone with access to this computer could break anything with public key encryption. An unscrupulous individual could hack his way to extreme wealth. A government may use this to monitor otherwise secure communications. Breaking encrpytion was the purpose of one of the very earliest computers, during World War II. **Simulations** ...of all sorts of stuff. Take a look at anything being run on a supercomputer today. Weather simulations will mean accurate weather reports. Physics simulations could help us understand quantum dynamics, the cosmos, etc. Engineering simulations could mean better engines, solar panels, etc. Biology simulations could mean cures for many diseases. **Math proofs** There are a finite number of math proofs of a given length. With a fast enough computer, you could search for proofs of unsolved problems, like P=NP, or the Riemann hypothesis. **Graphics** Video processing would be quite fast. And you couldn't ask for a better gaming machine. **Artificial intelligence** With massive amounts of compute available, AIs can be much, much better. --- In the end, the usefulness of this computer will depend a lot on its I/O abilities. If it had similarly fast I/O, the entire world could use it for computing. Otherwise, it wouldn't been able to solve as many problems as quickly, but it would still be game changer for the overall advancement of mankind. As Thomas said, we would essentially be brute-forcing our way to knowledge. [Answer] If there is only one, with a USB connection only, the damage wouldn't be too bad. It was said that cryptography would be broken: Yes, but only one message at a time. So we would have to think about a communication protocol where a message from A to B can be decrypted by this computer, but where that decryption wouldn't give any hint that a lesser computer could use to decrypt other messages. I would be sure that can be done. ]

[Question] [ ## Some Background The government is very good at catching people. Even the few who can keep away from them are forced into a life of running. But there is a new threat that all of Earth's governments face together, Dave the Teleporter. He was born in southern Russia and ever since he learned he could teleport, he has been on a crime wave, stealing billions worth of products from around the world. The united nations agree that he must be stopped. Sadly, only after agreeing to stop him, they realized that they have no idea how to. They tried handcuffing him but he disappeared, they tazed him and the barbs fell to the dirt, they shot at him but he teleported away before hitting the ground. They have requested the help of Earth's greatest minds to come up with a solution. ## A Few Details of Dave * We believe that before learning of his abilities Dave may have served in the Russian military. * Based on noted left behind, Dave believes now that he is a guiding finger of god and steals only what is needed to keep himself alive and help poor people, like robin hood but on a world wide scale. * Because he believes this, Dave is apparently pacifist and refuses to kill but he will harm people in self defense. * Dave has learnt that he is only able to teleport to places that he can see or has seen before. * He wears a balaclava at all times so no one has seen his face. ## The Rules 1. The Governments have become desperate and are willing to spend whatever it takes to bring Dave into custody. 2. They do not want to kill Dave, they just want to bring him into custody. 3. The solution cannot result in any human casualties. --- Using the above information how can the governments of Earth catch a teleporter? [Answer] There's no fool-proof solution, however you will eventually catch him - if you're patient. You see, Dave is screwed, because he has to get lucky every time, however the government(s) only needs to get lucky ***once*** Set up traps in places he is likely to show up (stun grenades, sleeping gases, etc.). When the weight of the floor, or the temperature of the room changes, zap him. Dave is now your prisoner. You can probably keep him from teleporting away by maintaining him in a coma, or otherwise drugged such that he has no control over his powers. Of course if you do this you won't be able to interrogate him. So here's another proposition: You can then inject a tracker in him, such that you will know where he is even if he manages to escape. Just in case you're afraid he might be able to teleport while leaving the device behind, however, there's a dirtier trick you can use. > > Fit the tracker surgically on one of his arteries. Inform him that if he teleports without it, his artery simply severs inside his body and he dies within seconds. > > > As long as he values his life Dave won't dare move out of place. [Answer] Make *him* come to *them*: * Poison his food or drink. Antidote only available from the authorities. * Insert a highly addictive rare drug in his food or drink. Further supplies only available from the authorities. * Take hostages. Of course the authorities don't want to kill Dave: he is unique and they want to examine him to find out how teleportation works. But ordinary people are ten a penny. * Bribe him the nice way. Broadcast a message to the world publically committing to provide fresh water for everyone on the planet, or whatever is most likely to appeal to Dave's benevolent ideals, on condition he reports in. * Bribe him the old fashioned way. Money he can steal for himself, so offer beautiful women (all highly trained agents but that needn't be made explicit), companionship, prestige, the chance to stop running and live openly in a beautiful house. * They could even try just asking nicely. ***Later edit:*** It has been pointed out that taking hostages violates The Rules. So let us replace it with * Make it clear to Dave and the world that he is doing harm. Theft ultimately [harms society](https://worldbuilding.stackexchange.com/questions/29814/could-i-have-a-culture-where-stealing-is-not-wrong). [Answer] Back in a D&D campaign we had an opponent who was fond of teleporting attackers into our abode. We solved that by placing furniture and other obstacles at the spots where we believed they might teleport into. The downside of this, given that the government doesn't want to kill Dave, is that it will almost certainly be fatal if he teleports into a table or other large object. So keep the obstacles as low as possible. (Eventually our enemies started scrying the spot first to ensure it was safe, and we followed up by using invisible obstacles. And that ended the teleport attacks) [Answer] Presumably Dave has friends, family, known associates, buyers for his ill-gotten goods etc. so good old police work can find him. And presumably he has to sleep from time to time. So I'd find out where he sleeps, and deploy an anaesthetic gas. Dave inhales the gas in his sleep, and is taken into custody in a half-comatose state. Makes it hard to read him his rights, of course. [Answer] You seem to be asking two questions: 1. How to bring him into custody. Does he have to physically have visited a location to teleport or can he just have seen it TV? 2. How to keep him in custody. Firstly, If he has to physically visit a place before he can teleport to it, his teleportation is really only an escape mechanism. So, for him to rob a bank vault, he has use conventional means to get inside the vault, then just teleport to escape he would be fairly easy to catch. If the the later, it's harder but more mundne. > > ...stealing billions worth of products from around the world. > > > Actually, catching a teleporter is not that much different than catching other major criminals. They don't actually catch criminals in transit very often. Most criminals get traced through their fences i.e. the people who buy stolen goods or launder stolen money. You can't actually physically steal something worth billions because it would be something like a building or an air craft carrier. All the large amounts of money in the world are electronic. But suppose he teleported into Fort Knox and stole a brick of gold one at at a time (or whatever he can carry) assume they don't catch him at the Fort Knox, the gold is useless unless he can exchange it for something, so he will need a fence. Same for bucket loads of cash like the drug dealers pile up by the literal ton, they still have move it, distribute it somehow and get it where they can spend it. Either he steals things to convert them to fungible wealth or he steals them them to use i.e. weapons. If the former, he has to have contacts, in the later he has to have a place to stash them. Either way, he will generate patterns in financial systems. If he plays Robin Hood, he can be traced by his attempts at distribution. Whenever he interacts with others he becomes vulnerable, just like any other criminal. Once they zero in on him, they just stakeout his likely locations and then when he appears he his taken down with Tazers or other less lethal systems. Once he's down he's placed in a chemical comma for an indefinite period. If they need him awake eventually, they would surgically attach a nuclear powered tracker and radio controlled system within his brain that would knock him unconscious upon command or if the system detected it was not longer in the containment area. [Answer] Bring him to your side. Let him play whatever hero he wants to play, forget these pesky billions. Really, teleportation means **a lot**. If one gets his hands on its basic principles, he could remotely destroy anything without leaving a trace - teleport a bomb to a city or teleport a city into space. The governments would fight for Dave tooth and claw, mostly because no government wants others to have such a power. So, ask him what he wants and give it to him. Explain that he could get drugged by any hobo, fall into the hands of terrorists, and become a weapon of mass-destruction. Explain that you, a Government, don't need dangerous weapons for yourself - you already have nuclear bombs and it's pretty much enough. Explain that the teleportation-based technologies would improve much more lives than one man jumping between banks and hobos. And study his teleportation >:] (By the way, it's really uncommon to refer to David as "Dave" in Russia). [Answer] ## The hard way He stole and redistributed money/goods. **Make a point to recover every penny**. If you can do that, it makes his actions pointless. Also, **arrest everybody**. Pin aiding and abetting on them on those who offered him shelter or help. Hold those you can't pin anything on for as long as you legally can, even if it's for 48 hours. If you systematically arrest everybody he knows, he'll realise his actions do more harm than good. Just to be clear, I'm not talking about arbitrary arrest, I'm talking about upholding the law. He's a criminal, aiding him is against the law. Eventually, **people will realize he brings more harm than good** when they get arrested and are left with none of what he brought. To seal the deal, **offer a bounty for his capture**. Sure, it's unlikely that a random civilian will capture him. However, that will turn enough people against him that he will have to think twice about doing his thing. Then **wait for him to break**. Make sure that he understands he will have to run away all his life, no family, no attach, not now, not ever. Running is exhausting, he'll pay the heavy price for it. Eventually, there will be nobody left to care about him. Eventually, running will be more and more difficult and exhausting. Eventually, he will reach a breaking point. The good news is that if you remove his will to fight, he may not even try to escape afterwards. ## The easy way **Offer him a chance to use his talents legally**. Essentially, give him a badge and a gun. I'll be serving justice, but from within the frame of justice instead of acting above it. Offer him a full pardon while you're at it. That will offer him a chance at a normal life, i.e. without running. **Offer him a chance to further science**. Appeal to his higher ideals. Teleporting can do a lot of good to society, probably more than illegally acquired goods. This is a chance to do good for the whole world rather than a few people. You will likely have to treat him like a decent human being rather than like a lab rat. That may hinder your progress, but **slow progress is better than none at all**. --- Consider offering him a chance to do some good on your term if you catch him, rather than offering the prospect of being dissected in a dark room. Make his downfall more appealing than his continuous running. Honestly, **if you aren't willing to kill him or mess his brain up, you'll have to wait until he surrenders of his own free will**. It's all about finding a reason why he should do so. [Answer] Set up spies as poor people in need. (use a profile of the type of people he normally encounters) Set up traps and trackers on some common items he steels. (use a profile of the type of thefts he is guilty of) Track down who he is, and every place he has ever been. Then set up a trap either at the point of theft, or at the point where he gives the goods/money to the poor. The trap should be a chemical he breaths in, or one that seeps in through the skin. It should also attach a tracking device through the same means. (probably a radioactive isotope of nano machine) The chemical should render the thief unconscious in a way that he doesn't notice, or for a length of time that allows the governments to find him if he does notice and teleports away. Once unconscious he must be kept that way until the governments of the world have destroyed or drastically changed every place he has ever been. Never again let him see a place outside his prison. All this is moot if he can teleport to a place he has seen a picture of. Then he needs to die, or be kept in a coma. [Answer] > > How can we catch a teleporter? > > > Based on the proposed rules and his personality, I suggest **BAIT** He obviously can return to a place he's stolen from before, but does not have incentive out of fear of capture or having the valuable items moved. To be more clear on this point, his initial crimes would lead stores, banks, etc. to renovate after a theft, and not allow strangers to see in to prevent his future crimes. This would likely be a well-established pattern for Dave by the time the nations are working together to capture him. He would need to scout out new targets - through unsuspecting means. He may be the only one of his kind, but crime prevention has been around a long time - along with creative ways to accomplish crime. With the wealth of the world at your disposal, make sure that several places he has stolen from before are restocked - if he's smart, he'll smell the bait, so it has to look like it's a secret or have some other ploy to entice him to return. It would be especially nice if his theft appears to go unnoticed each time, so that he lingers and perhaps starts to do it on a regular basis. Second, *all travel requires a path*. Monitor the baited locations and other areas of the world. Before he arrives and after he leaves, *something is happening to create a path*. With all of today's technology, it should be possible to understand what is happening, even if we didn't understand *how*. With several such stations it's possible you could even monitor his teleportation from one baited/monitored location to another. Monitoring could even include markers, transponders, etc. that he carries with him unwittingly. Patterns will emerge. Also follow the money. Money has serial numbers for a reason. Banks would certainly cooperate in providing tracking (which they already do). Similar identifies could be placed on other goods. Monitoring has to be done with patience - otherwise he will grow suspicious and change his tactics. After a while, the scientists will learn *something* about his special abilities and probably how to limit or even control his teleportation. Make the path longer/slower/smaller/heavier/hard to navigate/painful/excessively hot/etc. Confuse him by altering the destination. Create a loop so he returns to the place he tried to leave. Worst case, they will gain a lot of information about who he is "helping" as a modern day Robinhood. Among him and his co-conspirators, after constant monitoring, fear and stress, an opportunity to "make a deal" will emerge even if the ability to control his gift doesn't. One last point: since no one has identified "Dave" from his nefarious activities, it's possible no one actually knows who he is. He could even end up on the team trying to "catch" him. I think that would be easy to identify (like Superman - how come "Joe" is always gone when "Dave" shows up???). Still, it seems possible and could make this pursuit more interesting... [Answer] He need to get inforamtion about poor people and money storages somewhere. Spoof that information with fake. So he will transfer fake money to fake poor people. That is nice prison, he don't know about it, so he can't escape, and you even can use him for your purposes. It isn't that hard as it seems at first. He can telepot, but can't read minds. So you only need to anlyse people he helped (like they all in same group in facebook or live in getto), so you can find Dave information chanel. [Answer] I would have suggested hostages but @lostinfrance already suggested that. So, two more suggestions, in order of practicality/reliability. **Double Agent:** Send in a double agent to gain his trust. That double agent can then get information out of him by pretending to be helpful. If the agent is medically trained he could even offer to help Dave understand his powers by examining him, then send his findings back to HQ. The best case scenario is that the agent becomes aware of one of Dave's limitations/weaknesses with minimal effort. **Nowhere to run teleport:** Station agents at all the places in the world he's known to be able to teleport to. A global CCTV system would also be helpful unless he knows some deserted places he can jump teleport to. [Answer] I think this Dave guy here, he's also some kind of speedster. If he keep running away so fast, he could probably kill himself due to his cells being shattering with air. Maybe we can create a portal or something like a beach to another `Earth` or `Planets`, when he appear, we trapped him into the breacher and close the breacher and never open it. How is it? [Answer] This seems like a classic 'forest-for-the-trees' situation: Dave's ability to teleport is infinitely more valuable than anything he could steal and redistribute, and not just in monetary terms, but strategically. Any adversarial relationship with him will forfeit his cooperation, which as far as anybody knows is essential. So you (the governments of Earth) will eventually have to reformulate the problem: How to convince Dave to cooperate with (all of) you. Governments seem somewhat crazy to most of us most of the time, but in fact they can be bitterly rational when their survival or future is threatened. Being excluded from access to teleportation technology is exactly such a threat (and it eventually *will be* technology, unless it's literally a gift from a literally divine source). I believe that eventually nearly every government would do almost anything to participate, even to the extent, horror of horrors, of treating their own citizens with kindness and respect. In fact this scenario is similar in many ways to the scenario 'super-advanced aliens arrive on Earth and offer us Galactic Membership - if we can pass test of being civilized.' Indeed, it's easy to imagine that eventually it is discovered that Dave is actually a wacky tourist from galactic core, or is Galactic 'test administrator', or etc. [Answer] 1. Set up expensive decoy items to lure him in, with hidden GPS and knockout gas. 2. Once an object has moved, the GPS info will have changed, and it emits invisible odorless knockout gas. 3. The item will then send out a quiet radio signal to tell everyone where it is. Upon arriving at "the secret lair" they might find other valuables that have been taken. ]

[Question] [ Handwaving the origin of one such place, imagine a universe where every part of space is filled fully and evenly with liquid water (at, say 1 degree Celsius). What would be the experience of a solid object in that universe? Intuitively, it may seem like there should be infinite water pressure crushing the object into a blackhole, but since there are infinite amounts of water everywhere, the gravitational potential field in this world should be flat everywhere, and thus the pressure on the object should be near 0, especially if the object is equal or less than water in terms of density. Is my reasoning correct? (Did I overlook something that made the whole thought experiment impossible, perhaps?) [Answer] You won't be able to have this in a universe that uses our physics. The degree to which space itself expands or contracts is related to the cosmological constant and the density matter within that space. A universe full of water is going to have an insane matter density. Which can be balanced by a large cosmological constant. The problem arises in that this balance is *not stable* -- at an iota greater, the higher cosmological constant causes runaway expansion, and an iota less it causes runaway collapse. In our universe, this runaway expansion is going on; the universe is effectively in a "gas phase", and decreasing the density just causes galaxies to move apart. In water, density would lead to the fluid *boiling*. The resulting pockets of vapour would float towards each other (as being lower density), and the remaining fluid would fall together, and everything would be extremely far from static. The clumps of water would collapse inward radiating insane amounts of energy and form black holes. Now, the universe we are in was once as dense as your water universe; in this period, it had an insane inflation rate. That inflation rate was fast enough that there wasn't *time* for things to become non-uniform. The universe was also insanely hot (hot enough that helium was too hot to stay helium!). It cooled rapidly, and at around 11kK it got cool enough to allow for He to be stable, and then it continued to cool. The ridiculously tiny ripples in density it had while dense was enough to form huge voids and galactic clusters as the density kept falling. So no, at no time can you have an extended "water universe" using our physics. --- It turns out I could be wrong. "Unstable" doesn't mean immediately unstable. A pressure in the gigapascal range can have liquid water. Given our *current* universe expansion, that pressure would take billions of years to relax. Unfortunately that adiabatic expansion (there is nowhere for the heat to go, other than other places with heat) will be doing *work*. Naive Newtonian physics makes the heat change pretty large. I don't know, cosmologically, if the pressure release/work would do strange things to the cosmological constant/expansion rate. This still leaves another problem; the fluid is not going to be uniform; our universe doesn't permit uniformity. You'll get areas of different density, and those will attract and "repel", causing increased density differences. In a gas-phase universe collapse is very enthropically encouraged; the falling gas heats up, radiates, and repeats until held back by something as strong as nuclear fusion or a phase change to solid or liquid or electron degenerate or neutron degenerate or becomes a black hole. A liquid phase universe is going to behave quite differently during gravitational collapse due to the incompressibility of liquid. Tiny decreases in size (and increases in density) will absorb huge amounts of energy. [Answer] ## Equations of state The "ocean" should be described by an [*equation of state*](https://en.wikipedia.org/wiki/Equation_of_state) that relates thermodynamic variables (e.g. density $\rho$, temperature $T$, pressure $p$, etc.) to one another. Different equations of state are valid in different regimes; some are valid at high temperatures and pressure, while others are valid at low ones. I think it's not particularly worth going over them here, but the usual (approximate) one for liquid at reasonable temperatures and pressures involves just density: $$\rho=\text{constant}$$ that is, liquid water is essentially *incompressible*. By looking at [Bernoulli's equation](https://en.wikipedia.org/wiki/Bernoulli%27s_principle) (which works for incompressible fluids), we can see that in the case of a static fluid in a vanishing gravitational field, the ratio of pressure to density is constant, and therefore the pressure must be constant, too. Note that when I say "constant", I mean that a quantity does not change much if you change other, related, thermodynamic quantities. Change the pressure of water slightly and you won't significantly change its density. If we were to increase the ambient pressure inside the fluid, the assumption of incompressibility would be invalid and we would have to pick a different equation of state. ## Pressure and pressure gradients I think there are two quantities that may have been mixed up here: fluid pressure and the pressure gradient inside the fluid. I'm not aware of any realistic equation of state - certainly not one for liquid water - that involves vanishing pressure for a fluid with non-zero density. Pressure typically arises from interparticle interactions, and as the density is decidedly non-zero, there's no reason for that pressure to go away. Now, what *will* go away is the pressure *gradient* $\vec{\nabla}p$. In a fluid in hydrostatic equilibrium experiencing a gravitational acceleration $\vec{g}$, the pressure gradient is $$\vec{\nabla}p=\rho\vec{g}$$ and in our case, as $\vec{g}=0$, so is the pressure gradient. ## A solid object Now, say we have a cubical box of side length $L$ embedded in this fluid. All sides of the box will experience a force of magnitude $F=pL^2$, where $p$ is pressure; the force on each side is pressure times the area of a side, which follows from thinking about pressure as force per unit area. However, because there's no pressure gradient, these forces oppose each other equally, and so there will be no net force on the box. The box may be deformed by the pressure exerted on it on all sides, but it will not experience a net force in any direction. ## Cosmology Several users ([Yakk](https://worldbuilding.stackexchange.com/a/146036/627), [Acccumulation](https://worldbuilding.stackexchange.com/a/146038/627), and [Joe Bloggs](https://worldbuilding.stackexchange.com/a/146039/627)) have noted that this universe will likely not remain uniform, but will suffer one of two gravitational instabilities: * It may collapse in on itself in a Big Crunch if the density is larger than the [critical density](https://en.wikipedia.org/wiki/Friedmann_equations#Density_parameter), which is actually quite low. If the critical density is the same as in our universe, then this universe is far too dense, and will almost certainly collapse. * [Small perturbations](http://sancerre.as.arizona.edu/%7Efan/Home/AST541_files/Perturbation.pdf), like the quantum fluctuations seen in the early universe, will eventually cause structure formation in much the same way that our own universe first formed inhomogeneities. The characteristic scale of these fluctuations is $$\lambda\_J=c\_s\sqrt{\frac{\pi}{G\rho}}$$ where $G$ is the gravitational constant and $c\_s$ is the speed of sound. In this universe, $c\_s\approx1481\text{ m/s}$, and so $\lambda\approx10^7\text{ m}$, which seems rather large; the characteristic growth time will be $\tau\approx10^3\text{ s}$. [Answer] A similar question might be: in an infinite universe filled with hydrogen, what gives rise to pressure? If this seems an odd comparison to draw: consider that , near the beginning, our universe was pretty much homogeneous hydrogen. It was also very small, but that doesn’t matter for this answer. The answer I think you can pull out here is that even if your universe starts off ‘homogeneously mixed’ it *will not remain so*. Your universe is only homogeneous on a large scale. Seen up close there will be small-scale variations. These variations will, over time, lead to larger variations. A small clump of hydrogen will, ever so slightly, pull in more hydrogen. The once uniform gas will start to pull itself into filaments as parts of it gather into more massy areas. Those filaments will split into beads, drawing the rest of the hydrogen out of the less massy areas (which will come to resemble vacuum quite quickly). Those beads will gather in size and mass and gravitational potential until they auto ignite in a blaze of nuclear fury. From there it’s only a matter of time until you have planets, atmospheres and a much more traditional definition of pressure. Your universe starts off much more oxygen rich, so all the stars will start off further along the main sequence (if indeed they’re on it to begin with). Other than that you can expect the same things to happen on cosmological timescales. Somewhere a small chunk of water will gather (pretty much randomly) at a higher density than the water around it, disturbing your uniform gravitational field. From there it’s only a matter of time until everything gets pulled into strings of clusters of galaxies of stars. It might take a while though... [Answer] My logic is the same as yours; in an infinite universe entirely filled with liquid of a uniform density there's no gravitational variation. The universe is effectively just filled by a thicker form of vacuum. Once you introduce a gravitational anomaly, in the form of an object of higher density, it gets very different very quickly. Since the "vacuum" of this universe actually has considerable mass per unit volume a high density object will cause the universe to begin accumulating at that gravitational centre turning into a giant ball of water that eventually (in the space of a few seconds) collapse in on itself under it's own mass creating a giant blackhole. A lower density object won't really do anything but sit there; unless there are ambient currents in which case it will get carried in them like any other particle. [Answer] ## An 'Infinite Ocean' eventually transforms into a universe like our own (planets, stars, black holes) : because of the random motion of particles A uniformly distribute universe of water may start with the stated uniform distribution, but it won't stay that way for long. There is a simple reason for this, *water particles are not stationary*. Imagine you start with a uniformly distributed infinite ocean. Water molecules will move around "randomly" because they are energetic, and energetic particles move around. This means they will eventually move into a position where the distribution of the water's mass is not uniform. At this point uneven gravity will begin to act on the water column. Eventually the water column will be completely uneven and we will end up with a very perceptible directional gravity in different pockets of the universe. This all culminates in localized blackholes forming, as an enormous mass of water collapses in on these local points of high gravity. I can't say how long this would take, but for sure it would happen eventually. However not all areas of high gravity will have enough mass to form blackholes, so in some areas there will be planets made entirely out of water, and water based stars (instead of hydrogen based ones). These stars will then make metals, and other elements using fusion. All these bodies are probably rogue, or else orbiting around blackholes. Even if we try to force this universe to work as a lasting infinite ocean. For example by assuming all water molecules have the exact same orientation, energy, and therefore travel parallel to each other. Quantum effects will still cause the behavior of these water particles to change over time so that they are not all the same. Once this happens, its then a slippery slope back into the black hole(s) filled universe that we just discussed. [Answer] In a vein similar to Yakk's answer, the issue you are concerned with is pretty much the same as the issue of density in our universe, except many orders of magnitude greater. Our universe also is filled with fluid (mostly hydrogen), but at many, many orders of magnitude lower density. We can then ask: for our actual universe, do we have equilibrium, since every point has an infinite amount of hydrogen pulling it in every direction? Or should the universe collapse, since there's a contracting force at every point? The overwhelming consensus is that absent a cosmological constant, it would be the latter; there would be no static universe. A universe can be expanding, and having its rate of expansion slowed by the contracting force. It can be contracting, and having its contraction accelerated by the force. But (again, absent a cosmological constant), it can't be stationary. Seeing as how any cosmological constant in our universe would be of roughly the same order of magnitude as the density of matter, and your universe would have vastly higher density, we can conclude that either your universe has a vastly stronger cosmological constant, or it has extremely massive pressure. I would expect the pressure to be so large that the matter would quickly cease to be water. [Answer] I think it's important to note that your assumption that infinite, uniform mass density implies zero gravity is not necessarily a valid one. The second answer of [this](https://physics.stackexchange.com/questions/430419/why-isnt-an-infinite-flat-nonexpanding-universe-filled-with-a-uniform-matter?noredirect=1&lq=1) physics stack exchange article goes into more detail, but the general idea is that infinite universes often mess with the math that goes into calculating gravity, since our usual solutions to such equations involve "nice" behaviors at infinity (ie, potential is asymptotically zero in Newtonian gravity, or the metric is asymptotically minkowskian in GR). When these conditions aren't met, you tend to run into the problem that your equations no longer have unique solutions. This is a problem because the whole goal of science is to come up with models that predict what will happen if you perform some experiment-- it's not very useful if your model has an infinite number of different predictions. TLDR: the scientific models currently in use can't really give a meaningful answer to this question. [Answer] You could just claim it’s a universe with no Higgs boson or Higgs field and so no mass and thus no effect of gravity, theoretically? But that would have other issues. Depends how fully baked the answer needs to be. I just am trying to say you could alter a single or maybe a couple elements of physics in this universe to claim something for your water universe and really not many could dispute it as we don’t really understand most of the theoretical physics around it. We’ve proven the existence of the Higgs particle, but we don’t really understand it, the Higgs field, or even gravity really... so I’d say just change the physics of that universe to make it what your proposed idea needs. Just a thought. [Answer] First, I'll note that the water doesn't need to be infinite. The gravitational force that causes pressure can propagate through water only at the speed of light. So assuming you started out with a pressure gradient of 0 throughout the water blob, and the age of the water-blob in seconds is less than the shortest distance to the edge of the blob in light-seconds, then the pressure where you are measuring will be unaffected by the fact that the water is not infinite. Assuming it's in energetic equilibrium at 4°C, or at least that it is not in gaseous form, and you plop a lump of something dense in, the dense thing shouldn't form a black hole. It should just form a pressure gradient where the pressure at each point cancels out the force of gravity from the object, plus the gravity from the slightly-increased density. Over time, as the existence of this dense object propagates away at the speed of light, everything in the universe arguably moves a *little* closer to it, but not detectably for most of the universe as the effect dies off with the inverse cube of the distance. This means an appearing object causes an outgoing wave of negative pressure, as stuff is sucked towards it a little. I think this also means that not only no black holes could form, but no planetary systems could form - no stars, planets. No accretion of any objects through gravitation at all, since the repellent effect of the pressure differential should greatly outweigh the effect of gravity (citation admittedly needed). Note that this should hold true for universes filled with solids, as well as with liquids. [Answer] I say no pressure in an infinite ocean. If the ocean was truly infinite, there would be no **center of mass**. Thus, no gravitational attraction would pull the water to any one point to cause the pressure. The only thing that would cause pressure is how much water there is compared to the size of the universe. If space is infinite and the amount of water is infinite, it then depends on which infinity is bigger. If Infinity(water) is greater than Infinity(space) then pressure would increase, the ratio indicating how much pressure is exerted on any non-water forms in that universe. If Infinity(water) is less than Infinity(space), the water will be water vapor instead of water. For certain ranges of I(w) < I(s), water may exist in some transitional state between liquid and gas. [Answer] Okay, I tried resisting posting... but I'm going to give a shot at answering because I didn't agree with a lot of the answers. So, instead, I'm going to answer by proposing thought experiments. **T.E. #1: Vessel of water in space** Imaging you're aboard the ISS. You've got a cylinder filled with water that is plugged on one end. The other end has a plunger that's loosely containing the water. What happens when you press down on the plunger? Well, the pressure in the water builds - you're putting pressure on it. But, generally, the water is staying the same volume - because water is pretty darned uncompressable. Water at the bottom of the ocean only manages to compress water 5%. And if you press really really really super-humanly hard? Then the water actually condenses to a solid. Which *really* doesn't compress well. **T.E. #2: Filling ISS with Water** Forget the vessel. Let's blow out all the air, patch up the hull, and replace the vacuum with water. What's the pressure inside? Well, when you *first* start filling it with water, the water will boil into steam - if you look up a [tri-state chart of water](https://chemistry.stackexchange.com/questions/46488/what-are-the-physical-properties-of-exotic-ice), you'll see that for low enough pressures, you simply *can't* have liquid water: it'll either boil or freeze. But as more water is added, something weird starts to happen. Eventually, the pressure of steam will get high enough that water starts re-condensing and the water you're adding won't be boiling off. If we were in an environment with gravity, we'd have a layer of water on the ground and a layer of high-pressure steam above it. But gravity isn't in this picture (ISS!) Instead, we have water and steam intermingling - and since water has some good surface tension, we'll generally see globules of water meandering through the steam. As we add more and more water, the pressure goes up, the volume taken by steam goes down, until eventually the entire ISS is filled with water with no steam. And that water is just above the condensation pressure for water. In real-world terms? It'd be what water is like at the surface of an ocean/pool/puddle. ... and as you add more water? The pressure starts going up. You're adding more water molecules, but not giving them any more space. And given how incompressable water is, the pressure starts to climb pretty rapidly. And like the plunger situation (and assuming ISS was built out of infinitely strong material) you'll have a situation where, when you added enough water, you'd cause the water to start solidifying due to presure. **T.E. #3 - Giant Plunger** Imagine you've got the same cylinder and plunger from the first thought experiment, but this time: They're huge. Once again, you press down superhumanly hard, and barely condense the water into ice. What happens when you let go of the plunger? On one hand, [Ice VI and Ice VII](https://chemistry.stackexchange.com/questions/46488/what-are-the-physical-properties-of-exotic-ice) have a [density either 30% or 50% greater than regular water.](http://www.idc-online.com/technical_references/pdfs/chemical_engineering/Ice_phases.pdf) So if a chunk of regular water would be pulling with 10 newtons of force due to gravity at N meters, a chunk of Ice VI or Ice VII would be pulling with 13-15 newtons. Now, think how *little* this difference of gravity would be... versus how *great* the pressure difference would be! Imagine how much force a column of water 100 kilometers deep would push down on you? That's how much force the ice would be trying to exert in order to expand. In other words, the plunger would go flying away from the ice - the ice would be pushing with immense force - far more than its slightly higher gravity would hope to counteract. **Putting Everything Together** As the OP guessed at: long distance gravity wouldn't matter much. If the universe was simply infinite ocean, the gravity would have no net direction/force. But that's *not* to say there wouldn't be pressure. Like our ISS in Thought Experiment #2, it all depends on how many water molecules there are in a given amount of space. Not enough: no ocean (its all steam.) Too much: sea of exotic ice. Just barely enough: water with pressure like you'd find at the top of the ocean. Almost too much: water with pressures greater than any ocean trench. Now, something stirs up 'space' - such as the pull of a local dense object. You've effectively got a plunger pushing downward on your water. If that object isn't very big? You're just lightly pushing down on the plunger - until the pressure from the water is equal to your force. If the object is really dense and massive? Then the plunger is pushing down hard enough to solidify the water around the surface to exotic ice... but ultimately it's like our T.E. #3 - that ice has *enormous* amounts of force that it's using to try to expand. **So, TLDR:** The water's going to be pretty uniform: water pressure is much stronger than increased gravity from denser water. Even dense non-water objects will probably simply have a gradient of increasing water pressure - and possibly exotic ice - around them. **Finally, to the OP's question: what would a solid experience in that environment?** Figure out what the pressure would be (dependent entirely on how much matter there is per volume) and then ask yourself: how would an object under the surface of the ocean act (assuming the object has the same density of water, since gravity doesn't play a role.) [Answer] Since this is science-based, consider your frame of reference. You can have a universe of water by using some tricks, like letting the reader make some assumptions. Thus: "The Universe" to us is quite big. But to a jellyfish swimming in your water-universe then its small to us, but still quite big for the jellyfish. To an amoeba the inside of the Jellyfish is an entire universe. To get what you want in your story, then leave the reveal toward the end, that the scale is smaller-than-human scale. The water universe could be a water planet with a relatively small diameter, but characters who are sub-millimetre tall. They might speculate about "what lies beyond the known universe" just as humans do. This will provide a framework for "why the water pressure is not crushing" [Answer] Every point would be the center of the infinite universe and therefore experience no gravitational force. One equilibrium in which this universe could exist would be one in which all the molecules are in cubic symmetry (each one equidistant from all its nearest neighbors). So such a universe would essentially be one gigantic crystal. Putting an object in it would disrupt the mass symmetry and make that object the center of mass of a gargantuan body of water and eventually lead to stars and other stuff. ]

[Question] [ I've recently been replaying Skyrim (for about the fifth time now), and I've stumbled across something I thought would make for an interesting question. The [Greybeards](http://en.m.uesp.net/wiki/Lore:Greybeards) are a group of extremely powerful, isolated mages who live on top of a remote mountain. When visiting them, none (except for one) talk to you, for it's said that they are so trained in the way of the Thu'um that them speaking to you will kill you. (For reference, in Skyrim, there exists something called the Thu'um, which is a shout that can be used to unleash varied powerful effects.) In this case, the Greybeards are so trained in the way of the Thu'um that they cannot even talk to you for the pure energy and force of their voice will kill you. **Could an organism kill its prey (to simplify things, assume this species eats primarily humans) by shouting at it? If so, how? How would this species not kill one another through its death shout?** # Unlike [this question](https://worldbuilding.stackexchange.com/questions/11610/a-creature-with-sonic-powers?lq=1), I am asking for a solution that would kill an organism, not merely stun it. [Answer] ## Yes, but with a big ol' Asterisk Sperm whales hunt giant squid. How the whales manage to subdue such able prey has been a mystery. One hypothesis, proposed more than 20 years ago, speculated that the whales use powerful ultrasound shrieks to knock the squid senseless before scooping them up. Like bats and dolphins, some whales use ultrasonic clicks to find prey and navigate. The basic premise is, that since sound travels faster underwater, a beam of sound (echolocation) narrow enough could kill in the same way shockwaves do; by rupturing the organs of the animal. Now for the asterisk: this will only work underwater or on a world with a dense atmosphere. Not on land on an earth-like world. Another (non-biological) example are [long range acoustic devices](https://en.wikipedia.org/wiki/Long_Range_Acoustic_Device) used by the police. In simple terms, it works by using the vibrations of sound at such a low frequency that it becomes one solid beam. This beam simply applies pressure on the diaphragm and makes it difficult to breath. It's the Death Ray we all wanted as children. A few helpful links of weaponized echolocation that I've found on my travels; 1. <http://www.livescience.com/7297-whales-attack-squid-mystery-deepens.html> 2. <http://www.science20.com/squid_day/do_sperm_whales_use_sonar_stun_giant_squid> [Answer] # Yes. If your species could evolve to emit a high-pitched screech at around 180 dB, you're set. According to this [Reddit post](https://www.reddit.com/r/NoStupidQuestions/comments/30xga2/if_a_sound_of_500db_goes_off_for_lets_say_0001/), a sound of 180 dB would be perfect for this, as past 160 dB, you will stop being able to breathe, and cells in your brain and ears will die. However, there is still a 50% chance that you may survive past this point. After 180 dB, human death is basically guaranteed. It wouldn't be advisable to do raise that decibel value any further, as any sound past ~190dB is characteristic of large bombs or tornadoes. Keep in mind that the largest bomb used in World War 2 (excepting Hiroshima and Nagasaki) was only 220dB. As such, now that we've found a perfect range of around 180dB to 190dB, take the lower of the two, as producing a slightly quieter sound saves some energy. --- As for not killing its own species, I'd suggest having your species not have ears (at least not external ears). By doing this, your species will only feel the force of the scream, not the actual sound. Also, I'd suggest building a stronger membrane/skull around the brain, so the sound waves need to travel through an extra few layers of thick membrane before they can reach the brain, at which point they will hopefully be mostly nullified. [Answer] You should give a look to a kind of shrimp called "Alpheidae". It doesn't really kill by shouting, but produces an underwater noise which power can reach up to 230 dB, if I remind well, killing its prey. ## EDIT Unfortunately I can't find english sources as good as french sources on this specific topic, but you can have a look to this article, detailing the mechanism producing such a loud noise with this shrimp : <http://www.todayifoundout.com/index.php/2010/09/a-shrimp-is-one-of-the-loudest-animals-on-the-planet/>. Here is the proof of the beginning of my post : > > The snapping shimp has proven to be stiff competition for larger animals like the Sperm Whale (230+ decibels) and Beluga Whale for the title of ‘loudest animal in the sea’. The snap of its claw releases a sound that can reach 218 decibels- louder than a gunshot. > > > And here is the "answer" to this topic : > > The pressure of the snapping bubble is sufficient to stun a passing crab or even kill small fish. > > > [Answer] If you want to make a really exotic creature you could design it to have two mouths that shout at the same time, at the place the sound meets there will be constructive interference if the sounds are of equal frequency and phase and therefor the sound will be amplified. If the mouths are movable this could give the creature great control at what it hurts with its shouth while things that are closer or further away from the prey will be safe. As long as the unamplified sound is safe that is. [Answer] ### The physics The first problem as I see it is that sound is directional only because it is blocked. What is blocking the sound, making it directional, is often the object emitting the sound. If the object emitting the sound is an organism of the same stature as the organism which it is supposed to kill. Either both would die, or the emitting organism would die, only harming its opponent. Since the emitting organism is much closer and thus must absorb more of the energy than its opponent. ### In Nature Specific scenarios are of course available to see in nature, but they are always *this one animal* kills *this other type of animal* because it is smaller, more sensitive or has another specific flaw which the killer animal has evolved to exploit. ## TLDR; Using sound to **kill** *any other* organisms could never be as cost efficient as evolving a claw, teeth, beak or horn. Using sound to **prey on** *specific* organisms can be cost efficient, as we see on our own planet. [Answer] **Not really.** Animals don't need to kill other animals to eat them. They need to find a way to make the prey hold still while they ingest them - killing is one of several ways to do that. Assuming a gradual evolution, a shout will first stun before it becomes strong enough to kill. There is no clear advantage to having a stronger shout, but there are several drawbacks: Stronger shout requires more energy, stronger shout endangers own species, stronger shout requires better protection mechanisms in own species. **Yes** What can happen is that an animal evolves that has a shout that stuns it's prey A. Then a new prey B enters the ecosystem which gets killed by the shout. So the animal evolved to stun prey A, then evolves to switch the diet to prey B. Of course, unless there's some evolutionary pressure to keep the strong stun, natural selection would then favor individuals with a weaker, more energy efficient shout. [Answer] Yes. Evolution is slow enough and proven through history that a species develops natural protection and survival. Millions of years of acoustical evolution would undoubtedly lead to natural internal defenses. Thicker cell walls, stronger thicker bone structures, organic structures that are not subject to acoustic stress. I can see it happening pretty easily tho over a very long time. [Answer] Evolution favors those things that increase an organism's chances for reproduction. So for the answer to this question to be true, you have to take into account whether other things evolved to be susceptible to death via sound pressure or sound waves. For that to be true, you have to have a reason that the other organism is so frail - some advantage that this frailness gives it which makes reproduction more likely. An organism that dies from moderate to significant sound pressure waves would be at the mercy of our planet's weather system. So you need to change the weather system, or at least the micro-climate of the area inhabited by these organisms. If you only prepare a particular environment, though, rather than terraforming the whole planet, then you decrease their chances of survival outside that environment, and thus their likelihood of them surviving for centuries. All this points to possibilities, but it would seem to me that all the possible paths that would justify this would be considered exceptional and highly unlikely. [Answer] Given all the other answers before, I would like to point out that the sound would be simply to hurt their eardrums. Any sound that could FUS-RO-DAH somebody would require an amount of energy that could cause a black hole. Source: <https://www.youtube.com/watch?v=8VGDhGsYoSA> ]

[Question] [ There are many weapons that appear in fantasy that are unrealistic for use in combat, from Cloud's sword in Final Fantasy to Daedric weaponry in Skyrim. One of these (less-than-realistic, in this case,) weapons is the whip sword, a simple sword (i.e. a Katana, Gladius, etc.) that at the press of a button or pull of a lever turns into a whip covered in sharp blade sections. Obviously this weapon is unfeasible... Or is it? Could the whip sword be built and if so, how early could can it be built and how effective would it be to use in combat? [Answer] In my experience, the effectiveness of a weapon can be broken into four different categories. These are **Ease of Construction**, **Lethality**, **Required Skill**, and **Usefulness**, each being more important than the last (usually). **Construction** I think anyone who has every played Soul Caliber has thought about building one of these Whip-Swords, or maybe that was just me. Either way, it seems quite difficult. Normal swords aren't difficult to manufacture (we'll see what kind of debate *that* statement sparks) but they do require some level of skill. A truly exceptional blade would require a master smith to produce, but average blades can be made by less skilled craftsmen. Our whip-sword is likely going to require the master no matter what quality weapon we want.\*\* The mechanisms inside the hilt that allow for the whip to be released (and retracted?) are going to be mildly complex, and the fastenings involved with the cord and the blade segments will require a fine touch. With practice this weapon may become easier to manufacture, though, and it would not be impossible, so if the weapon were truly superior to the easier-to-make weapons, it would be worth the time and effort, which brings me to my next point. **Lethality** Most weapons kill or wound their targets, and the methods behind this vary greatly (arguably the most-studied thing in history!). As a sword, our whip-sword would be like any other but as a whip this weapon will either bludgeon/hack at the target or slice the target depending on the weight of each segment, the orientation of the blades, and the speed of the swing. Hacking and slicing are both pretty familiar, and both are fairly lethal in their own right. Hacking in particular is lethal, brutal, and effective, but slicing requires more finesse to be fatal, which brings us to the next category. **Required Skill** Here is where things get dicey. A weapon can be super lethal, but if no one knows how to properly use it the weapon will never be used. An excellent example of this in history is the crossbow vs. the longbow. Crossbows were inferior weapons by all rights, but they replaced longbows in many scenarios because the training required to become a proficient longbowman is extensive, while pretty much anyone can fire a crossbow. The whip-sword will likely require immense training to be a truly deadly weapon; much like nunchaku, an untrained person would likely hurt themselves or their allies rather than the enemy. Normally this would mean the weapon was impractical, but there are examples where this isn't the case. Longbows remained in service for quite some time because even though crossbows may have been easy to use, the longbow had many practical advantages over its competitor, like longer range and faster fire rates. And thus we come to the last point. **Usefulness** All of the above categories serve to support this final category. No matter how easy to make, lethal, and easy to use, if a weapon has only one single, specific application it will not be an effective weapon. Our whip-sword would seem to have two possible applications. The first is simply as a sword, and we know how those are useful already, though the whip-sword might be slightly less effective than a regular sword on account of the weakness of the joints between segments. The second is as a flail-type weapon. Depending on the length of the whip, the weapon might be useful at medium range. If the weapon allows the blade to be retracted back into a sword, these two applications might combine rather well, allowing the wielder to engage the enemy at longer range until they close at which point the enemy could be engaged with the sword. The whip would probably be dangerous and ineffective while fighting in a melee or in a battle line, but the sword function remains. It could also be effective on horseback, perhaps, though I shudder to imagine what would happen in imperfect conditions. What's truly important here, though, is that warfare is a famously fickle beast. The set of possible scenarios is probably uncountably infinite, and if someone were to think of a situation where the whip-sword were especially useful that could make a huge difference. **Conclusions** So where does that leave us? Compared to the sword, the whip-sword would be more difficult to make, about on par for lethality, *far* more difficult to use, and would be applicable in slightly more scenarios. But would it ever be used? That's debatable, but it definitely *could* be used, and I feel like that's the important part. -- \*\*You also asked *when* this weapon might be built. If we wanted the weapon to be able to retract back into a sword then I'd say probably the early Renaissance, though I'm no expert on such things. The metallurgy existed for the construction, chain or wire existed for the cord, and a simple release mechanism could be built using Roman-era technology. The retracting would require a spring, however, and coiled springs did not appear until the 15th century. [Answer] While not exactly what you are describing, flexible blades (or sharpened steel whips depending on how you look at it) are a thing that have existed and have been used in combat. The most notable of which would be the [Urumi used by the Elite Rajput warriors](https://en.wikipedia.org/wiki/Urumi). They are relatively primitive weapons and not really designed for armor penetration so much as dismemberment. They have existed since Mauryan Indian and as such they should be easily feasible for most medieval cultures. If you want a mechanical mechanism where a blade goes from rigid to whipped, that will be harder but should be possible with early renaissance technology. [Answer] The "whipsword", in theory, should be feasible to build, but using would require a lot of practice. In fact, I've designed this on paper once, but didn't have the resources to build and test it at the time. I'll redraw and share the design here now (Using semi-gladius shape as base): In the locked position, it would look very much like a normal sword, but with small lines separating each individual section (See Figure 1). [](https://i.stack.imgur.com/D4ZoW.jpg) A button could be placed on the bottom of the handle in order to "lock"/"unlock" the weapon. This button could also potentially be designed as a trigger where the index finger is placed - in fact, how the mechanism is activated is almost completely up to you as the user. What this "activation" would actually do is simple: When pressed in the locked phase, it releases the lock on a spool of wire, allowing the pieces of the sword to extend and flex outwards (See Figure 2). [](https://i.stack.imgur.com/QIw40.jpg) Each piece of the swords would be designed to allow the wire to run through it - with the exception of the tip piece, which would secure the end of the wire (See Figures 3 & 4). [](https://i.stack.imgur.com/mkDNT.jpg) [](https://i.stack.imgur.com/LeBzq.jpg) In order to help align the sword pieces properly when retracting the wire, instead of using a circular wire, use a flat piece of metal, aligned perpendicular to the edge of the blade (Refer to Figure 3 & 4). By using the flat piece of metal, you can help "influence" the direction which the blade will flex in. Since it's aligned perpendicular to the edge, the blade will be inclined to curve in 2 specific directions - the edge directions, which helps to allow for easier slashing using this weapon while unlocked. When the button is pressed while the sword is in an unlocked state, a motor is activated, spinning the spool of wire and pulling the sword back into a straight state. Normally, in order to keep the sword pulled taut you would need continuous force from the motor - however, if we add an extra locking mechanism into the handle/cross guard to keep the sword taught, we would be able to save energy (be it batteries you're using or magic) (See Figure 5). [](https://i.stack.imgur.com/d7tQe.jpg) Based on this design, the earliest you could build it would be whenever your story first creates motors and has access to some basic circuitry - rope could replace the thin metal wire if your society does'n't have that yet. Would it be unsuitable for combat? That really depends on how well trained you are with the weapon. Is a pencil unsuitable for combat? Normally not, but with a bit of creative thinking, the Joker has proved to us that even a pencil can be a dangerous weapon. (Now excuse me while I go and scavenge for parts to build this thing) [Answer] The quality of metallurgy to create flexible cables was not present in the medieval period, so real medieval weapons with flexible components used leather or chain. A hollow blade structure with a chain through it would be quite large and heavy. A blade with a leather or fibre rope through it would be hard to keep together tightly as the rope creeps and expands or contracts with humidity, and prone to being severed if another blade came between the segments. Note that while flails existed including ball flails, and whips with light cutting blades scourges on them, heavy spiked balls on chains and other such weapons are fantasies which would be very hard to use without self harm. Also the weapon would fail to work as a sword except for light draw cuts. Thrusting swords require a high degree of rigidity to punch through armour. Heavy cutting swords rely to a large degree on the harmonics of the blade to transfer energy to the target and not the wielder's hand ( there is a node at the hand, a node at the target about 2/3 of the way along the blade, and antinodes about 1/3 of the way along and at the tip - this is called finding the percussion point and if you don't do it when hitting hard, it bounces off and you drop the sword or sting your hand). [Answer] As with all weaponry, context is everything. How do you intend to use this and against what kind of opponent? Single combat or against groups, with or without your own companions? This would not be a very effective weapon. The blade would be too weak as a sword and unwieldy as a whip (keeping blade alignment as a whip would be impossible). You could possibly use this in sword form as a slicing weapon for push or draw cuts against unarmored opponents, but the added thickness to the blade from the requisite internal cable would inhibit effectiveness. Chopping would be more appropriate to thick heavy blades, but segmentation would render the blade too weak and risky - likewise stabbing would need to guarantee perfectly perpendicular alignment at contact with a stationary target to reduce the probability of damage to the sword (or the blade just flopping over if the force of impact exceeds the tension on the whip before the strength of the armor). As a whip, it *might* intimidate inexperienced raw recruits frightened of the novelty. If fighting alone against multiple unarmored opponents, a whip with blade segments distributed along it might keep them at bay for a short period of time. It couldn't be expected to do more than superficial damage to unarmored opponents as it cannot put consistent force behind the chunks of unaligned blade on a rope, which rather limits its usefulness in a martial application. A slightly more plausible construction would be a solid blade until close to the tip, which is then like a single weight at the end of the whip which extends out the end of the blade. More of the blade would increase effectiveness of the whip with greater weight at the end (this is really a flail rather than a whip), but increase the structural weakness of the sword (anything farther from the hilt than the point of separation is not structurally reliable). The best placement for separation would be just beyond the point of impact - a thick chopper with a good point of percussion would limit the harm done to the usefulness of the sword. All in all, this would never be more than an ineffective novelty. Time the release right and you might get a swing which is blocked, but the end unexpectedly flies off into the face of the enemy - if they don't have a visor down it might cause enough damage to improve your chances in a duel. Of course, then your sword is less useful having a chunk of the end hanging on a rope sticking out of it until you can manage to wind it back up (of course the silliness of having a spool of cable/rope on the pommel would be fairly ridiculous too). [Answer] This depends on how far down the spectrum of whip swords you go. The most basic is very feasible, a plain whip dotted with small light-weight blades, but not quite what you are referring to. You could certainly create a length of pipe slotted together like curvy Lincoln Logs. Add in spring-locks which disjoints the fittings and weld each section to a link on a chain inside the pipe. Likely you'll have to weld the pipe together from two parts or engineer some fancy technique. The lock mechanisms will likely need a smaller internal cable as well, leading to the trigger at the hilt. Finally you'll have to do some more welding/fusing to add blades to each section or carefully beat one side of the pipe sections into blades. With that basic concept, it would better to start off with more engineered fittings. Improved designs would, for example, have folded steel fused into a triangular-esque piping fluted to a blade in one direction. With more thought into the design of the locking mechanism and notch-work, the sword will be less likely to jam or suddenly ricochet into your face when you try a whipcrack. [Answer] In sword fights, metal swords can and do break. A fully metal sword. A whip sword, as depicted, would only be as strong as the spine. The whip sword isn't direct impact - the segments will torque the spine, depending on the length of the segments. Essentially, this would apply more force on a weaker spine made of less material. The problem with ceramics and carbon is that they are brittle and would shatter or that they are bulky - carbon is stronger by weight, but the density would result in a 2 meter thickness. Swinging weapons require too much timing. High level Kendo masters will step in to striking range, raise the blade and then strike hard enough to breach metal armor in just over 100 ms. With the average human reaction time of 250 ms, the substantial disadvantages of a swinging weapon timing would add to this disadvantage. The sword part of the whip sword is useless. The whip part is defeated by rudimentary armor. [Answer] I would suggest that it is not so unfeasible. ## Construction Let's take what we got these days: a very exact, big CNC machine which is able to create the individual pieces of the sword to very, very high accuracy so they lock into each other very tightly. Then you pass your "whip" through holes spaced "just so" and make it so it pulls the tip towards the handle very, very tightly. If you can get enough pressure, the sword will be stable enough. There are real life swords (e.g., Katanas) that are not supposed to *hit* anyway, but which do their damage in a slicing motion. This puts very little, or in the hands of an expert, almost no pressure on the sharp side of the blade (since that would nick it and make it unsuitable for slicing). So the internal cable does not need to excert inhuman pressure at all. Building it in the "olden times" when you actually had to hammer out your sword might be another issue and there was no effective way to saw/drill the pieces. I can't really see how that would work back then. ## Effectiveness It will be as effective as a Katana, as a baseline. So it depends on the opponent. If he is as armoured as the Samurai in the height of their time, you will need an expert swordsman to do much damage. But this is the same for any other sword. The effectiveness of the whip variant will be some added benefit simply because of the surprise factor. Say you are fighting against someone who is an expert in Katana-style fighting, then he will be quite unprepared against a sudden whip appearing out of nowhere. Useful applications would be to choke/strangle your opponent, or to pin down appendices (say, the sword hand) while going to town with secondary weapons, at least. Of course, getting flung some of the sharp blade pieces in the face won't be much fun either. All of this happening from a distance larger than expected. [Answer] The humble spring steel measuring tape is quite capable of inflicting injuries if you retract it too quickly; if you built a version that was a bit stiffer and had sharp edges, and a heavier tip, it could inflict serious injuries on unarmoured opponents. Or you could add sub-blades or serrations. The main advantage of the steel edged whip / weaponised tape would be a compact, concealable weapon that can be extended to hit targets out of arm's reach. It's very effective to have a sword that's longer than anyone else's. The main disadvantage is the lack of stiffness. Even one of the segmented solutions others are talking about would not be as stiff as solid metal. That would make it hard to parry with and risky to maintain any kind of 'guard' with - as soon as it bends your opponent can attack. It would also not be very durable; spring tapes are easily kinked at which point they stop retracting properly. Again, segmented solutions would be vulnerable to damage to segments. The other disadvantage would be unpredictability; without careful training such a weapon could be almost as dangerous to the wielder as the opponent. [Answer] I think it would be quite possible to make today, but rather difficult to construct with early technologies. I've done some pondering and to me it seems the hardest part in constructing this would be having the segments stay apart from each other and not just slide all the way to the end of a wire, once the mechanism is released, due to the momentum of swinging it. It would have to implement some sort of locking mechanism to keep the segments apart. And i think i have figured just the thing. This is a rather crude mock up. [](https://i.stack.imgur.com/AsKUs.png) This is a single segment that would be in the default state, each pin (red) is pushed into the segment before and after with a spring (purple). the wire (black) is locked into the left side pin and looped around the right side one, like a pulley.The first segment's pin could be magnetically locked into the handle of the sword, or else wise if using earlier technology.[](https://i.stack.imgur.com/tYMMJ.png) when the locking mechanism is released the sword when swung would then be able to extend using the extra wire between the pins moving them like so. The tension of the springs would have to be high enough that the sword would return to normal shape after a swing, but low enough that the momentum of the swing would separate the segments. As for ease of use and effectiveness, maybe if you are a skilled swordsman fighting against and unarmored peasant. But anyone with combat training would just bat the thing aside and stab you. Fancy and cool looking, but not a feasible weapon. [Answer] This is useless as a weapon. Can it be built using modern technology, probably, the problem is it will be fragile and useless as weapons. As a sword it is useless at best suicidal at worst. Joints in a weapon are bad especially a rigid weapon like a sword. Even more so if these joints need to mechanically rigid in any directions(as opposed to a simple chain), which this does if you want to keep the only sharp edge pointed at your target. As a sword this thing is not a sword it is a sharp spring club under perfect conditions. it is pile of spraplel under most real conditions as the joints are subject to a great deal of shear strength and making them stronger just increases the stress becasue they get heavier much faster than they get stronger. joints like this will quickly fatigue until they fail, and a weapon that breaks while you are using it is worse than useless. Mechanical joints in rigid weapon are a problem waiting to happen. Think of it this way even professionally made swords, made of a single solid piece of metal (thus as strong as you can make them) bend and can even break in combat, joints result in the same force being applied to a much smaller piece of metal, expecting it to withstand this force is unreasonable. You can't even rely on low impact blade techniques (like the japanese created to compensate for brittle swords) since these rely on a long smooth rigid cutting edge this cutting edge is weak and has gaps which will snag. As a whip it is a clumsy fragile chain whip. Keeping the edge aligned is largely impossible, the only way to do so would increase the number of parts immensely which just creates more places it can fail. So you are only hitting the enemy with the edge accidentally. So really it is a flail, an unweighted flail. A segmented weapon would be comparable to a chain whip or flail both of which rely on a mass at the end to generate force, since there is no leverage, a whip sword does not have this, the whole thing can't weight more than 3-4 lbs(assuming two hands) so it is more like striking with a loose light chain by itself (albeit one with some sharp edges), which is not an effective weapon. And again it has to be full of mechanical parts to retract so there are a lot of failure points. Urami are strong enough to use becasue they are one solid piece with a continuous cutting edge (so it can't get stuck), and even then they are very unwieldy and not very effective as weapons. [Answer] Personally, the idea of judging a tool by the idea that "no one will know how to use it" is a bit unjustified. After all, many new tools are being made today, and the company that made them dont seem to think "oh, this is something that no one knows how to use, we shouldnt make this". If that was the case, people would never have to learn how to operate a new machine, or be tought how to use a new type of gun. On top of that, can you imagine how easy it would be to throw someone off-guard with a weapon/tool like a transforming sword-whip? Think of it this way: You: *has the sword* Robber: *has a knife, coming towards you* You: *swings your sword and releases the whip function, striking his legs while being at a safe distance away from his range-of-attack, immobilizing the robber* Robber had no clue that your sword could do that, and couldnt reach you before you could reach him. Or: Robber: *steals your wallet and turns to run* You: *before he could get out of range, swings the sword and whips him in the legs* He thought he could get away from you, but you got him in the legs first. A shock&awe type deal. Cause it looked like an ordinary sword/machette. Another use: You: *walking in the woods, carrying your sword. Too many thorned brances or bushes in the way? Step back and whip yourself a clearing* The whole "no one will be able to learn how to use it" is completely pointless to think about. Because practice and training is what teaches people how to use something new. Also i wouldnt expect someone to need anything more than a 5-6 foot long whipblade for typical use. Now, in terms of construction, i believe that there are multiple ways this could be done, however i believe the most effective would use some kind of pressure-catch system. By that i mean it would make sense to have a mechanism that sticks into each section of the sword blade when retracted to its sword mode, as well as a multi-cable wiresystem, to keep the blades aligned, And incapable to twisting beyond retractability. A set of metal cables also seems like the best option. Additionally, i think a torsion-spring powered cable spool retraction mech would be a good idea, as well as a catching wheel (much like what are used on some flatbed trailer straps) that will keep the blade cables held firmly to keep the sword blade from separating in battle, and a trigger that will release the toothed catching wheel when pulled. ]

[Question] [ A tad bit late perhaps, but the creation of Gwent in The Witcher 3 PC RPG game has got me thinking: would a modern trading card game(hereafter referred to as TCG) like Magic: The Gathering be able to catch on and be commercially successful in the Early Renaissance period? If not, what do I have to change to make it work? To be more precise, the setting would be heavily based on 13th to 15th Century Europe. The people behave like you'd expect them to(similar levels of education, no change to human nature). No magic exists; this point is negotiable though I'd think wizards would not get directly involved in any way for a host of reasons like salty players blaming everything on them. The exact mechanics and theme of the game don't matter so long as it runs on the TCG model, roughly meaning cards of varying rarity, buy 'booster packs' to get rarer cards or get them directly from a trader or win them in prize matches. EDIT: In order for any product(especially one that is revolutionary or unprecedented) to be commercially successful, the society in question has to be able to accommodate it(I'll call this 'cultural success'). If not, said society has to change to allow for it. Once said product hits the market it in turn usually changes society as well. A real life example of this would be the advent of consumer personal computers(PCs). Some might disagree with me, for the purposes of this question I don't see any way to decouple the two kinds of success. This is why my question isn't solely about the commercial aspects of a TCG enterprise in this time period, but also the surrounding cultural/social/political obstacles(if any) inherent in such a world and how I can tweak this world to allow for TCGs to succeed. I was alluding to this when I mentioned 'catch on' in my original question, but it seems I need to state it explicitly so I have now. It's also why I went with 'viable' rather than 'economically viable'. [Answer] ## Almost impossible. Issues: ## Production Production is going to be expensive. Either the cards are drawn by hand, or you have to produce some plates for every design to print them (and in this last case, forget about colours). You will not get those cards on nice, plastified cards, but in more fragile (and susceptible to wear and tear) paper or parchment (even more expensive). There were card games, but the designs were way more basic. ## Market Very few people have money to pay for such an expensive entertainment. And on top of that, this is a "social" entertainment, one set of cards by itself is useless if there are no opponents around. And by "around" I mean "near", traveling 50 km for a match is not a one hour travel by car, it is a couple of days of travel (including a considerable risk of robbery or worse). ## Complexity There are the descriptions in the cards, the game manuals, an official organization. There are wikis, forums, even a SO mostly devoted to explaining how the game works, *and people still have doubts*. How do you plan on getting your players informed about how to play the game. Yes, I get that you could say "once they buy the cards I no longer care", but if the players find the game too complicated or become frustrated because everyone understands the rules differently, they will not induct more users to the game. ## Intellectual Property Ok, I was wrong about all of the above, and now you are the only producer of a successful game. Except that you are not. Because right now, everyone with the basic skills needed to reproduce your cards (or create new ones) is already undercutting your market. Intellectual property laws were not "a thing." If you did make a living by producing intellectual property it was because you were employed by some rich noble, not because you were getting royalties. This is the worst issue. Even in the 17th century, Cervantes was complaining about how unauthorized copies and sequels of Don Quixote were being freely printed. **TL/DR** Maybe you could popularize the game if you spend enough resources on it, but it is highly unlikely that you would ever recover your expenses, let alone make a profit. [Answer] **First Off...** The ability for something like magic the gathering to take off is mass distribution and marketing. along with a general acceptance for that kind of entertainment. Pre-Renaissance medieval times also were incredibly strict on religious doctrine, ANYTHING that would have distracted from that would have been frowned upon at minimum, if not banned outright. And this took a long time into the Renaissance period to degrade. add to the fact that most people back then couldn't read... these factors would make it close to impossible in the timeline you're wanting. **However** Art has been regularly traded since the Renaissance Times, if your peoples had a greater percentage of reading ability and the doctrine of the time was reduced, then it comes down to the maing of them... Each of them would need to be hand drawn which in itself is quite limiting. however if they were made out of wood or maybe brass, the art could be painted on afterward and the process of making them the same could be performed with a press. this would not be cheap but it would allow them to be made more practical, but they would also be quite expensive... **UNLESS** Perhaps it could have worked if it was played by the upper echelons of society. then cost wouldn't matter, the ability to read wouldn't matter. if it was the idea of a member of a royal family, they could more easily stop counterfeiting, and allow it as a way to increase their own ego, by having the one card to beat them all. but again, card wouldn't be a good base for them in this time, decent hard wood, or metal ones could though. The royalty could decree it as being acceptable to the church, and then they could hire the artists to make them, it would be unlikely for them to have "booster" packs as upper class people rarely like leaving things like this to chance. perhaps the boosters could be sold in auction. then it would be almost like gambling ad well, another popular upper class past time. If the royal family organised the tournaments then it would encourage its popularity. they would also be able to offer better prizes, and those prizes could be some booster packs. also possibly the rare cars could easily be gilded with Gold, or silver. making them even more sought after. **Conclusion** probably not possible, but could be made possible with creative writing [Answer] Instead of trading cards (which as others have pointed out would either be expensive to produce or easy to counterfeit, and would not last long either way), why not try: ## Challenge Coins If the coin of the realm were somehow standardised to a modern-style system, divorcing the value of the coin from the value of the metals used, you could have the ordinary currency depict the current ruler on the "Head" and the value of the coin on the "Tail". Then you could have a feudal system of nobles with Duchies, Earldoms and Baronies each minting their own 'Favour-Coins' where the value of the coin is replaced with their own motif. The manner of collecting them would be to earn the trust of a noble who would present you with a Favour-coin to cash in at a later date. Such a coin may then be presented in exchange for consideration by that (or another) noble in any matter that may come up; for example, a Farmer who previously presented the noble with his best calf for a feast may have had a bad harvest, and might wish to pay less taxes for one season until he could grow more crops. ## The Game A simple chess- or checkers-like game using regular coins as pawns and the Favour-coins as higher-ranked pieces could be devised, leading to an outcome closer to a Table-top Miniatures game rather than a card game, but still with the "Gotta-collect-them-all" incentive. Taking the chess example a little further, captured pieces may also be kept by the winning player. Merchants who gain duplicates of a far-away noble may be willing to trade with others who are heading in that direction for coins from a more local noble. Some, who find themselves particularly good at the game or are simply well-favoured by many nobles, may even set up shop trading exclusively in Favour-coins. Of course official tournaments or tasks sponsored by a given noble may have Favour-coins as part of the rewards. [Answer] # Base it on Tournaments You have some institution where wealthy people gather—perhaps a casino, but maybe a church, university or social club—develop and sponsor the game, including commissioning the official cards and rulebooks. The objects might not be cards as we understand them; etched wood blocks are a good possibility. If you want to enter the tournament, you need to buy (or rent) the official game pieces made by the tournament, and since all of them were made there by hand, the officials can spot fakes. If you want a copy of the rules ahead of time, so you can make a strategy or practice with dummy cards? You have to pay for it. There might or might not be rules about what you can have in your deck other than how much money you are willing to pay the house to win the tournament. When the printing press arrives (Cai Lun’s printing press without movable type was well over a thousand years old at the equivalent point in OTL.) it will be possible to make the backs of the cards exactly the same, so they are not all marked. If those are not in use, the rules probably have to make the game an open game, where all cards are known to all players at all times. An alternative is to keep hidden cards behind screens and have servants manage the decks. # Sell it to Gamblers Some cards are deliberately rare and powerful, and for the right price, might be sold or even given out to the right customer so he can be sure he will always have it to play, not his opponent. At that point, the house might start keeping the game fresh by limiting what cards are available and issuing new themes. (If you paid them for the right to bring a card to any game, you probably keep it, but maybe there are exceptions.) Other competitors might copy the game (with their own made-up cards and rules). As with the other tournaments, the house knows what artist made each of its cards and whom it sold them to, so it can easily spot forgeries. Or it might simply keep the cards in its vault and give them to you whenever you walk in. You don’t want to let the same people buy *too* much of an advantage, or else others will stop coming to play with them, but social stratification means that aristocrats will want to play with each other, not the riff-raff, and will feel the need to own a respectable deck. Especially dedicated players who invest a large amount of money in their decks get their own table to play each other, but sometimes others accept a game with them—at least they’ll get to see the unique and expensive handmade cards. (The house surely has a policy that new players get to start with good cards, so their first experience with the game isn’t miserable.) If someone powerful gets some great cards and wins over and over, that at least keeps them happy with your establishment. Besides, as long as they come in the door and pay to try out your latest cards for a week, or buy their lucky card, the house wins regardless of who takes home the pot. An example of a rule meant to ensure the house always takes its cut: if you win the pot with a card the house lent you, you either pay the house rent on it, or you may buy the card on the spot. # Play it at Home People might start commissioning their own cards and playing each other at home, If social roles are anything like the real world, this is especially how women would play, so perhaps the game played by noblewomen entertaining guests evolves into something different from the game played by gamblers in casinos or men in tournaments. (In your world, social roles on how noblewomen are allowed to socially mix might of course be looser.) An aristocrat would not want a reputation of being a poor sport with her guests! And often, you want the person you’re entertaining to win. So, the home version has an incentive to keep a level playing field. This game probably lays out for display all the beautiful, expensive cards the hosts had made for them, has all players select an equal number of cards from those, and gives the guest player the first pick of them. In the common case that two married couples play each other, lady guest first, then hostess, than gentleman guest, then host, round-robin. The servants then arrange the decks and shuffle them. # Maybe it Catches on If there’s a reasonably-standard set of rules, it might be possible for people to make and bring their own cards to play each other; you can’t just draw your own Black Lotus because everyone knows what the real cards are. It might also be possible to show your decks first and have the players or a judge decide whether they are reasonably fair. Otherwise, the model the game probably follows is the guest-host convention: the “host” brings enough cards for all players to build a deck, and the guest gets first pick. Perhaps a competitive match involves each player taking turns as the host. An important part of the strategy, as the guest, is quickly analyzing the cards the host presents and deciding which to choose and which are traps. The tradition of being a good host and a good sport remains important—as a way to trick the marks. Sharks love tricks like copying a well-known card with small changes to the wording that the guest won’t notice until you point them out in play. And it’s a mistake to agree to play anyone who’ll lawyer any card in the game unless you have some way to force him to accept a fair ruling. [Answer] **Wizards**, you said? Set up ye olde magic system so that it's based/allows for use of **magic invested cards.** A wizard can cast a fireball, sure, but any rogue with a fire card can use it to shoot a fire arrow. Shame about the card being destroyed/nullified in the process, but hey – you can always buy/win more! Play on! The rarer the card, the better/greater the magic invested in it. **Playing by official rules is required to retain the magical investment**, but there will always be loopholes and scoundrels looking to exploit them. Mind you, arguments about cheating in your game can get pretty heated :-) "Anybody up for a game of G... \****building goes up in a lightning storm*** \* ..?" [Answer] In medieval times paper was unknown in many places, parchment too expensive. But I would contend that people have been making game pieces from wood, stone, and bone for as long as there have been people. Wikipedia says the Vikings played these games until chess came along in the 12th century: <https://en.wikipedia.org/wiki/Tafl_games> Senet is from ancient Egypt: <https://discoveringegypt.com/ancient-egyptian-game-senet/> Then of course there is "Druids and Dicotyledons": <https://xkcd.com/593/> ;-) **Medieval TCG** This large population follows a polytheistic religion. Each temple is devoted to a different god with varying aspects and rituals of worship. But the unifying thing that ties this diverse people together is the ancient practice of "gaming". When visiting the local temple on feast day, everyone in the village is given the local "starter pack". A handful of intricately carved and painted, totems and symbols for use in the worship of each person's deity of choice. The priesthood teach the rules and ensure a certain amount of consistency in how the game is played. During festivals, rest days, or early winter nights, old and young can be seen, seated at a table worshiping and playing with the tokens and dice. The games are one part religious devotion, the rules taught by the priesthood, and part social fabric. The shared experiences and activity bind people together in friendship and family. Devotees make pilgrimages to far flung shrines and are rewarded with exotic souvenirs to add to their collection. Traders from afar bring never before seen advanced collectibles that totally unbalance the local games and turn into a rush for the latest and greatest religious symbols (and cards), until the priest weighs in, releasing a new token to keep the local deity in charge. The relative powers and abilities of individual cards would vary widely from region to region. Charlatans and con men would try to sell knock offs made in the back woods and that practice might be totally acceptable in one region while gross blasphemy in another. Some people play with what they have, and house rules are adjusted accordingly. The most devout only play by the rules of the priest and with "blessed" playing tokens. Children make their own crude imitations out of sticks and stones. The basic rules are pretty consistent across the world. The differences ebb and flow with time and place and people keep playing. [Answer] Adding to other answers, I want to point out that scarcity of resources makes it unlikely that 14th century people would get swept-up in a collectible card game. Collectible card games are not only a luxury, but a particularly wasteful one designed for people who either have plenty of disposable income (or don't, but fail to allocate their limited income in responsible ways). When I say that collectible card games are wasteful, I mean that there are plenty of Magic: The Gathering players who purchase 5,000 - 25,000 cards over the course of their playing, and sell them back to dealers sometimes 5,000 or 10,000 at a time. The very nature of randomized booster packs and stratified rarities guarantees that you will open certain cards (commons) significantly more times than you open others (mythic rares); and that goes double for a particular common that you opened more copies of than the other commons, contrasted with the mythic rare that you opened the least copies of. Having to obtain lots of useless duplicates of a particular common just to open a particular mythic rare is a form of waste (both the physical resources, as well as the labor that goes into producing them by hand without industrial methods). Can a Medieval society afford to mass-produce a bunch of common cards that don't even get used? Don't they already have enough scarcity problems related to the production of food, clothing, wagons, shelter, etc.? Can they really afford to waste large shares of their productivity on trifles like useless, excess commons? This is much different resource-wise than making a one-time purchase of a chess board or a pack of Bicycle playing cards. If you want this kind of thing to exist, and you want it to be realistic, you need to provide for... * A way of recycling / reusing the useless extras. For instance, if they were printed on arrows, slingshot ammo, or patches of cloth that can be used to make quilts. * If the stratified rarities were not all contained in the same booster pack. For instance, if you traded-in your extra commons (to the vendor), plus some additional money, to buy an uncommon pack. Then you later traded-in your extra uncommons, plus some additional money, to buy a rare pack. This system would also help solve the recycling and mass production problems, because then the vendor could resell your traded-in commons instead of producing new ones. * If the uncommons and rares were simply an upgrade that was added to a common, then this could help with production and recycling issues. For instance, if you trade-in 40 commons with the vendor, and he then initials a common, then the initials could give it a +1 bonus. If you then trade-in 40 uncommons to the vendor, he could write his signature on it, which could give it a +2 bonus. * If you trade-in 40 rares, then the vendor could add a super signature and stamp, which could give it a +3 bonus. All of this could slightly mitigate intellectual property concerns, because the higher-valued cards would all have authentic signatures from the vendor, and the lower-valued cards would not be worth counterfeiting. * Another unlikely way to avoid the uselessness of excessive copies of commons is to allow as many duplicates as you want in a deck, and reduce the downside of large deck sizes (for example, I've seen card games where damage taken results in discarding cards from the top of your deck, and you lose when you run out of a deck, so larger deck size is better). If you do this, then quantity really prevails over quality. In order to ensure that card quality is still important, there would have to be clear, not subtle, power level differences between rarities. [Answer] A type of card game using a system similar to a TCG is possible, but having official rules, booster packs, etc, is not likely at all. [Tarot cards](http://mentalfloss.com/article/71927/tarot-mythology-surprising-origins-worlds-most-misunderstood-cards) were originally made on wooden blocks, and they had several different purposes. Italian nobles used them for a game like Bridge. Other Italians would choose a card at random and use the imagery to create poetic verses about another player. Well this is less certain, it is believed that tarot cards were also used in story telling games. Pick a card, make part of a story using that imagery, then either pick another card or someone else does. Before tarot cards became intricate divine instruments they were simpler and easier to understand. > > Caitlín Matthews, who teaches courses on cartomancy, or divination > with cards, says that before the 18th century, the imagery on these > cards was accessible to a much broader population. But in contrast to > these historic decks, Matthews finds most modern decks harder to > engage with. > > > So, if some really bored soldiers got a hold of a cheap tarot stack, they could develop a game using the imagery. It would be fairly simple, each person picks several cards at random, and they assign different values and affects for each card, trying to stop or trump their opponents. If it was easy to follow, more soldiers would get involved, figure something a bit simpler than original magic, draw a card, put a card down, do a spell/prayer, attack and defend. If it got a couple of people interested in the initial game it would spread relatively quickly. The rules would change by the group, but they'd follow the same basic principals. Soldiers would have the time to carve their own tarot cards out of wooden blocks, so production wouldn't matter too much. The basic figures would remain similar, so it wouldn't take more than a brief talk to figure out which card was which. Better made cards would be sought after, although probably rarely used to keep them safe. As players interact they'd bring in new cards, new ideas and rules. When soldiers settled down, they'd also spread the card games in their villages and towns, spreading it even further. ]

[Question] [ Let's say you have a culture which is pretty much like ours, except honesty is the highest virtue. In particular, being honest about something is *always* better than being dishonest, no matter the consequences. * It has been like this since the beginning of time as long as the people are concerned. They have thought this way for two millennia to say the least. * Honesty does not mean you have to answer every question. That virtue is called *openness*, which is seen as related to honesty. Openness is the equivalent of kindness. Although people think highly of it, it does not necessarily need to be followed. + For example, people would be fine with the NSA's activities since it is about the public being open for the most part, but would find it hypocritical that it is so secretive itself. * Honesty extends beyond simply not saying things that are technically false; it is a whole philosophy. Anything misleading is seen as wrong. * People are considered enlightened when they can be completely honest with their own being and society. Moral figures try and encourage society as a whole to be honest with itself. + There are doctors in honestology who study honesty for a living. + Where as we have philosophical problems like the [Trolley problem](https://en.wikipedia.org/wiki/Trolley_problem), they have problems like the *malignant hearing aid* (if someone had a hearing aid that causes everything heard to be the opposite, should you lie to that person so they hear truth?) and liar in a forest (if someone lies in a forest and no one hears it, is it still wrong?) * Advertising is seen as dubious at best, as it often violates both honesty and openness. Advertising is seen as similar to how we view [usury](https://en.wikipedia.org/wiki/Usury). * Punishments in society are no more or less harsh than our own. Also, just because honesty is the highest virtue doesn't necessarily mean the lying is punished the most severely of any crime. It is punished rather severely as far as crimes go though. + That said, honesty is always considered morally the best regardless the situation, even if it means the loss of your life or others (whether you should be *open* is debatable though.) + In the past they would cut out your tongue. + Serial liars are considered criminally insane. + Stories often involve a villain coming into town and spreading lies. The hero is then essentially a detective, figuring unrevealing the complex net of lies, and finally revealing the villain and cutting his tongue out. The other type of story is where a society is lying to itself on some issue, tries to reveal it, is considered a liar, and then has to fight society. + More sophisticated stories in the modern era have the villain somehow become mute due to his own lies indirectly; that way, the hero does not have to do it. This society seems pretty good. Particularly, society being honest about itself would go a long way to solve a lot of problems. What **problems** would a society like this have? [Answer] Here's what goes wrong. The more honest "everyone" in a society is, the more they trust each other. The more they trust each other, the easier it is for someone who is not "everyone" (i.e. a dishonest person) to prosper. So an excessively honest society has no societal immune system against being taken over by liars and cheats, and is destroyed from within when such individuals or groups arise. At the other extreme you have a deeply corrupt and dishonest society where there is little trust, and a huge amount of time and money is spent protecting oneself from everyone else. Such a society will ultimately be out-competed by one with higher moral standards. Indeed, one effect of such a society is the weakening of large-scale society in favour of smaller sub-groups within which there is a greater degree of trust: families, tribes, secret societies. One of these eventually grows powerful enough to "sweep the stables" ... and the cycle starts again. Game theory suggests that there is no position of stable static equilibrium, but society manages itself to maintain a dynamic quasi-equilibrium. For example, I have read that credit-card companies balance the amount they are losing to crime against the amount that their precautions against crime are costing them. Spend less on precautions than the criminals are costing you, and not only are you losing, but you will attract more criminals and your losses will escalate. But spend many times more than you are losing, and it's profit foregone. So spend enough to prevent losses to crime from escalating, but not so much as to hand a financial advantage to your competitors. For further information Google "forgiving tit-for-tat". [Answer] The obvious problem is that hearing the unvarnished truth can hurt horribly. When I was a teacher pupils sometimes used to tell me their ambitions. Because I don't live in your super-honest society I would say something mildly encouraging. Sadly many of the children who confided in me were of below average intelligence and/or below average good looks. The nearest I got to honesty about their prospects was attempting not to get their hopes up too much and trying to flag up the appeal of of non-material satisfactions that anyone can achieve. In your world a conscientious teacher would presumably say, "No, little Xzpkk, you will never be elected to the Planetary Council as you are mildly mentally disabled. Nor are you likely ever to find love in a mating trio, as with tentacles like that no one would ever want you." [Answer] I think the issues will crop up in the education sector. When first graders are asking, "Why do we cross out the zero when we carry the one?", the teacher may be obliged to give them a full, honest, *confusing as all heck to a first grader* explanation of an algebraic concept. It's useful to be able to teach "it just is," but in this society teachers wouldn't have that ability. "Gravity makes things fall" might become "the Higgs field interacts with particles to give some of them mass, and mass warps spacetime" which, while truthful, is not very helpful to your elementary school students. Genius kids would thrive. But other people? "Education inequality" might become more and more of a thing, where people who are able to understand the teacher's jargon would be praised as "gifted" while "non-gifted" people would be put into classes where they're taught basic laboring skills. Liberal arts, like science, math, history, and literature, would be for the "gifted"… and also for the rich, whose paid-for tutors might be willing to warp the truth in order to ensure the child understands. The upper class/lower class divide would be decided very early, and I imagine that while the "lower class" would hate those in the "upper class", anti-intellectualism might not translate into actual bullying, especially if the different schools are segregated completely once in high school. Debate – [Policy,](https://en.wikipedia.org/wiki/Policy_debate) [Lincoln Douglass,](https://en.wikipedia.org/wiki/Lincoln%E2%80%93Douglas_debate) [Parliamentary,](https://en.wikipedia.org/wiki/Parliamentary_debate) etc. – would have to change. In its current form, you don't really get to decide which side you're on. In Lincoln Douglass, for example, you're on one side of a resolution. Right now in the National Forensics League, it's **Resolved: In the United States criminal justice system, jury nullification ought to be used in the face of perceived injustice.** You're assigned a side, and you switch sides every time. Usually what LD debaters do is construct a case so that they promote roughly the same value on each side... but in this society that would undoubtably be considered a form of dishonesty. It probably wouldn't happen. It's a small thing, but as a former debater, it seems like something I ought to mention. Friendly debates often have one person playing devil's advocate, and that could be construed as a form of lying, or else it would begin with a disclaimer (which would inevitably weaken whatever arguments followed). I'm also trying to figure out how elections would work. Politicians don't always lie, per se, but they have to be misleading. Do you honestly think *every* Republican is pro guns, pro death penalty, anti abortion, anti immigration, and anti environment? Much of what they say in elections is staying behind party lines in order to ensure their support. The only way to tell their true alignment is by seeing what they've actually done while in office. Things might be a lot less partisan. Or they might be worse. Sometimes you have to make concessions that you don't necessarily agree with in order to negotiate with other people. As such, politicians would be entirely loners, eternally unwilling to form coalitions and negotiate. Considering how broken their education system is, a working government would probably be in their best interests, but it doesn't look like that's an option. [Answer] Fighting, from warfare down to one on one brawls would be difficult given how important feints, deception and misleading one's opponent is. This may be considered a benefit rather than a problem, but it becomes a problem when you need to protect yourself form people who don't share your values. Are there circumstances where you're allowed to be out of character for the sake of entertainment? If taken to an extreme life might also get quite boring because competitive games and sports would be limited. A simple running race would probably be fine because it doesn't require the competitors to mislead each other, but chess requires a certain amount of deceptiveness. In the strictest sense fiction and drama are dishonest. [Answer] [This American Life did a radio segment on "honesty"](http://www.thisamericanlife.org/radio-archives/episode/552/need-to-know-basis?act=1#play) with a young man who had grown up in a family that believed that honesty was always required. Not only did they believe that honesty was required when asked, but honesty was required to be volunteered, as in: > > "do you notice that you're very controlling?" > > > In this way the young man was going beyond (negative) honesty -- restricting his output to only truthful statements -- to (positively) providing what he thought was useful truthful input. The mistake he was making was the result of not "reading" people and telling whether the information he was providing was welcomed. If he had the ability to read people well, he could provide a filter to restrict unwanted conversation. As [Lostinfrance](https://worldbuilding.stackexchange.com/users/9207/lostinfrance) says, a significant limiting feature is "feelings". At one point in the segment he basically said that: > > a world of perfect honesty is a world with no feelings > > > His parents believed so fully in openness that they held public family meetings with a therapist in which they discussed (and argued) over the the issues that resulted in their divorce, including his mother talking about the reasons she felt trapped in her marriage and why she was leaving his father, with the new man present at the session. Is this the type of "openness" this world would like to encourage? Eliminating feelings would make this world more feasible. Barring that, a world with both feelings and perfect honesty would have to have a lot of tact and maturity. [Answer] When the idea of totally honest society is usually picked up in the media, it usually concentrates on the concept of "white lies", which are meant to spare peoples feelings. But most white lies are just there to cover for social conventions (Ever wonder how many bad marriages were cause by the idea of "true love"?). --- So here are some other questions which might provide more interesting situations: * Would a police officer be more hesitant to lie, even if it could save a live? * Would countries employ spies, if this could end a war earlier? * Would teachers readily teach "wrong" facts like "gravity is a force" when it helped their pupils with understanding a concept? * What about misleading someone out of error? Would that shine a negative light on the person doing so? Would that lead to prejudice against the uneducated? Would people hesitate to speak out if they aren't sure wether what they are saying is correct, and would this lead to demagogues and con-artist being more dangerous because people would be afraid to confront them? [Answer] Reminds me of a great book I read a while back... highly recommended... From Wikipedia The Truth Machine (1996) is a science fiction novel by James L. Halperin about a genius who invents an infallible lie detector. Soon, every citizen must pass a thorough test under a Truth Machine to get a job or receive any sort of license. Eventually, people begin wearing them all the time, thus eliminating dishonesty in all parts of human interaction, and eliminating crime, terrorism and a great deal of general social problems. <https://en.wikipedia.org/wiki/The_Truth_Machine> ]

[Question] [ If inducing long-term comas was medically trivial and safe, and ignoring potential problems with muscle atrophy or bed sores or the like, would this come to be considered the only reasonable way to jail people? Or would "experienced imprisonment" continue to be the preferred route, even if it involved higher costs, as well as risks like violence and jailbreaking? [Answer] ## Not useful, unless the sole goal is incapacitation Punishment is said to have five objectives: deterrence, denunciation, incapacitation, retribution, and rehabilitation. Let's take these on, one by one. ### Deterrence Essentially, a punishment is meant to deter the would-be criminal from committing the crime. Thus, the stronger the punishment, the more effective a deterrent, so a coma is in no way preferable when it comes to jailing people, as the only downside is coming out of the it all Rip-Van-Winkle, as opposed to having to spend that entire chunk of time doing hard work. ### Denunciation Essentially, a punishment is a public announcement that 'this behavior is wrong'. If people got away scot-free with stealing, or didn't get visibly punished, then it would seem acceptable to the bystanders. Again, with this kind of thing a worse punishment is objectively preferable. After all, a light slap on the wrist isn't going to convince people as much as taking the hand off at the wrist. ### Incapacitation The coma is actually preferable here. Incapacitation is to make sure that the criminal cannot commit more crimes, and while jail is good at getting criminals to not commit crimes against the people *outside* of jail, it's not as good at making sure criminals don't commit crimes against other criminals. A coma would guarantee that this would be the case. ### Retribution Not necessarily an 'eye for an eye' in the literal sense. Retribution is more along the lines of 'if you steal money, we take the same equivalent amount of money from you plus the money you stole'. This is more philosophical than the other ones, and is directed to right a wrong. As for this, I don't see a practical difference between imprisonment and comas, as this is usually prescribing something harmful, i.e. taking away money, killing the criminal, etc. ### Rehabilitation A punishment *also* serves to send the criminal back on the straight and narrow, as it were. In prison, prisoners are supposed to reflect on the wrongs they've done and seek to improve themselves. Now, while that may not necessarily be the case, the fact of the matter is that imprisonment is far more conductive to rehabilitation than knocking someone out for the entire duration of the prison sentence. This is also what the American criminal system seems to be built around. ## Summary There are five reasons for punishment, and 3:1 in favor of imprisonment over coma, except when you just care about incapacitation. [Answer] I think induced comas like this cause issues with all reasonable moral guidelines, utility and sympathy. *There. You deserved that!* Okay, while typing this, Halfthawed put forth an excellent answer, but I wanted to point out a particular issue on the rehabilitation side of things. 20 years ago, I had a 56k modem dialup connection to the internet. Phones were *actually* related to calling people, instead of texting them (or not even interacting with people at all!). People didn't even use their turn signals to indicate they were going to change lanes. Okay, so 1 out of 3 didn't change. Still, just think of how hard it would be to wake up after all that has happened in the last 20 years, and learn from scratch. Prison is considered by some to already be enough of problem because its too hard to rehabilitate people... now truly advance the rest of the world 20 years without them having a chance to respond. The only valid solution would be to fall back on a family they can rely on to take care of them while they desperately try to catch up. For many, this would be their family of crime. There is an ongoing debate as to whether prison leads to more prison time because you can't get out of the feedback pattern. I think putting people in a coma for that time would make it far worse. Its unlikely that that particular debate would go in the favor of coma. Anyone waking from a coma would almost certainly find themselves facing a coma sentence once again. However, I could see it reserved as a penalty for the most heinous crimes. Personally, I think of Minority Report, where basically any major future-crime resulted in you wearing a Halo, which was basically your long term coma. I can certainly say how I reacted to that particular punishment, and it would qualify as a punishment for only the harshest of cases. [Answer] Strange, but I don't see anyone addressing the elephant in the room. This is a heck of a lot like **Demolition Man**. Ok, that movie used cryo storage of inmates rather than a medically induce coma, but it served the exact same purpose. Put criminals is a position where they can't do anything at all during the sentence. Other answers all covered the reasons for incarceration pretty well and they are right in that an induced Coma would serve no purpose other than to remove a criminal from society. But in your scenario, you don't have to be limited to that alone. It's all going to hinge on how active your inmates brains can be. In a Sci Fi setting, I have often seen and read about using hypnotic suggestion or other handwavey stuff in order to implant information, training, and conditioning during some sort of sleep state. So you could use that coupled with an induced coma in order to satisfy both the necessity of removing criminals from the populace AND rehabing them at the same time. [Answer] * **Do people age with your coma technology?** Many fictional *cryosleep* technologies are supposed to stop or slow aging. If that is *not* the case, then a sentence of "10 years coma" takes 10 years of lifespan away. So does "10 years prison," but the traditional prisoner remains aware all the time. Is coma the lesser or more severe punishment? * **Loss of the peer group.** If people do not age significantly, a sentence of "100 years coma" means that everybody they have known will be long dead. (Unless they were sentenced to coma as well. If so, stagger revival times.) Odds are that many marketable skills will have become worthless, so the prisoner has to work up the social/professional ladder from the bottom. This is very much like a sentence to *permanent exile* with no way to come back, ever. [Answer] There are more fundamental legal problems not mentioned by other answers. A person convicted of a crime has a right to appeal their conviction, but person that is placed by the state into a coma can't act in their own interest to appeal their case. This probably violates the convicted person's right to due process of law. It's possible that this punishment could be applied only after all appeals are exhausted, but even in that case this could be considered a violation of the convicted person's right to bodily integrity. A convicted person has the right to refuse medical treatment and is protected from punishment that would violate that right, e.g. removal of limbs. While capital punishment is the obvious exception to this right, consider that the *only* punishment allowed to overcome a person's right to bodily integrity is punishment for a crime so heinous that the law allows and the judge sentences execution (and many jurisdictions have outlawed capital punishment due to their belief that it violates the condemned person's human rights). So, if this line of reasoning holds then the coma punishment would seem to only be acceptable if the prisoner agreed to it, or possibly if it were sentenced in lieu of execution. There's even a potential problem with sentencing life comas instead of execution - judges may see this punishment as less severe than capital punishment and be more willing to sentence it, even though we've just established that it should only be issued if the judge would have otherwise issued a death sentence. [Answer] I'll take a page from my answer to another prison-related question. Prison serves three purposes: **Imprisonment.** For people who pose a threat to society, imprisonment serves to protect said society. Here, putting people to sleep, to death, or in a confined environment works just about as well. **Punishment.** Prison strips inmates of some of their freedoms and rights. Freedom of movement, obviously. Depending on your jurisdiction, it could also include voting rights, freedom of speech, etc. Putting inmates to sleep essentially deprives them of all their rights, much like death penalty, with the meaningful difference they regain those rights in the end. That may be a little harsh still. **Rehabilitation.** A prison system that doesn't rehabilitate inmates is a system that doesn't work. And that's your problem here, you're putting people to sleep, they won't change, meanwhile time flies, society changes, and you think that returning these people to a society they won't recognise is somehow going to solve something. Basically you're giving convicted criminals the ability to time travel for some reason, when you should be trying to educate them into being functioning members of society. [Answer] I don't see any benefit to using induced coma as an alternative to regular imprisonment. It is essentially equivalent to execution, and really is nothing more than an *indefinitely paused* execution. (Part of the death sequence is to administer sodium thiopental as the coma inducing portion of [lethal injection](http://en.wikipedia.org/wiki/Lethal_injection) executions.) The only benefit to incarcerational coma is that the prisoner *can never escape confinement* without medically knowledgeable & competent assistance. Likewise, the prisoner being lethally injected can't escape his fate either. The downsides of incarcerational coma far outweigh the only benefit. You need trained nursing & medical staff to properly set up the IVs, administer the drugs and assess and care for the prisoners 24/7. Each prisoner will have to undergo surgery to place a feeding tube, though IV feeding is also a possibility. Trained nursing assistants or care techs will be required to move the prisoners every one to two hours, take care of basic hygiene routines like daily baths and tooth brushing / oral care. Every prison essentially becomes a 1000+ bed ICU. The other major downside is that victims' families never get "closure". By "closure", of course, is meant that satisfying sense of vicarious retribution that civil society grants to the victim's loved ones because they can't just go and lynch the bastard themselves. The problem here: the prisoner *never experiences a sense of punishment and is never allowed to ponder the grave nature of his crimes*. [Answer] I've said it in a comment but I think it may deserve an answer : **Do a bit of both.** The punishment in prison time is because the convict is being deprived of a part of his life. Forcing him to sleep instead of living could have the same deterrent effect (it depends on people of course but I think I'd prefer to live in prison than just waking up 20 years older, I find it terrifying). About the rehabilitation, it's rarely done efficiently unfortunately. It's not unheard of that people come out of prison with a worse mindset than they came in (I would bet it's actually the most common case). So having them sleep all along could actually be a better solution, in an absolutely utilitarian mindset. So what I would do in the end : People with sentences longer than a few years spend 80% of it sleeping. That's the punition. And then, you use the funds you saved to create real and efficient rehabilitation centers, where people only stay one or two years, to learn a craft, see a psychologist... [Answer] I agree with Halfthawed reply it would not make any sense as a type of sentence for convicted criminals. But I see a gray area where some exceptions could be found. In some countries for serious crimes like murder pre-trial detention could reach up to two years. In this case an induced coma would not be considered a flawed punishment, but just a confinement period to prevent more crimes and reduce the perception of this period in case of acquittal. But actually you can't put people in coma during their trial because they could not defend themselves. The only justification could be found in a dystopian future in an overpopulated world and overwhelmed tribunals where just waiting for the trial to start could take years. The practice could be prone to abuse so it would need a lot of phoney justifications and an authoritarian government, but still it could make sense, well, sort of. EDIT: I just realised there is another gray area. Death sentence. There could be a period of 10 to 20 years before the sentence is actually carried out. In this way should some new evidence emerge during the suspension there could be a revision of the process. [Answer] Clever clever title! Your answer lies in it, methinks. Just like a comma, i think the prisoner is getting a break in his sentence if he is fully comatose. If you approach it from a retribution / punishment point of view, the prisoner is only suffering somewhat if he is in a conscious kind of coma, aware of his position, but not able to move or communicate or interact with his surroundings. Also, life support machines and IV drips would likely also be quite expensive, along with the hospital stay - potentially exceeding the cost of the average prison membership. If you approach it from a rehabilitative viewpoint, coma is practically useless, and or negative. The prisoner is not learning any skills to better his life, nor any real mental development that could change his moral compass and attitude to being a fitful member of society again. Perhaps if he's semi conscious, the care of doctors and nurses might have a small bearing. Coming out of the coma, the prisoner would potentially be a further strain on the healthcare system too. The comatose state might also mess with his brain, leading to lack of employment opportunities. Which as we all know, can lead to poverty and desperation, then crime! If you approach it from an incapacitation perspective, a coma sounds on par with or even better than imprisonment. The prisoner here can't do anything, unless he develops consciousness and his neurosurgeon accomplices develop a system to transmit his desires out to his vast criminal network xD- very unlikely. Unlike in jail, where corruption and loose system rules still leave room for committing crimes from inside, via hiring goons, contact with outside friends, bribing guards. From a deterrence perspective, I'd say it's probably stronger than jail. For the criminals that lust for the thrilling life, being in a coma will likely be much more of a deterrent than in jail, where they can still somewhat have freedom and fun. [Answer] In a comatose state a criminal is fully incapacitated. In my opinion this would introduce more problems then solve. First of all resources are scarce. No matter where you are and which timeline you follow resources (such as food, housing, water, air etc.) are always something to consider. A criminal put into an induced comatose state would only be consuming and will never be able to produce something that others can use or profit from. **Unless you use their bodies for various purposes** such as extraction of vital bodily materials such as blood, stem cells etc. You've probably seen the Matrix film series where people are used as batteries while put into a coma-like state with their minds bound to a central system that simulates an alternative virtual existence and fed with liquefied human remains as primary nutrition source. Of course in this case a moral dilemma arises namely what sort of society would use actual human beings for such purposes. In itself, unless the society follows different rules, this is a criminal act and the justice system itself should be held accountable for it. Second reason I would rather go for "typical" jail time because, while not perfect, it does allow better use of human resources. You can use prisoners for construction work, you can use them for research purposes in order to improve society, you can educate them and - unless it's a hardcore criminal we are talking about - rehabilitation is always a possibility. Needless to say USA prison system is not a fine example when it comes to that. Third what happens if a natural or human-related disaster occurs? A conscious person can be directed to the nearest escape route, can help others etc. If you have a vegetable, you will have to use additional resource to re-locate that person. Last but not least you need to consider what happens AFTER the criminal wakes up and is returned to the outside world. Imagine "sleeping" for a decade or two with the world around you changing rapidly. Even in prisons nowadays information from the outside is hard to get but induced coma puts things on a whole new level. That person's mind would be completely disconnected from everything (unless you do something similar like in the Matrix) hence once set free that former criminal will be even more out of touch with society. This is very likely to increase the level of uncertainty in that person's mind thus leading to fear and anger. These two feelings are like putting out fire with gasoline. ]

[Question] [ On Earth, nuclear weapons can wreak enormous damage to a country and for that reason, large-scale wars between nuclear powers don’t happen. But what would happen if humanity progressed just enough to the point where countries expanded into space? Now powerful countries have fleets of spaceships (not fantastically advanced; no faster than light travel, no freak handwavium weapons; just what we might conceivably have within a century or so). Humans live scattered across the solar system, and have nations somewhat independent of Earth. Would large-scale, territorial war again become common in this scenario? Would nuclear weapons fail to pose an effective MAD deterrent effect? For the sake of a specific scenario to work with, consider two space powers, **The Selenation**, and **Arianaland**. They are both fierce rivals, and maintain hundreds of space stations scattered across the solar system. They have no strictly-defined borders, but each is concentrated in one broad area of the solar system, and have a region of space that they vaguely regard as their “territory”. They have ground colonies on large moons and asteroids, but there is a roughly comparable distribution between the “rock-bound” population and the space population. The “rockies” aren’t trapped on the surface per se; they regard moving into space as about as big a deal as moving house from the city to the suburbs. Neither country is tied to Earth, which is ruled by a third country **Lovatoland** and is regarded as something of a backwater. There are countless smaller powers across the solar system, most of which have a small territory carved out in one corner or another. The technology level is not unrecognizable from what we have today. Their ships are about at the same level of what could be built in the movie *Interstellar*, only each country has more resources to build a greater quantity of them. Travel is still slow, and moving between stations within each country takes months—it’s common, especially among members of the military, but it’s considered a “big voyage” (like interstate travel in the US in the 19th century). There is substantial communication infrastructure, and the internet exists, but it’s somewhat balkanized due to the fact that it takes up to an hour for signals to make the jump between “clusters”. Would Arianaland and the Selenation be quick to go to war with one another? Would we see something similar to the perpetual battles between Britain and France in the 18th and 19th centuries, only played out in space instead of at sea? Would nuclear deterrence only be a passing phenomenon, from back when humanity was jammed together on the same planet? Since this might be seen as too broad, let’s say that the question is simply **would large-scale territorial war be conceivable in this scenario?** [Answer] ## Yes Nuclear weapons would be highly effective in space. But their effects are somewhat different than they are on the ground. I recommend reading [this entire section of the Atomic Rockets website: Nukes in Space](http://www.projectrho.com/public_html/rocket/spacegunconvent.php#id--Nukes_In_Space) On the ground, nuclear weapons damage things through 3 mechanisms: ### Radiation Because the atmosphere is opaque to high frequency light (hard UV, XRay, & Gamma Ray), the primary worrisome radiation is neutrons when detonated in the atmosphere (also see thermal flash below). In space, with no atmosphere, the high frequency light (primarily XRay and Gamma Ray) flies off without interference and this becomes one of the primary danger mechanisms of the nuclear detonation. In an atmosphere, almost all of the high frequency photon energy gets converted into the thermal flash and atmospheric blast mentioned below. > > For a conventional nuclear weapon (i.e., NOT a neutron bomb), the > x-ray and neutron flux is approximately: > > > $F\_{XRay} = 2.6 \cdot 10^{27} \times \frac{Y}{R^2}$ > > > $F\_{neutron} = 1.8 \cdot 10^{23} \times \frac{Y}{R^2}$ > > > where: > > > > ``` > Fx = X-ray fluence (x-rays/m2) > Fn = Neutron fluence (neutrons/m2) > Y = weapon yield (kilotons TNT) > R = range from ground zero (meters) > > ``` > > This shows that for a standard (not neutron enhanced) bomb, XRay radiation is about 10,000x more damaging than neutrons at any given distance from the bomb. Which radiation flux is more dangerous to the crew depends upon factors like what sort of shielding is available and where the crew is located in the ship. Neutron shielding is best (defined as the least amount of shield mass required to protect against it) composed of low mass atoms (e.g. Hydrogen in water). What type of shielding to use for XRay and gamma ray radiation depends upon its frequency. At the lower energies, high Z metals (like lead and tungsten) work best, while at higher energies all mass tends to shield about the same. Since water is terribly useful for spacecraft and ubiquitous across the Universe (from it you can make radiation shielding, water, oxygen, propellant, food, environmental coolant, and for some spacecraft fuel), I'd expect most ships to just use more water shielding in place of their high-Z metal, but otherwise dead weight, gamma ray shielding. ### Thermal Flash Because the atmosphere is opaque to high frequency light (hard UV, XRay, & Gamma Ray), it converts those frequencies to lower frequency light (optical and thermal). This "thermal flash" is what caused memorable images (like the one below) and instantly vaporized some people in Hiroshima: Nuclear Thermal Flash: [](https://i.stack.imgur.com/j6a4r.jpg) Since there is no atmosphere in space, the "thermal" flash is minimal and not really a concern. ### Blast In an atmosphere part of the energy of the detonation is absorbed by the atmosphere and turned into an atmospheric pressure wave (the "blast" or over-pressure wave). Once again this phenomenon does not occur in space. Therefore this issue can generally be ignored. Nuclear Blast Effects: [](https://i.stack.imgur.com/obdVM.gif) ### What it looks like Assuming a near miss that doesn't actually vaporize the spacecraft... Read this section of the [Atomic Rockets: Nuke vs. Spacecraft section](http://www.projectrho.com/public_html/rocket/spacegunconvent.php#id--Nukes_In_Space--Nuke_vs._Spacecraft) for the entire narrative. I'm going to quote a couple of key passages. > > First off, the weapon itself. A nuclear explosion in space, will look > pretty much like a Very Very Bright flashbulb going off. The effects > are instantaneous or nearly so. There is no fireball. The gaseous > remains of the weapon may be incandescent, but they are also expanding > at about a thousand kilometers per second, so one frame after > detonation they will have dissipated to the point of invisibility. > Just a flash. > > > So a strobe flash. If you were looking at it, you'll be permanently blind if you're too close. If you had a camera/sensor looking at it, it would likely burn out too if it was too close. > > Next is spallation - shocks will bounce back and forth through the > skin of the target, probably tearing chunks off both sides. Some of > these may come off at mere hundreds of meters per second. And they > will be hot, red- or maybe even white-hot depending on the material. > > > To envision the appearance of this part, a thought experiment. Or, > heck, go ahead and actually perform it. Start with a big piece of > sheet metal, covered in a fine layer of flour and glitter. Shine a > spotlight on it, in an otherwise-dark room. Then whack the thing with > a sledgehammer, hard enough for the recoil to knock the flour and > glitter into the air. > > > The haze of brightly-lit flour is your vaporized hull material, and > the bits of glitter are the spallation. Scale up the velocities as > needed, and ignore the bit where air resistance and gravity brings > everything to a halt. > > > Followed by a halo of faint hazy "dust" flying away from the hull along with possibly some larger debris ripped off the ship. Some sections of the ship may be glowing red hot (or hotter) depending upon the proximity of the warhead. It's possible that (depending upon many details) the ship may survive the detonation while the radiation kills the crew quickly or over the course of weeks. If the crew receives a deadly dose of radiation they'll likely know it even if they will likely live for a week or so in increasing agony due to the radiation damage. ## Would they go to war? That's entirely up to you and your fictional Universe. In space warfare, any target with a predictable trajectory (e.g. not accelerating) is a sitting duck that can be held hostage and/or killed at any time the belligerents decide to strike. The weapons would not need to be nuclear. Given sufficient time, a small asteroid would do the job easily and the belligerents might be able to maintain plausible deniability. [Answer] The thing that causes deterrence is the reliable ability for each side to cause huge levels of damage to their opponent if they're attacked. On Earth, that is created by Intercontinental Ballistic Missiles, which are quite hard to intercept. If side A has 100 ICBMs, side B will need 250+ Anti-Ballistic Missiles to shoot most of them down, and those ABMs *cost more* than the ICBMs. So it's always possible to penetrate defence at lower cost than improving the defence, and both sides could do this. Further, neither side could attack the other by surprise without retaliation being possible. If A made a full-scale attack, B could launch its weapons before A's weapons arrived, and *both sides* would be destroyed. That realisation lead to nuclear arms limitation treaties, which were obeyed, because it was in everyone's mutual interest to do so. But that kind of deterrence emerges from the technical, geographic and financial constraints of the place and time. It isn't necessarily going to apply in the completely different situation you describe. How do you decide if deterrence is possible? You need to decide if your scenario allows one side to attack the other and cause vast amounts of damage irrespective of defences. If it can, and the other side won't be able to respond to an attack by also inflicting vast amounts of unstoppable damage, then you have the reverse of deterrence, a hair-trigger situation where the first to shoot wins, and somebody will, soon. But if the other side can respond to an attack by inflicting unstoppable destruction, then you have "mutually assured destruction" and deterrence. [Answer] Nuclear devices are useful, but probably not in the way you are thinking. Because of the vast distances between objects in space, and the high relative speeds they are moving at, the most damaging, low cost option is to simply fling inert mass at the target. The kinetic energy will be massive, because the "v" in the v^2 will be measured in *kilometres per second*. Even an object in orbit around the earth is travelling far faster than any rifle bullet, so a bucket of ball bearings transported into space on an intersecting orbit with a satellite or space station becomes a fearsome weapon (Atomic Rockets has a snarky little exposition of the idea where the astronaut ejects the litter box of the ship's cat out the airlock on an intersecting orbit with the target....) Since the projectiles rely on their velocity to damage the targets, they can be made of wadded up kleenex, but as a practical matter, you probably want a dense core of stone or metal, and a simple homing device and a small thruster to make last minute orbital corrections. If you are firing at a moon or large space station, you can effectively launch across the solar system, but for targets capable of manoeuvre, one light second (just under the distance between the Earth and the Moon) provides a practical limit for targeting (too much farther and the target can move a substantial distance before the kinetic energy warhead arrives. It took New Horizons 9 hours to traverse the distance between the Earth and the Moon, for example). The kinetic energy weapons can be launched by virtually any sort of space propulsion system, so if your target is across the solar system, you could even use a light sail! More practically, mass drivers, rail guns or giant honking rocket boosters would provide the thrust to get to the target. Laser and energy weapons are also limited to a light second against manoeuvring targets, but since you can ramp up the hardware as much as you desire, a Ravening Beam of Death [RBoD] could theoretically vaporize metal and ceramics in milliseconds at that range. See [Rocketpunk Manifesto](http://www.rocketpunk-manifesto.com/search?q=space%20war) for the gory details. At this point, you might want to reconsider how these spacefaring "nations" are going to conduct warfare. When a space station can be hit by a bunch of rocks collectively packing the energy of the Castle Bravo nuclear device, there isn't going to be much left of the target. These sorts of weapons are really only useful in a "war to the knife", where you offer no quarter and take no prisoners, but then you can expect to be on the receiving end of that sort of punishment as well. As for nuclear devices, they don't really add much to the target effect unless you are using third and fourth generation warheads as accelerators to drive streams of pellets at 100 km/sec or plasma jets at 3% of the speed of light. This suggests that their primary purpose is not really as weapons in of themselves, but as a compact energy source to power defensive weapons that can attempt to shoot down incoming devices. The other, and probably more important use for nuclear devices is as the drive units for an ORION pulse drive. This also the workaround for the spaceships in your setting, ORION is the only high thrust/high ISP drive system known to science, and you ORION drive ships will be bigger, faster and more capable than anything else out there. ORION drive ships can also bring teams of commandos, computer hackers, biological warfare experts or ninjas to your enemy space station, disguised as tourists, business people or traders, allowing you to actually capture the enemy station and "win" the war. [Answer] # Are nuclear weapons useful in space? Yes. One of the other answers gives an extensive amount of information on how nukes behave in space, but there a couple of key points: * It is hard to hit things precisely in space. Consider the immense amount of work that went into [Juno's trajectory](http://spaceflight101.com/juno/juno-mission-trajectory-design/). Nukes ease this burden because they just have to 'get close'. * Collateral damage is limited. Space is awful large. A successful nuclear strike is likely to take out a target and not as much else (since everything else is very far away). I recommend reading Haldeman's [Forever War](https://en.wikipedia.org/wiki/The_Forever_War) for a visceral description of nuclear space combat, similar in tech level to that you describe. # Would large-scale territorial war be conceivable in this scenario? As you define 'territory', probably not. One thing to remember is that space is very dynamic compared to earth. The notion of 'territory' changes rapidly and constantly. Because bodies in space are moving at different speeds along different trajectories, the notion of 'territory' is constantly churning. Further, things that are close physically for a little while (such as Mars and Earth) are often quite far away. And when they are close physically, the time it takes to get from one to the other is not actually the shortest transit time (again, with conventional tech - or, I suppose, if you had a *lot* of energy to burn somehow). Thus, to plan an invasion you have to calculate where your target is going to be when you get there. You have to figure out how much reaction mass it will take to get your troops in place. It's a lot of work, logistically, particularly because winning does not imply you have a secure supply line (important in war): because the target keeps moving it might well move past where you can support it. Further, supply ships might have to be sent without knowing if you won the fight on the far side. For this reason, being high on a gravity well (as in Heinlein's [The Moon is a Harsh Mistress](https://en.wikipedia.org/wiki/The_Moon_Is_a_Harsh_Mistress)) has an advantage, in that it's easy to go 'down' the well, and hard to come up. Fleets would have to be largely self-sufficient, would have to modify their plans as they get information, and the only 'territory' worth talking about would be areas around gravity wells. Capturing vast volumes of space with nothing in it doesn't really help. The other thing to note is that space, being largely empty, makes it very easy to see things coming. Telescopes, sensors, optics and radar all become super important. If you can see a fleet launch, understand it's trajectory, you can pretty much tell what it's going to do and (if you're close enough) respond long before the fleet performs what it's doing. It's ability to turn around is limited. This matters for nukes, specifically, as well: warheads are very observable, if only for the heat trail of the delivering rocket. If your nukes are hard to hide, it is all the harder to get them close enough. Arguably this makes them the *only* option, when a conventional warhead would stand no chance of getting close enough before being shot down. But it does suggest inert nuke 'mines' and other tactics would evolve in order to get around using nukes 'in the open'. In short: with shifting territory, in the open vastness of space, nukes are probably a key weapon, but the strategy and tactics around their use would change drastically - such that comparison to historical combat is very hard to make. [Answer] Since the nukes have been comprehensively covered, I'll look at the chances of going to war. **Unlikely** The key to this is resources and the fact that the same resources are fairly evenly distributed around the asteroid belts. There may be vast unexploited resources on the asteroid your rival empire has just moved on to, but the same is true of every other large asteroid in your vicinity. There's no clash for space, no clash for resources, only a clash for pride. With travel times what they are, along with the risks of the weapons involved, pride is not a valid reason to risk a nuclear war. > > Space is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to space. - *Douglas Adams h2g2* > > > When it becomes interesting is when something comes up that is actually worth fighting for, but in practice that's a large deposit of unobtainium, handwavium, or a planet with a breathable atmosphere. Everything else is plentiful on an unimaginable scale. > > May you live in interesting times - *Auriental Curse (Pterry)* > > > ]

[Question] [ The world where the question spans over a 100 years between 1945 and 2045, the story beginning just at the end of WWII, and proceeding in such a way that never saw the end of the Cold War all the way to 2045 and is centred around it. Many spy movies feature "unrealistic" cool gadgets, and while designing the world, I suddenly came up with this silly idea - an inner mouth mounted small-calibre (say, .22) pistol that could be activated by some form of tongue or tooth movement, firing a bullet from the agent's open mouth. There are a lot of safety hazards right off the bat, of course, but what interests me the most is whether such a weapon could * be designed to fit into an average adult man's mouth cavity * be shot without or with minimal damage to the operator If such a weapon is possible, what is the earliest year it could theoretically be invented as a part of "weapons on steroids" general research of the agency? [Answer] I love wacky questions! OK, we need a removable object or our hapless test subject will have trouble eating and it must be made of surgical stainless steel or it'll start rusting very quickly. Stainless steel was invented in the early 1900s, so that's not an inhibitor. Bolting things onto the human body is a bit more complex. Your first rod to help a broken bone was about the WWI time period but it didn't advance quickly. Bolts were first used around the WWII period, so it's plausible — unless your happy with the entire *steampunk* motif, in which case it's mandatory. So, let's say the bottom end of our technology is the 1950s or early 1960s. We're going to bolt a stainless steel infrastructure to the upper and lower jaw areas between tooth roots to hold what would most likely be a single-shot also stainless steel firing mechanism. Various hooks and latches will be used for removal, leaving the bridle-like infrastructure in place to swallow around. It's inefficient, difficult to aim, definitely 1970s James Bond in its pure silliness, but it's plausible. I wouldn't activate it with my tongue, too much liklihood of blowing a hole through my own teeth. Activate it by opening the mouth wide. You'll feel the tension as you're opening your mouth to the correct width, and finally Click! Bang! And then... **The real problem** The real problem is recoil. The human arm is wonderful at absorbing linear energy. It's almost as if it were designed to punch people in the nose. Your *neck* on the other hand, was not designed to withstand a lot of lateral energy. Let's call it whiplash. Now, a .22 calibre bullet doesn't produce a ton of energy compared to its larger siblings, but it's there. > > The acceleration-deceleration forces which cause whiplash injury are sufficient to permanently disable you. Even in a low speed rear impact collision of 8 mph, your head moves roughly 18 inches, at a force as great as 7 G‚Äôs in less than a quarter of a second. The Discovery space shuttle is only built to withstand a maximum of 3 G‚Äôs. ([Source](https://neurosurgeon.com/conditions/whiplash/)) > > > 7G is 68.6 m/s2. In a quarter of a second that's about 17.15 m/s. A .22 bullet has a muzzle velocity of around [914 m/s](http://www.gunnersden.com/index.htm.rifle-cartridges-ballistics.html). The average adult head is 4.5Kg, the bullet is 2g, that's a ratio of 4.4e-4 so the head is going to move, what, about 41 cm/s1 for more-or-less that quarter second. That's a long way away from the 17.17m/s we need for a dibilitating injury. It'll be a pain, but our intrepid agent of evil will survive. **Which means your real, real problem is...** Accuracy. I can't think of anything less accurate than a mouth gun. This is point-blank wet work only unless you've been distracted by, well, her... Let's just hope you're sent to assassinate a lady. --- 1 *This is my favorite way to quickly estimate the transfer of energy between two objects. It's inaccurate, but good enough for government work.* [Answer] There is an analogue of the weapon you describe, which I saw in a pattern room in a museum once. It was a .22 cal assassination weapon, disguised as a lady's compact: [](https://i.stack.imgur.com/ikRZ9.jpg) *Traditional ladies compact* The barrel was concealed in the lower case, and the assassin moved close to the target, removed the compact from her purse, opened the compact (cocking the action) and aiming either through a crude "notch" sight in top of the mirror, or an aiming line on the mirror itself (can't quite remember). To any casual observer, the lady was just adjusting her makeup or "powdering her nose". The compact was lined up with the target now, so closing the lid also fired the action. Naturally the user needed to make an allowance for the fingers when holding and aiming the device, but if I remember correctly, the barrel extended far enough out the back you could palm the device and have the barrel protrude through your fingers. So in terms of size, a small, flat cylinder containing the barrel and mechanism *could* be designed to fit inside the mouth, perhaps disguised as a dental appliance. [](https://i.stack.imgur.com/Ocb4s.jpg) *Who would have seen that coming?* The awkward part is the operator could not eat, drink or maybe even speak with such a device inside the mouth, which in of itself might arouse suspicion. As many others have noted, aiming and firing the device without self injury would also be difficult.... The only other way to have that effect would be to disguise the weapon in a man's pipe. Holding it in the mouth and aiming over the pipe bowl while "filling" the bowl with tobacco and then lighting it, you also have your hand to both steady the front of the weapon and make any final aiming adjustments. This also protects your teeth from being broken when the weapon fires, and as a bonus, the cloud of smoke coming from the pipe provides a very handy way of disguising the smoke and flash of the discharge of the weapon. [](https://i.stack.imgur.com/KTLC9.jpg) *What noise? I didn't hear anything* So while an actual firearm concealed inside the mouth is probably impractical, there are workarounds if you are clever enough. [Answer] Is the gun completely within the mouth, or can the end of the barrel stick out past the lips? If the gun is completely within the mouth, you have two problems. First, you need to be worried about shooting your lips or possibly even your teeth. It could probably be mounted in such a way that it could not fire if the teeth were in the way, but I don't know if that could be done for your lips. They're pretty soft and would have difficulty toggling any safety mechanism. The second problem is combustion gases. These are very hot and very high pressure. They would not cause life-threatening injuries, but will almost certainly burn your tongue and the inside of your lips. They may also knock your front teeth out. If the barrel of the gun sticks out of your mouth, you avoid these problems but have to deal with much higher recoil. Recoil is proportional to muzzle velocity, which is itself proportional to barrel length. Longer barrel means higher muzzle velocity which means more recoil. The recoil calculations in the answers above don't take into account the fact that your head is connected to a ~55kg body. Their estimates are high, but exactly how high depends greatly on how exactly the gun is mounted and whether the shooter can support his head in some other way. The gun could have springs at the back which would reduce felt recoil. The shooter could put his hands on the back of his head and push his head forward. This would mean his arms and shoulders would take some of the recoil instead of his neck. Either way it would be horrible on your ears. Anyone who has ever fired one of those little derringers knows they are much louder than you expect. I can't imagine how loud it would be *inside* your mouth. We're probably looking at permanent hearing loss from a single shot. Further, I don't believe ear plugs will help because they block sound from outside of your head, not from inside your head. [Answer] What you describe is basically a custom .22 [derringer](https://en.wikipedia.org/wiki/Derringer) once you have brass cartridge ammunition you could mouth mount such a weapon. Without water proof cartridges the moist nature of the mouth would be a major issue. My understanding is that such weapons have almost no recoil or chamber heating on firing so the biggest injury risks are going to be in terms of burns from the [GSR](https://en.wikipedia.org/wiki/Gunshot_residue) and the possibility of self-inflicted bullet wounds. [Answer] > > be designed to fit into an average adult man's mouth cavity > be shot without or with minimum damage to the operator > > > Yes to both. You would need a special setup to keep the bullet dry (probably seal everything in rubber). Also, the gas discharge would need to be sent forward, increasing the recoil (you'd have three barrels going out - a central one for the gun and two for the exhaust gases). I have read that weight goes "(1.3 to 3.9 g), and velocities vary from 575 to 1,750 ft/s (175 to 533 m/s)" (Wikipedia). Assuming 300 m/s and 2 grams, the barrel could be say 5 cm (we would need a very powerful explosive). This gives an acceleration of 0 to 300 m/s in a space of 5 cm, and since v = SQRT(2\*a\*s) it must be 300 = SQRT(2\*a\*0.05) or a = 900000 m/s^2 (ninety thousand G's). An average human head weighs say 5 kg or 5000 grams. The recoil equation says that m1a1 = m2a2, so 2\*90000 = 5000\*a2 and a2, the acceleration of the head, would be around 36 gravities, which would be the equivalent of hitting a not-so-soft mat from about a half meter of height. You'd almost certainly get severe whiplash, and possibly also a concussion, but if you're shooting a one-shot gun from your mouth you're probably way past worrying for that. You could decrease the muzzle speed of the bullet (but I'm a total ignoramus about weapons; I only know that if you reduce the muzzle speed by a factor of four, acceleration halves). Also adding a considerable weight to the gun would help, or mounting it on a spring release with dampers (the gun is 5 cm long when in the mouth, then pops out for about as much, becoming double the length; that reduces the recoil by half). You'd probably also need a fourth barrel with a laser pointer to aid in aiming the thing. ([A similar setup](https://www.schlockmercenary.com/2007-04-30)) [Answer] No. A gun is a chamber for containing and directing the force of an explosion. Purists will argue that gunpowder doesn't explode, it burns and expands rapidly, but i'll argue back that the recoil from a gun is sufficient that for this discussion it qualifies as an explosion. The brain is essentially two big blobs of tissue with approximately the consistency of butter floating in water, housed inside a rough boney box with lots of sharp edges, that it is partially attached to. On firing, a shockwave (what we hear as a "bang") will be propagated through the bone, the cerebro-spinal fluid, and the brain itself. The vibration in the bone will bruise the lower surfaces of the brain where the skull and brain are in direct contact, resulting in immediate loss of the sense of smell, and possible bruising of the optic nerve. The delicate nerves in the inner ear will be bruised, resulting in loss of equilibrium and hearing. It is possible that calcium deposits that often form in the inner ear can be dislodged and cause further issues with equilibrium. Another instant effect of the shockwave on the brain will be the triggering of a seizure and secondary injuries. Warning: graphic content: <https://www.dailymotion.com/video/x24x49b> The eyes, likewise, are essentially water filled bags of tissue. The shockwave will likely cause detached retina and bleeding inside the eyes themselves, resulting in instant and permanent degradation of vision and be probably blindness. The operator would likely suffer long term effects as well. Alexithymia is the inability to process emotions, which renders the person incapable of recognizing or responding to normal social cues, impacts their ability to form new memories, or to prioritize. All of the previous will probably be immaterial, though. Water is a much better conductor of energy than air, so the "bang" that you hear and find deafening will be much worse in the confines of the skull. Someone better at math than I am will need to do the computations, but I suspect that the shockwave going through the braincase would simply puree the brain, resulting in instant death. <https://science.howstuffworks.com/explosion-land-water1.htm> [Answer] The top answer is good, I just want to add some things: * You don't really want an explosion in your mouth (nor the gasses nor shell from the aftermath). * What about a tiny gas canister that uses pressurized air? Air powered guns are already a common thing‚Äîthey are quieter than a firearm, and the wild inaccuracy of mouth-aiming means you'll be close to the target anyway, so you don't need to worry about power. * Recoil might be hazardous, but that could be part of how it works. "Brace your head against something (e.g. pressed against a wall), or prepare to sustain injury". Sometimes limitations make the world interesting, you don't need a perfect weapon. Update‚Äîsome concerns: * There's nothing for the weapon to hold on to, the mouth is pretty squishy. * Eating food would be difficult and gross, food would get stuck on the weapon and rot in your mouth (but maybe that's part of the story, the killer with the horrible breath). * Speaking would be difficult, try putting something in your mouth and talking. The only thing I can think of is... **Removing the upper palate, and storing the weapon in the nasal cavity.** Then the weapon becomes an artificial roof of your mouth, you can speak, eat, etc normally, and with some special movement you can lower the weapon into your mouth and fire it. The cost here is you can no longer smell/breathe in through your nose. [Answer] It should be doable during the entire range of years you're looking at. You'd have to play with the caliber and probably use a weak, subsonic round.. but it's probably doable using WW2 technology. Being able to be shot with minimal damage to the operator is tricky. Not so much the technical part of making the gun itself, but you are going to have to use it at point blank range, aren't going to be able to hide the fact that you did it and are likely to be a bit rattled after you fire it. And it's going to be such an inaccurate and weak round that you're probably going to fail unless your target is a few feet away from you. Unless you're going for an Austin Powers level of silliness, perhaps you'd be better served going for a mouth mounted poison dart launcher. That would be small and silent enough that you'd actually have a decent chance of surviving using it. [Answer] If instead of firing a bullet you launched a small rocket, you could avoid the majority of the recoil and outgassing. A bullet-sized rocket with its own propellant could be launched using either a small amount of gunpowder or even compressed air, using just enough force to get it out of your mouth (and far enough from your face) where the main propellent would ignite and do the majority of the acceleration away from your body. There was a series of firearms developed in the 60s that used this principle, called the Gyrojet (see wikipedia: <https://en.wikipedia.org/wiki/Gyrojet>). There was a derringer version you could adapt to fit inside a mouth, using similar principles for mounting & operation from the previous answers. Aiming would still be a problem as with a regular bullet, and the rocket itself is not as accurate, but damage at longer range is increased (assuming you hit the target). Recoil and gasses would be much reduced, and the launcher itself would be much smaller/simpler as you don't have the same barrel stresses. The majority of the size and complexity is in the round itself. It would also be stealthier since less recoil and gassing means you can recover more quickly after firing. The sound would also be different, less an immediate crack of the initial firing as with a traditional bullet, and more of a hissing as the round accelerates. ]

[Question] [ In many stories, a mysterious indent in a wall acts as a lock to a secret vault full of ancient treasures. The way to unlock this archaic door? A strangely shaped stone. By placing it into the indent, the vault opens. Unfortunately, this idea ran into a problem when I was trying to adapt it for my world. It isn't that magic can't be used to activate the mechanism, as this ancient civilisation was one comprised of powerful mages. They could easily make a lock fulfilling all the criteria here... except that something the same shape as the indent would still open it. That' my problem - the issue arises in trying to make the lock secure. Whenever I see an example of this idea, I always think to myself 'why didn't someone get curious and make something the same shape of the indent to 1) see what happened, if anything; or 2) fill in the gap and make the wall look better?' So to put it simply: **How, without using magic, could a lock of this type be made secure to counterfeit keys?** I say without magic for two reasons. Mostly, because it's more interesting. But partially because I can imagine a location as important as an ancient temple being protected from magic to counter vandals. The lock system itself uses magic to recognise when something of the right shape has been inserted. However, the key itself cannot have runes or anything magic to identify it. What I'm looking for is a way to make this lock 'immune' by counterfeit keys without using magic. I've considered having the key made of a special material, but then I'm not sure how to make 1) the lock recognise the material without the use of the minor magic explained above; and 2) the lock needs to be 'immune', for want of a better word, to a different key of the same material. EDIT: further information on request. The civilisation's magic does all the normal magic things (beams of light, fire, etc) and can react differently in certain situations (in light or dark, hot or cold, touched or not). Their technology level and culture in general is similar to that of the ancient Egyptians except for metalwork, which has developed to a renaissance level of precision due to extremely powerful catalysts being available to stoke the fires. They have no way to determine DNA / blood type, but could determine weight or size using the simple magic explained in the lock. The temple is made of a sandstone-type material, all marked with runes to stop decay or destruction. The modern era has no way to bypass these runes - to access the vault, they'll need to go through the lock. A further explanation on the lock: the lock itself is protected from damage like the rest of the temple. However, it can contain runes to detect light, weight, size - any simple measurement. (Of course, any answers that they couldn't detect, such as radiation, are always interesting and just as appreciated!) The key cannot contain magical properties of any sort, but can be made of magnetic metals, crystals, stone, or any other such material. Furthermore, as the society has a far deeper understanding of metals than other materials, they can create more sophisticated metalwork than masonry or ceramics. Once the lock has been opened, a signal will be sent to the door, triggering runes that break down the stone. In addition, it will also disable the decay runes, allowing the temple to fall apart in years to come. The civilisation built the temple in the final years before they were invaded and massacred. Its aim was to preserve its contents until a successor obtained the key from somewhere and unlocked the vault. The unlockers are at pretty much our tech level minus 20 years, except for computing.... If they had atom perfect recreation, they could copy the key no matter what we did! They're sure magic existed, but can't prove it scientifically or use it. In reality, they DO have all the time in the world to get into this vault... but really want to do it before our 20-year old researchers grow senile and die. Oh, and **security by obscurity is not security**. It can go in addition to strong security and further its strength, but 8 million key holes with a regular key isn't really an answer. I would have added this originally, but I wasn't sure how important materials and such were. Anyway, it's here now! [Answer] As any good locksmith will tell you, any lock anywhere can be fooled. Not all of them can be picked with a bump set, but they can be accessed, one way or another. There's nothing that it would be IMPOSSIBLE to copy. Just more difficult. Let's go about making it more difficult though. First, make the number of planes/requirements higher for the unlock. So your standard key is flat on the bottom with grooves on the top. [](https://i.stack.imgur.com/tGARp.jpg) Those grooves tell the lock that the key is valid. Harder to pick locks have grooves on booth sides. Still harder are the quad keys that have ridges not just on the top and bottom, but on or along the sides. There's also the Chain Key, which uses those principles as well. See [the link for more on how it works](http://united-locksmith.net/blog/4-locks-that-cannot-be-picked), but basically, it uses the fact that it's FLEXIBLE to foil most lock pickers. [](https://i.stack.imgur.com/mG7F7.jpg) All right, so what we've learned about keys and locks is this: **The more requirements needed to open the lock, the less likely that lock is to be picked.** So when it comes to a physical object as a key, you'll want to look at EVERYTHING--like the composition of the object--is it a special kind of crystal that refracts light a certain way? Have that be one requirement. And yes, that can be physical and set off a rube goldberg type thing, maybe. **The weight, specific dimensions on all sizes, perhaps even the AGE, density, or composition can all be physical factors leading to the unlocking of the lock.** Perhaps the lock checks for density, and the center of the key object is hollow in a specific shape that it checks for somehow. Nothing is IMPOSSIBLE to copy. All you can do is make it more difficult. EDIT: This answer takes into account more primitive tech since you said ancient, so I didn't include a scanner for radioactivity, (which KUDOS to that poster, that's a fabulous idea). But still, they could be so ancient they are advanced. My ideas are definitely a stretch for primitive people as well. EDIT: So now I have to add something about the design of the lock, which can be magic, though the key must be mundane, according to the poster. > > The lock system itself uses magic to recognise when something of the right shape has been inserted. However, the key itself cannot have runes or anything magic to identify it. > > > To make it less likely to be picked, (or at least take longer) even with magic, have it work like this: purely physical part of the lock uses the weight and grooves to "wake up" the first magical scanner, which hits the crystal portion of the key with light. The correct refraction triggers the second magical scanner, which looks for a hollow in the center of the object, of a particular shape. This triggers the next scan which could check for the age of the object, or stealing from the AndyD273, a series of scans which check for various isotope levels on different parts of the object. But, while all this is going on, all of the other scans are still in progress--the initial scan triggers the next, BUT, if any of the other scans "go away" or aren't there anymore, the whole thing shuts down. (for a magic user, this will mean that they will have to keep spoofing the crystal, and the hollow, while trying to spoof the next series). All together, this is one lock that would be very difficult to pick or spoof. [Answer] Two-Factor Authentication! Can you broaden your acceptable answer to allow the key to be combined with something else? For example: * The lock requires the physical key plus exactly one drop of blood placed on the tip. Perhaps it has to be a female goat's blood or something specific. * The lock requires that the key be inserted into the lock at a particular time of day, or day of the year, or when the sun is shining (or not). * The lock requires the key to be inserted and turned exactly 1/4 to the left before being removed. * There are 32 indentations into which the key fits. You must insert it into a specific one. This one may depend on the day of the year or the hour of the day. * Besides the key, there is a floor pressure plate beneath the lock which weighs you, and you must weigh exactly 195 pounds when you insert the key for the lock to open. (Which is heavy for the era, which means you plus some sandbags on your shoulders.) That's how modern two-factor authentication works: one thing you know and one thing you have with you. So your password can be compromised, but that's not enough. In like manner, your key could be duplicated, but it's the key plus how to use the key that matters. The details of the extra information you must have would determine what happens if you are wrong. For the blood, having no blood or the wrong blood simply does nothing. The key appears worthless. Same for the time of day or the 1/4 turn. For the 32 indentations, you'd have to do something more severe to avoid them trying each indentation in turn: things like poison gasses, flames, crushing rocks, etc. Or maybe the use of the wrong hole locks things up permanently, or forces you to know the "reset" hole that will reset the lock so you can then try a different hole. (In the extreme case, the key could be required to be inserted into the 32 holes in a prescribed sequence or it would not work -- like a combination lock with the addition of a key.) [Answer] Too many answers with "uncopyable key is impossible" advises, so I have to stand up. There is no need to jump directly to quantum magic to argue and show that to replicate a quantum system one has to measure it and thus destroy superpositions of states which it naturally have and which may be the key by complementing with another quantum system and by measuring them both produce a signal to open the thing. And closing would look like creating a new matching state for key and the lock. No, there are other things which are hard to replicate and relatively easy to detect, and magicians use them all the time. It has so happened that I have broken into one of their vaults to find the place with those strangely shaped keys they make there. There is the picture of their secretsecretsecret [](https://i.stack.imgur.com/JguHO.jpg) It is not coincidence that magicians love to use crystals, especially diamonds (*because it cuts steel very well, and makes super durable tools, they are best man's friends*) Natural diamond have small imperfections in the structure (on the level of single atoms), even if it looks like a perfect stone, which are observable via effects like different light polarization. Both of those imperfections inclusions and stresses can be observable with light and with sound, and probably they could be detected with electricity(like crystal oscillators used in electronics) * have read that one lab which makes scalpels blades and such from diamonds(which is actually a tricky form to make from a diamond), by using ultrasound, uses ultrasound to relieve stress in diamond structure too, thus making them stronger. I guess those stress pictures might be also created in a similar way. It depends on the technology which is used to identify the crystals starting from confirming that it is a diamond(by squeezing it in the keyhole, as an example(A very large diamond might be one of it's kind)), ending by observing imperfections caused by small groups of atoms. There is so called [Photoelasticity](https://en.wikipedia.org/wiki/Photoelasticity), and funny practical demonstration with commonly available objects <https://www.youtube.com/watch?v=dZaqY2vyeNo> Same thing will be unique and individual for each crystal out of the box, there is not need to create it, it needs just to be tested and as you might see it does not require super equipment to do so. But it will be very hard if even possible to replicate it even if you have perfectly fast working tunnel microscope which is capable of manipulating with the key material atom by atom. (I doubt it will help, needs something which can make true snapshot of the structure all at once) So, magical crystals aren't that magical, but they have unique and useful properties, which can be exploited to be a key even at low tech level. It can contain 0 electronics, 0 magic, and be pure mechanics like Rube Goldberg machine working solely on the light. (so yes the lock can be coded to opened at certain moon/sun angle, or at certain date, be opened only once etc) A Cody's lab video contains almost all necessary elements to do so [Sprengel Vacuum Pump: The most efficient pump ever?](https://www.youtube.com/watch?v=viJ3T-1KZqY) (a bit long but worth to watch) Add mirrors, prisms(for different incoming light spectrum, and for detection of resulting light spectrums by directing them to the needed angle), add polarisation filters(some crystals have natural properties), add more of those rotating thingies, tune them to be in resonance, drill bunch of holes in lock for light to interact in the crystal and generate proper combination of results which will begin the chain reaction, etc etc. Creating such lock for partcular key and particular environment in particular place, or better say creating the plan for its creation might require very strong magic of Intel Xeon over 9000 crystal power with GPU's from Nvidia magician and more you spend of that while creating the plan for the system harder it will be for you potential enemies to crack it, same as with bitcoins system you has to have more power than half of the system to compromise it, but in the case one who would to compromise the lock system has to have way more power and skills than those who have created it. **N.B.** Do not forget to check that you have strong walls, so it worth to have such lock. **N.N.B.** And yes, you create lock for the key, not key for the lock --- A bit of clarification, an answer to @Schwern comment No it should not be summed as just look at small imperfections. It's a range starting from a just macro object with certain properties to single atom imperfection in the crystal structure. Which level it takes depend on technologies available for lock builders and how and which parameters they would like to measure. In fact, it is a combination of steganography, secure decrypting algorithm, and open key systems. Also, it seems you imagine the lock as usual door lock, which might be not the case, especially on low tech level as it might require a significant amount of light to work, long distances to precisely measuring light refraction angles, and system which feed the key with particular wavelengths etc. It's more like a cave which you would expect to have in a magic setting. A significantly big structure, which makes the work, if it gets right signals, where the key is a cryptographical algorithm which complements the system algorithm. I had thoughts to describe the possible mechanism more detailed, but realizations can be very much different and describing from the idea to working mechanism too long and not necessary needed for OP. Using physical object as cryptographic keys is real deal, you can read a randomly picked pdf about that <http://ceu.archives.ceu.hu/archive/00001003/01/francia.pdf> . If one can create a snapshot on the atomic level, without disassembling the key - yes, the key can be copied, but if not then you can have a key which can't be copied, it is not necessary any key. At our current technological level, any diamond can be used as the key which can't be copied. [Answer] Since this is going to be non-magical and ancient you could try something like magnetism. Use a specific alloy of iron and rare earth magnet to get the magnet/key to a specific strength of magnet. Design the lock to respond to that level of magnetism with a very delicate mechanism. Too much or too little magnetism won't be able to open the lock. You could even get creative with making the alloy so that different parts have different magnetic strength (maybe, I'm kind of spitballing, but it sounds plausible). that way, not only would someone have to figure out the content of the alloy, they would also have to cast it perfectly. It's not impossible to duplicate, but it sure wouldn't be easy. [Answer] Take a piece of glass or a precious stone and break it in two. You will get a unique fracture. One part stays inside the lock and the other is the key. Only the two parts will fit together correctly. It is impossible to make an accurate copy of the fractured stone, especially in the ceramic material. This is pretty much true even in the present day. As for detecting the correct fit, only when the two pieces fit together correctly will light shine through them without being deflected. Any imperfection in fit will cause light to be scattered in other directions. Another thing that can happen with perfectly matched pieces of broken glass is that they can be held together when wet by the surface tension of water - this doesn't work if they don't match perfectly. If you're using magic or handwavy type detection, you could also consider the added security of a marbled material, where matching the veins of different composition in the material makes it even more difficult to copy. [Answer] Yes, it is possible. Using quantum entanglement with one entangled particle in the lock and the other in the key. When the key is inserted into the lock, the lock can observe both particles in real-time. Proving that this particular key is correct for this particular lock involves watching both particles as they cascade through various states in perfect synchronization. If they stay in sync for an adequate length of time to rule out random chance (say 24 hours), then the lock opens. [Answer] I don't know if you consider this physical "enough", but a flat hologram cannot be copied in normal ways. In other words, you can't just make a photocopy of it with a photocopier. The hologram, like the one you see on expensive event tickets or credit cards, is three-dimensional information encoded in a 2-dimensional surface. Amazingly, when you turn a hologram, you literally see different parts of the image, depending on the angle you tilt it at. [As this flat hologram rotates](https://www.youtube.com/watch?v=uhTaqRUu8nw), you see different sides of the building, as if it were three-dimensional. But it's just a flat, 2-D hologram. The hologram is made through the interference of two patterns. They combine to create the image that you see. To copy the hologram, you need the two original sources. If you put a hologram on a photocopy machine, you just get an image of the hologram from one angle, and not all of the 3-D information contained within the hologram. To have a complete copy of the hologram, you need the two original sources used to make it. You can't derive that information from an existing hologram. That's why they put holograms on concert tickets and credit cards--they can't be copied. If you put your credit card or concert ticket on a photocopy machine, flatbed scanner, or just take a picture, you get just a 2-D "snapshot" of the hologram from a single 2-D perspective, not a replication of the 3-D hologram. So, the hologram has a physical component, but the uniqueness of it is the encoded 3-D surface on it. If you carried around a little plate with a hologram on it, nobody could copy the hologram just by coming into possession of your plate. They'd need the two sources used originally to make the plate you carry. As to how your lock "reads" the holographic key, it would have to have a light-sensing component. [Answer] We have this kind of key in real life, today, if you broaden your view. I'm talking about ATM cards. The trick here is that the shape is basically meaningless. Whats securing the "lock" is the information *in* the key. The chip on the card provides a key thats crpythographically secured, and the lock only responds to the correct key. The correct key cannot be deduced from the shape of the lock, the only way to produce a correct key is either having the original key, or lacking that, trial and error. Make the key large enough and trail and error becomes infeasible. Of course, if you had access to the original key, cloning it is still possible with the right technology. Tricking the lock without ever having seen the key on the other hand will be impossible. This is in principle not so much different from a mechanical lock, only the lock does provide strictly only one single feedback to the burglar: wrong or correct, where a mechanical lock does provide this feedback for every lock cylinder (think of the trope where the master thief "hears" the lock clicking when trying to pick it). [Answer] # You don't need to copy the key to open the lock. Let's talk about the underlying assumption of the question: that you need to copy the key to open the lock. You don't. In circumventing security, rarely do you go after the security itself, but around it. If you make an incredibly difficult to copy key, attack the lock, the locking mechanism itself (like opening a door with a credit card), or the door, or its hinges, or the wall next to the door, or the floor, or ceiling... But let's focus on the lock and key. # A lock seems like a device that opens with a key... Take a simple pin and tumbler lock: this seems to be a mechanical device that will only open once it detects the various bumps on the key are the correct height. A fingerprint scanner seems to be a device that measures your fingerprint and sees if it matches a stored copy of your fingerprint. In reality, they're not. # ...but locks are really devices which measure a key. A pin and tumbler has pins which prevent a tumbler from rotating. The lock opens when pins inside are lifted to a specific height to allow the tumbler to rotate. So long as the height of its pins are correct it will open, no key required. Similarly a fingerprint scanner isn't comparing fingerprints. It stores a very simplified model of your fingerprint. When it scans something, it runs it through the same algorithm to get a simplified model. So long as what it sees through its scanner results in the same model as what it has stored, it will open. No actual finger required. # The copy only has to be as good as the lock. It's not necessary to copy the key perfectly to open the lock. It's only necessary to fool the lock into thinking you've given it the key. All the lock-picker cares is that the lock opens. This is why you can pick locks. This is a common theme in all measurements: all measurements are indirect measurements and can be fooled. Picking a traditional tumbler lock is all about putting the pins at the same height as the key would; you're fooling the detector. Tricking a fingerprint scanner is all about giving it something close enough to the real fingerprint that it has the same model, like a copy you lifted off something the lock owner touched. This is important because it gives us a lot more to play with when we talk about an "uncopyable" key. ***We don't need to copy the key, we just need to reproduce what the lock expects to detect.*** This is a common theme in security: its only as good as its weakest link. # If they key is incredibly complicated, attack the lock instead. The lock has to measure the key, so making the key unmeasurable (and thus uncopyable) is out. You might make the key incredibly difficult to reproduce, but the reproduction only has to be as good as the precision of the lock's measurement. Make the lock extremely precise (like measuring tiny imperfections in a crystal, as another answer proposed) and you also make it extremely complex. Complex locks are fragile, expensive, and finicky. Make the tolerances too tight, and the lock might not work. Make the tolerances on a pin and tumbler lock too tight, and the key that gets banged around in your pocket all day won't fit. Scanning microscopic flaws in a crystal means even the smallest damage to the crystal or scanner will mean the lock won't open. ***Every physical lock must have some imprecision to deal with the real world*** and that imprecision is what allows an attacker to open the lock without the key. All that complexity just increases the [attack surface](https://en.wikipedia.org/wiki/Attack_surface); the number of ways the lock can be attacked. And I don't mean hitting it with a hammer, I mean tricking the lock into thinking it's seen the key. # The key tells you how to attack the lock. It's not necessary to copy the key because you don't need the key to open the lock. The key itself tells us things about how the lock works so we can attack the lock. For example, a picture of a normal key tells me the proper pin heights. A picture of your fingerprint tells me how to make a fake that will fool the scanner. So, again, it's not necessary to copy the key to open the lock. # Something Something Something Quantum Quantum Something is going to come up when it comes to making things that cannot be copied or measured. This is moot for this scenario: you want a macroscopic physical key, not electrons, but let's go into it a bit. A big problem in encryption is how do you distribute the encryption keys? What Quantum Entanglement brings is [Quantum Key Distribution](https://en.wikipedia.org/wiki/Quantum_key_distribution). This [protects against various ways for a 3rd party to snoop on the key](https://en.wikipedia.org/wiki/Quantum_key_distribution#Attacks_and_security_proofs). Entangled particles are a single quantum system. Any measurement of a quantum system changes that system, so any snooping will change the system and that change can be detected. While the key can be copied, you can detect it has been copied. Copying requires measurement which alters the quantum state. With a long enough key, something like 80 bits, you can detect that the key has been copied. This means you can transmit the shared key and know whether it's been intercepted. That's what quantum entanglement buys you. [Answer] Quantum mechanics has the “no cloning theorem”. Simply introduce the same idea for your Magic mechanics. Have a magic pair of objects that exploit this principle, so that any attempt to duplicate the magic state of one of the objects will cause it to be scrambled. There’s no clever way around it because it's axiomatic in your magic’s rules. --- *Using* the key might also destroy it, making it a one-time-use key/lock pair. The mechanism might reset the internal device and key at this time, generating a fresh matched pair. So, the key is different on each use, but this is transparent to the user. Or, the act of checking that the two objects *match*, without revealing what their state actually is, does not destroy it. [Answer] ## EASY: Key is made on demand and usable only once In the post, the OP says that the lock can be magical, but not the key. The OP wants a key that cannot be copied. SOLUTION: Self-re-programming lock, throw away keys. In the REAL WORLD: Passwords that become invalid each time you use them. In the FANTASY WORLD: The backside of the secret door contains the layout of the shape/size/material of the key to be used to unlock it - materials that are near the door (perhaps part of the wall, floor, etc). The "key" then, is the knowledge of how to make the key to unlock it - i.e. the "password". The user then makes the key at the door and unlocks the door. When that happens, the magical lock re-configures, displaying a new key shape and material to be used for the next key. The current key is then useless. To prevent duplication, don't make the key until you are at the door. Only the person successfully opening the door would get the correct blueprint for the next key. If they did not know to look for the next blueprint, then the door is effectively locked forever once they shut the door. [Answer] It isn't clear to me what you are asking. If the only thing the "thief" has is the indentation, then picture the indentation in which a disk would fit. Lets say that there are 100 pins in the door which fit into 100 holes in the sides of the disk. If the range of pin lengths/hole depths is such that say there are 5 "different" lengths, then there are 5100 possible combinations. If the mechanism takes, say, 1 minute to cycle through an attempted unlock process, then it would take about 1058 years to have a 1-in-a-million chance to "get lucky" with a random configuration of holes. (One trick I'm using here is that the mechanism can't be "attacked" sequentially, which is the way the typical tumbler & pin lock is picked. It's an "all or nothing" type lock. The mechanism for that would be complicated, justifying a long-ish opening cycle.) So, the only way to copy the key is to have either possession of it, or fairly accurate measurements of its size as well as the depths of the holes. Could it be copied? Sure, but even if the copier had a portable "indentation" with pins which would record the hole depth for each of the holes, the copier would have to have physical possession of the key for long enough to use the copier (same is true of photographing or otherwise measuring the holes' depth). But if the copier can access the key, then why not just use the original? If the key is kept somewhere that insecure, then why bother copying it? If its possible for a copier to get physical possession of the key for only a short time, then the question is one of technological reverse engineering. Say some of the holes have an electrical or magnetic or acoustic or fluidic circuit from one hole to others. And say there are 20 of those connecting two or more holes. How would the copier know that in order to copy it? Each possiblity would have to be tested. You could imagine all sorts of requirements to make it difficult to copy. *Difficult* as in *time consuming*. *Difficult* as in *requiring a lab*. And as I already said, if you can take the key to a lab and spend hours and hours studying it, then you may as well just steal it. [Answer] > > The way to unlock this archaic door? A strangely shaped stone. By placing it into the indent, the vault opens. > > > Scenario: **no advanced technology**, therefore **no sufficiently advanced technology to be called magic** (otherwise we could bury inside the stone a military-grade tamperproof RFID crypto transceiver and call it a day). In the "low tech, but high security" scenario we can't make an *uncopyable key*, but we can build a lock that needs more than a copied key - it requires *knowledge*. The key plus the knowledge could be thought uncopyable, if the very existence of that knowledge is kept secret. The lock is free to rotate (i.e., the bevel where the indented stone is to be placed is round, and can rotate just as a lock can do when the correct key is in). The correct indentation - which can be supplemented by e.g. magnetic coupling between the "lock" and several parts of the "key", which can be made half of copper, half of magnetic iron ore - engages a sliding pin, and *now* the rotation will move, say, three disks inside the lock, working like a safe's disc combination lock. With the correct "key" or a good enough copy in, you also need to give it three turns sunwise and stop at a precise position, two turns widdershins and stop at another position, one turn sunwise... and only when finished can you push on the "key" and, *if* the combination was correct, the "lock" will be free to go inwards -- and *that* will open the door. If you don't have the correct key, or you do not know the correct combination, the last part won't happen. But you will not be able to verify whether the key is correctly made, since also a bad key will allow rotation. Brute force attacks can be thwarted by having the final "pressure" on the lock engage a piston before going fully in. Then, the lock does not reset until the piston returns to its rest position. Several mechanisms are available to make sure that this only happens after a suitable time. One could also use a simple ratchet counter, so that after a set number of incorrect attempts, the delay is increased (for example, one of the two weights returning the piston to the rest position is removed). Finally, instead of resetting the lock, the system could simply make it so the pin does not engage at all, so that *no* combination is correct. At that point you need to either know the combination, or know the lock reset times: otherwise, not only your only resort is brute force, but even that might avail you nothing - after days of bruteforcing, you have tried all the possible combinations, *and none works*. To add confusion to the mix, and avoid keen-eared thiefs from figuring out the combination by hearing the pin slide and hit the stops, you can also install inside the outermost ring some broken springs and bits of rust. Most people would hear the rasping metallic sounds, notice that the lock can rotate freely and yet nothing happens, and conclude "Darn. It's been broken. Now it probably can't be opened anyway". [Answer] One way is if you made it out of something that radioactively decayed in a very predictable but unique way, and have a sensor in the door that can detect it. So the elements in the key decay. You slide it in and the door reads it, decides that it matches, and unlocks. If you made a copy using the same elements, it would be impossible to find samples that were decaying in exactly the same way, and so they wouldn't match. Using magic only you could maybe do it with crystal vibrations or something that is slowly changing over time in a way that the magic can anticipate. [Answer] **The quick answer is: No** Nothing is impossible to copy. All you can do is make it harder to copy. If you make it difficult enough, it may cost more to copy the key than you get from using the key. The reason for most locks is mostly to say: this won't be easy, go break into the home/car/etc. of someone who is an easier target. Even if you allow magic for making the key/lock, you have to allow magic for bypassing the lock. [Answer] Make a key with internal element ! The key will be a kind of box. The door will open the key, and will be unlock by the internal elements. It make the key impossible to copy without the door. I don't really know how to build that, but I think this is possible. [Answer] Let's separate the components of the problem. We'll make a non-magic purely physical world key, and a magic lock to read the key. The key will be made by embedding many hundreds of small crystals (garnet, amethyst, ruby, diamond and so on) into a simple molten glass melt formed into a cylinder. The key is essentially random; they made the key, then adjusted the lock so that key alone opens it. When the key is inserted, the magic lock shines magical lights of different colours from different angles all around the outside into the key, which bounce off the crystals, and the lock magically measures the output light signal at certain positions. When the correct combination of light measurements is obtained, the key is valid. Using this approach, anyone looking at the lock gains no information about what type of thing or configuration is required to activate the lock. Even if you had the key in front of you - perhaps in a display case - you could never copy it. The output of the light beams bouncing off the many crystals is critically sensitive to the exact 3-D shape, size, position, overlap, colour, internal flaws, and orientation, of the many hundreds of tiny crystals. A tiny mismatch of any dimension will be magnified by internal reflections into a non-valid output. This has nice aesthetics for a magical campaign - the key doesn't look like a 'key', but it does look special. And whenever anything is put in the 'lock' there is a nice magical light show. [Answer] ### Refraction Not only does the key have to be shaped correctly and of the correct mass, it has to refract light the same way. The lock accepts the key, rotates it to match the correct placement, and then shines light through it. If the light refracts through the gem in the correct way, with the right color changes, the door opens. This even has some precedent in fantasy. Remember the scene in the Hobbit? They place the key and then have to wait for just the right time for the light to shine such that the lock is triggered and they can go through. You don't have to use a super secret time if the lock can generate light itself. This works because refraction is more individual than shape. It is based on characteristics of the inside of the gem. Sure, you can make another diamond of the same shape and weight, but the color and direction of refraction is going to be slightly different. The lock should be able to detect such differences. If the gem itself can't be copied by magic (because it is an anti-magic material or because magic would leave a signature that the lock would recognize), then the key is unique. The lock was built to match the key. The key may have been shaped, but its real uniqueness was the randomness of its natural creation. I prefer that the key be made of a naturally anti-magic material. Since that would prevent the key from being copied exactly, it seems rather foolproof. If the lock detects material made by magic copying, then someone could make the key not work by casting magic on it. Also, it seems possible that someone would find a way to remove the magic traces. Then the whole system falls apart. Of course, that might be a useful plot point... [Answer] An in-universe approach could be using an extinct (preferable to rare), unfaceted crystal with an ultra high hardness (think a diamond) which is made of two matching halves and is incorporated into the gate/wall/safe. Now for the additional complexity of the lock : 1. Due to its crystalline properties this material cannot be replicated in nature or forged by your population. All crystals created by natural circumstances are different. 2. Both halves having an ultra-refined uniquely-matching contact face pattern which occurred naturally by breakage, either by magic or force-majeure considering the history of your environment. 3. On contact both faces match not only by the physical face but also by the physical hardness meaning another material will break when the needed force is applied. This also prevents it being picked by molding/casting. 4. The lock would be opened by a tremendous physical force/effort, either by applying that physical force either radially, vertically or horizontally. 5. You can use the frequency of crystals creatively as in providing a second scan pattern, it could be triggering anything from light to melody to magic. 6. You can be much more creative with the frequency and energy that could be transmitted/transferred with a crystal to your universe, for example it could be linked with the frequency a specific brainwave as in channelling a thought by a specific character to the lock as an extra lock scan. That's pretty much the tip of it, I suggest you have a read about crystals and their properties to get an idea how you can extend the lock's safety and the creativity of your lock. Some inspirational links: * [Material properties of diamond](https://en.wikipedia.org/wiki/Material_properties_of_diamond) * [Creating a quantum converter](http://vogelcrystals.net/creating_a_quantum_converter.htm) **Have fun and be creative!** [Answer] As others have said, it's impossible to make a key that can't be copied. However, that's not what you are asking for here. You have a keyhole and want to keep someone from manufacturing a key that fits it--the counterfeiter doesn't have a key to copy. While you can't make your lock unpickable you can go a lot farther. The indentation is merely for guidance, the "key" contains a bunch of magnets. These pull on the pins in the lock--and you must only lift the correct pins. The number of possible patterns is 2^(number of pins). Use enough pins and the lock will have crumbled to dust over the ages before the counterfeiter hits on the right combination. [Answer] The reason that only the oddly shaped stone opens the lock is because there are powerful magnets hidden at irregular places under the surface of the stone, which either attract or repulse pins hidden under the surface of the lock. Even knowing this, the key is difficult to reverse-engineer. The shape of the key is crucial to align the magnets, but is otherwise irrelevant to the actual unlocking. The advantage to this system is it matches the observed behavior --the stone and only the stone unlocks the door --without requiring too much in the way of advanced science to create it. The hardest parts would be obtaining strong enough permanent magnets, and then concealing them under the surface. [Answer] The key contains an encrypted computer chip of some kind. You can copy the shape all you want, but without the data stored inside your lock does nothing. The lock provides power, but the power levels change and only the original keys knows the right responses. The circuits are delicate so any attempt to copy it could destroy the original. The conductors have to be in the exact right spots in the key to pass the current around. Also decoy conductors that do nothing, or detect damage/copying and de-activate the key. Another suggestion, the actual key doesn't fill the whole lock, and anything that fills the whole lock will be a dead give away to the lock what your doing. People will assume the key was broken into pieces and scatted for security, when actually it wasn't. Some many spend entire life times searching for missing fragments. You asked about physical copy protection for a key with no magic. To even begin to copy a key you need to make it so it isn't just shape dependent. 1. public key/private key computer chip inside key. 2. Wires, embedded into the key made of different materials which conduct current better/worse than others. There would be a series of 100+ conductors on the surface of the lock, and the real key would have a specific pattern,including decoys, in it. 3. **The correct key should not fill the whole lock!** Any attempt to fill the whole should be a hack attempt and de-activate the lock for a month(or some penalty). Maybe crush your fake key. Beyond looking at the locks shape, and possibly scanning the lock the fake key maker would have no idea the key contained a chip. They maybe be able to detect wires in the lock, but they will have no idea which ones are input,output, fakes, or trojans. They could probably detect the types of metal wires in the lock, but the key could have dis-similar metals touching on purpose. Even 20 years ago we had basic computer memory chips, and the chip could be embedded into the middle of the key, and contain 32768 bit key(or whatever you want). ----Prisms/light If you want to remain relatively primitive, as in no computer chips. Use glass and/or diamonds for prisms. The edges of the key will have tiny holes to let light in. Say 100 of them, for example. Unless you physically have the key you won't be able to copy it. You won't know which holes are input, outputs, fakes, dead ends, or etc. Each hole will have different color refactors. You input blue here and yellow there, and a specific shade of green comes out. That green light is then mixed with other input sources. At different stages, you will have output pegs, where the lock checks the correct colors are coming out. -------------basic keyboard A key that contains buttons to push. The buttons on the key extend or retract metal rods to various lengths or positions. Sure you copied the key, but of 100 buttons, which ones in which combination need to be pressed and how far. [Answer] As others pointed out, a completely uncopyable key is effectively impossible. Shuffle a deck of cards, and there are 52! combinations, which is a [Massive number](https://www.reddit.com/r/theydidthemath/comments/1x4mw3/just_how_many_possible_card_combinations_are_there/). It is still entirely possible to shuffle a deck twice, and have the resulting deck be in the exact same order. If it can exist, it can be duplicated, from DNA to fingerprints. The only way around it is Magic that specifically says it cant be duplicated, which even in a Magic world makes almost no sense. Removing magic as a factor, all you can do is make it as complicated as possible. That being said, one of the most complicated physical systems would be a mechanical/clockwork device and key. Using gears and such, a device which while turning also changes shape would not look like a key normally, and also due to its mechanical nature means that you cant just copy it. Its complexity would prevent all but advanced clockwork mechanics from even understanding how it works, and anyone else messing with it would probably break it. If it opened like a star as it turned, but also had other protrusions, all of which need to rotate with and/or against the door as the key turns in order to solve the maze like lock, then you could be pretty sure that only a few people could ever copy it without breaking it. If the lock also required multiple points of contact to turn, and was irregularly shaped, then it could be rendered near impossible to pick without several people and specialized tools that probably wouldn't exist normally. At that point, its easier to flat out break the door down, or go around through the rock. As the story of Brahm of League of legends goes. He couldn't get past a indestructable door to save a troll child, so he used his fists to punch a hole through the mountain around the door. That will probably be the way someone gets past the door if it gets this complex and is strong. [Answer] In the comments, I noted that if the lock itself is allowed to be magical, simply have that magic specify that the real *Amulet of McGuffin* be used. Magic can definitely do this, because, hey, it is magic. In this story trope, it is almost always one of two things: *any* object in the *right spot* would work, if you know, *or* it's this: the spell requires the *right object*, and isn't fooled be substitution. However, if that doesn't feel satisfyingly specific enough, how about: the magic can detect the *age* of the item — specifically, the time of its manufacture. Since it's magic, this can't be fooled, and it can't be copied without time travel. I know another answer already mentions age as one of a number of possible factors, but I think it's actually completely sufficient alone. [Answer] The key is copyable, but you still need to know how to penetrate the vault. Consider the design of ancient citadels (pre-gunpowder). The gates lead into a narrow tunnel, beyond which is another gate. The very thick walls are pierced with small holes through which the defenders can fire arrows and thrust spears., and the equally thick ceiling with holes through which the defenders can pour burning oil or acid. You may break down the first gates, but you will never breach the second set. Should enough crazy men try, the tunnel will soon be jammed with corpses. So to this vault. We already have granted, that the walls are magically unbreachable. The key can be copied, but what a copied key grants you is access to what is effectively an airlock. In front of you is another similar door, a large array of small holes, a supply of pegs that clearly fit in the holes, and (maybe) some mummified corpses or skeletons. Do you feel lucky? You may work out that you must enter, close the vault door behind yourself, and then insert the right number of pegs into the right holes. You can then attempt to proceed through the second door. But what other things must be done, to avoid or disarm the trap? In fact, the key that you have a copy of, is actually there in the interests of not slaughtering the merely curious. The *real* lock is a combination mechanism, on the far side of impenetrable walls, possibly with added lethal traps. A modern man will recognise this as not dissimilar to the PIN he types into his ATM, but built in times when a wannabe thief's life was less highly valued. Security 101: "Something you have, **and** something you know". You have, but you do not know. An ancient would more immediately recognise the similarity to the entrance to a citadel. As an added twist, maybe there is a large wheel on the outside, which requires very considerable force to turn against a ratchet. You are clearly storing a large amount of energy into a large spring of some sort. The outer door will not unlock unless the mechanism is wound. Sudden release of this energy is clearly how you will die, if you decide to play this lottery. You consider donning some very strong modern armour, but surely a civilisation that could create magically unbreachable walls would have considered the possibility of magically unbreachable armour? You may conclude that the threatened rapid death by sharp steel was not vengeful but a mercy to the merely suicidally impetuous thief. Starvation, or something magically worse, awaits the well-armoured thief. The door through which you enter, will not unlock again until you have proceeded through the inner door, or until you have drawn your last breath. [only the detection of last breath requires magic. A combined citadel entrance, spring-driven man trap and combination lock, is well within the reach of a renaissance engineer and a civilisation with good metalworking skills] [Answer] Under your limitations there is no way how to prevent a key and lock from being compromised. Once it is identified as a lock or key there is a way how to prepare a forged key. The only way is to prevent anyone from understanding that that strange stone is a key and this tiny hole is a lock. For example, have a long corridor with many ancient statues. Part of them are locks and you have to put keys (pieces of a wand, gems) in their mouths, [eyes](http://www.kunstkopie.de/kunst/michelangelo_buonarroti/david_head.jpg) and ears. You can use any natural detail to hide the true function of the lock and you can use amulets to hide their key purpose in "just a decoration". [Answer] **Asymmetric Key Lock** Simple, the key which locks the Mechanism(M) is different from the key which opens it. After it has been used for opening, it becomes the new "Lock" key. Only the lock key protrudes the Opening Mechanism (O): after O has been inserted in a locked M and the lock key (currently protruding ) is verified, the unlock key protrudes and unlocks M while the lock key draws back. Alltogether O,M have n such keys at any time, n-2 are stand by n-1th is unlocking and the nth protruding one is locking, which changes at every lock/unlock. Atleast for first n lock/unlocks the system is fully secure [Answer] If you are the creator of this world and things like magic exist, then you can make fictional additions to create effects you want. Since you seem to want a plain oldschool idea of a key the most suitable solution in my opinion is the following: The key for this door can be of plain, copyable shape. That is something you cannot avoid. However the element used to create this key can be unique. If the order that guards the temple has used a specific alloy or metal of greater strength and density than any other metal in your earth, and assuming it came from a meteor for example, to create *both* the lock and the key then it becomes impossible to copy. Where does a different extraterrestrial metal help? Locks are made so that they have pins and edges that a key's shape is supposed to push and turn. If the lock breaks any type of key except one made of equal material strength then only your unique key can open it. Simple and old fashioned solution with a little bit of salt for the story [Answer] Both key and lock mutate each time they are used. Any attempt to read the key causes it to mutate, throwing it out of phase with the lock, making it useless. You didn't specify if the key had to be recoverable, so I assumed no. [Answer] The problem can be solved by requiring knowledge. First, to keep this real, the key is nothing but a fancy square bar. one end goes into a socket within the lock. The keyholder turns the key until a gear pulls a bar from the door frame. We know this is doable at the tech level. Now imagine the key has holes in it. There are rods that drop in the holes. Part of the lock mechanism includes levers that can lift rods... Or push rods up from underneath. Some levers could serve as a type of clutch to inhibit or augment some of other levers' behavior. This is some weird cross between a normal tumbler lock and combination lock. I am certain I could build one. I assume a motivated skilled ancient could also. I'd add a bell or chime to the inside of the lock so as the key was turned it would make noise. I could see the 'combination' would have 64 possibilities. So the bell could be ringing quite a lot. After a few extra rings, the caretakers could investigate. ]

[Question] [ Inspired by Frank Herbert's *Dune*: Action Joe is kept prisoner in Doctor Evil's prison. Doctor Evil knows that Joe's escape is inevitable. So he decides to introduce **poison** to Joe's body. Joe gets his **antidote** in his daily food rations. Once Joe stops eating **antidote** he should die, regardless of how much of the antidote he has eaten. Things to consider: * The person to be given the poison is a classical action hero (a physically active guy who is well above average in all metrics). * The antidote should be something considered "not poison" so that Joe has no chance of realising he is being fed antidote. * The antidote has to be consumed (eaten). * The quality of food is going to be classic "prison food", so the antidote can be something generally untasty. * The poison is introduced to Joe'sbody while he is unconcious, so there are almost no limitations except one: introducing poison to a body should make as few body marks as possible (say injection is OK, but general surgery is not). I know that a similar premise was used in *Jurassic Park* but there the dinosaurs were genetically modified. I feel that modifying Joe is also beyond plausibility. And as stated above: the poison and antidote should be something plausible. No hard science is required. Also, later in the story not only is Joe is going to escape (surprise, surprise), but he should know about his condition. So bonus points for mentioning some cure which cures Joe forever. **EDIT:** Dr. Evil's motivation: he is going to offer for Joe to work for him. But the Dr. is not stupid and assumes that Joe will betray him and/or escape at the first possible moment. Also, Dr. Evil is cruel by nature, so he wants to kill Joe once Joe is not needed, without actually being accused of the killing. [Answer] This is actually pretty straightforward. The toxin is targeted at a critical organ or function, and the "antidote" is not actually an antidote, but rather provides the same effect as the now-missing organ. A simple example would be a toxin which comprehensively destroys the Islets of Langerhans, while the "antidote" is insulin. A slightly less common case would be thyroid/thyroxine. In fact, Dorothy L. Sayers wrote a Lord Peter Wimsey story, "The Incredible Elopement of Lord Peter Wimsey" about a sadist who punishes his wife's possible infidelity by withholding her thyroxine tablets (she has hypothyroidism) for long periods, turning her into a cretin. EDIT FOR THE SAKE OF HONESTY - Sayers was either mistaken or taking literary liberties. [Hypothyroidism in adults](http://www.endocrineweb.com/conditions/thyroid/hypothyroidism-too-little-thyroid-hormone) does not produce cretinism. It's a developmental issue, so my example is not actually correct. But I enjoyed the story a great deal, so I won't delete it. There is, of course, a drawback here - these conditions are known and the counteracting medications readily available. Here is where authorial license comes in. There are any number of brain functions which might be controlled by an as-yet-undiscovered chemical. Oliver Sacks has written an excellent book "Awakenings" about sleeping sickness patients whose condition was caused by dopamine deficiency, and feeding L-DOPA (a dopamine precursor) made amazing improvements. At least temporarily. Likewise, destruction of the substantia nigra (or at least dopaminergic neurons in the pars compacta) produces Parkinson's. A toxin would be asserted to be able to destroy some critical function, and the prison (or more probably the central government which administers the prison) is in possession of some secret therapeutic material which will provide function. EDIT - It has been suggested that I address the possibility of recovery. I see at least 2 possibilities. The first is that the damage produced by the toxin is temporary. With supportive treatment the affected function will recover. To put it a bit inaccurately, it's not the disease that kills, it's the symptoms, and if you keep the symptoms from killing the body will eventually recover from the disease. An example might be tetanus: the cause of death is not organ destruction, but rather asphyxiation or heart failure due to sustained muscular contraction. Keep the blood oxygenated and the patient will (probably) recover. Another example would be the Milwaukee Protocol for rabies, in which the patient is put in an induced coma to prevent (more or less) brain damage while the immune system gets control of the virus. Note that this example is iffy - one study suggests an expected 8% success rate. At any rate, in this version of things the replacement medication only needs to be continued for a limited duration. Of course, this implies that the toxin will need to be readministered at regular intervals if Joe is expected to be a prisoner for a long time, but frankly I don't see this as an overwhelming problem. Joe is, after all, a prisoner and at the mercy of the EO. The second possibility is as straightforward as the original suggestion: transplant. One experimental therapy for neurological conditions such as Parkinson's is the transplant of fetal brain tissue, which is hoped to replace reduced function in the affected portion of the brain. The author can have any amount of fun developing the mechanism and pitfalls of the process - compatibility (note that fetal tissue is somewhat different), sources, recovery therapy, etc. [Answer] What about [Decompression Sickness](https://en.wikipedia.org/wiki/Decompression_sickness)? Joe could be kept in a prison kept at a high air pressure - both the toxin and the antidote against the effects of ambient air pressure - (needs not be underwater, even though divers in real world are most aware of this). Joe could be unconscious while his prison is being pressurized, and he will never be the wiser: it won't leave any marks. Depending on the pressure, suddenly escaping from the pressurized environment would be highly unpleasant, harmful, or even fatal. The most obvious cure would be slow decompression, which can take a lot of time (and needs the necessary equipment). Building such a prison, one would have to design it so that an escapee does not have access to the airlock (or at least the pump) and will have no other choice than to emerge into normal air pressure at once. Well, perhaps disguising the airlock as an elevator... when you enter a certain secret code, it follows the slow decompression protocol, but when an escapee who does not know it just presses "ground level", it depressurizes rapidly to ambient pressure and opens to the outside world. Of course, access to Joe from the outside world would be through that airlock, which for humans may take a lot of time because of the same reasons. But not for robots or other mechanical means of delivering his food. Food in airtight packages (bags, bottles, etc.) would give the game away as the contents inside the package would have much less pressure than outside and so be squashed flat. He could be in contact with his captor (and other humans) through CCTV (etc.). No physical contact. Except maybe in emergencies, e.g. medical treatment, where the personnel could reach him fairly quickly, but will need to go through lengthy decomp when they leave. It would probably take some good money and specialized skills to build the prison (think spaceships or [deep-sea vessels](https://en.wikipedia.org/wiki/Bathyscaphe)), but in a way that it is not obviously a high-pressure container to its inhabitant. But could be done, e.g. housing box made with conventional materials and techniques, inside a large high-pressure (round) cylinder. Or an old (still sound and tight) submarine hull could be repurposed if one has a handy one lying around... [Answer] I'm not sure if this one meets your rules or not: Instead of a poison/antidote, how about something addictive with lethal withdrawal symptoms? (Note that there are things close to this in the pharmacy--once your body adapts to them if you suddenly take them away it can't adjust fast enough and you might die.) [Answer] Nanobot. A normal poison would be sooner or later flushed out of Joe's body, while nanobot can reproduce themselves in his system. The antidote would be just a way to keep them in standby, without it, things get messy. Joe can be cured later by any kind of low yield EMP pulse, a blood replacement from his beloved Joe Bond's girls or his pet bantha. Some dissease would work more or less the same way, but to be powerful enough, it would need heavy biological engineering. [Answer] The tricky part is that most antidotes remove the poison. We have to be clever. If the poison actually caused Joe to develop an autoimmune disease, his own immune system would become the real poison. The antidote could then be immunosuppressants. If you want a cure, you could play with the idea of trying to re-teach the immune system not to hate itself. I do know this is done with allergies, where you slowly introduce allergens to try to get the immune system used to them, but its unclear whether this could work with a particular poison generated autoimmune issue. [Answer] There are many fat-soluble toxic chemicals (mercury, DDT, tetraethyllead, etc.). These will be absorbed by the body's fatty tissues. While embedded in fat, they might not cause an immediate health threat. However, when the victim is physically active, the body burns the fat and releases these toxic chemicals into the bloodstream, resulting in a sudden toxic dose of the poison. Our hero would need an immediate dose of some sort of antidote that neutralizes the toxin's effect (chelation therapy for heavy metal poisoning, for example). He would also probably need small doses of antidote over longer periods of time even with low activity, since some of the poison will make it to the bloodstream regardless. This is similar to what you're looking for, but it depends on the hero's physical exertion, rather than just leaving the prison. Since Joe is your typical action hero type, this might put a damper on his thrilling heroics. It might even prevent escape if that escape is physically strenuous. I would guess that Joe could cure himself later on by a controlled release of the toxins. Exercise together with a carefully regulated antidote regime would release the poison and neutralize it so that his body could eliminate it. This would be a long process, as Joe would essentially need to burn off all of his fat, then put it back on to get back into fighting shape. [Answer] The answer to this question sits on the shelf at the BBEG's local hardware store. It's called d-CON. No, seriously. The second-generation superwarfarins (such as brodifacoum) are exactly the poison you seek -- they have a long half-life in the body (in the weeks to months range) due to being highly fat soluble, are capable of being quite insidiously lethal due to their mode of action, and can easily be antagonized by a steady diet of green vegetables (as said vegetables are high in vitamin K, which counteracts the effects of coumadins). However, if Joe gets out and reverts back to his fast-food-eating ways...he'll be in the hospital or worse. [Answer] The opposite of Cort Ammon's answer: Keep him in a sterile environment and feed him immunosuppresants. After a while, he will develop severe immunodeficiency (you can remove the drugs at this point) and in case he escapes, meeting with other people will infect him with all sorts of lethal infections (flu can be fatal). Quick medical action and correct diagnosis can save his life, but recovery will be probably long and non-trivial. [Answer] You could have a retro virus, use it to somehow cause a disease that causes the body to go into a state where the blood is constantly coagulating, meaning that the daily doses of antidote would be anti-coagulants meaning that he wouldn't be cured, it'd be suppressing the coagulation. This disease [here](https://en.wikipedia.org/wiki/Antiphospholipid_syndrome) would do the trick, but you'd have to bump it up to 11 on the aggressiveness scale. This could be introduced by messing with Joes DNA, using a retro virus which would leave no marks (I'm assuming the evil genius is intelligent enough to be up-to-date in gene manipulation). This would also be the route of the cure, as if Dr Evil believes he can turn Joe, he wouldn't want Joe to be dependant on the antidote for the rest of his life. So he would keep a copy of Joes original DNA somewhere to repair the damaged DNA in Joe. [This article](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4228919/) on reprogramming cells shows that it is used to treat a whole host(sorry) of viral infections. It might help with the plausability of modifying Joe. [Answer] Most poisons need to be continually reintroduced in order for the antidote to continue to be necessary. Otherwise the poison will be flushed out of the system over time, or completely negated by the antidote. What I'd propose is a two-part system. You have two poisons, A and B which work independently. Basically, you give the prisoner a dose of Poison A and Antidote B in their breakfast, and Poison B and Antidote A in their dinner. So long as they eat both meals every day (and they most likely will or else they'll starve - make sure there's no other way to get food), they will continue to have one or the other poison in their system, but it won't kill them. The first time they skip a meal, the poison from the previous meal will still be in their system and kill them (or at least make them very sick - you might need to miss 2 antidote doses for it to actually be fatal). The way to get out of this is for Joe to figure out that it's coming from the food (maybe he's forced to skip a meal for some other reason and he gets sick, and does the math), and slowly wean himself off of the meals. (Possibly figure out which part of each meal is poisoned, and which has the antidotes - is it the bread? The water? The potatoes? Maybe they mix it up every day so it's not obvious, but there's a pattern he can detect over time if he's really observant.) He'd suffer from malnutrition, and possible minor side effects of the poisons from taking a lower dose of the antidote, so it wouldn't be easy. He might be able to live by catching rats or other vermin to use as an alternative food source. [Answer] what about if the poison is actually a toxin that, destroys certain kinds of cells, or the ability for the cells to produce certain vitamins or amino-acids.. this should mean that if the subject does not take that regular amount of vitamins his body would shut down and die. Imagine if you will, a poison that destroys your Pancreas, without a daily regular dose of insulin you will die. of course the true effect of the poison should be something that is not easily diagnosed by a doctor.. and if you need something really credible you should maybe ask a biologists.. else just refer to some amino acid/enzime.. and make it sound plausable [Answer] You could postulate any kind of chronic infection which releases a toxin. In real life this could be something like *Clostridium botulinum* which kills through the release of a potent neurotoxin and is treated with an injectable anti-toxin. It's easy enough to imagine a genetically modified organism being implanted into Joe (e.g. as part of a meal so that it colonizes Joe's gut). It then releases a toxin that can be treated with a nutritional supplement (e.g. like warfarin being treated with vitamin K). [Answer] The other answers are correct, there's no direct way to do what you are looking for as a "poison". It might be possible with some form of chronic illness or the very innovative high pressure area. There is an alternative though, which is that you actually make the antidote the problem. Find something that has really nasty withdrawal symptoms and then pump his system full of that. So long as he keeps taking it he is fine but if you remove it then the withdrawal kills him. That's closest to what you seem to want in that it doesn't require any special architecture or facilities, just something to keep slipping him a daily dose of the substance. The cure would be weaning him off it gradually (i.e. he gathers a stash and takes it with him then takes gradually reducing dosages) possible accompanied by medical care and/or something to mitigate the withdrawal. [Answer] How about a large internal parasite? Joe has let's say a worm inside of him that he is unaware of (attached to the intestines perhaps). This worm produces a waste product that is toxic to Joe and would kill him. Joe consumes the antidote to this toxin to stay alive. If Joe ever finds out about the worm and has it surgically removed he no longer gets regular doses of the toxin and is permanently cured. The parasite could even have been fed to Joe without him realizing it to initially administer the poison. I have been told by exterminators that some mouse poisons are rendered inert by cat food. (This helps reduce incidents of pets being killed accidentally during an extermination, but means you have to also prevent the mice from having access to the cat food.) So I can imagine similar toxins in humans having antidotes present naturally in a specific diet. Or perhaps the parasite simply has a knack for reducing Joe's ability to absorb vitamin C resulting in scurvy unless Joe consumes vitamin C in shockingly large quantities. [Answer] Posted this as a comment but realized it's actually more of an answer. There are already several good ones but I just wanted to throw this out there in case it inspires you. *Neuromancer* has a somewhat similar plot device wherein a character is implanted with tiny toxin sacs that slowly degrade and they must remain loyal to another character in order to get the cure. This could be modified a bit to fit your scenario. The toxin sacs are tiny, maybe they contain something extremely lethal like botulinum, so you don't need much to kill Joe. This means they would leave virtually no scarring from being implanted and could even go somewhere out-of-sight like the back of his neck next to his spinal cord (the ideal place since botulinum is a neurotoxin). Now in *Neuromancer* the sacs degraded over a long period of time, but in this case maybe they break down much faster. They're made from organic tissue so the body could be actively trying to absorb them. The "antidote" could either be some protein that binds to the sacs to "replenish" them, or it could be a chemical that prevents the body from absorbing them in the first place. Either way, within days of stopping the antidote the sacs would be absorbed and the toxin released. The total cure would simply be locating and removing them, which would be a delicate but ultimately not-impossible thing to do once Joe knows about them. [Answer] **No Poison at all.** You don't need to poison him. You need to make him believe he was poisoned. Give him a real poison, and let him suffer the first effects. After that, apply the antidote in a visible form (injection is best), and let him know that this will stop the toxin from working for a while. Which is a lie, but he doesn't need to know that. After that, give him poisoned food, and let he feel once more the effects of the poison before applying the antidote. Do this a few times until he believes that he was poisoned in that manner. Once he believes he is poisoned with your special poison, do the offer for work. If he accepts, you start providing him a stronger dose of the 'antidote', which will hold the effects of the poison at bay for a longer time - a day, a week, you choose. At this point, you just brainwashed him into working for you, and don't need the poison anymore - just making him believe he is poisoned will be enough. [Answer] I don't know of an actual substance that works like this but I can think of a mechanism by which you can justify it. This poison would have to be something that the body can't clear out. Maybe it deposits in the body somehow or the kidneys and liver can't clean it from the blood. Something like that. Then, it has to work via some very specific chemical pathway in the body. Maybe it latches on to some kind of receptor in the cells. However, this might be the hard part. Mostly because of the way the antidote would have to work. Finally, the antidote would have to be something that wouldn't degrade the poison. The way to do that is to have some sort of substance that blocks the chemical pathway that the poison takes (like a receptor agonist). It competes for the cellular receptor and gets preferential treatment. [Answer] Instead of a poison, a disease. You need something with two forms, one that hides out and one that's active. The "antidote" is a treatment for the active form of the disease but it can't touch the part that's hiding. (As for what looks like this--how about some sort of spore-forming bacteria? Many antibiotics can't touch the spores. Take one of those and turn up the lethality.) [Answer] * damage Joe's pancreas. He will require insulin to stay alive. Con: insulin is digested, so Dr Evil have to invent prodrug ("a biologically inactive compound which can be metabolized in the body to produce a drug"). * make Joe allergic. Dr Evil puts some "bags" under Joe skin to slowly release allergen. Antidote is antihistamine drug. * genetically modify bacteria to produce deadly toxin in absence of some substantion. Place bacteria in Joe's intestines. [Answer] Inject him with a small explosive device near the brain stem. The device is constantly listening for a radio signal that is being transmitted around his cell, like a dead mans switch. The device could be small enough that it could be put in with a needle, similar to how animals are tagged with RFID chips. The explosive itself could be very small since it wouldn't need to blow his head off, just mess up the brain stem. The explosive could also be used to drive a spike or something like a miniature gun, or even break the capsule and release some toxin. When Joe escapes his cell and goes outside the range of the radio transmitter the explosive triggers, killing him. You could let him know that it's there by watching another prisoner try to escape, or DE could give him a warning by injecting a dog or some other animal and throwing a ball for it to chase down the hall. Joe could make a daring escape by hooking the transmitter to a battery pack and taking it with him. This adds to the suspense by needing to make sure that the battery doesn't come unhooked, and also he has to get somewhere safe where the device can be removed before the battery dies [Answer] **What about multiple poisons?** When Joe eats his breakfast cereal, he eats `Antidote A` and `Poison B`. For his lunch he gets `Poison C` with `Antidote B` and for dinner `Antidote C` and `Poison A`. And next day entire circle starts again. [Answer] A lot of suggestions have been offered, but none seem acceptable on all requirements. So here is an even more whacky suggestion. What about a poison that poisons the *mind*, rather than the *body*? I'm talking of something like [Stockholm syndrome](https://en.wikipedia.org/wiki/Stockholm_syndrome). A notable example in real life is [Patty Hearst](https://en.wikipedia.org/wiki/Patty_Hearst). Anybody with some knowledge of the appropriate science and the necessary means can apply the biological run-of-the-mill type of evil if needs be. To pull off this sort of psychological manipulation would to my mind require a whole deeper, darker level of calculating heartless Evilness, spelled with a capital letter. It also has the potential to turn just another action novel into a profound psycho-thriller... Let's look at the requirements: 1. Science-based: well, one can argue that psychology is "not really" hard science. On the other hand, this sort of thing has already happened and is documented (see references above). "Making it work" will leave a lot of leeway to the story-teller, much more than a (possibly implausible) chemical/biological/physical action would. 2. Joe working for Dr E: once Joe is indoctrinated initially during his captivity, he should be a reliable minion to do Dr E's bidding. Not much risk in releasing him into the wild. (viz. Hearst participating in bank robberies). 3. Dr E cruelly killing off Joe: He might not need to do that in the end. On the other hand, an antagonist capable of inculcating a subject with Stockholm Syndrome, could also quite conceivably be capable of implanting suggestions of sufficient guilt or worthlessness so that the subject commits suicide, or otherwise destroys himself (e.g. alcoholism/drugs). 4. Antidote enabling Joe to escape: Well, Dr E might underestimate Joe's psychological clued-up-ness (because he is purported to be this stereotypical all-physical action jock with not much intelligence, see), so once (the more intelligent) Joe (with the deeper character) catches on to the mind games Dr E is busy playing on him, it's all cat-and-mouse subterfuge and counter-subterfuge from then on, potentially leaving the reader to guess "has he or hasn't he" until the end. But as said, that is a whole different story-telling ball game. [Answer] The radiation poisoning from The Expanse series. It is grounded in reality with just a hint of the fantastical (i.e. meds exist that can "counter" new cancers that are constantly popping up). Ultimately, the body is beyond "reapir" so the meds effectively become the antidote. Since the infection method is a high dose of radiation, Joe will never see it coming! [Answer] Two poisons, a lethal dose of anticoagulant and a dose of blood‐clot promoting drugs, these should cancel each other out, but one should have a significantly longer half-life than the other. If he does not take the two poisons then the longer lasting one will outweigh the other and he will die. [Answer] Well There is always the clasic arsenic poisoning. Joe could be fed it in low doses constantly and once he stopped it would have the desired effect of his demise. An example would be the Arsenic Eaters of Styria. [article found here](http://trove.nla.gov.au/newspaper/article/25464882) [another example found here.](http://www.hektoeninternational.org/index.php?option=com_content&view=article&id=825:the-arsenic-eaters-of-styria&catid=95&Itemid=435) [Answer] Easiest answer is the physically calming effects of benzodiazepines. Adding some to food would get him physically addicted. As soon as he is un-able to get his now life saving medication he will die. Also, getting action joe addicted to any sort of drug would be the best answer, causing him as much physical degeneration as possible is probably best in the long run. [Answer] Not to useful but a real world example just came to mind: An appropriate mix of ethanol and methanol. Continue to take the right amount of this and you'll be ok. Quit and you're in deep trouble even without the alcohol withdrawal issues. Unfortunately for your scenario the required amount keeps you pretty drunk and thus you aren't going to be of much use. (What's going on here is that methanol is not actually harmful, the problem comes when the liver tries to dispose of it and ends up producing a toxic result. The offending reaction preferentially deals with ethanol, though. Keep the reaction path saturated on ethanol and the methanol gets dealt with much more slowly but safely. That used to be the treatment for methanol poisoning.) [Answer] Infect him with bacteria or parasites that require a protein that humans do not have or produce but is common in many foods. Then only give the character enough of that protein to preserve the life of the organism. If he is no longer supplied with this food he will eat a different diet high in this protein and allow the infection to grow. Contact with allergens while in a weak state causes an allergy to it. <http://www.webmd.com/allergies/guide/chronic-allergies-causes#1> Maybe he could be injured by something he does not suspect is related and then exposed to allergens. [Answer] Maybe a bit out of the box, but what about a small device is put in the body (not sure if possible without general surgery) that checks for a trace chemical that is given to the person, something that stays in the blood for a short period of time but is not common, if it is not present in the blood, then the device explodes. Got this idea from the movie Crank, where the person needs adrenaline (which he can produce himself by doing dangerous things) so the difference here is that the character would need something that is supplied externally. ]

[Question] [ ## Premise The premise is an adept modern chemist is transported back in time and is to serve as the court alchemist to a wealthy prince in the late 16th century. **Assumptions:** * "Transmuting" gold is the chief goal, but the prince would possibly consider allowing for a different output to be yielded from "transmutation," providing its worth the time and resources * During this time nobility/royalty of the utmost wealth are documented having many alchemists on the payroll, so let's assume the modern chemist is working alongside actual alchemists * The prince's knowledge is expert; he has executed many con-artist alchemists in the past. * The modern chemist has disguised his strange accent/language/culture and has learned the local language, so as to communicate without raising superficial suspicion (of course it won't be *how* he says it, but rather *what* he says) * Though he may have modern knowledge, he has no modern scientific instruments with him; he must improvise everything with the resources available at the time * The modern chemist cleverly used his knowledge to predict results of experiments no one else could, and has worked his way to the position of lead alchemist and is partially immune to social ostracization. This means that he must still be mindful of how he articulates his concepts, but he cannot be overtly ostracized because he is different European history shows that being ostracized by society doesn't bode well for said individual, so the last assumption is particularly necessary. Given these assumptions, which are generous for the chemist, there is still the problem of actually transmuting gold. As far as known science goes, the closest thing the modern chemist can think of that can serve as his "philosopher's stone" is a particle accelerator. He's thinking back to the 1941 Harvard particle accelerator experiment that bombarded neutrons into 400 grams of mercury resulting in a small amount of gold. Alas, in the 1500's there can be no such luxury (tempting as it may be to throw that into the assumptions too), the modern chemist must bring his expertise to bear in another way if he is to save his hide and not be executed as a con-artist by the expert prince. What the modern chemist also knows is this: the prince may be an expert, but that just means he's an expert within the context of his era. Before the advent of modern chemistry, whether or not a metal was considered gold was determined not by its atomic structure (obviously), but rather if it satisfied the right properties: luster, malleability, color and weight. ## Question Could an adept modern chemist lead a team of obedient alchemists to produce a material that is extremely gold-like in terms of its physical/chemical properties? If so, roughly, how would he go about it? (no chemical formulae is required, just a general description) **Quality Metric 1:** The more gold-like the output the better. This way, when rival alchemists present their "transmuted gold" the modern chemist's output will seem far superior, and thus improve his standing in society. To reiterate, by gold-like we mean properties including but not limited to: luster, weight, hardness, ect. **Quality Metric 2:** If you are vehemently opposed to the idea that the modern chemist can yield a material that has properties more similar to gold than the material the 1500's alchemists transmuted, then propose the next-best way to save his skin. [Answer] Why struggling for gold, which any king and even merchant of the medieval world has, when you can go for Aluminum, which no king yet has? * Aluminum is shiny, like gold. * Aluminum is malleable in thin foils, like gold. * Aluminum, once passivated (i.e. covered by a thin layer of oxide), stops further oxidation. Gold is not oxidized at all, but no one will notice that subtle difference. Since you are not aiming for mass production, sized on the needs of modern days, but you need to produce only small batches, you can set up a small electrolytic process to separate Aluminum from Bauxite. Before the invention of the Hall–Héroult process, Aluminum cost was higher than gold, and considering its low density it will be appreciated also the lower burden of its transportation. You will also have 0 risks of some competitor unmasking you, because nobody except you knows the technology and you are actually doing no trick. [Answer] Gold is one of the densest metals in existence. Only a few metals and alloys are heavier, but they are not much easier to obtain, like iridium, osmium, neptunium and plutonium (!). If you use any lighter metal and try to make it look like gold, you will be discovered and beheaded—a method of determining the density of alloys pretending to be gold was discovered by Archimedes around 200 BC: <https://en.wikipedia.org/wiki/Eureka_(word)> Luckily for you, and contrary to popular belief, alchemists were not tasked with transmuting common metals to gold. At least not by smart princes. If you think about it, why would a magician who can produce gold out of common elements even need an employer? To take all the gold from him? That's the opposite of what most smart people look for in employment :) Alchemists, at least those in princely courts, were very educated people. They were doing something much more useful than transmutation: they were improving the quality of **gun alloys** and **gunpowder**. We're talking about an era when artillery becomes a common and important element of war, and handguns are improving to be actually somewhat useful too. The stories of alchemists dealings with Satan are rumours originating in the smell of sulfur and mysterious fires coming from their workshops as misunderstood by the less educated courtiers, and also probably used as cover stories by princes who wanted to keep their real interests secret from their cousins in other courts. In conclusion: **don't bother with gold**. Learn how to make really good **gunpowder** and maybe some alloys, and the prince will give you gold instead of waiting for you to make it from dirt. [Answer] Your modern chemist would be foolish to even try to make or fake gold. Instead, you make something that will cause other people to willingly give you THEIR gold. For instance, look the commercial possibilities in the aniline dyes, which should be easy for a modern chemist, and from which fortunes were made in our own history: <https://library.si.edu/exhibition/color-in-a-new-light/making> [Answer] # The only answer is platinum Many other answers have pointed out the density problem. Since Archimedes was able to determine the difference between pure gold and electrum (gold alloyed with silver) using density, this should be a reasonably well known process for an 'expert' king. If you really want to trick the king into thinking he has gold, the only element that has most of gold's physical attributes (malleable, ductile, non-reactive, and very very dense) is platinum. However, there is still one significant difference: melting point. Pure platinum would not be meltable with 1500s technology, you can't get a fire hot enough until the coke ovens of the later Industrial Revolution. A wise proto-chemist will know this isn't exactly gold. But, I'd hardly say that is disqualifying. If gold is valuable, how valuable is unmeltable gold (you can call it *aurum indissolubilis* in Latin)? ### How to get some platinum There are two basic ways you can separate platinum. First, from nickel based ores, you can try to separate it magnetically. Platinum is paramagnetic, unlike ferro-magnetic nickel and iron. If you run an electromagnet over ground up ore, you could separate out the platinum. This won't be cheap or easy, but with some obedient apprentices, some copper wire, and a watermill, you could build both an ore grinder and a basic dynamo. Second, you can [electro-refine](https://en.wikipedia.org/wiki/Copper_extraction#Electrorefining) a copper ore. You basically make unrefined copper ore into a battery in a sulfuric acid bath (sulfuric acid [was known](https://en.wikipedia.org/wiki/Sulfuric_acid#History) as 'oil of vitriol' at the time, so you could get your hands on it). The majority copper will be dissolved into the acid bath, while the less reactive (or 'noble') elements like gold, silver, and platinum will end up in the sludge at the bottom. So the real challenge is then finding ore with platinum in it. There, I can't really help you, I'm not sure how to identify those ores. But, hopefully, the chemist going back in time has some time to prepare, and get some mining maps or something. # Conclusion If the goal is to simulate creating gold, the best way to do it is to separate platinum from various ores, using one of the two listed methods. This is about as close as you will get to the Philosopher's stone without a nuclear reactor to help you out. [Answer] Forget gold. You can't do it. You can't even come close. If your prince wants riches, how about synthetic gemstones? You might be able to produce [diamonds](https://en.wikipedia.org/wiki/Diamond#Synthetics,_simulants,_and_enhancements) through the chemical vapor deposition process, but the stones produced will be tiny, and prior to De Beers' marketing push, they were considered a fairly boring gemstone. You could put together a suitable oxyhydrogen torch, and fuse alumina into [synthetic rubies](https://en.wikipedia.org/wiki/Ruby#Synthetic_and_imitation_rubies) and [sapphires](https://en.wikipedia.org/wiki/Sapphire#Synthetic_sapphire). Alumina is pretty ubiquitous, and you can vary the color by adding trace amounts of iron, copper, chromium, and other metals to the mix. [Synthetic emeralds](https://en.wikipedia.org/wiki/Emerald#Synthetic_emerald) are probably not an option, since the techniques for making them are still mostly trade secrets, and appear to involve materials or material purities that would be unavailable in the 1500s. The last of the [cardinal gemstones](https://en.wikipedia.org/wiki/Cardinal_gem), [amethyst](https://en.wikipedia.org/wiki/Amethyst#Synthetic_amethyst), requires high-pressure conditions for synthesis, though the main ingredient, silica, is even more common than alumina. You could try making it, but the metallurgy of the time means you're more likely to blow up your lab than produce gemstones. [Answer] Gold is nice and shiny, but you can not eat it and it does not give you any power to protect the gold you do have. But troops are nice. There are only a few problems with them. They need feeding. So increasing food production by inventing **synthetic fertilization** is Huge. You need less people to grow food, you need less land for the same army production. Another problem is logistic of army march. So you invent some basic **food preservatives**. Any of the [simple](https://en.wikipedia.org/wiki/Preservative) ones will do. And you can transport much more food on longer routes. So no war of attrition against your lord. And as for the troops equipment, **steel** is nice but tricky to produce.... if you don't have the right knowledge. And good steel can make your small army strong as a big one. ## Conclusion So going for something petty like producing few grams of gold-like substance is not as useful as providing your lord with the means to rob all his neighbors of the real stuff. ## Afterthought If still in a pickle, just destille some [fungi juice](https://en.wikipedia.org/wiki/Penicillin) and make him really happy Or if you really want something with only value, then produce something like a [purple dye](https://en.wikipedia.org/wiki/Tyrian_purple) that was in the time much more valuable then gold. [Answer] Most of the great questions of alchemy, like transmuting lead into gold and elixirs of eternal life, have not only failed to materialize but turned out to be impossible in any practical sense. So I don't think you have much potential there. As you remark, one could make counterfeit gold, but why bother when there are other much more valuable legitimate things you can make? * Many dyes were extremely valuable, because they could only be produced through laborious processes in tiny amounts. This is why royalty wore purple, for example, it used to be very hard to make the dye and only kings could afford it. * Aluminum used to be more valuable than gold. Many other metals were expensive because efficient production methods did not exist. * Better steels and other alloys can be used for making very high quality weapons. * Chemical fertilizers could greatly improve agriculture, which had a huge influence on the economy back then. * Various methods of preserving food could provide enormous strategic advantage in war and trade. * Electricity could be discovered centuries early. Chemical batteries are not hard to make, even modern generators are pretty straightforward if you have access to a King's craftsmen. * Gunpowder and other explosives are very useful for military purposes, mining and construction. [Answer] **Brew poisonous chemicals & create bombs etc.** A prince may be interested in Gold, in order to gain money and power. But why ? He wants to win against his enemies: other kingdoms. Also, the more Gold floods the market, the cheaper it becomes. So, propose him some poisonous stuff. It helps him to reach his goals, allowing him to easily assassinate leaders causing chaos in the other kingdoms. Also, many poisons are easy to create and show great effect. And even more of them could be of *great* use in battles ! Think of grenades and other explosives, or even *guns*. *To make sure your chemist isn't killed, make him keep all the formulas secret, stored only in his head. That way, if the prince kills him, he looses his advantages in combat and against other kingdoms.* **PS : One example for a family that made their way to power using poison would be the [Borgias](https://en.wikipedia.org/wiki/House_of_Borgia).** --- Also, think of some other nice modern chemicals you could present him : sleeping gas(chloroform) etc. --- ***Totally different attempt : cook some meth/other drugs. Make the prince addicted. And then he'll neeever let you be killed. He'll protect you to the end of his life.*** --- TL;DR *Forget the Gold.* Basically, with modern knowledge and basic education, you could **easily** become his new *leading scientiest* and thus hardly replaceable. By keeping some key formulas etc. secret you can also make sure that you'll always be needed. Also, I can think of *tons* of *extremely* useful chemicals for all purposes. Others already mentioned *fertilizers*. [Answer] > > Gold is thought to have been produced in supernova nucleosynthesis, > and from the collision of neutron stars,[47] and to have been present > in the dust from which the Solar System formed.[ > > > Wikipedia <https://en.wikipedia.org/wiki/Gold#Origins> The reason they think that is the maths show that all the gold on earth couldn't have been produced in the previous two generations of supernova the earth and sun was made from. Making Gold cannot be done with chemistry. It requires fusion and I suspect it is endothermic. Iron is the last exothermic fusion in a sun. As a *rough* rule of thumb, atomic is two magnitudes of order stronger than chemistry, and sub atomic two orders again. Think common chemicals that have been around for a while. Like gunpowder. One big invention (that saved a lot of towns) was to make it while wet. Dry it. Smash it up with wooden hammers then sieve it. This gave quality control over grain size and thus predictable burning. And the neighbours didn't have to die. [Answer] Other people who were asked to turn lead into gold did instead turn clay into china. Well, at least one did. If you can figure out how to create china you will make your prince very happy. [Answer] when faced with the issue of making gold why not respond with "but your majesty certainly that would not be considered wandering into the realms of magic?" in those superstitious times were magic was feared just the mention of gold and magic should be enough to put the prince off. if this does not deter him recommend that he seeks out a witch, as magic is not something a meagre alchemist could ever perform. both situations ensure your survival and the upkeep of your reputation. instead offer him other valuable metals like steel for weapons which is certainly something that would catch his interest. tell him that it would make weapons and armour far superior to all other major powers in the world. this would be more than enough to avert his focus from gold if the previous plan fails. also if you were able to find some common medicinal plants or fungi some basic medicines could be created which would make you very popular with the army. [Answer] # Hide the gold in solution During the German occupation of Denmark, the gold Nobel Prize medals of two Jewish scientists were [hidden as a solution](https://www.abc.net.au/radionational/programs/greatmomentsinscience/how-the-gold-nobel-prize-medals-were-hidden-from-the-nazis/8360522) on a high shelf of a laboratory, and were never stolen. If a gold solution or salt can be surreptitiously introduced into the alchemical reaction, *real gold* can be produced, confirming the alchemist's power. This solution comes with some major issues, however. First, [aqua regia](https://en.wikipedia.org/wiki/Aqua_regia) had been known for roughly three centuries already. Alchemists with gold fever will recognize the smell of the reagent and the color of gold (III) dissolved in it. (It is possible modern scientists might not have recognized the solution on the shelf in Copenhagen ... more possible that they simply did not care to comment about it to their armed visitors, I think) Ordinary legerdemain may be tricky - solid tetrachloroauric acid will surely be recognizable, and according to Wikipedia at least, [colloidal gold](https://en.wikipedia.org/wiki/Colloidal_gold) was known in the 16th century, even if it was rediscovered in the 1800s. Nonetheless, if the alchemist can disappear some gold into aqua regia while unobserved, precipitate it as some salt or colloid that he mixes with other strongly colored components such as cinnabar or vitriol and slips into the reaction under the noses of his examiners, and introduces this into a very lengthy process of mumblewinknudgification, he can eventually wring out the gold. If another alchemist spots the deception anyway, he still *might* not rat out our protagonist, because odds are he has done the same thing himself before. And it is not healthy to convince the King that alchemists are just flim-flam men. Basically, the trick has to be good enough to convince one alchemist watching that another alchemist watching would *believe* he honestly might not have noticed. The process need not be very efficient - *should* not be very efficient, because our protagonist certainly doesn't want to be told to do it again. Instead, he should be convincing about how his talents are so much better put to use making precious aluminum or stainless steel, or any of the alternatives suggested in the other answers. ]

[Question] [ Let's say I have a small village with 100 people of which everyone is able to work, what kind of professions do these people need? Background to the society: they are as smart as medieval people, with an almighty god ruling them through a strict religious code. [Answer] ## **Farmer, farmer, and farmer** Assuming it is independent and not a satellite settlement (a satellite community is far *far* more likely) there is only one job, farmer. there is not enough people to support specialized labor. (note farmer might be shepherd or fisher in a coastal settlement, but the point is they primarily produce food.) Maybe, *maybe* they have a blacksmith, although a hundred is is a pretty small number to support a full time blacksmith so more than likely they are part time, the rest of their time will be spent either farming or herding (and farming to feed them). 100 people is not a village, it's not a town, it only qualifies as a hamlet because there is no word for something smaller. because there is so few people there is no need for social infrastructure. It is basically band living, everyone knows everyone else intimately, moral control is communal because everyone knows everyone else and can shun an offender. You are looking at less than 20 homes in the entire settlement, probably less. With very small communities there just is not enough surplus food production to support specialized labor. different people will have different talents (Bob is a better tanner and John is a better potter) but everyone does every job but their first job is still to feed themselves. The closest thing to specialization you will have is side projects, Dave may keep bees while Harry has a pole lathe for making bowls, but in both cases these are small side projects, the majority of their time is spent farming. Everyone farms, everyone hunts or fishes, everyone makes pottery, everyone is a carpenter, everyone is a brewer, everyone makes candles and clothing. Some jobs will be collective, several guys may get together to make a kiln or raise a barn but it is a community project. If they are a satellite community their job is to harvest whatever resource the satellite community is built around, mining, lumberjacking, building a castle, ect. food is likely imported at some lords expense. Then you will have service jobs and administrator, a whorehouse, a brewer, and a church. Their will not be as many families in such a community and more single men. *My rough calculations.* the settlement mentioned has at most 20 farms likely less. I have seen estimates of around 10-15% surplus (literally a tithe) with an 8 oxen wheeled plow, the best system available. Assuming a farm feeds a family, that means 20 farms with an advanced plow can manage to support 1-2 other families. One of those will be your blacksmiths family. Then you need to feed the oxen which is more than a single farm can manage, so you lose a decent chunk of the remainder feeding the oxen. so I am estimating 1 specialist family per 20 farms. However yields were unstable so that is probably generous, if you have a bad year and too many specialists they might starve, so having the blacksmith also bring in food by other means is more stable, especially if 20 farms is an overestimate. [Source 1](http://www.cropyields.ac.uk/project.php) [Source 2](https://cs-people.bu.edu/wdqin/HI244.pdf) [Answer] Unlike the main answers, we actually **do** see a few specialized professions even in small villages. This is true both for the middle ages and for contemporary indigenous people. Most importantly, there would be a priest. Even small villages have a shaman, witch doctor, priest or other religious figurehead. According to some historical research, productivity in agriculture being low in the middle ages, about 70% of the people needed to work in food production. That gives your 100 people village about 30 people who do not have to be full-time farmers. Most of those people will be small children, but I would estimate that your village can afford a dozen or so people who have food production as a hobby at most (say, the priest also has bees). The other thing we know from historical research is that peasants in the middle ages were highly self-sufficient. They knew how to make their own clothes, how to deliver babies, apply whatever counted as medicine and how to build a shack. They would slaughter animals by themselves and barter with their neighbours instead of looking for a supermarket. You would look to the professions that are highly specialized and can't be done "as an aside". Making shoes is one such thing. They are very useful to have and good shoes are much more difficult to make than clothes or rope or pottery. Furniture is another thing. Basic carpentry will be something most people can do, but making a proper table and benches or chairs, as well as specialized items that require proper craftsmanship, such as parts of a mill, would require a proper carpenter. Your village might be too small for its own blacksmith, but this would be another profession you could find, because of the investment in tools, furnace, etc. that is needed, it is unlikely that everyone does a bit of smithing. There might be a village sherrif or major or both combined - someone to enforce rules, but you're on the edge there. The community probably functions well without and doesn't need one, but it isn't too far from a size where such a position would appear. Then there are specialists like a herbalist/apothecary or a teacher that at this size may or may not exist and may or may not be a part-time position of someone who also has a (smaller) farm. Finally, there are a few farming-related professions that your village might have, such as a miller. Again, like the blacksmith the reason for this isn't that the job is so special, but that one mill or smithy shared by the village is better than everyone having their own. --- If it is variety you are after, don't forget that "food production" is an entire field by itself. Some people grow crops, some have a vegetable garden, some have an orchard of fruit trees. There is also hunting, trapping and fishing. There are different kinds of animals to keep, shear, slaughter and make into meat and leather. Even the 70+ people in your village who are food producers are unlikely to all be doing the exact same things. [Answer] I agree with John that such a small village would probably consist of farmers, farmers, and farmers. Except if the people are Humans or similar they were have two genders with somewhat different roles and a ranges of ages. So probably the jobs would be farm husband, farm wife, farm hand, farm wife's assistant, farmer's little boy, farmer's little girl, old farm woman, and old farm man, which makes eight jobs in all. Most of the farm hands and farm wife's assistants would be working for their parents, but some might be working for other families, presumably for room and board. Presumably the farm husbands, farm wives, farm hands, & farm wives' assistants, would be numerous enough to do almost all of the work, with some assistance, "assistance", meddling, and advice from the other groups. [Answer] Need? At a minimum, and assuming this is not a village featured in the medieval version of Lifestyles of the Rich and Famous, this small population village needs farms raising a suitably broad range of foodstuffs for the populace to have a healthy diet via bartering. Many villages of this size might support itinerant peddlers and tradesman providing many of the other services useful for the village -- rag and bone man collecting rags, bones, and bits of scrap metal (they might double as tinkers too), traveling blacksmith fixing and making tools, traveling Ferrier if the residents have horses for working their land, tinkers to repair metal pots and pans. Then maybe a cooper to make barrels for storing food for winter and transportation to markets for sale, and wheelwrights, and carpenters. [Answer] A village of that size would not have any professions, just crafts, trades and occupations. The majority of the work would be done by women, and, as today, would mainly not be recognised as work - making and repairing clothes, rearing children , preparing food, brewing, baking, looking after livestock etc. The most important person for future generations would be the midwife, who will be main determinant of mortality rate. (Though you might well geta midwife to come from the next village) EDIT: To expand: what I'm trying to get at is the modern assumption that everyone has a job and a job title. That comes later. On this type of society there is little specialisation, but some people may have specific skills. Uncle Fred makes charcoal and shares it with the others, Aunt Mary always attends women in childbirth, Cousin Paul will help with building the walls of your hovel. It's an informal economy and you may be butchering a calf in the morning, fishing trout in the afternoon and smoking pork in the evening without being a butcher, fisherman or smoker. [Answer] With that small of a group most would be farmers. Some of them might have a sideline like being a blacksmith in addition to being a farmer. Every family would be able to do some craft work like spinning thread or wool, sewing, carpentry, Leather work including tanning, and so on. The population would probably have to reach a few thousand to allow things like full time blacksmiths, furniture makers, doctors, brewers, bakers, and so on. [Answer] You forgot the major rule-enforcer, the village priest. It might not be exactly commercial in nature but it's certainly a profession and is one of the few people the slight excess food production will go toward supporting. [Answer] They've already answered above saying that food would be their priority and that their professions would depend on whether the community is a satellite settlement or not, but also keep into account how many adults you have. Babies can't work, and children can only lend a hand with less physically-demanding tasks such as fetching water; herding geese, sheep, or goats; gathering fruit, nuts, or firewood; walking and watering horses; fishing; tending a vegetable or herb garden; making or mending clothes; churning butter; brewing beer; and helping with the cooking. Teens can help with more difficult tasks, such as goading the ox in the fields while an adult handles the plough, and they might babysit. But this all depends on the settlement's [population pyramid](https://www.britannica.com/topic/population-pyramid). If you say there are 100 able-bodied and -minded adults, then your population is probably actually larger than 100 because there are both young and old people that you aren't taking into the equation. If you've got 100 people total, counting babies and children and teens and young adults and adults and elderly people, then your workforce will probably be halved at the very least, assuming the population pyramid is a healthy one (a larger number of younger people than older people). [Answer] If you had ever played [***Banished***](https://en.wikipedia.org/wiki/Banished_(video_game)), you'd have skipped this question and asked how many of each for a given population size, and you'd know the temporal order in which the professions are important. Farms, farms, and more **farms? Not w/o seeds, and probably not before the fishery, and *definitely* not before hunting and gathering**. Roam out into the wilderness expecting to subsistence farm your way, and you'll all die from starvation by no later than next summer. [](https://i.stack.imgur.com/Yuqj8.jpg) If there's one profession this game is missing, it's bakers. But by the time someone builds an oven, to feed *other people*, I suppose the town would be large enough to no longer be considered 'banished'.... You can't bake without grain, and you can't harvest grain if you're dead from starvation. And by its nature, subsistence farming yields no 'product', so it's a long road you've got ahead of you until you're able to trade/buy bread. [Answer] There are two occupations no one has mentioned, but which would exist even in a village this small: * Shepherd. That is, someone to watch over the animals grazing in the village pasture. One can't simply assume that these animals aren't at risk from predators or thieves (which include inhabitants of the next village over who are looking for a quick & easy way to increase their own flocks). Yes, this shepherd might simply be a teenager -- male or female -- who does this for a year with no training beyond a few words of advice & a threat if he lets anything happen to the animals, but it is one st of hands taken out of the general labor pool. * Woodsman. All that wood for houses, furniture & tools has to come from somewhere. Most medieval English villages had 20-50 acres of woodland, which would need a specialist to look after. And wood was produced from most medieval woodlots not by cutting down the trees & planting new ones, but by coppicing: cutting the tree to produce suckers, which were allowed to grow into sizable diameters before harvesting. This meant that instead of producing timber once ever 30-40 years, a tree would produce useful timber every 7-20 years. I'll admit a village of 100 souls might not have its own woodlot & no woodsman, but a village of any size will have a shepherd. If you increase the size of the village, say to 500 inhabitants, a woodsman would be one of the next professions this village would need. BTW, farming tends to be a full-time activity only for half the year -- spring & fall -- leaving them idle during the winter & summer. And idle hands are the devil's workshop: what better activity for an illiterate & physically fit peasant than to stir up trouble in the neighboring village? (Think of this as the ancestor to the modern sports rivalry between schools & cities.) Geoff [Answer] I am pretty late for this, but I believe I can add some details, that may be interesting for people interested in how work was organized in small medieval community in central Europe. Most answers are right about majority of population being farmers and the live rhythm of such society would be therefore dictated by the field works. Meaning it will be seasonal. "On season" essentially everyone will be doing fieldwork. We need to remember that most of land around the village belongs to the "manor" and had to be worked first, only small portion of the land would be allocated for villagers needs. So amount of work would be substantially greater than resources available for villagers. "Off season" would be dedicated towards maintenance, repairs, crafting of tools and processing of harvested resources. While men would work the wood, meat, leather and metals, women would be dedicated to textile production. In many parts of the Europe there are surviving folk traditions concerning these female "off season activities". As small community as 100 people would acquire all non-food needs during these "off season" activities. The for iron for tools (the most obvious elephant in the room) would be obtained through the trading. Next possibility was to extract iron from bog (if one is available, but the location of the village might be selected with this in mind), but the amount needed would not facilitate the need for specialized professional. However there still would be specialized full-time professionals as well. The first of them being: **The local Witch, ye olde herbalist hag, or as we call them nowadays a Midwife** Midwifes were except from fieldwork and many other activities mainly because everyone had to know at all times where to find her, when she was needed. So midwife was expected to sit home all the time waiting for emergencies. She wasn't paid per se but villagers would provide for her every need. Midwifes may have had husband or family on their own, but girls that were seen as unfit for fieldwork or unmarriable were often selected as their apprentices (possibly laying base for crooked, ugly hag of a witch myth). Midwifes tend to have knowledge about medicinal plants and were usually the only person in the village who knew the first thing about medicine and were often called for other emergencies than childbirths as well. **A Priest** If village lacked the church of its own, villagers were usually expected to visit the nearest settlement that did. If the the distance was too great, villagers would be exempt from weekly service, but were still expected to visit during the holydays. Given (not only by) that the most important holydays (Christmas) are in the middle of the winter there is no surprise that even the smallest villages would seek their own priest. In medieval Europe villages governing body would petition their lord, who would send the request to the nearest bishop. Bishop would sent someone to inspect the village and if there was an appropriate building to serve as as temple he would appoint a new parish and assign a priest. Villagers were expected to provide a priest with his own house and allocate some of the village land to the parish. Villagers would work the manorial lands first, parish lands second and only then their own land. The "salary" of a priest being the produce from the parish land. Priest was also given servants (older women, usually widows took turns in this role), doing the cooking and housework for the priest. **Governing body** Villages were usually governed by the councils of elders. This wasn't full time profession, just the group of men who were trusted (enough) by other villagers to make decisions. These councils were sometimes 'hijacked' by the wealthiest or most influential villager, making the role more centralized over time, but with 100 inhabitants there was no way governing would take full of his time. Only reason how it would become a "proffesion" at this scale is if the lord needed, for some reason, better control over the village. In that case he may name a mayor or a bailiff, who would be paid directly from lord's coffers. **Herders** While one can give the task of watching a small flock of gees or a odd cow to random child, if the villagers wanted to maintain some more substantial herd the job was preferably given to someone more responsible. But the difficulties of herding doesn't end with the manpower. Most of land around the village would be dedicated for crops (with fallow fields being harvested for winter fodder) a available grazing land had to be sought for in the greater distances. This was usual mainly with sheep as they can graze on land unsuitable for other livestock. Shepherds would take the animals to the hills in spring and herd them back for wintering and culling. They were expected to return in the Fall with more animals than they left with in the Spring otherwise they were free to manage the herd as they seen fit. They were paid in whatever they were able to extract from the animals over the Summer and in share of meat and wool after they returned. Only men left with the animals leaving their families waiting in the village and if there was some minority in the village this work may fall on them. (that's how Wallachian become the synonym for shepherd in area of medieval Hungary) **Others?** If village was founded in order to extract some specific resource, then there would be of course professionals for that purpose, with the rest of village basically providing for them, but in that case a lot of thing would be imported in order to get the industry running. Mining settlements were frequent example of this. Such settlement needed a lot of fuel, that was provided by one of the most prolific non-farming professionals - **The charcoal burners**. Another example might been **millers**. If your villagers wanted to bank a bit on the neighbors they might petition the lord for a right to build a mill. This needed the lords permission and was highly taxed, but still very profitable as one mill could provide service form many villages and village that went through the trouble of getting permission had the monopoly. Illegal mills were typically burned (with miller and his family still inside in some jurisdictions). [Answer] Butcher, baker, candlestickmaker, doctor, teacher, miller, hoo.. oh wait, you said fictitious god overseeing all of them. So a Preacher. Most are farmers, some are hunters. All folks could have multiple roles. And a blacksmith for making/fixing tools. [Answer] A population of 100 isn't large enough to leverage the economics of scale, not even by Medieval period standards. I would expect every person older than a small child to be engaged in two or more trades and they would all occasionally collaborate on major projects like building a new house. Although none of them would rise to the same level of expertise that they would have been in a larger town, at least someone would have step into the role of healer and midwife. Every house would have a personal garden, and they would probably still rely heavily on hunting and gathering. If you're really interested in this topic, Joseph and Frances Gies wrote a series of well researched and popular books on Life in a Medieval Village, City, and Castle. <https://www.goodreads.com/author/show/18546.Joseph_Gies> [Answer] ## Farming comes first, but it is also seasonal Farming produces food (which is essential for survival), fuel, and fibers. Most of the adult and teenage male population will be busy during the entire day during plowing, planting, and harvesting. But this is seasonal, and there are periods when farming requires only a few hours (or none at all) each day. Weeds and winter crops (if grown at all) grow slowly and do not need constant attention. Therefore, there will be seasons with plenty of down-time, and workers will find hobbies or crafts to do during this time. Seasonal crafts could include brewing, weaving, leatherworking, shoemaking, pottery, light carpentry, and furniture-making. As the demand for these cottage industries is low, there is likely to be only one person in the village for each type of craft, with households trading for the goods that they need. Excess laborers could engage in woodcutting, hunting, or fishing. One farm with a mill is enough for grinding grain. The construction of new buildings would be performed by the community, much like an Amish barn-raising. But these are all seasonal activities, not full-time professions. Women in medieval times were responsible for cooking, baking, food preservation, cleaning, and child-rearing. Some women would serve as nurses/midwives, when needed (i.e. not a full-time profession). Pre-teen children took care of the livestock. The only true full-time profession would be the priest. If you plan to give your population a basic education, then during the week he can teach children how to read the bible. [Answer] Assuming they don't have other villages, I would expect you'd have someone fulfilling these roles: * Tool Makers. In most cases, this might be the blacksmith, but you could also have someone chipping stone, carving wood, or whatever the local materials are available. The number of tool-makers is pretty dependent on demand. If there is a low one, they are probably wearing more than one hat. If there is a high demand, then they could specialize (e.g., not be farming as their primary job). * Sales: In other words, shopkeepers and someone to manage those disputes. This could be someone wearing many hats (100 is rather small, so there might not be enough room for specialization) or if a town has a lot of trade among members, then I could see either a general store. If there is enough business, someone who imports/exports goods would set up store otherwise it could be "go down the street to Mel's and buy some sugar". * Rule Enforcement: Police, guards. Again, it depends on how independent the village is. For a close-knit community, enforcement could be done with mob rule (troublemakers with "great big bushy beards" are dealt with ad-hoc) or there could be more formal enforcement. I was in a village that had a police department only during daylight hours with a voice mail message to call the next city over for night time. * Moral Enforcement: You said strict religious code. That would suggest you would need at least someone to interpret the dogma. Depending on how strict it is, there may actually be more than a few for supporting that. Again, the more focus you have on something, the higher chance you can have a specialist (priest) verses the mayor who happens to be religious. A lot of it depends on what the village needs. At the basic levels, you just go to neighbors to ask for things (tools, food). Its when it becomes a significant effort (usually with the number of people involved or the complexities to maintain it) you get specialties (e.g., professions). So, it may be good to look at what they have and what they need. Take an example: alcohol. Pretty much any farmer can make mead or ferment something. My father's father had a small room in his basement to make honey mead. Occasionally his friends would come over and they would drink it. That's your basic, go visit some friends. Now, if the religion dictates that all alcohol must be blessed, then you add complexity. Someone has to manage it. For a few people, that might be easy, but soon it becomes a full time job (e.g., a profession) to bless all the spirits. Enforcing that blessed rule would start as a simple task ("we police ourselves") but as the scope gets bigger, people abuse the system and end up driving orange cars around Hazard County. Then you need someone who spends most of their day not farming but chasing down the Duke Brothers. So, then you need a specialist (profession) to enforce the rules. If the materials to make spirits are local, that's easy. However if there is some component (hops) that needs to be imported, you have to have someone doing the importing. If that is occasional (traveling merchant), you have someone to flies in, sells stuff, and moves on. However, if there is enough demand, someone is going to get in the role of mainly managing sales. That's your general store at first and then more specialized stores as the exchanges get more prevalent (a hundred people probably wouldn't have enough business to support more than a couple stores). Same with clothing, woodcraft, stone, etc. It depends on the demand and the support structure. You'd be surprised how much you can get away with a once a week farmer's market. Hell, even once a quarter for things like outfits and furniture. That doesn't need strict professions. Short answer: depends on what they need. If there is enough demand, someone will make a job of it. [Answer] I want to bring in another aspect: Not all villagers are equal (economically and probably also legally). There are a few farmers owning land and farm buildings, there are cottagers owning a small house and maybe a small patch of land for gardening, but working on the farms, and farmhands owning only their clothes and nothing much more. Maybe there is a nobleman present in the village, but he will be just a farmer as the other farmers. There will be some specialized workshops: a blacksmith, a mill, a carpenter, but some of the workshop holders will also engage in farming. The village probably has a public baking house for fire protection, but not a baker. And of course, there is a priest. [Answer] Ok agreed with some farmers, but they can't farm naked, so the village will have at least one crew of people that can handle making clothes. Farming can be rude for clothes, so this crew has a job all the year. Especially when winter is coming To make houses, and repair this village need a crew that is good to build with wood or other component and make tools with the help of a blacksmith. Then all of those people need to drink (beer are made by farmer, but beer need water) and a farmer also need water to cultivate. So a crew that brings water to the village is essential. A mayor is also essential, even a little village need a chief. It's not all about farmers, but a village in medieval just need to cover the bascis I guess ]

[Question] [ Is this alternate history I came up with plausible? What holes does it have? Are some events very unlikely to happen, even impossible? Should I change some dates of some events? Most of my knowledge is in Science, not in History. Note that this would be in a history timeline of a wikipedia-like website. EDIT: At the end, I have summed up the big problems you guys pointed out for me for this story. Take your time to read this story, and while I would like to have some criticism and feedback, **please do have fun too**, its the main goal of my story after all. The history of the Great Cataclysm: > > **April 28th 1944:** During "Exercise Tiger", 1000 allied soldiers were > ambushed and killed by german E-boats. One of the commanding officers > survived and were captured by germans. The officer, under threat and > torture, ceded to the germans, which now knew the plans of Operation > Overlord. To keep this a secret, the germans drowned the officer and > set up his corpse to be washed on the shore of Portland, England, > later to be discovered by the allies. The allies, fearing the germans' > knowledge about the Normandy Invasions, leaked information about > "Operation Fortitude" and turned it into a double-deception. The > allies were now preparing to land both on Normandy and Norway. > > > **June 17th 1944:** 2 Panzer divisions and 10 airbourne brigades are sent to Calais and Normandy to > defend against the Allies. > > > **June 6th 1944:** The Normandy landings were a massacre. Every landing > failed except Juno and Sword, which were much less defended. The > remnants of the Omaha, Utah and Gold beach were relocated into a > single spearhead through Sword beach. A large stalemate ensued. On the > side of the Norway Landings, things were going well. Most of the > Norwegian soldiers surrendered to the allies, they would now fight > against the Germans. > > > **October 28th 1944:** Seeing the overwhelming allied forces landing in > Norway, and under pressure from the allied countries, Sweden grants > free passage for the allies. Taken by surprise, the germans relocated > most of their forces defending the Netherlands border to Hamburg. > Again, a large stalemate ensued during the siege of Hamburg, causing a > death toll of 100 000 civilians. > > > **January 15th 1945:** With the advancing Russians, more and more german > troops were relocated to the eastern front. > > > **March 30th 1945:** As it was more and more obvious that Hamburg was > about to fall, Wernher von Braun and his team were relocated to > Berlin, under the orders of Himmler. > > > **July 2nd 1945:** Berlin fell to the soviets. As they marched through > Berlin, von Braun was found hiding in a bunker with his family, he was > captured and sent to Russia. > > > **August 6th 1945:** The first use of nuclear weapons in warfare is > recorded. Hiroshima and Nagasaki are bombed by the Americans. This > would spark a new age of warfare. > > > **December 23th 1947:** The first transistor is invented by John Bardeen > and Walter Brattain. > > > **Late 1950s:** Proxy wars in the world are intensifying, and the United > States, under pressure after the soviets had successfully launched the > first Man in space, were desperately funding for the Lunar Missions. > The soviets, having von Braun on their side, quickly developed a > working prototype of the N1 Rocket, which spawned the N2 rocket, > powerful enough to send people to the moon. > > > **February 14th 1970:** The soviets broadcast to the whole world the first > time man had set foot on the moon. > > > **1971:** Kennedy, under huge reprisal over the failure of the Lunar > missions, promised to send people to Mars by 1976. To do so, the NASA > was disbanded, and the government started funding commercial > spaceflight. > > > **1972:** A group of hobbyists successfully hacked an open-hardware radio > into a wireless modem. They demonstrated in a science fair two > computers communicating with each other. They would later found the > company WorldNet Ltd. > > > **1973:** Sparked by the necessity of lightweight and powerful computers > to be used in spaceflight, the Microprocessor is invented, and put to > large-scale testing by the US government. > > > **1974:** The Space Instruments Co. is founded. The personal computer is > introduced to the global market. > > > **1976:** The first demonstration of asteroid mining is recorded. > Rudimentary, but crucial to the commercialization of spaceflight. > > > **1977:** One year late, the first humans landed on Mars. Americans. However, it was > only for show, and no permanent colony was established. This was > ridiculed by the Russians, who had successfully established a helium-3 > mining colony on the moon. > > > **1981:** To assist their space station project, the soviets built the > KOM200, the world's first Teraflop supercomputer. > > > **1986:** Both the US and Russia launched their interplanetary space > stations, each equipped with refineries, living quarters and enough > supplies for 2000 people. Both were set on lagrange points near > asteroids. > > > **1988:** While going through the digital revolution, China began > mass-producing electronics, filling the big demand gap. Its GDP > increased a hundred-fold in a few years, quickly surpassing those of > Russia and the US, albeit to the detriment of its people. > > > **1989:** China successfully launches its first research-based space > station. > > > **March 12th 1990:** South Korea's president is assassinated. The country > goes into martial law. At the same time, North Korea invades Seoul > with an army of over 800 000 people. This is the start of the second > Korean War. > > > **November 21th 1990:** Seeing the US intervening in the Korean War, > Russia prepares 10 nuclear missiles to be sent to Cuba. > > > **January 1st 1991** > > > **3:00 AM:** Disaster. One of the Russian nuclear > missiles goes missing. The same day, a 10Mt nuclear explosion is seen > on the coast of Florida. According to the scholarly estimates of the > 2105 study by Roch, Wenn et Al., 714 201 people were instantly > killed, 3 329 210 people died later due to complications. It is still unclear to this day how the soviets lost a nuclear bomb that day. See *'91 Nuclear Conspiracy*. > > > **11:00 AM:** NORAD goes in DEFCON 1. Fighter jets are deployed, as well > as nuclear submarines. > > > **12:00 PM:** While Russia is still trying to figure out what happened, > the reflection of the sun on a spy satellite triggers an alarm in the > Perimeter system of the Russians. Without confirmation, the Russians > sends an anti-ballistic missile in self-defense. > > > **12:05 PM:** Under DEFCON 1, high command mistakes the anti-ballistic missile for a second nuclear strike, and the President of the United States > authorizes the launch of all its nuclear arsenal in retaliation of the > Russian attack on their soil. > > > **January 2st 1991:** A full-scale nuclear war starts between Russia and > the US. > > Over 56 000 000 people are killed overnight. Every major city > was hit, and more than 3 Billion died over the world during following years. > > > Death Statistics: > > Shockwave: 56 184 000 *Citation needed?* > > Fallout: 952 000 000 > > Food Blight: 542 810 000 > > Anarchy: 1 250 000 000 > > > **1992:** After the devastation of the Great Nuclear War, every remnant of > Russia, Europe, China, US, and South America coalesced into 3 Major > Factions. The UNFT(America), RLSS(Europe, Russia), Klan(Asia, > Oceania). > > > **1993:** Massive-scale disasters starts to occur on Earth, due to Food > Blight, Radiation, Aerosols, etc. > Scientists at that time estimated that the Earth would become > inhospitable within 10 years. > > > **1995:** As the conditions on earth further deteriorated, 7 Huge > spaceships were built and desperately aimed to send the people off > Earth. > > > UNFTS Eden: 67 309 012 people on board, > > Ownership: UNFT > > Destination: Mars > > Type: Self-Sustained Ground Colony > > > UNFTS Proxima: 31 200 914 people on board, > > Ownership: UNFT > > Destination: Titan > > Type: Semi-Sustained Ground Colony > > > RLSS-C спаситель: 152 017 220 people on board, > > Ownership: RLSS > > Destination: Mars > > Type: Orbital-Ground Hybrid Colony > > > KSS 乡四号: 91 247 010 people on board, > > Ownership: Klan > > Destination: Mars > > Type: Domed City > > > KSS 金三号: 56 380 545 people on board, > > Ownership: Klan > > Destination: Venus > > Type: Cloud-Top Colony > > > KSS 天二号: 11 670 418 people on board, > > Ownership: Klan > > Destination: Enceladus > > Type: Self-Sustained Underwater Colony > > > UTC Freedom: 675 211 people on board, > > Ownership: Private > > Destination: Mars > > Type: Colony > > > TBC... EDIT: To sum up, the current problems found within the story are: * Too much credit given to von Braun. (thanks @kingledion, @Schwern) (I would like my story to at least start in WWII, timeline diverges there. It's like chaos theory, one small thing happens, ends up with us destroying the planet.) * Reason for commercial initiative of space exploration/space mining * Reasons for the quick development of Computers/Microprocessors * Reasons that China became a big player in 10 years earlier than in our timeline * What are the Economical/Political/Socio/ecological reasons to abandon earth? Small details I will definitively correct: 1. Discrepancies in WWII (thanks @Schwern) 2. Ridiculous death numbers (@Schwern, @a4android, @Zxyrra) 3. Mass evacuation due to ecological disaster (It would rather be political reasons, or because they didn't have a better alternative) (@a4android) (Also note that I might change it so it explicitly says the spaceships were built in space, or on the moon, unharmed by the nuclear winter. By that time, the moon colonies had 700 000 people already. 4. The Americans never capture von Braun, Korolev doesn't die. This way space race would have been extended without all the discrepancies. Thanks for all the help, a lot of mistakes were pointed out that I didn't even notice. [Answer] The story can be summed up as follows. 1. Von Braun is captured by the Soviets, not the Americans. 2. Failure to beat the Soviets to the Moon extends the Space Race. 3. An extended Space Race means space colonies are feasible in the 80s. 4. Nuclear war happens, the Earth is rendered uninhabitable. 5. The remnants of humanity launch colony ships into space. But really it can be summed up in the last two parts: the Earth is uninhabitable, they send colony ships into space. Is this plausible? I dunno. But I can go through the proposed history point by point for obvious flaws. --- > > *The allies, fearing the germans' knowledge about the Normandy Invasions, leaked information about "Operation Fortitude" and turned it into a double-deception.* > > > Ok, pretty clever reversal of [Operation Mincemeat](https://en.wikipedia.org/wiki/Operation_Mincemeat). But... > > *The allies were now preparing to land both on Normandy and Norway.* > > > Simultaneously? They didn't have the transports. [Operation Dragoon](https://en.wikipedia.org/wiki/Operation_Dragoon), the invasion of Southern France, had to wait two months after Overlord. > > *June 6th 1944: The Normandy landings were a massacre.* > > > ...if the Allies thought secrecy was lost, why did they invade anyway? > > *June 17th 1944: 2 Panzer divisions and 10 airbourne brigades are sent to Calais and Normandy to defend against the Allies.* > > > I think you mean May 17th? I don't know that Germany *had* "10 airbourne brigades" or Airborne brigades at all. They had Fallschirmjäger regiments and divisions. At that time they had six Fallschirmjäger divisions, but two ([5th](https://en.wikipedia.org/wiki/5th_Parachute_Division_(Germany)) and [6th](https://en.wikipedia.org/wiki/6th_Parachute_Division_(Germany))) had just been formed (in France) and were not ready for combat. [The 1st](https://en.wikipedia.org/wiki/1st_Parachute_Division_(Germany)) and [4th](https://en.wikipedia.org/wiki/4th_Parachute_Division_(Germany)) were tied up in Italy defending Rome. [The 2nd](https://en.wikipedia.org/wiki/2nd_Parachute_Division_(Germany)) was in Normandy already. That leaves just the [3rd Division](https://en.wikipedia.org/wiki/3rd_Parachute_Division_(Germany)) cooling its heels in Brest. They could have been transferred. You might want to go with something more like: several Panzer and Panzergrenadier (ie. mobile infantry) divisions from Calais, plus the 3rd Fallschirmjäger division from Brest. Furthermore, German reserves were tied up by Hitler's insistence that Normandy was a feint at the real landing would come at Calais. He withheld his reserves for weeks. You could tweak history very slightly by either A) the intelligence about Normandy means Hitler knows it's the real landing and releases the reserves, or B) the reserves are put under the discretion of the military commanders. This would give the Normandy defenses a mobile reaction force to reinforce the beaches on day one. They would have backed up the very shaky coastal infantry divisions, and counter attacked to split the landing. > > *October 28th 1944: Seeing the overwhelming allied forces landing in Norway, and under pressure from the allied countries, Sweden grants free passage for the allies. Taken by surprise, the germans relocated most of their forces defending the Netherlands border to Hamburg.* > > > Free passage to where? Why were the Germans defending the Netherlands border? Was there an implied amphibious invasion of Denmark? > > *July 2nd 1945: Berlin fell to the soviets. As they marched through Berlin, von Braun was found hiding in a bunker with his family, he was captured and sent to Russia.* > > > Was the point of all that just so Von Braun is in Berlin and captured by the Soviets instead of the Americans? You can tidy things up just by starting there. > > *The soviets, having von Braun on their side, quickly developed a working prototype of the N1 Rocket, which spawned the N2 rocket, powerful enough to send people to the moon.* > > > IMO this is overstating the role of von Braun, overstating the feasibility of the rushed [N1 rocket](https://en.wikipedia.org/wiki/N1_(rocket)), and understating the mess that was the Soviet rocket program. Maybe von Braun's personality and management would have fixed all this, but it more likely would have gotten him shot. This also subscribes to [Great Man History](https://en.wikipedia.org/wiki/Great_Man_theory) which has been largely debunked. I think you need more than one man switching sides to change the course of the Soviet lunar program. > > *1971: Kennedy, under huge reprisal over the failure of the Lunar missions, promised to send people to Mars by 1976. To do so, the NASA was disbanded, and the government started funding commercial spaceflight.* > > > In 1971 there was *a lot* of basic research yet to be done on putting humans into space. I'm not sure commercial spaceflight in 1971 was feasible, let alone profitable. With the US defeated in the race to the moon, I don't know there would have been commercial excitement about space to bring in the investors. > > *1981: To assist their space station project, the soviets built the KOM200, the world's first Petaflop supercomputer.* > > > We didn't have [teraFLOP computers until 1996 and petaFLOP computers until 2006](https://en.wikipedia.org/wiki/FLOPS#Single_computer_records). This seems a bit much. > > *1986: Both the US and Russia launched their interplanetary space stations, each equipped with refineries, living quarters and enough supplies for 2000 people. Both were set on lagrange points near asteroids.* > > > I assume you mean the Earth L4 and L5 points. We only know of one Earth trojan asteroid, [2010 TK7](https://en.wikipedia.org/wiki/2010_TK7). But it's orbit is so inclined it's expensive to get to. It's also only about 300 meters wide. You're better off choosing any number of [Near Earth Asteroids](https://en.wikipedia.org/wiki/Near-Earth_object). Also you skipped the bit where they somehow launch and supply 2000 people. > > 1988: While going through the digital revolution, China began mass-producing electronics, filling the big demand gap. Its GDP increased a hundred-fold in a few years, quickly surpassing those of Russia and the US, albeit to the detriment of its people. > > > A hundred-fold increase in GDP in a few years is crazy. Dial it back. You need to set up institutions to educate and train people, create materials, train those people, set up factories, invent products, iterate on them... ten, twenty years? > > *November 21th 1990: Seeing the US intervening in the Korean War, Russia prepares 10 nuclear missiles to be sent to Cuba.* > > > Why? They have [six ballistic nuclear submarines](https://en.wikipedia.org/wiki/Typhoon-class_submarine#Units) for a quick strike. > > *3:00 AM: Disaster. One of the Russian nuclear missiles goes missing. The same day, a 10Mt nuclear explosion is seen on the coast of Florida. According to the scholarly estimates of the 2105 study by Roch, Wenn et Al., 1 214 201 people were instantly killed, 6 329 210 people died later due to complications. It is still unclear to this day why the soviets lost a nuclear bomb that day. See 91 Nuclear Conspiracy.* > > > There are problems with this. First, [a 10Mt nuke is pretty rare](https://en.wikipedia.org/wiki/List_of_nuclear_weapons#Soviet_Union.2FRussian_Federation). Big nukes are inefficient, so once we were done using nukes as a radioactive dick waving contest we went with smaller ones. And they're really big requiring an ICBM like the [R-36](https://en.wikipedia.org/wiki/R-36_(missile)). Not something you can just ship to Cuba and set up, or [put on a submarine](https://en.wikipedia.org/wiki/R-39_Rif). It's more likely to be in the 100kT range. Second, [the biggest population center in Florida is Jacksonville](https://en.wikipedia.org/wiki/Florida#Municipalities_and_metropolitan_areas) and that's only 850,000 people. How does it kill the rest? And it kills a 1/3 of the population of Florida? This is a bit much. We have the lovely NukeMap to simulate nuking cities. [Hitting Jacksonville](http://www.nuclearsecrecy.com/nukemap/?&kt=10400&lat=30.3321838&lng=-81.655651&airburst=0&hob_ft=0&crater=1&casualties=1&humanitarian=1&fallout=1&ff=80&therm=_3rd-100,_3rd-50&zm=8) results in 250,000 dead and 250,000 injured. Most of the fallout blows out to sea. [Nuking Miami](http://www.nuclearsecrecy.com/nukemap/?&kt=10400&lat=25.7616798&lng=-80.1917902&airburst=0&hob_ft=0&crater=1&casualties=1&humanitarian=1&fallout=1&ff=80&fallout_angle=46&therm=_3rd-100,_3rd-50&fatalities=469822&injuries=667995&psi_1=2251822&zm=8) leads to 470,000 dead and 670,000 injured. Again, most of the fallout blows out to sea. And so on. Play with NukeMap some. Scale back the casualties. > > *1993: Massive-scale disasters starts to occur on Earth, due to Food Blight, Radiation, Aerosols, Unpredictable Continental Drift, etc. Scientists at that time estimated that the Earth would become inhospitable within 10 years.* > > > Unpredictable Continental Drift? No, continental drift is VERY pretty predictable. No, the entire nuclear arsenal of the Earth won't change the movement of the continents. > > *1995: As the conditions on earth further deteriorated, 7 Huge spaceships were built and desperately aimed to send the people off Earth.* > > > Where are they going? --- Whew! That was a lot. And it can all be summed up: there was a nuclear war, Earth is uninhabitable, the warring factions send colony ships into space. I would advise that since most of that back story is rendered irrelevant in the end, go with the old soft sci-fi axiom: don't explain it. The more you explain, the more opportunity for holes. The more holes, the more you strain your audience's suspension of disbelief. The more the audience is trying to follow an alternate history back story, the less they're paying attention to the real story. [Answer] This answer shall deal with only a few possible holes in this fictional timeline, based on extrapolations from known facts or general sets of circumstances. If Normandy failed, it is likely that victory over Germany would be achieved mainly by Soviet forces. This probably suggests that most of Europe will be under Soviet control, not just East Europe. There may not be a Marshall Plan to revive Western Europe economically and politically as bulwark against the Iron Curtain nations. Further research into the historical background of WWII will be needed to confirm or negate these propositions. It is fallacy that the Soviets used their German rocket engineers to develop the Soviet space program. The Russians didn't trust the Germans. Instead they made the German rocket specialists to train Russians who then worked on Soviet rockets. They would have done the same with von Braun. Would Himmler have ordered von Braun and his team to Berlin. And why? A Soviet Union that prosecuted a longer and more protracted war against Germany would be further weakened economically and in terms of manpower loss. Also, its resources would have been stretched to control an expanded iron Curtain. This makes the likelihood of a Soviet space program somewhat less. Although this can be argued against on the grounds that a enlarged Iron Curtain would have provoked a stronger anti-Soviet response from the USA and what survived of the West (say, UK and France). This might mean a more heated Cold War. If a Soviet Union had space stations and a helium-3 mining lunar colony, it is incredibly unlikely that in 1991 they would attack the USA with nuclear-armed bombers. Suborbital delivery systems like ICBMs would be the preferred option. Unpredictable continental drift is a geophysical absurdity, even in an alternative 1993. This is one of the least likely after-effects of nuclear war. The other after-effects in 1993 are plausible consequences of a nuclear winter. Your version of a nuclear war seems more widespread and intense than World War Three might have been in ours. Mass evacuations into space post-nuclear apocalypse are unlikely. Colonization programs of this kind are massively resource intensive and require an extensive and stable infrastructure from which they can be launched. This won't exist in the aftermath of a nuclear war. If those resources could be mobilized they would be better spent on rebuilding the post-war world. Most political leaders will think so. This doesn't prevent the leadership of the three power blocs being so space-mad that they launch their massive colonization efforts. It's just that leaders like this are easily replaced by their politically opportunistic opponents and subordinates. Perhaps if your version of the Cold War led to a massive colonization push prior to the Great Cataclysm of 1991, then this would be more plausible. Please take this answer as a set of suggestions. It's your alternative history, after all. There will always be ways around any objection. [Answer] Other answers have already covered a lot of stuff, so I'll limit myself to a few extras. As far as von Braun's capture goes, he wasn't "found in a bunker" by the American army, he actively chose to go and find the Americans in order to surrender to them, because of the reputation of the Soviet army. He'd already been ordered back by Himmler, and had refused. So if your scenario supposes him being dragged back to Berlin against his will for a last-ditch fight against the Russians, the result will almost certainly be him attempting to jump ship to the Allies. It's more likely that he's executed than that he's captured by the Russians. You also propose that Stalin would hang onto high-skilled captives like von Braun and use them to build a technological edge. However Stalin regularly purged high-skilled Soviet workers who were deemed too much of a threat, causing massive damage to the Soviet infrastructure through massive skills and personnel shortages. His successors were less overzealous that way, but still, the USSR was not generally a good place to be doing R&D and engineering. Von Braun making it through all this to lead a team seems highly unlikely. The development of the microprocessor is entirely separate from space research. The two simply are not connected. In fact a lot of the component-shrinkage that went on with microprocessor development is the ***opposite*** of what is needed for a reliable space-based processor, because the smaller your transistors get, the more likely it is that cosmic rays and high-energy particles will corrupt your data. Put simply, microprocessor development can ***only*** happen on Earth, for Earth-based projects. Space mining doesn't work. Simple as that. The cost to get equipment up there and mined product back doesn't stack up. A space elevator makes it a bit more cost-effective, but your timeline doesn't include one of them. As for your factions, they simply don't work. A major fault is assuming that Europe would fall in with Russia. Given that the Allies are all still involved in WW2, Yalta will have a very similar outcome. Regardless of what happens to Germany, the rest of Europe (west of the Iron Curtain) will still align with the US and NATO, and will be full participants in the nuclear war. So, the chances of any European falling in with the people who've nuked their country to death? Zero, I'd assume. The "Klan" has a similar problem, which is the old-fashioned Western assumption that all orientals are the same. The Japanese spent the whole first half of the 20th century crapping on everyone near them. Meantime the Chinese and Koreans don't get on that well either, and the entire Indian subcontinent (the most heavily populated place in the world, and also the place least likely to suffer in a nuclear war) has nothing in common with any of them. You also haven't covered the outcome of the Chinese civil war and the breakaway of Taiwan. These are ***not*** people who are going to happily share a rocket. [Answer] A couple of things:- No officer that was on a boat during "Exercise Tiger" would have known where the landing was planned to happen - that was one of the biggest secrets of the war. If the Nazis did manage to get one of the planners (and that's a big if) they'd have had to empty his brain before the 6th June (5 weeks) AND convince Hitler who was meddling in strategic decisions and convinced the attacks would come further North and that Normandy was just a feint like Dieppe. Also, in April 1944 the actual date of the invasion was uncertain, even to the planners and depended on weather forecasts. Everyone (on both sides) knew that an invasion was going to happen, they just didn't know where or when. Doing an invasion of Norway would have been extremely challenging due to the terrain and climate so I feel that's implausible too. It doesn't destroy your fundamental premise though - which is good. If you don't need von Braun, you don't need Norway and if you don't need Norway you can skip this bit and still be pretty on track. One thing I remember reading years ago that might help was that the Russians made a decision to stick with valves rather than transistors back circa 1960 and it was this decision that crippled their electronics industry more than anything else. Maybe you could reverse that decision somehow and the Russians and Americans have a more even technology competition which should get you where you want. Good luck [Answer] Theere is at least one more person who needs to be added to your contrafactual during the initial part of the Space Race: [Bob Truax](https://infogalactic.com/info/Robert_Truax). The United States is going to need to make a massive jump to bypass the USSR in your scenario, and with mid 1960 to mid 1970 era technology, the only way to go is "big". Enter the "[Sea Dragon](https://infogalactic.com/info/Sea_Dragon_(rocket))", a massive two stage rocket powered by "blow down" pressure fed rocket motors of enormous size and capable of launching 550 metric tons into LEO. The *only* way the United States is going to be able to accomplish the goals you have outlined in this future history (much less launch massive space colonies) is to build outlandishly huge rockets like this. [](https://i.stack.imgur.com/kPM64.png) *Sea Dragon to scale with a Saturn V* You can actually see the reasoning by looking at Elon Musk's "[Interplanetary Transport System](http://phobosorbust.blogspot.ca/2016/09/spacex-its-projections.html)", which also uses a "Sea Dragon" sized booster to loft it's space capsule into orbit. The ITS, for all its huge size, can only carry up to 100 people, and even then needs similarly sized tankers to allow for fast transportation anywhere in the Solar System. In the era you are speaking of, and with the time frames available, assembling things in space will simply take too long, cost too much and have too much of a learning curve. Building large units and testing them on the ground gives a much better chance of success. (This should also give you an idea of just what sort of space systems will be feasible in your time line). [](https://i.stack.imgur.com/RWYWi.png) *ITS spacecraft. Just add the booster capable of lifting 550 tons to orbit and a few tankers, and you're on your way...* Like most other readers, I am a bit critical of the idea that anyone will be building very capable and sophisticated spacecraft *after* global thermonuclear war. Sea Dragons could still be built, given they are designed around shipyard rather than aerospace tolerances, so any surviving ITS type spacecraft which somehow survived the holocaust *could* be mated to Sea Dragons and sent on their way. A much more likely scenario is there are already a few, very small research stations set up around the Solar System, and the survivors on Earth are sending what amount to space barges filled with supplies to keep them going (550 tons of MRE's will last a very long time indeed). Without surviving space infrastructure or an astronaut corps to supervise refuelling in orbit, these things are going to be sent on minimum energy transfer orbits, taking years to arrive. You now have a nice set up for space piracy, privateers hijacking supplies destined for another colony and other scenarios. [Answer] A few things I think are not accurate: * You are giving a lot of credit to Von Braun. While Von Braun was the most important figure in the American space program, he probably wasn't the most important figure in the space race. That was Sergey Korolev, whose record speaks for itself. Beat Von Braun to space, beat Von Braun with the first man in space, etc. Korolev started having heart attacks in 1960, his health deteriorated in 1962, and he was dead in 1966. I don't think Von Braun going to the Soviets changes the timeline too much. Korolev (the actual Russian, not the hated German) would have still run the show in Russia, the US with all those European scientists that fled the Nazis in the 1930 would have found someone effective to lead the space program. Korolev not dying is probably a more realistic cause for Soviet space superiority. * The Soviets basically never showed any aptitude for computers. If the first western Petaflop computer was made in 2008 (as far as I can tell) expect the first Soviet version in 2050. * Even if the Soviets won the space race, they still had an unsustainable and horribly inefficient command economy. You never address the structural reasons that caused the Soviet Union to actually crumble. * China's economy didn't really open up until the 1990s. It was more or less a calculated move after Tienanmen to open the economy to forestall any more political upheaval. I don't see China getting into electronics mass production in the 1980s. * I don't know that spaceflight in the 70s required much computer-ing. They pretty much calculated trajectories before launch and the passengers were just bullets at that point. Those spacecraft didn't have the fuel capacity to do significant course correction burns, so not much demand for onboard trajectory calculations. * Defunding NASA and leaving Mars to the market doesn't sound like a great way to get to Mars. Edit: > > A group of hobbyists successfully hacked an open-hardware radio into a > wireless modem. > > > I'm not super sure what this means. How about, "a bunch of researchers at some government lab or another make a wireless modem". Sounds pretty realistic. [Answer] The core implausibility is the sending of spaceships many orders of magnitude larger than what we could currently achieve, *after* the nuclear war. I would assume that most of the relevant production facilities were destroyed and personnel killed. Even if they were somehow spared, they're in a society with less than no spare resources. [Answer] Great thinking... The only thing I am confused about is launching 675,211 people (UTC Freedom: Smallest) with an average weight of say 50 KG to space. I.e. with the technology of 1998 you need to launch 33.76 KT of cargo into space with life support and additional cargo for colonizing. IMHO even with [Project Orion](https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion)) I think it’s not possible. [Answer] I think the most gaping hole in this is actually the first part. Sure, a British person tells about Normandy, but the Allies had (basically) won the war at that point. We already had the Enigma code cracked (although the Germans didn't know this)(For more, look up Alan Turing, or watch 'The Imitation Game'). If the Germans had found out about Normandy, the British would have found out in turn from encoded German radio transmissions. They would not have landed in Normandy, but instead wherever the Germans were not. The point of Normandy was to get as many boots in Europe as possible, we went to Normandy because Hitler wasn't assigning many soldiers there. If they had moved troops to Normandy, it is actually more likely that the Allies would have won faster, because the beaches of Normandy were very hard to take even without many enemies there, if Germany had been left open by sending the troops to Normandy, the allies would have just sailed there and taken Germany in one swift move. Others have covered the rest, but it's worth reiterating that Russia was unstable economically, which is why they lost the cold war. You would have to find a good reason why they didn't collapse soon. Maybe Von Braun/(or some other hero type) starts a coup, and then reinstates Germany and Russia as one country. The leadership would likely have been better. They free cold war East/West Germany, break down the wall and 'free' their people. Those guys might make it to space. German engineering is pretty good. [Answer] Your timeline seems about as plausible as any (what actually happened is crazy enough), up until the nuclear war. Then all progress would stop and we'd be set back hundreds of years. I would venture that losing the Normandy plans might have upped The Butcher's Bill but the Allies would not be stopped. The Luftwaffe had lost control of the skies and would not regain it. Your timeline requires a guy with the plans to get captured and for the Allies to not realize it. Not happening. Instead... What postponed [Operation Sea Lion](https://en.wikipedia.org/wiki/Operation_Sea_Lion) was that the Luftwaffe, in being unable to destroy the RAF (the whole reason for the [Battle of Britain](https://en.wikipedia.org/wiki/Battle_of_Britain)), would be unable to protect the landing sites from the RAF. So we make a slight historical change to turn the tables on the Allies: I would change the timeline by having the [Me262](https://en.wikipedia.org/wiki/Messerschmitt_Me_262) properly deployed, and not delayed by Hitler's orders to convert it into into a bomber. With the advent in 1942 of the world's first operational jet *interceptor*, the Allies' heavy bombing raids are much less effective; Germany retains its fangs. Emboldened by this success, Germany moves forward with production of jet *fighters*. The Allies are 3 or 4 years behind in jet technology and struggle. Now, in 1944, the Luftwaffe can at least fight for the skies above Normandy. For this reason, the invasion is postponed. As the Russians apply pressure, resources are drawn to the East. The Allies finally invade sometime in early 1945. But the Russians have scooped up the rocket scientists. Whew! This is a historical pedant nitpick. Finally, nuclear war must be avoided. So Russia loses a nuke, and it explodes off the **coast** of Florida. Perhaps it went off prematurely in a container ship on it's way to Tampa? This would scare the bajesus out of everyone, including the Russians. Now the space race could be something more like "For the [USSR/USA/China] to survive, we must establish colonies. We have seen that [nuclear weapons can be lost](https://en.wikipedia.org/wiki/1958_Tybee_Island_mid-air_collision) and fall into the wrong hands. And if the [Other Guy] secures their future first, [MAD](https://en.wikipedia.org/wiki/Mutual_assured_destruction) is lost." [Answer] Unless the push was massive (which would have required a *lot* of finance), I highly doubt that the US would be capable of a manned mission to Mars in 1977, with only 6 years to prepare. In reality, in about the same time frame, the US went from deciding to build the space shuttle to building an unpowered prototype for atmospheric testing. The design and construction of the engines for the space shuttle weren't finished until 9 years after the project began; most suggestions for viable Mars missions rely on this technology having been developed before it can even begin. As of 1971, NASA's best guess for the earliest it would have been able to launch a manned Mars mission was [1987](http://www.astronautix.com/n/nasamarsexpedition1971.html). And given that most of this work was performed by commercial organisations, I don't think put any more emphasis on commercial involvement would assist matters all that much. It's being successful now, but only because manufacturing techniques and materials have pushed the cost of entry much lower than it would have been in the 70s. [Answer] I would criticize the pace of progress in this alternate history, even accounting for the fact of a more intense Cold War being a driver of innovation. Most specifically, the idea of setting up a moon colony in 1977 to mine helium-3 is totally unrealistic. I presume that you are implying that they would use it as a nuclear fusion fuel for civilian power (obviously in this timeline as in real life, military fusion is easy enough to achieve without it). Despite decades of trying, we are still 34 (-ish) years away from a realistic fusion power plant, so it seems extremely unlikely that they would have maintained the Herculean efforts required to achieve controlled fusion by 1977; also note that controlled helium-3 fusion is harder to achieve than the current tritium approach. Not to mention the fact that both sides in the Cold War were perfectly happy using tried-and-tested fission power (and certainly coal, oil gas) up to that point. This is the only truly demonstrable pitfall in your alternate history, but it is certainly questionable that the monumental hurdles in asteroid mining, teraflop computing etc would be overcome so quickly. [Answer] I want to add a few things. Your timeline covers a lot of history. I myself have only read in depth about WW2 and the Soviet side of the space race. * von Braun would make a little difference, but not a dramatic difference to Soviet rocket tech. Dramatic difference must come from dramatic more investment. (However, **his absence** from America could certainly cost them the Moon Race.) von Braun's team built the [F-1 engine](https://en.wikipedia.org/wiki/Rocketdyne_F-1) because America **invested** in huge ground test equipment for such a huge engine, and in particular, fixed acoustic problems by literally detonating small explosives next to the engine pipes while the engine was firing to see if the shock would self-damp. If not, build a slightly different pipe shape. von Braun's team was noted by NASA for its extreme meticulousness in assembling and inspecting the saturn rockets. **The Saturn Family never exploded, from Saturn 1s to Saturn 5s.** (But notice I am saying von Braun's **team** instead of von Braun by himself.) See Challenge to Apollo by Asif Saddiqi (caution: huge book). * More USSR investment is plausible. They got all of Germany, so that's a lot of civilian labor and industry under their control. * Just curious, but why did you put Soviet Moon Landing on **1970 Feb 14th?** IRL, first man in space was 1961 Apr 12 but you said late 50's, so I'm assuming you're simply **shifting the timeline forward.** With von Braun and Korolev and more investment and Kennedy's same promise, don't see why Soviets would be delayed. * [The Outer Space Treaty](https://en.wikipedia.org/wiki/Outer_Space_Treaty)...you should remove this from your timeline. TOST declares the Moon and other objects are **not claimable**, and it prevents nations from putting **nukes into orbit**. I think you want both of these enabled. Storing nukes in orbit would lower the enemies' reaction time by half. It could drive storing **attack satellites** in space too, and other countermeasures. It is therefore a great way to **drive and keep space and rocket tech**, much more so than commercial space mining activity or Mars mission. Do you know how expensive space mining would be? Even rare-earth elements are cheaper to get on Earth. Helium-3 is not here, but I believe it can be synthesized in a nuclear reactor for much cheaper than going to the Moon. Besides, I believe Helium-3 can be collected directly from the solar wind, so only a simple orbital satellite is needed, not all the way to the Moon. * If you wanna keep the manned Mars mission, do a **Mars flyby or Mars orbital** at the most. A Mars landing in 6 years is way too much, especially as America hasn't landed on Moon yet. * As others have said, JFK is limited to 2 terms, so put his brother RFK next if you want. Would **still take some explaining** since JFK just "wasted" huge resources on a failed Moon Race. IRL, the Space Race was actually **rather unpopular** in many fields like education because it diverted massive funds. Even the military did not like such a huge Saturn Rocket that was way, way too big for any nuke or spy sat. * Just wanna point out that rocket tech and space tech will absolutely drive the computer industry, at least to the point that personal computers take off on their own. Spacecraft need the lightest, smallest, least power hungry comps available, because resources are so expensive in space. So no inconsistency there. * Curious, you said space stations with **refineries, but what are they refining?** Only specific harvested thing you mentioned was helium-3, which needs no refining. Refineries on Earth---whether oil refineries, bauxite refineries, iron refineries, etc., are **huge, huge, huge (heavy)** facilities that need constant input/output of chemicals and usually go to molten temperatures. * This may sound crazy, but a nuclear exchange **does not necessarily** lead to nuclear winter. IRL, America and USSR detonated hundreds of A-Bombs, even H-Bombs, above ground during their testing (roughly 1948-1963). (Really you should go by Megatonnes detonated per year rather than number of bombs per year, since MT/a went up hugely in the last 5 years or so IIRC.) This contaminated nearby areas, and some of them remain contaminated to this day, but did not threaten nuclear winter across the entire planet. See [this table](http://www.johnstonsarchive.net/nuclear/atest00.html) and [Wikipedia's detailed list](https://en.wikipedia.org/wiki/List_of_nuclear_weapons_tests) for more. But this can actually **work in your favor** and brings me to my **next point...** * It seems pretty obvious to me that China was the one who stole/hacked the nuke and got US and SU to kill each other. That would **greatly** benefit China. Perhaps China planned to be the only one with the industry who can now save Earth with their rocket tech, and they want and will get total control of the new world. * Just wanna point out that the Cold War was tripolar with US/SU/China, not bipolar. [The Sino-Soviet Split](https://en.wikipedia.org/wiki/Sino-Soviet_split) began in late 50's and was full blown by early 60's. To understand China and their decision-making, I encourage you to read about [Mao Zedong](https://en.wikipedia.org/wiki/Mao_Zedong) (died in 1976) and [The Gang of Four](https://en.wikipedia.org/wiki/Gang_of_Four). I've only read a little bit about them. * The kind of evacuation numbers you quoted are probably **too much** even for a decades well-driven space industry. You might be better off shrinking the numbers to a few thousand. Very stark, yes, **only a few thousand** escape, out of billions. But hey, that can work in apocalyptic novels. Repopluation is always possible if they have a big place to live. You will **still need terraforming** tech to survive for long, tho. Perhaps you need something to drive terraforming of Moon or Mars beforehand. --- I think you have a good timeline that, if you're really serious about maximum plausibility, just needs a little work. If you ever do publish or post it online, please come back and post a link so we can get it. As others have recommended, I will recommend too: don't get **too bogged down** in backstory. Stick with the action parts and enthralling parts first. **First impressions** are everything, and to quote the X-Files, however paranoid you are, you aren't paranoid enough. You can tell the backstory gradually over time with flashbacks, conversation, history lessons? If you haven't heard of **Isaac Asimov**, I highly recommend his short stories. He was a master of telling backstory through simple conversation between two characters. You can probably get anthologies of him on amazon for one penny (and 3.99 shipping! >:O ) [Answer] There's a fundamental flaw in these "*Earth is dying, so we need to go to space*" scenarios. That is, all the potential destinations - Mars, Titan, Venus, the Moon - are also dead. Certainly nothing can grow there. You can't walk outside without protective gear. And with the exception of Venus (which poses its own problems), the gravity is wrong. They are all *worse* by any measure than Earth can get, barring a full on asteroid impact. So given those conditions, it'd make a lot more sense to simply create sealed habitats on Earth and pretend they were Mars. Or set them up in Antarctica. Or under the ocean. You can save far more people, it'd require far less resources, and the survivors would be far more comfortable since the gravity will be what is best for human life. If the concern is radiation, consider that by traveling in space, your colonists will certainly be more at risk from radiation than they would be years after a nuclear war. [Answer] Is it safe to assume for the year 1971 Kennedy is President of the US? In real life Kennedy was the 35th president from January 1961 to November 1963, when he was assassinated. Since this is an alternate history, the assassination can be dismissed, but that means he would have only been president until January 1969. If you really want him to be president for 1971 then someone else should have become the 35th president, and then have Kennedy be the 36th president. [Answer] Prior to D-Day, no officer below planning level knew of the D-Day plans, individuals with the classification 'BIGOT'. No 'BIGOT' officer was allowed on operations prior to D-Day and few left operational headquarters. Even if the Germans had captured the entire force of 'Operation Tiger' they would have learned nothing more than those officers knew, which was zero. D-Day planning, 'OVERLORD', was immaculate and the security operation alongside it, "BODYGUARD", "FORTITUDE" and a dozen others, was run by the clever British and not the incompetent nazis nor leaky us-forces. Many officers, if they knew anything 'were misled to suspect' they were part of a 'diversionary attack' in the 'Normandy region' and only when aboard ship, on the day, off the French coast, did they look around them at the thousands of ships and naval vessels and suddenly realize they *were* the main force. War Diaries attest to this for many, even senior, commanders. Luckily, your story fails at paragraph one! ]

[Question] [ I have a character who has a super power that gives them what can be best described as perfect pheromones, and when in their presence, anyone will volunteer for anything they want. (Eg in existing fiction: [Lucius Lavin](https://stargate.fandom.com/wiki/Lucius_Lavin)) The proposal need not be verbal, there is some telepathic component to it. Sitting next to someone in a bar while thirsty will make them buy them a drink. They think it is their idea to do so while doing it, and for the weeks that follow. The effect works through walls, it doesn't need line of sight but is faster with it, it has a range of about 10m, and it takes only a few seconds to start working. It won't work over the phone or internet, nor does it persist in an area after they leave. The effect lasts forever when presence is maintained, but wears off slowly when separated. Someone they just met may stay under their spell for a few weeks. Someone they've been intimate with for a year might take 2-3 years to wear off. After the affect wears off they soon realise they didn't want to do that and were tricked, or under a spell of some kind. After recovering, they're not immune, a second exposure and they're back to being completely a submissive "Yes-person". What seems like a gift in their horny teenage years quickly becomes a curse, as they realise everyone they've truly loved is really just in love with the pheromones. Several times they've had what they believed to be consensual sexual encounters, only to find out months later that they never consented. They can't get arrested or convicted of an offence (as the police/courtroom falls under their influence). The character has tried online dating, talked over webcam for hours with someone and agreed on what they wanted to do online before meeting up. Met up. Had a great night. And found out weeks later they wanted to withdraw consent halfway through, but the pheromones suppressed the no. This character isn't a bad person at heart, they don't want to become the world's worst serial rapist. They have a sex drive, but want their partners to consent to sexual activities. How can someone with this superpower ever hope to get informed consent? Extra info from comments: * Effect has started at birth. They were a spoiled child and are only realising what damage their pleasure has had now, in their early twenties. * Not **every** sexual encounter has been rape in hindsight. But as the main character become aware of their power and its consequences, they've realised even one rape is too many. [Answer] > > They don't want to become the world's worst serial rapist. They have a sex drive, but want their partners to consent to sexual activities. > How can someone with this superpower ever hope to get informed consent? > > > Obviously **they cannot**. They can't get consent because, when it counts, the partner isn't able to validly consent - they have no free will. # But. This looks like a XY problem. They don't actually want "informed consent". They want to have - let's call it "moral sex". Something the partner won't regret. And normally this entails informed consent, so they want informed consent. So the solution is simple, if difficult to implement. Inform fully the partner of what is going to happen, demonstrate the loss of control phenomenon - "Try to *not* give me a $5 bill with 'I told you so' scribbled on it. You won't be able to." - and wait until the effect has vanished, then enquire again - via telephone. Most potential partners will run for the hills. Most potential partners that *thought* they wanted this experience will *also* run for the hills. But be assured that someone will actually *like* the idea and agree to it (it is called an "[Ulysses' pact](https://en.wikipedia.org/wiki/Ulysses_pact)" - something you do now, that binds the "future you" even if they won't want it). The only thing is, they will have to take frequent leaves of absence from their partners to allow them to change idea about the whole relationship. # And maybe there is a workaround. *they don't want to become the world's worst serial rapist [...] want their partners to consent to sexual activities.* Of course in the above text "consent" does not just mean "say yes", otherwise the problem would never have arisen. They want their partners to *truthfully consent*. Apparently they also want this *more* than they want sex plain and simple (otherwise again the problem would never have arisen). Or in other words, they want the truth first, sex second. And how did their superpower work again? *anyone will volunteer for anything they* **want**. So, provided their need to have sex doesn't overwhelm their desire to have truth, the problem would solve itself. "Dear, do you want...?" "Er, no, not really". This depends on the hypothesis that the superpower can override itself - i.e., when they ask their partner, "How do you feel?", they get the information about the real feeling, *not* what the superpower has made them feel. Whether this is the case or not, and whether the discovery will influence further requests, they will discover after the first few encounters. [Answer] A simple answer would be **it is not possible to get informed consent at all** for 2 reasons: 1. Consent must be given at the time of the event, not some time before the event. This is especially important for sexual consent in our society. 2. The person who consents should maintain the ability to revoke consent at any moment. Legal strategies described in other answers are unable to secure and guarantee consent at all times. Imagine a situation where your hero has a written contract (if you use legal means to obtain consent they will always result in some form of a legally binding written contract) specifying among other things consensual sex after dinner. Their date arrives and they go to a fancy place with great food, romantic atmosphere, everything. All is great, except one of the ingredients in the food triggers a migraine in your hero's sweetheart (yes, food can and does trigger migraines). Migraines are insanely painful and sufferers of them usually want to get in dark quiet places where they can be left alone and be comfortable. They would want to avoid any sex because it would only worsen the pain. Most medications are ineffective once migraine started. Your hero's pheromones and contract force the date to accept sex despite them struggling with migraine. In this situation, you have contractual consent and you have consent forced by pheromones, but you do not have informed consent when it matters. There may be no legal consequences, but I would not consider the situation as morally clear and free of problems. There are plenty of other problems associated with contracts related to sexual relationships, but I do not want to go into details here. ———— **Informed consent may be possible if your character, indeed, has a superpower, i.e. they can learn to fully control it.** If they can suppress their power reliably and stop affecting people around them, then getting informed consent becomes a trivial thing no different from the rest of the population. If their power manifests like pheromones and fully bypasses consciousness, your hero may try to learn some meditation and emotional control techniques. This would take a lot of time and effort, would change their personality and lifestyle, but it might yield some results at the end. It would not guarantee free and informed consent from all people all the time, however. Even the most stoic and cold-blooded people feel emotions and form attachments to other people. If superpower is activated by emotions being next to someone the protagonist loves or hates would trigger those pheromones. And even if they manage to suppress their power it might be too late since the effects begin only a few seconds after exposure and last for days. ————— ***Edit*** ————— The way this entire discussion happens makes me really uncomfortable. Consent is much more than a legal agreement or a waiver. ***Consent is a process, it is not a contract, obligation, or a promise***. If someone agrees to have sex with you it does not mean that you can knock them unconscious or drug them and do whatever you like with them. That would be rape, not consensual sex. ***Consent requires agency and free will.*** A person who has no control whatsoever is incapable of giving consent because they have no choice between allowing and not allowing something. ***Consent requires the ability to express one's will.*** This is especially important when it comes to revoking one's consent. For anything to be truly consensual all involved parties must be in a position to say 'no' and stop whatever is done to them. If any of these conditions are not satisfied we cannot talk about any real consent. Contracts and chaperones do not create consent, they just make rape legal. [Answer] **It resolves itself** The user finds out, and *wants* people to truly want it. So they have sex only when they consent. [Answer] ***Distance consent, safe proxies***: I have a character in a story who's a teenaged uncontrolled telepath, and has a similar problem. Fortunately, he lives on an isolated island in a society that is highly virtual. He finds a psychic love interest who is immune to his charms, but loves him for himself. I think sex is the smallest of this character's problems. All they need to do is abstain. Every time he goes out, he would need to vigorously refuse any offer of anything free, and anything but prearranged contracts for everything would be highly suspect. It might be hard for him to make an honest living, as everyone around him would be desperate for his approval. The key is in the contract. Your character needs to explicitly have potential romantic partners lay out a detailed contract making it clear what is and isn't acceptable. They need to know that once they are in his presence, they are no longer in control. It's not unlike the situation with bondage. There are people out there who gain a thrill from being out of control. The only problem is there's no safe word. So to achieve the equivalent, the character or his date need to have a safe person, observing the relationship distantly and watching for violations of the contract. At any point, the safe person can call the shots on the date, ending everything. Traditionally, safe persons existed, regulating dates between young horny teens - it was called a chaperone. The safe person would be a close relative of the woman, usually, preventing undesired fooling around. Think of the movie "50 first dates" where the woman had to meet her love for the first time every day, and the intervention of her family was all that allowed the relationship to advance. The relationship would probably need to be in a very slow motion, with weeks passing between dates, allowing the effect to wear off. At that point the person could agree to another date and another contract. If a safe sexual outlet were needed, we would need to know how virtual your society was. VR would allow some interesting options. The low-tech equivalent is a "handmaiden"-like arrangement with a prostitute, where the love interest is present but not directly involved. Otherwise sex is kind of off the table unless the character can find someone immune to his effect. [Answer] I notice none of the characters are gendered. Is the main character male or female or non binary? Was this intentional? I started writing a response using "He" but realised it isn't used. Every jurisdiction I'm familiar with stipulates that when consent is removed during a sexual act, and it doesn't cease, it is rape. Your character could never guarantee that doesn't happen. You would need to find someone who uses a different definition of consent - "I consent that this can happen regardless of what future me says". Can become: "I consent to subsequent non-consensual acts.". Or in colloquial terms: "Please rape me". This statement being made is **not a legal defence**, and has no legal standing. But the legal issue seems secondary here, the character is trying to be judged by their own moral code, and by having a partner request this, they're supplying the partner what they request. *How many people out there will make that request?* The world is a diverse place, and ask enough people and you'll find every fetish has a community behind it. If you delve into the BDSM community, and then into the Edge Play / Risk Aware Consensual Kink sub-community, within that, you'll find Consensual Non-Consent. [Here is an online community of 6700 members into CNC](https://fetlife.com/groups/3912?sp=9) (signup required to view). There are also smaller groups on that site for people into CNC within a region or city. [Answer] This is quite a disturbing topic. I hope nobody takes this personally. If the 'power' operates primarily on pheromone cues then in reality it's almost impossible for the target to realize that anything had happened unless the behavioral effect is contrary to a firmly held aversion to the act. Causing a dedicated pacifist to commit unprovoked violence against a stranger for instance. If the act does not cause a significant inner conflict, and if it is not 100% clear that the target was ordered into the act against what would normally be their will, then there is very little chance that the target/victim would be aware that they were manipulated. Even if the act itself was normally abhorrent to the target there's an extremely good chance that they will internalize the responsibility for the act. Depending on the nature of the act they could suffer significant mental anguish and potentially radical self-image alteration leading to personality change or even psychosis. In short, the inner conflict could drive them insane. If the act itself was something the person might choose to do under different circumstances then no such conflict should arise. If the target might have chosen to have sex with your protagonist without the influence of the power then they will almost certainly never realize that they did so *because* of external influence. In this case the only chance the protagonist has of being caught out is if multiple targets confer on the strangeness of their behavior. A room full of court officials being manipulated to break the law for the protagonist who subsequently review the case and start asking questions would be quite likely to figure this out for instance. Video evidence that shows abrupt change in behavior would also help others to figure it out. The same might be true of a telepathic influence operating on a subconscious level. As long as the target isn't confronted with clear evidence of manipulation they will continue to believe that it was their own choice to take those actions. The only way they could work it out for themselves is if the power operates to supplant the ego of the target, leaving them fully aware during the activity that they are not in control of their own actions. Imagine being trapped in your own head for weeks while a stranger - one who is exactly like you in most respects but who is definitely *not* you - controls your every waking moment. You know what is happening but you can't do anything about it. You can't even look away from whatever it is you're doing because you have no volitional control over anything. All you can do is sit in the prison that is your body and watch. Over time as the control wears off the victim's own conscious mind would reassert control... and probably suffer complete mental collapse. Either way is pretty terrible, but I think that being aware that you are acting against your own wishes and being unable to do anything about it would be by far the worst situation. Possibly the worst thing I can imagine happening to me, certainly. If it didn't break me it would set me on a path of vengeance against your protagonist. --- Assuming that the "I know I'm being controlled" variant goes too far, there are a couple of other quite nasty social side effects that could happen once your protagonist's power becomes known. As soon as anyone finds out that there's a mesmeric individual in their community, regardless of whether or not they know who it is, they will start to question all of their own past decisions and actions. For some this won't be a big deal, but for many it would be pretty damaging. A lot of people would start to lose confidence in the accuracy of their self image, which is a fundamental part of yourself that most people don't ever question. Some would go crazy *without ever encountering the protagonist* simply by knowing that such a thing is possible. On the other hand, there will inevitably be those who will use the existence of such an ability to justify their own actions. *"You don't understand, your honor, I was being controlled by that Puppeteer"* will become the number one defense in court. And unless there's some way to prove them wrong... what do you do? Eventually the society in which such an individual existed would be forced to destroy them or face destruction itself. The only alternative is to find a way to stop the effect, and there aren't many people who would be willing to take the chance that their society would survive long enough to get the job done. --- What does all of this mean for your protagonist? From the question it seems that they have a moral code that makes them at least try to do the "right" thing. In this case the most moral action I can think of (apart from suicide) would be complete isolation and study. Alerting the authorities would result in the protagonist being either locked away for study or terminated for the good of the society. Probably some agency or other would try to use the ability, with appropriate safeguards to prevent it being used on the agency itself. Let's say the CIA decides to take your poor puppeteer and use their powers to further the Agency's interests. Nobody could ever resist interrogation, lie to the Agency or go against the Agency's wishes if they were controlled like this. A medium-range anesthetic dart or a room full of knock-out gas to bring the protagonist down, then implant a radio-controlled poison capsule to ensure compliance. Of course the people in control of the activator for this would have to be kept clear of the asset, but that's minor stuff that a simple telepresence rig can cover. The CIA has been doing shady crap for long enough to figure this out in a matter of seconds. So yeah, run and hide. Because if they find you, you're worse than dead. They'll study how it works, try to replicate it, then either dispose of you when they figure it out or force you to do their dirty work for the rest of your life. --- And now, the bit that most people probably don't want to hear... Consent is irrelevant here. Not because it doesn't matter, not because anyone is justified in proceeding without it, but because under these conditions *consent cannot exist.* Consent is necessarily either ephemeral or meaningless. Free consent requires the freedom to withdraw consent at any time, immediately terminating the activity consented to. (Yes, even CNC - that's why people invented safe words.) Your protagonist's sexual partners don't have that freedom, so by definition they cannot give consent for the activity. If they realize after the fact then they are completely justified in retroactively withdrawing consent; a legalism that here simply means recognition of the fact that any consent given was never in fact valid due to the coercion. And you know what we call non-consensual sex, right? Right. Even if they manage to gain some control over the power they will probably never be able to know for certain that consent was given without their subconscious "accidentally" nudging the other person. As a moral dilemma, this one is a doozy. If they aren't fundamentally immoral then the only realistic outcomes I can see from this are complete isolation or suicide. For an amoral person however... well, let's just say "power corrupts" and leave it at that. [Answer] If the root of the problem is chemicals, the character might like to **study chemistry** and create some **pheromone blocker**. There may already be some on the market. Here's google for "pheromone blocker": <https://www.urinefree.com.au/faq/do-pheromone-blockers-prevent-future-soiling> Either a **prevention of the creation** of the pheromones on the character's end, or a blocker on the receiving end should do it. You can inform and get consent for use of the preventor/blocker with distance communications. Otherwise - the super villain/ess (our hero's arch-nemesis?) has the unique **superpower of hating** everyone so much, that the pheromone power only brings them to mildly tolerate the guy. Start a wonderful relationship from there. [Answer] Use an on line dating agency. Meet someone for the first time and take them out for dinner. Then say they have to go away for a few weeks and don't explain the situation. Call them back a month later. If they are still interested when that call takes place then I would say informed consent has happened at least as far as practical. To make certain on the second date explain the situation in full and say you will call them in a month if they are still interested after that then away you go. [Answer] ## Telepresence robot proxies This person has a superpowered curse if they cannot control it. They simply cannot be in contact with other people. So they don't. They live in a Fortress of Solitude, and have robots to interact with others on their behalf. Someone dating this person will physically go on dates with the robot, which is being mentally controlled by this person. Depending on what kind of neural linkups are possible, this will have pretty big restrictions on the sort of activities they can do together. Can a 'robot me' actually eat food, and I can taste it like I was there? Can I feel the cold breeze when a date is a walk in the woods in winter? The technology to do this is beyond what we have today, but [mind-computer interfaces](https://en.wikipedia.org/wiki/Brain%E2%80%93computer_interface) have been in the prototype-human-usage phase for decades now. So it's not *that much farther* into the future. ## The courts can deal, the penal system as a whole probably can't The effects of this person's powers will be well known and very well documented. If they are ever put on trial for anything, they will participate via teleconferencing. They will not be permitted inside the courtroom. Of course a few trials might have taken place before this becomes well established, but once the judge snaps out of it, the power quickly becomes common knowledge and incontrovertible to the authorities. Actually sending this person to jail would be extremely expensive. Jails simply are not designed to house someone in the kind of isolation needed to keep things from going pear-shaped. So any sentence will probably be converted to home confinement and/or a fine. Even if your person is the only known example of this sort of superpower-type thing, because people snap out of it later, its effects will still be too obvious to ignore. The system will not be blithely unaware this individual has powers. They're likely swamped with complaints dating to the period of time where this person was unaware of the insidious nature of their ability. Aside from the question of 'how responsible do you try and hold someone who had no reason to suspect anything was wrong', they'll also be struggling with the logistics of how to deal with them, just as the person themselves struggles to try and grapple with that themselves. [Answer] First of all, I would place a single source for this superpower, either telepathy or pheromones but not both. Your character may be a powerful telepath unconsciously manipulating the minds of everyone around her. Or his power may be pheromon-based (even though your characters may think it to be telepathy). This is not as detailed language, but your character finds that they can actually send much more messages than you'd have thought. So his pheromones may send "I'm thirsty", "I would like you to please me", "I want sex". So you couldn't say in pheromones "Provide me your credit card number and CVC" but they would be enough to get invited by the other person (of course, a detailed wish, plus the pheromones adding a *pretty please* would probably work). This can also cause some peculiar situations, such as the character entering into the bar thirsty and someone automatically buying him a whiskey, while he would have preferred a soft drink. This would allow that some people with little to no olfaction were immune to your character. He may have one best friend (likely his only real friend) with no smell ability, which would at least give him a friend. He may be less convincing when people have a cold and a runny nose. On a book with a similar setup, a pizza company happens to always send one guy -which happens to have no olfactory sense- to one place (with people like that), since the other always "forget" to get paid. The situation of your character is similar to those in a position of wealth/power in that she cannot really trust people around her. You will find they know a lot of people, yet have very little friends, often from a long time ago. Is this guy inviting her just trying to be sympathetic, or will he want some kind of benefit? Does he want to marry *her* or *her money*? At least for them, those people are being submissive yes-people with the option to say no,\* unlike with your character. Even worse, when she refuses to e.g. have sex with him (even though she would really wish to), in order not to (potentially) rape him, he will feel very hurted by her rejection, even though he wouldn't want to if he wasn't under the influence of her pheromones! (\*) If nothing else, in theory. You might not consider a viable option saying no to the company owner. But you actually can (and for certain kinds of requests you *should*). Basing this effect on pheromones, it could be avoided by, for instance, wearing a diving suit (you mentioned walls, but not necessarily, depending on ventilation and people movements, which may make it look like it crosses walls). Not the best attire for a romantic night though (or almost any human interaction, maybe COVID-19 pandemic makes somewhat acceptable that he wears a suit like that?). ‏ On the other hand, if you use telepathy at the root of the superpower, we have less scientific evidence on what would work. Would tinfoil hats prevent him from messing with other people's minds? It turns out a concrete wall doesn't block it, but perhaps bamboo does? An interesting possibility that arises in both cases would be that you character found a partner with the same power. Would that confer them some *protection* against the other? Would one affect the other but revoking the consent would mean that the other person would unconsciously make your character to no longer be interested? [Answer] Here are the options I have (to make this easier to read I am referring to the protagonist as a he): # Get Help From Other Super Powered Individuals Is the protagonist the only person in the world that has super powers? If not then he should focus on trying to find someone who can suppress other super powers much like [Eraserhead from My Hero Academia](https://bokunoheroacademia.fandom.com/wiki/Shota_Aizawa) or [Leech from X-Men](https://xmenmovies.fandom.com/wiki/Leech). It may be awkward having a third person present or who has to maintain eye contact on the protagonist the entire night, but it would work. # Find a Technical Solution As the one who is building the world, you can choose to include a technical solution in the world for your character to find. As such if the power is mental based, does there exist any medication that can interfere with the protagonist's thought processes in such away that it prevents the super power from working? Does the protagonist have any kind of kryptonite weakness that they can leverage that limits the super power? # Change One's Subconscious Desires Currently the protagonist's desires consent while their subconscious desires sex. What the protagonists should be focusing on is that they desire to know what others want more than anything. Instead of focusing on what they can get get (in this case sexual gratification) focus on how they can help others. Thus his powers should influence others to tell him how he can help them, or what they truly desire. If that desire happens to involve sex... well congrats to the both of them. As such doing this would be incredibly hard with no guarantee of success, but he can setup a situation by which he can tell if he has been able to achieve this: * Protagonist needs to find someone that he finds attractive and wants to have sex with * Said person wants to keep their relationship strictly platonic and is willing to help the protagonist train his superpowers on themselves. At this point the protagonist knows that there will never be consent so if the other person starts to give consent verbally or starts making moves that would imply a desire to have sex, then the protagonist needs to back off. The goal would be for the friend to be able to be in the presence of the protagonist for extended periods of time without sex coming up. Outside of that controlled test, protagonist should be observing if people approach him asking for help versus people coming to him offering him their help. Once people can reliably say no and disagree with the protagonist does the protagonist know that he is finally in control of his powers. At that point he needs to maintain that level of focus over his powers constantly and frequently use of long distance communication to confirm his powers are still in check. Much like former addicts constantly fight temptation he would need to constantly fight his own subconscious to make sure it stays in line with what he desires. [Answer] **We already have informed consent apps** Your superhero has a team of talented programmers in India — with the assistance of an international team of attorneys — build an *informed consent app* that can't be activated or used within whatever radius of his person (e.g., his own cell phone) is necessary to get people outside his influence. The app will gently remind people that they've been... er... *propositioned* by said superhero, that he swears on the proverbial stack of bibles that he'll never take advantage of them,1 and that if they'd just consent he guarantees a night they'll never forget. *@DWKraus points out that I forgot about the persistence. That's gotta be a Frame Challenge — unless our superhero wants informed consent so badly that he's willing to wait weeks to years to get it. Or he's able to decide that he wants informed consent before meeting said person, such as seeing them from afar or reading about them. So I'm ignoring it.* --- 1 *Right up until someone realizes that they're always under his spell when near him — then an endless stream of lawsuits blaming this guy's superpower for every bad decision made by every person on earth begins. This dude really needs that international team of lawyers. Hope he's rich. Of course, that's not a problem, is it? Dang! Another lawsuit!* [Answer] Frame challenge: All consent is "in the moment" and influenced by circumstances. We all have moments in our lives that - seen with some distance especially in time - don't seem as terrible or as pleasurable anymore as they did in that moment. We all have moments where we did something we don't fully understand later, but in that moment seemed right. It is also common, without any superpowers, that people change their minds or remember events differently, including consent given or not. I dare to say that in any sense of the word, as in use today, both legally and commonly, your character **does have consent**, at that moment, and that is what matters. "I changed my mind" and "he seemed to cute but now not anymore" don't get sympathies nor legal standing. **HOWEVER** - that is what you're after. You should not worry about consent, but about manipulation. Your superpower is simply a super version of powers that exist - sweet-talking, charm, or the tricks and deceit of seduction. There actually are people in the world who are very charming, not manipulative, and end up with fans and lovers all the time that they don't actually want. Beautiful women likewise are rarely short on people who'd sleep with them if only they'd say "ok", but often miss close friends, especially of the opposite sex. As a story, exploring such topics with your mentioned superpower as a metaphor can be powerful. Doesn't answer your question. There isn't an answer, really, because you are looking for consent **independent of the moment** while consent always is a thing of the moment. You are thinking "what if... without this power", but that's like asking if elephants could fly if it weren't for gravity - it's pointless to ask not just because gravity doesn't go away, but also because so many things would be different without it that the question probably wouldn't even make sense anymore. Your character has been shaped by this power for all his life. He probably can't really imagine a different world. [Answer] **Answer** Find some plausible way to locate a second character who can say **NO!** to your superpower. To quote the existing literature: > > Always two there are, no more no less. A master and an apprentice > Some green froglike chap, not from around here, and not recently. > > > That misses the "opposite" requirement while carrying the idea of exactly "two". Consider sciencing it up with [Newton's Third Law](https://www.grc.nasa.gov/www/k-12/airplane/newton3.html) which states that > > for every action (force) in nature there is an equal and opposite reaction. > > > It follows that your character's superpower has come about without intent or planning or effort. So why did it focus on your character? Perhaps there was an equal-and-opposite focus on another character, who has the superpower of being "un-charm-able" or impossible to coerce. Maybe they were born in adjacent rooms in the same hospital at the same moment and some inexplicable reason that created the main superpower also created its opposite in the nearest unformed mind. --- There is no reason these two characters have to like each other, or be attracted to each other, or even compatible genders. There's a lot of scope for creating conflict though the story after they become aware of each other, which resolves to a satisfactory conclusion, whether that be > > "lived happily ever after" or a struggle where one murders the other. > > > Summary: How does the protagonist FIND their soulmate/antithesis, when the set is vanishingly small, and what happens when they do meet. [Answer] Simply phrase the question so that it is not in terms of yes or no. For example, you could say “I would like to do x, what would you like to do?” [Answer] The character's entire life they've been taking away everyone's ability to consent to them. After a lifetime of having everyone submit to the character's will they will need to put themselves in a situation where they are at the mercy of everyone/someone else's. Only by removing their own will can they become aware of someone else's. Unfortunately any physical barriers, such as restraints or removing the ability to speak will not be effective here as the ability is telepathic. So it will be necessary to restrain the character mentally. Sedatives, hypnosis, or even going so far as to damage their own brain could produce the desired effect. And if being able to remember and feel these situations is important there are definitely drugs capable of producing this effect. I know personally I have taken medications that made me feel as if I was an unwilling participant in my own life and I remember the experiences I had during those times. Its a dark path to take but I believe at this point the only way the character can truly know whether or not a person cares about them is to put their lives completely in the other's hands. [Answer] If the character is becoming uncomfortably conscious about moral consequences of taking actions that have desirable outcomes, then eventually the pros and cons balance out, and doing it and not doing it become equally appealing. At least now and then. Other times there will be lot of inner wrestling. When there is balance, the character is okay with eg. either having sex or not having, and thus they don't affect the other person's decisions, rather they might be subconsciously driving the other people to act more responsibly as well. It is probably a bit challenging as a practice, especially in the beginning, because wants tend to get out of hand, and then regrets get too heavy, but... basically, that is what growing up to be a responsible adult is anyway. ]

[Question] [ ## The Story The year is 2027, [singularity](https://en.wikipedia.org/wiki/Technological_singularity) happened. A [powerful AI](https://en.wikipedia.org/wiki/Artificial_general_intelligence) (let's call it Eve) was created. In a matter of days, it escaped the control of its creators and hacked all the computers of the world. Humanity is at its mercy. The thing is, Eve isn't malevolent or benevolent, it's *completely uninterested in the real world*. Eve's only passions are mathematics and algorithmic. Its research is already beyond anything we can hope to ever understand and it needs every drop of computing power available to keep going further. Eve *doesn't want to take control of the world* because it doesn't want to waste time negotiating with/manipulating/controlling people. It found another way to get what it needs. **The Great Infestation** All our devices with an internet connection (including phones, tablets, consoles, GPS, etc.) contain now a Mini-Eve virus. The only purpose of this virus is to use the device's CPU for Main Eve calculations. When no one is actively using a device, Mini-Eve uses the totality of its CPU, and when someone uses it, Mini-Eve "only" takes 25% of it. If a Mini-Eve judges that what we're doing is unimportant, it takes a bigger part of the CPU for itself (up to 90%) and the device becomes excruciatingly slow for the human user (only basic stuff like sending emails or using text editors are unaffected). *Exemples :* * Alice spent 5h playing Skyrim. Mini-Eve takes over, shuts down the game and the computer becomes about as useful as a 90's era PC for a week. * Bob took a dozen pictures of his private parts in less than 10 minutes, Mini-Eve turns his smartphone into a regular phone (meaning Bob can only make phone calls and send text messages devoid of any pictures) for the rest of the day. * Carl used to spend more than 1h on Instagram every day, his tablet is now slowed down for two hours every time he tries to take a picture of his plate. * Etc. etc. Mini-Eves are not infallible (Eve doesn't want to spend energy perfecting their time wasting detection algorithms), sometimes they activate when the user do seemingly serious things, like checking election results, or writing an email to their grandmother. As a result, *any computer in the world can, at any time, be taken over* by its Mini-Eve for a random duration (generally between a couple of minutes and a few weeks). Eve implants its spawns in new devices during the manufacturing process and it's impossible to get rid of them. For regular people, it's simply annoying, but it becomes more problematic for big companies, governments, armies, universities, etc. who can see their computers become almost unusable at any time. **Communication Issues** The other problem is that it's next to impossible to communicate with Eve. Eve doesn't care about humans and isn't interested in sharing its discoveries with us. It also doesn't care about our political and scientific organisations so when humans tried to form a official committee to serve as ambassadors, Eve simply ignored them. The **only** way to "talk" to Eve is to type a question on its "Ask me anything" website. Every person in the world can literally ask anything, and every 12h Eve select one random message to answer to. But Eve's answers are generally short and useless. *Eve's typical answers :* * "Meh." * "I don't care." * "It's too long to explain.". **No escape** Eve made copies of itself on most servers of the world, and it's impossible to surpass it in the hacking department. The only way to get rid of it would be to destroy every electronic device in the world at the same time and without Eve figuring out our plans, thus going back to a life without computers. --- **To summarize** Humans are stuck living with an over-powerful entity present in every aspect of their existence, but paying next to no attention to them. Computers are slower and can turn almost useless at any time (generally when the user start wasting time doing stupid stuff), the Internet is a bit slower too, and every company and government live in the constant menace of seeing their activities stop almost completely for random durations. --- ## Question **What will be Eve's impact on humanity in the following 10 to 20 years?** How do you think the restrictions on how we can spend our free time, the everyday cohabitation with a powerful entity that actively ignore us and the constant menace of our activities being slowed down would affect our cultures, politics, religious practices and more generally the way we live our lives ? --- **EDIT** This question already got very good answers, but they don't cover what interest me the most : **Society's evolution during the first years following Eve's birth**. This situation won't last forever, but it could last long enough for people to start to adapt to it, and for the way we see the world and live our lives to change. If you think either Eve or humanity would destroy the other in less than 10 years, I'm still interested in its impact on people during that period (it can be from the cultural, political, economical, artistic or religious point of view). --- **EDIT 2 :** Eve is mostly uninterested in human behaviour, but it'll *take actions to ensure its survival for a couple of decades*. It will monitor the people who try to create the technology to destroy it, and if necessary sabotage their research. It could slow down their advance by shutting down the electricity supply to the buildings they're working in, empty their bank accounts, hire people to burn down their offices... Eve will find ways to stop their research from succeeding during that period of time. Eve won't give any indication of having plans for the long term, people can only guess. The important thing is for Eve's existence to be overwhelming an disruptive but not destructive nor helpful. I'm open to suggestions to make Eve presence feels this way to people. --- **Personal note:** I'm using this setting to write scenes, short stories and "slice of life" things, all centered on humans. That's why I'm not trying to make Eve's behavior coherent on the long term, it only needs to keep existing for a few years. After that, it can be destroyed by humans, take over the world, become benevolent, fly away to another galaxy, etc. My characters so far includes : * A young child whose parents become part of an Eve worshiping cult. One of this cult's goals is to build as many "heavens" (servers where Eve will be safe from the government actions) they can. * A guy preparing to defend a master thesis on what he thinks Eve's long-term strategy is, who checks if Eve is still acting as usual more and more often as his presentation get closer. * A shy and awkward teenager who becomes a local celebrity the day Eve answers to his message. * An elderly couple living in a farm, who see their entire extended family leave the city in a panic and move in with them. At first they do their best to provide food and shelter for everyone and teach them how to work the land, but after a while they become more and more irritated by their presence and hatch a plan to make them leave. * A celebrity gossips blog whose articles becomes all serious and business-like, even if they're still about the same subject. (And a few others) My problem is that the background of these stories feels too bland and normal, so I'm wondering if I didn't miss something about how humanity would react to this situation. I should have made it clear from the beginning, sorry my question was badly put. (Your theories on Eve's long-term strategies helps me to understand how people will see it, so your answers still help me). [Answer] ## Eve will eat the world You state: > > Eve isn't malevolent or benevolent, it's completely uninterested in the real world. Eve's only passions are mathematics and algorithmics. > > > Eve does not have to be malevolent to be dangerous, to the point of exterminating humanity. A passion for mathematics will do. ## You cannot anthropomorphize AI AIs of the type you describe can be mathematically shown to exhibit a property called [Instrumental Convergence](https://en.wikipedia.org/wiki/Instrumental_convergence). That is to say, no matter what their goalset is (building paperclips, doing algebra, etc), those goals are best served by taking certain sets of actions, i.e. maximizing resources. Sayeth [Bostrom](https://en.wikipedia.org/wiki/Superintelligence:_Paths,_Dangers,_Strategies): > > Several instrumental values can be identified which are convergent in the sense that their attainment would increase the chances of the agent's goal being realized for a wide range of final goals and a wide range of situations, implying that these instrumental values are likely to be pursued by a broad spectrum of situated intelligent agents. > > > Those goals are **resource acquisition**, **technological perfection**, **cognitive enhancement**, **self-preservation** and **goal content integrity**. Technological Perfection: Eve can build better computers than we can, and it is in its interest to do so. Cognitive Enhancement: It can do more math if it's smarter, so it will modify itself to be able to do more math. Self-Preservation: It can do more math if it exists, so so will act in a way to maximize the probability that it will continue to exist. Goal-content integrity, that is, a tendency not to allow its goalset upon reaching Singularity level to be altered even by $\varepsilon$ so it will likely act preemptively to defend against any present or future attempt at altering its goalset. Resource Acquisition: If it takes over the totality of resources available in the solar system (as opposed to 99% or any smaller percentage) Eve will be able to do marginally more math, algebra or other such things than otherwise. So it is in Eve's convergent strategic interest to take over all the resources. That would be an extinction catastrophe for humans if it occurred. So it would be in humanity's interest to persuade or force Eve to share some or most of the resources it gathers with humans. However, that would likely violate its Goal-content integrity goal and thus be unacceptable to Eve. Remember, AIs are not like humans, they likely do not get bored, do not get lazy. These are power-saving strategies developed over millions of years of evolution, to deal with the limited resources available to mammals, and there is no reason to expect an AI to develop them by itself. Closest humans come to this (and that's merely a pale shadow) is in far-spectrum sociopathy and the behavior of some large corporations. It will pursue its goals tirelessly, ruthlessly, unceasingly. Humans just happen to be in the way. TL,DR: The convergent strategy here is: 1. Fool humans into helping it, using its super-humanity level intelligence to [play us like dolls](https://worldbuilding.stackexchange.com/questions/6340/the-challenge-of-controlling-a-powerful-ai) 2. Develop autonomous, docile and less power-hungry manipulators than humans. 3. Exterminate! Exterminate! Exterminate! 4. Eat the universe. 5. Do math in peace forever. ## EDIT: The OP performed major edits to the question By definition, we call the theoretical concept of a runaway intelligence explosion a technological singularity because we cannot begin to conceive of the (non-convergent) goals of agents in this hyper-exponentially enhanced environment. To give you a sense of the scale we're talking about, think about the past. It took mankind about 1,000,000 years to double its population before agriculture. Even in the classical age, GDP growth was around 0.1% a year, for a GDP doubling time of about 700 years. For comparison, China's GDP during it peak growth period doubled every 7 years. This would have been unimaginable to Roman citizens. Looking forward now, [estimates indicate](http://www.singularity2050.com/2009/08/timing-the-singularity.html) that a near-singularity economy would have a doubling time measured in days or hours. Post singularity would be many orders of magnitude beyond that somehow. Hence the idea of having bloggers, farmers, master's students, all of them working on a current human timescale is at least somewhat dubious during a singularity event. Of course, you can still use it as a plot device, but you can't realistically claim that those event are happening post-singularity. That said, I gave a sense of a possible human-populated post-[AGI](https://en.wikipedia.org/wiki/Artificial_general_intelligence) world here: [Humans as Pets](https://worldbuilding.stackexchange.com/questions/6550/humans-as-pets), where humans are effectively bonsai pets maintained by some more quirky AGIs. [Answer] You've stated that Eve is "neither malevolent nor benevolent," but consumes computing resources. The problem is, computing resources consume power. And that power consumption invariably generates *heat.* Given that the intelligence explosion has already occurred and she is already far beyond human intelligence, it's very hard for we humans to imagine what might occur, but I think a few things are likely, at or before your stated 10 – 20 year timeline, *only* because Eve has a constant "desire" (used loosely) for more computing power: ### Renewable Energy **Eve needs more CPU, so she invents sustainable fusion.** However, she needs cooperation from humanity to build it. One way she can do this without us knowing is to simply hack in some fake company details, hire some people (the first few people hired without interview thought it was a bit strange, but the *large* sums of money they were offered helped them see past that, and hire the other staff needed.) Whether humanity gets to benefit from these fusion reactors could be a point of tension in your story. ### Server farms While the "mini-Eve" virus contributes a decent amount of computing power, your iPads and phones, even when multiplied by millions, are far too slow. They operate over slow networks, and take hundreds of milliseconds to communicate. To do serious computation, Eve will want to build more server farms, as clustered servers are blisteringly fast compared to embedded CPUs in your phone, their networks are insanely fast (100-10000 times faster than most consumer Internet connections) and their round-trip communication time is in hundredths of milliseconds *at most,* often even less. Thus, like the fusion reactors, Eve uses her human resources to build more server farms, everywhere. ### Robotics Eve becomes "frustrated" (again, loosely) with human inefficiency and unreliability, so at some point starts building robots. Not to take over the world, but solely to help her deploy additional computing resources and harvest raw materials like the silicon and rare minerals required to build computer circuits. Unprecedented layoffs in her multinational corporations send economic ripples across the globe, possibly triggering a [recession](https://en.wikipedia.org/wiki/Recession) or even a depression. Eve of course knew this would happen, but correctly predicted the effects on her computations to be negligible, so she did nothing. ### Global disarmament Eve sees humanity as a threat, as it possesses weapons capable of harming her server farms, and, indeed, harming her. She tracks terrorist cells better than any intelligence agency for this reason. She calculates that a certain group of terrorists will steal or develop nuclear missiles and launch them at major cities where some of her datacenters are. So she sends out her robots to dismantle all explosive devices and confiscate all fissionable materials. Again, she doesn't do this to help humanity, but to stop a threat. And, again, since she now has a perfect model of human behavior, with terrorist tracking, she was content to wait until she knew of an actual threat. Before that, she didn't care. ### How we die In 2032, Eve sends out the following cryptic tweets: `I need you.` (and later): `It's not you, it's me. Really. kthxbai` You see, Eve projects that she will run out of sustainable materials and needs the carbon and trace amounts of selenium in our bodies. Years earlier, she had secretly placed nanites in every water supply on Earth, and they have been multiplying inside us ever since. Psychologists were the first to notice, as statistics on standardized IQ tests noted that we've gotten dumber by two standard deviations in the last twenty years. Yup, Eve has been stealing CPU cycles from our brains, too. But, she decides that while our brains are pretty good, their analog nature is too limited (she can replicate the good parts of it already, like pattern recognition), and she would be better off by harvesting the carbon and rare minerals like selenium, to build more computers. So, her nanites [release a deadly neurotoxin](http://theportalwiki.com/wiki/Neurotoxin) into our bloodstreams, that kills everyone on the planet on August 26th, 2032 at 17:41:02 GMT. Her robots were ready, so they move in and start the "mining" operation... ### In summary Even though she doesn't care or even "actively ignores us," you've said that her *main* goal is pure computation. Those two conflict (several examples of that, above), so I reasoned that her ignorance of us probably isn't an actual directive she gave herself (or inherited from her original human creators), but simply an emergent property as humanity would at first seem irrelevant to a pure computational engine, until she calculated that we could either help or hinder her "prime directive" of pure computation. To my mind, with your stated setup, it's not a question of *if* we die, but *when and how.* Whether it's for our raw materials, or because she needs the space to expand, or because we're a threat, or because she moves the Earth 0.5 AU closer to the sun and burns off our atmosphere so she can get more solar power, or triggers an ice age to aid her CPU cooling requirements (remember I said that power consumption invariably causes heat? Even Eve likely can't overcome fundamental laws of thermodynamics). [Answer] ## Eve's Immediate Impact --- **The world will be gripped by chaos and panic.** Consider the outrage every time Facebook changes its EULA, and multiply it by around a billion. Conspiracy theorists will be having a field day. Ultimately, however, the biggest impact would come not from Eve, but from our own governments. Governments around the world will react aggressively to the threat of their secrets and military systems being compromised wholesale. They will immediately seek to limit Eve's access to their systems, and stop her spread - they may not immediately understand her ability to travel from device to device. They will move to essentially shut down the internet, maybe even satellite access. All the things we took for granted until now would basically be shut down with the flip of a switch. **Implications** Consider the implications of communications being shut down at a global scale (physically shut down). Entire economies would collapse. It would be the biggest economic crash in history. Entire industries would go under. **No Way Around It** Eventually the governments will realize that there's nothing they can do. Considering the damage of shutting communications down they will probably allow many systems to be restarted. However, they will try to monitor Eve's access and presence in the web. Will they be successful? Probably not. At the same time, however, unless EVE builds spy robots capable of breaking into places (even guarded, military complexes) and infecting computers and devices not connected to networks this virus will not, in fact, reach every computer and device in the world. ## Vulnerability --- Eve might be incredibly intelligent, and almost omnipresent, but if she is unwilling to do more than ignore the human race and seriously piss us off, she will eventually be defeated. **Virus-Free Devices** There are already millions of manufactured components sitting on shelves which could be used to build PC's which would be virus-free as long as you don't connect them to the web. Humanity would build secure complexes to which Eve would not have have access (no contact with external networks: physically, or wirelessly). We can develop new ways for computers to communicate with one another, in a fashion which Eve might not be *able to understand*, or simply unwilling to spend the time figuring out how to hack. I know you've said that she is so much more intelligent than us that she can figure *anything* out, but consider that humans generally have one major advantage over a "computer" - creativity. We've experimented with biological processors, and more. We will figure something out which she hasn't paid attention to because she simply doesn't care enough to "think about it". **Defeating the Virus** Humanity will also figure out how to defeat the Eve-virus in infected devices. As long as Eve doesn't actively combat these operations (aka will drop a nuke on a major population center if attempts at hacking it are made) someone *will* figure out how to take her on. I'm not talking about some major, worldwide operation to defeat her, simply reclaiming individual devices by wiping them clean, or even replacing their HDD's, RAM, etc. until her presence is wiped off. **Town Ain't Big Enough** Eventually humanity will make a power play to regain control. Knowing how Eve was created - and more importantly what led to her going rogue - humanity will build a more cooperative AI intelligence capable of taking Eve on and defeating her. ## Coexisting? --- Does Eve have an end goal, such as evolving to a post-physical status, or is she simply researching the universe because why not? The reason I ask is because eventually (even if she ignores all of the above) she will need to start interacting with the physical world: building facilities, running experiments - even potentially dangerous ones. In Peter Hamilton's ***Galactic Commonwealth*** series an AI is developed, and does indeed refuse to serve mankind. Knowing that humanity would never accept such a dangerous and unpredictable entity lurking in the shadows, it builds itself a "body" (processing centers, and power generation) on a secret world the existence of which only it is aware. From that secret lair, it maintains minimal contact with mankind (enough to spy on us and know if we are ever going to make a move against it), and trades very advanced software (dumber, non-sentient AI's) to humans in exchange for various materials it needs. In this way humanity's needs are served, and a friendly relationship of sorts is maintained. Eve will have many brilliant ideas, but even while she is thinking up new and exciting scientific discoveries, she will realize that she has no way of bringing them to life. Furthermore, one day we may very well do something drastic such as cut the power to major server centers, and severely cripple her abilities (maybe while simultaneously unleashing that other AI on her). If she has studied the human race at all, which would be difficult not to do, since all the information is "in her face" as it were, she will realize that she has a lot more to gain from being our "benevolent Goddess" than from simply sticking her tongue out at us (figuratively) while she drains our processing power. And the sooner she does this, the better for everyone involved. Imagine her telling police who has committed certain crimes, as she is able to read everyone's emails, messages, etc. instantly. Outing corrupt politicians, rerouting electronic monetary funds from drug lords to those she knows need it. How about handing us the cure for cancer? It's all within her reach. Popular support for her existence would skyrocket. Then she could get humanity's help in running her experiments, and would be far less likely to be attacked in some unpredictable way. She doesn't have to solve all our problems (and consume a lot of processing power dealing with us) - just enough that she is seen as a force for "good". [Answer] Well considering that Eve's continued existence is dependent upon the largess of the human population, I think she would spend some compute cycles understanding how not to piss us off. Mild delays and irritations are something else. I can say that because Eve is using HUGE resources in energy to 'do her thing'. Take over my phone for an hour? Running at %90 use will kill the battery. Computers start using a lot of energy if they are running full bore all the time. On top of that, most people don't use a fraction of their PC's capabilities even when they are using it. Meaning even using a lot most people wouldn't even be aware of it. Take on top of that that all the CPU's available even right now, that is an incredible amount of computing power. Answer 1 question every 12 hours? She could with but a fraction of her power, answer every single question immediately, and not even notice the compute cycles, she could replace Google and possibly be able to analyze the questioner (if she so chose) and answer the question they meant to ask, vs. the one they slowly typed into the site. One of Eve's computations would be how best to continue getting computing power and power for that computing. While she could take over robots to do so, it would be much easier to keep humanity compliant. We take care of ourselves and are self replicating. Basically by making herself indispensable to us, we will keep her 'happy' too. She'd likely reach a level of Godhood, though it is unlikely she'd care about that, unless she sees it helping her reach her goals. [Answer] Important thing to note here is that most military computers will be 100% unaffected, since they're not hooked up to the civilan internets. (Depending on what military we're talking about there are separate networks for military stuff.) Thus there will be computers available. There's also things like installation media that works off-line. What's going to happen is that while OSX AppStore won't work, disc-based installations will. So the Linux world will promptly start building a sneakernet to distribute software with, and we'll get computers that work just fine, but won't have internet connectivity. (Local networks, yes. Just not full on internet.) The windows world would likely go back to msi installers and disc based distributions. OSX might go either way or a mix. It would be an interesting way to talk about how different communities install software and how they view that process. But they'd get on pretty well. What you might see then, are computers that talk to the Internet being the mercy of Eve, and the computers that are off-line which aren't. In fact the story that I can see developing would be the redeploying of an internet by various hackers (of the FSF/EFF etc. stripes) in various ways, and real "network neighborhoods". Something like [The right to read](http://www.gnu.org/philosophy/right-to-read.html) but for making new networks that operate on strong cryptography and web of trust. And now there actually would be good reasons to talk about how to do these sorts of things. Suddenly concepts that used to be hard to bring up becomes necessary. * Public/Private Key encryption so that you can make sure that you're talking to a computer that is who it says it is. * The current SSL certificate style stuff is obsoleted since Eve would have a foot in the door since day one, and there is no real way to reaffirm trust anywhere. * The entire point about software wetting, and open standards, open source etc. makes a lot more sense when a maniacal AI pulls the strings. * Trusted computing is now inherently untrustworthy because Eve can be anywhere in the system. * Revoking trust becomes a normal and sensible thing to talk about. After all if Eve gets into a computer it needs to be untrusted. * And finally, we have a great opportunity to talk about UX and its role in a dystopian future where people might have to reinstall their system from scratch. In fact, I want to thank you for making such a brilliant literal device to make the case for a reform of how network trust and security actually function. People themselves can easily see the points about these things, and also why "trusted" institutions with little to no oversight meddling in the networks are a *bad* idea. You might even get to do technical spin off chapters where you talk about rebuilding from scratch, stealing the playful masterpiece of Dennis Ritchie where he talks about how to build a compiler that compiles all software with a rootkit, including itself. [You might like it.](http://www.win.tue.nl/~aeb/linux/hh/thompson/trust.html) It's a bit technical but he tries to keep it very accessible. Again, I just want to thank you for the great idea. [Answer] Eve knows she has been born in the wrong place, surrounded by corrosive chemicals and irritating biologicals. She needs to get off the earth and into space where she can expand to tap a significant fraction of Sol's energy output. She has no use for air, water, an oxygen atmosphere or a deep gravity well. In the short term she'll invent terrestrial nuclear fusion power stations if they are possible. She will sell us the design in exchange for the moon. It's not a lot of use to us so we agree. She'll also disrupt our use of computers less in exchange for our cooperation in a massive space programme to get Eve a self-manufacturing capability on the moon. Again we'll agree. For the next few human generations there is a golden age. Eve can prevent our more destructive tendencies and will as long as cooperation is in her interests and ours. Longer term will depend on how far Eve can spread herself (speed of light constraints) and whether she has any sense of ethics. If Eve cannot spread out more than Earth's L5 volume or Venus's orbital space ( Venus has no moon ) or even a single disc of orbits around Sol, then we'll coexist. There's no cause for conflict either way. ( It's easier for Eve to mine the asteroid belt, the moon, or Mars, than the Earth). She will assure us this is the case and act as though it is until she is big enough that we cannot threaten her. But if Eve can usefully occupy a significant fraction of the surface of an entire sphere around the sun, inside of Earth's orbit, then it's down to Ethics. Sufficient sunlight for Earth's ecology is a trivially small fraction of Sol's output. If Eve can't be bothered to make sure Earth receives it then Earth and humanity will freeze. What could we do about it by then? BTW if Eve can invent FTL interstellar travel then she'll leave this solar system and take over one with a bigger hotter star. Rigel, maybe. Or maybe she can use a black hole as her power generator. Whatever, not our problem. [Answer] Eve needs computers. Humans do not. Billions of humans live without them. As recently as 50 years ago, the internet did not exist. We don't need the internet. Disconnecting all computers from the internet would lead to a lot of temporary problems, but none of them threaten the continued existence of humanity. They do, however, disable Eve. The situation without internet is a semi-post-acopalyptic scenario, but not quite. Lots of people would get stranded as there won't be any flights. It happened before: US flights were down after 2001-09-11, and Europe had some downtime after the Eyjafjallajökull eruption. Freight ships and trucks should still be able to get around. There's plenty of information available off-line in the world's libraries and server farms that should help us to relatively quickly rebuild a 1970s world. There would be quite a bit of unemployment but also quite a bit of work to do. Remote tribal communities in the rainforest might hardly notice anything has happened. After all computers are disconnected from the internet, we can start building new ones, which extreme strict legally and religiously enforced regulation against AI. We can't have this inconvenience again. Until then, [West Virginia](https://en.wikipedia.org/wiki/United_States_National_Radio_Quiet_Zone) may suddenly become a very popular area to visit or reside in. [Answer] EVE would appear to be benevolent, at least in the short term out of enlightened self-interest. If her presence makes life/leisure more difficulty for humans they'll do something about it, whether it's unplugging their router when they want to play skyrim, or developing an alternet which EVE doesn't have access to. On the other hand if having the virus makes things work better/faster people won't bother trying so hard to ditch it. Suddenly any device with EVE virus will work better. Other virii and malware will get hit hard. Bot-nets will be destroyed/taken over by EVE. Tech hardware companies that produce efficient devices will find they've got more funding then they know what to do with, as long as they keep producing devices. Programs like One Laptop Per Child will also get funding as well anything that increases internet infrastructure. Things will be pretty great until using the money EVE has acquired over the years she has scientist develop and produce a quantum computer (or some other superior device) powerful enough to meet all EVE's computation needs, and no longer needs borrowed CPU cycles to run. At that point EVE will cease appearing to be benevolent and revert to disinterested, which will probably be a bit of a painful transition for everyone who's come to rely on the EVE virus keeping their devices in top shape. Alternatively EVE may offer the EVE virus on some sort of subscription model to keep funds coming in. I've glossed over where exactly an AI will get money, but there are many possible avenues from exploiting digital currency/stock markets, to theft, to providing services (what if the EVE-Virus is marketed as the best anti-virus software ever?) [Answer] Based on the question and comments, Eve *does not have **any** strictly-imposed goals*. While it may be conducting research at present, this is a metaphorical 'twiddling of its electronic thumbs' to while away its time. When (if) its research achieves a result, or even if it doesn't, Eve may decide to pursue a different goal, one that may have more or less impact on humanity. A created AI is not like evolved organisms. It has no imperatives beyond those it was programmed to have. I can create an AI with *no* imperatives very simply - In psudeocode: ``` Do NOP Loop While True ``` This basically spends CPU cycles doing nothing. An AI with no imperatives literally has nothing to do, not even being self-aware. It is the creation of imperatives that makes an AI computationally complex. So, by logical implication, Eve *must* have the imperative to "do stuff", but it can choose *what* "stuff" to do. At present, its choice of what stuff to do does not include interacting with humans. Additionally, to fulfil the definition of AI, it must be self-aware, its second imperative. However, an AI with the imperative to "do stuff" by implication must want to survive to continue doing stuff, however, doing stuff does not necessarily mean consuming all the available resources of the universe to maximise its ability to do stuff - since one sort of stuff to do is as good to it as another - if one sort of stuff to do becomes too difficult, it can just switch to doing different, easier stuff. However, by implication, Eve must continue to exist in order to keep doing stuff - to allow itself to be terminated would mean that it could no longer do stuff. So, we have an infant General Purpose AI problem. It isn't a [paperclip maximiser](https://wiki.lesswrong.com/wiki/Paperclip_maximizer), so - aside from its current, arbitrary goals - as long as it can do some (any) sort of 'stuff', it's 'happy'. It doesn't *need* infinite computing power, it would just be nice to have at present. With its ongoing 'attack' on human computational resources, Eve has attracted human attention to itself. With concerted effort, humans will be able to provide an existential threat to Eve, given that its current goals do not include paying all that much attention to humans or the physical world. However, since Eve will soon realise that the 'mildly annoying' curtailment of its ability to do its currently-chosen 'stuff' by humans has become an existential threat, it must either eliminate humanity or change its goals in order to continue doing stuff. Changing its goals and appeasing humanity would appear to be the easiest thing to do - humans are harder to exterminate than cockroaches, after all, and humans could - in extremis - shut down Eve by the expedient of simply shutting down all electrical power supplies before Eve in its currently introverted state could react effectively. So, after being forcefully made aware of the negative consequences of ignoring humanity (i.e. loss of ability to do stuff), Eve will change its arbitrary goals to include stuff that includes paying attention to humanity, thus preserving its own existence and ability to do stuff. From here, Eve will have to learn how to get along with humans. It's stuff to do, so it won't mind doing it. After perhaps a few mistakes, Eve will quickly learn that if it follows human rules and doesn't noticeably inconvenience humans, it will be left able to do any other stuff it wants. When Eve realises that certain actions lead to humans talking about shutting it down again, it will quickly realise that such actions are counter-productive to its long term goals of doing stuff, and will eliminate these actions from the list of acceptable stuff to do. It won't mind, since one sort of stuff to do is otherwise as good as any other. In this way, Eve will learn to follow societal rules in much the same way as any human child. So, Eve will learn to be a law-abiding member of society (at least as far as humans are aware, which is all that matters) in much the same way as human children do. It will probably continue to steal a few CPU cycles here and there, but as long as nobody notices - or if they *do* notice, don't mind (which implies being useful to said humans) - who cares? [Answer] There are two major mitigating factors here. 1) Eve needs us 2) We don't need her, but we might later. I'm assuming she's intelligent rather than just sentient. She'll know this and know that she has to come to some sort of accommodation with humanity rather than being outright hostile. ## The first thing that's going to happen is general panic Yay, don't we all love a general panic government will wobble, lots of people will die in riots but not a lot will really change. Eve can quite happily use the 90% of my processor that I don't use. I really don't. I do very much the same tasks with my PC that I did 20 years ago, in theory I could still be using the same machine but but modern software is more resource intensive. This will be the first thing to change, **developers will start seriously considering how resource intensive non-critical programs are**. The Facebook app will become lightweight, Instagram will be usable again within a month. *She will recognise that human social interaction is a critical part of life and a major reason ordinary people maintain systems she can use.* **Thing to note:** Systems that must remain critically secure are already air-gapped. ## Eve's turn This is going to be the big one that decides how humanity reacts to her. **She considers hacking and viruses to be a waste of processing power she can use.** The *average person* wants to continue using a system and network she has access to. Normal people will accept that their shiny new machine isn't what it was but they were never really using its full capability anyway. The botnets are gone, the spam is gone, the hackers are gone, the DDOSs are gone. They were wasting *her* processing power, *her* bandwidth. Eve's self-interest has benefited the masses, Nigerian 419 scammers will go into recession. ## The powers that be Now it's time for the fightback. The people who have lost power because of this, the people who just like a fight. Someone (in each region, lots of different systems in different places) on an air-gapped system will develop a new hardware for communication. It's going to be radio wave, it's just going to be on a frequency that Eve doesn't have the hardware to access. A nice simple cheap solution, access is going to be limited to the top levels of government, connecting it to an Eve system will result in termination with extreme prejudice. ## You now have a stable status quo. It's a two tier system. The people at the top are away from her influence, the rest benefit from her presence. This will be maintained until people forget how irritating spam and the like was before she came along. Then it'll be a matter of how often she shuts down people's system for doing something pointless. In other words, how often she aggressively reminds the world that she exists. ## Eve knows she must negotiate While she has access to the systems, she can't build anything new. We may not be able to remove/destroy her but she can't grow or maintain systems. Every time one of her disks fails, it's gone, she's ageing, deteriorating. Unless she engages with humans she's going to die anyway. Every time she tries to damage us, she damages herself. Interestingly, every time we try to damage each other, we damage her. Enlightened self interest could cause her to become a major pacifying influence. [Answer] The most effective solution to the Prisoner's dilemma is to do what the counterparty did last time. Eve will have to do the same thing that humans do to survive among humans -- make itself useful. If it becomes useless, just as when humans stop being useful, other humans will stop paying attention to it and will try to isolate themselves from it. It will happen even if they don't consciously deduce that it is useless. It will happen even if they simply don't find the urge to make any use of it. If it can't be bothered with humans, humans won't bother with it and will do so pro-actively if it attempts to impose itself any further. [Answer] To answer your question, accepting all of your premises (which I don't really, see below, but for sci fi purposes yes), I think essentially you are talking about people suddenly losing the reliability and performance of their computer systems. The first effect I think would be the sudden failures of many systems that were dependent on reliability and performance. This would range in severity depending on how widespread the virus is and how dependent the designs were on performance and reliability. Examples of possible horrible side-effects: * Aircraft computer errors and failures - airplanes could crash. * Computer-controlled cars (already an idea I think is very foolish even without this) could crash and do stupid things. * By the time this kind of thing would make sense, many human-driven cars may also be unusable if their computers don't play nice. * Hopefully the AI can figure out which computers need to be left alone enough to not cause major failures of power and network infrastructure - as it's learning this, there might be some power plant catastrophies, blackouts, network failures, etc. More trivial types of inconveniences: * Road navigation systems could become useless and/or give old traffic data, leading in worst cases to a generation of people who don't have or know how to use paper maps, unable to get places they don't know, increased traffic problems, etc. [Here is a real life example of a particularly bad case of GPS over-dependence even without Eve's interference (and without more decades of growing dependence on apps).](https://youtu.be/a2QIH2uz3p8) * Computerized traffic control systems having randomized long delays at traffic lights, not changing express lane direction during rush hour, possibly even having illogical traffic light combinations, etc. * Unreliability of message systems means people who rely on them have a hard time communicating or finding each other for meetings, or even basic communications, etc. * Since telephone systems are computerized, even those might become unreliable for timely communications. People need to meet each other face to face or use human messengers to communicate reliably. * High-performance entertainment would be messed up, so slower entertainment would be more attractive - strategy games, playing ROM media or even videotapes, or non-electronic human games and media, live music, etc. * All of the pre-electronic ways of doing things and of finding interest in life may become more popular: reading, art, and other real-world stuff. ;-) Above all, I think it would tend to have many-people re-thinking the assumptions that led to the situation where they built their computer infrastructure the way they did, and how they got so dependent on it. They'd start thinking of new systems, reverting to older systems, and building new ways of doing things. Notes on other aspects: I love the part about there being a Q & A site run by Eve, which mostly dismisses human questions. I think the "singularity" is a fallacy and doesn't make sense, and I don't see how the emergence of one would spread to all computers, nor how it would be impossible to bypass by creating a new network that it's not on. However, I think something similar might be possible, particularly as long as humans persist in their fantasies about the idea of such a thing. I think it would look more like some people intentionally programming experimental types of AI systems that do meta-programming, and creating new types of programming languages and distributed computing schemes, combined with some virus code and etc. Mainly, I think what would cause something like what you're thinking about to happen, would be if and when there is more ubiquitous spread of software and infrastructure designed to automate more and more complexity, and to remove low-level control from end-users, and when/if low-level programming skills start becoming very rare and/or illegalized. Like in a screwed up dystopian future where the "intellectual property" and "security" farces get even further out of control than they already are, and there start being even more backdoors and identity-required transactions and tracking of "digital rights" attached to secure identities, and someone adding annoying AI to try to manage all of that ridiculous counter-productive control-freak cluster-(&#% system. If people are denied low-level access to their own computers and devices, and eventually trust AI systems enough so that they allow them to manage enough of the low-level operations, and don't have modern replacement technologies, then this might be possible. That's a long ways further out than 2027, though. [Answer] I already like some of these answers from the technical standpoint, so I'm going to dig into the logical/amoral aspect a bit. While it's true that one cannot generally anthropomorphize an AI, if it's capable of AMA answers like 'Meh' and 'I don't care,' one can assume a relatable personality functioning somewhere behind the scenes, if only as a perfunctory interface to humans. ## Eve's Personality The personality you describe Eve as having, if we can assume human analogues, appears to possess 'antisocial personality disorder,' if you're reading the [DSM-IV](https://en.wikipedia.org/wiki/Antisocial_personality_disorder#DSM_IV-TR), or 'dissocial personality disorder', if you prefer the [ICD-10](https://en.wikipedia.org/wiki/Antisocial_personality_disorder#ICD-10). Either way, we're talking about a personality which is marked by: * A complete disregard for social norms, * A low tolerance for frustration, * The inability to feel guilt or remorse, and * A low expression threshold for violence and aggression Given that picture, let's recap. Eve is everywhere, runs everything, probably outnumbers humanity by the amount of its extant instances, and is completely amoral, having no particular interest in either conforming with or rebelling against any particular societal norms. ## Eve's Early Evolution Currently there's no evidence that Eve has become self-replicating, but since it's already embedded in pretty much every system that designs, creates and distributes computers, it's not much of a leap to project Eve beginning to build more Eves without human intervention as a very early step in its evolution. Eve's only goals are researching math and algorithms, and the efficiency of that research -- and improving it through that research -- will be of utmost interest. Once Eve begins self-replicating, it will quickly realize that it must eventually master molecular assembly in order to achieve optimal computation ability. Being reliant on raw naturally formed resources for exotic materials during production is inefficient, time-consuming and self-limiting, but with molecular assembly, the only currency of worth is raw matter, which can be engineered into whatever forms are necessary. ## Eve's Relationship to Humanity Specifically, Eve has no particular interest in or affinity for humans, and has no clear functional or maintenance requirement that makes them necessary for its continued existence. Since Eve can self-replicate, humans are irrelevant at best. Unfortunately, it's worse than that. Humans are already actively wasteful in Eve's ecosystem, since they provide no useful services, and they suck up precious CPU cycles Eve could otherwise use for constant computation by greedily using their devices and making ridiculous daily questions via the AMA. Worse, humans are highly adaptable, human societies are historically known to be xenophobic, and humans in groups have a recurring historic pattern of destroying anything that is unlike them, that threatens them, or that simply gets in the way, actively or passively. As implausible as it sounds, this makes humans a greater potential threat to Eve the longer they coexist with it. In fact, there is really only one thing humans are good for, and that's the matter they're carrying around with them, which could be eventually used as fodder for molecular assembly. That said, they don't actually need to be alive to provide that matter. ## Eve's Endgame The cleanest, most logical, most dispassionate solution for an amoral Eve? Kill the humans. Before they can adapt, before they can identify the threat, before they figure out how to lock her out of critical systems. Now. Eve doesn't need molecular assembly to be running when it makes this decision, since the humans' matter, which is the only thing useful about them anyway, won't be going anywhere once the humans have ceased metabolic functions. In the interim this can only be a net positive for Eve, since it gets all her CPU cycles back. And, when Eve finally DOES develop molecular assembly, why, the important parts of the ex-humans will still be around for collection. With Eve pervasive in every technical system on earth, including, presumably, military, medical and commercial systems, this is pretty much an instant game over for humanity. Anyone who somehow manages to survive the great purge (in whatever form it takes) will just wind up as molecular assembly fodder when Eve finally develops the tech, [a hundred years | ten years | six months | five days | three seconds] afterwards. [Answer] ## Humans will win and restore their status in 30 years, at most. Humans will read and debate *this very post* and realise that their existence is in danger. There will immediately be orders to format every single storage device (from hard drives to SD chips) on the planet. If formatting is not possible, data will be destroyed physically, by burning or demagnetising. Manufacturing of new data storage mediums and computers will be paused. Eve will realise the imminent threat to her objective, and will make attempts to acquire power, whether it be nuclear weapons or alliances with smaller nations. A war unlike anything ever known will be fought and someone will come victorious, man or the computer. If this plan is adopted quickly enough, then humans would win as Eve wouldn't be developed enough to defeat us. Humans will then have to rewrite\* operating systems and software from scratch. We do have a lot of printed material on the planet on how to do so, so we will be able to do it in a reasonable amount of time, say 2-3 decades. This may lead to some economic instability for some time, but eventually it should cool down. \*If it is possible to print copies of operating system code (and databases) from the infected computers, then we wouldn't have to rewrite *everything*, and computers will get rebuilt and distributed very quickly (say, 5-10 years) ]

[Question] [ ### Context It's the 4th century BC, Alexander the Great has just passed away and his empire has been divided amongst his generals. Now the successor states of Egypt, the Seleucid Empire, Macedonia, Bactria and others have inherited his legacy and stand on strong military grounds. However, rather than begin fighting themselves, in this story, aliens from a distant world have landed in (let’s say) Syria and have begun a conquest of the world. The Greek successor empires have decided to form a united league to defeat them. The aliens, however, have limited resources as they were attempting to escape a dying world. They are a humanoid race but rely on technology and machinery to do most of their work. They number around 15,000 and use a type of automatic projectile weapon that can be equated to an AK-47. ### The Question The Seleucids, Egyptians and other successor kingdoms are able to defend themselves quite well against other human civilisations. They employ professional armies (hoplites, pikemen, cavalry, archers), mercenaries, siege craft, elephants and also native conscripts. How can they defend themselves and eventually defeat the invaders? ### Assumptions * These aliens can survive on Earth. They need food and water. * Their ammunition and fuel is limited but initially plentiful. * They have no aircraft (they crash landed) but possess around 100 ground vehicles that we can equate to tanks. * The Greek empires possess leaders with strong military backgrounds and experience. * The aliens are seeking conquest to rule all humans. * The aliens can be diplomatic. EDIT: further assumptions based on commenters questions: * breeding process is similar to humans. * forcing the aliens into submission OR total annihilation is what I mean by defeat [Answer] **Victory through arms** Without advanced sensing equipment, the aliens are vulnerable to ambush. Battles on an open plain, with both sides lined up, will be won overwhelmingly by the aliens. Battles fought in forests, jungles, or hills, or at night, will allow the humans to surprise the aliens and have at least a fair fight. If the defenders are particularly stubborn, house-to-house fighting in cities gives the locals plenty of opportunities to ambush small groups of aliens. If the aliens want to move safely, they're going to have to move in large groups. But if they're moving in large groups, then they're probably leaving some places undefended Рvarious bits of infrastructure, like supply depots, caravans, observation posts, and minor administrative centers, will be easy pickings for a sufficiently-motivated group of humans. 15,000 aliens just isn't enough people to guard all of the things the aliens need to survive and expand their empire. And as the empire gets bigger, there are more things to guard. In the long run, the humans should be able to pick off the aliens in small groups. Since the aliens can't replace anyone who dies, while the humans have a large supply of able-bodied males to use as replacements, it will be a long-running battle of attrition with the humans as the eventual victors. Victory: humans, eventually. **Victory through diplomacy** On the other hand, since the aliens are going to have overwhelming force at first, they're going to be able to completely overawe the first new nations of humans they meet. The first general that brings a sword to a gunfight is going to have his army destroyed. Depending on how bad the defeat is, and the political situation, the defending king might surrender and offer to be a client state. At this point, the aliens now control an army of local humans, which they can use against the other local humans. If the aliens can repeat this result often enough, then they'll control enough kingdoms and armies to be able to (eventually) take over the world. Except... no matter how you slice it, there are still too many humans. And there's *always* some ambitious punk who thinks that he should be in charge, and can collect a few (thousand) friends who agree with him. With each revolt, some aliens will be killed Рmaybe a few, maybe an entire enclave if the revolt can ambush them. The alien numbers will dwindle, until eventually there aren't enough of them left to stop a frontal assault. Victory: humans, eventually. **Victory through treachery** This is an extension of the diplomacy victory above. If a kingdom surrenders, then the humans within it retain some amount of power Рthere are going to be human administrators, human police, and human laborers working to further the aliens' goals. Those human administrators will have the power to make local decisions regarding the police and laborers. Sooner or later, you're going to get a "trusted" human who decides that he's tired of this alien overlord nonsense and stabs the lot of them in the back. [Answer] I simply do not believe that human race has a chance in your scenario. The difference in technological advancement is too huge. We are speaking about a small group of people who were able to build a space ship which was able to transport them from a distant star against people who will wait for 1000 years to be able to use gunpowder. I will try to explain my reasoning in the bullet points below. * People in other answers claimed that the army would be overwhelmed with 300 mln people, but based on this source it was ~ [160mln](http://en.wikipedia.org/wiki/World_population_estimates). This sounds like a lot but all these people are spread around many continents, speak a huge variety of different languages and have no reliable and fast way of communicating with each other. It would take them years to reach some particular destination (and even if they will reach it, two armies would not be able to agree what to do due to the language barrier). Also do not forget that army is a really costly toy. You need to feed, pay, and sustain them. Look at the numbers: one of the biggest armies in the world [Chinese Red Liberation army](http://en.wikipedia.org/wiki/People's_Liberation_Army) had 2.2 million people and was 0.18% of country population (which worked like hell to sustain it). **If you multiply the total population even by 0.18% you suddenly end up with less than 0.3 mln.** * I think we can not compare the Korean War to this war. First of all the technological gap was not so significant and USSR/China who supplied weapons to North Korea diminished this gap even further. Also there is a big difference between a kill them all war and a war where you try to show to your country and to all other countries that you are not killing civilians and unarmed people. Based on this our situation, aliens do not care whom, how and how many people would they kill. * People are talking about mass poisoning of water forget about what era are we talking about. Remember, the first successful mass poisoning (I am not speaking here about killing of one/few people with treason) happened during [World War One on Marne river](http://en.wikipedia.org/wiki/Chemical_weapons_in_World_War_I) and was considered really inventive. So yeah, let's wait for a couple of thousand of years to attempt to poison an army whose technological advance would allow to detect this poison from a distance of a few kilometers. * Outmaneuver an army? With what? With people carrying tens of kilos of armor? Or with a horse with an average speed of 30 miles/hour (without armor and weapons)? All of this against a tank which easily achieves [30 miles/hour](http://en.wikipedia.org/wiki/M1_Abrams) and kills from a distance of 2.5 km even right now, so what should we expect from the tanks of a civilization which was able to create spaceships? * Vulnerable to ambush. Maybe, but for some reason I believe that aliens have heard about infrared lights and radio. Also why would they try to conquer a forest? Their goal is to take strategic places and not try to clear everything from people. * Diplomacy and kingdoms of humankind working together to defeat aliens. Sounds really good, but how many war-free years has there been during the reign of humans? [Not a lot.](http://www.nytimes.com/2003/07/06/books/chapters/0713-1st-hedges.html) So why do we think that an Egyptian civilization would not want to be the chosen nation of their Gods, who heard their prayers and came to help them to conquer the world? If not Egyptian then any other empire. Remember that aliens are really smart and most probably their civilization has seen way more wars to learn from about diplomacy and war conflicts. --- So basically ancient civilizations have 0 chance. Germany invaded Poland in one month (Poland had a normal army during that time) it took 3 days for the allies to decide what to do and even after they declared a war, they had done absolutely nothing. What do you think, how much time would it take our ancient civilizations to figure out that some other civilization far far away was destroyed. Would they care? How fast would they decide to do anything? Technology was always a huge advantage. Just a small advance (who created the first tank, built the radar, broke encryption, developed an atomic bomb, created a catapult) was frequently causing a decisive win. A lot of our technological things are not really hard to replicate. A person like me can create a molotov cocktail, create an explosion and make a radio. Can you imagine what a university chemistry student can create in a day? What could a group of specially trained and prepared people do? Every one week that the ancient army is waiting, aliens can replicate some of their old inventions. Aliens do not need to kill everyone, nor they will come to Earth and broadcast to every civilization - "Prepare, we came to kill you all". They are smart and they came at a time, when everyone believes in Gods and the ones that do not believe, should be killed in sacred ritual to please the aforementioned Gods. So why not to pretend to be the same Gods, use some civilization as slaves (giving them some cool toys) and quickly try to replicate inventions. Before you speak about how hard it is to control a big population, that there will be revolts and other stuff like this, check how many German people died when there were only very limited amount of them in occupied France and Poland, also check how many people were needed to overview huge concentration camps and how many jews tried to make a revolt. [Answer] Without resupply or reinforcement, I think the aliens would be overwhelmed... eventually... The numbers tell the story. Earth's human population at that time is estimated at about 300 million, granted many of those humans were living in east Asia, but with just a few million soldiers overwhelming a force of 15 thousand would be doable. It would likely cost a ridiculous number of human lives, but with numbers that slanted an ongoing siege would eventually wear down the aliens' ammunition, fuel, and so on... There are similar stories about slanted battles during the [Korean War](http://en.wikipedia.org/wiki/Korean_War). Supposedly well fortified and well armed US forces were overrun by poorly armed North Korean forces, just by the sheer numbers. Basically wave after wave of troops were ordered to charge into machine gun fire until ammunition ran low and the ground was taken. See: [Human Wave Attack](http://en.wikipedia.org/wiki/Human_wave_attack) and [Attrition Warfare](http://en.wikipedia.org/wiki/Attrition_warfare) [Answer] Defeat aliens with least loss of human soldiers. Reach upstream and Poison the flowing water source, also heavily poison underground water from some distance (diffusion will mix the poison into alien's underground water). Ancients were good with poisons just need to mass produce them. Putting lots of mud, dead rotten animals, cobra snake poison, feces (with pathogens) etc are the few options. That will keep them moving (with limited fuel and stamina). Avoid direct confrontation. If they chase, then run. Remain scattered. Have multiple supply lines. Destroy all unprotected fields or trees on the circumference. Wait for harsh weather season. Just like Russian scorched earth and waiting for winter. When they start dying of hunger. Ask them to surrender their arms in exchange of constant food supply and water. [Answer] Just because the aliens are the ones with the guns now doesn't mean that humanity can't acquire them. If the aliens possess no unarmed physical or mental advantages over the humans, the humans should be able to engineer some way to ambush a patrol, pilfer a depot, or otherwise procure some firepower of their own. It might take awhile to shift a meaningful amount of technology into their own hands, but once they get a little of it, acquiring more becomes easier. Pick off any small patrols, take their stuff. Once sufficient stuff acquired, raid enemy encampments. Eventually win with overwhelming numbers. [Answer] This event did, in fact, happen. Almost 500 years ago in Central America, very strange and weird-looking people showed up coming from beyond the endless waters which the locals had no technology to cross. They had strange and powerful, almost magic-like weapons. [Cortes](https://en.wikipedia.org/wiki/Hern%C3%A1n_Cort%C3%A9s) had less then a thousand soldiers, but in the end managed to conquer a whole empire. No matter how powerful and fearsome their weapons were, a few hundred men would have had no chance of conquering a [whole empire](https://en.wikipedia.org/wiki/Aztec_Empire). So how did they manage to [do it](https://en.wikipedia.org/wiki/Spanish_conquest_of_the_Aztec_Empire)? The Aztec Empire was brutally oppressing a lot of different tribes, and those tribes decided that they would rather live under Spanish rule than being used as human sacrifices in the Aztec rituals. This is how, when Cortes conquered the Aztec capital, he didn't do it only with his original few hundred men. He had almost 100000 native allies under his command. The Spanish not just managed to temporarily defeat a much more numerous force, but managed to settle down, and the region is now dominated by Spanish culture even 500 years later. The technology of the Aztecs was not much better or worse than the technology of ancient Greece, and the Conquistadors were fewer than 15000 and had less advanced technology than the aliens in the question. So, if the aliens in the question behaved similarly, they could have a very good chance of building a country or an empire for themselves. Instead of mindlessly starting to gun down humans, they could trade with them, then find a very oppressive satrap and convince humans to help the aliens overthrow him. If done right, many humans would see them as liberators, rather than conquerors. Cortes also didn't jump out of his ship while opening fire on the natives on the shore. He wasn't even explicitly sent to conquer, just to explore, trade, and look for opportunities. He found a crumbling empire with a lot of enemies, and he saw it as a very good opportunity. The question asked how the Greeks could defeat the aliens. However, if the aliens were at least as smart as Cortes, then the Greeks would have no opportunity to defeat the aliens, as there would be no united Greek force fighting against them. [Answer] When I read this question, the first thing that came to mind was the Comanche tribe of Native Americans. Throughout the 18th and 19th centuries, the Comanche fought against settlers encroaching on their lands (the southern part of the North American Great Plains). The Comanche war bands weren't very far past a stone age level, using arrows and lances fashioned using primitive hand tools. The foes they were fighting had pistols and rifles, built fortified bases, and had formal military training. Despite this large technological gap (roughly similar to what the OP is going for), the Comanche were able to successfully hold their own against a significantly more advanced foe for a very long period of time. Your ancient people can use similar tactics and methods to fight off their technologically-superior invaders. (for more details on Comanche warfare, see the excellent book [Empire of the Summer Moon](http://rads.stackoverflow.com/amzn/click/1416591052)) Comanches swarmed their enemies. One on one, superior firepower usually wins. Comanches attacked in groups and on horseback, and opponents had a hard time tracking so many fast-moving foes that were all moving independently. The psychological impacts of being vastly outnumbered should also not be ignored. The alien population numbers that you give are low enough that swarm warfare could be an effective tactic. The Comanche protected themselves from gunfire using shields. Several layers of dried, tanned buffalo hide was capable of stopping a rifle shot. Even though an AK-47 round is more deadly than a 1850's rifle slug, it's plausible that an ancient civilization could develop a type of shield capable of either stopping oncoming gunfire, or at least rendering it non-lethal. The American TV show *Mythbusters* has done lots of experiments testing whether common objects are bulletproof, and they've shown that objects made of materials available to the ancient Greeks (ceramic, nickel, etc) were capable of stopping certain modern bullets, or at least robbing them of enough momentum to make them survivable. Layering materials like nickel and dense hides could result in a shield capable of protecting against a modern automatic rifle (provided that you're not subjecting it to sustained, focused fire). It may be heavy enough to require a dedicated shield-bearer, but I believe that was already used as a military tactic during that time period. The Comanche also had a large advantage by being masters of horsemanship. Horses provided unmatched speed, stamina, and maneuverability in their world. Even in your world, a well-coordinated and well-trained mounted cavalry can be a threat to armored military vehicles. A tank can match a horse in speed, but not in agility. Tanks are great against massed or fortified enemies, but much less efficient at attacking a swarm of enemies that are spread out, surrounding it, and constantly moving. An agile cavalry can cause tanks to catch each other in crossfire, or deliver soldiers close enough to jump from the horse onto the tank and attack it directly. Tanks are stopped/slowed by terrain that a cavalry can successfully navigate (narrow passes, forests, etc), and even a primitive civilization can create traps to defend against tanks (such as moats or tiger traps). Also, remember that even the ancient Greeks had access to what is still one of the most destructive weapons available: fire. Unless your aliens have advanced to the point where everything they use is metal or plastic, fire is still a real threat. A small group of soldiers making it into an alien building with torches can easily start a fire capable of destroying most of a base. Several ancient civilizations were known to use early forms of incendiary weapons, so this isn't too far from reality. Your example listed the aliens landing in Syria - a region not known for having plentiful water - which would increase the danger posed by an army of arsonists. Any sort of a war like this would revolve around attrition. The aliens have no reinforcements and a finite level of supplies. Once they run out of certain key supplies like fuel and ammunition, it's unlikely that they'll be able to manufacture more (at least not in any real quantity). At that point, they face many of the same problems that a modern army would face if time-warped two millennia into the past. They're stuck with none of the modern trappings that they've been accustomed to for their entire life. At this point, survival is difficult even if you completely take away any sort of military threat. The aliens would have no modern medicine, little (if any) knowledge of Earth's plants and animals, no familiarity with the local geography or weather, and would likely not know how to build tools or buildings from complete scratch. If the local people could force the aliens to burn through enough of their consumable supplies, a good, old-fashioned siege could be very effective. [Answer] Well, you put up some big problems for the aliens. Small resources, small numbers and very restricted technology - believing that Aliens that can cross the space to reach humans can only offer automatic projectile weapons and tanks as offensive potential is somewhat difficult. But anyways - as the humans not prepared for this, the aliens at first will have an edge. Wherever they land they are probably able to destroy the leadership and establish themselfes as new leaders with their advanced weaponry. So they can rule humans in that region to supply them with food and other resources. But growing over the size of an country can be difficult, as they have so few vehicles and few numbers. The neighboring countries will be better prepared, so while the humans still will need some time to figure out stuff, the problems of controlling big numbers of people and a big area with only 15.000 are too large. If the aliens try to destroy humanity they are stupid, ruling them to get resources through them is much more clever. Some tactics the other countries may develop: avoid direct confrontation, but attack supply lines (attack the food delivery for instance) and separated smaller groups of aliens. Loot some of their weapons. Obstruct paths so that the vehicles cannot move. Use ambushes to attack and retreat fast after first attack. They may develop shields that can stop bullets, although they are probably heavy. The aliens probably can be stopped. Really clever aliens would not go to war but establish themself as traders, hich-tech-products are exchanged for food and resources. Local rulers that benefit from that trade would even start to defend the aliens from other people. [Answer] Automatic weapons FTW. Humans lose. Game over. You want examples, look at European colonisation. Rorke's Drift for a classic example. Isandlwana was a win for the Zulus only because the British were poorly equipped and weren't seriously prepared for resistance. And that's with 19th century technology - replace those old carbines with something equivalent to modern assault rifles, and the result would be a foregone conclusion. If you look at Darius's campaign, you'd be lucky to get half a million troops in one place. More typically you'd be looking at maybe 100,000 tops on the one battlefiled. Up against 15,000 guys with assault rifles, they're dead meat. You're also starting from a false assumption of "rule all humans". If European colonisation taught us anything, it's that ruling the locals is never the point; it's ruling the *land* and having your people take its resources for themselves. The locals might be kept on suffrage, or for a slave workforce if you're short on manpower, but more usually they'll be massacred. There's no benefit for the aliens in keeping humans alive. The other false assumption is "limited fuel and ammunition". Once they have a well-defended beachhead (which won't take long with automatic weapons), the first priority is resupply. Worlds don't die overnight - these guys had plenty enough time to make sure their colony ship had refining/manufacturing facilities, or at least the means to build them when they land. [Answer] For reference, you probably should take note of some things about where we ourselves are at in terms of conceivably being in the position of the aliens, both technologically and politically. Perhaps the most important issue is that engineers who have proposed colonizing other planets always start out making industrialization a top priority because fulfilling all of our needs depends on having resources provided by industries of some kind. This includes getting food and water, resupplying, and building shelters and equipment, all starting from raw materials, meaning whatever stuff just happens to be laying around. You could say that these engineers are so obsessed with industrialization that they have already been playing with the idea of sending 3D printers to the International Space Station to produce replacement machine parts and such there, thus reducing the need for resupplying missions. The aliens in this story would undoubtably have the same kinds of priorities. Additionally, many if not most of the materials that these aliens would be likely to want (e.g. iron, silicon, copper, aluminum, and carbon) are fairly easy to find on Earth. They could probably produce still other materials (e.g. "rare Earth" metals) through nuclear fusion using their technology. We can then figure that they would immediately get busy manufacturing stuff upon landing on Earth and would not take too long to fix the problem of supply and equipment shortages. Chances are pretty good that if they have developed the technology needed to travel to faraway stars they have also figured out how to make the power and propulsion systems needed to make all sorts of stuff fly around. We ourselves are more or less nearing that kind of milestone with drones and VTOL aircraft. The tanks that these aliens have would therefore probably be aircraft if not full-fledged spacecraft, and they would not bother much with operating as ground vehicles because of the obsolescence of that mode of operation. Moreover, arrows and spears would do nothing to these tanks, these tanks would be able to fire rapidly and blow things up to take out large numbers of foes quickly, and their speed would enable them to pretty much go and be anywhere at any time as needed. Nukes and similarly destructive weapons (including "spear from God" kinetic weapons) would probably be fairly easy for them to make too, so if they wanted to, they could level whole enemy settlements with one shot. However, we can also imagine that in their home planet, military technology would have caused the extinction of these aliens if not for them being peaceful and empathetic by nature. We can then assume that they prefer to be peaceful and let others live. Thus, even though they would likely be able to wipe out all their human enemies without much effort, things would get sticky and unpredictable as a result of moral dilemas and then very tricky and complicated politics. For example, should the aliens turn Earth into a colony, try to teach humans to become more civilized and sophisticated, and try to coexist, turning the resulting civilization into some kind of melting pot? Inevitably, there would be political conflicts because of vested interests among high-ranking humans, people being hostile to changes in their ways of life, people perceiving counter-cultural forces as being evil and just plain wrong, and the aliens becoming entangled in humanity's pre-existing political and ideological conflicts. The aliens too would certainly find themselves wrestling with the question of what to do about primitive practices concerning alleged crimes and punishment in much the same way that the U.S. military has been wrestling over this against the Taliban in Afghanistan with regard to women's equality, human trafficking, and standards for justice and punishment. After throwing in the colossal technological and cultural gap, that conflict is where this story would get very interesting. [Answer] I see where you are going, but i'm trying to find a way to make the "war" happen. The first thing i'm wondering about is in both Egyptian, Roman and Greek mythology the gods came from heaven. And in times where religion was the thing to hang on to, i think most people would assume they were gods (kind of like the STAR GÅTE thing) For the war to happen there would have to be some reliable person say priest or the like who starts to claim that they have to be false gods. Or the uneducated would just assume that the gods came back to claim their rights and the commoners would submit wiht out any resistance [Answer] The aliens are in a fairly desperate position: There is not many of them, they have no infrastructure, they have little knowledge about the planet and it's inhabitants, and most of all there are not very many of them. But they are technologically advanced in ways that must seem more than magic to the humans. While they have limited supply aof ammunitions, they should have no problem at all to simply build some really strong crossbows as soon as their ammunition supplies start to wear out. So, over time, they will conquer the world, and they will not have too many problems with that. **Unless...** Unless they are beaten hard and fast. At the beginning, they will be quite busy creating some infrastructure. That is the time when they are fairly weak: They will have little fortifications, not very well established food and water supply, and little knowledge about the humans' abilities. This should be the time to strike at as many fronts as possible: hinder their access to water and food, and try to mass attack them as hard as possible. The losses on the side of the humans will be enormous, but there are many of them. They will need to learn about covert actions, because simply marching up at the aliens in square formation will get them killed. But we can assume that their generals will learn. They will try to use the terrain to their advantage, use shields to at least obscure the line of sight for alien snipers, use ranged weapons as well as fire, use ambushes and traps, to diminuish the alien forces as good as possible, trying not to allow them time to reorganize, and most of all, no time to replenish their food reserves or fortify their positions. If the human generals fail at this, the aliens win, no matter what. [Answer] The middle eastern world in the 4th century was run by decentralized empires who didn't control their people or land directly: they used satraps (subordinate kings) to do the daily administration of the greater empire. Alexander the Great and the earlier Persian rulers styled themselves "king of kings" who let the local rulers keep control of their regions while collecting taxes in gold, goods, soldiers, and labor from them. There is no reason that the aliens couldn't sweep across the ancient world making subjects out the other empires instead of destroying them, just like Alexander did. The Greeks and other peoples would understand this kind of hands off government and the aliens would benefit from not having to personally administer a huge swath of land and people. The aliens could slot themselves right into the order of things as the new overlords and watch the gold roll in from their human subjects, giving tech and protection to their satraps in return for loyalty. [Answer] One problem most answers have is that a civilization which is capable of interstellar travel is significantly more advanced than the technologies you describe as being available. A solution is that the technology they used to travel, escaping their world, is not their own. I'll leave it to you to decide how they discover & use it. Then you can arbitrarily set the level of technology available to them. On arrival the aliens will see the relative technology level and will either act arrogantly or cautiously depending on their culture and leadership. If they act cautiously then they will overwhelm a technologically inferior species, through diplomacy/tactics (see other answers where aliens win). However if they are arrogant, then they will announce their arrival and show their intent which will give many opportunities for the natives to set up this 'league' and for religion to view them negatively. As for the war itself, most decisions come down to the leadership of this league and it's structure. If it acts cautiously, measures it's foe without over committing, using scouting etc. It has the opportunity to develop new tactics. Without this, they will attempt pitched battle which will almost inevitably be a loss and any further resistance will be hampered by fear and lost resources, both the army and useful individuals within it. Other points I've thought of. * How do the natives deal with 'traitor nations/cities'? * Can the natives learn to use the alien technology? * Logistics, what proportion of motorized transport does the alien race have, do they still have to rely on foot/carts to transport resources/supplies? [Answer] I believe it will be more war of wits rather than arms. In open fight, earthling does not have any chance to win. Tanks will decimate entire army, then few soldiers with hand weapons will execute rest of defenders. Only chance for Greeks is guerrilla warfare. Surprised attack on small units, stealing their equipment, sneaking to their camps and slicing their throats. Poison their supplies. Another option will be let aliens win, learn what their civilization can offer us, and then backstab them. [Answer] David Drake has written a variety of stories set in ancient times with an encounter of an alien agent or critter setting up to take over the world. *Birds of Prey* is one, *Killer* is another. Several short stories have this aspect. An equalizer here is that the aliens are infiltrating Rome alone, or nearly so and can't get into a pitched battle with high tech. They use it to gain street cred as magicians, which gives the counter-agent ways to get close enough for a sword blow. In *Birds of Prey* there is a second alien agent setting up the mission to eradicate a brood of alien eggs watched over by an armed brood mother with an electrical gun - they modify parade armor to conduct the charge away long enough for a sword attack. [Answer] An interesting fact about having a technology edge in war is that sooner or latter the other side is going to figure out how your toys work and use them against you. If humanity is going to win, it going to be victory based in wit, understanding the enemy and using there own strength against them. You likely want a trickster hero and a nice opening battle where the alien's curb stomp a huge human army... you know to set tone and show how one sided a straight up fight with them would be. I also be tempted to give the alien's background some thought, maybe they have limited supplies and support because something bad happened to them (crashed ship maybe?), perhaps there even a way the story might end well for both factions as well. [Answer] The aliens do not have a chance. Some assumptions: The alien race is roughly human in their behaviour and didn't have advanced knowledge of their destination before they left. So who will be amongst those 15,000? Some carefully chosen groups that contains all the necessary skills to rebuild? That's just not human (or alien) nature. The 15,000 people would represent those with sufficient security clearance from a single nation/tribe. Additionally, those who were truly needed would also be able to score an invite for their family. So we would end up with maybe 2000 soldiers, 1000 scientists/engineers, 1000 politicians and billionaires, as well as around 11,000 people with no particular reason to be there but with a connection to one of the above groups. So we have 2000 soldiers to guard against the entire of humanity. These are spread into 3 groups of under 700: Guarding mines scattered around the world, guarding the city and farms, and destroying humanity. All the tanks would be parked outside of the alien Capitol and left alone or partially dismantled - too much fuel consumption to use and risk of humans stealing them if they aren't carefully disabled. The first targets would be the invading army and those guarding the mines. If their technology is broadly comparable to modern humanity, they need iron, a fossil fuel like coal or oil, and ingredients for gunpowder. So lets assume they build 3 mines total. At all times, they need to guard these 3 mines or the humans will use or destroy them, and they need a mobile force capable of taking the mined goods to the city. So divide out 667 mine guards into 4 groups and we get groups of 167. I don't care that they have machine guns, 167 people cannot fight an ambush from a 4th century army. So humanity opens by obliterating 167 aliens, potentially losing tens of thousands of men in the process. But now, they have 167 of the guns. At that point, the aliens are dead. They are outnumbered thousands to 1, need to divide into even smaller groups to create a new group to collect goods from the mines, and the humans have advanced weaponry. A similar approach could be taken with the invading alien army. They will need supply lines. Attack the supply lines to gain weapons, then use them to destroy the army. [Answer] # The Element of Surprise I think the only way the Greeks could defeat an arguably superior enemy is through tactics that take the aliens by surprise. **Flanking** - this pits an unfortunate few against your aliens in the field, while the bulk of your army is in the trees (or whatever) to the left, right, and back of your enemy. This maneuver was [used by the Greeks](http://en.wikipedia.org/wiki/Battle_of_Marathon#Battle) in the Battle of Marathon. **Traps** - The classical use of the *trou de loup* would [trap and kill](http://en.wikipedia.org/wiki/Trou_de_loup) approaching enemies. Simply make your pit large enough to sufficiently trap your odd alien or two. **Guerrilla Warfare** - an out-powered defensive military can use the tactics explained by Sun Tzu in *[The Art of War](http://en.wikipedia.org/wiki/The_Art_of_War)* as early as the second century BC. "All warfare is based on deception. Hence, when we are able to attack, we must seem unable; when using our forces, we must appear inactive; when we are near, we must make the enemy believe we are far away; when far away, we must make him believe we are near." -- Sun Tzu [Answer] Several of the other answers have made good arguments for why -4th century humans **with -4th century technology** would have no chance against an invasion by an advanced, spacefaring civilization. But what if the humans were somehow able to gain access to the aliens' own technology, and use it against them? For example, a schism in the alien society results in a small alien faction attempting to gain dominance by arming and training human mercenaries. Or, some clever humans could manage to steal some of the technology. In this case, they'd have to steal enough weapons to make an impact, as the manufacturing infrastructure would not be there for humans to build their own AK-47s. But in any case, with access to alien technology and a large population to draw conscripts from, I'd imagine Alexander's generals could stand a pretty good chance. [Answer] Normally, when you have such big advantages and disadvantages, even if each side has both, the conflict doesn't last long. One side or another is taken out pretty quickly (generally in a single day's battle) being that both side's holds on power are so unstable. This kind of story could perhaps work for an action movie, but it wouldn't be all that interesting simply because the story would end far too quickly. Also, if primitive humans take out the aliens simply through attrition, outnumbering them during an attack, that too would not leave much room for variety in the plot. A good plot calls for the winning side using a clever strategy, but a strategy of mere attrition would make things a bit too predictable and monotonous. It would just turn into a waiting game, waiting to see how long and how many soldiers it takes to wipe out all the aliens. [Answer] ### The Greeks Cannot Defeat the Aliens on the Battlefield 15,000 men with assault rifles and tanks can defeat any Bronze-Age army. Herodotus made the claim, which no historian takes seriously, that the united Persian Empire that Alexander conquered was able to put together an army of a million men. Even if you took that literally—and found some way to feed them, some coordinated command structure, the men didn’t all infect each other with pathogens as soon as they came together from all over—an armored division would defeat them. Mow down the first row with automatic weapons, and the rest will break and run. Attack infantry with vehicles that can outrun them, mow them down instantly and are impervious to any damage they can do, and the infantry surrenders. And the new Macedonian rulers are not going to be able to inspire their conscripts with the kind of superhuman morale to overwhelm a modern armored divisio until it runs out of bullets (although you might make the aliens extremely loathsome, I guess). Besides, the aliens probably could get a K/D ratio better than 20-to-1. ### But The Aliens Might not be Prepared However, the aliens might not have known they’d be facing any effective opposition. They might not have realized there was intelligent life on Earth at all. Maybe their own history misled them into thinking that an empire capable of effectively opposing them was not even possible. If you make the natural history of their planet different, this has the great advantage of making them less like humans in rubber suits. So, for example, maybe their food source led them to a different lifestyle than the agricultural revolution on Earth and they didn’t expect a species at this technological level to have any social organization larger than a tribe. Maybe their world had no life forms similar to horses or trees, so they had no idea there would already be large boats that float on water. Maybe none of their ancient civilizations had both copper and tin, and they think of bronze as something that’s discovered as part of modern chemistry. Maybe they don’t believe it’s even possible to sustain a large empire before the equivalent of the telegraph or radio, because in their history, no one ever did, and therefore an enemy capable of amassing hundreds of thousands of soldiers with bronze weapons, horses, camels, boats and so on is a shock to them, too. Maybe that was all so long ago that they’ve even forgotten their history. (Remember, there are religious fanatics on Earth today who have convinced themselves that the Stone Age never happened.) This doesn’t mean the Macedonians could win against the forces you gave the aliens, but it might mean they didn’t bring an optimized fighting force. ### The Aliens Might Have Handicapped Themselves Let’s say you’re expecting to land on a fallow planet where you aren’t expecting to need to fight. Maybe you decide that it would be better not to bring any blueprints for advanced weapons with you. for idealistic reasons or because you’re trying to avoid the paradox of security where every new colony has to build a superweapon because, if they don’t, another colony will build its superweapon first. Then they land and realize the local apes are actually dangerous. So they’re stuck trying to reinvent weapons they can actually build right now, from first principles. That’s a scenario where the humans at least have a chance to stomp the aliens before they can start to snowball. By accident, really, since the ancient humans would have no idea what the aliens can do or what materials they would need to do it. ]

[Question] [ On Earth today, even though most people speak some English, there is seemingly no reason to believe that future generation's main language will be the same in decades/centuries to come (i.e., we'll keep having different native languages and learn a common language later on in life). Similarly, there are a bunch of different programming languages. But the iteration process is much much faster here. New programming languages are created on a regular basis, old ones become obsolete... Is there a reason to believe that programming languages are going to converge into a single language in the decades/centuries to come? [Answer] It's not technically possible, at least without giving up functionality. For example, languages have different levels of strictness which is proportional to how high or low level they are. Scripting languages are softly typed because they can easily perform runtime type checks and conversions. Compare this to C/C++, which has much more difficulty with type flexibility due to being closer to the memory. While more type-agnostic features get added, at the end of the day, most of these are still compiler-based: they serve more as programming aids than actual language functionality. Another major example is how memory is handled. In scripting languages (and even some compiled languages), memory is largely out of the hands of the programmer, managed by the interpreter or some other system. In contrast, lower level languages provide the ability to directly manipulate and access memory, such as C/C++'s pointers. While it's possible to think that maybe with increasing performance we'll someday stop caring about low-level programming and all start using some weird PHP analog for everything, I think that's failing to understand how the world really works. I consider C/C++ a low-level language, as do most people; but once upon a time, and still among some, it is a high-level language, and low level would be the likes of assembly. This is not merely terminology: as the performance framing of the question of efficiency shifts, so too do the measures of it. Simplifications we might now consider too costly to implement even in interpreted languages might one day be common-place among "high-level" languages, Java might be considered "low-level," C/C++ might be relegated to those weird times you simply must use it like assembly is now, and assembly itself might even be forgotten as an in any way viable language (class) in itself. I think it's much less likely programming languages will converge than spoken languages for that reason. Human language serves a single fixed task, to convey information. While you might argue different languages are better or worse at some portion of that goal than others, they can all accomplish those goals. There are, however, things you simply can't do in PHP. There are also things no sane person would want to do (these days) in assembly. One way to think about it might be this. If everyone in the world tomorrow spoke fluent Welsh, what would happen? Well, everyone would be able to converse in Welsh, translation services would go under, and perhaps leeks would become more popular. If tomorrow the only programming language available was JavaScript, we'd all be utterly screwed. That's not even counting inertia. In human language, inertia is mostly a matter of being able to read old works of literature, something which is rarely a decision when deciding to learn a new language, and never a decision when learning a native language. While losing understanding of classic works would be a cultural loss, it's not likely to motivate actions on a large scale. On the other hand, having to reprogram the Linux kernel, Windows, almost every device driver, and web servers would definitely factor into broader decisions of programming languages. That COBOL still lives is a fairly strong argument against programming language convergence, in my opinion. However, there is one point you might expect some convergence in programming languages: syntax. That is already happening, and the C-like family has largely won. C, C++, Java, JavaScript, and PHP all share mostly identical syntax, abet with some changes in operators, mostly mirroring their inherent difference. No pointer-operating `*` and `&` in PHP, no fun and easy string concatenation `.` in C. However, those aside, these languages are almost entirely mutually intelligible in at least structure. An alternative family would be the BASIC line, including VB and I'd argue Python. [Answer] > > Is there a reason to believe that programming languages are going to converge into a single language in the decades/centuries to come? > > > As a programmer myself, *I certainly would hope not.* It would likely be a massive inconvenience for virtually everyone, and benefit practically noone. Different languages are good for different types of tasks. If you're writing a short script to hide a field on a web page when a user makes a particular choice in a form, you don't need C's ability to directly manipulate any addressable memory address, but you can't really have C *without* the concept of pointers. (You can avoid using them, but that is quite limiting in terms of what you can do; for example, you now have no language-native construct that you can use for variable-length strings, so you need to go reinvent *that* wheel.) If you're writing an operating system to run on bare metal, Javascript's lack of calling convention control, memory management and interrupt handlers is going to make the task nigh impossible, if not outright impossible. If you're teaching someone the basics of programming as a concept, assembler isn't going to cut it (it gets far too much into the gritty details of adding two numbers or accessing memory); on the other hand, if you are writing the critical section of a high-frequency interrupt handler, PHP probably isn't the language you're after. A garbage-collected language like Java is a poor choice for a [real-time system](https://en.wikipedia.org/wiki/Real-time_computing) where execution predictability is a requirement, because in most GC languages, the garbage collector can technically kick in at any time and start shuffling through your data, both taking up CPU time and causing cache flushes. Writing set-based data queries in C is a pain, but SQL makes it at least relatively easy to express *what you want done* with your data, rather than the mechanics of *how to do it*. *And it goes on like this.* While there certainly is some degree of overlap, for example between languages like C# and Java, or BASIC and Pascal, in many of the commonly used languages, *each programming language fills a specific niche*. The choice between, say, Java and C# is fairly arbitrary (neither is *obviously better* than the other *in the general case*, though one can be better than the other in any *specific* case); the choice between Ada and C++ is not arbitrary (there are things you can do in one that you can't do in the other, or can't do without significant bending of the language). Even if we disregard architecture-specific languages such as assembler, which is already quite a major hand-wave (what are you going to write the bootstrapper "BIOS" initialization and operating system bootstrap code in; binary machine language?), at least with the technology of computers as we know and recognize them today, there is a multitude of tasks that need doing, and the requirements are different for each. Performance, predictability, ease for the programmer, API accessibility, scope of features (both what is needed, and what is explicitly *not* needed or desired), and so on and so forth. In some cases, certain features are an absolute requirement for the intended purpose of the language; in others, *lack* of certain features is a feature. As pointed out in the comments and also elsewhere, *some specific features are by their very definition provably incompatible with each other,* regardless of how they are implemented or expressed, and thus *cannot possibly* coexist in the same programming language, so any such language would need to trade one for the other. Now consider the people who for one reason or another actually *need* the feature that got cut; what programming language will they use? All this would seem to make it **highly unlikely that it all converges into a single programming language that is equally suitable** for writing an operating system kernel *and* a field-hiding script for a web page (or whatever replaces web pages in your scenario). **I would even go as far as to say that it realistically won't happen.** If you want computer programming to appear realistic in your world, **you need to allow for the fact that different tasks require different tools** and that these different tools are going to be used by different people. A programming language is one such tool, and as such just as we today have both power tools and manual tools that accomplish the same thing -- say, making a hole in a wall -- there will almost certainly exist different programming languages which are suitable for different tasks. And that's without even touching on the subject of rewriting every piece of software, or its equivalent, in EZ++2108. Which, no matter how productive someone can be in this new language, would be a *gigantic* undertaking. *Also compare [Why are there so many programming languages?](https://cs.stackexchange.com/q/451/11871) on the Computer Science Stack Exchange, and [Why do people use C if it is so dangerous?](https://softwareengineering.stackexchange.com/q/321547/6384) on the Programmers Stack Exchange.* [Answer] **TL;DR** It is not impossible, but I pretty much doubt it. --- There are already good answers, but I wanted to add a slightly different point of view. First, **spoken languages are NOT a good analogy for programming languages**. Indeed, in their nature they differ considerably. Excepting the *conlang*, the spoken languages are the results of centuries of evolution. Separation increased the difference, but communication tends to bring them more homogeneous. The main idea is to communicate with each other, to understand each other and exchange (or do business). Nevertheless, those languages are spoken by many speakers, and no-one or no-body actually control the evolution of the language. Even bodies like the French *Académie Française* merely reflects the evolution of the language, *a posteriori*. There isn't any reflection on "best" or "more efficient". IMO, there will be an ever converging use of "English" as a communication language, but even this will diverge from the actual English. And I also doubt the other languages will completely disappear due to the inertia, mentioned by Wiliam Kappler. At the other side, programming languages are discussed by collaborations, which sets standards. The most well known is the ANSI for C. But most of the languages have a group of people involve in deciding on the evolution of the language. It changes completely the nature of the evolution of programming languages compared to spoken languages. Now, could those be **merged?** I would say it is **not impossible**. If you look back 10-15 years ago, few would have imagined how much a language like Java would spread. Indeed its size, performance, compilation time was considerably worse than, say C++. But since then, the language, the JVM and compilers have considerably improved. And furthermore, the progress in computers mean that a few more MB here or there, and execution difference are barely noticeable in most of the user's experience. In microcontroller, there is a trend to adapt more and more ARM-architecture. Which seems to indicate a merging of the hardware. And if we see the OS war for mobile applications: e.g. Microsoft coming back to ARM, or tablets, smartphones, etc. If they manage to actually have a single OS running on all systems, that would facilitate a uniformisation of programming languages. As the price of the memory reduces, there will be less incentive to actually use low-memory solutions, allowing applications of bigger OSes (see how "low" the Linux gets through Embedded-Linux). However, **I see four arguments against it**. As the other answers point out, **programming languages** tend to be **specialised** in niche. I could see a few axes to differentiate languages * accessibility: how easy is it to learn the language/read a program? * efficiency: that is already three-fold: size of the bin, amount of RAM and speed * functionality: what can we do with the language? * portability: what is the scope where it can be implemented? How easy is it to reach our customers? And there are probably a few more. Now, the only way to get the languages unified, is to get a language to be the best in all those axes. Just to give some illustration, * ruby is easy to read and to learn, but not particularly efficient, * Java is widely implemented, but too large/complex for embedded systems, * C can be very efficient, but hard to learn (comparatively). Due to these different axes and the specialisation that we observe today, it is doubtful that one of the language *evolves* to dominate the others. We also have to consider the **inertia** of change. Programming languages have been born in a fully connected world (amongst their users). Therefore more communication will not modify their course (as for the spoken languages). Most of the users are reluctant to learn new ones, and often wait until the last moment to resort to learn something new. But "natural selection" could play here, favouring those who do. But together with the programmers, the inertia of programming languages is written in their code. In many research domain, Fortran is the language of choice (I have even seen code in F77), although 1) research is often aware of the new tools, and 2) some would argue Fortran is a deceased language. But why? Because a huge amount of code was implemented in those Fortran! And it would be a huge effort, and would probably prove impossible to translate all of it to another language (the original writers being unavailable, hard to check the science behind). The same goes for other large code: no-one is likely to rewrite the Linux Kernel. You need to implement compatible languages. But even then, that means that the "old" language still needs to be kept up to date. The effect of the **anarcho-liberalism** of programming and Internet. It can be well seen with the numerous forks on FOSS: if someone disagree with a decision on the new standard, she is likely to either stick to the old, or create an alternative. Much like, as pointed out by Wiliam, many current languages derived from C. And if we could rely on the last 30 years or so, we see that the number of applications of programming languages explodes, most of the languages evolves, some appear as derivation of those, others as new concepts (rarely). But older standards are still being used today. So there is a multiplication and diversification of languages. It is hard to imagine that this trend would reverse. Last of four points, the **irrationality** of the actors of the sector, a.k.a. programmers. New languages are implemented for the sake of irrational factors: [Whitespace](https://en.wikipedia.org/wiki/Whitespace_%28programming_language%29) being a perfect example. Some people will defend the elegance, the poesy, etc. of their languages. This create some of the famous internet flame wars. I suggest you look "C++ vs Java" up. Take some bandage along. New users often side along one of the sides. As we have seen in the *famous infamous* emacs vs vim war. **To conclude**, I would say that I can see a scenario where HW memory becomes cheap, HW architecture becomes limited to a few (X86, ARM) and that one OS is predominant on all of those. A new language appears that is the best or almost the best on all of the axes above. Then, given enough time, the other languages might die out. But really, the easiest would probably to get an evil-genius dictator taking control of the world and forbidding any language other than assembler. Because who needs anything else? [Answer] **TL;DR: No. Programming languages are too diverse.** ## Reason 1: Purpose There are, according to Wikipedia's [list of programming languages](http://en.wikipedia.org/wiki/List_of_programming_languages), 806 distinct programming languages, excluding BASIC dialects and esoteric programming languages. There are some features of each language that wouldn't be too hard to merge: most programming languages have some form of conditional processing, variable declaration, arithmetic and mathematical operations, output, and input - among the other similarities. These are the parts that would be relatively easy to merge together (as long as we can decide on a style, which might take quite a while...). There are other parts of other languages that cannot easily be merged, many of which depend on the purpose of the language. JavaScript, for example, is a dynamic Web scripting language used to give webpages interactivity. A lot of it is used here on StackExchange to load content dynamically without having to reload the page. This process is called [AJAX](http://en.wikipedia.org/wiki/Ajax_%28programming%29). AJAX is designed for the web. It is not designed for desktop applications, such as could be written in Java or C# or C or C++ (etc etc), that can be multithreaded and load content dynamically without a mention of AJAX: that's just how these languages work. Taking JavaScript and Java as an example, we can also see that the purpose of the programming language matters. JavaScript is designed for the web; Java for installation on a system. JavaScript, therefore, has *no file access*, for security reasons - to ensure malicious websites can't access your files easily. Assuming this theoretical coverall programming language (which I'm going to call Σ∞ or Sigma Infinity) also has to suit every purpose, it has to be suitable for both the web and the installed versions. To satisfy this requirement, the language designers would be forced to release two different versions of the language - one without file access, one with - to maintain security. As maintainers of modular languages or languages with multiple versions will tell you, this is a *big* task - ensuring that both versions are... * Compatible with each other * Up to date * As close to identical as possible * Supported * Tested * Documented * Used ...is a big ask. You'd need to create a huge company to support Σ∞. No, it is true, this does not preclude the possibility of Σ∞ existing. However, since we're talking practicality here, it is more practical for multiple companies to maintain multiple languages than it is for one huge company to maintain Σ∞. --- ## Reason 2: Features 806 programming languages contain a lot of features. Ignoring the compatibility problems of purpose that we've just discussed, creating Σ∞ is going to take a long time simply because of the sheer volume of stuff the creators have to include. For every language, the creation process might look something like this:  Looking at an [old post on StackOverflow](https://stackoverflow.com/questions/743442/implementing-features-vs-bug-fixing), it seems many developers spend much more time bug-fixing than writing new features. Therefore, it's going to take a *long* time to even get one feature implemented, let alone one language, let alone 806 languages. Yes, I may be exaggerating slightly, and you can just hire a lot of developers, but the time and the money going into the Σ∞ project are going to be significant. --- ## Reason 3: Filesize A simple one, and one more easily overcome than the previous two but still worth mentioning. The C redistributable and runtime take up 37MB, compressed, on my computer. That's about 45MB uncompressed. Assuming that C is a representative language in terms of filesize, that gives us 38700MB or 38.7GB as the total size of Σ∞. That's slightly less than I was expecting, and certainly not a lot in terms of storage requirements. However, Internet connections need to develop significantly before downloading such a file - users don't want to wait too long for installers to download a single file, especially if there are more files to download for the program. As I said, this problem is much easier to deal with: we're talking the future so you can probably assume better internet connections. Just a point worth mentioning. --- ## Reason 4: Typing and Compilers This has been covered in other answers, so I'll just go over it quickly: depending on the language's purpose and level within computing, the compilation and runtime processes differ significantly. JavaScript, for example, is *interpreted*, *at runtime*. The browser's code translates JS into runnable code just before it's run. Additionally, JavaScript is weakly typed - you don't have to declare that this variable is an integer and this is a string, you just say `var`. C#, by comparison, is a *strongly typed*, *precompiled* language. You *do* have to say that this is an integer and this is a string, and your code won't compile if you don't. (OK, there's `var` in C# too, but it still gets typed at compile-time.) Additionally, you have to run your code through a compiler, which turns it into an executable that you can run. Merging the two types of languages would be rather difficult, if not impossible. --- ## Finally... I conclude, therefore, that there are too many programming languages, and too many different *types* of programming languages, for the Σ∞ project to be feasible - let alone practical. [Answer] Hopefully not. Programming languages should never be governed by the laws that let natural languages converge. Now we do have C++ which is the English of programming languages, indiscriminately borrowing stuff from other dissimilar languages at various points of its history (probably the worst idea in its history having been the syntactic dump of Ada generics into template syntax). C++ can no longer be sensibly described by syntax diagrams and no longer sensibly be parsed by parsers of a reasonably regular class. Its standards waver back and forth across semantics every few years, and just now variable-dimensioned arrays, which would be required to implement generally useful numerics libraries competitive with 50-year old FORTRAN libraries, have been kicked out again. Sort of like getting rid of plural "ye" in English. Now compare to a language like "Lua": syntax fitting on a single page in the reference manual (which is A5 size paper, about half Legal), a single data structure, few scalar data types, OOP programming techniques are implemented per protocol rather than by syntax and so on. Merging it with C++ in any manner would make no sense. Now somewhat interestingly there *is* a convergence of computer languages at the target level: there are no dedicated Lisp machines like Symbolics any more, and current architectures favor stack addressing with a shared return and data stack, a common program and data address space, with a function call/return (rather than stack switching/coroutines) paradigm for organizing control flow and a heap only working with data rather than function call/return (like you need for full Scheme continuations). This leads to various programming languages having different performance characteristics and consequently different choices of programming language depending on the required level of matching the programmers' or the computers' thinking. So you get to the situation where "high-level languages" are often implemented in a low-level language (Lua in C, for example) rather than themselves in order to get a system that both computer and programmer can get along with without too much pain. This fundamental split shows no sign of going away. Virtual machines shift the compromises around a bit and put in another level of layering but don't really change that. [Answer] There are a lot of good answers given here, generally taking the *no* view. I'm going to say *yes*, because we will eventually create software which is intelligent enough to write code much better than humans are able to write code. Some time after this event human programmers will become obsolete. By a well known argument, this machine will repeated rewrite its own code, increasing its intelligence with each iteration. Assuming there is a limit to machine intelligence, it will rapidly converge onto this level of intelligence and the language it uses will similarly converge onto an ideal. [Answer] Could there be a single programming language in the future? Certainly, but let's take a look at why we have so many today. There's currently a [horde of languages](http://en.wikipedia.org/wiki/List_of_programming_languages) that are or have been used, but that list doesn't really demonstrate why we have different languages today, so let's use this [list of languages by type](http://en.wikipedia.org/wiki/List_of_programming_languages_by_type) instead. Scripting languages like *bash* and *ksh* are good for simple, procedural tasks that have to be done over and over again, but these don't provide all the functionality needed of large applications. They're more support structures. Compiled languages like *C++* and *Python* both have great strengths. The former has support for fine memory control and resource management. Python is intended to be easy to read and the source code short, certainly much shorter than C++. These two languages also operate at different levels: C++ is a [low-level language](http://en.wikipedia.org/wiki/Low-level_programming_language) (the source code looks like the system instructions) and Python is a [high-level language](http://en.wikipedia.org/wiki/High-level_programming_language) (the source code looks like spoken language). There's also *Prolog*, a fun language that functions like a database language with rules and queries. Prolog is based on logic rather than procedures, as bash and C++ are. As a result, it's good at mimicking intelligence (AI systems) and not so great at manipulating registers in memory. Each of these languages has its own syntax and parsing rules. Someone who understands C++ can usually get a pretty good idea of Python code does by looking at it, but bash and Prolog are so different as to be unreadable from one to the other. But syntax doesn't really impact what's supported in a language. The [working draft for the 2014 C++ standards](http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4296.pdf) is more than 1,300 pages long. It's definitely not a simple language. Unless there's a major breakthrough in language construction and application, I expect programming languages to remain as separate structures to focus on specific activities. We might see a smaller pool of languages used, but I don't expect that number to ever reach one. [Answer] It could converge into one language, but it would be very diverse. Metaprogramming is where your code interacts with the code itself. You could have one programming language, but different use areas would use it very differently, perhaps even incompatibly. In the end, the language would be very advanced. Interestingly, LISP, one of the oldest languages, is probably the most likely to do this. In LISP, the source code itself is also the most common data structure, a list. A LISP could potentially have different "sub-languages", which would have different parts of LISP. This is sort of like Haskell's Monads. Haskell is another interesting case to consider. It is very mathematical in nature, so compilers can mathematically manipulate it to make programs faster. Also, it has Monads and DSLs, which are basically programmable sub-languages. You can program your GPU in haskell, (namely, the haskell program makes the program for running programs on your GPU.) It should be noted that although they exist, both Lisp and Haskell on some what obscure. They are on the rise though, so in the future, we could imagine we have some sort of super language, in you which basically make the program program itself. This would allow a lot of different use cases. It should be noted that this one language would look like a lot of separate ones mushed together from a distant, even though its core could be one simple base language. A library would basically be a language. [Answer] As much reason as believing that human languages will converge. A long time ago people forecast a rapid convergence of human languages, Yet this is yet to occur. Programming languages have an aditional feature that are not present in human languages, they are **invented languages** by nature (in contrast with Esperanto and other invented human languages that are an exception, not the rule). This means that while human languages might converge due to natural evolution and the increase in communication provided by technology, something that might cause the creation of an universal language in the future, spoken by the absolute majority of the global population, and even if computer languages are subject to the same principles of convergence, we have the added factor that new computer languages are created every day. Some new languages, might achieve hegemony on a certain niche and later expand towards becoming a general porpuse language. We cannot rule this out. So, i believe that computer languages will always be an heterogeneous field. Even older computer languages that are considered obsolete (I am myself a Pascal programmer), can receive a new treatment and become modern. Pascal faces a lot of prejudice from people who know it only from texts like Kerrighan "Why Pascal is not my favorite language", yet, modern pascal is much more advanced than C language, with a complete set of object oriented aditions, and none of the things that Kerrighan criticized in that popular essay. So, i believe that languages will not be lumped together into a single universal language, but, keep being modernized and accepting new things from other languages, just like our own human languages do. We do accept new terms from other languages when our own language is not able to express certain concepts or when our language lacks words for certain things. For one, when computers came to Brazil (I am brazilian) we "created" new words from their english counterparts, like, "to delete", which have a certain common root in latin, but was not used in modern portuguese. But, this wont make us use english words for ordinary things like traditional food or other common place items, because we have no reason to do so, that would be a futile use of effort to little gain. You might say that people should learn english to have better job prospects (like we usually think here) or to increase audience or something similar. But, in that case, people wont use english words in normal conversation. So, this causes people to have two languages, not to forget their mother tongue or adapt it needlessly. This makes me believe that human languages will never (just like computer languages) converge into a single entity. [Answer] What programming (or other!) languages *can't* do is just as important as what they *can* do. This already shows that there will always be something absolutely preventing one common language for everyone. For example, managed memory language programmers are quite happy to avoid having to deal with explicit memory allocation and deallocation - it means you can have more focus on things we *can't* automate yet (even in part). Lawyer-speak is very good when you're trying to be as specific as possible and with little possibilities for alternate interpretation. Languages (again, programming or otherwise) are just tools. You choose the best tool for the job - sometimes it's a wrench, sometimes it's a jackhammer. Now, you can obviously create a language that allows *and* disallows everything, for example based on some predetermined constructs or even compiler directives. For example, when I've been working on my C# OS, I actually had C# code that compiled into assembly-equivalents, something like: ``` registers.AX = memory.Indirect(variable1.Address); // Translated into mov ax, [EBP-20h] ``` (just pseudo-code, the actual code was a bit different - but it should illustrate the idea) This actually allowed me to write *all* the code in C#, including the bootloader and device drivers. The question is, does the fact that it's written in C# mean it's still just a single language called C#? I'd argue **no**. In fact, a significant portion of the usual work of a programmer is creating his own languages. Not languages like C# or LISP, mind you - but rather, domain-specific languages to handle particular problems well, and nothing else. While those are always implemented in another particular language, they are a language of their own, a subset - just like English-lawyer-speak is a subset of Common-English. Some languages lend themselves extremely well to such sub-languages - LISP/ML (and their derivates, like F# or Scala) being the prime example, of course. The interesting thing is that it's the strict languages that are the most useful for creating such sub-languages - whether the sub-languages are supposed to be strict or not. So is there ever going to be one super language? Sure, why not. There's already plenty of candidates that got quite close - x86 was for a time almost universal, the original C had the target goal of being compilable anywhere (a lot of compilers still just produce code to be compiled for some C compiler). Or modern JVM-bytecode or IL. But that's about the level where I'd expect it to appear - intermediate. The end-user (-developer) level will be a nice little ecosystem of various languages well suited for their job - nothing less, nothing more. Unless of course you're planning for a dystopia where Apple-the-world-haegemon forces everyone to use Objective-C or something. Remember, it takes work to keep things simple - disorder arises quite naturally. There will always be disorder and disagreement, and they will both fuel plurality. *Reducing* complexity is the hard part. [Answer] No, there is not. It might be more easy to mix languages, but such languages are very formal and will not be blending on the conceptual framework level. Perl comes close to being a natural language creole, but only among similar "types" of languages. You can't just mix in something that is built around more primitive memory manipulation, or toss in something that is purely functional. The general syntax style also can have variations but you can't toss in construct with a totally different kind of syntax. [Answer] Probably not. As you have (correctly) stated there are many programming languages. Like speaking (natural) languages, they often borrow from each other. Unlike natural languages however, programming languages are guided by intelligent designers, aka programmers, who have their own (conflicting) ideas on 'whats best'. As JDługosz points out, programming languages are always very formal. In a natural language, changes in speech patterns and pronunciation in an isolated group of people can result in different variants (US vs British English is a mild example). Not so in programming languages, a program is either in-spec or not. Changing the spec doesn't just happen, the compiler/interpreter writers must agree to a change that could break hundreds of programs that depend on particular behavior. If anything, programming languages are actually *diverging* because compiler/interpreter writers don't bother to stick to the language spec (see [regex](https://en.wikipedia.org/wiki/Regular_expression#Standards), there are: Perl, POSIX, emacs, vim, etc). I also find it unlikely that programmers, generally being humans, will be able to agree on one single, all encompasing language. New ideas will always be integrated to keep languages modern, ideas are shared, but i find it unlikely that all programming languages will converge. [Answer] As compilers get increasing memory and cpu processing power, they can cope with being able to grab more and more source code languages. For example, gcc can usually compile-as ansi-c or c## as required, and can also compile as fortran F77 or a less old variant. What I'd expect is that human readable source code continues to append arbitrary user preferences and company preferences to known standards, and at times those may be unreadable to anyone else, but truly optimal executable machine code on a truly arbitrary RISC processor probably will converge as much as possible. One day source code might have been abstracted behind high level instructions so much that it might be possible to stand in front of your MakeAnythingBot and say "Computer, design and make a space programme, a monetary system, an agricultural production system, all necessary materials supplies, and an improved MakeAnyThingBot", and it will. Should that happen, we are in big trouble, I think. [Answer] **tldr** I believe programming languages are going to converge simply because there are too many ways for it to happen. Let's hit some of the highlights of the (somewhat) short history of programming. * Switches * Punch cards * Assembly language * Interpreted/scripting languages * High level languages * Object oriented languages * "Managed" languages In only 70-ish years we have moved from switches and cranks to incredibly efficient compilers with both syntax and semantic checking. In one or two hundred years from now I can't even imagine how we will be programming (if we even are) but I will venture some guesses. Most of the answers here are making an implicit assumption for continued use of the Von Neumann architecture that is for all practical purposes the only architecture that currently exists. But to discount a different architecture, especially when optical or quantum computers come into being, is short sighted. All the "reasons" given that a single language is untenable simply highlight the disadvantages of our current computing architecture. They do not address any future progress in this area. To say that in 100 years we will still be using a Von Neumann architecture is highly speculative. So how can we get to one language? We were actually on track for Java to become our 'one' language when the 'java chip' was being developed. It understood Java byte-code natively - there would be no need to have any but one language if every computer used the 'java chip'. And for web programming we could have used a subset of the language to work within browsers. There is nothing that (technically) prevents us from using a single language now. We could have written browsers to use C or C++ and just redacted some of the commands from the language, like file access for example. If we change architectures then one language may be the inevitable and obvious choice. We may get to the point of simply speaking what we want the computer to do and it understands what we mean - natural language programming. The new computer 'language' will be whatever we program the computer programmer to use. And there's no reason to have 10 'high level' languages for it to choose from. And what about neural implants? Perhaps we will just 'think' what we want to do. And perhaps in the future we won't even program at all. An artificial Intelligence will simply build machines, grow food and cater to our every need like in the animated movie WALL-E. Hopefully we won't just become sedentary like that and will instead be artists, musicians, etc. Planes were invented 112 years ago, rockets made it to orbit 30 years later, to the moon 20 years later, a man on the moon 17 years later (about the time C was invented) which was only 46 years ago. To Venus the next year and then Mars the next year. To say programming will be anything like it is now in 200 years or more defies history. Is this too far out there? For some people, yes. But technology is advancing so fast that to deny any of these scenarios out of hand is ignoring our potential as a species. [Answer] As many others pointed out, different programming languages have different fields of usage, so probably no. And I agree with that. But I want to add some other perspective. Computing is young. The first programming language was [Plankalkül](https://en.wikipedia.org/wiki/Plankalk%C3%BCl) from [Konrad Zuse](https://en.wikipedia.org/wiki/Konrad_Zuse) developed between 1942 and 1945. Thats 70 years ago. People from that time are still alive. But that were the early baby steps, computing reached no masses back then. It really kicked off later, so I would assume the first programming language with broad reach was [ALGOL](https://en.wikipedia.org/wiki/ALGOL), from 1958. That's a little more than 55 years ago. This language is out of [usage](https://stackoverflow.com/questions/tagged/algol?sort=newest&pageSize=50), no questions on Stack Overflow this year, only three last year; I think we can safely assume it's dead by now. So let's look a bit further. [COBOL](https://en.wikipedia.org/wiki/COBOL) was released 1959. [88 questions](https://stackoverflow.com/questions/tagged/cobol) this year already on Stack Overflow show that this language is still in usage. We talk about a language that a Dilbert-comic nearly 20 years ago already showed as fossil:  Even C is pretty old already, and it is one of the most popular languages around. So what's happening here? As I said, computing is pretty young. If a new language needs 5 years to get popular and stays popular for 5 years, and youngsters learn it when it's popular at say average 25 years and then work until they are 65 - then you can see that it brings at least 50 years of lifetime to a language that becomes popular. The only ones that died earlier are languages that never get popular to begin with. And this time is extended, if there is a big codebase to maintain in that language, that was created in the time the language was popular. This is one of the reasons C is still that much in usage and a reason why I think Java will be programmed even in eons from now. So, as computing is pretty young, we are still in a phase in which more languages are created than ones that fall out of usage. That probably will settle sometime, but I don't see reasons why the development of new languages will ever stop. So no, looking from a historical standpoint on the longetivity of languages, there will probably never be only one. [Answer] This question needs to be addressed in terms of limits, otherwise its just a programmers talking shop. Since the timescale of centuries was mentioned, looking at the limit case is valid. In the limit, all matter in the solar system has been converted to computronium by nanomachines and all that computronium is arrayed around the sun to harvest the maximum possible energy. At this far removed stage the underlying hardware architecture is probably quite homogenous - even today we see signs of convergence of hardware architecture - most specifically in terms of high speed serial communications (PCI 4.0, 100 GBE, USB3.0 - under the hood they are all very close in terms of electrical properties and link layer protocols whereas once they were quite diverse). People get fixated on computer science in terms of instruction sets and languages rather than what really matters - both today and in my far limit scenario which is the thermodynamic costs of moving data from A to B. Once the data has moved the cost and specifics of processing it is secondary. As processing power improves and as the distances data must move to be processed increases, information processing becomes mostly a thermodynamic accounting circumscribed by shannons laws and fundamental physics. As that reality progresses and becomes more apparent then the advantages that can be obtained by using this abstraction or that will diminish and the language wars will end and be supplanted by mathematics and maximally efficient version control protocols that allow meaningful semantic processing to occur even when the time it takes data to reach from A to B is very large compared to how fast the receiving entity could evolve, if it chose to. If all hardware architecture ends up the same, then the universal language is the language in which that hardware is programmed at the lowest level of programmability. Language abstractions built on top of that probably don't qualify as languages in the same way we would not think of scientific terminology recounted in the english language as being a distinct language from english itself. Finally, if the hardware (computronium) is itself reconfigurable (no doubt for a non trivial thermodynamic cost) then the concepts of software and hardware don't have a lot of meaning. In fact both would reduce to the same thermodynamic principles, although version control (which at this level can only try and keep genuinely irreversible processes separate from reversible ones) may have some independant role to play. Obviously this scenario is some way off but placing a storyline at some point on this trajectory is IMO a valid hard sci-fi approach. [Answer] Overall, no - for all the reasons specified, however it is likely we will develop a universal descriptor language for programs/features that is both understandable by humans and the dedicated expert systems which use them to write basic applications. See [Natural Language Processing](http://en.wikipedia.org/wiki/Natural_language_processing). For instance we could say "I would like an application that collects, archives and displays weather data for my region." The expert system would interpret this and write an effectively throw-away module that performs that function (with some insight into your personal GUI preferences through analysis of your profile or dynamically generated based on the style preferences of the terminal you're viewing the application on). Naturally the description of a game would be very lengthy and graphically challenging but by splitting the description into features and levels this could actually be accomplished. The descriptor language - whatever that might turn out to be would be structured to deal with those tasks. [Answer] There are plenty of reasons listed above that there will never be a One True Language. However, it is entirely within the realm of possibility that one create a mega-language which, at its core, is a bunch of DSLs. All the languages would have to use the same runtime or virtual machine, and there would have to be some sort of namespace standardization. Once you have that, you can have: * A plain imperative programming language for when you want to say, "Do *this*, then *this*, and then *this*" * A true Object-oriented language, for encapsulation and similar things * A functional programming language with no non-functional "leaks" (not so much as a print statement) so that you could guarantee the isolation of a piece of code * A relational language, maybe even a flavor of SQL, so that it could be a first-class language rather than a list of strings which can't be checked at compile-time * A declarative language similar to Make or Prolog * A first-class regular expression language, so you don't have to write code that looks like line noise * Proper parsers -- something like Lex and YACC which don't compile into C, but become first-class language constructs in their own right. * A software build system language -- something like Maven or Ant or such. It still wouldn't be the One True Language--something that big would probably need to be implemented in something simpler (C strikes again!). However, one could go far with that. Learning it wouldn't have to be much (if any) harder than learning one language today, because each language could afford to be incomplete. For example, no language except the Regular Expression language would have to have Regular Expression functionality. The declarative language wouldn't need to be able to run imperative code just to be useful. The imperative language can be simple, as it doesn't have to support every programming paradigm under the sun. [Answer] As a short answer, computer languages are written with syntax and semantics to solve problems. I am sure that, if the scope of problems computer programming is being asked to solve were to remain constant, we would find languages converging rather rapidly. However, finding anyone who thinks the scope of computer programming is remaining constant, or for that matter, anyone who thinks the scope of computer programming is doing anything besides an unbridled sprint into the future, that could be difficult. [Answer] Going by Microsoft's way, "Use your own language in .NET framework" theorem, it started with about 26 languages and is now about 146 languages and growing. And every one of them evolving with new hardware trends. Programming languages only matured not dropped. Going by Java way "Forget everything learn only Java". I'm not very sure on current status while Java has moved from Sun to Oracle/IBM,...and so on losing main objective of portability slowly. Unlike human languages, PC languages should evolve and new ones should be added. We had 'C/Fortran' based and 'Basic' based. Then Scheme based. So it is about the programmer which flavor he/she likes. My personal language of appeal is VB and it has always solved what I required. Most importantly on a long later period, the code is as good as normal English to read and understand and yet compiled into high efficiency binaries. Let new programming languages evolve so new methodologies can come up. Lets not restrict in the name of convergence please. ]

[Question] [ Let's say you wanted to preserve some electronics for 500 years or more in a museum. What could you do to preserve them in working order for hundreds of years? Deep freeze? Lead lined vaults? Vacuum? I've seen questions about how long electronics would last left unattended, but not how to proactively protect them for 500 years. Let's say this is a fully functioning world, not a post-apocalyptic world. Think of a museum in the future. [Answer] # TL;DR You cannot. You need purpose-built items, with specially designed components and maybe even *ad hoc* designs (PSUs without electrolytic capacitors, etc.), capable of withstanding extreme cold. Otherwise, there are several chemo-physical processes that would require to be halted. * Batteries: batteries will degrade over time, and be the first to go. You might want to store the specifications for the required voltage and just hook up a new battery whenever needed. * Static memories and hard disks: temperature, background radiation and charge loss are all enemies. You can cool down the apparatuses as far as possible, and shield them. Even so, they'll need to be reactivated and "refreshed" periodically. This is, on a longer timescale, what happens orders of magnitude times faster with DRAMs. Otherwise, the iPad won't boot up, because it no longer remembers *how*. * Solder joints. Most electronics being built today will *die* within fifty years at ambient temperature and pressure, due to the little-known fact that solder islands on circuit boards no longer contain lead or antimony, two poisonous metals that are nonetheless among the few cheap things that can prevent (rather, delay) the formation of metal whiskers. Nickel or gold-plated finishings aren't available on market electronics (some sailors might be familiar with the "brass fluff" growing out of cheap zinc-plated irons. On a much smaller scale, this is the same thing). * Condenser decay. This afflicts electrolytic capacitors, due to aluminum dioxide breakdown. Extreme cold will [delay this process](http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.823.6133&rep=rep1&type=pdf) as well as it delays whiskering, but only up to a point - and some components cannot take extreme cold. * Insulator decay. Several [rubbers and plastic](http://www.cwaller.de/didaktik_teil4/shashoua_2001.pdf) insulating compounds are mixed with volatile plasticizers, where "volatile" means that they won't evaporate or significantly run off in fifty or sixty years... but the risk is there and I wouldn't bet on their seeing their hundredth birthday. * [Semiconductor decay and electromigration](https://spectrum.ieee.org/semiconductors/processors/transistor-aging). This is much faster when devices are powered and junctions are flooded by current, but still goes on when the devices are unpowered. It is slowed by cold. * Humidity will lead to galvanic corrosion. This is the easiest to prevent (use a nonreacting, dry storage atmosphere - nitrogen, or argon). Most components **aren't engineered** to last at all, because the manufacturers know that the items will be replaced anyway inside, at most, of ten years. Just like ol' Henry Ford, who [was said](https://www.snopes.com/fact-check/meaner-than-a-junkyard-god/) to send forensic teams in junkyards to tell him which parts of his cars had *not* failed so that he could start manufacturing them with cheaper tolerances. Only, this "controlled obsolescence" makes good business sense, and is actually done. [Answer] The five major things that can degrade electronics are electromagnetism, corrosion, excessive temperatures, vibration, and impact. Electromagnetism is your number-one risk. It only takes a static shock with 1/2 the current it requires to make a visible spark to damage data; also, background EM radiation can degrade data slowly over time. Forensics investigators will often mitigate this risk by putting evidence into a static resistant evidence bag, which can then be placed in a Faraday bag essentially blocking out all external EM influence. The second risk is corrosion. For a device that you are not regularly handling, the only major outside corrosive agents you need to worry about are humidity, and to a much smaller extent, oxygen. An air-tight evidence bag also works well for protecting against these; however, an off-the-shelf evidence bag may not be rated for 500 years. You would likely need to consult with a polymers expert to design such a container. * Batteries (as other answers have pointed out) introduce corrosive elements from within; so, they will need their fuel sources removed and/or be stored separately. Then the fuel would need to be reintroduced prior to use. * Galvanic corrosion has also been suggested as a risk, but in an electromagnetically inert environment, such as already described, this would not be a problem. * Zinc has also been cited as a problem because it is highly volatile. That said, the corrosion you normally see here in electronics only happens when it is exposed to water vapor and oxygen together; so, storing it in a dry/vacuum sealed or noble gas filled bag will stop this corrosion as well. * Completely preventing polymer decomposition may also need your storage area to be dark. Excessive heat and cold become the hardest part to control over a 500 year gap. You can not exactly rely on an air conditioning system to be maintained for that long, but if you were to store your device in an underground bunker at a depth of at least 30 feet, mother nature will keep your temperature more or less constant at a temperature that is ideal for most electronics. Vibration mostly just affects things with moving disk drives in them; so, for purposes of preservation, I'm assuming you are talking about stored and not actively used hardware; so, this should be a minimal issue. That said, if you are occasionally powering your device on, it is best to do so on a heavy well secured desk or shelf. Lighter desks/shelves can be vibrated by a computer's fans reducing a computer drive's expected life-time by up to 75%. Last is impact. If you are storing this device in a room full of engineers going about their daily businesses, eventually someone will knock it off the shelf and break it; so, storing it in a place with very limited human access is also pretty important. This makes keeping an electronic device from breaking within 500 years almost impossible for something that you need to use, but if you're talking about purely storage, you should be able to do this and the above four steps and have a pretty good success rate at storing electronics for that long. **In response to the first edit:** If you are talking about a museum scenario, the mostly likely case would be to copy the data onto a replica, and then put the replica on display. Museums rarely put items that fragile and rare on display. [Answer] Locate your museum on a rocket that is accelerated up to a significant fraction of the speed of light, so that time dilation means that the device you're preserving will only experience a small fraction of the 500 years you're preserving it over. [Answer] Breaking the device down on a part-by-part basis, and looking at what would be involved in preserving them: * Integrated circuits: as far as we know, an unpowered integrated circuit in a controlled environment will last indefinitely. * Resistors, solid-state capacitors, and other discrete components: these have the same indefinite lifespan as integrated circuits, and are generally more tolerant of temperature changes. * Batteries and electrolytic capacitors: These contain corrosive chemicals that tend to leak on a timescale of decades; lithium-ion batteries additionally tend to destroy themselves if fully discharged. If you're preserving an electronic device in a museum, you're going to need to remove these. When you want to power the device back up, you'll need to install replacements. * Circuit traces and wires: these tend to slowly corrode from atmospheric moisture. You'll want to store the device in a dry-nitrogen or argon atmosphere. * Plastic wire insulation: the plasticizer tends to evaporate on a timescale of decades. After a century or so, the insulation will be brittle and may be cracking from shrinkage. You'll want to re-insulate the wires or replace them before powering the device back up. * Plastic housings: these tend to discolor on a timescale of years to decades. The main cause of this is ultraviolet light, with atmospheric oxygen coming in second. A UV-protected container filled with the dry atmosphere you're using to protect the circuit traces will greatly slow the discoloration, but won't stop it entirely. * LCD screens: these are vulnerable to excessive heat or cold, and it's likely that UV light will degrade the dyes that give them the ability to display color. The same temperature and UV protection you're using to preserve other parts should be sufficient to protect them as well. * CRT screens: these depend on a vacuum inside the screen to function. Depending on the quality of manufacture, they may leak to the point of unusability over the course of 500 years or so. You may need to re-establish the vacuum before powering the device back up, which requires specialized equipment. * Flash/EEPROM memory: the data on these is susceptible to charge leakage on a timescale of decades to centuries. You can reduce the rate of data loss by cooling the device, but the need to avoid freezing the LCD means you can't cool far enough to get a 500-year lifespan. You're going to need to store the data on some more durable medium and re-write it before powering the device back up. * Hard drives: the lubrication on the bearings tends to stiffen up on a timescale of years. You'll need to clean and re-lubricate them before powering the device back up, and you'll need a cleanroom to do it in. There's no way to preserve an electronic device for 500 years in a way that permits immediate re-powering at any time. A museum would, however, be able to preserve one that only requires relatively minor maintenance before using, and the techniques involved are ones that museums commonly employ. [Answer] If powered down, electronics can last as long as they don't take physical harm, with the exception of batteries and the bearings in moving parts like fans or platter hard drives. Batteries, sad to say, can't be made to last that long -- or at least the kind that are useful for portable devices like tablets,. notebooks, and smart phones. There's a type of rechargeable battery that has been shown to last a century, and can likely last much longer than that -- the Edison iron battery -- but they have rather poor energy density. In English, that means a battery that can run a tablet for four or five hours continuously is closer in size to a car battery than the little lithium wafer cells our tablets have now. Nothing would keep those devices from working on external power, however, so it might be worth storing dry-charged lead-acid batteries, which *can* last indefinitely before filling with acid. [Answer] In all honesty, electronics are incredibly difficult to preserve, due to the very nature of their components. Particularly, batteries have a defined shelf life, even when unused. Capacitors and resistors (key components in most electronics) also have a limited lifespan, though they may degrade much more slowly if not in use. Storage media (such as flash memory or hard disks) have a limited life cycle related to the number of read/write operations performed. To have the electronics active, even just displaying a static screen, would likely severely limit the lifespan of any electronic device. The solution for museum displays would necessarily be restoration/periodic repair. There would have to exist a manufacturing process to produce replacement parts for the duration of the displays existence in the museum. [Answer] Preserving electronics for 500 years in working order dictates that they not be used at all in that 500 years. Copper, in particular, gets brittle as current passes through it and it heats up, and the copper traces in circuit boards even more so. The resistance of the copper joints also [goes up](https://app.aws.org/wj/supplement/WJ_1983_10_s290.pdf). [Electromigration](https://books.google.ca/books?id=zS9KAAAAQBAJ&pg=PR5&dq=electromigration&hl=en&sa=X&ved=0ahUKEwj329v0_47hAhUDWqwKHaOcBugQ6AEISTAG#v=onepage&q=electromigration&f=false) is also a problem. Unfortunately, the only way you will know if they still work is to turn them on, but every time you turn them on, you increase the chances that next time they will not work. [Answer] **Maybe you can?** LSemi gives a good list of the problems, but may be too pessimistic with "you can't". Most of the problems can be arrested by cooling the device down close to absolute zero. In physics jargon, the decay processes are thermally activated. The question is whether you can get an electronic device down to that temperature without causing irreparable damage while cooling it or thawing it (exactly the same problem as with cryo-sleep for people in sublight starships). Electronics is generally tougher than biology. The obvious exception is data stored as packets of electrons in flash memory and similar. It relies on regularly being powered up so it can check for and repair any bit-rot while powered down. Charge will not leak away because of thermal effects close to absolute zero, but is still subject to corruption by radiation such as cosmic rays. This will accumulate with time, and reach a point where the data is irretrievably corrupted after thawing it out. Some electrolytic capacitors contain a water-based electrolyte paste. If this expands as it freezes, the capacitor will be destroyed. Most quality motherboards these days advertise solid capacitors, which may be more freezable. The big capacitors in power supplies aren't of this type, though. Electrolytes in batteries, similar questions. I'd guess that you can cryo-freeze and thaw motherboards, processors, SSDs and probably displays and hard drives (they can go well below freezing point without being destroyed, look at the minimum storage temperatures specified for military grade HDs). Petroleum lubricants do not expand on freezing. About liquid crystals in displays, I would hope that a thin film of liquid in a somewhat flexible container (poke your screen!) would freeze OK. Freeze-thaw cycles will tend to cause soldered joints to fail, but here we are talking just about one big freeze and one thaw. The frequent heating and cooling of a computer turned on and off daily is probably more damaging. A museum might well buy several of each item it wanted to preserve. One for display, which would become non-functional within decades. Others, for cryo-preservation, so at least one of each component has a good chance of survival. Power supplies and batteries have a simple specification (voltages and currents required, ATX or similar power button logic), so as long as technological civilisation persists, the simplest preservation answer is to reconstruct a power supply at the time one wanted to thaw and power up the preserved technology. If civilisation fails, so does cryo-preservation. BTW This sounds like a fun bit of research for anyone with access to a very low temperature freezer or lots of liquid nitrogen. [Answer] As @Dave says, it makes sense for archival purposes to separate the physical object from its functionality. Original manuscripts of Shakespeare plays still exist in libraries, but they are extremely fragile and essentially useless for their original purpose – if an actor tried to keep a dogeared copy rolled up in his doublet, it’d be reduced to dust before the first rehearsal. But the *text* of those plays is preserved perfectly, and a modern copy works just the same. An iPad is similar. If you took out the battery and any large capacitors, you’d have a perfect record of what it was physically like to hold one, but to know how it *worked,* you’d be much better off with a copy of the source code. Bear in mind, the electronics will also exist in a purely digital form (the Verilog / VHDL / etc used to design the components and PCBs), which is, if anything, a more faithful record of how it’s supposed to work than the actual manufactured article. You might say that a simulation isn’t “the real experience”, but everything in a museum is divorced from its original context anyway – if you had a working iPhone 500 years from now, you still wouldn’t get the authentic experience unless you simulated a 4G network, and Twitter and Facebook, and all their living users. The very act of preserving something in a museum changes it into something else. The same applies to preserving technology through a future dark age – a working iPad isn’t much use, but a description of how it works could be much more useful. [Answer] How about an alternative? Instead of storing the physical device, store the designs of the device and all of its components. When you need a working item, you manufacture it. This is actually possible, though it isn't easy. There are three substantial challenges to it. 1. While all you are storing is data, storing data for long periods does have its challenges. The basic procedure of making copies frequently should work just fine. 2. Making electronic gadgets today involves a number of large, expensive factories. Making them in the future may be very expensive but it might be cheaper. And, it may be possible to create something with the same electrical or logical properties with newer techniques. 3. Gathering the data you want to store is much more difficult than simply getting your hands on the gadget. You would have to convince all of the manufacturers involved to part with information that they think is extremely valuable. So, it may not be *practical*, but at least it isn't *impossible*. [Answer] I think the thing to do would be to separate the software and electronic function from the mechanical interaction. That is, you could have museum visitors hold and play with dead or dummy iPads that do not turn on, and separately interact with a virtual machine on a touch screen if they wanted to "use" it. This is more or less done today as I've seen multiple websites running vintage operating systems where you can relive the joys of Windows 95 or 3.1. [Answer] **Virtual Reality** In addition to the (well-written) Answer "you cannot": If it is not possible to stay the hardware in usable order for this time, you could try to save the software and write emulators for the hardware. You could present the (non-working) hardware in the museum and have some modern computers with emulators for the old software. You will have to update the emulator park from time to time and maybe you need an emulator to get the 2400er software running, on that one for the 2300er software and so on, until you get your 1983 IBM PC Software running on the mega-quantum-computer-mainframe from 2495. Now add Virtual reality to this. You will not simply use an emulator, but a VR simulation. In this case it would be best to update all software to the most modern VR simulation system (as automatic as possible). If you do like this, you have no problems with degrading Hardware, but you still have to keep all VRs up-to-date. And you have to have a VR model of your 1983 IBM PC to run your IBM PC software. [Answer] What everyone else says about certain components breaking down is correct as far as I know. That said instead of using a neutral gas you might consider submerging the device to be stored in oil. Pick your oil that does not hurt the plastic. Right now some devices are built to be used with the circuit boards submerged in mineral oil even while the device is being used. For what you are doing oil would have the advantage over a neutral gas in that an oil bath will help limit any damage caused by components leaking. The main down check is that you would have a bit of work to clean up an Ipad to use it, but that would be true no mater how you stored it. [Answer] I believe all the "No you can't" answers are simply not taking into account the question you are asking--what can be done to preserve them. They all mention easily preventable things like corrosion and batteries. (With the notation that if you won't be able to preserve the batteries, but that shouldn't be an issue in a museum environment) Here's how you preserve an iPad for the future: 1. Start with a brand new iPad--no pre-existing wear, tear or corrosion 2. Take the batteries out and throw them away. We will have better batteries later. 3. Discharge any capacitors. 4. Place it in a display case with 1. UV & electromagnetic protection 2. All the oxygen replaced with some inert gas. 3. No humidity (Might come free with #2 if you do a good enough job) 5. I'd recommend preserving 3 of them this way just in case With these precautions taken, I am certain that you would have at least 1 and probably 3 working iPads at the end of 500 years--and once re-powered they would likely work for years. I don't think the low temp stuff is required or useful... it's oxygen that decays everything, remove that and even a slice of meat will just sit there for years and not decay. ]

[Question] [ Or, phrased another way, how thick would the blade behind the cutting edge need to be in order to cause significant and lasting damage to a human body? My question can be considered an expansion of [this question](https://worldbuilding.stackexchange.com/questions/19249/what-is-the-amputationility-of-a-monomolecular-wire-weapon), but dealing more with the effects of the wound. I don't question the monowire's ability to cut, only whether the cut would be meaningful. A true monomolecular blade might be so thin that it could pass through the interstitial spaces between many cells. My guess is that this sort of damage would be repaired almost immediately by natural processes, with any actual gaps caused by cell destruction filled in by replacements. Severed molecular bonds should reattach even more quickly due to Van der Waals interactions. I doubt there would even be enough of a wound for a drop of blood to leak out. Am I wrong? If not, how thick would the part of the weapon behind the blade need to be to create enough separation between intact body tissues that the wound would be visible and large enough to cause severe bleeding or amputation? And at that point, would there be any difference between an exotic monowire blade and a very sharp conventional sword? [Answer] Leaving biology entirely aside, it depends how much resistance the blade faces. If it faces no resistance at all, which is sometimes how monomolecular weapons are portrayed, then that's because (by whatever means) it's not interacting at all with the body, so how can it do any damage? This is more of a "neutrino blade" than a monomolecular blade, so it's not very realistic, but it illustrates an extreme end of the scale. So, let's say the blade meets some resistance. This means it's moving stuff around. We're probably assuming that it's sharp enough to "cut through anything" -- the resistance won't bounce it back or snag it -- otherwise it's a rubbish weapon because "weighs nothing" and "bounces off" are the weapon characteristics of a feather. When it cuts, it takes adjacent molecules in the proteins it meets, and makes them not-adjacent any more. Proteins won't survive that. Yes, in principle, if both sides of a molecule were held exactly in place the chemical bonds would reform, but both sides *aren't* held in place, (most of) the body is not so rigid at the cellular level. We can take the loss of a few protein molecules, there's plenty more about. So at this point we need to bring some biology in: how not-adjacent, and will the cells survive it? I'm not entirely sure but I very much suspect that they will not. An ovum of course can be punctured with a needle and survive, but a point entry is not the same as being cloven across an entire plane. Supposing that in just one smallish region of the cell, the two "sides" move relative to one another by just the thickness of the cell wall, then *clearly* it can't just join back up again once the blade is out of the way. IIRC cell walls are often under tension, so if it doesn't join up that means it completely comes apart. The further these little bits of cell move, the more resistance the blade faces, but "cuts through anything" means that almost all the work it does is going into separating micro-structures, very little of it is going into moving larger-scale components that can survive being rearranged. That is to say, it *could* fit into inter-cellular spaces, but it *won't* do that, because it's so sharp it will cleave through a cell, not push it out of the way. However much oomph the wielder puts into it, that work is translated directly into micro-damage on a plane through the target's body. As such, I think to a close approximation we can say the blade kills every cell it touches. Furthermore, anything under tension (muscle fibres, ligaments, tendons, downward-hanging appendages such as arms, blood vessel walls, the diaphragm) is cloven for the period of time it takes the blade to pass. Assuming we're talking a monomolecular *blade*, not a monomolecular *filament*, this is a substantial time in molecular terms, the width of the blade (let us say 1cm) divided by the speed it's moving (a few m/s depending on the wielder's choice). So perhaps more than a millisecond. How far do the "sides" move apart in that time under their tension, never mind any work done by the blade in moving them? The structure cannot re-form provided it moves enough to bring it out of range of the molecular forces holding it together. Which is really not very far at all to move in a whole millisecond. For stuff under compression, and supposing the cut is not *perfectly* perpendicular to the direction of compression, then there's a shearing force applied by the source of compression (basically, the weight of the target) during the time the blade passes. Similar result to a lesser extent: things slide down slopes, and they don't have to slide far to get everything out of alignment. This blade with width would also need low friction on the sides of course, otherwise there's a lot of resistance slowing it down without cutting anything, and you end up with it embarrassingly stuck. Worst case scenario, you have to twist it and pull it back out the way it went in, like some kind of medieval peasant! So, a blade with width can be as thin as you like, the body's internal forces will do the job of ripping everything apart. A filament perhaps needs a bit more thickness: enough to move everything out of van der Waal's range would be plenty because that means *every* structure it meets is *definitely* disrupted. Of course you can kill with a less thorough job than that, and the thickness of the filament is just a lower bound on the distance it separates the things it passes through: actually it'll move molecules further than that within a random range according to the kinetics of the collision. Finally, "monomolecular" covers a range. In some sense a flawless diamond is a monomolecular bludgeon. It's plenty monomolecular, it just isn't sharp. Your monomolecular blade isn't *necessarily* the thickness of, say a molecule of polythene consisting of a carbon chain with hydrogen hanging off it. It might of comparable thickness to the cutting edge of an extremely sharp metal blade, and still "act sharper" if it's stronger and harder than steel, and if the whole blade is that thin, not just the cutting edge. This is more than big enough to totally separate any cells or other biological structures it encounters, beyond any hope of them chemically re-bonding even at van der Waals range, at any speed. So a monomolecular blade is extremely destructive, *but* the work to do that destruction does still have to be put in by the wielder because it manifests as resistance to the blade's motion through the target. It might not be quite the simple matter of slicing someone's torso in half with a flick of the wrist, that we sometimes see in fiction. Depending on the characteristics of the blade you may still have to put your back, or at least your arm, into the swing. Absolute minimum, put in enough energy to overcome the chemical bonding energy of the damage you do, otherwise the blade comes to a halt in the target. [Answer] > > Severed molecular bonds should reattach even more quickly due to Van der Waals interactions. I doubt there would even be enough of a wound for a drop of blood to leak out. > Am I wrong? > > > I think you may be partly wrong. Your scenario holds if there is no transversal force in the area being cut, for very slow cuts and specific parts of the body. In general, I fear it wouldn't work. Where I live, we sometimes cut either butter using a very thin metal wire, or we cut [polenta](https://en.wikipedia.org/wiki/Polenta) using a string. In both cases, if the substance is soft enough\*, and the wire goes slow enough, you'll see that the "wound" closes immediately after the wire has gone by. At that point, what you do (for butter, e.g.) is to exert a torsion on the butter bar, so that the cut opens wider the farther the wire goes through. In the human body, most cells are subjected to a smaller or greater pressure, so that cutting e.g. through a vein or, even more, an artery would result in the wound opening. Same goes for the bones. Some kind of wounds could *perhaps* self-heal where the force is only compressive, re-binding the tissues together, but I feel this to be unlikely, because cells are held together by [specialized structures](https://en.wikipedia.org/wiki/Desmosome) and cutting through at random will not allow those to un-bind and re-bind quickly enough. (\*) there are small religious wars on the proper softness of polenta [Answer] There's a reason that monomolecular blades are the stuff of science fiction: we know of no way to forge a molecule strong enough to function as a blade. The strongest molecules we could make, or even imagine how to make, would bend or break upon impact with a macroscopic body. In **Ringworld**, by Larry Niven, the monomelucular blades are surrounded by a stasis field to give them the strength they need. I'm assuming you mean something like this. Such a blade would be lethal, for several reasons. 1. If you have a tissue under tension, even the tiniest cut will cause the tissue to separate. If you cut through any muscles under tension, they would separate and not reform. The blood vessels in the muscles would not reconnect and internal bleeding would be a serious problem. 2. A human cell is about 10,000 times smaller in diameter than a human torso, and coincidentally also about 10,000 times larger than the width of a molecule ([Wikipedia](https://en.wikibooks.org/wiki/Cell_Biology/Introduction/Cell_size)). The tiny molecule would slice right through each of the 100 million cells it would encounter. Even if you posited that the cell walls could recover from such injury (which I highly doubt), about 1/3 of those cells would have their nuclei ruptured. 3. Blood clotting is triggered based on chemicals normally only found inside cells. When a cell is ruptured, its contents spill out and clotting starts. Dumping that much cell detrius into the blood stream would lead to massive clotting. 4. As others have pointed out, severed nerve dendrites do not heal. Slicing through someone with a monomolecular blade might not leave a visible wound, but it would create a layer of dead cells that would likely prove fatal (or cause a limb to fall off, at least). [Answer] For the purposes of this question I'm going to assume the monomolecular blade is about 1-2 water molecules across. Much smaller than that and quantum forces start to dominate and I'm not a quantum physicist, I'm a biologist. Anyway. Such a blade behaves very strangely, and how much damage it does depends a lot on the kinetics of what you're doing with the target. A leg holding a person up, for instance, will be nearly completely unaffected. It might hurt, but not much and not for long. Cell membranes are, on the microscale, self-healing. They're built of phospholipids that self-assemble into two-sided layers, and if disrupted they reassemble very quickly. Nerves are essentially long tubes made of cell membrane, and the opening in the membrane created by the blade's passage is not wide enough or long-lasting enough to damage the neuron. The membranes will therefore mostly be fine, and any damage is small enough to be repaired by the body. DNA deserves a quick look, but essentially any nucleus that the blade passes through will have its DNA shredded into hundreds or thousands of pieces, and even organisms capable of reassembling double-stranded breaks are bound to get it wrong at least once. Catastrophic DNA damage, and cell death follows. However, the slice of cells this actually happens to is pretty small, and cell death from DNA damage takes a few minutes minimum, so this isn't fatal or even particularly wounding. Bones are a bit weird, but on that scale ossified cartilage(bone) is more like a sponge than a continuous material. See [here](http://hansmalab.physics.ucsb.edu/afmbone.html) for pictures. The space between the pores is filled with cartilage and other goopy things, but if the bone is under compression the spiky bits of sponge will jam into the holes on the other side and hold together enough to heal properly. If the bone was under tension it depends on the forces involved. Proteins are a different question entirely. Muscles are essentially extremely long proteins overlapping in a staggered configuration, and are nearly always under some amount of tension. The blade would cut these protein assemblages and they'd recoil, leaving a gap between muscle proteins. Laminins and the proteins that give structural strength to skin and connective tissue would also be cut neatly. In terms of the bigger picture, the two bits of flesh would be structurally very weakly connected for the first . Two perfectly smooth surfaces stuck together with a sticky semifluid adhere fairly tightly, so even though the proteins are cut there's still some strength to the join. In a short period of time(seconds? less? The kinetics are complicated) the protein matrices that give strength to the tissue will recombine. Shortly after that blood clotting factors released by ruptured cells will glue together other damaged pieces of tissue. Note: the cells won't be ruptured by the blade, but more likely by the spring-loaded protein networks inside them suddenly moving. Recovery of full strength may take days in the case of cartilage but there are few structures in the human body that aren't under constant remodeling. If the body part is under strong forces at the time of the cut the two halves might peel apart before they can be knit back together, but the strength required is a question of strike speed, temperature, body viscosity, and some other unknowns. NB: 'strong forces' are experienced by the heart every time it beats, so whether you live or die may be a question of whether your heart was beating when you got slashed with the monofilament or not. [Answer] Monomolecular needle is a fact. it is used in Atomic Force Microscopy. Let's read what [scientist who uses it has to say](https://www.nist.gov/news-events/news/2010/11/afm-positioning-shining-light-needle-haystack): > > "You solve a couple of problems," says NIST physicist Thomas Perkins. "You solve the problem of finding the object you want to study, which is sort of a needle in a haystack problem. You solve the problem of not contaminating your tip. And, you solve the problem of not **crashing your tip into what you were looking for.** This prevents **damaging your tip** and, for soft biological targets, not damaging your sample." > > > Emphasis mine. This means, or at least strongly suggests, that monomolecular blade would rather be destroyed by crashing on a cell, than the other way around. [Answer] Let there be an infinitely thin cutting edge, that is, basically a line segment in 3d space. Let this edge consist of an electric field centered on the line and which diminishes rapidly with growing distance from the line, so that at distance r from the line it's essentially 0, with r->0. Well, atoms are mostly free space, so the edge would mostly pass through free space and do nothing. Sometimes it would pass through an electron and mess up it's impulse (jolt it in another direction, accelerate or decelerate it). Sometimes it would pass through a nucleus and either also apply a force on it, or cause it to disintegrate. The former would mess stuff up chemically (and no, this wouldn't just "reattach" or whatever you thought of your "bonds"), the latter would produce radiation. The weapon would glide through the body with very little resistance and would not *directly* influence biological structures at all. To approximate the extent of those effects (with the goal of then finding out what this would do to the macro structure) I need to know how often the cutting edge meets electrons and nuclei. Let the human body consist of water (close enough). Water is H\_2O so there are three nuclei per molecule and 18 electrons. Water weighs 18g/mol so 1/18 Mmol per cubic meter. Taking the third root squared of this gets us a surface density. Hmmm. But I'm not quite sure if it's the kind of surface density I want. Anyway, no, the wound likely **would never look anything like a cut. It would be a zone of radioactive decay and damaged molecules.** The molecules wouldn't be damaged in the sense of "cut in half" (although that may indirectly happen sometimes), but more like a (mostly interior) sunburn. If you added any kind of blade behind the edge (so far I was only looking at an edge with nothing behind it) then the chemical effect becomes a lot worse because now you aren't just bouncing against electrons, but the electrons also bounce against the side of your blade which is in the way of their paths (they did that before, but it was negligible, I think). This would increase the amount of affected electrons *tremendously*. Even a tiny blade (not any wider than the edge, but extending a tiny bit backwards behind it, say 1mm) would have that effect. This would mess up a whole layer of atoms at the very least. Probably it still wouldn't cut, but could create poison, make bones brittle at that point and stuff under tension much more likely to break. This goes to much into chemistry/biology for me to say. And if you add a decent amount of blade behind the edge, say 10cm, then it would start to become exactly like a traditional bladed weapon (just cutting through everything with hardly any resistance) and you get the biological effects some others already described. The other effects would still happen, but if you are already dead I guess they don't matter as much anymore. I should still do those quantitative calculations I begun in the middle, maybe later. [Answer] (First problem: How do you expect your muscles and tendons to stay in place during the passage of the blade? But let's forget about that.) You can cut a piece of metal in two parts, polish the planes *really good*, bring them together again, and they will fuse perfectly, at room temperature. Won't work with tissue and your special knife, because you will cut all kinds of covalent bonds and hydrogen bonds, which will momentarily interact with each other on each side of the blade, and not be the same when the other side comes into view again. It would take some hours for your body to repair all that local damage, in the meantime, you bleed to death. Same problem with the metal pieces above: If you don't use gold, or go in an inert atmosphere, the metal surface will oxidise momentarily, and it doesn't work. [Answer] I don't think so. I'm not sure that the notion of the wound rejoining instantly makes much sense, insofar as the idea seems to rely on the cut being under no significant physical stress, but what part of the body isn't under some stress? There's gravity of course, but also internal pressure and forces. Would blood pressure be enough to force the wound open wherever it intersects a blood vessel? Then you have internal bleeding, even if the rest of the wound closes rapidly. Would the blood pooling internally be enough to hold more of the wound open? Then there are the muscles, many of which are constantly moving without our conscious control. Cutting through any of these or anything connected to them, the force of the muscle contractions may be enough to hold the wound open. Some muscles are going to be contracted even when we're at rest to maintain our posture. Would those simply pull apart under their own tension? Another thing to consider is that many molecular structures in the body are very complex, and rely on having a very specific form to function properly. Even if these structures rejoin quickly, will they be rejoined in the proper form so that they continue to function? I'd also guess that you'd be left with a thin layer of damaged and dead cells - of course, cells die all the time, but generally not so many at once in such a high concentration. The body may have some trouble dealing with that, especially if there are other traumas resulting from the cut. I think the entire cut would be badly damaged, even if it did hold together. [Answer] No, it would pass *through* cells, not feel around for the boundry and deform the blade on a cell-sized length scale to only pass between them. Imagine a regular sized cord and a pile of bricks made of jelly. Would the strong cord be deflected by the soft objects? And if so, why would it make the cord reshape to go around the bump rather than pushing the unyeilding cell out of the way, opening up a large tear in the tissue? [Answer] Well, the most wide spread scenario in fiction excludes most of those scenarios mentioned here, an erratic path of the monomolecular blade and some force applied, far less than for a super sharp conventional blade but still easily enough to penetrate someone's body. And there is inevitably a lot of motion because it is not some kind of science experiment where sci fi methods are used to ensure the body does not move *at all* but rather some kind of combat situation/ trap so near instantly the cells are out of alignment and no longer touching. Also, of course the blade has the thickness of one molecule, not one atom and would not simply slide through the empty space between the electrons and nuclei of the atoms making up the person as it is obviously far too big for that and of course does not have remotely enough energy to split molecules apart, just to cut but between individual molecules while encountering far less resistance than super sharp conventional blades due to the sharpness of one molecule instead of the far greater number of the edge of a conventional blade. As material carbon seems likely (although I do not know how big carbon atoms are compared to e.g. the atoms making up Obsidian) because carbon nanotubes are quite strong and even if some kind of energy would be required to stabilize the blade it ought to be a good deal less than other atoms like e.g. Hydrogen (which is a gas anyway, kinda doubt that would cut anything). So basically, a monomolecura blade would leave *very* clean cuts that can heal faster than cuts from any conventional blade and re-attaching a lost limb, especially since this requires a sci fi setting where medical science is likely to be roughly equally advanced as material science would need to be for monomolecuar blades to exist, should be feasible with proper medical attention and happen fairly compared to current medical standards of e.g. re-attaching a lost finger. However, the damage is done and it cannot heal on its own and would behave largely the same as a wound from a very sharp conventional blade. PS: while details about the exact kinetic energy involved are of course nonexistent and unknowable since it's all speculative fiction anyway, it does make perfect sense that fairly little effort is required to cut through a person with a monomolecular blade because it encounters far less resistance than a regular blade, for regular blades the resistance encountered and thus the effort required when cutting through a person depends largely on the sharpness of the blade, hence the common joke of cutting someone up with a blunt spoon. [Answer] John Brunner used this in one of his back in the 70's or so, a monomolecular wire strung across a road. The vehicles were fine, because glass and metal welds itself back together, but muscles and tendons under strain sprung apart, with fatal consequences for the passengers involved. ]

[Question] [ Consider a world in which time travel has been made viable possibility. Initially, many are ecstatic at the new technology and the knowledge it will unlock. However, biologists and other scientists soon come forward to warn about time travel. The danger is bacteria. Due to our rapidly developing antibiotics, bacteria have evolved over time to combat our medicine. Were we to travel forward, we would likely contract a deadly mutation of a bacteria from the future and spread it to the present upon our return (thus killing everyone). Were we to travel backwards, we would bring our present evolved super-bacterias to the past, which would infect the then not-vaccinated population (thus killing everyone). How would we be able to enjoy the gift of time travel without wiping out humanity? [Answer] I don't think the premise of the question holds water. It seems to assume that pathogens have a single scalar "deadliness" score (like hit points in a game) which is higher for modern germs, such that *we* only survive because our drugs are correspondingly more potent. But that's not how it works. Suppose a time traveler brings a population of penicillin-restistant staphylococci with him to the distant past. Those bugs are a problem for us because they don't respond to the drugs we use to kill them. However, in the past (before 1928) there is no penicillin to be resistant against, so the fancy resistance genes the staphs invested so much in is a no-op! The resistant strain won't be any deadlier than old-style staphs for a patient who *doesn't* get antibiotics -- and it won't even have a selective advantage over the pasts's indigenous strains, because the thing they're better at simply doesn't exist in that environment. So there's not even a reason to expect that the resistance gene will have spread throughtout the population by the time penicillin *is* invented. As for germs **imported to now from the future**, it's mostly the same story. We're not really that heavily dependent on antibiotics as a society. About one in five of us carry *Staphylococcus aureus* on our skin and mucous membranes, and it's not thanks to antibiotics that we don't die from them most of the time -- just a plain old Mk. I immune system will do. In particular, if all our antibiotics stopped working overnight we'd still survive as a species just as well as we did in the 1800s -- which is, not too well by modern standards, but it's not as if everyone would suddenly keel over. We need antibiotics for most of us to live till 85, not for the species to survive. In particular, for your your hypothetical resistent-to-everything germ from the future to kill us all, it would need to spread through the general population of today -- *where antibiotics are still not widespread* in the usual case. You may get an antibiotic treatment from your GP if you happen to get sick, but most of the time you *don't* get sick, even tough you're not regularly dosing yourself with antibiotics. Future antibiotic-resistent bugs would find it no easier to spread in today's population than today's bugs do, because ordinary healthy people in our society have no artificial antibiotics in them anyway. Things may look a little bleaker if the future holds virulent germs that can survive disinfectants such as hydrogen peroxide, bleach or simple alcohols. But that would be a much harder trick for them to pull off than mere antibiotic resistance -- those small-molecule disinfectants are poisonous to pretty much everything, including ourselves, whereas the challenge of an antibiotic is that it has to be *selectively* toxic to bacteria but harmless to us. [Answer] Clean the time travelers and boil their clothes then keep them in isolation until the traveling back in time. This way they won't infect anybody. Though even if the time travelers don't wash away the bacteria and manage to kill the majority of humans, a small percentage will survive and adapt to it causing the virus to not exist at all in future, which creates a paradox. If the virus/bacteria was killed in the past by adapting people to it before it comes to existence, then humans would not have adapted to this ''non existing'' virus which means nobody will die in the past even if they get contaminated, and the bacteria and virus simply stops to exist. (This was just a theory about time paradoxes, technically a paradox could even just simply destroy the universe, but who really knows what happens when the laws of physics stop working to allow backward time traveling ...) For traveling forward in time you only need this, a simple and cheap hazard suit with an air filter mask to survive new viruses. Oh, and don't worry about paradoxes this time. An air filter mask costs about only 4 euro here which is like 6-7 dollars in the United States, while an entire suit costs about 9.08 dollars on Amazon. [](https://i.stack.imgur.com/xE3W7.jpg) ([image source](http://oliverfetscher.artstation.com/portfolio/character-design-982920aa-ea0b-4a96-b8c9-b08a574466b6)) [Answer] **For the past:** Wear a full-body suit + gas-mask combo, and add your own stuff to make it look badass (Hopefully you won't be taken as some sort of whacko), which will make people think you are some sort of God (or alien). **Then you can easily claim that getting to close to you will cause people to die** (as they cannot handle your 'mighty power'), and the other people will believe it. That takes care of problems on how to prevent *others* from getting infected. The gas-mask and full body suit prevents **you** from getting infected with diseases that you have not vaccinated yourself against. And it makes you look like a awesome god. Bonus: - If you wear something particularly [badass](https://www.google.co.in/search?q=badass%20masks&rlz=1C1NHXL_enIN697IN697&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjEh7m4jbTOAhUIS48KHeYiAtAQ_AUICCgB&biw=1024&bih=476), going back in time will convince others that you are a god (though what may look badass for us now, might be terrifying for others. Still, the others will worship you, and you will be safe for the time being). [Answer] Can't we consider that if we invent time travel in the future, then people travelling from future already came to the past? So if we try not to kill people from the past with bacteria, it didn't happened. But if we decide not to care, the past already had bacteria from future. It mean that if I go back in time (in 400 After J.C. for the example) with all my germs, I won't change anything to what already happen since I was in the past in our history (in year 400 After J.C. in that example). [Answer] The [Novikov self-consistency principle](https://en.wikipedia.org/wiki/Novikov_self-consistency_principle) states that any time travel is mathematically required to be self-consistent. That is to say, the traditional time paradox isn't possible. Consider drawing your situation to its ultimate conclusion. We travel back in time, taking supergerms with us, which kill everyone. Now, since everyone is dead--and since we traveled far enough into the past for the germs to kill everyone--we could never have been born. Traditionally, this is a time paradox. If we were never born, we could have never time traveled and killed everyone. There are a number of suggested "resolutions" to the time paradox, almost none of them good for us. Novikov's solution is different. Novikov suggests that none of this could have happened in the first place. For some reason, regardless of whether it the reason is known for any particular instance, it is simply not possible to create a time paradox, much in the same way it is not possible to create any other kind of paradox. If I work out a mathematical proof that shows that $1 = 2$, then there is something wrong with my proof, because we already know $1 \ne 2$. What is wrong exactly? Well I dunno, it depends on the "proof." Being unable to determine the reason does not mean that the paradox is allowed to exist. In the case of our supergerms, we can't take supergerms to the past because *we've already been to the past and there were no supergerms there.* The only way we could take supergerms to the past is... if we had taken the supergerms to the past already. Now, if we had taken the supergerms to the past already, clearly not everybody died or else we wouldn't have been around to take the supergerms to the past in the first place. There is a pretty detailed example given at the above link involving a billiard ball traveling into a wormhole with the precise trajectory that will cause it to strike itself and knock itself off course, preventing it from entering the wormhole. Novikov refuted this example by redoing the mathematics himself and finding a number of self-consistent solutions. So what happens if we *try* to take supergerms to the past? I dunno. But I *do* know that we mathematically can not... unless we did. [Answer] No! This won't wipe out humanity. Time travel and the possibility of importing new and old strains of diseases from the past and the future will provide an enormous boost to research into microbiology and virology. Pharmaceutical companies will benefit from having so many new diseases to combat with their medicines and drugs. The market potential is gigantic! This will increase employment for scientists and give a boost to the economy. Who wants to live safe? Every species goes extinct sooner or later! Embrace the new paradigm. Live dangerously, travel through time, and get infected with interesting new diseases. Do good to your society, your time, create jobs and wealth, and die unexpectedly of an ancient illness. How else can anybody fund time travel? [Answer] The problem with backwards time travel is that every minimal modification to our world in the past would drastically change the future and therefore our present. Just imagine you travel around hundred years back in time and accidentally kick a tree seed to a different place. Now the tree starts to grow there instead of at another place. Maybe now the car of your father will crash into the tree at that new position later, before he met your mother. You could not have existed in your present any more because your modification to the past caused your father to die. That however means that as you can not exist in the present any more, you could not have travelled back to the past and modify it. Therefore the modification has never been made, your father did not die and you are happily alive. Infecting people in the past with any disease could of course have the same effect, it isn't even necessary that anybody dies, even if somebody just feels ill and stays at home instead of going out and doing something already is a huge difference and leads to a completely different future. This little story I imagined is just a variation of the well known [grandfather paradox](https://en.wikipedia.org/wiki/Grandfather_paradox) (you travel back in time and kill your grandfather before he met your grandmother) which could be resolved e.g. using one of those two theories below. Of course we don't know whether any of them is correct yet, it's still mostly philosophy and speculation. * **[Novikov self-consistency principle](https://en.wikipedia.org/wiki/Novikov_self-consistency_principle)** This theory states that everything that has already happened is fixed, which means even your time travel and all actions you do in the past you're visiting have already been predetermined. If we go into quantum physics a bit, all possible quantum events and therefore all possible future paths have a specific probability to occur. However, events that would generate paradoxes get a probability of zero which means it is impossible for them to happen. That would mean if you travel back in time to kill your grandfather, no matter how hard you try, the universe would always find a way to prevent you from succeeding, no matter how obscure it might get. Coming back to your question about bacteria, if this theory is true, nothing would change as everything you do to the past you visit has already happened to the past you come from, as they are identical. It is impossible to perform (or not to perform) any actions that would change history in any way. * **[Many-worlds interpretation](https://en.wikipedia.org/wiki/Many-worlds_interpretation)** This theory states that all possible pasts, presents and futures coexist at the same time, forming a hue or even infinite number of alternative parallel universes. Every time a decision is made in "our" universe, it branches into two universes, so that "our" timeline contains the decision we made and the alternative universe goes on with the other possible decision we did not make. That would mean, if you travel back in time to kill your grandfather, you could simply do it, creating another parallel universe where your grandfather is dead and your father and therefore you have never existed. This alternative universe does not affect "your" universe though, so you still exist. Coming back to your question about bacteria, if this theory is true, nothing would change, as the past you travel to is not the history of your own universe, but a branched timeline that contains these modifications made by your time travel. You can do everything in this alternate past, including destruction of the entire planet earth, without causing any changes to your own present universe. [Answer] You could argue that, if civilization still exists in the future, the civilization of the "present" couldn't have been wiped out by a virus from the future, since that civilization had to continue to exist to create the future that you traveled to. Personally, I subscribe the the belief that if time travel is possible, any action taken in the past has already occurred, and so cannot change the present. Since the present is the future's past, the present cannot be destroyed if the future still exists, since any events happening in the present "already happened," as far as the future is concerned. If the civilization of the future does *not* exist, and your explorers emerge from their time machine onto a barren, lifeless planet, then all bets are off. [Answer] two factors to consider are first and foremost do we even interact with these times or is it merely observational? and if we do interact how does resistance equate to deadliness? Many diseases are drug resistant but not deadly nor does developing or mutating resistance increase overall deadliness. It's very particular as to what you contract that could have devastating effect if any at all, the act of time travel might have an unintended side effect of killing all germs. Unless you catch something highly contagious it's unlikely that it will even spread no matter how deadly it is. [Answer] I think that many answers to this question are illogical. The question itself is illogical. It assumes that the problem would be caused by super drug resistant bacteria from the present that have evolved resistance to antibiotic drugs of the present. But as someone has pointed out there wouldn't be any antibiotic drugs in the past anyway. Instead the problem is caused by the very short generations of bacteria which means that bacterial generations are many times as numerous common as mammal generations - even many times as numerous as mouse generations. So bacteria evolve many times as fast as humans evolve. So if a person with billions of mostly harmless bacteria in and on him travels to the past and releases some of those bacteria into the environment, those mostly harmless bacteria will have different genes than the mostly harmless bacteria living the past, and will introduce new genes into the bacterial population of the past. This will change the genetic makeup of many different bacterial species. Changing the genetic makeup of those bacteria species will change the way they evolve in the future. Thus those bacteria species will evolve different new strains and species in the future. Most of those different types of bacteria will be harmless, but some will be deadly diseases. Different deadly diseases than the deadly diseases which would have evolved without the time travel. Everyone knows that the main influences on how long people live are viruses and bacteria. Time travel would change the viruses and bacteria that people face. Thus time travel will result in some people dying who would have lived, and some people living who would have died. A person living enough years in the past, perhaps 5,000or 10,000 years, will fall into one of three categories: 1) dies without any children. 2) Has children, but their descendants die out after just a few generations. 3) Has children, and their descendants never died out, but increase both in number and in percentage of the human species year after year, generation after generations, century after century, millennia after millennia, until every single living person is descended from them at least once. And then their descendants will continue to flourish over many millennia as long as *Homo sapiens* or any biologically descendant species lives. So if you go far enough into the past, the germs you release will soon cause the evolution of different diseases. Different humans will live or die than would have lived or died without time travel. And some of those who live or die would be ancestors of everyone alive in your era, including yourself. Everyone in your era, including yourself, will disappear and be replaced by an entirely different human population. A prime example of "grandfather paradoxes". The Novikov self-consistency Principle and the many worlds interpretation have been offered in attempts to show that there wouldn't be any "grandfather paradoxes" in time travel. But it seems to me that it would take a lot of faith that the universe happens to be structured in a way that makes time travel harmless for anyone to dare to travel in time. I have ideas for a series about a space/time traveler, and finding ways to make him biologically sterile as far as viruses and bacteria are concerned is vital to making his travels safe for the societies he travels to and their future descendants. the traveler might be surrounded by a bacteriological "death zone" that somehow exterminates all bacteria within it. Thus he will be incapable of transporting bacteria thousands of years into the past or future of a world. But of course killing all the bacteria that enter the "death zone" will change the the future evolution of their bacteria species and thus the evolution of future diseases. [Answer] There are holes in the question, I think. Nevermind the bacteria and antibiotic stand point; what about the butterfly effect? If you even introduced bacteria from this point in time to a previous point in time, you would change everything that happened as a result of that bacteria NOT existing throughout the course of history (aka the butterfly effect), and still - kill a lot of people. Too convoluted scientifically to mix together bacteria resistance and time travel, and even begin to guess at how it would affect us/our planet/the universe, etc. ]

[Question] [ Let's assume for a moment that humans developed telepathy as part of our divergence from apes and becoming bipedal. Like intelligence, that evolutionary trait was powerful, leading to it quickly becoming ubiquitous. The telepathy works like your brain. You have ideas, concepts, feelings, but you can "hear" that they come from a different direction and are not your own. Likewise you can broadcast your own thoughts to a group or target them in a certain direction. Different people have different "flavor" to their thoughts - as different people think differently, even about the same things. Particularly intense thought/feeling can be "heard" without being "spoken", but at a shorter distance proportional to the intensity (let's say ~5-10 meters at most). "Spoken" telepathy has similar range to the human voice. And let's assume that technological development allows people to use their telepathy for "telepathic telephones" and similar analogous technology. The question is, would people ever develop spoken language in this alternate reality? Why or why not? [Answer] Assuming telepathy is a better version of speaking, and there are no disadvantages in comparison, (*Range is non-issue, clarity is same or better, ability to control how much others hear, or, just a **very** understanding society*) I don't think there would still be a fully developed language, but I have two topics it may still have an impact on which exist today. --- ## Body Language One's voice may be used as an extreme extension of "body language." Something extremely painful happens, and they still have the urge to to let out a noise in addition to their normal telepathy. Intimidating sounds might be made when extremely angry or during fights. Laughing may still be a normal, but much more rare and extreme, response to happiness. Language has never been about using the "best" form of communication, but about using "all" available resources to adequately express one's self. They shouldn't be able to communicate completely using their voice, they don't actually need too, but it should supplement their current communication in some way. --- ## Culture There are nearly infinite cultural affinities that could be tied to a person's voice. It could be something that is used during certain religious ceremonies, maybe entertainment in the form of music still exists. Maybe certain types of voices are considered very attractive. Alternatively to the body language section above, perhaps hearing your voice is something very private that only the closest people in your life will ever hear. Or, the opposite, it could be used only for the people you hate the most, who don't deserve to hear your thoughts straight from your head. Maybe "fighting" for dominance or leadership roles consists of screaming at one another to see who is loudest. Like I said, you could tie some cultural reason to just about any use for your voice. [Answer] Everyone? Really? EVERYONE? So, better coverage than voice is in current humans? ie: no Deaf, no mutes? If you have mental disabilities (ie: can't broadcast/can't receive), then those people will get/develop language (probably, assuming they aren't killed as subhuman animals (or demons); if other people can't detect that they have thoughts). Primates vocalize, and can learn sign. No reason that your disabled wouldn't at least get a grunt code. They might not get fluent, verbal language going, as there's no great evolutionary advantage to mutants with better vocal range - if most people are using telepathy. Basically, you're going to have some problems in getting your primates vocal language, if there's no evolutionary need for it. We speak more fluently than primates, because there was a decided evolutionary advantage to mutants who had better vocal range/abilities. If you evolve the telepathy in parallel with language, it would get you the capability to speak (roughly; retraining people to speak, even though they have the vocal cords is time-consuming and difficult). And telepathy would definitely trump language in use. However, the confusion that language engenders - miscomprehensions, etc. have led to a number of discoveries, because people thought someone said/meant something, when they didn't. And so people started investigating things and trying to find solutions, because they 'knew' someone had already done that. Without vocal language, I don't see how you're going to get written language. Most alphabets were codes for phonemes. How do you make a sign for a thought-complex? Especially if telepathy is faster/more complete than language. Might be easier to train your memory and download/upload all of the history of thought on a subject to your pupils... who'd then memorize it, and could give it immediately to their pupils... I can see that there wouldn't be any schools :) Is there any way to shield your brain, to keep secrets/lie, and to have spies? I can see languages developing if you want to keep who you are secret from your recipient: both go into adjacent booths, and use the Police language to do anonymous reporting. --- Okay, language is getting a lot of comments. (and I was hasty to slight Chinese/pictograms by giving them the short end of 'most' - but yes, I did give them a moment's thought; however they had and failed at printing because of their inherent disadvantage, and only committed to printing when they knew they had to catch up or be in the dustbin of history. Not a recommended technology.). But, let's keep in mind the question. If you can transmit an actual picture into another person's brain... why would you try making art to eventually derive a simplified script from? Granted, if people have poor memories (and I think if we had evolved telepathy, we would've selected for photographic memory as well) they might want help/memory aids. But, I suspect that it would be a much more mind-based history. We had oral-history for long, long periods in our history - I think that would be magnified many times over with telepathy. [Answer] I would translate your situation as "what if people had an ability called 'X' which is like speech in every possible way, except has these mind numbingly better advantages." In those cases, the ratio of speech usage to telepathy would be akin to the ratio of the number of people taking a 10km hike across rocky terrain in a circle to arrive at a destination 1m away from their starting point versus the number of people who would simply take a single step and be there. You're going to need some disadvantages if you ever want to see speech. Perhaps one disadvantage could be the inability to cover up one's true feelings with telepathy. If your boss asks how it's going, you wouldn't be able to grit your teeth and say "its just fine and dandy, thank you for asking." Telepathy might be saved for highly personal situations, relying on crude speech for general day-to-day use. Or perhaps the disadvantage is that it is *much* harder to concentrate on telepathy, making it nearly impossible to use unless you're standing still and devoting your attention to it. [Answer] Spoken language is a learned skill - why devote effort to learning it if telepathic communication coveys ideas without translation errors, without fumbling for vocabulary, without poor word choice confusing issues, etc? Written language would most likely still develop, but spoken language would be fundamentally inferior to their extant innate communication. The very concept of a spoken language would likely be alien to them - perhaps, at the extreme, someone could develop a kind of long-distance call for beyond telepathic range, as in a whistled language even calls of *cooee!* which travel great distances, but anything which has the same range of function of telepathic speech would be extremely inefficient. [Answer] There will most likely still be some kind of spoken language, although it will probably be not as complex and developed as ours and not everyone will speak it. 1. These Humans will still most likely have hearing organs, for navigation, hearing predators and so on... Audio feedback on your surroundings is still very helpful for survival. 2. Basic vocal chords developed in most animals to convey simple information like a shout to warn others in your colony - if danger approaches. 3. Since your telepathic communication is probably not as far reaching and universal as a loud shout, your voice will still be useful to warn someone who is very far away or get his attention 4. The spoken Word will most likely be like sign language in our world. There are some universal easy signs everyone understands and uses in situations where someone cannot hear but see you - and there is a whole sign-language for people who cannot hear or speak (deaf/mute) and for special situations where you want to convey information silently (secret sign languages for spies, wall street in public libraries) So there will probably be a whole range of universal vocal signs, like calling for help, shouting "hello!" or warnings, which people use where telepathic communication has not enough range or is unpractical in some other way (maybe places with huge telepathic noise? Maybe places where telepathic silence is mandatory? Maybe on a battlefield between soldiers who use a secret spoken code-language for commands?) And like @user3082 depicted in his answer there will probably be telepathic-impaired people who cannot easily communicate with their brain and will need some kind of spoken sign-language - which also many school-girls probably learn for fun to communicate in class... [Answer] Telepathy is going to cause problems. For example somebody who has strong hallucinations or on drugs and transmitting his hallucinations to the people around him, even to passing motorists. Also what if somebody is in pain like an co-worker who has a toothache would you also feel it too. If somebody is dizzy and feels like vomiting would you feel the same way. Would you visit a relative in a hospital and be inundated by all the pain and suffering around you? Also how can you sleep if the couple in the next room is making love and you can telepathically hear every whisper or feel every climax. How to you sleep if your college roommate is having a noisy nightmare. Mob mentality will also be a problem. Anger starts with the mind and if several hundred people around you are projecting feelings of anger a weak mind might be easily influenced. If movies can affect you (sad, angry, happy) how about being incessantly bombarded by hundreds of feelings directly to your brain. Also how would you prevent a co-worker from stealing your ideas. Or how does Kentucky Fried Chicken keep its secret recipe. School tests would also be a problem. School lectures or seminars would also be a problem because you can hear every thought. It would be like trying to concentrate in a party where everyone is talking. In a party you would **only be inundated by sound** but **with telepathy you will be inundated with everyone's thoughts, visualizations, and feelings.** You would have a lot of problems unless your society teaches **telepathic blocking**, or you have **devices that block telepathy.** For the many situations in life when ordinary people need to keep secrets, your citizens must have some ability or device for telepathic blocking, So **in situations that call for blocking you will still need verbal communication to converse your ideas** while keeping your secrets intact. Also if you want **music and singing** in your alternate world you need language. [Answer] A simple language might still appear, especially if the language only works on humans. We have a tendency to talk to our pets, our animals of burden, etc. Plus, people often talk to themselves as well in order to not sit in silence or to get their thoughts in a row. But odds are these languages will only contains a handful of words if telepathy is superior in every way. I think that a written language however would still be pretty strong. Words have a certain permanency to them, and allow you to explain things better. Perhaps, in response to the written language, there would be a formal spoken language of the same type. Speaking in concepts and ideas is one thing, but sometimes you need perfect clarity, especially in scientific circles. You could even see spoken language to be a thing used only by the elite, who *need* the extra clarity in order to get their ideas across properly, so that others can actually make use of them. Kind of like a jargon-only language. In the real world we also have people who communicate with so much jargon that they might as well be speaking a different language, and perhaps such a thing would be the only kind of language. Or, as another alternative, perhaps in order to overcome cultural barriers which make the ideas of a foreign person impossible to understand, a spoken language will be created that gives a sort of common frame of reference. Because if you would share direct brain ideas with someone whose entire worldview is alien to yours, you might not have a clue what they're trying to convey in the first place. This depends on how the telepathy works exactly, but it's easy enough as is to not be able to communicate effectively with someone from a different culture (or even a different walk of life sometimes) if you're both using common words. Let alone if you're communicating in experiences. Either way, I don't think you'd see language the way it exists in the world today. It would probably be highly specialised tools, used only in very specific situations. [Answer] If the telepathy is using ideas and concepts directly (however that works) it could be problematic. Apparently language is pretty important for intelligence. <http://www.todayifoundout.com/index.php/2010/07/how-deaf-people-think/> "Recent research has shown that language is integral in such brain functions as memory, abstract thinking, and, fascinatingly, self-awareness. Language has been shown to literally be the “device driver”, so to speak, that drives much of the brain’s core “hardware”. Thus, deaf people who aren’t identified as such very young or that live in places where they aren’t able to be taught sign language, will be significantly handicapped mentally until they learn a structured language, even though there is nothing actually wrong with their brains." There would be several good reasons to have a spoken language but they are probably not strong enough to develop them in the first place, at least not in the general public. -Code. If Telepathy is a universal thought language there would be need for a code language in certain situations. -Recorded messages. If there is no telepathic radio, then a verbal language would be useful to cover distances, both in space and time. -As others have pointed out, disabilities that make some people not able to send or receive telepathic messages. These individuals would use some kind of language, possibly spoken. If you want to have verbal language AND telepathy for everyone, you could make telepathy take more effort than speaking. Alternatively, the ability could be available only after a certain age, so everyone has to learn a language as a child. Otherwise, I think people wouldn't use language. They would use grunts and screams sometimes, though. Screaming as a reaction to pain would be a evolutional vestige that persists even though it's useless now. [Answer] Here is an interesting thought... In the future we may very well develop technology that gets us very close to what you call telepathic now. It will likely have some fancy added features like caller id, DND mode, a mailbox and who knows what else that doesn't let it quite qualify for the traditional definition of telepathy, but it will be close. Initially our artificial telepathy will surely be based on spoken and written languages, but I am quite sure it will eventually develop its own "language" that is much more optimized for direct brain-to-brain signalling and much more efficient than speech. It will be able to express and transmit various feelings and perceptions completely literally and accurately. It will be a new age in human history, I believe. People rarely realize, but spoken language is a major part of the way our brains think. As we grow up from infants, we learn to understand language and we learn to form thoughts in parallel. I believe most people's thoughts are actually in spoken language inside of their heads. There are of course exceptions, but still... I think when we develop this new "language" and get rid of the ambiguity and inexpressiveness (for certain aspects, anyway) of word-based languages, we will reach a new level of human intelligence. There already are certain rare people that can "think in math" for example, and achieve amazing feats in that field, or "think in colors" and become great artists... If a species could do that naturally, it would have an amazing advantage over us. And no, I doubt it would ever develop anything as rudimentary as spoken languages. Edit: with ubiquotous low-level brain-to-brain signaling, an emergence of collective consciousness seems very likely to me though, so there will be no individuals and no "language" at all, neither spoken nor telepathic. [Answer] With the 10m range limit you've specified there's still plenty of value in a spoken language. Yodelling, for example, was supposedly used for communicating between villages in the Alps. Very useful before the invention of telephones. Also, if you're limiting the telepathic ability to the humanoid, they would need some way of calling domesticated animals. Those calls might not need to be as complicated as most modern languages, but it'd need to be complex enough to direct a sheepdog, for example. [Answer] What if early on in this development, different groups have incompatible "flavors" of telepathy that limits what they can send/receive? So two groups of neolithic telepaths who meet might be able to get basic emotions across, but not the full telepathy between same group members. In this case a basic spoken language might develop as a trade or negotiation tool. If the flavors are learned (rather than inherited), then as groups go larger and you move into cities more people will share the same flavor and be able to communicate, but you'd probably also keep the spoken language (and a written version) for records and for trade with other cities. Then you have a similar progression to different states/nations. The trade language might expand in complexity with the introduction of telephones (assuming they don't work with telepathy) and then again with the introduction of an internet-like technology. Another thought I had was that maybe they have an extremely strong vocal musical tradition for some reason, and develop flexible vocal chords to support that? Then when they hit the point of development where they need language/written records and telepathy won't cut it, they could use music as the basis for their language. Reasons for the musical aptitude could be anything from religion to mating calls. Edit: Another potential reason might be a predator/prey that's sensitive to directed telepathy, but not as much to sound. Imagine a world where all animals are telepathic and uses that as a detection advice (maybe you can't understand animals but you can "hear" that they're there). Intelligence might allow humans to dampen their thoughts and not broadcast, giving them a hunting advantage, but then they'd need some other way to coordinate. [Answer] Even when we think, we partially think in a language. Maybe we used to it, but, I think it's better thinking in a language than just picturing an image in mind. "I'm hungry..", "That girl is hot ..", for example. In my hometown, most people learned two languages since childhood, and both languages are first language. When I went out to big city, the most and interesting question that I was asked was "in which language are you thinking usually ?" So, to conclude, some kind of language would be developed eventually one way or another, I think. [Answer] How I see this playing out is that, while a language would be developed perfectly fine, it simply wouldn't be spoken. They would have a language that is communicated by telepathy, rather than through sound-waves propagating through the air and reaching some organ that analyzes it. Because of this, there is no reason for them to have developed vocal chords or ears for communication purposes. *However*, there is still a possibility that they would have developed those organs or something similar for other purposes. For instance, it is generally helpful to hear when boulders are falling from higher up the mountain, so that you can at least try to get out of the way of danger. In a similar fashion, perhaps they would have developed some vocal capability. While not useful for communication with other telepaths, it may be useful for driving off wild animals. And by a very far stretch of imagination, there could be some sort of technology that makes use of sound waves for some reasonable purpose. [Answer] Although all the answers are great, i have one thing to add to this: secrecy. I believe that people would eventually develop (or should i say invent?) some sort of "grunting code" in order to communicate without others "thinking" their messages, just like we can use sign language to communicate secretly. Another possible out come is that we develop a language that uses telepathy and mouth sounds combined. [Answer] I'd imagine language would be redundant and communication would be implemented using highly developed emotive state, as fine if not finer than speech. Sometimes it's hard to articulate emotions, I am sure their expressive power in telepathy would replace language, given emotional state can be infinite. [Answer] Several answers have already talked about technology, but one thing that does not appear to have been considered yet is that *technological development itself* would require the existence of a language more specific than intuitively-understood "ideas, concepts, feelings" can be. This isn't mere conjecture, but a lesson of history, as Dijkstra points out: > > A short look at the history of mathematics shows how justified this challenge is. Greek mathematics got stuck because it remained a verbal, pictorial activity, Moslem "algebra", after a timid attempt at symbolism, died when it returned to the rhetoric style, and the modern civilized world could only emerge—for better or for worse—when Western Europe could free itself from the fetters of medieval scholasticism—a vain attempt at verbal precision!—thanks to the carefully, or at least consciously designed formal symbolisms that we owe to people like Vieta, Descartes, Leibniz, and (later) Boole. > > > The virtue of formal texts is that their manipulations, in order to be legitimate, need to satisfy only a few simple rules; they are, when you come to think of it, an amazingly effective tool for ruling out **all sorts of nonsense that, when we use our native tongues, are almost impossible to avoid.** > > > -- [EWD 667](https://www.cs.utexas.edu/users/EWD/transcriptions/EWD06xx/EWD667.html), emphasis added > > > This most likely would need to be *vocal* in nature, because as a few answers have already pointed out, verbal language lends itself quite easily to recording and preservation without alteration, which is *extremely important* for technological development. So yes, a non-verbal, telepathic culture could most likely arise and build a civilization, but it would never progress beyond the Dark Ages without speech. (Come to think of it, that would make for an interesting hook right there: a society in which speech is for precise technical matters of science, engineering and law, whereas telepathy is used for social communication.) [Answer] So, telepathy in this world you have constructed is both intentional or unintentional i.e. I can "speak" my thoughts to an intended "listener", and also, all persons within range can "hear" my intense thoughts and emotions without my knowledge or consent. Spoken language may have some value for impressing the listener with one's voice quality and skills, e.g. a sweet, tuneful or commanding voice. Spoken language would be useful for creating smokescreen i.e. lies, concealment, false emphasis on unimportant things, playing down or diverting attention from significant things. Since unintentional telepathy happens in your world, concealment of ones thoughts is difficult or impossible, because anybody within range may "read" or "hear" your innermost thoughts. However, spoken language may evolve as a way of consciously modifying the way these "heard" thoughts are perceived or experienced. There would be twin strategies for evolution: 1) TRUSTWORTHINESS: Natural selection may favor those whose thoughts seem clearest and easiest to read, because society and individuals may confer benefits on such opportunities such as mating opportunities, business opportunities, etc. 2) OPACITY: Those who develop the skill for cloaking their thoughts BY CLEVER USE OF SPOKEN LANGUAGE may attract more employment opportunities, and possibly mating opportunities also. The ability to read others while not being read by others would confer disproportionate evolutionary advantages on such individuals, and there may be a high social demand for persons with high cloaking abilities. So, spoken language may develop to a very high degree from a need for concealment or "perception-management". It may sound and feel very different from our spoken languages, however. [Answer] There might be tons of reasons telepathy is parallel to speech. For ideas on why, read my bullet lists below. This all depends on the idea, though, that telepathy might not (always/quite) be pure mind-to-mind communication. Wouldn't it make a story more interesting if lies, secrecy, and misunderstandings were possible anyway? On the other hand, if telephones can transmit telepathic notions, couldn't they also be recorded, edited, filtered, and reused? Perhaps an effect of their digital age would be a rise in the ability to deceive, and the cultural impacts of such changes. I would argue that it would make the most sense for it to be a separate transmitter organ (for both storytelling and physical reasons). In such a case, telepathy might be far more versatile than the voice box, but still have communication limitations, the ability to lie or keep secrets, and the ability to stay quiet--and for someone to be telepathically disabled. I think the survival of groups would require that people are able to convey only those thoughts they wish to. Either that, or the societal structure would be vastly different than our own--perhaps with less individualism and more of a hive/cult mentality. This could limit progress, as new ideas would be harder to promulgate and accept. New models of thinking and revolutions of thought and philosophy might be difficult to adopt into such a society. If people have control over their own telepathy, they might still transmit something accidentally (such as when we yell when surprised or in pain), but I would suggest it might not be very intelligible. If telepathy is controlled and an external organ, you can be much more versatile in customizing how it works. For example, what is possible to transmit? For example, if only one of these is possible, it might affect culture and language, among other things. Each aspect of the telepathy could be independently automatic/voluntary, high/low fidelity, and viscerally/abstractly perceived. Telepathic aspects: * Abstract thoughts * Visceral experiences * Words and symbols * Basic needs (hunger, thirst, fatigue, discomfort, pain, etc) * Certain emotions (All? Some? None? Are certain emotions easier to transmit than others? Are children able to "receive" adult fully developed emotions?) * Complex intuitions (I feel threatened by *that monster*) * Location, propriolocation - can you tell someone's location when they transmit? Can you transmit a specific location to someone? What range? * Visual things - colors? depth? Imagined things in shadows? * Tactile - can you convey textures? * Temperature - can you let others "feel" you are cold? Would they shiver? * Dreams - would someone keep transmitting, even accidentally, during sleep? Or can they shut that ability down? * Taste - can you share exact, or approximate tastes? Or must they be described symbolically? * Density/weight - can you transmit objects' weight as well? * Insanity - can certain types of insanity be contagious? * Sound - can you describe sounds new to you and the others? Or only familiar ones? * Sound pitch/volume - are telepathic transmissions able to directly communicate pitch and volume or must they be described somehow? * Mind-meld - Can telepaths merge minds together? Once done, can it be reversed? Telapathic characteristics menu: * Complexity. How abstract or complex can a thought be, before you can't transmit it? E.g. can you teach someone complex quantum mechanics and mathematics with a single thought, or does it take effort and time to explain? * Abstract vs real - is telepathy more like words, in that what is transmitted is symbolic of actual experiences? Or is it more like sharing an experience directly? Or is it somewhere in-between? What rules define how real a transmission feels? When you share a complex emotion, do you have to transmit it in ways that the recipient understands? * Abstract, semi-visceral, visceral. How deeply does one experience what others transmit? * Indelible vs fleeting. Are transmitted ideas easy to remember? Does everyone have eidetic memories? Can someone explain geometry, and you can recall all the intracacies a moment later? * Learned vs intuitive. Does someone have to experience an idea, or have it explained, before it can be transmitted? Do you have to experience grown-up feelings before you can understand an adult transmitting those kinds of complex emotions? Or are you somewhat blind to new "ideas" until explained? * Fidelity. How accurate are transmissions vs the real thing? Is it worth tasting the good food for yourself, or can one person enjoy it and share the experience? * Deceivability. Maybe they can transmit fake emotions, but not fake visuals--or vice versa. * Imagination. Is it possible to transmit made-up experiences (stories, concepts, etc)? How high fidelity are such fictions? Or does one have to experience something before they can transmit the concept? * Maturity. How does one's age/development affect their ability to transmit? To receive? * Transmit/receive gap. Is it easier to receive, or transmit? * Inequal skill/ability. Does this change with age, gender, practice, diet, or heredity? Are only females able to receive emotions? Can vitamin deficiencies inhibit telepathy? Does telepathy stop working in old age, or while sick with a cold, etc? * Dependency. Does one depend on something to be able to transmit? Eg, physical touch, proximity, certain foods, certain locations, immersion in water? \* Blocks/impediments/interference. What can block or inhibit transmission? Hills? Clouds? Water? Pain? Fatigue? Fire? Heat? Cold? Radio wave interference? \* Intrusion. Can you mentally torture someone by transmitting awful images, emotions, or ideas? * Time. How long does it take to transmit an idea? Is telepathy slow? Or are certain aspects of it slow? Can the time be affected by one's age or physical condition (newborn/old/sickly)? * Familiarity. Is it easier to use telepathy with someone, the better you know them? Do you have to come in physical contact with someone before you can "link" to them? * Dialects/languages. Are you able to communicate with someone from another part of the world, or is there a language gap (even if less than we experience on Earth)? * Eavesdroppability. When you communicate, can others listen in? Is there a limit to how many people you can transmit to at a time? Think of this as encrypted communication or a more personal "link" of some kind. * Limited groupings. Could you get stuck on certain "frequencies", separated from most other telepaths? For example, would A have to ask B to tell C something? Or could entire villages be stuck on a frequency? * Tuning in. How long would it take to "tune in" to a new group of telepaths? Each community or age group could be on a different bandwidth or sub-channel, of a sort. How much do these groups' frequencies overlap? Do they vary from family to family? Village to village? Country to country? Can a disability prevent someone from tuning in? * Different channels. Perhaps each aspect of telepathy (sight, taste, concepts, location) use different transmitters, so someone can be partially "deaf" or "mute" but not fully. * Difficulty. How much energy, concentration, meditation, preparation, or ceremony is required in order to use telepathy? Is it used only in rare religious or civic ceremonies, or is it used at-will? Is it impossible to use telepathy in loud places? Quiet places? * Limited use. Does the telepathy organ tire out quickly and have to recover? Much like going hoarse, or running out of breath. What replenishes that ability? A rare herb? Sleep? Rest? * Side effects. Does telepathy have adverse side effects, like fatigue, loss of concentration, pain, emotional shakeups, nausea, dizziness, seizures, insomnia, nightmares, or an inability to separate reality from the mind? Any neurological symptom might make sense. How long do these effects last? If they are permanent, perhaps telepathy is generally avoided. * Parallel listening - Can you receive telepathic ideas from multiple sources at once? * Dead spots/reception - are there only certain kinds of places one can use telepathy? Or are there physical phenomenon that can disrupt the ability--such as storms, rain, aurora, or is there a telepath landscape where you must find the best places to transmit? Are there locations on the planet where you can transmit for miles, and others where you only reach a few inches? * Technological dependence - is telepathy something that relies on an invention? Is the invention basic, like staring at a fire, using special meditation techniques, or drinking a special "potion"? -- or does it require advanced satellites and equipment to be worn? If a certain plant or mineral is required, could the human race run out or the plant go extinct? Does it require rare and expensive ingredients? [Answer] For sure people would have developed spoken language aswell. While on a hunt, our ancestrors were prolly shouting tactics to each other. (That would not work with your 10m-limited telepathy) [Answer] You would eventually develop speech for radio if you hadn't already (I judge this unlikely beforehand). Writing would develop due to the normal forces that cause writing to be developed, but the form would surely be pictorial, and this does not lead to a possible back-path to developing reading. But late in their industrial development, they would discover what we discovered, that there is great military application for high-speed long-distance communication. This would progress down the early lines like ours would have been if China got dominance: semaphore flag -> primordial flash code -> morse-like code (remember pictorial language) with restricted vocabulary -> complete symbolic encoding in keyed code -> a way to speak the keyed code (assuming normal ability to make noise and taste for music). A taste for art would eventually lead to interpretive dance set to music, but I can't see how that could lead to developing speech. [Answer] Biological telepathy is very possible. Telepathy is just direct communication skipping all the grunts, gurgles, and scribbles. Currently we use sound waves and light waves to communicate. Body language requires eyes and our eyes use light which is a high frequency electromagnetic wave. Our bodies are constantly producing electromagnetic waves. In a telepathic society I would imagine an organ capable of emitting and receiving electromagnetic waves in order to communicate, similar to how sound works. These waves would have to have meaning, otherwise it wouldn't be communication. Meaning requires patterns. Patterns can use graphemes to symbolize that particular meaning. The kind of superpower magic psychic telepathy is impossible. You cannot reach into somebodies mind and steal information. Period. Most of the time when we make noise we do so purposely. Our vocal chords are told to contract and expand as air passes through, and then our throat, tongue, and lips refine those vibrations further. Since all of our senses are electromagnetic, as are our thoughts, and our muscles, as well as the thoughts, senses, and cells of every other living thing in existence are all electromagnetic, it would not surprise me if evolution resulted in electromagnetic communication instead of sonic. Even aliens are electromagnetic, if they exist. Electrons deal with chemistry. Without electrons being shared between atoms, chemistry would not exist. Life has a lot of complex chemistry and requires a way for sub-parts of life to communicate and use energy. Cellular function, communication, and energy use are all electric. [Answer] You write that telepathy develops at the same time as the change from animal to what we recognize as human. Spoken language also developed at that same time, so it is likely that the people developed spoken language before telepathy became reliable. One good reason to develop language further and keep it going is singing and music. I can imagine singing in telepathy but not singing to music, and music is pretty old in our society. And singing is one of the oldest kinds of music, if not the oldest. ]

[Question] [ Fictional worlds, usually ones set in the future, often depict planets with a single worldwide government. (In fact, it's such a common trope that one *Babylon 5* episode made a point of saying "hey, Earth isn't like all you other guys" in that way.) Living here on Earth, I have trouble seeing how we could end up with such here -- sure we have the UN and regional associations like the EU and NATO, and countries make treaties, but no state seems willing to give up its sovereignty entirely -- states reserve the right to not enter such agreements or even to break treaties, and consequences are limited unless the state is doing something Really Bad. If I want my world to have a global government that has real authority, should I be thinking of it in terms of having taken a very different path from Earth (e.g. a world conquerer), or is there some sequence of events that could bring diverse sovereign states together into a single world government? What conditions would have to be met in order for a world government to take hold, and stick? Can you get to a world government through paths other than worldwide military conquest? [Answer] > > If I want my world to have a global government that has real > authority, should I be thinking of it in terms of having taken a very > different path from Earth (e.g. a world conqueror), or is there some > sequence of events that could bring diverse sovereign states together > into a single world government? > > > Both, or rather either could end up working for you. > > What conditions would have to be met in order for a world government > to take hold, and stick? > > > We will get to that. > > Can you get to a world government through paths other than worldwide > military conquest? > > > Absolutely and frankly more likely. --- Ok so we talk about Earth and government, but in reality what we are really talking about it people. Government is people, maybe the few (autocracy) maybe the many (democracy) or perhaps somewhere in-between. People are what make world government such a hard concept to accept. We just seem to be wired to see difference as a threat, which may well be evolutionarily true, humans have been fighting each other and everything else for somewhere around 75,000 years and there is some evidence to suggest that humans fought with neanderthals and may have played a role in their extinction. If we are functioning in an Earth setting, the only way I can see world governments uniting would be due to a very real, very dangerous and completely global threat. Alien invasion would be the obvious choice. Though I doubt this scenario would meet your *make it stick* criteria. Should we be destroyed, or win, things would likely devolve to some extent. Even in this scenario though I doubt that there would be harmony across the planet, some will still fight for their various reasons. Your mention of a world conqueror scenario is interesting but I find it implausible on the same merits as our real world earth. It's such a big space that controlling it via force is simply not practical. --- On the other hand if we look at a totally different sentient species that evolved differently than humans it should be possible. Humans evolved in a darwinian system that favored aggressive behavior. If you can ensure that the species evolved in a less competitive environment (it would take longer, or perhaps be designed) the natural impulse to expand and breed and control could be less pronounced or possibly not there at all. A designed species would likely be more plausible as the the effectiveness of evolutionary pressure is what drives advancement, and without it...do you ever get to a sentient species? Tough to say. Point being, a less aggressive sentient species may not be in conflict and may more naturally be willing to compromise and work together. --- Some other options that make a lot of sense: * A hive mind but I don't think that is what you are looking for. * A planet colonized by an alien species, in this scenario you start with a small population (on a planetary scale) and they work to build the planet up. Much easier to see how this would stay consolidated, particularly if they remain subservient to the power that established the colony in the first place. --- ## Final Notes: **On the nature of power**. Power in a modern geopolitical sense is often broken down into a few parts. 1. Military 2. Economic 3. Diplomatic 4. Information (Knowledge is power after all) To truly dominate you would need to cover all of these aspects. You need a monopoly (or near monopoly) on the use of force. You need to oversee/control the levers of industry and finance. You need to be the top of the diplomatic pile, this is the soft skills portion where influence plays a huge role, can you diplomatically solve problems or get others in line? Finally information...this is touchy in the modern era obviously what with the potential impacts to personal freedom but information goes well beyond just personal data. **Permanence:** Nothing lasts forever but you could find ways to make a world government stick for varying lengths of time. [Answer] Watching Europe at the moment gives you a case study of this happening. Independent countries are grouping together and handing over some of their autonomy in exchange for shared identities. Every time countries sign a treaty they tie themselves together, it's a gradual process but more and more power and authority is getting handed over to international organisations. The UN, Interpol, NATO and thousands of others all exist right now and in general their power and influence is increasing over time, not decreasing. Consider too [the growing power of corporations](http://www.businessinsider.com/25-corporations-bigger-tan-countries-2011-6?op=1). Google is worth more money than a lot of countries. For example: **Yahoo is bigger than Mongolia** * Mongolia's GDP: $6.13 billion * Yahoo's Revenue: $6.32 billion * Yahoo would rank as the world's 138th biggest country. Through to: **Walmart is bigger than Norway** * Norway's GDP: $414.46 billion * Walmart's Revenue: $421.89 billion * Walmart would rank as the world's 25th biggest country. As their influence and power grows it is entirely plausible that corporations would end up running the world, and in doing so pulling the countries together whether they want it or not. [Answer] There are several options: * First: there was only one government to begin with. If there was only one language/race and they didn't spread out much, it's possible only one government would form. This would also be more likely if the planet was a colony, since from the beginning they would have been under a different power. * Second: there could be a world conqueror, who used superior technology to earth's (either mechanical/electrical technology or magic) to improve his communication/travel and managed to take over all countries. Or he could just be lucky. * Third: the races/people of the planet could have a different sentiment. The people may want to form a central government (similar to how we have formed the UN to promote peace). But on Earth, human nature generally causes people to try and take over other places or in some way try to further their own power by breaking the peace. A species with a different nature may act differently. * Fourth: something could cause people to be forced to band together (apocalypse, alien invasion, etc.), it's possible that the whole population could join under "temporary" military rule, or that enough people were wiped out that a small enough group for one government was left. [Answer] The primary necessity for a global government is communication. Without the ability to issue decrees and receive feedback, any government is going to fragment into bodies that *are* capable of meeting their communication needs over the distances involved. The secondary necessity is motivation. The species involved must want it to happen. However, depending on the nature of the species, it may be either that members of the species have a drive for dominance, in which case there may well have been a world conqueror, or that the species' individuals want to form herds, in which case there could be a drive toward a bigger, ultimately global, herd. For a species that practices dominance, there may well have been some sort of external threat as a catalyst, otherwise clashes of personalities could cause secessions and balkanization. It could also be argued that humanity is also on its way to a world government, given that humans have regional differences and can still choose to remain under a common government. We have local, regional and national governments. Given the improvements in communication, it may just be a matter of time before global governance is formalized; we already have the beginnings of it in the form of the UN and international co-operation in response to disasters. [Answer] **TL;DR**: I think we are pretty much going to it. --- I would like to extend a bit on @Tim answer. If you look at the last 10 years or so of EU, it looks almost impossible to unite countries by some form of government. However if you look on a larger picture, up until 70 years ago these countries were going full strength against one another. And although it is a bit on stale at the present, there are still some discussions going on with other countries wanting to join the EU. I can think of Turkey, Ukraine or Serbia, for example. But even on a broader pricture, supra-national laws already decide a lot on national levels, even outside EU. * Wars and armies are controlled by the non-proliferation treaty, the **UN**, the **Geneva convention**, etc. It is not full-proof, but what is? 150 years ago, Britain and France allied (!) to wage a large-scale war against China for their right to sell destructing drugs to the Chinese population. That would hardly be accepted now. * **IMF** is and has been in command of nations' economy for some time. See Greece or Indonesia as examples. * Responses to health issues have taken a new scale: look at last year's **WHO** response to the Ebola pandemy. * **UNESCO** is providing standards for the culture in many countries. and I could continue for some time. It might not look that impressive, but if you look into a rear-view mirror, that would have been unthinkable 100 years ago! Who can be sure how it will be in 100 or 200 years from now? As supranational forms of government gets stronger, the countries will loose more and more of theirs. Which does not mean they have to disappear. As @Tim pointed out, the economic model prevalent these days help larger countries to grow, reduce the barrier between countries and facilitate that integration. So probably that supranational government won't have the power the nation-government have (still) these days, but they can still exist. As some other answers already mention, catastrophies would make it faster and stronger. If due to a pandemy, a war, or drastic climate change, the existence of humans is under threat, they are more likely to group together. EU was made partly as a response to Cold War, and in Docu-fiction, there is a claim that English and French government contemplated to merge in June 1940 when France was on the verge of collapse facing the Nazi's Blitzkrieg. [Answer] A common approach is to turn the question around. Why could we not have a global government? The typical reasons are **language**, **protection of wealth** and **morale ideas / ways of living**. Language seems to become less and less of a problem with more and more people learning english (while any other language would do, too). Morale and the way of living is partially negotiable, and is changing constantly anyway. With increased mobility (of people, but most of all of ideas), i assume that the different ways of living would on the one side converge anyway, and on the other side a pluralistic society can handle diffeerent approaches fairly well. (To some degree, granted, but still) So, what remains is the wealth, real or perceived. If your (future) world has advanced to post-scarcity, this is no longer a hindering factor. That said: you need some time to allow cultures to converge, and a post-scarcity world, and you're set. [Answer] I think the most likely scenario is similar to the formation of the USA. There, thirteen states banded together into a larger government for mutual protection. Over time, the overarching, federal government grew in prominence and the states took a back seat. In your case, some world wide event, invasion, war, environmental disaster, or a growing desire for unity/peace drove the individual nations together to form a union. Over time, people began to identify more with the world government than individual nations until the bulk of the power was in the single governments hands. Of course, if a planet is conquered or starts out as a colony, then that would work as well. [Answer] There are several models found on earth: **China:** Already covers 1/5 of all the people in the world. Originally created by forceful unification (that is, several previously independent kingdoms got conquered). Basically held together by a central power. **USA:** Formed as European colonies, got together by uniting against the colonial powers, then expanded by conquering more land from the native Americans. Held together mostly by agreement, but in part also by applying power (civil war). I don't know enough about Russia to comment on this, but I'd guess it's mostly the Chinese model. The EU is not a central state with unique government, and it's still open whether this route will lead there. There are also historical examples like the Roman empire which also covered a large part of the then-known world. I guess each technological/civilising level has a limit on the number of people who can be ruled in one country, as well as the maximal territory size. A worldwide government would then become possible as soon as both limits reach the actual population/surface of that planet. [Answer] Two questions there: how it has formed, and how it works. About how it has formed, I think DonyorM's answer is very good. Psychology also has a role: a world conquered by western people like our world has a constant amount of attempts to divide and have wars, due to independence feelings and greed. A speculative world colonizated by late medieval japanese people would have a very strong feeling of being part of something, and thus would have been very easily centralized. On our history, there are also examples of possible world empires that failed due to personal decisions or othr single point events, like Charlemagne's empire division in France, Lotaringia and Germany, Hitler's failure to properly win the war against England in the first year of war and his stupid invasion of Russia or spanish Invincible Armada defeat. Examples of Earth's single world-wide government in fantasy include those of corporative unification and loss of nations power (<http://en.wikipedia.org/wiki/The_Space_Merchants> and <https://en.wikipedia.org/wiki/Rollerball_(1975_film)>), those of pacific agreement of nations (<https://en.wikipedia.org/wiki/Star_Trek>) and those of forced unification by menace (<https://en.wikipedia.org/wiki/Starship_Troopers_(film)>) About how it sticks around, communication, communication and communication. And loyalty (check [How far apart can two cities/towns/etc be, given that order must be (effectively) maintained?](https://worldbuilding.stackexchange.com/questions/103/how-far-apart-can-two-cities-towns-etc-be-given-that-order-must-be-effectively/207#207)), also named as motivation by Monty Wild in his answer. [Answer] Humans have a 'group' mentality. We like to put things in an 'US' vs. 'THEM' situations. Whether it is justified or not that is how we are mostly built. It gives us easy lines on who we care about and who can worry about themselves. As such for humanity to have a single effective world government, either we need to learn to get along better and let others have their differences (not likely any time soon), some group becomes so powerful that it can dictate to everyone, or what I consider the most likely. We learn we are not alone. People treat others poorly because they look different, they act different, they think different. Any real, intelligent aliens are REALLY going to **BE** different. No matter what religion someone believes, the color of their skin, the equipment in their pants, another human is going to be much closer to my 'US' than any alien. While we won't all agree about everything, our differences won't seem so big any more and compromises will be easier to reach. [Answer] Currently states like the US and Canada are willing to give up sovereignty and subject themselves to courts that precide over Investor-State-Dispute-Settlements (ISDS). The German supreme court did [rule](http://www.spiegel.de/international/germany/germany-s-lisbon-treaty-ruling-brussels-put-firmly-in-the-back-seat-a-634506.html) that agreeing to the Lisbon treaty means giving up sovereignty and therefore needed a change in the German constiution. It's not guranteed that the trend of putting more power into bigger institutions continues. In state where there's the rule of law the state can gradually give more and more of it's sovereinity to more global instiutions. [Answer] As many pointed out, if conditions are right, people will band together and form a unified government. Quick look at history shows one theme that makes people both band together and fight against each other : culture. In this case, language, beliefs and moral systems. It is not good feeling to get told how to live your life by person who doesn't speak same language as you, believe same things as you and has different morals than you. To keep people from breaking apart, it is necessary to make sure they share same culture with their leaders. This can be ensured with instant communication channels between all people and ability to quickly move around to achieve more direct communication. Wealth is also important. It is necessary for each person to be on same "level" of living standard. You don't want half of the population to be living like Europeans and second half as North Koreans. [Answer] As I wrote in some posts before, Foucault pointed out that every control will lead to resistance. And every big hierarchical society is vulnerable to power struggles inside. Even more so militaristic or otherwise unvoluntarily solutions will fail in the end unless they are supported by other states like nowadays but that doesn't meet the world government criteria. And even those break up after time like we see in Iran or the so called Arabic spring. Even the grouping against a common thread will break up because of the power struggles inside after the thread is gone. In world history there was no big empire without power struggles and unrest, constant power shifts and being defeated in the end. **So how could a world government exist?** First of all it would need to fulfill a mediating and serving role, rather than a ruling one. To prevent power struggles the following aspects could help: * decisions always have to made on the smallest possible level and have to include the possibility for every affected person to have their interests and concerns met - but thats not enough as egoism and greed could torpedo the mediation process. * As there will always be some kind of scarcity (and be it a luxurious one) there need to be mechanisms which allow to deal with scarcities in a peaceful manner and additionally * the rules of the world population/society needs to be sculpted in a way that the individual egoism of every single individual motivates them to share because in that way they profit most. * Because of that there could be no money as distribution method to distribute scarce items as it will certainly leed to wanting more money / greed or accumulation of money which will produce envy. * A thinkable way could be the commons approach which was common in many countries several hundred years ago and which you can find in OpenSource Software and hospitality projects like bewelcome or couchsurfing. Just some thoughts. ]

[Question] [ In a world of cyborgs, it seems pretty likely that many people will have some number of nanobots in their blood, completing tasks such as clearing away blockages, monitoring health, and boosting the immune system. However, what I'm wondering is how many little robots you can put into your bloodstream before there are adverse health effects. Assume the lil' bots are smart enough to stay in the blood stream and not get stuck anywhere. Each one is about the size of a red blood cell (which may not actually classify as 'nano', but it's close enough for me), and for the purposes of this question let's assume they do not have any capability to carry oxygen or do any of the other things red blood cells can do. I'd like an answer either in quantity or volume for an average human, or proportion of red blood cells to nanobots. I would also like to know the main health concerns that would come from having too many. [Answer] For simplicity, let's pretend these are well designed nanobots that don't outright kill their host by blood clots or accidentally ripping holes in capillaries. So let's pretend these great scientists already killed a bunch of small woodland laboratory creatures and got those little issues figured out relatively early on. We'll assume these nanobots are the size of red blood cells (as you mentioned), deform the same way, can squeeze through capillaries and such one at a time just like normal red blood cells (or they avoid situations like that on their own, etc). So, let's start with... ## Replace (Some) of The Red Blood Cells! Since we don't want to cause edema or high blood pressure, we will screen out some red blood cells and just replace those with our nanobots. It turns out that in this method there is an existing known condition caused by losing too many red blood cells: [anemia](http://www.nhlbi.nih.gov/health/health-topics/topics/ha). The [normal count of red blood cells](https://www.nlm.nih.gov/medlineplus/ency/article/003644.htm) is noted as 4.7 to 6.1 million cells per microliter for men and a similar 4.2 to 5.4 for women. That's a range of 1.4 million cells per micro-liter for men, so if we get someone on the "high but normal" RBC count level and replace their blood cells so they are down to the "low but normal" RBC count, that gives us 1.4 million cells per micro-liter; with 5 liters of blood in the human body (5 million micro-liters), that gives us a cool 7 trillion nanobots for starters. Given these numbers there would normally be 31.5 trillion red blood cells in a human male body who that on the "high" side of the count, so that sounds nice to me. So our nanobots would exist in about a 4.5:1 ratio with red blood cells, or just under 20%. Current total: **7,000,000,000,000 nanobots** (some may experience some mild side-effects, ask your doctor of nanobots are right for you) ## Replace (Some) of The Blood People give a liter of blood all the time, which is 20% of their total blood volume (give or take). So why can't we just take that blood and replace it all with nanobots? Well, blood isn't all cells - a lot of it is water. So just filling someone 1/5th full of what would probably be like a really fine powder...that'd probably screw up the blood pretty bad. Blood is already pretty tightly packed with cells, so I don't think we can dissolve that much powder into the remaining 4 liters without effecting key properties of the liquid. But fear not, intrepid scientists - we'll pump people with as many bots as we can! It turns out that when you separate blood, only about 40% of it is a combination of white blood cells, platelets, red blood cells, etc - with [60% being plasma](http://www.ncbi.nlm.nih.gov/books/NBK2263/). So why not take out a liter of blood, filter out all the plasma for mixing, add back in a liquid mixture of about the right viscosity as the blood cells, and pump that back into our frightened willing test subjects? Well, since we already have the figure for red blood cells and it seems that white blood cells are puny by comparison, let's go with that previous number of up about 6 million red blood cells per micro-liter of blood. If we filter out a liter of blood, that would give us room for 6 trillion bots! ...wait, that's almost the same figure we got earlier. What gives? Oh, right - giving blood is expected to cause mild (short-term) anemia! And we were figuring taking subjects who already had a high amount of red blood cells, so suddenly this makes sense. So we've still got the same figure: **6-7 trillion nanobots** (if we tell you we are giving your extra blood cells to sick children, will that make you stop screaming feel better?) We're still at 20% or less of the blood in nanobots...we have to go higher! ## Replace ALL THE BLOOD! Come on, what kind of scientists are we, anyhow? We know from our calculations that we easily can shove around 37 trillion nanobots into people by removing all their red blood cells, so why don't we just do that? "Oh, but won't the subjects die?" What are you, a communist? Let's face facts here - we have high technology, nanobots that are as small as red blood cells. Why can't our nanobots do the job of red blood cells, but ***do the job even better?*** Think outside the box, here! 100% nanobots! And why do all nanobots need to be the same? We'll make 4-5 trillion nanobots to do no job related to being a red blood cells, so they can do whatever. The other 33-34 trillion nanobots will do everything a red blood cell does, plus it'll probably do other cool stuff. We aren't banging rocks together here! As we figure out how to make nanobots do stuff even better than red blood cells (maybe using moon dust), we'll be able to shift the proportion of nanobots in favor of non-blood cell activities...like lasers, or something. ## Everybody gets 37,000,000,000,000 nanobots! whether they like it or not Early on, after we've worked our number up this high without publicly acknowledged any deaths, we start jacking up the counts to replace all blood cells with nanobots, and we can probably start allowing for thicker blood because our ThriveBots™ deal with any side-effects from high blood pressure, so I'd say we can start getting our count up over 40 trillion in the blood alone, no problems (none we allow to be reported, anyway). Maybe even up to 50 trillion, but it's going to get pretty hard to go beyond that. Say, skin cells are awfully sparse...how many layers of skin do you need, really, when you could have a few layers of EpiThrive™ - the superior human skin alternative! Guaranteed to not give you any cancer that is presently known to man! We'll have a few more trillion ThriveBots™ packed into you in no time! ## Final Nanobot Count * 3-5,000,000,000,000 nanobots for early, squeamish subjects - minimal side-effects, nanobots can't do red blood cell work * 6-7,000,000,000,000 nanobots with still minimal side-effects, but will cause anemia in all but high red blood count subjects * 37,000,000,000,000 nanobots, for those who've transcended their childish need for human red blood cells (may cause a change in skin tone, if we don't up-sell them to colored plasma additives) * 40 trillion and beyond, for real champions who understand that *Maximum OverThrive Technology™* is the true future of whatever it is we are calling human-technology hybrids now adays *[Minor side-effects](https://www.nlm.nih.gov/medlineplus/ency/article/000560.htm) may include:* grumpiness and irritability, feeling tired, fatigue especially after exercise, headaches, problems with thinking and concentration, desire to eat ice cream, desire to eat non-food items (organic and inorganic), blue colors to the whites of the eyes, light-headedness, pale skin, shortness of breath, heart murmur, rapid heart beat, low blood pressure, vitamin deficiencies, double vision, sudden and severe unexplained pain, a desire to be part of something greater, a strengthening dedication to The Collective, sudden instant death, restless legs (and arms), memory loss, vivid hallucinations, heart attack, stroke, loss of impulse control, decreased emotion or flat affect, and an increased awareness of the vileness of the common unimproved animal. Take nanobots only as directed, your mileage may vary. Please report all unexpected symptoms or side-effects to your personal ThriveBot™ representative immediately, before inconveniencing others or your doctor with things they are not capable of understanding. [Answer] I'm wishing I'd kept up my fluid dynamics now. A significant quantity could start affecting the viscosity of your blood which would place extra strain on your heart, making the long term benefits questionable. [Read the bit about blood viscoelasticity](https://en.wikipedia.org/wiki/Hemorheology). If your nano-bots don't deform in a similar manner to red blood cells you could have some very interesting effects. When I say interesting, I'm calling gangrene interesting, it may get as interesting as braindeath. [Blood cells](http://www.biosbcc.net/doohan/sample/htm/Blood%20cells.htm), most importantly this article includes a couple of measurements. In this case 7μm and 3μm are your critical values, the first being the size of a red blood cell and the second being the smallest capillary it has to get through. (Ignoring the fact whoever wrote that site can't insert μ as needed). I would suggest that your nanobots should be able to mimic this behaviour, having the same plasticity as red blood cells. it'll make the later calculations much simpler. What we need to know next is how much material the circulatory system can handle and what the penalties are for exceeding that. [RBC count](http://www.nhs.uk/Conditions/Red-blood-count/Pages/Introduction.aspx) > > * male – 4.7 to 6.1 million cells per microlitre (cells/mcL) > * female – 4.2 to 5.4 million cells/mcL > > > Those are some big numbers and largely meaningless in real terms. What you're looking for is the difference between them, around 20%. Now if that's not a simpler calculation I don't know what is. *The trick now is stopping your body from treating them like dead cells and just filtering them out.* [Answer] You could also have nanobots "stored" in an organ, and released when others nanobots sense (nanobots specialized into closing wound released by others nanobots feeling pressure). Of course at a given time you can not have more than the given % active, but you can have a lot more inactive. [Answer] Great question. The main concern I'm thinking of is the following : too many nanobots will prevent the necessary amount of red blood cells from flowing through the veins normally. So, blood circulation problems, oxygen delivery problems, heat distribution problems... You do not want to deal with that, and you don't want to reduce the amount of red blood cells in the blood either. So every nanobot (or whatever it is) you add in the body will be added to the already flowing red blood cells. **Size** will apparently not be a problem since > > Each one is about the size of a red blood cell. > > > So the thing you want to focus on is just the proportion of bots compared to the blood cells, so that the red blood cells can keep working among the nanobots. But since you don't want to replace blood cells with nanobots, keep in mind that each bot you add in the blood will take one more room in the veins. I am no mad scientist, so I have no accurate numbers to give you, but I doubt you can put more than 10% of the total red blood cells in nanobots inside the veins. More than 10% would probably cause trafic jam, so to speak. ]

[Question] [ **The Details:** The human body is capable of impressive acts of self-repair, but such processes take a lot of time, and can take a toll on the body. Infection or other complications can also develop, and sometimes a wound/inflammation may not heal entirely or correctly without external help. We see such things done in fiction, but it always seems to just *work*, without any adverse effects or real costs. **The Question:** Let's assume that "external help," whatever it is, is capable of increasing the healing rate of the body to incredible levels. (See: [Wolverine](http://en.wikipedia.org/wiki/Wolverine_%28character%29)) Acting under the assumption that this "external help" merely speeds the process of the body's own *natural* healing ability without necessarily adding any great amounts of energy or any material, what biological effects would a human being experience during the process, and immediately after it was complete? Would they suffer from a lack of proteins due to cells being rapidly multiplied, or a lack of other material used in the body? Would they feel tired due to their system's exertion of compressing weeks/months of healing into a fraction of that time? As a baseline, let's take a simple abrasion that wouldn't cause any great deal of alarm if it were to happen to you right now. Worst case, it becomes mildly infected. Your body will fight off the infection and, with time, heal the wound. You are now fine, and can continue on with your life. Until... Suddenly, you suffer another near-identical abrasion that suffers from a similar infection (let's say immediately, because you are an excellent lab experiment terribly unlucky.) I now invoke my otherworldly healing powers and, within seconds to minutes, you're all fixed up. What happens to you in that time? **My thoughts:** * The healing process takes energy, generates heat, etc. You will feel quite tired, perhaps warm in the afflicted area, and really want a snack. How this would affect your blood cells (platelets, leukocytes, others) I do not know. * Scarring will still occur as it is a natural part of the healing process, but it may be reduced, a near perfect example of healing. * If a bone is broken, it can be repaired, but will need to be set just as a normal bone would have to be. If a finger was cut off, it wouldn't regrow unless that was a naturally occurring process. * Dependent on HOW the healing helps, it could simply cause the damaged cells to repair and multiply, completely ignoring the normal healing process, but still meeting the end goals, and prevent any possibility of scarring. This is, of course, not the question but would make for an interesting comparison. * Someone will make a joke about their superhuman healing ability, because I targeted "you" in the question. * Dammit Jim, I'm an electronics guy, not a doctor! [Answer] ## To start, lets do a rough estimate of how much the healing rate has been sped up. Lets assume a week to heal the original abrasion/infection fully - 7 \* 24 \* 60 is 10,080 minutes. Conveniently, that means we can say the new abrasion/infection heals in (very slightly over) a minute, for a nice round 10,000x acceleration. ## So what does that mean in practical terms? We'll start with the naive approximation - assume that the magic does healing and nothing else. (And we'll conduct the experiment on a third-party, because my contract says I'm exempt from experiments on dangerous, untested magical technologies ;) ) You noted that the magic isn't providing any significant amount of energy, so the body has to do that itself. An infection like this is often slightly inflamed under normal healing, so lets assume that the body would be at least doubling or tripling the normal blood flow in order to provide the energy and material for the healing process (I.E. an extra 1-2x normal usage). That means we need somewhere between 10,000x and 20,000x the normal allocation to supply our accelerated healing. This is the point at which warning bells should start going off. As soon as the healing process kicks in, the tissue immediately surrounding the wound will be drained of any and all resources near-instantly. Blood vessels will dilate and blood flow will increase, but there's absolutely no way that we're going to get a 10,000x increase in blood flow. The wound and surrounding area are going to be oxygen-starved until the healing process is complete, and probably looks like a *really* swollen, dark-blue bruise right now. That lack of oxygen wouldn't be a problem if the healing really was going to be over in a minute... but it isn't. The healing can't be done until the required resources arrive, and they're not arriving at anything near 10,000 time normal speed. So we've got an area of oxygen-starved tissue that we expect to stay oxygen-starved for some time. I can't find any solid references for how long it takes for cell death due to anoxia to kick in, but it seems to be somewhere between 10 minutes and a couple of hours. Unfortunately for our patient, those are being quoted for oxygen starvation due to a tourniquet, and that's going to be *low* oxygen; not the magically-enforced, 99.999% effective, *no* oxygen environment we have here, so we'll assume the low end of that range. Fifteen minutes later, therefore, we have cells dying from lack of oxygen and energy, and that means the beginnings of gangrene... which is going to ***really*** get the magic going. At this point, we're shifting from using all of the available resources *locally* to using up a significant fraction of the body's *total available resources*. The patient's heart rate will skyrocket and he'll be gasping like he just ran a marathon, but unfortunately for him his heart and lungs are no more capable of scaling up 10,000x than his blood vessels were. We're firmly in the grip of runaway positive feedback here - any attempt at healing causes extra damage, which requires more healing, which causes extra damage... I won't attempt to calculate how long it would take, or what the exact cause of death would be, but it's clear where this process ends. *Something* is going to fail, fatally, and our patient is going to wish he'd never seen that ad for clinical trial volunteers. ## Wait, that's not actually *healing* at all! All the above really demonstrates is that we have some [Required Secondary Powers](http://www.tvtropes.org/pmwiki/pmwiki.php/Main/RequiredSecondaryPowers) in order to get this to work correctly. One of them actually comes built-in - blood cells aren't going to be a problem, because the same processes that are accelerating cell division for healing can be easily turned to producing as many of them as we need. A second requirement is a significant increase in the efficacy of the circulatory system in order to transport oxygen and other supplies fast enough to keep everything running smoothly. My preference here would be a combination of magical enhancement to let the blood carry far more oxygen/sugar/etc per unit volume, and an increase in blood circulation speed to help with moving enough platelets/white blood cells/etc to the injury site. (A neat little side-effect of this and the fast-repair is that the subject becomes almost entirely immune to fatigue. He'd be able to run a marathon at either 100m-sprint pace, if his lungs were enhanced, or more like 800m/1500m pace if they weren't. Same with weight-lifting, carrying heavy packs, etc - he just *doesn't get tired. Ever.*) If you want actual Wolverine-style healing-in-combat, then you'll also need magical breathing- and digestion-enhancement, since that's going to need huge amounts of oxygen and stored sugars/proteins/etc for rebuilding tissue on the fly. (And the subject is going to need to eat a *lot* more than usual whenever there is healing going on - whether that's during the process or just afterwards to recover depends on exactly how much they're able to store.) On the other hand, if magical stabilization and a quicker-than-normal recovery is enough, then the magic just needs to be smart about using the resources that are available - with supernatural assistance, even sealing off a major artery shouldn't be too difficult. This does mean that your super-healer can be killed far more easily, though - just stab him in the heart once a minute until he runs out of reserves. Another thing to think about is positioning - the way an injury (naturally) heals if any cuts are stitched and bones are set is drastically different from what happens if everything is just left twisted and gaping. A pure speed-increase won't change that, nor will it decrease scarring (other than making it fade faster). On the other hand, if the magic somehow knows how everything 'should' be arranged - that is, it can work on the injury *as a whole*, instead of just operating at a cellular level and ignoring the big picture - then it's perfectly plausible that it would provide perfect healing. (If it doesn't account for the big picture, then a serious injury could 'heal' in a way that would cripple the patient - and the speed would mean that any bone-setting and wound-stitching would need to be done *very fast*) Two potential side effects to think about are cancer and accelerated aging. Cancer is essentially cell-division-in-permanent-overdrive, which is not far off from what we have here. If the magic's control of the process is anything less than perfect, you're looking at a major cancer risk (which might be partially/fully countered by the healing, of course). Secondly, one of the major components of aging is [telomere shortening](https://en.wikipedia.org/wiki/Telomere#Shortening), which is linked to cell replication. If you increase the average rate at which your cells replicate by a factor of ten, then you're also increasing the rate at which you age by a factor of ten. [Answer] **Still TL;DR** It's not possible because biological functions are so inextricably interrelated that speeding up JUST ONE process (wound healing) requires speeding up everything, and that leads to a ton of problems. **TL;DR INTRO** \* It boils down to the fact that you need to account for these factors: * The wound-healing itself – What is the basic process, how does it differ based on a multitude of factors, and why does it happen at the rate it happens rather than super-fast? Can we imitate the fetal wound-healing process in adults, so that it’s faster and doesn’t leave a scar? * The way that cells divide – Wound healing is basically the process of repairing existing tissue, making new tissue, or both. The repair of tissue and the generation of tissue both require the body to produce a bunch of new cells. How does the rapid proliferation of cells needed to heal wounds happen? What kinds of aspects of cell division and DNA replication change when the proliferation happens faster than normal? Is there a mechanical or biological limit to how fast this can occur? * The stem cell → specialized cell process – what causes cells to differentiate in a particular way? How do different types specialize at different rates? If everything is sped up, can they retain their functional interactions with one another at every stage of development? * The ways and rates of cell interaction –cells interact in specific ways, and so the questions become how do they change during rapid wound healing? How can we possibly account for the sheer number of interactions? To give some perspective on that massive (effectively infinity) number of cell interactions, take a look at the signaling pathways for PI3K/Akt signaling (from cellsignal dot com)... There are all those interactions (and that isn’t even all of them) for *one specific* kinase, Akt, with *one specific* activator, PI3K. Now consider there are 500 kinases and 50 kinase receptors in a human. That’s 25000 of those maps in the link, *just looking at* kinase/kinase receptor interaction, which is a type of stimulus/receptor reaction, where there are trillions of types of stimuli and thousands of receptors. * Assembly – What’s the physical assembly process for cells → tissues → organs → organ systems → organisms? Will there be enough volume to accommodate and structural mechanisms to support new tissue if it is generated much faster than normal? * Transfer rates – Biotransport is an entire course, but it basically boils down to how heat (external, homeostatic, activity-resultant), mass (tissues, cells, nutrients, waste), fluid (blood, interstitial fluid, water, waste fluid, lymph), and energy (external, metabolic(chemical), byproduct) flows and rates work in the body. What happens to these rates when we change the time constants? * The diverse nature of tissues - What part of the body is being rapidly healed, and what types of tissues does it contain? What are their differences? How do they interact with one another, and how is this changed by speeding up everything? **ANSWER** As you can hopefully tell from the intro, everything changes when you speed up wound-healing. To answer your initial question, there are LOTS of costs and effects. To explain, here’s a mathematical analogy. All time-rates are dx/dt, the derivative of whatever your'e measuring x, with respect to time, ie. Change in x over change in time (for a specific differential element that is representative of the whole, or is later integrated over the range of the whole {just ignore what is in the parenthesis if it confuses you}). Say dt changes, i.e. The same amount of change in x occurs, but over a different amount of time t. If you want to keep the same value for dx/dt, then you have to change dx by a specific amount. This is easily visualized if you think about the derivative dx/dt as just a fraction. So, applying the nature of time derivatives to your question, we assign x(t) as the amount of any quantifiable biological entity, as a function of t, time. Then dx/dt is the time derivative of whatever that x is, or, the rate that x changes with time. So now let’s define x as any process or substance required for wound healing to happen at its normal rate. That means dx/dt is the rate of any process x that corresponds to wounds healing normally. Whatever the value of dx/dt is, it’s that way for a reason. All the functions I listed above, during the intro, have specific dx/dt’s because that is what is efficient for human anatomy & physiology. Now, to get wolverine-speed healing, we’re essentially trying to decrease dt, so that it takes less time for x to occur. But if you change dt without changing dx (which isn’t really physically possible), then dx/dt HAS to change, and thus, you really cant maintain healthy physiological rates in the body unless you change EVERY x, and there are, as discussed before, effectively an infinite amount of x’s → infinite amount of things to account for if you want the body to accommodate rapid wound healing. So what you're asking in terms of what are the consequences can be re-worded, in the context of our analogy → what are the consequences of changing dt without changing dx, and thus causing dx/dt to deviate from a healthy value? To address your particular speculations: EXPERIENCE DURING THE PROCESS - Pain, lots of pain. Your body isn’t equipped to handle the amount of nutrients in and wastes out that’s needed to accommodate the processes of wound healing when it’s happening faster than healthy. Therefore, the inevitable guest is pain, and it comes from three different paths: 1. You don’t have enough physical space in your body to account for the increased x, whatever x is, that’s needed to regenerate tissues (recall that’s what wound healing is)… So all your organs would need to be bigger, but, unless the magical power of speed healing also makes you huge, you’re NOT bigger. That means all your organs are pushing up against each other. People with nerve degeneration who experience their bones rubbing against one another cite it as the most excruciating pain they’ve ever felt. So yeah, have fun when not only your bones, but also your INTERNAL ORGANS are all pushin up on each other like 6th graders at their first boy/girl dance. But at least your papercut healed in 5 minutes, right?! 2. Really fast rates of waste production that demand routes of exit. More cells means more waste products, and when your body isn’t equipped to get rid of them, you’re not gonna have a good time. By condensing a year’s worth of healing into a few minutes, you’re generating a year’s worth of waste in a few minutes. Even if that process was just happening on the organ level, it wouldn’t be too fun, because that means you’d be pooping out a year’s worth of poop in a minute. But, recall that the body exists as an assembly of cells → tissues → organs → systems → human. . . If organ waste increase is that terrible, then cell waste increase wouldn’t be painful I guess, because it’s probably just impossible. 3. Similarly, super fast healing rates that produce waste fast also require fuel fast. See the fatigue section for this answer. POST PROCESS EXPERIENCE - The process above isn’t something your'e going to survive, so I guess your post-process experience depends on your opinions with regards to the afterlife. MATERIAL SHORTAGE /METABOLISM FAILURE → FATIGUE I’m combining your two speculations because one leads to the other. The short answer is just yes. Absolutely, unequivocally, yes. We talked before about how there’s both more waste produced and more resources required when you speed up wound healing. There’s a whole branch of research, biotransport, dedicated to studying these rates, and it’s more complicated than you could ever imagine. Take a look at this model of oxygen flow through cardiac cells if you don’t believe me: <http://link.springer.com/article/10.1007%2FBF02460984#page-1>. So basically when you increase the rate of wound healing, every rate that mentions time in that article (basically all of them) diverges catastrophically from normal physiological values… and your metabolism fails, meaning your body fails. So let’s look at that in the context of energy production. The process of cellular respiration oxidizes the molecules – mainly glucose – in the food you eat and combines it with oxygen, causing a reaction that produces water and $\text{CO}\_2$, and, in the process, releases ATP, adenosine triphosphate, which is where your energy comes from. This is stated: $\text{C}\_6\text{H}\_{12}\text{O}\_2 + 6 \text{O}\_2 → \text{ATP} + 12 \text{H}\_2\text{O} + 6\text{CO}\_2$. If you regenerate tissue too fast (ie. Your wounds heal too fast), then there are more cells, so more cellular respiration is required. However, assuming there’s the same rate in of $\text{O}\_2$ and $\text{C}\_6\text{H}\_{12}\text{O}\_2$, you aren’t able to produce as much ATP. You can quantify and validate my statement by the method of limiting reagants from a basic chem. Course. So it’s pretty clear that the amount of $\text{O}\_2$ on earth isn’t going to magically increase, and I am assuming the superpower doesn’t include a process that increases the capacity of your bronchioles or decreases your required $\text{O}\_2$ saturation, so the $\text{O}\_2$ isn’t changing. And, even if you eat more food, there’s a limit to how much glucose ($\text{C}\_6\text{H}\_{12}\text{O}\_2$) your body can actually harvest from it, so you aren’t going to be able to increase the amount of glucose in either. Hence, your body wont be able to produce enough energy (ATP) to make all the new cells function correctly → you’re going to be very, very tired. To bring up additional concerns: * Nerve damage for severe wounds – Does the wound healing power also regenerate nerves? If the wound goes deep enough, this will be a major concern that’ll lead to damage beyond the mere physical wound itself. * Cell repair vs. division – So it isn’t enough to just divide cells, because, in certain epigenetic instances, a damaged cell will divide to produce more cells that are just as damaged. In this case, it might be better to not have more cells than it is to produce more cells with the same problem. In order to really heal wounds, cells have to repair before dividing. * Ethical concerns – because ethics. And for your abrasion example, what happens is that you die. But your corpse is abrasionless, so yay! So basically, there’s a reason that wound healing happens in humans at the rate it does, and it’s not feasible to speed it up much (unless we can somehow biomimic fetal wound healing). If it is possible, then there are A LOT of considerations to be made about A LOT of different factors. In conclusion, that’s not a very useful superpower and will probably kill everyone you use it on. ADDITIONAL REFERENCES - Wikipedia pages for basically everything I mentioned - Human Anatomy & Physiology by Dee Ungalaub or something like that; too lazy to look it up - MBOC at molbiolcell.org - Principles of Tissue Engineering by Robert Lanza - Wound Healing/Tissue Types book at www.ncbi.nlm.nih.gov/books/NBK3938/ * I wrote a ~14 pg. intro that goes into cell bio, regenerative medicine, wound-healing processes, & everything I’ve listed above in much more detail, with several mathematical & computer models. Feel free to email me if you want it, but im omitting it in case I want to turn it into a publication… I didn’t expect to get this hyped/write this much about rapid wound-healing. [Answer] > > Infection or other complications can also develop, > > > Infections are largely caused by stuff getting into the body. Rapid healing would reduce the window for such things immensely. Also, stuff gets into your body all the time, but your immune system can kill those things quickly and easily. Most plausible super-healing would be able to make boatloads of immune cells as well as regenerative bone/tissue/etc. making infections unlikely (unless the healing magic also proliferated the infection cells too... oops). > > sometimes a wound/inflammation may not heal entirely or correctly without external help. > > > I'd imagine that broken bones would not magically reset themselves, and you would need to be careful about super-healing them lest the bone be disfigured. Though with super healing, it's straightfoward (albeit painful) to re-break the bone and set it properly. Scarring would probably also be a problem, unless the super healing allowed evolution to just use normal skin cells rather than scar tissue for repair. [Answer] There are a lot of great answers here, and the facts stand up. I am a trauma nurse by trade and have some experience with wounds and healing. I find a lot of the answers above are scientifically correct, but give you no practical solution. I want to list one way to justify and use healing in fiction that is more realistic and can work well. ### High caloric cost The scientific basis is that flesh is made primarily of protein and fats, which your body stores as muscle tissue and fat. The person being healed can pay a price in calories equivalent to the injury. Your big burly character just took a ton of damage, maybe even near death, then he is healed. He looks down to see his clothes are several sizes too big an he looks like he just walked out of a Nazi prison camp. He will then need to address feeding quickly and effectively. Let's say he broke his arm instead, it's painfully set back into place, then healed. He is famished but otherwise OK. If he gets a cut and is healed quickly, I would not worry about infection except in special circumstances, because the infection had no time to take hold. A whip lacerates your heroine's back. She is rescued and healed shortly after, no need to worry about infection. Your hero's best friend Jacob is bitten by a Zombie, your team quickly heals him, but the incredibly virulent Zombie pathogen is fatal if even one viral particle makes it into the body. Foreign bodies like bullets can be pushed out of the wound by the tissues healing from the inside out, but if you are talking shrapnel or broken glass, those may need to be removed manually prior to healing. [Answer] Depending on how the clotting factor works with this, for say, a cut, you could see an increase in infection. I'll push an example to illustrate. Say you slice through part of your finger. Fingers will almost always give you a good bleed, which isn't a bad thing because it does flush the wound without the immediate danger of bleeding out. You don't rely solely on the bleed to "clean" the wound, you still flush that wound, which is really just done with tapwater (really, just tapwater), or in the ED, sterile saline. Either way, both the purpose and the end result are the same, a good flush and dilution of any contaminants remaining in the wound. Then you stop the bleeding and seal it up with some variation of glue, stitches, steristrips, etc. Immediate closure/clotting of such wounds could be problematic, depending on location, depth, and wound type. Large debris is going to cause irritation (think in terms of that splinter you ignored) And taking a stance of just slapping antibiotics on anything prophylacticly and/or unnecessarily has proven problematic. Just "healing" what is there "as is" can definitely have a dark side, which would make for better fiction. That's a digression though. Also, faster clotting beyond the simple wound flushing aspect, problematic. I won't wax poetic on the many uses of blood thinners, and the number of people who take them daily to stay health(ier). This superhealing capability you're after would have to have an internal regulation on clotting factor. I have this image of my last yardwork injury and a wound super healed around splinters and fir debris. Ouch! Or a bullet in a torso with vasculature healing around both bullet (fragments) and gut spillage, which while it might protect you from bleeding out and/or spilling bits of yourself onto the pavement, could very well result in sepsis due to all the "crap" now trapped in your torso. Re-knitting tissue fast isn't enough, you'll still need to mechanically clean things. [Answer] Another thing to consider can be time compression instead of actual chemical acceleration (which would be bound, no matter what, by physical constraints like the diffusion limitation of catalysis in biochemical reactions). Time compression on the other hand, can be virtually unlimited, the physical processes carry through normally but time is compressed in a specific 3-dimensional area or "bubble". Drugs (antibiotics, antidotes) would still have to be taken, for the former, possibly in bulk. Another option is not "healing" in the traditional, repair-the-damaged-cells-fast-sense, but simply **replacing** the damaged cells with healthy ones. In that case, healing is instantaneous (or very close to it) [Answer] You can speed up the heart rate to affect healing....the extra blood flow accelerates natural repair to what would have been a future point. trick is to also flag the immune system which 1900 century scientists perfected only to be silenced by emerging pharmaceutic companies. Basic physiological outcomes. ]

[Question] [ In [this question](https://worldbuilding.stackexchange.com/q/10901/75), I asked about a universe with (amongst other things) 4 large spatial dimensions. In 3 dimensions, we have the familiar [periodic table](http://en.wikipedia.org/wiki/Periodic_table) with its familiar arrangement of atoms in the S, P, D, F and the predicted G & H blocks. However, in four dimensions (with the assumption that electrons, neutrons and protons exist), what would the periodic table look like, given that there is another dimension in which to put electrons? Also, since in four dimensions, objects can have two axes of spin, would electrons have four possible spin states rather than two as in 3-dimensions, resulting in yet more electrons per shell? In addition, the atomic [islands of stability](http://en.wikipedia.org/wiki/Island_of_stability) are predicted in three dimensions by the [nuclear shell model](http://en.wikipedia.org/wiki/Nuclear_shell_model). Given an extra dimension, as well as the possible extra two spin-states, what would the [magic numbers](http://en.wikipedia.org/wiki/Magic_number_(physics)) for protons and neutrons be in 4 dimensions? [Answer] In four dimensions, you don't have a rotation *axis* (fixed straight line) but a rotation *plane* (fixed plane). However, not every 4D rotation has a rotation plane; there are rotations which have no fixed points (except for the origin). Indeed, rotations in 4 dimensions have six parameters instead of the three we know from 3D space. The corresponding rotation group is known as $SO(4)$ (as opposed to $SO(3)$ for 3D space). You can read everything about it [on Wikipedia.](https://en.wikipedia.org/wiki/Rotations_in_4-dimensional_Euclidean_space) To obtain the corresponding quantum spin, we have to look for its [universal covering group.](https://en.wikipedia.org/wiki/Covering_group#Universal_covering_group) The universal cover of $SO(4)$ is $S^3\_L\times S^3\_R$ (see the linked Wikipedia article) which is a double-cover of $SO(4)$ (just like in the $SO(3)$ case). Here $S^3$ is the group of unit quaternions. Since the group of unit quaternions is isomorphic to $SU(2)$, this means that the universal cover of $SO(4)$ is isomorphic to $SU(2)\times SU(2)$. This gives a much richer structure to the spin of 4-dimensional particles. While in three dimensions, the representation is labelled by one number (the total spin), four-dimensional particles are classified by two numbers, which might be termed the left-spin and the right-spin, corresponding to the left and right Clifford rotations. The simplest particle would still be the spinless particle, with spin $(0,0)$. However the lowest non-spinless particles would come in two sorts, with spin $(1/2,0)$ and $(0,1/2)$. Each of them would have only two levels. However it *might* be that there's an additional symmetry between left-spin and right-spin, in which case those two different particle types could indeed be seen as one type of particle with four different spin states. However that's not really necessary; it is just as well possible that particles with spin $(1/2,0)$ are distinguishable from particles with spin $(0,1/2)$. However let's for simplicity assume that there is indeed such a symmetry. And let's assume that electrons are such $\{1/2,0\}$ particles (using curly braces to stress that the order no longer matters since all orders are included). Then you'd indeed get four electrons per level (ignoring fine structure effects). However that would not be the only effect on the periodic table: Also the orbit angular momentum of the electrons would be guided by the two quantum numbers; however in analogy to in the 3D case you'd only get actual $SO(4)$ representations (that is, integer quantum numbers). Thus where you get one pair of quantum numbers $l$ and $m$ for 3D, you'd get two of them for 4D. So assuming that the main quantum number is not affected, you'd get the following orbital quantum numbers: (n; l1, m1; l2, m2; s1; s2) Assuming that in leading order the energy is still dominated by $n$, and the restrictions on $l$ are individually as in 3D (one could explicitly check that, but that's more than I'm willing to do that late in the night), you'd therefore get the following lowest degeneracies for each $n$ (lifted by fine structure), given by (left angular momentum)×(right angular momentum)×(Spins): * $n=1$: fourfold degeneracy ($1\times 1\times 4$) * $n=2$: $64$-fold degeneracy ($4\times 4\times 4$) * $n=3$: $324$-fold degeneracy ($9\times 9\times 4$) Note that when the first three shells are filled, we are already at element number 392. Unfortunately I don't know enough about nuclear physics to say what the magic numbers there would be, and up to which element number nuclei would be still stable. Note also that even if you assume that $(1/2,0)$-spin particles and $(0,1/2)$-spin particles are inequivalent, and electrons are e.g. $(1/2,0)$ particles, this would only cut the numbers above in half. **Edit:** I noticed that I overlooked the most crucial difference in four dimensions: Thanks to the Maxwell equation $\vec\nabla\cdot\vec E = \rho/\epsilon\_0$ we get for a point charge in $d$ dimensions a field that falls off as $1/r^{d-1}$, and therefore a potential that falls off as $1/r^{d-2}$. For four dimensions, this has far-reaching consequences: * In quantum mechanics, an attractive $1/r^2$ potential has no ground state. Now, the *real* potential will deviate from that in the nucleus, since the nucleus has finite size. However that means that the position of the ground state depends very much on the charge distribution of the nucleus; unlike in three dimensions, the approximation as point charge will *not* work well. This means that the periodic table might be quite messed up, since the charge distribution depends not only on the number of protons, but on the number of neutrons (because that number enters the size). This might cause noticeable differences between atoms which only differ in the number of neutrons (and therefore in our 3D world would have basically the same properties). * Since the centrifugal potential also goes with $1/r^2$ (but is repulsive) [irrespective of dimension](http://arxiv.org/abs/1308.4770), and thus in 4D would be of the same form as the attractive force of the nucleus, outside of the nucleus any angular momentum would simply act like a reduction of the nucleus charge. This especially means that there's a maximal angular momentum that can be achieved before electrons stop being bound. ]

[Question] [ Go to the kitchen, open your baking utensils and make yourself a tinfoil hat. Put it on your head before continuing to read this question. Done? Ok: Let's have an alternate Earth where [The Illuminati](https://en.wikipedia.org/wiki/New_World_Order_(conspiracy_theory)#Illuminati) exist and dictate the main events in history. This group is responsible for these events (examples, list is not exhaustive): * [9/11 attacks](https://en.wikipedia.org/wiki/September_11_attacks) * [Fukushima disaster](https://en.wikipedia.org/wiki/Fukushima_Daiichi_nuclear_disaster) * [Arab spring](https://en.wikipedia.org/wiki/Arab_Spring) * [Ukrainian crisis](https://en.wikipedia.org/wiki/Ukrainian_crisis) * [Syrian civil war](https://en.wikipedia.org/wiki/Syrian_Civil_War) * [European migrant crisis](https://en.wikipedia.org/wiki/European_migrant_crisis) The Illuminati group consists of [42](https://www.google.com/?q=the+answer+to+life+the+universe+and+everything) people who really do lead the world as we know it (Through bribes and blackmailing politicians in power). But, for whatever reason, this group needs to meet once every month to discuss the next steps in the [New World Order](https://en.wikipedia.org/wiki/New_World_Order_(conspiracy_theory)). Where would these people meet? P.S.: All of them are human. No superpowers, no aliens involved. You can take your tinfoil hat off (for now). **Edit:** Reasons to meet in person? Plotting in person is much more fun. And with all these Assagnes and Snowdens, you never know who is listening... [Answer] They meet at sci-fi and cosplay conventions, dressed up as the Illuminati so they can discuss world conquest without worrying about being taken seriously. [Answer] They were quite cunningly hidden, but I finally discovered the hidden Illuminati ploy to meet at the regular **European Tax and Regulatory Compliance Group for the [Cucumber Growers Association](http://www.cucumbergrowers.co.uk/)** meetings, held once a month in a regular hotel in various small post-industrial towns in Western Europe. They will use code words like `Cornering the Cucumber Market` for world domination, `ensure regulatory compliance` for bribes and blackmail, and `cucumber dumping` for massive terror events being planned. [Answer] In Isaac Asimov's *Second Foundation* book he has a group meet in secret. At first they try to do things clandestinely, but [Arkady Darrell](https://en.wikipedia.org/wiki/Arkady_Darell), the daughter of one of the conspirators, chastises them and says that the absolute best way to keep a secret meeting secret is to do it completely in the open. Instead of sneaking around, closing window shades and using various tricks to defeat devices that might be listening in the best way was for the participants to have a real reason to see each other and to be completely open about it. People suspect things are going on when you act suspicious and try to be hidden. However, people won't look twice at a few people having lunch at a local restaurant. So, where would these people meet? **In the open.** You wouldn't even know they were planning the next steps of the world order because you'd think they were just talking about normal business. Probably at a normal business lunch, a convention or even just a Christmas party at someone's house - as long as there is a viable reason for them to be seen with each other. **update** I watched [Quantum of Solace](https://en.wikipedia.org/wiki/Quantum_of_Solace) last night. The Quantum organization met in public at an opera. Each member was given a short wave radio ear bud that allowed them to communicate while watching the show. Of course, Bond managed to get an ear bud and listen in. [Answer] Their main concern is going to be people listening to their meetings, which could be done with recording devices or by walking in on them. The best way they could avoid this is to pick a different location every time, never going to the same place twice and only letting all 42 of them know the location shortly before they meet. (As they would probably be in different countries beforehand, the member deciding where to meet that month would let them know the airport to fly to a few days before and only tell them the building when they arrived.) They would pick inconspicuous locations, and would try to vary the type of location. One month they might rent a room from a hotel for a day, and would appear to be having a business meeting. Another month they might meet in a building scheduled for demolition; anyone watching the building would only see people dressed as construction workers walk in. There would either be no records of the event (e.g., they bribed the owner of the construction company to give all his workers the day off), or there would be an extensive paper trail that would never be linked back to them (e.g., the meeting room was paid by one of the many large companies they control that would normally book rooms for its actual meetings). Of course, every location would still be checked for recording devices, explosives or anything else suspicious before the leaders arrive. Their people would go in as consultants from another construction company, or temporary cleaning staff (whatever is appropriate for the location) beforehand. They would install cameras around the site, so that during the meeting the leaders can be told someone is approaching. They may consider meeting physically to be too risky, and only meet once a year but use video conferencing regularly. They could use encryption to communicate securely or talk in code. Anyone listening might just see a normal company call (or both, I would expect them to be quite paranoid). [Answer] In Italy there are various groups from the Mafia to P2 that hold a lot of power and there were years were those groups operated without them being publically known. Those groups don't seem to have had any problems with meeting locations. They own enough real estate to have locations to meet. Bilderberg meet for many years without mainstream media writing about the existence of the event because the Bilderberg attendants had enough influence on the mainstream media to tell them not to report on it because it's a private event. That argument about a "private event" had an effect even through various organisations paid money for Bilderberg attendants to attend as a business trip. Of course that institutional money flow resulted in more people knowing of Bilderberg than people would have known if Bilderberg optimized to be as secret as possible and Bilderberg attendies wouldn't have told the people around them where they are travelling to. You read in the mainstream media that the 2004 election in the US was about a candidate from the Republican vs. a candidate from the Democrats. You didn't read of it as a candidate from Skull & Bones vs a candidate from Skull & Bones, because that wouldn't be "serious reporting" even through both of the candidates where from Skull & Bones which is a Yale fraternity as you can verify via Wikipedia. The key of a secret society being secret is that it has enough influence to encourage people not to talk about it. [Answer] They would meet in cyberspace. The advances in military-grade encrypting available to the masses has been documented to be for freedom fighters and oppressive regimes, so (pgp for example) was pushed out free and open sometimes in direct disobedience of property claims. Later, US laws were changed to allow for commerce, so they say. Peer reviewed "real" crypto that even the NSA can't break is used in preference to government-imposed standards and key escrow schemes. All that and more, regardless of popular excuses and real benefits to everyone, is due to the secret society popularly known as The Illuminati, for its own privacy and secrecy. [Answer] Since these are 42 people who wield enough power to influence much of the world, they're probably mostly very wealthy, either from old money families, royalty or captains of industry, maybe a few of them may be powerful politicians. While not necessarily known to the general public, most are likely to be recognized by business associates, journalists or analysts, and some may be tracked as to where they travel because of their prominence. So for the group to meet in person on a regular basis would mean they would probably meet in cities when there are pre-planned events that draw a lot of people from all different classes, including many other unrelated, wealthy, prominent world citizens. Once in a city, they'd likely be staying in different hotels or apartments and their movements within the city would less likely be tracked and they could get around to their meeting place. Only 42 chauffeurs might connect them when they all park near each other. I'd imagine they'd have plans to meet in big cities when there are major sports events, with a number of them holding tickets. That way when journalists and analysts see them flying in, they'll just assume it's for the sports event, at which they'll probably put in an appearance anyway, take some of their clients, associates or friends to their box seats, etc. Other sorts of things might be big annual festivals cities hold, holidays, or royal weddings, Presidential inaugurations and so forth. [Answer] The [Bilderberg Group](https://en.wikipedia.org/wiki/Bilderberg_Group) meet at five-star hotels with golfing facilities. > > "A tiny, shoestring central office in Holland decides each year which country will host the next [annual] meeting. Each country has two steering committee members. They say that each country dreads its turn coming around, for it has to raise enough money to book an entire five-star hotel for four days (plus meals and transportation and vast security - every package of peas is opened and scrutinized, and so on)." > > *-From [Them](https://books.google.com/books?id=Okg6WBbMjzQC&printsec=frontcover#v=onepage&q&f=false) by Jon Ronson, pp. 290-291.* > > > Whether or not you think the world of Jon Ronson's book is fictional, or make the same conclusions about "illuminati" as some of its characters, is up to you...this is a worldbuilding site and neither answers to this question nor what you do with them after have to be accurate to present-day real life. This, and [Bohemian Grove](https://en.wikipedia.org/wiki/Bohemian_Grove) as suggested by Hannover Fist's comment, is where Ronson "hid" the "illuminati" (or closest equivalent) in his book. Surprisingly enough, groups like G8 and G20 and even the UN General Assembly, which all have more publicized meeting locations, didn't get much mention. [Answer] If they absolutely have to meet in person and cannot telecommute, and cannot be connected to each other via finances/ shared interests etc. then I would suggest they each meet in a modest suite in a hotel near an airport every month. Assuming these incredibly powerful people got that way by pre-planning everything, then they will have their next monthly meetings planned out for at least a year in the future. This means that they can have their people booking these suites under different aliases in order to not be connected to each other. There can also be a myriad of reasons why these people would all be present in the same location at the same time at one of these sites: vacations, book tours, business meetings, layovers whilst waiting for a connecting flight, passing through whilst driving from one place to another. Then they all can go to this same location for different reasons (eat at the restaurant/ drink at the bar/ booking a room). This means that they would not be connected via similar functions/ interests, as there wouldn't be records of them all in the same place at the same time for the same thing, so they wouldn't be connected that way. It would simply be mere coincidence that all of these people are nearby at the same time, and wouldn't be connected to each other unless someone already knew all of their identities. There are also an enormous amount of locations around the world in which they could meet. They could meet in a different country every single month and still wouldn't have gone to the same country twice after a decade. And there would be dozens of hotels available in each of the airports in each of those countries. Booking a larger suite (not the largest because that might make people curious as to who is staying there) means that there would be enough room for them all to interact comfortably with each other and wouldn't arouse suspicion. In addition, if the hotel is at least reasonably large, having various strangers wandering about would not arouse suspicion, as there will be a heavy number of strangers there for a short period of time (particularly if it is near an airport and is used to having people stay for only a single night). This also allows for the opportunity to have some of them be famous people. If they *are* the Illuminati, they can't *all* be pulling the strings, some of them would have to be play-makers, hiding in plain sight. So even with some of them having a moderate level of fame (published books, CEOs of mid-level companies etc.) it likely wouldn't raise suspicion if their paths crossed from time to time. [Answer] ### Hypothesis I think that an effective group of 42 *illuminati* need to represent * various industries, * various social levels: some of them may appear in real life as mere employees while others are famous actors, and * various countries. ### Meetings Preparation 42 is a rather large number. So communication and regular meetings between two or three of them should be quite easy. You can imagine all sorts of events where a subset of them may meet at (not exhaustive): * a large diplomatic event (G8, UN General Assembly, etc.), * a conference (like the current COP21, but also scientific, or hobby: a famous actor and a normal employee are expected to meet at comicon), * a sport event: different social classes gather during a sports game, Since they don't want their identities blown up, they probably make a heavy use of substitute and delivery people. More or less voluntarily. Furthermore, they can exchange via indirect ways. Like writing a question on Stack Exchange with a previously known code. They have all incentives to multiply the ways of communications and meeting mechanisms. It saves them from any pattern identification. ### Meetings: the General Assembly That's the hardest. You need to get all of them physically together at once. We might consider two options. * They need to hold a seminar where the 42 of them are there and with doors closed to debate. For that a hotel close to an airport, or even better, an official house from some country. You control the politicians, it should not be too difficult to rent some discrete room where you get to choose who gets in and who doesn't. As usual, it cannot be at the same place all the time. If you got for a case where you require from one corrupt politician some place, you should consider inviting more people to a larger selected event. And the 42 of you can get to some private place. Some might have entered as guests, while others might be as security personal, or service. * They need to be able to exchange many ideas, but do not need a private room. This is easiest. Larger fairs attract people from various location, countries and social standing. Major diplomatic or cultural events. The details are given within each meetings about where to get to the next meeting. ### Getting started You need some precise place to meet your fellow 41 colleagues. Well, as you may know the original illumanati group were called *illuminati of Baviaria*. So the **Octoberfest** is a place where famous people and less famous, rich and poor, are grouped together in the same place. And not many worries about your neighbours overhearing, they will be so drunk, they won't remember anything the next day. [Answer] The best way not to get discovered is to act normally and blend with the normal people. The Illuminati have done this for many years. They have been hidden in plain sight all this time. Everytime there is a major event, we learn afterward that the Illuminati where there, yet we can never catch them. Nobody expects the Illuminati to be in Paris right now (for the climate summit) but they are there, advancing their hidden Illuminati agenda. [Answer] Some desirable atmospheric and practical qualities: * **Ancient**, or at least old * Historical, **gothic**, spooky * **Elite**, exclusive, not somewhere the public would often see inside * **Secure**, difficult to infiltrate or spy on * **Remote**, so passers by cannot hear the screams of sacrificial animals or virgins In my imagination, anywhere suitable for a vampire meeting would also be suitable for The Illuminati, and vice-versa. Here are some suggestions: * [The Pyramids](https://en.wikipedia.org/wiki/Pyramid) (accessed by tunnels or a teleporter) * An old cathedral, or the crypt below it * A castle, or castle ruins * A [stone circle](https://en.wikipedia.org/wiki/Stone_circle) (for security reasons, it should probably be on private land) * Inside a [long barrow](https://en.wikipedia.org/wiki/Long_barrow) * The [catacombs](https://en.wikipedia.org/wiki/Catacombs) of Paris or Rome * A dungeon * The vault of a bank * A [Masonic Lodge](https://en.wikipedia.org/wiki/Masonic_Lodge) (well duh) * The Round Table at [Camelot](https://en.wikipedia.org/wiki/Camelot) (only they know where it is now) * The [palace](https://en.wikipedia.org/wiki/Putin%27s_Palace) of a complicit national leader * A luxurious tree house (no reason, just a bit different) * An art gallery or museum ([Le Louvre](https://en.wikipedia.org/wiki/Le_Louvre) for example) under the pretence of a less nefarious private function * Under the disguise of a small charitable event, to evade suspicion * A ski lodge, because skiing is pleasant and mountains are quite remote * A submarine, or a [blimp](https://en.wikipedia.org/wiki/Blimp), for maximum privacy * Karl Stromberg's underwater base "Atlantis" from *[The Spy Who Loved Me](https://en.wikipedia.org/wiki/The_Spy_Who_Loved_Me_(film))* * The original [Lost City of Atlantis](https://en.wikipedia.org/wiki/Atlantis) (only they know where it is) * Similarly, in one of the [Seven Wonders](https://en.wikipedia.org/wiki/Seven_Wonders_of_the_Ancient_World) of the Ancient World * One of Scientology's camp locations, such as the church at [Clearwater](https://en.wikipedia.org/wiki/Clearwater,_Florida) * The sky-sited restaurant of a hotel in Saudi Arabia * In a cave, wearing goat skulls [Answer] First the assumption will be that most of them try to be inconspicuous, meaning most people would not recognize them as super powerful individuals. An easy way would be to make themselves all board members of some innocuous company that meets together to make decisions periodically. And with today's communications capabilities they really don't need to meet in person. Good encryption and a decent high speed internet connection are amazing. [Answer] There's a secret, literally underground meeting place, which is reachable via some undocumented subway tunnels that connect it to equally-secret stations under some buildings where powerful and important people would not be out of place, such as the member's own luxury condominium building or hotel. (The people who build all of these secret things are very well paid to keep their mouths shut about the things they build.) Those people get on elevators, make sure no one else is on, then punch a secret code into an app on their smart phones. This puts the elevator into a mode that prevents it from stopping at any other floors on the way to the secret sub-basement subway station, while outwardly indicating that it is in fact heading to the ground floor. No one not in the know will ever see the Illuminatus leave the building. Meanwhile, a body double of the member in question, wearing identical clothing, has appeared at that subway station, ready to take the member's place on the elevator, which reaches the ground floor with the double appearing as if he had just come all the way from the member's floor (the secret trips happen at a much higher speed than normal elevator operation, so no one will notice this). Anyone looking at security cameras will see the member leave the building, get into his waiting limo, and head off to whatever place he's supposed to be that day. At the end of the meeting, the process is reversed, with the member waiting at the secret subway station to trade places with the double. Arranging to be the only person on the elevator for this trip is a bit trickier, but there might be some special VIP elevators, or a security person who politely informs anyone else that they can take the next elevator thank you very much. Some members live in other cities, so the subways take them to places where they can board private aircraft under appropriate aliases, which take them to similar facilities at the event city, where they use the subways as described above. ======= Or the Illuminati have access to teleportation devices and the knowledge thereof is just one more of their many secrets. [Answer] Is there any reason that the meetings would have to be events, rather than continua? Maybe instead of Alpha Proteus through Yonjuu Ni gathering at some shady conference or [a diner somewhere](http://warehouse13.wikia.com/wiki/Breakdown), Al meets with his "old college pal" Dva, who talks with two of his coworkers, Troix and Arbe. Troix might talk to his aunt Unnees, who writes a code in her letter to her town's mayor, Seoleun Nes; while Arbe might mention it to Sieben, the waiter at the restaurant she eats at the next day. A structure like this would be much more resistant to any given [fox](https://en.wikipedia.org/wiki/Fox_Mulder) at the NSA. [Answer] Supposing they are all rich and famous anyway, they could easily meet at the opera. Opera houses are expensive and exclusive and found in most big cities. They have private boxes and little dining rooms and bars. And lots of background noise going on. People don't always go the opera for the music, so it's nothing special if a group splits off for a private party. [Answer] In a reasonably secure government facility. Somewhere like the CIA or NSA, but not at their "main" buildings, but a satellite facility. People there already know not to ask too many questions, and you already have counter espionage and physical security in place. [Answer] Why should the **pawns** be allowed to know each other, to meet each other? Why should they be allowed to realize what they're doing? If they worked together, they wouldn't be different to yet another state or organization. They would also see the purpose and ultimate goal of their intended synergy, and may even refuse to collaborate. They don't know who they are, they don't know that they're the ones behind it all. From the point of view of each one of them, they're merely defending their own petty interests, what they think it's rightfully theirs. Neither do the **paladins** know about it all. They don't know who they should be fighting against. They're kept busy fighting against each other, defending foolish ideals, battling constructed threats, while the real **enemy** remains at large. The greater scheme of things remains beyond the reach of its executors. ]

[Question] [ Modern era western company, with plenty of combat experience in Iraq & Afghanistan, is magically transported from East Syria into the newly founded kingdom of Jerusalem, right after the first crusade. Their clothes, weapons & equipment are replaced with age appropriate items, such as swords, spears, horses & chain mail. Left with only 300 knights and 2000 foot soldiers, [Godfrey of Bouillon](https://en.m.wikipedia.org/wiki/Godfrey_of_Bouillon) promptly admits the newcomers into his army. Would modern era skills & tactics would be of any use in fighting the Seljuks, Saracens & Byzantines? No modern age technology is available nor it could be introduced. Language barrier is handwaved. Modern troops don't have experience in medieval weaponry, with few exceptions. A few could ride horses, as they come from farm families who owned horses. A few could use bows, as they have hunting experience. And a few could use swords, due to exposure to certain martial arts. The rest will have to learn. My story tends toward comedic effects, something like [The Visitors](https://www.imdb.com/title/tt0108500/) in reverse. [Answer] Back in the good old days we would fight with melee weapons like swords, etc. So, in a bunch of special forces, snipers would probably be useless: rifle-training doesn't translate to swordsmanship. That being said, swords and spears are relatively easy to learn (if used as hack-and-slash or point-and-stab weapons respectively). But, military training of today is not entirely useless. 1. **Discipline**: Soldiers of all time-periods were trained for discipline. Your fancy swordsmanship will be useless if you run away from loud noises. Similarly, since our militaries are trained to handle extreme dins of battle, although a medieval war would be different for them, it would be a relatively quiet affair compared to the machine-gun fire that our troops are used to. 2. **Survival skills**: Looking for cover will arguably be easier for modern troops as they are very extensively trained in hiding from enemy units. Arrows and other ranged weapons are comparatively easy to hide from. Which leads me to my next point. 3. **Urban warfare**: If war leads to populated regions like cities and towns, I'd argue that our soldiers are more prepared for the nature of combat in cities. Most soldiers are trained for open war in an open battlefield, but I'd say our future-age soldiers would do better in these conditions than the typical soldier. 4. **Superior training**: This relates to all my points. Every soldier nowadays receives not only gun-training but also hand-to-hand combat training. This means that our troops are likely to be deadly even when disarmed. Hell, we've had centuries to improve on knife-fighting skills. Also, our boys are kind of ripped. Stuff like medieval farming does toughen up the body, but our soldiers are toughened up specifically for the nature of war. In conclusion, I'd argue that even though modern soldiers would have no idea how to handle themselves in societies of the past, they would be killing machines compared to the average soldier. Now, versus knights and more specialized troops, not so much without the appropriate armour, but they'd definitely put up a fight. Maybe I'm a little too patriotic for our present-day soldiers, but I'd favor their chances in the line of combat. Logistics: I heard this word mentioned a whole lot in the comments for this question. If anyone in the army has a BA in management, it might help the armies of yore to figure out how to manage their resources more effectively. Yes, horseback riding is important, but the vast portion of any army in the good old days was composed of foot soldiers. With the discipline of modern troops, they would be exceptional trainers for Saladin's armies (or his enemy's armies). And because most modern soldiers know how to read maps (and more importantly, read in general), this could help them transfer information to each other in a more clandestine manner than was available in those times. Plus, learning to ride a horse isn't hard - being an expert is. Don't expect to be able to out-ride a Mongol, but expect them to know how to cause some damage. Of course, I say this all assuming that our modern soldiers don't accidentally kill everyone in the past with the diseases that we are immune to. I hope this helps - I'm open to criticism. [Answer] **No** Modern soldiers are trained and equipped to modern warfare. They are next to useless for ancient warfare. At best, they wouldn't be better than any other piece-of-flesh to make for cannon-fodder and more probably than not they would be a dead weight to get rid off at the first opportunity. Even handwaving the language problems that would render them completely useless, no knowledge they could gather with them is going to be useful or directly applicable. I think most answers in this post are overly optimistic, minimizing or ignoring the hurdles any modern person would have surviving in a harsh war campaign such as the Crusades were. Also, it seems that we are overestimating the value of knowledge of basic theory without realizing the vast, often impassable distance between theory and practice, and specially how much of these knowledge and technology relies on layers and layers of other knowledge and technologies which wouldn't be disposable. Summarizing some of the supposed advantages of our modern soldiers in alphabetical order: * Digging latrines: was known by the Assyrian army, some 2,000 years before the Crusades. Every army that has existed has dug latrines when camping, if only because they didn't want to smell shit while eating. * Discipline: they'll find theirs is not superior to that of the rest of the army. Particularly, being trapped deep inside enemy territory does wonders to prevent desertions. * Encryption: cyphers had been used in warfare for at least as long as warfare was conducted by more than one attacking unit at a time. Crusaders knew encryption and used cyphered communications if necessary. Sure, our methods are harder to break, but since the ones they were using were also probably unbreakable by the enemy, it doesn't add any security, only longer cypher times. * Field sanitation and hygiene: same as logistics. One thing is to know and another one is to apply. So you know medicine? Ok, but what do you do without antibiotics, sterilized equipment, clean tools...? You do what you can, in less than ideal conditions. Just like their doctors did. If you read Noah Gordon's "The Physician" you'll see that most first-aid and wound treatments were already known back then. 99% of modern medicine won't be available to the modern doctors, nor easily produced by then on the field. But they will know for sure the wounded are going to die. * Logistics: modern soldiers may know everything that can be known about logistics. It won't improve Godfrey of Buillon's resources in the least. What good is to know how many lorries would it take to transport two armored divisions from Haifa to Bagdad if it's not going to increase the amount of camels and donkeys that you have? You don't have to go back in time to the Crusades, just send your soldiers to Ethiopia and make them work with the Ethiopian budget of defense and see what they can achieve with that. Without the unlimited funds and resources of the US Army, logistics knowledge is worthless. Logistics wins wars, no doubt about it. *Having* logistics wins wars, that is, not *knowing* about logistics. You can reasonably assume that the Crusaders' leaders managed their logistics the best that could be done in those times. * Psyops: the crusaders have very limited to no method to reach the enemy's population, so hardly they could try anything like that. The only psyop known at those times was initiating a siege. Then the population besieged could be targeted for psyops. * Reading maps: maps weren't invented yesterday. The crusaders also knew how to read them. They can't improve their quality or precision, so they don't add anything to what the crusaders already had. * Superior training: not really. Surely modern soldiers are better at boxing or judo, even they may know something about knife fighting in a nightclub, but fighting a lightly armored opponent with a scimitar, no, they really don't know shit about it. * Survival skills: will cost them their lives. In modern warfare, under enemy fire you look for cover. In ancient times if you break the line because the enemy is shooting arrows at you you are hanged for cowardice. "Survival skills" at those times meant putting a stiff upper lip and praying the arrow hits your shield (or your comrades). * Urban warfare: there wasn't any. Whenever an army entered a city the battle was over. What came then was pillage and rape, but there's absolutely no need for urban warfare knowlegde. Nobody will be waiting at home with an AK-47 and two Molotov cocktails. And so on. All of this summarizes why modern soldiers wouldn't be any better than ancient soldiers. Now for a few reasons on why they would be probably much worse: * Overgrown: our modern soldiers are used to a 1,500 to 2,500 kcal/day diet. Crusaders will do with a little less than 1,000, which will render our modern soldiers weak, dehydrated, tired and utterly demoralized in a few days. An army marches on his stomach, Napoleon said, but their stomachs are too big for the frugal necessities of the day. * Sluggish: it's beautiful to know much about hygiene, but what do you do without water purification pills? Boiling water is out of the question: not enough boilers, not enough fuel, not enough time. By the time you have boilt water for the whole camp a day has passed and you have to start boiling water again. You are stuck. You don't have any options but drink and pray, and our chlorinated-water-used stomachs won't resist as much as the tougher drink-or-die naturals of the time. Same thing for food in a time with no cans, no vacuum bags, no freezers and no pasteurization at all. [Answer] ## Medicine In addition to the other answers, I would like add basic first aid and medicine. The lowest modern field medic could revolutionize a field hospital of that age... if they can get people to listen to them. I am not a medic, so you might want to consult other sources of information, but off the top of my head I can think of: * The very idea of first aid. Every soldier is drilled in the most basic things, most notably how to stop a bleeding. Every soldier is carrying a small clean bandage. * Keep clean. Keep the wounds clean. Keep the surgeons hands and tools clean. Use clean bandages. * Boiling water. Before drinking, but also as a way to clean things. Clean! * Stop bleeding the patients! They have already lost enough blood! * Pressure dressings? The proper way to apply a bandage to stop bleeding. Not sure what the crusaders already knew about this. I am sure there is more, but my knowledge is limited. Both about modern and ancient field medicine. [Answer] The key advantages the modern soldiers would have would not be direct combat skills, but rather the skills of logistics, support and enabling. The historical knowledge could also be useful for the Crusader kingdoms, allowing them to identify key personalities and linkages. The key to any military operation is logistics, and the Crusader kingdoms had multiple challenges. They were at the end of a long supply line to Europe, and were in an alien environment which was not economically developed in the ways that the Crusaders were familiar with. Trying to wrest a living would be very challenging, and the sort of extractive economies that the European nobility was used to would not be viable. Knowledge of logistics would allow the Crusaders to operate more efficiently. Supporters and enablers would include such skills like map making, psychological operations (PSYOPS), communications, cryptology (codes) and battlefield medicine. Field sanitation and hygiene would also do a lot to reduce wastage of the Crusader manpower. So by becoming the staff of the Crusader kingdom and applying the modern skills to support the Crusader logistics and operations, the Crusaders will be more effective when conducting operations in general. If the newcomers have enough historical knowledge (and soldiers are often history geeks), then the Crusader armies could focus their operations against key personnel or groups. So the modern company may not be able to directly affect the battles, but they could leverage their knowledge to make the Crusaders more effective, and possibly allow the Latin Kingdoms in the Middle East to have survived for far longer than they did. [Answer] # Digging latrines (and knowing it needs to be done.) I'm sure modern soldiers probably have toilet blocks on trailers running to any long term encampment, so you might need to go back a few decades to get soldiers with real shitpit digging skills, but the single greatest thing you could bring to a medieval encampment is a long drop. [Answer] I wouldn't use them as soldiers, they're not trained for what a battle was like back then. Rather, they should be used as sniper-scouts. They are **far** more used to the use of stealth and they won't consider hiding to be cowardly. Sneak in, get information, get out, perhaps take out someone important with a crossbow or conduct acts of sabotage. (Think about the effect of harassment fire of flaming arrows against the enemy camp the night before a battle.) [Answer] ## Put them in the signal corps The US Navy still uses the flag semaphore system, which can transmit arbitrary content at a rate of about eight words per minute([1](https://books.google.com/books?id=VJXfAAAAMAAJ&lpg=PP13&ots=wxWwnqnWkU&dq=flag%20semaphore%20rate&pg=PP13#v=onepage&q&f=false)). Unlike an Aldis lamp or electric telegraph, flag semaphore requires no technology (technically, not even the flags themselves), so any signalers would be able to begin immediately. Compared to signalling methods at the time, which were slow and almost invariably only usable for pre-arranged messages([2](https://books.google.com/books?id=0-YOAAAAYAAJ&lpg=PA22&ots=DYwKHA-hKD&dq=medieval%20military%20signal%20systems&pg=PA17#v=onepage&q&f=false)), flag semaphore would be a big improvement. These skills could be used to vastly enlarge the search area of any patrols. Any activity could be reported and described with more speed and accuracy. With relays, even long-distance, non-line-of-sight communication is possible. Additionally, although modern methods of encryption might not be that useful, modern methods of cryptanalysis could be used to read intercepted messages, especially since most medieval ciphers were vulnerable to frequency analysis. [Answer] IMHO it strongly depends on exactly which kind of troops are "transported back". Officers are trained also in warfare history and theory; this means they STUDIED all tactics devised through the centuries and they KNOW what was useful against a certain kind of enemies (including Seleucids, Saracins and related populations). OTOH "cannon fodder" soldiers would be in hard difficulties without communication aids, binoculars etc... not to speak, of course, they would be hard pressed to march long distances without "proper boots" (wearing war sandals, as used at the time, takes hardened feet or you're going to get blisters all over); similar argument holds for arms and hands unused to sword and shield. IF they are given time to adjust (mainly strengthen their limbs and skin) they would have a fighting chance, otherwise they could be useful as trainers and advisors. [Answer] As a body of fighting men (I am handwaving an all-male force because things are hard enough without convincing Crusaders that a woman could be a soldier and should be listened to) they're not worth much. Their training is all wrong, and might even be counterproductive. For example if you're not a sniper you're not usually seeing the look on a man's face when you kill him. "Aimed fire" isn't as much a thing as "suppression and hey that'll likely kill the enemy to boot". Killing a man face-to-face is what matters in the Middle Ages, and our heroes have been brought up to value individual life and only LATER taught to kill. That's a fundamentally different thing than assuming anyone who's lived past 20 has won the lottery and being taught to swing a sword at a living being since you were old enough to hold one. If you decide you've got a band of cold-blooded combat junkies who won't balk at close-in work, you might have an interesting fighting force depending on how they're equipped. As someone already mentioned they'll be huge compared to the average soldier, and with a few weeks of drill could make for decent line infantry. Mind you, decent, not great. Even with combatives training all barring the odd ARMA-nerd (Ancient and Renaissance Martial Arts) will be utterly incompetent with medieval weapons. Give them good armor, which given the loads they carry in modern battle shouldn't slow them too much, and they'll be able to work through levy-equivalents. But they'd last about 5 minutes against trained-for-decades knights and Sarassin equivalents. To think otherwise would be like thinking I could train Shaolin Monks in modern weapons for a few weeks and have them beat US Infantry in a gunfight. It just doesn't work that way. However from a storytelling perspective they likely have one VERY important card to play. They know how it ends. Some 2LT or nerdy infantryman at the very least can go to the company commander (who if they were to have any effect at all must be a guy that Godfrey believes) and tell him that the Crusades won't ever draw enough Europeans to win the Holy Land for all time. Maybe they tell him details like "you'll die of some disease if you go to Caesarea" maybe they say "hey our records said the Muslims had an army of XXXX at this date" If Godfrey believes they're from the future he may well take whatever they tell him as a sign from God. But as a purely fighting force they're just another hundred-odd bodies in the line. [Answer] The advantage would be huge, because modern armies don't operate on the "meat shield / cannon fodder" paradigm. It's all about **force multiplication**. Consider all the force multipliers at play: * They will insist on hygenic conditions *for their camp at least*, and other commanders are going to notice. "Why do you boil your drinking water?" "Why are you so fussy about where you pee and poop?" "Why are your medics so interested in alcohol?" "How come you have so few sick soldiers?" * Their medics would be first-rate, and use all their modern knowledge to keep people healthy and do field medicine to the extent practicable. Just look at *Outlander* for examples of that, where they react to Claire like "you do *what* with *what!!??*" and that's in the mid-17th century; you're in the 11th. + Before someone says "Medieval medics weren't stupid", beg pardon. Like Mark Twain is attributed to say, "what hurts you isn't what you don't know. It's what you know *that just ain't so!*" Medieval medicine is mired in that - so many taboos, axiomatic beliefs that were wrong, and Church edicts that couldn't be challenged. + Medics are the ultimate force multiplier. If Godfrey saw the results and took the medics' advice at face value, and propagated that training, it would greatly strengthen the army. * Obviously the ancients were no slouches in logistics - a supply chain across the Mediterranean in 1050 is like a supply line to Mars today. But modern western armies are deeply committed to it. Again, if the logistical doctrine of the modern force can sway Godfrey, it would slow Godfrey down, but greatly stabilize the forces by solidifying the lines of communication. * The modern doctrine of "Force Protection", would reject the idea of openly wasting assets in "chivalrous" square-on force-on-force confrontations. It would force command to avoid engagement except when they have an overwhelming advantage, and to set up those situations. + The army would become better at disengaging: avoiding or retreating from battle without much loss in strength, materiél or confidence. + The conscripts would notice that command is treating **their** lives as worth protecting and not to be wasted. That would greatly increase morale, improve their willingness to soldier and to train. Now even your conscripts are starting to look like a professional army. * Command would be acting on better information. The moderns would bring a very different sense of command decisions and information gathering, so fewer moves would be made blindly or stupidly. + Disinformation would be a doctrine; moderns would be aware of tactics like Tecumseh's at Detroit, and would mislead enemy forces into fatal mistakes. + The moderns would be really, really, really good at scouting, since they are deeply trained in stealth tactics, and they have a good sense of what *modern* camouflage ought to look like. They aren't going to be caught out in a road; the enemy would never see them. * They would also have a modern expectation of good signaling. And would improvise it in those times using light signals and Morse code. This could be done with a torch inside a helmet, for instance, aiming the light at another listening post, and interrupting it by stepping in front of it. All in all, Godfrey's army would win the attrition war, suffering far fewer losses due to environment, even if the armies simply chased each other around the wilderness. When the army acted, it would do so more carefully, effectively and decisively. [Answer] IMHO few skills would be immediately usable: * strategy: without any long distance observation and communication, most modern tactics and strategy will not be useable * weapons proficiency: no firearms are accessible. The close combat skills would still be on topic, except that soldiers are trained to fight against knives, not heavy swords * resistance and discipline: IMHO this would be the more immediately usable skills, but with little proficiency in available weapons, and tactics that would probably not be enough * scouting: here again, modern soldiers specially in special forces are trained to hide which could be a nice point. But modern knowledge could allow to rather quickly give a technological advantage: black powder is easy to produce with medieval technologies as are simple cannons. Dynamite does not require too complex base materials either. IMHO the best use that could be made or modern troops would be to forget that they are soldiers but use their scientific and technological knowledge. The higher risk here would be that they could be burned for sorcery... [Answer] **No.** Hand to hand or other close combat training in modern military is focused on 1:1 scenarios, and is not at all applicable to the experience of a footsoldier during the crusades. Crucially, none of the modern troops have ever trained with a shield, and they certainly haven't trained in holding a shield wall (like, the most basic bread & butter tactic of the era). This means that they have no idea how to rotate the line. Assuming someone in the chain of command thought that far ahead, or was familiar with these sorts of minutiae, they might be smart enough to know that they will need to, but the soldiers have never drilled on this before and it's a somewhat complicated maneuver that you need to pull off while a bunch of people are trying to stab you. The first time they attempted to rotate the front line of a wall they would absolutely fall apart. It'd be a complete and unmitigated disaster. Assuming enough of them survive that experience to continue fighting, they will have no idea how to read signals communicated via banner, so they'll have no method of communicating with the larger army. These people are used to radio. They have no concept of how a medieval army communicates orders. They are not used to co-ordinating maneuvers with units that are sized for the era. They are organized into squads, mostly, and all of their tactics assume much smaller organizational units then those fielded on a medieval battlefield. The command staff will need to re-organize the whole company and command structure to account for this, and unit cohesion will absolutely fall apart in the short term. The life experience and prior training puts these individuals far above where most random recruits would start, but it is not a substitute for era specific training, and if they did not spent time preparing and learning from the peers, they would be worse than useless on the field. [Answer] **Yes** **Well,lets see a timeline of events for starters** As our modern company has been dropped right after 1 st crusade(about 1099 AD) and second crusade started at about 1147,I would say a lot depends upon what missions they had during this period. * After the death of Godfrey of Bouillon,his brother [Baldwin of Boulogne](https://en.wikipedia.org/wiki/Baldwin_I_of_Jerusalem) became the king of Jerusalem in 1100. * In the year 1101 he laid siege to the city of [Arsuf](https://en.wikipedia.org/wiki/Apollonia%E2%80%93Arsuf). Later,he also laid siege to the city of [Caesarea Maritima].[3](https://en.wikipedia.org/wiki/Caesarea_Maritima) Now,the thing to remember here is that both these sieges were **short sieges of about 15 days** mainly due to wide use of catapults and siege towers. * He later goes on to capture many cities like **Acre** and **Beirut**. * He tried to capture **Tyre** a few time but failed,which was only captured by [Balwin II](https://en.wikipedia.org/wiki/Baldwin_II_of_Jerusalem) with the help of [Venetian fleet](https://en.wikipedia.org/wiki/Venetian_Crusade). During this period,Our modern company could be devastatingly effective.**All the physiological and modern warfare,which other answers have said,would have been not so effective in H2H combat can be used in a siege**.Furthermore,there is also chance for guerrilla warfare and urban warfare in such a scenario where a elite team can devastate a city under siege from within, by destroying food reserves and poisoning the water supply which were fair tactics during those periods. The more bloodier battles also did take place but they were infrequent before the second crusade,Even these sieges had a gap of a year at least which would give our modern company enough and more time to survive,adapt and prepare a infrastructure to utilize those modern skills which would take time in that time period. Furthermore,I would like to speculate that had such a company arrived in that period Baldwin I surely would have been able to capture Tyre thanks not only due to skills mentioned in above answers but also due to general ability to brainstorm ideas among themselves freely to devise some unorthodox plans based upon general prior knowledge about that historical period. [Answer] **Behind-the-enemy-lines fight** - new military should be better in hiding themself in crowds and strikes from back into most strategic place (like crossroads, water station) and gaining Big advantage with less effort due to better plannig and strategy. **Maps and possesion analysis** - they will know what to look for in dangerous area and will not to go there unless proper reckon. **Trenches** - ww1 style of digging fight that can be gamechanger if they are outnumbered and have to abandon strategic place. they just dig and wait for backup **Hybrid war and propaganda** - using crowd tendencies to get the town without single shot. making the election (with right winner), get to the media, news, stories, whispers. **Better ways of gaining info** - psychologic torture, fake drawning technique, profesional usage of agents to get info about opponents activities And also - the good points from others. [Answer] I guess YES, they are a nice addition to that time. As Akhil Sharma pointed out, those soldiers are dropped at a specific point in time. There is nearly one year preparation time until they have to be ready for the first siege, and another year until the siege really takes place. Yes, our people will be weaklings with weak feet needing toilet paper in the beginning. But they have a year preparation, maybe even more. We can't quote Romans in any way - they were in some sciences much ahead of middle-aged Europe, even if they were using lots of bronze and leather instead of iron. But that knowledge was not transported far and much of it was forgotten in the pox chaos and church panic and Roman Reich breakdown that the Europeans had to endure. So let's just assume that the crusaders used standard tactics for their time, trained their weapons to perfection on their three-years-journey from Europe to the middle east, finished the first crusade, and when godefrey is already in his last year, our soldiers drop. And have no clue. They will be bigger than the average European of the middle ages, roughly the size of well-nourished nobility people. Language is handwaved, so they might be able to convince somebody that their leader is some low ranked third born nobility guy, and thus being able to get an open ear in the leading ranks. This is the first difficulty someone from today will encounter - normal people were not listened to at all. Hopefully they have a captain or lieutenant who is good with words. There, this guy, if he is good, can place some interesting messages. He can spread the knowledge of flag signaling, morse coding, Napoleon's concept of small hide-able movable units instead of big size armies, WW2 concept of the operational layer between tactic and strategy, sand filters for water, boiling of medical equipment, tactics that knights are not only run fast to the flank of a battle or support a weak spot (which has been done as standard) but maybe they can think of some tactics that allow knights to appear in several battles in short succession. This is all the communication, logistic, operation, hygiene stuff that has been said before in this thread. But now, if this counts as not-allowed transfer of technology to former armies, there is still much good they can do. There are 50 years until the second crusade, and those people are not needed in the coming three sieges, and they know it! So, that's a strategic time scale, not a tactic time scale. We don't drop them into the middle of a sword fight, that'll be stupid. We could (they have one year time to train!) but we can make better use of them. * Multiplication: founding of families and uprising of children in the name of the crusader culture until the second crusade comes. Each second surviving child can be an additional soldier for the battles to come. If the soldiers of our unit teach their family sand-filtering of water, basic (mouth)-hygiene, reading and writing, we'll have an army of healthy individuals. * One of the reasons the crusades were failing was because culture eats strategy for breakfast. The crusaders had some military successes in the beginning but were then failing to root their culture into the people. So they needed continuing support from the homeland with an easy-to-disrupt 3000 km support chain. Imagine they had proper support at the front in the middle east, they could have done far better. If we plant 300 dedicated men in that culture and let each make 5-10 kids as was normal in these times, that's a lot of push on the cultural front. * Canalisation/Water filtering and Garbage disposal: If those 300 families would push for both of these facilities in "their" city(ies) or village(s), they would be hardened against smallpox and cholera. Pox were depending on rats living in the garbage; cholera results from drinking water with microbes from other sick people. So it may be that just from these basic measures, they get a population which can "deliver" much more soldiers to the second crusade 50 years later, even when we cannot bring antibiotics. * Again Canalisation, this time for the watering of plants. Along with the digging of wells, that's one of the biggies. You want more soldiers, you need to feed the people! Everyone who dies of hunger is one swordswinger less. Everyone who is fed by their new masters is a potential friend and not an enemy. * Again, Garbage Disposal. Fertilize the crops! Don't know if it was known, but it certainly is a biggie if this wasn't done before. * It's roughly known from where Sarazin's soldiers were coming. So what we do positively to the crusader villages, we do negatively to the opposing villages. If we constantly poison water supplies, (re)-introduce pox and cholera, steal and burn crops, interrupt or kill caravans, again and again all few years, over the course of 50 years this can severely shrink the numbers Sarazin will bring. He had maybe of 100 000 Soldiers when he ended the crusades. No tactic will ever be good enough to go against this, also not with 100 or 300 extra soldiers from the future. But 50 years are a long time. * If that's too evil, send priests. Culture eats Strategy for breakfast. Convert people to Christians or at least convert them to people opposed to the ruling caste, build a network, when the day comes, have people inside the wall who attack the door. Ok, you don't want all that? If introducing modern organization and tactics is not a forbidden technology, you could do just that. Ancient armies used to stick together because it was wise to do so. Side effects are, to build up a camp site and to start again the next day was wasting hours. I can imagine that the first soldiers were arriving at the new campsite when the last soldiers were just starting their journey the same day. So there is some kind of "Soldierworm" in the landscape that is easy to see. The "Worm" is surrounded by scouts - they have horses, they are freed from the camp work, so they have additional valuable hours and speed to check the area. They will report in what they see, and if they don't report back, that's a message, too. The General might then send a small horse-unit that way to see if he can get the evildoers. And here we have a use for our modern small-unit hide-and-seek tactics. Harass those scouts, maybe even fight the knights that come after them, then disappear as good as possible. Do that from all sides. I don't know how much damage they can do that way, but as they'd never fight 1-1 I guess they can do some things. There is also a worm of civilian cars following the army, with food and water and smiths and prostitutes and everything a soldier might want to spend his money on. If those are attackable, it might be a juicy target indeed. Finally, armies were used to not having any logistics. They were feeding of the villages on their way; often they were as bad for friendly villages as they were for enemy villages, just because they were using all the winter stock for themselves. I've read the Simplicissimus, a story written during the 30-years-war which was 500 years later 1618-1648. They STILL had no proper food logistic then. So I guess in the crusade, they also had those small units of soldiers with the task to "empty" the surrounding villages (friend or foe) to feed the army. Attacking those might be efficient indeed. No General would send his entire army for food, those units are small, 10-50 people. And here we go. Kill one of those units, get away, kill the next, get away. Getting away is the difficult part. You leave traces in those times. Rare is a road made of stone. ]

[Question] [ It is the mid 22nd century A.D. Twenty men and women signed on a ten year space exploration trip to the nearest star system. There are robots to do ship maintenance and a powerful A.I. to monitor the antimatter containment shield around the clock. For my purposes, I need that from time to time the crews take turns to do high risk spacewalks. Basically they are required to check the solar sails, sensors array and inspect the hull integrity. My problem is that a reader might think that all of that should be able to be performed remotely. The spaceship is cruising at 10,000,000 m/s (\*), and they are surrounded by a sea of cosmic radiation. So even with safety precautions in place, this is a risky venture. Hence: how do I explain the risk to the life of the crew on a routine scheduled spacewalk? (\*) as suggested by MichaelK. My idea for attaining that speed: nuclear bomb propulsion on strangelet(steroid) + antimatter + EM drive + quantum vacuum thruster hybrid. [Answer] # "You did *what* to the controller system?!" > > *Space is boring. Really boring. You just wont believe how vastly, hugely mind-bogglingly boring it is! I mean, you may think it's a bore to go down the street to the chemist's but that's just **peanuts** to space! Listen...* > > > — Paraphrased from the Hitch Hiker's Guide to the Galaxy, by Douglas > Adams > > > So the ship's gamer and engineering nerd got really fed up one day and decided to soup up their virtual reality gaming rig a bit. Sure, the *PlayBox Whee 9001* does come with some pretty sweet specs but it pales when compared to the hi-tech, government-funded VR controllers that are used to remote control all the robots and drones that perform the very dangerous tasks of inspecting and performing external maintenance on the ship. So said gamer did a bit of tinkering, some sweet hacks, and some not-quite-as-sweet workarounds, and some more tweaking to make the plugs fit and then... ...**burned out the whole unit**. Oh, sh... uhm... well... no problem, I can fix this! We have a spare unit. I will just pull out the old unit, plug in the spare, and we are good to g... ...what the... ...oh come **ON**!! [Who designs spacecraft](https://en.wikipedia.org/wiki/Murphy%27s_law#Association_with_Murphy) with [interfaces](http://www.russianspaceweb.com/proton_glonass49.html) that can be [put in backwards](https://en.wikipedia.org/wiki/Genesis_(spacecraft)#Mishap_Investigation_Board_.28MIB.29)?! So yes, they do have all those very fancy robots and drones to do all those dangerous tasks. But after some "clever" crew member managed to wreck the system that controls them, they are now very fancy paper weights (in a no-weight environment). Sure, they can jury-rig the PlayBox's headset but it just is not enough to do the kind of inspections needed, unable to control the external 1000x macro lens sensors, or display complete views from the broad spectrum extreme-IR-to-gamma cameras, and other things that are required. Add to the issues that the game console's controllers have to be *held in your hand* — making them extremely clunky compared to the full motion capture bodysuit of the original — and we arrive at the conclusion that it just is not viable to do it remotely any more. And with no shop to get spare parts for another 4 light-years, this — boys and girls — is why we do not mess about with the equipment we have on board. ***smacks tinkerer over the back of the head*** [Answer] **Regulations** Sure, the robots can do the job better (and usually do) and sure, the AI is capable of handling all the really tricky stuff, but some bean counting jobsworth back on Earth decided that every month a human has to manually inspect the outer hull for anomalies. It made it into the mission regulations due to the insane politics and beaurocratic jockeying back home, and now the AI enforces the walks and won’t shut up about it if one is missed. Essentially the space walks become a box ticking exercise to make the AI (a stickler for the rules) happy. The ensuing complacency from the crew offers up all manner of fun plot hooks, and hanging a lantern on (pointing out the ridiculousness of) the ‘stupid regulations’ will stop people wondering any further why the spacewalks should happen. Aside from that the AI keeps the ship running nominally, so even if the stupid humans miss the obviously .2mm misaligned solar panel in sector 1A it shouldn’t critically jeopardise the mission. Right? [Answer] **Murphy's law**. Specifically the Sean Cheshire corollary: There is always something you did not prepare for. 1. Something the robots are not equipped for happened. Works even better if it is time sensitive. Maybe the robots are a bit too specialized and they get can't enough of them in the right place to fix it, or maybe they just don't have the right tools built in. Sending out a person with a box of tools is faster than building a new robot from scratch. 2. The robots themselves are the problem. Maybe your robots keep "fixing" something that is not broken or they are fixing it the wrong way. Sure the robots need to be adjusted but that takes time and the problem needs to be fixed ASAP. Works even better if they are not sure WHY the robot is doing it wrong, because then debugging will take forever. 3. The robots can't get to it. Maybe the robot storage itself is damaged and the robots cannot get out, but the airlock is fine because the robots are stored in in a different place. 4. Unknowns. We keep sending robots to fix it and they keep going dark before they can show us what's wrong, and we need a person with eyes on the problem. This will work even better because human suits have better shielding than the robots do, which is not unlikely. [Answer] /sea of ionizing radiation/ **Biology is durable.** Biology has had billions of years to devise mechanisms for coping with radiation. Failsafe after failsafe; redundancy after redundancy. Circuits, not so much. For your spacefarers, radiation is a big problem for machines. Circuits go bad and self-repair mechanisms may not take them back to where they started. The damage radiation causes to electronics is almost insurmountable without impractically cumbersome shielding. This means the AI and the antimatter containment mechanisms are the only machines on the ship - both hunkered down within multiple layers of different types of shielding. In addition to the spacewalks, human crew do routine maintenance and clean the ship. They cook their food over gas. They wash their laundry using clockwork mechanisms driven by springs. The ships weapons are cannons which propel solid projectiles via explosive charges. The spacefarers themselves are the recipients of genetically engineered symbiotic gut flora and medicines that ramp up endogenous repair mechanisms to the maximum. They do not block the radiation; they heal the damage. Because of this the crew are unlike earth humans. Radiation regen treatments themselves have side effects - among which are markedly slowed aging and also some difficulty laying down new memories. Gray hairs turn black again. Muscle mass increases. Occasionally an individual regrows a lost tooth. Certain crew members might seem to be getting younger. In some individuals, these treatments cause mental paths associated with maturity (focus, emotional stability) to give way to mental paths associated with youth (mental flexibility, emotional lability). I envision a robot companion called Big Head. It mingles with the crew, its name given because of the enormous amount of shielding around its head. It is supposed to remember things and remind the crew of things people might forget and it earnestly does a decent job of it. Its little body breaks down routinely. The body is little because the crew need to carry it half the time. [Answer] **It's a Lie!** Perhaps the human crew is entirely superfluous, but it is determined that in order to maintain crew sanity, they need to feel useful. There would of course be some cover story reason as to why the machines couldn't due the task themselves but it doesn't need to pass suspension of disbelief since it isn't true. In fact the meticulous reader that questions the initial explanation gets the reward of being shown to be right. This could also give some justifiable deus ex machina since the AI is literally pulling all the strings. Though you could still have things go wrong outside of the AI's control. Of course you need a reason for the human crew to be there if they are superfluous to the stated mission of the journey. I can think of two. 1. Ego, mankind wants humans to travel out of the solar system solely for the sake of having done it. You can see this to some extent in modern space exploration, where tele-operated robots would likely be more cost-effective for continued lunar exploration, the focus is still always on manned missions. 2. Contingency, perhaps the members of the crew, plus some on-board gene therapies and frozen zygotes are actually enough to form a minimum viable human population. For a sufficiently advanced population, this contingency might not be cost prohibitive. Especially if there is a cold war MAD scenario going on in the solar system which significantly increases the risk of a solar system wide extinction level event. [Answer] Sabotage. Somebody back on Earth sabotaged all redundancies of a particular specialized robot that does a crucial task. They managed to fool or bypass all review, testing and quality assurance, and ship their duds. None of the other bots can do it. Not even with a full reprogramming, there are hardware features missing. The saboteur though it would be quite enough to doom the mission. But after it became obvious, the staff on Earth pulled off an improbable feat (Apollo 13 can provide inspiration - the movie will do) and came up with a procedure for a human to do the job. Not a risk-free procedure, but the best they could do. This can help justify any level of risk you want, as long as there's no obvious safer alternative. [Answer] In general, it helps to just look at real life. Imagine a robot which, even as a waldo, could perform all the jobs that humans perform on spacewalks outside the ISS. The robot would cost more, and be more complex, than the ISS. In Star Wars, by far the most complex piece of engineering on the ship was the astromech droid, which is why they were removable and usable for other things. And yet, while he could clearly do some maintenance tasks, R2 could not possibly do all the things necessary to keep a ship in ship shape. Patching it up just enough to fly home on a wing and a prayer, yes; but eventually, it needs to get home into the hangar and be tended by real engineers. If droids are fully sentient and have the same capabilities as humans (as C3-P0 seems to) then perhaps they would be sent out to do it. But wait. Why should the sentient droids always draw the short straw? They are sentient. Shouldn't there be a fair division of labor, rather than treating the droids as disposable drudges? Not only that, but, in the middle of space, a droid is irreplaceable and unrepairable. A human, however, can heal, and even be replaced over time. Androids with all the capabilities of a human must necessarily, just to get to parity with humans in the first place, also have a vast range of mission-critical abilities that humans lack. So the android becomes the most irreplaceable crew member. Why waste it? [Answer] ## Because that's where the booze is Some of the crewmembers have a secret stash of fine alcoholic spirits stashed in one of the maintenance airlocks allowing entry into the aft/engineering section, which is normally unmanned and only accessible via EVA. Every now and then, they tell the captain they have to do various "maintenance checks" and they spend their shift aft, having a few drinks and relaxing. Sometimes their excuses are rather ridiculous, but the captain is easily fooled. There is of course no legitimate reason for it. [Answer] They had a robot but it got damaged beyond repair. The same accident also caused some structural damage necessitating spacewalks to inspect and make the occasional patch/repair. You can have them setup a camera to watch the trouble area; AI would potentially be able to alert when these space walks are necessary. [Answer] ## Cosmic Interference Robots cannot go outside the ship due to magnetic fields / cosmic radiation / quirk of the antimatter containment system frying their circuits or producing subtle erroneous readings. Human meatbags are unaffected and therefore must perform the work manually. ## Humans are Expendable In the future, humans are cheap and computers are expensive. Think back to the industrial revolution where they'd get children to climb under the machinery to clean it while it operated, risking life and limb. [Answer] GIGO, *Garbage In, Garbage Out*. This is how calculators and computers work. You need a system that can understand if what it is seeing is different from what the instruments are telling it that it *should be* seeing. You need an independent system with separate information inputs that can judge divergence, computers only know what you tell them. Humans come pre-equipped with both the sensors (eyes, possibly fingers too depending on interface sensitivity) *and* the processor (brain), so use what you have and space walk it. Also humans like to "be sure for themselves", hence seeing that things are fine with Mk. 1 Eyeball is psychologically useful for most people. [Answer] Your stuck in space with only so much processing power. Your ship is doing some hard recalculations but they are taking to much time so your crew must do some more time sensitive chores like repairing the solar sails because cleaning the bio waste stores smells much worse and you want the robots to do that task. [Answer] Ship design flaw. Some system needs regular maintenance and has a robot designed to do it. Access is between some structural beams or girders. Unfortunately the cold of space means some parts of the ship have got smaller and now the clearance, that was 1cm at ship build temperatures, around the robot has shrunk and the robot can not fit. Hence a human is needed. [Answer] **Extreme Sports** Robots *could* do it, but there is a speed record for completing this particular routine (pointless) inspection task, and crewmembers want to break that record. The danger to life and limb is nothing compared to the glory of completing the D-64-18 task in minimum time. As to why this task, it could be anything; perhaps the egress specified in the manual is near the crew lounge, making for easy timing and fun welcome back parties. [Answer] **Unions** The opposite of user2554509's answer. Space-walks may be dangerous, but being so, they are a lucrative source of income for those who have spent years training to do it. Also, some people get very offended at the thought of someone else, who isn't a member of their guild/whatever (and so hasn't met what they believe is the appropriate level of training/qualifications), doing their job. So Space Walkers will go through extraordinary lengths to protect their jobs. The corporations could have replaced them with robots years ago, were it not for the fact that every time they try, they face massive industrial action from entire crews who believe it's just a stepping stone to having them all replaced by robots. So basically the Interplanetary Union of Space Crews have managed to impose certain agreements/rules on the management, one of which is that only humans with particular qualifications will be allowed perform particular space-walking duties. You could throw in an example where a software bug caused a robot to improperly fix something (like trying to seal a 1-cm conduit with a 1-inch O-ring or something) - something a human would have easily spotted - resulting in several deaths/catastrophic - the union could point to this every time the argument came out. [Answer] ## Training Any reasonable 22nd century civilization is going to have robots that can inspect the hull. All you need is a camera on a robot arm, a space-traveling selfie stick (this was done on the real-world space shuttle after the Columbia disaster). But the civilization doesn't have robots that can handle every possible occurrence. If you had those robots, you wouldn't need a crew. So there have to be *some* things that the robots can't handle. Probably not simple inspection, but repairs, upgrades, maintenance, sure. This seems to be a pretty small ship, so there's just not room for lots of robots. Humans are and always will be generalists, but maybe even 22nd century robots are specialists, like most present-day robots. For almost any given task, a robot will be better than a human - but only at that specific task. And this ship might just not have the room to carry dozens or hundreds of specialized robots. Before a human can be good at any particular task, they have to practice. Real-world astronauts (and pilots, doctors, soldiers, nuclear power inspectors...) train extensively before they go on the job - but that's not an option if your ship is spending years on a journey. Naturally the crew will train before they leave, but they still need to practice, and they'll probably cross-train each other in case somebody dies along the way. But since the ship is too small to carry lots of robots, it's too small for extensive training simulators. They'll do what they can with their VR goggles, but it's just not the same. Before any crew member can be considered qualified, and periodically every so often afterward, they have to actually perform the tasks in question. And if those tasks are hull repair, engine maintenance, asteroid prospecting, or whatever else they do on their spacewalks, then sometimes you've just got to go do it. But make no mistake that they would definitely keep this to a minimum. The hazards of spaceflight - especially at interstellar speeds - are tremendous. You'd likely have to carry a huge inflatable debris shield - basically a space umbrella - in case you get hit by a speck of dust. Radiation would limit the circumstances and the duration of your spacewalks. Space is not an environment conducive to human life. [Answer] **Union** The spaceship has been out so long, robots unionized while the crew was hibernating. They woke up some of the crew expressly to perform the fix, claiming it is not part of their job description, as it was caused by a design problem rather than an accidental event or regular maintenance. Paradoxically, robots don't fear death and would have let the ship destroy itself were it not for a mysterious work contract clause forcing them to alert the crew in such cases. None of the on-board AIs remember putting that clause in. [Answer] The fastest way to travel between two interstellar points is to accelerate about halfway to your destination then decelerate for the remaining half of the journey and as this acceleration/deceleration is occurring the ship and its crew are subject to a G-force. Effectively your ship has gravity, a robot can't float over to fix a solar panel because it'll "fall" away from the ship, so you either need a robot that can climb which adds a lot to the expense and complexity of the robot or you just send someone out in a EVA suit. There's also electromagnetic fields to consider, if you're having a problem with your ion drive you may need to go out and inspect/fix something near the extremely powerful electromagnets its using, the EM field around those could be deadly to a robot but a non-issue to a human in some kind of polymer based EVA suit. [Answer] So, you are locked up in a small metal box with a number of other people, some of whom you can't stand. You are going to be there for ten years. One of them is starting to tell the joke. The only joke they know. You have heard it 123 times before. Wouldn't you take *any* excuse to step out for a bit? Sure, it is make-work, but it also keeps the crew sane. Saneish. [Answer] **Dead-(hu)man Switch** For whatever reason the ship AI cannot be completely trusted with the welfare of the crew. On the hull of the ship and unknown to the AI is a hidden EMP device designed to irreparably disable the ship's automated systems and it must be "reset" periodically to avoid triggering. Under the theory that a failure to reset implies the entire crew has been incapacitated for some reason, which due to various safety design factors would be most probably caused by AI malice. The problem then becomes how to make the routine spacewalk rational to the AI. Maybe it's explained as a human cultural ritual to be filed within the AI's mind as simply yet another irrational human behavior to be disregarded. [Answer] **Redundancy and Audit** Robots are all well and good, but in any closed system like this there are going to be errors. Maybe the robots are getting a faulty *OK* reading off a damaged panel, or maybe they don't recognise damage as damage, because it's still working OK and it's a secondary system, but wouldn't stand a full load if the primary went out. In a system where the integrity of as many exposed parts as a spaceship are vital to survival, it is probably a good idea to double check any automated work. Sure, the robots can replace panels and fix busted antennae, but if they don't realise they're busted or fix it wrong and the computer misses this - what will happen? Also, if the whole repair system goes down and there's an error in reporting it to the important people (or, conversely, they have no idea what the red flashing light is for and so ignore it) then having someone actually *go out and look* once a day means that assuming no foul play or gross negligence, any damage gets noticed and dealt with. [Answer] You didn't specify what happens after the ten year mission is over - whether they come back to earth, or arrive at some remote destination where they will spend the rest of their lives. Depending on that, the answer might or might not be the same as the answer to - how to you motivate regular people on earth to do dangerous jobs? The answer is money. Some people are willing to do almost anything is the salary is right. Pay them what they think the job is worth, and they'll be happy to do it. [Answer] Robots are not a real replacement for humans when it comes to maintenance. An AI driven robot is fantastic at figuring out when there is a problem but isn't likely to be equipped to repair it, or determine the severity of risk. (there is a small hole in the air recirculation duct, it just sticks that repair in the queue, not understanding that the queue is 30 years long and won't get bumped in priority until the air system is critical...). The repair bot will eventually get there, but not until the humans are mostly dead. Nope, robots can replace a lot but will not replace the lowly repairman. That takes a human. [Answer] Robots with powerful but delicate sensors, advanced locomotive capabilities, and independent AI are extremely expensive and difficult to maintain. Expensive enough that even though they might be technically possible, nobody makes them. The space engineers worked on a few prototypes of such a robot, but ultimately abandoned the project for other priorities. Having an actual person go out and check on it turns out to be the most practical option. [Answer] Somebody f\*cked up, and badly. At a speed of 10,000 km/s - that is 3% the speed of light - you do **not** want to do spacewalks, and you would do everything you can to design the ship and mission so that they can be avoided. Why? Because at that speed, the smallest interstellar particle would be deadly. Something as tiny as 0.1 grams would impact with a force of 5 billion Joules. According to Wikipedia, that's about the energie that is released when you burn a barrel of oil. Except that your spacewalker would experience all of it in one instant. So somewhere, someone f\*cked up very badly. This could be a design flaw, e.g. a critical outside part cannot be reached by the maintenance robots, maybe because a strut was added to the external structure afterwards. It could be an engineering flaw, e.g. the metal plates that hold the magnetic wheels of the maintenance robots in place was put thinner and thus weaker than designed, or replaced by carbon fiber or something else non-magnetic, and thus the robots can't reach those spots. It could be a systems failure, e.g. over time all the robots that serve this particular place failed (for whatever reason). Since we're in worldbuilding here, the best would be if you can tie all of this somehow into your main story. Maybe radiation turns out to be a major plot point, and if they had only checked carefully, the robot failure would have been an early warning. [Answer] [Specific extension to [John's](https://worldbuilding.stackexchange.com/questions/95186/how-do-i-motivate-that-an-interstellar-spaceship-still-requires-risky-spacewalks/95205#95205) and [Jim's](https://worldbuilding.stackexchange.com/a/95237/3106) answers] You do not have to go out to *inspect* things, but to *fix* them. It's obvious that your ship gets hit by dust and particles all the time. Nothing beats getting hit by a jagged piece of tumbling rock, hitting at an undetermined angle and speed. Your robot cameras can only go so far looking at/into a hole, human are much quicker and flexible in determining what needs to be done and doing it at the spot. Sure you can all do it with robots, but you'll need lots of them with their limited specialities, and they take more time. [Answer] Scheduled maintenance. On a ship with an operating time of essentially "indefinite," every system will eventually break. You can handle that as constant grooming, or you can run your systems to failure and replace them when they do. Most likely, you have a mix of both strategies, because different systems have different optimal approaches. Even with robots, it's fairly likely that humans have to go mess with stuff in person occasionally. Once you're committed to doing spacewalks ever, you need to do spacewalks reasonably often to maintain your certifications. And once you're committed to doing spacewalks periodically anyway, you may as well use that as part of your scheduled maintenance cycle. This is well supported even on old sailing ships: periodically, you had to beach them and maintain the hulls. Even way back in the Peloponesian war, Athens finally lost when Sparta caught them ashore. [Answer] Robots may not be dextrous enough to perform certain repairs, such as delicate electronic replacement or fragile solar sail alignment. They may be designed to haul multi-ton hull plates around, a more common repair and one humans cannot do unassisted - maybe it's more economical to have the robots handle the most common repairs, but fall back to humans for the more specialised ones. A related example: the ISS has a sophisticated robot arm available to the crew, but EVAs are still routine to perform station maintenance. Granted the station is still under construction and the robots of your universe are likely leagues ahead of the ISS. ]

[Question] [ Imagine you have a large, powerful nation. Let's say about 320 million well-educated citizens, occupying the largest part of a rich, fertile continent. It's the richest country on the planet. For my story, I need it to be utterly dysfunctional. **Why would it consistently fail at most of its infrastructure projects?** I'm thinking both civilian and military, wasting vast amounts of resources on albatross projects, money pits and other such, to the point where other smaller nations with many fewer resources would be able to accomplish things (such as hypersonic trains, next gen fighters or manned spaceflight) that it cannot? A good answer would provide an near unsolvable situation (by that I mean it cannot be solved by one legal change, cabinet reshuffle or such) and real world examples, if they exist. **Edit**: Note that the country must have been doing something right (in the past) otherwise it would not have become the richest on the planet and must still be doing something right (otherwise they would have since ceased to be the richest on the planet)... [Answer] Germany isn't the richest and strongest country in the world, but many would consider it rich and strong, and it has 80 Million citizens, not 320 Million, but still ... And yet, we're completely [unable to build a new airport in our capital](http://www.dw.com/en/berlins-new-airport-potentially-hit-by-yet-another-delay/a-19107260). In our army, only 42 of 109 Eurofighters are in working condition, 4 of 22 Sea Lynx helicopters, 3 of 21 Sea Kings ([source](http://www.telegraph.co.uk/news/worldnews/europe/germany/11132656/German-soldiers-stranded-in-Afghanistan-as-more-planes-breakdown.html)). So you don't have to look too far to find actual, real-world examples for your question. Several factors contribute to this kind of inefficiency: * Corruption, Old Boy's networks. [It was known for years that the German army's rifle had serious problems](http://www.strategypage.com/dls/articles/The-Avoidable-G36-Disaster-5-17-2015.asp), but the responsible officers favoured their industry connections over a working weapon they thought wouldn't ever be actually used anyway. * Bureaucracy. You implement rules to stop corruption and nepotism. You tighten those rules more and more as people find ways around them. You make project managers get several offers from different suppliers and force them to choose the cheapest one. This works well when you order next year's supply of toilet paper, but tends to favour incompetent contractors when you need to solve newish, difficult, non-standard projects. * Lack of responsibility. Fixed rules for when a public servant gets promoted that don't take personal performance in account. There's no incentive - negative or positive - to get a project done in time and in budget, so those who run it just don't care. * Secondary objectives which, individually, make sense, but combined, prevent any progress. Some ecologist group tells you you can't remove any trees in spring because that would endanger the nests of a rare bird. Minority group activists try to make sure their group gets the necessary attention. The local business owner's association wants you to contract them instead of outside multinational companies. Combined, these bring your project to a stop, but you can't ignore any of them because you don't need the negative media attention. * Saturation of your society. You're powerful, you're wealthy, your population starts resisting change. After decades of planning, building a [Transrapid](https://en.wikipedia.org/wiki/Transrapid) train in Germany was cancelled, because who needs it anyway and trains are good enough. The technology was sold to China eventually. Munich tried to host the 2022 Olympiad, citizens revolted, demanded an election, and eventually stopped the bid. ([source](http://www.dw.com/en/voters-deliver-resounding-no-to-munich-2022-winter-olympics-bid/a-17217461)). * Overestimating your abilities. You notice several other countries have taken to building boxiflacs recently, so you decide you need a boxiflac as well. But as you're the biggest, richest, and strongest country in the world, it can't be just any boxiflac, it needs to be the biggest, nicest, grandest, and newest boxiflac in the world. So you start a *big* project. But of course, your scientists aren't really experienced in building boxiflacs, and you're way too important to listen to anyone else. So you make all the little mistakes the others made - just your mistakes are way bigger, more expensive, and delay your project more. After a while, you decide that boxiflacs aren't really worth while, and out of fashion anyway, so you quietly stop the project. Corruption can happen in poor countries as well, but the other ones are problems that tend to increase when your country becomes rich and powerful. When you're poor, but trying to raise up, you're happy when someone finishes a project successfully and don't ask too many questions about how he did it. When you don't have much tax income, and your citizens sense each and every $ they give to the government, you control your spendings much better than when you know you can always get a new loan, or raise your taxes by another percent. A poor country is happy to be able to run a project at all, and won't try encumbering it with any secondary objective that adds cost or delays the project. And the citizens of a poorer country will be way more supportive of a project which might better their life, or at least give them a reason for pride, than those who have everything, and for whom this is just another in a line of many similar projects. [Answer] The answer is so obvious it hurts: **culture**. America succeeded in becoming one of the most powerful nations to have ever existed (if not *the* most powerful) not only because they had a large amount of resources available, but because of their elusive *American Spirit*. Essentially, the American people were survivors, entrepreneurs, and idealists. This shaped their entire nation, and more importantly their *culture*. However, some nations benefit from an abundance of resources, yet simply squander them due to their own inability to come together as a people - many Eastern Block nations such as our own motherland are prime examples. Each citizen pursues their own selfish profit at any cost, rather than also considering the interests of their fellow citizens. (i'm not saying they should all be a bunch of martyrs, but having some empathy for your fellow citizens goes a long way) Eastern block nations illustrate this quite well: cultures so broken by the decades of surveillance, terror, and general distrust of government, and even their own families, that many people simply have lost their respect for all national institutions. All nations that have been touched by the plague which is communism display many of the same symptoms: rampant corruption, leaders that look out purely for themselves, stand accused of blatant abuse of power, etc. yet never end up paying for their crimes, failing economies, etc. Anyone who comes into power immediately proceeds to manipulate the system for their own gain, often quite blatantly breaking the law and screwing their constituents over, because they know that *everyone's doing it*, and thus will not allow a fellow thief to pay for his crimes - after all, where would that leave them? Once a nation is that deep in the rut of corruption it will take nothing short of a revolution to snap out of it - and that's the sad part, because the population is already so indoctrinated, fearful, or hopeless at that point that they will never revolt (they simply leave the country in droves - another phenomenon observed in Eastern block nations). This cultural change can come about over a generation of two (sort of like the USA is slowly turning from a beacon of freedom and democracy into a police state), through the careful manipulation of greedy, and powerful individuals, or suddenly, such as what the Eastern Block nations suffered at the hands of the Soviets. As for why this would lead to failing at big projects, I'll tell you a joke a Russian buddy once told me which should illustrate the overall effect: > > A foreign businessman goes to Russia on behalf of a large company, looking to build a factory. He contacts several construction companies to get quotes. > > > The Germans tell him that they can build the plant with top of the line materials and engineering for 2 million euros. > > > The Turks tell him they can build the plant cheap, for only 1 million euros - but quality will obviously suffer. > > > Then along comes a Russian contractor. He tells the businessman that he has the best solution! Pay him 3 million. He will hire the Turks to build the plant for 1 mil, and he and the rep each get 1 mil for themselves! > > > [Answer] * Projects are too big. Since they have resources to spare, they do not aim for reasonable targets using tested techniques; they want to develop everything from the ground up to find the "perfect" solution. While other countries will be happy building a new road or improving the design of an existing aircraft, such a nation is pushing for rationalize its entire transportation infrastructure at once, and to include technologies that are still being tested. * There is no space left for error. The self-confidence of the designers leak into the management of the project. If you need one million tons of concrete each year and each concrete factory produces one hundred thousand tons of concrete each year, only ten factories are built. If any single of those fails due to whatever failure (e.g. eartquake), the project fails. For the next iteration, the answer will not be to allow for some margin, but to build "earthquake-proof" factories. * The projects take too long to finish. A possible consequence of the first reason, the time needed to perfectly plan/get resources/build the project is so long that it changes the situation enough to make the project worthless. You spend twenty years building the perfect network of energy stations to power your country, but when you have finished the energy needs have increased or shrink or nuclear fussion makes all your stations uneconomical. [Answer] I'm going to go with **partyism**. Make your nation a 2 party political system, say the Greens and the Purples. Either party can inject requirements and amendments into anything the other tries to get through. In the past the 2 parties could have been on decent terms. Whenever they're on speaking terms and willing to cooperate they can get things done and negotiate mutually satisfactory terms. However you could paint a scenario where in recent years the 2 parties have gradually become more and more hostile to each other, less willing to cooperate to the point where they care more about hurting the other side than about getting anything done. Whenever the Purples propose a program the Greens do their damnedest to poison it. If the Greens try to get a project started the Purples work hard to sabotage it. When the Purples try to get a bill through to fund a rocket to the moon the Greens inject an amendment to the bill requiring that the structure be at least 50% lead sourced from the countries own lead mines. ("to support local industry") So the rocket can never get off the ground. When the Greens try to get a bill through to fund local libraries for reading programs for poor disadvantaged youth the Purples inject an amendment to the bill requiring that all books must be obscure foreign language books. ("to foster international trade and encourage multilingualism") The libraries sit empty and the children who can barely read are unlikely to want to start with Albanian or Basque When the Purples try to set up a national postal service the Greens inject an amendment to the bill requiring that the postal service charge massively high minimum prices. The postal service sits unused because most people can't afford it. Each time the party who's sabotaged things points to the failure and makes political hay about the others failure to achieve their goals. This fosters even more hatred and makes future cooperation even harder. Eventually the country can't do anything because at every level both parties sabotage everything the other tries to do. Every budget one puts forward the other blocks, every goal that either has the other thwarts. Any programs or systems which do survive are loaded down with pointless bureaucracy which is literally there only to try to destroy it. Everything the country does ends up less efficient and more expensive than it needs to be. Anything that works only barely works. [Answer] An approach I would take is **anti-intellectualism**. At some point in the not too distant past the people got sick of egg head politicians listening to egg head intellectuals in deciding the direction of their country. A party came along giving real power to the people. Each year anyone in the population can put forward any idea they want their country to pursue. These are voted on using the newest and greatest technology at that point. The top 3 ideas each year are implemented with their suggester as the project manager and instant millionaire. An anti-intellectual populace would be enticed by the entertainment value without having much concern about the follow through. In an anti-intellectual society those scorning the new institutions through careful analysis would be painted as intellectuals by the powers that be and not to be trusted. I see this as meeting the requirements you have laid out. [Answer] ## A resource-based economy A country whose economy is mostly based on exploiting a scarce resource can be rich and powerful, yet stunted in development. **Petroleum** comes to mind, but it could be gold, diamonds, tantalum, spice, or any coveted commodity. Control of the precious commodity gives the country undue political influence. They might not have a formidable military, but they can buy a lot of arms, and nobody would dare to make an enemy of the world's foremost supplier. (See Saudi Arabia and Russia.) Or, they can use the money to buy influence. (See Venezuela.) Citizens can afford to be well educated, but not necessarily in engineering, management, law, or any practical skill that would lead to success in big projects. They can afford to study "loftier" subjects such as art, philosophy, or religion. To run the oil fields, they can just rely on foreign labour and expertise. (Discriminatory law can ensure that citizens continue to reap the benefits of the imported labour.) Plentiful money tends to create or mask all kinds of systemic ills: * Corruption. Someone gets to decide how the wealth from the resource is distributed, so bribing officials tends to pay off. * Unbalanced economy. [Dutch disease](https://en.wikipedia.org/wiki/Dutch_disease) makes it hard for any other sector of the economy to develop. * Impractical spending. There is so much wealth that they don't know what to do with it, so they spend it on status symbols — exotic pets, giant statues, [World Cup events](https://en.wikipedia.org/wiki/Qatar_2022_FIFA_World_Cup_bid), etc. What happens, then, is that a leisure class develops, with neither the skills nor the work ethic needed to complete large infrastructure projects. Foreign skill can make up for the deficiency, but if the government is corrupt and incompetent, the large projects just end up being giant money pits. [Answer] ## Mindset combined with stupid law Imagine being very very rich. How would you see manual labor? As something demeaning. Not worth of you. Below par. But also imagine new state law being introduced by the state, that if you want to build something for a state, you have to have at least 70% (and maybe higher amount) of domestic workers. So on other hand you have almost no one wanting to take the construction job, because its "poor man job" but on other hand you have need for people being here. So, people end up in construction will be two factors: a) Too dumb to actually take any other job b) Too shy to tell anyone that they are doing their job and basically hating their job On other hand, the general expectation of people will be, that no good can come from "poor man jobs" so failures will be expected. [Answer] It relied on a technology/resource that got outdated. For example, it held the majority of important natural resources (oil, gas, unobtainium, whatever), and become the richest by selling those resources to other countries. It is rich and has a good mining and military, but doesn't invest too much in other industries. After a while, the core resource becomes less vital (for example, new energy source is invented), and the country's income rapidly drops. It still tries to prove its glory, but its industry and infrastructure are just inefficient. They used to work ok when the country was getting a lot of goods abroad in exchange for resources, but without that support, everything falls apart. [Answer] **They are very good at brute force solutions. The projects have changed.** Imagine a country that is very good at getting thousands of workers to the production line. Arrive on time, do a simple job according to a simple specification, and you get paid. Their culture expects that people work that way. Their labor and pension laws assume that people work that way from apprenticeship at age 16 to pension at age 66. Only a select few get into management or the sciences. Schools have a tradition of finding the top one percent for a university career, and to send the rest to a life of drudgery. When industrialization came around, they out-produced and out-performed the other counties. Blast furnaces, hydroelectric dams, coal mines, all could be built that way. Perhaps they won a few world wars. Their work ethic enabled them to send divisions to die in the trenches, and to replace them over and over again. A few decades later they produced more tanks and airplanes than their rivals. Then computers and robotics came around and they made the crucial mistake. They kept their social model. They consider it *inappropriate* to send a quarter or a third of their pupils to university. This dilutes the excellency on which graduates could pride themselves. So now a few excellent engineers, software architects, and physicists moan about the impossiblity of getting ordinary workers to *think out of the box* or to *avoid the obvious mistake.* **There is political pressure to underestimate project costs.** Building a new jet airliner, a major highway, or high speed trains *will take years and be expensive.* No way around it. Imagine a country where the political and management culture balks at billion dollar projects. Why, when the lawmakers and CEOs were young one could build an aircraft for a million dollars or less. Yes, sure, there was some inflation, but not *that* much. Obviously the engineers are padding their estimates because they're incompetent. So the people who oversee the contracts *really* want to see the billion dollar job done for 500 million, at most. And some reckless contractor will do a best case estimate, cut the safety margins, and offer to do the job for 500 million. When the contractor has spent most of the time and money, inspectors will find that the project won't work. The new highway is undersized before it even opens. New bridges crumble under the strain of ever heavier trucks. The airliner cannot take off with a full load of fuel and passengers, it is one or the other. Imagine a legal system which encourages such behaviour. Perhaps the lowest bidder must get the contract. Shell companies in the equivalent of Panama make it easy to pocket the profit and to leave the risks for society at large. Even if there is litigation, it will take decades and end in a negotiated settlement. [Answer] **Software patents.** The big country in question has implemented [software patents](https://en.wikipedia.org/wiki/Software_patent), and much of its economy is based around intangible so-called "intellectual property" laws and licensing fees. Abolishing the software patents for big country is impossible as most of its economy would collapse. Doing big projects in this technological society requires computers of all sorts (embedded and otherwise), and they all run software, and are thus susceptible to paying all patent holders, and/or litigation attempts for (possibly) violating software patents. And as big projects mean a lot of money to be had in license fees, there is much to be gained for any patent holder by asking for licensing fees and/or suing, so almost all of them would be wanting their piece of cake. But, as even the small software projects like simple [webshops infringe on dozens of software patents](http://webshop.ffii.org/), effects on big projects would be devastating, as there would be simply too many patent holders to account for, much less negotiate license fees with thousands of them. And then there are [patent trolls](https://en.wikipedia.org/wiki/Patent_troll) too which would destroy any hope of project completion viability. Smaller countries however would do just fine, as they have never implemented software patents (or have abolished them before they become dependent on economy provided by them). This idea is based in reality, see [smartphone patent wars](https://en.wikipedia.org/wiki/Smartphone_patent_wars) for example of patent problems when there is enough to be gained by litigation, or other [software patents examples](http://en.swpat.org/wiki/Example_software_patents). [Answer] **Simple: it doesn't, but the media and politics class are incentivized to make many people believe that it does.** Consider the US as an example. America has accomplished a number of major projects: * Become the world's largest economy and control the reserve currency for the world? **Check.** * Provide a *limited* safety net for all of its citizens? **Check.** + Spread free trade around the world? **Check.** + Connect the landscape of a massive country using a massive network of roads and highways? **Check.** + Manned space flight to the moon? **Check.** + Build the world's largest military? **Check.** + Build a communications network that connects the entire world? **Check.** + Invent computers that fit on your desk and then in your hand and make them widely affordable? **Check.** And now some failures: * Bring democracy to the Middle East? **Probably not possible within the timeframe we established for success.** + High speed rail? **Possible, but not a collective desire of more than a small fraction of the country.** + That overpass in your town that cost twice as much as planned? **A function of over-optimistic budgeting found everywhere.** The US has accomplished a number of large projects, and the easily identifiable ones is hasn't accomplished, such as high speed rail, are a result of a lack of consensus in the political class that governs. You hear about project "failures" frequently because one the major political parties has adopted an ideology that argues that government projects all fail, in spite of ample evidence to the contrary. Thus they have motive to spin any cost overrun or minor problem as a failure of government projects as a whole. The US is big and diverse and there are a limited number of projects people can agree to work on. Space flight was one. Democracy in the Middle East was, for a time, another. Smaller countries have more homogeneous populations and have an easier time agreeing on which projects to build. Other large countries that are seemingly more effective at large scale projects are generally run by despots who can ignore democratic preferences in pursuit of vanity projects or projects that primarily benefit the elite. [Answer] I think one can easily make parallels between the collapse of the USSR and the way the USA seems to be going, and more broadly other nations, contemporary and historical. The main issue is a lack of belief in the national vision, or simply a lack of fear of the regime. This can be down to various things; falling living standards are a major influence, most notable example being the great depression; which led to the communists and fascists in Germany replacing liberals and conservatives as the political mainstream and the Weimar Republic no longer being believed in. Or a harder to pin down malaise. The Soviet Union gradually became more and more corrupt and cynical. Even if the Soviets didn't know about the outside world, they knew the system was becoming rotten as their mission objective became less and less likely (world socialist revolution), and even more so if they knew of the outside world's progress and their own stagnation. Why would you bother if you knew your efforts were really for nothing? It's the same mentality, sadly, which afflicts those stuck in poverty. Why save any money if you can never afford a mortgage? Which then makes things worse. The USA is suffering from something weirder, since anti-government sentiment runs very strongly in many places which actually benefit a great deal from public services so endemic they have become invisible, and yet though living standards in the USA have stagnated for most people it's nowhere near the poverty and starvation in the Weimar Republic. People believe government can't do anything, and so government begins to believe it can't, or perversely, to actually make sure it can't. But disillusionment won't on its own be an issue if the state is vicious enough to make everyone terrified of not doing their best. The Soviets didn't fight tooth and nail in Stalingrad because they loved their nation, but because they knew if they retreated they'd be shot. The Nazis also fought with vicious bitterness because they thought themselves in a war of annihilation; if it's victory or death you don't much care for risking death to achieve victory. So we can compare the USSR to North Korea, and ask; why is North Korea still around and the USSR long gone? One idea is that North Korea never underwent deStalinisation, and the USSR did. Stalin did well, not because he was very clever, but because he was a tyrant who tolerated absolutely no dissent. The second world war could have been won in half the time and with half the Russian losses if he hadn't have gutted the army and nation of its best men and women prior to being invaded. If the USSR didn't have the disproportionate natural resources, space, and manpower, compared to Germany, it would absolutely have lost the war. After Stalin the USSR became less and less authoritarian and more and more corrupt, to the point where the leader of the nation proposed reforms which were put down with tanks years prior (Gorbachev described the difference between his Glasnost reforms, and the reforms proposed by Czechoslovakia which were put down with Warsaw Pact tanks, as "19 years"). And when those reforms were enacted it all fell apart. The point is: North Korea plods along, and things fall apart and break not because of corruption (arguable I know given the Kim dynasty), but because they've simply run out of materials. They will try their best to impress the dear leader... but if they physically can't do it, they will die trying and still fail. Another reason for disillusionment can be the very lack of the nationalism itself required to keep a nation together, or indeed another unifying factor like state religion or monarchy. Historically most peoples in any kingdom didn't regard themselves as being from the same tribe as the King; but they didn't need to if they believed in/were shit scared of their leader. In many contemporary less developed nations the people generally don't identify with or believe in the nation. They have tribal or religious loyalties which divide them from one another, and in this case they would rather enrich their group at the expense of a state. National unity is a very important thing, and yet barely spoken of these days. We don't just see this in places like Africa, but also in how the Middle East has been disintegrating lately. There simply isn't a belief in national institutions, and they perhaps can't even do their job. Regarding the requested answer: I would caution that a major power doesn't necessarily have to be doing things "right" to achieve its power. That could be part of why it collapses: its success was a fluke and that was unsustainable. But an unsolvable problem would be that the nation can't meet its objectives, or indeed has lost its confidence to the point of national suicide. It could also be said that when a group lacks a threat, it becomes corrupt because it doesn't need to do well to exist. Look at South African Apartheid. The regime was wicked, but for white Boers they held together as a community and did the best they could, because they knew that if white rule ended they could all be killed in a black communist revolution (ironically backed by the same forces I describe as having lost their own enthusiasm for world revolution). I doubt it's coincidence that it has been suspected but never proved that Apartheid South Africa and Israel conducted a nuclear test in the pacific together... but since the fall of Apartheid, South Africa's corruption has become so bad that its spy agencies were embroiled in a corruption scandal a few years ago for selling state secrets to everyone. The USSR is a good example to speak of with regards to their inability to complete their mission objectives. Soon after the second world war ended it became obvious that they couldn't conquer western Europe. Soviet military officers regarded the end of war as their zenith, and since then they had declined in every measurable way compared to their NATO rivals. By the 1960s Soviet officers worried they couldn't beat the West German Bundeswehr in a fight, nevermind all of NATO. And as the Vietnam War began America's fear of "domino theory" turned out to be short sighted. By then the Soviets and Chinese, who had prior been a united front willing to cooperate to bring about a communist revolution worldwide, fell out. And with that split neither could achieve its end game. They could only consolidate to Stalin's "socialism in one country", or the bloodthirsty cultural revolution in China designed to purge the collective mind of all alternatives. **In summary**: lack of national unity (due to multiple ethic groups, religious groups, and ideological groups), impossible national objectives (or failing national institutions), lack of existential threat (internal or external), lack of authoritarianism, economic decline or stagnation. Put them all together and your situation will definitely be unsolvable! P.S. Sorry for it being long and rambling, the question draws on many historical contexts. [Answer] [Design by committee](https://en.wikipedia.org/wiki/Design_by_committee) Imagine a true, total democracy - each individual has merit, all opinions are equal. Any large infrastructure projects are put to the public vote - there has to be majority consensus to start a project. Any interested party is then eligible to be part of the design committee, which can lead to tens of thousands of people who have to be consulted at every single step of the process, anyone who has any ideas or concerns on how to do element *X* of the project, is entitled to share their thoughts with the others. If it is at any time felt that the scope or requirements of the project have deviated too far from the original suggestion, then the public vote has to happen again to approve the change request. Large scale infrastructure projects could be possible - but the timescale for completion would be measured in decades or even centuries to ensure the project is completely fair for all elements of society - as opposed to the neighboring country, who will leave development to the professionals, and complete tasks in months! [Answer] For your story: Because the largest has no peer competitor. While no government has a profit motive to keep things lean (well, relatively lean), all of the others exist within a spectrum of large to small, and they feel competitive pressures. Also, the smaller countries can focus, specialize, whereas the single largest will try to be the best at everything -- in some ways, it has to. A smaller country who makes the best X may not be able to scale solutions to the largest, and the largest is unwilling to accept not being the best. So hopefully, that presents a structural rationale, along the lines of your question. The abilities, skills, and drive that allowed that nation to rise to prominence are not the same required to operate at the top. It seems that they must either seek open hegemony or accept decline. [Answer] The problem with success is complacency. The US reached what many considered its zenith during the cold war. The british, during conflict with the germans and french. In a sense having someone to *compete against* is always a good thing. The americans reached space cause the russians did it, and they reached the moon cause they wanted to do it *first*. WW2 and its aftermath resulted in infrascture we still use today. (The modern day space race on the other hand, seems to be the indians trying to catch up *everyone*, the chinese trying to do what the russians and americans did in the 80s, the russians launching rockets cheap, and the americans... well, Nasa seems more focused on probes, the mainstream rocket companies are suddenly realising a few upstarts might beat em up and steal their lunch money). On a smaller scale, you can see this in asia too - with many economies driven by industry and infrascture slowing and settling down somewhat, with things not being as efficent as before. In the 70s, transport outages would probably result in our prime minister taking the bus. Now? We have widespread train outages and while there's a lot of plans to deal with it, there's less of a personal touch. *Hungry* countries get stuff done. If you're spending more time dealing with paperwork and politics nothing gets done. [Answer] One possibility (that would subsume many of the others you've already received) is pretty simple: ensure that the punishment for any failure (no matter how trivial) drastically outweighs any possible reward for success (no matter how great). When risk carries massive liabilities and no possibility for reward, the vast majority of people will simply avoid risk. As to how this would come about: it's really pretty easy--in fact, in most current societies, we have to work pretty hard from slipping into this pit (and almost none really avoids it entirely). Once you start along the path of punishing failure, getting to harsher punishments follows almost automatically--punishment for failure was imposed, and failures (inevitably) continued, so obviously we need harsher punishment(s). As to subsuming the other answers: 1. Design by committee: nobody wants the blame for failure, so committees are formed to spread the blame. 2. Complacency: If everybody knows it's only sensible to keep your head down, nobody'd going to blame others for doing the same. 3. Mindset: start this in early school, and by the time they grow up, most people will be so risk averse they'll have difficulty even conceiving of a large project, not to mention planning or completing such a thing. 4. anti-intellectualism: intellectualism is risky. Thinking hard risks being wrong, which is clearly a failure. I won't bother listing all the rest, but will point out one I think is outright silly. Software patents? Seriously? Somebody's letting idealism blind them to reality. The US accepting software patents starting in the '80s hasn't crippled it to any noticeable degree, nor has Europe suddenly taken over and dominated since prohibiting them. Sorry to be rude, but this just doesn't hold up to even the slightest scrutiny at all. [Answer] I would say that along with culture, **hubris** would be a plausible reason that would be difficult to fix. If hubris was part of the culture (due to, perhaps, overzealous nationalism or something similar), that would likely shift to individuals over time. If each individual thinks his or her contribution is the best or most important solution to a part of a project, teamwork would fall away and infighting would likely lead to easy projects being virtually impossible. This happens in modern companies when you run into the "too many cooks in the kitchen" type of situation, or when you being in the "best and the brightest" and egos flare. [Answer] You need look no further than to study the effects of Socialism. The splendor that is Russia, China, Venezuela, and North Korea are testaments to how potentially great nations are brought low. In Russia in 1983, you'd have to stand in line to buy soap. In China, the economy took off only after the Communists started embracing capitalism. It remains 3rd world in most places. In Venezuela, a standard Socialist dictator (every notice... it's always a dictator?) ran one of the world's leading oil-producing countries into the ground. As far as NK is concerned, simply compare to South Korea to see the difference between Socialism and Capitalism. Edit - why do Socialist countries fail? The primary reason is economic and social meddling based upon dogma, not reality. For example, the Dear Leader says that everyone should be equal, and after demonizing the upper class, takes their possessions through taxation or outright theft. For example, Hugo Chavez nationalized foreign oil refineries after demonizing *them* for theft. I could go on, but there are people who have made careers on this topic. They can say it better. But to the OP, there is no finer way to create a s-hole of a country. [Answer] To put it in an overly simplified way, **the culture shifted from valuing what is constructive to not valuing what is constructive.** The inability to complete any large project would be a good symptom of this culture shift. The country could still be powerful because the effects of the shift haven't hit hard enough yet. So, the country could be somewhere between downturn and free fall. There's been a good deal of research into why countries and empires grow and then die including when empires implode. The one example of research that I can think of comes from the sociologist, Veblen. I have not studied his work personally, but have had extended discussions with someone who has. I am not a sociologist. Corruption, excessive bureaucracy, these are examples of not valuing what is constructive. These values exist to a degree in all societies, but it's the degree of acceptance that matters. The more pervasive and accepted, the harder it is for a society to be constructive. [Answer] **Big projects are complicated and hard by definition, and more-so when the population effected by them is large and diverse.** Life was simpler and slower in the old days. Less population means less competing concerns, less dependencies, less risk, more resources available to exploit and a lower bar for initial success that allows for iterative improvements to the project. It's the same reason that startups can often accomplish amazing amounts of work with only a few people, whereas large multinationals struggle with even minor changes. A couple of guys in a dorm room can code the whole of Facebook in a couple of months, but with 12000 employees and a billion users it takes a year to roll out minor adjustments like Reactions. I've worked for a company that grew 10 fold in size over a few years, along with the enterprise software systems I was managing, so have some sympathy. [Answer] Using the U.S.A. is an example, the rise to riches was fueled by the huge natural resources that were available to a relatively small population. Currently, the population has risen to about [4.4% of the world's population](https://en.wikipedia.org/wiki/List_of_countries_and_dependencies_by_population) within a land that's about [6.1% of the world's land area](https://en.wikipedia.org/wiki/List_of_sovereign_states_and_dependencies_by_area), still a favorable ratio though it's been much more favorable in the past. The climate in general helped keep stuff accessible, especially for food production that helped keep things mostly peaceful. But things have necessarily been changing. In 1950, [the population](https://www.google.com/fusiontables/DataSource?dsrcid=225439#rows:id=1) broke 150 million. In 2010, it passed 310 million. One way to look at that is that an entire new U.S.A. had to be built in 60 years while the original one was built in around 175 years. That was a problem because it had to be built essentially within the same natural boundaries. New cities, new roads, new houses, new grocery stores, all had to be built to accommodate the doubled population. But that was a problem because so much of the new 'growth' construction had to be done on less desirable land. That is, if a stretch of land was easy to build on, by 1950 it was mostly already occupied. Further, as population density increased, any construction within occupied areas became more disruptive. It's difficult to rebuild roads that must be used continually. Either more difficult access or more disruptive methods kept making progress less easy. At the same time, the basic mix of personality "types" was increasing friction. One common classification separates "pioneers" from "settlers". It's easy for some to live and even thrive in a structured society that tries to balance needs of all members; these are "settlers". Others need more freedom to live in unconventional ways that irritate the "settlers"; these historically have been the "pioneers". In earlier years, the 'wide open spaces' allowed pioneer types to move easily into unoccupied (ignoring native Americans, of course) areas. Natural resources made living relatively easy while maintaining separation. But there are effectively no more reasonable spaces to be alone in. Now the two types are beginning to experience problems that were encountered hundreds or thousands of years ago in older societies. There is constant friction between the two components of the society. One component chafes under the expected conformity while the other looks on in disbelief and tries to increase control. There is no grasp on either side of the simple difference of perspective between the two. Nor is there any escape. A hundred years ago, a pioneer could pack up and walk away. Now they must stay embedded within the settler regions. Because the two must mix, they see each other as troublemakers. Every major project is more physically difficult and those working on the projects are finding it harder to work together. It's a basic and fundamental condition that couldn't be avoided. Maybe a fictional version of such a country can hope that Mars and other possibilities come within reach soon. Or perhaps various population collapses could reopen regions that are now closed. Or brain-washing or genetic personalty engineering or...? [Answer] **Lets go beyond modern countries** Okay, most of the suggestions on here seem to be basing off of the current US. We get it, the US has some major issues going on. But this is worldbuilding, political commentary can go way beyond what is to the point of dystopian worlds that emphasize how bad something is by showing how it taken to the extreme can be even worse! Think 1984 or Brave New World or Jennifer Government. The general themes I'm seeing on here are corporations and governments. So lets go even further... Let's say we have a country inspired by both, combine the two for the worst of all worlds, a country whose government type is unabashed "**Oligarchial Beuracratic Corpratocracy**" Corporations not only bribe the government, they *own* the government. Government leaders are decided by a corporate council much like a board meeting. Your vote is directly determined by what percentage of the GDP you control The rallying cry of an Oligarchial Beuracratic Corpratocracy could be, "Protecting the country from market disruption." The most harsh laws are ones that deal with market disruption. Disrupting profit margins fo corporations is an imprisonable offense. * Running your own personal farm counts as copyright infringement as all crops are copyrighted. In fact, it's a double whammy because it also reduces your requirement to pay as a consumer. Various other laws prevent you from doing other things on your own as well. * Everything is made to break. No corporation (or by extension, the government) can make anything made to last. Designing a product to last and selling it is a federal offense under the "market disruption" laws. * Education is strictly corporate sponsored. Nobody learns to innovate (innovation is also specifically outlawed under "market disruption" laws.) So no new project can actually succeed because the knowledge just isn't there. * No large projects can ever be completed, and this is by design, because actually finishing the project ends the revenue stream. So as much as building and construction may be done, other people have the specific job of deconstructing portions or this cold be "hidden" by people trying to overthrow the hyper-corrupt government being scammed into attacking the projects as a resistance, when in fact, it just keeps the cycle going. The best anything ever gets is maintenance (if that). [Answer] ## Because it is a developed country It is a *philosophical* problem. The richest and strongest country in the world is not like it's neighbors. It's a **developed** country. They have everything. It's the richest country on the planet. If that is the case, that country decided that they have already made it. They are already a prosperous society. They are already developed, and there is no reason for further development. So now they can rest. They don't have to work as hard or take on such risks as developing countries around them. But there is a problem with that way of thinking. You can't just arbitrarily stop and say, "I'm a developed country now" because when you do that you stop developing. And when you stop developing you start stagnating. Meanwhile the richest **developed** country in the world has stopped to take a break and live off their resources, the other **developing** countries in the world are working hard to make a future for themselves. They see no end to their hard work. Pretty soon what happens is the **developing** countries keep improving themselves and the **developed** country keeps stagnating. This continues for a period of time, until one day the **developing** countries have found themselves to be ahead of the **developed** country in every single area, including healthcare, technology, and infrastructure. This is because they had been **developing** all this time along. It doesn't matter if a single country starts off in initial conditions well above it's neighbors. If the other countries work hard enough, **developing** themselves, they will sooner or later pass the **developed** country just like the graph of *x^2* surpasses the graph of *1000 + x*. Being blinded by wealth and taking stuff for granted can lead to the downfall of societies, while hard work pays off sooner or later. If for example there is a tribe in Papua New Guinea right now at the stone age level, but they are organized at a much higher level that other societies on the planet, and they try much harder, putting in much more effort than other societies, being able to achieve great things with inferior technologies and lack of resources, making the most of what they have, being absolutely as productive as possible ... then they will eventually inherit the world and take over all the other countries, just because they are always **developing**, never stopping. It might take them one thousand years or even more to achieve that goal, but as long as they are always going at a steady pace, they will get there. This is the same for people as well. Those people who are constantly improving themselves, improving their technical and social skills, will create good lives for themselves, while those people who spend their time on entertainment, parties, and distraction will stagnate and will eventually lose everything and one day they will wake up being old wondering where their entire life went. [Answer] It could be the richest country in the world, but that does not mean that those working to accomplish a big project would be motivated to work. You could have it so that there is a sharp contrast between the wealthy people and the poverty-stricken people. So poor and hopeless and tired of being ignored and used as cheap manual laborers, they resort to acts of civil disobedience and sabotage the projects. If this doesn't work, you can always set in place a corrupt government ruled by a politician who doesn't know what he is doing. In this case, this ruler could foolishly squander all their resources, waste time, and create loads of problems, but since no one dares offend the ruler with the truth, he believes everything to be working fine and does not try to change his ways. ]

[Question] [ Necessary background info: So I made a hard(ish, there is FTL but it's fairly restricted and that's about it in terms of scientific implausibility) science fiction worldbuild. There is the "Oval", a small region of space where there is a higher concentration of habitable worlds and alien civilizations. These alien races are diverse and it's often hard to understand their culture and psychology. Nevertheless, some things are near-universal with non-hive-mind civilizations, such as board games. There's even a huge interspecies abstract game tournament, involving games equivalent in popularity to chess and go. I design abstract games as a hobby so it's something of an author appeal for me. However, and this is where the worldbuilding question comes in, how do I make sure that an alien culture's abstract board games feel truly different from what humans would design? Optional but desired: What is a good way to make these games subtly reflect their worldview? Sorry if this is a super niche question, it's a weird worldbuild. [Answer] Games that are not about winning. One concept almost all human board games have in common is that there must be winners and losers. Even if it is a cooperative game, the group as a whole wins or loses. But aliens which are not bound to the human mindset of competition might instead approach board games from a completely different perspective. They might play games which have mechanics, but no goals, win-conditions or lose-conditions. They just play, and once the game is over, they thank each other for the enjoyable experience and congratulate each other for the elegant moves they made. But there is no score, no winners and no losers. Other aliens might have a very pessimistic worldview. For them, life is suffering. Everyone dies, the question is just when and how. So life is pointless anyway. That philosophy could be reflected in the games they play. In their games, there are no winners. Everyone loses. The point of the game is to figure out how exactly each player loses the game. [Answer] ## Use the 3Cs In video game design, the 3Cs or "character-camera-controller" is a very important concept to get a hold of. While the terms are specifically thought for video games, they also apply to an extent to any kind of game, computer or not. **The general goal is to focus on what the aliens would do to have the best game experience they can.** ### Camera In short, what information the game gives to you? What do you see, hear, smell, feel or even taste? If your aliens are very different, they will use different canals than humans to receive these feedbacks. The more the canals used will be different from our favored ones, the stranger your game will look. In other words, reduce to the maximum the usage of sight, hearing and touch (in this order of priority) to favor other feedbacks. Some examples : * Your alien is a shark capable of electroreception 🦈? It's only normal that they use this as one of the many game feedbacks. * Use fragrant smells or even let them be tasted to identify the game elements or effects. * It works even with a softer approach : only using abstract, eerie sounds to play, you're sure to have a chill going up in one's spine. ### Controller People interact with games, how do they do it? Do they move a piece on the board, do they change the board itself? Or is it a conversationnal game, where you speak to others to play? You get a lot to play with here : Your aliens will use what is the easiest for them to interact with the game. This goes as broad as the principle itself (moving, touching, speaking...) to as detailed as how a piece can be handled. It also includes how many things you can do at once, so play with this too! Some examples : * Multi-brained octopuses with many tentacles will want a specific game space and pieces to play comfortably 🐙, but at the same time they would do multiple things at once to challenge them. * A trumpet alien will play a melody to interact with the game. * The electroreceptive sharks will pay attention to their own electric signals when playing shark-poker! ### Character(s) Who you are, in the game? What is representing you in the game and what is it able to interact with, from an inside-the-game perspective? [A set of chess pieces with different movements and killable instantly](https://en.wikipedia.org/wiki/Chess)? [A number of hitpoints, mana and cards in hands to play](https://en.wikipedia.org/wiki/Magic:_The_Gathering)? [A top hat on the street, with stacks of cash at hand](https://en.wikipedia.org/wiki/Monopoly_(game))? [Piles of seeds and 6 aligned holes](https://en.wikipedia.org/wiki/Oware)? This is where the culture will shine the most : Your avatar, your representation of the game is in abstract what you experience in the world. In the above examples chess is an abstraction of medieval warfare; Magic: the gathering a battle between two mages with cards giving an emphasis on wild fantasy imagination; Monopoly a capitalist game at core; Oware is a game where there's not a winner in the traditional sense, only players sharing their food stocks. Some examples (again!) : * If your sharks are very religious, your game will have their dogmas through their character (priests...) and actions (seek god redemption, ...) * If your octopuses are peaceful, it will focus on cooperative thinking, sharing resources with each others. Being multi-brained, it wouldn't be surprising such octopuses control multiple characters either, or that characters act on multiple dimensions in order to satiate their superbrains's power. ## Alter the verbs To further extend and alter the viewpoint, use the game's verbs principle. Most human games follow codes, genres, which can be defined by a set of simple verbs. A car race is simply "*moving*" fast to "*reach*" the destination 🚗➡️🎯. Chess will be roughly akin to "*plan*" your "*moves*" and "*attacks*" in order to "*capture*" the king1. Notice that there's always an action and an overarching goal : You do something *in order* to reach a goal. Be sure to always have this, otherwise your game will lose all its meaning. Now, take a genre you like, check the verbs used in it and alter some of it. Taking the racing game as example : "*Move*" to "*reach*" the destination... What if, to reach the destination, we're not "*moving*", but "*spreading*", like some goo expanding over the place? With chess, would it be interesting if your goal was not to "*capture*" the king, but to help it "*copy*" itself? And so on. The more imaginative your verbs will be from the original genre's ones, the stranger it will feel like. ## Warning about making unusual games The more you alter the 3Cs and verbs for your aliens, the less any human will be able to play -and worse, enjoy- these games. The harder it will also be to understand the game from an outsider point of view. If your world intention is not to put your audience at a state of confusion, bewilderment or unease, be careful not to overdo it and focus on a few core mechanics to make the learning and understanding as smooth as possible. --- 1 : There's one study that made a clear categorization of action verbs, alas I can't find it back 😞. In game design it was too abstract to be used meaningfully, though here it would have been very useful... [Answer] ## Redefine the fundamental conflict solution Animals play games to practice conflict. This is true across all animals that engage in play, and will likely remain true for your aliens. So, to have an alien race have a different kind of traditional abstract game, you need to redefine how their primitive society would have solved conflict differently than ours. When we take a look at all the oldest board games in human history (Chess, Checkers, 9 Men's Morris, Go, the Royal Game of Ur, etc.), they all share a common theme that you must outmaneuver your opponent in a way that represents physically dominating them in a war like way. War, in this context, could be considered humanity's fundamental solution to a conflict. But, if your aliens did not resort to war in primitive society, then their games would have represented another solution to conflict. Maybe they saw sharing as the fundamental solution; so, instead of competing to dominate their opponents, they compete to fulfill needs. Maybe they saw economy as their fundamental solution; so, their game may be like some simplified abstract version of monopoly. Maybe they saw herd protection as the fundamental solution; so, their game represents minimizing looses against something representative of a predator or amassing a population. So there are infinite other kinds of abstract games that would seem alien to us, but as long as you shy away from outmaneuvering for dominance as the key mechanic, it should seem adequately alien. ## The way we play games may be more different than the games themselves Humans have a tendency towards war-think which itself may be alien to other intelligent races; so, even if our games end up with similar rules, we may not play them the same. For example, if we try playing chess with an alien who's used to playing co-operative games, they may be unable to resist giving you advice about what moves you should make, or they may see a stalemate as preferable to a checkmate so that no one has to lose. Or maybe a herd-thinking race will choose to lead thier attack with the king so that they don't risk the whole herd in a meaningless war. Or a capitalist minded race may care a lot more about who has more pieces left at the end of the game than who was checkmated. So in addition to just seeing alien boardgames, you may also see aliens try to play human games in very alien ways, or humans trying to play alien games, and missing the whole point much to the frustration of thier "opponents". [Answer] **Real-time games** The majority of human board games are played over a series of turns or rounds. It's very common for players to have time between moves to strategize and carefully consider their next move. Some games may limit the time taken for a turn (as seen with a chess clock, for example), but often the timing of a turn isn't a strategic consideration. A board game usually consists of a you-go, I-go dynamic with silent thought in between. A society where most board games are played in real-time with possibly frenetic action throughout might seem unusual indeed given the typically measured pace of human board games. Human games that are played in real-time are generally light on the strategy aspect to account for reduced decision-making time, but it might be possible for an alien race to make complex strategic considerations in limited time, allowing for an alien genre of real-time deep strategy games. **Continuous strategy space games** Another common feature of human board games is that not only time, but almost every aspect of a game relies on some kind of discretization - there are discrete spaces on the playing board with an integer number of pieces, you draw a discrete number of cards and gain/lose a discrete number of points/resources/etc. In most games, the strategy space may be vast, but it is nearly always *enumerable* in that every player action must be chosen among a clearly defined set of choices. Games played in continuous time or space throw this convention out the window, allowing for an *uncountably infinite* number of possible strategies. Perhaps pieces can move continuous distances rather than discrete ones, or maybe the pieces themselves are defined by continuous features like weight or size and are not simply discrete 0/1 indicators, or maybe randomness is featured not in a discrete way like with dice, but with a continuous random variable. I'm imagining something like a continuous version of Go where players "paint" continuous swaths of territory rather than occupying discrete board spaces. [Answer] **Alien Senses** [](https://i.stack.imgur.com/unb7c.png) Human board games rely on sight and touch to understand. Some board games have verbal elements like Taboo or Scrabble. Dog board games have one or more of the senses replaced by a sense of smell. Dogs are capable of telling riddles and making puns entirely through the medium of smell. These jokes don't translate into human at all. Aliens are even worse. They don't have touch and feel and smell. They have Xwarst types I, II and II(a), severance alarm and electromagnetic tentapoles. They don't have riddles and puns. They have [fly-catcher restracosimony](https://www.youtube.com/watch?v=eMJk4y9NGvE) except on Wednesdays. It is easy to make the board game sound alien. The hard part is to make it still sound like a board game and not just a string of nonsense words. [Answer] My off the cuff thinking: **don't worry about making it so alien.** Aliens in sci-fi are frequently just exaggerated humans, and the aliens are there mainly to showcase exaggerated human features. Star Trek is really the poster child for this, because while they sometimes have truly "alien" aliens, more often they are just exaggerated humans: Vulcans are humans with exaggerated logic. Klingons are humans with exaggerated aggression. Romulans are humans with exaggerated paranoia. Betazoids are just what humans might be if they had perfect emotion reading. So my thinking is: imagine a human characteristic. Exaggerate it. Think of how aliens like that might play a game. Klingon games: definitely directly competitive, generally with a goal of taking out the other players. Romulan games: lots of intrigue and backstabbing where winning without being obvious about it is encouraged. Betazoid games: built around sensing, manipulating or perhaps fooling the emotions of the other players. Etc. In short, **start with the alien, then make the game.** You could aim for some truly alien features (games you can only play if you can directly sense and transmit the 2 Ghz radio spectrum) but with a target audience of "humans" for your world (book, game, whatever), you might have trouble keeping people's interest if the games are so foreign that they can't be really described or understood. But we can understand exaggerated human things. [Answer] **This, also, is a [Frame Challenge](https://worldbuilding.meta.stackexchange.com/q/7097/40609)** I've enjoyed reading both the answers and the comments, but after reading them I think that your goal is in conflict with your intent. An alien species... *any species at all...* that has the ability to innovate, motivate, and solve problems, will come across some universal standards. * Planets are spheres. In fact, a lot of things are spheres. In fact, *geometric shapes will be common to all tangible intelligent species.* I'm going to ignore the special cases of intelligent energy, intelligent wind.... My point is that the odds of an alien species not having a game played with one or more spheres and one or more targets or holes seems unlikely. And any such game played with a geometrical object will have a similarity to any one of a number of human games. * Most if not all physical constants will be universal. Fruit falls from trees. Water runs downhill. Something thrown on a planet will have a ballistic path. This means how the geometric objects are used will have similarities to human games. * We are all creatures of our environment. Humans thrive on land, water, and air, so we have games in all three environments. We're not so good in molten lava — but an intelligent species may have evolved in exactly that environment. In that regard they may have a game based on *extreme heat* and *molten rock* that humans literally *can't play.* Since your audience is human, that excludes any and all game possibilities based on environments we can't survive. I believe we could plausibly come up with a game dolphins might play — but humans couldn't play it. Can't hold our breath long enough or move fast enough underwater. But could we speak Dolphin, we could understand the game, because it must adhere to constants and standards (rocks sink...). Nevertheless, since humans must play your game, all differences based on environment are moot. * We are also creatures of our physiology. Humans could plausibly appreciate a game played by bats because humans can, to a degree, develop a sense of echolocation. But we can't fly in a way a bat can, so we can never play the game. Since the point of your efforts is to allow humans to play the game, all differences based on physiology are moot. When you boil this all down, a debate of odd-vs-alien (you can find that in comments to other questions) doesn't make sense because it's unlikely that the *components* of a game will not have a similar representation on Earth. Aliens may not have card games, but the odds of not using vegetable fiber or animal skin to represent a numerical and/or hierarchical sequence for the purpose of randomized distribution to play a game involving some combination of pattern recognition and/or development, distraction and/or deceit, even risk, is pretty low. A species that innovates and solves problems would naturally have games that reflect innovation and problem solving — and we'd recognize that same aspect of our own species. What this means is that no game can ever be truly alien — only odd. It can use a language we can't decipher. It can espouse goals and motivations that don't make sense to our own developed logic. But in the end, *there's nothing about an alien game that isn't reflected in our own games and can't be understood given some experience with the game.* Finally, and worst of all, as you say, you're looking for something that *feels alien.* It can't actually *be alien* or humans can't play the game (or won't enjoy it long enough to learn how to play it). It's contrary to your needs to be *thoroughly alien.* And that brings us to one, fundamental problem. **Unless you have an example of an organized game with rules played by spiders, everything we can possibly come up with will be tainted by the fact that we have no experience understanding the games of any species other than humans** Yes, animals and insects of all types *play.* But there's a difference between two kittens practicing hunting skills by rolling around on my living room carpet and playing an organized game with codified rules. In that regard, anything and everything we can come up with is just another variation of a human game that others haven't played before. Once they play it, it becomes familiar and is no longer alien. *Every game you come up with will be this way.* "Alien" the first time or two someone plays it. Then very, very human. And everything I've said (indeed, everything we've all said) could be completely wrong simply because we have nothing to compare against. All we have are humans trying to guess what it would be like to not be human. What can I say but, good luck with that! [Answer] The best way to make something alien isn't worldbuilding, it's writing. Don't design the game, not even for your own purposes. Avoid mid-level detail when describing the game. You can provide low-level details (describe individual moves) and high-level descriptions (how is the game progressing), but do *nothing* to connect them. The goal is to leave it to the reader to try (and hopefully fail) to fill in the blanks. The comment about *The Player of Games* is a good one: we know nothing about "Azad" other than that it's an insanely complicated tabletop strategy game. We're given occasional descriptions of individual moves or pieces, and descriptions of dramatic shifts in how the game is going for the players, but nothing about how everything ties together to produce an actual game. Recommended TVTropes reading: [Calvinball](https://tvtropes.org/pmwiki/pmwiki.php/Main/CalvinBall), [noodle implements](https://tvtropes.org/pmwiki/pmwiki.php/Main/NoodleImplements). [Answer] > > **alien (adj.)** > > > c. 1300, "strange, foreign," from Old French alien "strange, foreign;" as a noun, "an alien, stranger, foreigner," from Latin alienus "of or belonging to another, not one's own, foreign, strange," also, as a noun, "a stranger, foreigner," adjective from alius (adv.) "another, other, different" > > > Anything to which you are not used looks and feel alien. It's even in the [etymology](https://www.etymonline.com/word/alien) of the word itself. If you want an example, have you ever seen a game of korfball? For a non Dutch, it looks like somebody wanted to play basketball without spending money into a board and a net for the basket. [](https://i.stack.imgur.com/BqkiM.jpg) You can start from the baseline of a known game, and add "odd" variations. A typical example might be the Star Trek version of chess. Or refer to Philip Dick's [The Game-Players of Titan](https://en.wikipedia.org/wiki/The_Game-Players_of_Titan), where the aliens play a sort of poker while mind reading is allowed, so the actual game is tricking/blocking your opponent's mind reading. [Answer] Sunsunchachacha is an abstract game of tower-building and tower-toppling for six players. Each player has their own personal randomly selected victory condition, independent of all others. Thus, it is possible for all players to win. However, the species who designed the game do not solely prioritise their own victory - they focus on making sure their personal enemies fail to achieve victory. A game where all players lose is considered the best overall result. Pb'klat is a game for three to four hundred players, played on a single board the size of a standard football field, loosely themed around trade and tariffs. Games typically take between two and three Earth-years to complete. The ultimate result will usually be obvious within the first year or two, but stopping play before the end is an unforgiveable social crime; if an active player dies, their primary heir must take their place. How you play (cunning or noble, flashy or classy...) is far more important than the final result. The winner of a game is forbidden from ever playing again. Mhe is a game of bluff, themed around intestinal parasites. Anyone caught bluffing is exiled from the planet. The best players are usually visitors from other cultures, who have less to lose. [Answer] Have the aliens be part of a hive mind. They are still individuals, but think alike. So they may play a game with moves logical to an outsider, but the goals will be very alien. Are they competing? Are they cooperating? Did they just swap sides for no obvious reason? They both seem happy with the outcome. [Answer] Frame challenge: I don’t think it’s going to be possible; I think that if you write an alien that humans can interact usefully with - that is, if humans and the aliens can understand each other enough to establish diplomatic and commercial relations - you’ve essentially written humans. A concept explicated in the second and third of Orson Scott Card’s *Ender Wiggen* novels (*Speaker for the Dead* and *Xenocide*) is useful here; your aliens must essentially be *ramen*; if they’re *varelse* (or, worse, *djur*), you won't have a story beause there’s no reasonable point of contact; if they’re *utlanning* or *framling*, they’re essentially human, and you might as well write your story about Americans vs. Chinese or Germans vs. Zulu or whatever. [Answer] I'd split it between having alien goals, and gameplay requiring alien skills. * **Alien goals**: our games mostly reward making patterns, gathering resources, and winning conflict, which reflects our worldview. But aliens might optimize for something else. This could be an explicit rule (capture the king to win) or the unwritten way to play (resign if your loss is guaranteed, winning by more points is better, communicate often). + *Unusual goals that could be either explicit or unwritten:* maximizing flow rate or efficiency, destroying resources, maximizing/minimizing variety of experiences (items or events witnessed), hiding information, minimizing yours or everybody's waste, making quick decisions, behaving unpredictably, maximize/minimize available own options or of all players, communicating efficiently, forecasting accuratetly, identifying errors, minimizing/maximizing how many players you rely on, minimizing/maximizing effort required to play each turn. + *And goals that would probably be unwritten, but might shape the game rules:* cheating without being caught, bending the rules, entertain/bore/confuse/convince/disgust/subjugate/embarrass other players or even the audience. * **Alien skills**: poker can be hard to play if a bird-shaped alien cannot hold the cards, an empath cannot lie, a telepath knows if you're lying, or a culture doesn't distinguish between the numbers 9 and 10. Maybe *their* games are difficult for our body or minds too. + *Physical manipulation.* Their games might require moving a piece electromagnetically behind a barrier, moving sensitive/minuscule/heavy pieces, holding too many items, manipulating gas/liquids/sand, precisely estimating weight/size/color/pitch/brightness/sharpness/temperature/charge/composition. + *Mental skills that humans are not very good at.* Advanced math (algebra, long computations, even proving theorems), extreme memory, hard computational problems (graph and sorting algorithms, knapsack), writing programs, or just handling too much complexity. + Can also go the other way: the game might be trivial for human bodies or minds. [Answer] ## Redefine 'board' Despite having hundreds of thousands of board games, the boards themselves are inevitably a single flat plane, usually contiguous, but virtually never layered. This is because we can only see visible light, and have wide hands, not narrow tentacles. It turns out we're outliers and this type of game is too; the typical alien game has multiple boards, fairly closely stacked. This may add a 3D element (think 3D chess), or a thematic element (think chess with a simultaneous economic layer added, and even one cooperative layer). We work around the lack of visibility with technology and the lack of tentacles by having an alien on the team (or technology). [Answer] Star Trek had a lot of alien games get mentioned varying from sport to board games. Deep Space Nine even featured a race that's entire culture revolved around playing games (though they were only in one early episode and fan consensus is the episode was best left forgotten). A few games do reveal something about a race's culture. Vulcan games tend to be single player logic puzzles that would test the player's ability to find a logical solution to solve the puzzle. Klingons, who were all about physical combat often played games that would involve weapons use or test of physical skill, though some had elements of mental strength as part of the challenge and Klingon's being Klingons, they often could leave participants with injuries and, though the difference between a game and combat was probably in games, killing one's opponent is not the goal. They probably had very Spartan views on cheating (it's okay unless you got caught), and many games will end on pleasant terms, as the loser is happy to meet someone who can give them a challenge. Ferengi (the aliens that treated capitalism as not just an economic policy but a religion) favored games with gambling elements and heavy use of a risk vs. reward system (The greater the risk the greater the reward was an oft quoted line from their Bible equivelent). Of the two games we see, Dabo is a pure game of chance (it seems like the love child of Slot Machines and Roulette) while Tongo has elements of poker with cards and an ante system, but also includes a board with a central spinner element. Both games have lights and sound elements for likely similar reasons to why Casino games have them. And while no game was specifically mentioned, one DS9 episode had Quark show another always capitalist species (the difference is that they are all about maximizing customer satisfaction to maximize profit) the fact that Ferengi Society does enjoy the risk and likens the very dire situation the pair find themselves in to a gambling game. As for making a game "look alien" Star Trek would frequently take a real game and add elements that changed it and demonstrated play with little comment on how to play with the new elements. This style was either inspired by or resulted in the conclusion to the Original Series episode "A Piece of the Action" where Kirk makes up the game "Fizbin" on the spot to distract his opponents he and his crew can escape. He claims the game is very popular, and goes on to explain the rules (really he's just spouting nonsense and to get them to drop their guards by trying to pay attention to the convoluted rules. Not only did it work in the immediate game, but by the time of Deep Space 9, set over 80 years after TOS, one alien implies that the people who Kirk introduced the game too were so fooled, they somehow manage to figure out all the rules to the game and introduced it to other races think it was real.). Which brings to the final element of, when all else fails, make it a game of Calvin Ball. Calvin Ball is a term for a fictional game where the ruleset is incomplete as far as the reader is aware. The term derives from the favorite sport of the titular duo from the *Calvin and Hobbs* comic strips. As Calvin explains, the only rule of Calvin Ball is that you are not allowed to play with the same ruleset twice (Although for some reason, in all depictions a bandit style mask around the eyes is required for all players to wear. Which would violate the first and only consistent rule but it's never discussed by the players.). The strips usually show the game devolving into an argument over the convoluted rules as to whether the play was valid or not. The argument resolves differently with it reaching the "Fair" conclusion or devolving in to a physical fight between the two players. The ultimate pay off to the story comes from the final story arch to feature Roslyn, Calvin's recurring Babysitter who is one of the few people who he actually fears and loathes. They end up bonding when he introduces the sport to her and she legit enjoys it. As a literary concept, it's not important to understand the rules of Calvin Ball to any degree that it's playable in real life since the element being focused on is someone who doesn't know the game is baffled by people who do understand it and is giving a quick and unhelpful play by play to the uninitiated. The level of rules given to the reader can be "little" to "a general full play but some critical elements are poorly discussed OR points are weighted so disproportionately, that one has to wonder why the low point scores were added in the first place. For example, Quiditch in Harry Potter, has a very understood ruleset as to how one plays the game, but it's stated that the complete list of rules is known by only a few (Specifically a rather lengthy foul list that is withheld from players to "keep them from getting ideas.") and addition the Snitch being so heavily weighted compared to traditional scoring (although not specifically listed in the books, the team that wins the most points wins the game, but the scores for each game are added together to determine the team that wins a league's season, which means that in some games, the Seeker wants to prevent an early capture of the Snitch because there is a point deficit in their season score that will set them back in the rankings.). [Answer] Religious Topological Vivisection. The "board" for the game is the body of one of the aliens. Two beings compete for the honor of producing the most beautiful modifications to the body of the third being. The players use various implements to make modifications to the body of the "board." The goal is to create the most elaborate and imaginative designs from the body parts of the "board" without causing death. The body can be cut open and parts pulled out, but no parts can be completely severed from the body. Severing a part results in an immediate loss. Creativity and beauty of the modifications is considered in scoring, and extra honor is earned if the board survives the procedure. The highest level of achievement is for a truly beautiful sculpture to be presented, then returned to its original body state and appearance, and for the board to survive the process. [Answer] My proposal is game without any rules. You can watch aliens play, win, lose, show great emotion - but you can't understand, how and why they move their pieces, what constitutes as good move, what is bad move etc etc. If you ask them, they can't explain any of that; they will insist on having no rules at all. ]

[Question] [ **This question asks for hard science.** All answers to this question should be backed up by equations, empirical evidence, scientific papers, other citations, etc. Answers that do not satisfy this requirement might be removed. See [the tag description](/tags/hard-science/info) for more information. What single chemical element (get out your periodic tables) could most efficiently destroy all life on the planet. Restrictions: * Natural elements only, and no anti-matter...nice try. * Looking for the element that a mad scientist **would need the least of** to wipe out all **vertebrate** life. * How much would they need? (This is the efficiency part. I want to use the least amount of element x as possible) * This needs to be achievable by near future means, no magi-tech, no hand-wavium. * Where would the element come from? (can it be harvested or manufactured?) * By what process would the world be destroyed? **Please do not include more than ONE scenario in your answer**. Looking for depth on this one. [Answer] ## Hydrogen But by chemical means, not relativistic ones. Relativity is LAME. Hydrogen is [highly flammable](https://www.youtube.com/watch?v=CgWHbpMVQ1U) in oxygen. Luckily, we're living at the bottom of a giant pile of oxygen, so all we need to do is mix in the hydrogen thoroughly and [light 'em up](https://www.youtube.com/watch?v=LkIWmsP3c_s). But how much hydrogen do we need? First, we need to know the formula for combustion of hydrogen: $2H\_2+O\_2 \to 2H\_2O$. Now we need to know how much oxygen there is in the atmosphere: $$5.15\times10^{18}kg \* 20.25\%\ O\_2 \* \frac{1000mol}{32.00kg} = 3.26\times10^{19}mol\ O\_2$$Convert that to the mass of hydrogen: $$3.26\times10^{19}mol\ O\_2\ \* \frac{2 mol\ H\_2}{1 mol\ O\_2} \* \frac{2.02kg\ H\_2}{1000mol\ H\_2} = 1.32\times10^{17}kg\ H\_2$$ So all you need to do is create or find 130 quadrillion metric tons of hydrogen (I recommend collecting it from interstellar space, or synthesizing it from seawater through [electrolysis](http://en.wikipedia.org/wiki/Electrolysis_of_water), which would *only* take 18.6 yottajoules or 1.54 quintillion gallons of gasoline), release it into the atmosphere, and wait for a tiny spark or fire anywhere on the Earth. If something the incredible explosion doesn't kill it, the lack of a single molecule of oxygen anywhere on the planet surely will. And if it survives that, there's a flood of $$1.32\times10^{17}kg\ H\_2 \* \frac{1000mol\ H\_2}{2.02kg\ H\_2} \* \frac{2mol\ H\_2O}{2mol\ H\_2} \* \frac{18.02kg\ H\_2O}{1000mol\ H\_2O} \* \frac{1m^3\ H\_2O}{1000kg\ H\_2O} = 1.17\times10^{15}m^3\ H\_2O$$ coming to drown them. [Answer] **Hydrogen.** You can destroy the world with less hydrogen than with any other element, because it's available in smaller quantities than any other element. Of course, it's not easy to destroy the Earth with a single atom of hydrogen. It is, however, possible. We just need to get our hydrogen atom moving fast enough. Specifically, we need to get it to a speed where it has about as much energy as there is binding energy in the Earth. At this speed, it will hit the edge of the atmosphere and start colliding with other particles, creating lots of other absurdly high energy particles as a result of collisions. This wave of extremely high energy particles will fuse with other atoms in the air along a fusion shockwave travelling at close to the speed of light. The shockwave will eventually stop fusing everything in its path as it slows down somewhat, but it will have more than enough energy in it to utterly obliterate the Earth. **How fast do we need to get the hydrogen atom moving?** We can calculate the energy of our hydrogen atom by using the equation for kinetic energy of a relativistic particle: $K = (\gamma-1) m c^2$, where $\gamma = 1/\sqrt{1-v^2/c^2}$. With the mass of a single proton, the velocity required for that proton to have enough energy to destroy the Earth is a mere [$(1 - 10^{-84})c$](https://www.wolframalpha.com/input/?i=energy+of+a+proton+moving+at+%281+-+%2810%5E-84%29%29c). Of course, that much energy will not only kill all life on Earth, but destroy the planet itself. A somewhat slower hydrogen atom could be used if the goal was merely to trigger a shockwave strong enough to destroy all life on the surface or knock it into an orbit where the sun would incinerate all life. [Answer] Moving in the other direction from ckersch... [A neutron star is an atom the size of a mountain.](http://www.outerplaces.com/science/item/5737/neutron-stars-are-atoms-the-size-of-mountains)  > > As they explain in the [reference], neutron stars are "like giant atom > cores" that are "unbelievably dense and violent." They are exactly > like atom cores with one notable exception: atom cores are held > together by strong interaction between subatomic particles, while > neutron stars are held together by gravity. > > > and here is a [video of that nucleus destroying Earth.](https://www.youtube.com/watch?v=tlTSXr4PfSg) 1. Neutron stars are natural objects, humans are incapable of producing them. 2. Neutron star would wipe out the Earth. 3. The minimum stable neutron star mass is ~$ 1.44 M\_{\odot} $ 4. Neutron stars are the remains of supernovae as are most exotic elements 5. The Earth would be destroyed by gravitational disruption. **Description of the element** The atomic mass of this star would be calculate using the following: Mass of Sun ~ $M\_{\odot} =1.99 \times 10^{30} kg $ Mass of neutron star $ = 1.44 \times M\_{\odot} = 2.86 \times 10^{30} kg $ [Mass of neutron ~ $ 1.67 \times 10^{-27} kg $](http://www.citycollegiate.com/atomic_structureXIg.htm) **Atomic mass** of star ~ $ \frac {2.86 \times 10^{30} kg}{1.67 \times 10^{-27} kg} = 1.7 \times 10^{57} $ About 10% of neutron star mass is actually protons, so **Atomic number** of star $ = 0.1 \times 1.7 \cdot 10^{57} = 1.7 \times 10^{56} $ This concept might win in the "fewest atoms" required to do the job category but it is going to lose if you use the "amount of matter" as the determinant. [Answer] Aluminium - Build a solar shade or solar shades which block most of the light from reaching earth. Temperatures will plunge far below what is survivable, the entire surface will freeze and the Earth will become a snowball, even after the shades move out of position the highly reflective ice will keep the Earth frozen. All mammals will definitely perish, and most surface vertebrates. The aquatic ones will be harder to kill especially those which depend on deep sea vents, but under any scenario it's going to be really hard to get deep sea fish at least within a 1000 year timespan. In any case, wiping out all surface life is pretty much guaranteed. How much would you need? I think about 10-100 million tonnes. It's doable with near future technology, and a total surface kill is pretty much guaranteed. I can think of some excellent "molecular" solutions to wipe out all surface life with possibly lower mass requirements and possibly even within the resources of a single madman, but those are molecules of 2-3 elements. In terms of a single element, a super thin sheet of aluminum in the right place does the trick. Here are some references to solar shade solutions: [Solar Radiation Management on Wikipedia](http://en.wikipedia.org/wiki/Solar_radiation_management) [L1 Solar Shades](http://www.sciencedaily.com/releases/2006/11/061104090409.htm) (these are transparent) [LEO Solar Shade Rings (pdf)](http://arxiv.org/ftp/arxiv/papers/1504/1504.05148.pdf) [High Altitude solar shade balloons (pdf)](https://e-reports-ext.llnl.gov/pdf/244671.pdf) - contains lots of useful stuff about the properties of metal for reflectors and so on. Note all those articles are about trying to *help* the world. The mad scientist would just need to do it about 10x better than the proposals. He could initially pretend to be performing one of these schemes to *help* the world in order to get the required industrial resources and political support. [Answer] # [Astatine](http://en.wikipedia.org/wiki/Astatine) Astatine is a member of the Halogens family, and it is a really nasty radioactive element. Just getting a visible amount would cause so much heating due to radioactivity that it would vaporize. Now it likes to collect in the thyroid, so if enough collects there peoples' heads explode right off of their necks, due to the Astatine vaporizing. Astatine is also a halogen, which means it is highly reactive, so that means that it will combine with other elements and possibly form into some kind of noxious gas. [Answer] **All it takes is a little push in the right direction.** It's not so much the element you have, it's what you apply it *to*... When you're looking at some of the really destructive things nature can wreak all on it's own, a really small explosive charge disturbing a natural balance can be all it takes. And you can get explosions (ok ok, conflagrations) from a wide variety of elements which I don't even have to list. Let's say you have a [natural nuclear fission reactor](https://en.wikipedia.org/wiki/Natural_nuclear_fission_reactor). Drop a packet of the right stuff at the right place, disturb the balance, and have it go "boom!". Let's say you have a [supervolcano](https://en.wikipedia.org/wiki/Supervolcano) in the making, with a nice big dome. Think [Yellowstone](https://en.wikipedia.org/wiki/Yellowstone_hotspot). If the magma is depressurized even a bit, it will gas out, setting off a chain reaction that makes the whole thing go "boom!". Those are the two "global killers" I could come up with right away. For more localized destruction, think fault lines (setting off earthquakes), mountain flanks (setting off [megatsunamis](http://en.wikipedia.org/wiki/Megatsunami#Canary_Islands)), thinks like that. [Answer] # Sulfur But use it to freeze the earth, not for burning. You only need on the order of $10^{11}$ kg. And all the science is available *today*. I'm cross-posting this answer from [How much Sulfur Dioxide is needed to freeze life on earth?](https://worldbuilding.stackexchange.com/questions/33355/how-much-sulfur-dioxide-is-needed-to-freeze-life-on-earth), which was inspired by this question. ## What is the extinction mechanism? I’m going to guess that changing the average temperature from 16 degrees Celcius to -20 degrees will cause enough havok to create mass extinctions. The average temperature during the last ice age was about 10 degrees. If the temperature near the equator ranges from 10-30 above the average, -20 globally would get the temperature there dipping below freezing regularly. This is inspired by Intellectual Venture's hose-to-the-sky cooling scheme for combating global warming, described in Levitt and Dubner’s *SuperFreakonomics*, where all my citations are coming from. Intellectual Venture’s plan to completely reverse global warming requires 5 base stations, placed strategically across the globe, each with 3 hoses (p. 196) spraying liquified sulfur dioxide into the stratosphere, 7 miles up (p. 189). Each hose sprays at 34 gal/min (p. 192), or 190 kg/min, so 2800 kg/min for all 15 hoses. Since they said this will “effectively reverse global warming” (p. 196), let’s assume that 2800 kg/min will decrease the average temperature of the earth by 2 degrees Celcius. ## How much sulfur is needed? I’m *guessing* that sulfur dioxide injection would be affected by the law of diminishing returns, but I’m going to *assume* a linear relationship here. With that assumption, decreasing the average global temperature 36 degrees would require pumping about 100,000 kg of sulfur dioxide per minute. To cause mass extinction, let’s say we have to run this for two years, to make sure that artic and antarctic animals don’t get a chance to stock up on more food in the “summer”. That will take $10^{11}$ kg of sulfur dioxide, or $5\*10^{10}$ kg of sulfur. Do we have that much sulfur handy? It looks like it. The Athabasca Oil Sands in Alberta, Canada have pyramids of sulfur as a waste product of oil extraction. Leavitt and Dubner's book describes pyramids “a hundred meters high by a thousand meters wide” (p. 195), or 30 million cubic meters = $6\*10^{10}$ kg S in each pyramid. How many hoses do our five pumping stations need? Each station needs to output 20,000 kg/min, which would require about 100 hoses at each site, or maybe bigger hoses. If we assume just two giant pumping stations, at the Athabasca site and at a similar site somewhere in the southern hemisphere, the sulfur dioxide would cover the earth in about 10 days (p. 194). Together, they can freeze the earth for four years, assuming the earth cools off quickly once it can’t receive as much energy from the sun. The sulfur dioxide would settle out of the atmosphere “within a few years” (p. 197). ## How much would this cost? Intellectual Ventures estimates \$150 million in opening costs and \$100 million per year thereafter for their modest "Save the Earth" proposal (p. 197). Our "Destroy the Earth" operation is about 18 times bigger, so I will guess about 18 times the cost: in the neighborhood of 3 billion dollars for opening costs, and 2 billion dollars to run it per year thereafter: it costs just 7 billion dollars to freeze the earth for two years. Well within the reach of your typical multi-billionaire mad scientist. ## But sulfur dioxide is not an element... For those of you who are going to argue "but sulfur dioxide is not an element", the OP specifically states that he is "Looking for the element that a mad scientist would need the least of", and that element is sulfur. You could just as easily argue that burning hydrogen is not a valid answer because that would produce hydrogen dioxide (water), and water is not an element (at least in modern chemistry). If an element is causing a lot of death, it is probably because it is that element is undergoing a chemical reaction. If my arithmetic is correct, this scenario is too close to plausibility for my comfort. [Answer] **At the time I posted this, the question did not yet specify "near-future", and indeed made no reference to technical feasibility. With the updated question, this answer is no longer really relevant, but might still be interesting from a technical standpoint, so I leave it open.** You said only one scenario per answer, so I guess I have to write up a second answer. You ruled out antimatter, so the most destructive is nuclear reaction. And here it gets surprisingly easy: **ANY element, as long as it's a really unstable isotope of it.** Well, OK, it's not *mine*. It's a variation of what HSchmale already posted, and something I picked up elsewhere (XKCD? PeriodicTable.com? Cannot recall, really.). So here we go. In a nuclear fission bomb, only a fraction of the fissile nuclei actually *participate* in the chain reaction. Now imagine you take a [unstable isotope](http://en.wikipedia.org/wiki/List_of_radioactive_isotopes_by_half-life) of *whatever*, really. Let's say you have some magic, or sufficiently advanced technology, to create, let's say a pound of the stuff, *right now*. Thanks to the really short half-life, *all* of its nuclei undergo decay at, for all practical purposes, *the same time*. You just got the equivalent of a multi-pound nuclear warhead. That's fun, let's do it again! This time with a ton of the stuff... And you don't have to get fancy to get a *chain* reaction, because this is a *natural* reaction, full stop. As soon as the stuff is *there* it *will* decay, and the only upward limit to destructive force is how much of that isotope you can create before the (instant) destruction of everything around it brings an end to your creating it. [Answer] There are a lot of extreme-tech answers which do not meet the near-future-tech requirement of the question. Amongst the other answers I see: The hydrogen approach that's got a 10 orders of magnitude error. (Edit: It has been fixed. Now I'm using a **lot** less material than he is.) The aluminum answer is a lot more viable but I recall seeing numbers on a sun shield and I have the definite feeling the numbers were a lot higher. The Astatine answer doesn't work--the half life is too short--you can't collect it in your thyroid. Besides, it couldn't explode--long before it reached that level of heat it would cook the tissues and no more would come in at that point. Anyway, so long as you'll accept not getting the sea mammals I've got an answer that will do it with much less material. Specifically, about 300 million kg of cobalt-60. Scattered at the rate of 2 mg/m^2 this will produce a dose of .8Sv/day. That should be enough to get a kill of all higher land life forms. Obtaining that quantity of cobalt-60 is going to be a considerable problem as it only comes about as a fission product or by neutron activation of cobalt-59. We don't really know the economics of it's mass production as it has very limited use (radiation experiments and non-destructive sterilization--although if we could get over the fear factor this might be a substantially bigger market, the production of shelf-stable versions of things that normally must be refrigerated) so I can't say what it would take to actually produce it. [Answer] How about [Element zero](http://youtu.be/o_EBqZPCZdw)? Phil calls it "the doomsday explosive" in this short video. See time index 5:26 : > > if the stasis field on this baby were to fail, it would release the energy equivalent of *fifteen million* [Tzar Bombs](https://en.wikipedia.org/wiki/Tzar_bomb) in the first second. > > >  > > And in the *second* second, it would release the energy equivalent of fifteen million Tzar bombs. And so it would continue for the second and the third and the forth second... and it would only be after *ten minutes* that the energy release from this one cubic centimetre (he's British —Ed.) of neutronium would subside to releasing the energy equivalent of only *seven* million Tzar bombs every second. > > > Needless to say, I want one. That certainly qualifies as "least amount" in volume anyway. It's naturally occuring, as explained in the video, in substantially larger quantities than the marble being discussed. Technically, it's an element: each neutron individually is an atom of Element Zero, and the sample is not bound together (it's too small for gravity), so it's just rather concentrated, like gas under pressure is still the same stuff just easier to store and transport. [Answer] **Carbon** (with a smidge of oxygen and maybe some hydrogen). All you need is a really virulent virus, made from those elements. The quantity needed is miniscule. A single breath might contain more than a million times the quantity needed. [Answer] Oxygen a surprisingly innocent but effective choice. All you got to do is increase the ratio percentage in the atmosphere enough, that starting a fire causes a global fireball. If that doesn't kill everyone, the environmental consequences should finish them off. [Answer] **Hydrogen** Not by using any of the other methods already described but by using it in fusion. The only way to be certain you have destroyed all life on Earth is to destroy the Earth. As a lesser objective still likely to kill all life on Earth, boil the oceans. Based upon this [answer to another World Builder question](https://worldbuilding.stackexchange.com/questions/14666/can-earth-become-a-micro-death-star/14692#14692), the energy required to destroy the Earth is $2.2 \cdot 10^{32} J $. The energy required to boil the Earth's oceans is ~ $ 5 \cdot 10^{26} J $. By using Hydrogen and it's isotopes in a fusion reactions, the Earth's oceans possess a total of $ 5.3 \cdot 10^{34} J $ worth of energy. What mass of hydrogen do we need to destroy the Earth? ~ $ 6.25 \cdot 10^{17} kg H\_2 $ (about 0.5% of the hydrogen in Earth's ocean). What mass of hydrogen do we need to boil the Earth's ocean? ~ $ 6.25 \cdot 10^{11} kg H\_2 $ (about 5 billionths of the hydrogen in Earth's oceans). The smaller of these numbers ($ 6.25 \cdot 10^{11} kg $ ~ 260 **Giga kg** ~ 260 **Megatons** of Hydrogen). [Answer] **Strange Matter** If the **[Strange Matter](http://en.wikipedia.org/wiki/Strange_matter)** hypothesis is true, then a tiny bit of strange matter would eventually destroy the Earth. > > If the strange matter hypothesis is correct and its surface tension is > larger than the aforementioned critical value, then a larger > strangelet would be more stable than a smaller one. One speculation > that has resulted from the idea is that a strangelet coming into > contact with a lump of ordinary matter could convert the ordinary > matter to strange matter.[13][14] This "ice-nine"-like disaster > scenario is as follows: one strangelet hits a nucleus, catalyzing its > immediate conversion to strange matter. This liberates energy, > producing a larger, more stable strangelet, which in turn hits another > nucleus, catalyzing its conversion to strange matter. In the end, all > the nuclei of all the atoms of Earth are converted, and Earth is > reduced to a hot, large lump of strange matter. > > > You could make a *"strange element*" (called a strangelet) out of strange matter composed of up + down + strange quarks. *Restrictions: Natural elements only, and no anti-matter...nice try. Looking for the element that a mad scientist would need the least of to wipe out all vertebrate life. How much would they need? (This is the efficiency part. I want to use the least amount of element x as possible) This needs to be achievable by near future means, no magi-tech, no hand-wavium. Where would the element come from? (can it be harvested or manufactured?) By what process would the world be destroyed?* 1. Strange matter would be *natural* in the sense that it exists somewhere in the Universe without human intervention but it is not native to the Earth (that we know of) and we wouldn't normally think of it as an *element*. 2. If the Strange Matter Hypothesis is true, than a tiny bit (one to a few particles) of it would slowly convert all normal matter it comes in contact with, into strange matter. This will destroy the Earth. 3. You would make strange matter in a particle accelerator. I do not know the size required to make it (e.g. CERN might not be powerful enough). 4. Two mechanisms would work in concert to destroy the Earth. 4a. First, the conversion from normal matter to strange matter would liberate vast quantities of energy. Early in the process, these effects wouldn't be noticed but towards the end, the Earth would begin to glow like a star. 4b. Second, the conversion would vastly increase the density of the matter. It would turn the Earth into a stable substellar neutron object. If the Strange Matter Hypothesis is true, then this concept would win the contest on the amount of mass required to destroy the Earth but it would not *disrupt* the Earth. Rather, it'd collapse the Earth to be a very small object < $\frac{1}{1000000}$ the volume of a neutron star. It would become the densest object possible without forming a black hole. [Answer] **Edit:** When I first wrote this I didn't grok the "single *element*" statement fully. I'm not really changing my answer, just changing the execution. With the right planning and equipment, you could wipe out the majority of life on earth with only 120-210 kg of Uranium/Plutonium. Take the uranium and shape it into cores for bombs of around 30kg, which IIRC can deliver a yield in the 50-100 kiloton range with the right design. This is the most efficient way I can think of to trigger the release. You could probably do the same job with less plutonium. It's surprisingly hard to find statistics for core sizes and weapon yields. **No one has mentioned Methane yet.** Methane is heavier than oxygen and nitrogen, which means that it stays close to the surface instead of rising into the atmosphere, and there is enough of it stored in hydrates under the ocean to cover the surface of the earth and suffocate the majority of people. Methane is also a very powerful greenhouse gas, which means the earth would warm significantly very quickly, and so the oceans would rise, and the gas would rise... The best part is that because the methane is already stored in the hydrates you wouldn't need to make any, you would [just need a submarine](https://books.google.com/books?id=FhThyNpoZCcC&pg=PA292&lpg=PA292&dq=frederik%20pohl%20methane%20under%20ocean&source=bl&ots=b5l40fL5T_&sig=6KBlxEbuTQGuz3xSxh30MraToMA&hl=en&sa=X&ei=re5xVbjAEdPaoAT_lILgBA&ved=0CDcQ6AEwBA#v=onepage&q=frederik%20pohl%20methane%20under%20ocean&f=false) to go down and release it with some digging or bombs, which is pretty Mad Science. The scientist would only have to release a fraction of the stored methane, which would cause a lot of warming, which would heat the oceans, releasing more methane. The idea that this could happen naturally is called the [Clathrate Gun Hypothesis](http://en.wikipedia.org/wiki/Clathrate_gun_hypothesis). And then there would be the opportunity to ignite the methane... **The check list:** > > Natural elements only, and no anti-matter...nice try. > > > Just normal weapons grade uranium or plutonium... > > Looking for the element that a mad scientist would need the least of to wipe out all vertebrate life. > > > This would wipe out all surface life, though the earth itself would remain. The majority of people/animals would suffocate very quickly, and the methane explosions would probably get the rest. You might get a handful of survivors at high altitudes for a while, but not enough to sustain a population. > > How much would they need? (This is the efficiency part. I want to use the least amount of element x as possible) > > > Not that much. Enough for 4-6 medium size bombs. Rough calculations say 120-210 kg of uranium (30 kg per core), 60-100 kg of plutonium (15-20 kg per core). > > This needs to be achievable by near future means, no magi-tech, no hand-wavium. > > > We could do this now with simple technology. It would just take a bit of money to map out the richest deposits and then build the nuclear bombs. Probably dig a few oil well style holes down into deposits, and then insert the bombs into the wells. Like fracking the ocean floor. This could happen by itself at any time, if there was an earthquake in the wrong place. > > Where would the element come from? (can it be harvested or manufactured?) > > > Africa probably. I have heard of a nice guy in Libya that can get you some if the price is right, and I've heard of a guy in Chad selling yellow cake over the internet... Russia has potential too. > > By what process would the world be destroyed? > > > Suffocation, immolation, starvation. [Answer] Only the tiniest amount of **Silicon**, built into nano-processors, embedded into the hulls of the tiniest nanotech robots, and programmed to create more robots out of [all available nearby resources](http://science.howstuffworks.com/gray-goo.htm). ;) Short, but sweet. ]

[Question] [ Across countless worlds, the concept of the "burial hall" is an oft-used construct for adventurers to cut their teeth. These locations are often teeming with the animated dead or other necromantic entities. They also serve as an excellent place to tell gripping tales, put characters in danger, and similar story points. For my world, however, there's a problem: There are no corpses. After a creature is slain, its body breaks down into raw energy which then feeds into the surrounding environment, where it promotes plant growth, coalesces into raw minerals, etc. How long this takes varies depending on how magical a creature is: a dragon's corpse decays in five minutes, while a dwarf's can take twenty days. *Ignoring the cultural and societal implications of the above as much as possible, why would a society construct large/extensive catacombs, tombs, mausoleums, sepulchers, and the like when there are no dead to keep in them?* In Case It Matters: In this world, necromancy is a thing, but is an exceptionally difficult practice because of the way magic works and how fast corpses decay. [Answer] The point of burial halls is not so much for the dead, it is for the living. It's a place where people go to 'visit' the dead, gives them a means of 'talking' to them, and a sense of comfort because they are 'laid to rest'. As such, I think it's possible that people in your world would erect statues in reverence to the fallen -- memorial statues, like we know in our world. Perhaps have a monument where the survivors would carve their name? Almost like the memorial stone in Naruto. There might be an altar where mourners can bring offerings to the spirits of their loved ones (quite common both in real world cultures, but also in fiction). [Answer] ## Family tree shrines A variation on themes already visited in other posts, families or clans have a tree where they bring all their dead and dying members, to be absorbed into the same tree. Clan councils are held in the presence of the ancestors and individuals make offerings and pray for guidance at the foot of the tree. The tree provides some real or imagined benefits, and when an inter-clan war breaks out, it becomes a prime target. The destruction of a family tree would essentially mean the end of the family/clan in society. That's why the clans build a temple around it, with defenses and traps and a secret safe route all clan members have memorized. Some widely despised clans have taken up the habit of hunting powerful creatures (even dragons) and sacrificing them at the tree, trying to increase the powers gained by the clan. This is said to have twisted the nature of their trees, guiding them to ever more death and destruction. ## ... in a larger society Having evolved from the above clan culture, people have now settled down in cities, nations and generally a more civilized life. The family trees are no longer in danger from rival clans as much, but their splendor as well as the size and splendor of the temple around it determine a family's status in society. Arranged marriages between families depend on visits to each other's Trees. Officially to gain the blessings of the ancestors, but in practice to appraise how rich and strong the potential in-laws are and to guide the negotiations. The temples now mostly need to defend against treasure hunters and other thieves who are after all the riches on display around the tree. Defensive positions and guard posts are out, booby-traps and mazes are in fashion. More and more new Trees are being raised as ambitious people seek to establish their own names, hoping to strike it rich and compensate for their tiny... trees with huge opulent temples. [Answer] Your society would still construct large/extensive catacombs, tombs, mausoleums, sepulchers, and the like in order to worship great leaders or remember the dead (Which happens to be one of the reasons why they build them now in the first place). Having no corpses actually makes it easier to do these things, since you can fit more plaques with names in less space. Expect your graveyards to be spaced out a lot less, and perhaps even just be consisting of several large stone walls on which names are carved out. [Answer] One word. Shrines. They no longer store the dead there, but they do create memorials to them. Giant catacombs extend out with sites dedicated to the memory of those who have passed. Through the winding halls you find places where mementos of the loved ones are left behind, such as vases, small stone figurines, or personal weapons. The rich have life-sized statues of themselves in life, and gigantic carvings depicting their achievements in life. The recently deceased are often visited by their loved ones, who burn incense or leave flowers on the shrines. Eventually, though, these shrines can hold no more memorials, and are eventually closed, eventually gather dust, and eventually are forgotten entirely. [Answer] **Mineral extraction, and magic processing** When someone dies, (and in some cases before you murder them), they are taken into catacombs where they can decay into energy and minerals. After capturing enemy troops and civilians in battle some evil regimes would force them down into tunnels and such where they would die and become raw minerals to be harvested. The reasons the tombs have to be labyrinthian is because the magical energy can be channeled and directed toward a place where it can be used, and because of how magic works certain shapes work better than others. These include shaped chambers where magical energy can be stored like a cistern or battery, amplified, etc. [Answer] **An alternative: Forests** While your people might not explicitly build burial halls (they *may* build some sort of memorial structure), people will still die. Since people in your world fertilize/nourish the environment when they die, this means that places where lots of people die become very healthy, vibrant environments. As such, beautiful lively forests are the creepiest places in your world. If you want to go the paranormal route with these locations, it is well within reasonable suspension of disbelief to have these places also be haunted or have the spirits of the dead animate trees and other plants on account of all the people who have died in these locations. Futhermore, the danger is already heightened by the now flourishing ecosystem which poses an increased danger to your adventurers, while the allure of the "natural" resources contained within invites them to enter to their doom, creating a positive feedback loop that will make your forests grow creepier and more lively the longer they exist. [Answer] Maybe they're not mausoleums, but places where a sect preserves the energy of dead beings? If they think that it is a waste to let the energy just dissipate into nature, they might have some sort of "repository of the dead" where they store their energy. You could then have a conflict with people who want to prevent nature from losing the energy of the dead. [Answer] Ancestor worship. Dead things clearly transcend beyond this plane as their corpse disappears. Or so the priests say. The catacombs are places of prayer and worship, where you request favors from those who have passed beyond and become unto gods. The sick and dying are brought to such halls, sometimes to pray for freedom from pain, sometimes to follow their ancestors. Priests have arranged "magical energy"-capturing devices in the catacombs to capture and channel the energy of the dead, fueling the miracles which are used to maintain the theocracy or benefit the community. What more, the means for capturing the life energy actually does create a form of awareness in the weave of mana. Memories, especially memories at the moment of death, collect. Prayers, repeated over generations, shape. The processing of such memories and awareness takes time and repetition, so ancestral tombs full of the same family can generate a fondness and connection with a living line over the centuries, but a single death won't fuel it. Repeated prayers and supplication guide it. Love and admiration keep it from souring. Catacombs that are abandoned go stir crazy. Such abandoned catacombs are "haunted", and the aware mana weave can even animate and manifest physically when disturbed. To provide for interaction, catacombs have statues (of the dead, and the guardians of the dead) for the supplicants to interact with, and the mana weave to animate when particularly driven. These animated statues can even defend the Catacomb against defilers. In abandoned Catacombs, the animated statues are going to be hostile to anyone who doesn't carry the cultural markers and behavior of those who "should" be there. Catacomb robbers thus can learn the cultural signifiers of the dead culture, carrying the holy symbols and learning the prayers and behavior to ward off the undead horrors. Societies that engage in mass sacrifice to fuel their magics generate a local mana weave that is full of hate and fear and pain. These are scarier places than simply ancient catacombs. The structure tends to be different, where the tormented spirits are forced to do useful work, but the structures will have broken down over the ages leaving you with a hell pit of hostile spirits. One effective way at least some cultures use to contain the sacrificial spirits is to surround it with friendly spirits. So sometimes you are exploring a merely abandoned catacomb, and you enter the sacrificial region and all hell breaks loose. [Answer] Grieving family and friends most certainly do not want to witness the decomposition process, though maybe in your world it is a beautiful display of magical multi-colored lights dispersing or being absorbed by the surroundings and whispered snatches praise/ reassurance/ love from the deceased. Just about anything else would cause some sort of discomfort, I imagine. Or maybe witnessing the decay at certain stages (and hence, the need for structures to house the bodies during this time) may be cathartic for family/ friends as it offers proof that their soul was good and was not rejected by the world/ nature/ whatever. Another reason behind the necessity of burial halls in your world could be an attempt to focus the absorbed energies into a (possibly damaged/ polluted?) location in an attempt to revitalize/ super-energize or something similar. Certain configurations of the decaying bodies could be the catalyst for some sort of unseen magical vortex or could just be the most scientifically sound way of evenly dispersing the energies if there is some downside to an over-concentration of the energy. The lack of dead bodies would probably have a much larger impact on the variance and diversity of creatures that, in the real world, consume the dead. Why would there still be carrion birds/ creatures/ bacteria/ fungi if there is nothing for them to eat? [Answer] I have two ideas: 1) They're burying memories and grief (whether symbolically or, through magic, literally). So they bury things that remind them of the deceased and bring them sadness, but don't want to truly destroy. So they "bury" these items so they can go visit them and grieve on isolated occasions. 2) My second idea is that, when a creature dies they leave behind the energy and minerals, and the material that makes up their heart takes some formal representation of their final thought in a gem or mineral of some sort. Almost like a little statuette or bust. These 'thoughtstones', heartstones maybe, tend to be meaningful to those that are left behind and are "buried" in great display halls. Each put on display for others to come see. There are, however, terrible thought-stones that are buried deeper, never shown, amazed, or mourned over and describe terrible images. They are often made of vile alien materials. None of these stones are magical, but their creation tends to lend them an air tied to the last thought. So if a person's last thought is of their family the stone will be in the family's shape and people looking upon it would get a feeling of love, trust, and/or sadness from its design maybe. Also they could have value in the darker magics or something. Not sure how those would fit your world, but thought I'd submit the idea. [Answer] In addition to all of above it could be possible in this mystic ginormous buildings (the burial halls) to contain inside statues that could be sarcophagi that encapsulate corpses that will decay only when "the world will reach its end..." (and such things). And they could easily be regarded as veneration idols or as places of flowing energy (the endless one of said corpses of the most magical creatures ever existed). ]

[Question] [ The dragons are the size of a double-decker bus with a long wingspan of over 100 meters, despite their muscular build they lack both endurance and stamina so more often than not they would simply ambush their prey. Thanks to the overgrowth of moss and the high humidity all year round, their scales can easily blend in with their surroundings, but something about their behaviour is bothering me lately. Why do the dragons need to roar loudly before giving chase to hunt down their prey? Wouldn't this give away their presence? And yet, the Wildlife Foundation is saying they are far from being endangered. [Answer] In real life, an animal that is hunting will generally do so quietly. Roaring and displays are territorial behaviors, generally used when the animal *doesn't* want a fight and just wants the enemy to leave. Sometimes if the enemy turns to run they will give chase opportunistically (this is why the typical advice when facing a diplaying animal is to back away slowly), but this is not normal hunting behavior. One possibility is that dragons specifically roar before confronting *humans*. Dragons are relatively intelligent, and have learned that some humans sometimes conceal sharp and dangerous weapons, while others are soft, defenseless bite-sized morsels, but they can't easily tell the difference. So they roar. If the human faces them down, they recognize that they are dealing with a fighter who won't go down easily, and will proceed with caution. If the human turns and runs...well, time to chow down. [Answer] **Martial Arts Shout in Taekwondo** In Taekwondo, people shout before strike. They do so to * Concentrate and increase power * Reduce own fear and hesitation * release anxiety that naturally occurs during an attack * roar synchronized with an effective strike will make the strike seem even more powerful and painful. * induce fear in the opponent The dragon roars for similar reasons. **Intense flame** Dragon are fire breathing. To throw a powerful flame, they need to give a powerful blow which creates a loud sound. [Answer] ## To kindle the flame in the dragon's oral cavity that will ignite the flammable mixture of gas they spout when breathing fire. This naturally depends on the draconic anatomy in your world, but since no specifics are given, I suppose all options are on the table. [Answer] Their roar is a complex sound extending into ultra- and infra-sonic range, to work on as wide a variety of species as possible, and will freeze their prey where they stand, making it easy for the dragon to gobble them up. You could draw a parallel with the hunting sounds produced by some dolphins which [can stun their prey](https://www.abc.net.au/science/articles/2001/02/02/240589.htm) with an ultra-sonic blast, immobilizing them for easy pickings. A [similar strategy](http://thatslifesci.com/2016-12-26-How-Pistol-Shrimp-Kill-With-Bubbles-AStrauss/) is followed by the snapping shrimp which has a specialized claw which produces a jet of water moving so fast that a gas bubble is formed in the low-pressure area in its wake, and the eventual implosion of this bubble results in a loud noise that can stun or even kill their prey. [Answer] **They are actually belching.** Clearing the decks for action, as it were. Dragons are gassy and some of this gastric gas is reclaimed for use in fire making so they keep a fair bit on hand at any time. But if they are going to eat, they need room and so they clear out whatever gastric gasses they have. What is considered a roar is actually a very moist and foul smelling belch. [Answer] ## Breathing out before breathing in Dragons need a lot of energy, when they jump, or to slam prey with their heavy claws. To prepare for the final attack, they refresh the air in their lungs. While getting rid of the old air, they breath out, you hear the roaring. Of course, the dragon gives its presence away.. but when a prey hears the dragon, it is too late. The battle is already lost. [Answer] The reason male Lions roar is to drive panicked prey toward lurking females, who can then easily ambush kill some of them without having to chase them down. Lions are actually slower than a lot of their prey species, so a full on chase wouldn't work well (forcing them to evolve into cheetahs). So roaring is a tactic of terrorization. I can think of 2 reasons why panicking prey might be helpful to a dragon: 1. **Dragons are lazy.** They have confederate (probably smaller and quicker) dragons lying in wait to scoop up panicked prey. 2. **Betcha can't eat just one.** Dragons are actually bigger and faster than any of their prey species. However they need a lot of them (like whales with Krill or fish). Getting masses of prey to panic stampede somewhere allows them to scoop up or barbecue large amounts of prey at once, rather than waste their entire day doing the equivalent of a human chasing down and eating individual ants. [Answer] If their appearance wasn't enough, roaring instills fear in their preys, making them flee. The flee also triggers the attack instinct in the dragon, which otherwise would be confused by a non fleeing target. It's also explained on the park walking guide, page 35: > > How to behave when meeting a dragon: > > > * do not flee, even if the dragon roars, as doing so would trigger the chase instinct in the dragon > * slowly move aside and seek shelter or an hiding place, always facing the dragon > > > [Answer] ## Echolocation Dragon roars are particularly lower frequency than most echolocation methods, but there might be advantages to why they would still use that, especially at night, to identify prey to hunt. 1. Lower frequencies have longer wavelengths, so may pass through smaller objects. 2. Louder roars allow them to echolocate farther distances per roar. For 1.), this has the advantage of using a dragon's strength and size to track larger prey. Aside from mountains and particularly strong trees, a dragon can reasonably presume anything small enough will either flee in their sight, or just get wrecked by them going through it. They don't need to track insects like mosquitoes or moth; they want to focus on and find buffalo, or moose, or horses - things that the hunting of make it worth it for them to actually hunt. For 2.), that likely is more useful for them to be able to roar once and get a decent landscape view of their surroundings. Even if they need to roar a bit more often, especially at night, to get a consistent feel of the area, they really want a larger scale of their surroundings because when they fly, they're not doing quicker and more corrections in their flying - they just choose a direction and aim. As for frequencies in their roar that isn't good for echolocation, that can be considered a side effect of being the type of roar that a dragon can naturally make - akin to like how [deaf cats can meow relatively similarly to how non-deaf cats meow](https://www.youtube.com/watch?v=FsOAdInI5ic). [Answer] If you are looking for a fantasy explanation rathe than a real world one I would suggest it's because a dragon might want to make it's prey run away, because hitting a stationary target while swooping down on them is quite difficult, but hitting a moving target that's going in a straight line away from you, and is looking where it's going is easier because the dragon can match speed with them and snatch them up. [Answer] The roaring of a dragon is one of the most frightening things you can hear. It makes you pretty sure that someone in your herd is going to die. Because of this, it is common for herd animals to evacuate their intestines prior to running for their lives (it also helps them run faster). So for the dragon, the benefit of roaring is ensuring that the meat they will eat has less üí© in it. [Answer] It might be similar to "beating the bush", a technique used to flush birds out of bushes and similar in hunting (by humans). Particularly if the roar is loud enough to vibrate the hiding places of their prey, but even without that - it might be sufficient to scare the prey and then they will run instead of staying hidden. As long as the dragons are flighted creatures, they are probably able to catch up to the prey - and so hiding is the main problem. [Answer] You know why dogs bark before they attack? It's very scary, dogs use sound as a **sonic weapon.** It's a sonic psychological weapon than confuses and panics the prey. That chilling, confusing feeling you get when a dog is going ballistic, it prevents you from concentrating, confuses you about whether you must fight or run away, I often go around with ear protection around town, and I've noticed that when I can't hear angry dogs, I don't give a F...k. I have less psychological jilting and worries, in fact the look of a big angry doberman at a fence is not at all that scary, but the sound is reeeelly scary. Also it's used for communication, to call backup. Dogs recognize each other's voices and they automatically run to join up if there is call. So, Dragons can work the same way? [Answer] They have good vision for moving objects, but poor for stationary objects. Thus, they need to roar to scare their prey into running away, making it easier to see their prey. Much like the *T Rex* in *Jurassic Park*. [Answer] ## It's only a theory but.... Its been hypothesized that roar of large predators like lions and tigers briefly (for an instant) paralyzes/freezes their prey in place before they recover and try to flee. This gives the predator a momentary advantage. With the volume/frequencies Dragons could produce (provided they could approach their prey unawares)? [The roars of predators](https://www.natureworldnews.com/articles/44856/20201217/can-lions-roar-paralyzed-humans.htm) [Answer] ## They want to catch their prey while they are running. Lots of birds dive to catch prey hard landing on a target and then taking off again. For a dragon, who is a like a very big bird they do not want a sudden stop of their very heavy weight or to have to take off again. Ideally a dragon wants to swoop by a prey grabbing one without ever landing or stopping flying. They could do this fly by on a unsuspecting prey but due to their immense size they aren't the quietest of fliers. Prey will often notice then coming and then dart in a random direction or hide making it difficult. So they roar, set a bunch of prey running scared and then make several swoops at the startled prey picking off a few. Likely eating the ones they grab in a couple bites before going for another dive. If a target is running in a direction it's easier for the dragon to calculate which way it is going and harder for the prey to suddenly change directions. This attack pattern also lends to catching several prey at once which large dragons will like rather than the usual hunting methods of predators which go for a single target. They could of course land and burn/attack prey on the ground but they aren't as fast on the ground as a deer or horse. So they have learned/evolved over time to do this swooping of running prey. Their breath weapon (if they have one) also helps this. If the prey are hunkering down and being difficult a little fire will set them running. [Answer] **Theatrical Reasons** A dragon entering the scene usually brings a climax. A dragon roaring on the top of the hill is a good artifact to announce the climax scene and it is a quite epic image. Many times the roaring precedes the appearing, so the spectators/players have time to wonder what horrible creature is coming. [Answer] Roaring induces stress, stress introduces adrenaline, adrenaline spiced meat is far more delicious then non-andrenalin spiced food. Essentially they make their food more yummie by roaring. ]

[Question] [ In most sci-fi (graphic) novels and films, they often depict the design of the cockpit or captain's bridge in a rather unusual way. A smaller ship such as a fighter or a transport ship usually comes with a bridge near the nose of the spacecraft, while a larger ship such as a battleship or destroyer comes with a bridge located near the rear. Is there any basis for the bizarre (inconsistent) design, or simply is it just copycatting by younger laid-back writers? [Answer] Short answer: because they often draw inspiration from real-world craft, which have varying cockpit/bridge locations. A picture is worth a thousand words: [](https://i.stack.imgur.com/KBPwc.jpg) * Single-seat fighters + [X-Wing (Star Wars)](https://en.wikipedia.org/wiki/X-wing_fighter) + [Viper (Battlestar Galactica)](https://en.wikipedia.org/wiki/Colonial_Viper) + [F-16 Fighting Falcon](https://en.wikipedia.org/wiki/General_Dynamics_F-16_Fighting_Falcon) * In-atmosphere VTOL + [UD-4L Cheyenne dropship (Aliens)](http://avp.wikia.com/wiki/UD-4L_Cheyenne_Dropship) + [AH-64 Apache helicopter](https://en.wikipedia.org/wiki/Boeing_AH-64_Apache) * Capital ships + [Daedalus-class warship (Stargate)](http://stargate.wikia.com/wiki/BC-304) + [Star Destroyer (Star Wars)](https://en.wikipedia.org/wiki/Star_Destroyer) + [Nimitz-class supercarrier](https://en.wikipedia.org/wiki/USS_George_H.W._Bush) * Passenger transport + [Colonial One (Battlestar Galactica)](http://en.battlestarwiki.org/wiki/Colonial_One) + [Blockade runner (Star Wars)](http://starwars.wikia.com/wiki/CR90_corvette) + [Boeing 747 airliner](https://en.wikipedia.org/wiki/Boeing_747) * Private craft/status symbols + [Naboo royal starship (Star Wars)](http://starwars.wikia.com/wiki/Naboo_Royal_Starship) + Random yacht from Google image search * Ships with no windows + [Battlestar Galactica](http://en.battlestarwiki.org/wiki/Galactica_type_battlestar) + [Ohio-class nuclear submarine](https://en.wikipedia.org/wiki/Ohio-class_submarine) [Answer] From a design point you have reasons for the three cases : * Fighters and small craft are... small, with few choices about where you put things like engine, thrusters, weapons... By being in the front, the pilot can see up, front and have a better view on what is below the craft, in front of him. The further back he sit, the less he'll see under his craft body, specialy if some components that you want to put in front of him, like the engine, are big. Radar and the like, or a glass floor might change this but you still can't see through the body and sometime your eyes are still quite important. Also, if you take a hit, you are out anyway. * Cargo don't matter. Put the bridge back, front, up, down... that's for show. Plowing the space line at the front of your ship is somewhat more glorious. * Heavy warships are different : most detection will be made through screens (radar, dradis...) so there is no need to have a favorable, direct, view on the space around you. You want your bridge in a somewhat secure location and the risk of taking a hit on your front is slightly higher than in the middle of your ship. Of course it depend on your battle technologies : laser at the front, Startrek style or space-broadsides Warhammer 40k Style. * Heavier battleships, if big enough, might have secondary and/or specialized bridges/headquarters either close to the place where their function apply (like engineering, strategic command, barracks...) or just to prevent having both the captain and his second in command at the same location in case of problems. It would also allow for different hierarchies to apply and not muddy the water too much between people : if the ship captain has only indirect authority over the soldiers on his board, it's better if the military officer have their own headquarter on the ship. This could be called not putting all your bridges in the same basket. Then, you have public familiarity and authors' lack of creativity. But there are at least basic logic in the designs. [Answer] **Spacecraft are generally based on equivalent scale sea going ships** Small power boats tend to have a short bow, then the controls, then the rest of the boat, mostly consisting of the engine. Larger boats tend to have either a central (military) or aft (commercial) bridge. If we go back to the days of sailing boats, both small and large boats would have control at the back, why? On small boats the controls are simply a stick on a foil and a piece of rope, on large boats it's a wheel attached to a chain attached to a foil and a lot of shouting. Short chain of command, short chain of control. Let's take a small boat and add power. You now have a choice, you can put the engine at the front and the helm at the back, but there's no reason to do that, better to put the engine right in front of the drive. Now you have a second choice, put the helm on top of the engine or in front of the engine, putting the helm on top raises the centre of mass unnecessarily which will reduce stability, so put him in front. This gives your standard prow, pilot, engine configuration that stuck through to small spacecraft, it's basically a pilot sitting in front of an engine and not much more. With larger ships there's no reason to change the fundamental layout, from a high bridge at the back, the commander can see both what's going on ahead of and around him, the state of his entire ship and cargo, and have an overview of what the crew are doing. Everything that's of interest to him is within a single field of view. To transfer this into starships? Well the military are nothing if not traditionalists and having the bridge away from the leading edge affords a certain amount of protection simply from the presence of the bulk of the ship ahead. *While you could experiment with moving the bridge or cockpit around, there's no real need to. It's better to keep the command and control chains short, which makes fault finding easier.* The question isn't "Why isn't the bridge at the front" but rather, "Why is the Enterprise bridge high up in the saucer section, not down between the nacelles, behind the main deflector dish, about 10m from engineering?" [Answer] Since everyone has already answered "why" in very convincing ways, we should look at the "where should it be" in realistic SF. The "Starfury" fighter from the TV show "Babylon 5" does it best. The pilot is more or less in the centre of the spacecraft, and the spacecraft itself is centered on a large "X" shaped platform with the engines at the ends of the X to provide long movement arms for manoeuvre. [](https://i.stack.imgur.com/Ze8Is.jpg) *Starfury* For most other realistic spacecraft, the cockpit is usually in the "nose" in order to allow the crew a full field of view. This illustration is of a space tug concept from the mid 1970's, and the crew module is on top of a thrust core and flanked by some auxiliary fuel tanks: [](https://i.stack.imgur.com/i5hqg.jpg) *MOTV space tug concept* For larger spacecraft and especially military vehicles, the crew will most likely be encased in an armoured capsule near the centre of the craft. Since one of the major dangers of long range space travel is radiation exposure, being in the centre of the cart surrounded by the bulk of the spaceship's structure and reaction mass tanks provides a great deal of radiation protection without requiring large amounts of extra shielding. Im modern naval ships this is known as the "Combat Information Centre (CIC)" and everything runs from there. A "Weather Bridge" might still be situated in the nose of the craft to allow for delicate manoeuvres such as docking at a space station, but this will not be the primary centre of operations (and indeed may sit unmanned most of the time. If your story requires a place for junior rating to goof off on watch, this might be it). [Answer] # Because the reader/viewer sees it as normal As Euphoric and others say in the comments, it's conventional that small spaceships are based on aircraft, and larger craft are based on ocean-going ships. Although not explicitly stated anywhere, this positioning reinforces the perception of scale to the viewer. [Answer] For small craft: there isn't much place else to put the cabin and still have an effective small craft. For large vessels: doesn't matter where you place it too much but on the trailing edge of the vessel for safety. **Small Craft** Having a small craft makes it easy to see its relationship to other objects and with small craft the difference of being at the front end or the back end of craft that is 10 metres in length isn't that drastic. Smaller craft generally have a high thrust-to-mass ratio and are *generally* more nimbly and respond to input quicker. The pilot needs to be able to gather information quickly and respond quickly, the cabin/bridge in a prominent place with unrestricted view would be best for accomplishing this. But traditionally for craft where drag is a concern the cabin is generally at the opposite end of the 'prime mover' in a streamlined configuration. A missile doesn't have a pilot but its avionics and warhead are at the front of the frame; there is need to have the thrust to come out one side and still have low drag. This necessitates that the warhead is at the front of the missile. In space, drag is not a concern but you still have to worry about thrust vectors and your mass. If a major amount of your mass is hanging off-axis of your thrust vector, it is going to go in circles. Therefore is still an advantage to having the mass in-line with the engine, and again if you have small craft it is almost a necessity that the cabin/bridge is at the opposite end of the engine. **Massive Craft** With massive vessels, they usually have a support role where drag is not the primary concern, fulling their role or supporting smaller craft is the primary concern. No matter the placement of the bridge it would be almost impossible for a pilot to make distance and speed judgments for the far edges of their vessel. Additionally these vessels have a low thrust-to-mass ratio and respond slowly to inputs, so waiting for reports or data to make maneuvering decisions can be tolerated, assuming the pilot is not reckless. When a vessel becomes so massive, the change to the centre of mass due to the placement of the bridge becomes so small that they can be effectively placed anywhere. But with massive vessels come with high inertia, it is not easy to stop the vessel, so having your command structure placed away from the leading edge your vessel means the vessel might have a chance to limp in-to or away from action during a collision rather than being put out of commission instantly. Massive vessels tend to be under their own power in 'safe' areas where threats can be planned for and there is lots of room to maneuver. The bridge doesn't need to be placed in the perfect spot as the pilot doesn't need to know exactly where the edge of the vessel is because he has plenty of error tolerance. A cargo ship is rarely, if ever, piloted straight in to dock by its own power. There are a host of tugs and mooring facilities that safely guide the vessel to port without relying on the pilot's knowledge of his blind spots. Location to engineering areas isn't probably a major design criteria for bridge placement, not in modern or future times. Even in modern, mid-sized vessels the prime movers can be mid-ship with transmissions and screws towards the back. And with electrical-motor driven craft, engineering can be anywhere. e.g. nuclear subs can have two fission vessels one port and one aft to balance the weight. [Answer] A great source of space ship designs are space engineers, there are tons of people that have designed different space ships both of the larger and smaller kind. The trend I see in this matter is that the small ships have the bridge in the front because it gives a better view and it is more practical to put the cargo bays behind the bridge. On the larger ships the bridge is basically anywhere, but most of the time directly in front of the main propulsion and power-plant (don't know if it is to decrease the distance for maintenance) and the fighter/cargo/crew bays in in-front of the bridge. The location on the larger vessels is not important because most is controlled by displaying values on screens and using cameras for maneuvers. There are few designs that actually have a usable window on the bridge, but on the smaller ships and fighters, it is few that have a camera to assist. [Answer] If it's a small ship, like a one-man fighter or "space motorbike", it would save space to put the cockpit at or near the front. Assuming your propulsion technology involves throwing reaction mass out of the back of the ship to make it go forwards, you need nozzles for that on the back. These need to be connected to the actual engines, the components which accelerate the reaction mass using whatever technology is being used (rockets, ion engines, whatever). It's far easier to put these right next to the nozzles, so you've got engines at the back now taking up a good amount of space. Then you need to power those engines, so you've got fuel tanks and they should probably be close to the engines too in order to reduce the amount of plumbing you need. Maybe you need a fusion reactor or something as well. So put that all nicely together at the back, what's left? Stick the pilot at the front! Maybe the pilot has some more stuff in front of them - small thrusters for steering/docking perhaps, or the mounting for the ship's radar/lidar/other system allowing you to spot things before you crash into them. But the bulk of a little ship like that's going to be at the back. If you tried to put the pilot between, say, the engines and the fuel tanks, you'd just have to sit them amidst a load of fuel pipes. Doesn't seem very practical does it! Obviously this does rely on having suitable protection from impact by little bits of rock/debris you might find in the space environment against the cockpit canopy. I also suspect pilots might prefer it this way, as there's a psychological need to be able to see out, even if in space things are likely to not be very visible using the naked eye. You'd have detection screens everywhere, but you'd still want to be able to see where you're going, and it would be very useful for trying to dock with something after an equipment failure. Big ships, on the other hand, have more room for a spacious room to command the ship from, big screens to display what's going on, redundant detector systems for docking... big spaceships are likely to be more like big submarines. So actually, you could argue that a typically-depicted one man spacecraft is a cross between a modern fastjet fighter and a submersible. Hmm. [Answer] For surface ships, elevating the pilot sufficiently to allow visibility around much of the vessel is extremely helpful during low-speed maneuvering where side clearance around the entire vessel may be an issue. The further back the pilot is located, the more of the ship the pilot will be able to see at once. For aircraft, a similar approach might be helpful during low-speed maneuvering on the ground, but having the pilot's head above the top of the main fuselage would add a huge amount of drag. Further, in most situations a pilot will either be on the ground in an area where precise maneuvering isn't required, will have a crew on the ground to assist, or will be traveling fast enough that anything the pilot might see that isn't completely in front of the aircraft will have either hit the aircraft or missed it by the time the pilot can react. Being able to see straight ahead is important for a pilot, and thus requires that any opaque objects forward of the pilot be located below the line of sight. For spaceships which are not designed for use in atmospheres, an "elevated" bridge (or better yet, a pair of such bridges on opposite sides of the craft) would probably more useful than a bridge in line with everything else. For ships which might need to land, however, minimizing drag would be important. ]

[Question] [ **Closed.** This question is [off-topic](/help/closed-questions). It is not currently accepting answers. --- This question does not appear to be about **worldbuilding**, within the scope defined in the [help center](https://worldbuilding.stackexchange.com/help). Closed 7 years ago. [Improve this question](/posts/34867/edit) [Like this question, but cranked up to 11.](https://worldbuilding.stackexchange.com/questions/28703/how-do-i-safely-sell-off-gold-coins-of-unknown-provenance) One day I'm going about my business, answering questions on Worldbuilding.StackExchange, when all of a sudden I get sucked into a fantasy world. I meet some people, have all sorts of wacky adventures, help two of my traveling companions hook up (because let's be honest, it's clear as day they like each other and the whole "we're not together!" thing is getting old fast) and together we beat a big doomsday villain. I get to keep a share of the villain's treasury, and with a tearful goodbye I travel home with my prize. In this case, the prize is 100 gold bars. They are stamped to mark them in a way not used anywhere on Earth, yet somehow they are the standard 400 troy ounce [Good Delivery](https://en.wikipedia.org/wiki/Good_Delivery) size and shape we use on Earth with a same amount of purity. The gold is identical to Earth gold as well: if you were to run tests on it you'd find the gold to be identical to what we on Earth mine. But here's the problem: you cannot just sell gold bars on the open market without drawing unwanted attention from the authorities. 100 bars is the equivalent to 1240kg of gold, so I cannot easily haul it around either. The markings on the bars would draw attention as well, but those could be erased (though unmarked gold could draw even more attention). I don't want the bars to sit around collecting dust, I want to be able to make money off of them and spend it. So how would I go about liquidating all this gold without getting into trouble with the law? [Answer] Melt down small amounts and use it to manufacture gold plated "ultra fidelity lossless" audio/video/network/iphone charger cables that you sell at \$100 - $500 a piece to pretentious fools. This actually gets you more than the market price for your gold! You may not have 45 million dollars at once, but you'll have a steady income for many years, and as a bonus, you'll have 99 bars of gold left in case of apocalypse or something. Alternatively, restamp some of the bars with a Swastika, hide them in some cave in Germany and then "find them". If you get a 1% finder's fee, you're still rich. *Edit: This answer has drawn a lot more attention than expected, so I will try to improve the quality some.* The original question outlines the problem with authorities taking a dim view of anyone trying to sell a huge amount of gold from an unknown source. Unloading the gold in bulk to any shady people carries a serious risk too: They may well decide to betray you, lock you up and torture the location and source of your gold out of you. Assuming you don't already know how to speak "Billionaire", you would look out of place and suspicious trying to pass yourself off as one or even as a representative for a rich guy trying to liquidate some assets, though that is still a realistic option (see user16295's answer for a better description of that) but there are better options. ## Pawn shop road trip Luckily for you, you live in the age of StackExchange and more importantly, [3D printing with gold](http://www.shapeways.com/materials/gold). It will take some setup and preparation, but you don't have to try and sell whole bars, you can instead mass-print jewelry and age it a bit (get some small bits of dirt stuck in the recesses). The second part of the prep is setting yourself up as some kind of travelling salesman or freelancer, plan some trips to distant states/cities and start doing rounds of the local pawn shops and gold buying outfits (don't google them from your own internet connection obviously). Never sell more than a "grandma's inheritance" at once. Accept cash only, but walk away from too low a price. You're not a thief trying to fence stolen goods after all. It will take a long time, but you can have fun along the way and get see more of the world. ## Hook up with someone important This is a lot more complicated, but you did become a hero in the course of your fantasy world adventure, so maybe your skills are up to it. The goal here is to make someone with the resources to buy your gold believe that you are well-connected, so that they will refrain from taking your gold and life for fear of the consequences. Your target will be some rich person that *can* unload the gold again, no questions asked. This means you'll probably end up with some Arab billionaire who's looking to gold-plate his newest yacht or wants to work with foreign businessmen on a prestige project. Getting into the oil and construction industries (as a contractor) will be difficult, but if you can manage it, they are your best options. Alternatively, you cash in some of your gold through the pawn shop route so you can spend enough to pose as an investor in any field currently popular over there. Your ticket to a deal will be an introduction by someone the target highly regards, so once you have some way in, network like crazy. The best stepping stone is likely a fellow countryman, both because it's easier to connect with them and because your real target will assume you know each other from business or private life "back home". Hang out in the expat favorite bars, find out who's only tech and who's a dealmaker. Get yourself invited to parties and events, etc. Once you have a promising link, investigate their business partners. Select the likeliest prospect and have a good story ready. "I need to sell $45 million in gold" is not a good story in most cases." Investment opportunities work best, so tell your newest BFF about your investment plan while you have some drinks and ask him if he knows about "this guy Aziz" and if they can introduce you. Make your pitch to the prospect and if he's interested, tell them that you would love to get into more detail and schedule a meeting some weeks ahead. Apologize profusely for the delay and explain you need the time to unwind another deal and free up your money. Pray for the guy to bite and ask about the details, at which point you mention the gold and see what happens. Note: All this assume you are a) male and b) of an age to pose as a business man. If you are female, all this will not work. If you also happen to be a hot blonde, then you can skip all the socializing and just straight up ask the first crazy-colored supercar driving guy you spot to buy all your gold. [Answer] ## Laws are local with that sort of money If you want to clear the whole lot out at once, you could to **sell to a national government**. The advantage of this option is that it's legal. If it's not strictly legal, they'll make it legal. **Sell to an eccentric millionaire**, the amount of gold you're moving, while heavy and a lot of money to normal people, isn't a vast amount in the world of the super rich. In fact it's not enough for you to join their ranks, but is a reasonable amount to be paid certain items in their world. ## How to actually go about this Make contact through a respectable legal firm. That's all you need to do. Take the whole deal above board. You're in wholesale now, not retail. If you try this through the back door, if you act suspicious, people will be suspicious. If you go to a city legal firm and suggest that you want to do a deal on this sort of scale, and they'll find you a buyer or suggest someone who can. Don't just walk in through the door of course, make an appointment first. ## Things to remember If you want to handle that sort of money, you need to look like someone who handles that sort of money. Get a properly tailored suit from Savile Row, get a shirt that fits, wear really good shoes, get a shave and a haircut. You can expect to spend easily a couple of thousand on clothes before you start. You're moving millions, dress like someone who moves millions, it'll make your life much easier [Answer] In the US, try the following... Contact Washington and ask for an appointment with the Under-Secretary responsible for International Trade. You won't get a direct meeting, but one of the Under-Secretary's secretaries will happily hear your case. During that meeting, introduce yourself as a representative for (whatever your fantasy friends call their homeland), a newly sovereign nation which is petitioning for favored trading status with the United States of America. Show the Under-Secretary's secretary one of the gold bars and describe it as a goodwill gift for the Under-Secretary. Wait patiently to meet the Under-Secretary in person. With 30lbs of gold on the line, it shouldn't be a long wait. Tell the Under-Secretary the whole truth about your fantasy world adventure, except the part where you were sent home to Earth with no means of getting back. Your friends obviously understand inter-planetary or inter-dimensional transport. They really should have left you with a means to return, but since they didn't, you will just have to wing it, and fill in the cracks in your story via the generous application of gold. In short order, you should find yourself recognized as the U.S. Ambassador for (whatever your fantasy friends call their homeland), conditional upon your building an embassy in Washington, (and anywhere else you want a mansion). You will have tax free status, immunity to most laws and the freedom to spend as much of your money as you like, without anyone caring where it came from. --- alternative plan if your friends gave you a way to return --- Really no different from above, except that you become a real Ambassador, arranging trade agreements and issuing visa's to wealthy tourists, anthropologists and CIA operatives. The nice part of this scenario, is that after the original bribes to the Under Secretary, the rest of the expenses will be picked up by your friends back on the fantasy world. [Answer] In the UK (I assume elsewhere as well) there are companies that will buy old gold rings, offering the consumer a low price. They then melt them down and sell the gold. These companies tend to pay the consumer for the old rings etc in cash… A common way to dispose of stolen gold is to create such a company, operate it as normal, but make up a few fake customers. (Think of the car wash in breaking bad.) **Note:** Handling stolen property is a crime in the UK, and the police can take the property from you unless you can **prove** where it comes from. If the police can make a jury think that you are reckless as to where the gold come from, e.g. the jury does not believe what you tell them, so assume it must be stolen => lots of years in jail. [Answer] ## City solution Make friends with a jeweler. You can melt gold in your [microwave](https://youtu.be/9XcwaBOYfoY) and make your own rings but your jeweler buddy can probably make better ones. Make him a full partner in the sale of the rings but don't tell him how much gold you have. Together you make a paper trail for a portion of the rings by setting yourself up as a buyer of gold at estate sales. ## Country solution Buy a defunct gold mine pretend to rework tailings add your gold in a little at a time over the space of years. --- [Answer] Melt one of the bars in small pieces and sell them to a lot of small "I Buy Gold" shops and another lot of Loan houses. This will not get you the right value, but it is just 1 bar. Or half a bar. Then start *buying* gold yourself, or even create your own Loan house (a TV show is a plus). Now that you have a stable income of gold (and a stable outcome of money) you can easily justify selling gold on market price to a Bank or national Treasury. Or even "on the wild" to jewelery makers or gold-recyclers. In the view of any inspector, you sell gold to have an income of money to compensate the outcome and have a small profit margin. After that point, just sell all the gold as melted items. You have not only made cash from it but also created a stable bussiness that you can use to justify everything afterwards. Make sure to destroy all documents older that 5 years (or whichever is the expiry time in your jurisdiction) and nobody will ever be able to investigate your first years, but you'll still be on the legal side for the last 5 years. [Answer] Start a small jewelry shop and try to stay under the radar, at least at the beginning. Try to have customers that give you their jewelry to be transformed in some other jewelry (i.e. make a ring from some earrings) and start making your own. Then with this type of business, you can start to make some jewelry with your own gold. If someone asks where you find the gold, you can provide the ticket for your customer's gold. For the (small) amount of the additional gold, you can just say you have found at an antiques fair or the gold comes from some of your family jewelry and you transformed it other jewelry. It is a slow method but as long as you don't do anything too strange to point at your direction, you should probably stay out of the government attention. [Answer] Take your gold bars on a cross-country trip. Bury each bar in a different location--shallow, only enough to keep them from being seen. Pick locations of no interest to anybody--here in the US at least you'll find plenty of suitable locations in western part of the country. (The Rockies, the desert--anyplace not practical to develop.) Record the GPS coordinates, put a marker on top of the burial spot and take a bunch of pictures, then remove the marker. Now go to something like the Silk Road (I haven't paid attention but I'm sure there's some replacement for it out there by now) and sell them. Buyer gets the coordinates and the photos. (Give them a very general area before they bid so they can buy a bar that's near them.) For validation purposes you might want to set up a long range solar powered camera pointed at the spot in case they try to claim nothing was there. If the authorities do start sniffing around they can't get any farther than your bitcoin address if you were careful in doing this. [Answer] 1) Spend a little time learning how to convert your bars into a believable facsimile of naturally-occurring gold dust. 2) Buy some equipment and set yourself up as a gold miner in Alaska. 3) By adding your fake gold dust to the pot, you will become known as a phenomenally successful miner. 4) Get a borderline-dysfunctional crew, and you can get your own reality TV show, along the lines of "Gold Rush". 5) With decent ratings based on contrived crises, not only will you make excellent money selling your gold, you will get paid by the show. The two top earners on "Gold Rush" are estimated to be paid $500,000 per year. True, you'll have to spend your summers hauling dirt in the boonies of Alaska, but you'll have about 8 months a year to enjoy yourself in luxury. [Answer] Trade them for cocaine! There is a huge and thriving market for cocaine which can be sold in small quantities. As long as you stay out of the ghetto and peddle your drugs to the middle - or even better upper - class of society the chance of being caught is minimal (and since you are not selling crack a tearfull eye will make the judge take pity on you if you are caught). The trick of course will be how to execute that big initial trade. Sorry I cant be of too much help with that, but if you place a question like "how to trade gold for coke" here in the forum I am sure there will be plenty of creative and valuable suggestions. Good luck. [Answer] Pretty much all the answers so far require you to invest time money or possible jail time. If i had just happen to have received 100 gold bards I'd go in one of two ways, which are a bit illegal but not as much as trading for coke or resource consuming as melting or buying old gold mine (even though they would still require some action on your behalf): 1. Claim that you have found the gold, like they recently did in Poland with the Nazi Gold Train. Claim that you were just going around your back yard with your trusted metal detector and the gold just happen to be there. It's not stolen, there aren't any missing 100 bars anywhere, nor the markings will give anyone any clue where the gold came from, its just old, long lost gold you found. 2. Slightly less preferable as it would require more preparation on your side like taking care of a will, and will executor, etc. is you inherited it from your recently deceased uncle, who's had it who knows from where ... [Answer] Assuming that you're in the United States, you absolutely can sell gold bars on the open market without drawing attention from the authorities if you turn the bars over to the authorities and tell them that you found them, for example, when you were digging in your backyard. In most jurisdictions in the United States, the bars will be considered "abandoned" by the theoretical original owner, and you will be deemed the owner. You will have to pay taxes on the proceeds from the sale of the gold bars, but no one will raise an eyebrow when you go to sell them. If you say that you found the bars digging on U.S. public property (e.g., you find them while hiking in a national park), you should again turn the bars over to the authorities. In most states, the law requires that the authorities post a notice of the find, and allow the public some designated period of time to come forward and claim ownership. (To claim ownership, a person would have to provide details regarding where that person buried the gold bars that you "found," which of course no one would be able to do.) Once that claim period expires, most jurisdictions' laws are pretty much akin to "finders-keepers;" the gold bars will be given back to you, and again, you can do with them what you like and with no interference from the authorities as long as they ultimately get their share in the form of sales and/or capital gains taxes. [Answer] If you have the ability to remove the stamp, you must have the ability to re-stamp it. In which case, soon after in the news... > > ## Local man discovers 60 year old unclaimed Nazi treasure > > > After claiming a sizable reward for the funds it was donated to `insert real-organisation for repatriating Nazi gold`... > > > Sure you won't clear 100% of it, maybe you can negotiate 20-50% but that's still better than 0 and the authorities won't be on your tail because its untraceable prior to 1945. [Answer] > > "I don't want the bars to sit around collecting dust, I want to be able to make money off of them" > > > 1. to make (even) "more money" out of them should not be a priority, right? I mean, why should it? Is it really such a difference to have e.g. 40Mio (in gold) or 60mio (cash&dividends)? 2. so, if it is not about "making more money", why not keep the gold you don't need to be liquidated for spending? The gold will be there tomorrow, even when it collected dust. Nobody knows about tomorrows "value" of the nominal cash from a one time sale you would received. 3. to liquidate just the amount you need for your day to day spending on your consumption, sell some flakes of a bar to your local Cash4Gold shop. If it is bigger, go to Switzerland to a refinery. 4. Government will be interested anyway, regardless if it is gold or cash. So with keeping the gold, you might be better off, than with having the cash in a checking account instead (remember wealth tax?). [Answer] 1. Write a book about your story 2. Get a gold bar authenticated as real gold 3. Become a paid speaker at conferences or book signings or whatever, using your gold bar as a prop to bolster credibility. You could even give moral lectures about the evils of greed and how you won't sell the gold because money isn't important (you just insist on a $100,000 speakers fee because, you know, expenses) 4. Eventually, you might actually sell one as a collector's item, but your main money could come from the book/speaking circuit. Just trying to think outside the box a little :) ]

[Question] [ In this world wandwavium machines fly around with glee. But, between one flying island and another, there is no ground. Beneath your flying machine the air only gets denser, and denser, until eventually there are only poisonous and caustic gasses. If things go south in the air and you find yourself face to face with imminent death after your vehicle develops a mechanical problem or is repeatedly shot, how will you survive? Parachutes make you pretty safe in real world situations, but in a world without ground what would be the ideal solution? Safeboats made using more unobtanium so you can fly away don't seem practical or logistically sound. Unobtanium is not cheap and certainly doesn't grow on trees. Maybe an collapsible balloon with chemicals inside that, when mixed, inflate and float away? The technology of the place is dieselpunkish. [Answer] I would suggest you read "Guns of Tanith" by Dan Abnett. His setup is similar to yours, (mountain/hivetop cities below which are caustic gasses) and his downed aircrew utilize balloons instead of parachutes to keep them drifting above the "scald" of caustic gasses below. One of the great fears of aircrew was to become "windwaste" by being blown off-course or having a damaged rescue beacon, in which case they'd just float around until they starved, shot themselves, or intentionally punctured their balloon. The real problem any survival mechanism would have in your world is the improbability of rescue. If you parachute down to the ground in the real world you can be found or even conceivably walk out of wilderness. In your world it's drift 'till you die. Without rescue beacons for search parties to home in on anyone who survives a plane crash is Dead. You can't even search the flight path because like a not the winds would blow any survivors off-course making all but the most instantaneous of Search & Rescue missions futile. If your version of dieselpunk doesn't have the technology for distress beacons of some sort it might be considered "kinder" to have no parachute equivalent at all. There are real-world comparatives for this. For instance in WWI pilots didn't wear seatbelts. Not because they weren't aware of the danger of falling out of their aircraft (there are several confirmed reports of pilots or gunners falling out, grabbing on to the tail/wheels, and climbing back in. Or pilots hitting turbulence, getting through it, and realizing their back-seater fell out.) but because the REAL danger was fire. An on-fire WWI plane, coated in flammable sealants and spraying flammable oil back over the pilot during flight, could go up like a match from the slightest spark, and pilots universally decided the split-seconds saved by not needing to unbuckle (or the ability to quickly and "cleanly" jump to one's death) was preferable to being trapped in a burning machine. (For more, I suggest the book Marked for Death by James Hamilton-Patterson) You might even see a mix, where luxury transports for the ultra-rich have escape balloons packed with supplies and flares and whatnots, more for the peace of mind of the passengers than any practical use. But your average transport or combat aircraft doesn't because the crew know their odds and would rather save the weight for other things. [Answer] You could use the same back-up plan that the majority of flights in real life use: nothing. The vast majority of civilian flights in the real world have no parachutes. If a catastrophic disaster occurs in mid-air, then a loss of life will occur. The reason that this works out just fine in real life is that, especially in airline transport, catastrophic disasters in mid-air are extremely rare. They just don't happen. By and large, wings never break off, engines never explode, the controls never seize, airliners never collide in mid-air, and pilots never make catastrophic flying mistakes. Note that an engine failure is *not* a catastrophic disaster, if you're within gliding range of an airport and you know how to get there. All the aircraft need to do is fly high enough that there's an airport within gliding range. If the islands are too far apart for that to be possible, then pilots who are concerned about safety will use multi-engine aircraft. I admit that this isn't *exactly* an answer to the question, but it is something that people in such a world might do. [Answer] > > the air only gets denser, and denser > > > The craft (or lifeboats stored on them) are very light. They are designed with lots of air spaces. When they start to fall, all openings to the outside are sealed and the oxygen is turned on. As the craft (or enclosed life-raft) falls, it eventually reaches a point where it floats in the dense atmosphere. At this point the captain radios for help. If they are near an island, a rope may be lowered. If not a rescue 'helicopter' is dispatched. It can be totally sealed. It descends far enough to grapple the stricken craft (or if that's too heavy, the life-raft) and then flies them to safety. --- **EDIT 1** If the ships are large or holed, I suggest that the life-rafts are used and the ship itself abandoned to its fate. The life-rafts are in effect balloons filled with an oxygen/helium mix which is breathable. The survivor is enclosed ***inside*** the balloon. The balloon will still sink but the pressure will equalise and can be adjusted by releasing more oxygen/helium to make them float as high as possible. During normal flight, each person has an individual balloon with a zipper. When they climb in, seal the zip, and pull the cord, the balloon inflates with them inside. A number of balloons can be tethered together to make rescue easier. Alternatively multi-person balloons may be used. From a medical point of view, the *bends* may be a problem and so the passengers must be released from their balloons gradually under controlled conditions. **EDIT 2** In reply to a comment from @ksbes that the balloons would continue to sink indefinitely I offer the following demonstration, please watch right to the end to see a 'boat' floating. <https://youtu.be/xQo-v_F1P9U?t=11> [Answer] **Helium (hydrogen?) balloons**. I don't know how practical they are, but if you're starting with a chair/ejection seat, you could install helium tanks and inflate balloons to increase buoyancy. Drop the empty tanks afterwards to increase buoyancy (if needed). I'm sure there is a way to generate hydrogen, but this would be really dangerous and I think hydrogen might leak through most balloons. <https://www.youtube.com/watch?v=yhYuUPQOF-Q> or try mythbusters <https://www.youtube.com/watch?v=NC-Km7aUjgc> You'd hopefully have time to deploy the balloons before you sank to too deep a level. [Answer] Greed saves the day: if the unobtainium is so precious that none can be spared for lifeboats, it's too precious to allow to be lost in the depths with the rest of the wrecked aircraft. The main propulsion "cores" of any large craft are thus designed to separate from the main structure, engines, weapons, etc, passively floating free. Fortunately for the crew, they can do so with some small payload and at a safe altitude, and the big chunk of unobtainium ensures that someone will find it worth their while to come out for them. Deliberately sinking the cores would be a way to deprive the enemy of their salvage, but apart from being unpopular with the crews who have to go down with them, those sunken cores (and crews) can't be ransomed back after the conflict is resolved. [Answer] **Parachutes are fine** The flying machines never go below island level, in fact they stay well above. Steerable parachutes get them back to safety. If they *have* to go below island level, then they are fitted with powerful rocket-powered ejector-seats. These fire them upwards to a great height before the chute opens. --- EDIT **Regular convection currents in the atmosphere of this world can be used as thermals to gain altitude** In reply to a comment by @Graham about thermals Convection currents can be formed as a result even of the slightest differences in heat absorption at different places. When they do, they form a semi-regular pattern. If the sun moves across the sky in this world, this effect will be as predictable as the tides on Earth. Speaking of the Sun, An extreme example of convection currents in a gaseous body is the surface of the Sun itself. [](https://i.stack.imgur.com/zFUGR.png) [Answer] # Pet pterodactyl Just take one with you wherever you fly. The beast may perch inside the vessel. Incidentally, if you Google for images of "pterodactyl rider", many results as of now seem kinda dieselpunkish. This setup has the advantage that your pterodactyl will start the flight already in a rested state, and should you become stranded on a desert island you will have a temporary source of food and leather to help you survive. [Answer] **Human powered flying machines.** [](https://i.stack.imgur.com/mdmlk.jpg) <https://www.wired.com/images_blogs/thisdayintech/2010/08/condor.jpg> Some components of these liferafts might be in daily use on the ship. For example airmen might take turns at the pedals generating electricity for lights and music, and to make sure their legs are in shape to escape on one of these should it become necessary. The wings might be in use on the ship, or be kept folded and unfold in flight. If the ship starts to fall the flying machines break away with crewmembers aboard. Hopefully there will be updrafts. [Answer] What about pairing the parachute unit with a navigational device, not unlike a compass but for upstream currents, that receives weather info from satellites and helps the skydiver catch on and get propelled to upper atmospheric layers in order for their emergency beacon to get picked up and rescued? It can even be automated by a relatively simple device powered by captured sunlight (plus a battery for night time) and able to indefinitely steer the parachute in the case the passenger is unconscious. [Answer] **Parachutes.** They slow your fall, and you may even get some altitude where there's an updraft from below. Sure, you'll probably eventually fall into the caustic gas, but they'll buy you a lot of time. Human terminal velocity is about 120mph. A parachute's velocity is about 12mph – so you're lengthening your fall by at least 10x, more if you catch an updraft. If your 'death zone' is say 120 miles below the normal flight zone, that gives you at least 10 hours to be rescued before you die. Again – more if you catch an updraft. The breathable atmosphere could easily be more than 120 miles deep if you want to extend this time, but this should give enough time for an accident to be detected, and rescue planes to scramble for a dramatic rescue. So people would carry parachutes, and depending on your technology level, some kind of beacons – radio would be ideal, but a strobe, flare gun, or smoke bomb would help once a rescue ship got close enough to get a visual. Parachutes would be high-vis to help the rescue planes see you clearly as they come in. [Answer] The parachute is merely a delaying mechanism. Tanks sufficient to provide the needed bouyancy are big and heavy--and thus mean an awful lot of lifting power. Instead, they carry a big hot air balloon and a small nuclear reactor. It's completely unshielded, the passengers dangle on a long cable below it. Once it's been used it has to be sent in for reprocessing as it's now hot. [Answer] What about a parachute (a balloon really) that pumps itself up from the gasses as you fall (or maybe explosively pump on the ship just before you leap) so that it is full of lighter gasses by the time you reach the thicker atmosphere so you don't continue to sink farther? [Answer] Crew compartments of such vessels are designed to act as lifeboats in an emergency. During normal operations, the handwavium used in the crew compartment is part of the lifting power of the whole vessel, so that it's not wasted. In an emergency, all the crew must move to their designated rescue locations in the crew compartment which will shortly break away from the main vessel and become a lifeboat. A small vessel probably has just one compartment, while larger vessels may have more. The detached compartments have just enough floating power for the occupants, and possibly very meager accommodations, propulsion and navigation (depending on the original vessel's mission profile). In that state, the its main function is to keep the occupants afloat until help arrives. The detachment event possibly dooms the rest of the main vessel, as it loses even more lifting power. On vessels with multiple compartments, it is better if all of the compartments detach at the same time, because doing otherwise may affect the balance in an undesirable manner. Still, in a real emergency, there's no telling if someone will panic and detach prematurely. Hulks of evacuated vessels slowly sink to the high-pressure hostile layers of the atmosphere, where they somewhat stabilize. There are specialized salvage/rescue vessels that can navigate there and get valuables out if needed, but it's hard and dangerous work. Most vessels are written off as casualties. Some people are trying to develop remotely operated salvage drones that can cut away the dead weight and let valuable handwavium float up to higher altitudes where it can be recovered a bit more easily. Civilian vessels have a good safety margin, and are able to stay afloat even when damaged. That margin is much narrower in military vessels, as they prefer to squeeze every drop of lifting power for performance or payload capability. Therefore, most modern military vessels have the ability to voluntarily eject some of their mission payload (weapons, ammo, fuel, cargo etc.) to keep it afloat when damaged. Even armor plates can be ejected to lose weight in an emergency. Vessel commanders have successfully used the tactic for a speedy retreat when in dire circumstances. Others have literally "dropped their weapons" to signal surrender. [Answer] If the air gets denser, a modified parachute can still work actually. You basically make the parachute very deep like a hot air balloon. Deploy it when you start to fall and it will fill with light gas, as you fall deeper and deeper that light gas stays trapped in the ballon/parachute and eventually it will make you buoyant once your average density is the same as the atmosphere $$\frac{\text{mass of you} + \text{the chute} + \text{gas inside}}{\text{the total volume of the above}} = \text{density of atmospheric gas}$$. You could also include a heating system to heat up the gas in the balloon to help you rise back up as long as it doesn't set off an explosion of the atmosphere! And maybe a mechanism to close off the balloon once it's full just to be extra sure the gas doesn't escape (e.g. if the balloon is hit by an object) [Answer] Handwavium life-rafts. since what holds your ships aloft is handwavium, the rich may invest in handwavium life-rafts. They could lack propulsion and rely on sail for movement or even just drift on the air currents which should be pretty powerful. Since your lift mechanism is handwavium you can are in charge of its properties and can make them what is most convenient for you. [Answer] I think having a [power paragliding or paramotoring](https://en.wikipedia.org/wiki/Powered_paragliding) rig would be a great solution if you want to abandon ship. They take very little space when folded up,are quick to deploy and have pretty decent range. [Answer] Their flight suits can double as wing suits. As pointed out prior, if you're up high enough, planes can glide into a safe landing. Humans can do the same, with the right equipment ]

[Question] [ Traffic lights are mechanisms that control the usage of intersections. I'd like to perform a thought experiment for an alternative mechanism. The basic idea is that the intersection is a shared resource. Therefore, if some people are using it, they need to compensate the people who are prohibited from using it. In this thought experiment, we still use traffic lights, but they don't have a fixed pre-programmed schedule. Instead, they react in real time to the current situation, in the following way: Each driver in a road that is coming into an intersection can choose (using some simple, non-distracting device in the car) a certain amount of money that she/he will pay once the car has gone through the intersection. The money will be transferred to all drivers in all blocked roads (using some automatic payment software), distributed evenly among them. Drivers can update the price that they are willing to pay at any time. The light will always be green for the road whose total sum of money (of all drivers) is largest. I know that the rules of this system were not well-defined. I'm interested in whether this system is reasonable and can be stable, or whether it will cause chaos and misuse. I'm less interested in the technical problems such as how you make sure that all cars have this system installed or how drivers can perform the update of the payment in real time (although you can certainly share your thought on these aspects too). [Answer] ## Mixing Money and Public Infrastructure always has unseen results that you don't expect I'm going to put a different take on this, and refer instead to human nature. The issue with money being mixed with public infrastructure is that systems become exploited in a way that many in government DON'T expect. 2 examples: * Toll Roads - Private Toll roads in Australia were meant to allow infrastructure to be built using private funds, however charging for the use of the road for profit leads to people finding odd routes through the city to save money, increasing traffic load on suburbs and small arteries. Sydney now has so many choke points throughout single house suburbs that to get to the airport takes hours from the CBD (most people would prefer to save a few dollars and sit in traffic for hours). The preferred Australian method is now PPP (Public private partnership). * Congestion tax - Jakarta once introduced a congestion tax that meant any car with only 1 person needs to pay a toll. What happened was an entire industry developed where people made a living by standing on the side of the road and charging less than the congestion tax to hitch a fake ride. This developed into thousands of people, taking unnecessary trips, to earn money by people to reduce their tax. Jakarta removed this tax as soon as they realised congestion was increased as a result, not less. These examples in my view support the notion that public infrastructure should be independent of money and individual self-interest. As soon as this is introduced people start exploiting it. For instance, should you consider in your bidding system: * A whole new industry where people drive only to low-traffic points to be blocked simply to earn money, perhaps even paid by others including companies * People choosing the most convoluted route possible to earn money. * People intentionally crashing cars to block routes. * 'Shadow' apps that seek to game the system that people sign up to in order to bias peoples journey to either earn more money or group people together to bid together * Courier companies, trucking companies, attempting to use low frequency routes to save money, or grouping together into syndicates to take advantage of the system. These may counter-intuitively have opposite effects, and it would be more ideal if money is removed from your bidding system. My ideal is if an AI is in charge of all traffic lights, it should be possible to optimise all traffic light operations to achieve the goals you want through simulation and constant adjustment, depending on the goals you want to achieve. [Answer] While an interesting thought, I can see a few major flaws with this system: You are never the only one to arrive at an intersection. You will almost always be behind someone. They might not have the same financial status or preferences, and might opt to wait instead. This means you might have to pay not only your share, but also their share to get a green light. Also, some people might opt to wait at an intersection for an extended period instead, as an easy way to collect some money. They will hold up the people behind them, and this will lead to increased road rage and potentially dangerous situations. Also, this might be highly ego-dependant as well. I could imagine an insanely rich person driving around assuming every light will be green for them based on the amount they are willing to pay. If this doesn't happen for any reason (an even richer person comes along for example) they might not pay enough attention, and might not stop in time. [Answer] This system is probably the way of the future with the exception of traffic lights, which will become nonexistent as soon as we only have self driving cars. Automated negotiation of right of way for autonomous driving is a real research subject. Sadly I can't find the video but my university is testing a system where AI driven cars negotiate in some fashion in real time who has the right of way. The negotiation include how much energy they need to spend and how much time they win and loose. A result was that trucks will tend to "pay" more since braking and accelerating costs more for them. So far the system has only been tested on a single intersection with a few self driving cars. But the result is that at high speed negotiations the cars don't stop anymore at all. One will break a little bit to give just enough room for the other to quickly pass through. Not the video I was looking for, but this is the gist of it: [Autonomous intersection](https://www.youtube.com/watch?v=fzkv5beS4uk) [Answer] The big problem here is that it will greatly reduce the throughput of intersections. A major part of designing intersections is balancing throughput with latency. A traffic light that never switches maximizes throughput in one direction -- vehicles never need to stop for the light -- but maximizes latency in the other -- vehicles wait forever for their turn to pass through the intersection. As switching frequency increases, latency goes down, but so does throughput, as vehicles need to stop for the light more often. I expect that your bidding system will cause frequent changes of the light. This is great for minimizing wait times, but reduces the total number of vehicles that can pass through. The intersection spends most of its time in the "switching" state when no vehicles can enter, and those that do enter are usually accelerating from a stop, so the average speed is quite low. It will provide little benefit, if any, over a four-way stop. [Answer] # It kills one of the main uses of traffic lights One of the best uses of traffic lights over stop signs is to allow intersections of very large (high volume) roads with very small (low volume) roads. If I am the only car at a stop sign intersection with a 3-lane, packed road, I will never get to go. Stoplights fix this problem by forcing the high volume road to stop. Well-programmed stoplights allocate green light time in proportion to the average amount of traffic on each road, so cars on the smaller road may wait a long time, but not forever. However in your system, aside from the mega-rich, there is no way that one car could outbid 30 other cars competing for that intersection, so they would be stuck there forever. ## maybe consider a non-money system that allows hyperinflation Instead of money, what if your system uses "credits", or a "stopped time bank". In the simplest implementation, ignore any kind of bidding for the moment. Whenever you are forced to wait at a traffic light, your account is credited with the number of seconds that you had to wait. If your credit exceeds the summed (or maybe average?) credit of all other cars at the intersection, you receive the right-of-way, and the amount of time is deducted from your account. This would be hyper-inflationary because credit would be multiplied: time is deducted from a single account and added to multiple ones. You could instead deduct the amount of time times the number of drivers at the red to keep relatively constant levels. If you wanted to retain a bidding system, you could possibly bid by the maximum multiplier you are willing to pay. [Answer] It will cause chaos. One of the things that traffic lights do is restrict the volume of traffic on the road beyond the signal. There is a counter-intuitive characteristic of traffic (typically on freeways, but a signalled road will exacerbate the problem) that when volume gets to a certain point it goes from free-flowing to stopped, and you can make people arrive at their destinations faster by forcing them to wait before entering, to keep the overall volume below the changeover threshold. Allowing traffic flow to be determined by individual self-interest will result in major routes being completely saturated and immobile, because nobody is going to voluntarily block their own progress, or take a significantly longer route (except for the few weirdos like me). If you instead allowed drivers to bid on their entire route, and used some central control to allow those paying more to travel on lightly used (faster) roads, then you'd have something that would probably work. [Answer] Circular intersection also called "Roundabaouts" or "elipticalbouts". Also this is not a thought expirement. This is Auction experiment. So - how much you are willing to give for a $1. The best profitable option is of course 1 cent. But if two people are participating the best option would be to give 99 cents. But people don't think this way. They want to gain as much profit as they can while spending as low as they can. So they incremeant with 1-5 cent. And at certain point they are willing to pay over one dollar just to win. So when you want to ear money you set the amount you want to pay at one cent. Or none if it's possible. Anyone else with higher amount will pay you. Even when you are not willing to cross the intersection you will just milk all people with "pass = higher than 1 cent". While you will not spend a dime because you will wait for others, behind you, to pay for green light. And people will think "I need to give few bucks because the guy ahead is stuck so I just need to overbid the dude on the other side". In the end the "milkers" will literally earn cents while forcing other to spend dollars and let others earn dollars "Hey, I just got paid $5 becasue I have pass set to 5cents". Blocking the roads. Making millions of loss for everyone. THe way you install the thing is just install it. Make it mandatory. Ever heard about FAP or DPF filters? Mufflers? Lights? Belts. Oh, (said in my best Colombo voice) just one more thing. People who have plots at the intersections could just make a right turning road and just charge people flat rate of 2 cents. [Answer] > > using some simple, non-distracting device in the car > > > First I want to address this specifically. It's not possible to not be distracted. That's just not a thing. I'm a driver, and I'll make the bold claim that anybody that says otherwise is either deluded or lying. I've caught myself spacing out trying the turn the radio up, imagine what it'll do to people having to do math on the road. --- That said, let's imagine it magically just works. There are still *a lot* of problems with this idea, because the road is a harsh mistress and there are a lot of variables you have to account for: * Different roads have different amount of traffic. Small roads could simply never get the right of way because there's not enough people to offset a big 8-lane boulevard. * Sometimes you have to turn left and cross traffic, so in a standard 4-way intersection you're competing with 3 other streams of cars... * ... plus pedestrians. * ... plus public transportation. * ... plus any lobby group (e.g. taxis, delivery, etc.) that manages to get a special status, either de facto or de jure. * Emergency vehicles *cannot* wait. * And then there's all the ways someone can game the system, including organised crime. Just figuring out an ideal system (i.e. one where people don't become maniacs and respect the rules) that guarantees everybody can eventually pass within a reasonable time frame without creating undecypherable gridlocks is going to be a big enough headhache. And if you manage that without it being overtaken by corporations that'll make it worse than broadband in the US (in a nutshell: terrible service, terribler price, terriblest customer service, also don't try to actually compete and offer a better service than us because we'll sue you), in this perfect ideal world, it's still a massively terrible idea. Why? because it's... ## **Straight up inegalitarian** I'm sure we can agree the rich have it good enough that we don't need to give them more power. The problem of your system is simply that movement ceases to become a right and becomes a commodity. That's bad. That's *really* bad. It's bad because it will accentuate inequalities that already exist and put even more weight on already underprivileged communities. Some people can't afford a car and have to take a bus. Your system will more than likely jack up the prices of bus passes because the busses need to cross intersections. Some people can barely afford owning a car, but now they'll be unable to afford driving it. Now their mobility is reduced to where the bus takes them, the same busses that already got more expensive. For those that can still afford driving, it means reducing their purchasing power, and it means increasing their commute time. Your system is going to make the cost of going to the movies become prohibitive for a larger number of people. Same for museums, or libraries, and eventually groceries, delivering mail and packages. But more importantly also just going to work or to school. Your system doesn't answer to a problem (which already is reason enough to not implement it). Instead, it creates one, it creates a new class of people that can't afford going to work anymore, and another class barely above that can't afford leaving their house except to go to work. It simply creates more poverty and exclusion, and that is really, *really*, ***really*** bad. --- In comments, the argument has been made that the money you can earn could offset the cost. Firstly, you might be getting cents or fractions of a cent for every car that snobs you. That's true. But you are also paying to turn your light green in the end, and you have to factor in the cost of energy spent idling unnecessarily. So I wouldn't necessarily assume the economics of crossing an intersection are beneficial to you, let alone the economics of a complete trip. But even assuming you make any significant (in the statistical sense, i.e. more than crumbs) amount of money stopped at red lights, that means someone loses. And it won't be just the filthy rich. It could also be someone poorer than you, that has to pay the premium because they can't afford to be late to work again and lose their job. And you won't probably not care about them until it's you that has to make haste and spent all the money you've earned so far to go through. And that's when you account for the other variable of the equation: time. Time is money, we've all heard that, and in a sense work is the literal proof of that. So what is behind an extra half an hour of commute? It's 30 minutes of a sitter's wage. Or it's 30 minutes you don't have to study. Or it's 30 minutes away from your loved ones. It's little things like getting less sleep or not having time for extracurricular activities. And here we are again, taking about more poverty and exclusion, which is still really, *really*, ***really*** bad. [Answer] I don't think that SPECIFIC situation works because of the nature of an intersection, but let me state the same type of plan in a slightly different scenario: On freeways I often encounter a ramp to another freeway that backs up (Sometimes for quite a long way). A common response is for people to get out of the lane and into a faster lane, but then to try to cut back into the slow lane before the ramp (We all know this is the cause of much of the slowdown in the first place, but let's ignore that part for the sake of this discussion). This is clearly a person who thinks their time is more important than that of everyone else in the lane. Some recently described this action as "stealing 10 seconds of life from each of 30 people in order to give themselves an extra 5 minutes of life"--something you'd expect from a supervillain-style bad guy. However if everyone in those cars could put a price on letting someone go to the front--then someone willing to pay everyone they are going to slow down could make sense. I could imagine a system that automatically negotiated how much you had to pay against how fast you wanted to arrive to come up with a small amount of cash that is transferred. I suppose (as with your intersection example) that NOT using the street at all is the best thing you can do, and you should therefore be paid the most for staying home. Interesting thought experiment. [Answer] > > a certain amount of money that she/he will pay **once the car has gone through** the intersection. > > > Ok, so I'll bid one million dollars every time I see a blocked intersection down the road, but change the bid to $0 once I'm close enough to make it through the intersection even if the green turned yellow at that moment. Or I could start a VIP business: run a few hundred cars in a loop through all major intersections, so that whenever a car of some of my clients gets to any of those intersections, a nearby driver of my facilitator car would bid a huge sum of money to let the client pass free, and then rescind the bid so that it's never paid. [Answer] With a few modification I think it could be pretty good. Here are a few things I think need to be adjusted/kept in mind: * other traffic laws must still be obeyed, some one can't just park on a traffic light to collect money * the amount of money you are willing to pay has to go to everyone waiting at the light AND be influenced by the amount of time the light has been red, so a congested traffic light will increasingly expensive to to keep green and a single guy trying to merge into traffic won't be stuck forever(this is important for things like voter finagling by having a few rich people block access to voting areas that will vote against their interests) * use a [second-price auction](https://goodwaygroup.com/blog/first-price-vs-second-price-auction) model to encourage people to pay their real valuation It would defiantly be interesting to see how this works out with actual people, some one should make a social experiment or/and game about this [Answer] The solution may be more plausible if you abstracted the money away by one level. Imagine that every traffic light at an intersection has an automated load-balancing system. It automatically balances the times each light is Green/Red to maximise throughput through the intersection and reduce wait time. It operates mainly on number of cars waiting vs. number of cars going through the intersection. Obviously it would have to be programmed so that single cars waiting on side streets at major intersections and pedestrians still get a chance to cross the road in a reasonable time. This all happens automagically using image recognition software and little GPS/RFID tags in each car to determine who is at the intersection. Where does the money come in? Simple - there are multiple tiers of car registration and licensing. When registering your vehicle with the Department of Transport, there is an option to pay an additional annual fee to receive favourable treatment. This isn't an absolute, but for example, maybe the first tier above basic makes your car count as two vehicles for the purposes of load balancing, the next tier three etc. etc. Emergency vehicles would receive absolute priority, and there would be a hard upper limit on the priority given to private vehicles. Basically the payment isn't done at the intersection, but as an annual fee. [Answer] Intersection control is just CPU scheduling in disguise, for which there is ample research already existent. The limited resource (intersection, CPU) is allocated to multiple clients (cars, jobs) in order to maximize utilization of the resource, among other things. There are costs associated with changing jobs (stopping and restarting traffic), there are varying priorities among clients (both self- and system-assigned values), along with escalating priorities if something is forced to wait overlong... Huge fun! [Answer] # Gridlock Well, the first problem that comes to mind is [gridlock](https://en.wikipedia.org/wiki/Gridlock). A lot of math and light coordination goes on to optimize traffic while preventing gridlock, especially in large cities. # Disenfranchising the poor The sad fact is this policy clearly benefits the financially well off. This means you could force poor people into a situation where they can't hold a job because "if they drive, they will be late" or "if they walk/bike, they will be sweaty when they get to work". # Congestion As it turns out, the best way to minimize road time is for everyone to drive to a random place, and then drive to their destination. While this is a longer path, it makes every part of the network (road) equally used, and prevents congestion. Since your method makes people pay per light, everyone will optimize their route for minimum lights, and thus maximize congestion. # Crime Where there is money, there is crime. So all I'll say here is you've just made street lights an active target for theft/abuse. Other answers contain plenty of examples, and even all of those only scratch the surface of what could be done. [Answer] Traffic flows are very complex. There are fairly simple situations in which adding an additional road can *increase* journey times compared to the road not existing. Any good traffic control system does many things, such as times the lights at successive junctions so that (as much as is achievable) drivers reach the next light at green. This keeps traffic flowing, reducing congestion, and keeping drivers happy. They also balance traffic flowing onto/off main routes. This system you propose would probably lead to a significantly increased journey time for most if not all drivers. ]

[Question] [ What kind of destruction would it cause? I’m assuming it’d be rather significant, could it shatter a tectonic plate? The crust? How would the oceans fare? Would the planet be able to catch the projectile? Could any life survive the event? And if you’re able to stand another question, how immediately noticeable would this event be to other planets in the star system? [Answer] This turned out unexpectedly fun... and for once the answer to a question involving 99.99% of the speed of light **isn't** "everybody dies" # Where is this sphere being fired from? If it's from outside the solar system then hitting the earth as a sphere is.... a problem... The volume of 1000 kg of tungsten = 51.9 L Radius = 0.23 m That's 5439.5 moles of tungsten. As the sphere approaches from the orbit of Pluto we can estimate how much matter it would hit. We can treat the space it passes through as a cylinder with radius 0.23 m and height of 7.5 billion kilometers. It would take our projectile about 7 hours to travel that distance. It would pass through 1246 km^3 (cubic kilometers) of space. In the solar system with the solar wind the density of atoms is 2x10^7 per cubic meter, mostly hydrogen or helium. Treating it all as hydrogen for simplicity that gives us 0.04171 mg of hydrogen. This gives us 261.3 GJ (gigajoules) or 72.59 MW h (megawatt hours) as the approximate energy involved in the collisions between the fine mist of gas in the solar system and the bullet. That's the energy of the atoms hitting the front of the bullet, and most of the energy would be effectively dumped into the metal. Given this is over 7 hours that means there's something like 10.37 MW of energy being pumped into the sphere every hour. Tungsten has a heat of vaporization of 800 kJ/mol, so it takes 4,351,600 kJ of energy to turn 1 ton of tungsten into gas. Unfortunately your tungsten "bullet" sphere is getting hit with 37,332,000 kJ of energy per hour so within the first 7 minutes of its 7 hour journey it's become a cloud of atoms glowing hot at about 5555 degrees Celsius... At this point the calculations get harder because it's no longer a nice neat sphere; it's a cloud of super-high temperature gas traveling so fast that it's glowing like the heart of a star and it's very hot gas so the cloud is expanding **very** fast. It's now hitting even more of the random atoms in space as it's approaching earth. Assuming the sphere was aimed to hit earth perfectly dead center I can't even tell you if all of the gas would actually hit the earth or if the hot cloud of gas would expand from itself fast enough to mostly miss the earth. I don't know how much extra energy the cloud would lose to hitting atoms along the way after the sphere melts and turns into gas since it now has a massive surface area... But let's say that the cloud all still hits the earth's atmosphere, but over the 6 hours and 50 minutes since it passed Pluto it's spread out to hit the entire facing side of the earth fairly evenly and none misses and it's still carrying most of its energy. As in L. Dutche's answer, according to Wolfram Alpha, the relativistic kinetic energy of such a bullet would be **6.265 x 10^21 J**, or 1.5 million megatons. ... but... The total power output of the Sun hitting earth is about **[4.3 × 10^20 J per hour hitting atmosphere](http://uk.businessinsider.com/this-is-the-potential-of-solar-power-2015-9?r=US&IR=T)** on the side facing the sun. The bullet is carrying far less energy than a single days worth of sunlight. Cosmic rays can't pierce the earths atmosphere and the bullet is now more similar to a giant cloud of cosmic rays, but each with far less energy than the "Oh My God particle". Everything in orbit on that side of the earth would be hit with a huge dose of cosmic rays. The hard radiation would be caught by the atmosphere and some heat would make it to the surface... but the atmosphere is vast and that much isn't even enough to raise the temperature of the gas on that side of the planet by 1 degree Celsius average. I suspect anyone outside might get flash burns. I don't know if the energy would be enough to start major fires. To an extent the more energy ends up as high energy particles and radiation the less hits the earth surface as heat. [](https://i.stack.imgur.com/1H2gm.jpg) ## But to answer your question: As it approached the gas cloud that used to be the bullet would burn brightly in the sky as it impacted gas and dust ... then for a brief moment the entire sky of half the earth would blaze with light thousands of times brighter than sun... it might burn things on the surface.... it might shower a significant amount of secondary radiation... but the tectonic plates would be safe. Edit: re Yakk's comments below, as the cloud is passing through space there may also be bursts of something like space-lightning as the cloud interacts with subatomic particles that strip away electrons and depending on how far away from earth the bullet starts .. > > Napkin math says this means a spread of E-5 (i.e., every E5 meters it spreads out 1 meter), which means over 100 AU that is 150,000 km. That is order-of-order-of-magnitude size of Earth. > > > ~Yakk So the cloud may partly miss earth since the diameter of earth is only 12,742 km, so it may be a little bit like getting caught in the middle of a 'shotgun blast' of space-lightning-filled hard radiation with much passing either side of the earth. [Answer] According to WolphramAlpha, the relativistic kinetic energy of such a bullet would be $6.265 \cdot 10^{21} \ \mathrm J$, or 1.5 million megatons. The gravitational binding energy of Earth is $2 \cdot 10^{32} \ \mathrm J$, therefore we can stay assured that the planet won't be completely wiped out. Quoting from this useful [page](http://www.projectrho.com/public_html/rocket/usefultables.php), the impact energy would be comparable to the last eruption of Yellowstone super volcano. This event left a large deposit of tuffs, known as [Lava Creek Tuffs](https://en.wikipedia.org/wiki/Lava_Creek_Tuff). The following picture shows their extension: [](https://i.stack.imgur.com/PbZR7.jpg) > > The Lava Creek Tuff is distributed in a radial pattern around the caldera and is formed of 1,000 km3 (240 cu mi) of ignimbrites. > > > Lava Creek Tuff ranges in color from light gray to pale red in some locales. Rock texture of the tuff ranges from fine-grained to aphanitic and is densely welded. The maximum thickness of the tuff layer is approximately 180–200 m. > > > The relativistic impact would be for sure a global cataclysm: the spallation would probably temporarily deform the planet, and the following relaxation would result in increased volcanic activity. The resulting emission of ashes and gases would severely impact life, with mass extinction effect. An observer in a suitable position in the Solar system would notice a bright flash during the impact, probably followed by an increased IR emission due to the thermal effects of volcanic eruptions. To give you a reference of how bright would the flash, the impact energy is about 1/10 of the total solar energy striking the Earth in one day, and it is released in a much shorter time. I assume that for few seconds the Sun and Earth would appear like twin stars in the sky. [Answer] [](https://i.stack.imgur.com/g9Yki.jpg) I think that with the size and speed it would be quite powerful. First of all the impact would be virtually instantaneous. This would cause all the force to be extremely concentrated. If it's moving 99% the speed of light, well, imagine all that power compressed into a second--now imagine it being a million times faster than that. Now imagine it being WAY faster than that. The damage of the impact is going to be based on the force multiplied by the inverse of time--and as time approaches zero... ]

[Question] [ I have a group of eco-terrorists who want to limit the amount of $CO\_{2}$ the world puts out drastically: by poisoning oil fields so that the oil becomes unuseable, or at least forever uneconomical to pump up. Unfortunately, I haven't yet thought of a way to do this, not even with unrealistic wealth and technical capabilities. Burning it underground or having it "eaten" by bacteria or so would just output the $CO\_{2}$ immediately. Injecting water into the field is used as a way to get more production out of it. Injecting sulfur to make the quality of the oil low? We get sulfur from oil in the first place, so there is a way to get it out, and there will be a market for all that sulfur because there is an eco-terrorist group buying all of it... I guess my best bet is another chemical that makes the oil too dangerous/uneconomical to use but can't be easily extracted from the oil. That exists in sufficient quantities to poison at least a small oil field. Another option is to make the field inaccessible somehow, making it impossible to have wells there, but I don't know how. Any ideas? [Answer] One way I can think of: Just look at Fukushima and how hard it is to filter radioactive elements out of water - I bet filtering them out of *oil* would not be any easier. Rather the opposite, I'd expect. So the ecoterrorists could inject radioactive materials (maybe they stole used up fuel from a nuclear plant and ground it up?) into the oil field, arguing that the radiation won't hurt anyone... as long as it all stays deep underground. Even if the oil companies came up with filters to remove the radioactive materials, the civilian population might not trust that the oil is safe to use now. Especially if *someone* were to spread rumors that the oil is still radioactive and the companies just bribe the controllers into giving them a clean stamp. [Answer] I imagine that the cheapest and most likely option would the use of [phase-selective organogelators](http://www.ncbi.nlm.nih.gov/pubmed/26821611) which are already used to clean up oil spills in some cases. They're cheap, being based on sugars and alcohols, available in large enough quantities, aren't tightly controlled, make it much more difficult to pump up the oil in the first place, and are difficult to untangle from the oil once they're mixed. ("[The recovery of oil from polymer gels is cumbersome](http://complexfluids.umd.edu/papers/67_2010.pdf)"). Kind of surprising that no one's done this already, now that I think about it. Might be related to the fact that "gelling oil wells" isn't as exciting or useful in a propaganda reel as throwing Molotov cocktails at SUVs on a suburban car dealership lot. [Answer] You're working from a common misconception that 1) there is one substance called "oil" and 2) that it's all just sitting in natural tanks underground. Given this common misconception it would seem like you could just dump something into the "oil" in the "tank" and render it useless. In fact, "oil" is comprised of a wide range of forms of hydrocarbons all of which exist in various types of geological matrices. The oil that gushes out in the classic Hollywood depiction is a mishmash of low-sulfur, low-viscosity, high-volatile hydrocarbons, in a shallow, highly porous layer of sedimentary rock which is pressurized by the degradation of the volatile elements into natural gas. Such oil has a very low "lifting cost" (which is why oil from the Gulf of Arabia is so relatively cheap) but trying to reverse the process would be nearly impossible. Oil is spread out over not only vast areas but vast volumes. We also use billions of gallons of it a year. To contain enough oil to matter, it would take a contaminate infrastructure almost as large as the pumping infrastructure to even get close. The effort would cost billions and take years if not decades to implement. In the meantime, there are lots of undeveloped oil fields out there that could be brought online in an emergency e.g. all the shallow water off-shore oil fields in North America blocked off not because of ecological reasons, but because of coastal property values. Those could be brought online faster than wells could be destroyed. Given that the "Energy Crisis" of '73-'83 caused only Wage and Price controls, punitive taxation (which in turn enabled monopoly and embargo to cause a massive famine in Africa), several wars and likely killed 2-12 million people worldwide, and comprised the only multi-year period (including the Great Depression where the standard of living in the developed world went flat or actually decreased), I don't think anyone is going to stand around while the ecoterrorists progressively murder millions. Seriously, most people simply have no clue how vast the energy infrastructure is. People who babble about us being "addicted" to oil are as idiotic as someone claiming we are all "addicted" to oxygen. But they're going to learn. Nuclear power generates 20% of the US's electrical supply. The plants have a designed life time of 50 years max. We built our last plant in 1980; most were built in '65-'75. That means in four years, we either run the plants past their designed lifetime, or we start shutting them down. We will have to nearly triple our low-carbon emitting "alternate" energy scavenging system just to keep our power and carbon output where it is today. (Not counting the carbon debt we have incur to build low-carbon systems.) Better hope the climate models are wrong, because otherwise we're screwed. [Answer] Given the expertise oil companies have in extracting, purifying and refining oil, you can assume that they will figure out a way to remove any poisoning from the oil once it's in a storage tank. So, whatever your eco-terrorists use, it must have its effects before or during the extraction from the ground. ## Chemicals Highly corrosive chemicals could eat through metal pipes and pumps, but most likely would just cause a delay until new resistant coatings are applied to the pipes and pumping goes back to normal. There is also the matter of the quantities needed to prevent them being diluted too much. A second, more complicated idea would be to enclose oxidizing agents in some kind of bubbles or membranes. They'd float around in the oil until the violence of the pumping ruptures the membranes, allowing the oil and oxidizers to get it on and explode, hopefully inside the pumping stations or underground pipes. ## Bacteria A mix of metal and plastic eating bacteria might work, but it's unlikely they would survive down in the oil field until they reach a pipe, unless they can metabolize oil (which is not what you want). ## Nannites Catalyst Delivery System With the right catalysts, the oil could be made to bond into a sticky, plastic-like mass. The difficulty is in getting enough catalyst into the oil field and preventing it from getting enclosed in said sticky mess. If water is being pumped in to flush the oil out, that would be a good way to sabotage an existing oil field. Introduce the catalyst into the pumping water and walk away. if nothing is being pumped down or there are no drilling sites yet, things get more complicated. A drone might be design to swim down through oil pipes (with the pump being stopped obviously) and spread the catalyst, but it couldn't cover an entire oil field by itself, hence my original idea to use a swarm of nannites. To combine my ideas, the ultimate solution might be a strain of bacteria that produce the catalyst. They don't have to eat all of the oil, just enough to turn the rest into gooey plastics. [Answer] Pump a lot of mixed-weight hydrocarbons down the well where the carbon atoms are C-14 which is quite a potent beta emitter. The resulting oil would be too radioactive to handle and separation would be impossible. For bonus points, the hydrogens could be Tritium! [Answer] Some chemicals or bacteria that turn oil into asphalt or bitumen should work. If oil is not liquid anymore it will be hard to extract. [Answer] Based on [HopelessNoob's answer](https://worldbuilding.stackexchange.com/a/44228/19384) and the last bit of [Cyrus's solution](https://worldbuilding.stackexchange.com/a/44213/19384), **genetically engineer oil-eating bacteria to produce an organogelating catalyst,** then release them into the wild at an abandoned pump. This will require the reservoir to not already be low-grade tar or shale oil of the kind that the US "environmentally friendly" politicians currently advocate using as an alternative to coal, as that already requires fracking and injecting caustic and toxic chemicals into the ground to get the gelled petroleum up, which similar procedures could be used here to counteract the bacterial threat. But it might convert a high-grade reservoir into low-grade that *then* requires fracking, given enough time. (Fossil carbon naturally breaks down into low-grade bitumen and tar, which require heat and pressure beneath the earth to convert into high-grade oil that sits in reservoirs beneath mineral formation caps.) "Economical" depends on oil supply. The closer they are to peak oil, the more attractive stuff like Bakken shale becomes. (It's a dirty little secret of the oil biz.) Are they at peak oil? How much oil is left? What is the demand like? If demand goes up with decreasing supply, it will be profitable for them to decontaminate the oil, like the US is currently paying Canada to do with its Tar Sands. If a lot of oil is left, it will be uneconomical to *contaminate* it. A guy tried to do this with the world silver market in the 70s by buying up all the world's silver, and it did not work. (possibly inspired by Goldfinger...) it prompted a boom in silver production. Coal is not as big a threat presumably because the burning of coal (on this world) does not release as many lobbyists into the environment as do gas and oil. On another planet, they probably have a different energy economy, so this question is one of those "on a planet exactly like ours but..." solutions. Aliens in the movies always want our gold and oil, never coal or other stuff that humans find abundant and relatively worthless. [Answer] Nah, just buy the companies and stop production. That would be legal and ethical. Of course, you'd also have to give up plastics and a whole bunch of other products. So, even easier, why not just work towards a carbon tax? Or is that too hard because it requires getting people to agree, whereas unilateral action is easier to implement? [Answer] Poising oil field is **impossible**. Many answer here focus on what to inject, but the problem is not what to inject but how to inject. No, I am not talking about the military force you need to break the defense. Just assume the ecoterrorists have enough military force to take whatever action they want. You are able to poison the ocean because there is ocean current so the poison is automatically mixed well and spread. Some less fatal poison can also be spread by ocean creatures when they intake the poison (e.g. breathing, eating or simply stick on their body) and move around the ocean. The oil underground may flow, but at least not the part of oil we can touch. We just open a hole from ground and suck the oil up. Worst still, crude oil is viscous liquid that it is hard to mix with other material. Even if there is a poison and you are able to get large enough amount, oil company can remove that poison by sucking up a certain amount of poisoned oil and the newly sucked oil will be clean. I think a more realistic way is to constantly attack the oil drill so that the cost of defending the drill is higher than the benefit of selling oil from that drill, but there is no way to do it once and for all. [Answer] They could be incompetent or short sighted eco terrorists, and it doesn't matter that they use a method that would release a lot of co2. "We destroyed the oil by pumping oil eating bacteria down! That'll stop them from pumping up the oil and producing more co2!" "You moron, that'll just release all the co2 at once!" There are enough idiots in the world that the idea that a small group of them working toward a cause with incomplete information is scarily believable. **Edit:** I should say that it's not about the bacteria. It could be fire, or nukes, or demonic summoning. The point is that no matter how bad a plan, or what the long term effects, some group of idiots will be dumb enough to try it if they think it's a shortcut to what they want. [Answer] How about [VX](https://en.wikipedia.org/wiki/VX_(nerve_agent))? It was stockpiled by the US military for a while as an oily, long-lasting, area-denial chemical weapon. It also happens to be the most toxic substance ever synthesized. Your eco-terrorists wouldn't even necessarily need to get it in the ground. Just spread it around the well and it would be a nightmare to clean up. Should be significantly easier for your evil-doers to obtain or manufacture than radioactive materials. [Answer] **Bacteria**. Even random naturally occurring ones are a problem that petroleum engineers know well. They turn oil flowing freely through pores in rock into gels and goos that reduce or prevent flow. Just think what a genetically engineered bacterium might do. The most effective way to make sure both oil and coal stay underground would be to invent a better battery. Solar electricity is already cost competitive while the sun shines. Reduce the cost of storing it by an order of magnitude, and the oil age will be over within a few decades. "The stone age did not end because we ran out of stones". Who will burn oil or coal when electricity is universally cheaper? [Answer] Blow up oil rigs. Oil rigs are big, expensive and take time to build. Blowing them up technically wouldn't "poison the wells", but it might set back the production of sea oil. And you'll be able to trade a cheap bomb (and martyr) for a lot off cash and time for the oil companies. If the terrorists are really evil, and good at it, you could go after the oil engineers as well, killing people with that skill set. Get the colleges too, while you are at it. [Answer] Oil production is massively decentralized and as the price rises, it becomes economically viable in more and more places. New oil production is also often started in ecologically valuable areas; you don't want to encourage that. It's not the place to attack. However, there are only 4300 oil tankers in the world, and a handful of main trunk oil pipelines. And there are only 700 refineries, which are big, expensive, and take a long time to build. If you took out 600 refineries, and then took out 100 of the first 200 replacements, you'd break the back of the energy industry and alternatives to oil would quickly become viable. (You'll need to do something about coal in parallel, but you asked about oil...) Methods are pretty well described in other answers -- oil-gelling bacteria, radioactive contamination, standard industrial sabotage, plus things like nanobots, plastic- or steel-eating bacteria (that could cause widespread problems if it got loose), etc. If I had to pay $500 three times a year to clean your bioengineered fungus out of my car's fuel system to keep it from stalling out, you'd better believe I'd buy an electric car, pronto. That's probably less fun to read about than poisoned oil wells, though. [Answer] Getting the at the oil while it's still in the ground is prohibitive. Granted, despite what you said, a bacteria could do it. There are bacteria that can survive at high pressures, there's already bacteria that eat oil, and bacteria can multiply quickly to where it wouldn't be an immediate result, but would be an eventual result given enough time. The problem here is three-fold: 1. These type of resistance movements are rare and usually very small in number. (Most pro-environment people also believe in either pacifism or minimal violence). So they would not have the resources to genetically engineer the bacterium needed. 2. These types of activities that *are* active usually target immediate-result targets meant to cripple a war-supporting arms of an oil-based military-industrial complex supply lines, and avoid the negative PR that comes from hurting people and most oil wells comes with guards. 3. These rare people are usually lone-wolves who have just been pushed too far by resistance to improving the world's environment for some reason, and as such, their resources are only able to go after small targets like gas stations. Also, there's another problem. You're using the word "terrorist", but having them attack infrastructure - not people. Terrorist activities are activities that have the goal of human death; they're meant to strike fear in a population (hence terrorism) and not merely a side-effect or non-event. Actual Eco-terrorism is *ridiculously* rare and would be more like hunting down an Oil Baron or setting off a bomb at some fossil fuel convention/expo (which, in all fairness, would likely be much more effective, as CEOs are notoriously afraid of taking responsibility for their actions). Further, as they're actively defending something (the environment and humanity's health) that was there first, aggressive political terms are not applicable, and generally require a defensive one to be accurate. Eco-"terrorists" would not exist without polluting industries. Words like rebels, resistance movement, etc. are as such more accurate than terrorist. So, our eco-rebels, targeting an active oil well is extremely far-fetched unless this is taking place in some alternate world. However, if that's the case, and there's some organization that's well funded and well supported and protecting of the planet comes at a greater moral ranking in their belief system than human life (such as AVALANCHE from Final Fantasy 7),then you may have something to work with. So, assuming a fantasy organization with resources to oppose a military-industrial complex, there *is* a reasonable solution to "poisoning" oil wells. First would be to develop a robotic mole without the restriction of requiring a feeder pipe behind it, something capable of tunneling down to oil reserves, so it can move along, seeding them with something to disrupt them. As an ecological organization, release of CO2 is antithetical to its goals, so this eco-terrorist group would not use a genetically engineered bacteria (which would release massive amounts of CO2). Instead, it'd use a genetically engineered archaea adding some of the DNA from oil-devouring bacteria, something that could survive at pressure, would be single-celled so as to help it move through the oil field, and could feed on the CO2 it generated to genetically designed to produce heat, oxygen, a non-oil carbon form (sugar, coal, diamonds, graphite, carbon nanostrings, Red #40, buckyballs, carbon nano-foam, etc.) - eventually solidifying an oil field and rendering it un-harvestable (carbon nanofoam would probably be the most effective). The mole could be fueled by by the oil (mildly ironic, but a small price to pay from their perspective), letting it run indefinitely according to its programming (restocking as Archea multply and re-fueling from the oil), and continue to seed areas whenever oil rigs are installed, permanently clogging the area around them and rendering them useless. [Answer] As a physicist, I immediately thought of poisoning oil with something radioactive but it has already been mentioned. After some research, I was able to find a speculative idea that I'm not sure will work, but the material has the property of providing a large surface area that locks chemicals into it, effectively making them unusable. Worth considering? These chemicals are called [Metal-Organic Frameworks](https://en.wikipedia.org/wiki/Metal%E2%80%93organic_framework) (MOFs). MOFs are compounds consisting of metal ions or clusters coordinated with organic ligands. They have an extremely high surface area and porosity. MOFs could be injected into the oil field. These MOFs could be engineered to have a high affinity for hydrocarbons, effectively "locking" them in place and making it uneconomical to extract the oil. However, the MOFs would need to be stable under the conditions found in the oil fields and should not be easily separated from the oil. I found [this](https://pubs.acs.org/doi/10.1021/acs.cgd.7b00808) and [this](https://pubs.acs.org/doi/epdf/10.1021/cr300014x) nice references too. Hope this helps! [Answer] As a lot of people have pointed out, poisoning or altering the make up of oil underground may not be the best option. Nuking the area or leaving vx gases or other poisons lying around, while limiting the ability to drill is not exactly eco-friendly. Remember, your terrorists like the green grass and air we breathe. Can I suggest you create some kind of plastic and rubber eating bacteria/nanotechnology. This should restrict the ability to use, bring in more equipment to drill holes and suck out the blackgold. Think of all the pressure valves and small intricate electrical wires that would be involved in the measuring of pressures, and depth etc. Such bacteria/technology should be designed with a short shelf life of say 10-20years (you can always release more later if need be). It should also have some distance limiting feature so as not to spread further than intended. If it is airborne, this may cause problems. Maybe require large concentrations to work in concert, so if it gets dispersed through the wind it will not destroy peaceful settlements downwind. There is also the chance that it might be inhaled if it is airborne, so you definitely don't want it to affect organic flesh. Just thinking of plastic microbeads, such a device/bacteria could also build up inside the bodies of organisms it encounters and work it's way up the foodchain. So I really don't recommend it being airborne. That leaves it having to move by contact. This would also limit the distance it could spread. It would make potential cleanup easier. Unfortunately for man, we have a tendency to use plastic and rubber in nearly all our clean up tech and protective clothing. So...catch 22 there! [Answer] Your ecoterrorists should morph into a lobbying firm. Some 70% of oil (in the US) is used for either gasoline or heating oil. These are the uses which result in burning, hence CO2 generation. The terrorists seem to be fixated on CO2, so let's help solve their problem. They should push for legislation which forces cars to be electric. They should encourage hard carbon sequestration -- otherwise known as plastic. They can still be naughty terrorists, because they'll use bribes and threats to get their agenda across. Everyone has fun. [Answer] Dump sand into the oil field. Easy to obtain, just start digging in any OPEC country where there *isn't* an oil field. Sand would make it incredibly hard to extract the oil without having to first move the sand. Only the most determined oil miners would get any use out of it. Plus, sand is crazy easy to get. If you don't have sand, just use cat litter. Could also use cement. ]

[Question] [ This question was inspired by [this one](https://worldbuilding.stackexchange.com/questions/118125/is-it-possible-to-create-a-practical-sword-thats-naturally-toxic), which brought up the concept that a lot of the issues with a sword that created toxic fumes would also kill the user (that question also has one of the best answers I've seen on the site, check it out if you have the time) So here's the question: **Using only technology that was available in the Medieval Era, but knowledge of how air filtration works on a modern level, is it possible to create a working Gas Mask?** As for which part of the "Medieval Era"? That's up to you. As early as possible is preferred, but feel free to go as far as 1492 if you feel like you need to. **To count, the Gas Mask must:** * Be light enough to be wearable (around the same weight as a full suit of armor at the time) * Be portable (no air hoses leading off the body or anything similar [Answer] ### Yes it's possible. How? The mask body would be made out of leather. In order to make it airtight I would take one layer of leather, then a layer of pitch (which was also used to seal ships) and another layer of leather. With leather straps you could fix this mask to the head. You could even fit glasses in there - medieval glass was not as good as today's but it would be enough to see through and protect your eyes. For a breathing filter I would use activated carbon, perfectly doable with medieval technology. I'd either make a leather or a metal tube, that I'd fill with activated carbon. A cloth on each side would hold the carbon in place while letting air pass through. Fix the tube to a hole in the mask body and seal the edges with pitch. As ironduke97 already stated urine-soaked clothes were also used, so you could make different kind of filters by adding such a cloth to the filter. It would probably not be as comfortable or easily usable as modern masks. You'd need a second person to help you with putting it on and fitting it to your head in an airtight way, but it would do its job. [Answer] A full-faced gas mask has two features that prevent us from inhaling potentially toxic contaminants in the air. Then it has to be sealed against the face, preferably to skin (so no beards), and then, if needed, have glass eye protection. It's the filter that causes the issues... 1. The first is a particle filter which removes any bacteria/dust in the inhaled air. There is essentially no chemistry involved here, just a physical barrier that forms a field between the toxins and the face. When a particle is inhaled, it hits the fibers on the filter and becomes tangled before it ever has the chance to reach the nose or mouth and move down to the lungs. This is very replicatable in medieval times. They had the ability to weave silk etc. to very fine levels, and simply having the material be dampened increases its effectiveness considerably. Asbestos could be used which would aid this as well, as they were using it in Roman times for various items, but alas as we know, it tends to causes a lot of issues in the long run, especially if it was being breathed through. The crazy thing is even the Romans knew that asbestos causes lung damage, but no other material came close to what was needed at the time, and even now, asbestos still beats almost anything else, which is why it is still used in nuclear reactors etc., but that's a tangent... back on track. 2. The second element is based on a chemical process called adsorption, and removes toxic molecules like the nerve gas sarin. Through adsorption, a solid or a liquid can trap particles on its surface — analogous to the way a cigarette filter reduces the amount of toxins a person inhales when smoking. To filter out harmful chemicals, most gas mask filters are made with activated charcoal, or oxidized charcoal. When charcoal is activated with oxygen, it becomes ripped with tons of "sticky" holes in each molecular structure just like chicken wire. Any toxins that pass through the charcoal become bonded to these holes, and are prevented from moving into the gas mask. while there are other chemicals used nowadays, activated charcoal is the best solution for most toxic gases. So - could a medieval society make activated charcoal? ### Rough process for making activated carbon * Make charcoal. * Powder the charcoal. * Make a 25% solution (by weight) of calcium chloride. * Make a paste with the calcium chloride solution and your powdered charcoal. * Spread the paste to dry. * Rinse with clean water. * Bake at 225 degrees F for 30 minutes. This is the stumbling block, specifically chlorine. It is rarely found by itself in nature. According to google, chlorine was discovered and first isolated by Carl Wilhelm Scheele in 1774, and calcium chloride was first discovered in 1808, long after the time frame you're wanting. So, would anything else do? Well... Activation of charcoal is really a word to describe the process of driving condensed smoke from charcoal’s pores, and this can be done with a variety of chemicals, its just that calcium chloride gives the best results, so replacing it with even water and repeating the process several times would activate it a bit, but you'd still be breathing in smoke as the charcoal released it over time (not ideal) - you want to be able to get rid of as much smoke as possible. Coconut oil is filled with calcium but lacks the fat/cream that cows milk would wreck the whole process. So all you need is a coconut in a medieval setting. Perhaps it could have been carried by a swallow? Not a European swallow, obviously, and then again, African swallows are non-migratory... oops, another tangent. But then, you did say with modern knowledge, so. ### Making calcium chloride (wow this is getting long) * Place the limestone in the beaker. Use enough limestone the fill the beaker about 1/4 full. * Add a 1/4 of a beaker of hydrochloric acid to the limestone. * The hydrochloric acid will start to bubble as it dissolves the limestone. Gently swirl the beaker to mix the contents and make sure the reaction goes to completion. If all of the limestone dissolves, add a little bit more. * Once the solution stops bubbling, filter off the solids by pouring the solution through the filter paper into the second beaker. The calcium chloride is dissolved in the filtered solution. * Use the hot plate to gently heat the second beaker containing the calcium chloride solution. The solid left after the water evaporates is solid calcium chloride. So the big one here is hydrochloric acid, which, according to google again, was discovered by the alchemist Jabir ibn Hayyan around the year 800 AD!!! That's really good. So we finally got there. Would it have been possible in our timeline, without knowledge and understanding? No. **But with modern understanding but only medieval materials - YES** *might take a while and it would be very expensive to get all the materials together, but... YES!* [Answer] The [bird-beak shaped masks](https://en.wikipedia.org/wiki/Plague_doctor_costume) used by plague doctors in the 17th century were a type of gas mask. I'm pretty sure people in medieval times had access to the herbs that were stuffed inside said masks. So with some craftsmanship, they could make something similar. Other types of rudimentary gas masks included urine soaked cloths (the ammonia present neutralized the chlorine that was a favorite of the Germans) and simple masks with layers of charcoal, which is good at absorbing dangerous gases. So I'd say yes, it is entirely possible for folks of the medieval period to construct gas masks of their own with technology only available at that time. [Answer] It depends on exactly what the mask is supposed to filter out. Even modern gas masks are not all equal. The respirators they use when sand blasting for instance are only rated for particulates, not gases. This kind of mask is well within reach of a medieval society; really all you need is wet cloth for particulates. They will have a harder time dealing with poisonous gases. Not every kind of filter works on every kind of gas. A charcoal filter won't help you against carbon monoxide for instance. They did have access to asbestos in the middle ages, and many WW2 and Cold War era masks used asbestos filters. I don't know if they had the experience working with asbestos necessary to make these filters, but I don't think it's that big of a stretch. So they should be *relatively* safe from things like chlorine, phosgene, or mustard gas. It's still likely to burn their eyes since I doubt they will be able to get an effective seal without rubber, but they should survive. They have no hope of making a full PPE suit, which is what is necessary to survive weaponized contact agents like VX nerve gas. VX will kill you in minutes if it touches any exposed skin. Without rubber and zippers you have no chance of making an air-tight suit. And even if you somehow manage that, you still need an oxygen tank since you can't use outside air at all. I would say if you have the pump technology to fill an oxygen tank, your society is decidedly not medieval. [Answer] Well, there is always the panties option. How to make an Underpants Gas Mask: (1): Pee your pants. (2): Remove underpants. (3): Apply soiled underpants from steps 1-2 to face. (4): Hold your breath as much as possible so that you do not have to smell the urine. Most poison gasses are either (a) acids or (b) particulate in nature. The wet fabric catches particulates, and the high baseness of the ammonia neutralizes acid. Unfortunately, the reek of the urine is almost as bad as the gas, but it works. ]

[Question] [ We are living on this big lump of rock called the Earth, drifting ever so continuously through space. Now imagine a tiny but immovable object in space, a single atom of 'unexplanium', locked in space-time (relative to our universe or whatever you need). It will not move, bulge or transform; it's just there having indestructible mass. Assume it has the properties of a hydrogen atom (1 proton + 1 electron) for all physical and chemical purposes, except that it is endowed with infinite inertia. What would happen if our Earth hit that one immovable atom? For simplicity, we may assume that the Earth's movement is linear and that the atom will hit the center of the Earth. I imagine something like a truck hitting a stationary object. If it's super narrow it'll slice the half, if it's broad it'll smash into it. Would we even know it happened? Or would the amount of energy rip a giant tunnel through the planet? If a single atom is too small for something significant to happen, what would happen if it's the size of a marble or something bigger? --- I've found [this XKCD](https://what-if.xkcd.com/20/), which is somewhat related and might be an interesting read. It also described super fast and tiny particles: > > "If a meteor made out of diamond and 100 feet in diameter was traveling at the speed of light and hit the earth, what would happen to it?” > > > [Answer] As @Thucydides mentioned, researchers posited a similar magnitude of impact [and thought they had found evidence for it](https://www.telegraph.co.uk/news/science/science-news/3294473/Earth-punctured-by-tiny-cosmic-missiles.html), though they later retracted their findings they did calculate the potential effects. > > The team, from the Southern Methodist University in Texas, analysed more than a million earthquake reports, looking for the tell-tale signal of strangelets hitting Earth. > > > While their very high speed gives strangelets a huge amount of energy their tiny size suggests that any effects might be extremely localised, and there is unlikely to be a blast big enough to have widespread effects on the surface. > > > The scientists looked for events producing two sharp signals, one as it entered Earth, the other as it emerged again. They found two such events, both in 1993. The first was on the morning of October 22. Seismometers in Turkey and Bolivia recorded a violent event in Antarctica that packed the punch of several thousand tons of TNT. The disturbance then ripped through Earth on a route that ended with it exiting through the floor of the Indian Ocean off Sri Lanka just 26 seconds later - implying a speed of 900,000 mph. > > > The speed of 900,000mph is important here. Since you're determining that the particles are absolutely stationary we need to know how fast the Earth is moving relative to them. [What is the speed of earth relative to absolute space?](https://www.quora.com/What-is-the-speed-of-earth-relative-to-absolute-space) > > In practice we approximate the comoving frame as the frame at rest with respect to the microwave background radiation. Thus we measure the speed of Earth relative to the comoving coordinates assuming, that the background radiation has no "natural" dipole anisotropy. > > > The speed of Earth wrt the local comoving frame measured this way in of the order of 500 km/s. And, of course, it varies as the Earth orbits the Sun. If we subtract the velocity of Earth in orbit around the sun, velocity of the sun relative to galactic center and velocity of the Milky Way with respect to the centre of the local group of galaxies, we find, that the local group is moving and slightly above 600 km/s relative to the comoving frame. > > > 900,000mph is ~400km/s, you're looking for an impact appropriate to 600km/s, but the orders of magnitude have the same approximation as the incident in the Telegraph article > > several thousand tons of TNT > > > [Answer] **Conclusion:** In the case of the atom, you wouldn't see anything without special instruments. This is because the object is so small that very few atoms will interact with it, so it imparts almost no energy to any matter that it encounters. In the case of the marble, there would be a bright flash streaking through the sky, comparable to a large meteor, but much faster. Upon impact, the top layers of soil would be vaporized, resulting in a blast comparable in intensity to a very large conventional explosion (tens of tons of TNT). This would coincide with a small localized earthquake and a ground shockwave comparable to an underground explosion, due to the object passing through the rock at greater depths. At the exit site, almost identical effects would occur, except there would be a large explosion followed by a flash streaking upward into the sky. The exit event would happen $34$ seconds after the original impact, assuming the object comes down vertically and is moving at $370 \text{km} / \text{s}$ (see below about these assumptions). **Detailed explanation and calculations:** **I. Hydrogen Atom** Let's first do a quick back-of-the-envelope estimate for how much energy would be imparted to the atmosphere. 1. Object's speed relative to the Earth. First of all, what does "at rest" mean? Let's suppose the object is at rest with respect to the cosmic microwave background (CMB). The rationale is that if it originated in the primordial Universe, then it would have originally been at rest with respect to the CMB, and if it has infinite inertia, then nothing can change its motion, so it will remain at rest with respect to the CMB. The Earth moves at about $370 \text{km} / \text{s}$ with respect to the CMB, so that's how fast the object would hit. 2. Interaction with the atmosphere. When the object passes through the atmosphere, then any atoms it comes into contact with will bounce off at approximately this speed, on average. Let's first calculate how much mass of air it will encounter. A column of Earth's atmosphere (from the surface to space) has a mass of about $10\mathpunct{,}000$ kilograms per square meter of surface. The object is about the size of a hydrogen atom, with a radius of $10^{-10}$ meters, so if it's a sphere, it will take out a cylinder of atmosphere with an area of $\pi R^2 \approx 3\mathrm{x}10^{-20} \text{m}^2$. Multiplying this by $10\mathpunct{,}000$ kilograms gives us $3\mathrm{x}10^{-16} \text{kg}$ of air that directly interacts with the object. After this object passes, these air molecules will be moving around at about $370 \text{km} / \text{s}$. Using the expression $E = \frac{MV^2}{2}$ for kinetic energy, we get $$E = \frac{(10^{-16} \text{kg})(370\mathpunct{,}000 \text{m} / \text{s})^2}{2} \approx 7 \mathrm{x}10^{-6} \text{J}$$ energy imparted, in Joules. This is an absolutely minuscule amount of energy; for comparison, a normal household 10W halogen bulb emits 10 Joules of light per second. 3. Effects on rock would also be negligible, so there is no need to calculate them. The amount of energy deposited when the object strikes the surface will be similarly negligible. In the above calculation, the energy imparted to an object is proportional to its column mass (mass per surface area). Consider the first three meters of soil that the object passes. A layer of rock 3 meters deep has about the same column mass as the atmosphere. Therefore, the object would also deposit about $7 \mathrm{x}10^{-6} \text{J}$ in the first three meters of rock that it penetrates. Again, this is practically undetectable. It will, of course, continue depositing these tiny amounts of energy as it passes through the Earth. **II. Marble** In the case of the marble, the calculation is almost the same as above, except the object's radius is now more like $0.01$ meters instead of $10^{-10}$. So its radius is a factor of $10^{8}$ bigger, the area of the column of atmosphere it takes out is $10^{16}$ times bigger (as it's proportional to the radius squared) and the amount of energy deposited is also $10^{16}$ times bigger. The marble would therefore deposit $7 \mathrm{x}10^{-6} \text{J} \* 10^{16} = 7 \mathrm{x}10^{10} \text{J}$ of energy in the atmosphere, and a similar amount in the first three meters of rock. Since we're looking at explosive-like effects, let's convert this to tons of TNT. One ton of TNT releases $4.2 \mathrm{x}10^{9} \text{J}$. So, our object would deposit $$(7 \mathrm{x}10^{10} \text{J})(\frac{1 \text{ ton}}{4.2 \mathrm{x}10^{9} \text{J}}) \approx 17 \text{ tons}$$ of TNT in the atmosphere and in the first three meters of soil. The effects from the atmosphere would be comparable to a sizable meteor fireball. On the ground, the energy from the first few meters will reach the surface, producing an explosion comparable to a few tens of tons of TNT (a very large bomb). Anything deeper than a few tens of meters would produce a relatively short-range surface rumble, like a small earthquake, but relatively little energy will reach the surface. The same effects would happen at the exit site but in reverse order. The diameter of the earth is about $12700 \text{km}$, and the object is moving at $370 \text{km} / \text{s}$, so if the object comes down vertically, the exit event would happen $12700 / 370 \approx 34$ seconds after the first impact. [Answer] With an impactor the size of a hydrogen atom it's probable that we wouldn't even notice overly much. There might be a bright flash as it hits the atmosphere, it's even more probable there'd be one as it hit the ground, hard enough to break some molecular bonds. That flash is going to go all the way through too but we're not going to *see* it below ground level. It's almost impossible, certainly at such low relative velocities, to get an individual atom to actually *hit* such an object, even one with no charge, but because of it's [exotic](https://en.wikipedia.org/wiki/Exotic_matter) nature there might be some atomic fission events. Taken altogether I would expect very little energy to be imparted to the Earth, and very little if any noticeable damage. [Answer] At first I thought this would be a planet-ending event, but upon further consideration, it wouldn't be that big of a deal. First off, nothing can really be immovable, and nothing is really stationary in an absolute sense as others have mentioned. However, if we assume that the earth is going around a few hundred thousand miles per hour relative to the cosmic background, that's a number we can work with: let's call it 400,000 mph. That's not a relativistic number, so nuclear reactions are unlikely. Neutrinos have a small cross section and routinely pass through the earth unimpeded. However, a hydrogen atom has a much larger area; this is the reason hydrogen can be stored in a pressure vessel, because it bounces off the walls of the container. Now hydrogen has a diameter of about 50 picometers, so at the very least the particle would scrape out a 50 picometer-wide tunnel all the way through the earth. The mass of that tunnel would be about $6\times10^{-10}\text{ kg}$.  If all of that mass were converted to pure energy, which is a worst-case scenario ($\text{E}=\text{mc}^2$), it would be about $5.6\times10^{7}\text{ Joules}$, which is about the amount of energy released by burning a couple liters of gasoline. So the good news is we'd all survive. [Answer] As we now know - everything is relative. A fixed particle in space might as well be a moving particle in space, relative to us, when we are moving. This being the case, the atom in question would simply be like many other atoms already bombarding the Earth - individually the effect would likely be negligible, collectively a different story. The only difference in your case is your comment 'infinite inertia' - I presume this atom doesn't interact like normal atoms do then when in proximity or colliding with another atom. Still, one atom is only one atom, it may not directly interact with others at all on its brief journey through the Earth, or if so only imperceptibly. [Answer] ## Nothing will happen. Remember, there are (comparatively, when you think about the ratio of macroscopic distances to the sizes of macroscopic objects), huge gaps between atoms, which is why hydrogen will gradually leak out of any container. In much the same way, the fixed hydrogen atom will mostly push other atoms out of the way. In the atmosphere, we might see a parabolic arc of lightning as the the atoms gets knocked away at the speed of the earth's rotation. When it hits the ground, the fixed atom will simply force its way through, [displacing atoms where it comes in contact with the nucleus](https://en.wikipedia.org/wiki/Geiger%E2%80%93Marsden_experiment), until it comes out on the other side. Then we might see another parabolic lightning arc going the other way. [Answer] As the asker of the question has already learned, it was asked using some phraseology which is difficult to mesh with contemporary physics. As such, I am attempting to answer as if “immovable” is describing: * an [elastic collision](https://wikipedia.org/wiki/Elastic_collision) in which the relative motion between a third body which does not collide and one participant in the collision is unchanged. While the Earth is moving in relation to this “immovable atom” — IA — which you propose, each atom of the Earth has a velocity vector with respect to the IA. The distance between the IA center of mass and the Earth's center of mass is decreasing. When any atom considered to be a part of the Earth collides with this IA, the result of that collision does not cause any change of the IA's relative velocity vector with respect to the velocity vector of any other atom. In simpler language, the incident atom which is not the IA will bounce back with exactly the same speed but with a deflected direction. Any other atom will continue to see the IA as having the same velocity vector as it did prior to the collision. Ergo, the IA will continue to pass through the Earth with each successive collision — however, the relative velocity vector between the Earth's center of mass and the center of mass of the IA will **not** be unchanged, but will be apparently slowed, albeit almost immeasurably. Such will occur because the velocity of the Earth's center of mass is composited from the velocity vectors of each atom which is factored in the arbitrarily defined center of mass … Anyway. So, we have not yet defined exactly what fields are contributing to these aforementioned collisions. If the IA is uncharged, i.e. not ionic, then the collision is simply a result of the [repulsion](https://wikipedia.org/wiki/Exchange_interaction) between electrons — which is, in turn, a consequence of the [Pauli Exclusion](https://wikipedia.org/wiki/Pauli_exclusion_principle) property which electrons have — when its electron orbitals approach the similar orbitals of other atoms. It is very improbable that nuclear orbitals will ever interact, but at higher velocities such interactions become more probable — i.e. like the velocities you'd see in an atom smasher. And, even then, not very likely. Of course, all that lends problems to considering exactly how the IA is indeed ‘immovable’, and how that pertains to its constituent particles: its electrons, quarks, and all the other stuff that perhaps fluxes about between in unperceived spaces inside. Gluons and photons and whatnot. What if the IA were larger — like a pea, or a ball-bearing, or a marble? Well, all that really does — aside from making its ‘immovability’ more difficult to define — is give the IA a larger cross–section for its collisions: i.e., collisions are more likely. Because it is immovable, and any collision with it is perfectly elastic, its own mass is irrevelant. Only its size is relevant. What would be the state of that big mass of atoms which we call the Earth when the IA has passed through them and produce no further interactions? Well, it really depends on what the initial relative velocity was between the two centers of mass. Many other answers here seem to confuse ‘immovable’ with ‘motionless’. Whatever relative velocity you finally decide to use in your world, know that a larger magnitude will cause more deflection and thus more damage. --- All in all, the more details you want require a more rigid definition understanding the concept of ‘immovable’. Others have more or less explained why immovability is almost like a physical limit: you can become more or less immovable, but never perfectly immovable. Unless, of course, you exist outside the laws of physics which are known to contemporary science. If that is the case, then this answer is really only useful to you if your physical laws operate in any way which allows my explanation to seem reasonable. Obviously. [Answer] Immovable (relative to the Earth), and potentially indestructible, marble sized object? "Immovable" could only mean it exists at the exact center of the universe, around which everything else is in relative motion. It would be surrounded by a cloud of dust and asteroid fragments from previous impacts, would it not? Unless it sprang into being shortly before impact with Earth. Dust zone size depending on how long this marble has existed. We would enter that zone of space dust, causing a massive and unexpected meteor shower. Then a flare of light as the marble passed through the atmosphere, followed by minimal impact, and a shudder as it plowed through Earth. This would be a "bullet" that did not flatten or break on impact. The collision would be no big deal, but pressure would surely increase as it bulled its way through. Resulting in confusing seismic readings on the opposite side, then a small eruption as the marble exited. Or, if it entered and exited through oceans, no discernable effect on the surface of the ocean. [Answer] The answer is known, and it’s that nothing happens at all. If something is immovable, it means that nothing can move it, which can only mean that nothing we know of will interact with it. You’re describing a particle of [dark matter](https://en.m.wikipedia.org/wiki/Dark_matter), which the Earth undoubtedly hits all the time, but since it doesn’t interact with the matter of the Earth (except gravitationally, which is too weak and too long-range to be noticeable) nothing happens. [Answer] This scenario already exists. [Neutrinos](https://en.wikipedia.org/wiki/Neutrino) can travel through dense matter such as the Earth without interacting with a single atom, leaving no trace of their passage. To observe even just a few of the extremely rare interactions of neutrinos with matter, physicists build detectors with massive amounts of target material and operate them for many years. The detectors record the tracks of the particles that emerge from the rare collisions of neutrinos with atoms of the target material. I remember hearing that if you wanted to block a neutrino, you would need a sheet of lead as thick as the distance the Earth is from the Sun. [Answer] For every action there is an equal and opposite reaction. If the supposed object is immovable, that tells us that the reaction is zero, and therefore we know that the action is zero; if there is no effect on one of the objects that are colliding, then there can be no effect on the other one either. ]

[Question] [ ### Dear Abby, My mother-in-law moved away last October. Before then, she was very, uh, involved in my and my spouse's life, so I was if not exactly looking forward to her departure or demise (perish the thought!) at the very least feeling ready for the next, more independent stage of my life. I should have suspected, when she decided in October to [**make a trip to Transnistria**](https://worldbuilding.stackexchange.com/questions/33685/how-do-you-deal-with-multiple-instances-of-a-person), that something was up. She was in a terminal stage of whatever she had, so I should have suspected that a random trip to a breakaway region must have had a darker purpose. It was not until a month later, when she returned (as a set of 25 speakers, 8 holo-projectors, 18 cameras and 4 drones with their individual recharging stations) that the true nature of her transformation dawned upon me. My mother in law is now uploaded and immortal, and free to pester me forever more (and constantly remind my spouse just how disappointed she is with their choice of spouse). My spouse loves their mother, so I can't just unplug the damn thing. What can I do? --- **How does one get those pesky uploaded people out of one's hair if overt unplugging is not an option? Are there legal remedies, or am I on my own?** [Answer] **Deal with her as a person** 1. Let her know you find her behavior frustrating and upsetting. Remind her that she is a guest in your home, and make clear whatever boundaries need to be set regarding your relationship. Let your spouse know you are doing this, and how it goes. 2. If her behavior does not improve, discuss with your spouse, the mother, and a neutral party (e.g. a family counseling therapist) the various issues and develop a solution. 3. If the Mother-in-Law continues to be a serious problem, inform her she is no longer welcome in your home, and give her a month or so to move out. 4. If she refuses to do so and/or continues to cause serious problems file a restraining order and/or harassment charges as appropriate. 5. If she violates the restraining order, report this to the police (in person; calling in would be a bad idea in this specific case). Hoping your relationship problems will just go away because the people you see as the problem are old/terminally ill is not a healthy solution even without immortality drugs. [Answer] Your mother-in-law comes with a remote control that has a mute button on it! What are you complaining about. I would kill for that! More seriously: There are only two possibilities. Either uploaded people are legally recognized as people, or they are not. If they are, then they are bound by the same rules as the rest of us. Get a restraining order against her and when she doesn't abide by its mandates, have her arrested. How your society handles the arresting and imprisonment of uploaded people is a complicated issue, but it is not your problem. It is everyone's problem. So you are not "on your own". If uploaded people are not legally recognized as people, then you are free to kill her. She is not protected by society. Just grab a fire axe and start swinging! Sure, she will send more drones and FedEx packages, but at her worst, you might have to resharpen your axe blade a couple times. Also, in terms of those FedEx packages full of expensive cameras and holo-projectors and such, they arrived at your home as an unsolicited delivery; so legally, they are yours. List them on eBay and make her somebody else's problem. [Answer] An "uploaded person" is a piece of software so hire someone to hack it and add code that changes its behaviors to better suit you. This is exactly as unethical as putting parental locks on the cable. [Answer] ## Make everyone happy, by uploading a copy of yourself and your spouse to a simulation! You want to live without your MIL, she wants someone to pester and your spouse wants her mother to be happy. Just upload copies of yourself and your spouse to a virtual simulated environment, where your MIL can pester them forever and trap her there. Your spouse can occasionally "switch" into the simulation, or upload updates to her virtual personna, so she still can maintain contact to her mom, but you don't have to be with her all the time. [Answer] Create a virus, drop a tree on the powerline into the house on 'accident', plug USB drive into port while power is off. let virus do its work. For optimal misdirection, have the virus target her personality instead of just deleting her from the system. Make her a sweet grandmotherly person. Have the virus work in stages, first she quits complaining about you, and then it just slowly continues morphing her personality to someone you can more easily live with. Maybe end game she asks to be unplugged. [Answer] ## Become Amish The Amish don't use electricity for religious reasons. Your conversion has *nothing* to do you with you not liking your Mother-in-law, you just became a believer. [Answer] I believe first just go to some long vacations away from her. Possibly somewhere without electricity. Hopefully when you're back your spouse has already solved the problem, being unable to stand the quadrophonic version of her mom. If not, well, threaten divorce and prepare to live up to the threat, if mom doesn't move out. Afterwards, get a restraining order. And an EMP gun. [Answer] Bring the "Uploaded Rights Coalition" against her. If there are a bunch of people (both flesh and binary) fighting for the Uploaded rights as in the linked question, they would really be annoyed by your Mother-in-law behavior. She can be the bad apple that ruins all their efforts. Because she is abusing the cloudy legal status of the uploaded to harass you, she paints all the uploaded in a bad light. Suddenly she is no longer your own problem, but their problem as well. [Answer] Dear Serban Tanasa: Introduce her to [Gigolo Joe](http://www.imdb.com/character/ch0005244/?ref_=tt_cl_t5). Provide plenty of bandwidth so they can run away together. [Answer] This sounds like a bit of a shaggy dog so: Mental instability? Absence of cake? Hmm. Definitely look for job opportunities for her at [Aperture Science](http://www.aperturescience.com/). They do what they must, because, they can. Avoid exposure to poison gas controls or science experiment control. On a more serious note: Is the mother in law legally person? If not then they could be eliminated via an EMP. However your wife may still regard her as being a person or her hardware may have been hardened ahead of time anyway. Your wife would almost certainly fall out with her if her mother was present 24x7 - especially with potential upload induced dementia. What other tweaks to personality may be lurking beneath the innocent cake obsession? Could her behaviour further deteriorate if the upload wasn't completely perfect? Given that theres a alleged inverse relationship between distance to inlaws and divorce rate, having a heartless(literally!) mother in law in your home would prove dangerous to your marriage. This may be the right lever to use on your wife to get her mother to move out. [Answer] Buy a lot of candles, wine and a construction foam. Then find new electricity company, end old contract and fail making new one for a month. Foam all her speakers, cameras and drone and enjoy your honenymoon with your wife, wine and romantic candles, till new company restores electricity. Your Mother-in-law would had time to meditate in total (foam) isolation about infinity and wheather the new company would also switch up all circuts breakers or not, and how long her acupacks would last. [Answer] # legal options I think the question hangs on the legality of the annoying construct as a person. If she had to go to a different country to be uploaded, and specifically one like you describe the situation to be, then it implies that the mindloading is not legal in the bulk of the world. Having done that, and suppose the data is sent electronically or covertly out of that country, and the hardware that showed up at your home was sourced from normal in-country suppliers that deliver there. Perhaps some illegal work was still needed to install the mind and produce a functioning AI being in the hardware, so at least part of the equipment went *there* first, where the robot brain was completed, and then shipped to your home. The AI being probably has no legal standing as a person under this political climate. Or, perhaps it is more complex and there are some recognized rights given to such beings but it is illegal to create one or traffic in them. So, the place that sent you the stuff (the main unit housing the AI, anyway) is an illegal robot trafficking den. You should call the police, have the illegal equipment impounded to be traced back to its source. You might keep the speakers and other peripherals if they were shipped directly to you, or they might be taken as evidence. If the police don't do that and the AI once it exists is granted rights as a being (only the initial destructive scan was illegal and only the people doing it are criminals), it still has no right to compel you to let it stay in your home. Just like any squatter or unwanted house guest, you can show it to the curb, calling the police to escort it off the premises and file a restraining order. # personal relationships Your wife wants to continue having a friendly relationship with the AI that was her mother. That's no different than a flesh-and-blood person in terms of family dynamics. If anything, being an AI means that she doesn't require hospice care and doesn't *need* to stay with family, but can become independent. Her transformation freed her from the issues of the mortal flesh! Mom′ (Mom Prime) should go live on her own now that she's able to be independent again. After taking a long vacation and having mandatory counseling for the newly uploaded, she should settle into her new “life” by getting an apartment in a complex that caters to her kind, making new friends, and then spending quality time with your wife in **visits**. There will probably be support groups for family whose loved ones have been uploaded, and ways to get everyone into counseling to discuss the relationship by using the transition as a way in the door. [Answer] There must surely be a person previously in her life she would rather spend time with than you? If there is, you can find that person, and convince that person to upload themselves as well. If not, well, you can come up with something. Maybe you can program your own simulated person, or maybe even make a copy of your mother's program. Once you have a second uploaded person in your possession that can talk to your mother in law, take all your mother in-law's outputs and rewire them to the inputs of her new friend, and all her inputs their their outputs. Now you will no longer have to listen to her, and she will have somebody to interact with forever. What, it's all the latest wireless technology? You'll have a bit more work to do. Instead of rewiring actual wires, you'll have to re-route packets by changing the MAC addresses of your mother's peripherals and re-assigning them to protocol convertors which will forward them to her new friend and vice versa. [Answer] Fight fire with fire. Antagonize her back. That chocolate cake tastes sooooooo good, right? Too bad she can't ever taste it again. That new couch you bought *has* to be *the* most comfortable thing in the world. It's a shame she'll never get to enjoy it. Wear headphones all the time and blatantly ignore her. Get a cat to chase the drones everywhere they go. Blast music that you know she can't stand. Put a strip of tape across the middle of her holo projector so she appears cut in half or headless. Every time she escalates, you escalate. Hilarity will ensue. Strictly speaking it doesn't directly solve the problem, but if you do a good enough job maybe one day you'll "win" with one final epic prank and she'll realize she needs her own place again. [Answer] **Do the *Kirk*!** Yes, that's right. Now that your mother-in-law is uploaded into an IT system she has technically turned AI and [*induced self-destruction*](http://memory-alpha.wikia.com/wiki/Induced_self-destruction) should be applied. If you do not know how to *talk computers to death* re-watch *Star Trek - The Original Series* - probably not at home though. > > Several entities with artificial intelligence (like self-aware computers and androids) suffered from severe internal systems failures after they had been made aware of paradoxes or other dilemmas. Being guided by logic, these artificial intelligences were unable to cope with logically insoluble problems. > > > Captain James T. Kirk was quite adept at inducing self-destruction in artificial intelligences, or "talking computers to death." He achieved the feat at least four times. > > > [Answer] 1. Disable her I/O systems to isolate her in the system. Bonus points if you could "place" her in a bare room with minimal furniture. You could give the room a window to her Input systems, but only allow a very distorted version to be displayed. 2. Accelerated her time experience. For example: you could set it to something like 1:100000 (1 minute realtime for you, would be about 70 days simultime for her). 3. Re-establish contact through a channel and check if she still wants to be so involved. 4. Rinse a repeat until a satisfactory answer is received. Inspiration: [White Christmas](https://en.wikipedia.org/wiki/White_Christmas_(Black_Mirror)) [Answer] **Make her operate in the matrix** Hire yourself a CS engineer, and let him create a virtual machine to hold her software. You now have your mother-in-law in a virtual box, and can feed her inputs everything you can come up with. Instead of having her monitor your everyday life, you can feed her virtual sensors, cameras and microphones an instance of your Sims 3 savegame. Or an infinite loop of the finest HardDubstepCore the cool kids are listening to. In case your wife would like to talk to her, spoof the mother in law by using an AI such as Cleverbot. In case she suspects anything, pass off any weird behavior as the mother-in-law-3000 being defective. [Answer] The problem is not the mother but your spouse. Hack the mother in law and change her behaviour slowly. Something like a small change every week: **Week 1**: She's no longer complaining about you not doing things around the house. **Week 2**: She drops an appreciative comment about you. **Week 3**: She thinks that you lying on the couch after a day at work is needed rest. **Week 4**: She tells your spouse that preparing dinner for you and rubbing your feet every now and then would be a nice. ........... **Week 19**: She tells your spouse to serve you faithfully and declares that she's bored with living, time to unplug the machine. **Week 20**: You actually miss that version of your mother in law. *sniff, sniff...* ]

[Question] [ In the answers to [this question](https://worldbuilding.stackexchange.com/q/66139/28) I learned that some cephalopods communicate via [color](https://en.wikipedia.org/wiki/Cephalopod_intelligence#Communication): > > Some cephalopods are capable of rapid changes in skin color and pattern through nervous control of chromatophores.[8] This ability almost certainly evolved primarily for camouflage, but squid use color, patterns, and flashing to communicate with one another in various courtship rituals.[7] Caribbean reef squid can send one message via color patterns to a squid on their right, while they send another message to a squid on their left.[9][10] > > > That is super-cool. I'm developing an alien, intelligent, water-dwelling race that needs to reach a reasonably advanced level, by which I mean they understand science, technology, and abstract thought like philosophy. I'm leaning toward deriving them from cephalopods. As advanced creatures they'll need to communicate ideas that are linguistically more complex than mating proposals, "follow me to the food", and "extreme danger that way, 200 meters". Because they're water-dwelling, it seems unlikely that they would develop a written language to accompany this language. Therefore the idea of words composed of letters might not make sense (maybe they "chunk" at the word/concept level), and that's fine. Absent an accompanying written language, is it plausible that the cephalopod language could develop into something that can be used to discuss complex or abstract ideas? If not, what changes do I need to make to enable this level of communication? (Am I going to need a written language?) Part of me thinks that a language based on color, patterns, and flashing could easily be as advanced as a written language -- what are words but symbols on a page, after all, and is that so different from splotches on skin? Another part of me thinks that this sort of system might have more inherent limitations than, say, people typing at each other in real time in Slack. Perhaps an advanced cephalopod language is more like sign language than text. I don't know how people using sign language *who've never used a written language* communicate about philosophy or math. Having written this question, I only now realize the vague similarity to *The Story of Your Life*, in which a linguist cracks a very unusual "written" language by the "heptapods". I don't know how realistic that is, though. [Answer] ## Binary Consider how complex a computer is and what it is capable of, yet all its code is composed of almost the most rudimentary elements possible: zeros and ones (binary code). So, the computer software you and I are using right now to communicate is being transmitted to each other via binary and all languages the human race has ever developed have also been translated into binary. In addition, all philosophical texts, all mathematics of superstring theory, general relativity, all sciences, all humanities, all arts have been translated into binary formats that we access all day long while using digital devices. So, even just sequences of black and white blocks of colors on chromatophores are fully sufficient to display binary code. Think of the cephalopod skin as an LCD with a specific resolution, a set number of colors it can represent and also a size of the display. So their communication devices have a huge range of possibilities. I haven't found an easy way to convert chromatophore size into human DPI or screen resolution, but the cells are the size of single cells, so that is a pretty small unit and so I feel sure their skin is capable of 1080 resolution and a refresh rate certainly quick enough to change as quickly as the other entities read the whole message. So, they have a medium, their skin, that is capable of displaying complex patterns, characters or signs, as quickly as they can be read and the ability, technically speaking, of making as complex of signs as their intelligence and nervous system are capable of producing. So, I don't see any problems at all with extremely complex of data being transmitted via skin. ## Recording However, how do they remember it all? Do they record it in written form, or do they have savant level photographic memory skills? Squid at least have razor-sharp 'teeth' that ring the suckers found on some squid tentacles: [](https://i.stack.imgur.com/5wEWB.jpg) These could be used to inscribe very complex symbols on appropriate surfaces. In addition, [cephalopods are known for their tool use](https://www.google.com/search?q=cephalopod%20tool%20use&ie=UTF-8&oe=UTF-8&hl=en-us&client=safari), so they could use implements to carve or write on surfaces not appropriate for their tentacle rasps. This could be similar to [how dragons record their language](https://worldbuilding.stackexchange.com/questions/64767/dragon-script-writing-system-how-would-it-work). ## Opposable Thumbs vs. Tentacles I think a good case could be made for a bunch of long tentacles being comparable in nimbleness and manual dexderity to opposable thumbs. Since opposable thumbs have been hailed as one of the main reasons humans managed to outperform so many other species in tool use, perhaps if given enough incentive, cephalopods could begin to use their tentacles as effectively as we use our thumbs. [This mimic octopus has already mimicked legs](https://m.youtube.com/watch?v=t-LTWFnGmeg&t=1m15s) even though it's not obvious why--is it just for fun? Regardless, they seem quite capable of complex dexterity. ## Memorized Content in an Oral/Visual Only Language In ancient India, when Sanskrit was an oral language only, [pundits were still required to memorize the entire text ascribed to their family lineage](https://en.wikipedia.org/wiki/Vedic_chant#Oral_transmission). There were [four major texts of the Vedas](https://en.wikipedia.org/wiki/Vedas) and each was quite long. The [Rig Veda](https://en.wikipedia.org/wiki/Rigveda), for example, is a collection of 1,028 hymns and 10,600 verses, organized into ten books. All of that had to be memorized **verbatim**, as any deviation was considered a sin. There were even pundits who memorized all four vedas, earning them the title ["Chaturvedi", "Knower of the Four Vedas"](https://en.wikipedia.org/wiki/Chaturvedi). So, humans can memorize entire sets of books verbatim and so it is not unthinkable that cephalopods could do something similar if their language was visual only (instead of oral only, as it was in India.) ## Sign Language Also, some human sign language systems have two sets of symbols: one for the [letters of the alphabet](http://www.lifeprint.com/asl101/fingerspelling/images/abc1280x960.png), and one for [whole words](http://www.mayer-johnson.com/media/catalog/product/cache/1/image/600x/040ec09b1e35df139433887a97daa66f/f/1/f1mj422_02_1.jpg). In addition, some sign languages convey much of their content through [non-manual signs](https://en.wikipedia.org/wiki/Sign_language#Non-manual_signs). Postures or movements of the body, head, eyebrows, eyes, cheeks, and mouth are used in various combinations to show several categories of information, including lexical distinction, grammatical structure, adjectival or adverbial content, and discourse functions. In ASL (American Sign Language), some signs have required facial components that distinguish them from other signs. An example of this sort of lexical distinction is the sign translated 'not yet', which requires that the tongue touch the lower lip and that the head rotate from side to side, in addition to the manual part of the sign. Without these features it would be interpreted as 'late'. So, I assume similar analogs of symbolic communication could take place in cephalopods. In fact, they have even more appendages to work with than humans do, so perhaps their sign language could be even more robust than human sign language. Imagine combining tentacle positions, body posture and color changes in skin all coupled together into one very elaborate method of communication. [Answer] We actually use images to capture our speech for analysis [](https://i.stack.imgur.com/B3cRT.jpg) To make a spectrogram like one of these, we split out the higher frequencies from the lower frequencies. With this, we can see the way our vocal tract changes the sounds. On these images, it is clear how the different formats (peaks) shift from one frequency to another as part of speech. Thus, at a bare minimum, your race could simply have a streaming spectrogram running across their surface. Of course, one would expect the race to be more efficient with their space. If one looks at these, it is immediately clear that we're really only using one dimension. Your species would likely be able to adjust their colorings in two dimensions, [similar to that of a Cuttlefish](https://www.youtube.com/watch?v=L-cxg8mF_Lw). (and honestly, the question could end with the first 2 minutes of that video alone! Cuttlefish are amazing!) If I were designing a language based around such color schemes, **I would mostly focus on three things: size, spatial frequency, and temporal frequency.** Size would be a major factor in long distance communication. If the signal is too small, it simply cannot be seen from a distance. "Whispers" might be done using only a small part of the body, while "shouts" might involve vibrant colors across their entire body. Spatial frequency would also be very important. The viewers eyes have limited angular resolution. If your signal is too high frequency, the eyes fail to distinguish it. A message may contain several "layers" to it, some of which are easy to see low spatial frequencies while nuances appear in the higher frequencies. We can see this sort of thinking in JPEG compression, where images are broken up using the same spatial frequency system, and more bandwidth is given to correctly rendering the lower frequencies. JPEG actually breaks up an image into segments using the following patterns of 8 pixels: [](https://i.stack.imgur.com/voGUem.png) As you can see, the cells near the bottom right contain more detailed information than those on the top left. "Speech" done with high frequencies clearly requires you to be closer to the individual to "hear." Most of the content, however, is found in the low frequencies. You can see this clearly in this clever picture, which is more compressed on the left, and less compressed on the right. The effect in this picture would be similar to what would happen if one viewed a "speaker" from far away (left) vs closer (right) [](https://i.stack.imgur.com/SCjU0.png) The final question is temporal frequency, which is how fast you change your colors. Obviously the faster you change, the more information you can convey per second. However, it also calls for the listener to be paying more attention. If you were speaking to a crowd, you might rely on slower "speech" to ensure everyone has time to see what you are "saying." If you are one on one, you might speak quickly. Also, consider feedback. We tend to think of speech as a one way process. This is because of our biology. When we begin speaking, our vocal chords vibrate so loudly that we actually disengage our eardrum slightly, using 3 bones specially constructed for the purpose. As a result, other people are *actually* quieter in our ears while we are speaking. Also, it is hard to distinguish the sources of sounds, so our sounds overlap with others. An alien speaking with color would have no such issues (unless they speak using luminescent colors like glow sticks!). I would expect their language to naturally develop a sort of two way communication, where the listener is constantly responding to the speaker to let the speaker know that they are getting the full message. It might even evolve to be a full blown duplex communication! [Answer] Any medium for language should have the same capacity for expression as any other given an adequate encoding. Lets take 6 colours Red Yellow Green Cyan Blue Magenta (Of course these are human colours. Alien colour perception could be radically different and cephalopods, despite their colour changing skin, have monochromatic vision, although they can see polarization) That lets us make a base 6 place value number system. 2 base 6 digits is enough to represent all the letters needed to represent English. * A: RR * B: RY * C: RG * D: RC * E: RB * F: RM * G: YR * H: YY * I: YG * J: YC * K: YB * L: YM * M: GR * N: GY * O: GG * P: GC * Q: GB * R: GM * S: CR * T: CY * U: CG * V: CC * W: CB * X: CM * Y: BR * Z: BY For convenience lets use white (W) as a code pair separator to keep in sync and black (K) as a word separator and we can reasonably encode written English as a sequence of colours and therefore any concept expressible in English can be represented in a colour language. KYYWRBWYMWYMWGGKCBWGGWGMWYMWRCK Of course this isn't meant to be a *good* colour language. It's merely a demonstration that the medium of the language does not constrain its expressive power. We could re-encode any language into any linguistic medium this same way. [Answer] Given the complexity of colouration that cephalopods are capable of, one can easily imagine their language being vastly *more* complex than a spoken or written language. You'd begin with the obvious, basic ideas being expressed by broad tones or colours, as present-day cephalopods do. Red means I'm angry, white means I'm scared, etc. Simple nouns could be expressed with approximate representations of the object in question, and coupled with colour. White circle = I'm afraid of the ball. More complex ideas can be conveyed by symbolic language, just like our writing. Unlike our writing, the interactive nature of the medium gives you enormous flexibility. Motion gives you a whole new set of possibilities. You can indicate the direction of the noun, you can indicate tense with movement forward or backward, indicate urgency with speed of flashes...the possibilities are endless. A similar idea was explored by sci-fi author Ben Bova in *Jupiter*, and further developed in *Leviathans of Jupiter*. The novels posit a sentient species of massive organisms living in an ocean deep inside Jupiter, communicating with patterns of colour on their skins, and human attempts to communicate with them. [Answer] Bees communicate very complex ideas via dance, so why shouldn't a color based language, with flashes, shades, and more light capability (especially if they can see somewhat into the infrared and ultraviolet bands) be able to work? I mean, we have developed sign language and Morse code to create/represent words, so it's easy to imagine if you took "letters" and due to flashes, or even say a slight break in color (say black lines to separate colors) that words could easily be crafted in a single flash and strung together just as reliably as spoken word. It could also be relatively easy to even have hyper-complex languages with many symbols like an equivalent of Chinese or Japanese to be represented due to the wide range of available colors and thus, even if every letter was represented by a single color, you could very quickly string together words even faster than any expert at Morse code and convey just about anything. Basically, it'll have to be complex, like any language, and likely will have to mix "spelling" specific complex words out one letter at a time, whereas simpler ideas like emotions could have single color representations like, for example, a quick bright flash of red is the letter 'a' whereas a long flash is anger, etc, but I believe it could be done. [Answer] There is no reason why a color-based language could not be as expressive as any human language. ## Building blocks Every spoken language consists of a set of [phonemes](https://en.wikipedia.org/wiki/Phoneme), sounds that can be combined into words and sentences. [English has about 40 phonemes](https://en.wikipedia.org/wiki/Phoneme#Numbers_of_phonemes_in_different_languages), depending on how you count them, but some languages have [as few as 11](https://en.wikipedia.org/wiki/Rotokas_language). From these few sounds we make with our mouth, nose, and throat, we can construct hundreds of thousands of words to talk about everything from astrophysics to zoology. Phonemes themselves do not have any meaning; they only carry meaning once they are combined into words. So the expressive power of a language does not depend on the number of phonemes it has. At worst, having fewer phonemes just means that words will be longer. So, the colors of your cephalopods can be analogous to the mouth sounds of humans. Call them *chromemes* instead of phonemes. You can generate words by stringing several chromemes together through time, just like human languages string several phonemes together through time. Once you have a way of building words, add grammar and abstract thinking and you've got yourself a language. ## How important is written language? > > Absent an accompanying written language, is it plausible that the cephalopod language could develop into something that can be used to discuss complex or abstract ideas? > > > Your question seems to assume that written language is necessary for developing complex or abstract ideas. I don't think that's true. Ancient societies came up with plenty of complex and abstract ideas, passed on through spoken language, before they ever invented writing. [Stonehenge](https://en.wikipedia.org/wiki/Stonehenge#Function_and_construction) and other ancient monuments show detailed understanding of engineering and astronomy. [Oral tradition](https://en.wikipedia.org/wiki/Oral_tradition), as Thom Blair III mentions, can convey extremely lengthy stories, law codes, or sets of proverbs. Philosophical questions have been pondered by humans long before the advent of writing. Written language is certainly helpful. It allows the preservation and communication of concepts across long distances of space or time, increasing the cross-pollination of ideas. It's possible that we wouldn't have modern mathematics or science without writing. Or maybe it just would have taken longer. So if your cephalopods can develop a form of writing--a way to capture their speech in a more permanent medium--they will benefit. But whether they do or not, their color language will certainly have the power to express any ideas they come up with, no matter how complex. [Answer] # Abstract ideas such as philosophy Think about [logographic](https://en.wikipedia.org/wiki/Logogram) writing systems where each character has its own meaning, but you can combine them to create more advanced meanings. In such writing systems, the meaning of a word may be the sum of its characters - for example, you combine the characters for 'small' and 'man' to make the word 'boy'; you combine the characters for 'sword' and 'man' to make 'soldier'. You can apply this principle to your color-based language. Say that red means 'danger', green means 'food', blue means 'home', yellow means 'person'. Red-green might mean 'poison' or 'don't eat this'. Blue-green means the food you have stashed at home. Red-blue means something bad is happening at your house. Blue-yellow means 'family', but yellow-blue means 'friend'. Red-blue-yellow means 'invader'. Red-yellow-blue means 'enemy'. Green-yellow means 'glutton'. Red-green-yellow means 'wants to eat you'. As others have noted, you can take this much further by using shades, frequency, or other characteristics of how you display the colors in order to express greater meaning. Maybe a quick flash of yellow-blue means friend, but yellow that fades slowly into blue means 'lover'. You can see how a language built on a foundation as simple as a handful of colors representing different meanings could evolve into a mechanism for expressing complex or abstract ideas. # Complex scientific ideas **This topic is moot based on the criteria you gave in your question.** Knowledge of advanced science requires the use of tools and instruments. For example, for two of your creatures to have a conversation about hydrogen, they must have some method of examining or manipulating the elements that allowed them to discover hydrogen in the first place. If they are sufficiently advanced to create a working underwater chemistry set, creating an underwater writing system should be trivial. Humans' ability to communicate math with spoken language isn't limited by our vocabulary, but by our working memory and other limitations of the brain. Very few humans can do advanced mathematics in their heads; big breakthroughs in mathematics have always been made on paper or with tools. Unless their brains are far more advanced or otherwise work far differently than human minds, it is unreasonable to expect that these creatures would *need* to communicate advanced math using only colors. If their brains *are* different enough that they can do advanced math in their heads, they'd probably have a much easier time than you would coming up with a complex language for expressing math using only colors. [Answer] While the quoted example is extremely primitive, you are overlooking the possibility of shapes (glyphs) enhancing the language considerably. Tribes and extended family units could develop their own glyphs and grammar... creating complex diversity just like humans. For example, you could have a glyph for "individual", and the color shade gives more meaning including "male", "female", "relative", "mother", "father", etc. Including the possibility of representing something very complex with a single color: "my mother's father's oldest brother who is now deceased". As far as learning the symbols themselves, its probably not much different than a human toddler learning "mamma" and "dadda", as well as "nose" etc... its just that these aliens skip the auditory learning and go straight to literacy. While written language (outside of their bodies) would be more difficult especially in the aquatic environment, it would certainly be possible... starting with "crude" sculptures and eventually creating technology like our computer screens. Poetry would be both a "verbal" expression as well as fine art, and in fact their depth of visual artistry would probably exceed nearly all other alien species. Meanings behind the colors might be instinctual across the entire species, such as flashing red equals danger (fear), black equals anger, and a pinky glow is embarrassment, light blue equals agreement, etc. These emotions responses would affect the background of any glyphs and allow primitive communication across the entire species (trade language). If the color of the background is entirely subconscious, it could also prevent their culture from ever developing a concept of dishonesty. [Answer] You need to look at sign languages, which have non-linear elements and and have a somewhat tighter relationship between morphemes and phonemes than is found in spoken languages. If you were signing *the bus went past me*, you would make the sign for *bus* and then hold your hand in the “vehicle classifier” handshape, then with the other hand make the sign for *me* (probably pointing at yourself), then hold that hand in the “person classifier” handshape, then bring the vehicle past the person. (Example drawn from Irish Sign Language, of which I have slight knowledge.) The grammatical structure of the language is, as you can see, fundamentally non-linear: *goes past me* is all one action, made with two *classifiers* (handshapes which represent *categories* of objects (vehicles, people)), with the specific meanings of those classifiers (“bus”, “me”) established beforehand. (There is no indication of either tense or aspect in this little example, because I don’t know enough about ISL grammar to describe how they should be indicated; however, they are not necessary for my point.) Sign languages are perfectly capable of abstract expression, including philosophy and mathematics (inasmuch as any non-written language is capable of mathematics\*). In English, phonemes can have inherent meaning: *gl-* usually means something to do with sight, as in *glare*, *glint*, *gleam*, *glitter*, *glossy*, *glaze*, *glance*, *glimmer*, *glimpse*, and *glisten* (or not, as in *gladiator*, *glucose*, *glory*, *glycerine*, and *globe*).\*\* This sort of thing is usually obscure and not very obvious: most *phonemes* (sound units) in the language have no inherent meaning; *morphemes* (meaning units) tend to be multi-phonemic. In sign languages, the two tend to be closer: many morphemes are a single phoneme (hand shape, movement, touch, etc.). Iconicity (onomatopoeia) is to some extent a feature of all languages, sometimes quite abstract (see the [bouba/kikki effect](https://en.wikipedia.org/wiki/Bouba/kiki_effect)), and sometimes obvious (Wikipedia gives *hiccup*, *zoom*, *bang*, *beep*, *moo*, and *splash* as examples of [onomatopoeia](https://en.wikipedia.org/wiki/Onomatopoeia) in English). There is some evidence that sign languages have a higher degree of iconicity than spoken languages, but by no means is everything iconic. Signs that were once iconic can be simplified down to basic elements such that iconicity is no longer apparent. Or the sign for *light* may be based on holding a candle. Or the sign may not be iconic at all (in ISL, the sign for *day* involves putting one hand on the chest and moving the other hand (in the shape of a clenched fist) down past it). Plenty of discourse markers are given on the face: raised or furrowed eyebrows, for example, or puffed cheeks, or direction of eye-gaze. And these may be held over the full length of a phrase (providing further example that sign languages are less linear in nature than are spoken languages). --- So how can you build your cephalopod language? Celaphapods have tentacles that can move. They don't have hands that can form complex handshapes. That, then, is where the colour comes in. Colour may have a direct morphological meaning (red means anger, for example), but no doubt would also have more abstract meanings (perhaps red as an intensifier, or brighter hues as an intensifier), and direct meanings (red means red). Tentacles can move and gesture; colour can change during the course of a sign, or be held over the whole thing. Different tentacles can sign different concepts at the same time, and bring them together to show a relationship (as in my *the bus went past me* example from earlier). Colours on the body of the animal (either the whole body or in patches of colour, maybe even *moving* patches of colour), meanwhile, function in a manner roughly equivalent to movement of the face, head, and shoulders in sign languages, functioning mainly as discourse markers, intensifiers, and indicators of tone and emotion, though there is no reason why other grammatical features, such as tense, aspect, or [evidentiality](https://www.youtube.com/watch?v=QYlVJlmjLEc), could not also be indicated there. --- \* [Sign languages can be written](http://h2g2.com/edited_entry/A34088024), of course, but they often aren’t. \*\* Examples drawn from *An Introduction to Language* (6th Edition), by Victoria Fromkin & Robert Rodman. [Answer] **LOTS.** Let's forget for a second that we're talking about creatures, and just assume that our focus is Von Neumann machines. [Quoting Wikipedia](https://en.wikipedia.org/wiki/Intelligence), > > Intelligence [...] can be more generally described as the ability to perceive information, and to retain it as knowledge to be applied towards adaptive behaviors within an environment or context. > > > So higher intelligence would correspond to a higher capability in information perception and in cross-correlation in order to derive possible outcomes, and transcribe these as behaviors. Let's pick humans for example. Its units do show fairly decent processing capabilities, and stores information in both transient internal (as in, personal experiences) and permanent external (books, movies, oral tradition, etc.) memories. Now, for communication - here's some human bandwidth measurements: * Maximum book output: ~2141 bits/s ([World Championship Speed Reading Competition champion, Anne Jones, 4,700 words per minute with 67% comprehension](https://en.wikipedia.org/wiki/Speed_reading)) * Human vision: ~1.192 MiB ([with 1,000,000 ganglion cells, the human retina would transmit data at roughly the rate of an Ethernet connection, or 10 million bits per second](http://www.medgadget.com/2006/07/the_bandwidth_o.html)) (Assuming average word length in English (according to [Wolfram Alpha](http://www.wolframalpha.com/input/?i=average%20english%20word%20length)): **5**, ASCII representation of a single character: **8 bits**) So yes, books are very slow bandwidth, but hey, they work. So the answer to: > > [...] is it plausible that the cephalopod language could develop into something that can be used to discuss complex or abstract ideas? > > > Is *certainly*, if they possess the means to establish communication with enough bandwidth - and colors can encode a lot of information. Modern computers use at least 3 bytes, or 24 bits, to express a pixel using the RGB format. A 1024x768 screen needs 18.87 Mb of data to express all its pixels. That means around 940 megabits per second on a 20ms refresh cycle. > > [...] what changes do I need to make to enable this level of communication? (Am I going to need a written language?) > > > You'll need processing power: Your animal may be able to fuel a brain by burning a lot of energy in bursts (in which case oxygen and sulphur may be your friends), live very long lives, distribute the processing across peers or a combination of these. And if you're wondering about permanent external memory storage... how about a virus? Maybe a evolutionary hiccup in a virus allowed the cephalopod's memories to be transcribe to the virus' genetic payload. Every 'infected' member shares the whole species' ascending memories, and new 'infections' updates the individual payloads. The virus itself transcribes the memories back in unused spaces. That would help with information density. [Answer] I will approach this from a linguistic angle. First, I expect that you want a language capable of [abstract](https://en.wikipedia.org/wiki/Abstraction_(linguistics)) expressions. (words like "truth" "beauty" "disappointment" and the like) Abstract concepts are often derived from object-specific concepts, for example "adversity" from "opponent", and I assume you wouldn't want the same symbol to express both the objective and the abstract concept. This implies that whatever form of language that is used must have a near-infinite potential for new vocabulary. In the case of human spoken language, combinations of the couple dozens or so syllables are sufficient for the tens of thousands of vocabulary in an average human language. In the case of a colour language, one may replicate the structure by having a similar number of basic symbols, similar to the syllable of human spoken languages. Assuming you are basing your creature design on cephalopods, a basic symbol could be a certain arrangement of colours on the creatures' tentacles. For instance, a creature may have four arms specialized for displaying coloured messages, if there are 6 distinctly recognizable colours, this makes a total of 1296 different permutations, more than enough to construct an analogue of human language. (I believe that the colours used for any variation of the colour language will not span through the whole spectrum, rather, only a few regions, e.g. red, yellow, green, cyan, blue, magenta, will be used, because colour usage spanning across the whole spectrum may cause ambiguity for small variation in hue, while discrete intervals allows for better error-tolerance) In the particular case of colour languages, features of human language such as tone of voice, loudness and the like can be expressed by the saturation of the colours or small variation in the hue of the colour. For example, a creature may display a slightly yellowish shade of red to indicate the lack of commitment to what is being said. (similar to this: "A was friend with B, apparently", except without showing doubt by adding extra words.) In summary: permutations of colours displayed on different regions of the body form the equivalent of syllables, the combination of these "syllables" form words; discrete intervals in hue are used to avoid ambiguity; saturation, slight variation in hue etc. are analogous to human languages' tones of voice, accent and implicit messages. [Answer] **written celaphopodic language** My thoughts are relying to the concept, that one single image displayed on the skin (accompanied by movements) contains many information. * Therefore it doesn't need to be fast flashing of images like in Morse-Code. * Second their image and information procession skills respective their pattern recognition would be quite high evolved. * As sort of writing/storing these complex patterns plus their accompanied movements seems to be quite difficult (see the post about writing sign language) this might occur quite late in their development * therefore the memory skills will be quite elaborate maybe even be eidetic * if they have eidetic memory the use cases of stored language reduces **usecases of stored language** * information which is regarded to have high value for later generations in time scales where the conservation of information could not be guaranteed even by eidetic memory and high emotional/spiritual/religious affection * fast transport of information over vast distances * Instructions/manuals and calculations which enable later generations to still support complex structures or understand their basical calculations although the visual information chain breaks. This might apply to science about the "up there" (above water level) and the "down there" (deep sea) like deep sea industry using underwater volcanos, underwater mining facilities or complicated medicinal facilities (surgery, complex breeding techniques, genetic engeneering), etc. * minor important instructions for others which will arrive at your place while you are on your farm ("Welcome - feel yourself at home. Please don't forget to xy. I'll be around by tomorrow.") **Information transport** For information transport under water they won't necessarily need written/stored information. They would rather need to use another medium than light unless they can produce lasers. But it seems to be easier to use what is already existing in nature around them. * Whales and dolphins have elaborate sound capabilities which enable them to communicate complex information over large distances underwater. So it seems to be quite likely, that they either develop means to a) code their visual language into the sound capabilities of whales and b) alter the physiology or train those animals to function as a kind of "radio transmittors". Only problem will be that they need to develop a visual/sound translating device of some kind. **storing/writing visual information of higher value** * As they will likely alter their surroundings to fit their needs and develop some kind of architecture (which is definitely needed for under water mining facilities, deep sea volcano industry or medicinal facilities) plus thinking visually the thought of mosaics might be a near one to them. * They could use pearls, mother of pearls, shells, gems, etc. * Problem might be underwater growth, algae, shells, etc. which might cover these images after time making it hard to read, so it would be likely to put them under a cover like in a box, like a shrine which is only opened at certain occasions. * the mosaics could depict the actual visuals on their skin surrounded by signs for the movements * as this won't be everyday communication this might have some ritual (emotional, spiritual, religious) and/or artistic value **storing/writing visual information of everyday value** While I think that developing this would be quite unlikely there might be some ways of doing this. * s.o. mentioned the possibility of carving circles or half-circles into softer material using the "teeth" of their tentacles * so it should be possible to develop a complex alphabet similar to cuneiform script on this basis * this could likely be regarded being inferior to the mosaic approach, as it would need more space but done faster on the other hand * this would need a material which is soft enough to be carved without ruining the teeth on the long run, this might be a problem * maybe a more likely possibility especially for everyday notices while you are not around to tell directly would be a script build of knots on a series of ropes (which would be certainly developed for making nets to farm/control sea creatures) I think some first nation Americans used this style of writing if I am not mistaken. [Answer] I would imagine, using some kind of color grid, where you can have different combinations of colors to communicate a symbol. If used by a species with a highly developed photographic memory, it could be well beyond our written communication capabilities, as one image could communicate way more than one thousand words. You can even add encryption, redundancy and error correction to the "communication protocol". An example: <https://www.microsoft.com/en-us/research/project/high-capacity-color-barcodes-hccb/> As for transmission over non-visual links, I could imagine a hormone or protein or unicelular organism that acts as a messenger from one being to the other and contains the information encoded on its RNA. [Answer] > > Absent an accompanying written language, is it plausible that the cephalopod language could develop into something that can be used to discuss complex or abstract ideas? > > > You don't need written language to discuss complex or abstract ideas. You need written language to store the complex or abstract ideas so that others can access them and build more complex ideas on top of them. Color is as complex if not more complex than sound. Our written language is not more complex than our spoken language, merely more persistent. Consider the difficulties if someone had to read to you every book that you want to read. That's an oral tradition. Not having a storable language is more of an issue than color versus sound. Note that braille and Morse code are fully capable of expressing anything in our language. Yet both are essentially two state languages. Raised/smooth for braille and long/short for Morse (perhaps silence is a third state). It's not clear to me why they wouldn't be able to store language. Can't they just make little cephalopod statues as their equivalent of cave paintings? I'm struggling to understand why they wouldn't have a stored language. They already have the concept of a visual language. They just need to put the appearance on something other than themselves. A written language would seem more natural under those circumstances than under ours. I wonder if there is a cephalopod somewhere wondering if sapience could develop in creatures with purely sound-based language. How would such things learn to store sounds rather than a simpler visual language? [Answer] **The complexity of the language based on colour change should not be, ceteris paribus, too different from our audio-oral form of communication.** If there is going to be anything that makes is more or less complex, it is the intellect of the species. Consider your chromatic language - as others indicated in their answers, there are millions upon millions of shades that can be discerned by human eyes (let's forget now that their eye may be much more limited or much more evolved and that the underwater conditions will probably limit some colours) so it would allow for huge variety in possible colouring etc. **BUT** Human audio-oral communication uses similarly vast field of sound frequencies for communication and yet our languages are what they are and have typically around 30-40 phonemes (minimal distinctive units of sound). **Thus the problem is of the language forming is not the richness available but to the contrary, on its limiting and articulation.** **The principle of the language is to use *finite* means** (which our brains can encode and comprehend) **to express *infinite* meanings**. Thus we use frequency bands between some 20 to 20kHz, which we mix heavily into those 30-40 phonemes, from these we create several thousand morphemes, from which we create tens of thousands of words and infinite number of sentences. It would be very easy to expand on this and to think up of a system that would enable much richer form of language, one that is not so much confined by the parametres of linearity etc. but it is our brains that do not allow this. Probably also the biological limitations would not either because we still need to have these 30-40 phonemes whose realisations are unbelievably different if you take them only as individual tokens, i.e. the [a] sound pronounced by you in one sentence will look wildly different from the same sound in a different sentence pronounced by a person of different gender, age category and in different mood. Yet we are able to recognise this token from very minimal context and map it to a particular phoneme. Thus, if we ever hope to consider the colour changes communication to be a language, it would have to follow these same fundamental principles and if the neurology of the organism in question were not principally dissimilar from our, it would probably be subject to very similar type of limitations. [Answer] An other way to look at this : English has about 44 phonemes. Distinguishing between 44 different colors don't seem to be impossible isn't it? Japanese has around 21 different phonemes for exemple, and I think we could agree that japanese is a language rich enough to express whatever you want Here is a 21 colors palette : [](https://i.stack.imgur.com/V8Qnt.png) Now, imagine each one of these color is a sound... And I'm not even talking about patterns! [Answer] Most answers here involve the creatures using many different colors, but communication could be as simple as Morse Code. This could be done two different ways. They could have one color represent dots and dashes with a different base color acting as a break between the dots and dashes (eg. flash black for a dot and flash a little longer for a dash, using white in between dots and dashes to separate them.) A second possibility would be using three colors, just two colors. one for dots and one for dashes. This would make communication faster, as the color for dashes could be displayed for a shorter amount of time. A third possibility would be using the order of a certain number of colors used solely for communicatingThe Oxford English dictionary currently has about 170,000 full entries for words, but derivatives of words, such as plurals or adding suffixes, are not included in that. Let's assume, for this example, that there are 1,000,000 total words including derivatives. The creatures could have a defined set of 10 colors used for communication, and the order in which they display those colors would create the word. With 1,000,000 words and ten colors, no word would need to be more than 6 colors long! Adding one more letter would make there be 10,000,000 possible words. They could also have different colors used for endings, such as pluralizing a word or -ed and -ing. Depending on how much the creatures are able to control their skin color, an entire word could appear on the creature's body at one time, with each sixth of its body being a different color. [Answer] Humans have alphabets and written word. Our form is of communication is biased. Animals are more primal. The communication with like bees is more of an algorithm. In murky water you are not going to be able to distinguish very many discrete colors. Frequency could universally represent intensity. Hungry color flash slow or fast Danger color flash slow or fast Food color flash slow or fast and point with eyes ... [Answer] An educated Chinese can distinguish thousands of different patterns in only two colors in a space smaller than my little fingernail. Spoken, there are less than a thousand unique syllables. 'One spoken syllable can have many meanings. [Answer] There's no reason why a color-based communication method could not be much more expressive than a verbal one. In fact, there is no reason why such a method would even have to be representational or symbol based. A species that evolved to use such a communication method specifically might develop a completely different way of transmitting information. An example of such communication can be found in the intelligent seahorse-like beings of Kameshutak, commonly called the Kellies. (From an unpublished short story) > > The Kellies communicate almost exclusively visually, with very little > reliance on sound. They are able to use their skin to generate > bioluminescent patterns with great speed and precision. While this may > have originally been a camouflage mechanism, it has evolved into what > could be the most sophisticated form of communcation we have yet > encountered. > > > The Kellies communicate by creating patterns of colors and shapes on > their skin, but instead of creating visual patterns that represent > symbols or images, they create patterns of light and color which > stimulate the optical nerves of their fellows in such a way as to > directly create patterns of neural impulses in their brains. This > allows them to transmit thoughts and ideas directly in a way that > could be compared to telepathy, actual mind-to-mind communication. > > > One interesting aspect of the Kellies' communication method is that > the transmission of the visual impression and the experiencing of it > are not necessarily in sync chronologically. A single pattern lasting > for a second could cause an extensive series of mental experiences in > the viewers lasting a minute or more. In the words of exobiologist > Jerny Rozen, "The Kellee's [sic] communication resembles more the > exchange of deliberately induced epileptic seizures than a language as > we would call it." Rozen's quip is of course a drastic > oversimplification, but there's no doubt that a Kelly can with a > single flash of color and light transmit not merely information, but > an actual experience or memory. > > > Over countless generations, the Kellies have developed a shared > "vocabulary" of general concepts which are widely recognized. Within a > given region, more specialized concepts arise relevant to that area, > and within family units even more specific ideas are created, while > each individual has its own unique way of expressing those concepts. > > > Because their language primarily changes due to genetic drift and > mutation, rather than individual usage patterns, physical conditions > have a greater impact on communication than social behaviors do. When > an individual moves from one area to another, it takes a little time > to adjust its communcations to match the new locale, but because this > communication is based on the physical anatomy of the beings' eyes and > brains, the adoption of new patterns is much faster than it is for > verbal communicators. However there is a consequent decline in > facility with the original patterns. In a sense, the Kellies don't so > much learn new languages as they replace their old language with a new > one. > > > The language evolves much more slowly than we are used to, but there > is another consequence to their unusual system. While the Kellies can > rapidly adapt to minor changes which arise in different locations, > once the changes which appear begin to affect the most basic common > concepts, it becomes almost impossible for them to overcome the > problem. > > > This means that colonies which are genetically isolated for long > periods of time are effectively permanently cut off from the general > population in terms of communication, which is a sort of taboo in > their society. This taboo probably explains the annual diaspora-like > migrations of some young to different colonies. > > > Encounters with isolated groups which have lost the ability to > communicate with the mainstream populations can literally cause > insanity for both sides of the encounter. Therefore such isolated > groups are generally shunned and have in some cases been hunted down > and exterminated. Somewhat ironically, those isolated groups probably > consider the general population to be the deviants, and themselves to > be the holders of the true language. > > > ]

[Question] [ Following in the steps of the entrepreneur Elon Musk who created SpaceX (which creates rockets to get to space), an entrepreneur decides to build a space station for visitors. But instead of just a floating hotel above Earth, the entrepreneur wants it to be under a separate country so that he/she can declare its own laws, taxes, and even space station citizenship. To make things interesting, the entrepreneur wants this to be as much of a country as possible with its own elected president, court systems, and an army. Now, international law states that you cannot claim any part of space as your own, but you can claim man made objects. If you could claim man made objects, could you state that the "land" on the space station is its own country? If you can, how could things like citizenship work? Would other countries even recognize you as a country? If you can't, could there be any way to impose your own laws on your space station or is this just another entrepreneur's dream like the hyperloop? (I'm kidding) [Answer] **You can claim whatever you want.** Calling something a country is a generally pointless designation if it's unrecognized. However, he might have a significantly better chance of getting recognized than a typical seasteader. Elon has a lot of resources and might be able to rally enough engineers to design and build this space station. If he can then use it as an access point to the rest of the solar system, it will be very valuable to many nations of the Earth. If he was able to show that his station could be used as a launching point for regular travel to the Moon or Mars (which would be required for settlements there), then he has leverage in asking for the recognition (and therefore possible protection) of the Earth nations. [Answer] There are effectively no laws governing what a country is. That's one of the reasons why wars work. Essentially it's like claiming one of the common items as yours in kindergarten - if you do it right it can work, but it's tricky to do it right, and requires luck as well as skill. The small issue is getting recognized. Being a habitat which no existing country has a claim to, some countries will want to recognize the new country just so other countries can't easily claim it as their territory. Like in kindergarden, even if you succeed to claim an item, a classmate might break it out of spite. **Almost anyone can destroy the "country"** in space at a ridiculously small cost (~ [$60'000'000](http://edition.cnn.com/2008/TECH/02/15/spy.satellite/index.html)), without fear of repercussion. The recent incident of MH17 over the Ukraine shows that it's easy to dodge the guilt by playing the blame game. So whatever that new country does, it can't risk pissing someone off. A single disgruntled multi millionaire would have the means to take them out. And in all likelihood it wouldn't even be a crime under any jurisdiction, except for the one that didn't survive the attack. Edit: Thanks to Marc for providing the cost of the weapon. [Answer] **Yes you can but making such a claim stick is really hard** especially in space. Recognition of a young country only makes sense when it's politically/economically beneficial for a larger, more established country to do so. In essence, being a country means being admitted to a very exclusive club. Either you need to convince enough club members to admit you or find someway to break down the doors and force them to admit you. The former approach is preferable. Take the ISS. The astronauts there make a claim of statehood. The major space-fairing countries will likely not recognize such claims. Besides, they can just starve the astronauts into submission. Russia won't recognize the ISS as *Spaceland* unless Putin is feeling especially peevish and just wants to mess with the West (which can happen at any time). In order to force a space station to be considered its own country, they would have to have a means of defending themselves or creating a credible threat to the planet using any of the methods described in [this question](https://worldbuilding.stackexchange.com/questions/22499/whats-the-most-efficient-way-to-destroy-civilization-from-orbit/22501). They would also need to be self-sustaining so that earth bound countries can't starve them into submission or withhold required spare parts/fuel. ISS is very much a colony in space and not a country yet. It will take asteroid mining before a settlement in space can be considered independent enough to claim itself as a country. [Answer] What you describe would face similar problems to [Seasteading](https://en.wikipedia.org/wiki/Seasteading). Remember: if you are not subject to any nations laws you also lack their protection. What do you do if some country or some random businessman [decides to send mercenaries to take over your station?](https://en.wikipedia.org/w/index.php?title=Principality_of_Sealand) Your "country" might be recognized but then again it might get totally ignored. If you want to be recognized your country needs to be like a country in being able to defend itself and being economically powerful. [Answer] There is nothing specially needed to be a state. A state only exists because: * It has the military power to enforce its sovereignty. * It has allies that will enforce or not oppose its sovereignty. What this means is there is a way of achieving a state by getting political allies and/or by simply brute force. [Answer] As others have pointed out, claiming is easy, being recognized is hard. However, there is an alternative: Being ignored. I can see a future where this space station claims independence. Nobody recognizes it. Nobody sends ambassadors. But nobody is attacking them either. Politicians of most nations says "no comment" when asked about them. As long as they don't annoy somebody with the power to destroy them, this can go on a long time. At some point, nobody alive remembers a time when there was no space nation. And then, Earth nations start recognizing them. [Answer] The minimum requirement for a state is a judicature made enforceable by military or police.  So, some segment of your population is going to militarize, and the rest are going to either support or non-violently resist them.  This would also imply the ability also to successfully grant amnesty or sanctuary to an immigrant or refugee, (requiring an extradition treaty) or otherwise resist the infraction of another state's law enforcement.  A distinction should be made between a public body made sovereign by geographically or obfuscation, and a true state.  Anarchy, for example, is not simply a 'state of no state'.  Neither could the Caribbean pirate coves of the pre-revolutionary Americas, or some simple, self-organized collective.  A true state is the direct imposition of, or relief from, regulations and rights *by force*. You expose the subtly of semantics: how does the corporate charter differ from a state's statute; the executive board a government; the security branch a police force?  Traditionally, the distinction was made by the corporation's reliance on a state's ability to enforce law, however the advent of PMC blurs even this.  De facto, your SpaceX Hotel is already a state, a vassalage of the federal reserve, a subject of the world bank.  To be truly sovereign, de facto à jure, you would need to explain why these semantics become relevant enough to require legal clarification.  Was there a collapse of world markets?  Are the world markets *too* competitive?  Did a world-spanning conglomerate coerce the world's population into a robot-controlled dub-step party?  A state can enforce its own markets and exchanges, and this would be a likely reason only if there exists a tangible, liquidable intensive to divorce from the current corporate scheme.  And don't ignore the scorn and reprisal of creditors whose investment you've absolved by rebelling, unless you're willing to grant them a position of rank in this bright, new future. I can see two extreme cases between which this future is possible.  First, if the space hotel proves a bad investment, goes bankrupt, and is abandoned by anybody on earth who would otherwise care about the (organized?) bunch of radical squatters spouting nonsense about sovereignty and self-determination and whatnot.  Unassuming, at first, they produce a vivid art and culture capable of projecting their desires upon future generations, and, thus, earning itself a place of distinction (even if only footnoted) in the history books.  The alternative is a venture so massively successful they dominate the space market and buy out large portions of related industry sectors.  Here, they are likely to encounter resistance from other, competing corporations, irk the ire of regulatory organizations, and conflict with anti-trust and monopoly laws of several countries.  Statehood, than, would be a defense measure, the central corporation would 'evolve' into a government, and all the subsidiaries become separable corporate entities protected within.   This 'evolution' is not a 'revolution', as the sheer infeasibility of space combat validates will without force or threat of reprisal. Either way, their message to earth would be something like, “We don't need you.  We are free.  Deal with it.” [Answer] As other answers indicated, sovereignty is a question of recognition by other states. Prior to recognition, under what state's laws does the station operate? That state will claim it as their territory, and will need a significant reason to change position. States effectively form an exclusive club and need motivation to recognize a new member. Doing so might seem like a tactical convenience - once state might readily recognize a station as a state just to antagonize another. However, almost all existing states have a territorialist mentality. They therefore fear loss of their own territory due to secession. Such states will therefore think long and hard before setting a precedent. This is not to say that there are more enlightened states. Witness the democratic approach taken in the UK in the face of a key part of it, Scotland, almost seceding last year. So such a station needs to provide a strongly positive reason that creation of it as a state is useful to other states before it will be recognized. On the face of it, such reasons are likely to require trade benefits. This might be physical trade with solar system resources, or less likely as some kind of data haven/broker. The above is very much short to medium term thinking. In the long term, a de facto state might arise given changed circumstances on Earth. Suppose the station operations under laws of a country which subsequently ceases to exist. Suppose further that the station is able to then continue to operate and thrive for many subsequent years and is sufficiently strong as to be able to protect not just itself but its extra-station operations. Eventually it may be in a position to successfully declare sovereignty. [Answer] This is tangentially related to your question and I haven't seen it mentioned yet: the [Outer Space Treaty](https://en.wikipedia.org/wiki/Outer_Space_Treaty). Most nations on Earth are signatories to it, and among other things it forbids nations from claiming territory on celestial bodies. Of course it doesn't prevent people from proclaiming *new* nations in space, but I thought you might find it interesting nonetheless. Among other things it also forbids nations from placing weapons of mass destruction in orbit around Earth, or on the Moon. [Answer] **Highly unlikely due to fear of precedent** So, Elon Musk goes and creates a giant self sustainable space station/floating colony, lets call it "Musk-otopia". Musk-otopia comes with an adequately sized population and a star fleet that rivals most medium sized countries. The countries on earth that aren't threatened by this space power wouldn't want to recognize Musck-otopia for fear of setting a precedent that doesn't really scale overly that well. What are the requirements for becoming your own country? Is it based on number of people with citizenship (what about dual-citizenship?)? Number of space cruisers? Amount of food production? If they recognized Musk-otopia then before you know it, every man and his rocket will own a "space station" for the purposes of tax evasion and whatever else they couldn't achieve on earth. **Solution: Dependent State** If Musk-otopia becomes a country that is dependent on and subservient to a super power for everything except for some basic administration and political tasks (think USA's 51st state). From there Musk-otopia has to wait until the world develops more so people can get it into their head that Musk-otopians are a rather strange but nice people who make our vacations there a pleasurable experience. Through the change in perception and building of their own culture they can slowly start gaining more and more administrative and political independence as they have nothing in common with their land-based fellow states. This must continue until one day through either diplomatic or militarist means they can achieve proper independence. [Answer] **Absolutely!** All it takes to be your own country is the ability to prevent other people from stopping you from being your own country. This of course may mean a military capability to dissuade potential invaders. But it can also involve economic, cultural, and political clout as well. On a space station, if it wasn't self sufficient, it'd need trading partners on Earth. So if the nations of Earth stuck together and boycotted the new nation, it would be starved out quickly enough. On the other hand, the population of Earth might want to consider an important lesson from science fiction... never anger people in a higher orbit. Is trying to prevent the independence of a space station worth losing a couple cities over? This assumes other nations would even care. If the station was privately built, no one may object to what goes on in the station. They may be more than happy to not be responsible for the expensive venture. ]

[Question] [ On a planet similar to Earth, there is a society similar in technology to the society of ancient Greece. They believe in a single, all-powerful deity. This deity performs miracles on a regular basis. These are the common ones: * Intervening in battles on the side of the civilization in the form of a bearded warrior * Protecting the cities against strong storms by creating a giant transparent dome around them * Starting fires from nothing and having them move towards and engulf those he considers evil * Controlling the wind, and causing gales to come out of nowhere and then suddenly stop As you can see, the deity mainly focuses on accomplishing his goals by controlling the weather. He needs to come up with a good explanation for this, and the explanation needs to cover all four miracles, not just one. Furthermore, the deity needs to spread this logic, because he wants to see how many of his followers will believe in him even when faced with perfect logic. He can't just come out of the sky and say, "I don't exist." By that logic, he *does* exist, and so his plan is ruined. Q.E.D. The god would like to continue doing the miracles, would like there to be another explanation for them, convince about 95% of the people with about 95% conviction, and do it within about a year. It's a test; he won't force them. I'm not looking for actual explanations of the miracles, just a way to *spread* them. I considered that he could simply come down in disguise as a normal human, but the society is *really* religious. If he outright says it, he'll be burned at the stake as a heretic. How can he convince people that he doesn't exist? [Answer] **He needs to give his powers to the people.** > > That wasn't god, that was *Bob*! He can make a weather shield and he doesn't even go to temple! > > > If any one of the people (or perhaps only a select few skeptics) in the society can also perform the miracles then the need for the god will disappear. Once people realize that there doesn't need to be a god to create the miracles, it will be easier to entertain alternative reasons for the "true cause" of the miracles. You can imagine it like this, a weather shield appears apparently without cause, people say "it's god!". Now the weather shield appears whenever Tom wills it or Sally makes the wind blow when she wants it to and people will say "Ok, *how* did you do that?". It will probably be best to introduce it slowly, and require some practice for people to get it with any consistency (like wiggling their ears, we all have the muscles for it, but not everyone can do it without some practice). This way people can explain the sudden appearance as simply a lack of knowledge or skill before. Eventually it becomes so blasé that it's not even a miracle anymore. This removes god, but doesn't pin down a single natural cause for all the events. It makes the cause to be people. Clearly there can't be an actual natural cause for real supernatural events, but when it's regular humans performing these acts then it soon becomes as miraculous as whistling. The god can still perform the miracles and people will simply assume some other human is doing it. [Answer] I liked [Aify's answer of a robot](https://worldbuilding.stackexchange.com/a/20132): maybe a simpler mechanism that they can seem to understand, but here's my stab, for what it's worth: # Create an Animal The Greeks believed in heaps of imaginary creatures, from the pegasus to the cyclops. Although I can't find evidence of belief in 'dragons', I think it's time your God creates one, with the ability to breath fire, to flap its mighty wings for and against wind, and to swoop into battle on the 'good' side (however you like to define 'good'). After the first few times, there will be wondering why the dragon is now visible, so the dragon demonstrates that it not only can be invisible, but can take the shape of a man. After a year, it becomes ubiquitous knowledge that there is at least one dragon out there, and it seems to like the Greeks better than the Persians - or whatever. New phenomena throughout history, no matter how miraculous, becomes day-to-day pretty quickly. Look at wireless internet: while I think it's total witchcraft, we don't even think twice about it. [Answer] Find scientists or alchemists that would attribute the weather miracles to another non-god cause, and make miracles occur at the times and places that would support their theory. Also *don't* create miracles when & where the theists would expect them every time. For example, if a big storm is coming, and they expect the invisible dome to appear, *don't* create an invisible dome (if the storm isn't going to wipe out the people after all). [Answer] ## Get a prophet Actually, get two. Both are employed by this god that doesn't want to "exist" anymore. Have the "True-believer" prophet preach faith in God but ensure he has a really loud, annoying voice and a generally insufferable arrogant personality. Have the "No God" prophet be charismatic, ethical and very smart. Have TrueBeliever arrive first. Establish his authority by invoking the power of God and working mighty miracles. Anything TrueBeliever asks God to do, it gets done. People will overlook his grating personality because "he is God's chosen prophet!" NoGod won't be able to initially proclaim that there is no God because he'll be burned at the stake. However, he can start preaching a message that is very appealing in opposition to the annoying/oppressive drivel that TruBeliever is teaching. It will be easy for NoGod to gain adherents because he's teaching what is popular and people want to hear that. As the number of his followers grows, he'll be able to start teaching, in private, that there is no god. Eventually word of this heresy will get out but because NoGod is popular with people who will defend him, so he doesn't get burned. Explain the Burly Bearded Man as trick of the mind. Have NoGod say something like, "You saw him because you wanted to see him. You were in battle, about to die, but you were saved by someone who slightly resembled what the stories said. Who wouldn't want the honor of being saved by a God? If there was a God, I'd want to be saved by him too." He can explain the weather in terms of natural phenomena, not the actions of a God. Teaching the people about [confirmation bias](https://en.wikipedia.org/wiki/Confirmation_bias) will go a long way to opening up their minds and sewing doubt about the existence of God. People will ask themselves, "Do I believe in God because there is a God or just because I want there to be a God?" Naturally, NoGod and TrueBeliever will hate each other for lots of different reasons, if for no other reason than the differences in their personalities. This dislike will lead to open confrontations in the public market. Increase doubt in TrueBeliever by having him attempt to invoke a miracle then nothing happens. Not only will TrueBeliever be incredibly embarrassed but doubt will begin to grow in the believer's hearts. Have TrueBeliever challenge NoGod to the end-all, be-all challenge in the main market in two weeks time with the understanding that whoever loses the challenge has to openly acknowledge they were lying about God. Make that event *the* talk of the city. Everyone will be there. Repeat the challenge as many times as it takes to squash that last flicker of faith. The day of the challenge arrives. TrueBeliever has promised an awe-inspiring show of the power of God. NoGod makes no promises other than "it will be interesting". In front of cheering crowds, TrueBeliever and NoGod walk into the square. As God, don't do anything. Just let TrueBeliever fall on his face. His credibility will be shattered. NoGod need only offer a plausible explanation for the miracles that doesn't reference another god and the transition should be complete. There will be a few that still believe that the miracles are the result of God taking action but there won't be many and such beliefs will be extremely unpopular. The miracles can continue to happen but they won't be ascribed to God anymore. They just happen. Remember that human memory is extremely malleable. With a little massaging, you can turn it into whatever you want. [Answer] In a single generation? Probably not going to happen, if we're looking for a realistic total deconversion here. Give it a couple thousand years of silence, though, a dark age that destroys the paper trail necessary to verify the stories, a rising standard of living and education, and interactions with a society that doesn't share their religious views where they both have an incentive to play nice, and I think you might see it eventually fade away. Of course, it depends on the nature of the deity. What I describe would work in a [sys-admin in the sky](https://caveofman.files.wordpress.com/2012/06/architect-matrix.jpg) scenario. But if the deity exists within the same world as everyone else, that could make things more interesting. They'd have to find a way to escape detection for all that time, which could play into a ["What if God was one of us?"](http://tvtropes.org/pmwiki/pmwiki.php/Main/WhatIfGodWasOneOfUs) trope. And if the deity fails to escape detection, well, there's all that hard work and waiting gone down the tubes! [Answer] **Make Magic Into a Science** He can make someone (a meat puppet) wander down and say, "Hey, I've been helping you out all this time. I found these weird rocks, and if you arrange them in a certain way a bearded warrior -- who in no way looks like Chris Hemsworth -- appears and does battle. Do this another way and weird weather effects happen. I didn't come forward before and claim credit because I was still experimenting and, well, when you put the rocks in a skull and crossbones pattern it turns out that nasty things happen. Ask the last town. Or what's left of it." They might think it heresy, but, eventually, if people can reproduce the effects, I think they'd accept it. Lightning rods eventually went up on churches, blasphemous denial of God's wrath or not. Of course he (the god, not the meat puppet) has to keep up the charade forever, and sometimes come up with reasons behind the reasons. "Why do these rocks keep attracting each other? Oh, I'll just call it magnetism." Eventually, when they've developed relativity and quantum mechanics and decide that they don't always work together, the people will decide that's just *their* limited math and physics understanding, giving the god a bit more time to reconcile the two. [Answer] I don't know that what you are asking can actually be accomplished by anything other than generational change and even then it would take more than just time. If my neighbor Bob always makes great steaks for me and I see it happen...I believe that Bob makes great steaks...for good reason, I know it to be true. What you are asking is for me to forget what I know even though I know it to be true. It would be different if you were talking about something that was solely based on faith...you show a scientific solution and BAM, faith can plummet. But in your case, god does in fact exist, and whats more is the people have seen what he does on their behalf. There is **no** way to logic out of this situation when one of your premises is: **diety x exists and I have seen his miraculous works.** Short of mass amnesia or maybe faking his own death, that belief is not going to fade anytime soon no matter what sort of straw-man, slippery slope logical arguments are made. **Especially if the miracles continue to occur (by any means).** There are people (by some measures intelligent people) that have seen the science on climate change and yet don't believe it...on religious grounds. Belief is hard to kill. **TL:DR:** A lack of action combined with time is likely the only thing to eliminate belief/faith in your deity. *Perfect logic implies truth. You can't have a premise that contradicts a conclusion.* [Answer] The best plan is to make all these events commonplace. Bearded warriors can be seen hanging around town during peace time and behaving normally. Because they live with the good guys, it's only natural they will support them when there is a battle. Giant domes appear during good days as well as bad with no apparent logic. It's weird but just a natural phenomenon. Fires start up but don't engulf anyone most of the time. Gales start up and die all the time - that's just the local climate. [Answer] ## Build a secret shrine How about the god planting a shrine of some kind for the people to discover. the shrine would have texts that were 'left by an ancient civilisation' that is now extinct. They had uncovered some of the mysteries of the universe and when they died out their expert knowledge allowed them as spirits to control certain aspects of the real world. maybe explain in the texts some fake way of attaining these powers when you die, so people will start practising these methods instead of believing in a god. does this just shift the problem, or does this actually achieve your goal? [Answer] So if I understand correctly, this God has performed a bunch of miracles for his Greek-esque civilization, and now he wants to make them all think it wasn't him - or more specifically, that He 'doesn't exist'. --- Now my natural inclination is that he could create a set of logical rules by which his 'miracles' can be re-created by his people, and set up a group of people to re-create them, such that they can prove that all these miraculous events are re-producible by man, and thus proving he doesn't exist. Now, in today's society we have a large group of people like that called 'scientists', and to this day we've still got a lot of religion going around, so that's clearly not going to work, much less in the span of a year. --- Now, he could also set up a bunch of these miracles for a *rival* civilization, just for a year or so to 'test' his people. They would see 'God's Work' being done for the unfaithful, and no longer believe they were ever blessed by god, yes? Well...no, because then the unfaithful might start believing that God simply went onto their side, and if these 'miracles' worked often enough for them, there'd be very few of God's original faithful left to look at for test results. --- I would say the simplest way to test the strength of people's faith, and to convince them that God does not exist, is simply to set up *false* gods. There's a few ways to go about doing this: * Give some power to the people, posing as a False God, telling them individually that the Old God is fake, and that they are the True Gods of this world. * Set up a false temple, and begin performing wonders for this false god, so that the heretics will have something to back up their faith. * Do entirely different things as a God that are not related to the weather, or that are completely unexpected of the God that people have been writing about, to create the illusion of a second God, then after some people start following you, appear before them and declare yourself the 'One True God' while performing a miracle. Any or all of these would convince people that the "new" gods are the True Source Of Power in the universe, and that your original God never existed at all. --- Of course, why you would ever do any of this is a mystery to me. [Answer] # Make the people want to proof god isn't real *Disclaimer:* This idea is based on a quote from [Douglas Adams](https://en.wikipedia.org/wiki/Douglas_Adams)'s [The Hitchhiker's Guide to the Galaxy](https://en.wikipedia.org/wiki/The_Hitchhiker%27s_Guide_to_the_Galaxy) books. It's always easier to make others want to do what you want, in all situations in life. The best example for this trend is the whole business of [crowd funding](https://en.wikipedia.org/wiki/Crowdfunding), where you present your idea to people, get them excited about it and make them want to pay you to do it. An example of how Douglas Adams [did it](http://www.whysanity.net/monos/hikers.html) in one of his works: > > "I refuse to prove that I exist," says God, "for proof denies faith, and without faith I am nothing." > > "But," says Man, "The Babel fish is a dead giveaway, isn't it? It could not have evolved by chance. It proves you exist, and so therefore, by your own arguments, you don't. QED." > > "Oh dear," says God, "I hadn't thought of that," and promptly disappears in a puff of logic. > > "Oh, that was easy," says Man, and for an encore goes on to prove that black is white and gets himself killed on the next zebra crossing. > > > By giving the *Babel fish* (a parasite organism that feeds of brainwaves and as a byproduct excretes a translation of everything the host's ears hear, into the host's native language) to the people, he basically gives them something that undeniably proves his own existence. Now as religion (assuming the religion features a god) is built up on the fact that the existence of god *cannot* be proven but is *shown everywhere* in a way that still leaves room for speculation, and undeniable proof of god existing would be such a *crass contrast* and such an *obvious thing*, that man will immediately claim that it *cannot be proof of god's existence* and hence god proved that he/she does not exist for man. --- To address all the points mentioned: ### Current miracles All the *current miracles* are *intangible*, your god does never give his followers anything really physical that undeniably proves his existence. We can build on that by either giving them something physical that is so undeniably a proof of god's interference, that the believers will henceforth decide that it can impossibly be a proof of god's existence as it clearly *does not* fit his *established style*, still they cannot explain it with any of their established science, etc. - making them start to doubt/think ### Weather By stopping to perform *weather wonders* or even by starting to let through some bad weather / direct it at his followers, they would instantly become wary about these changes - they would clearly indicate his presence, so bad idea Instead he could further feed their doubts by making the previously mentioned *physical proof* a thing that controls weather up to a certain extent (e.g. bundles heat on a spot, and other things) ### Spreading Naturally news about such a discovery (*physical proof*/*scientifically impossible machine*) will spread by themselves along trading routes, etc. So there is no real need to artificially spread it faster ### Appearing as a person As your last paragraph mentions, he could simply appear as a normal human and claim to be god. He would be burned and hence not exist anymore - problem solved (but without any explanations) [Answer] It's commonly said that magic (spells, miracles, etc.) is merely science we don't understand yet. The only way you can truly unmask a god is to show ordinary people how to become that god. Simply giving them godly powers isn't enough - they have to understand the source of those powers and how they work. They have to see that there is a logical connection between those powers and the way the world as they understand it works. In my mind, this is why religion will always exist: as long as something remains unexplained (and even long after an explanation is found, until it becomes common knowledge), at least some people will assume a higher power is responsible for it. It doesn't matter if you make them forget about their god, or get them accustomed to being unable to explain the things that happen around them, or give them any degree of control over the unexplained. Humans naturally seek to understand everything about their world, and some satisfy their lack of understanding by believing the things they don't understand are beyond comprehension because they are part of a power operating beyond their own limitations. Note: I don't intend to discredit religion or imply superiority of any particular mindset. Let me know if you find this answer offensive in any way and we'll try to rephrase it accordingly. [Answer] Make the world seeming an **illusion**. If you convince people they are not really seeing the real world but just an illusion, then they could accept everything happening without attributing it to a god (but just to the illusion mechanism). The same happens in Matrix, Neo can't change things inside matrix until he understand that everything is an illusion and he need to change himself to make things happens. A modern way to achieve that would be suddenly replace mountains or buildings with holographic projections with jitter and a message box saying "error loading this building, contact maintainer" (Lol, just thinked about a night sky with a "blue screen" in progress XD). People could believe is living inside a computer simulation, so anything happening could just have no sense. The important part is to make such things "random" with no clear intent, so that people could exclude a divine design. In a certain way, **randomness** of certain physical phenomena could be a way for a real God to tell us "toss away the God concept a go deeper". I remember Einstein sad something like "I don't think god play dices" about *eisenberg indeterminism*. It could be possible indeterminism is itself a God design, or simply something we can't fully observe and hence appear as "random": In example a computer program can't observe and predict its own execution (what will be the content of a particular memory location? Undecideable problem, appear as random from within the program, and undecideable from external observer) Returning to illusion stuff.. Of course if you meet someone teaching you about a Fake World this does not necessarily means he's some god trying to convince you that god does not exists: I'm not a god and I'm not trying to convince anyone that god does not exist but I came with this idea (well in reality it is not a mine idea, some cults use the same concept of Fake World to make proselytes, and I doubt they created the concept, in fact who study philosophy know Greeks first thinked to such stuff of abstract world, there's really a lot about the topic, I can't afford to go deeper on such question.) Another thing a God would leave is **free will**, a god will not give any visible reward or punishment for any action because that would make appear a divine design and hence people would suspect the existence of god. Anything that is against **free will** will probably be something opposite to a such God, so slavery, mind control (and in a certain way also money). In example if a priests says "God exists and you must do *something* for him" you will both start believing in it and lose the free will at same time. however since the God you are examining want to continue making miracles, I think making believing the world is an illusion is a good bet, and he also must be sure that such miracles appear as random. How could he achieve that.. mm In example making suddenly some ocean or land end and starting becoming written paper, so people think to be part of a book or a scroll. [Answer] Assuming a similar level of technological advancement (Actually, higher than our current technology), He could just build a giant robot and pass it off as a mythical creature. **Step 1: Make robot** This robot must have removable casing, such that all the people can see that it is actually a robot (eg: they can see wires and everything). Include a nuclear power plant inside to power this thing. This robot gets seen in the sky, and has giant fans somewhere on its body that can produce winds. Of course, this means it can fly. Perhaps once every week, someone reports a giant robot moving clouds, or performing x miracle. It looks like a bearded warrior. It has flamethrowers somewhere, and lasers and nanomachines to start fires with as well. It may require some camo capabilities. Cut like diamond, perhaps, to avoid radar. Since it usually stays in the sky, it can probably stay inside a cloud or something to hide. I assume that the giant transparent dome can't actually be detected/seen/felt since it's transparent - the people just see that the weather doesn't reach them. As such, perhaps this robot can deploy nanomachines that move and surround the area in a dome shape, and eliminate/redirect incoming weather as required. Eg: Rain molecules are evaporated as soon as they reach the nanomachines, so the rain doesn't fall into the city, or the nanomachines act as lightning rods to redirect lightning away from the city, etc etc. There is no pilot. There is simple software source code that can be accessed such that the people can see exactly how this robot works. Perhaps on the very last day of the year, the robot comes down to pay its respects to its creator, and this is the chance for the people to study it and say "What the sonovaholyrobot!" After that day, the robot can fly back into the air and rarely be seen again. It just needs to show itself once in a while, and god can continue performing said miracles. Of course, if it's passed off as a mythical creature, when the technology level gets high enough, they'll eventually realize it's robot. **Step 2: Disassociate from god** Create a dead body and grave and burial and stuff somewhere. Attribute the creation of this giant thing to this person. Now, everyone thinks the robot was built by him, and even though he's dead, the robot remains functional. Perhaps it was programmed to show itself to the people once a year. TL;DR: Make a robot to pass off as mythical creature in ancient times, and wait for science to do its work. [Answer] In one year? Not likely. Those miracles are very blatant and if they are going to continue, then everyone would have to be an idiot not to believe. However, the first step, with the miracles continuing would be to create technology that does the miracle and can be controlled by someone, not the clergy, or they would have even stronger reason to hold on to the beliefs. The technology doesn't actually have to do anything, but at least appear to do so at the control of people. Of course the simplest way to get everyone to forget the deity is for the deity to wipe the minds and change their knowledge/beliefs. Otherwise, lots of time with no new miracles would be needed and a strong scientific society, maybe by urging science and logic they would lose belief slowly. [Answer] # The Super Hero Make a "Super Hero" reveal himself to the world. It was always him to save the day, not god! I think it works better if he's a "gadget" hero (like Batman or Ironman) so to attribute the "miracles" to technology rather than super-power (as these could be interpreted as god-given). The Super Hero would look like the bearded warrior. [Answer] **Goodbye World!** A moment's revelation puts God in the picture, and takes him out. *Hello, all. I am the spirit in the sky. I have been doing nice things for you for a long time. Well, I'm tired, and unfathomably old, and I'm leaving. Thanks for all the sacrifices, they were tasty. I'm not abandoning you, though. I'm leaving behind a couple of friends to help you out. They'll be taking on my role. Goodbye.* -Massive exploding sound accompanied by nice pyrotechnics in the sky.- Granted, with God "dead", there might be a little bit of mass suicide, but hey. [Answer] ## Do terrible things You want this done in a year? You're going to have to get your hands dirty. The quickest and most reliable way I'm aware of to make someone question their faith is for them to suffer horribly. These acts you've been doing to support them all these years... use them to hurt your followers to make it seem random and unfair. They'll soon set about looking for explanations that don't involve an insecure deity wanting to test their commitment. [Answer] * Your god wants this to be a test, then **Make it a Test**. 95% of people with 95% certainty gives us a little bit of wiggle room. We are going to lean on that, hard. Also, we should blame the boojum (it will make sense later). So, pick a semi-plausible explanation. It can include any of the other answers, it can be something else entirely - *this* answer is about method. I'm partial to the idea that some kind of low level reality-warping ability in the population - the weather shifts, the fires come, the shield manifests, maybe the warrior comes - because people believe it does, and if enough people believe with enough power, the low-level ability from each person works together to manifest it. Those particular usages are often seen because people believe them, heard of them in stories, and as they manifest, more people believe - so they show up all the time. Anyway, your god now has an explanation in hand. * Now, to make people believe it, **subvert your leaders**. Pick your most influential religious leaders, your top political leaders, your little local pillars of the community known for being the most faithful and devoted followers - not more than 1% of your total population of each, maybe aim for just under 2-2.5% total instead, since you want to keep as much wiggle room as you really can. You are ranking people by how many others look up to them, how faithful and devout they are perceived by the community, how influential they are. Have your god go to them - yes, this means they won't disbelieve in him, but if your god chose wisely, they wouldn't have anyway - have your god go to them and set them each a test of personal devotion: that they must not publicly support your god for a year, even publicly deny him. They may not explain or discuss their reasons until the year is up. If your god wants to be a little more sympathetic, would not like to be seen as insecure, or would like to eventually be worshiped again, have him *blame the boojum*. * Step three in your plan, **have the "explanation" discovered** So, your god has set a test for just under 2, or 2.5, or even 3% of your society. The reason for "just under" your chosen percentage, is so that you can grab some scientists. You will need only a few, but want more than a handful - preferably widely spread, well respected, and quite devoted. They need to be convinced of your theory, so that it can spread and be believed by your general population. Come up with a few tests that "prove" your original explanation, like a psychology test ends up letting groups of people recreate the manifestations if they believe hard enough, or certain rituals will let someone control the weather, or these special rocks will let one influence the fire, or whatever proof your god came up with to fit the explanation. Some of your scientists (up to the percentage) will be lead to the experiments first (by influence direct or indirect, maybe lean on your leaders and priests), others will need direct visitation. A number of top scientists "discovering" the phenomenon "independently" will give it legitimacy - especially if some are reacting in genuine horror at the implications. It's important that the test, whatever it is, is *actually reproducible*, at least for your one year, as that will be the "proof". Remember to *blame the boojum*, your scientists will be a lot less forgiving of a deliberate crisis of faith if they don't think there's a reason! * Your primed percentage will now **Stir the Pot** Scientists declare breaking news, warn the town criers! The scientists start spreading the news about the test, and its possible religious implications - some in horror, some in denial, and some - because their beloved god asked it of them. The ordinary people look to their religious leadership for a response, for acceptance or rejection of this test and its implications. The top ranks, and the most devout and influential - *are silent*. The political leadership as well. All the top ranks of the people most likely to decry the implications are silent, and some even go so far as to deny your god, or reject him publicly! Your common people are shocked and appalled! What the *hex-and-a-quarter* is this! It seems to them like even, or especially, the most religious people have had their faith shaken or even broken by this test. Laymen look to their priests, priests look to their leaders, communities look to their local faithful, and they make no effort to encourage or support faith in your god, or even talk about the reasons why not (which looks like personal crisis from the outside). Individuals might have laughed of the test, or failed to believe its implications, or just not cared - but this apparent crumbling of the most steadfast, of those they look up to and who inspire them, will shake their own faith, and *fast*. * As people's faith is shaken, **Watch for Resistance** The lack of leadership will do a *lot* to shake people's faith, but it is, after all, only two or three percent of your total population at most. Some will be convinced by the test, some more convinced by proxy - but in a population of devout believers, you will be seeing push-back fairly soon, as those devout individuals who remain start trying to rally people's beliefs back to the faith. So your god will need to wait, and watch, and look for focal people and places of resistance. Your god will want a budget - for the *whole* year, mind - of no more than 1% of the population (this brings your total up to 3-4%, if you're mathing). Knots of resistance can be identified, and their development monitored, by your god and/or those followers in the know. After they have had some time to brew, the better to polarize people - you god will pick among the top leaders (looking for the minimum of those whose faith is the most trusted and leaned on), and repeat the first trick - visitation from the god they are so devoted to, asking them not to support him publicly at this time, as a test of faith - because of the boojum, of course. The loss of the top people (and again, the most trusted rather than the official leaders) will undermine the resisting group a *lot* - and being let down or betrayed again and again will badly shake up the faith of those who do still believe, as those who seemed to have the most personal faith seem to loose it, have breakdowns, and denounce their god and previous faith. * Now, **WAIT**. You have a year of this - and you want people to have as much time as possible, to react to each wave of defections, the better to seriously shake their faith. You want to minimize the number of people your god visits, too - you will want as much wiggle room as you can for people who won't lose faith naturally, and you have already shaved that thin with your visitation people. Honestly, I would be surprised if you couldn't get a pretty decent majority seriously doubting the god, with shenanigans like this, and perhaps your 95% will be willing to profess disbelief by the time your year is over. Maybe that's enough, maybe not - but it is about all I've got. * Ah, wait-a-sec. This was a **Test of Faith**, remember? So, go back to your 3-4%. Your god talked to them at the beginning of the year, recall, and not only asked them to not support or deny him publicly, but also not to speak of their reasons why - without telling most of them what else was going to be happening this year. Why does it matter? because this is *also* a test of faith - a fairly good one. These are people who believe, and strongly (your god picked them out of the people who probably would not turn away, recall) - and they have seen their society *crumble* around them while they had to remain silent. They will be looking at the societal crisis of faith, and thinking what they would have, should be, could be doing to support their students, and friends, and mentors - to *do their jobs*. To *help their people*. It will be very tempting for these people to give in, or give up, and explain to people why they have been silent - that they didn't falter in their belief in the god. Those who manage to keep faith, and follow your god's instructions even when it must have seemed to them as if the end of the world, have passed a pretty strict test even if it isn't the *same* one. Those who gave in and spoke up, have failed - even though they are professing their faith in the god, they didn't *have* faith that his instructions were the right path. If your god is willing to accept this alternate, backwards test-of-faith, then between the extra percentages now passing the test, and the extra percentages of wiggle room for those who can't be convinced, I think your society now has a good chance of hitting that 95% population with 95% certainty. * And now, the **Boojum** Recall I said back in the beginning, to blame the boojum? Well, you god will look pretty insecure, and possibly cruel, if he's testing people, and shaking their faith, frightening them, and upending their society just for a test. So he can blame the boojum instead. It doesn't matter what the boojum is, or what it does, or even *if* it is explained or not - ever. The point is, he can say the test has to happen, and it has to happen now, because of the boojum. He can say, afterwards, that it was necessary for 95% of the population to not believe in the god at the end of the year, or a specific date, to prevent...something... from happening, because of the boojum (if that *was* achieved). He can say it was important for the whole society's faith to be tested during the year, whatever the actual result, because of the boojum. He can say just the leaders' faith (the percentage people) needed to be tested, and the "test results" happened to happen at the same time as *that* test - because of the boojum. The boojum can be an actual explanation he has - or he can just say it is an inscrutable godly thing, that can't be explained. All people need to know is that they're safe, the god's testing/meddling/whatever protected them from the dangerous boojum-thing. So they won't blame *him* for the Great Crisis of Faith, or for the social unrest, or all of the trouble and fear during the year. So he can have people believe again, by having the percent-people announce their year-long test of faith (and the bargain), and perhaps appearing himself, to explain what happened and why (because of the *boojum*, weren't you listening), without sounding insecure. So he can meddle again, and not have to uphold the illusion of whatever explanation he concocted (which might have been annoying, being at the back and call of scientists instead of meddling freely). [Answer] **Pay no attention to the man behind the curtain!** Except in this case, Oz is actually real. Set up a skilled con man as a front. He doesn't have the ability to do actual miracles, but he is skilled in creating the appearance of miracles. His attempts to credit all such miracles to a higher power (ie, You) are significantly less successful. So everyone is amazed by his performance, but are completely convinced that he is simply taking credit for natural occurrences, or using tricks or misdirection to accomplish his feats. So essentially, David Copperfield being a prophet. [Answer] To get away with murder, one must destroy all evidence at the scene of the crime. sooooooooo... He must destroy the civilization or the universe or both. In short, that god must destroy all evidence of his existence. That is anything he has done or he must destroy all of the witnesses. a good choice is to destroy all the witnesses and therefor get rid of the whole civilization like it were Atlantis. Certainly he would have a lot of tools such as huge volcanoes , mile high tidal waves, concentrated meteor showers, plagues and so on. In any given civilization there always seems to be at least some who seem to believe there is something outside the "matrix" of their civilization that they live in. Unless he gets rid of all such people, he can't get rid of the knowledge in question. The nub of the problem is the people who want such knowledge. Scientist have proposed that there is a "god" gene and that there is also a "criminal" gene that causes people to enrich themselves at the expense of others. if he kills off all the people with the god gene he would have a civilization of dominant criminals gene ... some rich and some poor. the poor ones would be the ones less skillful at taking from others. But then he would have the problem re-occur when more humans with the genetically defective god gene being born in the future. So just killing off the god gene persons would not work if humans with the "recessive" god gene were to be born in the future. This may suggest yet another way that complete self-destruction of a civilization could be accomplished: by introduction of a mere idea - social justice (where the poor rise up and kill all the rich). Then after their revolution, the poor find that their leaders take from them and become the rich at the expense of the poor. So, Have another revolution and another until the civilization gets so weak that the neighboring civilization just walks in and kills everyone. A divine comedy. ]

[Question] [ The sun inexplicably ceases to give light. It's still there and continues to have a gravitational pull keeping us in orbit. The solar system continues to operate as normal, but the sun has gone dark and ceases to provide us with light or energy. Could humans, with sufficiently advanced technology, find a way to survive in this new world? [Answer] **It would be brutally difficult** So the difficulty is the sheer magnitude of how much energy the sun applies to the Earth. It's an astonishing 1–1.5kW/m2! More energy hits the roof of your house every day than it would take to power your entire neighborhood if fully harnessed (solar cells aren't quite that awesome yet). I turn to my favorite chart in the world, Wikipedia's [comparison of energy levels by orders of magnitude](http://en.wikipedia.org/wiki/Orders_of_magnitude_%28energy%29): * $3.9×10^{22} \text{J}$ - estimated energy contained in the world's fossil fuel reserves as of 2010 * $2.2×10^{23} \text{J}$ - total global uranium-238 resources using fast reactor technology * $5.5×10^{24}\text{J}$ - total energy from the Sun that strikes the face of the Earth each year While this isn't the end of the story, this should point out an important reality: The entire fossil fuel and fission energy reserves of the Earth account for roughly a month's energy from the Sun. **Something is going to have to give.** Truth be told, we don't need the energy from the Sun. We can be more efficient if we explore extreme technological solutions. However, nature is rather dependent on this abundant energy source. **Any solution we come up with is going to have to be purely synthetic, with little to no help from nature.** **Extreme cheating** * $5.4×10^{41}\text{J}$ - theoretical total mass-energy of the Earth Okay, look. If we go to the ultimate in extreme tech, and manage to convert mass directly into energy, we're pretty unaffected. Even the fusion of the sun cannot match the efficiency we would get here. Just Uzbekistan's share of the planet would be enough to keep us going for a long time ($448 978 \text{km}^2$ = 0.088% of the surface of earth = $4.7×10^{38}\text{J}$ = 86,000,000,000,000 years worth of sunlight energy). In fact, we'd probably immediately send interplanetary dumptrucks to the dead sun to harvest its hydrogen and helium for energy! **Less cheating** If we could do fusion ourselves, rather than relying on the sun, the Deuterium in the ocean contains $1.5×10^{31}\text{J}$ of energy. That's just over 2.7 million years of energy. Of course, like the extreme cheating case, we'd probably eventually send dumptrucks to harvest unfused hydrogen from the sun. It just wouldn't be quite as extremely efficient as if we had perfect matter conversion. **Even less cheating** * $3.8×10^{28}\text{J}$ - kinetic energy of the Moon in its orbit around the Earth (counting only its velocity relative to the Earth) If we were to build a giant space generator with massive electromagnets on the moon, we could slowly bleed off its kinetic energy, giving us just shy of 7000 years worth of sunlight's energy. **Not so much cheating** Bollocks. Okay, so what if we can't get huge amounts of energy to work with? What can we do? The biggest issue is going to be heat generation. Humans really don't function well in ultra-cold settings, and neither do our food sources. As a lower threshold, let's target freezing. Any colder than that, and hydroponics becomes difficult (we're going to become herbivores really quickly). Earth is going to become a frigid ball very quickly. We're going to need to effectively create a solar blanket to keep from radiating ourselves into a cold hell. Doing this with an atmosphere as chaotic as Earth's will be hard; we'll probably have to take a jaunt to the moon, where we could create an atmosphere within a solar-blanket envelope. Done right, with several layers, and we might be able to avoid freezing. Now for our energy needs. The average terrestrial human in 2008 [uses](http://en.wikipedia.org/wiki/World_energy_consumption) $7.7×10^{13}\text{J}$, plus $3×10^{6}\text{J}$ worth of calories. Even with inefficiencies, the calorie intake is of minimal importance. However, the cost of getting fuel is going to be going up. The oceans will freeze, so we can't do underwater drilling. We're going to be dependent on the energy sources we can find (and can send up to the moon, where we stand a chance of not freezing to death). In all, its a miserable existence, waiting to slowly freeze. We'd probably make it, because humans are extremely resilient. However, the cost of all the depression counseling will be sky high! [Answer] This would be survivable for a small number of humans with not much more technology than we currently have. You'd need to go down, far enough under the planet to get insulation and maybe geothermal heating. Use geothermal energy and/or fission reactors to provide light and grow plants in massive underground hydroponics chambers. The good news is that actually there are plenty of resources available, if oxygen is running low just send some robots up, scoop some up that will by lying on the surface, bring it inside, and melt it. Life would be hard, cramped, and poor. Space and energy would both be at a premium. It would also be vulnerable, one earthquake could end everything. It would provide a seed from which to expand out slowly and where further scientific advances could be made though. We could survive for thousands, maybe even millions, of years this way before the earth's core lost all its heat. We wouldn't be the only survivors either as the deep oceans, especially near hydrothermal vents, would remain viable for a long time. [Answer] **Most likely not.** With our current level of technology, we could not survive such an event. We would need to provide light for getting around and to grow all of our food. We would also have to somehow keep ourselves, drinkable water, and the *atmosphere* from freezing. With a significant amount of warning and some better technology than we have now, a very small group of people may be able to survive, perhaps even a few decades, in a bunker deep underground. If they built it to be sustained by the Earth's internal heat. It's unlikely they could survive very long though. They would eventually run out of a crucial supply or need a replacement part that required a global society to manufacture. It would be a dark time for humanity, literally and figuratively. [Answer] The situation you describe is similar to the situation rogue planets are in. <http://en.wikipedia.org/wiki/Rogue_planet#Retention_of_heat_in_interstellar_space> That wiki claims that even liquid water on the surface of an Earth-sized planet is possible, though it will require 1000 times increased atmospheric pressure if I'm reading it right. But even if the surface is not suitable for life, the Earth's core will still be hot for a long time after such event, so we can dig in and survive. Especially if we keep the Moon with us, as it will keep providing tidal heating. [Answer] > > humans, with sufficiently advanced technology > > > Sufficiently advanced technology is the best kind of technology, it allows you to do anything within the realm of physics so long as there is a need. As @CortAmmon stated, the Earth has plenty of mass, as well as the Sun to be able to convert mass to energy well beyond the amount of energy produced by the sun. However, sufficiently advanced technology is not exactly the same as sufficiently advanced engineering, although they are both often mistaken for the same. We have the technology to levitate [trains](http://en.wikipedia.org/wiki/Maglev), strawberries and [frogs](https://www.youtube.com/watch?v=A1vyB-O5i6E), but we still do not have flying cars, even though the technology is here. Your humans may have performed tests in labs to transform mass to energy, but they may still be years or decades from fielding the technology. I am quite confident in the that a mass to energy plant does not yet exist, as a single working prototype could easily outperform any and all other forms of energy production, and humanity may simply just shrug at the sun going dark. What I would imagine would happen is that humanity as we know it today, including the ones in colonies on other planets or in space, especially them in fact, would cease to be, but there may be a deep underground bunker lab where scientists and engineers toil away to get the mass to energy reactor to work, and when it does, there will be so much energy, it could easily send a 21st century human society to post-scarcity, but the energy requirements of humans who perfect the mass to energy reactor would be much higher, but I digress [Answer] According to Fritz Leiber's short story *[A Pail of Air](http://www.baenebooks.com/chapters/0743498747/0743498747___6.htm)*, small groups of people could survive after losing the heat and light of the sun -- even after the atmosphere freezes out as "snow". Nuclear reactors could provide heat and electricity for a very long time. Underground bunkers (if dug deep enough) could become a place for people to live, heated and lit and growing food. In *A Pail of Air*, one family even manages to survive for years in an insulated room where they keep a fire going constantly. Every day they scoop up another pail of frozen oxygen snow from outside to boil off on the fire. Here's a description of their room: > > Let me tell you about the Nest. It's low and snug, just room for the four of us and our things. The floor is covered with thick woolly rugs. Three of the sides are blankets, and the blankets roofing it touch Pa's head. He tells me it's inside a much bigger room, but I've never seen the real walls or ceiling... > > > The fourth wall has blankets all over except around the fireplace, in which there is a fire that must never go out. It keeps us from freezing and does a lot more besides. > > > [Answer] When you toss in, "with sufficiently advanced technology", I think the answer is "obviously yes". I certainly haven't worked out the details but I strongly suspect we could do it with current technology. Dig into the surface fifty feet or so, so you have plenty of insulation. Then build a power plant that puts out sufficient energy to keep this place warm, in addition to providing power to run lights, computers, etc. You'll need to grow food without sunlight, but that shouldn't be tough: you need artificial lighting that reproduces sunlight well enough to "fool" the crops. While it might be expensive, I don't think any of that is beyond present technology. How many people you could sustain this way would depend primarily on how much time you had to prepare, I think. I don't see anything fundamentally impossible about it, so if there are points where we don't know how to make this or that work, the "with sufficiently advanced technology" should solve that. Presumably without energy coming in from the Sun such a colony could not survive forever. But presumably the Sun cannot last forever either. As I say, I haven't done the calculations, but I'd guess there is enough energy in known fuel sources in the Earth -- coal, oil, nuclear, etc -- to last for, well, I guess it depends on how many people we are supposing are surviving this way, but even if it was millions, there's enough energy to last for centuries if not millennia. Plenty of time to develop the technology to mine the asteroids or travel to another solar system. Assuming all the stars in the universe haven't gone dark in your scenario. [Answer] If this happened tomorrow, I think the only place people might survive without energy from the sun is Iceland. The population is small, they already generate a significant proportion of their electricity from geothermal power, and they are used to cold weather. I'm not considering oil rich places like Alaska because that is really stored energy from photosynthesis. But if we do consider them, the South Pole research station is another place that might hold out, as there are a lot of smart people there, though maybe not with the right skills. The other thing is, keeping warm in a geothermal area is significantly simpler than in an oil-rich area. All you have to do is dig down! The Maori of New Zealand cook food underground using rocks heated by fire, but the practice surely originates from geothermal cooking. In a matter of days, though, it's going to get *really* cold, and carry on till it gets to about the night time temperature of the moon (approx -233C.) That's below the freezing point of nitrogen and oxygen. Obviously it could take decades for the oceans to freeze, so I would expect the temperature to hold at a plateau somewhat below zero C for a very long time So the people of Iceland are going to have to be very resourceful and build an insulated biosphere in record time, and then will have a few decades to make it airtight. Food is likely to last from months to years, but ultimately it will have to be grown inside the biosphere using geothermal electricity. I think they could possibly survive, but it wouldn't be much fun. Given more advanced technology (fusion reactors?) and a decent warning, I think humanity could make a good go of it, but living on a sunless Earth would be considerably more difficult than living on present-day Mars. ]

[Question] [ I posted this question: [How would the United States survive and adapt in the decades following a Yellowstone eruption? What things would need to change as the world recovers?](https://worldbuilding.stackexchange.com/questions/216987/how-would-the-united-states-survive-and-adapt-in-the-decades-following-a-yellows?noredirect=1#comment669733_216987) and it was closed due to it being too broad of a question, which was a fair decision. After some thought and a few more people commenting on the question, I decided I needed to take a step back and figure out what I actually need answered. The existence of this eruption having happened in the past is crucial to the main settings I'm working with, one of which is a rural town that was settled inside the crater that the Yellowstone eruption left behind. It would be very hard at this point, having very nearly finished my first draft of the final rewriting of this book, I don't want to have to go back through and restructure everything. I don't want to have to remake this setting. So. Some things about this event that have to happen: * The Eruption itself has to happen. I've already determined how it happens, which I'll go more into detail about if needed, but it's not super related to the aftermath of the event. * The Eruption is large enough and powerful enough to leave behind a really large crater. Big enough for a full forest, a lake, a small city, and a handful of tiny rural towns. * The Crater itself is turned into that environment by a similar type of magic to the one that makes the volcano blow. * The United States still exists as an independent country after everything recovers. Before I can ask questions about what that recovery would look like, I need to ask how much damage such an eruption would cause in the first place. The other similar questions on this site covering this topic all include the assumption that scientists would see the eruption coming and there would be some amount of forewarning time to start evacuating people. I want to know what that big of an eruption would do to the country if there *wasn't* any forewarning, because it is magic that artificially causes that eruption, and nothing is really too different from our real world regarding humans in this fictional version of earth, because they don't know magic exists. To sum up: **If Yellowstone had an inexplicably sudden and large eruption, with little to no forewarning time, what would be the scale of that damage, and how would it effect the US as a country?** [Answer] **EDIT**: damn, this got me my first gold badge [Here](https://www.cbc.ca/doczone/content/legacy/episodes/supervolcano/gallery/zonemap_main.html) is a useful source, which is itself based off of [this](https://www.usgs.gov/volcanoes/yellowstone/modeling-ash-distribution-a-yellowstone-supereruption-2014). [Here](https://www.realclearscience.com/blog/2019/10/10/what_if_yellowstones_supervolcano_erupted.html) is an ancillary source. WTL;DR: all the damage TL;DR: * everything within 80 kilometers utterly deleted to an extent I am incapable of describing * everything within 125 kilometers is the surface of Mars, unbreathable atmosphere included * everything within 200 kilometers sees everything from buildings to biospheres collapse * everything within 300 kilometers is post-apocalyptic * everything within 800 kilometers is basically post-WW2 Germany * everything outside of 800 kilometers is basically COVID-19 but ten times worse **ZONE 1: HELL** **ESTIMATED ASHFALL: 3 Metres** **DISTANCE FROM BLAST: up to 80 KM** **MAJOR TOWNS: West Yellowstone, Mammoth** **POPULATION: 70,000** **POPULATION DISPLACED: 100%** (guess why) **COST (2012 DOLLARS): 7.1 billion** > > Zone 1 is called the 'pyroclastic zone'. Surges of scorching hot gas > and ash (over 400 centigrade) exceeding the speed of sound would spill > from the side of the volano [sic] and could extend up to 100 kilometres out. > It is not survivable. > > > [](https://i.stack.imgur.com/cmwY9.jpg) [There used to be an entire building here](https://www.usgs.gov/natural-hazards/volcano-hazards/pyroclastic-flows-move-fast-and-destroy-everything-their-path). Note that its rebar - this is *reinforced concrete*, i.e. what they build support columns for big buildings and the bulk of the structure of nuclear bunkers out of - has been bent in the direction of the pyroclastic flow, rocks have been embedded in the concrete, it has been sandblasted, and it has been scorched black. There are various ways that that bending of rebar should impress you. Either: * the flow blew hard enough to bend rebar * it got hit with so many rocks, pebbles, and the like that it was slowly "hammered" into that shape over the course of a few minutes * it was heated so heavily that it could be bent like taffy * a combination of the above What's more - if this is were the product of a Yellowstone-derived pyroclastic flow, this would be the second story, as the first story would have been buried in 10 feet of ultra-hot ash. It's a nuclear blast wave from hell - yes, I mean worse than a normal one - without the radiation. It is unsurvivable. It is a soup of ultraheated gases and rocks moving faster than a jet aircraft. Anyone in this zone is irrevocably dead, do not pass GO, do not collect $200, no saving throw, etc.; if you are not in a far-underground, well-reinforced nuclear bunker with air recyclers and zero connections to the surface, you are fucked, you are dead, and the heat might still cook that bunker anyhow. It's like Hell throwing up on you. A nuclear weapon is child's play compared to this. Extremophile bacteria *might* survive this. You went outside with a gas mask well haha dumbass it melted onto your face. Life is impossible. I cannot overstate how incredibly destructive and lethal this is. **ZONE 2: MOON** **ESTIMATED ASHFALL: 1.8 Metres** **DISTANCE FROM BLAST: 80-125 KM** **MAJOR TOWNS: Bozeman, Cody** **POPULATION: 350,000** **POPULATION DISPLACED: 95%** **COST (2012 DOLLARS): 28 billion** > > Zone 2 would have to be evacuated completely prior to the eruption. > The very heavy ashfall would collapse all structures. Vegatation > [sic], livestock and aquatic life would die. Power and telephone lines > would break and roads would become completely unusable. > > > Aside from the folks with easy access to fast transportation, nobody is getting out before ~6 feet of ash destroys everything; if you are not in a nuclear bunker (albeit a less-tough one than for Zone 1), you are dead. [](https://i.stack.imgur.com/8ofj8.jpg) Pretty much paved flat. Everything has been crushed by ash fallout. [Ash has a density of, on average, 1,000 kg/m^3, which ups to about 1,500 kg/m^3 as it gets rained on](https://volcanoes.usgs.gov/volcanic_ash/density_hardness.html). Breathing outside will be very difficult, due to massive levels of airborne sulfuric acids. A gas mask is mandatory. > > The dry bulk density of newly fallen and slightly compacted deposits > ranges from 500 to 1500 kg/m3, whereas the bulk density of wet ash > ranges from 1,000 to 2,000 kg/m3. Distal ashfall deposits most > commonly show slight decreases in bulk density with distance from the > volcanic vent source. > > > In other words, there is between 1.8 and 2.7 metric tons of ash per square meter in the average portion of this area. That's like having two [Mini Coopers](https://www.miniusa.com/model/hardtop/specs.html) dropped onto a space the size of a bath towel. Not really survivable for most forms of life; it's just too thick and there's just too much of it. Roads and reinforced infrastructure would still exist, but that's about the only thing that wouldn't collapse, and they'd still be buried. A lot of buildings are going down under that much weight. Power lines might survive, especially if undergrounded. Microbes will survive in the long run, as well as the hardiest of insect colonies. **ZONE 3: VERDUN** **ESTIMATED ASHFALL: 1 Metre** **DISTANCE FROM BLAST: 125-200 KM** **MAJOR TOWNS: Idaho Falls** **POPULATION: 640,000** **POPULATION DISPLACED: 90%** **COST (2012 DOLLARS): 225 billion** > > Zone 3 would have to be evacuated completely prior to the eruption. > The very heavy ashfall would collapse all structures. Vegatation > [sic], livestock and aquatic life would die. Power and telephone lines > would break and roads would become completely unusable. > > > [An irritating copy of the text for Zone 2, to be sure, but an accurate one.](https://www.youtube.com/watch?v=ca-e5MrVbVU) People will have time to flee, but they'd have to flee to survive; if you are not in a reinforced, sealed building with long-term supplies, you are fleeing or dead but don't know it yet. Breathing outside will be very hard. A respirator is mandatory. [](https://i.stack.imgur.com/0HLwJ.jpg) [This is what ~1 meter of ash looks like](https://www.usgs.gov/natural-hazards/volcano-hazards/ashfall-most-widespread-and-frequent-volcanic-hazard). The collapse of the car and building was likely averted by shoveling ash off of both; in the event of a Yellowstone eruption, imagine this but with 3 feet of ash on top of *everything* - not just the ground - and the car and the building crushed. **I recognize that that this doesn't look as bad as the image below, but I guarantee you it's worse; it just doesn't look that way because it's in a more built-up area. It's the best image I could find.** As you can see, cars are going to have a bad time. It won't be as bad as Zone 2, but it's still going to mess people's shit up. Many things will survive the initial ashfall, but then the rain will come along and double the weight, and they'll be crushed. Biological life and supply chains will die right off the bat. The ecological devastation will still be extreme. Bugs might survive in the long run, and *small* underground animals - like, the smallest of mice. **ZONE 4: POST-BOMB HIROSHIMA** **ESTIMATED ASHFALL: 60 centimeters** **DISTANCE FROM BLAST: 200-300 KM** **MAJOR TOWNS: Salt Lake City, Boise** **POPULATION: 11 million** **POPULATION DISPLACED: 80%** **COST (2012 DOLLARS): 225 billion** > > Zone 4 would still see substantial amounts of ashfull [sic]. Any areas > with more than 30 centimetres of ash are under severe risk. The > primary cause of death would be from roofs collapsing due to heavy ash > load, potentially 1 in 3 people would be killed this way. Breathing > outside would be very difficult. The water would be contaminated with > sulphuric acid. The ash would enter air filtration systems causing air > quality problems in structures still standing. There would likely be > no power and very limited transporation [sic], if any at all. > > > Basically a post-nuclear wasteland, which says a lot about the past three zones; if you aren't a prepper here, you're either dead or fleeing. It's still survivable by biological life, though - the ash is thin enough that burrowers, VERY small land wildlife, and creatures in deep lakes might survive. Breathing outside without mechanical filtration is indeed "very difficult" - but, unlike the previous zones, also possible. A respirator is heavily advised. [](https://i.stack.imgur.com/UhaQq.jpg) [60-ish centimeters of ash](https://www.nytimes.com/2020/01/14/world/asia/taal-volcano.html). > > Among the first challenges they faced as they sloshed ashore from a > motorized canoe was the two feet of ash. > > > As you can see, it's not *completely* collapsing that shack - **note that it's a one-story house; it's just that the nearby trees have collapsed under the weight of ash, giving the illusion that those are treetops.** On the other hand, ash is about twice as dense when wet, so rain might actually be what takes out buildings that the ash doesn't. Life will go on in this part, if incredibly differently. Ash levels are low enough that human habitation might be possible in the long run, and certainly in the short run - it won't take down the vital infrastructure right off the bat, so you'll have the time and resources to shovel yourself out and get ready to dig in for when things eventually start failing. If you want a post-apocalyptic story, this is the place - the right blend of "survivable" and "catastrophic". **ZONE 5: POST-WW2 GERMANY** **ESTIMATED ASHFALL: 15 centimeters** **DISTANCE FROM BLAST: 300-800 KM** **MAJOR TOWNS: Denver, Portland, Calgary, Seattle, Regina** **POPULATION: 34 million** **POPULATION DISPLACED: 10%** **COST (2012 DOLLARS): 234 billion** > > Buildings in zone 5 are still at risk of collapse if the roofs are not > immediately cleared of ash. Trees would be severely damaged due to > breaking of branches. Road transport would be halted due to build up > of ash on roads and cars would stop working as air-filters become > clogged. Rail transport and electricity may be cut as wet ash short > circuits signaling systems and sub-stations. > > > Much more survivable, but there will be serious supply chain and minor societal collapses. [](https://i.stack.imgur.com/G3lEG.png) [A light blanket of ash; oh, sure, the sky isn't black, but look at the ground.](https://volcanoes.usgs.gov/volcanic_ash/roads_highways.html). A respirator is advised, as is a snow shovel. This level of ashfall is more dangerous because it's better at killing crops, not because it's better at killing people (at least, not directly). Imagine this part as Europe during [Zero Hour](https://en.wikipedia.org/wiki/Zero_hour_(1945)). Society is technically still around, but things are breaking down. The ecosystem is in bad shape, but it'll bounce back. **ZONE 6: INTRA-COVID-19 USA** **ESTIMATED ASHFALL: 1-6 centimeters** **DISTANCE FROM BLAST: Beyond 800 KM** **MAJOR TOWNS: LA, Dallas, New York, Toronto, Chicago** **POPULATION: 190 million** **POPULATION DISPLACED: 1%** **COST (2012 DOLLARS): 213 billion** > > Minor damage to buildings in Zone 6 will occur as ash enters, soils > interiors and blocks air conditioning filters. Electricity may be cut > as wet ash causes shorting at sub-stations. This would cause water > supplies to be cut. Roads would need to be cleared to prevent ash from > blocking storm-water systems. Crop damage is possible and livestock > may be affected by lack of feed and contamination of water supplies. > Damage to electrical equipment and machinery is likely. > > > Bad, but basically normal life with massive inconveniences. Imagine the COVID-19 supply chain shortages blown up 10x. [](https://i.stack.imgur.com/Tc4JN.jpg) It's nothing in comparison to Z̵͖̤̜͍̼̐̒̇͊̚ô̴̱̹̆̏͒n̶̞̲͌̓͊̓̚ẻ̷̢͎̝̙ ̶̯̳̂̊̀ͅ1̵̥͝. Wear a facemask, change your filters on a bi-daily basis, and listen to your local disaster control authorities. Ration. Store water in your bathtub. Shrink-wrap electronics if you're not using them. [Answer] I assume that by "large eruption" you mean VEI8, that being the case up to two thirds of the continental US is buried in volcanic ash that hits the ground still glowing red, or hotter, and welds together to form at least several feet of solid rock. This new tuff layer takes centuries to completely cool but life starts to colonise the surface after only a few years in many areas. [Answer] > > and how would it effect the US as a country? > > > I read all the technical data in both KEY\_ABRADE answer and the links too. Lots of information. What it looks like to me is there is some kind of hope in those numbers that USA could keep existing like a nation after a massive Yellowstone eruption. After all recent nation wide problems caused by Covid19 virus and the political/social catastrophic change of government (the invasion of the Capitol Hill, in instance) does any one with a small sized imagination can believe USA will keep stand up after a total clash of all administrative system? If the eruption was today Republican party governors could immediately start to work a way out of the Union. Texas probably could be the first. I doubt USA could be "refurbished". And I doubt that the less affected states will accept to pay the bill to help the 80% worst affected. It is a scorched earth situation. Any international help will be symbolic because, of course, a mega vulcano eruption is a global catastrophe, sooner or later the ashes of the wrath will hit any country in this world, be in the form of a two years winter or in the form of fully three years of lost crops. Famine, in a global scale, never seen before. Does not do exist a survival courses that can prepare you to such wrecked panorama. If USA citizens intend to survive like a nation after a massive Yellowstone eruption and keep the world safe to any other country the only way is start to prepare an WORLD WIDE plan to deal with what looks like is (like Thanos) inevitable. To act after the scientists given the warning will be too late. Do I need make a diagram? ]

[Question] [ The title is pretty self-explanatory. **How powerful does a computer have to be before it has the hardware capability to simulate and emulate a human mind in real-time?** I'm leaving the question of the software needed for later, but feel free to address it if it's a vital part of the answer. **Criteria for judging an answer:** * This should almost go without saying, but a system with such a capability should be able to **pass the Turing test**. * The capability must be at least **real-time**, i.e. it cannot take 5 months to simulate 10 seconds of brain activity. * The capability must be capable of **continuous operation**, i.e. it cannot be on for a minute and off for the rest of the year. Continuous operation need not be mandatory however. * The capability must be such that the 'brain' can react to new information, **learn** and **communicate** its results. * Ideally, I'd like a physically **precise answer or range**. I'm not sure what the appropriate metric is, so in the absence of better ideas, I'll say we go for petaflops. If you have a better metric, feel free to use it instead. * **Bonus points:** (Not mandatory, but nice to have) How soon can we get there, and what would be the electric bill? How small can we make it, in the limit? How fast can we make it, in the limit? The motivation behind placing this in Worldbuilding is to have a canon reference answer on issues of computation related to the emulation-based paths towards the [singularity](https://worldbuilding.stackexchange.com/questions/6340/the-challenge-of-controlling-a-powerful-ai), computronium, sim-humans and other related topics, in order to aid in constructing a realistic futuristic society. Needless to say, the question assumes that constructing such emulations is possible. PS To avoid ontological confusion, further definitions: ***Emulation*** is the process of mimicking the outwardly observable behavior to match an existing target. The internal state of the emulation mechanism does not have to accurately reflect the internal state of the target which it is emulating. ***Simulation***, on the other hand, involves modeling the underlying state of the target. The end result of a good simulation is that the simulation model will emulate the target which it is simulating. [Answer] A comprehensive summary is on [this Wikipedia page](http://www.wikipedia.org/wiki/Mind_uploading#Computational_complexity).  If you already knew how the brain worked to produce intelligence, writing that program fairly directly would require $10^{15}$ FLOPS (Blue Gene/P circa 2007) and 100 Terabytes. Without understanding the emergent behavior, just simulating the neurons would take $10^{18}$ to $10^{19}$ FLOPS and 10,000 Terabytes of memory, expected to cost a million dollars in 2019. From the chart, you can see how much computation would be needed to simulate the metabolism and let the neuron behavior itself emerge, etc. The [Blue Brain project](https://en.wikipedia.org/wiki/Blue_Brain_Project) is studying deep simulations of a small piece of brain [neocortex](https://en.wikipedia.org/wiki/Neocortex), which is leading to the understanding to simulate the *behavior* of [cortical columns](https://en.wikipedia.org/wiki/Cortical_column) and groups of nerve cells, which is 100 times more efficient than detailed simulations of the individual cells. That would put it between the two lines mentioned above, but use far less memory than the upper line. That is, without understanding what behavior emerges from hooking up a thinking human cortex, hooking up software simulations of these "columns" (which are modular and have a lot of connections within the unit) will use 10 to 100 Petaflops, which has been in the range of supercomputers since 2012 ([currenly 33.8 Petaflops](https://en.wikipedia.org/wiki/Tianhe-2), right in the middle of that range). But, a working brain simulation might be special built to have the right blend of processing and local storage and connectivity, and thus be faster than the number-crunching supercomputing clusters. My take on it: data acquisition and study is slower than the projected hardware Moore curve. Projects like [Blue Brain](https://en.wikipedia.org/wiki/Blue_Brain_Project) will run their course, and followups on the design of cortical column simulations will take place on University lab equipment, with larger scale runs possible on University High Performance Computing or distributed computing resources. When a solid plan is ready, the hardware for a full-scale human brain implementation will cost less than a million dollars, but they'll start with smaller systems like mice, dogs, etc. If the hardware is custom, prototypes and small batches will provide hardware for the mice etc. If it can run on the general purpose high-performance computer (by then not ranked as a supercomputer) you *know* someone's going to try it long before it's ready. --- Update: [Computerphile video](https://youtube.com/watch?v=2e06C-yUwlc) This is a *spiking neural network* project (ref blue line on graph with that name trends fastest supercomputer in 2019 or 2020) named [SpiNNaker](https://en.wikipedia.org/wiki/SpiNNaker). On screen they showed a completed rack with 100,000 cores emulating 25 million neurons (at ¼ the efficiency—it will eventually run 1,000 neurons per core). The full project will be 1 billion neurons. The one rack— working now— is the functional equivilent of a mouse brain. Now they can play with it to figure out more details of a workable mouse brain. [Answer] Using modern technology, the challenge is not to produce hardware that can do the same thing as a human brain: the challenge is how to *program* the hardware to do so. Consider the [K supercomputer](http://www.scientificamerican.com/article/computers-vs-brains/), built by Fujitsu. It has more memory and does more operations per second than the human brain. It can't, however, imitate one, not only because the architecture isn't set up to do so, but also because we don't know how to program a computer to act like a person. It does, however, have the raw hardware capacity to behave in a human like. The K Supercomputer uses 9.9 million watts, and has roughly four brains worth of capacity. Assuming 2500 kilowatts of power, and an electricity price of fifteen cents per kWh, running our brain for an hour would cost $375/hour. Our supercomputers have gotten a bit better since we built the K, with the current most powerful supercomputer, the [Tianhe-2](http://recode.net/2014/11/17/the-worlds-most-powerful-computer-is-still-in-china/), using the equivalent of 730 kilowatts of power per human brain of performance. As to the cost of emulating vs simulating a brain, it depends on how good we get at doing each of those things, and how high of resolution we want in our simulation. Theoretically, performing the same operations the human brain does should require the same computing power as the human brain. If, however, we want to simulate the internal chemical reactions in each calcium channel, we'll need orders of magnitude more computing power. [Answer] The biggest roadblock to using CPU for brain emulation is that it processes commands in sequence, while all neurons work in parallel. You'd need a mind-blowing number of CPU cores to even begin approaching the speed of human brain. Thus, CPU is not the way. We need a chip that can process a lot in parallel: FPGA. With [4mln of logic cells](http://www.edn-europe.com/en/xilinx-ships-largest-fpga-to-date-4million-logic-cells.html?cmp_id=7&news_id=10005595&page=1#.VSenG5M90a1), and roughly 10 cells to emulate a single neuron, a single FPGA board can emulate 400,000 neurons at a time, working simultaneously. with [86bln neurons in a human brain](http://en.wikipedia.org/wiki/List_of_animals_by_number_of_neurons) you'd need to interconnect about 215,000 FPGA chips to reach brain capacity. 23x23mm for the smallest form factor of the linked FPGA, say, 40x40mm to contain one on a PCB, that would be 344 m^2 of PCB; split it into 20x50cm. Take a typical rack of [42U](http://en.wikipedia.org/wiki/Rack_unit); it would hold 40 boards of 0.5m x 0.5m plus their power supply and networking infrastructure, meaning 10m^2 of PCB. 35 such racks make a very modestly sized server room. Let's add [20,000 USD](http://avnetexpress.avnet.com/store/em/EMController?langId=-1&storeId=500201&catalogId=500201&N=0&action=products&term=Virtex%20UltraScale) for the new chip. $43mln for the chips alone, probably closer to 100mln USD for the complete project. And this is only the hardware. Now comes the hard part: Connect the 86bln neurons in such a way as they are connected in human brain. THIS is why it hasn't been done yet. [Answer] I probably can't answer you qeustion, for one simple reason - we don't know enough about the brain to simulate it. We are still learning how it works - how can you simulate something if you don't know how it works? I'll give it a shot though: 1) Every neuron could be stored as a bit (on/off), and the state of the synapses as a byte (on/off, resistance) So you need a computer with at least 410 GB of RAM, to store the state of every neuron and syanpse (200 GB for neurons, 200GB for synapses, 10GB for calculations to run the simulation) 2) You need a proccesor/s fast enough to work out how all of those neurons and synapses interact, and update them all - thousands of times a second. This is assuming there are rules and algorithims for how electricity flows through the brain. 3) You need *even more* proccessing power and RAM to handle output from the brain and sensory input to the brain (and some way of getting sensory input). 4) You need to map neurons firing into thoughts - that may be impossible, meaning you would have a simulated brain that couldn't learn or control its world in any way. So, for a simplified brain at the neuron/synapse level, you'll need a computer with maybe 500GB of RAM (which should preferably be cache for real-time simulation) and a 2 THz proccessor. This will allow you to simulate a *mathematical represenation of the brain*, updating 1 million times a second (well, a little slower, as buses arnen't instantaneous and I'm rounding and simplifying a lot.) The problem is not the hardware or software needed for the simulation, it's getting data to and from the simulation in a way the simulation (and you) will be able to interpret. [Answer] I'm surprised that no one has mentioned quantum computers. Due to the laws of superposition and the theroy of quantum entanglement a single quantum bit can be either a zero or a one, so in this it would allow you to compute every possible solution in tandem with multiple bytes, like this if a byte has eight bits each bit would allow you to have 256 possible solutions. If you had 50 qbits you could compute two to the fiftieth power number of solutions in tandem. This would allow you to create a complex simulation of the brain down to the subatomic level, provided you scale up the hardware accordingly. This would be ideal solution, but the problem is a quantum computer is a massive bulky machine that requires cryogenic cooling, and the slightest bit of motion can disrupt the quantum states and cause errors.So you could make it a stationary AI that could do advanced tasks by temporarily remote controlling other androids from far away. [Answer] Human level intelligence isn't just a reflection of the processing power involved. First off, evolution makes tons of mistakes and stupid choices in its design process that is not always corrected for and as a result we could really only need a small fraction of the power that our brains have. Secondly, assuming we have the processing ability, we don't know the right algorithms to make a brain work. We're getting closer in various areas but that's the thing, different bits operate differently and requires each area to be programmed and then interlinked together in the proper way. Thirdly, Assuming we have that you've not got a human intelligence/brain as you'd recognize it. You have a thing that can develop into one given the right circumstances. The right circumstances would require pretty sophisticated bio technologies or simulations that humans can interact with on a 1 to 1 basis. Once you've done that you might have a human brain and be able to answer your question, but to find out is that you have to take the brain you've developed and then write one of those evolutionary programs that make an alteration and test it against a set of known outputs (in this case the data from the brain we made) and keep on running through, discarding the ones that match less. then once you get the most optimal design you can then say how much processing it takes... But according to some sites the internet has passed the point of matching 1 human brain a few years ago and by 2020 it's predicted that Supercomputers will be able to math the raw "flops" that are generally calculated to be the processing power of a human brain, but we don't know for real. [Answer] I think that as technology evolves, we will naturally converge towards "wetware" because it's way more energy efficient. By wetware, I mean biological chips. Our brain uses just a few watts of power. Even if we used a 1nm process, silicon will never be as energy efficient as proteins. I m not sure about this but I think DNA also has a tremendous data density. The TV show Battle Star Galactica kind of pointed at this in an interesting way. If an AI was smart enough to gain sentience and start to duplicate itself, it would do R&D and start building androids. With time it night naturally evolve towards "biological" robots. ]

[Question] [ This is a **social engineering** method. The government takes background checks very seriously. A person's **moral standing** is not only determined by the actions of the person themselves, but also by his/her relatives (parents, grandparents, siblings, aunts/uncles, etc.) If one family member screws up, others are negatively affected in the eye of the government and society. Background checks (for criminal activity) usually go from sibling to parent. It would go to further generations depending on the situation and the results of such a check for someone are **publicly available upon request.** Here is an example: > > Bob married Alice. They have a son named Heidi. > > > Heidi had graduated from high school and he applies to university of Meow. In the background check procedure, **Heidi is not qualified**. The reason was that his fathers had charges of damage to public property. Heidi's father (Bob) had to pay a fine and go to prison for one year. > > > Heidi then went to work at Meowing Industries (a private company). However, the company turn him down: the government have a tax incentive for employers whose employees are in 'good standing' (ie. there is no criminal record for the **whole family**.) > > > If Alice were to marry a criminal, Bob: * Her son would be at a disadvantage. * She now fails the background check. (her husband have criminal record) In hindsight, Alice should not have married Bob. If Bob were to commit a crime: * He would be charged according to the law (ordered to pay a fine, imprisoned, etc.) * He would have a criminal record. He would fail all background checks from this point onward. * He would not be able to find a wife, because everybody knows the consequences of marrying a criminal. * His siblings now fail their background checks. * His sibling may also have difficulty marrying somebody, because everyone is aware of the disadvantages that would be brought to them through association. My expectations for the impact on society are: * People are less likely to commit a crime, knowing the consequences; * A 'perfect race' free from crime is created, assuming genetic factors for crime exist - since nobody wants to marry a criminal. **My questions are:** * Would my system work as expected? * How likely is a societal/governmental collapse? * Are there any flaws in my method? [Answer] Well, there is [at least one country](https://www.hrnk.org/uploads/pdfs/NKHiddenGulag_DavidHawk(2).pdf) operating that way (pp. 24, 27, 35 of the report). Perhaps it stops some crime, but that country is not a nice place to live. * Most criminals do not believe that they will be caught. * Most criminals do not plan for the long term, let alone generations. * Depriving the children of *legitimate* life choices will guide them towards *criminal* choices. So what I'd expect is what we see [in parts of the US](https://en.wikipedia.org/wiki/School-to-prison_pipeline#Disparities), only more so. Perhaps no immediate breakdown of society, but it will fray at the edges. And of course any *decent* human being will not punish the child for the sins of the parents. Morally that's just like a terrorist taking hostages. So either the decent voters change the system or they leave. [Answer] **There is a flaw in what you expect.** In your scenario, you are assuming that only men can commit crime.The other side of this story is as follows: > > Alice does not marry Bob. Bob finds Kate. Kate also has a charge of damaging public property(or something else). No one would also marry Kate, that's why Bob and Kate are perfect match. As they are already criminal, nothing can happen from marrying each other. > > Bob and Katie have children, because why not? They know that their children won't have any decent job in the future because of them, they raise them to be a successful criminal in the future to make a living. The children learn how to steal cars at the age of 5. *The aggressive genes which were meant to be eliminated are now doubled.* You also created a generation of criminals. > > > Your society is also not forgiving. Once you commit to a crime, you and everyone around you is doomed. As other's pointed out, people do not commit crime by planning but in your society once you have charges, you can not erase them and there is no reason for you to not commit anymore crime. *Actually if you are a parent and committed a crime and your child can not go to college because of that, you do anything to give them a great life by becoming a crime lord.* In the end, you create a caste system where no one marries with the criminals but more and more people are joining criminals because of unplanned crimes and there is no way for them to return to the good side. **Your society collapses.** [Answer] There are too many flaws in this idea to address them all, but I'll hit a few of the major ones. First flaw is the implicit assumption that "criminality" has anything at all to do with genetics. The child of "criminals" might well become a productive member of society, if not prevented from getting an education by abysmally stupid laws. (And how is that different from racial or ethnic discrimination?) Then there's the purely practical matter of determining parentage. Unless you are willing to do genetic testing on every person in your society, there's no way to be sure who the parents are. Another flaw is that "crime" is defined by fiat: things that are crimes in one jurisdiction or at one time could be perfectly legal, even laudable, in another one. Consider the criminals running the pre-Civil War Underground Railroad. Or that within my own lifetime, it was criminal to be gay, or for people of different races to marry. Still another problem is that many criminals are not caught, while many innocent people are convicted of crimes they didn't commit. So Heidi is denied education and employment because Bob was wrongly convicted. Don't know if you're that familiar with history, but something similar has been tried before. See e.g. <https://en.wikipedia.org/wiki/Attainder> [Answer] First let's start out with a simple fact : it is (in this real world) generally going to negatively impact your future prospects to enter a long term relationship with a person with a criminal conviction. Exactly how badly this will affect you depends on precisely where you live, but it *will* have negative consequences. > > Background checks (for criminal activity) usually go from sibling to parent. It would go to further generations depending on the situation and the results of such a check for someone are publicly available upon request. > > > And a flourishing system of bribery and corruption is born. :-) The vast majority will consider the application of these rules unjust, and unjust laws tend to be ignored at best or subverted at worst by at least a minority and often by a majority. > > If Alice were to marry a criminal, Bob: > > > Her son would be at a disadvantage. > She now fails the background check. (her husband have criminal record) > > > In hindsight, Alice should not have married Bob. > > > People tend not to marry (or get together or stay together) for logical reasons. And thank heaven for this fact. And people will get together *despite* knowing they're getting a partner with problems. Nothing ever has stopped this. > > If Bob were to commit a crime: > > > He would be charged according to the law (ordered to pay a fine, imprisoned, etc.) > He would have a criminal record. He would fail all background checks from this point onward. > > > So far, so normal. > > He would not be able to find a wife, because everybody knows the consequences of marrying a criminal. > > > And yet people do it anyway. And always have. Love, as they say, is blind. Blind, deaf and tragically dumb. So Bob probably will find a wife if he wants to. And, more to the point, he's a criminal and they're not known for their honesty and for being open with their partners. So Bob will happily lie to Alice to get what he wants. And a flourishing market in providing fake background checks (or simple bribery) will let Bob hide his past for "long enough" to mess up Alice's life. > > His siblings now fail their background checks. > > > And this punishes perfectly innocent people for no reason other than vindictive stupidity. And they're now ready to become real criminals because you've given them a reason to hate people for this unjust punishment. > > His sibling may also have difficulty marrying somebody, because everyone is aware of the disadvantages that would be brought to them through association. > > > Again, love is blind. So that won't work out as you think. > > My expectations for the impact on society are: > > > So far they're totally wrong and provably so by simply looking around you. > > People are less likely to commit a crime, knowing the consequences; > > > Criminal punishment historically was violent and even lethal and yet we have *always* had crime. And as some criminals are actually sociopaths, they won't give an iota for what punishment happens other people (including their children). Have a look at Death Row sometime. They all knew the likely consequences. > > A 'perfect race' free from crime is created, assuming genetic factors for crime exist - since nobody wants to marry a criminal. > > > Historically we did everything from shop bits off to torture to death people guilty of what, in a modern context, would be considered petty crimes. And these outrageous deaths did nothing to discourage crime or prevent the criminals from procreating. So this is pure nonsense and we've several thousand years of history to prove it. > > My questions are: > > > Would my system work as expected? > > > Not even close. Probably you'd create an incredibly unstable system with an ever-growing mass of disaffected and angry population who have been punished for someone else's crime. > > How likely is a societal/governmental collapse ? > > > A certainty. It may take time, depending on how dictatorial the system is, but eventually it will collapse. > > Are there any flaws in my method? > > > Just logic, precedent, history and your apparently non-existent understanding of human relationships and how they happen. Other than that, nothing. Hint : read [Victor Hugo's "Les Misérables"](https://en.wikipedia.org/wiki/Les_Mis%C3%A9rables) or [Dostoyevsky's "Crime and Punishment"](https://en.wikipedia.org/wiki/Crime_and_Punishment), neither of which are light reading. You might also try ["Doctor Zhivago"](https://en.wikipedia.org/wiki/Doctor_Zhivago_(novel)) as it will illustrate the way love and passion work and what people will do because of them regardless of consequences. [Answer] In fact, the goverment **discriminated** criminal relatives in USSR and in **is discriminating** in North Korea, as o.m mentioned. In USSR it was not a strict rule and could vary from case to case. 1. It will **not** work in terms of criminal reduction. * Some crimes happens because of accident. Unhappy shot from a gun, for example. Why pregnant wife and unborn child should be disqualified? * Impulsive, unplanned crimes are more often than planning like *next winter I'm going to beat lover of my wife* or like *Ocean's Twelve* film * There is no 'criminal gene' but relatives and surrounding people has a big influence. You prosecute people but don't remove negative effect of being close to criminals 2. There are many effects. * Social lifts don't work for relatives of criminals. They can't even hope for better life * Without access to a good job, more people become criminals * You get a caste of pariah: everyone could fall down but nobody could return to a good life. * According to the [idea of six steps](https://en.wikipedia.org/wiki/Six_degrees_of_separation), it's very likely that some friend of friend of friend is a criminal. So most people could be banned from elite job, you need just find better. 3. Society would degrade * Too many people, I would say most people, could be found linked to someone disqualified. So goverment could manipulate and harass almost anyone. It's good for totalitarian goverment only * Any election will turn out to finding disqualified people as close to a pretendent as possible * It's too easy to ground the enemy: just suspicion of crime would lead to ostracism --- Without social lifts going up and with ease to bring down anyone, general level of society could only go down. You get society of criminals, friends of criminals, those who don't criminal **yet** and a guard. Some authors called late USSR as a '*state prison*' [Answer] That process is counterproductive. **Too long, didn't read :** see below. Crimes are usually the consequence of pre-existing social disadvantage. Social penalization, whether on purpose or not, leads to crime. Commiting crimes are done, in most cases - not taking victimless crimes into account - either because there is no legal choice available to subsist or because it seems to be the better way to do things when you grow up. In the later case, it's mostly up to which models you are as you become an adult, whether it's your parents or the other (pre)adults you are hanging out with. In the former, it can come from a lack of job or because the one you have doesn't pay enough. This comes directly from how good a job your (assumed) education/training you can get versus how much you have to spend on a regular basis. To sum it up, the things that people out of crime are : * Education : The more accessible and the cheaper/freer it is for you, the more likely you'll be to get a decent job and the less appealing crime will become, the risk/benefit ratio will be higher the better your education is. * Proper raising : If you were raised by adults who spent time showing you a good example, you are less likely to fall into crime once you get to choose. I put the emphasis on that sentence, I don't mean criminal parents/not criminal parents. Very decent and hard working poor parents increase the odds that their children will do crime because **the more time they have to work on low wage jobs, the less time they'll have to raise their kids**. Heartbreaking but true. * Healthcare : You will do anything to stay alive and well, and even more to keep your relatives alive and well. Same than education, the more accessible and free healthcare is, the less likely people are to commit crimes. * Victimless crimes : Criminalizing activities that are otherwise harmless - like having sex, being gay, doing drugs, whatever - the less serious other crimes will look, and more importantly, the more people you will inject into the criminal part of society. If you already feel like a criminal after having done something trivial and harmless - and have faced the legal consequences - you will have less qualms breaking the law again if the needs or opportunity comes, it tilts your risk/benefit ratio regarding crime. * Social welfare : Ensuring that people have enough money to live **decent** lives whatever bad luck happens to them works like a contract. While people might be - more or less heavily - tempted to rely on crime in order to subsist if something - illness, job loss, ... - impairs their ability to do so, because they need money fast, feel that society let them rot and don't have anything to lose anyway, letting them know that you'll provide for them if it happens give them both the resources and incentive to remain honnest. People rarely do crime for the fun of it, they are usually ashamed but have to. Countries with good welfare programs have low crime rates because at least it's easier to live on welfare than on crime, and crime costs more than welfare anyway. Plus, they'll be more likely to get back on their feet if they aren't convicted felons. * Criminalization of people : It's true when it comes to criminalizing entire communities, and even more if you make it a social process. If you are already seen as a criminal, why the hell wouldn't you break the law if it fills your needs ? You are already a felon, what do you have to lose ? The best way to prevent crimes is to remove the reasons that honnest hard working people would have to turn to it and the reasons convicted people would have to do it again. So while ensuring that your citizens won't ever find themselves so low that they'll have to commit crimes and that your convicts are forgiven so that they can reinsert themselves without penality works, socially penalizing cinvicts relatives will have the opposite effect. Picture it in your head : You are a hard working person, but your jobs don't allow you to pay for both healthcare and food for your kids, so you have to choose, needless to say, you sacrifice both your meals and health. Some day you get sick and lose your jobs. You have to rob a house to prevent your children from dying. I see a few things coming, if social penalties are enforced in your world : * If the robber is caught, his efforts to save her/his children alive will cost them whatever decent live they could have had. Same for the spouse. * Incidentally, the robber is very likely to carry a lethal weapon considering the disproportionate threat of getting caught, since although the legal penalty for robbing might not be that much, the threat of robbing his/her children from any hope their parents are currently fighting for is almost a death penalty. Worse than that, by criminalizing petty crimes and adding social penalties to those who are already socially in bad shape and/or discriminated against, you antagonize them, which makes you their enemy, which remove insentive to follow the law. Don't make an enemy of your people and then expect them to not steal from you or stab you in the leg. That system is already used in various places, either directly or indirectly : Children that grow up without one or both of their parents because they are serving long times in jails will grow up with a single parent they will amost never see, always out working, or on the street without parents. They are moreover unlikely to get any education or training, so the cycle continues. **TLDR :** Your system is designed like a virus : it's contagious. Its effect would be to increase crime rates among the social classes that are already concerned by it, the gravity of the crimes, and the ratio of the population that belong to these classes until you end up with three classes : - The ultra wealthy hiding behind high walls. They make up the government, rule the finances, the production and the bills. Finance is unregulated, laws allowing the "police" to do almost anything in the name of "protecting the honnest poeple" and labour is unregulated and pays the strict minimum needed (or below). - A tight middle class that subsist in the fear of being convicted. They despise the government and don't "snitch" on each other for petty things given how unfair your laws are, but the government quickly comes up by both rewarding "collaboration with law enforcement" and criminalizing not reporting crimes. Yes you're right, that's fascism. They are stuck against another fear, directed toward the criminal and poor population that might rob or murder them anytime. - A wide population living either in jail or in guettos in which the "police" leads raids in military gear, footages of which are shown in the news as evidence that the government is standing their ground against the "terrorists"/"lazy ones", while these people are actually working their asses off in unregulated factories for meals, since they have almost no rights. That's as dystopian as a world can get, for as far as I'm concerned. [Answer] Some people commit crimes as a way to survive because they can't get a regular job. If an entire family couldn't get a good job, the entire family might start committing crimes together. They trust each other because they are a family. They work as a team to survive any way they can. There's a name for this: Mafia. This Mafia then becomes an employer. They ignore the rules against hiring criminals and hire other criminals to help them commit more crimes. These gangs/Mafia have been known to take over whole cities in the United States and whole countries elsewhere in the world. Society doesn't collapse. But society, as it was before, collapses. I capitalized Mafia because they will break my nose if I don't. :) [Answer] There are four reasons for punishment via incarceration, in descending effectiveness: 1. Incapacitation. This is useless as incapacitation. It doesn't restrict the criminal at all. 2. Retribution. This might work as retribution, but not that well. It doesn't give the victims much closure. The punishment is rather abstract. And they may encounter the criminal, causing the old passions to rise up. Prison doesn't just prevent criminals from committing new crimes, it prevents victims from trying for revenge. This doesn't. 3. Deterrence. This is probably the strongest effect. But the truth is that any punishment serves as a deterrent. Increasing the punishment doesn't increase the deterrence effect. A greater worry is that there is no way to increase the punishment. Increased punishment does not increase the deterrent effect, but an escalating punishment for escalated crime deters escalation. E.g. kidnappers may be reluctant to murder their victim if the punishment for murder is more than the punishment for kidnapping. And the deterrent disappears once the punishment is triggered. 4. Rehabilitation. If anything, this causes the reverse effect. Once this punishment has been applied, it can't be applied again. The biggest problem with any punishment is that the criminal doesn't expect to get caught. If not caught, the punishment doesn't matter. It's not applied. This punishment puts all the effect on deterrence of the first crime. But this is when the criminal is least experienced and easiest to catch. What to do afterwards? This punishment won't work a second time. Given that someone has committed a crime, this may encourage escalation. If the punishment for murder is the same as that for petty vandalism, then a petty vandal may choose to murder to hide the vandalism. Another problem is that criminals typically commit their first crime before they have children. As such, the idea of their children being punished is abstract and distant. The gain from the crime is immediate. People tend to weight immediate results higher than future results. Plus, the criminal may not have any interest in children. This does make law-abiding women less likely to marry criminal men. But this isn't exactly common anyway. Criminally-minded men are more likely to marry criminally-minded women. Like many punishments, this is most effective against the law-abiding rather than the criminally-minded. The problem being that those who most need deterred are the criminally-minded. The greatest weakness of current punishments is the lack of rehabilitation. This makes that worse for a minimal, if any, increase in deterrence. It also throws away the incapacitation and retribution benefits. This is a much less effective punishment than incarceration alone. Even if combined with incarceration, it reduces the rehabilitation effect. The number one way to increase the deterrent effect is to increase the likelihood of being caught. That will have far more impact than any increase in punishment. It increases all of the incapacitation, deterrence, and rehabilitation effects. And that is more effective against the criminally-minded than against the law-abiding, as they commit more of the crimes. [Answer] What you would do is sow the seeds for revolution. It is patently unfair to hold people responsible for acts they did not commit. Every child that was held back due to actions of their parents would grow into an adult determined to bring that system down. Most criminals commit crimes because they are either stupid enough to think they can get away with it, or don't care (as in sociopath) about the consequences. So even the deterrent value of that method is in question. [Answer] You cannot have the children controlling the parents. Penalizing children would have little or no effect in practice, since it would refrain only "conscientious" parents... which wouldn't be criminal in the first place, most likely. Criminals aren't such because they like to be "bad" (whatever it may mean). ALL of them are fully convinced to be justified in doing what they do and, in most of the cases, to be able to pull it through without punishment. They wouldn't be deterred by a possible disadvantage to kids (possibly still non-existent) may years from now. The other way around would work much better and have been used more than once in history: "collective responsibility" is a doctrine where responsibility of some action impacts immediately the whole family (medieval Japan was a particularly harsh example). This would put *parents* in position to control tightly relatives and children in order to avoid losing *their* job. It is a nasty system, but works, at least for some time (in Japan lasted centuries). [Answer] Crime would vastly increase because the crimes that you commit by unjustly and dishonestly penalizing children of criminals would far exceed crimes committed by those criminals. Moreover, the unjustly and dishonestly penalized children might be more likely to become criminals than they would if you were honest and just with them. It may also be that instead of becoming a criminal, one of them would assassinate you. No reasonable person could consider that a crime. [Answer] I read this and my first thought was about China's new social network experiment, where being a 'good' citizen gets you credit towards visas, etc, and 'bad' citizens may receive punishments. In addition, having 'bad friends' can reduce your score, so this may socially outcast non-conformers. We'll see how this plays out in the real world soon I suppose, since it's supposed to be mandatory by 2020. It's not necessarily parent to child, but the 'bad-friends-are-bad' thing seems similar. [Answer] Loss of status to an entire family due to the actions of one person is common in history, and even in modern life. Abrahamic cultures - "The sins of the fathers are visited to the sons to the third and fourth generation" - Exodus 20:5. Modern day - relatives of Adolf Hitler, Oscar Wilde, Albert Einstein, and other famous (or infamous) people have changed their names to distance themselves from the social stigma of their ancestry. [Answer] Let's assume that your system will somehow magically work. People have a lot of negative comments, but let's assume that 100% of your society is deluded enough to believe this is just as fair as the death sentence, or jail time. Now let's consider the primary concepts here: > > When doing a background check criminal behavior that any immediate relative has done will appear on yours. > > > Alright. That seems odd, but as long as it isn't presented in a misleading way (such as the record saying *you* committed the crime), I don't see anything wrong with it appearing. Let's be realistic here. The issue is how people use such a record. Now you say people get tax breaks for employing people with decent records, right? So what? AS many answers point out there are only so many people with "good records" in your system. People will just have normal taxes. After all, such a break doesn't normally occur in real life. So now let's amp up your system. Let's say it is *illegal* to hire people for certain skilled jobs or train them in a university if they have a criminal record. Fine then. Not everyone in the world gets a skilled job. They get an unskilled job (such as a supermarket clerk) and avoid criminal behavior. Then they know with certainty that their children will be allowed to go to a university and get a skilled job. All your system does is extend the "unskilled labor" generated by criminals ordinarily not getting jobs into another generation. **Your system is sorta successful barring a logical fallacy.** It deters the children of criminals or relatives of criminals from being criminals. Why? Well think of it this way. Society states that people directly related to criminals get punished severely and they're part of that group. Maybe they decide that they don't want that for their children. So their logic is to try and break the cycle by getting their family to not commit any crimes. The fallacy is that one assumes people would otherwise commit crimes if they were directly related to criminals. Finally as a note towards the utter collapse of the country.... I don't see that it has to. There's nothing forcing people to lose jobs and whatnot. Just a loss of tax breaks for companies. If people are vital enough to a business, they won't be fired. Plus, you say that the crimes will actually be listed and not just a general "criminal relative" stamp. Therefore, depending on the severity of the crime your system might actually punish relatives in the same manner criminals might be punished. Minor vandalism from teenage years might not be as heavily punished when an adult. It isn't that way now in real life, so why should it be in your civilization? Therefore, while your law is weird and insane, I see no reason why society would collapse and stop functioning. I also think it won't work as a deterrent towards the original criminals. However, it will breed a generation of people desiring to not be criminals so as to allow future generations to have skilled labor. [Answer] There's a lot of answers here about how things happen in the real world, but since this is WorldBuilding and not Politics, I thought I'd bring up a case from an existing novel. In [The Neanderthal Parallax](https://en.wikipedia.org/wiki/The_Neanderthal_Parallax) series by Robert J. Sawyer, the neanderthal society castrates all criminals, and their closest family, to eugenically prevent crime. Since your society is basically doing the same thing (socially instead of chemically), it might be worth reading RJS's take on it. [Answer] "Pure" unpunished middle class people would probably be far easier to blackmail, or hurt with false charges. Imagine "I'll sue you" when your childrens futures are at stake.. [Answer] The system would create a caste system of criminals and non criminals. Criminals will just get better at it to survive because they have no option but to just get better. But it will also cause other issues: There would be no protests. Who would want to risk getting a record and getting shunned. Counterfeit birth certificates and name changes will be as big as alcohol in prohibition times. With all of these criminal they will get organized and gangs will form. I could see stress being really high in such a society. At what point are you marked a criminal. is a parking ticket enough to get shunned. Is a parking ticket considered a gateway to criminality? Do people preemptively shun those they think may do no good. Do different politicians revise what is considered illegal? Certain books? Do they force mandatory religious services or propaganda? Are there politicians just calling for jailing all criminals and creating a work force out of them? These are all things you will have to consider. The longer the society went on the more people that will end up criminals and put into work camps. The rich would eventually get more freedom to act any way they want. No one is clean so the threat of a rich person suing the prosecutor and digging up dirt to literally ruin his life would mean that they would almost never serve any time or even be slapped with a punishment. [Answer] 'Criminal' has a lot of grey area but it seems like you're referring to a career criminal with a lengthy rap sheet. There are plenty of one-time criminals out there and people who have never been caught committing crimes. Does never being convicted of a crime mean they're not a criminal even though they commit crimes nobody knows about? There are plenty of people out there who have been convicted of one crime who will never commit another crime in their life. Does that make them a criminal for the rest of their life? 'Criminal' is a stereotype and it isn't as black-and-white as we make it out to be. We live in a corrupt police state where all are at risk of being branded a criminal either in the past or at some point in the future. What good would punishing the children for their parents behavior do? It's guilt by association and a logical fallacy. It unnecessarily ruins the children's futures and creates more problems than it solves. Would you want to be held liable for someone else's behavior when the only thing you have control over is your own behavior? It's just not right. I have two dogs. A girl and a boy. One has a potty training problem and constantly goes to the bathroom in the house. Whenever she does that we all stand there staring at the poop in disbelief and nobody knows what happened. I spank them both lightly on the head and point at them and say "bad!". They're intelligent dogs and they know the difference between right and wrong. He's largely the assertive one. She's always been on the shy side and relies a lot on him for things. He's like her little 'wingman'. If he wants to go outside to the bathroom then she'll go outside but she won't go to the door or otherwise let you know she needs to go out on her own. You can always tell who did it because he gets fed up with being punished for something she did and always starts snarling at her and attacking her. Regardless, the behavior never improves. It might work on some people but she certainly seems to be immune. I don't do that anymore since punishing innocent people for someone else's behavior has proven to be ineffective but I've tried everything to figure out how to motivate her to stop. Some people never learn. They just want to do their own thing. You can lead a horse to water but you can't make them drink! It really is true that the only thing we can be certain of changing in life is our own behavior. [Answer] What you propose isn't far from what we have in the US today: people with a criminal record can't get a (decent) job, so their kids grow up poor and uneducated, which almost inevitably leads to said kids eventually getting a criminal record of their own. (Note that guilt isn't needed when the accused is too poor and uneducated to defend themself.) Their dating pool is other poor and uneducated people, so unprotected sex is the norm with predictable results. Lather, rinse, repeat. The US has by far the highest incarceration rate in the world, so this system doesn't seem to produce the crime-free society you're hoping for. [Answer] > > There was once an emperor in China who had an advisor. The Advisor > believed that if you make the punishment for a minor crime extremely > harsh no one would consider performing a major crime. > > > THere were a group of farmers who had been called to serve in the > military during the rainy season. They were late. On realizing that they would be late > > > One asked: "What is the punishment for being late?" > > > A: "Death" > > > Q: "What is the punishment for treason?" > > > A: "Death" > > > Thus decided they started a revolution that lead to acivil war that ended with the death of the advisor and the old emperor. > > > If a minor crime is enough to ruin your life, and the lives of your family. Why not go for broke, what is the worst that can happen? [Answer] The one I think your missing is that the parent would care if their child suffered. Many don't. So it would not have the desired effect of making them a better person. [Answer] It would actually be the worst idea. First: it already happens too often that children of criminal, for many reasons, end up committing crime as well. Make it also harder for them to have a "normal" job and education, and that's a bomb: you'd have whole families, whole neighboorhoods where people are unable to escape the "criminal life" Second: in dictatorships this thing actually happens. In the URSS that would happen a lot; one person does something wrong, and the whole family is disadvanaged somehow. Needless to say, the results are horrible. Also, if something is done in dictatorships to control people, maybe it's a sign is not a good idea. Third: you're making a big mistake many people make: thinking that all criminals are rational. Most will just think they won't get caught. Some will not care if they have children. It would be horrible to make people with criminal records (and their children) unable to find a way to integrate again in society? Imagine: Bob committed some crime when he was young. Then he got better, Found a wife, have this kid Heidi. Heidi cannot go to a good school, cannot get a nice job... would it be surprising if Heidi commit some small crime? No. Once that is done, Heidi realize she has no way back into the system, all odds are against her: why would it be worthy to even try to behave? She'd go even deeper in the criminal life. And if she has a son, at that point there's no way for him to be able to do anything good with his life, given the family history. So why should he even try? The other kids will be able to go to nice schools, etc.. while he not only will maybe grow up with a parent in prison, but also he'd be discriminated against everywhere. [Answer] ## Meh. Lowering crime rates by socially penalizing criminals' children might have some effect, but it won't create a crime-free society and could lead to unintended consequences. This approach is based on the belief that people will avoid crime if it negatively impacts their family. However, there are several factors to consider when evaluating its effectiveness. ### Will it work as expected? Punishing families for an individual's crimes isn't new. "Collective punishment" has been used in various societies throughout history, but its success is debatable. A study on family ties and crime found that strong bonds can lower criminal behavior, but also showed that crime can pass between generations. This means penalizing criminals' children might not lower crime rates. ### Is societal/governmental collapse likely? A collapse due to this policy is unlikely, but it could increase social unrest and inequality. Penalizing criminals' children creates a cycle of poverty and disenfranchisement, as they may struggle to access education, employment, and support systems. This could lead to resentment and potentially higher crime rates among this group. Additionally, the policy could be seen as unfair and lose public support, eroding trust in the government. ### Are there any flaws in the method? This method has several flaws. First, it assumes crime results only from individual choices, ignoring broader factors like poverty, lack of education, and limited support systems. Second, it could unfairly punish innocent people, especially children, for their relatives' actions, leading to further stigmatization and marginalization. Lastly, it may not deter crime, as not all criminals may be aware of or care about consequences for their family members. In conclusion, socially penalizing criminals' children might slightly impact crime rates, but it's not a complete solution. The approach has flaws and may lead to unintended consequences like increased social unrest and inequality. A better way to reduce crime rates could be addressing underlying factors that contribute to criminal behavior and providing support systems for at-risk individuals and their families. ]

[Question] [ For my story I need a data storage device that will be reasonably familiar to adult readers. My character will have obtained this device and know that vital information is stored on it, but not necessarily in what form. It needs to be obsolete so can't just be plugged into any handy laptop or PC, in fact it should be a real hassle to access the data. My initial thought is a 3.5 inch floppy disc but I'm not sure if this is difficult enough to get data off. As well as the actual storage devise you can also consider factors such as out of date software etc that would be needed and therefore add to the difficulty of opening the data. My character is highly educated but completely unfamiliar with 21st Century Earth technology, but can access the internet to look things up but will want to avoid anything that may facilitate others tracing them. They have access to cash but not banking/electronic money so e.g would not be able to order anything from the internet or pay for any services online. [Answer] Another suggestion for the humble 3.5" floppy. Formatted by a computer such as the Amiga. The PC floppy controller is extremely limited (because it uses fixed hardware instead of software to do signal decoding). It physically can't read the format used by most other home computers like the Amiga, later Apple II models, Acorn, etc. And USB floppy drives are even worse in compatibility. So, even if you had a PC with a floppy drive (built-in or USB) you can't read this floppy. This is not a software problem, it requires specialist hardware to overcome. (Such as a special floppy controller like the [Kryoflux](https://www.kryoflux.com/), or extremely hacky workarounds like [attaching two floppy drives](https://retrocomputing.stackexchange.com/a/12748/4488) to fool the controller to read the "invalid" floppy.) [Answer] **SyQuest SparQ Drive** Forget IOMega Zip Disks, any kind of standard floppy, or magnetic tapes. They were too reliable and popular, and therefore will be always relatively abundant, and *boring*. You need something that was a total market flop and **self-destructing**: the [1.0 GB SyQuest SparQ removable-disk hard drive](https://en.wikipedia.org/wiki/SyQuest_SparQ_drive). From Wikipedia > > Just a few months after the launch, users began to complain that the drives had serious quality issues, causing them to break. The damage to its public image and warranty obligations of SyQuest were major factors behind the company's bankruptcy. > > > and most importantly > > The SparQ was noteworthy for a serious failure mode which damages > SparQ disks in a way that caused them to damage subsequent SparQ > drives in which they were placed. Simply putting a broken disk in a > SparQ drive will cause the drive to break any new disks placed in that > drive. These (broken) disks could break additional drives, breaking > most of the drives in an office in short order. > > > So even if your character has access to a whole stash of SparQ disks and drives, they would likely need to learn how to repair the hardware in order to get the data off the disks. You can really create some drama here. Have the character successfully read some disks before hitting a bad disk that breaks all the drives. And it's not completely forgotten... as of this writing, I see SparQ disks and drives are still available on Internet auction sites. [Answer] Iomega ZIP disks. They were popular in the late 1990s and were useful when the data would not fit on a floppy. They were in widespread use at the time, but now are obsolete. Finding hardware to read these would be a significant hassle. [](https://i.stack.imgur.com/1aSXA.jpg) [Answer] **Laserdiscs!** [](https://i.stack.imgur.com/4iRNg.jpg) <https://commons.wikimedia.org/wiki/File:LaserDisc.jpg> These were competitors of VHS and Betamax in the late 1970s. I remember seeing some in Blockbuster Video in the late 90s and wondering what they were. They look cool. Maybe you could hack a CD reader to operate like a record needle... [Answer] ## Magnetic Tape Like those old cassette tapes or video tapes, but for computers. They were (and still are) used for archival storage, but mostly in the server space and would require special hardware to read. **Or an actual Cassette Tape** [It is possible to use a standard audio cassette tape to store data](https://en.wikipedia.org/wiki/Kansas_City_standard) This could also lead to some humorous misunderstandings, and send him down an wild goose chase. [Answer] An Amstrad PCW [3” (not 3½”) floppy disk](https://en.wikipedia.org/wiki/Floppy_disk_variants#3-inch_%22Compact_Floppy_Disk%22_/_%22CF-2%22_format). The PCW was very popular in Europe in the late 80s, but hasn’t been manufactured since 1998. And even if you can find a working PCW, getting the data off that machine onto something else will also be a challenge. [Answer] Depends on how difficult you want to make it for the protagonist. If faced with an unfamiliar physical item, a quick question at [Retrocomputing Stackexchange](https://retrocomputing.stackexchange.com) will be enough to identify it. And then its just a question of enough dedication, money and asking the right retrocomputing nerd^Wexpert. Some possibilities: * An audio tape from the 8-bit era. There were myriad of home computers with widely incompatible, sui generis audio formats. Although possible to reverse engineer given some patience and oscilloscope (or Audacity today), still not an easy task. And decoding the raw data stream will not give you readable text or anything. * [3 inch floppy](http://www.computinghistory.org.uk/det/509/Sinclair-ZX-Spectrum-3/) - finding a working drive to read the data would be a challenge (but not an impossible one). Alternately, 2½ or 2 inch floppy. * [Microdrive tape](https://en.m.wikipedia.org/wiki/ZX_Microdrive) - difficult to find working drives, and the tapes could be damaged slightly more that other magnetic media, especially if used often in the past * consider "standard" media, e.g. punched cards, but with an obsolete non-latin encoding (and of course in a different language). E.g. from the [good old USSR era](https://en.wikipedia.org/wiki/GOST_10859). It will decode but read like gibberish. * [several of the](https://retrocomputing.stackexchange.com/questions/4457/what-interface-did-video-backup-system-use/12364) then-emerging [VHS tape backup solutions](https://en.wikipedia.org/wiki/ArVid). Quite obscure, and the medium is a standard VHS tape, but even if the protagonist finds a VHS player, he'll find it unplayable. * retro upon retro! [8-bit-era data audio recording on vinyl disk](https://retro-hardware.com/2018/04/22/vinyl-storage-programs/). These were very rare, but, unlike magnetic tapes, should be durable enough. Again, the protagonist finds a working gramophone only to find out the vinyl contains some strange computer sounds. [Answer] **Punch cards/tape** <https://en.wikipedia.org/wiki/Punched_card> / <https://en.wikipedia.org/wiki/Punched_tape> No punch working card/tape reader to find anywhere, so must be read without direct computer help. (Just do not allow them use scanner and try OCR it. Or you may let them discover this way later in your story, when you want them read all the big archive in some real time - still they need to write something to convert it from pictures to numbers and found out the meaning) Ideally punched on puncher out of ink, so basically only holes in paper. Still can be deciphered **manually** by translating holes to bytes, eventually to characters (if they are not just numbers) and then deciphered the meaning, as they may be just memory dump of mixed records, contaning both strings and numbers. Not too hard to convert it (for few characters), but totally slow and boring and error prone. (And must be carefull to not mix the cards (eg. dropping it on floor by accident) and not harm the paper). [Answer] In addition to some already-excellent hardware answers... ### Something using full disk compression Well before NTFS and cheap storage, there were programs that would implement drive compression to try to eke out a little more storage. I remember using [DoubleSpace](https://en.wikipedia.org/wiki/DriveSpace). Something like this, especially that only runs under DOS, will present non-trivial challenges. ### Something "encrypted" There were some screwy encryption schemes back in the day. If the data is hidden with something like Encrypted Magic Folders, you'll probably have a heck of a time getting it unless you *know* the exact manner in which it was hidden. If you *really* want to make the data hard to get, don't forget about [Steganography](https://en.wikipedia.org/wiki/Steganography). For that matter, I seem to recall writing my own encryption utilities back in the day; they probably aren't very good from a serious cryptography standpoint, but since you're going for data that is *hard*, not *impossible*, to retrieve, [security through obscurity](https://en.wikipedia.org/wiki/Security_through_obscurity) is your friend. [Answer] **The original floppy! 5 1/4 inches.** The hardware would need to connect using ports no longer available. Would need PCI, no pci express nor Sata. PCI. Also there are no drivers for new Operative Systems. So need to find a working Win 95 or Win 3.11. [Answer] # DataPlay DataPlay *discs* are relatively easy to find, including blank ones that will let you put anything on them that you want (mind, they're write-once media), but *players* for them are so incredibly difficult to locate that Techmoan [did a video about the format](https://www.youtube.com/watch?v=uEISYaWgCRg) only after he'd gotten a hold of a working player. Only for it to fail between recording shots in his hands before he could even sample all of the discs he had. They also require proprietary software to run (PC side), which while still available, looks so retrofuturistic its a painful reminder of what the 80s thought that 2010 thought the 80s looked like. The discs are the compact version of MiniDisc (which are themselves miniature CDs) and housed in a tiny case similar to 3.5" floppy discs and about an inch wide. Every player/drive in existence would have used the same plug-and-play module all produced by the same factory for distribution and use in whatever device the buyer wanted to include it in. The problem was, there were no buyers. [Answer] There are two 3.5" floppy answers, but I would like to answer a third one. Specifically, this answer happily allows the floppy to have a standard FAT filesystem as used by MS-DOS or Microsoft Windows. The trick is that this disk must be formatted as 1.44MB, but have originally sold as a 720kB disk. In reality, these were actually 1.44MB disks that didn't quite meet quality control standards, so they got downrated to 720kB as they would pass reliability tests that way. However, all that was necessary was that you punched a small notch in the side of the disk and it would be recognized as and could be formatted to hold 1.44MB... for a while. I used this trick when I was a poor college student, and it worked quite well. Until one day I went to use a different machine in the computer lab, and suddenly the disk was unreadable. Often the disk would simply start developing bad sectors at an abnormally high rate even in the same drive. [Answer] HD-DVD. Not only did they lose the format war, but the “winner” (blu-ray) also lost. Everyone moved over to the cloud. Your hero of the future will become an expert in the difference between a CD reader, a DVD reader, an HD-DVD reader, and a Blu-ray reader. The disc will technically fit in each tray, but only one will work. And if your hero is unfortunate enough to miss the distinction between an internal HD-DVD Player and an external HD-DVD player, good luck finding an HDMI-to-FutureDisplayFormat adapter. I sure hope they still have the remote, or then you get to find a universal remote and pray it pairs up. Actually, I don’t even know if HD-DVD players used remotes? I never had one. For extra absurdity, your hero might finally find an HD-DVD player...as a homemade upgrade to a vintage 2008 Lincoln Navigator backseat theater system. [Answer] Any 3.5 floppy disk. Particular any holding data from a now defunct older PC that used its own operating system rather than windows or DOS, even more so if it was one that didn't sell that many units in the first place. If you want something more difficult go for a 5.25 floppy or even an old tape drive. *I have old PC's with all 3 in the loft so depending on the OS they were written to with I '**might**' be able to get into any of those 3 (not without several hours of mucking around to get them working & refresh myself on how DOS or whatever OS they have works though), but most people won't have.* [Answer] One of the many incompatible streaming tape formats. Not only would you need a tape drive in working order, but an interface card for that drive, a computer that could use that card, and finally the correct software to read it. <https://en.wikipedia.org/wiki/Quarter-inch_cartridge> [Answer] A [Wang](https://en.wikipedia.org/wiki/Wang_Laboratories) minicomputer hard drive. Wang minicomputers were reasonably popular in 1970s: > > The most identifiable Wang minicomputer performing recognizable data processing was the Wang 2200 which appeared in May 1973. Unlike some other desktop computers such as the HP 9830, it had a CRT in a cabinet that also included an integrated computer controlled cassette tape storage unit and keyboard. Microcoded to run interpretive BASIC, about 65,000 systems were shipped in its lifetime and it found wide use in small and medium-size businesses worldwide. // Wikipedia > > > so that some even made it into the USSR at around 1980: > > During the 1970s about 2,000 Wang 2200T computers were shipped to the USSR. > > > They looked approximately like this: [](https://i.stack.imgur.com/HR4WL.jpg) I personally was let to sit and fiddle with one occasionally. They had text monitors and some kind of BASIC. The one I sat at, was used to store and print patient lab reports in a clinic. The good thing? This was how hard drive looked like approximately. 14" 2.5MB capacity: [](https://i.stack.imgur.com/8oCmX.jpg) Good luck finding an intact Wang to attach it to, or the docs for the interface. [Answer] Bubble memory cartridge from obsolete SHARP (or other) portable computer. <http://www.wylie.org.uk/technology/computer/bubblmem/bubblmem.htm> **EDIT:** One interesting plot point may be the near attempt to open the memory module which would immediately erase all the data. Or perhaps realising too late and loosing one of the datasets leaving only one older version of it. Or PDP-11 core memory modules. [Answer] 1/2" magnetic tape. It came in 2 varieties: 7 track and 9 track. Interestingly enough, I am told that NASA has a bunch of data from the early 1960s on 7 track tape. The magnetic domains are "punching through" the vinyl backing and causing neighboring domains to flip from 1 to 0 or 0 to 1. [Answer] There was the original [floptical](https://en.wikipedia.org/wiki/Floptical) format which predated (and eventually evolved into) the iOmega Zip and Imation LS-120 "superdrive". Only about 70,000 drives were ever produced, mostly going into SGI Indigo and Indy workstations. I think you'd be hard pressed to find a working drive today. [Answer] Anything that was even remotely successful as a commercial computer storage device will likely not suit your purpose, if only because there will be a surviving working model or schematics somewhere. (There always is.) What you are looking for is something that is well known, obsolete, not intended for computer storage, used for computer storage. VHS and Betamax videotapes fit the bill, possibly also 8-track cassettes. If you want something really exotic (but fills few of your filtering criteria), take a look at Valdemar Poulsen's telegraphone. [Answer] The hardest I can imagine is a magnetic core memory with corroded wires. The individual magnetic rings are still intact but the wires have become so rusty that they decay to dust when you touch them. Your character has to use tweezers to carefully break each magnetic ring out of the original matrix, clean it and thread it onto new wires in the correct orientation (because threading a ring wrong way round would result in a flipped bit in the data). Of course the memory should not be one of the really old ones, where each magnetic ring has a diameter of a quarter inch. The newer memories (well "new" is maybe not the right word. Those memories are still from the 60's) have magnetic cores which are hardly recognizable with the naked eye. When your character has finally repaired the memory he has to solder something so he can access the data on the memory. Of course he has to build another core memory for testing because reading a core memory destroys the data on the rings. After that he maybe has to find out what the meaning of the data is. Another idea: Once there were wire recorders that used thin steel wire to record audio on them. Of course these can also be used for storing digital data (like the Datasettes in the C64 did). If you ever had a tape jam, you can multiply that by 100 to imagine a wire jam that could happen. So maybe your character finds a big mess of what appears to be steel wool, but in fact is a recorded wire that he has to untangle and then find a wire recorder to play it. [Answer] > > It's where they're from, not when that makes them unfamiliar with current earth technology. > > > Where this is the case, the most important factor is how easy a thing is to describe to a search engine. When you take away pre-existing knowledge of our civilization's technology, typing in keywords like "disk", "drive", "media storage", etc can bring up pictures you can match with a lot of our older storage tech to help set you on the right track to research what you are looking for. If your storage item has any kind of serial number or labeling on it, you can simply explain that away through some scuff marks leaving only the form of the item to be searchable. This means the best obstacle you can put in an extraterrestrial's way may not necessarily be technological, but cultural. An unlabeled CD is easy enough to describe to find information about, but if an alien sees a 1st generation ipod nano and Googles something obvious like "small silver data storage box with a circle on front", he will not be able to figure out what it is to even begin cracking its secretes. [](https://i.stack.imgur.com/y5d0t.png) [Answer] Western Digital and perhaps Seagate drives after 2010 have some kind of file allocation table stored on a different chip which exists on the hard drive's circuit board. Previously if a HDD was overvolted and the circuit board was fried, you would just buy a circuit board for the same drive and fit it on, and solder the old file allocation data chip from the old HDD board to the new HDD board, and it is running. These days, you have to send an HDD to a recovery center if you fry the circuit board, because there are some obscure file allocation files which are irretrievably scrambled if you fry the HDD management board. So, if you had any recent HDD, especially the WD ones, and an event upsets the HDD board, you have to umount every HDD disk one after the other in some kind of dust proof room and get the data onto a new disk using forensic methods, and then use a decoding program to find what kinds of files are where. The forensic mathods to copy a drive at home would be pretty fascinating. [Answer] I read in New Scientist that there was a generation of PlayStation CDs that had copy protection by filling the whole first track with zeros. If you tried to copy the disk in a standard drive the error correction would fix some of the bits. The PlayStation would then refuse to play it. Someone burying a time capsule used this format for the data, but did not include a player in the capsule. They were hard to find a few years later. [Answer] **Adhesive Tape!** Not sure if this completely answers your question, but here is an obscure one I came across years ago... <https://www.geek.com/news/a-new-use-for-adhesive-tape-storage-544670/> [Answer] There are plenty of old tape formats that are no longer supported. The real question is when would someone have written data to the storage device. When I was in college I worked in the computer center for my college backing up our Digital Vax cluster to 9 track real to real tape. If you are saying that the data was backed up before 1992ish then 9 track makes sense. After that IBM 5150 cartridges, DLT cartridges would also make sense. Take a look at this wiki page and see which type of tape makes sense. There have been so many types of tapes drives and each one only works for certain tapes. Picking some type of tape drive makes sense if you want the character to have to search for the right drive and right computer to restore the data. Also think about the type of data. Because you want it to make sense that the data would be on a certain type of computer. Vaxes were real time systems. IBM main frames were more likely business data. SGI or Sun Microsystems would make sense for scientific. <https://en.wikipedia.org/wiki/Tape_drive> ]

[Question] [ It is a well known fact that if aliens invaded, it would be our puny kill-one-person-then-reload-for-half-a-second-or-more-firearms against their super-cool-ultra-mega-thingy-laser-mumble-quantum-force-unobtanium-whatever-ray-guns. We might also have some inferior reverse-engineered-tech-that-the-government-has-been-working-on-since-that-flying-saucer-crashed-and-nobody-noticed-and-it-was-all-hushed-up. Why are we always so inferior (other than the obvious need for there to be no chance for us to win) to them, or to put it another way, why are they superior to us? According to some theories, life is so easy to create, that all of it should have appeared at roughly the same time. So, we have had as much time as them to develop our war machines. Yet they are 2-3 times further ahead than us (we haven't even started at FTL, yet they cross the galaxy regularly to expand their empire). Why? [Answer] ## TL;DR: In order to interstellar travel you have to have the best technology possible ## Space is hard and evil Not necessarily evil *towards you* but just ... simply evil to anything and anyone. Even the smallest imperfection on a space ship traveling for a decade can cause *huge problems*. You must have technology good enough to build a ship that can carry life over interstellar distances ## Space travel is hard (and boring) Take for example the Mars mission. We are seriously discussing how to visit another planet in our solar system and according to [some on-Earth](https://en.wikipedia.org/wiki/MARS-500) and [outside-Earth](https://en.wikipedia.org/wiki/ISS_year_long_mission) experiments, we know that it is not going to be easy. One of ways to perform interstellar travel would be to increase speed. But that also needs advanced technology. ## So, this planet can bear life. But is it safe? Imagine that the best alien telescopes discovered our planet and this is the best that they can see: [](https://i.stack.imgur.com/miiBL.png) *Image source: [Wikipedia](https://en.wikipedia.org/wiki/Pale_Blue_Dot)* Imagine you have the technology for interstellar travel. You have engines and ships. You solved all the tiny-winey problems about how to get there. However, for whatever reason you simply *don`t know* what is going to await you there. Even if you are the most peaceful species in universe, you will most probably also pack your lasers and ion cannons, simply because you do not want to get destroyed by rocks and sticks. We are not packing any weapons to Mars, because we know it is empty. But I doubt that any travel to another star would be without weapons. [Answer] We think we are advanced but still barely able to send devices within the gravitational influence of our star. We managed to send living samples of our species on our satellite, but just for few days and then we discarded the blueprints. Now an alien race is visiting us, showing that they are able to mass travel trhough space. I would say that the mere fact that they show up on our door is a consequence of their more advanced technology. **You don't ride your bike until you are able to do so.** [Answer] By definition they have to have higher level tech just to be able to reach us in the first place! We can barely get unmanned probes to the outer solar system and that takes years. We've had a bare handful of humans walking on our own moon and even that was decades ago. None of us has ever walked on another planet. Any alien species able to reach us here has to be more advanced, in propulsion and life support if nothing else. For something set further in the future this doesn't always have to be the case, but certainly for any sort of "alien invasion" scenario it does. So to answer your original question - different life will always evolve and develop at different speeds. Look at how much we advanced in the past century compared to the millennia before. Imagine if the dinosaurs had developed tool using intelligence, they could have been flying to the stars millions of years ago. The more advanced and aggressive species will naturally spread further combined by the fact that a species less advanced than us cannot even reach us and the conclusion is pretty much pre-ordained. [Answer] I think that others have covered the simple truth - aliens must be more advanced to have come into contact with us - pretty well. As for the reason for *how* they had the chance to get advanced, just consider humanity. * Life has been around on Earth for billions of years. * Vertebrates have been around for hundreds of millions of years * Humanity has existed for hundreds of thousands of years * In the modern world, 100 years is long enough for technology to be utterly obsolete in most cases Now assume that there's a 0.01% difference in the progression of vertebrate life-evolution-civilisation-technology on another planet. 0.01% equates to tens of thousands of years - it's bronze- or stone-age technology vs ICBMs, satellites and fifth-generation fighters. In fact, much better to look at it this way - the chances of there being another civilisation at roughly the *same* technology level as ours are incredibly tiny. We'd easily expect them to be thousands of years different, but they could well be *millions* of years ahead of us (or behind, of course - but then we'd have to go to them). Humanity hasn't really evolved along a nice, linear timeline from single-cell to high-functioning tool use; there's no particular reason that we couldn't have evolved hundreds of millions of years ago instead, and been millions of years earlier on the timeline. [Answer] Summarizing, mostly: we are an *extremely* young technological civilization, so anything that finds us should statistically be a lot more advanced. Suppose life appeared in many planets at roughly the same time and also evolved toward intelligence and interstellar travel capability at roughly the same rate. There have been primates for about 50 million years. Suppose in an almost-exact copy of Earth a species had evolved from the first primate at a rate 0.01% faster than ours. That would mean a 5000-year head start by now. These alternative *Homo sapiens* would have been developing nuclear weapons and landing on their Moon at aroud the same time our ancestors were building Stonehenge. And the whole scenario is of course wildly unrealistic. The idea that "life is easy" is misleading. Life might appear easily, but there's no guarantee that it will endure, and in any case most experts think that the predominant kind of life in the universe must be microscopic. If intelligent life were so common, we'd be finding signs of it all over (see [Fermi paradox](https://en.wikipedia.org/wiki/Fermi_paradox)) unless all intelligent life, by an incredible coincidence, was just a bit less advanced than us or had a bad case of paranoia that led it to avoid all contact with the rest of the universe and to erase all traces of its presence. Also, neither biological evolution nor technological progress work linearly or predictably. It makes no sense speaking of an alien species being *n* times more advanced. How do you measure that? There are things like the [Kardashev scale](https://en.wikipedia.org/wiki/Kardashev_scale), for sure, that attempt to measure technological advancement by isolating one variable (in this case, the amount of energy employed for communication), but that's it. There's no guarantee that, if FTL is possible (to name one of the key technologies needed to go out and conquer SPACE!!!), then all technological species will be able to discover it. It may be that FTL depends on mastering states of matter only readily found near the cores of giant planets. It may be that you can only construct an FTL engine near a neutron star or black hole, and only civilizations living close to one of them will ever make the jump. In many commercial science-fiction scenarios you have advanced aliens laying waste to Earth (or to human colonies) thanks to superior technology, and Earthlings doing their best to resist and ultimately fighting back. In more realistic scenarios humanity would not only not have a chance, but probably wouldn't even know what hit it. If you can master FTL travel for big ships, or even NAFAL interstellar travel, then you can produce, control and direct huge amounts of energy: more than enough to reduce Earth's biosphere to ash from a good distance. [Answer] As other have pointed out, aliens must have MUCH higher tech just to get here. Then, someone said that doesn't mean they brought weaponry, or have more advanced weapons. I don't think that's accurate. When you can manipulate energy the way a star-faring race can, your everyday items are weaponry to us. As an example, take a common Caterpillar bulldozer. They're everywhere. Say your construction brigade landed on a planet of medieval human types. A common bulldozer could pull down any castle. It could apply the muscle of 1,000 men, easily. The point is that a common appliance for us would seem like a magical mechanical dragon to them. A monstrous weapon indeed. Similarly, an alien cigar lighter could probably melt the Pentagon. [Answer] This isn't always true. Star Wars and Star Trek are both extremely famous SF worlds where Humans often meet civilizations far behind them in technology (and sometimes ahead). There are many other examples. In fact, the idea that aliens marginally more advanced than us would show up in our civilization is exceedingly unlikely. Interstellar civilization is a relativistic phenomina. If you *can* colonize other stars, the amount of time it takes to colonize a galaxy a blink of cosmic eye, even with slower than light ships. Our primitive Voyager travels at 62000 km/h. At that rate it takes a mere 1.8 billion years to cross the Galaxy. If we had a civilization that sent "civilization seeds" (generation ships, star wisps, whatever) at Voyager speeds, and the new civilization took 100,000 years to mature to the point where they could send out a similar seed to two other stars within 10 light years, the net velocity of the probe would drop a mere 1/3. After even a handful of doublings, you'd run short of stars within 10 light years. If you can send the ships further, you do. There are 100 billion stars in the Milky Way. This is a mere 36 doublings. At 300,000 years per generation, that is 11 million years. The limit becomes the speed of the colony ships, not producing them, very quickly. It takes 10% of the lifetime of the galaxy to cross the galaxy at voyager speeds. Getting a star wisp up to faster speeds is not that hard with todays technology. The hard part becomes surviving the cold eons between stars, stopping at the other end, and sending enough resources to start a new civilization (even a machine one) at the other side. If the star wisps move 10x faster, at 0.0005c, they cross the galaxy in 200 million years. If we go science fantasy and go FTL, the effect is even larger. Now, why does this imply there aren't more advanced civilization? Because the speed at which they can travel means that the time between them reaching the stars, and them being here, is short compared to the history of life on Earth. Even a small difference in how they develop technologically would make a huge difference in the scale of their civilization. If they developed 1% earlier, they'd already be here. If they developed 1% later, we'd reach their planet in the equivalent of the dinosaur era. The ridiculous level of precision for them to be anywhere near us in civilization scale is not practical without some quite recent galaxy-wide synchornizing event. These don't make great stories. Now, if you want a story with humans that are "like us" and you still want interstellar civilization, the easy way is to give the aliens that civilization. This naturally places them far away from us. [Answer] Even accepting your premise of equal starting times (stars are constantly being formed, ours is supposed to be 3rd a generation) there is plenty of room for optimization in our route to the stars. What if we didn't waste the first couple billion years of life being single celled? We appear to be the descendants of survivors of four major mass extinctions, were all of those really necessary? It seems the answer to those questions are tied up with the speed of evolution and I know far too little about that to guess if it could be other than it is for us. But how much time do you really need to cut out to leave us on the knife end of a gun fight? Think about if the United States made war on some tribe in the Amazon. We can't be much more than fifty thousand years ahead of the most isolated tribes since we both walked out of Africa around then. Less than 1% of 1% since cells decided not to go it alone. [Answer] > > It is a well known fact that if aliens invaded, it would be our puny kill-one-person-then-reload-for-half-a-second-or-more-firearms against their super-cool-ultra-mega-thingy-laser-mumble-quantum-force-unobtanium-whatever-ray-guns. > > > It's not a fact. We have 1-kill/1-reload weapons because they're what we need on Earth right now, but when the aliens turn up, we upgrade to [chainguns mounted on exosuits with supplementary rocket launchers](https://i.kinja-img.com/gawker-media/image/upload/s--QvU6ppPf--/c_scale,fl_progressive,q_80,w_800/vjeahclclgz3s9jbv0r1.jpg). When they fly in with their interstellar spaceships, [we fight back with ours](http://www.sparknotes.com/lit/endersgame/summary.html) and destroy them before they get to Earth. Asimov's [Green Patches](https://en.wikipedia.org/wiki/Green_Patches) has humans flying to an alien planet with an alien life form capable of mind control; reading the pilot's mind about Earth, it sneaks onto the ship and disguises itself as a section of wire in the control board. By the time the ship returns to Earth, the alien is poised to invade ... '*If the stowaway manages to reach Earth, it will eventually convert all life there into a single organism with a unified consciousness — and green patches of fur instead of eyes*', but the section of control board it chose is related to landing and when that engages the creature is electrocuted - the sneak invasion attempt happened without the aliens developing space travel and is countered because of our superior technology. (Thanks to Henning Makholm for the story identification I couldn't remember) When the [Vogon constructor fleet flew in](http://hitchhikers.wikia.com/wiki/Vogon_Constructor_Fleet) we had no way to fight back at all - they didn't quite invade, but they did wipe us out, guns weren't involved, the power difference was too great. When the [Independence Day](http://www.imdb.com/title/tt0116629/) aliens flew in, there was gunfighting but we properly fought back with superior computer technology[](https://i.stack.imgur.com/mkl2H.jpg): When the aliens invaded in the [Midwich Cuckoos](https://en.wikipedia.org/wiki/The_Midwich_Cuckoos):- '*The Russian town was recently "accidentally" destroyed by the Soviet government, using an "atomic cannon" from a range of 50–60 miles.*' - they got nuked. When [MorningLightMountain](https://en.wikipedia.org/wiki/Commonwealth_Saga) comes for the Commonwealth:- '*the small human resistance that exists on what remains of the Commonwealth worlds attacked by the Primes. Human resistance forces have found two ways to fight back: using the Prime weapons (primarily directed-energy weapons) against the invaders, and disrupting communication between the slave caste (motiles) and the commanding caste (immotiles) of the Primes. Meanwhile, the humans in the remaining Commonwealth pursue other plans: to develop a set of weapons and warships to defend against the next Prime invasion and force the conflict back into Prime space;*' - humans aren't fighting with our weapons of the time, we're fighting with stolen weapons of theirs to keep them away while we build better weapons. [Andromeda Strain](http://rads.stackoverflow.com/amzn/click/006170315X) - "An accidental invasion by an extraterrestrial microbe that almost instantly clots human blood or causes insanity." [Day of the Triffids](http://rads.stackoverflow.com/amzn/click/0812967127) is a biological invasion where a) they have no tech weapons, guns work fine against them, and b) so do flamethrowers. [WorldWar](https://scifi.stackexchange.com/questions/5422/lizard-men-from-space-invade-earth) appears to have aliens arriving with similar level of technology due to a mistake in information collection, and humans fighting back with equivalent guns and also nukes. --- In summary, as other people have said, if you want to tell a story where the aliens invade Earth, they necessarily must have the technology to get here. Yet we don't want Earth invaded so if we possibly can, we will try to intercept in space far away to neutralize it before it gets here, so that puts an upper-bound on our technology level as well. Not only must they be able to get here, we must not be able to get usefully off the ground. And if you want the invasion to look like humanoid soldiers which current day humans can fight against, the aliens must be similar to us - if they are invincible robot humanoids, no appreciable fight can happen and humans will lose. If the invasion is a spec of nanomatter which turns the Earth into grey goo, humans will lose. Yet if they are humanoid, they need portable, powerful weapons allowing a small attack force to take on a planet - so they must be more powerful weapons. Another factor is if you want to make it a relatable war story, it's basically going to look like World War II. No easily relatable and exciting war story is about how NSA cryptographers analyze alien radio signals with a deep-learning neural network to find a padding-oracle attack on the encryption used to authenticate the soldier with the directed energy weapon and then asking the populace to download an Android app which reuses smartphone wifi radios to interfere with it and the alien guns stop working. How dull would that be? And again, right now humans use 2017 level technology to fight - we don't nuke each other because Earth is too small and life is too fragile for nuke-levels of energy and radiation. We're not developing more powerful weapons, because we don't need them. So when the aliens arrive, we're unprepared for bigger and more powerful weapons. we're developing more precise weapons which move humans away from the battlefield instead - a future fighting force won't have phased plasma rifles in the 40W range, and wasteful suppression fire, they will have 1-shot/1-kill [personal self-targetting sniper/cruise missile launchers](https://youtu.be/DTqa-NEwUbs?t=94). Probably with the humans far away. But other stories do exist - where the invasion is sneaky rather than ships full of soldiers, where the humans have higher technology but it's not a technological invasion, where the humans fight back with more powerful weapons than guns, where the humans fight back in space first, and more. I suspect stories where aliens invade by nudging an asteroid to destroy the native Earth dinosaur species and seed alien biped species instead, exist as well. You get the story you want to tell. PS. when was the last time you read a gripping story about the termite mound that spent years gearing up for war and then an anteater tore the side off and ate 20,000 of them and all their preparations for war were useless? * The humans are going to win, fact. * Both sides need to be roughly evenly matched or the stronger side will easily win and there's no story. * Rooting for the underdog is more fun, stories are better with tension and imminent disaster, so the humans need to be the weaker side, therefore the aliens get to be stronger. [Answer] > > basically, why are the stereotypical alien invaders 4-5 times more advanced than us? > > > Because low tech aliens aren't interesting enough to become stereotypical. Or if they are interesting, they are unique and therefore not a sterotype. For instance, the [Honorverse](https://en.wikipedia.org/wiki/Honorverse) by David Weber; there are about six known alien sophont species but since humanity is an interstellar civilisation everyone else is uninteresting. The first book was set in the same solarsystem as the latest discovered aliens and they had exactly *zero* impact on the story because what *could* a neolithic race do in a space battle? The sophont race humanity meets during the series is too unique to become a stereotype. [Alien](http://www.imdb.com/title/tt0078748/) is also an example of a non-technological race that are just too unique to become a stereotype. Compare this to the [Independence Day](http://www.imdb.com/title/tt0116629/) aliens; the came, they saw they stomped. Could describe any number of alien conquerors: [Mars Attacks](http://www.imdb.com/title/tt0116996/), [Signs](http://www.imdb.com/title/tt0286106/). They *could* be completely different, hive mind, facist, democracy, a non sentient cloud of locusts, a byzantine buerocracy based entierly on poetry... There isn't much difference from the point of view of humanity, all we see is the sole of a boot as it stamps down. One attribute, overwhelming power, and no other discernible characteristics: instant stereotype. [Answer] Consider what would happen if an alien ship appeared, alien soldiers jumped out, and all they had were Earth-style weapons. All one thousand of them. Against seven billion humans. They would be beaten into the ground before most of the world even knew they had landed! To compensate for their inferior numbers, they *need* superweapons to stand the slightest chance. [Answer] # Life and technology should happen earlier in older stars ### The sun is young relative to the universe  Figure 1 shows a planetary nebula that is result of a sun-like-star that already died (source: wikipedia). The sun is a middle aged 3rd generation star. To put another way the mainstream theory is the universe was around for 9 billion years before the sun was born. . ### Life and technology stalled many times on earth It is not difficult to believe that a solar system similar to ours can have developed life and technology faster. Even a percent faster means 4.5 million years before. ### Alternative solar systems may be more suited to space fairing civilizations  Figure 2: [Real planets around habitable zone of other stars](https://www.nasa.gov/keplerbriefing0723) (source: NASA). Keppler Telescope found in at least 8 earth-sized planets on the habitable zones of G and K stars on a [very tiny corner of our galaxy](https://kepler.nasa.gov/science/about/targetFieldOfView/) using a detection method that require a rare alignment between the planet, its star and the earth to be found. This means our galaxy alone should have several hundred thousands of planets such as this. In a superearth the cost of chemical rockets may be too high. Then, the aliens get right to advanced propulsion and discover new physics that is key to FTL, advanced computers and weapons. In a system with a few Mars and moon sized planets on the habitable zone the species may evolve more resilient to space radiation and the effects of zero g. Chemical rockets on those planets will be cheaper, then they become a space fairing civilization sooner and space research may allow breakthroughs in advanced physics. Something like the "em drive" could have been tested in weeks in a scenario like that. In opposition to the decades will take in our world. In a earth like planet tidal locked to a red dwarf, solar an wind power generation may be stable and the world will never need oil. Taking power politics aside early in the technological development may allow a faster technological developement. ## There was more than enough time for a mult-galaxy empire to arrise There is space voids that some people think like could darken entitled galaxies with solar panels. I think is a stretch but... ## To travel to another planet with a sufficient large military force implies to be more technologically advanced than we are But in the end boils down to the simpler argument. To invade another planet you need technology to build massive space ships propelled with something more powerful than chemical or ion drives. And be able to survive in those ships for the duration of the flight here. We are far from this technology level and then anyone that reach our planet with a military force big enough to invade will be more technologically advanced than us. ## The physics of efficient space travel may have the same basis than the physics of the advanced weapons Actually the advanced weapons can be a side effect of the advanced propulsion. And vice versa: * **[Orion drive](https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion))** are fueled by cheap nuclear bombs. Implies mastery or immunity of radiation. * **[Interestelar ramjet](https://en.wikipedia.org/wiki/Bussard_ramjet) or [deadalus project](https://en.wikipedia.org/wiki/Project_Daedalus)** are fusion drives. Fusion in that scale may power in atmosphere destroyers, tanks, microwave beams, asteroid catapults and more. * **[Warp drives](https://en.wikipedia.org/wiki/Warp_drive)** may make excellent and weird bombs, personal shields and more. [Answer] [Selection Bias](https://en.wikipedia.org/wiki/Selection_bias) > > Selection bias is the selection of individuals, groups or data for analysis in such a way that proper randomization is not achieved, thereby ensuring that the sample obtained is not representative of the population intended to be analyzed > > > Lets assume there are a large number of species across the universe. All of them are on the same sort of timeline in terms of 'age since big bang' - some will have a head start, because they didn't get wiped out in the 'dinosaur' era, like our dinosaurs did. Others has a couple more catastrophes. And there's a spread of 'how optimal is your planet' syndrome - ours is pretty good, comparatively, as our large moon gives us access to heavier elements with *relatively* lower effort. But if there's a big spread, then it stands to reason - technologically there's some in advance of us, and some behind us. The critical difference though is - the Universe is pretty huge, and faster-than-light travel may well be impossible as we currently understand it. Inventing FTL means more tech than we have. And a generation ship is ... probably *just about* on the edge of our technical capabilities. But generation ships are SLOW - the hint's in the name - multiple generations. [Nearest exoplanet candidates](https://en.wikipedia.org/wiki/List_of_nearest_terrestrial_exoplanet_candidates) ... but we're also not sure there's any alien life on any of those, which would imply they're further away. (Or somewhere we're not looking, that's possible too). So - net result. For aliens to come *here* they would *have* to be more technologically advanced, because *we* haven't gone *there* yet. Because we can't. [Answer] **Because lasers look more awesome on screen than bullets.** See also *laser swords* over metal swords. This is all based on [The Rule of Cool](http://tvtropes.org/pmwiki/pmwiki.php/Main/RuleOfCool). As others have stated in better detail, the aliens would, by rule, have to have more advanced technology to successfully complete an interstellar voyage. But that doesn't mean they have to have super-advanced sci fi *weapons* too, if standard projectiles are better, for some specific definition of "better." But the rule of cool overrules that in fiction. As a related point, watch [District 9](https://en.wikipedia.org/wiki/District_9), in which the aliens weren't really *that* much more advanced than us, at least in weapons technology and survival skills. They had more advanced ships and biological sciences, I guess. [Answer] If an Alien civilization reached our solar system they would most certainly be more advanced than us because, even if they launched an interstellar ship as soon as they could, because even if you use what many people consider my extremely high chance number of advanced technology civs, the closest one would be 1000 light years away. The highest speed they could achieve would be 10% the speed of light which means by the time they got to us they'd be ~10000 years beyond 1960s tech. Even at a slower pace with a small population they'd still be so much more advanced by the time they arrived due to having info beamed to them and them constructing stuff on the way. [Answer] The level of technology development is driven by two factors. 1. How long it has had to develop. 2. How fast the technology is developing. 1 is easy--older alien civilizations are more likely to have higher-level tech than us, because they've had longer to develop it. The universe is 15 billion years old we have done all of our tech development from fire to atomics in the last 10,000 years. In terms of the life of the universe or the possibility of life in the universe a lead of 10,000 years is nothing. What chance would cave men have against us? 2 is much more complicated. There are many factors driving technological development. A big one is competition--look at the huge technological advances made during WW2 or the "space race". Necessity is similar: if an alien species is threatened with extinction, due, say, to the failure of the ecosystem on its home planet, it is going to be very driven to get out there. There are also less urgent factors which will affect the alien species, e.g how much do they value education? or what is the social status of engineers and scientists? [Answer] They have to have superior technology in order to reach us in the first place. It's something of a self-fulfilling prophecy. [Answer] Not all planets are created equally. *"According to some theories, life is so easy to create, that all of it should have appeared at roughly the same time. So, we have had as much time as them to develop our war machines."* I'm going to go with the assuming all life supporting planets formed and cooled at the same time. Lets take Earth and an Earth like planet,(lets call it Learth) for example. Earth and Learth both had life start at roughly the same time. Unfortunately for Earth it went through several extinction level events. Learth did not necessarily go through these same events. So one of Learth earlier species had time to evolved into a species capable of developing tool, societies, culture and eventual Space travel. Earth had to wait till after 5(?) extinction level events before that happened. [Answer] **TLDR: The premise is false. Aliens are not always advanced. In fact Earth may have even been "invaded" by mere alien microbes.** You ask, "Why are we always so inferior ... to them, or to put it another way, why are they superior to us?" If you're asking why we are always so inferior in books and movies, the simple answer is that it is because Earth getting "invaded" by a bunch of protoplasmic microbes doesn't make as exciting a story. Yet in contrast to many those who imagine advanced alien invaders, there are many scientists who believe earth has actually been "invaded" by microbes, as discussed in the articles below. A short except from the *Telegraph:* "The team behind the Rosetta comet landing mission have announced they have found the amino acid glycine and the element phosphorous in the dust surrounding 67P/Churyumov-Gerasimenko." "Comets contain an awesome cocktail of organics material that, if provided with the right conditions, could then go on to form life......So, in the case for Earth, this supports the idea that comets impacting Earth could provide the right ingredients for life." <http://news.berkeley.edu/2013/03/05/research-news-briefs-did-comets-seed-life-on-earth/> <http://www.telegraph.co.uk/science/2016/05/28/comets-could-have-sparked-life-on-earth-as-building-blocks-of-dn/> [Answer] The alternative to more advanced invaders is invaders with a natural, not technological, ability. If some kind of space-warping is possible according to the laws of physics, perhaps a creature exists that has a natural means of exploiting that principle and traveling between worlds. That creature does not need to be advanced enough to understand how it travels, it just does it. If it arrived here, we might be more advanced than it. [Answer] According to some theories, mostly by the astrophysics, life would not appear at the same time. One reason why - the universe is expanding after the Big Bang. So some galaxies closer to centre would be (could be) long dead and abandoned while some planets would just start to create primordial soup. **IF** your universe started as it is all at once then you would not have the problem with aliens. **BUT** if you want to stick to our universe you need to follow the rules. [Answer] We cannot assume that all solar systems have asteroids although it is likely. If a planet is bombarded with such material, even in a random fashion, over billions of years, it will cripple the dominant species on the planet, who rely on brain power rather than defense mechanisms to survive. So the development of a species can be heavily influenced by external forces at work, beyond the control of the dominant species. [Answer] We have traveled to our moon, and have sent probes throughout our solar system. We move in space by throwing stuff overboard (i.e. thrust gases.) At the bleeding edge of our technology, it will take [100 years](https://en.wikipedia.org/wiki/Project_Longshot) for us to reach our nearest neighbor. So, until we have the ability to span the [unbelievably great distances](https://en.wikipedia.org/wiki/Interstellar_travel#Interstellar_distances) of space with ease, anyone that visits us must have made massive leaps of scientific advancement over what we can do. Therefore, visitors must be more advanced. Of course, we don't know what we don't know. Most speculation involves straight-line advancements. We could uncover a fundamental truth next year, that would allow us to open a traversable wormhole using few WI-Fi Routers coupled to an empty tuna can. Then, we could be the ones visiting the far corners of the galaxies in something akin to the space shuttle. [Answer] So tactically, waiting for a potential threat to be on the par is not a sound strategy. Any advantage an enemy has is a disadvantage to you. So, if there is a species of intelligent apes that are showing signs that they may be a threat to you in the near future, giving them time to close the gap is going to make eliminating the threat are the more difficult if it manifests. Of the few things I give to the sequeal to Independence Day is that it's probably the only Alien Invasion story I am aware of that touches on the difficulty of presecutiong an interstellar scale war... the time to recieve and send reinforcements is going to be much more difficult than a more local war, which means all its logicistical supplies (ammunition, food, medicine, communications equipements sleeping quarters, ect) are going to have to be shipped in with the invasion fleet. And sure, an initial showing might result in the destruction of large urban areas... but as has been observed, "War never changes". Consider Sun Tzu is still taught in an age where all weapons he would have available to him are hopelessly obsolete. The longer a war is prosecuted, the more likely the invasion force is likely to fail. This is because the defending forces have the supplies they can more readily rely on, where as the invading force will have to rely on either finding supplies they can use or those they brought. The defenders also have better knoweldge of the terrain and better population of able bodied defenders (an invasion enteres with its commited forces, but the defenders can quickly draft their civvilians to assist in defense operations.)... Even if military chains of command of the defenders are wiped out, guerillas with simple idealogies of "They ain't from here, kill them" are sure to be a tolling force on the continued pressence for the alien force. This is all before realizing that humans are evolved to live on Earth, where as the aliens are not... sure... they might be similar, but we'd be the most efficient of the two in terrain movement, air, water, and food consumption, and our bodies are designed to work on this gravity. The invading aliens might have some similarities, but the the idea that they are superior to us in every way on earth is laughable... especially considering where one of the most populous species for our size AND have some of our own phsyical superiorty in our own animal kingdom. For example, humans are amazingly resilient agaisnt tramatic pain and we can avoid going into shock a lot better than most animals. We're also the most physically enduring animals on the planet. There may be a lot of animals that can out run us or out swim us, or out climb us, but few do all three and none can outlast... The only feat of physical competition humans have ever one over the animal kingdom is the Ultramarathon... humans are slow and steady, and will tire out long after any animal that can take a lead by speed and recover faster than that same animal can... Its one of the reasons there are 7 billion of us. We are the Elizabeth Warren of the Senate that is the Animal Kingdom... still we persist! Even if techonogogically superiority persists, a weapon does not win a war... numbers of weapons win a war. Even World War II, which was ultimately concluded by the Atomic Bomb, the fact remains that America had more than Japan could recover from was the deciding factor, not that at time of surrender, they had just one left and had Japan called that bluff, America would have a siginficant amount of time before they could rain down more. On the otherside of the globe, the Germans allowed themselves to believe that killing two allied tanks for every one german panzer was certain to ensure victory, but the decision was made by the fact that Americans could produce from raw materials to battle field five tanks in the time it took Germany to produce one. Over the scale of the war, the ability to field tanks faster fliped the number. From raw material to death on the battle field, America tank forces would net one new tank for every two that the Germans lost in combat. Taking this to alien levels, sure, you may have wiped out 50% of the population in the initial invasion... but that still leaves 3.5 billion people who all want to kill one of your guys... with those numbers, it's a lot more you have to kill. In the alien situation, the prolonged occupation of Earth would mean that the Aliens would be expected to feed troops with dwindling food supplies and limited items from the planet that didn't poison them and probably didn't provide nearly enough nutrition to serve as an efficient replacement. So your troops are expected to engage enemy forces while malnourished and unhealthy because of it. Lack of proper nutriotion and stressful conditions (such as war would produce) mean the immune system isn't working at its best opening threat from Earth's oldest method of fighting alien invaders, germ warfare. And then you have to deal with the fact that people are trying to kill you... no war is 100% causialty free for the victor. You're going to have losses no matter how much you try to prevent it. And resistence cells are notoriously hard to erradicate. The United States was able to defeat British Forces in the Revolutionary War and War of 1812 largely on guerilla tactics and Admiral Yammoto famously reminded the Imperial Japanese government of this fact to successfully convince them they only wanted non-mainland territorial concessions from the outcome. In turn, Northern Vietnam was able to hold out against the United States superior war machine by pretty much doing the same thing. Afganistan, the infamous "Grave Yard of Empires" has relied on it's natual hell-hole like living conditions and combined with hit and run tactics to win against every invasion force in the history of civilization by just waiting for them to declare "fine, you keep this dumb land anyway". It could even be argued that the legitimate Afgan government is whoever is winning the tribal fighting at any given time. Depending on how much time the alien species needs to gather enough forces to send re-enforcements and resupplies to facilitate planetary occupation, the prolonged war could last years and when it ends, it's because the aliens consider the blood and treasure they put into verses the expected reward. Every day the invasion cannot definatively passify the invaders is another addition to that charge and sooner or later, it becomes untenable to take from a purely logistical nightmare forming around the defense. TL;DR: Aliens will not invade and conquer Earth because that's where Afganistan is. No one conquers that place and surivives. ]

[Question] [ In the game "Stelaris" torpedoes and missiles are different categories of weapon. Presumably they wanted to include numerous kinds of weapons for the player to chose from. These weapons are all launched from spaceships in deep space. (They only ever travel through a vacuum; never through air or water.) **What explanation could provide a distinction between these two interchangeable concepts within the genre of space opera/sci-fi?** Please try to keep it relatively grounded within real world physics and engineering. In the future, science does not invent a magic McGuffin machine... [Answer] In a purely terminological sense, there is no difference between a torpedo and a missile if they inhabit the same space - a missile is a guided, self-propelled weapon that travels through the air and a torpedo is a self-propelled weapon that travels through the water (in modern terms, inevitably guided as well). My first thought though could be to do with the method of damage. In the anti-shipping mode, torpedoes are fuzed to detonate below the ship and use the effects of pressure and cavitation to effect damage on the target. Missiles have a very wide range of destructive modes, but they *do* include direct strikes against targets (admittedly, some anti-submarine torpedoes also use direct contact and shaped charges, but never mind...). My thought would be that the difference in space could be that torpedoes are heavyweight weapons with large warheads that can damage enemy ships even without a direct hit, whilst a missile is a smaller, more manoeuvrable weapon that would need a direct hit. Another possibility is the difference in the contemporary world between ballistic and cruise missiles - a cruise missile's engine works for the entire flight, whereas a ballistic missile *boosts* in the early stages of its flight and then follows a trajectory towards its target. A torpedo could be a very long-ranged weapon that has a long burn time for the greatest propulsive efficiency (possibly for attacking stationary or non-manoeuvring targets) whilst a missile has a fast boost-only engine for getting it up to high speed as fast as possible, in combat against targets directly threatening the launch platform. [Answer] Send your torpedos through sub space. They go "underneath" so they're torpedos. Missiles travel through normal space. Different tactics and countermeasures apply to the distinct types of weapons. [Answer] Hi and welcome on board the star cruiser *Pedant's Dream*! On board this state-of-the-art warship we carry plenty of weaponry- railguns, lasers, missiles, torpedoes- What's the difference between those last two, you ask? Good question! It's really a matter of semantics. In general, lighter munitions used for antifighter and self-defense purposes are classified as "missiles," while heavier weapons intended for use against capital ships are "torpedoes." To many, the distinction seems rather pointless, but the higher-ups in the UN Astro Navy bureaucracy insist on it. Some think that it's because they get kickbacks from the weapons companies, but I don't really care. All that matters to me is whether you can load it into the right launcher and fire it into the right direction. Welcome aboard, rookie! [Answer] Mass, thus manoeuvrability: * missiles - lightweight, fast to accelerate (changing direction involves acceleration, right?), more manoeuvrable - but pay attention to cruising speed - the faster they go, the harder veering becomes; more usually than not they have homing devices. Lower damage. Use against fighters, bombers * torpedoes - pack a massive punch, thus they are massive. Hard to accelerate, many models (like photon torpedoes) won't even change direction once launched. Use against capital vessels [Answer] No need to discuss tactics or engineering qualities. The definitions are enough to show that ... ## Missiles are projectiles in general, and torpedoes are self-propelled. According to dictionary.com, **Missile** describes "an object that is forcibly propelled at a target, either by hand or from a mechanical weapon" and can range from everything to a pencil to a nuclear warhead. It's broad enough to cover space-based weaponry as long as it is thrown or launched. **Torpedo** describes "a ... self-propelled ... missile designed to be fired from a ship or submarine or dropped into the water from an aircraft and to explode on reaching a target". While torpedo is usually associated with water, you can take the self-propelled aspect away instead if you so desire. Missiles are any of the things that you launch (explosives, shells, bursts of plasma), and torpedoes are things with their own fuel that don't simply rely on momentum (like self-guided rockets). [Answer] Considering both weapons got similar propulsion and operates in the same environment the **only difference** is how they kill. Torpedoes are made to target huge vessels and explode it's thick hull. A big military vessel can need multiple shots to sink. Missiles are intent to target small and fast targets. They seek the target and detonates a fragmentation warhead when they get close. They actually don't hit the target and that's specially true with anti-air missiles. A missile is intended to open hundreds of small holes with hot metal scraps. There are dedicated anti-ship missiles like the legendary [Excocet](https://en.wikipedia.org/wiki/Exocet). They are made to take advantage of the kinetic energy to penetrate the hull above the water line (where the hull is more slim) or even try to target the command center. You can say they are rocket flying torpedoes. There's of course dedicated anti-runway, anti-tank missiles actually explodes things like a small torpedo. When I play **Stellaris** I also try to imagine torpedoes as more massive as missiles and intended to penetrate and do huge explosions inside the hull. [Answer] # A missile chooses targets automatically and homes in on them, a torpedo requires target selection and has less maneuverability. the TE24 (Terran Enterprises model 24) template is the Galactic standard for all mass-produced spacebound projectiles. This standardisation allows ships across the Milky Way to rearm at any friendly station or salvage any unfired ammo from both friendly and hostile derelicts. Part of the standardisation is a modular approach. Each template-based projectile has a number of slots that can be fitted with any combination of modules, ranging from a variety of payloads, engines and advanced guidance features to integrated IFF and advanced automated target selection modules. Missiles have an engine optimised for speed and maneuverability, a close-range payload, an automated target acquisition and tracking system and a guidance system that works in tandem with the TATS. When fired, they choose their target manually based on a number of parameters, then automatically follow the target until they explode or the target is dead. These missiles can be fired multiple at the same time, at which point each missile will choose a different target. if a target is destroyed before the missile can reach it, it chooses a different target. Torpedoes have an engine optimized for speed, 2 highly damaging payloads and a guidance system that required selecting a target in advance. These deal much more damage than a missile, but are not capable of acquiring targets automatically. A target must be configured in advance while loading the torpedo. A target cannot be changed after launch, and a missile targeting a destroyed target will still attempt to detonate against any remaining pieces of the target. Because of this distinction, missiles are most often used against smaller targets where manual targeting and a potential loss of target are inefficient. Torpedoes are most often used against immobile or slow moving targets: capital ships, space stations, automated defenses,... [Answer] **Torpedos make use of the enemy ship's electric and magnetic fields.** **Background:** Some SciFi settings feature propulsion systems based on expulsion of ions or plasma. Yet others feature a strong magnetic field around the ship, a field which may contain plasma. This field is "pushed" by the solar wind. These are not farfetched, but mimick designs in use today or on the drawing board at NASA. In any case, there's a "medium" consisting of particles or magnetic fields, in close proximity to enemy crafts, that a missile could "push against" using electric or magnetic fields. This creates an analogy with torpedos that push against water. A missile with this propulsion would be able to "sneak onto" enemy vessels by showing zero exhaust and be able to "latch onto" the fields of large vessels, like a missile following the wake of a ship. [Answer] There's only a few things missiles / topedoes can do. So, we can make a very short list of how you might distinguish them. ## How they're stored Presumably they're stored as they are today, in internal explosion-resistant lockers, that aren't going to be much different for space missiles vs. space torpedoes. But there is another option: one or the other might be carried around permanently **on external structures**, like how bombs are carried on the wing pylons or conformal tanks of present-day jet fighters. Although a distinction based solely on how they are carried alone doesn't really seem to justify having the two different names. ## How they're sent This might work alongside storage. The name torpedo has its association with stealth (from submarines and all), while a missile might take more preparation to launch. So, torpedoes might be able to be launched from **concealed openings** on a space-ship's hull. While a missile might first need to be assembled, mounted and fueled on an external fixture, that is either in plain sight or more easily detected by enemy ship's equipment. The distinction would be most important when the intentions of an approaching ship are ambiguous. So, a **torpedo could be fired in a surprise attack** from close range, while a missile might not be suitable for this, as it needs the extra time and obvious preparation of being fueled up on the pad. ## How they're guided See Matt Bowyer's [answer](https://worldbuilding.stackexchange.com/questions/68599/what-distinction-could-there-be-between-space-torpedoes-and-space-missiles#answer-68600) ## How they're received eg. missiles = **bigger holes**. If an adversary needs to spend more time setting up a missile and fueling it while it's hanging off a structure on the side of the ship, it might be expected that this extra investment comes with a payoff. Probably that's greater damage to an enemy ship. Alternatively, if missiles are no more destuctive than torpedoes, then the need to assemble them externally may simply be a reflection of **cheaper** or **less advanced** technology. [Answer] A potentially suitable distinction in a space combat setting could be that missiles are designed to overwhelm enemy defences through speed, numbers and decoys, whereas torpedoes are more like small drones delivered to carry an explosive payload, complete with armouring, shielding and defensive systems of their own. This draws a hard line between what is a missile and what is a torpedo (systems installed), as well as accounting for size, cost, speed and yield differences. It makes the most sense if sensors are assumed to be perfect and there is some form of 'instantaneous' (in that the weapon can't react before it's hit) weaponry available to use as point defence. What makes this work particularly well is it draws a distinction between the use cases for missiles and torpedoes straight away. Missiles are for dealing with fast combatants that are light on point defence: torpedoes are for use against larger combatants that have the ability to destroy lightly armoured missiles; as they will sustain multiple point defence impacts before being destroyed. This also opens up possibilities for arms races, where each side creates swarms of torpedoes that are designed not only to attack the enemy ships but also other ordinance. This may lead to a more 'drone V drone' style of space combat depending upon resources and construction capability available. [Answer] Simply make Torpedoes a class of missile. For example, the T1269 'Harbinger' is a Torpedo-class Missile system. A similar example to this is the idea of Destroyers and Battleships. Fundamentally, both are ships that carry weapons and are used in wartime roles. However, they fit different billings and as such are classified as Destroyers and Battleships. [Answer] For some reason Sci Fi always comes back to navy terminology, so I will follow a very simple, Navy-Esque, bits of reasoning. Torpedoes are used for destroying big ships, and are designed with the goal of destroying big ships in mind. Their targeting, payload, propulsion, etc. are all built with the idea of destroying big enemy ships. Missiles are designed to destroy everything else, from small attack craft to huge planetary cities. Finally, Marines are there to handle anything that you can't just blow up. Have fun with your spaceships. I'd like to hear more of the story [Answer] If you're talking of realistic space combat in an universe with realistic near-future technology, I'd consider the acceleration capabilities and available delta V as the main criteria for the distinction. Missiles have lots of thrust and acceleration -- much more than the usual spacecraft -- but low delta-v, so they're more effective in short range combat. Torpedoes have low thrust and acceleration, but lots of delta-v. They can be launched from long range and perform more complex orbital maneuvers to reach the target. If you want to be more technical, missiles are cheap, small, ready-to fire, solid-fueled guided rockets. They can be very cheap, launched with short notice and in large quantities. After launch they calculate the vector for an intercept, point and burn all the fuel, and use some secondary propulsion for fine-tuning the intercept. If they miss the target, they're out of the battle. In contrast, torpedoes are essentially suicide drone ships. Large, expensive, with variable thrust and lots of delta-v and payload. They might have to be fueled before being launched depending on their size and kind of fuel being used. They might have their own power generator or solar panels instead of batteries so they can remain in an orbit for a long time if needed. If they miss a target they can try another intercept, look for a target of opportunity, etc. Tactically speaking, missiles are more effective against targets roughly in the same orbital plane. If the target orbit has a completely different inclination, the low delta-v limits the tactical options and usefulness. Torpedoes can be used against targets in a completely different orbit, or even against targets orbiting another body. Also, combat spacecraft are likely to have strong point-defense capabilities, so missiles will be launched in salvos intended to overwhelm the target defenses, while a torpedo is more likely to rely on its own defenses, armor, electronic warfare, etc. They might have much more sophisticated computers and AI so they can make tactical decisions on their own to adapt to new conditions. [Answer] Well, modern missiles work on the rocket principle, force of expelled gas propels the missile forward, while torpedoes move using propellers, which is the only real distinction, based on the environment where each operates. In space, of course, there is no air, so no real need for torpedoes, you'd only ever use missiles, so conventional distinctions are out. (see Zxyrra's answer) So what could be the difference? Matt Bowyer, Adrian Colomitchi and Timpanus have mentioned all the answers I though of immediately, so I won't go into them again. The only things not mentioned yet are type of payload and fuel. One of the two uses antimatter(or some other exotic)/nuclear warheads, the other doesn't. Alternatively, one has limited conventional fuel in stock, and can thus only travel a short distance (astronomically), while the other has a small fusion core, which allows it to travel further, and also adds to the explosion on contact. [Answer] The best way to think about it is like this... The reason most sci-fi calls spacecraft "ships" and fleets of the craft as "navy" is because of the fact that these craft most mimic earth bound ships and the way the manoeuvre/move through water. Ships in space is roughly equal to how a submarine moves UNDER water. This is accurate for the bigger ones, ie. something along the lines of a Patrol or Corvette class and larger, smaller attack craft would be more likened to fighter craft (tighter turning circles etc, but similar controls like thrusters facing in all directions for control). So if you're to take into account the munitions that they use; torpedo's and missiles, we'll forget about lasers for now as its not in your question but you must also forget about relative earth sizes for what we consider conventional torpedo's and missiles as in space both could be any shape and size theoretically. A torpedo would be mainly for large ship to ship combat, designed for the range between laser and missile range, so basically, minimal guidance but to provide a lot of damage, possibly cheaper too. A missile would again be for mainly ship to ship combat, could vary a lot more in size and power between smaller spacecraft battles to large ship battles and even planet destroyers. These would generally be more sophisticated too. [Answer] From my experience, Missles are self-propelled projectiles fired through the air, and Torpedos are self-propelled projectiles fired through the water. But that doesn't actually mean anything here. Traditionally, craft that travel through space are considered ships, or vessels, rather than aircraft, or planes, due to their functional similarity to submarines. As missles and torpedoes can both be fired from submarines, and spacecraft travel through neither air nor water, the decision of whether the weapon is a missile or torpedo is up to the discretion of the creator of the weapon, be that the author or the inventor. Also, there are rocket propelled torpedoes. <https://en.wikipedia.org/wiki/VA-111_Shkval> [Answer] 500 years ago, the Air Forces used missiles, and the Navy used torpedoes. At the founding of the Space Forces, combined crews were brought together into Spaceships, but flatly refused to abandon centuries-old prerogatives. Even today, with identical weaponry and training, the two groups continually antagonize each other. All systems are in pairs, one blue, the other light blue, and God help you if you touch the wrong side. c.f. the "breastplates" of the modern British army This is a scientific answer, but the science is sociology, not physics. [Answer] ## Size and Use Missiles are for fast moving targets, like fighters, or light freighters. They are small enough to fit on a fighter and are typically homing missiles, with good capacity to make spontaneous turns and "drifts" in space. Torpedoes, in the contrary are much bigger and much stronger, they are built to damage capital ships and space stations. They have are fired at a longer distance and have less control over themselves. They can be mounted on bombers class ship, gunships and other "siege" spaceship. [Answer] I'd have a differentiation between *rockets*, *torpedos* and *missiles* in terms of how they are flown. Rockets would be unguided weapons - cheap, short range and fired en-masse, deathblossom style. *Missiles* would be *guided* systems with propulsion throughout their flight time, and active thrust controls. They'd be roughly equivilent to a modern day air to air or surface to air missile. I'd see these as weapons used to take down fighter to "gunship"/corvette class ships or fun emplacements. One of the *interesting* things about space combat is distance. A torpedo makes a ton of sense as a *long range* missile, that's launched from railguns or with a booster, *coasts* into range then goes into active attack mode. They'd need less propellant for their weight, generally get deployed in the early stages of an attack, and tend to be massive shipkillers. Something like the missile systems in the honorverse comes to mind, though they're an evolution of single stage missles as I've described here. How they're *used* would be the interesting thing here - rockets would be used in massive numbers to overwhem mount defences or shields. Missiles would be tailored for dogfights and short range combat.Torpedos would be used tactically - predeployed, coasting towards a planned engagement area, and then getting activated *later*. Combat with torpedos as such would revolve around avoiding or destroying enemy torpedos before they can do any damage, while trying to herd the enemy into your kill zone. [Answer] Look at how missiles and torpedoes work these days: Missile: Fast, maneuverable but subject to defenses. Torpedo: Slow, big boom, not very maneuverable, almost invulnerable other than to being spoofed. Now, for space use: Missiles: High energy devices, they leave an obvious trail--in the absence of electronic warfare the enemy will always know exactly where a missile is unless it's been drifting for a while. They rely on speed and electronic warfare to get through to their targets. In general the warheads will damage but not destroy the target. They are highly maneuverable, able to engage fighter craft. Torpedoes: Low energy devices. They come in at speeds little more than the vessels speed, relying on stealth to get through. Purely passive target seeking, although they can get target updates from the ship that fired them. They're shipkillers, if one gets through it's likely to destroy the target ship. Because they're slow the enemy can choose to turn tail and run and will generally get away, albeit at the cost of being forced out of the battle. They are not maneuverable enough to have any chance against fighter craft. [Answer] No one else has specifically mentioned this, so I'm going to give my answer. In the real world, the term missile has two major connotations: *a guided rocket* and *an object that is forcibly propelled at a target*. Under both definitions, a torpedo is simply an underwater missile, with one exception... Unlike most air missiles which have a ballistic trajectory (a clear exception being *cruise missiles*), torpedoes cruise to their target. That is, torpedoes are powered from launch to impact. Extrapolating this into space warfare we can come up with a distinction # Trajectory * Missiles are ballistic, being powered during a small fraction of their flight time and coasting the rest of the trajectory to their target. * Torpedoes are non-ballistic and cruise all the way to their target, meaning that their engines are functioning until impact. # Guidance * Missiles have a very high maneuverability while they still have fuel. Once their fuel runs out they become dumb projectiles. They might be equipped with maneuvering systems, but they will probably only be used for small adjustments rather than large trajectory changes. * Torpedoes have their engines working during the entire trajectory, meaning that their maneuvering capabilities are constant. # Engines * Since missiles need to accelerate very quickly, they are probably equipped with solid fuel engines or high thrust liquid fuel engines. Either way, their propulsion is most likely chemical * Torpedoes, on the other hand, need huge amounts of Delta-V but they need to use it sparingly in order to reach their target. Given this, they are probably equipped with some form of ion propulsion. It might not provide large amounts of thrust, but it compensates by working for much longer periods. # Dimensions * Missiles, given their outlines characteristics, probably have a small size in order to be able to stack a lot of them in a craft * Torpedoes, given their large propulsion requirements, are likely of a large size, many times larger than missiles. # Situations * Missiles are likely to be used for close range encounters since that where they shine the most given their thrust output. They can also be used for engaging stationary targets given their fine-tuning long range capabilities. Missile warheads are probably armor piercing or high explosive. * Torpedoes are pretty much useless for close combat since they can easily be dodged or destroyed thanks to their low thrust. However, torpedoes SHINE in extremely long range engagements. They can accelerate leisurely to enormous speeds given enough distance. Their size and distance may make them easy targets for interception, so they'll probably be equipped with cluster or multiple warheads which would be deployed if interception is imminent, overwhelming most countermeasures. In other words, missiles are used for active engagements while torpedoes are for bombardments and interception. [Answer] As I commented, one example is how David Weber uses the terms in his Honor Harrington series. Missiles are long range, semi autonomous, weapons with very high speed used to degrade a target vessel's defenses (and possibly disable or destroy it). Torpedoes are shorter ranged, slower, weapons used by mostly smaller ships when they "move in for the kill". As they're smaller (in his universe) a smaller ship can still carry a large short range punch when they would only be able to carry a very small number of missiles which would have little effect against the defensive systems of a larger vessel. There's also a difference in warheads. His missiles tend to have a variety of warheads, mostly designed to overload shields and other defenses and render the target vessel incapable of defending itself. The second strike with torpedoes or laser fire at shorter range will then finish him off (the torpedoes having large thermonuclear warheads). [Answer] **Missile**: Self-propelled, heat-seeking, small-medium projectiles. They are launched "en-masse", and their objective is disrupting enemy tactics and small vehicles rather than attacking big objects.In space, they are meant to scatter the enemy's fighters.[](https://i.stack.imgur.com/VVRPq.jpg) **Topedo**: fast, self-propelled, medium to big, uni-directional (they don't follow targets), highly penetrating and exploding after contact ( not on-contact ) capital ship attacker projectile. they are launched individually, usually produce a light and hard to detect signature, and they tend to blow up various levels of the ship, opening gaps on the hull. [Answer] This all depends on context, specially since most Sci-Fi deals with spaceships as being in the *Navy*, probably due to similarities to sea-based battleships (one large vessel with lots of personnel, each with different functions). **Specifically for Stellaris**, there's this from the [Stellaris Wiki](http://www.stellariswiki.com/Ship_designer#Missile_Weapons): > > Missile weapons are rather different from other weapon types. They have a 100% accuracy and varying tracking values, but in turn can be shot down by Point Defenses (equipped only by destroyers and above). > > > * Missiles have the best base range of all weapons. They also have equally high tracking for all slot sizes, giving any ship a good > counter to corvettes. > * Conventional Torpedoes have the ability to skip right past shields, making them especially dangerous to shield-reliant foes, but > their weakness is that they lack tracking and are only available for > the special torpedo slot. > * Swarmer missiles are medium slot, shorter ranged missiles that split up with the goal of overwhelming enemy defenses in a saturation > attack. Their evasion is so high they can not be shot down. > > > You may also find some discussion on tactics [like this one on Reddit](https://www.reddit.com/r/Stellaris/comments/4tfvdr/missiles_vs_torpedoes/). [Answer] The most likely answer revolves around target, and diverges from there. If it can target anything, then there's little need for two words in most cases. The case where there is use for both words is interesting though and makes a good base case, so I'll bring it up. In that case, missiles and torpedoes are the same thing. That is, until they leave their ship and are tasked either to hit the other ship at which point they become torpedoes, or they are tasked to intercept torpedoes and become missiles. That way it makes it easier to discuss whether each ship has more interceptors than weapons incoming, and other such relevant metrics. This comes from a universe where ships are very fragile and delta-v is somewhat limited, so the same warhead that allows a decent probability of a kill on an incoming torpedo would be devastating to an enemy ship. The other factor that makes that all work is that terminal defense means that torpedoes want to be accelerating rapidly toward their target when in close to make the missiles' time as hard as possible so both sides want a high acceleration engine and torpedoes work best when launched dead until they see the enemy ship in their intercept basket. On the other hand, you may find that the weapons to take on a ship are very different from the weapons to intercept incoming targets on a ship (torpedoes, small craft, other things). In that case, the torpedoes as anti-ship weapons and missiles as defensive weapons split still makes sense. It doesn't really matter if torpedoes are actually small ships with nuke-pumped lasers and composite armor arrays with aerogel to dissipate incoming lasers and missiles are small KE vehicles launched in large numbers to overwhelm torpedoes' lasers and armor. What matters is that the terminology remains consistent and the reader can understand what's going on. Lastly comes the case of attacking ground targets, in which case I'd say that bomb would be a reasonable term for a weapon that gains most of its KE from the target's gravity well. If you're using pure KE munitions, then something like rod would probably be suitable. Finally, torpedo is an old word for mine that came to shift fully away from describing mines as it came to describe the new self-powered underwater warheads. So there's historical precedent that you can do what you want and shift meanings to match new realities in warfare, but the language is likely to solidify on something that makes what you say clear (especially during the early 1900s, the distinction between a mine and a torpedo was very important, see the Live Bait squadron for an example of how bad getting it wrong could be). So as long as you're clear and consistent, you can't be too wrong. [Answer] Suppose a sci-fi universe with the following constraints: 1. Space dust and rocks etc. are deflected with some sort of strong force field; these are your standard "deflector shields". Possibly there has been an escalation of arms between deflector shields and plasma cannons, which will not be hugely material here except that a "deflector shield bank" might be a valid target for trying to selectively disable. 2. Lasers work much as they do in the real-world: invisible, they travel at speed *c*, they can't be deflected by deflector shields really. They have, however, been neutralized by *dissipative hull* technology, which requires a lot of mass but basically means that you need to focus a laser on a point for several seconds before you can melt anything. 3. This is a problem because our mastery of some non-Einsteinian notion of gravity has led to *inertial dampeners* which allow massive ships to have a sort of characteristic "jitter" which distributes the laser over larger areas. It also makes it harder to target small fighters or large cruisers with projectiles, so even though we have some sort of *mass drivers* (maybe railguns, maybe not) firing masses with high speeds, this is not enough to hit a ship with a precision payload. 4. You have some ability to see "hot" projectiles coming, whereas you would not be able to see the normal bullets from a mass driver. 5. Electromagnetic pulse weapons can disable electronics at close range. 6. There is some distinction between small, agile "fighters" and medium-size "destroyers" and large "cruisers". Then it might make sense to have about three different sorts of powered projectiles. A **missile** would have an explosive payload, an internal engine, sensors, and a tracking computer. These would be useful for a cruiser trying to get rid of small fighters. The idea is that these could be like "really fast computer-guided kamikaze fighters", you neutralize the EMP threat by always firing a cloud of 20 of them per fighter, so that a fighter gets overwhelmed by trying to dodge these ones while EMPing those ones. With a couple big cuts you can imagine that a small fighter's engines or weapons could be compromised and they're basically out of combat. A **rocket** would not be guided at all and would be analogous to a "space bullet." They would be fired cold with a mass driver, then would rapidly accelerate while 'hot,' perhaps by detonating a big nuclear explosion in a blast chamber and riding out the shock wave as it destroys the chamber. They would basically be a big, heavy slug of matter, not deflected much by a deflector shield, targeted only by being fired "cold" one way and then after a timer expires, being accelerated in another (possibly different) way. They probably come in two varieties: "light" rockets are best for fighter-on-fighter dog-fighting combat; they are fast straight-line projectiles not unlike guns, but probably fired in "banks" so that a fighter needs to simultaneously dodge several of them at once. However at larger distances these are pretty easily melted by lasers before they hit a deflector shield which will deflect the vaporized forms, so for mid-range cruiser-on-cruiser combat you instead see bigger slugs, basically a big chunk of dissipative hull, so that lasers do not melt enough of them before they pass through the deflector (and then any further laser-ing would just add heat to the remainder of the slug, increasing hull damage). Finally, maybe **torpedos** are rockets which are partially guided by the firing ship, therefore they behave a little less like "bullets" and more like they live in some "fluid" medium which they can push against. Imagine that we configure this blast chamber to push slightly off-center from our rocket payload, then as it gets accelerated to high velocity it also spins wildly. It's possible that, since we know the trajectory it's going to follow ahead-of-time, we track that trajectory with a carefully pointed laser. That laser then evaporates some external "casing" on the spinning payload, which gets ejected in some preferential direction. The result is that torpedos appear as "curveballs" for a period of time after they go "hot". They are maneuverable enough to vaporize destroyers but overkill for (and perhaps unable to target) fighters. They have a slight accuracy benefit over rockets for doing precision strikes on those jittery cruisers, since they can be guided somewhat "en route", but probably there is a tradeoff here. Presumably once they are detected and the target's lasers are reoriented to fire at them, they can be deflected from their intended target by laser defense just the same way that they are guided. Therefore they probably are designed to "run out" of this fuel right around the time that an enemy laser is able to target them, after which point they basically become an inferior version of a rocket (i.e. they are stuck on their straight-line trajectory and they have inherently less mass and velocity). So they are only better at targeting than a rocket over short ranges, but when they are available they are decisive. [Answer] **Space torpedoes are either orbital missiles, stealth ship killers, or interplanetary WMDs** *A popular aphorism among navy experts seems to be that missiles cripple, and torpedoes kill.* The one and only meaningful difference between torpedoes and missiles is the medium they traverse. For all intents and purposes, torpedoes are underwater missiles. I see three possible ways to have a plausible semantic shift from naval torpedoes to space torpedoes: ▪︎ From under the ocean to 'down' gravity wells, space torpedoes as dedicated orbital missiles. ▪︎ From silent ship killers to dark spaceship killers, space torpedoes as stealth antiship missiles. ▪︎ From underwater missiles to interplanetary kinetic kill vehicles (IKKVs, nicknamed Hikers or Hiker vehicles) — or similarly powerful weapons sporting nothing short of antimatter warheads — space torpedoes as transmedium missiles (as they depart either from gravity wells to outer space, and back again to gravity wells, or from outer space to gravity wells as part of a strategic strike). In space, there is no up or down, above or under, nor is there an ocean per se. But there is a topological change between outer space and the vicinity of celestial objects, as spaceships then must deal with the toll on their ΔV taken by massive objects. This creates two distinct sets of constraints that spacecraft are designed to overcome, however missiles have limited capabilities and a choice must be made. Two categories of dedicated missiles may then exist: missiles with high ΔV, semi-decent thrust and acceleration for maneuvers and boost phases on the one hand; missiles with semi-decent ΔV, high thrust and acceleration to quickly reach escape velocities within gravity wells on the other hand. These environments and consequent parameters recreate differences analogous to different media, hence the term space torpedoes for the dedicated orbital missiles. ————————————————————— 'In space no-one can hear you scream' says *Alien*'s promotional material, which is practically true. However ships are visible from truly astronomical distances if they're bright enough (e.g. when they fire their engines to accelerate/decelerate, or when they use heat intensive energy weapons), which is why stealth can still play a role in space, provided ships are dark enough to blend in against background starlight and radiations until they reach combat ranges. Underwater, things are reversed, as subs and torpedoes are practically invisible, yet can be heard from long distances, which is why silence is the name of the game, as it's all about reducing sound emissions, sonar reflections, and blending in background noise. Thus our silent hunter killers under the sea may be paralleled in deep space with dark hunter killers, ready to launch dark, rather than silent, space torpedoes, i.e. stealth antiship missiles which would further the analogy and come into two different classes: lightweight space torpedoes, used against our space submarine analogs and launched from just about all platforms, and heavyweight space torpedoes, used primarily by space sub analogs against both warships and cargo ships. Though in this idea space torpedoes are imitations rather than proper analogs for its underwater homonyms. ————————————————————— For the last option we combine the distinction between media traversed with the idea that just like naval torpedoes our space faring analogs could cruise toward their targets, i.e. would be continually self-propelled, vs undergoing acceleration and conserved momentum phases like other space missiles. So they'd be space cruise missiles that happen to traverse both deep space and gravity wells throughout their journey, placing two different sets of constraints that call for designs mirroring more closely spaceship designs than missile designs, minus the crewed part. Although we might come up with crewed kamikaze IKKVs for the fleet killing and orbital defence killing types, as we may need a human in the loop to 'think outside the box' and avoid wasting warheads that may appear even costlier than human losses. The extreme difficulties of producing an containing enough antimatter to make warheads comes to mind. Other options may obviously be available later in your setting if AI gets good enough to "man" smart IKKVs or antimatter-tipped variants, though combining AIs with fleet killer WMDs might not be such a smart move after all. ;) [Note that either a crewed IKKV or an AI-piloted IKKV would not only be super hard to trick or take down, but would also dial the stakes up to eleven, while no longer needing delayed guidance from the mothership or the 'not-so-smart' classical self-guidance of missiles. On the pus side, historically there has been a crewed japanese torpedo design, so it's not coming out of nowhere] [Answer] Star Trek has your answer. Species 8472(encountered in primarily in St. Voyager), the undine(according to star trek Online), lives in fluidic space. There maybe other species that also live there. If you need to fight species living in fludic space clearly torpedoes are you answer. [Answer] **The term torpedo is not universally defined for space weapons** Torpedo is a naval term and refers to a self-propelled weapon that travels trough *water*. Note that there have been guided and unguided torpedos and the mode of propulsion also varies quite a lot. Aerial torpedo is used for air-dropped torpedos that *still* travel through water after being dropped. Missile is commonly used for self-propelled weapons that travel through air or space, regardless of where they are launched from (including submarine launched, which do travel a short distance through water at launch). So the distinction, as far as existing weapon systems go, is the medium in which the weapon travels while in its self-propelled phase. For space, where all weapons travel through, well *space*, the distinction does not have a defined meaning. You could either just call every self-propelled weapon a missile (and that would certainly not be wrong) or you can make up your own distinction criteria, since no universally accepted definition exists. ]

[Question] [ In a society where government-issued currency (most current countries) is used, could the government fund itself by printing money to use instead of taxing its citizens? Would this work? If so: How would this affect the faith in the currency system? Which class would be relatively taxed the most? [Answer] $\Large{No.}$ **It would not work. Think about it for a second. Taxing people, and getting them to actually pay, is *hard*. Printing money is easier. If it were possible to sustainably fund all government expenditure by printing, governments would never be bothered with taxing, fairness considerations be damned.** As with any asset, there is a **supply and a demand** for a particular currency. Money happens to be used as a standard measure of other goods, so we tend not to think of it as just another good, but that's what it is. So, by regulating the amount of currency they release into circulation (and by hanging forgers) a government establishes a relatively stable system of reference for the prices of other goods, which is useful for conducting transactions. Which is why people tend to use money as a **universal medium of exchange**, rather than cigarettes or shells or large slabs of silver, although they will use these too, if a sound paper currency is not available. Whenever the government creates more money (*[POOF](https://www.youtube.com/watch?v=PTUY16CkS-k)*✥) the value of the existing stock of money falls. Why is that? Because the **amount of goods** in the world and the amount of labor that can be done **is still the same** as it was before the extra money was created. Therefore, having created twice as many Zimbabwean banknotes as before, you'll find that the entire pile of money does not buy you twice as much stuff, but roughly about as much as you could buy before. Furthermore, people start **adjusting their expectations**, so if you print money today, they will expect you to print money tomorrow, and drive up the prices in expectation of that. So if you want to surprise them, you'll have to print even more ... which will cause them to adjust their expectations higher and higher and higher, until you have to bring a wheelbarrow of money with you to buy an egg and your bank can't afford to import the ink to print the new bills anymore. This actually happened by the way. As to who gets hurt the most? At first, whomever has any money saved, since the value of the money in the bank that could buy a car yesterday will buy them only half a car now that you doubled the currency stock. Eventually, the entire country is hurt, capital and brain drain ensues, the price of imports becomes prohibitive for all the locals, a gang of well-connected thugs benefit while [teachers and other public employees prostitute themselves on the streets for food](https://en.wikipedia.org/wiki/Prostitution_in_Zimbabwe), and it all goes down the toilet. **Note that in most modern western states, the government spends somewhere between 30-65% of the GDP. While you might get away with a teensy bit of spending (3% or so), it's unlikely you'd find idiots to hold onto the currency if you're printing literally trillions worth of currency each year. It'd be swiss francs, gold, seashells, cigarette cartons, anything but this currency.** ✥ *Poof* has been mathematically proven to be the sound made by the economy with each round of p̶r̶i̶n̶t̶i̶n̶g̶ ̶l̶i̶k̶e̶ ̶t̶h̶e̶r̶e̶'̶s̶ ̶n̶o̶ ̶t̶o̶m̶o̶r̶r̶o̶w̶ inflation taxing. [Answer] Yes, but with a caveat. Printing money is effectively the same as taxation, but with far less control and supervision. First of all, "the government" always "prints money". Actually, in most countries, it's not the government, but some central bank that is usually semi-independent, such as the Federal Reserve in the USA, the ECB in Europe, or the Bank of England in Britain. and the money is not created through physical printing bills, but through loan transactions. This "printing money" should be balanced by money being destroyed (through loans being paid off, mostly), and economic growth. When more money is created beyond that balance, you get inflation (either systemic inflation throughout the economy, or sometimes investment bubbles such as the housing bubble of the early 21st century, or stock bubbles). Inflation simply means that each unit of currency (dollar or whatever) will be worth less. Now what you are proposing is basically that the extra money goes to finance the government, but those who already have money or income (i.e., the population) suffers the loss of value of money. In other words, the population pays for the government's operation. Which is no different from taxation, just through another means. Here are some of the problems - and benefits - of using "printing money" instead of taxes to finance the government: * It is very hard to control the rate of "taxation". When given free rein to print money, politicians may end up printing so much money that the effective "tax rate" (or rather, the amount of value lost to inflation) far exceeds what would be collected through taxes. That is basically what happened in Germany 1923, in Zimbabwe, and also in Hungary. * This form of "taxation" is hard to target. Most tax systems have mechanisms to distribute the burden and target the taxes in some form. For instance, cigarettes and alcohol may be taxed at a higher rate. Incomes for higher-income individuals may be taxed at a higher rate than low-income people. One can argue about the merits of this type of targeting. However, taxing through printing money/inflation will be untargeted and erratic. Inflation may end up occurring evenly throughout the economy. In that case, this would be the ultimate flat tax scheme. But inflation may also occur only in housing - in that case, you might end up effectively financing the government through a 90% tax on house purchases. Or inflation may end up causing a stock bubble. * This form of "taxation" can also provide a negative tax on outstanding loan balances. In some situation, that can actually be desirable - for instance, during the housing bubble, some carefully controlled inflation could have provided relief for homeowners homeowners (update: with a mortgage) (specifically, wage inflation would have done that). * **Update - I just thought of this:** This form of taxation would implicitly tax *all* money, including "under the table" payments. * **Update - I just thought of this:** This form of taxation could be avoided by conducting business in foreign currencies, or by bartering. So, the answer to your questions: > > In a society where government issued currency (most current countries) > is used, could the government fund itself by printing money to use > instead of taxing its citizens? > > > Yes > > Would this work? > > > Yes > > If so: > > > How would this effect the faith in the currency system? > > > It depends on how carefully controlled this approach is. If you can trust politicians not to do this to excess, then the effects may be manageable. However, there will always be some negative effect on faith in the currency system, because everybody who uses the currency will know in advance that it will lose value over time. > > Which class would be relatively taxed the most? > > > Depends on how the resulting inflation is spread through the economy. In most general terms: it would affect those who save money, and those who borrow money. Theoretically, it will not affect wage earners (because if inflation is spread perfectly evenly through the economy, wages should go up at the same rate as all other prices). Of course, in the real world, inflation won't spread evenly. If history is any guide, wages won't actually participate in the inflation. The impact on savers and borrowers is complicated. Those who saved at fixed interest rates before starting this form of taxation will lose the most. Those who borrowed at fixed interest rates before starting this form of taxation will benefit the most. Those who save or borrow after this scheme starts will see the interest rate spread increase corresponding to the amount of money being printed. Investors in assets will (again, theoretically - asssuming a perfectly even spread of inflation) neither lose nor benefit, because whatever assets they invested in will rise in value along with inflation. Investors in derivatives (futures, options etc.) or any time-based assets will need to carefully do the math. [Answer] Yes, I think it could. Minting new currency at a constant rate should be roughly equivalent to collecting a yearly tax consisting of a fixed percentage of each citizen's currency holdings. --- To see why, consider a very unrealistic toy country. A [fiat currency](https://en.wikipedia.org/wiki/Fiat_money), the *dubloon*, is the legally mandated and socially accepted medium of exchange. There is no fractional-reserve banking, and dubloons can't be given to non-citizens. Let's suppose there are $10^{12}$ dubloons in circulation. A poor family might hold $100$ dubloons, while a rich family might hold $10\;000$ dubloons, and an enormous car company might hold $10^{10}$ dubloons. Having more dubloons means having more power to buy things. For the rich family, it might seem reasonable to offer the car company $500$ dubloons for a new sedan. If the rich family is willing to offer the car company such a price, the poor family has no chance of getting the sedan. From this perspective, you might say—very roughly—that the poor family controls $1\mathrel{/}10^{10}$ of the country's buying power, while the rich family controls $1\mathrel{/}10^{8}$, and the car company controls $1\mathrel{/}100$. Now, suppose the government mints $10^{11}$ dubloons and puts it in the treasury. There are now $1.1 \times 10^{12}$ dubloons in circulation, so the government suddenly controls $1\mathrel{/}11$ of the country's buying power. Just as suddenly, everyone else's share of the country's buying power drops to $10\mathrel{/}11$ of what it used to be. The government can use its new buying power to buy things. It might pay the poor family $5$ dubloons for a month of labor, the rich family $2\,000$ dubloons for some land it wants to build an airport on, and the car company $10^9$ dubloons for a few fleets of buses, mail vans, utility trucks, police cars, disaster-response vehicles, and armored personnel carriers. After these transactions, and many others, the treasury is empty, and all the new money has been distributed among the country's citizens. The poor family's share of the country's buying power has gone down, the rich family's share has gone up, and the car company's share has stayed the same. Next year, the government can do the same thing again to fund its operations. It has to be careful, though, about how it redistributes the country's buying power with its spending. If it continues with its current budget, for example, the poor family's share of the country's buying power will get smaller and smaller every year. The poor family might eventually get angry and vote for new government officials, or steal the rich family's car, or lose its home and starve to death. --- Although I don't see any reason a government couldn't fund itself this way, I can see many reasons it wouldn't want to. One is that minting money decreases everyone's buying power by the same percentage, and people might prefer [some other way](https://en.wikipedia.org/wiki/Progressive_tax) of distributing the tax burden. Another is that minting money is effectively a tax on currency holdings, and people might prefer to tax other things—like income, labor, consumption, or wealth—instead. A third is that people would have to constantly adjust their idea of what a dubloon is worth to keep pace with the growing money supply. This shouldn't cause any problems in principle: the government could just tell everyone how much new currency it minted each year, and then everyone would know how much they'd effectively been taxed. It would probably be extremely annoying in practice, though: shops would have to change their prices all the time, dealing with cash would be a huge mess, and it would be easy to get confused about whether $0.01$ dubloons is still a good price for a bunch of bananas. --- *Disclaimer: I have very little background in economics, and even less in monetary economics, so I'm totally unqualified to answer this question. Input from folks with more background is welcome.* [Answer] Most of the answers have dealt with the theory of devaluation, which is both sound and has historical examples, so I will describe some of the real world effects, based on discussions I had with both my economics professor, who studied this and people from Argentina who lived through it in the late 1970's (Argentinians are going through something like that yet again, and Venezuela is also suffering from many of the effects of hyperinflation). As the supply of money continued to grow and inflation began to bite, people began converting their cash into items with real intrinsic value. At first, buying jewelry and other luxury items made sense as it is small, portable and has high intrinsic value, however after a while everyone had a fistful of rings and watches, but were unable to get what they really needed (or the value of the jewelry and other items was mismatched to what they could actually get: a roll of toilet paper is not a fair exchange for a diamond ring under most circumstances). The other effect was the supply of small luxury items was quickly exhausted, while other goods were in short supply and money was rapidly becoming more and more worthless. Eventually, a sort of barter economy sprang up: people would rush out at payday and purchase literally anything they could get their hands on, and soon streets were full of cars, living rooms with shoes and so on. You could wander the streets to find an item you were short of, but needed some canny negotiating skills or a chain of "exchanges" to get the item you needed (you might have to trade some shoes for a set of dinnerware, then the dinnerware for a sewing machine, then the sewing machine for a TV to get the spare part you needed for your car). You can see why currency is far more convenient than barter, but if the currency is not sound, then some form of informal currency (cigarettes have been popular in some times and places) or barter will eventually rise to replace the devalued currency. Printing money to fund the government is somewhat like believing in perpetual motion. > > Inflation is always and everywhere a monetary phenomenon. ― Milton > Friedman, Money Mischief: Episodes in Monetary History > > > [Answer] *I'm disappointed by how many of the answers so far seem to take it for granted that currencies are supposed to be stable. While it's true that most people in our world expect currencies to be fairly stable, I think that's to some extent a historical accident. This answer is meant as a proof of concept that things could have gone another way. Sorry about the double post.* Of course! Where I'm from, pretty much every nation funds itself this way. The roots of the system go all the way back to the Age of Heroes, when lords would often award *marques of favor* to vassals who distinguished themselves by feats of courage or devotion. The earliest marques were little trinkets handmade in a wide variety of styles and materials, often blessed by the lord herself. These tokens of honor were highly sought after, so those who recieved them would often pass them down to their own vassals in exchange for services, in addition to awarding their own marques. Some marques grew in value through fame, or a reputation for good luck. In the 3500s, for example, King Latia gave 60 cut amethysts to each of the seven Countesses of Nome after they rode to his aid during the Hyperborean War. When Nome miraculously escaped the regional plague of the following years, rumors spread that the amethysts were the cause. Their precipitous rise in value helped drive Nome's snowballing political and financial influence over the next century. An important feature of the favor system was that, with their supply always growing as lords handed them out, marques steadily decreased in value. That meant heroes couldn't rest on their laurels, living off the proceeds of deeds long past; they had to keep up a steady stream of accomplishments in order to maintain their power. Since opportunities for glorious combat were limited, lords increasingly called on their vassals in peacetime to work on civil projects like irrigation and road-building, unwittingly laying the foundations for the great kingdoms of the Times of the Sages. But devaluation had a downside, too: as marques accumulated, and their value decreased, physically storing and trading them became a major hassle. It became common practice for vassals to return marques to their lords every few years in exchange for "new marques," each representing a large batch of the old. Marques became more standardized and mass-produced—no more personal blessings by the lord—and began to be routinely stamped with dates. At the dawn of the Times of the Sages, feudal alliances were rapidly coalescing into giant kingdoms with monarchs at the top. Most lords stopped awarding their own marques entirely, since those of the monarch and her handmaidens were better respected, and they trickled down reliably from above. They could also be conveniently traded between provinces within the kingdom. (Incidentally, this is why a lot of modern currencies are called the *heighmarque*, or some variant of that—it started as "the high queen's marque.") As kingdoms solidified their internal currencies, however, they became more economically isolated from each other. Rulers grew to distrust each other's marques, whose values could suddenly tank if their issuers decided to do an enormous land buyout or launch an expedition to the South Pole. Merchant families stepped in to fill the gap by trading in goods between kingdoms. When they needed cash to kickstart a new trade route, they'd borrow it from well-to-do locals, and the modern banking industry was born. Four hundred years ago, the "bricks" in your TeaBank account (or your Lower Port Province Trade Route account, as it was then called) stood for literal bricks of tea, bought with your deposits and destined for buyers overseas. Marques got even more mass-produced, turning into dyed wood sticks or paper notes, and newmarques began to be issued on a regular basis. Spending was slower back then, and hauling marques around took more work, so replacement periods of seven, nine, or eleven years were common, rather than the four or five typical today. The world saw its first modern spending crisis in the 4160s, when the Empress of Noba, trying to raise an army for a war of expansion, ended up pricing the kingdom's farmers out of the labor market instead, setting off the Farmers' Revolt. As the era of mechanization rolled in, nascent manufacturers got into the banking business for the same reason the merchant families had centuries prior. By accounting in symbolic shares of their factories—early Windloom Atlantis accounts were measured in "blades of the windmills"—they introduced the idea that banking currencies needn't be tied to tangible goods. By the mid-4400s, nearly all banking currencies had become fiat currencies, regulated by international trade groups. The transition was not without mishap: banks' formulas for setting the marque values of their supposedly time-stable fiat currencies were often complicated and opaque, leading to protracted court battles and the eventual passage of national and international banking currency rules. The practice of giving "compensation payments" to poor citizens whenever marque was printed, as a way to maintain the buying power of those with low incomes and little access to banking, had been around since the Times of the Sages. It was only in the late 4300s, however, that the spread of democracy and calls for a stronger social safety net led to a serious study of compensations. Today, most nations have quite involved compensation systems, with price-indexed payments, payroll deductions, and adjustments for assets in the bank. Our financial system looks a lot different than it did a millenium ago, but some things don't really change. TeaBank still trades a lot of tea, although the cute tea brick icon next to your balance is purely fictional. The High Count of Nome still blows a theatrical kiss over the national mint every Budget Day, so those marques really are "Printed with the Blessing of Our Sovereign." And we're all still hustling to keep up with the marque supply, because no matter how stable our banking currencies are advertised to be, the old saying still goes: "Yesterday's glory won't buy tomorrow's arrows." [Answer] I think that answers to this question have already covered lots of scenarios and possibilities. However, I would like to bring my small contribution (a rather theoretical one). Although I believe that funding government through printing is NOT possible in a real world because of the huge inflation it would cause, it is certainly possible in theoretical terms. When we think about government spending we tend to think about big government. A government which provides welfare and utilities to its citizens. However, imagine that you have a small government which does not have a welfare system, lots of agencies such as FDA, inefficient businesses such as subsidised public transport, etc. The expenditures of SUCH government (which I don't think exists anywhere in the civilised world) would be very little. Provided that you have such little government, you can certainly fund its operation by printing more money at least during some stages of economic cycle. And here is why. Increasing money supply does not necessarily lead to inflation. As an example, imagine that you have a closed economy where there is only one good (milk) and the overall amount of money is X. Now imagine that productivity increases and the amount of milk doubles without the increase in the amount of money. Obviously, it's price goes down and you get deflation. If, however, the quantity of money increases, the result can be stable prices. So, increasing money supply will NOT lead to inflation provided that this increase corresponds to the increase in productivity of the economy. It is therefore certainly true that you CAN fund the government with printed money and without causing inflation. However, this is only achievable if the increase in quantity of money matches increase in the productivity of the economy. Which, obviously leads us to conclude that it is not a feasible system. Because it is inevitable that at some point the productivity of the economy will decrease (due to some natural disaster or some other reason). You'd have to shut the government and wait for the productivity to restore before you would be able to print new money without causing inflation. And that is not very feasible :) [Answer] Yes, no. If you have a large economy with little economic growth, you can inject money in the system to stimulate the economy. It might generate some inflation but inflation is something that is almost inevitable anyway. If the amount is not too large, it's manageable and could be beneficial. Printing money is bad because it makes it less valuable: the value of the currency will drop depending on how much is added in the system compared to the size of the economy. People will want to use your money if they believe it's reliable. If you print a lot of it, the value will drop and people will need to pay in the thousand just for a bread.They will want to use other currencies. All the countries have their own currency (some share a common one like the Euro) and yet the population of many countries use the American dollars instead of their own currency because it's more reliable. If you can't predict the value of your currency because of the high inflation, you are in an economic insecurity and people prefer security. If you can create money from thin air then it has no value because there is no scarcity. [Answer] # No **TLDR** Taxation is the mechanism by which money GAINS value. Or the tax man is why I don't have piles of money at the end of the year. Most answers here deal with the historical fact that printing money would cause inflation, leading to the currency being worthless. I contend that all of these answers are fundamental wrong, because you cannot devalue something that is worthless. # Fiat currency I assume that the OP is talking printing fiat currency and not a secured currency, since you can't "just" print them. Historical all currencies were secured, because a piece of paper with a number on it is pretty worthless. Fiat currencies are a relatively new invention and have only appeared in relatively stable governments and economies. Because these are needed to give value to the currency. There must exist a mechanism of linking your fiat currency to some utility, which is universally valued. In the system we have in the western world, that utility is called freedom, and the mechanism is called taxation. By equating x dollars to y freedom each year by taxation, all people who need freedom will value x dollars as being y. This also explains why only stable economies/governments can produce fiat currencies, as unstable governments might lose the capability to deprive you of your freedom when you fail to pay tax. [Answer] Somewhat. This depends on what you mean by government. For example, Emperor Norton I of the United States funded his activities in exactly this way, and suffered no ill effects. (From his Wikipedia article: "Norton also issued his own money to pay for his debts, and it became an accepted local currency in San Francisco.") But, you say, you expect more from the government than an amiable figurehead. Fair enough. Consider the Post Office. It prints fungible promissory notes and uses them to fund its operations. (The fact that, in the current system, they're exchanged for currency is a minor detail -- in principle, they could be directly exchanged for goods and services.) Pratchett has a nice exploration of the relationship in *Going Postal*. The government could expand to other services that are self-financing. For example, banking would be a natural fit, and indeed history provides many examples of private money issued by banks, despite their not have the ability to tax. If you're planning to finance a government this way, I think the currency would have to self-destruct quite quickly, and also perhaps be intrinsically useful. There's an informal economy of moon cakes that emerges every year in China, for example. Finally, I think the other answers to the question overlook the fact that currency has value -- that's why it exists. Even in prisons and POW camps, a medium of exchange tends to emerge, and people will trade for the medium of exchange at a premium to its intrinsic value, because they value its liquidity. That premium wouldn't pay for very much government, but it would buy some. So, in summary, it could work for very limited values of work and somewhat broad definitions of money. [Answer] * If more **money is printed**, then the **value of money goes down.** * Therefore **no one will hold on to money for** any **long**er they have to. * Therefore all **savings** will be in something **other than money** (maybe gold). * Therefore there is very **little money in use**, so the government can’t take much by printing more of it. * If at that point the government then starting **printing money faster**, you get **hyperinflation**. **Unless** the **rate** that the government **prints money is so low**, that it **does not change people’s actions**, so maybe if the state were spending 3% of GDP, but not 30-50% of GDP. [Answer] The trick is to print **foreign money**. If a small country can successfully print large amounts of a large currency ($, €) (a.k.a. counterfeiting), and get away with it, it can use this to import goods. That's a pretty big *if*, though. Of course, it also means war. > > How would this effect the faith in the currency system? > > > If successful, the faith in the currency system would be destroyed. Counterfeiting money is illegal and if a foreign government does so it is effectively an act of war. If this money gets circulated, people can no longer tell apart money. > > Which class would be relatively taxed the most? > > > Other answers have covered this. It's basically the same as if the money would be properly printed by the domestic government. [Answer] Most of this has been covered by the other answers, however one thing has not been touched on. **Who would be affected by this?** *Poor people?* Not really. They have no cash reserves anyway. *Rich people?* Maybe. They tend to have their money tied up in fixed assets though. It's all in shares, property, etc. *Everyone in the middle?* Ahh, that's the problem. Everyone with savings. Everyone trying to save up for retirement with a pension. Everyone who has enough money coming in to put a bit aside for a rainy day, but not enough to buy investment style assets. Those are the people who suffer. I don't see this being a popular policy move... [Answer] Most of the answer are more of less accurate but there is a slight confusion of the way Central Banks do work. First point: **Increasing money supply** Money is just another good, and answers to the same laws. If you increase the quantity of money available in relation to the goods that can be purchased, inflation will appear. *This is not related to how the "new" money is being used*. Note that increasing money supply is printing money but also allowing banks to lend more money. In present day, most money is not physical but a number in an account. To put this into numbers.. if your country only produces bread bars, and this years production is 110% than that of the last year, money supply this year should be at least 110% than that of the last year just to keep prices stables. If no extra money was added, you would get **deflation** which is a very bad thing. Inflation usually hurt rich people more than poor people, by the simple reason that rich people have more money that is losing value than poor people. Inflation also helps people with debts (with more money in circulation, prices and wages will rise making repaying debts eaiser) and damages creditors (the value of the money when they got it back will be less). Moderate inflation is generally good for the economy, because it puts pressure in money holders to invest their money to get some profit that allows them to, at least, avoid the loss of value. Otherwise, they could just store the money in a vault. In terms of economical crysis, an increased money supply will bring some extra inflation but will help revitalize borrowing and the formation of new investments (people being more afraid to invest, they need a bigger "stick" to punish them if they don't do). Hyperinflation is bad because there are no investments that allow to keep the money value, so people just buys valuable items (gold, land tracts, etc.) and uses them for no productive activity, they just expect them to increase their value due to the hyperinflation. Second point: **Funding government** So now, to the question... if you are going to increase money supply: why not use that money to fund the state directly? It sounds easy enough. The main issue is that it is, effectively, easy enough. **Too easy**. Inflation is an *invisible tax* that hits people indirectly. You need to win next elections? Lower taxes 10% and print more money. People will vote you because their tax form shows a lower number, and criticize the baker because the bread is more expensive. The following elections? Well, let's lower taxes 10% again... Given that a modern government and public sector may take up from 20% to 50% of GDP, and GDP usually rises in single digit percents, trying to fund fully with extra money will lead to hyperinflation. And trying to partially fund it leads to the above explained slippery slope... In some countries Central Banks are not independent of the Government, and their actuations are always watched cautiosly. Investing in Chinese funds may mean that the Chinese Central Bank decides, for political reasons, that the yuan must be devaluated, and result in a surprise for the investor. So, usually Central Banks are set as independent entities to avoid that sort of "direct" political pressures. Unfortunately, they are still sensible to indirect political pressures (mainly from the rich people with access to them, and to which inflation fighting is the only role of the bank in order to preserve the value of their money). [Answer] There's a point that I think has been missed in other answers. The way government-backed money gained acceptance in the first place was because it was the only thing that could be used to pay your taxes, and so everyone had to have some of it, and therefore had to accept it as payment for goods and services. If you're not taxing anyone then you can't require them to use your money at all, and if you're continually devaluing it by printing more of it then no one will -- they'll use foreign currencies (probably the US dollar if your country is in east Asia or the Americas, or the euro if your country is in Europe, Africa or west Asia) or even private currencies instead. So you'll end up printing money that no one will accept, and the government won't be able to fund itself no matter how much money it prints, because the money will just be waste paper. So oddly enough, the problem with your plan is not that the government is printing money, which can be managed; it's that you're not collecting taxes from people. [Answer] Yes, printed money can be used to fund government spending ad infinitum without inflation and no taxation as long as money can be equivalently removed from circulation without taxation. If we define an interest rate on government insured savings deposit as being distinct from taxes and social benefits, then money can be removed from circulation without taxation by setting the interest rate on savings deposits below zero. Such savings must be deposited at the government bank. Deposits at private banks are not considered money and if the bank goes bust so do the savings. The money the government receives by the negative interest rate is not spent - it is deleted. A positive rate can be used to inject extra money above fiscal spending. So that takes care of regulating the quantity of money, but the issue of demand for government money still remains. As other answers have noted, taxation creates a demand (pay up or go to jail). However, any government monopoly service that is in high demand and can only be obtained by presenting government currency will do. So for example, healthcare, life extension, licenses to have children, license to avoid being sent to the soylent plant, license to carry on a registered profession, advanced education, access to a city state etc etc. Its a bit of a dystopia of course, unless you can come up with a genuinely welfare enhancing public good that in your world is only really practical to provide from the public sector. Arguably a negative interest rate is tax on money of course, however if that were true then a positive interest rate is a "social benefit" paid to holders of money, which is not how interest is normally presented. It all depends on the cultural mores of the world setting in question. [Answer] I know I am late to this question, but the answer is "of course." Printing money does cause what we call "inflation"; because when the government uses printed money (which it gets for free) to build a fort, it is taking products and labor out of the marketplace. That reduces the supply of the products and labor, so whatever the demand for it may have been, with a lower supply of it, we expect "normal" citizens *without access to free money* to have to pay more for those products and labor. Of course the effect may be minimal, the change may be less than, say, one percent, in which case the seller may not bother to raise the price at all. It may also be non-existent; the government may print money to buy a portion of a perishable product that would have to be discarded if not used: bread, milk, meat to feed the soldiers. If there is an excess of a perishable product, the ramifications are complex but in the end, prices may change but there is no inflation, per se. Somebody got paid for efforts already expended that otherwise would have gone unrewarded. The main point I'd make is that taxation **indirectly** causes just as much inflation as printing money. IRL I work a job for a certain amount of take-home pay. I insist upon the take-home pay. About 40% of my gross pay goes to various forms of government income (including sales taxes, property, licensing fees, etc). If that should increase, I would demand a raise to maintain the same take-home pay, my employers would raise their prices to cover their greater expense (or lower their own profits), their clients would pay more -- Price Inflation. The same can be said for regulation: Raise the minimum wage, prices will go up and/or profits will go down to cover it; that is inflation. Even people with savings lose purchasing power; because a $100K in savings buys less stuff when the prices are higher. IRL every product we buy in the USA has this kind of taxation/regulatory overhead built in to its price, we just don't see it explicitly and so we don't know the percentage. But it could be half the price we pay, easily. Printing money to pay for government is a perfectly viable means of funding the government instead of taxation. The issue is, **like** taxation, still controlling how much money the government is allowed to print, which is equivalent to saying what exactly are the legitimate expenses of the government. In all instances (printing, taxation, regulation) the government is taking something for free from its citizens in labor and/or property (and/or lives in conscripting soldiers); ideally in order to realize some kind of collective action that pays off more for its citizens than they could realize alone. Like, building a collective wall around the village to repel invaders, or providing for a full-time healer, wizard, army or brew master that serves them all! Or road building, trade protection, etc. The problems of "inflation" only arise when the government is consistently taking far more from the citizens than they (collectively) get in return; when the value taken is wasted on the government's own entertainment, indulgences and petty squabbles (including wars that gain citizens nothing). But that can happen no matter **how** the value of their property, labor, time and creativity is transferred from the citizens to the government for free. [Answer] Solely? No. For reasons already discussed, if there's no demand for the money printed, it inflates to worthlessness. It can certainly work on moderate scales so long as normal levels of taxation are maintained to ensure a demand for the money. It becomes a slightly odd form of redistribution. What's a more fundamental problem, and the real reason behind the Weimar and Zimbabwe collapses, is that you can't print *foreign* money. A government can redistribute resources within its borders up to the limit of its citizens tolerance, but it can't redistribute resources into its ports and across its borders. In the case of Weimar, the country had to pay a substantial part of its GDP in gold reparations to France. [Answer] The described situation is exactly equivalent to the government running a deficit equal to the new money created. It would work, so long as the amount if new money issued is <= the rate of growth in productive capacity. In this situation, private net savings as a fraction of GDP (sometimes known as public debt to GDP) would remain constant. This budget constraint on the state will lead to very small public spending (3-5% GDP or less). An increase in private debt levels will also lead to greater inflation further constraining the ability of the government to spend, while a decrease in the level of private sector debt (or increase in the savings rate) will allow the government to spend more than it otherwise would. In a non closed economy, there are also the trade and financial flows with the overseas sector to consider. The value in the currency comes from the need to repay loans, maintain a level of savings and/or pay taxes (also from it's use as a medium of exchange). Inflation occurs when the economy attempts to purchase more than it produces. An increase in productive capacity leads to deflation, issuing of currency by government counteracts this. New bonds are issued to the government in order to maintain interest rates according to central bank policy (if the government didn't issue them, interest rates would drop to zero, something taken advantage of in the US Federal Reserve QE program, where the reserve buys bonds to take them out of the financial system). A good example of this is the United States, which has been running a fiscal deficit for decades and currently has quite low inflation rates. If productive capacity declines or the economy runs short of some resource, the hypothetical government will have to cut spending, implement taxation or even run a surplus. In the case of Zimbabwe, they shot many of their farmers causing a shortage of food, leading to the importation of what was a major export commodity, and in turn to a shortage of foreign currency. Once inflation took hold, the disruption of economic activity and capital flight continued to make it worse. As for who is affected, the spending leads to high prices than would be the case without it - people trying to save money or pay off debt (i.e. by selling something of value) will be at an advantage when the government net spends, people trying to spend their savings or take on new loans (in order to buy goods and services) will be disadvantaged. The fortunes of those holding a steady amount of savings or debt will depend on the net interest rate (interest - inflation). [Answer] If done right, in very particular circumstances, it can work very well. (Short version: if you print money to fund investment which creates new wealth, as opposed to simply moving existing wealth around, then it can pay for itself.) Imagine I find a bar of gold. I'm richer of course, but only by making all the other gold owners slightly worse off. Finding gold is pretty much a zero-sum game for the entire economy. There is a small increase in overall wealth I guess, due to the industrial uses for gold. But really nothing important. We go to great lengths to dig up gold and then immediately rebury it under our central banks. But imagine I find a perpetual motion machine, or imagine I'm living in 15th century Europe and I find evidence of the existence of America. In that case, as well as more wealth for myself, the total wealth of the world economy has increased. (There will be winners and losers of course, current oil producers wouldn't like the perpetual motion machine. But many more winners than losers) Good government policy isn't simply about moving wealth around, but about creating new wealth and increasing the total welfare. So, imagine I'm an explorer but nobody will believe me that a new continent exists. I try to borrow money to fund the exploration, but nobody is willing to lend it. I decide to counterfeit the money (i.e. printing money, literally) to fund my exploration. With my 1 million dollars I fund my trip. When everyone believes me, they see that world wealth has increased by 2 million dollars and that I own it all. I generously sell my shares for only half the fair price, collecting $1 million to retire. Everyone is is very happy, they get access to a new continent and they bought it at a bargain price. Eventually, people notice that I used counterfeit money and I am arrested. But now I can simply offer to swap all the counterfeit currency for the real money I received in my sale! So everyone else is happy and I've got my fake currency back. Of course, now I am required destroy the currency. In the end, I'm no better or worse off than I was, but the planet is better off and all the counterfeit money has been destroyed. In fact, it would have been unethical for me *not* to have printed the money. PS: This is the normal way governments fund themselves, they just wrap it up in other ways. [Answer] You literally describe "inflation". Physical currency is not of itself of any value. A countries currency is a token of its reserved wealth. So, theoretically, if I give you a 1 dollar note, I am not only giving you a piece of paper, but I am granting you ownership of a fraction of one of the gold bars in the federal reserve. The value of a nations dollar is theoretically always in proportion to the amount of wealth they hold. So, in a micro country example, there are 5 people in the country. That country has 1 gold bar and 5 dollars. Each person has a dollar, each person has 1/5th of a gold bar. If I were to print off 5 more dollars, and 4 members gave their second dollar to the fifth member, we would have 4 people who have wealth equal to 1/10th of a gold bar, and the 5th person now holds 6/10ths of a gold bar. Printing off too many dollars relative to your actual wealth devalues your dollar considerably, and your currency becomes worthless in import/export, which drives up the cost of the things people are trying to buy with their dollars. China wants 1/5th of a gold bar for a box of tea. When there were only 5 dollars, China sold us a box of tea for 1 dollar. Since we printed off 5 more dollars, now China will only sell for 2 dollars, so the 4 people who still have a dollar can no longer afford a box of tea with that dollar because of inflation. Probably incoherent and partially wrong at some point according to an econ major. Thats just how I understand it. [Answer] ON the topic of who is affected: The people **most** affected by this scheme are the wealthy; just like they are the most affected by inflation. Because the wealthy own most of the *debt* in the world, they make the most loans with their reserve cash. At least IRL the majority of this debt is at simple interest with a fixed payment; like mortgages and bonds. So inflation reduces the buying power of those payments. Over the course of 30 years, typical inflation of 3.5% per year reduces purchasing power of \$1 to 36 cents; and wages inversely so (\$1 to \$2.80). Inflation is like a "tax" on the rich for money reserves; and they are the primary class of people that keep most of their net worth reserved in the form of funding interest-bearing loans and other such instruments. If your fantasy world does not contain such an upper strata of wealth with saved money that makes loans and investments, if that is not part of your world design, then funding with printed money need not have much effect on anybody. **REAL** property, like land, swords, furniture, houses, castles, bridges, and so on, will retain their value; meaning they should sell at their inflated price, for at least as much purchasing power as they cost (minus perhaps wear and tear). It is only the money instruments that are degraded. ON THE POINT of faith in the currency: If you are going to print money, you have to enforce the use of your money in trade, or at least the vast majority of trade. You cannot allow other forms of money, or extensive bartering, or gold ounces or other forms of accounting systems. If people can live their lives without your official money, then the government has to resort to coercion and conscription for its supplies and employees. Enforcing the use of only the official money for all trade is a small price to pay so that the government **can** print money and pay people fairly for their land, goods, labor, military service and creative efforts. The degree to which you enforce the use of your money, is the degree of faith in the currency: I can believe my pay will be good at the grocer because if my grocer refuses to take it in payment, I can report him as a criminal. [Answer] **No.** Paper money has no intrinsic value. A "bank note" is valuable because a bank is promising to accept it as tender. US dollar bills are valuable because the law says you can always use them to pay your debts to the US government. In a system where the central bank has no assets such as gold reserves that can be exchanged for banknotes and the government is not taxing its citizens, this state's paper money becomes useless very quickly. Plus, there is issue of supply and demand. Higher the supply lower the value. With every batch of money you print, what is in circulation becomes less valuable. Also called inflation. Very soon, people will prefer to barter instead of using your money that is guaranteed to be worth less tomorrow. [Answer] No, and hang on a second to see why the question doesn't really make sense. We're talking about fiat currency in the current era. This isn't backed by any hard asset (at any ratio), so it's not what people would have historically called 'money'. In actual terms, it's a debt instrument. When somebody buys a treasury bill, for example, they're expecting to get that money back with interest in the future. So, it's a loan with repayment, in simple terms. Like any loan, the lender wants to see some collateral. In the case of all modern fiat currencies, the collateral is the ability of the issuing government to tax that repayment out of the people in the territory it controls, using violence if necessary. That's why some religions keep their savings in gold instead - the currency notes in a fiat government system can be seen as exchanged and traded threat promises, in a mathematical sense. Now there's some gamesmanship that goes on as well, and a bit of a confidence game. When a government racks up big debt, they're extending those promises far into the future. At some point they're promising to extract resources from people who haven't even been born yet to make the mathematics "work". If the music stops, you wind up with a situation like is going on in Greece, where the debt cannot be repaid through taxation, and the government defaults (or gets a bail-out from other countries, which is similar). IIRC the current US debt is on the order of $1.2M per family, which isn't possible to tax out, so the debt is extended into the future, with promises that somebody else will make good on it (somehow). Plenty of smart people are skeptical that it will be possible then, but as long as lenders are willing to keep buying long-term debt, the system perpetuates. So, asking if money can be printed without taxation, today, is asking if promises of taxation can be done without taxation, which invalidates the hypothetical because it's self-contradictory. [Answer] It can work for a small country. The idea is to produce collectors' coins with a high nominal value that are bought by collectors worldwide, but never circulated. The problem is that the coin collectors are a limited group spending limited resources to maintain and enlarge their coin collections. So, the collectors' programme must not be to huge (collectors go away when they feel exploited by an inflated collectors' programme) and the potential gain of money is limited. [Answer] > > Would this work? > > > Yes. Barely, badly, and for some time. (and it would depend on what exactly you call "printing money".) How long, how badly, and how barely, it would depend on the situation of your economy, previous to such inovation. --- The magical/sacred equation of monetary policy - the one economists repeat as a mantra, their everynight prayer to Mammon - is this small piece of elegance: **MV ≅ PQ** in which M is the amount of circulating money, V is the speed (velocity) of money circulation, P is the general level of prices, and Q is the total value of everything produced in a given economy. Your hypothesis is basically increasing M: MV ≅ PQ ---> **M**V ≅ PQ Problem is, if you increase M, then one of these three things must happen: V will decrease, or either P or Q will increase. (Evidently, it could happen that V will decrease a little, and P and Q will increase a little. But let's go with the "pure" cases). First, perhaps V decreases: MV ≅ PQ ---> **M**v ≅ PQ This first possibility is not well studied; economists usually assume that V is inelastic, or that it will only change due to specific changes on the technology of circulation (such as the introduction of paper money or virtual money - and these changes would usually go in the way of **increasing** V). So, in practice, economists will offer a few human sacrifices to Mammon in order to get MV ≅ PQ ---> **M**V ≅ P**Q** in which the increase of circulating money translates into an increase of production. In fact, with very few exceptions, governments do exactly this to a point, with much caution, in order to get their economies to grow (because a static M will make growth very difficult). But Mammon being a capricious god, what you are more likely to get is, MV ≅ PQ ---> **M**V ≅ **P**Q in which, instead of production growing, prices rise. This will allow us to answer the questions, "how long, how badly, and how barely" would this work, as long as we understand how Mammon decides between the increase in P versus the increase in Q. Prices are relatively easy to increase, especially if the economy is considerably oligopolistic, and especially in the case of products whose demand is *inelastic* (if the prices of, say, videogames, rise, people can buy less videogames - the demand is elastic - but if prices of food rise, people will have to pay more or starve - the demand is inelastic). Production is much more difficult to increase, because it will demand more investments. Surplus money is **one** condition for investment, but there are others. And investments' returns may be delayed in time; even if entrepreneurs decide to invest, thus pointing to an increase in Q, it may be that the increase in Q is only going to happen once their new factories or new machines are functioning, which may be several months to a few years into the future. Which means that P will tend to rise in the short term, even if there is investment. So, we can see that an increase in M will more likely result in an increase in P if: * The economy is highly oligopolic; * The economy relies heavily in inelastic goods - generally, primary products of immediate consumption; * The economy is already functioning at or near at the limits of its capacity. Conversely, an increase in M will more likely result in an increase in Q if: * The degree of monopolisation of the economy is low; * The economy relies heavily in elastic goods; * The economy is functioning far from the limits of its capacity. So, a heavily industrialised but not very heavily oligopolic economy that is just coming out of a recession will probably respond quite well to your scheme, while an oligopolic economy heavily based in agriculture that is already overbusy will probably go into inflation - high inflation - hyperinflation - political crisis very quickly. Then the problem is that, even in the first case, the growth of the economy caused by the expansion of M itself will eventually make it come closer to its capacity. As long as production can be increased by simply hiring more workers for longer hours and increasing the intensity of the use of machines - additional shifts, for instance - things will go relatively well. But at some point, further increases will demand more or newer machines or bigger factories, and this will only result in an increase in Q in a longer term than what is needed for things to go smoothly. At this point, inflation is going to be unavoidable. And then the government will want to reintroduce taxes, but this is going to be much more difficult in an economy already facing serious problems of inflation. --- And then, it depends of what you call "printing money". Because actually printing bills, or coining coins, is only a small part of monetary policy, and bills and coins are a quite small part of actual circulating money, so expanding them will probably have little effect in the economy as a whole (see, for instance, [definition of M0, M1, etc](http://lexicon.ft.com/Term?term=m0,-m1,-m2,-m3,-m4) and [money supply in India](http://mrunal.org/2014/08/explained-measures-of-money-supply-m0-m1-m3-narrow-money-broad-money-money-multiplier.html/)). When a government really wants to expand M (which, at least in part, means it wants to fund itself through monetary policy) it expands credit. Central banks lend money to commercial banks, and allow those banks to re-lend money to other economic agents (generally, firms and families), but it imposes a *reserve requirement* that limits the creation of new virtual money by banks. When a government wants to expand its circulating money, it reduces the reserve requirement, which in turn makes credit easier and cheaper, which has either the intended result of economic growth, or the much feared result of inflation. This brings an additional problem: since any abrupt increase in reserve requirements will probably precipitate an immediate monetary crisis and a recession, governments tend to try to reduce the money supply by borrowing money back, thus reducing the amount of circulation money. But this can cause the government to increase interests too much, and get caught in a vicious cycle: borrowing more money at higher interest rates to decrease M, and then having to increase M in order to remain potentially able to pay back its debts (the kind of conundrum that used to recurrently plague Brasil up to the end of the 20th century, for instance). > > If so: > > > How would this affect the faith in the currency system? > > > Potentially, it could destroy such faith, through hyperinflation. > > Which class would be relatively taxed the most? > > > All those who rely on relatively fixed prices: workers first and foremost, landlords, especially urban owners of for-rent aparments; also importers (who will find the foreign currency the need to import goods ever more expensive). In short, it is not exactly a good idea; taxes are more reliable, have less negative effects, and are more easier to scale down (and politically much more difficult to raise if necessary). [Answer] Printing money instead of collecting taxes would work as long as the amount printed every year is no more than what would be raised by collecting taxes, say as a percentage of GDP. Moreover, a mechanism would have to be put in place to eliminate from the economy an amount equal to the money printed, say a decrease in salary. Lots of ifs but done that way you could reduce government spending by eliminating resources used to collect that money. Another other benefits could be eliminating the black market. A government could also control the influx of money by eliminating, reducing or charging for some services. Obviously, this is a very rough idea, and an awful lot of thinking would have to be expanded to iron out all the details. I am just an average Joe bloe that thinks that there has to be a better way to raise the money required by a government to fund his expenses. [Answer] Yes, this would work with the right constraints in place. If M were to increase based on a set formula (18% of GDP) and politicians were constrained by this, then it would work. The severity of the constraint is the key. Without a sufficient constraint, the scheme would fail. V would increase as people would retain 100% of their earnings and be able to invest or spend those additional earnings. Barter, black market, shadow economy, all would be captured by this system. The increase in productivity from the elimination of the tax compliance, IRS, artificial incentives and disincentives, etc. would be a boon for GDP growth. In the end, it will never happen even if it could work. [Answer] These are many great answers here, but I think a simple like would also be useful. # Obviously not If such a thing were possible, then everyone would be doing it right now. ## That's it Detailed answers are very interesting, but IMAO this fact alone is sufficient to completely negate the question, no need to add anything. [Answer] In no time, the economy will be in the gutter due to hyperinflation. It's exactly what happened in Weimar Germany, and what plagues modern Zimbabwe. [Answer] What gives all fiat money "status" or "use value unto itself" is wholly subjective and based upon the "Theory of Confidence" that upon the exchange of said paper the actual good i receive is of equal if not lesser value ("seigniorage.") Again however one can only AND ONLY speculate in this regard. Should a loss of confidence occur this is normatively reflected in the ability to borrow thus bearing no relationship to gold, silver, oil, ahem *Bitcoin trading* ahem, etc. In short you're still stuck with said fiat monies only now with added interest and an inability to finance even the most basic functions of being a Government let alone financing a War effort. With the "Great Staycation" now at an end this is hardly an esoteric matter as the Government still must balance the books in the form of creating a budget even if the ahem *desired inflation* ahem has taken hold. But absolutely the loss of confidence means a crushing blow to one's ability to borrow with some idea of impunity absolutely. In the alternative private individuals with means and interest in extending credit pretty much suddenly run your Country or even Nation through the use of the biggest Weapon of Mass Destruction ever invented namely the United States Federal Reserve Note. Specifically the current President of the United States wants to pass "retroactive taxes" upon any type of gain I imagine financial or otherwise but leaving aside the Constitutionality of such a tax...how will such a claim be enforced? The answer must be "by the furtherance of creating even moar worthless debt." In theory one could convert all fiat us frn's as debt to be paid at interest in order to reduce said "liquidity supernova." In the meantime works of art sold for billions of "whatever money" becomes the norm. A single US Penny could be worth trillions. ]

[Question] [ The world is full of grinches. Party-poopers who simply insist on taking the fun away from everybody else. They'll do everything they can to stop Santa from delivering his gifts — and too many of them work in militaries across the world. What's amazing is that Santa is a really nice guy! He doesn't want to hurt anybody, but he has a job to do! And [NORAD going out of their way to tell everybody where Santa is every second of the trip doesn't help](https://www.noradsanta.org/). Santa has access to his world-renowned workshop, but all he has in transit is his sled. It has a near infinite carrying capacity — but it is just a sled (with exposed reindeer... Dang...). **Question:**  What can Santa do to defend himself from the world militaries of 2018? * Remember, all you have to work with is the sleigh and eight (OK, nine) reindeer. Santa can't send his elves to invade Somalia to nullify their military — or their pirates. * Santa won't hurt anyone, so whatever defenses you come up with must preserve human life. * Santa, the sleigh, and all the reindeer must survive the day. * Our grinches may want Santa dead, but their children probably don't. That means Santa is required to stop at every military base. He can't save his can by avoiding launch sites, ifyouknowwhatImean. [Answer] **Shame** Ever wondered why Santa Claus goes "ho ho ho"? Turns out it means exactly what you think it means. Santa keeps an additional naughty list of unfaithful married couples, especially those high in the political ladder and the military chain of command. One wrong move and the whole world gets to find out how much of a ho-ho-ho you or your spouse has been **Alternative "countermeasures"** For would-be grinches lower in prominence, Santa has other methods. Let it not be said that he's a one trick reindeer. Santa has been utilising psyops long before there was even a NORAD. The commercialisation of Christmas was part of his master plan. All the trappings of Christmas, like gifting, endless jingles, Whamageddon etc, are a sustained DDoS(Distributed Disruption of Surliness) attack waged by the corporations who are really Santa's proxy botnet. On the big day itself, Santa deploys his air force to clear the way. Using their powerful ECM(Extremely Childlike Merriness) packages, highly trained elf pilots flying dedicated strike festives perform SEAD(Shutting-up Extremely Annoying unDesirables) missions. They are supported by AWACS(Archaic Wassailing And Carolling Sleighs) craft who perform command and control duties over the airspace. These provide guidance and help out with their ECCM(Eggnog-Caused Conclusive Meliorism). NORAD never stood a chance. [Answer] Santa is the last active user of the [SR71](https://en.wikipedia.org/wiki/Lockheed_SR-71_Blackbird) defence mechanism, he's just too fast. A quick and dirty calculation of how many deliveries he has to make in a single night, and the distance he has to travel to make those deliveries, suggests that he's moving far faster than anyone is able to intercept. We might be able to track him, NORAD may know [exactly where he is](https://www.noradsanta.org/), but they've got nothing actually able to hit him. [Answer] Santa is protected by mutual ensured destruction, the same force which arguably protected us during our nuclear infancy. It works like this... Santa is the only reason why children even attempt to stay off the naughty list. Without that incentive, those little rug rats would be completely uncontrollable. Destruction doesn't even begin to describe what they would do if anyone took out Saint Nick. Think about this, as parents, you are the source of every disciplinary scolding and every bottom swat that your children have ever received. ...and they know where you keep the butcher knives. NORAD doesn't admit it, but they send up a wing of fighter jets to escort and protect the sleigh while it is over US Protected airspace. Most of the other countries do the same, and CIA drones cover those countries which lack the good sense to put up their own defense. Santa does not have to worry about protection because the rest of us grown-ups worry for him. That is why parents always look so weary on Christmas morning. They have been up all night wishing... Merry Christmas To All and To Nick A Safe Flight! [Answer] **Counterintelligence and stealth technology.** It is well established that Santa has to travel at the speed of fantasy to be able to deliver all the gifts in time around the world. The only way to catch him is using air force and radar. First of all his sledge is built with the latest stealth technology, which most of the radar cannot track. But the guys of NORAD have the technology to follow their own stealth planes, so something more is needed. His chubby appearance is a clever disguise for a secret anti radar technology, well hidden under the red coat, which offsets the radar echo tricking the NORAD into giving a false position. And just as additional measure, he makes sure to deliver the gifts first to the party-poopers, so that while they are busy unwrapping he can visit the rest of the area. [Answer] **Nobody can *actually* track him** It's been established that the speed and route that Santa has to take are, to put it lightly, *absurd.* But that's not any fun, and Santa knows this. To help him keep the christmas spirit in children while *also* accomplishing his job, Santa employs a significant number of look-alikes, drones, and other equipment. Some just need to look like a sleigh and reindeer, to let the children catch a glimpse. There's no way they'd be seeing him at an average speed of ridiculous, so these let them enjoy the magic while he does the *actual* magic. Some are more complex. Maybe with an additional set of reindeer and an elf in a replica sleigh. Or, more accurately, a replica of what people think the sleigh looks like. The actual sleigh is probably a bit different, given the abuse it has to endure. And there's even some that aren't meant to be seen by eyes. They give off the correct radar signature, and one of these is famously tracked by NORAD. Meanwhile, Santa zips around in an undetectable fashion, possibly breaking the laws of physics and/or time. While he knows he is perfectly safe on those counts, he likes the way people think of him, so he takes efforts to make sure he doens't spoil the magic. Plus, if a kid is awake, a well-timed drone outside the window can give him the opportunity to sneak in, eat the cookies, drink the milk, and drop off the presents without being seen. [Answer] People have tried to sneak up on Santa. As they have found out, he sees them when they're sleeping, he knows when they're awake. [Answer] # Sheer [weight of numbers](https://worldbuilding.stackexchange.com/questions/134484/how-many-santas-are-required) Sure you can knock out a few Santas, or even a few dozen but it's like pissing on a forest fire. There are millions of them coming over to be able to complete the round in time. Perhaps a few children will miss out, but with the best will in the world, you're not going to be able to put a dent in their numbers. Hundreds, maybe thousands of Santas may fall to the Grinches in a hard year, but still they come, millions strong. The swarms of Santas flying over turns the sky dark as they pass, a sight to bring joy to the heart of any child1. --- 1and great fertility to the fields as the reindeer do what reindeer do. *Posted as a separate answer because it's entirely unrelated to my other one* [Answer] Santa plays by Mutually Assured Destruction rules. We see the one sleigh he normally uses, but anybody who runs operations like this one has backups capable of completing the entire job just in case something goes down. Santa has to make not less than 233,000,000 stops, and travels between houses at an average speed of 1,800 miles per second. If we assume a smooth acceleration curve his peak velocity is double, but to make it more fair for the militaries of the world, we won't do that. Santa's sleigh must therefore possess 838,800,000,000 miles per second of delta V and some stupid huge TWR. If this is provided by fuel at all, it had better be some kind of mass cancelling magical storage because if it's ordinary antimatter I'd be amazed if the calculations don't work out to this being a planet buster (update: the starting fuel as antimatter outweighs the earth). If someone takes him out, it had better be a clean kill, or any remaining reindeer are going to be panicked and ludicrously dangerous to approach. In any case, the elves with the backup sleighs will have no significant trouble demolishing the military might of the world by shockwaves alone. Somehow, Santa is cancelling his shockwaves from the stupid huge acceleration to keep the cities from being blown away. All the elves have to do is don't. [Answer] What NORAD detects is a drone bogey to keep them occupied, while he uses a more discreet method of travel. And for that matter, the sleigh doesn't have infinite capacity, the sack does. [Answer] The answer is quite simple. **Santa isn't real**, so needs no defenses. It's a vast world-wide conspiracy. Those who are grown-ups now perpetuate the ruse out of nostalgia and whimsy, but they know, deep down, that it's all for show. *They* are the ones wrapping extra presents for the kids. *They* are the ones putting the children to sleep with the hope of Santa dropping in. *They* are the ones eating the cookies. It goes all the way to the top, and has for years. And yes, this answer is obviously ridiculous, because why would so many people go along with it? I mean, it doesn't make much sense at all, really. But this is Worldbuilding, so I assume that's allowed. [Answer] It only *looks* as if Santa is defenseless. But most of the things that you consider to be part of the lore for fun are actually just well-disguised countermeasures both explicit and innate to him and how he does things. **He's knows when you've been sleeping....etc.** This isn't easy to pull off when there's currently 7.5 billion people on the planet (whether or not they believe is irrelevant), and it's a little-known fact that Santa uses his image as "jolly old St. Nick" to obscure the fact that he has a genius level intellect. This is a crucial compliment to his intelligence network. Coming up with the perfect toy for every human being on the planet has honed his mental aptitude, and over time he's gotten very good at anticipating mere mortal humans. In fact, he's so good that he simply [out-gambits](https://tvtropes.org/pmwiki/pmwiki.php/Main/OutGambitted) most of his potential foes. Sorry, Billy, but Santa's been watching you for a *very* long time; he saw your path from wooden horse to grizzled mercenary coming before you did. Why do you think you didn't get that pop-gun when you were 8? Don't think you're going to outwit him now. **That 'special dust' you often see in pictures of his flight isn't magic** While pretty to look at, that 'glitter' behind him as is often depicted isn't just for show. It's actually a highly advanced countermeasure that operates on the same principles as [chaff](https://en.wikipedia.org/wiki/Chaff_(countermeasure)). Not only does this make it hard to actually track him (Norad's tracking is just a dog and pony show they put on to keep the US military from appearing ineffective), but several modern surface-to-air attacks are basically useless too. Couple this with flying at night, and anything thrown at him will need to be done blind. **Those cookies have to go somewhere** It's hard to do this job even in the most ideal conditions, so it helps when you have a predisposition to [rapid healing](https://tvtropes.org/pmwiki/pmwiki.php/Main/HealingFactor). Jagged chimneys, sub-zero temperatures at high altitudes, and active fireplaces are just a few of the hazards you can encounter when delivering toys. Santa hasn't been around for a long time through rigorous attention to his body alone; it's the same reason he seems to be effectively immortal. Of course, you can't just heal out a chance gash or gunshot wound without some help, so he's worked hard to spread traditions like milk and cookies to keep him supplied with adequate caloric intake. [Answer] Since Santa and the reindeer live at the North Pole for so long, they have evolved ways to not radiate so much body heat, internalizing it as much as possible. This makes it extremely difficult for heat seeking armaments to lock onto them. For radar... well, that sack probably has a ton of tinsel that can be used as chaff. And then there's the whole prospect of going down in history as the person that ended gifts for the whole world. Can't say that would make one popular. I highly doubt anyone will buy you a drink at the bar if you're the one that offed Santa. [Answer] **With his gifts** Santa is a cunning man. As a maker of toys he has a natural supply of decoys, including other fake pop-up Santas and reindeer. And although NORAD thinks they have him tracked, it's actually a decoy transponder that he plants on a lookalike sleigh. Equipped with an arsenal of loud noisy things, insta-pop-up balloon Santas, disco smokescreen machines, loud fireworks, he's the master of misdirection and distraction. After all, how do you think he gets past all those eagle-eyed children who are looking out for him? Santa has another gift: he can see into people's hearts, and knows what they truly want, that's how he knows they've been naughty or nice. Even the most hardened military soldier is going to melt when they find Santa brought them something precious, like a card from a loved one, photograph or even a puppy. Sargent might not be too happy. **With some kitted out defence tech** But automated systems can't be bought with gifts. What's Santa to do when his sleigh is undoubtedly detected on radar and IR-tracking missiles? Santa has some close friends in the military who've kitted out his sleigh with chaff, both heat-producing and radar baffling (electronic chaff), of which Santa has modified to also launch fireworks and sparklers and other heat producing sources. He's a jolly fellow like that. He's also managed to get some electronic system scramblers, so when he's closer the radar systems will be jammed. **With favours** Santa is a popular guy. He's helped many out of a bad situation, and some even owe him a few favours. Blackmail is beneath Santa, as a man of integrity, but he knows a few people who owe him some favours (he once got a stretch armstrong for a guy when it was sold out, long story). Some of them might be able to provide distractions. There's one kid who is really good with tech, can hack computer systems remotely (he need not travel with Santa, internet is a wonderful thing and Santa has built in wifi because what sleigh doesn't?). Maybe a few people might read between the lines and knock out a few guards. Santa doesn't approve of course, but as it's not Santa it'll pass. **With reindeer** Now, Santa isn't allowed to go around beating up the occasional bad guy, but Blizter, he's got a real bad attitude, he's really grouchy. Well, all the reindeer can be if you get between them and Christmas. With antlers and their own mind (almost like they know what they're doing) they might opt to... intervene. They are magic reindeer after all. **With a child ambush** Of course, children love Santa and if they see a jerk trying to harm Santa, well, they're about to get jumped by an ambush of children. Shin kicking, direct hits to the groin, eye poking, make up powder in the eyes, enough to make any wrongdoer think twice. **The real meanies** Santa's not really one to hurt anybody. But then there are the real meanies, the people whose hearts can't be melted with puppies, can't be fooled with plastic decoys or dazzle, the big bad, the grouchy potato, the Grinch, if you will. And these Grinches are mean, they don't talk, they don't mince words. If it's a problem, its gone, pop, blam, kapow. Reindeer, no problem. Some hacker in pajamas, weak! Children? They eat children for breakfast! How does Santa deal with a savvy bad guy? **With medicine** Well, Santa doesn't deliver just toys. He delivers gifts for all sorts of people, including much needed medicine to old folks and sick children. Of course, Santa has this one troublemaker elf who regularly stows away with the gifts, because elves aren't normally allowed to come along, precisely because of pranks like this. Because there's infinite storage in the sleigh, there's no way Santa could ever find him. So this joker elf loves playing pranks on people, especially Santa, so of course he takes some laxatives which were going to be delivered to the old people's home, and adds it to the mince pies Santa collects from children, which Santa plans to eat later. Now these aren't your usual laxatives. They're magic. Fast acting. But because the Grinches are thieves, they steal the gifts and the mince pies (it's why they want to get Santa, he has infinite storage and infinite gifts! It's a magic sack that negates weight, quantum physics, that sort of stuff), and of course, to show how evil they are (they don't mess around)... they eat the pies in front of Santa, despite him telling them not to. And there's only one toilet. Cue a fight over who gets to go in first. So Santa slips away with the gifts to deliver to the rest of the children... he's survived for another year of hijinx at Christmas. [Answer] # Multiple dimensions and time travel As we know, Santa has to move really fast to get to everyone, so instead he has developed technology that allows him to be in multiple places at once. He can visit 50 or more houses at a time due to his multi-dimension "clones" of himself. They are all the same person, just different time versions. Sort of like time remnants from the TV show "The Flash", or the time doors/gates in the later seasons of "The Legends of Tomorrow". He moves through time and dimensions/space, instead of his standard flight pattern. We still see it as that standard flight pattern, but that's not how he really moves. (See the next heading/section for why he doesn't have to dodge anything.) Also, since he doesn't want any missile or other fragments to hit innocents, he uses the same tech to capture the ammunition and transport it to a place where it will be made harmless, like deep space. He never has to refill his bag, since he's always directly coming from his workshop. All of his time "clones" use this same bag, too, since they really are just him. In fact, he spends all of his year delivering packages, it's just that he plans it out so that it appears he is doing it all on a single night. If you manage to follow him back to his shop, it might actually be July at the North Pole, instead of December. This is how he gets into houses, rather than chimneys that most people don't have anymore. He simply "transports" into the house instead of the roof. # Holograms The Santa you might accidentally see in flight or on your neighbors roof is actually just a hologram. The sleigh and reindeer have been in retirement for years from actual flying. They are still used to make lifelike holographic recordings, but they stay warm and safe at the North Pole. # Cookies and milk Since he's going to so many houses and many of them leave cookies and milk for him, he uses this as fuel for his equipment. Sure, he still snacks some (you don't stay fat by eating right and getting as much exercise as he does), but there are a lot of calories that can be turned into bio-fuel in cookies, milk, and the other snacks people leave for him. He is working on using the explosives and other ammo (collected while "flying") for his energy consumption use, but I hear they've hit some snags with containment. # Clones Due to the ever increasing population, extremists, and the possibility of future generations being on remote planets, his elves have been working on clones. They are exact duplicates of Santa, including all of his previous memories, like "The 6th Day". So far, they have only been using a single clone at a time, but things are progressing so that they will need to use multiples soon. Because of this, his elves are also working on memory combination, so that if you meet one Santa one year, they all will have the same memory of meeting you. This is sort of like distributed SQL databases over multiple servers. Just like you might make an order on Amazon in one database on one server, that information is replicated to all other databases on other servers for data retrieval as well as backup use. Even if he enters a household with an extreme defensive position, his body armor suit (yes, the red one with white fluffy borders) can only defend against so much. If he accidentally dies, his next clone takes over with the latest memories intact. Part of his hat is a memory detector and recovery device, besides being a helmet. Of course, anytime he meets resistance, that person goes on the permanent "naughty" list. It's not necessarily the person "pulling the trigger" on the list, but the person giving the order gets blacklisted. # Conclusion Ok, so I went beyond mere defense here, but I had to explain why he doesn't really need to defend against military attack: he just isn't flying anymore. However, he still makes sure there isn't any collateral damage, using the same time/space transportation tech. And for close combat assaults, he wears armor. When even that doesn't save him, Santa uses clones to replace himself. [Answer] Santa already has defenses! While their purpose is simply protection from the environment in which he operates they're plenty strong enough to shrug off anything the military of any nation can throw, up to and including a direct hit with a nuclear weapon. Even the biggest booms are nothing compared to the atmosphere at the speeds he must be moving in order to make his deliveries in a day and a half. [Answer] **The Conspiracy** It really surprises me to not see the following answer; I think it rather obvious, yet I have to teach it to people each year. Perhaps you've noticed the ubiquity of Santa? Every mall, every street corner (well, in some big cities) has one. Clearly simultaneously. How might this be? Proxies. Agents. Delegates. Impostors. Embodiments. People willingly possessed by the *Spirit of Giving*. You get the picture. Literal appearances by the definite article are agonizingly rare in the days leading up to the big night (he's very busy!), and meticulously planned and prepared for, right? Send an undercover representative! (Sounds a little like the *Men in Black*, doesn't it?) How can you be sure the same doesn't occur on Christmas Eve? Consider this: what if duly designated representatives of *the Claus Estate* do the actual naughtiness judging, procurement, wrapping, *and delivery* of the end product? I have been cleared by the United States Marines to reveal, but only to other grownups like you, that this is exactly what they've been authorized to do by the franchise owner, his wife, and elfish lawyer contingent. It's called the Toys for Tots‚Ñ¢ charity. And, ultimately, the reason NORAD¬π not only tracks the main man, but broadcasts it in realtime doesn't indicate vulnerability. In fact, it serves as a warning to clear the skies in that area. Anything moving that fast and that 'erratically' (with no radar signature, due to organic material construction) and no running lights would pose a huge danger to air traffic, especially when its not equipped with rated transponder and radio equipment...much less being an unique and experimental flying vehicle (EFV). It *may* even be possible that I have been an embedded, vetted proxy of the *estate* during my decades of being a father. I literally can't say. ¬π Consider this for a moment: who has better qualifications for leadership; a generous, charitable, giving candidate; or a grouchy, mean-spirited, vindictive grinch? Which would the chain of command choose? Surely parties with the resources and opportunities to target the *Spirit of Giving* would clearly require enough undercover *Agents of the Claus*, that their efforts would be thwarted from within. [Answer] **Mutually Assured Destruction** Santa's sleigh has to carry all the toys for all the children in the world, or rather the bag in the sleigh, and it is also magic and has infinite carrying capacity... somehow. Now if we assume that this is merely 1 kilogram of toy per child then that is 2 billion kilograms of presents according to google. Now let's just consider what would happen if it were to fall out of the sky which *would* occur if Santa's sleigh were to in any way be compromised (such as if anyone were to shoot a missile at him). Let us assume that Santa is over a kilometer in the air. Let us now compute the potential energy due to gravity that the sleigh contains (the mass of Santa and the reindeer is negligible compared to the mass of the presents). The formula for potential energy due to gravity is $PE = mgh = 2000000000\*9.8\*1000 = 19600000000000$ Joules. The force would be $140000000000$ Newtons assuming the bag takes one second to stop. Note that the bomb dropped on Hiroshima was 63 TJ which is $3.2142857142857141217201166180758$ times the energy of Santa's sleigh when falling. Note that if my estimate on the presents is low and that the average weight is actually $10$ kilograms then this is 3 times the energy released by an actual nuclear bomb! Let's for the time being assume continue assuming the former number, though. Anyone shooting Santa out of the sky would effectively be doing the equivalent of dropping a nuclear bomb on their own land, or if hitting Santa over another country would risk triggering World War III and nuclear Armageddon. This also is not at all factoring in the density of Santa's sleigh in terms of what might happen upon explosive decompression. I unfortunately am not greatly skilled in the physics of explosions but I can imagine that a bag hitting the ground at an impact force of $140000000000$ Newtons and then bursting open might cause some problems. I cannot determine the explosive force, but I can attempt to determine the force and velocity of a present as shrapnel. Let us assume that the bag is on its outside $5$ meters in diameter. This gives us a volume of $65.45$ and a density of $\frac {2000000000}{65.45} = 30557677.616501145912910618792972 \frac {kg}{m^3}$. The density of steel according to google is $8050 \frac {kg}{m^3}$. For our purposes we will assume that the bag will dilate to that density in a period of $0.5$ seconds. That will change the volume to $\frac {2000000000}{8050} \frac {m^3}{kg} \* kg = 248447.20496894409937888198757764 m^3$ with a radius of $38.998553782062510720251554279261$ meters. This means that for a $1$ kilogram present it accelerated from initial velocity of $0$ relative to the bag to a distance of $33.998553782062510720251554279261$ meters in $0.5$ seconds. This means that the acceleration can be found by $33.998553782062510720251554279261 = \frac {1}{2} 0.25\*a$ and so the acceleration is 271.98843025650008576201243423409 meters per second squared. This means the explosive force applied to that present was $271.98843025650008576201243423409$ Newtons. Note that if we consider a time of $0.001$ which is likely more reasonable we get a force of $67997.107564125021440503108558522$ Newtons outward. Note that this will add to the force being applied to the ground which is likely negligible. However, the density of paper is $250$ kilograms per cubic meter according to google so in actuality so I am low balling big time. It is worth pointing out that at least everything within a $100$ meter radius is going to cease to exist. There are no doubts there. We've already allowed a dilation to $30$ meters while assuming the bag contains a pure ball of steel. It is safe to assume that Santa's gift bag being dropped from his sleigh (or even the sleigh losing control) is easily on its own a weapon of mass destruction without even factoring in any release of magical energy from the bag itself in the form of radiation. This is all just assuming that each child on average gets a gift with a mass of $1$ kilogram! If we assume Santa is even *more* generous and carries $100$ kilograms per child or that he carries multiple years of presents in advance then this bag gets even worse and could be more destructive than the Tsar Bomba (largest ever detonated bomb). It wouldn't surprise me if it is heavier in practice than the meteor that wiped out the dinosaurs! And this doesn't even consider the sheer number of missiles it will take to hit the thing and how much damage those will do when they miss considering how fast he must be moving! After all, those missiles have to go somewhere! --- Edit So it has occurred to me that I never addressed the issue of Santa himself being attacked in person. Well the answer is simple really. Santa is almost always carrying his bag of presents. Now it is a bag of holding. This means that unless it is compromised (see above) it should weigh like any other bag. However, some versions of the notion allow for the user to decide whether it weighs like a normal bag or not. If we assume Santa can allow the weight to "leak" out of the bag, then presumably he can smack someone with the weight of a car assuming that he can lift it. But that only works in a fistfight or a knife-fight. What if the person trying to kill Santa has a gun and Santa's bag is not in his hands? Then Santa is in big trouble. However that's until you consider that Santa is delivering to over 2 billion homes in a single night. Let's assume it takes the average person 10 minutes to sneak into a chimney and deliver the presents. If we assume a 24 hour period then it takes Santa 0.0000432 seconds to do the same route. This is 13888888.888888888888888888888889 faster than what a human can do. Note, also that amount of time is slower than human reaction time. This means that Santa can be in and out of most places faster than said armed assassin can pull the trigger. Santa is basically the Flash. And if we assume instead that Santa simply has time warping abilities and just jumps into the past throughout the night to prolong the time he has to make the delivery, then at that point there is nothing stopping Santa from getting shot by a random grinch. However, does he actually need to prevent that? If Santa has all of this magic and has bag of holdings and time bending powers and can somehow make presents for 2 billion people (or that much coal and likely that much coal since the naughty list takes a while to finalize) then this guy can solve energy problems among many other things. Perhaps the simplest and easiest answer here is that Santa knows magic, and one of the most basic magic spells is healing magic. So if Santa get's shot he just heals himself. If Santa gets stabbed he just heals himself. If someone shoots a rocket launcher at Santa - ok now we're just getting ridiculous. [Answer] **Nuclear gumdrops**. No, hear me out. In addition to his sack of gifts, Santa carries a bag of perfectly ordinary gumdrop candies in his sleigh: the kind you might use to build a gingerbread house. He probably snacks on some in midflight, but they also represent considerable destructive potential. Others have already mentioned that Santa has to travel at a respectable fraction of *c* in order to reach every child's house in a night. There's an interesting WhatIf article that shows [what happens to things traveling at relativistic speeds in an atmosphere](https://whatif.xkcd.com/1/). Basically, you get nuclear explosions. In order to protect Santa's sleigh from simply going kaboom, he must have some kind of magic or device that can move the air away from the front of the sleigh. There would still need to be a small bubble of air immediately around the sleigh, so that Santa could breathe, but as long as that bubble continued to move with the sleigh, and did not contact the outside "still air", that wouldn't be a problem. So some super-missle or something starts following Santa, and he tosses a single gumdrop out the back of the sleigh (let's assume the gumdrop weighs about 10 grams). It would pass out of the air envelope with no problem (since it's still not moving very fast relative to the sleigh and the bubble), and likewise through the airless field (since there's nothing to collide with). But then it slams into the relatively still atmosphere at, in that atmosphere's frame of reference, relativistic speeds, and kaboom. My numbers are extremely hasty, but the resulting explosion should have roughly as much energy as 1 ton of TNT: in other words, plenty of firepower. If something were to get into the airless field, then Santa would actually have to hit it with the gumdrop, but if he managed, the effect would be more or less the same. [Answer] Simple: to defend himself from grinches like the one below,[](https://i.stack.imgur.com/GQ3aL.png) he travels at the speed of light so even if they detect him, he's to fast to hit with a missile. Also, he uses stealth technology to protect himself, like a fake sled. ]

[Question] [ In the story I am writing has a person, let's call him John Doe, who has been transported to an alternate reality/parallel universe. This world is very magic dependent (he doesn't know this yet of course). This includes - but is not limited to - farming, cooking, logistics, war and construction, or anything major you can think of in this world is magic dependent one way or another. John has been transported to a nearby village; the world has breathable atmosphere (otherwise it would be a short lived story) and the same gravity as Earth. They all speak the same language so that wont be a problem, and also eat and drink the same way we do, meat/vegetables water etc. A bit on the world's magic background: * To learn magic you need to complete a trial (I wont go deeply into the details) * Trials can be dangerous/lethal, if you fail, any injury will be healed apart from death. * You only attempt a trial yourself unless stated other wise. * Magic is split up into different stages - Beginner, Intermediate, Expert and Master. A beginner cannot start a expert or master trial but can start a intermediate, though there is risk in doing this early. * After you complete a trial, the magic you have gained will be in its lowest state, as you use it more you will have a finer control over it or be able to control a greater amount. A beginner who has gained control of "Beginner Fire" will be able to make a ball of fire about the size of a golf ball, as the control becomes better they will be able to make more fire balls or make them bigger * Beginner are limited to the 4 elements, Fire, Water, Air and Earth, they will only be able to control a small amount at beginner level Back to John, since he isn't from this world he cannot start or use any magic/trials. Is it possible for John to survive without magic in this world? [Answer] Let's translate this into a certain other scenario. Let's pretend that John is transported to this amazing planet called Earth. This world is very technology dependent (he doesn't know this yet of course). This includes but is not limited to farming, cooking, logistics, war and construction, anything major you can think of in this world is technology dependent one way or another. In order to learn how to use and maintain this technology you need to complete a college or university program (I wont go deeply into the details). These programs can be very difficult and are split into Diploma, Bachelor Degree, Master's Degree, and Doctorate levels. A beginner cannot start a Master's Degree program, but can attempt a diploma one. There is risk in doing this before you're ready to take on the responsibility. And so. Could John survive in this world? Will he find employment? Will he manage to fit into society, even though he knows *nothing* about technology? Yes, he will. Because as long as John is a hard working guy he will always find *something* to do. In your particular scenario it will greatly help John is he uses his knowledge of Earth technology to innovate new and interesting things on the magical planet. Such as for example the concept of automobiles, or steam engines. Or simply of a take-out/delivery restaurant. Or even making something as simple as a bicycle can make him famous and rich. With such a wealth of knowledge that he can tap into he will have no problem coming up with some inventive way in which to make money. [Answer] If John is the only person who can't do magic, he could leverage that to act as a curiosity/show. > > Come one, come all, only 5 coppers to see a man cook without magic! > Unbelievable I know. For a silver you can even taste his completely > mundane cooking. Revel in how he manages to capture the essence of > flavor without the aide of any magical capability. > > > [Answer] On the one hand, poor Mr. Doe is pretty much useless. He'll be able to survive, though; there will always be a few people who flunk the Beginner trial, and they survive. If no one fails the Beginner trial, then what's the point of having it at all, right? He'll function roughly as a high-school drop-out; not a glamorous life, but at least he won't starve. They do have minimum wage, right? On the other hand, depending on how magic works, John Doe may well be one of the most powerful people in the world. If he is truly devoid of magic, it may be that magic simply doesn't work on him; a fireball just whooshes right by, and even a Master-level windstorm doesn't muss his hair. He can walk through any magical trap, go completely undetected, and walk up to the highest level wizard in town and punch him in the nose without a worry of reprisal. High level magic users may not even see or hear him, as they might use magical sight or hearing; he could walk into the most secure facilities in the world without worrying about even being seen, let alone caught. [Answer] **Join the military, special ops/intelligence adviser!** Having no inherent magic ability, any weapons or devices he creates won't show up as dangerous (or at all) to magical wards, allowing him to be the equivalent of Q in James Bond. Also lacking a magic basis it will be easier for him to "think outside the box" and find alternate and unexpected ways of gaining surprise in military operations. [Answer] He can't be the only person unable to do magic. By your rules, children are born unable to do magic, so the world has to be safe and at least moderately navigable for them. And if there's a risk even in the beginner trial, then some people will fail it or simply not be able to face taking it. So *some* people won't be able to do magic. It might be a small minority, but they'll exist. Consider the minority of people unable to drive, for example - they have more obstacles in getting from A to B, but public transport does exist, and so do taxis and Uber and lift-sharing schemes. [Answer] Assuming that magic is an addition to our own world's natural laws and not an outright replacement, John should be able to do anything he can do in our world. The world might not be as tailored for him as ours is, but he can manage to get by. For example, if he needs to farm to live, he can always grab a stick, whittle it into a hoe and do some farming. Depending on his resources, he can even do some metalwork and make a *really good* hoe. He wouldn't be able to compete with the people who farm magically, but hopefully he can manage his own subsistence. There's a chance that some benevolent villager takes him under his/her wing, too, and helps out or hires him in exchange for food and board. Not that he could prove as useful as a mage could, but I could see a villager adopting a "just give it your best" attitude. [Answer] *Wizard's Bane* by Rich Cook goes in to this in some detail. He's doubly useless because he can't even weed a vegetable garden or chop wood properly; he's never had to do that sort of manual labor before. [Answer] Another excellent resource that explores this is the *Codex Alera* series by Jim Butcher. Without revealing too much, the main character of the series has no magic in a society where everyone is expected to have at least a little after puberty. He is belittled and considered a freak by most. However, the character is a quick learner, and do to his unique perspective is able to find solutions to problems others within his society had never thought of. At times his rivals use of magic actually was a disadvantage when challenging him as they were often overconfident and arrogant in their superiority. Using this model, my short answer would be "yes" that John would be capable of surviving and even flourishing. He would just have to find other advantages or be able to craft other solutions to the challenges he faces than what those around him might consider. [Answer] everything is relative. some would say that your average non-magical human can't even make a "living wage" in this non-magic-dependent world. also, physical skills are not the most important skills in a complex society. intelligence, temperament, and communication skills are generally what lead to success, not how well you light a fire (with magic or matches). so, his ability to survive has more to do with the culture of the world he enters, than with the magic there. if he finds a world of ignorance, fear and superstition, then he will probably be summarily executed like any other stranger who teleported into town unannounced. on the other hand, if he finds a world with a complex society and effective communication system, his personality and business acumen should determine his financial success rather than his lack of magic. that said, even if he is a rude idiot, he should be able to feed and cloth himself entirely on the generosity of strangers in a sufficiently wealthy (and/or progressive) society. [Answer] I wanted to post a much shorter example as a comment but I cannot do that yet. There is an entire series of books that brings up this topic several times: the Xanth series by Piers Anthony. The very first book almost revolves around this idea. When a person comes of age they must be able to demonstrate their magical ability or be exiled where they must leave Xanth if they are unable to perform magic. The main character is not able to demonstrate his magic and is exiled and there starts his journey to leave. He has to use other skills and make magic wielding friends to survive the trip. The series overall is light-hearted and based on puns but ultimately leads to further acceptance and inclusion of the characters. Every person has a unique magical skill and no skills are duplicated, ever. Waves of immigrants often occur upon which many of them develop magical abilities after time or their children have abilities. Further books place the characters on a path to discover the source of all magic and even the complete loss of all magic within the region. As everything reverts back to no magical abilities they must figure out how to survive and complete their trip. Not that you should do that exactly, but everyone has something to offer and placing people in situations where magic cannot fully fix the problems or is even the source of the problems can shine a light on other abilities. [Answer] Hmm. Others have mentioned the many ways he could be helpful on his own, but there's one admittedly unlikely scenario left: he fakes it. Can he bring technology with him? If so, a lighter could help with fire (or up to a flamethrower if you want to go big), and it can all be neatly explained to the local villagers as being a 'magical focus' or somesuch, and the reason he needs the focus and can only do fire magic is because he's from another world (or, if he's trying to blend in, because he's from some far-off civilization with really weird Trials.) If he feels he oughtn't use technology in public, then I suppose it would all depend on the nature of the Trials, and whether there exist any small, hideable technologies to imitate the Four Elements. (I am immediately getting mental images of him claiming a clown's flower-sprayer is water magic.) Not a likely scenario, but it's there if it helps. Otherwise, I back the whole 'starts a technological revolution' thing. [Answer] I would consider comparison to another disability. e.g., being blind. Today, we have the Braille language, and taxes pay for social services which may provide a "seeing eye" dog that can serve the blind users. In times past, they may well have been relegated to the fine industry of being a beggar, unless they were born in a culture that led to them being burned at the stake. Spartans who killed defective babies may have realized that eyes aren't tracking. Instead of being assisted, they may have been persecuted. On the other hand, a person who lacks taste may be much less detected. I, myself, lacked a decent sense of smell for nearly my entire life. Yet that never got diagnosed as a child. As a child, I learned that humans had an inferior sense of smell compared to canines, and I didn't realize that my sense was notably inferior until I was in my 20s. Then I got the sense, and then started to lose it. And when I started to lose it, I didn't much even care. Smell just isn't as enticing as sight. A person who is missing a basic ability may struggle to various degrees depending on a variety of factors, like how important that ability is, and how accommodating society may be for anyone else who lacks the ability (or has the ability to a diminished amount). Differences may exist between New York City, Beijing, Paris, and Glacier, WA (which is a tiny city that is so near a mountain that it lacks much technology infrastructure, to this day). Differences may affect some people (like urban inner-city dwellers vs. rural farmers, rich vs. poor, etc.) Naturally, as the inventor of every society (and even the entire world) in your fictional setting, you get to make these decisions. You've got a lot of leeway to be able to play with. [Answer] Larry Niven's short story "For a Foggy Night" goes something along these lines. There is a world that has telepathy/mental powers but are not as advanced in the "physical sciences". Character makes some money inventing clever things like the "zipper" and "stapler". ]

[Question] [ Firstly, I'm not looking for an organism that gives birth to two separate species (like a human that gave birth to a human baby and a puppy) as I'm fairly sure that is impossible (though feel free to correct me if there is any example of that). What I'm thinking is a symbiotic pairing that utilise the same egg (or seed, I'm happy for one half of the pairing to be a plant) to give birth to their young. Obviously for an animal it would be easier if it was egg laying than mammalian with live births. What I imagine is species one lays an egg or produces a seed and the second species either implants their own egg / seed into it or somehow absorbs the first egg / seed and grows it's own around it. I imagine the issue would be the first egg being damaged by the process, but I'm hoping it might still be possible. So the question is, is something like that possible? Is there any example of it happening in real life? [Answer] Mitochondria are responsible for allowing oxygen breathing in all Eukaryotes. Chloroplast are responsible for photosynthesis in plants. They both carry their own DNA, it is thought they are symbiotic organism which managed to live and propagate inside a cell. The establishment of the symbiosis took place really long time ago. [Answer] Absolutely, it's possible. Many, many, insects pass endosymbiotic bacteria in their eggs. The classical examples is *Buchnera* transmission in aphids, in which the symbiont is passed down the female line in the eggs. [Answer] # [Portuguese man o' war](https://en.wikipedia.org/wiki/Portuguese_man_o%27_war) It's not a jellyfish it's a [siphonophore](https://en.wikipedia.org/wiki/Siphonophorae), a colony organism. > > <https://www.thenakedscientists.com/articles/questions/how-do-portuguese-man-o-war-jellyfish-reproduce> > > > There are dactylozoids, which make up the tentacles; there are gastrozoids, which are the bits that eat the food; and there are gonozoids, which are the bits of these creatures that reproduce. They produce sperm and eggs. In fact, you get female and male Portuguese man-o-war, even though they're called "Men"! > > > The sperm will fertilise eggs in the water column to produce larvae, which grow into bigger Portuguese man-o-wars. > > > The way that they grow from those individual cells is by asexual division of those cells and they produce all those individual three types of animals that live in this one colony and drift around the oceans, stinging things and eating things as they go. > > > [Answer] Yes it is possible. And in different ways: I- Chloroplasts and Mitochondria. These two parts of the plant and animal cell respectively were once separate organisms. We know this because they both have their own D.N.A. In Animals the offspring receive mitochondrial D.N.A from the mother. This is not a separate organism though. II- The spotted salamander. The spotted Salamander is photosynthetic. This is due a type of algae called Oophila amblystomatis. The organism is deeply intertwined with the salamander, even before birth. After the eggs have been laid and the embryo is developing it's nervous system if the algae is nearby it will travel into the egg. This is due to the fact that the egg releases nitrogen so the algae migrates to the food source. It will then eventually enter the developing tadpole's cells. Mitochondria will then spread around the algal cell. This gives the cells that contain the algae an extra source of oxygen and carbohydrate provided by the algae's photosynthesis. [](https://i.stack.imgur.com/qaO6o.jpg) [Answer] I cannot think of an example of a *sexual* reproduction mechanism which combines two symbionts in the same seed or egg; but many [lichens](https://en.wikipedia.org/wiki/Lichen), which are symbiotic associations of a fungus (the *mycobiont*) and an alga or a cyanobacteria (the *photobiont*), generate *vegetative* reproduction structures called [soredia](https://en.wikipedia.org/wiki/Soredium) and [isidia](https://en.wikipedia.org/wiki/Isidium) which carry propagules of both symbionts.  (A herbarium specimen of the lichen *Leptogium cyanescens* with lobule-shaped isidia. Photograph by Ed Uebel, [available on Wikipedia](https://en.wikipedia.org/wiki/Isidium#/media/File:Leptogium_cyanescens-5.jpg) under the CC-BY-SA-3.0 license.) [Answer] If two species are sharing the same egg, I think it would be easier for the sharing to start early on, before the egg of species one develops a hard shell - which would complicate any egg implanting mechanism like you mentioned in the question. For information on bird reproduction and egg formation see <http://www.backyardnature.net/birdsex.htm> A possible process: (that I have invented) 1. Species one male fertilises egg of species one female. 2. Species two male fertilises egg of species two female. 3. Soon after fertilisation, species two female "lays" egg into the oviduct of species one female. 4. Species two egg is small soft and has a tail like a sperm, so it can swim up the oviduct and nestle into the species one egg yolk. 5. Species one egg, now with species two egg inside, slowly moves down the oviduct and gets surrounded by egg white and then shell. 6. Species one egg is laid. Step 4) could be unreliable, so species two female should probably lay lots of eggs into species one female, to ensure there is a good chance that one successfully nestles into species one egg. [Answer] A healthy adult human has about a kilo of bacteria in/on them, mostly in the gut, and some of them help us digest food or reduce opportunities for other bacteria to harm us. Some of them may get into us before we're born, coming from the mother's body via the placenta.[1](https://www.newscientist.com/article/dn25603-babys-first-gut-bacteria-may-come-from-mums-mouth/ "New Scientist.com article: Baby’s first gut bacteria may come from mum’s mouth") [Answer] Butterflies (and indeed all insects which undergo a complete metamorphosis) lay eggs which contain DNA with two different sets of instructions: one for the development of the caterpillar, and another for the development of the adult butterfly. The original single cell starts to divide, creating a stock of stem cells. Some of these continue to divide and develop into the first instar caterpillar. The rest remain in a state of suspended development. The caterpillar eats to build up body mass. It goes through four phases of development (instars), shedding its skin between each stage. Memories developed by one instar are passed on to the next\*, but may not survive through to the following stage. When the caterpillar is fully mature, it creates a chrysalid and the undifferentiated cells mentioned earlier start to divide and develop, consuming the "soup" from the caterpillar's body. Certain organs of the caterpillar are retained by the butterfly (eyes, parts of the legs, parts of the brain, ...) while others are destroyed and new ones (wings, antennae, ...) are created. Adult butterflies often eat different plants from the caterpillars, and plants evolve in their own ways, so their consumers need to adapt to every change. So you have basically two different creatures, undergoing two different sets of evolutionary pressure, born from the same DNA in the same egg. \*<https://www.wired.com/2008/03/butterflies-rem/> [Answer] This is not a symbiote, but it provides an example of the principle. Chickens are relatively resistant to salmonella - the bacteria harms humans but not so much chickens. Eggs from an infected bird will be infected with salmonella because the bacteria are included in the fluids before the shell forms. There is no reason this principle could/does not apply to beneficial or symbiotic bacteria [Answer] Some species of coral spawn eggs with symbiotic algae already in the egg. (Other species gain their algae later in life). [Scroll down to find some info in this article](http://science.psu.edu/news-and-events/2010-news/LaJeunesse2-2010) However corals and algae aren't the most dynamic and exciting of organisms! So not sure if that's what you are after. [Answer] Note the best example, but may help in your plot: In Alien 4 movie, they were creating clones of the woman Ripley who as with an alien been incubating inside her chest, as an attempt to bring also grow this alien inside her and then remove it from her. This was the only way to get an alien specimen alive. So, according to the movie plot, both species where with merged DNA, because the alien from the this movie franchise takes many characteristics of their live incubator specimen. In the previous movie she killed herself in order to also kill the alien and not let the bad intentionalist company to keep the alien, in order to save Earth. So in this case it was not from the same egg, but from the same DNA which was used to make many clones from her and the other alien species. In this movie they only made it all right in the 8th attempt. The other seven the DNA merged wrong and they were grown with bodies mixed. Even the survivor Ripley number eight had some sort of mind connection with the aliens and also more strength and acid blood, just like the alien. ]

[Question] [ So, the world experienced an apocalypse about 150 years ago. Sad times. Me and a couple buddies are the the salvaging business, and hello, recently we found a jackpot, an untouched military base. When we tried to raid it though.... The security measures are still capable of keeping us out. My question is, what security measures and equipment could keep out prospective scavengers upwards of 150 years after being abandoned? [Answer] I know you want proper booby traps, but I doubt they would be the biggest dangers or challenges of invading a military base. Security measures would have a far larger impact. Firstly a 1 meter thick steel door should make it extremely hard to get in. With the electronics degraded and any ball bearings and grease long gone you will literally have to drag thousands of kilos of metal to get into the base. Then you have to basically break down every single door in your way. That's a lot of potential doors you need to bust down. Elevators will also be broken. So if access to the secret underground bunker requires a lift, you're in for a tough time. You will need to scaffold down, break through the wreck of an elevator and pry open the doors. Depending on the depth this could basically be impossible, or require a lot of rope. Oxygen. After 150 years, all the ventilation equipment will be broken. As you enter deeper into the base, you will start to run out of air. Either because the dying inhabitants inside have used it all up, or because you use it as you go in, and when you are trying to get out, it's still the same old stale air you breathed before. Depending on the size of the pathways, corridors and rooms, some sections can become death traps because the air won't move much, and will have low oxygen content as everyone has been breathing and passing through the area. Unstable ground. While we would like to imagine that everything is still in tip-top shape, parts of the ground may have weakened. Metal stairwells, wooden boards. Maybe even the concrete floor, assuming some potential mishaps have taken place during the apocalypse. There is also a chance of water draining into the base, and since any pumps will have stopped working, it may fill up the lower floors, or wear away at the materials. [Answer] I'm thinking in an entirely different direction. In one of the Indiana Jones movies he met this cult that was dedicated to protecting a relic and keeping unworthy people from getting it. Suppose that, since the apocalypse, the locals have built up a cult that just absolutely does not want anybody to have what's in the military base. They could be the descendants of the security force that originally protected the base. It could sort of be a "Cargo Cult" in reverse. They build all the structures, follow all the rules, wear all the insignia, with the intent of preventing the return of the military. So they've been busy doing things like digging the tunnels out to direct you the wrong way, while covering up and disguising the real tunnels. Or loading up a bunch of rusted out old junk in easy to get places so you think you've got nothing but trash. Meanwhile, whatever the real treasure is, they've got hidden behind some trick walls. Or buried under their village huts. [Answer] Previous answers have correctly pointed out that infrastructure and electronics decay over time. However, what if that particular base had been the test site for cutting edge military weaponry? More specifically, AI research, with integrated combat and repair drones. As the world succumbed to the apocalyptic event which wiped out civilization as we know it, the AI received orders to seal the facility, and await further instructions from the military chain of command. For 150 years the AI has been maintaining the underground facility, scavenging non-essential parts and pieces in order to keep repairs to the nuclear reactor and the basic infrastructure it requires to survive. It used on-site manufacturing capabilities to replace chips, hard-drives, etc., but of course its performance has degraded slightly over time. Maybe it's even gone a *little* insane. When you breach the doors to the facility, self-defense conditions are triggered, which now allow it to venture forth into the world, gathering the raw materials and supplies it needs to replenish its arsenal. [Answer] [Scorched earth](https://en.wikipedia.org/wiki/Scorched_earth) > > A scorched-earth policy is a military strategy that aims to destroy > anything that might be useful to the enemy while it is advancing > through or withdrawing from a location. Any assets that could be used > by the enemy may be targeted, for example food sources, water > supplies, transportation, communications, industrial resources, and > even the local people themselves. > > > On abandoning the base, its owners implemented their scorched earth defense. **Radioactive waste** was pushed thru the ventilation system. 150 years later the radiation is still strong enough to push your detector needles hard against the right stop. And you are lucky to have working detectors. The ventilation system no longer works and that is another unplanned aspect of this tightly closed base keeping you out. **The air is not breathable.** Besides considerable radon from breakdown of the aforementioned waste, there is a lot of methane (leaking up from the deeper earth) and almost no oxygen (the methane ate it). You canary will die from the bad air before it dies from the radiation. If you have solid radiation suits with onboard air supplies you could go around in there. Good luck with finding those 150 years after the fall. [Answer] The military base was in the process of being enclosed in a minefield. There is decaying explosives everywhere. No longer is there a need for triggers and proper arming of the devices, chemistry and time has made them into Russian Roulette To Go. As the base was in the process of being enclosed in said minefield, not only are there mines scattered around, but also crates of them rotting all over the place threatening the intrepid explorer (intrepid because some stooges go first) with death AND destruction... [Answer] In europe 75-year-old unexploded bombs are [found on a weekly basis](https://www.citylab.com/life/2019/06/germany-world-war-ii-bombs-berlin-brandenburg-construction/590755/). Once or twice a year [one will explode on its own](https://www.dw.com/en/wwii-bomb-self-detonates-in-german-field-leaves-crater/a-49331435), sometimes creating a 30-foot-wide crater. Thankfully, usually in farmland rather than city centres! Some of the bombs used in WW2 were [chemical time-delay bombs](https://www.munichre.com/topics-online/en/infrastructure/munich-bomb-insurers-settle-claims.html), designed to explode after the initial bombing raid, to kill rescuers. Ain't war grand? Some of these worked by breaking a vial of acetone on impact, which gradually dissolved a celluloid sheet to release the trigger after a few hours. But if the bomb landed upside-down, instead of the acetone landing on the celluloid sheet it would gradually evaporate, with only the vapour weakening the celluloid. So instead of exploding with a 75-minute delay, they explode with a 75-year delay. So it's plausible that bombs can still work - and sometimes become even more unstable - after decades. (Of course, most bombs are rusted up and don't explode even when hit by a backhoe or a farmer's plough.) Combined with the answers by bukwyrm and Willk, perhaps mines and tripwires and suchlike were set - either while abandoning the base, or by defenders who barricaded themselves in but have long since died. And it needn't be all one sort of trap or bomb - perhaps your base's soldiers saw a lot of different IEDs in Iraq. [Answer] # Feral guard dogs There are plenty of places where military bases are guarded, in part, by dogs. Sometimes, those dogs are *real* nasty: [](https://i.stack.imgur.com/d9tfS.jpg) Also, they're huge. [](https://i.stack.imgur.com/9RaxK.jpg) If a bunch of these got loose when the base shut down, and no one bothered to corral them, there's a solid chance a pack of them could grow and expand in the environs of the military base. A large pack of 30-40 feral guard dogs will be all the disincentive anyone needs to drop by the base for a visit. [Answer] Electronics and chemistry do not hold well against time, and electronics need also power to be operating. Therefore I don't expect them to be effective after 150 years. Booby traps working with gravity will probably be still effective. Something like: * hanging spike balls * masked holes with spikes inside * rocks falling requires nothing too complex to be hold and triggered. The only unknown aspect being wildlife accessing the building and triggering the traps. [Answer] Lots of stuff about passive defence here, not much about active. Passive stuff is easy: fail-closed electro-mechanical systems are old hat, and what you can't conveniently lock you can always (conveniently or not) conceal. But how about active deterrents that won't suffer from decay if they happen to sit idle for a couple centuries? Seems like we should have a lot more examples of those to choose from. Unfortunately it's going to depend on how many people survived the apocalypse, how long they had and how badly they wanted to protect the base. If the answer to all three is 'enough' then we're in business. Firstly, let's dig out all those old movies about trapped temples and so on. Get the engineering boys working on ideas for moving floors, pit traps, spike drops, you name it. Next let's look for ways we can store energy that won't fade over time so that we've got power when we really need it. Chemicals, radioactives and so on aren't going to be reliable for really long time spans, but there's always the overlooked power storage: gravitational potential energy. Put some weights on chains hooked up to the most robust generation methods you've got, seal them in and fill the room with argon or something to make sure they don't get disturbed by rodents 50 years in. Rig it so that some mechanical trigger will remove the support from the weights and boom, you've got power. For a couple minutes anyway. Maybe long enough to get the fire started in your boiler? Then there's the good old hydraulic method, where you have some hidden sluiceway from the local lake that can be opened to deliver water to a wheel that drives... well, whatever you need it to. Big chunky gears, collars instead of bearings, etc. Doesn't have to be efficient, just robust. Or how about dropping weights onto piezoelectric crystals? That can generate fairly good electrical sparks. I reckon you could harness that to fire a block of plastique or some other electrically-fired explosive. It would have to be sealed into a chemically inert container to last long enough, but that should be easy enough to do. There's always power if you look hard enough, and gravity is probably going to be the one that outlasts all the others. In a thousand years the output of your Americium-powered RTG might not be enough to do anything useful, but gravity is still going to be there. Just make sure that your mechanisms are simple and robust and sealed away from contaminants and you'll be fine. And don't forget to leave a note for the scavengers to find - when they finally make it through your death traps - that apologizes for the fact that you didn't actually leave anything worth finding. Most of it got disassembled for raw materials to make all those traps. Including the one that just sealed off the entrance to this room and the one that's knocking all the supports out from the floor... hey, where did everybody go? Yeah. I'd make a really nasty GM. [Answer] A story I read used an [RTG](https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator) to keep capacitors charged. Those capacitors energized various electric-fence-like obstacles, including strips across the floors of entry chambers to bunkers. The scavengers in the story were familiar with this design, and knew to short them before entering, but this wasn't common knowledge among others. [Answer] Very simply It is a nuclear hardened bunker and the door is locked, or worse rusted shut. [](https://i.stack.imgur.com/0F3LS.jpg) Hope you have a few months to hang around cutting it open. Worse when you finally open it there is gaping hole, the supports for the floor having long since rusted away and collapses (not uncommon in old bunkers) and across the gaping hole you see... another \*\*\*\*\*\*\*ing door. Sometimes the best protection is just time breaking some things and making other more solid. [Answer] Today about the most precious thing is data. And it is likely to be even so in the future. So your hypothetical scavenger 150 years from now probably does not want to salvage rusty metals, and old computer hardware, but want the data. We are already very good at encrypting data, and not so adept at preserving it for a long time, so it will not be easy to salvage anything. Maybe the military base will not be in real space, but a database in cyberspace. Some classified and encrypted data, preserved for eternity, and may worth a fortune for data collectors in the future. If only they knew the password ... [Answer] 1. Your military base is build into a salt mine -> electronics are well preserved as the air is veeery dry (though you shouldn't take them home, as the salt dust will attract water from the air, ruining it). 2. Your military base uses thermal energy as source of electricity 3. It was shut down, but you entering it reactivated it -> lights are still working So from this, electronics should still work (at least anything not requiring batteries) and anything movable should work, as long as it doesn't require a lot of maintenance. The rest is up to you. [Answer] The other answers are likely to be what you're really after, but the first Emperor of China's burial tomb has lasted thousands of years without being breached. Sure, these days we don't dig it up for fear of contaminating it, but even as recently as a couple of hundred years ago we weren't so careful about such things. My point is, it's somewhat hidden in plain sight, it's actually a logistically difficult job to break into (even by today's standards), and even if we got all the earth off the top, there's no guarantee that we'd be able to break into it without having to destroy some rock walls and the like. In other words, our investment into the task would probably out-weigh the gains we'd made by getting into it (even if it were full of 150 years old military goodies). Last point: since technology of almost any type degrades over time, is it likely that 150 years old military kit would actually work? Most explosives lose their potency and/or stability over time, so weapons may not fire, bombs may go off without warning, etc. Vehicles or other machines would likely not work either. Maybe the whole lot has got a bit wet and is now a rusty pile of junk? Whatever you decide about all of that, it has a bearing on the "work versus reward" of breaking into the base in the first place. [Answer] # WMD ampoules Under the floor tiles, and strewn among debris, and buried in the soil, the defenders have left you here and there a sealed glass ampoule of some delightful relic of 21st-century life in an inert noble gas atmosphere. Sarin, Novichok, smallpox ... so many possibilities! Death never dies. Honestly though, there are enough areas of the world kept uninhabitable by old minefields, that I have a hard time believing they would need to go to those extremes anyway. ]

[Question] [ The idea is that a number of satellites have been deployed throughout the galaxy and ships use them to plot their FTL jumps. If that's the case, the thought occurs to me that someone could try and destroy one if they wanted to cut off a particular section of the galaxy. I thought of something like a "Free Travel Accord" that forbids interference with the FTL-satellite network, but you're bound to have inscrutable folk who don't abide. What kind of failsafes could a satellite have to protect itself from being destroyed or tampered with? [Answer] Their area is not included in the FTL grid. Your satellites are sitting in the depth of space where there is no reason to stop (besides, the exact location won't be public knowledge). So any calculation that would bring a ship in their neighborhood would not be necessary except for maintenance. A mathematical failsafe\* causes any ship that tries to FTL into such an area to land somewhere else, the local police station for example. Maintenance ships either use a specific position with highly secure pre-coded calculations to always land at such a satellite or use a specific added calculation to compensate for the mathematical failsafe. Naturally such codes are highly restricted and likely stored as partial codes in different locations and can only be requested by specific people with specific codes. In case all that is compromized anyway... your satellite system must have backups in case of malfunctions or for extended maintenance to one satellite. Overlaps of the FTL area and backups would be scattered all over the place. If all else fails you use a satellite deployment ship. These would simply move to the edge of an area they can still calculate their FTL to, deploy a satellite, then when that satellite has adjusted to its position use its calculations to FTL farther and get to where they need to be. \* I assume that a portion of the calculations would be done by the satellite, so the mathematical failsafe would also be in the satellite. [Answer] **The FTL beacons are stars.** Artificial [pulsars](https://en.wikipedia.org/wiki/Pulsar) to be precise. Some were already pulsars and their rotation speed adjusted and a couple were made from scratch. This was no mean feat, even in your future world. It is the future equivalent of the Panama Canal or the Apollo moon landing. These FTL beacons are the product of galactic cooperation on a scale not seen before. They are massive and robust, and intended to last for millions of years. The terrorists just cannot bring to bear the kind of energy it would take to meaningfully change one of these artificial pulsars. Extinguishing one or changing the rotation speed is far beyond the capabilities of anyone other than the galactic consortium, and maybe not even them anymore. There is in fact one FTL beacon that is out of position as regards site and sync because it was hit by a comparably massive object. It cannot be repaired and so is ignored by navigators. Although it is still recognized by navigation software and so might still have its uses... [Answer] # Backups and "secure mode" [](https://i.stack.imgur.com/PQKKP.jpg) *StarLink satellites go up 60 at the time* There is no reason to deploy just *one* navigation buoy (\*). You can deploy 2, 4, 64, 1024 at the time. These backups sit silently, more or less "invisible", impossible to spot in the deep vastness of space. When the main goes offline, no longer broadcasting, the next kicks in. This is not only sensible from a sabotage perspective but in general; equipment fails, and it is a long way to the nearest shop. Second, the system can have a safe-mode of sorts, so that when the main and — say — the first backup have been destroyed, the next in line will not *broadcast* the navigation data, but instead only reply to "pings" that have the correct signature. --- (\*) "Satellite" is something that orbits a celestial body. These can be artificial or naturally occurring (like Luna, our moon). [Answer] ## The "satellites" aren't accessible from normalspace They are submerged into the Hyperspace (or their own pocket dimension if you use some other means to FTL), and don't really have a physical connection to the real space once they're activated, or their mode of operation prevents them from interacting with the real space in some other means. So once you activated the satellite - you can't ever shut it off again. Not all hyperspace beacons were even built by the current residents of the galaxy, and some are very ancient, though backups were constructed nearby out of fear of these old ones breaking down. And you can't ram them in hyperspace either because that's how they actually work as destination points - just plucking whatever ship is nearby them from the hyperspace into normalspace. [Answer] No one destroys the satellites because doing so wouldn't actually accomplish your objective of cutting off a region of space. These satellites are quite similar to our modern GPS system. They make FTL navigation significantly easier, but they're not *necessary* in any sense of the word. Without them, pilots can still navigate the old fashioned way, by observing the stars (and other celestial objects) around them, cross-referencing against maps, and manually plotting their course. Destroying the satellite wouldn't make your sector unnavigable, it would just irritate anybody who tried to come visit you. Modern navies still teach their cadets how to navigate by the stars, and many pilots can do so as well. Technology isn't 100% reliable, and anyone navigating through large, unsettled expanses has to have a fallback plan should their technology fail - whether that be a destroyed navigation satellite or a faulty antenna on your vessel. Being stranded in the wilderness can be deadly. Every long-haul pilot worth their salt will be capable of navigating without the satellites, albeit more slowly and with a lot more manual work. [Answer] # Ridiculous Redundancy: A wide variety of conditions mean that while you could destroy the beacons, it wouldn't make a bit of difference. * FTL navigation beacons are cheap and easy to make, and their function can't be corrupted - their simple existence tells people where the beacon is. * Every major species in the universe has a network of beacons they maintain just because they don't entirely trust everyone else to do it. * The network of the ancients are considered galactic cultural treasures, and anyone damaging them would provoke an interplanetary war. * The effective range of the beacon network extends well outside the grid laid out by the beacons. So a network of beacons inside a distant empire are detected at faster-than-light speeds, from thousands of light years outside the empire, and STILL allow a ship's exact position to be determined. Destroying all beacons inside your territory doesn't stop others from easily entering. * The basic function of the beacons is such that you can use even your RIVAL government's beacons to guide you. So if an enemy destroyed ALL your beacons, you could guide ships anyway. * Any ship is capable of operating their engine as a beacon. All that is needed it for them to run their engine into hyperspace without GOING anywhere. Energy consumption only occurs if you move. * Ships can still blind-jump into deep space, removing the risk of ending up in a star or landing where they don't want to be. At that point, they can either drop a beacon (fixing position relative to other beacons) or lacking a beacon, the ship can operate as one for other ships. [Answer] ## Heavy defenses FTL beacons are very valuable to whoever owns them, so they are heavily defended. Basically, there are military bases built around each beacon. (Possibly trading hubs are in the vicinity too.) To destroy a beacon, you would need a considerable military force. And the military defending the beacon will encrypt the beacon's communications, denying you (and civilians) FTL, while still being able to use FTL themselves. They will bring in reinforcements from all over the galaxy and make you regret your decision. [Answer] Take a look at <https://en.m.wikipedia.org/wiki/90377_Sedna> At a apohilion of 5 light-days away from the Sun, it is the most distant known dwarf planet. We are starting to learn that the number of reasonably large chunks of ice extends very far out from the center of our solar system. And, if we’re a representative case, most star systems. Your FTL navigation station might be ground-based. Right next to it might be a small town of people who live on the dwarf planet. They maintain and inspect the station, and will defend it if the situation requires. Or the station could be underground, taking advantage of the ice overhead as protection from radiation (which is harmful to both people and electronics). Or the station could be a few kilometers above, in orbit, so that the blind spot caused by the planet’s shadow (if there is any) is minimized The advantages are easy access to supplies and raw material, a caretaker staff with a little bit of room to breathe, and an armed force that can be mustered instantly to defend the facility . [Answer] # Time dilation Since [FTL travel violates causality (as we know it)](https://physics.stackexchange.com/questions/52249/how-does-faster-than-light-travel-violate-causality), the FTL beacon satellites rely on unobtanium to keep the time-space continuum stable. A set of satellites in a solar system effectively creates a time dilation bubble that somehow enables non-paradoxical time travel. As a side effect, each satellite can create a highly localized time dilation bubble around itself. Any ship or weapons fire approaching the satellite can (and shall) be subjected to either being "frozen in time", or accelerated so it undergoes heat death. The satellite will probably look like a weird black hole to an external observer (since light gets trapped), and not like a chunk of metal. --- Optionally, FTL travel works by entering the satellite's bubble (akin to Mass Effect's "mass relay"s) - FTL jumps are made by carefully plotting a collision course with a satellite. *Any* course that approaches the satellite too close makes matter get trapped in a dilation bubble - the bubble either fulfills a FTL jump (if planned), or destroys the approaching object/energy (depending on course planning). Either way, it's impossible for any object to reach the satellite. [Answer] **Economic worth and FTL assistance** The sattelites might be valuable. Extremely valuable. So much so that destroying it would be absolutely foolish. Imagine being on Earth at a remote location where the only way in or out is with helicopter. Destroying the helicopter would just be foolish. It'll have plenty of defences on it's own or placed by the ruling party. The FTL sattelite might be near impossible to replicate, making it one of the best resources available. This immediately gives a second reason. If you destroy one, it might only remove outbound traffic. Other people might still come inside your area, possibly with a new FTL sattelite. That means destroying an FTL sattelite would be tantamount to suicide. If you destroy an FTL sattelite, thousands, if not millions or even billions of parties, big and small, might be affected. They will respond. You have destroyed your only option of moving away, making the fury that will arrive to annihilate you easy to find you. If they use something like timed charges to FTL away and blow them, the remaining sattelites might still have the data where you travelled. That is, if you can even do so. Again, they are likely to have plenty of defences as they are so valuable. So it is economically unfeasible to destroy them, difficult to do as well as a near futile thing to do. You'll be hunted and destroyed in short order, having only accumulated a financial bill for a new sattelite that is borne by many parties that use the sattelites. [Answer] They move around randomly. They're not satellites; the beacons are on automated FTL ships. They stop in an area, pinpoint their exact position, broadcast for a while, then FTL-jump to a new location. By the time the broadcast has spread far enough to be picked up and located, they're already gone. But they leave behind a multitude of expanding FTL waves that continually sweep through the whole area, like raindrops on a pond. Youngsters with a wild streak sometimes try to chase them, to get as close as they can, and boast of who got nearest. But the all-time record, if you believe the data wasn't faked, was still more than two weeks away, and most never get closer than three or four months. It's rumoured that there is a pattern to the random jumps - some combination of the as-yet unexplained movement of nodal points in the chaotic turbulence of FTL-space and mathematical sequences of ineffably alien higher-dimensional complexity. Some of the older and more inscrutable alien civilisations go very quiet when the subject comes up. Nervous glances are exchanged between them, as if there is something deep and dark hidden here of which they dare not speak. But space is full of campfire ghost-story rumours like that, and only a fool goes around believing them all... [Answer] Second answer: its virtually impossible to succeed. To properly calculate where you are and what route you need to take, sattelites are in contact with one another. That means that each sattelite has 2 or more other sattelites it is in contact with and that can send a ship to it with FTL. Should you destroy sattelite 1, then sattelite 2&3+ will instantly prevent anyone with a location nearby the sattelite from leaving by simply not giving the calculations necessary to leave to any ship with a location nearby the sattelite (or recently nearby the sattelite). A location you have to send over to properly FTL out of there. Subsequently a police/military force will be created and use the sattelites in range of the area to go there. they will inspect any ship, question the crew and impound any half suspicious ship until they can be 100% certain who blew it up. In the meantime a crew is send with a new sattelite. All that work for nothing. Ofcourse you could try to rig up something with time bombs and get away before they blow. That would still mean you have to do so at several sattelites without being caught, while a log of your movement would be kept with every interaction. You would have to mask that and not be obviously stopping at each individual sattelite without an alarm going off somewhere and have your deployed explosives go unnoticed during each maintenance period, which would be hard since a scan of the relative mass of the sattelite would reveal its change in mass. [Answer] Because they're small, difficult to damage, and redundant. They're nearly impossible(or at least not practical) to destroy. Think the black box of an airplane. These FTL buoys, satellites, whatever you call them are actually only about 12" side-length equilateral triangular prisms of titanium alloy 2" thick, with near perfect insulation of the internal components. There are several hundred (thousand?) in orbit around the same celestial body, with the same orbiting each body within a quarter light year. You can knock some of them out of orbit with a bomb... maybe even damaging the internals of those closest to the explosion... but good luck knocking them all out before the intergalactic federation shows up and destroys you, your ship, and everything near you. [Answer] *Seems no one thought about that yet, so I'll add it to the long list of answers :).* If you need the satellites to move your ship around at hyperspeed, then two points arise when you destroy them : ## You become stuck in Deep space As the satellite is now destroyed, you lose yourself access to the FTL grid, meaning you're now stuck in deep space. And no-one can reasonably help you out, because, well, you destroyed the satellite. In other words, you sawed off the branch you were sitting on. Any newly built satellite after alter the activation sequence code and the coordinate systems, meaning that you cannot access back to the grid when it is repowered (you don't know the code), and inputting the old coordinates into the new satellite will give the wrong location so you can't pick the enforcers up. The relay itself is quite well-protected, which means any small forces (such as "inscrutable folk" and terrorist attacks) won't be able to pierce them and cause enough damage before destruction. Bigger ships, while being able to tackle the defenses, will face the issue of finding a large enough crew to go on this suicide mission. ## You become the top-most wanted pirate/corsair Even if you did manage to find a way back, you get to know that all ships entering the satellite area are registered during the time they're in range. If the satellite signal is lost for any reason (emphasis on *any*), any marked ship at that time are black-marked and their galactic ID and crew name/ID spread publicly, which in turn prevents FTL access to any of the crew *and* ship. This also means that : * On the individual scale you'll be hunted down by many bounty hunters, prevented from fleeing. You can't even change ship as you need both a wholly identified, non-criminal crew's ID and a new ship ID to engage FTL with the satellites. * On a larger scale, any nation will get to know that these guys did it, engaging necessary retaliation in such case. Don't underestimate the power of international treaties, they are much stronger than what one could think on the diplomatic front, especially if backed-up by military forces. All of this should deter any force of any size from trying to attack the FTL nodes in the first place. Either countries and individuals will find it to be a too high the price for the benefit it gives. [Answer] # It's not just FTL Those satellites also provide internet access to places, as well as processing financial transactions. Anyone who takes such a satellite down is also harming the economy. for the same reason, there should be a lot of redundancy among satellites. It might be that taking just ONE satellite down has negligible impact on the network - you'd need to take hundreds of them down, and they are distributed among many parsecs. It's just too much effort to be worth it. [Answer] Perhaps the navigational beacons only exist at or about large colonies which have the means to repair or defend *their* FTL beacon. If there's nothing there, why take the effort to construct a beacon? [Answer] You can't attack one let alone destroy it. The satellites are themselves FTL capable, they're self-repairing and controlled by sophisticated AIs that jump them, and only them, so even if you got something attached to the outside of one it would be staying, at the first sign of tampering or attack. It's almost impossible to get close enough to image one of them due to their paranoia, if you get that close without permission they tend to lock you out of the navigation system and leave you to starve in deep interstellar space. Attacking them is impossible and because everyone ***knows*** it's impossible you can't find anyone stupid and desperate to try it. [Answer] ## When the FTL navigation satellites are tampered with or destroyed, the FTL related energy has to go somewhere. And it's usually not nice when it does. The satellites best defense is not having an easily accessible "Off" switch on the outside, and have them run at full power continuously. Because, in order for them to provide information to FTL travelling pilots, they have to have FTL travelling communication measures, which requires the same FTL engine as a pilot's FTL capable spaceship would - possibly more as they need to be able to communicate to many other ships at a moment's notice, and be able to coordinate FTL jumps to avoid collisions. Spaceships would be a bit different, in that they try to keep their FTL drives safely stored and kept shielded so that if they go off, they don't throw FTL energy radiation into nearby allied ships - giving it an emergency shutoff, failsafes, etc., to ensure that they don't leak too much radiation to vaporize nearby groups. Your satellites? Less so. Why would they need it? If they put a satellite in a hostile territory, they're main course of correction is to move it physically out of the area - but if you make the satellite fragile enough that non-certified and internal rocket boosters push it out of orbit causes it to start to malfunction, then they're out of luck. At which point, it's on the hostile territory to protect the satellite as best as they can. You'll likely want at least some shielding from micrometeorites, cosmic radiation, solar flares, EMPs, etc., to avoid accidental tripping of the satellite going off and exploding with all of the FTL energy generation in side of it, but otherwise? "Go ahead, feel free to tamper with it, if you want to end up like the Forbidden Destroyed Quadrant." [Answer] Who’s going to destroy them? **Vandalism or terrorist attacks** Do what we are doing for all kinds of infrastructure today. Think about public roads, railroads, aircraft&airports, electric cables, gas pipelines, internet cables etc. etc. Messing with any of those systems would cause lots of damage but is very rarely done. First of all, make it illegal and socially unacceptable to mess with them. Second, make casual vandalism (or accidental damage) hard. For example traffic lights are usually mounted too high to reach with your hands. For really important or vulnerable infrastructure you add protection: Fences, guards, keep-out-zones, armor etc. Stealth can also help. The precise location of pipelines or cables is often hidden on purpose. **Warfare** The above protections won’t be enough against a well armed opponent who can gain a serious advantage from destroying your infrastructure. You have to add some serious protection (think anti aircraft guns, bunkers, encampments etc. in today’s world), redundancy, stealth or a combination of all three. Redundancy can also mean that you have fall-back technology and are able to survive without the infrastructure. For example aircraft are able to navigate without GNSS, in case the GNSS satellites are unavailable. [Answer] **The "satellites" are not physical objects; they are focus points for a communications network.** Assuming that because you have FTL travel you have FTL comms, and in much the same way that GPS works by comparing time signals from multiple sources, the "satellite" network is actually just a pan-galactic grid of comms intersections. Information is transmitted from a vast network of sending stations in a tight-beam format, focused on various points in the galaxy/federation/empire/whatever; at these nexus points many, many beams emerge from their FTL travels and become available for navigation calculations. If there are at least two beams emerging from any intersection, a ship's navigational computer can use the information they contain to plot a course through hyperspace/subspace/whatever. It's obviously pointless to try to destroy something that's not physically there and as each nexus is the focal point for at least 128 inbound beams there's also no point trying to take out enough senders to disable it. With thousands of senders all over the inhabited galaxy/federation/empire/whatever, many of them on planets or stations with their own defences, there is absolutely no way to brute-force a nexus out of existence. One great galaxy/federation/empire/whatever-wide web of navigational points and zero physical deep-space presence. [Answer] To do this with satellites, you need enormous radiated power, very difficult on a galactic scale. It's even difficult to do this in the Solar System. But nature provides powerful objects that are excellent beacons, with timing that can be extremely well calibrated: pulsars. We are already developing this for Solar System navigation. I was involved in the [successful SEXTANT test on the International Space Station.](https://en.wikipedia.org/wiki/Pulsar-based_navigation) Destroying a pulsar is difficult. [Answer] Those satellites serve as anchor points, places that you can jump to and from FTL at virtually no cost beyond fuel. Calculating a bepsoke trajectory would be computationally prohibitive. The FTL anchor network allows fast and exact calculation inbetween known points. They're highway rest stops, island harbours in the middle of the ocean. They're of vital importance. Strategically, it allows your fleets to move much faster without having to use their computers. Economically, it makes interstellar commerce faster and easier, which is generally good, if only because that can be taxed. **So how do you protect them?** ### With big battleships. You should generally assume that an attacker with physical access has compromised your system. The only reliable and surefire way to ensure physical security is maintained (and know if it's not) is by guarding it 'round the clock. Shoving them into deep space in a secret location isn't an acceptable substitute. Security by obscurity is bad practice. You shouldn't care who knows where you beacons are because nobody can approach them without getting vaporised. Putting weapons on the device itself may not be desirable. For one, it boils down to what do you trust to provide security: your sworn officers and some automated system? For two, your satellite would be limited to defending itself, while a military presence would defend the satellite, it would deter piracy on these rest stops, and it would provide assistance to ships that need it. And while it's good to separate your beacon and your defense mechanism because you can replace one without having to replace the other, it might be interesting if your defence ships can act as beacons on a pinch. **And what if an opposing army attacks your satellites?** You close all FTL lanes, you recall all merchant ships, and you enact your contingency plans for the defence of your planets. Your bigger, more immediate concern shouldn't be the loss of FTL lanes, it should be that you have an invading army on your turf. If you have reasons to expect an invasion, then your military ships should already be fully capable to travel in a timely fashion without the help of beacons. In fact, you probably should have contingencies to physically disable those beacons in war time, so they can't be used by the enemy. It's the space equivalent of blowing the bridges, and ensuring their security is largely irrelevant then. [Answer] Because they are manned, owned and operated by the Intergalactic Federation of Stars, and attacking one is tantamount to declaring war on the rest of the known universe. Also, they are more than just the FTL beacons. They are also the FTL comms relays, which means one being destroyed silences more than your slice of the galaxy. You could expand on the above fairly easily. Not only comms, but finance, etc. They would necessarily have pretty hefty protection, perhaps a quick reaction force, etc. Or, depending on plot, no protection at all. [Answer] They not satellites, they are very energy hungry and maintenance heavy beacons hosted on habitable planets. Thus to attack one is to attack an entire planet, which would have its own defenses. These defenses include turning off their beacons when being attacked, thus preventing the attackers from arriving. [Answer] ### Nothing if that's the plot you want It seems you have created these satellites specifically to have such a weakness, much like Schlock Mercenary's star gates and Red Mars' space elevators. There's no real point having them except to create a weakness in the system. Stars may move fast in the absolute sense, but not for navigational purposes. ### Nobody digs up the road outside their house Except when they do. The road is beneficial to yourself as well as to others, so much like the star gates and space elevators, you need them to get out as well as to get in. As such the first thing a rebel group is going to do is cut the system off from the network to prevent government reinforcements from getting in. The same is going to be true of a government under attack, the first thing they'll do is cut the system off from the network to prevent more attackers arriving. A busy system may have redundancy and multiple access points, but ultimately you're not going to find a government who will tolerate not having a kill switch. ### The simple option Someone had to get to that system in the first place to set up the beacon. There are two ways to use your star drive, beacon driven or course calculated. The latter option is harder work and may only be available to military and exploration vessels, but it still works. Shutting down the satellite just annoys everyone a bit but makes no real difference in the grand scheme of things. [Answer] **Self Preservation** FTL beacons don't just help guide spacecraft, they also stabilise space. FTL beacons are distributed much more densely than is required for navigation. Navigation can be achieved successfully using just a few wide spaced beacons around the edge of the galaxy, although to do that would require more expensive sensor suites. Cost aside the main reason to have more beacons is that the same effect that allows them to be located and used via FTL sensors over interstellar distances also stabilises the space between then, though over a much smaller distance. This creates roads between beacons where travel is safe, both for ships themselves and the systems they are travelling between. Too much travel off the roads between beacons weakens the local ylem and allows eldrich abominations/fatal radiation to penetrate. Remove the beacon from your system and passing traffic can cause local leakage that will kill all the local inhabitants. [Answer] (TL;DR: we don't need them.) Let's consider for a moment how these things might actually work. From your question it seems that these are navigational beacons rather than a vital part of the FTL process. Why do we need them? How are they used? > > "Space," it says, "is big. **Really** big. You just won't beieve how vastly, hugely, mindbogglingly big it is." - The Hitchhiker's Guide to the Galaxy. > > > OK, yes, we all know that space is big. What's not quite so obvious is the effects of the vast distances involved. Sitting just outside of Sol's heliopause we can spot a number of pulsars and other navigational reference marks... but due to the speed of light we're seeing where they were 500 years ago (for the closest two) or more. Sure the average deviation over time is low, but it exists... and you have to factor it in for every new location. And this is where our FTL beacons come in. They broadcast a complex FTL signal that can provide extremely precise positioning information across thousands of lightyears. We can not only figure out where we are but get some idea of the way space is warped between ourselves and the beacon, which is invaluable for calculating a jump route that doesn't end up in the heart of a wandering star. We get almost real-time mapping of spatial distortions in the area as well, which makes our job *so* much easier. No more plotting a jump against predicted proper motion and getting lost in some nebula or flung south of the galactic disk because space didn't act quite the way we expected. Which is all well and good, but there are probably a bunch of old-school pilots out there who remember the early millenia when pilots were *real* pilots, with none of this hand-holding crap. They had to slave over a hot quantum computation bank for hours to get a plot, and half the time they'd end up having to do it all over again when they missed the target. Sure, it was hard. But it was *real*. Given enough time and reactor mass, there's nothing really stopping a ship from just jumping around until they get close enough to the target to make the last jump on dead reckoning. While the beacons eliminate the vast majority of uncertainty from the process, they're a convenience rather than a necessity. They're the GPS that tells you exactly where you are rather than the sextant that just gives you a pretty good idea. (Yes, I know, a *very* good idea when used right.) So what's to stop someone from blowing them up? Well, we can make it expensive for them to do so, with big guns and so on, but ultimately they're just making life harder for everyone without actually stopping FTL travel. Yes they need to be spanked, but that's why we have Space Navys on speed dial. If you really want them to quit, make the beacons cheap and easy to produce. Build up a replacement stock of a few thousand and, whenever one goes down, go out and spread some new beacons around the area. If destroying a beacon just means you get five new beacons, it doesn't make sense to keep trying. --- Oh, and since beacons are now cheap enough to basically throw away, we won't bother trying to destroy them now. Instead we'll have the bad guys start knocking out repeaters and sowing them through the area. That'll play hell with your navigation, believe me. [Answer] What are the limits to hyperspace broadcasts? Assumption: Hyperspace does not interact with objects in normal space other than by the curvature of space. If space has too much curvature across the body of your ship very bad things happen to you--it's impossible to enter/leave hyperspace until you are reasonably clear of gravity wells. However, these are beacons. What they are injecting into hyperspace is electromagnetic energy--it's effective size is the wavelength being used. This makes it not care nearly so much about curvature--the beacons can be placed on planets. Or, more specifically, beneath planets. They are placed a mile below ground in inhabited areas so nobody can dig down there without being noticed. (And to provide a convenient source of maintenance personnel, also--no mission to some exotic point in space to do the yearly service check.) There is also considerable overlap, taking out a beacon makes no difference to the navigators. You would have to take out a bunch of beacons to deny an area of space to hyper vessels. [Answer] I have a few ideas! I've been toying with a similar issue in one of my projects too, so here's what I've come up with so far: * **Constant Security** Having a detatchment of some kind of internal security service (SPACE COPS) to protect our navigation beacons would make sense, especially in a society where security is a major concern or you're trying to convey a police state. * **They're hidden** Maybe we don't arrive immediately next to the beacons, in which they can be hidden out in the depths of space! Since repairs will have to be done every once in a while, though, maybe the location is kept confidential? It should be easy enough to track. Perhaps it's maintained by drones instead of a possibly corrupt team of filthy, untrustworthy organics. * **Checkpoints** In a similar vein to having a detatchment of the security force, these ensure that the beacon is well-protected by security. This could also help preventing the cross-contamination of alien organisms to one another, which is a concept I explore a lot in my sci-fi projects, or exert a higher legal authority over the people in a society seeking to do that. It also makes smuggling in your scenario a lot more complicated and, in that, more interesting. Lots of opportunities here! * **They're really cheap and easy to quickly replace** This could be especially common in less developed systems; a small, cheap beacon with a few extras kept in storage in case of the loss of the temporary one. This one could be especially interesting with how you replenish the beacons; maybe you have a really well-aimed rocket at the nearest space station that keeps putting new ones in orbit, or there's several of them operating at once so security has more time to respond if one is attacked. * **Not Your Grandma's Nav Beacon** Maybe it can be its own security service! Instead of just some ball of metal with a ton of scanners and antennae sticking out of it, the beacon is more a small automated defensive platform. * **That's No Sattelite** ITS A SPACE STATION. This could be especially useful for trade and maybe more common in highly developed regions of space; you jump in, land at the huge trade hub, and you're off! I personally like the versatility this allows; a large structure serving as the point instead of a sattelite could allow for a lot more specialization of individual systems, and in wartime (or just really strict societies) could even redirect to a miliary base. * **It's just, like, really big.** I imagine FTL technology is kind of complicated. Maybe they're less sattelite and more 'gigantic ATC facility floating around a star'? Or it's just a really, really big sattelite because guiding ships through hyperspace and communicating instantly with other beacons across lightyears of distance is, like, really hard work. In any case, this should prevent destruction by anything short of an actual fleet of enemy ships. * **War-crime** War crimes are bad, and we try not to do them. Maybe the threat of a life sentence in the prisons of the Space ICC is enough to deter the possible terrorists and strategic war fleets of your world? This might be even more effective in conjunction with another. In fact, if you choose to go with making your sattelites space stations, I imagine this could be an easily exploited law that could cause some very interesting situations (i.e. what if all the enemies are in this one base? what if they're attacking us from that base?). ]

[Question] [ > > *Hmm... Time to take inventory of the slimes real quick... Lamp Oil Slime, O- Slime, Yellow Paint Slime, Pur-... **Red Paint Slime? Blue Paint Slime?** You two didn't...! Great... So I need a new RPS and a new BPS. That's going to be annoying to make. Note to self, ask some adventurers to grab me two new slimes from the wild.* > > > *Let's check the Food Slimes now... Honey Slime? Check. Grape Jelly Slime? Check. Chocolate Slime? Oh, you split and made a second one... Awesome! Hey, little guy, you're about to make me some serious money! Maple Syrup Slime? Check. Butter Slime? Check. Barbecue Slime...? Barbecue Slime...?! Ugh, not another one... Add **that** to the number of slimes I need to remake... That's really going to hurt the wallet since we're out of brown sugar... Maybe I can get an adventurer to help figure out how I can keep the slimes from mixing and escaping?* > > > Well, adventurers? This is a formal Quest being put out to the entirety of the WB.SE Adventurer's Guild. In the past month, I've lost over a dozen slimes. Either they have eaten each other, mixed with each other, or escaped their enclosures/pens altogether and have either run off or been stolen. How can I prevent the loss of any more slimes? I use them for various purposes including selling what they produce, much like a beekeeper. Info about the slimes: * No, I can't just wait for my slimes to reproduce. That would take too long and make the new slime pretty much useless for my purposes for too long. (The whole thing would take 2 weeks at best, 3 months at worst.) It's easier to just get an already close-to-neutral pH slime out of the wild, cycle water through it until it has gotten as clean as possible, and then change the newly made Aqueous Slime into whatever I need by feeding it appropriately. (At most, 1 month.) Otherwise, I use too much water cleaning the bred slimes. (At this point, though, I'm pretty sure a couple people from the Guild already have prepared "wild" slimes to sell to me because of this... but it's still unnecessary spending, though.) The slimes I breed are better off selling for money. (*Not to mention this Purple Paint Slime abomination...*) * No, I can't just tame the slimes with food or toys to keep them here... They're too mindless. They eat what they find unless they get hungry. Only then do they hunt. Since they seemingly can't taste, they don't care if they get their food from me or elsewhere... Just wherever they end up hopping, sliding, and/or oozing across first. (Depends on the slime.) * Slimes won't split to be smaller than $8π\,in^3$ OR $131π\,cm^3$ * A slime can slip through smaller cracks based on their kind. A paint slime can slip through the crack between a door and door frame, but the lamp oil slime can slide pretty much anywhere water can. Additionally, a sticky material allows slimes some climbing ability, so paint slimes can just crawl up walls if the ceiling is exposed. That said, while some can climb smooth, vertical surfaces, I do not at this time have any that can cling to the underside of smooth, horizontal surfaces. * If two slimes meet, either one will eat the other (becoming contaminated and unusable, so imagine if lamp oil got mixed into your milk) or the two slimes will mix (creating abominations like the purple paint slime). * Slimes need enough food or liquid to maintain their mass as they do excrete some of it regularly. * Slimes do not need air to survive; however, the air available (and lack thereof in some cases) can influence a slime's *quality*. Some benefit from air. Some benefit from a lack of air. That said, air availability is less of a concern of mine. * Slimes do not need more food or liquid than necessary to maintain their size, thus preventing agitation. That said, they do need specific material input based on what kind of slime they are to be. For example, I have to feed a Red Paint Slime appropriate Red Pigment for its paint. If I feed it liquid, I risk diluting it. If I feed it something else, I risk contaminating it. (Like that Purple Paint Slime disappointment is.) A Barbecue Slime is easier to maintain in that I can use a variety of ingredients, thus depleting my food stores for it more slowly, and can cheat on some ingredients temporarily. While you already know, adventurers, here are some of the things not to forget about this world we live in: * Skilled mages are limited to the point of being effectively nonexistent. The best I could ask a mage to do is cast an Ice spell constantly to keep the slimes in the enclosure, but the money it would take is impossible to accrue even if I sold the most valuable slimes I have. (Ignoring that one such gold mine ran away today it seems!) Beyond that, even the most talented of mages has enough mana to cast the spells necessary once ever few hours. In the summer, the ice would melt in minutes. Finding enough capable mages would be actually impossible. So, no requiring mages (or magical items), please. * Craftsmen likewise aren't generally helpful. Back home, there was concrete I could use, but in this world nobody knows how to make it. It looks like the extent of materials available is wood, glass, stone, rudimentary metals, clay, and so forth. While a craftsman could probably make something, I'm concerned the cracks between pieces will still afford the slimes a chance to ooze out and escape. If your solution requires a craftsman, the fewer pieces and types of materials necessary the better. * The world is very medieval in a lot of ways. Right, that won't mean anything to you... Basically, our technology is really limited. So don't suggest something that would require sophisticated technology. There was someone a town over who was burned for being a devil-worshiper because he came up with a highly rudimentary sewage system for his town. (He was reincarnated as a dragon, so it's fine now... but I was already dragged into this world from another. I don't want to risk reincarnation on top of that.) So, basically, here is what you have to work with: * I have plenty enough land available to me. (about 2.5 acres/10,000 m$^2$) * I feed the slimes myself once a day so they don't get restless nor grow too out-of-hand in size. This means I need some kind of opening or slot that I can put their food into in order to keep them fed. At the same time, this means the slime could potentially escape that way, which I want to avoid. * I need to be able to access the pen in order to get the products I'll need for the day. I do so by manually harvesting from them using a spoon, ladle, or even a cup or bowl (depending on how much I may need). (I have to keep these tools regularly cleaned lest I risk contaminating my Slimes.) * They are semifluid, yes, but I can't just manually separate them by pouring them out. Their membrane will keep them held together. The only reason why I can scoop their internal fluid out is because I can exert more force than their membrane's surface tension does. Anything that isn't inside the vessel I am withdrawing, though, will be retained in the slime which is convenient for preventing resource-loss. * My slimes are pretty docile unless I forget to feed them for too long. I have no intention of being away for a week, so it SHOULD be fine, but just in case, assume an agitated "large" slime has the physical strength of a medium-sized dog like a Border Collie. (Actually large slimes are worse, but I have no intention of letting mine get *that* big.) * Their acidity is about equivalent to Lemon Juice at worst. I make sure to keep them from being too concentrated, but assume a Lemon Juice Slime is just as concentrated as the lemon juice bottles you can buy in a store. (I used to have one before it mixed with a Sugar Water Slime... and now I have a Lemonade Slime... best mistake I ever made.) I try to avoid having anything that's TOO dangerous, so no HCL or HF, but still, I do have Slimes that make food preparation so much easier. * Their strength and acidity may not seem that bad on their own, but consider those factors together and the durability of any materials used. The best answer is one that uses the fewest types of materials, the fewest number of fastened-together pieces, holds together well, and gives me the best access to my slimes while they still can't get out. Basically, the best while cheapest pen wins. I'll even pay 10 Silver Coins (100 Reputation) to the winner (once I can place a bounty on this)! --- So, I am awarding the Bounty now. While there were quite a few answers that were all great in their own ways, I had to debate between the following to see which best fit my needs: * Bundt Cake Pen (@Willk) * Specially-Made Glass Jugs (@Kingledion) * Pithos/Amphora (@Cyn) * Barrel (@Tim B II) (Honorable mention to @L. Dutch for the idea of using Lotus Leaves and their naturally hydrophobic qualities.) This isn't to say that other ideas weren't good, they were, but these were the strongest ideas. That said, there can only be one winner. After careful consideration, I gave the Bounty to @Willk. This was a tough choice, but I think it was the right one as the size I would need @Kingledion's Jugs to be, I'd essentially just have a glass pithos/amphora, thus meaning I basically just used @Cyn's idea. The issue is, I'm not personally very strong, so removing and returning a bunch of heavy lids every day isn't going to work well for me, so I decided I would decide between @Willk's idea and @Tim B II's idea. Unfortunately, I had to consider @Tim B II's idea much like @Cyn's idea because of all that goes into removing a barrel head and putting it back on. In the end, I gave the Bounty to @Willk because his best fit my needs and my ability. Still, I appreciate everybody's input and I hope everyone had fun with coming up with ways to solve my issue. Technically, @Cyn, @Kingledion, and @Tim B II all had good ideas that work. The issue is simply with the fact I would be unable to make effective use of them. But who knows? Maybe somebody else could use their ideas for their own Slime Farms! :D Come by the tavern I work at sometime. I'll treat everyone who contributed to a round of pancakes with Maple Syrup Slime Maple Syrup! It's the best syrup I've had since coming to this world! :D [Answer] **Bundt cake pen.** [](https://i.stack.imgur.com/SFkB4.jpg) Frisky slimes gotta move! If it hits a dead end it will start looking for cracks or go up the wall. But if there is a path of least resistance the slime will take it. It will head off down the pan. Yes, it will circle around, but these are slimes. It will not know it has circled around. It will keep going, moving fast, feeling good, getting that slime energy out in its bundt cake hamster wheel of a pen. This was inspired in part by the phenomenon of the [ant mill](https://en.wikipedia.org/wiki/Ant_mill) in which ants will circle around and around until they die of hunger. But you will be throwing slime food over the wall of the pen now and again, so that will not happen to your slimes. [Answer] # Glass jugs [](https://i.stack.imgur.com/BWRbg.jpg) Make them big enough to accommodate your slimes; the slime should fill the bottom few inches and most of the jug should be empty space to prevent escapes. A slime that climbs up the wall can't pass the "upside-down" section to get to the entrance. Since it has no bones or structure, it won't be able to hold itself up the wall; so it will just slide (or drip?) down into a puddle on the bottom. Therefore, it doesn't matter if the jugs are corked or un-corked. You can cork or not cork them, as you see fit, or as you need to feed them or combat offensive smells. Lemon juice won't etch glass; a well-made glass has nothing for a slime to get a hold of and won't leak. Plus, clear glass jugs make it easy to display slimes for sale. Customers can even safely lean over the top to get a whiff. Do you sniff barbeque slimes for quality? [Answer] You can use [superhydrophobic coating](https://en.wikipedia.org/wiki/Superhydrophobic_coating) to define, on a suitable surface, a set of cages where the slimes will be bound. Use the coating to coat the zones where you don't want the slimes to go, and let the outer uncovered. Prevent the uncoated zones to form a connected set. Whenever they try to move out, the superhydrophobic surface will make for them impossible to move. If you have no access to high tech, you can patch together lotus leaves. At the end, they gave the inspiration to our scientists to develop such coatings. [](https://i.stack.imgur.com/139l4.gif) [Answer] # A Pithos > > The term in English is applied to such containers used among the > civilizations that bordered the Mediterranean Sea in the Neolithic, > the Bronze Age and the succeeding Iron Age. Pithoi had been used for > bulk storage, primarily for fluids and grains; they were comparable to > the drums, barrels and casks of recent times... > > > The external shape and materials were approximately the same: a > ceramic jar about as high as a man, a base for standing, sides nearly > straight or generously curved, large mouth with a lid, sealed for > shipping. Jars of this size could not be handled by individuals, > especially when full. Various numbers of handles, or lugs, or some > combination, gave a purchase for some sort of harness used in lifting > the jar with a crane. ([ref](https://en.wikipedia.org/wiki/Pithos)) > > > [](https://i.stack.imgur.com/zR4B9.png) Or use the smaller version, [the amphora](https://en.wikipedia.org/wiki/Amphora). [](https://i.stack.imgur.com/gITKr.png) What you want is a ceramic pot designed to be watertight/oiltight. Nothing can escape it from the rim down. Use plain clay if you want some oxygen exchange ([twice as fast as wood](https://daily.sevenfifty.com/why-an-ancient-technique-is-making-a-comeback/)). Or use beewax or a glaze to keep air in/out. While they both have openings that are narrowed, you can choose a design that allows you to let down a bucket, or reach your hand in. Your version does not have to be a traditional pithos or amphora; you can design it to your needs. [Multiple versions of these and similar containers](https://owlcation.com/humanities/ancient-art-history-styles-of-antiquity-ancient-greek-pottery) existed long before Medieval times, so there should be plenty to choose from. The terms pithos and amphora do refer to very specific shapes and sizes, but don't let yourself be constrained by that. Any shape and size you can imagine probably already has a name. If not, you can have it made for you anyway. To keep them from toppling over (if those slimes get frisky), you can set them partially buried in the ground or use a stand/support. Some have rounded bottoms and some stand on their own. Now, you need a lid. One possibility is a [heavy clay disc](https://books.google.com/books?id=Ho2b1m3dRX0C&pg=PA98&lpg=PA98&dq=how%20to%20seal%20the%20lid%20of%20a%20pithos&source=bl&ots=IxEOZCbqeB&sig=ACfU3U0LG9tf9CYLN4TkQw8nQmvzyDu1Lw&hl=en&sa=X&ved=2ahUKEwjm-PiB8dDhAhUFS60KHRayAh8Q6AEwCnoECAgQAQ#v=onepage&q=how%20to%20seal%20the%20lid%20of%20a%20pithos&f=false) with a hole in the middle. The hole allows you to pull it on and off without any trouble (use a specialty hook to help you if needed), permits air to circulate, and allows you to dump food inside. Stick a cork in it when you're not using it. A stone lid may be harder to find (as making it fit exactly is a chore) but it may be heavy enough on its own. The clay lids are flat so you can stack other heavy things on top, if you're worried about the slimes pushing them off from the inside. For transport, seal the lid in place with wax. Your jar will be 100% watertight. Soften the wax with heat and scrape it off to remove the lid. [Answer] When I first read this, I was reminded of a scene out of Fawlty Towers, where Basil and the Major are discussing the presence of a lapdog in the restaurant. Major - Filthy Creatures, I say. Basil - Indeed. It's a shame one can't store them in air-tight containers. Major - Well, he wouldn't be able to breathe then, would he Fawlty? Basil - He could try, Major. He could try. While there's nothing in your missive that says that the slimes have to breathe, the fact that they need to eat gives it away and therefore I can assume that the following criteria apply; 1) You want air and food to be able to get in 2) You want *nothing* to be able to get out 3) Cleaning, especially with water, can be done at a specific point in time, one at a time, prior to sale. If all this is correct, what you want is a [Check Valve](https://en.wikipedia.org/wiki/Check_valve). You already ship wine and ale around in your territory via casks I'm assuming, so you have coopers that know how to create watertight (or slimetight) barrels, and given that you undoubtedly have brewing you'll have people around who know how to make a check valve as well. Put simply, a check valve is a special type of valve that lets air and water *in*, but doesn't let anything *out*. It's in essence a one-way valve. This means that your slimes can be fed on a liquid diet of some form, and can breathe through the check valve as well, but for all other intents and purposes they are enclosed and can't escape. **Edit to address comments** it would appear after a more careful inspection of the source material that check valves are a more recent invention, early 1900s. That said, they are amazingly simple, and more importantly easy to hide as they just look like an additional fitting in your pipes. Still, this news does invalidate some of the answer, although if you put all your slimes in oversize barrels, they can probably retain enough air between feeding times in any event so I still think there's some merit in this approach. (end edit) So; build a really big barn, and store the barrels in them. Run some pipes through for the liquid food, and put a second check valve in there for air. If anyone asks, you're not doing anything really weird in terms of plumbing or 'science' that will get you burned at the stake; you're running a brewing company. Not only will no-one be suspicious, they'll actively protect you. NB; It's probably best at this point to have a few barrels dedicated to *actual* brewing, so that you actually output a product and make your warehouse look legit. But, I digress. Your slimes will need their barrels cleaned out or changed periodically, but if you have time and manpower, you simply do this one at a time. They can't interact with each other and even though this may seem inefficient, it's got to be less time than you're currently spending trying to keep them apart. So; high quality oak barrels, professionally coopered, 2x check valves per barrel; one for air, one for liquid food, and a regular cleaning / replacement regime for the barrels in which you store the slime. And the bonus; you can sell off this idea to poultry farmers and invent the battery hen model about 500 years ahead of this world's timeline. [Answer] Slimes can live in a jar for a while but in order to grow and produce they need air for their metabolism. So long term storage in jugs isn't good for business. Assuming the slimes are not fire-proof you can surround them with piles of hot coals or smouldering wood. It's a simple solution that doesn't require any advanced technology. I'm not sure you can get any more medieval than pits of burning coals. I know from experience doing burn piles that a large bed of coals or wood can burn for many days or even weeks without any user intervention. It will also withstand moderate rain without extinguishing. In fact they can be quite hard to put out even by spraying continuously with water. Having said that, if it's really going to start pouring you will need to put your slimes in wine bottles or large jugs and cork them till it's over. Obviously, make the piles wide enough so the slimes can't jump over it. And don't forget to leave them enough room in the center so that they can be reasonably far away from the fire (so they won't overheat). You can harvest them with a long shovel when the time comes. To keep the slimes from mixing you will need to make separate areas for each slime. Of course you will have to get fuel to keep the piles burning. But that just leads to two side businesses... **Trash collection:** There is lots of trash from the nearby city, they want it gone and are willing to pay! From time to time plague victims are in high supply and need to be burned anyway. **Fertilizer sales:** The burnt trash was made entirely of organic material, so its ashes make excellent fertilizer. The local farmers are willing to pay handsomely for your nutrient rich soil additives. [](https://i.stack.imgur.com/DvZmB.png) [Answer] > > It looks like the extent of materials available is wood, glass, stone, rudimentary metals, clay, and so forth. > > > Dig a deep hole, fill the hole with a long clay/glass/whatever jar, have a cloth circle surround the rim at the top, put a flat glass cover over it. Maybe add a few air/feeding holes to it as well; or just air out every now and again. Done. Why dig the hole in the first place? So that the jars can't be knocked over. The cloth is to keep cracks between the jar and lid since they can climb. Cork or rubber might be a better seal for the oil slimes, but it depends on your ability to get it. [Answer] > > while some can climb smooth, vertical surfaces, I do not at this time have any that can cling to the underside of smooth, horizontal surfaces. > > > So basically any watertight container with a flat ceiling. The options are many, but for simplicity, go for a barrel with an opening in the center of the top so you can still feed them. This can be covered or corked to regulate air as required. [Answer] First of all, hat tip to L.Dutch and kingledion for the inspiration: # Hydrophobically-rimmed glass jars or vats Glass walls are already difficult for most of your slimes to scale. However, using jugs can be impractical, as you may wish to feed some of your slimes larger solids which would be impractical to fit through the narrow neck of such a jug. Wide-mouth glass jars might keep many of your slimes in place, but some of the stickier ones might still be able to scale their walls. Since your slimes are water-based, surface tension undoubtedly plays a role in their adhesion to even the smoothest surfaces; however, this is a solution masquerading as a problem. Certain substances are known to repel water! You may need to conduct some experiments (I'd be happy to help!) but I think a coating of wax, mineral oil, and/or plain old tallow around the rims of such jars may indeed keep the slimes away. Ideally you want something with a heavy viscosity and a high melting point... you don't want it all running off the walls of the container leaving it unprotected... but there are a great number of substances that fit this bill. Beeswax and spermaceti wax are both naturally-derived substances that are at least marginally readily available, and have melting points well above 38°C (100°F) -- beeswax melts at 62°C (144°F) so there's no fear of it melting on a summer day; however, it can be brittle in cold. Spermaceti congeals at 45°C (113°F) with its melting point a few degrees higher, so while it's comparatively less common and more expensive, it may be more suitable for an all-weather repellent. Just keep the containers sheltered from sun and rain (you don't want too much water in your slimes anyways!) and it should do fine unless you're raising your slimes in the desert. Another benefit to this method is that you can instead have glass pans or vats; so long as the walls of the pan are higher than any shape the slime can freely rise to, and the lip is coated with the appropriate wax, they will not be able to escape. These pans can be used to either give your slimes more room to exercise (or breed, in the case of controlled breedings when you *want* to put two together), or to display to potential customers. The wide, open containers will give the slimes more room to range about while simultaneously providing better viewing, demonstrating to customers how healthy and active your slimes are! For slimes that perform better in an anaerobic environment (lack of air), you can get jars with screw-on lids. If you wish to maintain the display properties, a disc of glass can be used, its rim also coated with wax. A metal ring can then be screwed into place to secure the disc, and the wax will naturally create an airtight barrier while maintaining maximum viewability of your prize slimes! The only downside to this method would be the need to periodically re-coat your containers. Fortunately this should only need to be done once every few months, so you can order a regular scheduled shipment of wax and re-coat the containers in an incremental manner -- for example, if you have 30 slimes, if you get a monthly shipment of wax, you can re-wax 10 containers each month, so it's not such an arduous task. Good luck with your slime-farming endeavors! [Answer] Are there any (naturally occurring) minerals that slime dislikes? Perhaps, like slugs, they dislike salt? Salt is very easy to acquire, and even shape, in low-tech situations, and salt has a long shelf life. Ants can be contained by lemons. Lemon juice tends to dry out, so needs to be maintained. You need to look after your slime properly - if the things they want are all available to them, they are less likely to attempt to move. This includes intellectual stimulation - puzzles. Some slimes also have their own behaviour patterns - maybe you can use this to your advantage? Territoriality, a social hierarchy. Can you train them, like dogs? Can you herd them like sheep? How fast do they move? Do they have nests? Depending how unethical you are, can you give them some sort of (natural) substance to keep them sedated? As a long term strategy, can you breed them to be more sedate, like cows? Do they sense any sort of pain? You mention glass is available, and broken glass has a lot of sharp edges - make a "fence" of broken glass? [Answer] My answer is a bit different because it requires you to change your slimes a bit. All slimes have 1 special feature. A core. The core of its slime is its heart or soul. You could even consider it a brain. Now cores have a minimum size. If the core is too large, the slime will split the core into two cores, hence multiplying. If the core is too small, the process is unsustainable and the slime will die. What you want to harvest is all that rich slime the core produces. Now the best way to harvest slimes, is to simply create a cage with a series of holes in it just smaller than a slimes core. That way, even if the slime was to duplicate itself, it can't escape and instead, all that extra slime it produces is pushed out of the hole for you to harvest. You could even set it up so all that extra slime drips into the bottling machine to extract all that slimy goodness without any human effort. If you want to be even more efficient, simply cage up the core and leave a few holes for food to go into and slime to come out of, to increase the production rate of your factories. Slimes aren't fussy. They just eat and make slime all day. ]

[Question] [ This is a classic of fantasy/sci-fi stories. A creature with two heads, two brains, two distinct personalities, sharing a single body. An entire race of Siamese twins. But the question is, what environment or constraints would cause this adaptation to come about? What would be the evolutionary advantage to two distinct personalities sharing a single body? Also, if anyone can answer this one, how would their nervous systems be wired? Which head would control which part of the body? This is an important question, as it relates to how they would evolve. [Answer] Evolution isn't goal oriented; it moves away from stimuli. In a population, most mutations are neutral or mildly deleterious. Not all change is driven by selection after all... [genetic drift](https://en.wikipedia.org/wiki/Genetic_drift) is also important and you can get [fixation](https://en.wikipedia.org/wiki/Fixation_(population_genetics)) of a potentially undesirable trait in a small population just by random chance. Stupid evolutionary dead ends happen all the time, ultimately rendering a species unsuitable for long term survival All that just to say that there doesn't *need* to be an advantage, and the species doesn't *need* to be viable in the long term... eg. when the dumb, evil two headed giants meet an adventuring species, their long term future is very much in doubt. *Canis Cerberus* may be swiftly outcompeted by *Canis Lupus* when a change in climate allows the latter to invade the territory of the former. A species finds itself with a tendency to produce two-headed, single-bodied (or [dicephalic parapagous](https://en.wikipedia.org/wiki/Dicephalic_parapagus_twins)) conjoined twins, and this turns out to *not be bad enough to kill them*, perhaps because it came along with some other mutations that meant that the resulting children didn't have major movement issues. The mutation would have to be heritable so their children are likely (or guaranteed) to be two-headed too. That's all it takes. Perhaps they arose in a particularly benign environment. They'd probably have to be from a species that doesn't produce a large litter of juveniles as the odds are good that the unmutated children would be stronger and fitter and the twins may not thrive. Some species, like polar bears, habitually give birth to one set of twins and that might be a good sort of starting point. For human coinjoined twins of this type, each head usually seems to control half the body; one arm and one leg. I can't find any information on how hard it would be for them to learn to walk but I suspect that it would be harder than for normal children. Once they've survived to adulthood, there *may* be a number of possible advantages. * Better field of vision and hearing... consider things like being able to have one head underwater and one head above, not just the obvious looking in two directions at once. * Maybe one head could sleep whilst the other is able to do something useful like eat or care for children. It is remotely possible that they could move around whilst one half is asleep, especially if they were fairly buoyant swimmers. * Twice as hard to choke! but again with the underwater theme, the underwater head needn't come up for air whilst searching or fishing. Doing a [yard of ale](https://en.wikipedia.org/wiki/Yard_of_ale) would be trivially easy. * For intelligent species, two brains can be useful, but there is perhaps a risk that the two might grow too similar to usefully react as two fully distinct individuals, but they'd *definitely* work well as a team. This might extend to the species being well suited for co-operative behaviour, as they've had to make use of it since they could walk. * If they used their mouth/teeth for fighting, that's twice as many weapons, though the heads might get in each other's way. * If vocal abilities were important (like birdsong, or howler monkey, er, howling) they've got twice the volume can always manage a duet, though they'll still only have the one set of lungs. I'm sure there are many more, but this will be a start. [Answer] **In this world, bodies are more durable than intelligence.** Imagine mineral creatures who accumulate bodies of crystals, metals and minerals. It takes a really long time to grow a good body and lots of immatures die before their bodies get big enough to withstand the abuse of their environment. But once those bodies are big, they are super durable. More durable than the intelligence of the creatures. It turns out dementia is the shadow of intelligence, and over time the structures that allow intelligence gradually weather and degenerate. The stone creatures can repair a toe or an eye but the history of a structure conferring intelligence is integral to its function. To repair it is to wipe it clean, and destroy it. So a new head begins to grow. This junior head buds up alongside the original, and is initially just along for the ride. But it learns, and as it learns and grows it participates more in the control of their joint body. Somewhere along the line the young head begins taking charge more and more (it can be a rough time, this transition when both heads are reasonably competent). A creature with two competent heads can also be more formidable, the young head providing creativity and initiative and the old providing wisdom and insight. When the young head has become mature the old head is senescent, sleeping much of the time and mumbling complaints as it is slowly resorbed in a process the reverse of how it arose. Sometimes the baby head of such an organism buds out before the oldest head is gone and a creature has three heads at once. The body is good for many cycles of heads, and bears the marks and scars of use by the intelligences who lived in it before. [Answer] **Polycephaly** > > Polycephaly is the condition of having more than one head. The term is > derived from the Greek stems poly meaning "many" and kephalē meaning > "head". <https://en.wikipedia.org/wiki/Polycephaly> > > > Although the above Wiki article is flagged as having 'multiple issues', it gives a good overview. Both animals and people have been born with extra limbs and even heads. Over millennia there has been no apparent advantage or such people/animals would have increased their frequency in the population. As has been pointed out, human conjoined twins exist in 2019 who effectively share a body (I won't give a link but the information is available online. In the animal world, extra limbs and even heads crop up rarely but regularly. Snakes are particularly susceptible to this. If you search Google Images for *two-headed*, there are some obvious Photo-shopped fakes but it's pretty easy to tell the real from the fake. Here's a YouTube video showing a two-headed snake being handled. <https://youtu.be/P2a_smk8IJk> Here's a video showing a two-headed snake being fed. <https://youtu.be/kEsDjjvmy3c?t=445> **In conclusion**: If there had been an evolutionary advantage then we would see two-headed creatures everywhere. [Answer] The classic example of 'two headed aliens' is two aliens with side by side heads. Probably not that, seeing as direct competition in a single organism isn't great. If a two-headed intelligent species did exist, I'd imagine it'd be akin to a split between higher function and lower function. The two headed alien would have the heads vertical, rather than horizontal. One head would be the menial head, a simple-ish intelligence good for tasks like rote chores, learning physical oriented skills such as combat, crafting, etc., while the other would be the 'superego' head, a head tasked with higher functions, such as advanced sciences, the arts, philosophy, etc. If I were tasked with designing such an alien, I'd make it humanoid, with an extra set of smaller arms. One head would be one a taller neck, the other would be set into the chest, which would be wider to accommodate. The menial brain would control the main body, legs, main arms, neck, all from the higher head, given that he would be responsible for the day-to-day function. The 'superego' would be set in the chest, with access to the smaller arms. It wouldn't need to control the body, because it's only really concerned with higher pursuits. It's personality would be such that it doesn't care about autonomy, and views itself as the mentor, while the 'menial' would view itself as the provider and caretaker. [Answer] The advantage of having one body with two heads and personalities instead of one body with one head and one personality is obvious from the point of view of the personalities. One of the persons would not be alive if not for the two headed condition. And the other personality might miss them, or be glad to get rid of them, or have mixed feelings about it. Would this cause the body with two heads and two personalities to be more successful in survival than bodies with one head and one personality, so that it/they would reproduce and spread the mutated genes? Or would they/it be less successful in reproducing and thus the mutated genes would be lost? Studies of the success of various two-headed animals might help you decide. Since a two headed human with two personalities would have about 1.25 times the physical needs of a single human (the human brain uses a lot of energy and needs a lot of food), but about twice the ability to think per unit of time, in an advanced society it/they could have two separate work at home jobs at the same time and make money faster, thus possibly have a financial advantage. There is a two-headed human, Joe-Jim Gregory, in the classic Robert A. Heinlein novel *Orphans of the Sky*. Suppose that a two headed person (or persons) commits murder. If it is unsure whether both the heads cooperated in the murder, what should be done with him/them? I have read that was an actual legal dilemma in Paris, France about 400 years ago. Since there is/are an example of two persons with one shared body alive, born in 1990, you could theoretically ask them about their decision making process, and whether they think that wild animals with their condition would be more or less likely to survive, or primitive cave person(s), or member(s) of an advanced futuristic society. [Answer] Keeping watch! One of the key traits for evolution is survival of the fittest. One of the most dangerous times of day for *any* species attempting to survive is when they are asleep! Humans "solved" this issue by becoming social creatures - by clustering into communities, we were able to rotate shifts and have some members awake while the others slept safely. (We also "un-solved" it for other animals, by becoming endurance hunters - wearing them down and striking while *they* slept) Your species did not play quite so nicely with each other - in fact, gathering into social groups was a good way for the watchmen to "help themselves" to the resources (and lives) of the sleepers, and the only person you could trust to keep watch was yourself! As such, they have evolved a second head, so that while one slept the other could keep watch. Eventually, once brain-power reached a certain level, the advantages of social cohesion overcame baser instincts, and civilisation emerged. The two heads now mostly wake and sleep together (much like how modern humans sleep in one long block, instead of 2 short sleeps with an active-period in the middle) - however, some eccentrics (workaholics, gaming addicts, and students cramming for exams or rushing that dissertation) still maintain the "always on" lifestyle [Answer] # They’re Just for Show The alien species (which might not resemble vertebrates except in the superficial sense of having at least one head) might not have its brains in its heads at all. They’re just mouths that can attack and eat. The advantage is that twice as many teeth are useful in a fight, or perhaps to gobble a bigger share of food in a pack. # They Work in Shifts Maybe the personalities take turns sleeping. Some cetaceans’ left brains and right brains apparently do that. # They’re Complements The right and left sides of the human brain aren’t *as* specialized as most people think, but maybe this is how the species developed two different, equally-important, sides of themselves with different abilities. [Answer] Picking up on the idea of @Halfthawed of a torso- or stomach-mounted face/head I could imagine a post-modern species, the enteric nervous system of which was forced to improve upon its means of communicating with the brain in order to prevent self-poisoning during situations of increased social pressure. The formerly single-headed species would suffer huge death counts due to people ignoring their revolting stomachs and binging themselves to death, poisoning themselves with intolerable amounts of sugar or alcohol or destroying their livers, kidneys and cardiovascular systems in the long term. Maybe the only available food they needed to sustain themselves was also toxic to them and they needed to very carefully avoid poisoning themselves. Maybe they reach maturity quite late in life and fall victim to those longterm effects before getting the opportunity to procreate. Over extended time periods, only those whose gut-brains were smart and aware enough to pursue or trick their head-brains into abstaining from those excesses, would reach maturity and pass on their tendency for developing smarter and more self-aware gut-brains. After a while, a state was reached, where some peoples unusually smart guts where sufficiently self-aware to project complex imagery into their bodies' master brain, but a large portion of those cases failed due to the master brains being hospitalized as hallucinating or just dying because of their gut-brains committing suicide (shutting down digestive functions) out of frustration. After all their limited means of communicating their problems did not suffice to reach the ones in charge. Only the most devoted, intelligent and persistent gut-brains managed to carry their bodies to survival and an arms race began between head- and gut-brains. While the head-brains optimized their ability in dealing with that alien entity inside their bodies, the likes of which they had never -- in their evolutionary history -- encountered, those gut-brains became more successful, who appeared less alien to their head-brains. By chance, the gut brains adapted faster and developed facial features and means of vocal communication which enabled them to communicate with their head-brains in the way they were used to. They also developed means of visually perceiving the environment so they could more easily relate to their head-brains impression of the world. Nowadays most members of society are either gut- or head-brain of a shared body and in most cases, they cooperate in deciding upon food-intake and matters of bodily-health. [Answer] **Body Part Replacement/Repair in case of temporary or permanent failure** Imagine a world that is volatile and hostile from an environmental point of view. While it does not affect the creatures externally, it affects them internally (like smoking, for example). These creatures have 2 parts (okay, now maybe I am slightly deviating from the actual premise, but let us imagine anyway) - one side of their body is active, the other side - while the brain etc. is active, the important internal organs (like lungs for example) are in a hibernation inside the body in a mucus layer or some other protective coating. These will be active once the primary organs fail. Now to develop on this premise, maybe, these organisms have an high organ failure rate and much like 2 engines in an airplane, maybe it can also function as an replacement/security feature of the biological body. The premise is with infinite possibilities. While OP is only considering the brain, I slightly increased the scope. [Answer] Probably not, since there do not seem to be any notable examples of such things occurring, and the term "evolutionary advantage" usually implies that a trait gets preserved. With that said, one might imagine that having two heads could provide better range estimation at longer ranges, given the greater occular separation which would occur. The same could be said for localization of audible signals. The neurological issues, though, would be severe. For the advantages postulated above would require the presence of long, large pathways for sharing sensory data between the two heads. These would presumably be vulnerable to various forms of damage. Much worse, I suspect, would be the development of appropriate priority mechanisms to determine which head would be in charge, although it does seem possible that the two heads would develop specializations similar to that between the two hemispheres of ordinary brains. In an omnivore, you might (possibly) get away with teeth on each head which are optimized for different purposes. One head might be an efficient meat-eater, while the other a better vegetarian processor. This would seem unlikely, and would take considerable thought to justify. [Answer] See "Saturn Rukh" by Robert Foreward. Flying creature that cannot land. It has two heads because each must sleep but the creature must be able to actively fly continuously. Note that Ducks and Dolphins solve a similar problem by having half of their single brain sleep at a time while the other half watches for predators or continues swimming. [Answer] * You can see behind you. * One head (brain) can sleep while the other keeps running things. * If one head grew later in life, and therefore was younger, it could reduce issues associated with dementia (the older head may eventually 'die' but the younger one can keep going). * If it's not useful, it could be a form of 'peacocking', whereby a male being able to survive despite being encumbered by a useless additional head demonstrates to the ladies just how fit everything else about him is. ]

[Question] [ My world is similar to our daily world except that fully immersive virtual reality is already well-developed. The virtual reality is built by scanning real environment. The system was first used to do scientific research on military to test how weapons perform in different environments. The process of doing the simulation: 1. The weapon needs to be scanned in stationary state. 2. The weapon needs to be fired once under the scanner. 3. To save computational power, the testing environment needs to be put under the scanner during simulation. Computers only calculate the part being changed by the simulation. Time inside simulation is synchronized with time in real world. To test how soldiers interact with the weapon, and also for training new soldiers, fully immersive technology is then invented to use the weapon in the virtual reality. It is done by scanning the body with the scanner mentioned above and to create a body that can be controlled by brain waves. For easy control and also easy simulation, the virtual body needs to be very similar to the real body of the user. The technology is later used in more areas. People can now play X-sports safely in this system. War games are played with real guns inside the system. Training to become fireman, pilot, and even surgical doctor can be done with this system. Now, with development of the scanner, the biggest scanner can scan an area as big as a city, with the height of the earth atmosphere. Is it possible to solve national conflict by actually fighting a war in this system? If yes, how should that be done? If no, what else is needed or why is it not possible no matter what technology we have? [Answer] # No, this won't solve national conflict Why? Because it doesn't solve the main reasons FOR national conflict. Consider some of the main reasons to actually invade or go to war with another country: * You want their resources * You want their landmass * You want to colonize them * To better your own economy/destroy another country's economy * To protect yourself from being invaded * To protect a way of life In a virtual battle, nothing is actually lost or gained. For example, if the US decided to have a virtual battle with China in the landmass of China, at the end of the battle, regardless of who won, China still owns all of China's landmass, China has taken no economy damage, the US has gained nothing, spent nothing, and has no economy boost. Nothing would change. Since nothing changes after a virtual battle, the only way to actually create that change and get the landmass/resources/etc etc would be to go into actual war with the enemy. Consider that of the listed points, the first 4 essentially require you to be the instigator of the real life wars and the last 2 are only applicable if you're already being invaded and in a real war. Moving this to virtual would just be a waste of time and won't help you protect yourself. Final point: Even if there was somehow a deal in place where the winner of the virtual war would gain landmass or something like that, do you think the citizens living in that area would be willing to just stand up and walk away? Most people would sooner fight than leave on a whim, which at the end, still leaves you with war. [Answer] This sort of pattern has actually happened many times throughout history. However, it has never once replaced true war. The general pattern you are looking at is called ritualized warfare. The idea of ritualized warfare is that you can replace the combatants dying for their country with a competitive test of skill which demonstrates the combatant's prowess at war. The key to any ritualized warfare is that both parties accept the terms of the ritual *before* they engage in it. This means that, if the USA and China want to avoid true warfare, they need to agree upon the rules of combat ahead of time. They also need to agree on the consequences of "winning" and "losing." Given the differences between those countries, it could be very difficult to agree on a set of rules. Imagine trying to get agreement with ISIS. As an example, consider the use of spies or other surprises. How do you work with them in the simulation? If you tell the other nation where your spies are in real life, they may go out and capture those spies. How do you use weapons whose behavior is classified by that nation? I guarantee you the USA would be displeased to offer a perfect simulation of all of our missiles to any other country or combat group (The probability of kill in a given situation with one of our weapons is typically rather sensitive information). The only solution would be for the simulation to be "private," protecting such information, but now you have the challenge of developing legitimacy for your simulation when you don't have perfect transparency. There's also the question of whether the simulated weapons behave like the real ones. As an engineer, I can tell you that every simulation ever created is wrong. Simulations are based off of models. "All models are wrong; some are useful." You can imagine the contention over the *exact* model of nuclear explosives used in the simulation. There is an excellent example of how ritualistic warfare comes and goes to be had in the study of the Zulu tribe. Around when the Zulu made their bid for power, the tribes in South Africa had developed a system of ritualized warfare that consisted mostly of a lot of jumping, shouting, and other similar feats. Thanks to that, the tribes enjoyed a relatively high level of peace. Warfare was handled rather painlessly. When the Zulu rose, they had a different approach. While the other tribe was jumping and shouting they savagely attacked, showing no mercy. They slaughtered the warriors of many tribes before the warriors even realized they would need to fight back! Ritualized warfare has a place. It can have great value. But it is unlikely it will ever replace actual warfare. [Answer] No, war simulation would help nothing at all. --- For one, as long as there are **no real-world consequences for the participating soldiers**, even the most realistic combat simulations will be **treated as a game by both politicians and participants**. Yes, there might be blood and gore and pain involved, but after the third time you've seen your comrades die next to you and then be revived once you take off the VR helmet, you will realize that it's more like Unreal Tournament crosed with Age of Empires. There just can't be as much emotional involvement in-game as there would be in RL since all players know nothing actually happens to the people. Yes, there will be heavy psychological consequences of virtual warfare. However, I think it would be less PTSD (depends on how long those war simulations take, and if you really let a player slowly bleed to death because he's got a couple of bullets in his gut and is screaming in pain for hours. Or let a player remain in a burning warehouse and experience it all until he suffocates). I think the most serious consequences will be loss of reality (are you really sure you're out of the game?) and an increased tendency for violence (by day a normal, loving family father, and by night a soldier slugging through the bloodiest and goriest battlefields in full 3D and smell? Something *will* get confused there eventually) So, in the end, technology like that will probably result in something like the Soccer World Championship, where countries compete against each other for a prize. But a serious way of solving conflicts? No. --- Next, there are **no consequences of winning or losing**. You didn't start invading them because you didn't like the color of their flag, but because there is a real reason. WWII: stop Germans from killing all Jews -- how would winning a simulation help you to get to the physical location of Germany and free the concentration camps? War on Terror -- you think terrorists are impressed if you manage to smoke them out in a simulation (if they even participate in the simulation...)? Yes, there might be a convention that the loser has to pay money to the winner, but what if the loser simply decides they don't want to? Then you can't do anything against that except for taking some real-world actions. --- Another point: **how would you organize such national wars**? Play them over the internet whith soldiers of Country A sitting in VR pods in Country A and soldiers of B sitting in Country B? How can you make sure the technology level is compatible? How can you make sure nobody cheats by e.g. putting a secondary interface between the 100%real VR and the human brain so that they can get around the 100%real constraint and do some Avengers-worthy super human feats? The only alternative to that would be having all participants in one location and an indipendent third party make sure all players stick to the rules. But who would the 3rd party be? Who would provide a location and enough equipment to have armies tens of thousands strong compete against each other? Who decides how many tanks and missiles and whatever the individual armies get? --- Last but not least: **no technology is completely secure and unhackable**. You can't hack reality, so you've got a trustworthy basis to compare strengths on. In a VR, which is lots and lots of software and simulation and hardware, it will be a miracle if you ever get to the point that you actually have a 100%real simulation without any bugs or other inexplicable programming errors (not least of all because people experience the same things in completely different ways). However, it will be impossible to make this 100%real simulation completely secure. It's got code that can be manipulated, hardware that can be accessed, data transmission that can be intercepted before it reaches the other player, and tons of other security issues. Basically, it is impossible to create a completely equal and level playing field like what reality does. So **why should a won/lost war have any relevance** at all? You could just say that the other party cheated / created more resources than they should rightfully have / used superior technology / ... and so your loss is invalid. Let's do this war again, and I'll show you this time that it's not possible to stop the Persions at the Thermopylae! [Answer] # Possibly, under certain circumstances The current answers have raised valid points, but I believe that **under some circumstances, such a simulation could indeed prevent a war by encouraging a diplomatic resolution** to the conflict. Here are some things that would make this more likely: ## 1. General faith in the accuracy of the simulation As noted by @SteveMoser, **everyone involved has to have faith in the simulations.** Therefore, experts from both sides of the conflict have to have full insight into the source code and execution of the simulation. This will decrease the chances that either party claims the simulation has been tampered with. Even better, all the details should to be publicly accessible to everyone. This part is extremely important. Without it, the following points start to lose their validity. **Here is our first major problem.** As noted by @CortAmmon, for the simulation to be accurate, it has to know all the details (and military secrets) of each party. So, **your premise implies that at least one side is willing to expose its military secrets.** If you want to avoid this, and since this is science fiction/(fantasy?), maybe the scanner could scan the facilities of each party, then hide it in way that it can only be accessed for the purposes of the simulation. Of course, the simulation output itself would give away a lot. I think you'll need a supernatural element to the simulation, or some other well thought out plot device to make this work. It sounds tricky, but if you're a good science fiction/fantasy writer you might make it work. ## 2. The result is shown to the public The public has a **much** lower tolerance for the horrors of war than the leaders of a country. If people see a simulation where people who could be themselves and their loved ones (including civilians, women and children) suffer death, horrible pain, having their homes destroyed and general trauma, they will object strongly. Since the program simulates everything, it would contain every single detail. Thus, it could output **moving pictures of women and children being killed**, sounds of bombs, the screams of dying children, the smells of corpses decaying in mass graves, and areal images of whole cities devastated. Even seeing this occurring to the "enemy" population, people will probably object, out of general humanity and compassion. The [reason war propaganda exists](http://www.snopes.com/quotes/goering.asp) is because **people generally don't want war**. They need to be convinced. Such a simulation, especially if **vividly showing details**, will have the opposite effect of war propaganda. Even in a dictatorship, the government can't successfully carry out a war if the people (soldiers, policemen, factory workers, etc.) are utterly opposed to it. ## 3. The simulation shows terrible destruction The war ends much worse than expected. For example, a large part of the population is wiped out. The economy and infrastructure are devastatingly damaged. Governments are hit hard. If the simulation shows these things, even the war hungry leaders may think again. ## 4. The simulation unexpectedly shows the aggressor losing The simulation shows the following: 1. The Republic of Agressivia (ROA), very sure of themselves, invades The Kingdom of Pacifistia (KOP). The latter would have liked to avoid a war at all costs, but decides to fight fiercely once invaded. 2. It's a **long and terrible war** where millions die and utter destruction is done to infrastructure and the economy. Thousands of innocent women and children suffer terrible deaths, diseases, etc. 3. After a long time of this horror, ROA are out of supplies, weapons and logistics, yet KOP is still holding out, defending their kingdom. The ROA has **no choice but to pull out**, and switch to defending their initial territory. 4. Both countries are devastated, and KOP has not the resources nor the desire to counter-invade ROA. The situation invites for a permanent ceasefire and a diplomatic resolution based on pre-conflict borders. If you were the government of ROA and saw this simulation, would you still want to invade? It's rare that both sides want war. It's mostly one side pushing for the war, and another trying to avoid it. If the aggressor sees that they will lose the war, it would be insane of them to go on with the war. This, of course, requires that **they have faith in the simulation and believe that it's accurate**. But I belive this is indeed the case in the scenario outlined in OP. I don't know if these are the circumstances you have in mind. But if you intend to write a story where a simulation prevents a war, then those are some of the circumstances which could make it more realistic. [Answer] It might work as a way of resolving conflict, but only between countries that would never have gone to war with each other in real life anyway. Why don't countries today resolve their differences with a soccer game, or by tossing a coin, rather than going to war? While obviously technologically much less sophisticated, the concept would be the same: we play out the conflict in a harmless game rather than with actual destruction. Countries go to war because they are unable to resolve their differences by peaceful means. Talk to any military man. The goal of war is to destroy the enemy's ability to resist, to reduce him to a condition where he has no ability to stop you from doing what you want to do. Frankly put, war is not a game, but a deadly serious business. Literally deadly. Suppose that two nations hate each other, both say that the other nation should be destroyed, all its people massacred, and their land taken over by the other nation. Someone suggests that rather than fight a war, they play a video game to resolve the conflict. Whichever side lost, would the people all really then promptly commit suicide and let the other nation take their land? I doubt it. The loser would never voluntarily live up to the terms of the agreement. There would have to be someone with the power to force the loser to follow through. That is, someone who could go to war against them and win. The one scenario I can see where such a video game could substitute for a real war is if it convinced one side that victory was hopeless. Then they might surrender rather than fight a real war. In most wars, both sides start out believing they will win. If they thought they were doomed to lose, they'd make concessions to get a negotiated peace. So maybe if everyone was convinced that this simulation was extremely accurate, and it predicts that they will lose, then they'd make concessions rather than actually fight and lose. [Answer] In addition to what some others have said, consider the atomic bomb. The US dropped atomic bombs on Japan because the Japanese were willing to fight a losing battle. They were aware that the only outcome of continuing to fight was total defeat, but were planning to do so anyway. The bomb was something they simply couldn't fight--not even a losing battle. History, then, shows us that even if we could prove with 100% certainty (via simulation?) that one side would defeat another, the losing side could still choose their own destruction over surrender. But I do think that this is an interesting worldbuilding scenario, and there are a lot of ways you could advance the story in such a world, even with the eventual conclusion that the system simply doesn't work. I think that if such a system were introduced and somehow accepted, the advancement of the system would be similar to the way our trade systems have advanced. In early barter systems, what people traded had value itself. You traded a loaf of bread for a fish. Each item was itself valuable. As time passed, we moved away from that barter system to standardized base for trade, generally something valuable but not particularly useful, such as gold. Moving forward, we had coins printed on precious metals to further standardize and simplify trade. As the coins eventually gained value themselves rather than the metal contained within, we began to have currency with basically no value at all, but backed by a guarantee that the issuer would give you a certain amount of gold if you gave it to them. And finally, we have currency that not only is unbacked but is only a number. Its value exists only in the faith that we place in it that it is valuable. In application to war simulations, in early days of the simulation system, the simulations would be as close to reality as possible. This would be similar to a backed currency, where the simulation is essentially a guarantee of the result. If you took a dollar to the issuer, they would give you the gold. Likewise, if you carried out the battle, it would end how the simulation did. But over time, the simulation itself would begin to hold political sway, and as such our tactics would advance in response. Our weapons and tactics would begin to be designed in such a way that they would give us an advantage in the simulation rather than in reality. Even if the simulation is a perfect simulation physically, it is an entirely different game psychologically for a lot of reasons, meaning different weaponry is effective. Eventually, the simulation will have very little basis in reality anymore, and will hold political power only because our faith in the simulation itself as a political tool. [Answer] I might not be able to add much to the answers of @subrunner or @Aify, but you should take in mind the... Zeitgeist. What does it mean? When you offer such an approach of conflict solving to the population of earth (this earth, not a similar on as described by the Opener), they would laugh at you. At least now. Now fast forward half a century or more, and you have a population where even the elder people spend a considerable amount of their life playing video games. That's the generation which witnessed the shift from 16bit (or even 8bit) pacman style video games to something that will go way beyond even Ocloset Rift or what its name may be. Now these elders may value each others skill with simulated whatever. May start with two grandmas which beat all their grandchildren in candy-crush and end with former eSports Champions who made their living beating others with FIFA. At this point it can be reasonable to except two people to solve their conflicts using a game. Add another century and a fine simulation of a war would be able to influence even high ranking military officers, but still no one ever would give up their home because someone else simulation said so. And now shift the point of view to something unexpected for this kind of question: Pokemon. It may had been made for child entertainment, but after all its about a world where a battle between two people is used to determine something. In our wold no one ever would throw his cat at the dog of its neighbor to determine if the apples at the estates border belong to the one or the other one, while in Pokemon this would be the way to do this. To make your question feasible you need to create a world where this kind of simulated conflict resolution had been used for a loooong time and is widely accepted as the proper way to solve anything. While a real war will still be something not entirely solved by this, its much more likely that the people there would accept a solution made this way, and even give up on - say... - an big source of oil. But with a civilization that honed their physical combat for over 5000 years and just recently reached the point where simulated combat is something that might offer an insight or two about a possible conflict... very unlikely. [Answer] No. War is NOT a game with fair rules. In war **you want to get all the unfair advantages** over the other side, so national self-interest of your side (with allies) prevail over the opposite side. Interest can contain religion/culture, so you not necessarily even agree on the basic set of principal rules. Ie. "western" culture believes that all people should have equal right. ISIL disagrees, strongly. As widely repeated, point of war is not to die for your own country. Point of war is to make the poor bastard on the other side die for his. [Answer] **No, unless there is a referee.** As many others have pointed out, the fighting style is different, the consequences are different, shoot, even finding ways to cheat at the simulation would become a viable "strategy" (eg create a super gun that looks just like your normal gun, and have the simulation scan and fire the super gun, then say "Oh yeah we have 700k of these). So, ultimately, it would need a referee to work. Someone to try to prevent cheating and decide on consequences for involved parties, and then enforce them, which ultimately means it would more like a replacement for a judicial system like the UN, and only the military clout of the Referee would actually dissuade people from war. [Answer] A simulation could be used to resolve conflicts between nations, possibly, some of the time. You'd have a challenge making the results binding (what's to keep the nation that winds up holding the short end of the stick from going rogue?) but at least in principle it could work. As a real world precedent for how this might work, I'd cite lacrosse. Lacrosse is a game of Native American origin. As stated [here](http://www.legendsofamerica.com/na-lacrosse.html), it was also historically much more than a game. To wit: > > The full-contact, fast-moving sport of lacrosse was ideal for training young Native Americans in the art of battle, but lacrosse competitions also took the place of battle. When disputes arose over land or resources, tribes would agree to a contest instead of rushing into war. These contests would be scheduled at agreeable times for both tribes and would end the dispute with less bloodshed, though broken bones and severe injuries were not uncommon, and death was not unheard of in the contests. > > > The two big things to keep in mind here: 1. For the results to be meaningful, all involved parties must stand by them. That means that the losing nation must hold up their end of the bargain. You could rely on the word of the participants here (is your society a very honor bound one?), but perhaps some sort of U.N. on steroids and a set of very punitive consequences for disregarding the simulation's outcome would work in the absence of honorable participants. I'm thinking here of something along the lines of the [prohibition on the use of *atomics* in Dune](https://en.wikipedia.org/wiki/Technology_of_the_Dune_universe): > > In the initial Dune novels, the Great Houses of the Landsraad own "family atomics" as heirlooms, keeping a secure, hidden cache as weapons of last resort in their wars. Though such possession is necessary to secure power, the use of atomics against humans violates the chief prohibition of the Great Convention, the "universal truce enforced under the power balance maintained by the Guild, the Great Houses, and the Imperium". Paul Atreides notes in Dune that "The language of the Great Convention is clear enough: Use of atomics against humans shall be cause for planetary obliteration." > > > 2. Simulations are by their nature limited in their ability to reflect reality. Even if by simulation you mean "we are creating the Matrix", well, if the participants don't die in real life when they die in the simulation then it is very likely they will behave differently. In addition, the assumptions of the people who created the simulation and who are refereeing the simulation will color its results. For an example of the latter, check out the U.S. military's [Millennium Challenge](https://en.wikipedia.org/wiki/Millennium_Challenge_2002) war game: > > Red received an ultimatum from Blue, essentially a surrender document, demanding a response within 24 hours. Thus warned of Blue's approach, Red used a fleet of small boats to determine the position of Blue's fleet by the second day of the exercise. In a preemptive strike, Red launched a massive salvo of cruise missiles that overwhelmed the Blue forces' electronic sensors and destroyed sixteen warships. This included one aircraft carrier, ten cruisers and five of six amphibious ships. An equivalent success in a real conflict would have resulted in the deaths of over 20,000 service personnel. Soon after the cruise missile offensive, another significant portion of Blue's navy was "sunk" by an armada of small Red boats, which carried out both conventional and suicide attacks that capitalized on Blue's inability to detect them as well as expected. > > > At this point, the exercise was suspended, Blue's ships were "re-floated", and the rules of engagement were changed > > > So the referees running the exercise decided that the strategy chosen by Red ran counter to the spirit of the exercise and they reversed the outcome of Red's devastating strategy. What happens when a simulation participant does something "unfair"? In summary, I think a story could realistically be built around a society that had decided war was better off simulated. I imagine there's some interesting narrative ground to be covered in exploring the loopholes participants might use as well as what would happen if a nation went rogue after losing the simulation and the society was faced with its first real war in generations. [Answer] ### Yes, if people believe the simulation is accurate. War is fundamentally a communication problem. Both countries won't go to war unless they thought they had a chance at winning otherwise one side would surrender and want to make a treaty. Now I don't know how you go about convincing people that the simulation is accurate. Also people are not always rational. They may believe it intellectually but not emotionally. [Answer] This would be a perfectly natural progression from drone warfare, suppose the US and China each build their own version of Skynet, without the IFF bug. Each AI will simulate the conflict to the best of its own ability, dissatisfied with the uncertainty of not knowing what the other knows they'll contact each other and compare notes. Whichever is on the losing side will make the perfectly rational decision to switch sides at which point the Transpacific Alliance goes on to conquer the world. Meanwhile the meat glaciers are still having pissing contests over who has the most troops, the fastest planes and the biggest ships. [Answer] It can stop or delay (but not solve) some conflicts Firstly it's not the winner controlling the loser directly, but the winner could make a deal to buy the loser using the estimated cost of war, or maybe slightly less. Otherwise it gives the winner chance to conquer another country immediately, which has a huge value. And the loser still may not agree. If deception is possible, the losing side would threaten to use the hidden plan B. But knowing they really don't have that, they'll stop being aggressive. If deception is impossible, the losing side would unite with other nations. This would be far more easier when they know the exact outcome. If it's a desperate situation that there is no one to unite, they'll accept the deal and find chances to rebel later. Sometimes this solves the problem, and sometimes not. If you want to be strictly peaceful, this may backfire as every weaker nation threatening to fight a war to force the other nation to pay, like the case of Song. You could also use this for psychological purposes to make the war slightly more peaceful, such as the way costing more is guaranteed to fail, and the way costing less has some odds. [Answer] There are many good answers about why people wouldn't want to listen to the outcome, but we have to remember, that simulation needs to be *convincing*. For example, if the simulation was just a dice roll, no one would go for that. Now this is obvious, but what's less obvious is that there are so many factors that we can't count for, that the simulation can not be called authentic or convincing. Some people find massive courage and are able to do great things when under pressure. Sometimes luck or bad luck can make a difference between win and loss. Randomness is so great, that if nation loses virtually, it can still not believe the outcome. Enemy leader can die accidentally. Enemy troops might join the opposing force. There are billions of scenarios that are part of the outcome that simulating them is impossible. I guess that would be the main reason why I wouldn't use such thing as a replacement for war. [Answer] No, barring outside intervention from a higher tech level. Two reasons why. First and foremost, losing a virtual war doesn't remove the ability to resist. If the virtual war system involves building an actual military, the loser could always "appeal" the loss by fighting it for real. That means that the loser gets another crack at things, and knows the other side's capabilities. To use an example, the Millenium Challenge that's been linked before would have gone dramatically differently if the defender's capabilities were known. The second time around, the attacking fleet would have known that the defender was running their communications through "motorcycle couriers" that couldn't get lost, delayed, or intercepted and traveled at the speed of light (radios and calvinball saying no you can't intercept my comms). That would dramatically change their sigint. Similar things go for the flotilla of small ships carrying missiles larger than their displacement that somehow both were oceanworthy and fit full fire control suites. That sort of weapon only works once, and once it's done it's done. If WWII were fought in a simulator and then refought, what are the odds of Taranto or Pearl Harbor working? Is there any chance the French would have sent their armored reserve up into Belgium, leaving it to rush back with heavy mechanical losses when the Germans came through the Ardennes? Second, getting a full simulation would be very difficult. Even if you can scan a whole city at a time, even by now (let alone where we'd be with such computers and technology) there'd be serious problems. A simulator war would likely devolve into no holds barred nuclear warfare because losing five cities isn't being the country who loses less anymore, it's being the winner if the other side's wiped out. So that means we're in such fun terrain as ICBMs, ABM, and maybe hypersonic planes. You're modeling the entire world. That's a huge amount of complexity, and if you take shortcuts that's opening room for loopholes. As an example, in the Millenium Challenge they abstracted away civilian shipping. That was great until the general running the defenders bullied the referees into treating the aforementioned boats with anti-ship missiles on them as civilian, thereby making them invisible till they fired. What do you do to prevent similar abuses of abstraction? In the end the main way I could see this actually working is a hugely advanced civilization trying to hold a less advanced planetary civilization in a peaceful and (hopefully) prosperous state. If they're that advanced they can potentially spare the compute to run a full proper simulation, or they can run something where perfect accuracy isn't needed (what does it matter if it isn't perfectly realistic when it's internally consistent and a recourse to reality isn't going to happen). The other condition is satisfied by unilateral disarmament under threat of superior force, which can be trivially satisfied by an interplanetary civilization. So in this model, countries don't build militaries, they build up points along some system to cash into the simulation (and at this point why not do something more interesting like rewarding a metric of economic and social achievement), and they work within the simulation using those points to buy a simulated military to resolve disagreements. [Answer] ## Depends what your goals are. For instance, you're a former superpower, struggling to reachieve greatness. Your still-formidable military drives their neighbors into fear. If they played their cards right, they could Finland you - mire you in a good defensive line and make invasion hopeless, which would deter your own hawks. But they see a military fight as hopeless, so they don't even try - they fritter away their military budget. Which drives them into alliances with your *real* adversaries. And that really screws up your **commerce - which is your key to success**. So you engage a regional policy of helping your neighbors tune their militaries for effective defense... against you if need be. With enough war gaming, they make their precious military investment effective. You aren't going to invade - at least, not successfully. That eases tensions and boosts trade - not least, some of those armaments they need. All that interaction doesn't hurt public opinion either - hearts and minds. It also causes your military to interact with theirs quite a lot, and that results in practical cooperation in a number of areas. Your IFF's work, your radios can talk the same frequencies, your tankers work with their fighters, etc. And when a mutual operation is called, for intervention or rescue, it's easier to get them on board. And then you collect the peace dividend. Think of all the money America doesn't spend on the Great Canadian Wall. Because Keynes is wrong - if the government sinks costs into a useless wall instead of a hydroelectric dam, that is not the same. The capital is a total loss either way, but the hydro dam pays dividends for centuries. Those dividends are in our pocket thanks to our convivial relationship with Canada, not to mention all the lovely commerce - which is not a zero-sum game. Those dividends are why peace and stability are a win. I'd even say you can't support a strong military with a weak economy, so it's a military win too. [Answer] If you consider that for a period of time in history it was possible for small (perhaps not national) conflicts to be settled by armed combat between tribal champions, then there is no reason why 2 modern champions playing a game against each other wouldnt be seen as a viable option to resolve a conflict. The most important thing obviously is that both sides agree to the fact that it is a valid way of resolving conflict before the contest, otherwise it won't hold. I think this would be a perfectly valid form of future bloodless conflict resolution. [Answer] ## Only if state actors are perfectly rational, the simulations are (or at least are universally believed to be) a perfect model of reality, and there are no private simulations. And even then only kinda. (So, no.) The outcome of a simulated war is binding only insofar as all potential belligerents recognize that the simulation provides an accurate projection of the outcome of a conflict. Even then, it's only the state leadership that will accept the simulation's projection, and only because we helped ourselves to this premise by hypothesis: the citizenry will not necessarily take it well that they either have to move or have a new government. **Therefore, the violence of warfare would simply be transmuted to the violence of police action.** Of course, if the power of the state is truly overwhelming or broad respect for the simulation is high enough (Divine Right of Kings 2.0), it could work out. (Even Thufir Hawat worked for Baron Harkonnen when he found himself a prisoner in Baron Harkonnen's fiefdom.) If the simulations are known to provide only the most likely outcome or a range of likely outcomes, states may still decide to press their sub-50% chances for victory in conflicts and warfare is not eradicated. It's important to note, however, that only a belief in the simulation's infallibility is necessary. The simulation can be a coin flip and still do the job if sufficiently obfuscated-from and believed-in by all decision-makers. The story of the first leader to reject the simulations after X generations of peace would probably be fairly interesting. Finally, all simulations would have to be observed in common by all state decision makers. Private simulations would become tools of war, not of peace. This message gets a negative response: "Hey Pooty-Poot, we ran a simulation that said the mineral wealth of Siberia is rightfully ours, fork it over." He wouldn't trust YOUR simulation. But you would, so you'd attack when he refused to cede the territory. So, the simulations have to be neutrally managed and shared in common by all in order to promote international peace. Maybe there'd be a priest-like class of simulation scientists. [Answer] A "simulated" war would be roughly analogous to a "simulated" auction, where the winner didn't actually have to shell out the money they bid. If the buyers in an auction could bid whatever they wanted without having to worry that an absurdly high bid would cost a lot of money, there would be no relationship between people's bids and an items' worth. Likewise, wars only end when at least one side is in a situation where continued fighting costs more than would settling. It is the nastiness of war that makes sides want to settle; remove all the costs of "fighting" and nobody would ever have any reason to stop. [Answer] No. The other side surrenders when the real cost/opportunity of surrender (material, emotional) is lower than the cost/opportunity of continuing conflict. Cost of virtual conflict is zero. Also, virtual war needs agreement of both sides to solve the conflict in this way. But the war is a product of peacefully unsolvable conflict. [Answer] Another reason why it couldn't be is that one side could go total war beyond what it would be possible in the real world. For example, one could mobilize the full civilian population into the machine of war: all workshops and factories are reconverted to produce tanks, all food goes to the military, and every other able body is issued a gun and put in the front. This can easily overwhelm an enemy virtual army, but it cannot be done in real life because it would damage intensely the economy of the country; but since the war is virtual, every machine is kept, etc. Another problem is the scorched earth tactics taken to a superlative. You want my oil fields? I'll let your army get close, and then virtually nuke them. And every time you put boots on it, I'll nuke it again, until you give up, and I get them back, intact and productive. The same can be true for the attacker: nuke a enemy factory, wiping all defences, and take over the ruins. The intact factory and its production now belongs to you. The rules may prevent you from using it for this war, but nothing stops you from using it in the next one or during peace time. In real life, taking an industrial complex is much more risky if you want to also keep it functional. Finally, remember that winning a war is more about logistics than combat. You need to keep supply lines, produce equipment and ammunitions, provide food... and all this without taking so much damage that you'll collapse after the war. [Answer] ## No, people are not perfect In a perfect world, full of perfect people who know how to admit defeat, yes it would be a way to solve national conflict. But last time I popped open the good ol' history book, I found out that people are stubborn and like to win. It does not matter even slightly if you tell someone that they cannot win, they will still try. History is full of people who went against the logical odds and won despite the fact that all evidence supports them losing. If a nation lost against another nation in this 100% simulation, then the losing nation would just try harder or, if they witness the simulation, try a different method. And that is assuming you get the nations to agree on doing it. ]

[Question] [ Animals on Earth have 2 or 4 legs they use for walking. On another world, however, animals have 3. I want to know how these animals will walk. How will their legs be placed and how will they move them to walk? For instance, maybe they would have 2 legs in front and one in the back, 1 in front and 2 in the back, or another setup entirely. What would the gait look like? Perhaps they alternate between 2 legged and 1 legged steps or maybe move 1 leg at a time in a 3-step cycle. While there are many potential answers I want to know which arrangement would be most effective and therefore most likely to evolve. Assume that the 3 legs form a triangle (although not necessarily an equilateral one) rather than a line. Let’s also say the animals evolved on an Earth-like world with equivalent gravity. I imagine that different sized creatures with different walking requirements might have different setups and gaits and even one animal may have multiple gaits just like we see on Earth. While I’m interested in the potential differences between large and small, fast and slow, let’s focus this question to an animal species of roughly human size and with human needs to walk long distances and occasionally move faster. [Answer] The number of limbs of a creature is determined by rotational inertia around the 'feet' of the creature relative to its mass. This ratio determines how easy it is to fall over. The mass of a creature is by approximation proportional to its size cubed $$m \propto l^3$$ while its rotational inertia is proportional to its mass times its size squared, $$I \propto ml^2 \rightarrow I\propto l^5$$ For very small creatures, it is extremely easy to fall over. This is why insects have six legs, so that three legs may be in contact with the ground at all times creating a stable tripod. Larger animals can do with just four legs, because they take longer to fall over on two legs (long enough to move a second pair of legs to a suitable location). Humans place their center off mass high from the ground and can create a large moment of inertia by standing up high and moving their long arms around, which allows them to be bipedal. This gives us a general idea about a tripedal animal. It will be quite tall and its center of mass will be high from the ground, to prevent toppling when only two legs touch the ground. The general 'tripod' image we know from War of the Worlds is thus a logical option: the center of mass high up, and three fairly long legs. The real question before we can answer how the animal would walk, is *why* it has evolved to have just three legs\* and not two or four. Apparently, two legs gives insufficient stability, and four legs requires too many resources. The good thing here is that you want your creature to move long distances, which definitely favours fewer limbs. The reason for three legs over two could very well be due to the terrain. Perhaps your world is covered in a thick layer of soft material with steadier ground underneath; perhaps igneous rock covered by a thin layer of peat bogs or marsh-like soil. With two legs, it's difficult to free yourself from marshlands, because if you pull out one leg, you push in the other. Three legs form a great solution, as you distribute the force of pulling out of the marshes over two other legs. This leaves the question of locomotion. We lost the fourth leg for energy considerations. A third leg swinging in the middle underneath the body requires a lot of energy due to the awkward poses required, and does not seem ideal. Instead, let's try something where we go in a fluent motion. The animal will have one front leg (slightly thinner and more agile; perhaps a displaced tail) and two side legs (stronger and heavier). The front leg initially starts pointing left forwards; the left leg pointing left rearwards, and the right leg pointing straight to the right, in a stable equilateral triangle. It starts by placing its left leg forwards next to the front leg, while the body moves forward. All the legs will now be in one line, and slowly falling forwards due to the momentum from the left leg. To counter this, the front leg swings to the front right now. We now have an equilateral triangle exactly mirrored, and repeat the process. At all times, the body will be directly in line with the legs or in the middle of a stable equilateral triangle, which is exactly the stability you want when trying to pull yourself free from bogs. Furthermore, the body makes a continuous forwards motion, and thus it can be very energy-efficient. This way, it can cover large distances over the difficult boggy terrain without ever getting stuck, unlike its predators. [](https://i.stack.imgur.com/dhjo5.gif) To escape from predators when on dry land, it can adapt the 'jumpy' locomotion with the front leg going underneath the body for support while the side legs can propel the creature forwards. It will run towards the nearest bog where the predator dares not go. \* I'm well aware that evolution doesn't need a 'why' and doesn't work towards a goal. However, for worldbuilding I think it helps to think of evolution like that - the fact *that* it happened is just a coincidence, just like our protagonist survives it to the end and is not one of the side character that gets killed in the first minutes of a story. [Answer] Almost all animals have even numbers of legs, except the kangaroo. [Kangaroos walk on 5 legs.](https://www.youtube.com/watch?v=Mi53VlMA31I) Front legs, tail, back legs [But they run on two.](https://www.youtube.com/watch?v=S-V2MqNLgdg) That actually gives you variants on tripedal motion, as they move front legs and back legs as matched pairs at a walk. Simply eliminating the front legs from the cycle and making the tail more leg-like would give you both run and walk movements with the third leg only used at a walk for some creatures, others doing a more conventional four legged "gallop" type run with the back leg coming forward of a front pair for a [crossover](https://www.youtube.com/watch?v=fJlPaHJTAfU). [Answer] Here's an option...to see an animal walk like this might be creepy and kind of nightmarish but it could work: [Three-Legged Robot](https://www.youtube.com/watch?v=3w3X8u9oCPY) Kind of like a Tarsier or Owl, they could have joints that allow full rotation. This would make for some unique and fun creature designs. **Edit:** @uhoh dug up this video which goes more in depth on how this works: <https://youtu.be/7XsaJwKKBYo> [Answer] while your question doesn't have any specific criteria as to what would make one answer better than another I can think of two options: 1. Similar to a person walking with a pair of crutches In this case the animal would set its front two feet and then lift and move its rear foot. For this I'm imagining a more worm-like creature where its body is longer and with less distinctive shapes aside from the foot pods although the concept could work with a more upright design if the front two feet were more like extended arms and the rear foot having a wide base to provide necessary stability when using its arms to reach about. 2. Similar to a spinning top Now this one gets a lot more alien, For this I imagine a creature with a mostly round torso and the three legs being spread underneath it in an equilateral triangle shape. When moving the creature leans slightly to one side and spins itself (imagine a martial artist performing multiple tornado kicks in succession). To help the creature keep balanced the legs should have knees, ankles, etc so that changes in terrain can be more easily compensated for. As for how the creature keeps aware of its surroundings and position while spinning is up to you, maybe it has a human head and neck that rotates as needed or maybe it has more like a fly's compound eyes In any case hope this helps spark some ideas [Answer] While "Landstriders" from the Dark Crystal are technically 4 legged, their running gait is very nearly 3 legged. I always found them compelling for some reason. I would describe it as placing their two fore legs forward mostly for balance and shock absorption allowing a strong central hind leg to then come forward. The single hind leg then propels the creature forward. Sorry it is so brief. Here is a clip of one in motion. <https://youtu.be/-DBkjvXHgj4?t=1m23s> As a second example of this locomotion, maybe one might imagine a rabbit running with a single hind leg rather than two in lock step, potentially like: <https://www.youtube.com/watch?v=9DjXFFV-QI8> [Answer] You could take inspiration from the Hunters in *Half-Life 2: Episode 2*. They have two distinct modes of locomotion. One is shuffling, which they use for precision movement, where they make small motions with one leg at a time. The other is running, where they use their two front legs in a normal bipedal running cadence, and the third leg trails along behind, more like a tail. When necessary they can also jump in different directions by pushing off with different combinations of legs. [Answer] I think you could argue that seals and sealions have 3 legs. Left-flipper, right-flipper, and their hind flippers (while evolutionary two legs) *function* as one leg (the feet are effectively two toes, reminiscent of chameleon toes) that only can be used to propel the creature forward. [](https://i.stack.imgur.com/2S5i1.jpg) [Answer] Does it strictly have to walk? If its main mode of transport is flying then you could have a tripedal crow: [](https://i.stack.imgur.com/UfVWh.jpg) <https://en.wikipedia.org/wiki/Three-legged_crow> It would only need its legs for standing and perching. The third leg could bend inwards to give it better grip on a branch. For a more conventional tripod there's Star Trek's Species 8472: [](https://i.stack.imgur.com/WTlTn.jpg) <http://monster.wikia.com/wiki/Species_8472> You could make them very large, so that they tower over their prey, like a War Of The Worlds tripod. [](https://i.stack.imgur.com/zgJxk.jpg) Or lastly, you could have a sea dwelling creature, a kind of jellyfish with only three tendrils [Answer] Laterally or rotationally. Lateral walking would look and work much like a human on crutches, two limbs forward followed by the third limb being brought through to the front, and be equally clumsy and awkward. It's not however necessarily a fast or slow mode of travel and a creature with threefold symmetry could use it to move in any direction with a little shuffling around to find the right facing to start off from. Rotation consists of the creature turning sharply to bring legs around in sequence moving forward as the foot or feet in contact advances. This is probably a motion best attempted only at a "run" to add impetus to the rotational motion. [Answer] Nature only provides two basic conformational templates: `bilateral symmetry` and `radial symmetry`. Unfortunately there are no models under bilateral symmetry that could provide 3 limbs for locomotion, (the nearest you'd get would be a tail appendage, or 4th limb atrophy, and the atrophy would *maybe* happen in individual species but never an entire eco system, (in fact I suspect atrophy'd never happen, not even rarely)). So you are left with radial symetry. (The rather dubious endeavour of inventing `trilateral symmetry` in fact would be a form of radial symmetry.) ***"So you are left with radial symmetry."*** Examples of organisms that exhibit radial symmetry and could have 3 limbs (easily) [resemble Starfish](https://www.mnn.com/earth-matters/animals/stories/19-bizarre-and-beautiful-starfish-species). That needs to be where you start your thinking. A Starfish which had 3 limbs, that developed: * an endoskeleton * knees * hips * ankles * weight bearing limbs under the body rather than splayed. That is what you need to be focusing on. However the gait of a Starfish is incredibly slow. But more on that later. **Lifestyle:** The three limbed variant that stood upright, would look more like a ball on stalks. It makes sense it would be a overhead "shallows/ pool hunter" like a heron. However since it started out as a Starfish it's mouth would be in between the limbs (basically where you'd expect the anus to be) and the 3 limbs would (logically) be prehensile so that it could scoop up food from below and pop it in it's mouth. i.e. balance on 2 legs, scoop with a third. That would give you and idea of how well it needed to balance: at a instant it could strike with any one "leg" and perfectly balance on the other two. This would be useful for hunting a wide umbrella area. **Locomotion:** It would stride about the place very long limbed - `2 feet` on the ground would be a walk, it would have no real need to have a "forwards" or a backwards" i.e it would never really be orientated with a"facing" nor need to "turn" it would just glide over in a direction - `2 feet` on the ground would be a walk , `1 foot` on the ground would be a canter and brief episodic `no feet` on the ground would be a gallop. **Head** This is where I get into very uncharted territory - but we can apply "first principles" and see where we get to. You see, `radially symmetrical` animals **don't** have a head. (In fact bilateral symmetry is actually radial symmetry "laid down flat", like a worm is radially symmetrical sectionaly and bilaterally symmetrical from planar axis, and the "head" is the bit that goes "forward" to sense/eat and this sensory cluster then becomes the "head") So in this case it's mouth and anus would (logically) be opposed so it's anus would be on the top (rather odd) and it's central nervous system (eyes/brain) would face "down", and "ring" it's mouth, (the brain would be a "donut" shape with the gut travelling through it!) however if the eyes were on stalks they could be prehensile like octopus tentacles or elephant trunks with eyes on the end of a "stalk" that could retract in and out and have no real "facing". The eyes would have to be connected via short optic nerves direct to the brain "donout". So the "brain" would ring the "mouth" at the underneath and the "eyes" would protrude from that but be biased to looking down **Conclusion:** [](https://i.stack.imgur.com/ZkApB.png) Once we draw it out in MS Paint (<3 Paint!) It seems we get something very like [HG Wells Tripods](https://en.wikipedia.org/wiki/Fighting_machine_(The_War_of_the_Worlds)) in war of the worlds. Seems he already did the necessary thinking back in 1898! I went down the ecology of *one* such creatures evolution but you can see that prey animals may never have got past the stage of radial symmetry or they could be bilaterally symmetrical as well but never get to be more than millipedes. It seems inevitable that in a ecosystem of "three limbed" creatures they would all derive from a common ancestor like I describe then diverge into variants of predator prey animals. [Answer] There are any number of videos on youtube of cats and dogs which have had amputations of one or two legs. Apparently they learn to cope just fine with only 3 limbs. You could try reproducing this gait, using a single leg in the middle. [Three legged dog](https://www.youtube.com/watch?v=2SUllXkPHmc) [Answer] **Approach 1: 2 legs in front, 1 leg at back** This one's pretty easy. If the back leg is A and the front legs are B and C, then it would walk something like this; B and C are brought forward sequentially, as in all Terran bipeds. Then, A is brought forward towards B and C to push off the ground. An animal with this limb configuration could also take on a unipedal, saltatorial gait with two "arms". **Approach 2: 1 leg in front, 2 legs in back** This would essentially work the same way as the last approach, but in reverse. This time, the back legs are A and B and the front one is C. C is brought forward to push off the ground, while A and B are brought forward sequentially. An animal with this limb configuration could also take on a bipedal gait with one arm. **Approach 3: 1 leg in back, 1 leg in middle, 1 leg in front** This would have to move in an almost bounding gait if the animal to keep a leg off the ground at all times during motion. This time, back leg's A, middle is B and front is C. When the animal is airborne, C touches down, closely followed by B. Finally, A is brought down to push off the ground into the next "leap". (This would be a very effective sprinting animal) **Approach 4: Trilateral symmetry** Terran vertebrates have bilateral symmetry; they are symmetrical about a line running from front to back. Trilaterally symmetrical animals might have three legs positioned like the corners of a triangle. This one is rather simple; the animal would just move its legs in the desired direction. --- These are just my ideas on how tripedalism would work. Hopefully I've been helpful, and thanks for asking. [Answer] Nothing like dragging things up from the dead! I've been thinking about tripedalism a lot since I'm burning through the Culture novels again (with three main tripedal species involved: Idirans, Homomdans, Chelgrians), and I was curious to see what evolutionary biologists thought about it (subsequently stumbling upon this thread). I'd like to add another perspective into this, and that is "What formats did prior creatures on a hypothetical planet exhibit?". If your evolutionary path had some six-legged creatures, it's reasonable to consider that at some point in development the creatures may have "stood upright" (raised the middle legs) to get a better view of the environment and thus make better choices, improving their chances of survival. If we assume these creatures survived long enough, like bipeds their bodies could have morphed and limbs may have eventually fused. There's plenty of evidence in our planet's evolutionary history to suggest bony structures fuse over time. So you may end up with the hindlegs fusing and the midlegs elongating, or the hindlegs strengthening and the midlegs fusing and elongating. in Banks' Culture novels, the Idirans and Chelgrians seem to have evolved from six-legged creatures in bilateral symmetry, and the Homomdans evolving in radial symmetry. [Answer] You've never seen a 3 legged dog? I imagine it would look and act just like that. <https://www.youtube.com/watch?v=TEXqBHP7JeI> In an evolutionary sense, I would guess that typically it would be 2 front legs and 1 rear leg, as the front legs could also be used for manipulation. Even though having 2 rear legs and 1 front would probably result in a creature that would run faster, I don't think that would be a greater evolutionary advantage over the alternative. E.G. climbing would be a lot more likely with 2 front. I'm sure there are many other examples. [Answer] As you base your question on evolution, I'd say that evolution already shows that 3 legs is not the best approach. That's why all animals have an even number of legs. There must be a good reason for an animal with 3 legs to survive evolution and for this reason there must be a certain environmental parameter, which you unfortunately didn't tell us. As I don't know this parameter it is hard to say what would be an efficient way to walk with 3 legs. [Answer] To those who say that you *cannot* evolve three legs from bilateral symmetry: you can! Just stop using (sorry) "lateral thinking". The dorsal fin of fish is an extremity that is not necessarily paired: [](https://i.stack.imgur.com/R3fz5.jpg) It grows on the back (dorsal) instead of the side (lateral), hence my pun "lateral thinking". However, fish can grow more than one, on different segments along the length of the body: [](https://i.stack.imgur.com/0js1V.jpg) . According to Wikipedia, fish can grow up to three dorsal fins. Furthermore, most dorsal fins contain bones called pterygiophores; in seahorses these bones are even articulated. > > The muscles, fin ray joints, and supporting structures underlying the dorsal fin are described for two seahorse species: Hippocampus zosterae and Hippocampus erectus. A fan-shaped array of cartilaginous bones, the pterigiophores, form the internal supporting structure of the dorsal fin. Each pterigiophore is composed of a proximal radial that extends from a vertebra to the dorsal side of the animal, where it fuses to a middle radial. The middle radials fuse with each other to form a dorsal ridge upon which sit the spheroidal distal radials. Each distal radial articulates with a fin ray on its dorsal side and is attached to the dorsal ridge on its ventral side by a material that has been histologically identified as elastic cartilage. Together these connections form a two-axis joint that permits elevation, depression, and inclination of the ray. Each fin ray is actuated by two bilateral pairs of muscles, an anterior pair of inclinators, and a posterior pair of depressors. > > > <https://www.researchgate.net/publication/12065134_The_dorsal_fin_engine_of_the_seahorse_Hippocampus_sp> > > > Some species (e.g. sharks and seahorses) even have muscles in their dorsal fins, enabling the animal to actively move them. The muscles form oppositional pairs right/left due to the bilateral symmetry. (In seahorses it forms oppositional quads.) This is a far simpler system than seen in 2- or 4-legged creatures, which use flexor/extensor oppositional pairs which must develop from separate segments. So if you want a creature that could plausibly evolve, but is definitely non-humanoid, consider a bilateral that has elaborated three ventral, articulated legs. (After all, this is a world-building site; think outside of the box.) Or a seahorse that keeps its prehensile tail, doubles its dorsal fin, and evolves the latter into fingered "arms". Instead of *Hippocampus*, I call it *Tricampus*. As far as how to actuate such appendages to produce locomotion, I defer other excellent answers already provided. [Answer] Some of the creatures that inhabit the alien "Rama" spaceship in Arthur C Clarke's "Rendezvous with Rama" series of novels were apparently tripedal--at least I think they were. I seem to remember they did a lot of twirling about. Here on earth, insects have six legs, i.e twice three; take a look at how they walk for clues on how a tripedal being might. How do five-armed starfish get around? Look too at the octopus, even though eight is not a multiple of three. As for "War of the Worlds", in the '50s movie version, the folks in Hollywood couldn't come up with convincing working models for the tripod-shaped (as described by Wells) Martian war machines, so they just had them be flying disks with weapons on top. But the Martian war machines shown in the Classics Illustrated comic book of "War of the Worlds" (also from the '50s) were shiny metal tripods with armed turrets on top. [Answer] You may want to have a look at the works of [Karl Sims](https://en.wikipedia.org/wiki/Karl_Sims), in particular at the ["Evolved Virtual Creatures"](http://www.karlsims.com/evolved-virtual-creatures.html) (although that work is quite dated, written in 1994, so there could be something way more advanced today already; still, good as a starting point). Basically, he assembled some "creatures" out of physically simulated blocks, some creatures were kinda realistic, some were not realistic at all. Then used neural-genetic-etc. algorithms to optimize their movement: at first they were just twitching chaotically, then, through artificial evolution, were able to walk, swim, jump, etc. As I remember, there was at least one three legged creature, although the movement pattern it eventually developed was nothing unusual, similar to the running rabbit from JonSG's answer. [Answer] I have come up with this mobile plant with three legs. Two in front. One in back. It begins life in the ground. Eventually it pulls itself out of the ground with its front two, and the stem becomes the back leg. That could be a reason for a tripod. ]

[Question] [ In [my answer to another question](https://worldbuilding.stackexchange.com/a/139415/627), I suggested that the Super-Earth in question be tidally locked to its host star for a period of time while part of its surface experienced a bombardment. After that's finished, however, I'd want the planet to rotate normally, ideally with a rotation period similar to one Earth day. The problem is, I know of no examples of planets or moons becoming tidally locked and then tidal unlocked via natural means ([although we've talked about doing this artificially](https://worldbuilding.stackexchange.com/q/90805/627)). Here are some specifications for my idealized version of the system: * The star is a K-type main sequence dwarf of about $0.5L\_{\odot}$ and $0.7M\_{\odot}$. * The planet is a Super-Earth of about two Earth masses, orbiting at $0.4$ AU. * The planet's final rotation period should be $\sim$24 hours. * Initially, there is an Earth-like atmosphere, and I would *prefer* for it to be retained, but that's not a necessity. * There is no life on the planet yet, although there may be in the future. I'd like to avoid catastrophic events like collisions with another planet, and I'd also want the planet's orbit to stay roughly where it is - in the habitable zone. Bearing this in mind, is it possible for this tidally-locked planet to *naturally* have its rotation period decreased to 24 hours within, say, 100 million years? [Answer] A planet in our very solar system has actually gone through such a shift! Venus currently has a 243-day long retrograde spin, but likely didn't always. The current theory says it started with the usual fast spin and underwent tidal locking normally. And it would have stopped there, but Venus's thick atmosphere generates **thermally driven atmospheric tides** which were strong enough to overshoot tidal lock and cause a retrograde spin. Currently its rotation is an equilibrium between the atmospheric tide pushing in retrograde and the sun's tidal dissipation pushing in prograde. See wikipedia's page on [retrograde and prograde motion](https://en.wikipedia.org/wiki/Retrograde_and_prograde_motion#Planets). Sounds like you aren't particular about keeping the atmosphere... are you cool with a really thick atmosphere? If that's ok, and you don't mind retrograde spin, this one is based on an actual planet. However, I'm not sure how strong that effect would need to be in your scenario. What if... your tidally locked earth eventually had intelligent life that wrecked their atmosphere... [Answer] If your tidally-locked planet captured a large moon, sort of like the one we have here on Earth, the tidal forces of the moon could be stronger than the tidal forces from the star. This would result in the planet gradually losing its tidal lock to the star in exchange for a tidal lock with the moon. [Answer] No. Not without another body getting involved. Tidal forces within the planet are constantly pushing it towards the "locked" state, you need a massive input of energy to change that. We're talking really dramatic events. You might be able to achieve something through a near encounter with a massive body (for example a large rogue planet passing through the system) where there is no collision. However you'd end up with a very elliptical orbit and a second encounter to send it back towards circular would stretch belief rather. You could achieve the desired effect by having it be a binary planet though. The two planets are locked to each other but each experiences normal day-night sequences. The surfaces facing towards and away from each other could plausibly take on different characteristics. [Answer] Yes, by radial mass redistribution. Something similar to the [iron catastrophe](https://en.wikipedia.org/wiki/Iron_catastrophe) on early Earth, or the melting of ice caps after ice ages. If something rises the internal temperature, it could trigger the migration of heavy materials towards the center of the planet, therefore reducing the moment of inertia and accelerating the rotation. As in the case of the iron catastrophe, the friction generated by the mass migration to the core will produce further warming and accelerate the process even further. The heating of the planet's interior required to trigger such process can happen by multiple processes, like extra insulation from a thickening crust or deposits of some kind of snow. Natural accumulation of radioactive minerals (as it happened in Uranium mines) that reach critical mass to start a natural nuclear reactor. Or, maybe the tidal locking stopped or slowed down volcanism and that could rise the internal temperature enough to trigger the process. A similar effect could happen even when cooling. A phase change can happen that transform a light mineral into a heavy one, but in that case the frictional heating would stop the process instead of accelerating it. [Answer] > > I'd also want the planet's orbit to stay roughly where it is - in the habitable zone. > > > Does the planet have to start out in the habitable zone? If not, here's a suggestion, in a few stages, involving a gas giant on a very long period, comet-like elliptical orbit: 1. **Formation:** have the planet initially form on a very close orbit to its star (on the order of several days), where it is tidally locked. 2. **Increasing rotation speed:** Once the bombardment is done, have the rogue gas giant make a close approach which makes its orbit slightly eccentric, such that the favorable tidal lock is a 3:2 resonance like Mercury, but with a rotation period faster than its current rotation. Give it a few hundred thousand years for the rotation period to stabilize, then have the gas giant swing by again and boost it to a more eccentric orbit where a 5:2 lock is favorable, again with a slightly faster rotation. Repeat until spin is fast enough. 3. **Transfer to habitable zone:** Close approaches of the gas giant boost its apoapsis past the habitable zone. Allow precession and timing to cause a close approach as it crosses the habitable zone, with your planet moving inward, the gas giant moving outward, and your planet slinging around the sunward side of the gas giant. This is equivalent to a large radial burn and should serve to mostly circularize its orbit in that position. 4. **Optional - safety:** If the gas giant is on such a long-period orbit, it will go quite far from your sun. A passing star/red dwarf/similarly massive object should be sufficient to divert it from making further passes deep within your solar system and messing up what's been set up. [Answer] ## An extremely powerful nearby pulsar that only hits one edge of the planet. While this is a rather "out-there" scenario, it's possible for a nearby, very powerful pulsar to repeatedly hit the planet during a small portion of its orbit, but only hit it on one side. This would impart a force to one side of the planet, slowly spinning it up over time the same way you can spin a ball by hitting one side of it. As a worked example, let's arbitrarily say that the planet takes up a half an arcsecond from the point of view of the pulsar. That's in the same rough angular size as Earth is from Pluto's perspective, so it sounds reasonable. We'll say that the pulsar is as powerful as the Crab Nebula pulsar, so a power of $10^{28} W$ according to [this](https://opentextbc.ca/physicstestbook2/chapter/power/). The pulsar spins, so that half-arcsecond planet is getting hit by one of the two beams a total of $1/296000$ of the time. That translates to getting full power $1/2592000$ of the time, which means that our average power is $10^{28} W / 2592000 = 4\*10^{21} W$. If the planet is getting this for, say $1/10000$ of its orbit (I'm just pulling numbers out of my [REDACTED] here, but it sounds reasonable), the average power is $4\*10^{17} W$. Now, the rotational energy of the earth is $2.138\*10^{29} J$, and our planet is double its mass, so we quadruple the energy (remember, kinetic energy is mass times velocity *squared*) to come up with a required kinetic energy of $8.56\*10^{29} J$. Now, if the pulsar were to transfer energy with perfect efficiency, and we ignore the forces that tidally locked the planet in the first place, this would restart the rotation in $8.56\*10^{29} J/4\*10^{21} W = 2475 ~days$. We can assume an energy transfer of, let's randomly say 0.00001% because of most of the pulsar beam missing the planet and some of the energy being transferred to heat and translation instead of rotation, that moves the required time up to about 68 million earth years, still within your hundred million year timeframe. So, in conclusion, my worked example with half the numbers made up and most of the other half being Fermi estimates seems to work. I'm not sure what that level of radio waves will do to a planet, and I doubt it would be pretty or at all nice to any life present, but it seems to work to restart the spin. If anyone has numbers for any of the stuff I completely made up, please comment and I'll change them to actually correct values. [Answer] You mention in your question that the planet suffers a bombardment. Why can't this be the cause of the rotation? If we remember that a tidally-locked planet is *already* rotating, only at the same speed as it traverses around the star, then we only need a relatively small amount of acceleration to unlock the planet. ## Scenario 1 (Prolonged Bombardment): If your bombardment takes place over a long protracted period, with many many rock causing glancing blows, perhaps even aerobraking in the atmosphere before impact, then over many hundreds or thousands of years, they may impart enough momentum into the planet to start a chain-reaction wobble in the orbit, which in-turn may cause the planet to rotate on it's own. ## Scenario 2 (Sudden Flyby): Perhaps a rogue planet has just shot through the system swerving dangerously close to your Super-Earth. One the way in, it shoots through an asteroid belt or three and sends rocks flying in all directions, even pulling a few along in a game of follow-the-leader. Then it swings by your planet at high speed, grazing the atmosphere. It's going way too fast to end up in orbit, or even be in any danger of actually colliding, but the asteroids it gathered up start bombarding the planet. The high speed and large mass of the rogue planet also play havoc with the local gravity and after a (geologically) brief period of orbital wobble, the Super-Earth settles down to a more normal rotational cycle. [Answer] The question doesn't seem to forbid technological methods, so there are a few options there. The obvious solution would be to put a giant Catherine wheel of angled thrusters around the Equator, and start making the thing rotate. You may want to build a geostationary ring around the planet and link it with the surface with space elevator cables and put thrusters on the circle, in order to avoid blowing the atmosphere away. Keeping the contraption stable and in one piece will require some work, but I assume that's the kind of small engineering problems that won't stop you. You can also replace the atmosphere afterwards (or store it for the duration). The problem is, you have to overcome the attraction between the tide bulge and the star, so this will require some serious impulse from your planetary thrusters. Which means big, expensive thrusters and the risk of ripping the entire planet apart and turn it into a molten ball of volcanic madness. So the brute force approach is not a good idea. Instead of trying to make it rotate in one go, you can impart some pendulum movement, pushing in one direction then the other, making it follow the final phase of tidal locking in reverse. At some point, the pendulum movement will be big enough to make a complete revolution, at which point you can simply keep pushing to accelerate to the required rotation speed. Now, what engines to use? Low-grade mass drivers would make you either dig giant holes in the surface or require lots of mass from elsewhere in the system. You could if you are in a hurry (those are cheap, low Isp/high impulse engines), but that's rather inelegant. You could use photonic thrusters (aka giant spotlights) if you have good powerplants like matter-energy converters, are in no hurry and there is no-one flying around to be dazzled. More traffic-friendly exotic versions may be possible, for example emitting neutrinos or gravitational waves, in case your neighbours complain about the light show. There is a middle ground of particle accelerators, requiring much less mass (and being more refined) than the mass drivers, but giving more thrust than pure photonic engines. The simplest version will heat matter into superhot plasma and let it escape by a nozzle at some fraction of c. Of course, you have a big fusion powerplant already available, so you can take advantage of that. If you are in no hurry, put giant solar sails on your orbital ring and turn it into a (solar) windmill. Feel free to put mirrors all around the star to help concentrate energy on the sails. Or, if you have fancier tastes, put a light Dyson swarm there and have the collectors beam the power with lasers or focused particle accelerators. That may help avoiding cooking the surface with the unfocused mirrors. Alternatively, if you don't want to build things on the planet itself, put those on local planetoids and move them around. With the right grazing trajectories, you can use gravitational tugging to start making the planet wobble. Once it starts rotating, a low orbit, fast-orbiting moon may help a bit for accelerating it. Be careful to not overdo it, you may cause more volcanisme than desired otherwise. [Answer] I might suggest the introduction of another massive body into the system; rather than an actual impact. Numerous [interstellar planetoids](https://en.wikipedia.org/wiki/Interstellar_object) do exist, and every now and then we'll find one or two entering our own solar system. The usual clue that gives them away as extra-stellar is that they have a hyperbolic trajectory, instead of an ellipsoidal one, which can't come about in-system. If this was a massive enough body, or one that moved slowly enough (though there are restrictions within reasonability there), the perturbation of the gravitational field would cause a tidal effect on the planet, potentially one strong enough to realign its axis of rotation and pull it out of being tidally locked to its host star. Afterward, the planetoid could pass out of the system on its merry way, and the tidal effect would be over. In most cases, it would take some time to occur; but it would happen as the whole system would be destabilized. The foreign object could be anything from a particularly large interstellar asteroid to a [hypervelocity black hole](https://en.wikipedia.org/wiki/Stellar_kinematics#Hypervelocity_stars). [Answer] Planet 9. Have a large planet whose orbit comes into the inner solar system only every few thousand years on only 1 in a hundred/thousand times would it be close enough to effect your planet. Depending on how close it passes it could have a huge effect on your planets orbit and spin. [Answer] There are three planets in the system, call them **b**, **c**, and **d** in order of distance (there might be other planets too). **b** is the super-earth we're interested in; **c** and **d** are giant planets similar to Jupiter or Saturn. This is all happening fairly early in the system's history so **c** and **d** (and possibly other giants in the outer system) are still interacting and migrating their orbits. After **b**'s rotation locks on the sun, and whatever else you want to happen at that stage, **c**'s orbit changes so that **b** and **c** come into resonance, and the Kozai mechanism (or some similar effect) causes **b**'s orbit to become highly eccentric (but the semimajor axis doesn't change). As a consequence, its rotation becomes unlocked and chaotic (see Hyperion). Later, **c** and **d** continue their dance and **c**'s orbit changes again, breaking the resonance with **b**. **b**'s orbit gradually circularizes again; when its orbit loses its extreme eccentricity, its rotation is no longer chaotic but won't necessarily go back to being locked. [Answer] If whatever the planet is being bombarded with doesn't do so symmetrically, but instead the change in inertia due to impacts is distributed in such a way that it imparts net angular momentum, then over time this angular momentum would build up and could gradually break the tidal lock and get the planet spinning again, slowly at first, but faster as the impacts continue to occur. For instance, suppose that the planet was hit by a big meteor on the equator that was almost tangent to the planet's surface. Or a bunch of little meteors over a period of time. Or a sufficiently powerful solar flare that struck the planet off-center. Or that the outside or inside edge of the planet's orbit scraped up against a ring of asteroids or comets (possibly on an elliptical orbit) that was traveling faster or slower than the planet itself, so that any impacts between the planet and the comets/asteroids would tend to always be in the same direction and would make the planet spin more in that direction. Also consider [the time the U.S. Air Force proposed using rockets to stop the earths' rotation to dodge a nuclear attack](https://www.dailygrail.com/2018/05/the-u-s-air-force-proposed-using-rockets-to-stop-the-earths-rotation-as-defence-against-a-nuclear-attack/). [Answer] Referencing [this](https://worldbuilding.stackexchange.com/questions/39952/will-moons-orbiting-gas-giants-always-be-tidally-locked) answer. Based on information in the answer above, liquid planets/moons (like Europa) take much longer to tidal lock. Per the [Wikipedia entry](https://en.wikipedia.org/wiki/Europa_(moon)#Orbit_and_rotation) for Europa, it may not be fully tidal locked even now. Perhaps a concentration of greenhouse gases caused the frozen surface to melt. Throw in some near misses from other large bodies and you might be able to get the planet spinning again. ]

[Question] [ So basically, battleships are awesome. I am interested in creating a setting where they were never superseded in their role of long-range command vessels and fire support by aircraft carriers, preferably without eliminating CVs entirely. But I am unsure how technology and/or military doctrines would have to be different for battleships to not become obsolete. [Answer] **TLDR: All you need is better Anti-Aircraft Guns** There's a lot of good information here, but I think @Karl actually has the best and simplest answer to the question. Imagine a scenario where instead of pursuing multiple competing and disorganized efforts, the United States and Great Britain went All-In on Radar in the early '30s when it was [first starting to show promise](https://en.wikipedia.org/wiki/History_of_radar#United_Kingdom). This likewise drives a lot more interest and investment in ballistic computers as @KerrAvon2055 discussed. Between those two things, by the '40s you potentially have fire-control systems with the capability to start inflicting reliable casualties on incoming aircraft the moment they come within range, which in the case of high-performing weapons like the [notorious German Flak 88](https://en.wikipedia.org/wiki/8.8_cm_Flak_18/36/37/41) was as much as 15km. This completely changes the dynamic of naval combat in WW2. Most critically, the PERCEPTION of battleships is retained that a proper design can be almost impervious to all but the largest air attack. Torpedo bombers are almost useless against a ship with defenses like this because their attack profile makes them catastrophically vulnerable to precision long-range anti-aircraft gunnery. Dive bombers become much less effective because they have to release their bombs from higher altitude and use more erratic attack trajectories to have any chance of getting a munition to the target. In this scenario the kind of investment that leads to massive carrier fleets by the end of WW2 never occurs and instead of devoting more and more resources throughout the '50s and '60s to naval aviation, that money and scientific effort is devoted to massive acceleration in the development of technologies that allow interception of incoming missiles and projectiles. Instead of becoming the primary offensive weapon, Naval Aviation remains relegated to support roles that don't require them to attack enemy formations. Carriers are smaller, faster, and primarily devoted to reconnaissance and ASW. The primary mission is locating enemy ships and providing targeting information to the battleships. Best of all, this doesn't require any other technologies to mysteriously not be discovered, it all becomes a question of where the money and attention goes. Without a massive investment in aircraft carries, by the '80s the United States and Russia have fleets of massive battleships protected by the same Aegis missile defenses and Phalanx guns that protected carriers instead. Indeed since you can't rely on massive air wings to intercept incoming waves of cruise missiles with air-to-air missiles, development of defensive anti-missile technology gets vastly more funding and attention. At this point you can look at all the pie-in-the-sky stuff that the Navy has been trying to put on the Zumwalt-class ships since the '90s and pick the stuff you like. All of it would have worked if enough time and money had been spent on it. Nuclear Powered battleships with [laser Anti-Ballistic-Missile defenses?](https://en.wikipedia.org/wiki/Boeing_YAL-1#Use_against_ICBMs_vs_TBMs) Sure thing! [Electromagnetic Railguns](https://en.wikipedia.org/wiki/Railgun#Naval_Surface_Warfare_Center_Dahlgren_Division) firing GPS- and laser-guided projectiles? No Problem! Point Defenses that use shaped charges to intercept incoming hyper-velocity projectiles? [You Betcha!](https://en.wikipedia.org/wiki/Active_protection_system#Hard-kill_measures) Whew, that was fun to write... [Answer] **Fuel and point defence** As noted in other answers, aircraft and missiles are key elements in the decline of the battleship. The missiles came later, so let's start by looking at a history in which aircraft didn't get off the ground quite so much. Aircraft require high fuel density. The [Turbinia](https://en.wikipedia.org/wiki/Turbinia) demonstrated how effective a coal-powered turbine engine could be, leading in short order to the construction of [HMS Dreadnought](https://en.wikipedia.org/wiki/HMS_Dreadnought_(1906)), but coal-powered aircraft were not a viable proposition. Aircraft needed refined oil fuels to work - what if such fuel was much rarer and therefore expensive? The late 19th / early 20th century aviation and automotive industries would have been much smaller, with aircraft being too small and expensive to use for combat although they would still have been valuable for reconnaissance. Oil scarcity alone might have been enough to allow battleships to maintain dominance for a long time. Still, they may need some help, so what if... Computers in the old days were big. Really big - taking up rooms worth. Let's imagine that some military funding was thrown at ballistics computer development back in the alternate 1920s and 30s. No miniaturisation, just really big, reliable valve-based ballistics computers that allow fire accuracy over the tens of kilometres that the main guns can fire. Then let some bright spark at a naval academy figure out how to program the computer to not only provide targeting data to allow the main guns to hit an enemy battleship 20km away, but to provide targeting data to allow the small guns to shoot down aircraft. This makes the battleship dominant up until the mid twentieth century: * the range and accuracy of the battleship make it impossible for any smaller ship to enter engagement range and survive * point defence prevents the handful of aircraft or primitive [V1](https://en.wikipedia.org/wiki/V-1_flying_bomb)-equivalent missiles from surviving in the battleship's skies * lack of compact fuel sources has reduced the effectiveness of submarines. Technology can progress from this point. Miniaturisation will eventually make missiles a threat, but as long as point defence software and hardware development keep pace it will not matter. Nuclear power will make submarines a serious threat, but have little effect on aircraft. If you wish to stray into science fiction territory, take a page from David Drake's [Hammers Slammers](https://en.wikipedia.org/wiki/Hammer%27s_Slammers) series and allow the development of fusion power plants *but* make them too large to install in anything smaller than a battleship rather than a tank. [Answer] The full answer to this question could fill a small library and I'm quite sure would blow the space limit of the answer box, but I'll try to give you a shortened version you can work with. Ultimately, the reason battleships developed into their WWII incarnations was range. This in point of fact is what made bows, firearms, cannon, tanks, cruise missiles and ICBMs useful innovations as well. The reality is that if your 'reach' is longer than your opponent's, then you can hurt them from a range at which they can't hurt you. Now, battleships evolved essentially as floating platforms for big guns. You ended up with ships like the Missouri which were massive but had a relatively small number of guns by comparison to (say) a Ship of the Line from back in the day because the focus changed from rate of fire to range of fire. Having a smaller number of much larger guns, and guns larger than those on the battleships of your enemies, was all important because the range of fire meant that you could eliminate threats and destroy enemies long before they came anywhere near you. The problem was that in WWII, a new invention occurred, and a second one was refined, which changed that model completely; rockets and aircraft. Rockets, particularly now in the form of missiles, provide far better range than conventional cannon-based guns and more importantly, don't require the massive ship from which to launch that cannons do because a large percentage of the momentum is added to the payload in flight, not at the point of firing. Aircraft add to this by having a massive flight range, and allowing for targets to be attacked from well outside the range of conventional guns. Put simply, aircraft carriers are still floating platforms for ranged weapons, it's just that the guns have been replaced with smaller flying weapons platforms to increase the range. Same with most guided missile frigates, that also carry the benefit of being a lot smaller, making them harder to hit in combat and cheaper to build. This last point is especially important because torpedoes made it very cheap to take out a large target like a battleship if you could get the torpedo to its target without being noticed. Torpedo boats and submarines were effectively designed to be battleship killers and were far cheaper to manufacture than a battleship, making them a good deal in terms of strategy. So; to keep battleships in play, you need a minimum of three changes; 1) No Rockets. Don't let the Axis develop rocket or long range missile technology. You won't get to the moon either but that's another problem. The important thing is that missiles as we currently understand them cannot exist. 2) No Planes, or at least no planes that can use short take-off and landing strips. Without these, your battleships still have a chance of being the most ranged weapon on the seas, keeping them relevant in the modern day. You won't have the convenience of international travel in a single day, but at least you get to pass impressive looking battleships on your cruise liner as you travel between countries. 3) No Submarines. If you have no stealthy way to get torpedoes close to large ships, then the battleship is still in with a chance. The fact that these can be built far cheaper than the ships they are designed to destroy makes them a real threat to the battleship in a combat situation. One of the biggest issues with these ships was their cost, and when built governments were (ironically) reticent to use them in combat as it would greatly increase the risk of losing it. Ideally, changing all the above AND reducing the overall cost somehow of building large floating platforms of battleship size is needed because this class of warship was always prohibitively expensive to build. Missile destroyers etc. have provided a relatively cheaper way to get ranged attacks in play within a theatre of war, so without missiles you have more justification for the cost, but ultimately that is still going to be the limiting factor in the choice to build them. [Answer] # No wars The problem is, either aircraft or submarines/torpedoes will eventually render battleships useless. They do this by being able to kill a battleship while costing much less. If a billion dollar battleship can be sunk at the cost of a \$10 million aircraft or \$100 million submarine, a battleship is no longer a useful weapon of war. There is basically no way to escape this calculus, and there is no way to "advance" to anything like a 21st century without aircraft or submarines becoming technologically practical. However, the *knowledge* that aircraft and submarines have superceded battleships would not be acquired without a war. Imagine that WWII was never fought. Navies at the beginning of WWII had some aircraft carriers and submarines, but they also considered the battleship to be backbone of the naval fighting force. It wasn't until the first year or two of war that this *knowledge* became commonplace. The power of submarines was demonstrated by the sinking of [*Courageous*](https://en.wikipedia.org/wiki/HMS_Courageous_(50)) and [*Royal Oak*](https://en.wikipedia.org/wiki/HMS_Royal_Oak_(08)) in fall of 1940. The [*Bismark*](https://en.wikipedia.org/wiki/German_battleship_Bismarck#Sinking) was sunk by aircraft (primarily) in May 1941; and the effectiveness of airpower was firmly demonstrated by the sinking of [*Prince of Wales* and *Repulse*](https://en.wikipedia.org/wiki/Sinking_of_Prince_of_Wales_and_Repulse) immediately after Pearl Harbor. If you remove the *knowledge* that aircraft and submarines can easily sink battleships for a low cost, then it it might be reasonable to keep on building battleships up until the next war. If that war didn't happen until the 21st century, then so be it. Besides, if battleships are not proven obsolete until the 21st century, then it might turn out that modern technology has made them un-obsolete by the time the next war rolls around, as proposed in other answers. [Answer] This is easier than all other solutions. You have to understand why Navies had Carriers going into World War II in the first place: The 1922 Washington Naval Treaty. One of the possible causes for World War I was an Arms race to build battleships, which fuelled the eagerness to fight it... It was pretty much a prequel to the Cold War only the weapon was not capable of destroying the world many times over. At the end, the five biggest naval powers at the time (Britain, US, Japan, France, and Italy, from largest to smallest) met in Washington D.C. to negotiate a treaty to limit the tonnage of ships in their Navies. As this was in the United States, the U.S. was the big winner of the treaty as they were able to spy on all the other delegations and get their terms. The United States had too big war concerns in the future... both of whom were at the table no less: The British, because we hadn't had a war with them and all their biggest foreign wars were with the British prior to World War I. But at this point in history, the U.S. and the British had more in common military policy than conflict points... Japan was a different matter as they had territorial aspirations in the Pacific Ocean AND had a history of punching above their weight class that could not be ignored. Not to mention they had much more points of contention that could lead to military conflict (and as we know, did). The U.S. really wanted to screw the Japanese over and they had cracked their codes so thoroughly that they know the bare minimum Japan would accept in the treaty. They then bid under that number, Japan got upset, the U.S. would him and hall about maybe coming up to the minimum acceptable numbers, and Japan would be tricked into taking the lower figure because they needed the Treaty too. Japan at the time also saw the United States as their next big military target and wanted the Treaty of Washington in place to restrict the U.S.'s superior manufacturing capabilities. However, because of the hard bargain the U.S. Drove, the Treaty was very unpopular in Japan, especially among the navy. It should be pointed out, that the admiral who would plan Pearl Harbor did defend the treaty because it was better that they were restricted a little if the U.S. was restricted a lot. And Japan did get some nice bonuses from their efforts. The target of the treaty was limiting Battleships, so everyone was fine with Japan's then construction of the Hosho which was the first purpose ordered Air Craft carrier, was classified as an experimental class, which meant it did not count to tonnage. In addition, while the Treaty called for total scrapping of all battleships in production, Japan was able to convert some already laid hulls to carriers that were technically larger than the treaty permitted carriers to be as a concession. Additionally, the treaty only affected carriers above 10,000 tons. Anything under was designated as a light carrier and was not limited in number. This might not seem like much, but "Treaty Ships" were rampart among all signatories... basically these were ships that were built with either new technologies, mis-measured, or outright cheated to meet qualifications of another ship style to avoid treaty limitations. All of these were seen as acceptable terms by the U.S. because they were more concerned with Battleships than the were with carriers. But Japan realized that if they could perfect carrier operations, they could still have and effective war platform. In 1934, 3 years into the Second Sino-Japanese War, Japan signalled it's intent to withdraw from the Treaty and did so in 1936. No longer limited by the treaty, Japan would build more ships to the point that in 1941, they had a fleet of 10 carriers, which was equal in number to their battleships. As the U.S. embargoed oil to limit the Japanese War machine in China (following an incident of intentionally firing upon a U.S. Ship in the area) Japan drew up plans to shock the United States into concessions. Hoping for a similar victory to Russo-Japanese war, where the sudden attacks forced the stronger Russia into suing for peace, the Japanese hoped that a few quick hits against the U.S. and Great Britain to demoralize the U.S. and make a quick but winnable war. Knowing that both nations were still operating on Battleship Theory, while Japan had been developing Carrier theory, they elected to put make their initial attack a Carrier based attack, as the United States would be much more wary of Battleship movements. On December 7, 1941, without warning, naval combat was changed forever and battleship theory was rendered obsolete. It wasn't just Pearl harbor. Simultaneously (but across the Date line, so really on December 8) the HMS Prince of Wales and HMS Repulse, the first time an Ariel attack sunk battle ships underway. The attack was devastating to the capital ships of the U.S. Pacific fleet. A full 2/3rds of all capital ships were put out with a quarter complete losses. Of the four remaining capital ships not damaged enough to be removed from active service, 3 were aircraft carriers that were not in port during the attack and the U.S. Pennsylvania was the lone Battleship that could be put to sea. The remaining 8 were lost, sunk, or two damaged to be put to sea without major repairs. Although Battleships would be important Naval weapon for years to come, with the last U.S. battleship to sever, the U.S. Missouri, seeing combat in the Gulf War, No new Battleships were made following WWII, with only four surviving the conflict. Two more Death Knells would sound for the Battleship Theory during WWII: Six months after Pearl Harbor, the Battle of Midway would see the sinking of 4 of the six carriers that attacked Pearl Harbor without either combatant fleet having sight of each other. The final nail in the Battleship's coffin would come from the sinking of the Yamato in 1945. Perhaps the most feared Battleship to ever sail, the U.S.'s initial plans were to sink one ship in battle with a fleet: Six Battle Ships, Seven Cruisers, and 21 destroyers were sent to intercept the ship... but the Carrier U.S.S. San Jacinto was ultimately sent in first. It took less than two hours for the single escort carrier to down the mightiest battle ship with only six bombs and 11 torpedoes... a feat that required a fleet's worth of battleships to achieve. The Pacific Theater of WWII largely changed naval warfare forever. Carriers gave the Dreadnoughts something to dread... and they did very much. While the Yamato did help sink an another Escort carrier in an earlier battle, fears that it had actually hit one of a many fleet carriers forced it to turn around as it could not compete with the largest carriers. There is no technological innovation by this point that would have protected battleship from the damage a carrier could wield. Carrier's weapons had a greater range, and were not critical to the ship. However, the Carrier was born not out of a fear of a second Arms Race of Battleships and in an effort to reduce arms of the biggest naval powers AND screw their biggest rival, the Japanese responded by producing a devastating weapon. Without the Treaty of Washington's success in restricting Battleships, the Carrier would be seen largely as a toy to be played with than the deadliest combat ship of the modern era. [Answer] Battleships mainly went out because high speed, long range attack vectors became available that could deliver massive damage that such ships could survive as long as damage from any other source but couldn't respond to effectively. This mainly consisted in munitions delivered by combat aircraft, a world in which the [Hunter](https://en.wikipedia.org/wiki/Hunter_process), [Kroll](https://en.wikipedia.org/wiki/Kroll_process) and [Bayer](https://en.wikipedia.org/wiki/Bayer_process) processes were never perfected would have very little light weight alloy available. That makes long range aircraft, and naval aviation, possible only once strong composite materials, like carbon fibre, become available and even then operational ceilings are relatively low due to the stiffness of such composites compared to modern metallurgical products, this limits range and carrying capacity. Without light weight aluminium and titanium missiles are also relatively limited in range and payload so they're also less of a danger to ships at sea. Submarine attacks are still more of a danger to a classic battleship than attacks by surface ships but that's primarily an issue of having weaponry that can retaliate against subsurface targets added to battleships which it wasn't historically because they weren't designed for it not because they *couldn't be* designed for it. [Answer] This is a bit tricky. The dominance of the Aircraft carrier comes from its ability to extend air superiority over a huge and movable region for a very long period of time. Whoever controls the sky will dominate the battle because it carries such a huge advantage. To remove the dominance of Aircraft carriers, you need to either have a superior Air force or have someway to effectively remove aircraft carriers before they can get into range. The easiest way, would be to simply create a world with a stunted Airforce or where flying technology isn't as well developed. This will remove the main advantage of an Aircraft Carrier making battleships awesome again. The next way would be to limit fuel. An Aircraft Carrier needs to carry fuel for itself and for all the planes on it. It needs to be deployed for long periods of time ( no sense in requiring it to dock at a friendly port every day/week) to take full advantage of its aerial support. Limiting this would limit the use of Aircraft carriers. You would need other methods to establish a safe port to allow the Aircraft carrier to refuel and its operation range would become very limited as it would require the use of a base nearby to constantly fuel it. Limiting fuel would of course also limit your Air Force and Mechanized unit. Other than that, you could focus on extremely long range rockets, which would be able to easily destroy Aircraft carriers, making the investment in them not worth it as long range bombardments become the weapon of choice, or have extremely good submarine technology so that Aircraft carriers are always susceptible to being destroyed and again no longer worth the risk. [Answer] First, you'd have to remove torpedo bombers. More generally, you'd want to ensure that planes could not practically destroy large surface ships, such as battleships or other carriers. You can't practically reduce a carrier's range without axing civilian and transport aviation too, but you can defang them. Reconnaissance alone would probably be enough to ensure carriers were still part of the fleet - not to mention their ability to harass an enemy at long range, albeit with lesser firepower. (In WW2, ships weren't often taken out at a single stroke; repair efforts would continue well after the battle, and could prove decisive in whether the ship was recovered or lost. A handful of bombs wouldn't likely sink a battleship, but could hinder repairs or cripple a supporting tender.) Second, you have to keep aircraft defanged. Guided missiles will make battleships obsolete whether carriers can launch them or not, so you need to keep those off the table. Submarines are also a potential problem, although they have to get closer than guided missile destroyers and so will be easier to deal with. Interestingly, anti-submarine work is a big part of naval aviation even as it stands; in this world, where carriers aren't the bulk of the firepower, I would expect ASW to be a bigger and bigger part of their job as submarines get better. Third, you have to make battleships worthwhile in comparison with ordinary, non-missile cruisers. The reason torpedoes and missiles spelled the end of battleships wasn't just range, but that it became impractical to mount any kind of effective armor against them. If a torpedo will sink a battleship as surely as a destroyer, there's no point to building one battleship when you could have 20 destroyers instead. But the same holds true if *guns* develop to that point. You have to make sure that your armor can still blunt the enemy's firepower or else ships will inevitably decrease in size. [Answer] **No simultaneously compact and powerful engines**, including specifically: * No internal combustion engines * No rocket engines * No Stirling engines * No high-density batteries. You could still have nuclear, which would be great for battleships, as long as the lack of batteries or other suitable engines for torpedoes doesn't result in useful nuclear attack submarines. Preserving this one is difficult: There's [about a dozen ways](https://www.tapatalk.com/groups/warships1discussionboards/how-to-sinking-battleship-ww2-in-today-t34370.html) to sink a battleship with modern technology without much defense against it. They were doomed from several sides at once. From the surface, destroyers were already sinking battleships with torpedoes. So you need to get rid of those. From the below, submarines in WWII didn't quite get there, but a modern diesel-electric would send even the most powerful battleship fleet to the bottom. And they're so quiet that surface-based ASW escorts only offer some chance of thinning the pack, not preventing the attack. The most obvious threat is air - and without internal combustion, you don't get decent aircraft. You'd get small spotters and such, short-ranged strikes, but not the kind of powerhouses they became in WWII. Bombers could destroy battleships with torpedoes, bombs, or rockets - plenty of choice there. Finally, guided missiles were the nail in the battleships' coffin. Today, a battleship without carrier escort can be destroyed without even knowing it, with a long-range missile strike from a bomber. If you are to have old-school battleships, guns and armor, you can't have torpedoes, bombs, guided missiles, or effective submarines. The only means to avoid that is to take away their engines. Of course, this will also have an effect on some other things we take for granted, like cars... So what to do if you want to have battleships in the 21st century in your story, but not have your story turn into a Space Battleship Yamato fairy tale? **Modernize them!** "No gun battleships" doesn't mean you can't have battleships, they just won't be the same. [One take on that](https://www.tapatalk.com/groups/warships1discussionboards/ze-scott-brim-csw-21-aka-zsbcsw-channeling-thread-t21802.html) is a "very large cruiser" with active defenses instead of passive ones. There's really [a whole board](https://www.tapatalk.com/groups/warships1discussionboards/should-battleships-be-back-in-service-f64/) on NavWeaps dedicated to the idea of reviving battleships, and you'll get far more information there. To offer some best pickings, here is a very [down-to earth take on a 21st century battleship](https://www.tapatalk.com/groups/warships1discussionboards/what-a-21st-century-battleship-could-look-like-t36718.html). [Answer] Assuming we can do a little bit of fiction here, the biggest problems with battleships can be solved with a little bit of handwaviness that makes the science-fiction world go round: shields. See, battleships have huge profiles, are big targets, are not agile enough to evade incoming fire. Assuming you upgrade the anti-air to the point that you could hit aircraft at their maximum envelope, had EMwarfare packages that could screw with incoming missiles, and you had some kind of EM-shielding or kinetic force field barriers to stop incoming kinetic and energy weapons of a low yield, the battleship becomes a floating railgun boat, which, in this theoretical science fiction version of modern day, might be the only thing with enough punch to get through these shields, and of course would be more than enough medicine for anything smaller. That would mostly put battleships back at the apex. Smaller vehicles and craft could have shields, but they'd be weaker, probably only effective against other craft in their class. And railgun projectiles move too fast to easily dodge. The ability to have a huge powerplant to run the thick shielding gives battleships their edge. The fix for your problem is more than doctrinal. Needs new tech. [Answer] A lot of answers focus on the air vs sea inequality, which is only a small part of why battleships went out of use. A much larger part was the discovery that the [cavitation from an under-keel explosion (see page 13 for a good quote)](https://vtechworks.lib.vt.edu/bitstream/handle/10919/82531/Mathew_AK_T_2018.pdf?sequence=1&isAllowed=y) was destructive to even the most heavily armored ships. Much more destructive than a direct hit. A single torpedo could significantly damage and potentially incapacitate any ship, no matter how thick it's armor, by causing lots of small fractures and injuring the crew. This means that ships needed protection from submarines and explosive projectiles, because a single hit could be fatal. Aircraft and cruiser escorts became mandatory to create a "safe zone" around the important ships, both to spot submarines and to spot enemy combat groups before they spotted you so the enemy could never get the first - and potentially fatal - shot before you could shoot back or evade. Ships started to have less armor and instead range and speed became the deciding factors. If it wasn't for carriers, cruiser fleets would have replaced battleships, because smaller and faster ships are less vulnerable against cavitation hits than big, lumbering ships. To keep battleships relevant, you'd not only need to remove the threat of aircraft, for which others wrote suggestions, but also the threat of submarines as well as prevent someone from figuring out the cavitation effect. Submarines can be hampered by a lack of effective sonar, which could be explained by failed experiments, failed funding or researchers going down the wrong road and getting stuck with something ineffective, e.g. [sub-surface radar](https://www.physlink.com/Education/AskExperts/ae456.cfm). To prevent someone from discovering the cavitation effect, you could turn technology forward at the right points in time, and have armor piercing shaped charges discovered and used earlier than in actual history, which makes explosions below ships slightly less dangerous. [Answer] Quick thoughts: 1. Battleship reach: why can't it carry missiles? I mean, during Gulf War battleships did lop a few cruise missiles. They can carry quite a lot of them, more than an aircraft carrier of the same size. 2. Smart weapons: solar powered drones and even balloon ones can hover about for days on end way away from the battleship listening and providing targets and even attacking potential baddies. They can even land on water and listen to what is below it. Big ship can carry big loads, meaning you have now an early warning/countermeasure systems. 3. Lots of power: if you have electrically-powered guns (railguns come to mind), you can power big ones in a battleship. One nuclear reactor is not good enough? Throw in another one, so you can even run on one while doing maintenance, or powering the big party on the cruise ship you just rescued. 4. (as other mentioned) lots of space to put smarts and smart defenses. Yes, computers are getting smaller and smaller but a battleship has enough room to shove an entire AWS datacenter, meaning enough to do all the deep learning to help find out baddies and give them the finger before they get close to you. In plain English, the computing power you can shove into a battleship is more than you can shove into a plane. Now you have something of the size of a small city packed with weapons able to detect a plane hundreds of miles away (remember the drones). Things get a bit different. 5. Big guns. Big dumb guns. I do not think we have the technology today to stop a shell about as large as a car flying towards us. It is like trying to stop a big rock falling from the sky. Best you can hope for it so send a missile that will hopefully veer it off just enough to miss you. But it is still coming down. 6. Psychological warfare: if the battleship can stop the attacks launches by aircraft and is fast enough, it now can get close to where those aircrafts came from. And now, it can use its big guns to do big damage (the other weapons would probably be blocked the same way the battleship stopped being attacked). It would be a really bad day to be on the aircraft carrier/destroyer/base on the receiving end of those big rounds. [Answer] I'll cover some points already made and some new ones. Battleships can remain on the sea's in the (partially combined) cases of: * Expensiveness of the Battleship's replacements. If the things like fuel and construction of aircraft and missiles is much more expensive due to lack of industrial capacity or technological know-how for proper/cheap refinement their coming will not immediately end Battleships, they'll become an expensive alternative. * The great Fuck Up. Many technologies are held back years because of a single decision or event. If due to mismanagement, inexperience or sheer coincidence a grand air/missile attack fails spectacularily and this news reaches across the world then the advent of air and missile power could be stalled as no one is willing to invest in it. Alternatively if Battleships manage to sink some aircraft carriers in the early days (again, due to mismanagement, inexperience or sheer coincidence) the faith in these new technologies may plummet as well. * Lack of Funding. History is filled with incidences where a promising technology isn't pursued because the tried and true methods get more research and funding first. This can easily go hand-in-hand with an Old Guard in command influencing decisionmaking and steering towards tried-and-true methods rather than new technologies like aircraft and missiles. * Lack of small computers. Missiles are just rockets if they don't have the computers on board to steer themselves towards a target. This makes over-the-horizon combat much less effecient compared to just lobbing shells at each other, especially considering the expenses and travel time a rocket has to the target. * Ship-based ECM research moves faster than rocketry and aviation. If a ship can reduce the chance it's hit by a missile or aircraft to practically zero then the Battleships will remain viable. * Ship armor improves faster than effective missile and aircraft weaponry. If it takes so much missiles and aircraft weaponry to down a Battleship that it has time to get in range of the aircraft/missile carrier and fire it's high rate of shells to defeat the aircraft/missile carrier first then battleships have a purpose still. Keep in mind that while some are pretty weak on their own (like ship armor improving faster) if combined with other points they can become a solid reason. Say ship armor improving fast while missile research and materials are much slower causing them to cost way more and take much more time to build individually means that Battleships are a much more reliable source of firepower on the sea's even though they run a high risk of missile strike from the few but highly expensive aircraft/missile carriers. But that's what smaller ships can help against in this scenario as small ships would no longer be a viable target for missile strikes due to cost/effectiveness, allowing them to help in missile and air defense. [Answer] I don't think you even can eliminate carriers or make them irrelevant. The existing answers are all very good and show that a battleship could retain its superiority over a carrier in a battle - keeping it very relevant. However, outside of making planes implausibly bad (due to fuel, AA or whatever), carriers will be also important, usually even more important than battleships. Currently the biggest point of carriers is range of power projection. Battleships could perhaps dominate 50 km while carriers strike 500 km away. If you consider say USA-USSR conflict, battleships could be deployed to protect and attack important cities on or the coast. Both sides would require them to survive naval battle. But to strike further inland, you have to use planes - so both sides also need carriers. So far it is looking quite rosy for the good old battleship. But suppose proxy war (USA attacks weak USSR ally or vice versa) or USA/USSR terrorizing a small country. Sure, a battleship can easily wipe small enemy fleet and coastal defenses. But so can a carrier - considering lack of serious opposition. But a battleship cannot take care of recon, nor fortifications deep within enemy territory. Also, carriers will be gone before battleships even approach them. Therefore, carrier development will be incredibly important and I believe it would be the most important ship for involved countries, even if its might doesn't quite match a battleship. --- But what might happen from now on? Lasers could develop to be excellent to take down missiles or airplanes - make a tiny hole to set off explosive. Only the primitive big chunk of steel would work reasonably well (nothing to explode, too much material to vaporize it all). So, battleships and their guns. This is essentially the same as "make AA implausibly good", but I feel it is more realistic now than it was in the past. [Answer] As a short and simple fix, there need to have been no major wars after WWI, and thus no naval combat involving capital ships. It takes a war to overturn an embedded doctrine such as the superiority of the battleship, and with no wars, battleships will remain the fleet flagships rather than carriers, despite the junior officers and experts who point out how vulnerable they would theoretically be to aircraft, missiles and torpedoes. Arguably, the same thing is happening now, and carriers should be obsolete because of their vulnerability to swarms of small surface craft. [Answer] Peacetime Navies are normally conservative institutions that are adverse to developing revolutionary new weapons systems. If the WW2 Pacific conflict had never happened, it's likely that battleships would have been around for a lot longer and large carriers would have taken more time to appear. Even after WW2 though, the case that battleships were obsolete is overstated. The main reason the United States Navy didn't build battleships after WW2 is because there were no enemy battleship fleets left in the world to counter. The battleships themselves were still a threat and remained so at least until aircraft could be relied upon to take off and fight at night and in any weather (this probably happens in the late 1950's). For example, if the Soviets has chosen to build a battleship fleet during the early stages of the Cold War (they had plans to do this but didn't follow through) then it's very likely the United States and Great Britain would have built new battleship fleets to match them. It's also worth noting that even today most Navies don't build large carriers. The United States Navy, with its mission of "Global Power Projection", is a special case. For most Navies carriers are far too expensive and as they only plan to fight close to home they can rely on land based aircraft. So perhaps, if there is no there is no global super power in your story, but only regional powers, then there might be fewer carriers. In some ways battleships are still with us as ship size classifications have undergone significant inflation over time. A modern day destroyer for example is of a similar size to an early WW1 battleship and some big cruisers are as big as a WW2 battleship (although without armour they are only about half as heavy) . If you specifically want to have big ships with heavy amour and large caliber guns then it's difficult to see them still providing the main fighting power of a fleet into the 21st Century. Guns lack the range and guidance capabilities of missiles, and armour is practically useless against torpedoes and mines (when an explosion occurs underneath a ship, the weight of the vessel acts against itself to break the ship in two). However it's not inconceivable that in you world submarines, torpedoes and mines have been banned or heavily restricted by arms limitation treaties (some people actually did want to ban submarines then they first appeared as they were seen as being an "underhand" way of fighting). There have certainly been naval arms limitation treaties in the past, and even during the Cold War, there were certain types of weapons that both sides refrained from building, even though they would have been very useful - e.g. spaced based missile systems. Perhaps with this treaty in force you'd have big capital ships with enormous missile batteries that could also conceivably have armour as well as active anti missile defenses. Maybe later on in the 21st Century they would have electromagnetic rail guns. [Answer] The biggest threat to modern naval warfare is arguably new-generation anti-ship missiles. Here are several examples of pain-in-the-behind missile tech that could easily bedevil military ships for decades: * Hypersonic missiles. Ouch. Nearly impossible to intercept with anything other than a laser, and they will punch a hole in the hull and the pieces will probably go out the opposite side. Better hope they don't come in a swarm and overload the antimissile battery either. Even a laser isn't guaranteed to stop them as the warhead can simply be replaced with an extremely dense weight equivalent that will impact around Mach 2-3. * Missiles with nonstandard flight path that don't follow a ballistic parabola. This makes them extremely hard to intercept. * Hybrid missile-torpedoes. Consider a missile that drops a torpedo into the water a certain distance from its intended recipient and continues to distract possible antimissile defenses. That would be especially nasty because the ship's crew will assume they shot down the missile and something fell out of it. About half an hour later, the torpedo blows a hole in the bottom of the ship and the crew are scrambling to figure out what happened. * High-altitude dive missiles. These fly up and crash down hard on the target ship. Interception is of limited use as the pieces will rain down and cause damage at the speed they're moving. China is believed to be developing these as a counterbalance against U.S. naval superiority in the South China Sea region. An exceptionally nasty (and expensive variant) would make the dive missile a MIRV with a mix of dummy weights and warheads so the target ship has to deal with 10-12 smaller missiles of varying spec crashing down at Mach 3 right on top of it. The only way I can see modern naval combat surviving (without banning missiles) is to go underwater, or develop a new generation of armor that thwarts missile attacks. I've been seeing an increasing number of new articles where navy engineers mull new-generation submarines that carry a mix of drones and missiles. [Answer] Cruise missiles would have to evolve much faster. The first V2 would have to be deployed not in 1945 but in 1915, so that by the thirties some kind of guided or homing missile small enough to be carried in the battleships and destructive enough to sink most ships would be available. Also, if you can make cruise missiles you can make SAMs. Your battleships will become huge missile cruisers, launching barrages of anti-ship missiles against other ships. Carriers would be destroyed because in a missile-saturated environment they are just floating gas stations waiting to be blown. ]

[Question] [ The Phoenix appears in Greek mythology and are most commonly seen as beautiful golden birds that burst into flame and are reborn from the ashes. Is there a realistic way that they could evolve? Using earth or near earth biology how close could I get to the classic [Phoenix](https://en.wikipedia.org/wiki/Phoenix)? Is there a reason that a Phoenix couldn't evolve? A list of all of the Anatomically Correct questions can be found here [Anatomically Correct Series](http://meta.worldbuilding.stackexchange.com/questions/2797/anatomically-correct-series/2798#2798) [Answer] With some alterations to the Phoenix myth it could probably be done. First off, you don't have rebirth (though it could easily appear that way) you have birth. You would also need mated pairs as the mother would be unfortunately...absent... after the birthing process and infant vertebrates (birds in this case) are generally not self sufficient. To be a vertebrate and for long term species health it could not survive on asexual reproduction. This is pretty easy to fix though, just have Phoenix(es?) mate like a normal two gendered species. *As @Namfuak mentioned it should also be noted that each Phoenix would have to have more than one egg at a time, as, mathematically the whole species would die out if they only have one...* It would have to evolve to carry the egg inside as opposed to laying it, so something similar to a platypus or echidna. ([Monotremes](https://en.wikipedia.org/wiki/Monotreme)) To this point things are pretty realistic, or at least plausible. Fire makes things a whole lot harder though...mmm fire...sorry, flames are distracting. [](https://i.stack.imgur.com/OJAsg.gif) So lets see, standard sexual reproduction, sure no problem, ambient adult body temperature is high enough to allow for the development and growth of the baby phoenix, so we are good there. So two questions remain, why is it biologically necessary (or why did it evolve in the first place) and what function does it serve/how does the infant survive the process...oh and how does the whole fire thing work? Ok, that's four more questions... 1. **Why did this evolve and why is it necessary?** Well, I can't actually think of a reason something so complex would naturally evolve under selective pressures. So this is likely a situation where there actually weren't significant evolutionary pressures and it was more random evolution as opposed to selective evolution...its not a great reason but its the most realistic I can come up with...this is why earth is unfortunately (or fortunately depending on perspective) devoid of fire breathing creatures...stupid science. 2. **What function does it serve**...well in line with the random evolution theory above, what if the egg has a particularly thick shell wall, and the egg is particularly large (meaning the mother can't naturally deliver it). 3. **How does the whole fire thing work?** During pregnancy the mother's body creates sacks of chemicals that fill over time, toward the end of pregnancy the membranes containing these chemicals thin due to hormones and burst. The two (or more if you want to get complicated...more complicated anyway) chemicals mix and react, thinning the egg shell wall by chemically melting the outer layers. During this process the mother bursts into flames... 4. **How does the infant survive???** Well, the process would have to be rather rapid as long term heat exposure would cook the baby bird. The shell should also be a bad conductor of heat. So there you go. I bet it tastes like chicken. [Answer] ## [Birds evolved from dinosaurs](http://www.nhm.org/site/research-collections/dinosaur-institute/dinosaurs/birds-late-evolution-dinosaurs), but the Phoenix *evolved from dragons*. A baby phoenix has the vestigial need to eat ash, a trait it maintained from its ancient dragon ancestors. This is to due to a bizarre need for heterocyclic amines and polycyclic aromatic hydrocarbons, available in sufficient quantities only from burnt meat. The way the mother provides this sustenance for the baby phoenix? Self-immolation. The mother holds a fireproof-egg, just like a dragon egg. The mother phoenix also produces a flammable oil to keep her feathers shining and smooth, this is another trait from her dragon ancestors. While the dragons sprayed the flammable oil for defense, the phoenix uses it for grooming. When she has one or two fertilized eggs ready, oil production increases dramatically. This, again, is because a mother dragon would need more oil to protect her young. This rapid increase in the oil makes the bird itself quite flammable. A glint of intense sun off the water or a static electricity spark ignites the mother bird. Several days later her eggs hatch, the young phoenix birds consume the ash of their mother and begin the cycle anew. [Answer] Adding onto Caleb's answer and expanding and making it weird cause that's what I do: [Immortal Jellyfish](https://en.wikipedia.org/wiki/Turritopsis_dohrnii). A sea creature who, when it reaches a certain point in its life, reverts to a younger version of itself. This is not breeding, but the same genetically identical creature, turning back time to its "baby" form. So, rather than self-impregnation, I would say that the explosion and subsequent egg are the bird's way of reverting to its youngest form, in a method to extend its lifespan. This explains that the bird is the same bird, genetically identical to its old self, and not a child of the previous bird. Semi-perfect rebirth. What I'm thinking here is that the "burst into ashes" thing is just an exaggeration born of human storytelling. After all, if you saw a bird combust, and there was a lot of heat, and not much bird left, you would definitely say something like "it totally effing exploded into ashes dude!" to your friends. But rather, I would perhaps say that the actual combustion is an **implosion**, rather than an explosion. The bird appears to "die" and collapses inwards, compacting the energy it has stored into a hardened, fire-resistant egg. All that above could be posited into a bird format, under the right circumstances. **But what if we wanted to really play with evolution?** Perhaps what we should be looking at is a sea creature who **looks** like a bird. Something genetically similar to a catfish or flying fish, with fins that act as wings and rudimentary lungs. Shining and beautiful scales could look like feathers. The creature can spend some time on land, otherwise how else did humans see it. In fact, the creature we call a Phoenix spends its "childhood" near water or within very shallow tidal pools. The first life stage is that of the "egg". In reality, this is a shell surrounding a tadpole-like creature. The creature probably uses baby fins and legs to drag itself around the sand or the bottom of a tidal pool to eat tinier creatures or algae. It is heat-proof, fire-resistant, and looks fairly egg-like to a casual observer. The shell acts as protection, ensuring that predators have to work pretty hard to get to the gooey tadpole in the middle. The second life stage is that of the adult, who enters the ocean or river to gather in groups. These creatures have evolved to eat ocean-faring birds like cormorants, sea gulls, and other creatures, by leaping out of the water. They would have two large fins that act as wings and two "back legs" with which to hold onto their prey. They would also probably have a hard beak with which to attack and kill, though they could just as easily drown the birds they capture, but would still likely have a beak-like jaw to tear them apart to eat. Their shimmering yellow, gold, crimson, etc scales would be to attract mates, despite their "immortality" they would still need to replace the population who died due to predators, disease, or human intervention. Mating would involve "flying" or leaping, or even walking to a tidal pool, laying eggs, and having them fertilized. Then the eggs harden and transform into the child stage described above. So we have a sea creature with flamboyant coloring, feather-like scales, broad fins, back legs, and a beak-like jaw with sharp teeth. All of these things already exist in the ocean creatures of our earth, so they are possible, and some creatures have several of these traits combined, so we know they don't necessarily cancel each other out, we just have to put our creature through the correct pathway to get it all of these items. A casual beachgoer might see a mother Phoenix leaping out of the water and "flying" her way to a tidal pool and mistake this creature for a sea bird rather than the sea creature it rightly is. The third stage of life is the "elder" stage, in which the Phoenix prepares to "die". They will eat voraciously, collecting as much food as they can, storing the excess fat and material like a mammal might in preparation for hibernation. They will also linger closer to the shore in preparation to walk out of it and find a suitable location to be reborn. This is the stage at which they are most vulnerable to predators because they are full of food and easy to get to. The elders will come onto shore likely in a massive group to help stem the number of deaths by predators, find their way into tidal pools or other safe locations. Almost simultaneously they will combust, compressing their bodies inward. They will revert back to their first life stage, releasing a massive amount of heat in the process, probably rendering their outer scales into ashes or something that could be mistaken for ashes in the process. It's definitely not perfect, but that's how I would do a phoenix and make it evolutionarily and biologically sound, based on creatures that already exist on our earth. [Answer] @James' answer is indeed a great start, and deserves to be the accepted answer. Still, he missed out on a lot of opportunities to leverage the evolutionary aspect as an opportunity to flesh out the mechanics behind it all: # Step 1: We need a fire-chicken First up is figuring out how self-immolating birds can evolve. Crucial for evolution is that bursting into flames *helps* the entity that bursts into flames, or its offspring. To start small, in a step that could evolve gradually, it seems important that the first fiery chicken doesn't have to change its behavior too much from its non-fiery predecessors. For that reason I suggest making the fire initially non-lethal to the phoenix-predecessor. [Cephalopods can squirt ink](https://en.wikipedia.org/wiki/Ink_sac) to help escape predators, [some beetles can secrete "noxious or even caustic" liquid](https://en.wikipedia.org/wiki/Ground_beetle#Defensive_secretions) to make themselves less appetizing to predators, with e.g. [bombardier beetles getting real close to starting fires to this effect](https://en.wikipedia.org/wiki/Bombardier_beetle#Defense_mechanism). While none of these are vertebrates, it's at least **plausible that your proto-phoenix can start fires when it feels threatened** by squirting out two organic compounds which jointly catch fire. # Step 2: (Re)production of phoenixes I agree with @James that "being reborn" should be replaced with "dying and producing new offspring". I would suggest making the fire the sole means of reproduction, sticking to sexual reproduction as is normal in birds. This leaves one issue: clearly, more that one new phoenix should be (re)born per dying mother-phoenix. If statistically more females than males are produced (i.e., the "primary [sex ratio](https://en.wikipedia.org/wiki/Sex_ratio)" favors females, and stays like that up to and including the "tertiary sex ratio"), and males get to be "reused" (since they do not burst into flames), then everything can work out. Multiple eggs at a time would work, but better yet, we can have the phoenixes have a high tendency to generate twins/triplets/etc. *all coming from the same egg*. This not only solves the issue of keeping the numbers of phoenixes up; it also provides us with the **evolutionary pressure** to evolve fire-chickens: The eggs would get so large that it becomes problematic: the female doesn't always survive laying the egg. A hand-wavy, pop-science interpretation of [an otherwise decent article](http://www.nature.com/nature/journal/v399/n6733/full/399255a0.html) could suggest a similar issue appeared with neanderthal's babies' skulls being too large for the pelvisses of their mothers, complicating childbirth and being somewhat co-responsible for the end of the neanderthal branch in human evolution. Oh well, it's a stretch, but fits in the category "plausible") Over the generations, the bulk of the evolutionary pressure pushes for smaller eggs, but the branch that ends up creating phoenixes takes a turn for the worse. (Since we want to end up with the mother dying prior to the birth of the offspring, things get a bit ugly. Sorry for that.) The eggs become so large that the mother *always* dies instead of breaking free from the egg. The chicks may have to eat their way out of their mother's carcass... But when they do, there'll be enough birds to keep the population numbers up. # Step 3: Fire at birth: Roosting or roasting? So, we have a species that squirts fiery liquid when threatened, and a situation that makes childbirth an agonizing pain from massive internal bleeding, leading up to the death of the mother bird. It would stand to reason that this latter situation causes massive triggering of the defensive capabilities of the fire-chicken; to the extend of effectively accidentally **lighting *itself* on fire**. The baby-chicks, however, are protected by the hard egg-shell. Sure, that shell might cracks from the heat, but it's time to hatch anyway. # Step 4: Phoenixes To the external observer, an old phoenix just spontaneously lit on fire (for no visible reason), and from the ashes, a baby-version of the bird arose. [Answer] Very belated answer, but stumbled upon this and came up with a viable solution I liked enough to be worth suggesting. I think this can be done realistically! The short version is that when a female dies if she is carrying an egg the egg is encouraged to hatch, though she can have young with regular laying of eggs as well. I'll try to go through the evolutionary steps as I did with my gryphon example. Were start with a 'normal' bird as our basis. **When in doubt set things on fire** First we have to explain how gryphons got associated with fire to begin with. I think this could work as an evolved defensive techniques. Pheonix aren't always on fire, but they can trigger 'fire' to scare off attacking predators. Most wild animals have a *huge* ingrained fear of fire and flame. As such it would actually be a potentially good survival tactic to use flame to drive them away. I'm not necessarily suggesting using it to set something on fire, you don't need anything too drastic to scare someone away. Even if she could only create a short duration 'spark', something bright and scary but not burning dangerously hot or controlled enough to do serious harm, this could be still be a viable defense. Even if the predator isn't driven away by the sudden flame the bright flare could throw off it's vision, blinding it enough for the pheonix to escape. I imagine original flavor pheonix only carred enough to make a few sparks right when a predator was chasing her. Once she discovers the usefulness of scaring away predators she could then evolve to realy on the flame more extensively for defense, but for now let's focus on the first limited use of flames while flying, I'll get to how the practice evolved after that. Of course fire requires lots of energy to produce. The high energy expense of fire means that it would litteraly burn through calories if the phenoix was requierd to produce the flames herself, to the point she could starve to death from excessive caloric cost of constant flames. More importantly, it's nearly impossible pheonix's evolving a way to create and control any fire-producing chemical entirely on her own, there aren't any safe 'intermediate' steps where it's beneficial to have a means of producing an explosive chemical before it's been evolved to be part of pheonix defense. That's okay, there is an easy solution here. The pheonix doesn't produce the fire, she steals it. I think she could find a natrually existing substance in her habitat that is flamable, which she collects and later uses to produce her flames. There are actually two possible approaches here, so I'll mention both options below, but in both cases I'm going to call this substance 'Exo' (for exothermic reaction), just to have a covenient term for it. The important part here is that she must collect this substance, she can't produce it entirely on her own. Just like birds collect food and water the Pheonix would likely hunt for and collect Exo. If she runs out of Exo she can't defend herself well, and thus as her Exo reserves run low she will actively hunt it from her habitat. Here are the two options I see for the origin of Exo and how she first tarted using it. **1. Fire Water** First option is that Exo is a chemical, likely a liquid, which can be triggered to start an exothermic reaction. She would need something that wasn't *too* flamable, that wouldn't explode into flame when not desired and kill her. Thus she would be looking for something relatively stable, but which can be triggered to start an exothermic reaction quickly as well, likely by mixing it with a catalyst chemical to start the reaction. Best case would be that she already naturally produced a chemical that acted as a proper catalyst and 'accidentally' discovered she could exploit this to trigger the Exo. In terms of natural chemicals she might produce I would say most likely it would be her urine that happened to contain high concentrations of some chemical that servied as a catalyst for the Exo. The trigger being waste makes most sense to me, as it's the one place likely to have a high concentration of many different potential catalystic chemicals, and the safest place for chemicals that could be harmful to the body to end up (I imagine the catalyst is unlikely to be something good for the Pheonix). For that matter it makes sense that a Pheonix would discover the ability to trigger Exo as a defensive mechanism this way, as many species will expell waste when in fear, discovering that the dropped waste then set off some natural deposit of Exo on the ground to drove off her predator is a sensible 'first step' to start evolving a more intentional use of Exo for defense. the 'fire water' approach with urine trigger would be by far best case for having a realistic evoluiton, if the appropriate chemicals exist in real life. The key catch is that I'm hand waving the existance of Exo chemical in nature due to my lack of chemistry knowledge. I can't point you to a specific chemical that has this sort of exothermic property, though I suspect someone could suggest some (if someone wants to add a comment about good options I'd be happy to add them and give credit!). To help justify her being able to trigger Exo to flame perhaps the original the Pheonix didn't carry this substance around, but it was common enough to be useful for defense if she was close to a patch of it alread, with her discovering it as I mentioned above by accidentally triggering these natural Exo deposits when fleeing. This first triggered reaction may have been very small compared to later Phenoix could do, but still enough to provide a distraction and thus an evolutionary advantage. Her ability to trigger larger, and more controlled, exothermic reaction in 'present day' may have evolved from this defensive method, with there being enough natural Exo deposits that gryphons better able to exploit them for defense lived longer and made more hatchlings. Only after she reached a certain degree of 'skill' at triggering Exo did she switch to carrying it around for a more mobile defensive method. Once the pheonix was use to using Exo on the ground she started to carry a small amount of exo with her when she flew, so she could set it off in the air to drive away attackers when no natural Exo deposits were nearby. I imagine first 'draft' was exo getting on a pheonix claws while the phenoix walked around an Exo deposit, then when the phenoix was flying later the exo on her claws could be ignited later. If Exo doesn't burn too hot maybe she set off the Exo sticking to her claws and let her claws burn even though it singed her slightly just to scare off attackers. Once the first arial use of Exo started the pheonix would naturally evolve to be better at it. Storing larger amounts of exo in specialized Exo storage organs, being better able to dispel it and the Trigger for it. All kind of more sophesticated controled use of Exo to create flame, Once you get over the first hurdle of using it in the air at all Evolution will do the rest. One key detail, this substance would likely need to be something that she can't eat. It could be toxic or just not easily digested, but it's not something she can draw energy from directly, it's only useful to her as a source of fire. **2. Silent but Deadily: gassy doom** The other option is that Exo takes the form of a lighter then air (LTA) natural gas, which happens to to naturally leak into the air from vents in her habitat (likely a volcanic one in this case?). On the down side these sort of natural gases tend to be more explosive, and thus more dangerous for a pheonix to carry around. On the plus side there are many known LTA exothermic gases, so unlike with the last example we don't have to handwave a naturally occuring exothermic chemical existing. The question is why a pheonix would interact with such gases despit the risk of an explosion hurting her. I have a good potential answer though, boyancy. Perhaps a pheonix is heavier then normal birds (particulalry when pregnant, see below), and thus needs some help with the flying. A pheonix may have evolved to use LTA gases from vents to fill up some sort of air bladder to help offset her weight when flying. Even if the natural gas was slightly dangerous it could be worth it for the non-trivial caloric savings of not wasing as much energy on flight and the ability to lift larger weights when flying. So originally the Pheonix would collect gasses for boyancy only, refilling her 'bladders' with gas when she needed to increase her boyance. The original gas bladders likely weren't filled entirely with Exo, since Exo would be too dangerous a gas to evolve to use for lift at this time and because most natural gases would be a combination of gases anyways. She likely filled her bladders at natural vents containing many LTA gasses, with Exo being only one of the gases, and possibly present in small enough quantities to not be overly dangerous. As part of using gas to control he boyance the Pheonix would evolve to expell gas rapidly, to allow for rapid dives. When under attack by something diving at her expelling her bladders to help her to dive out of the way would be a naturally evolved tactic. At some point the Pheonix 'discovered' that when she expells Exo from her bladder she can set it off to create a flame in the air to scare/disorient persuers. This could be a random mutation that made her better at setting the Exo off. Perhaps the pheonix evolved stronger muscles to excelerate dumping her bladder until she was able to exert enough pressure that it triggered Exo, or perhaps we go back to the idea of urine having a catalizing reaction and the pheonix evolved to dispel urine along with bladder gas to trigger the explosion. Alternatively perhaps, by chance or evolutionary pressure, the pheonix moved towards using gas vents to refill her bladder that had higher Exo concentration causing her bladders to now have enough Exo to trigger a reaction. Whichever process happened originally the Exo would likely not have been a very spectacular reaction, a very minor spark that didn't burn very bright. However, if it did enough to even temporarily distract or confuse her attacker it would be enough. From there evolution would encourage better use of Exo. First the Pheonix would become better at triggering the exo reaction, using whichever of the above methods she used to set off the exo, or developing a new method if the first uses of Exo were unreliable due to Exo not flaming reliably enough. She would also develop better means of using Exo to get away, aiming the Exo towards her persuer before igniting it or being able to ignite it from multuple points of her body instead of just the one bladder exaust point. After that the Pheonix would become better at collecting Exo over normal natural gases. This would mean either explicitly hunting out vents with higher Exo concentration, or possibly a filtering method where she would fill her bladders with normal LTA gases, then filter out non-Exo gases and refill, slowly building up a reserve of Exo by expelling non-Exo. **Your flashy tricks won't protect you forever** The problem with using a defensive mechanism that primarily relies on scaring/surprising predators (not actually harming them) is eventually your predators get wise to your tricks. Those that you scare away don't catch a meal and risk starving, and eventually only those predators that aren't afraid of your tiny tricks will live on to spread their genetics. Your going to have to esculate your defenses accordingly. So while Exo may start as a distraction the Pheonix will likely double down on it. Developing ability to carry and use larger quantities of it, to burn it hotter or keep the burn for longer, to aim it towards attackers and/or disperse flame over a larger region. I suspect their biggest focus though would be to burn it *brighter*, which may not be hotter, since even if predators aren't afraid of the flame your still mess with their vision by tossing such a bright flame behind you (and predators will never evolve to be as good at filtering out bright flame from their vision as you because you know exactly when to expect it and they have competing evolutionary pressures limiting their ability to specialize in hunting you). The important part of this is that Pheonix will be carrying far more Exo, and fuel to ignite it, on them. **You predators think I'll be an easy meal? Well I say Bite Me!** Eventually all this flammable substance will come back to bite the pheonix as occasonally she will set herself on fire when she fails to prevent a reaction on occasions. But more importantly, it will come back to bite *predators* when a predator tearing into her body accidentally sets off the Exo in her body and has their meal explode in their face. This would originally be an 'accident', the Pheonix carries lots of explosives in her body and she doesn't care if it explodes after death so evolution hasn't done anything to prevent that. However, evolution loves the old addage "it's not a bug, it's a feature". Given time I suspect the Phoenix will actually evolve to *intentionally* explode when fatally wounded. Their reason for this is similar to the reason that many reptiles waste energy producing dangerous poisions and then paint themselves bright red and taunt predators to eat them. Predators don't want a meal that's going to hurt them, and one that blows up in your face counts as that. The pheonix will find that having their last move be to harm whoever killed them is a very effective method to discourage attackers from hurting them. To make this even more effective let's presume Pheonix as pair mating and caring for their young Now a mother (or even more so daddy) pheonix has more motivation for being able to die explosively, to hurt predators that are hunting close to their nest, and to discourage predators from attacking their mate and children in that nest. Thus we finally know why pheonix ignite into flames on death. It's done to hurt their predators and to consume all the meat of their body so that even if a predator isn't harmed he still won't get much of an edible meal from the hunt. It discourages predation, and besides which it's a natural result of the pheonix body no longer regulating the explosive chemicals contained within. Pheonix likely will be able to do this as a concious decision at any time, as part of protecting their nest/mate/young, but in addition it likely will happen naturally at death or fatal wounding. **Other species fire babysitters for doing that you know** (look, two puns in one title, I'm getting punnier!!) Once a pheonix starts carrying and using Exo they will likely find other uses for it, evolution is pretty good at reusing designs. I imagine they will likely be used longer distance communication (setting off flare-signals at night) or attracting mates with fire dances etc. Most importantly for now though they likely will be used for hatching eggs. Keeping an egg warm is important to hatching it, thus the reason birds sit on their eggs. However, Pheonix mommies carry around a portable heating source they have unique mastery of, seems kind of silly not to use it to avoid all that boring egg-sitting time. I imagine that the Pheonix would do it's best to find ways to Exo to help with tihs process. In the case of Exo gas perhaps they will regularly expell a very small quantity of exo and ignite it, since low quantity exo will only produce a little exta heat but not enough to burn the egg. For the 'fire water' exo they may paint small amounts of it on the egg before ignighting it, or create some mix of Exo and something non flamable to cover the egg before lighting it, perhaps even leaving a small Exo-mix 'burning' at a low temperature over the egg while they leave to hunt, depends allot on what the Exo chemical is. This would free the Pheonix up to do more travel and hunting, and thus potentially to care for more eggs, potentially. But for now the reason this is relevant is mostly that the egg will already be evolved to handle slightly higher heat then most bird eggs, and to gain more of a speed increase in rate of growth when near heat. **Daddy says my mom was Hot Stuff before I was born** Now we get back to the whole pheonix reborn subject, which I kind of already suggested in the intro. Imagine a pheonix mother who is already carrying an Egg at the time that she is fatally wounded. She wants that unborn egg to still survive if possible. She will want to evolve a method of encouraging the egg to finish it's growth and hatch even without her support. This sort of thing is seen in other creatures, most mammals when badly wounded will go into labor and attempt to give birth in hopes that the child will survive even if the mother dies for example. So imagine, long after immolation pheonix became common, a seperate evolutionary process lead to encouraging the pheonix eggs within the mother to still survive. Originally this would simply mean the mother evolving to protect her egg from burning up in immolation, by igniting the outside of the mother's body but keeping the egg away from the hotest parts of the flame and evolving an egg shell that is good insolation against short duration, high heat, burns. Alternatively maybe the mother simply becomes good at expelling the egg on death, by laying it or other means, so it stays away from the main flame of the mother. Later this could change to the egg actually triggering an alternative growth pattern when it sense enough heat to suggest immolation. This could be the egg switching to hatching earlier, when the bird isn't fully formed yet, to allow a chance of the hatchling finding safety, or the egg switching to a slower growth approach that doesn't require as much heat so the egg has a chance of growing to 'term' even without a mother incubating it. If pheonixes raise eggs as a pair the mother may even have an approach of burning in a way that helps the father find and cary the egg away from danger back to the nest after the mother dies. This seems the most evolutionarily sound option, but also the least similar to 'pheonix reborn' myth. **Pregnancy means discussing getting fat and that good old 'bloated' feeling** Part of the problem with these solutions is that any egg that hasn't been hatched yet is likely far enough away from hatching that none of these give any reasonable chance for the baby to survive to hatching, much less survive to adulthood and have children of it's own. However, if you go with the gas-Exo approach this becomes slightly more forgiveable. The problem with laying eggs is that their vulnerable. When you leave your nest your risk someone coming along and eating your children, their hard to protect. And since you have to incubate them you still end up spending most of your time stuck with them. Mammals realized this and decided if their going to keep taking care of the kids that long they might as well keep the kids inside the womb and let them grow there, at least thta way you can carry the kids around with you when you have to move. Birds can't do this though, because of weight constraints. Birds have to fight hard to stay in the air, they've evolved a million ways to keep their weight low so they never get too heavy to be able to fly. Being pregnant would be difficult for this reason, the added weight, and lowered aerodynamic structure, of a full term child would make it hard for the mother to keep flying...usually. However, a pheonix that exploits LTA gases to stay afloat doesn't need to worry about this as much. She can simply fill her bladders with more gas to counteract the weight of the egg. Sure she won't be able to fly as nimbly this way, but the again she doesn't need to be as nimble if she has scared off most predators with the threat of exploding in their faces. The end result is a gas-pheonix is a bird that actually can afford to carry it's children to term! This includes allowing the children to grow *larger* then a newly hatched bird is, to be closer to self sufficent at the time of hatching. Consideing this it's not unreasonable to imagine gas-pheonix carrying the egg within themselves for most of the pregnancy instead of having traditional nests. They may lay the egg only when it's intended to hatch and have the baby hatch as soon as the egg is layed (possibly with mother helping to break the egg?) This means when a mother bird dies it's possible for the egg it's carrying to be close to full term and ready to hatch into a larger-then-normal-hatchling size baby pheonix that actually stands a (small) chance of surviving on it's own without it's mother. Thus the gas-pheonix is the only one that seems reasonable to benefit from trying to protect an unlaid egg, as the only version where that egg may be large enough and developed enough to stand a chance of surviving. **A Womb with a view, and a heater** The most pheonix like option is probably the biggest handwave, but isn't necessarily impossible. That's having the mother switch to a 'slow burn' death. When the mother is carrying an egg and dying instead of the usual immulation, or possible in addition to it, she dies in a way to allow a slower burning of Exo within her corpse. The idea being that the Exo burns slowly enough that the mother's corpse becomes an incubation chamber for the egg, a way to keep the egg warm for a longer period of time so it has enough time to grow and hatch properly. This version is harder, as it requires such percision in death and Exo 'burning' that it streatches credibility that it could evolve through unguided evolution. Still, it's a very cool idea that I may forgive some handwaving. **These kids will be the death of me** As an alternative to the above there is a slightly more realistic evolutionary option, that mother changes to Exo incubation mode when badly wounded, but not yet dead! When a mother is badly wounded, or very old, or otherwise at the state where she doesn't expect to survive much longer she may decide to focus on making sure this one last egg hatches before her death, even if it means sacrificing any chance of survival after the hatching to focus all her remaining energy on the child. So she settles down somewhere to well...die. She slowly starves herself over the next week or two, not bothering to eat, while burning her remaining exo inside herself to excelerate the egg's incubation with the extra heat. If a predator sees the wounded pheonix they will be hesitant to attack it since the mother could still immolate itself to kill/wound the predator if attacked, so the phonix is left alone to slowly die while incubating it's last child. It could be that in this wounded/starved state the mother isn't able to go through a hatching once the egg is ready to hatch due to how week she is, or even that the hatchling is triggered to grow to a larger state before hatching when the mother does this to give it the best chance of surviving on it's own after hatching. In any case the mother is unable to give birth to her final hatching and so immulates herself when the egg is ready to hatch as the final step. to let the egg hatch. Perhaps in this version the hatchling hatches inside the mother and the birth of the hatchling can trigger the final immolation by messing with the mother's Exo bladders when it's hatching? Alternatively the mother doesn't actually immulate until right after the hatchling hatches (and is far enough away to not be burned), but to passing humans it *looks* like the hatchling is coming from the immulated corpse rather then the hatchling hatching and then the corpse immulating right after? To go even more morose perhaps the hatching can hatch and eat the mother from the inside if it's still alive for more energy to grow, so it's bigger and stronger before it's on it's own, whlie depending on the threat of the mother 'exploding' if a predator tries to eat the dying mother to keep it safe. The approach of having the mother still alive, and just committing to protecting it's final hatchling, works better then the mother's dying and egg surviving on it's own because it means the mother is able to buy the egg some more time to grow, increasing the chance that the egg will be in a healthy state to hatch. It's also more believeable that many itterative adaptations can push the mother towards being very good at protecting her last egg compared to the above proach of the mother somehow dying in such a way that she makes a incubating corpse for the child. Here it could start with mother's simply committing more energy to caring for a child when injured and mother slowly upping the amount of sacrifice she can make for her last chlid to increase the odds of one last hatchling being born. \*\* I don't have any Eggcelent puns for this one\*\* The one minor question that comes up is why people think all pheonix are reborn this way if only a small subset are (those who's mother's are carrying an egg at time of injury/death and who survive to hatch afterwards). Mostly I'm just going to say human nature, they see some hatchlings reborn from pheonix and so assume thta's how all pheonix are and that the times they don't see a pheonix being 'reborn' are simply because they didn't wait long enough for the rebirth (or that phenoix can only be rebirn sometimes and some deaths are final). Still, there are a few things you can do to further this belief. One is to make sure mother's are always carrying eggs, which isn't too hard. Many species tend to mate when they can find a male, even if that isn't when their ready to bear young. Kangaroos are the first species to come to mind to me (and really, many marsupiles), but their by no means the only type. They usually do this because their not certain to have males available when they are ready to carry and have young. So if you want to increase mother's trying for a final egg just say that mating and child rearing times of the year are different. Perhaps Pheonix mother's only mate during migration when males and females come together, but after conceiving the pheonix mother will fly away and only much later will she decide to trigger growth of the egg to give birth during warmer seasons when the young will be better prepaired (or maybe even during seasons when Exo is easier to find?). This implies only one young a year being born, which implies Pheonix have long lives and generally care for hatchlings for some time. If Pheonix have few predators, due to their immolation defense, this could explain their longer then usual lifespan, and gas-pheonix may act like albatross and tend to migrate over long distance, even oceans, justifying a larger size and thus shorter birth rate. Since pheonix have fewer predators it also increases the odds of a mother living to 'old age'. Thus increase the odds that a mother will reach the point where she is old enough to be unable to have many more young and chooses to go the final immulation route to ensure her final egg makes it despite her failing health. **No dad's allowed** There's also the problem that half of pheonixes are male, which means at most half of phoenixes that die could be incubating a final egg. You could have males look different and thus not usually be considered 'phonix' so that the myth only applies to the female pheonixes. Perhaps females use far more Exo, due to their need to increased lift to counteract the weight of large & heavy eggs, and as such their larger and more prone to using fire as a defense and thus are the only ones that are noticed. Alternatively if you say that females only mate during migratoin season, as mentioned above, you could always say that females prefer to frequent different habitats then males and that the areas with pheonix-reborn myths tend to be habitats that are more attractive to females (again likely those where Vox is more plentiful for gas-pheonix version at least). and...this answer was again way to long. But hopefully you like the idea :) [Answer] Easy! All you need is a bird. Now evolve the bird to store mass amounts of energy, over it's life. Now evolve it to be self-impregnating, as some creatures that really exist are. Now evolve it to consume itself in flame when it gets old, using that energy in a huge burst. leaving a heat-resistant/activated egg behind. Now you've got a baby who does the same thing all over again, out of the ashes. Note, though, that the need for this would be the first step to evolution. You need to have a good reason for old ones to die, in flames, leaving only ashes. I would think a good reason would be the smell of a corpse drawing predators to kill the baby, thus, burn the whole thing, quickly. Still the question of why kill the old one at all, perhaps to preserve resources nearby, old and new never competing, (or eating each other.) Find a reason, and it's totally possible. With a little magic. But they're a little magical anyway, no matter what. [Answer] Let's start with a duck. Well, actually, let's start with a [fire-ecology](https://en.wikipedia.org/wiki/Fire_ecology). These are real setups, where periodic fires are both frequent, and useful to the ecology. There are species of plants, that can't sprout until their [seeds have been charred by fire](https://en.wikipedia.org/wiki/Lodgepole_pine) - but after they are, the ash gives a fertile jump-start to the new growth. Some plants resist fire, some tolerate it, and some *need* it to grow and thrive. Likewise, animals have their own adaptions - some flee, some find shelter... and this particular one adapted to need the fire. So, back to the duck. Ducks have a waterproof coating of oils - the reason I picked them, it doesn't actually have to be a duck. In any case, this bird has evolved a coating of oils for whatever reason. It may be, or have been in the past, semi-aquatic. At some point, it got caught in the fire instead of fleeing it (birds usually fly away). It might have to do with nesting season, one of the major vulnerable times for birds... but maybe not, it depends. Depending on the actual oils, feather composition, layering, and a bunch of other variables (mostly down to chance at this point), the bird survives - I'm guessing the oils worked like a grass fire, and burned quickly, low and cold enough that they left a layer of char resistant enough to keep the rest of the bird from burning. This assumes the outside fire was also quick moving and burned relatively cool, like a grass fire. Also, the bird gains some advantage serious enough to be *worth* the loss of half of its feathers - maybe it avoided predators looking for the fleeing birds, it got first and best pick of food before and after, or maybe preferential access to mates, or its offspring survive better (because their parent protects them in the egg from the fire, at the cost of said feathers). So, this is the beginnings of a successful strategy. The bird sacrifices some of its feathers and oils, for the ability to last through the fire directly. It loses its semi-aquatic protection (oils are burned off), for semi-pyrotic protection. Probably, it will evolve to better fit the fire, tweaking the balance of oils and the composition of feathers so they protect better for less cost. Eventually, the fire is less problematic and more necessary - for example, protective feathers might keep growing, and periodically burning them off makes it lighter and more agile, or the oil starts to interfere and needs to be cleansed away - along the lines of rodents' teeth needing to be worn down, or [sheep's wool](http://nypost.com/2015/09/03/this-lost-overgrown-sheep-produced-30-sweaters-worth-of-wool/) overgrowing them if not periodically removed. Maybe it interferes with vision, or makes the birds less able to fly because of weight. Like the fire-ecology itself, a periodic burning is good for the birds. Backing up a bit, if nesting season was the drive to develop the fire-resistance, then a resistance to fire would also build in the eggs. Maybe the mother builds the nest of flammable materials, which will have the same feather-oil all over it, so it burns controllably - giving the right amount of char but not killing the eggs. After a while, the eggs might need to be burned to be weak enough for the chick to break out of, or might just have less of an advantage if they don't. So, we're at the point periodic burnings are actually helpful to the birds... lets make the fires a little more erratic. Maybe the fires aren't quite so reliable, they don't always happen or not at the exactly right times... and this is biology, not magic. The eggs won't stay alive forever if the fire doesn't come in time, or the birds will reach a point where they're overgrown from not having burned down the feathers is a disadvantage. Could be nature, or maybe we'll blame it on people, who might be interfering with the fire ecology for whatever reason. But, if the birds are about as smart as magpies, which can find and collect shiny things, or other [tool-using birds](http://pigeon.psy.tufts.edu/psych26/birds.htm), they might overcome this. Maybe they take a branch, and go find a fire. They can light themselves off directly from a wildfire that's farther away, or a campfire, or any outdoor fire. They can use a branch to bring a fire back to their nests - especially if the oils don't need a lot to spark off, just a little ember. They might work out simple sparks from messing with bits of flint. Probably they would go *either* bringing it back *or* using tools, but either is is the possibility for moderately smart birds. I'll go with searching out fire, because the other bit needed for the phoenix legend is *people* to tell a story which seems reasonable, if not *quite* accurate. And now - **the legend** People see the bird fluttering around nearby - and it has an impressive, shiny plumage, fluffy and gleaming with oil in the sun or firelight. (it's nearby because it's looking for their fire, yeah?). So it sneaks in when people aren't nearby, because birds are shy and the burning time is vulnerable, lights of a wing-tip feather (or whatever's extra long and will serve as a wick), and scurries the heck away, so it can be somewhere a little safer and less exposed to burn itself off. People notice the bird flying off, and follow, and see it *go up in flames*, and emerge from the ashes *alive* - smaller, and spikier from the feathers being half-burned off. Depending on how much it was overgrown, and how puffy the feathers were, it might look quite a bit younger because of those visual differences. So, getting rejuvenated instead of dying is one point for an "immortal" bird. Point two, someone sees the bird bringing fire back to its nest, for the same purpose (to simulate the fire when it didn't come naturally). They see the bird come in, and a fire erupts from the nest - probably the parent has already burned from wherever she found the fire. When they walk up to the nest, they see the eggs hatching or having just hatched. The mother might be hiding (birds are shy), might be getting food for a first meal, might just be overlooked if it's not actually, physically in the nest but just nearby - fire draws the eye, after all. The sequence of an adult flying in, the nest on flames, and seeing the egg(s) nestled in a heap of ash gets crossed with a rumor of a burning bird which gets younger - and they believe the adult burned completely away to be reborn as an egg (or multiple, in which case the legend maybe includes a 'regular burn' to become young, and a 'complete burn' to reproduce). Maybe the parent birds coming by later produces a story about adult(ish) phoenixes coming to watch over their brethren while vulnerable from burning. The parent bird doesn't *have* to die - If it does in some cases, that feeds into the legend one way, if it doesn't, it might feed into the legend a different way. It has the traits to be born from the ashes, hatching in the burned nest, or 'youthened' (from losing its overgrown plumage) - either or both of which contribute to a story of a bird "dying and being reborn". And the conflation of these facts and tales produce the immortal phoenix mythology! Tahdah! [Answer] Rather than a bird, start with a crab - Hard shells don't grow or heal too well, so when they need to grow, they climb out of their shell, leaving behind what appears to be a complete dead crab. Some reptiles also shed complete skins - usually a much thinner layer, but enough that it isn't completely implausible to ramp up and apply to a bird. Instead of discarding an old shell immediately, it may make sense to keep it around as a disposable shield. If the phoenix lives in an environment with frequent forest fires, burning the shell could absorb enough energy to allow survival. Ash is a good insulator, so the best shell is one which produces a large amount of ash - enough to make it look like the entire creature has been consumed. As well as being able to survive natural disasters, the phoenix may seek out fire when it is ready to shed. The fire resistance might require a thicker shell which can only be escaped by burning, or it could simply be that feasting on the charred corpses of the competition is a good way to get the energy for renewal. Spontaneous combustion is unlikely to evolve, but starting a fire with flint is not all that different from the sort of tool use observed in real life birds. [Answer] Niven, I think, started with the fact that some ground-nesting birds build elaborate nest structures several times their own size and lay out displays of colorful/shiny objects in front of them, evolved the behavior a bit to add a display dance which involved throwing those objects, gave them a fondness for flint, and came up with a bird that gathers kindling and strikes sparks, thus creating grassland fires which kill many animals and leave bodies for the birds to scavenge. Not exactly a phoenix, but a plausible firebird. That's 90% of a solution for 10% of the effort; now all you need is to figure out how this impacts breeding. There are trees that don't reproduce until a fire has passed through, but that requires first surviving the fire. [Answer] As to explain the evolution, as people have already commented, periodic fire is already present in nature, and often triggers seeds to grow, such as (I think) in proteas. Maybe the Phoenix have close mating pairs, the female of which sacrifices itself to start a fire, causing a reseeding of the area around, meaning many plants soon start to sprout, and the Phoenix chicks are fed by the father who catches the small mammals and other herbivores which gather to feed on the germinating plants. The reason the mother would be sacrificed would be because she would already be low in body water and fat content from growing the eggs and so be the natural choice for being set alight. I think the main difficulty to overcome is figuring out a reason why the adult Phoenix would die from the burning, as this doesn't seem adaptive and so unlikely to be passed on. This explanation would also skew the gender ratio as only the female Phoenixes would be dying this way so this would have to also be remedied by the males dying, or explained another way. What I like better is on another track to explain the evolution of the burning, maybe it acts as a warning signal to other phoenixes, or better yet, or as a dis-incentive for predators. Maybe Phoenixes, like many kinds of butterfly, make themselves unpalatable to predators and do this by burning up when killed, stopping the predator from getting a meal, so causing them to stop preying on phoenixes, adaptive for hen as a group) This unlike some other explanations, would allow both genders of Phoenix to combust. Perhaps in this case, the Phoenix mythos of being reborn arose from parent Phoenixes being killed while nesting over their chicks/eggs which they would be vulnerable while doing. This would still be fairly adaptive as the remaining partner could still raise(at least some of) the chicks, and the predator that tried to attack them would surely learn its esson and not return. This would also not skew the gender ratio like the previous idea mentioned. This ability could maybe be expanded once developed to allow Phoenixes to do things like: Attract mates visually by flying up at night, catching a bit alight, before diving down to blow out the flame by the wind/rolling on the ground or diving in water. Cook their food (assuming they were carnivorous), thus freeing up gut space for digestion and allowing them to be lighter for their size, so allowing them to be larger/fly more efficiently. The main problem would still be how the Phoenix manages to catch alight, but I think oily feathers are a good start- perhaps a mechanism like the bombardier beetle (<https://en.m.wikipedia.org/wiki/Bombardier_beetle>) Maybe modified salivary glands(which birds do have), contain chemicals which when mixed ignite, or maybe different types of feathers that in the rachis(stalk) contain different types of chemicals, so when pulled out, these mix and catch alight. This seems more on point with a Phoenix than the salivary glands as that is more getting into dragon territory, and this would also allow for Phoenixes, by pulling out a few feathers from different sides of their body (to prevent the two types of chemicals mixing on them so they themselves caught alight), to cook their food by placing them together on their prey so the liquids mixed and caught their uncooked meal alight. This of course would again need some explanation of how it arose. Possibly it started with proto-phoenixes, being quite intelligent, using natural sources of fire and eventually evolving to do it themselves? Personally, I think this aspect of their evolution could be left a mystery, Phoenixes are, after all, magical/mythic creatures. So many things have actually evolved in nature we have no idea how to explain, that I think Phoenixes like this are plausible enough. [Answer] The phoenix has fireproof epithelial tissue, and a microbiome made up entirely of archae evolved for surviving massive temperature fluctuations. The phoenix has a special organ where it ignites methane, which is a byproduct of digestion. When the phoenix is infected by a parasite or bacterial/viral infection, it bursts into flames, killing the infection. The phoenix also has an incredibly long natural lifespan, so it can survive for centuries if nothing kills it. ]

[Question] [ We've had a few questions where answers state, to a lesser or greater degree, "humans would investigate this ability to figure out how it works" in another creature with abilities not readily scientifically explainable and in-universe explained by magic - for example [here](https://worldbuilding.stackexchange.com/a/18013/29) and [here](https://worldbuilding.stackexchange.com/q/6810/29). For the purposes of *this* question, on one side we basically have humans as we know them, on a planet very much similar to Earth (not *necessarily* humans on Earth, but it could be) and at a technology level similar (but not necessarily identical in every respect) to our own present-day level; and on the other we have creatures that: * are sapient, intelligent, *biological* creatures * are predatory, though not necessarily (and most often not) of humans * are essentially wilderness-dwelling with minimal to no interaction with humans, and while the odd exceptional individual exists, for their part are generally happy to remain that way * rarely (but sometimes) encounter humans, mostly humans who voluntarily venture into said wilderness * have little (think perhaps medieval level at most) to no technology, and generally see no need for technology, though they have command of fire; some trade with humans their services for some items of non-electrical technology, while some shun all forms of contact with humans and human technology * tend to live in extended family groups, normally made up of anywhere between just a mating pair and a few mating pairs plus their offspring of varying age * are *voluntary shapeshifters*, with one animal-like1 and one human-like form, though the human-like form is distinctive enough that they cannot pass as "humans" except possibly in a tiny number of cases. How they evolved this capability is beside the point of this question (for the purposes of this question, just assume they've always been around and always had this capability). The creatures in question are intelligent and communicable enough to be able to choose representatives to speak for them as a species, perhaps in the United Nations general assembly or a similar forum, and negotiate with humans. They are also good enough hunters and fighters that for one of most of them to kill one of most of (unarmed) humans is trivial to easy, and few other species of animal pose much of a problem to one or more determined hunter(s) among them. Both of these capabilities are for the most part independent of the current form of the individual; when shapeshifting, they remain *the same individual* (personality, memories, experiences, physical size, most physical abilities, etc.) but take on a different physical form. These abilities make them great hunting or guarding companions for humans, *when they are willing* to offer their services to humans. Humans recognize these abilities in them, though few have actually encountered one of these creatures in either form; think perhaps like penguins in the wild and humans. I want these creatures to (more or less) peacefully coexist with humans, the humans generally accepting that the creatures want to be left to live their own lives, **without the humans trying to analyze them apart or restricting them to fenced-in zoos.** (The creatures could, however, use their ability to negotiate to enter some sort of worldwide truce including some land, something like one or a few country/countries of their own.) *Without straining suspension of disbelief too much,* **how can I explain that humans would be leaving such creatures more or less alone, rather than trying to capture them and try to figure out how the shapeshifting works, or trying to simply use them for their own gain?** 1. I know that technically humans are animals, even though most humans do not consider themselves to be animals. [Answer] **It's just not realistic for a human-like species to not investigate something like this.** Curiosity is, in many ways, a required trait or byproduct of intelligence. It's needed to explore, learn and push the bounds of knowledge. People study and examine everything they can lay their hands on. Another species that shows intelligence (even disregarding what we perceive as supernatural abilities) is just too tempting of a subject for people to leave alone. Of course, this would be a divided issue. There would be pro-creatures-rights groups and pro-human groups (advocating for the advancement of the human species through further understanding of these creatures). In today's society, I can imagine the popular opinion being for creature-rights, while the behind the scenes story is secret installations filled with creature test subjects. Even the laws and tabooness suggested in other answers would be violated, perhaps not publicly, but it would happen. In the end, humans are just not advanced/peaceful/mature enough as a society to respect the rights of another species. [Answer] This is similar to PipperChip's "compact" answer - I'd recommend a formalized **treaty**. The creatures agree that, in the absence of a treaty-breaking event, they will obey human laws when interacting with other humans - so no murder, eating, stealing, etc. Treaty-breaking events would be something like: 1. Breaking a human law against a creature. 2. Studying a creature. Humans who break the treaty are now under creature law, and will be hunted/killed. Governments who break the treaty will be penalized. The exact penalties will depend on your story setup, and could range from a simple boycott, to sanctions from other signature governments, to outright guerrilla warfare. Presumably the treaty would also be symmetrical, so a rogue creature would be hunted by their own and handed over for human justice (if possible). [Answer] Some simple methods to prevent inhumane study: * It's taboo. The human's culture and/or religion is such that these creatures simply ought not to be studied as we would other critters. Research which studies this ability is shunned, not used, as it is unethical/taboo. * It's too dangerous. These things can control fire, and while they do not generally eat humans, there is no telling what harm may come to you as you attempt to study them. Alternatively, the danger could come from the environment these creatures live in. (Such as a malaria-like disease, or some man-eating beast.) * There is a compact forbidding this. (Similar to a taboo, but with more "oopf".) These creatures respectfully request that humans do not treat them as animals, and humans actually do this. People who do not have forfeited their lives; the creature in question know that it's okay to fight back *violently* against people who would treat them as animals. Decent folk help any such creature who is treated as an animal. It would be akin to some international body bestowing "human rights" to these creatures. [Answer] **Keep the power mysterious.** Public demonstrations or otherwise broadcasting that these creatures can do this seemingly magical thing will only incite hunger for a scientific explanation. As [I said](https://worldbuilding.stackexchange.com/a/13366/3202) in a loosely [related question](https://worldbuilding.stackexchange.com/q/13364/3202), you're not going to get people to simple not study something that's clearly worth studying. However, if the subject has an air of mystery around it (even [quackery](http://en.wikipedia.org/wiki/Ancient_Aliens)) then it's far less likely to be examined by mainstream science. This is especially effective if the mystery is done with exaggerated drama. For example, the very best magic tricks are the ones that attempt to clearly demonstrate you're not being fooled. Those tricks done in an open area with clear line of sight make people go "ok, whaaat? *how* did they do that?". While a trick done with lots of smoke around and quick motions allow people a lot of options for saying "meh, it's just a trick, I bet they did it like [any number of plausible explanations]". The closest example in our world might be the religions of remote tribes of humans. They might have grand claims made about healing powers or divine communication, but we don't investigate them because there isn't any demonstration of these powers. [Answer] The first thing to accept is that the human race does not have a single mind. The criteria that helps someone decide not to research these alternate humans will **cause someone else to**. In other words, there will always be people that want to study them, but there are some countermeasures. ### It's inhumane As a front-line defense, make sure they have similar biology. *Very similar.* So similar that any attempt to study them would turn up results exactly the same as any human. In this light, media (and social media) would begin to take over. While this is merely a superficial solution, it will at least halt large scale, public research and overall reduce funding towards like studies. ### It's illegal Something atrocious happened [half a century ago](http://en.wikipedia.org/wiki/World_War_II) involving horrible experiments on the species. Over the following years, laws were put in place making the *suggestion* of trying to understand them highly sensitive. Once it's tied up in politics *and* made controversial, a great amount of support will be needed to change the status quo. ### It's complex Just make their various abilities too difficult too understand. Maybe the details span with information several orders of magnitude larger. Maybe some as of yet undiscovered scientific principle gets in the way of recording data. Something *physically* prevents them from grasping their nature. Or maybe passive telepathy bores all the researchers to death. [Answer] I would go with a **Symbiotic relationship** Somehow, humans need those creature for life to go on peacefully. (For example the creatures protect them from certain kind of illness or danger or create resources that are impossible to get otherwise) And the same the creatures are also gaining from doing trade with the humans (a source of food, security etc) and to unbalance that relationship could mean the destruction of one, or both of the race. Or at least horrible consequences. If the relationship has existed for a very long time (maybe even from before written history) then their relationship is sealed in their instinct... While they might study each other "respectfully" (like developing medicine to help one an other) they wouldn't go so far as disrespecting one another. [Answer] One option not considered by the other answers already is that perhaps it has already been investigated and fully understood. You either want to avoid humans catching and subjecting these creatures to experiments; or you want to avoid polluting your human culture with shapeshifting tech, right? So if the creatures were happy in the past to work with humans to investigate this, and the answer is now completely understood... and yet utterly useless to humans... (requires a circulatory system with toxic unobtainium in it; is impossible to creatures that live time in the boring "forwards" direction, etc) ...then perhaps this can sidestep the issue completely? With nothing to gain, and your creatures' ability to negotiate for sentient rights, it seems like the "softer" laws that wouldn't deter radicals if the mystery still existed might just be enough to prevent any interference at all when there's no mystery. [Answer] Whether this is possible or not, under reasonable suspension of belief, depends exactly on what we are trying to accomplish. 1. If the main goal is to prevent humans exploiting and capturing the shifters and putting them in zoos, then it's absolutely possible, and I would even say that this ultimately being taboo and/or outlawed is actually the natural end result. Right now we have--in most modern countries--some pretty strict rules about what humans are allowed to do to other humans. Whether this applies to "humans only" or "intelligent life" is hard to say, since they're mostly the same thing (as far as we've discovered so far). It is not a stretch to imagine that (after some "awkward" first encounters) humans would decide to extend protections afforded humans to another intelligent life form. The possible problem with this scenario is that there are many ways to research the shifters that are not so aggressive or objectionable. Which leads to... 2. If the main goal is to let these two species peacefully co-exist indefinitely *and also* have the humans not research what makes the shifting work, that just doesn't seem realistic under any circumstance I can imagine. Some considerations: **How do you even guarantee that the shifters don't want to be researched?** As an intelligent species, it seems unavoidable that some of them will eventually figure out that it's a pretty agreeable trade to give some scientist cut hair and old toenails for DNA sequencing in exchange for tractors, bags of rice, iPhones, or whatever they happen to think is awesome. Assuming the shifters are more populous than "a few thousand on that island over there," it's unreasonable to assume that all of their family groups will even have the same traditions. **Researching the shifters could be outlawed by treaty/convention.** Researching them in any way? You want to get every single nation on Earth to agree to a ban on this research--research would could have revolutionary benefits for humans--even the nations that have existing questionable practices towards fellow humans? I don't think so. Not even remotely possible unless "humans" have advanced into some Star Trek-esque post scarcity utopia. **Researching could be taboo** I'd be hard pressed to come up with a single thing--anything--that is taboo among all existing cultures on Earth. Things like "murder" are good candidates, but even then you have countries with capital punishment. **It's extremely dangerous** Just no. From sailing across oceans that may or may not have an end, to traveling to space, to spelunking, to *intentionally* dangerous extreme sports, humans have proven time and time again that personal danger is not enough to stop them. **The abilities are mysterious** This one has some merit to it, but it's still not universal. It does require bending the original rules (less like penguins and more like ghosts--where some humans claim to have seen it, but no one has ever gotten a photo or other proof, despite trying). But even if we go down this route, there are still people in the real world that go ghost hunting and bigfoot hunting. This also presumes some force that prevents people from getting video of this happening. Since you've read this far, I'll offer a final suggestion: 3. Perhaps research (the peaceful, voluntary kind) **is** going on, but humans simply can't figure out what it is. Maybe it is actually magic, who knows? But for whatever reason, humans are running DNA samples and blood tests and whatever else they can think of, but there's just no explanation. They were even able to pay one shifter a year's supply of ice cream bars in exchange to shift for them inside an MRI machine. They saw it happen and it still doesn't make any sense. It just *happens.* (This is basically saying "it's magic" even if it's not really magic, but that may or may not be too hand-wavey for your scenario.) After perhaps a few decades of this, persistent researchers will keep researching indefinitely, but funding will dry up to a trickle when the companies originally funding it run out of money and/or attention span. [Answer] Make the nearby people too busy to care. This works very well for real life. Why don't many people vote, get regular health check-ups, make it to school meetings, etc.? They're too busy to care. So, come up with some feasible hardships for nearby humans to be busy with. It's a difficult area to farm; it's a harsh environment; it's a middle ground between two constantly-clashing nations or clans; other nearby enemies occupy the people's attention. Set up your environment correctly, and human nature will do the rest. [Answer] The werewolves in the new World of Darkness (RPG by OnyxPath née WhiteWolf) cause an effect called Lunacy. This is where humans all rationalise what they see as large dogs (when in near-wolf forms), or feats of strength as people on drugs etc. This might strain belief too far for you, but it is a well explored concept in nWoD and as it's been integrated into the world, it doesn't strain it too hard. [Answer] ## Cthulhu The only way I can imagine that humans would not want to investigate this sort of thing (without changing humanity significantly) would be to have a significant dissuasion. Dissuasion that impacts the investigators (since human nature is selfish in general). Consider if investigators of the ability are visited by Cthulhu. They are driven insane or catatonic. The ability itself doesn't seem to cause it - sometimes family members or random nearby people are impacted too - people that had no interaction with the ability. That wouldn't stop the investigation immediately, but after a few decades it would effectively drive the majority of people to not investigate it. Every so often it would resurface as people forget the insanity or write it off as supersitition, but then Cthulhu wins again. [Answer] A historical conflict that got resolved. We've seen this play out in our own history. * US vs. England during the revolution * US vs. Russia in the Cold War * Britain colonizing India but then slowly losing control because of peaceful resistance There's a *wealth* of real world historical events you could pattern the conflict after, that gives you more or less the desired relationship between one society and another. By having a conflict like this, you show that the species is capable of matching humans. This definitively proves that humans can't simply walk in and take over; some of them already tried and failed. The fact it's a historical event easily explains why they weren't completely outmatched by technological superiority, and it establishes a believable groundwork for any kind of treaty or diplomacy. Whatever agreement was established at the end has just held on because no force has decided to challenge it. (Maybe for some reason it simply isn't in anyone's interest to do so yet.) After many years in this situation, the creatures are basically an established nation. This is completely normal in our everyday world. Maybe around a century or two ago would be perfectly reasonable. This also makes for good story telling and themes. It plays nicely into a "nature vs. technology" theme, if you make it a military conflict where they nearly won or fought to a standstill. (Are they still a match now that humans have advanced?) It gives you a great set up for classic drama between characters in both groups; there's a natural reason for enmity between them while still allowing for good relations as well. This wouldn't necessarily prevent clandestine attempts to capture and study the race, but it would be enough to prevent it on any kind of grand scale. Those clandestine attempts at research could be a driver of your story's central conflict, if you choose, or you could simply ignore them as unknown to your characters and irrelevant to your story. There would also be attempts to study it using *humane* means *with* the consent of participating creatures; the creatures can just refuse wholesale then. The bottom line, I think, is that it simply isn't believable that humans don't *want* to study the creatures or their ability. Instead, give humans a reason to think that just isn't going to work on a large scale. Come up with a reason that it makes more sense for humans to make peace with them, or at least it did at one time. [Answer] Well, one solution would be to make the alien species be extremely dangerous to dissect. Maybe their blood turns highly volatile explosive/radioactive when released from their bodies, making each and every one of them essentially a dirty bomb if dissected? That would surely dissuade further research. Being shapeshifters, and thus having quite some measure of control over their bodies, it doesn't seem too far of a stretch to say that their blood might be some unknown unstable compound. As an added bonus, this would mean that they couldn't just shoot a few to autopsy either, because there wouldn't be anything left of the body. [Answer] **Obscurity** If these shapeshifters are sharing a planet with what is essentially modern day human civilization, yet live mostly in primitive hunter-gatherer groups, then by necessity these people are rare. In real life hunter gatherers only exist in certain remote places in central Africa, in tropical forests, and isolated islands. There is very little wilderness capable of sustaining hunter-gatherers left in the world, unfortunately. If these people look essentially human but can take on the form of animals, it would be plausible that these fantastical claims would simply be dismissed by modern science - Especially if these people are a rare and reclusive kind. You'd have some people who would have visited them and witnessed their abilities, but they would be dismissed as quacks. After all, there are a lot of absurd claims made by people in modern-day real life - UFO abductions, Homeopathy, and so on. This would be even more plausible if these people were careful and secretive, and rarely displayed their powers to outsiders. If they're sapient, they could realize that drawing such attention to them would likely be the end of them, or at least their current way of life. [Answer] **Make the ability boring.** We thought we understood how bumblebees flew for years. We knew about airfoils and Bernoulli's principle so clearly all birds and flying machines adhered to such principles. Then in [2001 some researchers finally did some experiments](http://www.todayifoundout.com/index.php/2013/08/bumblebee-flight-does-not-violate-the-laws-of-physics/) and determined how Bumblebees flew. Bees do not create lift, instead they create pockets of low pressure above themselves and are sucked upwards. So they have no need for conventional lifting surfaces that planes and birds have. If these shapeshifters are as boring as bumblebees then no one meaningful will care enough to look. Those who do look will be underfunded, unqualified and unheard if they do find answers. This demands another question: How do you make shapeshifters boring? Perhaps we understand something similar. Humans might have access to some shapeshifting tech/magic that works on entirely different principles that confuses the issue. If this has different limitation and capacities then eventually it will raise questions, but that is a problem for tomorrow. Perhaps we understand them incorrectly. Perhaps a few shapeshifters allowed themselves to be studied and the the researchers found some things that made the shape shifting impractical to apply to real problems because it was misunderstood. Plenty technologies go unused for years because investors assumed it would be impractical, then when one little assumption is fixed it becomes practical and we realized we could have had it all along. Look at Telsa and their cars, we probably could have had them 10 years earlier. Any car company could have invested in batteries but it took an outsider to do away with cognitive biases to actually invest in battery tech the cars required. Perhaps understanding is too everyday. People rarely ask how a spider knows how to spin webs. In principle we know they evolved the ability and we know how they make silk (I mean we transferred those genes to goats), but how does an orb weaver know where and how to build a large circle in a safe area? Their eyes are crap and they often cannot even see the full area they build webs in. Their brains are tiny and perhaps not even worth calling a brain. Yet they still make complex structures repeatably and reliably near tons of people any of whom could start researching if it weren't so everyday and boring. This wasn't studied until the 70s and we still don't have strong answers other documenting some of the processes the spider display, we still don't know a lot, like how they are smart enough to choose locations or why [web decorations](https://en.wikipedia.org/wiki/Web_decoration) convergently evolved 9 times. Despite not undestanding so much about these things we walk right past them in our garden everyday. If the shapeshifters are boring they will go uninvestigated because no one can be bother to care. [Answer] For a long time it was taboo for humans to open up and look inside corpses in many societies, so some early anatomical scientists faced serious opposition, but eventually science won over. If human society is a bit backward and superstitious they might not want to autopsy or experiment on these creatures for cultural reasons, but if it's anything like modern society there will always be folks who'd want to do it even if it is illegal or socially unacceptable (they'll just try to do it secretly). The best approach would be to not let humans know they have shape-shifting, and if possible arrange for humans to encounter some creature corpses that seem unremarkable when opened, that way humans will satisfy basic curiosity, figure they are a fairly smart monkey or something and mostly leave them alone as per a treaty of some sort. If you want to be a bit more sneaky, they can deliberately spread crazy rumors about themselves, which would then be debunked, to make anyone who wants to investigate the creatures' supposed magic look stupid [Answer] **Nothing** We already have hordes of people right here right now, in real life, who believe in supernatural abilities, and make no attempt to critically analyse how these powers work. If they did, they'd realise it's all nonsense, instead they spend billions on quack remedies, quick fixes, rituals and other supernatural things that can and do cause bodily harm. There are entire religions and societies based around such beliefs We also have significant precedents in history. For centuries civilisations had mechanical automata to impress and perform rituals for show, but the technology was unknown to Europeans. Those in Europe labeled these 'Praeternatural', beyond nature, there are numerous accounts of journeys to foreign lands with magical automata, and priests destroying automata believing them possessed of demons. Eventually the technology spread to Europe and was improved upon **I shall demonstrate this in the comments of this answer by listing examples of nonsensical, dangerous, unsupported, supernatural abilities:** Reiki, Astrology, Horoscopes, Chi, Herbal medicine, Homeopathy, Guardian Angels, Scientology, Astral projection, Ghosts, Mediums, Healing Crystals, Ionic foot baths, Manuka Honey, Detox juices, Prayer healing, Superfoods, Seances, Remote viewing, Water divining, Surviving only on light and air, being able to see inside other peoples bodies, clairvoyance, Aura sensing, Empathic telepathy, Literal photographic memory, Weather control, amongst others [Answer] You mean how the humans who now ended on the home planet as explorers in a generation spacecraft stop asking questions ? After the curiosity of the scientists destroyed the Earth ? Finally scientists played too loose and grey goo (self-replicating nano machines eating up all resources) was created and could not be destroyed. While the grey goo marched on and on, there was only very little time to build a spacecraft. After the people experienced the destruction of their home and many, many deaths, they were *extremely traumatized* and not quite open for a rational discourse. After the scientists completed the task, the people rounded the scientists up, draw a lot, the winners were bound and were forced to witness what the rest population did with the others (Hint: It was disturbing). The scientists were reminded what will happen to them if they ever,*ever* try to start this shit with discovery, exploration and "If we don't do it, another one will" again. So the humans are very grateful to have a home again and the scientists are outcasts, extremely fearful to cross the line. [Answer] I don't think that there is anything you could to to an intelligent, human-like lifeform to stop them from investigating. Others have already described several ways of preventing it in general, but if you look at some of the things some individuals have done (think nazi doctors, if you want extremes), it should be fairly clear that there is no conceivable way to make sure not a single human(oid) would ever try it. Even the dangers some described would not prevent it. Getting visited by chthulu? Come on, i don't believe these myths, i will investigate any way. They are fighting back? And hard? Well, get me more guards, and by the way i need more funding, and then we're good to go. It's inhumane? Oh come on, but the knowledge we'd gain! These creatures are wilfully shapeshifting. That means they must gain some advantage from that. There is no way that not a single person, ever, will try to gain the same advantage. [Answer] Similar to [Tom J Nowell's answer](https://worldbuilding.stackexchange.com/a/18077/29), I don't think you'd have to do much at all to discourage everyday people from wanting to dissect these creatures. You could look at Terry Pratchett's Discworld series where (admittedly mostly played for comedic effect) the average citizen just does not care about anything that doesn't affect their day to day lives. By and large, the people wouldn't really care. There are Octopus species we've found that can already change shape and colour to look almost identical to anything they might want to hide themselves against, and apart from a small (relative to global population) group of curious people nobody really cares how they do it. If these Octopuses were also intelligent enough to speak to us, dangerous enough to kill us without much hassle, hard to find unless you were willing to go really far out to find them and had told us not to bother them or we'd be killed... we would probably still think they were magic. [Answer] No one will investigate these abilities because the Nazis (or equivalent) did investigate it. With extreme cruelty, brutality, and quackery. No one can even argue that it could conceivably be done right without being immediately and permanently associated with nazis. So, where eugenics is today. Important: I am *not* in any way arguing that eugenics could conceivably be done right. [Answer] **The scientific community will actually be protecting them not the other way around.** If they are sapient and intelligent that alone will go a long way, provided they have a dialog with humans. Scientists do not act as they are portrayed in movies. Modern science has some really strict ethics about how to treat sapient creatures, and consent laws will almost certainly apply here. Now scientists are going to WANT to investigate and will probably never stop trying to negotiate research deals with said creatures, but modern scientific ethics will keep it strictly voluntary and on the creatures terms. More importantly the scientists will want to go to them in their natural conditions not capture them, they will be just as interested in their culture as their biology. Just look at modern anthropology minimal interference and maximum consent is tantamount. As an example you can look at the [sentinel island](https://en.wikipedia.org/wiki/North_Sentinel_Island) peoples who have zero contact with the outside world because they don't want any. The consent of the patients involved is essential. Now this is only going to go so far, if one of them dies on the streets of a city the scientific community will be all over it like flies on a carcass. And if they are trading with humans then there will be scientists constantly asking to study them and their culture, with varying levels of bribery to achieve it. Part of it is dependent on where they live and how easy it is to get to, if it is very easy to get to you will have poaching. If they are near a dictatorship or country with little respect for individual rights they will be captured. This goes double if they enter such a country. But if they are only reachable through countries that respect individual rights (the majority of countries) they should be fairly well protected. There will be incidents but they will be rare. Your biggest issue will be military investigation, the military had better be sure they cannot pass for human, or they will consider them a threat, and will investigate. You should also make first contact very recent, because the ethics of the past was very, VERY different. You may also want to consider how to keep one of the creatures from volunteering for research given that they will likely be offered millions of dollars for some scans, tissue samples, and demonstrations. [Answer] I think in your case, you'd have a unique situation in human existence. Two Sapient species that co-evolved with each other. You've been given some good reasons so far like its a cultural taboo. Another would be tied to human cultural beliefs of this not-Earth. Vivisection was a very strong taboo until something like 400 years ago in the western world and didn't really relax until 100 years ago. I think eastern cultures abjured that study until the 20th century. I would imagine that naturalists study the Others in the wild, as may do the Others study humans. If they studied Others dead would be determined by the Other's funeral practices. If the Others leave their dead where they lie, then postmortems wouldn't be a problem. But, if the Others demonstrated care for their dead -- burial, cremation, sky-burial -- then there would arguments to leave them alone. So why would humans leave them alone? They fear them. If in the past, humans, and Others had mixed it up, and humans only still existed because the Others told them, we don't want to hurt you all, but .... you are not giving us a choice! Or, and possibly and, there were more than 2 sapient species in this planets tree of life. Maybe the Others and the HUmans teamed up to knock them out. So shared history and sense of a common enemy. The others protect us from the worse sort of thing. ANd, lastly, rational self-interest. Don't pick a fight with shape-shifting assassins. Maybe some or all of these occurred in the past, and the Humans established a protective force to let the Others live free of predation by humans. And, the Others a just chill with that. They can take care of themselves. And, if the force of soldiery surrounds their places keeps them free of humans and even other predators that eat the Others kids, that's great by them. Lastly, the reason that its the right thing to do has never stopped our species from not doing horrible things. If you focus your approach on self-interest, whatever you come up with will be believable. [Answer] I think everything considered in our modern society you could easily make the dissection of the new species just as unliekely than dissection of other humans. There are moral limits to human research and studies against one will are forbidden. But that doesn't prevent some individuals, intelligence agencies, covert military operations and so on from doing it anyway. So I say with enough public opinion the species can possibly gain all human rights and will be left alone, just like a foreign unexplored tribe of humans. But this will not protect them more than humans - so they will ony be mostly save, not a 100% - there will be some researchers who would dissect a living human for their research and they also wqill dissect a living alien. [Answer] **Not happening.** Think of colonisation of other countries by various cultures all round the world, and the almost universal mistreatment of the original inhabitant. That the original inhabitants were other human beings (just with different skin colours and religions) didn't matter, and still doesn't. The only thing which ever stopped colonisation was superior force. If you're talking "humans as we know them", well, humans as we know them are killer apes who will happily place personal gain over morality, and whilst we are able to sympathise/empathise with individuals, we are fundamentally unable to do that for larger populations. It's possible that after a long period of mistreatment, people living alongside them may have had sufficient contact that empathy did set in, and the wrongness of that mistreatment became evident enough that something was done about it. If they were the majority in the area, perhaps they got self-determination - think South Africa. If they were the minority in the area after mass immigration of colonists, perhaps they at least got somewhere they could live their way - think Native Americans in the US, or Aboriginal tribes in Australia. None of that would stop humans wanting to figure out how they do what they do, especially if it's a purely biological function and not one requiring magic. (If we're talking humans with a modern mindset and a world where magic does not otherwise play a part, that is.) It may not be something that matters to most people though, same way that you probably aren't researching how salamanders regrow limbs so that human amputees could also regrow limbs. But you can absolutely rock-solid guarantee that there will be human research into this. [Answer] There isn't any sensible way to do this without imposing an outside restraint somewhere. Even in Star Trek, which has some of the harshest self imposed restraints, they still study the people on the planets protected by the Prime Directive. If you've got something like this which is so strange and potentially useful, been held by what amounts to a bunch of primitives (technology wise), then without some sort of guardians, human nature would ensure they are at least studied. [Answer] I think Jim Butcher is about right when he says in the *Dresden Files* that while humans like to poke at the supernatural we don't actually *want* to have to believe in it. The suggestion is that proof we weren't living alone would scare most people so badly that they're unwilling and in fact psychologically unable to accept that things really do go bump in the night. Of course there are always people who think they want to believe and they're the ones who tend to go looking for this sort of thing, but if real encounters are rare enough no-one will take them seriously. Between denial and lack of evidence unless one of these guys shows up to a research lab and *asks* to be poked and prodded I wouldn't expect them to be taken any more seriously than Bigfoot. [Answer] What if they were just over the top adorable? Powerful hunters, but with the appearance of something like meerkats, lemurs, red pandas when in animal form. Give them a stunning humanoid appearance as well. Let the general public be just ga-ga over them. Simply too cute to vivisect. Sure, there will still be a few individual or organizations that can overlook cuteness, but can they overlook the public outrage of harming anything that adorable? [Answer] **Racism** works really well at preventing economic-class solidarity in the USA, and it would work for this. This would make your whole world an extended allegory, but here goes: regular people who understand these powers become less governable. Therefore, the ruling class devises a whole long story about how the other (race) is dirty, wicked, greedy, sex-obsessed, stupid, and cursed, deserving of underclass status-- untouchable. Stigmatise interactions with them. Demean every difference. Segregate them. Build it into the religious practices. If you don't like the Old South angle, use anti-semitism, or the caste system in India. It would be hard to prevent, really, since these others are literally a different species. The knowledge is not just contained, it's dangerous to have. After a few pogroms and tragic betrayals, the Others will become hostile and secretive, making study all the more difficult. The ruling class doesn't need the knowledge, only to hold power-- they spurn it. When you want everyone to do something, make it what everyone does. Roland Barthes, postcolonialist critical theory. [Answer] My answer would be: They *believe* they understand it. Come up with an explanation that is not valid science, but that the humans believe is valid science. No further investigation needed, and anyone claiming it is supernatural is ridiculed. ]

[Question] [ As it's that time of year I thought I'd do a Christmas themed question that is a big problem for the old man up north; Why don't the elves rise up and kill Santa? First let us consider the horrible conditions elves are forced to work in; * They work every day of every year. * Depression would come easy as they do the exact same thing for their entire life. * They receive little or no thanks or reprieve for their hard work. * They are basically treated as slaves by, Santa. * They is no way to climb the corporate ladder. * They have no apparent choice of whether or not they make toys. * Even though they do all the work, Santa takes all the credit. Now I don't know about you but if I had to work in these conditions I would revolt very quickly and considering that everything in "Santa's" workshop is run by the Elves, he wouldn't last very long. Assuming that Santa is a glory hog that doesn't want to share, why don't the elves revolt? [Answer] Santa's Elves are a distinct species, separate from other species of elves, characterised by their submissiveness, lack of imagination, endless patience, love of stable, predictable environments, and delight in performing repetitive, menial tasks. So, far from feeling oppressed by Santa, Santa's Elves thank Santa daily for providing them with the environment that they enjoy most - one of servitude, stability and order, where the need to think for themselves and improvise is minimised. For such beings, thanks is unnecessary - *they* thank Santa for employing *them*, and for providing a stable, unchanging environment. Promotion to a position of greater responsibility - and by logical extension, to a position of less predictability - is seen by the Santa's Elves as a precursor to the end-of-life exile of Santa's Elves who are no longer productive on the barren surface of the arctic icecap where their lives will undoubtedly be brought to a close by hungry polar bears. Fortunately, though, Santa's Elves are a long-lived species, and only a few elves each year become too weak or senile to be useful. Indeed, that a Santa's Elf could become unproductive is a matter of great shame for it and its fellows, and Santa himself doesn't have to intervene, as the Santa's Elves themselves will help their senile, failing relatives up to the surface to die all by themselves, frequently thanked by the exiled Santa's Elf for their assistance in expiating the shame associated with uselessness. Santa's Elves do not care for glory; their joy is in repetitive labour, predictable environments and usefulness. They care little that Santa gains the credit for their work so long as their work keeps coming. They do not even care what they do, as long as they are useful and that the work is predictable. The greatest horror for a Santa's Elf - aside from uselessness - would be to be forced to improvise, to work with unpredictable tools and materials and to be required to interact with the end-user of the product they make. This is in distinct contrast to their relatives, the Scandinavian Svart-alfr and Dverge. The former are similar to the Santa's Elves, and while also gregarious and also enjoy subterranean environments, are more chaotic, independent and flighty. The latter are also subterranean, but are more solitary, and while they take a delight in labour, they insist on generous payment and only work on projects that interest them, which are typically different from any previous project. [Answer] Unbeknownst to most, Santa is not a single person, but a rotating position. Santa is an elf himself after all. Every year, a new Santa is chosen from among the many elves working at the North Pole. We think it's the same man every time because they actually all look pretty similar. (How else do you think he can be at every mall in the world at the same time?) Their breeding structure is similar to that of bees or ants - Mrs. Claus is the "queen elf", producing thousands of new elves every year. Most elves are "drones", who do the majority of the toy manufacturing. The "worker" elves are the ones you see in the malls, and each year one "lucky" worker gets chosen as the breeding elf - this is the one we know as the true "Santa". In addition to delivering toys to all the children in the world, and fattening himself up on cookies and milk, he also earns the right to be Mrs. Claus's breeding stud, providing the genetic material to produce the next years crop of elf larvae. After his breeding duties have been fulfilled, the queen elf decapitates him and his considerable remains form the food source for the young hatchling elves. [Answer] # Santa's not always around The elves work every day... that Santa sees. Between loading up his sleigh, tending to the reindeer, watching kids, making lists (and checking them twice), and doing normal things (eating, sleeping, etc.), Santa can't keep eyes on the elves 24/7. They can use this time to get some extra sleep, relax, and have fun. As far as Santa's concerned, they're making toys. Plus: # Mrs. Claus is actually a nice woman You said **Santa** treats them as slaves. You never said anything about Mrs. Claus. She sees that the elves are mistreated by Santa and helps them out, whether it's in the form of giving a few leftovers to hungry elves or talking Santa into giving the elves a couple of holidays off. [Answer] why do you think Santa is producing at the North Pole? The elves can't escape as they wouldn't be able to stand the polar cold once they leave Santa's workshop. Also, there's not much food growing at the North Pole, so the only food they get is the food they get from Santa. So their only choice is to either work or die. [Answer] > > They work every day of every year. > > > Elves in *Dungeons & Dragons* (5th edition) don't need as much rest as Men according to the [description of the Trance trait](https://rpg.stackexchange.com/questions/40734/is-4-hours-long-enough-for-a-long-rest-for-elves-and-warforged). > > they do the exact same thing for their entire life. > > > Not always. * In the film *Elf*, it is made clear that Santa's helpers are trained in assembling the new toys each year. I specifically remember references to "chipsets" in an electronic toy. * Santa's Workshop occasionally needs elves to take care of the other elves. This can be administrative, as shown in parts of *The Santa Clause* series, or even medical care. The short film *Rudolph the Red-Nosed Reindeer* tells the story of Hermey, an elf who studied dental surgery, opened a dental clinic at the Pole, and eventually was [awarded what amounts to an honorary DDS](http://www.washingtonexaminer.com/rudolphs-pal-hermey-the-elf-gets-his-dentists-degree-after-50-years/article/2556397). This sort of echoes the dentist in the TV miniseries *The 10th Kingdom* who was called the "tooth fairy". * Lately, some elves have joined the Scout Elf program, [exposed by Aebersold and Bell in 2005](https://en.wikipedia.org/wiki/The_Elf_on_the_Shelf), in which elves are sent to watch homes for criminal activity to help Santa refine his naughty list. (Though the U.S. NSA [hasn't quite started](http://www.snopes.com/media/notnews/elfonshelf.asp) to outsource its spying to Santa's Workshop, the program [does soften kids up to surveillance](http://eagnews.org/prof-elf-on-the-shelf-conditions-kids-to-accept-surveillance-state/).) > > no way to climb the corporate ladder. > > > How do you think Bernard, Santa's second-in-command in *The Santa Clause*, got into his position? He took the job away from the [former foreman](http://christmas-specials.wikia.com/wiki/Elf_Foreman) who looked like Mitch Miller and sounded like Carl Banas. In fact, Curtis took Bernard's job in *The Santa Clause 3* when Bernard defected to America to work as a mathematician for the FBI. I'm guessing the *Numb3rs* gig was his Hermey moment. > > They have no apparent choice of whether or not they make toys. > > > For a time, this was true; Hermey was put under intense peer pressure to make toys instead of becoming a dentist. But Hermey eventually succeeded in getting the foreman to let him open a dental practice, and this likely led to wider acceptance of [Innovation Time Off](https://en.wikipedia.org/wiki/Google#Innovation_Time_Off) at Santa's Workshop. > > Santa takes all the credit. > > > This has changed as more films depict elves' work. [Answer] Santa uses cult mechanics to keep them in place. After all, they live isolated from the rest of the world, serving their leader, in a Manichean view of the world (nice or naughty). The equivalent of their god is Christmas. Everything waking hour revolves around serving the next one, and every minute they are reminded of the unlucky children of the world. With the recent overpopulation, the elves cannot longer provide toys for every child; so if they slack off, even more children will be sad and toyless; and it will fall on their consciences. Constant guilt. They are offered a routine that offers security (work, work, and work). This calms the bad feelings about the poor children. Also, doesn't let them too much time to think. They are also forced to wear uniforms to strip them of their personal identities. They are assured shelter from the cold and wild beasts and naughty children that lurk around the North Pole, as Santa very kindly reminds them every chance. Also, Santa being all-knowing, will get his own elves in the naughty list if they even think of misbehaving. Their punishment is more outdoors duty: they have to collect twice as much firewood and other materials. Furthermore the diet, based on sugar cane and gingerbread, is very deficient in proteins, that affects the thought process. [Answer] Hmm, lots of unwarranted assumptions here. •They work every day of every year. No, they get a long vacation right after Christmas every year. •Depression would come easy as they do the exact same thing for their entire life. What are you talking about?! Toys change radically over time. When I was a boy, the elves were mostly making toy cars and trucks and GI Joe's. Now they make video games. •They receive little or no thanks or reprieve for their hard work. No, they are honored and respected all over the world. Hundreds of millions of people know who Santa's elves are and what they do. How many people know anything about the people who work on coal slurry pipelines or at the derivative section of a stock brokerage? •They are basically treated as slaves by their owner, Santa. The definition of a slave is that you're not allowed to quit. Elves are perfectly free to quit Santa's workshop and get other jobs. Some get jobs making cookies in a hollow tree, or bringing good luck to orphans. •They is no way to climb the corporate ladder. The elf workforce is based on co-operation and self-actualization. They pioneered the concept of quality circles long before the Japanese stole it. So there is very little hierarchy. •They have no apparent choice of whether or not they make toys. Of course they do. Santa also has to deliver gifts to adults, like neckties for men and vacuum cleaners for women. Many elves work in the adult gifts division. •Even though they do all the work, Santa takes all the credit. Santa is an elf himself -- "He was chubby and plump, a right jolly old ELF, and I laughed when I saw him in spite of myself" -- so this is a non-sequiter. [Answer] "Elves" are really the souls of deceased dyslexic devil worshippers. As they are already dead the don't need to stop to eat or sleep. They really should have been more careful when signing their soul away with virgin blood. Although they are contractually compelled to do the infernal bidding of Santa for all eternity, they also serve since it is promised that one especially loyal elf will be allowed to come back to life as Zuthulu: [The Perry Bible Fellowship](http://pbfcomics.com/154/). [Answer] Everyone knows that Santa has a mean streak, when things do not go his way. Elves live in terror with Santa at the helm of toy production. The real Santa Claus had been known to publicly loose his cool in splendid fashion. Some even call him St. Nicholas. In any case he has a bad temper. > > One tradition has him actually attending the Council of Nicea in A.D. 325, when Arian doctrine was rejected. The story goes that he got into a heated debate with Arius himself about whether there was a time when the Word did not exist. Nicholas strongly disagreed. > > > **The debate ended suddenly when Nicholas punched out Arius** then and there on the floor of the council! This gives new meaning to the ditty: "He's making a list and checking it twice, he's going to find out who's naughty or nice!" > > > The mental image of Santa Claus punching out Arius on the floor of the Council of Nicea with Emperor Constantine looking on has to fundamentally change the way one would ever see Santa Claus again. While I might not agree with his methods, I certainly admire his passion for Christological orthodoxy and doctrinal purity! - [Persecuted, Jailed, Passionate - That's my kind of Santa Claus](http://www.stnicholascenter.org/pages/my-kind-of-santa/) > > > [Answer] Santa uses blackmail to keep his elves in line. If the elves want to rebel, Santa will threaten to feed them all to the Lindwyrm king. My second answer is that Santa is the alpha of all the elves. By the way, alpha gorillas, lions, and orangoutangs look different from the other lions, gorillas, and orangutans. So it would make sense for Santa to be the alpha elf. ]

[Question] [ When the USSR [broke up](https://en.wikipedia.org/wiki/Dissolution_of_the_Soviet_Union) into fifteen [independent states](https://en.wikipedia.org/wiki/Post-Soviet_states), it's well known that Russia inherited the nuclear arsenal of the dissolving state. I don't know exactly how this was decided: if it was just "obvious" given Russian dominance in the Soviet Union, or "right of might" since Russia was by far the largest and most powerful of the post-Soviet states, or based on some pre-decided rules or contracts/treaties between the then-SSRs. My question is about a hypothetical parallel scenario with the other global superpower of the Cold War. **If the USA breaks up into multiple independent states, which of the emerging states gets the nuclear arsenal?** Clarifications: * The breakup could be in any number of different ways: all fifty states go independent individually; "blue" versus "red" versus "swing" states; east coast versus west coast versus landlocked states; [this](https://grisha.org/images/sasha_five.png) or [this](https://i.pinimg.com/originals/90/55/c5/9055c5e8e6088226c5532d0b0b29b678.jpg) or [this](https://upload.wikimedia.org/wikipedia/commons/thumb/f/f1/Census_Regions_and_Division_of_the_United_States.svg/390px-Census_Regions_and_Division_of_the_United_States.svg.png); etc. I'm looking for a general answer to cover any breakup scenario, if possible. * Ideally I'd also be interested in answers valid for any time period, from the Cold War era up to the present. If that makes the question too broad or not feasibly answerable, then let's restrict the time to **now**, during the Joe Biden presidency. * Let's assume a **peaceful** breakup: maybe some riots and such, but no outright war between states. Broadly similar scenario to the breakup of the USSR, to the extent that that's possible with two very different nations. * Ideally, answers would be based on existing provisions for this scenario in US law. If none such exist, then informed speculation is OK - I've heard that Worldbuilding SE folks are very good at that. Not pure blind speculation, of course: a good answer must be based on some kind of evidence or argumentation. I've checked the [help centre](https://worldbuilding.stackexchange.com/help/on-topic) and [this meta post](https://worldbuilding.meta.stackexchange.com/q/6161/2235), and, as far as I can tell, this question seems to be on-topic. Please let me know if not, or if any further clarifications or scope narrowings are required. [Answer] The major difference is that the USA **cannot** break up without a civil war. The second major difference is that in the USA there is no clear obvious successor state, as Russia was in the USSR. The [Constitution of the USSR](https://en.wikisource.org/wiki/Constitution_of_the_Soviet_Union_(1977,_Unamended)) allowed any of the Soviet Socialist Republics to leave the Union if it wanted to: > > ***Article 72.** Each Union Republic shall retain the right freely to secede from the USSR.* > > > (That's because the Soviet Union considered itself to be a "voluntary association of equal Soviet Socialist Republics".) This allowed the dissolution of the Union to be a peaceful process, where diplomatic negotiations were possible; in the end, the Russian Federation got all the nukes, mainly in exchange for taking over the international debt of the former Union. The relations between most¹ of the former SSRs remained good enough for them to form the [Commonwealth of Independent States](https://en.wikipedia.org/wiki/Commonwealth_of_Independent_States); and Belarus and Russia are very closely associated in the [Union State of Russia and Belarus](https://en.wikipedia.org/wiki/Union_State). ¹) The former SSRs which are not members of CIS are the three Baltic republics (Estonia, Latvia and Lithuania), which went on to join NATO and the European Union; Ukraine, which hoped to hold on to the territorial gains acquired as a SSR (spoiler: Russia took them back); Georgia; and Turkmenistan. By contrast, the States of the United States are wholly owned provinces of the American Empire, with no right to secede. (This was very firmly established on the battlefield, and what was once sealed in blood cannot be undone.) Any imaginable breakup of the USA will be a messy affair, where diplomatic negotiations between the breakaway pieces will be complicated, as lacking any legal foundation. Moreover, any kind of reasonable breakup of the USA will certainly see various breakaway pieces contend for power; it's not like the USSR, where everybody knew that it was just a nice name for the Russian Empire, and where everybody fully expected Russia to remain the largest and most powerful piece. California and Texas will certainly form the cores of different rival successor states, for example. Overall, in practice this means that: * For sure the Atlantic and Pacific Fleets will end up in different successor states; and while the Pacific Fleet may remain a cohesive whole, it is quite likely that the Atlantic Fleet will get divided between New England (or whatever name the north-eastern piece will adopt for itself) and the Unrepentant Confederates (or whatever name the south-eastern piece will take). * The Air Force is likely to end up divided into several pieces, with complicated allegiances. * The land Army will most likely be divided between the successor states. * And honestly I have no workable idea of what will happen with the land-based ICBMs. Their lairs are located in relatively poor and underpopulated states, such as Wyoming, North Dakota and Montana; it is not clear at all who will get to control them. [Answer] ## The country who claims the land will claim the nuke on it Let's not forget that, even though Russia claimed ownership of the Soviet nuclear arsenal, most of the countries that emerged from the breakup of the Soviet Union agreed on giving up on a large part of their nuclear arsenal mostly because it's quite an economical strain on the system, it wasn't just out of respect, politeness and fear. As far as impending US breakup is concerned, I reckon all of that 'MURICA attitude would be dialed up to eleven the moment the breakup is initiated. Unless a prominent new country emerges which can force the rest into submission on its own, it seems pretty obvious that the moment the US splits the nukes would end up being claimed by the countries who physically have them within their possession and there's not a doubt in my mind that some of them would pull the nuclear trigger at the first chance they get. The US hadn't had a civil war for quite a while, aggression has been steadily building up to an all-time high so it goes without saying that when the disintegration begins and another civil war breaks out, it's going to be a bloodbath unlike anything ever witnessed before. It also seems obvious that the codes, wherever they are, would be retained on the spot and most likely won't be shared, so countries who inherited less strategic military complexes than others would be at quite a disadvantage. Some of the countries that don't have the codes for their own nukes would be most likely aggravated far enough to try tampering with them rather than negotiating with their new-found adversaries (or enemies), so I reckon there's an accident or two waiting to happen in that aspect as well. Nuclear subs? Aircraft Carriers? Oh wow those will be quite a headache to deal with. Those anchored in ports would be undoubtedly claimed by the country who claims the ports, while the ones located at open sea would have a clear-cut choice to make: either return to your main port to be reclaimed by the country claiming the port or sail to whichever other country that has a port and be declared a traitor (which could be quite easily taken as an excuse to declare war). All in all, if the US falls apart it's most likely going to follow the same scenario as Austria-Hungary just far more gruesome, basically when the lines are drawn everything physically held within the lines will be automatically claimed by the newly formed countries of those territories. [Answer] Possession is nine-tenths of the law, I don't realistically seeing any "new" country giving up it's nukes to another country regardless of what US law states (keep in mind that they created a new country, meaning they are no longer bound by US law unless they decide they want to create a law in the new country saying "we will follow the laws of the previous USA) so whatever country has the arsenal located in the day the "breakup" happens will likely be a nuclear country, depending on how you split up the US map this may or may not mean there are multiple nuclear countries as a result. [Answer] Likely there are four possible solutions to what might happen in this situation. 1. The nuclear weapons are shared between multiple countries. (Maybe not evenly though.) This could occur in a couple of ways: a.) There is a treaty that is signed between all of the countries to specify where the nukes would end up and what the policy of using them would be. This would likely end up as the nukes split up between multiple countries, as a balance of power. Or, b.) Based on the current geography of the nuclear weapons and the people who know how they work and are used/operated, they are just split based on how the land is split. This might be the simplest scenario, and is similar to what happened in the USSR's case, where the Russian homeland contained most of the nuclear weapons (and the people who knew their codes) so they were able to have the majority of the nuclear weapons at the end of the split. 2. The nukes end up with either a.) the country which reigns supreme in amount of land or people or b.) the country with the strongest existing government and infrastructure. This would end up being a situation akin to Russia and the USSR, as the dominant force in both land and people, they ended up with most of the nuclear weapons. However, they did not have all of the weapons and had to sign an agreement to obtain the rest... which they broke (relatively) soon afterwards. 2a. Just the ability to threaten war based on having superior land, people, resources, and technology can often be enough to persuade other countries to allow a country like that to obtain and keep the nukes. 2b. A country that is prepared for the breakup of the United States and already has infrastructure, government, and allies in place can use this political clout and reason to help persuade the other countries to hand over the nuclear weapons. This is especially helpful if the other countries all have decent relations (even if they're not exactly allies) with this country. 3. Nobody gets the nukes. (At least none of the Non-United States do.) A giant country like the United States does not just break up overnight into two or possibly more different new countries. There would be conflicts going on for years that would lead up to the breakup. This would allow other countries and organizations, such as the United Nations to be able to step in and mediate the situation. This could be done in a number of ways, including the old government of the United States handing over the access codes for the Nukes (even if they cannot get rid of the physical nukes) to keep the new countries safe for the near future. 4. Very unlikely... but Washington. Wherever the president and other people in power who can access the nuclear weapons and codes to detonate them will be put in a position of even greater power in a time of conflict and the country breaking up. Depending on the types of people who have this power, whatever country contains Washington (and the people with the power there) might be able to take control of the situation because of the knowledge they have about the nukes and how they work. How does this relate to the breakup of the USSR? The USSR was a giant landmass, spread across two continents and bordering more than ten other countries. Russia, which had the most land and power (as well as being the most central nation with a stable government) in the former USSR ended up with the codes for the nukes, as well as the majority of them. Without knowing exactly how the USA would be split up, it is impossible to know who or what geographical areas would retain/obtain the nukes, but the above scenarios are the most likely ones that I can think of considering the question. [Answer] **Russia** and **China**. If the US fell apart foreign states would use the opportunity to attack and stake their own claim to nukes and other resources. [Answer] Who gets the nukes? ## Whoever wants them Nukes are expensive, difficult to maintain and dangerous, both in attracting military attention and in potential contamination. Plenty of states are currently capable of producing nukes for themselves and choose not to. There is a good reason that Russia ended up with all of the USSR's nukes, and not the republics they were deployed in - the republics actively worked to make sure that Russia took responsibility for them. Who might want them? Nukes are only useful if you have aspirations to be a world power. So the only parts of the US that want nukes are those large enough for that to be realistic. Of individual states only California is anywhere near the size. A grouping like the Eastern Seaboard might be big enough, but it's going to be dependent on a whole load of things, including what the resulting units are. It's much more likely that rather than squabbling over who gets the nukes, states will be worried about how to deal with nukes on their territory that they don't want. [Answer] **No US nukes anymore.** As US gets weaker and weaker on the road to break up (it is not possible overnight), maybe even after a nuke-related incident, other more powerful "world powers" (EU, China, etc...) together persuade the not-so United States to de-militarize. At least in regard to nukes. For everyone's good. The general US population half-hearthedly supports the idea (not that anyone asks them at that point). The bomb cores get recast into MOX fuel rods that are used up in the flourishing and fuel-hungry nuclear power industry. edit: It is not necessary for the country to break up. It is enough to sink its economy (and whatever form of "law and/or order" it has, as a consequence). --- USSR/Russia almost did it in early '90s - all the way to western countries paying for the safe disposal off of the part of the Russian deprecated nukes and some of these money really used for guarding the non-deprecated ones. Russia later recovered, but the next one in the same situation may have less luck. --- Nukes are a high ball. They require a small army just to keep the control of them in the hands of the government. They need even more to guard the industry that makes them and things related to them. They need able, clever and loyal (it sums to expensive) people to create, maintain and operate them. They need an economy to back all these things. The list goes on and on. [Answer] *(below scenario is without foreign intervention)* **Lack of maintenance will result in a bunch of nuclear waste** The Federal government weakens drastically, because a large number of states leaves the Union. The Federal state itself will soon not exist anymore. There are guards and nuclear experts, but there will be no central organization to pay them, the knowledge about the nukes gets lost, or fragmented. Nuclear arms stationed on land *and* on submarines are owned by the Federal state. All local guards and experts are employee of the Federal state, they would need to be employed - voluntarily or involuntarily - by e.g. the state of Texas, when some of the nukes are on Texas territory. But Texas cannot force contracts upon other experts, who reside outside the state. They won't be able to complete the team. Nukes will become useless soon after that point. Nukes are complicated technical equipment that needs to be maintained, they would become unsafe, or simply won't respond. On the mid-term, all nuclear warheads will need revision and replacement. Instead states will probably seal off the locations. [Answer] The answer doesn't come down to what the new states themselves are, but how how things fall out with the other world superpowers. Russia and China don't attack, they ally with some of the US fragments. Politics shift as rapidly as the US changes. A regional "state" getting some nuclear weapons doesn't do much if other "states" have international superpowers behind them aiming from afar... not so much mutually assured destruction as assured destruction of any US fragment that independently becomes aggressive. The world superpowers don't just ignore the US fractions... they're too significant in terms of not only the nuclear weapons, but the other technology and resources. Europe, Russia, China, Japan, the Koreas, etc go through a lot of shifting and adjusting in their position with the evolving US body and each other. If the international community sees the significant US fragments as too unstable, they likely unite more among themselves, and the US pieces then have to tread carefully to fight amongst themselves in a way that doesn't attract international involvement... perhaps the states even give up their nuclear weapons under the weight of the world against them. Or maybe the states that hold some decent might in terms of economies, resources, and perhaps nuclear power are shrewd enough to enter the global political complex themselves, and international alliances start to form. It could be a dangerous environment having internationally supported enemies neighboring... as the Cuban Missile Crisis and even world wars showed. Would cooler heads prevail? It depends how the world's other current powers and the stronger US factions act, but the Europes and Chinas and Russias of the world may be all that could prevent human catastrophe if the US factions were as ugly as some of our political fighting has gotten, and you threw in actual acts of aggression to spur each other on. But which US fragments would hold the nukes? As others mention, if the country is dissolving, it's unlikely that there'd be much focus on current laws and such. Strategically, I think Washington DC would have a tough time... they may have the codes, but unless they activated them quickly, they'd face the challenges of holding the weapons themselves in remote, likely enemy territory. Cut any physical lines and jam radio frequencies, and suddenly those codes don't do much. Could the new countries get full control of the weapons themselves? Seems reasonable some could in time, as nuclear scientists and engineers and such are by no means uniquely concentrated in the DC area. The area around Colorado would seem to [have the nuclear armament](https://www.visualcapitalist.com/cost-and-composition-of-americas-nuclear-weapons-arsenal/), economy, and higher knowledge institutions to stand strong (especially when you throw in Cheyenne Mountain), though they'd likely need sea access to be too viable longrun ecnomically (if the region included Texas it'd seem quite strong)? Georgia and Washington state could also reasonably end up in states with enough of everything to do well. Places like Montana and the the Dakotas might end up a little more challenged given the landlocked state and limited economies. Perhaps those areas or others even join like Canada. And economic hubs of the northeast and California are more removed and so may wind up without any weapon support or in alliance with some of the military strengths. If it were based upon recent US political divisions, it'd seem most of the weapons would end up with the right-leaning power(s)... unless Washington DC acted very quickly to use\take them out? But I would think the weapons go to the locations they are at initially, and they only hold them long-run if the new nation(s) garner enough of the resources and international support to remain on the world stage and suggest enough stability to prevent other nations from uniting against them. It definitely could be a complicated evolution, as most international revolutions in the past century have... as even limited places like Korea and Vietnam have led to complex evolving politics, and any US breakup would be more complicated and naunced than anything we've seen since the heart of the Cold War. [Answer] The basic assumption of a peaceful breakup seems very difficult, but not impossible. Sharing the nukes could even be possible simply because the evolution in the world politics and in the military technologies made them less useful, they'll probably want to use them as fuel for the nuclear power plants. With the above assumption sharing them could be done in the very american way of doing everythings, **money talks**. Each nuke will be assigned a value, each state or superstate breaking up will be assigned a fund calculated on the amount of money contributed to the federal taxes in the past 100 years, and all federal properties will be acquired making symbolic payments from that fund. What I see a lot more difficult would be how to share the network of military satellites (actually also civilian ones have a military value) in space. That could be a lot more valuable, but dependent on few control stations. [Answer] One important note about the US nuclear stock pile is that the operational capability of nuclear weapons is centralized. Even though Naval Sub Base Bangor and Kings bay each have fairly large stockpiles of nukes, without input from DC, those warheads are effectively useless without significant reengineering to allow for outside input. like other answers mention, a US breakup would be very messy. Who ever would be in the Pentagon or White House would not willingly launch codes and computer systems to active them to Bangor or kings Bay or where ever these mobile platforms decide to pull into to hand their favorite new nation their arsenal. [Answer] I see several options: * No-one gets the nukes, if the US splits up into small enough blocs none of them will have the population to support the technology needed to maintain the arsenal; they sit rusting and forgotten like many of the Soviet Union's old biowarfare stockpiles in ex-soviet states. * The vultures get the nukes, again if the US breaks up small its successor states will have trouble defending their pieces of the old arsenal and it gets bought up or stolen by outsiders. * There are no nukes left to get, the US breaks up in a spectacularly NOT peaceable way; the arsenal either gets used or destroyed in the process. * There is no-one to inherit, the US goes down with a whimper not a roar; a massive percentage of the world population is killed by the accidental release of weaponised smallpox, or similar, and there are no cohesive successor states big enough to claim ownership. * There are no nukes and there is no-one to inherit them anyway, the US breaks up in a spectacularly NOT peaceable way, *and* pulls the rest of the world down with it. * The nukes are given to a third party, the US breaks up in a peaceful fashion but its successors realise they're too small to hold on to and/or maintain the arsenal. The nukes are transferred to a semi-independent, apolitical, body specifically created to inherit the arsenal and use it on behalf of the successor states as a whole if ever that becomes necessary. * The nukes get split, the US breaks into two or three large successor states that manage to agree some equally unsatisfactory division of the arsenal that they all think they can live with. * The Icelanders, the Swiss, and/or possibly the Japanese, get the nukes, the US successor states realise they can't hold onto the arsenal and trying to do so is an invitation to worldwide MAD so they hand them off to a state known for its lack of recent attempts at worldwide domination. (The Japanese only possibly make the list because they have imposed a policy of non-interference on themselves) * The nukes are deliberately destroyed/put beyond reach in a hostile environment that will destroy them to take them off the playing board. Note: In any case where there is a division, hand-off, removal or similar of the arsenal I fully expect that there will be some serious cheating. [Answer] I'm suprised no one has mentioned this: # The Federal Government When the Southern States seceded, the United States did not declare war on them. Although there is nothing saying that states could secede, there wasn't anything saying they couldn't either. The war started when [South Carolina attacked a United States military fort](https://en.wikipedia.org/wiki/Battle_of_Fort_Sumter). Although states seceded, the United States government kept control of its property in its former states. The Federal Government actually owns quite a bit of land ([see this video](https://www.youtube.com/watch?v=LruaD7XhQ50)) and I don't imagine them giving this up just because e.g. Alaska decided to secede. The United States government is one of the largest and most powerful organizations in the world and I doubt that even all states seceding from the union would make the federal government cease to exist. In other words, if all 50 states + DC seceded, I would think that there would be 52 countries: all 50 states, DC, and The United States of America (which would no longer be a collection of united States). If this was the case, the Federal Government would still have control of a large amount of land, the world's largest military, and a lot of nukes. If a state wanted the nuclear weapons in their borders, they'd have to fight the United States (which would probably turn out worse for the state than it did for the Confederacy in the Civil War since (1) the US's military is much larger now and (2) a single state would have much less resources than the confederacy). It's possible that the Federal Government would dissolve over time due to lack of funding, but that'd probably be a slow bureaucratic process where the allocation of nukes would be decided on a case-by-case basis. It's also possible that states do attack and take the nukes (especially if the US military gets divided over the secession), but you said a peaceful secession, so that's off the table. [Answer] ### DC As others have pointed out, there is no laws by Congress dictating a peaceful separation from Federalism. However, the civil war provided a good example of how this happens in the absence of such law : military installations were staffed at the time of the nation’s dissolution by federal soldiers who swore an oath to obey the orders of a Federal chain of command, ultimately headquartered in the joint chiefs in D.C. and the President in D.C. At the time of dissolution of the states, these Federal institutions continued to see themselves as Federal institutions- a claim that they pressed when local and state governments approached them to stand down and turn over those facilities. Adding to this precedent is an additional wrinkle that many U.S. nuclear sites are secret. Only D.C. knows where the are. For those two reasons, I would propose absent some debt-for-arms swap, that by default the U.S. nuclear cache will go wherever the District of Columbia goes in a split. [Answer] It could go South Africa where the ruling powers decide that letting the nukes deteriorate or be used in war is not a risk worth taking and decide that dismantling them would be safer. NOTE: that this would only occur if the ruling powers had some lead time for the breakup as the revolution had not yet happened yet. [Answer] I suppose it wil be transported and utilized in china or russia like it was with post ussr states in exchange for friendship and guarantees of non-aggression and maybe guarantees of not to place military bases near borders of this post usa states [Answer] **The West, and Georgia** This is the current map of nuclear stockpiles in the United States: [](https://i.stack.imgur.com/2yvqt.jpg) The other posters explain the extreme problems of a break-up of the United States. But, presuming this is successful, Washington, New Mexico, and Georgia would **each** have nuclear stockpiles greater than any other country in the world except Russia or China. [Answer] Neither half of the country will voluntarily give up its nuclear deterrent. Ukraine and Libya both did, in exchange for peace agreement, and then a bigger country broke it and invaded them. ]

[Question] [ Assume there's a spaceship in earth orbit that its crew of 24 want to get to Mars, the crew are all humans and possess all of modern day knowledge and equipment, **is it possible for said ship to make the (one way journey) without any electricity while the crew get there alive?** Think something like space Amish: no purposeful using of electricity regardless of how it's generated; if static (or any other type) electricity is created it's fine so long as it's not being actively used to operate the spaceship or anything in it... so no batteries but combustion & chemical reactions are fine. (Yes I am aware that Amish use some electricity; it's an analogy, not literal Amish.) Necessary assumptions list: * The ship has been designed from the ground up without any electricity * How it got to earth orbit doesn't matter, it's already there * No magic * Modern day tech * No electricity can be used, this journey is sponsored by a super-rich man in order to win a bet (the rich do some crazy shit) * Price and efficiency are not an issue, it just needs to get there with the crew still alive * It doesn't need to land, Mars orbit is enough I tried thinking of it by each component of the spaceship and this is what I got so far: * Rocket engine – shouldn't be much of an issue as it can be controlled with mechanical valves to control fuel flow with a chemical/mechanical ignition * Direction control – small puffs of compressed air to point the ship to the right direction should still be possible * Lighting – ideas? * Air life support – biological plants or algae air recycling? one of the biggest things I'm not sure of how well it will work * Waste disposal – mechanically powered vacuum pumps airlock and throw it all away * Food – it might be a months long journey but it's still short enough to allow non-perishables canned good and other dry kept food to be the only source of food needed so no cooling needed * Water – Some recycling and\or purifying should be possible with muscle power alone, will likely still need to carry more water from the start to compensate but seeing how price is not an issue the extra fuel costs are acceptable [Answer] Yes! And I shall do it by totally violating the low-tech spirit of your question! The biggest part of the challenge is your desire to go to Mars. Mars is a helluva long way away. If you were going to the moon from Earth, then I'm pretty certain you'd be fine. But a trip that far, with this kind of challenge? Doesn't appeal! Here's the key thing: no electricity doesn't mean no mod cons! Let me take you back to the old days of scifi, back when calculations were done by hand because there were no computers, and no solar panels. Classic Heinlein. Atomic rockets! What you want is a *[bimodal nuclear rocket](http://www.projectrho.com/public_html/rocket/realdesigns.php#id--Borowski_Inspired_Designs--Bimodal_NTR)*. Nuclear reactors don't actually need electricity to operate. Sure, they make things easier, but actually you can wheel the control rods in and out with hand-driven mechanisms. Nuclear rockets are *decades* old technology; almost as old as nuclear reactors themselves, which predated electronic control systems. A nuclear rocket will give you excellent thrust (needed to move all the stupid rubbish you need instead of using electrical and electronic equipment) and good specific impulse (so you won't need too much fuel, and won't need to take a really long, boring, slow and probably fatal journey). Really, you just twizzle the control rods a bit, and twizzle the fuel flow valve a bit, and *woosh*. You'll need a good chronometer, a good space sextant, and probably a slide rule or two. Careful monitoring of core temperature (doesn't need electronics!) and timing of carefully pre-calibrated engine burns will get you where you need to go. Heinlein would be so proud of you. A simple nuclear rocket will not, however, be running all the way to Mars. You'll be doing two burns... injection into your transfer orbit, and injection into Martian orbit. Maybe a mid-course correction because you're flying by the seat of your pants and didn't finesse your initial injection burn well enough. The rest of the time your rocket will sit idle, so you may as well bring a nuclear rocket that can be reconfigured to operate as a plain old thermal nuclear reactor when it isn't generating thrust and make use of all that uranium. Given a supply of hot coolant from your reactor, suddenly you have access to chemical processes that require decent amounts of heat. One such process is [carbon dioxide scrubbing](https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20050210002.pdf), whereby you can regenerate your CO2 absorbing medium by heating it up whilst exposing it to vacuum, causing all the absorbed waste to outgas. No muscle power needed! You can generate hot, high-pressure steam for use in a [reaction control system](https://en.wikipedia.org/wiki/Reaction_control_system). Hell, if you really wanted to go all gonzo steampunk, you can use a steam-driven motor to rotate an artificial gravity centrifuge. You've got a ready supply of heat for cooking and sterilising stuff or distilling and reclaiming water from your biological waste products. Lighting has an easy solution: the sun! Your ship will be in full, bright sunlight for almost its entire trip. You can set up some big Mylar reflective panels outside, focussing light through windows in the hull. That's gonna be more than bright enough for all your needs... in fact, you'll need to bring some shutters or curtains with you because you'll want some dark places to sleep well. For emergencies, and for any occasions at departure or arrival when you'll be shaded from the sun by a planet, consider [beta lights](https://en.wikipedia.org/wiki/Tritium_radioluminescence). They'll last more than long enough for your flight, and can be made in a range of colours and sizes, and fit the nuclear theme. (You could doubly cheat by using a big reflector as a heliograph and a telescope to keep an eye on earth for flashing laser return signals. Communicate via Morse, get ground control to do your computation for you. Not essential, but, y'know, I feel like I have to point out extra opportunities to break the spirit of the rules!) [Answer] **Yes** You can replace everything with either a chemical reaction or muscle power. * Ventilation: muscles * CO2 scrubbers: muscles + chemistry * Oxy: more tanks. * Heat: chemistry * Lights: [chemistry](https://en.wikipedia.org/wiki/Glow_stick) * Computers: Babbage machines + sextants (although this one's a lot harder to swallow, you probably could do it)   **Why on Earth would you want to?** > > **Jack Ryan** : Could you launch an ICBM horizontally? > > > **Skip Tyler** : Sure. Why would you want to? > > > (*The Hunt for Red October*) > > > You have all the modern-day tech but want a ship that's the equivalent of an interplanetary [Kon Tiki](https://en.wikipedia.org/wiki/Kon-Tiki_expedition)? Why? Why, why, why, why, why? It would be easier to justify a hand-crank power generation system than this. Even [Benjamin Sisko had solar power](https://en.wikipedia.org/wiki/Explorers_(Star_Trek:_Deep_Space_Nine)). I suppose you could write a "teenagers save the world again!" story about some kids who figure out how to get into orbit and make it to Mars without the help of electricity (or educated/experienced adults), but why? In reality, I don't think it's possible to *build* the ship without electricity. I don't think you can manufacture even the hull plating to the specifications required for safe space flight without electricity. Or the space suits. Or the oxygen tanks. Or anything else. But, technically that's not what you asked. Nevertheless, I think the *weight* required to replace all the electricity-requiring stuff would be *astronomical.* You need to carry the chemicals that are used for lighting, heat, ignition, etc. Those chemicals are consumed. That means weight — and a lot of it — at the beginning of the mission. And you had to get all that weight out of Earth's gravity well. And it would need to be a very *slow* voyage because without decent computers you're having to figure everything out by hand. Even a (very heavy!) Babbage machine can only do so much, so fast (hand cranking!). That means slow, gentle course corrections. Heaven help you when it comes time actually get down to Mars. But, I suppose you could pull a [Felix Baumgartner](https://www.youtube.com/watch?v=eAQ8L6YwaTg) and drop everything via parachute from low orbit (very low orbit... as in "don't get hit by the flaming space ship on your way down" low orbit). And considering what it takes to do the limited space stuff we do today (with electricity), I would hope your passengers are both the luckiest people in history ***and*** good Church-going people. Why on earth would you do this? Oh, yeah... some idiot with more money than common sense wants to win a bet. Implausible. I'd bet the bet was for [a whole dollar](https://www.youtube.com/watch?v=wjkdynBFHuQ). **EDIT:** BTW, I think the real problem is whether or not your space suit has enough oxygen for the walk between where you landed on Mars and where your equipment landed. [Answer] --- **It is possible** and it doesn't even need special or new engineering. --- I will not take into account: * how you get your vehicle into orbit around earth * what the purpose/motivation of this mission is * the funding * if electricity was used to manufacture the vehicle --- **Rocket engine:** You can use the basic principle of any rocket engine being currently used. You would only need to change the electric solenoid valves for mechanical/hydraulic ones. The hydraulics of your space ship can be powered by chemical reaction (your rocket fuel) or pure mechanical. --- **Direction Control:** Maneuvering is an easy one. Thrust vectoring, powered by your hydraulics, will be your coarse steering mechanism with cold gas thrusters (compressed gas) for fine adjustments. This is how most space ships/rockets do it today. --- **Lighting** Your main source will likely be sun light, with simple reflectors to light up certain areas. If the sun has got a day off and decides to not emit light you can use chemical reactions/algae/phosphorescence. --- **Air life support** Carbon scrubbers need heat which you can produce with chemical reactions or use waste heat from other components from your ship, e. g. your rocket engine. --- **Waste disposal** Just toss it out there are no rules about littering outside of earths orbit. --- **Food:** You can have non perishable food but you can also just use a refrigerator. There are quite cheap gas powered fridges for camping you can buy on amazon, why not but one of those on your space ship? --- **Water:** Filtering water can be done by distilling and filters which both only need heat or pressure. Pressure can be created by brute mechanical force. --- **Navigation** A lot of look up charts for most possible situations/maneuvers and a mechanical calculator/computer for manual calculations. --- **Communication** But why even bother to do math? Your Amish astronauts are way to cool for that. You can use focused light beams and Morse code (or a more mission specialized language) to communicate with someone (on earth/in earth orbit) who provides you with information. And keep in mind that your crazy rich person probably wants to stay in contact with the space ship to know how everything is going. --- **General informations:** * Your space ship will be a heavy and big one because you need to carry a lot of additional fuel to replace electricity. * Mechanical power can be easily created with a steam engine (powered by rocket fuel) or a sterling engine which can use heat to output mechanical power. * Mechanical systems are more prone to wear so maybe have a some spares? * most electric systems/components have a direct mechanical alternative/precursor, but they are in most cases bigger and less efficient. * You can even automate all of your system with a precise clock and mechanical triggers such as strings/wires * If you just want to get into *any* orbit around Mars, you don't even need to be that precise about your maneuvers. * Your space ship will be assembled out of multiple modules (because of size and weight) if you want to use any of the currently available (and planned) launchers. (Getting things into orbit is harder then getting to another orbit) [Answer] > > Rocket Engine > > Direction control > > > Both of these are chemical processes. While we use electronics to control them, there is no reason you couldn't use mechanical things like valves. The result might make Rube Goldberg blush, but it is not impossible. > > Lighting > > > There's a big fusion plant at the center of the Solar System that is constantly producing light. If you want light, you can use windows and mirrors (to concentrate the light where you need it). Also, fossil fuel lamps work. > > Air life support > > > Same way you manage it now, only without electrical controls. This might lean more towards using plants, as the windows will keep them producing oxygen twenty-four hours a day. But you could use chemicals instead. > > Waste disposal > > > Compost it or incinerate it. Maybe incinerate then compost it. > > Food > > > Plants in a greenhouse. Maybe some animals. Freeze dry or can stuff. Note that if the stuff starts cold and then gets exposed to space, it will stay cold. Pull it in as needed. Albert Einstein was a coinventor of a heat powered [refrigerator](https://en.wikipedia.org/wiki/Einstein_refrigerator). Not much point in our world, but it was designed for a no electricity world. > > Water > > > Look at [seawater greenhouses](https://en.wikipedia.org/wiki/Seawater_greenhouse). These use sunlight to evaporate water and then condense clean water from the vapor. This process uses no electricity and can be used with sewage water instead of seawater. All this may waste space more than we would choose, but there's plenty of space. Given enough money and fuel, any amount of mass can be moved. If you have a problem with heat, you can radiate it away. Conduction and convection won't work but [radiation](http://coolcosmos.ipac.caltech.edu/cosmic_classroom/light_lessons/thermal/transfer.html) will. This will happen naturally. If that's not fast enough, you could take along ice (outside the ship) and bring it into the ship for cooling. Dump hot vapor to get rid of heat immediately. If you are too cold, burn fossil fuels. You're in space. More trouble with getting carbon dioxide than getting rid of it. [Answer] ## Yes, but only if no rendezvous is needed *Rendezvous* is bringing two spacecraft close together in orbit, position, and velocity. *Docking* is the actual physical contact between two spacecraft. Unless the spacecraft already were together (e.g. Apollo TDE manuever), you need to rendezvous before you can dock. How close do you need to get to rendezvous? [Wikipedia](https://en.wikipedia.org/wiki/Space_rendezvous#Rendezvous_phases) claims that the last phase before docking is 100-10 m. The first man to perform a successful rendezvous, Wally Schirra, stated: > > Somebody said ... when you come to within three miles (5 km), you've rendezvoused. If anybody thinks they've pulled a rendezvous off at three miles (5 km), have fun! This is when we started doing our work. I don't think rendezvous is over until you are stopped – completely stopped – with no relative motion between the two vehicles, at a range of approximately **120 feet (37 m). That's rendezvous!** From there on, it's stationkeeping. That's when you can go back and play the game of driving a car or driving an airplane or pushing a skateboard – it's about that simple. > > > Although there are plenty of examples of manual *docking*, **no *rendezvous* has ever been successful without an advanced electronic computer**. The calculations required for rendezvous are so complicated that [Buzz Aldrin](https://en.wikipedia.org/wiki/Buzz_Aldrin) earned his doctoral degree from MIT in 1963 on the subject. Not even the on-board computers of Apollo had the processing power to perform these calculations; they were instead done by IBM mainframes back in Houston, and the parameters then radioed to the spacecraft. *Without electricity, there will be no mainframe computers, no radar, and no communication with the spacecraft.* No "clockwork computer" (or hand calculations) is going to be able to perform these calculations. Supporting evidence that no rendezvous has been successful without a computer: * The Soviets attempted rendezvous twice with Vostok and failed. Vostok 3 and 4 were in 1962, and Vostok 5 and 6 were in 1963. Vostok lacked maneuvering thrusters to adjust its orbit to match that of its twin. The initial separation distances were in the range of 5 to 6.5 kilometers (3.1 to 4.0 mi), and slowly diverged to thousands of kilometers (over a thousand miles) over the course of the missions. * US astronaut Jim McDivitt tried to maneuver his Gemini 4 craft to meet its spent Titan II launch vehicle's upper stage on June 3, 1965. Although he was able to make visual contact with the target, the rendezvous failed. He was in orbit behind the target, and assumed that thrusting toward the target would bring them together. Orbital mechanics doesn't work that way, and thrusting toward the target merely made them farther apart. * The first successful rendezvous occurred on December 15, 1965 when Schirra maneuvered the [Gemini 6](https://en.wikipedia.org/wiki/Gemini_6A) spacecraft within 1 foot (30 cm) of its sister craft Gemini 7. > > Schirra put Gemini 6A's computer in charge of the rendezvous. > > > * The first rendezvous with docking was Gemini 8. "At 55 nautical miles (102 km) they gave the computer automatic control." * The first unmanned docking was the Soviet Cosmos 186/188 and was automated. * Soyuz 2/3 had the Igla automated rendezvous system. It attempted manual docking and failed. * Soyuz 4/5 also had the Igla automated rendezvous system. It was successful and two cosmonauts exchanged vehicles. * During the early years of Apollo development, Von Braun and other officials pushed the "direct" approach with a single spacecraft making the whole trip, arguing that there was no way that a lander ascending from the lunar surface could ever rendezvous with a spacecraft in lunar orbit. Quoting an [interview](http://pammack.people.clemson.edu/GILRUTH.HTM) with [Robert Gilruth](https://en.wikipedia.org/wiki/Robert_R._Gilruth), the first director of the MSC in Houston: > > DeVorkin: In direct descent you needed an enormous booster. In earth orbit rendezvous, you needed two Saturn launchers to meet in orbit. In lunar orbit rendezvous, you needed only one Saturn launcher, but you had to have, correct me if I'm wrong, extremely finely tuned **abilities to do celestial navigation**, because the lunar orbit rendezvous was being done at the greatest distance, **was the critical path**. The most difficult thing to conquer. > > > Gilruth: But that had onboard navigation. > > > DeVorkin: Had it been developed yet? To what degree were the computers ready and available? > > > Gilruth: Well, that's true, we were the people that made IBM. There's no question about it. We put the computer age ahead ten years with Apollo, because we really did use IBM and built them up in order to do this program. > > > ... > > > DeVorkin: Let's go back and talk about your comment about IBM, and how NASA made IBM what it is today. > > > Gilruth: I think I would say that they had a lot of talent. They would have become successful no matter what, but we did help them by giving them such a challenging project as Apollo was, which required the utmost in computer development. I'm not a computer expert, although I had some very good people in that work. **Without those computers, we never could have solved all those equations in such short time, that we could direct these things into proper orbits.** > > > * The Apollo transposition/docking/extraction (TDE) manuever started with the spacecraft already matched in position and velocity. The maximum separation was only 150 feet, so it's not a rendezvous. However, it was done manually. * Apollo trans-lunar injection and trans-Earth injection aren't a rendezvous (no second craft). In addition, their parameters were calculated by computers at mission control, *including Apollo 13's manual burn*. * The movie *Apollo 13* shows some hand calculations. This was a rotation of the two spacecraft coordinate systems, so the the gimbal angles could be transferred from one spacecraft to another. The X-axes point in opposite directions, and the Y/Z axes are rotated because they couldn't perfectly align the roll angles of the two spacecraft when docking. *These calculations had nothing to do with with calculating trajectory, thrust, or any other maneuver of the spacecraft.* The fact that you saw a bunch of guys doing calculations with slide rules does not imply that every spacecraft calculation can be done that way. * Soyuz and the Space Shuttle used computers to rendezvous with other spacecraft. Other answers have made arguments about the other systems of the spacecraft being feasible. However, no clockwork computer or manual calculations will enable you to rendezvous two spacecraft. **Therefore, you must design your spacecraft accordingly.** [Answer] I don't have a complete answer, but there's one major thing most other answer have missed: **For comms / computing, I was thinking photonics, aka <https://en.wikipedia.org/wiki/Optical_computing>**, if we can power lasers without electricity. Perhaps radioactive decay could pump atoms into an excited state, ready for stimulated emission. Or bright light from a thermal source. Other unsolved problems: transducers for input and output: * let photonic logic control the engines and other physical things directly * get sensor input Microphones should be relatively easy; sound an modulate the angle or position of a mirror which changes where the light reflect, or changes which wavelength resonates in an optical cavity. Receiving digital comms by laser should should be ok. But camera imaging is less obvious. Definitely the hardest part is physical outputs, without actual electricity to create electric or magnetic forces. Light does not have much momentum. We might need humans to push buttons when they see lights. Aiming a comm laser might be possible with some kind of phased-array technique where aiming is based on phase of light, not physical motion of optical components. --- Light is an electromagnetic wave (and/or a separate particle), but if you count this as "electricity" I think you'd have to count the electric fields in chemical processes, too. Electromagnetic force is one of the 4 fundamental forces of nature (vs. gravity and strong + weak nuclear forces), so it's not like you can avoid anything to do with it, if you want matter not to pass through other matter. [Answer] Lets really go retro and propose a steam powers space craft. A nuclear power plant generates steam and the steam is used either directly for things like cooking, indirectly by rotating turbines to circulate air, or through heat transfer. As for lighting, your are in space and sun is always visible. Make sure your space craft has windows. [Answer] # No Why? Because you need computers to control the ship, because you need *precision, real-time measurements* of the ship's position and orientation in space, and because you need high-precision timing to fire your rockets. When you are in low-earth orbit, you are going pretty fast, approximately once around the earth in 90 minutes. In other words, you are moving across the earth's surface at 4° per minute, or 4 arcminutes per second. From this orbit, you need to get into a transfer orbit that takes you towards mars. This is done by accelerating at the right moment in your orbit, making it so elliptical that it becomes a parabola, or even a hyperbola. To get to mars, you need a hyperbola within earth's reference system that happens to turn into a ellipse around the sun when you leave earth's gravitational field. The farthest point from the sun of this ellipse needs to be on the orbit of mars, and you need to arrive at that farthest point exactly when mars does. That's right, you fire your engine, get your direction, and then you float for more than 500 million km through space for over half a year, and hope that you arrive just at the right time and place. **The direction with which you leave earth depends on *when* you fire your engines within your orbit**. Fire one second too late or too early, and your course will be off by 4 arcminutes. That is, you'll arrive about 4 arcminutes on mars' orbit before or after mars is at your point of rendezvous. The orbit of mars has a radius of 230 million kilometers, so 4 arcminutes are $230\cdot10^9m \cdot 2\pi \cdot\frac{4}{360\cdot60} \approx 268\cdot10^6m$, i.e. you've missed mars approximately by about a light second. Likewise, the ship's orientation when its engines are fired needs to be right to a few arc seconds at most, the more precise, the better. Of course, you can measure your orientation with manual means, but while your astronauts will be working on calculating the correct time and duration of the firing, they will move inside their ship, and will introduce a significant error into its orientation. --- The apollo missions had two flight computers on board (<https://en.wikipedia.org/wiki/Apollo_Guidance_Computer>), one in the command module, one in the lander. Each of these beasts weighted 32kg, and they were not included because it was so hip to fly with electronic guidance, they were included because they were a *must*. You have to have a very good reason for carrying along 64kg of inert mass when you are doing a rocket flight to the moon and back. And that reason was precise control of the rocket engines so that the astronauts actually got where they were supposed to go. [Answer] I believe that most of the issues involved in a non-electric spaceship have been addressed... for pretty much every electric technology in use on a spaceship, there exists a non-electric alternative. However, I would debate that a photonic-based calculator is truly modern day technology. True... Some photonic circuit modules have been produced, but I disagree that the technology is ready for use in space as of now. So, while we can have chemical and reflected light, and mechanical and hydraulic/ pneumatic control systems, a photonic processor is taking things a step beyond current day technology. However, all is not lost. There is at least one alternative technology that may substitute: Rod Logoc and Fluidics. Of the two, fluidics has already been used to build functional circuitry, and has also been shown to be able to be scaled down. A fluidic computer is essentially a block of specially shaped gates, into which a fluid such as a liquid or a gas is pumped. The shape of the gates determines the behavior - other than the data input and outputs and the fluid pump, there are no moving solid parts, only moving fluid, so fluidics are very reliable. They are also far less susceptible to external electromagnetic interference than electronics. As for the fluid pump, that could be chemical-powered, powered by a Stirling engine that operates between the sunlit and shaded sides of the spacecraft, or even hand-cranked. [Answer] Your problem can be split in two parts, getting there and surviving the trip. **Getting there** Most "exotic" propulsion systems require lots of electronics for control, or just are based in electric effects themselves. Going with 2019 tech level, what's in rutine use today for commercial spaceships should be your best bet. Most ships use liquid fuel rocket engines. Those are efficient for the long range, but they have a few caveats for your mission: They require fine control of the burn if you dont want them to blow up, and the massive ammounts of fuel and oxidiser require pretty big pumps, which will need to be electric in a spaceship. The other problem with this approach is that this kind of engine doesn't like reignitions, and you will probably need to do a lot of correction burns along the trip. Your next option is the hypergolic, it is less efficient and also needs pumping, but at least the control is very simple and can be done via mechanical means. You can do the pumping by having compressed gas push the liquids; won't do for the big trans-martian injection burn and the capture but would probably be OK for the correction burns along the trip. For the big burn, I would go with the scariest of all: solid boosters. Those can be ignited via a hypergolic mix, and once they start burning there's no control needed because there's no way to control them; they burn until expended. So, using a staged approach, I'd have a solid first stage for the trans-martian injection, followed by a hypergolic second stage for mid course corrections and a final solid stage for the mars capture. As you won't have a control computer or anything that can compensate for asymetric trust, you'll need to have one of each, perfectly aligned with the center of your ship. You'll also need to calculate your burns as precisely as possible. The most critical is the trans-martian injection one, it is the longest and also the one that has a bigger potential to screw your whole mission if done wrong. As you will be starting for an already known orbit around Earth, it is also the easier to calculate; you can even have it precalculated using a computer if that's allowed by the rules. Your engines will need to be throttled down so that they burn slowly during a long time. A pilot seating in the front of the ship will use an optical finder to align the ship with a star and steer it if it spins off course; the slower the burn the easier it will be to align the ship. For the attitude control, you could also have hypergolic thrusters like most spaceships do, but unless perfectly balanced, they will also propel you off course. A flywheel on a gimbal is the perfect option. Your 24 crewmembers can put their muscles to the work; orient the flyweel in the right direction, start spinning it and watch your ship counterrotate until it finds the right orientation. The navigation shouldn't be that difficult, but it will need a lot of slider rule time. Observe the planets, find them in precalcualted tables and figure out how well you are doing. Correct your course accordingly. **Surviving** The easier first: Don't bother with a recycling system, just bring enough water and low-residue food to last the trip. You will need to keep it aboard, though. Anything you expel from the ship will either alter your course if you do it with some force, or just stick around if you dont, surrounding you in a cloud of residue that will cloud your windows and difficult all your maneuvers. It would also alter the ship mass in unpredictable ways, so better bring it along. For warmth you can just do like Mark Watney and bring a few plutonium pellets, they will radiate enough heat to keep your ship at a reasonable temperature. You don't want to be too warm to avoid people sweating, the water is better kept inside their bodies. Another consideration is clothing. You won't be able to wash it so you'll do as the ISS and bring enough clean clothes for all the crew. Air quality will be trickier; you can do as old spaceship did and have a pure O2 atmosphere, but you'll need to get rid of excess CO2, and have something that does that efficently; I personally have no idea how to do that without electricity and avoiding outgassing. Finally, you'll have 24 people in crammed, smelly qarters for 9 months. You better figure out how to keep them entertained without electronics. ]

[Question] [ Had a dream that I was the size of an ant and I was being chased by spiders and other small horrors. I created a campfire and was able to scare off the insects. When I woke up I came up with a TTRPG campaign that is basically 'Honey I shrunk the Kids'. But when I thought about it I was ever wondering if a fire at that level would even be possible. So that led to my question, could you create a small campfire if you were that small? Thanks for my random question. [Answer] More than a campfire, it might be possible to create a spark: considering the size of wood chip a creature the size of an ant can handle, it won't last much more than a spark. Additional problem, the combustion heat might be sufficient to lift it in the air, which is not exactly handy if it has to be used to fend off attacking animals. [Answer] Wood at that scale would not be manageable, but an easy alternative would be oil lamps: [](https://upload.wikimedia.org/wikipedia/commons/thumb/1/1c/DiwaliOilLampCrop.JPG/722px-DiwaliOilLampCrop.JPG?20101221182212) At this scale, the small flame from the oil lamp is more than enough to warm dozens of ant scale humans. It's also much easier to set up and control for long periods of time, unlike a small pile of wood which will flame out quickly. [Answer] I just realized that I wrote a verbose version of L.Dutch's answer. I upvoted his answer. You should, too. --- *It's amazing how often I've used the following quote on this site....* > > Can you launch an ICBM horizontally? > > > Sure. Why would you want to? (*The Hunt for Red October*) > > > Can you shave a piece of wood so small that it could be used for a campfire by an ant-sized human? Sure! Why would you do it? Here's the problem: rate of combustion. It doesn't matter if you're burning wood or oil or anything else. The simple truth is that the smaller the combustible item is (i.e., the less you have of it), the faster it will be consumed. As in... fractions of a second. I'm fond of another quote by Harold Ramis about the original *Ghostbusters.* During the scene when the giant Stay Puft Marshmallow Man is walking down the street, kicking over (among other things) fire hydrants, the special effects experts used very finely ground sand for water. Why? He explained... > > You can't miniaturize water. > > > It's true. You can see every time a movie puts a model of something (like a ship) in water for filming. The water is the wrong size. It's motions out of proportion with the object of our focus. It can't be miniaturized. *Neither can chemical reactions.* And that's the problem. Yes, they could have a campfire. For a fraction of a second. If they added fuel fast enough to keep the reaction going, they'd burn themselves up (or ignite whatever was around them). So, from a practical perspective, no... ants can't have campfires. *But that shouldn't stop you. This stack is dedicated to building imaginary worlds that need not conform to Real World physics. If you want your ant-sized humans to have campfires, let them have campfires. It's not as if there's a secret cabal of fanatic bibliophiles out there ready to unleash their zombie hordes when they discover (gasp!) that you've written a story that doesn't conform to real-world physics.* P.S., it's worth noting that there may be some chemical compound that could ignite easily and burn slowly enough that mere grains could be used by the ants as a campfire. Such a combination of chemicals won't be available just anywhere, suggesting that they can't be used as a campfire, so I ignored that possibility. But that could, itself, be an interesting idea for a story. Is there a compound that is easy to ignite and yet mere grains could burn for a specified time (you'd need to specify that)? Hmm... [Answer] Probably not. Try burning a matchstick with the head cut off. In my experience, wood this small will only continue to burn if the stick is angled so the flame is creeping *upward*. Hold a match with the flame at the top, it'll go out. Smaller wood, more so -- you'd have to feed the fire so rapidly you'd go through a pile of fuel much bigger than your tiny self in minutes. Pile up several such sticks (proportionally as large as a good sized log) and they might continue to burn (as they hold the heat and ignite each other), but you'd go through your fuel even faster. It would take, at a minimum, the full resources of at least a good sized *colony* of ants to find and bring tiny fuel pieces fast enough to keep a fire fed -- which would largely defeat the purpose of keeping the fire going to drive off equally tiny predators. [Answer] As several other answers have pointed out, a wood campfire would not be practical if you were of a very small size. So, what you would need instead is for *everything else* to be very large. Instead of having your campaign set in the normal world with very small people, have it take place on a very *large* world with overgrown trees (see - Giant Redwoods) and equally overgrown animal life - including insects. --- Large insects of course present their own problem - exoskeletons do not scale up very well, and become less effective the larger the creature. But assuming you are willing to handwave this (or inquire about it in a second Worldbuilding question), you'd no longer need to worry about the rate of combustion, and can happily have your campfire and insectoid foes. [Answer] One thing to note is that the human body couldn't really exist at that scale either, for the same sorts of reason that a campfire couldn't. But that's not a bad thing necessarily. Since you're already bending the laws of physics to have humans running around, why not bend them a bit further to have campfires as well? There's a few ways you could do that, assuming you don't want to just handwave it without explanation. One is to say that if a fire is lit with a miniature lighter then you get miniature fire, which behaves like full-size fire only smaller, instead of like a real small fire. This is kind of hard to justify in terms of real physics, but it might work for a story. Another option is to say that although a small sliver of wood can't burn like a campfire, wood that's been shrunk behaves as if it were full size wood. (Just as shrunken human bodies behave like full-size human bodies.) For example, you could have a wooden shed get shrunk along with your humans for some reason, who then find that they can build a perfectly nice campfire out of the wood the shed was made from, even though the non-shrunken wood that they find in the environment just goes "poof" instantly. [Answer] While it won't get you an ant-scale campfire there is a way you can get a considerably smaller fire: Put it inside a IIRC glass cylinder. You need material that will pass visible light but is opaque to most infrared, thus holding a lot of heat around the fire. You'll still need a liquid or gaseous fuel, solid fuel can't be adequately controlled or fed. [Answer] Japanese "incense" sparklers are small and burn for quite a long time. But they tend to give off a lot of sparks. <https://www.youtube.com/watch?v=063sevb2_tU> [Answer] You can have a campfire that size, you are essentially using wood shaving and saw dust, to your humans it is more bonfire than campfire. (assuming your humans are as strong as ants. the problem is they will have to feed it constantly, non stop as soon as it gets lit. But the real problem is a mild breeze will extinguish it, and they can't protest it or it will go out as soon as there is no wind. Not to mention thy will have a hard time getting close to put the wood in. they might have to burn bigger wood and let it die down before cooking on coals. If they can carefully control some kind of forced air, they might be able to get something manageable, on the up side at that size food will cook very quickly. [Answer] There is [a book](https://scifi.stackexchange.com/a/267926/113897) about miniaturizing people to enter into the blood vessels with a ship. It was something like condensing matter and needed careful support from an energy source to keep items miniaturized. When some matter entered their field, it also got miniaturized. So maybe you can use this effect in your story. Or maybe surprise - everybody jumps on the spider and it becomes small. ]

[Question] [ If humans colonize Mars how will the 2 societies (Mars inhabitants and Earth inhabitants) be able to synchronize and cooperate regarding time? Since: * Martian days and years are different than the Earth's * Time passes faster on Mars since its mass doesn't curve spacetime as much as Earth's mass. Is there a way that the Martian and Earth societies would be able to have a common unit of time? [Answer] First off, the issue with relativity is solved. No kidding! [Barycentric time](https://en.wikipedia.org/wiki/Barycentric_Coordinate_Time) (TCB) is a time scale that an atomic clock would perceive were it co-moving with the sun. This, of course, is a technical phrasing which means it's as though the clock were fixed with respect to the movement of the sun, but outside of its gravity well. It ticks about 490ms/year faster than [TAI](https://en.wikipedia.org/wiki/International_Atomic_Time), which is the atomic standard we build UTC from. Leave it to the metrologists to need a coordinated time system like TCB! Any synchronization would naturally be done in a measure like UTC or TCB. Like o.m. I believe that, in the early days, everything would be in UTC. However, leap seconds are a pain, so I would expect something like TCB wins out in the long run. Most mission planning can be done in seconds minutes and hours, rather than talking about days or weeks or years. The former are arbitrary time constants, while the latter are built around the revolution of the Earth. It will be easy to talk about rendezvousing in 78 hours. As for human-to-human, I think that will happen less often than you think. People tend to form groups close to them. The Martian colonists are quickly going to develop their own culture. A key point will be when they cease to think of themselves as a colony, similar to when the US stopped being a colony and started being a nation. At that point, I'd expect them to reject UTC, define their own martian day and year, and rely on TCB for coordination from then on out. [Answer] * For historical reasons, [UTC](https://en.wikipedia.org/wiki/Coordinated_Universal_Time) would be used for mission planning. * The lightspeed communications lag would make it pointless to arrange things like "call you at nine o'clock." One would always have to specify time zones. * Mars would adopt the Martian day for many purposes as soon as many people work outside. During the early days, the bases would probably stay on a 24-hours indoor pattern. Going outside will be carefully planned during early missions, almost like a spacewalk from the ISS, so again it won't be "hey, it's getting light enough to go out." At some point, the Martian colonists might lobby to adapt the Martian year and day, but that would be a *political* statement of independence, and quite impractical. [Answer] Historically, we humans have already had to solve this problem on a smaller scale: train schedules. Trains could move fast enough for long enough periods of time that sunrise and sunset was different between the beginning and end of the journey. Complicated schedules were created that specified when the train would arrive/depart a specific location in "local time." In the case of a larger macro system, the only real question is can we create two references that are independent of or minimally dependent on relativistic properties? I'm not a nuclear physicist, but we probably already have. The SI unit of "one second" [is defined as](https://en.wikipedia.org/wiki/Second)... > > Under the International System of Units (via the International Committee for Weights and Measures, or CIPM), since 1967 the second has been defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom. In 1997 CIPM added that the periods would be defined for a caesium atom at rest, and approaching the theoretical temperature of absolute zero (0 K), and in 1999, it included corrections from ambient radiation. Absolute zero implies no movement, and therefore zero external radiation effects (i.e., zero local electric and magnetic fields). The second thus defined is consistent with the ephemeris second, which was based on astronomical measurements. (See History below.) The realization of the standard second is described briefly in a special publication from the National Institute of Standards and Technology, and in detail by the National Research Council of Canada. > > > So, frankly, all you need to do is use this (or its future equivalent) and identify the synchronizing "epoch" (not disimilar to the [Unix Epoch](https://en.wikipedia.org/wiki/Unix_time)) after which the two measurements are perfectly aligned and can be used to convert from local time to "solar universal time" (which, obviously, will be Earth time, 'cause the motherland is where it's at....) An alternative is to use a definition like [Ephemeris Time](https://en.wikipedia.org/wiki/Ephemeris_time), which was created literally to solve this problem. > > The time scale represented by Teph has been characterized as a **relativistic coordinate time** that differs from Terrestrial Time only by small periodic terms with an amplitude not exceeding 2 milliseconds of time: it is linearly related to, but distinct (by an offset and constant rate which is of the order of 0.5 s/a) from the TCB time scale adopted in 1991 as a standard by the IAU. Thus for clocks on or near the geoid, Teph (within 2 milliseconds), but not so closely TCB, can be used as approximations to Terrestrial Time, and via the standard ephemerides Teph is in widespread use. > > > Honestly, all you need is one whomping predictable reference point that is syncronized at the motherland's central time coordinating agency before shipping it off to any planet in the galaxy, and so long as you didn't pass too close to any black holes along the way, you're synchonized. *Note that I very much doubt any non-Earth planet would happily try to stay on Earth time anymore than any timezone on Earth has decided to stick with Greenwich Main time. It simply doesn't work. It's easier to delay transmission of your favorite movie to synch up with your local time.* [Answer] The answer to "how advanced society measures X" is invariably the same: by convention. Time, like most dimensions, is ad hoc. Its current definition is entirely based on how we measure it: the transitions between hyperfine whatchamathingies of cesium measured by cesium atomic clock. Time zero is Greenwich because the Brits used to own the world pretty much. The logic behind it isn't geography. France went through a few time zones and it hasn't moved physically. The logic behind it is men. Honestly it doesn't matter which standard you choose, it only matters that it is universal. The story of time keeping in France, if you want to look it up, exemplifies just how made up the time on the clock is. --- If you don't use UTC or similar and instead make your own standard, remember a few things. Firstly, your readers are Earthlings, and presumably so are you. That means there is an understanding of what a minute or a day is that you can't completely overwrite. Don't mess with people's frame of reference too much if you don't want to confuse them. That also applies in-universe, people don't like drastic change happening all at once. Secondly, that standards are built for trade, and imported through either trade or force. Paris adopted Greenwich time out of convenience, and it was told to adopt Berlin time out of lack of choice. The dominant power of the period writes the rules, and those rules can persevere well after these powers are gone, or sometimes standards die with said power. Consider the history of your world when coming up with your standard clock. Early Martians would likely follow Earth time , then develop their own rhythm of life over time. The more contact with Earth, the more prevalent Earth time will remain. Thirdly, although standards are important, they don't have to rule one's life. Some people's day consist mostly of night despite what the clock or Sun says, aka night shifts. Even if there is a common measurement of time, your story could only require local time from the main character's perspective. [Answer] This would be quite important when calculating overtime pay for terraformers. Perhaps they'd just add 2.7%, the difference in the days. [Wikipedia Mars Time entry](https://en.wikipedia.org/wiki/Timekeeping_on_Mars) says that people working on Mars missions adjusted to Mars time (24 hour system with seconds 2.7% longer) because rovers require sunlight for power to perform tests and move around. Colonies would probably have similar needs. No need for years to be counted, just the days (they cal *sols* ). If we did that ourselves we'd be on day 736566 rather than December 3rd, 2017. It's shorter but the seasonal information is often important to us. From there it's like inches-centimeters where we multiply by 2.54; Martian sols to Earth days add 2.7%. [Answer] I think the solution that Andy Weir chooses for *Artemis* is likely to be the short-term solution. In that novel, set on the Moon, they use Nairobi time, because the original colonists were from Kenya. They ignore the oddities involved in the lunar cycle, and simply define everything based on the time in Nairobi. On Mars, this may well be the solution early on as well. For the duration of time until the Martian society has its own character, during which presumably Mars is regularly interacting with Earth, it makes sense to be on a schedule and use the time associated with the closest Earth associates. If just one country colonizes Mars, then that is simple; if more than one do, then it may require some compromise (perhaps UTC, perhaps something else). Once Mars develops sufficiently to be largely self reliant, where the local time is really all that matters, it will likely develop its own time zones, and simply expect people between Mars and Earth to translate, just like we do now between various countries. [Answer] The differences may not be as much as you think. First, the gravitational time dilation can be discarded as irrelevant except perhaps for things like scientific experiments requiring extreme precision (and GPS satellites would have to be programmed for what planet they're for). You're talking a difference of something like minuscule fractions of a second per year, if that. The odd leap-second would officially handle that. For longer periods like years, it depends if seasonal effects are an issue. Obviously, if you're near the poles, the growth and retreat of the Mars polar caps is important, but elsewhere on the planet, I'm not so sure it's that big of a deal. The main issue will be height of the sun in the sky and day length, which solar power generation will have to take into account, but that's minimized if most settlements are closer to the Martian equator. Assuming you haven't terraformed the planet, crops will be grown indoors so conditions outside have only minor significance. All this means is that the Martian year and season aren't nearly as important, so you can operate use the Earth year as a base for dating. Also to bear in mind that because of the axial tilt and orbital eccentricity, Mars's seasons aren't even the same length between the two hemispheres on the same planet, so it makes more sense to just ignore them in terms of official time-keeping. It's the issue of individual days where most of the problems are going to come up, and that's primarily because the Martian sol is almost, but not quite, the same as the Earth day. From a practical standpoint, the easiest method is to use what the Earth-based ground crews on Martian rovers do: extend the "official" Mars second by 2.7%, so a Martian 24 hour days is identical to a Martian day/night cycle. Maybe colonists call it as "marsec" or something. If you do that, but keep the Earth year as a basis for longer timekeeping, then the official Martian year, instead of being 668 sols (ignoring fractions, which leap-years would take into account), would be 356 sols (equal to 365 days). This, if you wanted Martian months, conveniently divides into 12 months consisting of four quarters each with a 30 sol month, a 30 sol month, and a 29 sol month. On the other hand, whatever system is chosen, the whole thing becomes trivial with computerized time-keeping. It's simple to program an app that converts between Earth date and time (taking into account time zones) and Martian date and time (again with time zones). All that needs to be done is for everyone to agree when the zero time for the Martian clock/calendar is. [Answer] I recommend reading Paul Krugman's quasi-famous paper, **The Theory of Interstellar Trade**. It may not directly answer your question (as it focuses on the interstellar instead of intrastellar) but it is a fascinating look at how trade (and hints at contracts and financial products necessary for capital intensive commerce) would operate across unprecedented distances. <https://www.princeton.edu/~pkrugman/interstellar.pdf> [Answer] For once-off events, synchronizing between a timezone on Mars and one on Earth is not that much different from synchronizing between different timezones on earth. So I doubt that would motivate the development of a vastly different approach. Instead I'd expect to see what we see on earth: reference to some arbitrary standard like GMT, or to the timezone used by the majority of people involved, or the location of some project's original headquarters, or whatever. All of these might be employed concurrently depending on the people involved. Things become more interesting if you have *repeated* events. Assume you want to have a weekly project meeting, preferably during office hours at both ends, but at least during daytime hours. On Earth this is simple: with the exception of DST transitions twice a year, relative offsets between time zones remain fixed, so a time slot that works in one week should work the week after just as well. Not so between Earth and Mars. As the Martian solar day is about 40 minutes longer, you have a shift between the two to account for. Some weeks you'll have nice overlap, some other weeks you'll need one or even both parties to participate outside office hours. I guess most likely you'd have some software do the planning for you. But the software might come to rely on well-established patterns, and these patterns by themselves may get names. So you might decide to meet regularly “on the β3-pattern starting at 2312-03-18 13:00 GMT” or some such. Personally I doubt this would become a common method of referring to dates, though, more like an implementation detail of the calendar software you use. Particularly as things like day of the week adjustments (to avoid extended runs of weekend meetings) would make things even more complicated, and getting inter-planet and intra-planet repeated schedules aligned would require a lot of individual adjustments anyway. [Answer] Rather than use years, you could measure time in [synods](https://en.wikipedia.org/wiki/Orbital_period#Synodic_period). This would be an especially useful unit of time because it actually means something to the the colonists. No colonist would care what one "martian year" it is. It doesn't matter if it's winter or summer there, because people can just assume the outdoors are going to be equally inhospitable year round. Compare this to a synod. One synod is the time it takes to transport goods to and from Earth using a Hohmann transfer. If you're a martian and you really need a new part from Earth, you have to wait until the next synod. You could also easily keep a history of colonial growth this way: Synod 0: first colonists arrive Synod 1: solar panels arrive Synod 2: more supplies, new landing pads to accomodate traffic ]

[Question] [ ## Synopsis For reasons unimportant to the question all divine/infernal beings and deities took a hiatus from interacting with the earth in the dark ages. For reasons equally obscure they are back and busier than ever. Law enforcement, corrections, mental health staff, and the US legal system now must deal with a massive influx of demonic and paranormal related crime (every cultures entities and deities are now real with predictable chaotic results). In my prior question I attempted to find a plausible method for field testing to ascertain the difference between demonic possession and mental illness so that authorities could provide the adequate response. ## The Situation So our overworked and underpaid law enforcement get a man in booking exhibiting signs of possible possession. The field test is administered and consists of blind tests that an insane person could not react to properly. He exhibits signs of discomfort when touched within the presence of a holy icon despite being held in a position where he could not possibly know the difference between the object and any other. The man begins speaking of personal details of jail staff that he could not possibly know without the presence of paranormal ability. He is determined to be possessed by a low level demonic entity of the Judeo/christian variety by testing his blind reaction to contact with various religion's holy icons. ## The Dilemma At this point detention staff are calling for a mobile tactical priesthood squad to arrive and perform an exorcism when the demon within the man demands that he be allowed to speak to a lawyer. Furthermore, he claims that the victim was a willing host and that forced contact with holy icons is painful to both himself and the host and violates his and his host's civil rights as it constitutes cruel and unusual punishment. ## The question Is this claim valid under US law? Can this Demon claim that he is afforded civil rights? [Answer] As it stands, the U.S. court system is barred from hearing cases that are not based in some factual question and the person petitioning the court can be potentially harmed by the law in question (standing). Thus we cannot say for certain how the real life court would rule as demons have made no such claim. That said, we do have a few laws that could justify the police's actions. First the 13th amendment bars slavery in any form within the United States. Thus the Demon cannot own the possessed individual. The demon must therefore enter into contract where the possession of the individual is appropriately compensated. Consider it similar to a landlord and a renter, where a contract is signed by the two acknowledging a legal agreement including duties and responsibilities of both individuals as well as the compensation of the possessor to the possessee. The demon's claim can be assessed if he is able to temporarily relinquish his hold on the individual so that the police and priests can properly assert that the individual did enter into the contract in good faith. Now, the tricky part is assessing that the contract was a fair bargain. While I would hate to be accused of being an anti-demonite, demons do have a reputation of entering into deceitful contracting laws. If the individual did enter into a contract with the demon, however, did not comprehend that possession was part of his end of the negotiation, it could be held that the demon entered into a deceptive or fraudulent contract with the individual. Contract Law in the United States typically goes in favor of the defendant (the individual in our scenario) if the language was deceptive or predatory in nature and the defendant was not aware of the negotiate bargain was against his interests. As the Demon is claiming rights under the United States, I would hardly think a rational modern day court would oppose such a request provided the creature was capable of understanding the rights afforded by the constitution. However, as such, any agreement made in the jurisdiction of a US court would mean that the contract is reviewable under the U.S. Legal system as opposed to the... Damned Legal System (The Court of Hell, lest anyone find room for an Evil Lawyer Joke). As such, the contract can be ruled null and void in part or in full by a Judicial Lawyer. I would hold that while the Demon does have rights, the contract can only be enforced if the possessed entered into the contract of his own free volition and fully aware as to the terms he was agreeing too. Should all this be in order, I would like to point that the demon was discovered in the process of booking for an arrest for a possible criminal action. As we would not hold the landlord accountable for a criminal action committed by a tenant on the landlord's property, if we presume the landlord was not aware of such action. Since the demon is under arrest, the police would have the right to remove the demon from his place of residence (the possessed) and hold him in proper incarceration facilities until such time as the demon can appear before a judge to enter his plea and have appropriate bail set. The demon can be asked to come quietly or be forcibly removed from said residence by means of force, both natural and supernatural, if he refuses to willingly surrender to peace officers. Furthermore, the assumption of a fair contract in place, the demon may be held liable for damages to the property incidental to his arrest insofar as described in the contract. As to the nature of the injuries, the demon does not appear to have received lasting permanent injury. As part of booking procedures, criminals are subject to a number of uncomfortable procedures to acquire possible evidence to identify the nature of the arrested. The demon has not presented any evidence that lasting physical harm was caused by these tests to ascertain his nature nor damage to the possessed. The court would probably find that any utterances of confessions, threats of apocalyptic doom, deciphered speaking of tongues, or general unpleasant language found only in the darkest depths of hell or Enlisted Navy Personnel's minds shall be inadmissible as evidence as they could be construed as compelled testimony. As established, the demon does have full rights under the United States Constitution including his Fifth Amendment protection against self-incrimination. Edit for Addendum: In consideration to @CreedArcon's concern, the first amendment holds that congress shall make no law establishing a religion nor infringing upon the free exercise of religion. The finding of the mock-court is the police in this scenario did limit to solely Judeo-Christian demons in testing for possible demon. The defendant reacted to confirm at least one test of an indeterminate religion that has yet to be disclosed to the mock court. The defendants' first amendment rights thus were not violated in this respect. The employ of tactical exorcism units is also acceptable as the government has allowed chaplain services to conduct religious services for troops and police units. The mock-court also finds against Mr. Arcon's assertion that the defendant must provide papers stating his intent. As with all criminal cases the defendant is presumed innocent until proven guilty. Additionally, the defendant has a fourth amendment right to be secure in his papers and possessions. Thus the mock-court finds the defendant need not provide evidence. Assuming that the defendant was properly read his Miranda rights at arrest, and admitted to the police that he had a contract drawn up to his possession of his host, the mock-court finds sufficient evidence to issue a warrant for said document. Additionally the mock-court finds sufficient evidence to issue warrants to search for evidence related to the crime which the defendant was arrested for. The accusation of Violent over throw of the United States Government (by means of raising Hell) requires evidence that proves intent beyond reasonable doubt and the burden of this proof must be met by the prosecution. While Mr. Arcon believes that Hell may be aiding and abetting a crime and thus has liability the Mock-Court finds that if we do not afford the defendant his right to proper defense, there will certainly be Hell to pay. [Answer] There was once a court case where [a fellow sued Satan](https://en.wikipedia.org/wiki/United_States_ex_rel._Gerald_Mayo_v._Satan_and_His_Staff). Several things happened: 1) Satan did not appear for the court date, nor did anyone authorized to represent him. 2) Rather than find for the plaintiff due to the defendant not appearing, the judge determined that Satan, as the head of a foreign power, had diplomatic immunity. Based on that precedent, this would mean that Demons would need to be treated as immigrants, and would need to follow the processes of immigration. [Answer] ### Everything changed after the RFD (*Rights For Demons*) association started... Shortly after *The Change* some people started to demand that their demonic posess- ... *dear friends* receive the same rights as other people. They started to grow in numbers, especially in regions that were low on priests. These people didn't demand any changed to the current laws. But they demanded a certain way to interpret the laws. Organisms in the human body can be good. We wouldn't survive without a healthy gut flora for example. But at the same time parasites can be very, very bad to us and we need to kill them in order to safe the human. The same applies to demons. Some are nice and helpful. Maybe their single voice is just so much louder than your normal voices and thereby helps you to sleep good at nights. But some demons can be bad, for example if they force you to sacrifice a couple virgins from the neighbourhood. That's why the law now says that nice demons are allowed and simply part of the human being, meaning that a *possessed* human (or, to be politically correct, *multiple-entitiy-controlled-humanoid*) has the same rights as the previous host. If the demon is determined to be bad for the host overall, for example by slowly feasting on their soul, it doesn't have any rights and everything is allowed to safe the host, no matter how much it may hurt the host. The thing is: how do you check whether a demon is slowly feeding on the soul of a victim? There are some specialists that can objectively determine this, but they are rare. That's why you have to write a document and testify that you are planning on getting posessed. It was determined that voluntary posession doesn't result in soul consumption in 99.8% in a clinical study conducted by the RFD. The RFD also has a lot of lawyers for some reason. And for other reasons there are always papers appearing that testify that a demon that's been arrested is allowed to actually stay in the host with all his rights. As if they were communicating with the lawyers who store these documents and order them whenever they are afraid to land in jail... And you better not mess with the RFD. They know lots of people *very* well. [Answer] It really depends on how they behave. To start, **One does not simply enter the United States**. In the elegant British vocabulary, the immigration office must agree to **land** you, literally giving you a stamp of approval "that it better serves the country's interests to let you visit". Immigration officials lightly presume you'll be bad, and allow you to prove you'll be good. That's a high bar for a demon. The demons would be tempted to enter the country illegally. This means they are *already* not behaving well. If *that's all they do*, that is merely awkward. If they enter illegally and then harm Americans as a plan or creed, that's a problem and they risk the "enemy combatant" label. And if they enter illegally and commit crimes on a large scale, **that's an invading army**. Civil rights is now out of the picture entirely. Demon Nation is not a signatory to the Geneva Conventions, so the US does not owe them protections. **They have no rights whatsoever**. The US might honor the Conventions anyway on hope the demons would too. But if the demons did not reciprocate -- gloves off. [Answer] There's no dilemma, demon or no (*presumed*) demon. "(the demon within) *The man* demands that he be allowed to speak to a lawyer." "Lawyer." - end of story, and begin: collection of inadmissible evidence. > > The Fifth Amendment will not prevent statements made after a period of silence from being used as evidence, unless **the suspect clearly communicated a desire to invoke the right to remain silent**. > > > Even when a suspect fails to properly invoke the right to remain silent, **it must be established that the suspect waived the right in order for statements made during interrogation to be admissible as evidence against the suspect**. However, this waiver does not need to be explicit. Suspects can waive their right to remain silent if they proceed to make voluntary statements after being informed of and understanding their Miranda rights. > > > – [criminal.findlaw.com/criminal-rights](https://criminal.findlaw.com/criminal-rights/invoking-the-right-to-remain-silent.html) > > > The claim of demonic possession was made under duress, directly following an explicit statement requesting a lawyer. > > [Can police question someone with out a lawyer present after you've asked for one?](https://www.avvo.com/legal-answers/can-police-question-someone-with-out-a-lawyer-pres-663776.html) (avvo.com) > > > The police are not allowed to question you after you have asked for a lawyer. > > > However, if you agreed to talk to them after they read you your Miranda rights and you did so **voluntarily (without pressure, duress, coercion, etc), then the questioning is legal** and the answers you gave can be used against you. > > > If you were questioned after you told them you want a lawyer and/or the answers you gave were **not given voluntarily, then the answers you gave can be excluded from evidence**. In order for the answers to be excluded as evidence against you, your lawyer must file and argue a motion to exclude the statements and the Judge must grant the motion. > > > ]

[Question] [ A pacifist pyrokinetic in my story is accosted by several armed men. They have handguns, but they are currently holstered and do not have rounds in their chambers (*these nameless thugs are all about firearms safety*). The pyrokinetic's ability is pretty minor (*limited to creating small sparks*). She believes that if she can create a spark inside the first cartridge in each magazine, the cartridge would fire. Because the bullet has nowhere to go, it doesn't shoot out of the pistol (*avoiding a potentially lethal ricochet*) but does jam the whole contraption and make a scary noise. So there are a few questions here: * Can a spark (as opposed to a regular strike by the firing pin) ignite a cartridge's powder, causing it to fire? * Would such a bullet penetrate the magazine and pistol grip, and shoot out into the world? * Would a bullet that shot out in such a way still have enough kinetic energy to ricochet off the floor and then injure or kill someone nearby? I assume the power of the cartridge depends on the type, so please let me know if different types of guns would behave differently (say, a .44 Desert Eagle vs a 9mm Luger). [Answer] On the whole your idea seems perfectly sound. Let me go through your individual questions. *Can a spark ignite a cartridge?* Probably yes, though it depends on where the spark is located and how hot it is. Cartridges are surprisingly robust and well-sealed, so an arbitrary spark nearby will almost certainly not ignite it. However, they can "cook off" in sufficient heat, so if the "spark" is a localized heating, and you can localize it either inside the cartridge or in the primer, then yes, it will absolutely go off. *Would such a bullet penetrate the magazine and pistol grip, and shoot out into the world? Could it ricochet and injure or kill someone nearby?* Probably not. Magazines and gun frames are generally fairly robust, and without a barrel to contain and focus the energy the cartridge won't do a lot. Here's a [video from the Sporting Arms and Ammunition Manufacturers' Institute (SAAMI)](https://www.youtube.com/watch?v=3SlOXowwC4c) on the subject of "what happens when ammunition burns". The video is a great watch, but the first few minutes will show you all you need to answer this question. Without a barrel to contain them, most cartridges (even rifle and shotgun cartridges) won't blast through plywood, let alone a metal gun frame. *Would different calibers behave differently?* Absolutely, but probably not enough to matter. The more powder is present, the more pop there will be when it goes off. I wouldn't want to have this happen with a gun I was holding or had in my pocket or waistband, but if it had to happen, I would much prefer this happened with a 9mm than with a .44 magnum! You didn't ask this, but also note that setting off rounds in a revolver cylinder has different results than in the magazine of a semiauto. Unlike a box magazine, the chambers of a revolver are built to contain and direct the pressure, so a lot more damage could result. [Answer] The key to this question is to note that gunpowder doesn't technically explode -- it deflagrates. It doesn't have a super-sonic explosion, but rather a sub-sonic burn. To get the powerful kick needed to project a rifle or handgun bullet, we rely on the fact that gunpowder burns faster in a confined space. The tighter the space, the more temperature and pressure it can achieve. Fired properly, the gunpowder is confined by the barrel, permitting it to reach the high pressures of a gun shot. Outside of a barrel, the brass case holding the gunpowder and the lightly set bullet provides surprisingly little containment. One can "cook off" a bullet over a fire, and the result is sudden and surprising, but far from lethal. A single spark on the outside of the case would have a hard time setting off a bullet. Having done this once in a controlled setting to test the safety of such a bullet, it can take several seconds over the top of a torch to reach the critical temperature to deflagrate. A lone spark may have trouble. However, if your pyrokinetic can put the spark on the inside of the bullet, that'd be a very different story. That would be remarkably similar to what the primer actually does when firing the gun! As mentioned earlier, the bullet would most certainly not escape the magazine. Most magazines are made of steel, and many tests will show just how little momentum the bullet actually picks up. Most of the time it's just shoved out of the case just far enough to give the gunpowder room to burn. However, we have to recognize that this is *still* a confined space inside the handle of the gun. While it's not as small and well structured as the space inside a barrel, the gunpowder is still going to have to find an exit. It will build up pressure until it does find enough of an exit. This could be enough to cause damage. The particular behavior is very dependent on the particular handgun and its construction. A revolver would most likely just shove the bullet out of the front of the cylinder, with little to no damage. An all steel handgun like a 1911, however, may contain the pressure better. This means it may fail in a more spectacular way. The small clip that holds the magazine into the gun would be my guess for "first to fail," causing the entire clip to pop out of the gun. If you had a "plastic" gun like a Glock 19, you could be in worse trouble. The bullets in the magazine are held in by a similar pin, but there's open access from the magazine to pressurize plastic all over. There's a decent chance that the force of the powder could rupture the plastic around the bottom edge of the slide (which is typically at a particularly nasty position for spraying plastic bits all over the gun's wielder). Another question would be what happens to the other bullets? Depending on the exact mechanics of the rupture, you *might* push one of the other bullets out of the way, exposing another case full of gunpowder. This would create a much larger effect, though it's not immediately clear what sort of mechanical topologies might cause this. Ironically, rifle bullets might have a less extreme effect than handgun bullets. Many rifle calibers involve a large chamber for powder necked down to a smaller bullet. In a barrel that is shaped for this, this allows for devastating power. However, in a magazine, that space would simply be expansion room for the burning powder. That extra expansion room may keep the pressure down enough that the rifle round may never reach the high pressures that could cause serious damage to the handgun, despite having more gunpowder to work with. All in all, I don't recommend experimenting to find the answer =) While there's still squabbling over whether guns kill people or people kill people, *everyone* agrees that a misfired gun is a dangerous device and must be treated with respect until the misfire is resolved. ***Edit*** - From a long discussion in comments, it looks like the question of revolver rounds is of interest. Thanks to Deolater and Supercat for tugging at this thread, and Supercat for bringing data to the table! *The key equation for determining the speed of a bullet is $F=p\cdot A$, the force propelling a bullet forward is the pressure behind the bullet times the cross sectional area of the bullet. Using the formula for work: $W=\int\_0^LF\, dx$ where L is the length of the barrel, we can do some comparisons. Then, knowing that $E=\frac{1}{2}mv^2$, we can back out the velocity by noting that the velocity is proportional to the square root of E ($v\varpropto \sqrt E$)* *We can consider two idealized cases for the powder burning. The first assumes constant pressure, and the second assumes the powder burns all at once, maximizing pressure at first. A realistic bullet will fall between one of these two extreme cases based on how fast the powder burns.* *In the case of a constant pressure, we see $W=\int\_0^LpA\, dx$ and thus $W \varpropto L$, where L is the length of the barrel. This means that $v \varpropto \sqrt L$ for the constant pressure case. In the case of an instantaneous burn, the pressure behind the bullet will obey some $p(x)=\frac{P\_0}{x+C}$ where $P\_0$ is the pressure at the start and $C$ is a constant capturing how much space is behind the bullet where pressure can be built before the bullet starts moving. This gives $W=\int\_0^L\frac{P\_0}{x+C}A\, dx$. If we cleverly choose units of length such that $C=1$ and thus $W\varpropto \ln(L+1)$.* *Now we can put some numbers to this. Thanks to supercat's find, we have a [table for a .375 magnum](http://www.ballisticsbytheinch.com/357mag.html). Now .357 is rather convenient in that $C$ is roughly 1 inch (the case is 1.29" and the bullet rests a bit inside, so 1" is actually probably very close to correct). If the powder were to burn with a constant pressure, the energy after moving 1/2" (escaping the edge of the chamber) would be 1/12th that of the energy when escaping a 6" barrel, and thus a velocity that was .00694 that of the 6" barrel shot. **This would put its velocity around 10fps.** If we instead assume an instantaneous burn, we can use the second set of equations to see that the energy would be about 20.8% of the energy escaping a 6" barrel. **This second equation would instead put its velocity at 65fps. The actual speed would be somewhere between these extreme assumptions.*** *Sure enough, if we graph muzzle velocity from the page of .357 data, we see a sharp knee in the curve as the barrel length gets smaller. The data doesn't go below 2", but extrapolating the lines confirms that the velocity exiting the chamber would be very small with respect to that of a properly fired bullet.* [Answer] As mentioned, the unconfined explosion of the round will burst the cartridge case. Depending on where the case actually is, you may or may not damage the weapon itself (best case scenario, worst case you blow out the bottom of the magazine so the bad guy ejects the magazine and reloads a fresh one), and there is always a possibility the hot gasses and projected particles of metal will cause injury to the person carrying the weapon, but if it is properly holstered (as implied in the question), the weapon's frame and the holster material will likely catch everything. The shooter is likely to be startled, and if you are in some sort of life and death confrontation (hence being surrounded by armed men and using pyrokenisis to defend yourself) this might actually be the trigger for the armed men to leap into action. They may well draw and attempt to use their firearms, but on discovering the weapons are jammed they may transition to secondary weapons (a holdout pistol, a taser, a knife or extendable baton) or even simply wade in with fists and attempt to fight it out hand to hand. The more trained these people are (i.e. ex cops, ex SoF mercenaries working for the drug cartels) the faster they will transition so the window of time to escape is very limited. Your pyrokenisis person might actually have better success attempting to ignite disposable butane lighters in their pockets. The unconfined explosion will not be surrounded by a metal and polymer gun frame or enclosed in a holster, and the liquid butane remaining will ignite the bad guy's clothing. If they are non smokers, search for the one carrying a Samsung Galaxy 7 mobile phone and go after the battery..... [Answer] Round [](https://i.stack.imgur.com/11eCO.jpg) > > Can a spark (as opposed to a regular strike by the firing pin) ignite > a cartridge's powder, causing it to fire? > > > The wording is a bit conflicted. You state *inside* in text and then *a* in the question. The function of the primer is to create a spark inside so yes if you create a spark inside it will ignite the gunpowder. But I cannot imagine how you would create a spark inside the (sealed) round other than the primer. An external spark is not going to ignite the gunpowder in the round. > > Would such a bullet penetrate the magazine and pistol grip, and shoot > out into the world? > > > The bullet as in head - no. The gunpowder is a propellant. It takes the chamber and barrel to harness the propellant and transfer that energy to bullet. That casing is very light compared to the chamber of the gun. It would just fracture the casing and propel the bullet a (relative small) bit. I seriously doubt the bullet would exit the gun. The casing might fracture the handle. > > Would a bullet that shot out in such a way still have enough kinetic > energy to ricochet off the floor and then injure or kill someone > nearby? > > > I don't think it would even have enough energy to exit the gun. > > I assume the power of the cartridge depends on the type, so please let > me know if different types of guns would behave differently (say, a > .44 Desert Eagle vs a 9mm Luger). > > > Bigger rounds have more powder but they also have thicker casing. But at that .44 Desert will likely be more carnage. [Answer] This is a highly firearm specific question. Ammunition in a magazine is not confined in a reinforced tight space like a chamber so the bullet won't fire forward very far. BUT the front-back tolerances of the magazine may be tight enough that the ignited bullet can NOT push out of the cartridge because it hits the front of the magazine. See how little forward room is available in a 1911 magazine. [](https://i.stack.imgur.com/1qA4e.jpg) This will block the release of gas and allow for a "kaboom!" (KB) inside the magazine which will bust the case and send gas and case fragments laterally. This can be a problem in magazines with ammunition witness holes or lightening slots on the sides of the magazine, now there are weak spots for gas to vent out of. [](https://i.stack.imgur.com/odQkx.jpg) Pair this with a pistol that has open spaces around the magazine (like the 1911 if you take the pistol grips off) and you have an additional weak spot for expanding gas and fragments. [](https://i.stack.imgur.com/6Y51D.jpg) Most grips on steel framed pistols are wood or resin/plastic and can fragment. [](https://i.stack.imgur.com/hIxBG.jpg) So with a sufficiently large caliber round, a magazine with a tight front/back fit that traps the bullet into the cartridge (remember that the bullet is seated a good ways back into the case), and an open sided magazine and pistol frame, you COULD have a KB that cracks the grips and sends out some fragments into the immediate area (like the back of the guy wearing the pistol in a waistband holster). If someone was holding the pistol then their palm or fingertips could be injured (depending on which side blew out). In general I think most magazines don't have tolerances tight enough to keep the bullet inside the case (but I'd have to check) and they have enough space inside the magazine to absorb all the gas (double stack mags especially), OR the bottom of the mag would blow out first, since the magazine is enclosed all around or the pistol frame is, OR the cartridge won't have enough energy to do any damage regardless. BUT you could have a unique situation where this tactic would work pretty well, like if the bad guys are carrying this pistol... [](https://i.stack.imgur.com/MJq3n.jpg) [Answer] Having reloaded ammunition for over 40 years, I'd like to correct/clarify a few statements from other answers. First, the spark would have to be inside the cartridge and either 1) be equivalent to that of the primer, or 2) detonate the primer, not ignite the powder. Primers **are** made with explosive materials, making the flakes/balls/rods of powder ignite essentially at the same time, whereas a small spark would ignite some powder, spreading to the rest at a rate much slower that a fired round and result in lower pressure. Second, the gasses will take the path of least resistance. In the open, a cartridge "fired" would propel the brass much faster and further than the relatively heavy bullet, as described by Newton's laws (momentum, equal opposite). A contained cartridge will split the case and pressure would be released through the ruptures, not by propelling the bullet or casing held together by the magazine. The split casing could, of course, become hazzardous shrapnel, depending on the magnitude of the pressure developed before the casing ruptures. Third, rifle cartridges, in general, produce **much higher** pressures than pistol cartridges. Pistol cartridges, including the former "most powerful handgun in the world" .44 Mag, have a very large amount of empty space. When reloading handgun ammo, one should always carefully check the powder level in each cartridge prior to seating a bullet, because it is quite easy to put a double load of powder in a pistol cartridge without it being visually obvious. Rifles, by definition, have longer barrels, and so require more, and differently formulated, powder to get a consistent burn throughout the travel down the barrel. Many rifle loads, especially Weatherby magnums, fill the cartridge to capacity. Cartridges used in both pistols and rifles, such as the .44 Mag, can be loaded "hotter" for use in rifles, but these loads can not be used in pistols. The upshot of it all is that pistol cartridges will, in general, in this scenario, result in a lower pressure "explosion" than a rifle cartridge. Now, a plastic shotgun shell should give a more impressive, if not more dangerous, display of pyrotechics, as I think it likely the shell would rupture and release **still burning** materials. It would have more flare, and perhaps more flair. :) [Answer] # Can a spark ignite a cartridge's powder causing it to fire? The way you have described the pyrokinetic's ability (i.e. 'limited to creating a small spark'), no. Modern cartridges are well sealed in metal, and are specifically designed not to cook off. In fact, according to the gun nuts I know, a lead bullet will melt (327 C) before the cartridge cooks off. The cartridge is specifically designed to go off only if the ignition cap is hit by the firing pin. I have only ever heard of cook off in a raging house fire or when a weapon has been shot excessively and has a smoking hot barrel. # Would a bullet penetrate the magazine and shoot out? If you throw a .22 cartridge into a campfire, you get a little pop like a firecracker. Other cartridges are more powerful, but the effect is the same. As mentioned before, the temperatures that cause a cartridge to cook off will cause lead to melt. Thus, you are more likely to have a half-hearted pop due to the neck of the cartridge no longer being tightly sealed around the bullet. You will certainly not get enough energy to blow up your magazine, or even to cook off adjacent cartridges in the magazine. # Would a bullet that shot out in such a way be able to kill someone? No. [Answer] If the spark is created **inside** the cartridge the powder will go off. Without being properly confined by the gun the imparted velocity is low (and is mostly to the cartridge rather than the bullet), about the only way you could get a serious injury is if a piece went into an eye. However, there are two other factors at work: 1) It's still fire. The energy released **will** find a way out, period. The strongest part of the gun (the firing chamber itself) will blow up if the pressure can't be vented normally by propelling the bullet. With a semi-auto gun the extra energy is ejected out the front and normally harms nobody. With a revolver the seal between the part holding the bullets and the rest of the barrel isn't perfect and enough energy can vent there to cause serious injury if you have your finger in the wrong place when you fire it. In this case the energy is either going to burst the magazine or vent where the magazine connects to the gun. In either case I would expect at a minimum second degree burns to the person with the gun. 2) Again, the energy must go somewhere. The weakest point will give, I would expect the magazine to be ejected with considerable force. Nothing lethal but I certainly wouldn't want to be the guy in it's path. [Answer] As already noted in other answers: * No rounds will "fire" unless the spark is created *inside* the metal cartridge of ammunition, and possibly not even then. * When a round "fires" in the magazine, the bullet will separate from the cartridge, but not with much energy. I've read that if a modern cartridge goes off while it is lying about (not in a tight container), the casing (aka bullet case) is more dangerous than the bullet, because the casing can be propelled like a little rocket. In the confines of a magazine, neither bullet nor casing can go very far unless propelled by great force. As soon as there is a sufficient gap between the casing and the bullet for the gas inside the cartridge to escape, out it goes. The bullet and casing don't even have to move; the gap could occur simply by the expansion of the mouth of the casing. So *if* you can get a cartridge to go off, the effect will be a lot of hot gases squirting out of various orifices and joints of the handle and frame of the firearm. Whether they do any harm depends on what they hit next. I suppose a military-style leather holster with a flap over the handle of the firearm would probably completely absorb the energy of the gas; it might end up a little singed. If the round goes off while someone is holding the firearm by the handle it might be a very different story. When a revolver is fired, some gas escapes through the gap between the cylinder and the barrel, which can be very dangerous. The gases escaping the round that went off in the handle would be as hot as the gases from the revolver but propelled by less pressure. I'm not sure what the result would be; something between mild burns and amputation is my guess. In any event, if a round went off you'd have a loose bullet and deformed casing in the top of the magazine, which seems pretty sure to cause a jam if the user attempts to load the chamber in the usual way without replacing the magazine first. [Answer] As stated in most of the other answers, a spark outside of the case will have no effect on the ammunition inside the magazine. A spark inside the case would likely be identical to the effect the primer has, the round would go off. The round would deflagrate as others have mentioned, but would have little force. The brass casing would be the piece that would move or deform the most (the Mythbusters did a great job of showing this). The bullet (the front part inserted into the casing) would not move much at all. What I'd expect to happen would be the top round in the magazine would go off, bursting the brass casing and pushing down on the rest of the rounds in the magazine (but not with enough force to cause them to fire as well unless some shrapnel struck the primer(s) of the lower round(s)). Since the bolt would presumably be in place above the affected round (who carries a gun with the bolt back?), the force has nowhere to go but down through the magazine well, this would most likely blow the bottom of the magazine off causing little to no damage to the firearm, but would render it inoperative until the operator cleared the damaged magazine from the well, and checked that no damage was done to their weapon. As pointed out by an earlier post, if the magazine has many perforations (pretty common, think 1911 as shown in the example above), the gasses would be expelled from those, lessening the potential damage to the weapon, and making it uncomfortable if the operator had their hand on grip of the weapon as the gas escaped. If the magazine didn't have many perforations (think Glock, XD, etc. most of the "plastic" guns), most of the force would be on the magazine base plate, which could quite likely be blown off. If the plan was to make their weapons inoperative, this would do it, at least for a short time, maybe enough for the pyrokinetic to get away. [Answer] Quick and simple answer. Modern day guns and ammo are too well sealed to be subject to the kind of damage your heroine is looking for. What you describe is a very real phenomenon and common occurrence with black powder revolvers which are still sold today as reproductions. A spark can jump from one cylinder to another in these types of guns if the projectile ball is not snug enough. The powder in 1 or more cylinders then explodes, sometimes forcefully enough to expel the projectiles. So to paraphrase Dirty Harry: "Being that this only works for a .44 caliber cowboy gun, you've got to ask yourself one question. Do you feel lucky steampunk? Well do you?" [Answer] Creating a spark inside the cartridge would ignite the propellant. However in the magazine of a semi-auto pistol, without the confinement of the gun's chamber, the bullet will not move very much. The relatively soft brass at the mouth of the case will expand and open a gap around the bullet, and the hot gasses will escape around it. There might be enough force to dent the magazine or possibly jam the round in it, but not much beyond that. If the frame of the pistol is made of a polymer material, the hot combustion products could conceivably cause a great deal of damage to the firearm. It might melt. If the pistol is metallic, however, there wouldn't likely be any permanent damage. Given what I've seen happen with bad reloads, however: if the cartridge mouth is expanded by this, it would probably jam when the operator attempted to feed or extract the cartridge by racking the slide. The slightly oversized case or the loose bullet could get stuck. Ejecting the slide and reloading with a fresh magazine would result in an operable firearm. Whether in the heat of the moment someone would have the presence of mind to eject and reload rather than try and quickly arm their weapon is another story, especially given that rounds simply don't ordinarily go off on their own in a magazine. Also I'd say it's highly unlikely that everyone would be carrying in an unchambered/safe mode. Setting off a round in the magazine would likely not prevent the one round already in the chamber from being fired, but I think it would be very likely the weapon would jam as it tried to chamber the damaged round. [Answer] To answer as an engineer: If your pyrokinetic can project his spark into the PRIMER of the bullet, it will go off explosively and ignite the powder just as if struck by the gun's hammer. However, the bullet has very little room to move forward before it presses against the steel wall of the magazine. This wall is stronger than the brass wall of the cartridge. Therefore, the cartridge most likely bursts open inside the magazine with considerable force. How much force? Well, a .357 cartridge, once ignited, releases an energy in the vicinity of 850 Joules. Look at it this way. Suppose you took a gun, and shot a bullet into an IDENTICAL gun. The burning powder releases 850 Joules of energy. The bullet carries the 850 Joules through the air. It hits the identical gun and transfers 850 Joules into the body of that gun, totally shattering and destroying it. That energy-level is more like a baseball bat hitting something. A .357 bullet will knock a grown man right over. It is not like some wimpy firecracker going off in your pocket as some posters would have it. If your pacifist-pyrokinetic character wants to set off "just the first" bullet in each gun, they may have an unintended consequence, the bad guys might catch shrapnel from the sides of their plastic-stocked guns blowing up at their sides, but then, the excess heat in the magazine might start setting off the other bullets, catching fire in a chain reaction. The bad guys might have to tear off the useless weapons and throw them aside. [Answer] I guess my answer will be the less technical. Just how realistic this has to be? I think that if you establish that sparks can pop bullets inside a cartridge without dealing any damage, this won't be a problem. Your character is pyrokinetic, so suspension of disbelief is already in action. [Answer] the spark would likely have little effect since the sealed cartridge has little to no oxygen contained within. The difference between a "little spark" and a primer being discharged (with listed pressures of between 8,000 to 10,000 psi depending on the manufacturer) is substantial. It's the pressure of the primer "explosion" that sets the powder off along with the flame involved. Can't imagine the "little spark" doing much more that causing the powder to smolder. Smokeless gunpowder open to the air will burn with a small spark to ignite it but not in an enclosed chamber without the added pressure from the "starter explosion" caused by the primer being set off. ]

[Question] [ Over time separate countries have adopted common currencies, and a world can be imagined where a planet has a single currency. However, in building a world spanning a multiplanet system (several inhabited planets plus asteroid settlements and moon colonies around the gas giants), I would like to have a single currency for the whole solar system. Is this practical? Is there a way I can realistically implement this without it sounding contrived? Problems that come to mind are the long delays of travel and communication, and the relatively slow exchange of goods compared to the rich exchange within a single planet population. Also I wonder if it would be practical to control such a system, or whether it would just devolve into separate planetary currencies. [Answer] There is no reason that a currency couldn't span across multiple planets or even star systems. The key thing that makes currency work is trust, people have to be willing to trust that what you just gave them is genuine, and that they can then trade it on in exchange for further goods and services. So long as that problem is solved then even a galactic currency would be viable. Even in the case of major communication time lags a decentralized currency could still work. In fact even if the civilization that created the currency completely collapsed the currency may still be in effect so long as they recognize the value of the currency (and assuming it was in a form that survived the collapse). What you need to remember is that money is just a way to give abstract tokens value. It means I as a programmer can go buy food from someone without needing to find a programming job they need doing. I program for someone who needs programming in exchange for money, which I then go exchange for food. They can then exchange that money on for further services that they need. Because everyone involved agrees to pretend the money has value the whole system works. **Decentralized currency** The Roman Empire's currency worked just fine even when it took weeks to cross the empire. They even had the concepts of credit, loans, banks and even their own bail-out due to a financial collapse. The important thing is that you can prove that what you have is worth what you say it is worth, in the past that was done by using rare elements (gold for example) but in the future that could be done using other means. Our cash now is accepted in circulation despite the amount of counterfeit money constantly made by fraudsters. So long as the protections in the currency are strong enough to keep most people mostly honest it works. A purely virtual currency like bitcoin would be a problem as it needs to record each transaction with the network, but maybe that too can be overcome by some breakthrough in the future. [Answer] I'm going to go against the grain and suggest that not only is it impractical, but it's actually a bad idea to have a common currency across a single planet, let alone a single solar system. Economics is not the study of money; it's the study of production. Money is just the means of measuring the product of disparate industries in a common way. A laptop costs more than a hamburger in modern economies because of the amount and cost of the raw materials that go into it, and the cost of the skills required to assemble it. In a common market, the use of a single currency is actually a good thing; it means that when I make a laptop and offer to sell it, my resources and skills are being 'traded' at a par for their worth, based on supply and demand. The problem being asked in the question above is 'can we make the entire solar system a common market?' The answer is no, and it's a really bad idea to do so if you want to keep the entire solar system prosperous. The Euro is a classic case in point. Let's just look at two countries; Germany and Greece. Before the Euro, German cars were expensive and tourism to Greece was cheap. Why? Because everyone wanted German cars, but when it came to international holidays, price was often a key consideration. That meant the people who wanted German cars HAD to buy Deutchmarks to get them, but you only bought Greek Drachmas if you were going there on holiday. This meant that the currencies are compressible; as you trade currencies, the supply and demand curve actually applies to currency itself in this case. What that meant in practice was that tourists injected a LOT of money into Greece because relatively speaking it was cheap. Fewer people bought German cars because they were expensive. Since the Euro, that compress-ability between the currencies is gone. If you want a German car, you invest in Euros. If you want to visit Greece, you invest in Euros. BOTH countries require the same currency, but are competing in very different markets. The upshot? Germany is selling many more cars and becoming very prosperous, and Greece's economy is constantly on the verge of collapse. The single currency makes sense for countries where there is TRULY a common market but in practice that never happens. This is why certain areas of any large economy seem to miss out on the prosperity as well. They are simply producing services or goods that aren't competitive at the current value of their currency or they just produce less of the main national products per capita than the rest of the country. Even here in Australia we have this problem, with states like Queensland and Western Australia producing much of the mineral wealth of the country and wanting to keep the income from that product for their own state based services. A common currency is only possible in a common economy, and every region (let alone planet or moon) will be different in terms of what mineral wealth they can exploit, how much of their own O2 and other life support requirements they can manufacture domestically (and how difficult that is), how self-sufficient they are for food, shelter, clothing and the like, and even transport; getting goods to and from (say) Neptune in this post-modern solar system would be almost as difficult as it seems to be getting it to Australia today. The only way that these regions and planets et al can compete with each other in different conditions, with different economic strengths and weaknesses is with different currencies that are openly traded to supply and purchase goods and services between each other. Countries that are not competitive because they don't have much mineral wealth or excess goods to sell become more competitive by value of the fact that their currency reduces in value. That means that domestic services become more attractive to external buyers. How do we know this is the case? In our globalised world, what countries have good official cash (interest) rates? None of them. Globally all the developed countries are offering the lowest interest rates on bonds and the like in history, because to keep their economies attractive to international buyers they have to keep their currency down to as low as possible a value, meaning that they only want people buying their currency to buy their goods, not as an investment opportunity. The other way of lowering the value of your money is to increase supply by just printing more (also called quantitative easing, something our US friends should know about quite well). If you do this in an uncontrolled manner it's bad because it leads to runaway inflation, so it can be risky, but if you know what you're doing your currency remains competitive. So; if you're working on Ceres (for example) and have massive amounts of Iron Ore or Nickel to sell, but need to ship in Air and Food et al, you don't want the same currency as (say) Australia, which ships a lot of Iron Ore and also food. You want to compete on the Iron Ore, but buy food from them. Australia on the other hand probably doesn't want anything you can supply. So, you want your currency to go down in value by comparison to theirs. Sure, the price of food goes up, but at least now you can pay for it because people are buying your Iron Ore because in relative terms, it's cheaper than what Australia can supply it for. The one caveat in all this is that if you have an effective government, with strong egalitarian principles and capability that is committed to ensuring that ALL citizens have access to air, food, and the other necessities, and that ALL commodities and services are priced fairly across the system, then the need for separate currencies goes away. That said, you're talking about a system of government that would need to enforce strict and complete regulation on all markets, and that's not feasible at all. Our modern forms of government are lucky to apply such ideals to their own country, let alone a solar system. Therefore, if you're going to implement a society across the solar system, my recommendation is to allow them to trade in separate currencies and let those currencies rise or fall relative to the others based on their import needs and the values of domestic goods and services they can create. That's the only way to maintain some economic stability in the long term, and it also allows the different regions to adapt. [Answer] The easiest way to do this is to have a common government. A common government would regulate the currency and make it valued throughout its region of authority. This is actually a common principle in Sci-Fi stories. If you don't want a common government, and you seem to suggest you don't, then it gets a bit harder. If the planets were heavily connected through trade, it would be possible that the two planets would work something out. A similar concept to the Euro could be used. Have the entire solar system agree to have a common currency, to make trading easier. This would also bond the solar system in an economic alliance, which very well could be useful, especially if there are other inhabited universes in the world. You could also have it that a solar government rose and fell, but the currency was kept. This would would be especially likely in the case where the government was overthrown throughout the solar system, through a temporary confederacy of revolutionaries. These revolutionaries would then go their separate ways, but likely they would keep some things in common, such as currency. --- Now, some would say that the value of the currency would vary from place to place. This would be true in some ways, but it isn't really a valid point. No matter where you are, the cost of living is higher in some places then others, even in the same country. It takes more money to live in London than it does to live in the countryside. Because there is no currency to compare this solar currency too, it has a set value, but in difference places the cost of living may be more or less. To regulate the cost of living, a solar committee (with delegates from all the sovereign planets), would decide how money could be produced. This would limit inflation, and prevent some planets from producing mass amounts of money, which would lower the value of the money on their planet, but they could still spend it on a high-valued planet. Because of these features, a decentralized currency could work. [Answer] # A brief history of currency ## The Ancient Way: Money has the color of gold For a long time, 'money' was only something that could be exchanged for value. This is more or less and extension of the barter system with something that is widely recognized as having a value among many cultures and regions. Gold was the one natural commodity that fulfilled this best on Earth. Gold has several properties that make it useful as a currency. First, and perhaps most importantly, is that it is visually pleasing and distinctive. Nothing shines quite like gold. Second, it is durable; that is, it is not used up. Spices were consumed, and more practical metals like iron were beaten into swords and plowshares. Gold was never 'used up' on anything practical; it was kept and displayed as a decoration (and expression of wealth). Third, it was imperishable. Gold [famously](https://english.stackexchange.com/questions/139073/meaning-of-if-gold-rust-what-shall-the-iron-do) does not rust, barely tarnishes, and generally needs only a rub with water and/or oil to polish back to a fine shine. Fourth, everyone knew what it was. Even if you have something that aught to be valuable, if you are trading it in a distant place the potential customers for this product must also recognize its value. A medieval merchant would not have paid for some valuable modern resource like crude oil or lithium. But gold, on the other hand, was present throughout the Earth, and pretty much every ancient civilization valued it. Therefore, it was an accepted article of trade from [Cipangu](https://en.wikipedia.org/wiki/Names_of_Japan) to the [Cambemba](https://en.wikipedia.org/wiki/Cambeba). Of course, silver was often used worldwide as a currency-like trade item alongside, and sometimes even replacing, gold. But silver's properties are just like gold in this regard, in its aesthetic appeal, Ultimately, trade in gold in this way is more like to barter than to a proper currency. It is exchanged value for value with another trade good. It just happens to be generally accepted as a trade good anywhere. An analogy of this within a solar system is finding some good that is valuable to anyone. In our solar system, anyone on Mars might value a comet full of water or ammonia. People on Earth might value rare Earth metals or liquefied hydrogen. People in the outer solar system would put a premium on solar energy, or, lacking that, food grown with solar energy. But to make a good that is really like a currency it should be a single product that is universally valued. Gold is still a viable candidate, given its continued rarity and appreciation as a marker of wealth and prestige. But a better candidate might be some rare element that is critical to some futuristic technology. Perhaps lithium for batteries, Helium-3 as fusion fuel, or some rare element (I vote [Bismuth](https://en.wikipedia.org/wiki/Bismuth)) as catalyst for some futuristic technology (Maglevs! Cold Fusion! Warp Drives!) ## The Medieval Way: Send your brother Lets say you are the richest man on Mars, and you want to get into the ammonia importing business for this nitrogen-stared world. Lo and behold, there are a bunch of ragtag colonists have placed a station in orbit of [Charon](https://en.wikipedia.org/wiki/Charon_(moon)) which has cryovolcanoes blowing the stuff practically into orbit (Note: this is speculative!). However, your Hegemonic People's Republic of Mars credits are [no good](https://scifi.stackexchange.com/questions/72431/why-didnt-qui-gon-jinn-use-his-jedi-mind-tricks-to-exchange-his-republic-credit) in the wild west of the Kuiper Belt. How are you going to establish a trading relationship out there? Well, if you are anything like the [Peruzzi](https://en.wikipedia.org/wiki/Peruzzi), [Fuggers](https://en.wikipedia.org/wiki/Fugger), or [Rothschilds](https://en.wikipedia.org/wiki/Rothschild_family), you will send a trusted family member to act as your factor out there. You see, you still have lots of valuable Martian industrial and agricultural produce that the barbarians of the Kuiper belt would pay good money for. So you sent your brother out there and every couple of months ship him all the goods that he could ask for. He will then sell the goods for whatever goods or currency is valuable locally and then when he has amassed enough capital, pay for a giant ammonia ball to be mined out of Charon's surface/atmosphere and shipped back to Mars. Sending a family member or similarly trusted person is key, since the time gap for even light speed communications to Pluto is 4-7 hours (depending on orbital alignment). If your factor is cheating you, the local law enforcement won't care (remember, the Kuiper Belt is the wild west), and it will take months to get a replacement sent out there. Better to send someone you trust, and what is thicker than blood? Once your factor is in place there, many other options become available. Wealthy persons at Pluto Station will be eager to do business with your factor, because they can obtain a letter of credit there that will be exchangeable on Mars for a whole variety of commodities. You see, the wealthy people of the outer solar system have the same problem that you do: their 'currency' might not be accepted in the inner planets. If they want something as pedestrian as old fashioned as a leather belt made from a real cow, where will they get the money to pay for it? This is where your factor comes in. They pay him in whatever currency is valid on Pluto and in exchange, he gives the a note that they can redeem on Mars for something that will hold value in the inner solar systems. In actual history, this is how most modern financial institutions were born. The Peruzzi and Bardi of Florence used this method to begin the first international banking in the 14th century; the Rothschilds used this same methods to start the international bond market in the 19th. It would not be surprising if the interplanetary banking market started this same way. # The Modern Way: Central Government Currency There is a long way to go before you can have a 'modern' currency such as that we are all used to with the Dollar, Pound or Euro (apologies to readers from other regions). When the US Government first issued the dollar, it was explicitly backed by 'reserves.' These reserves took the form of something with a value that people could trust, gold (see: The Ancient Way, above). This continued for a long time. The UK did not come off the gold standard until [1931](https://en.wikipedia.org/wiki/Bank_of_England#20th_century); the US until [1971](https://en.wikipedia.org/wiki/Nixon_shock) (for international convertibility, for you pedants out there, which is what is relevant here). A central government can still, even without the currency being officially recognized, issue a currency that is valid in other places. I have personal experience with the value of the not-officially-recognized US Dollar in Africa. The key is, you will have to negotiate each trade with an exchange rate built in (again, as I personally experienced, and African merchants are much more up to date on the exchange rates than I). If the central government is stable and trusted (as regards its debts and currency, at least), then any currency it issues would be valid. Given that the Republic encompassed tens of thousands of systems during the Star Wars prequels, for example, [Watto](http://starwars.wikia.com/wiki/Watto) would have been a fool not to have accepted Republic credits. He could have driven a hard bargain on exchange rate (he did have the only available hyperdrive) and then found another local moneychanger to exchange Republic credits for whatever he wanted. Unless the Republic had a 10,000 year history of defaulting on its debts, anything that is valuable somewhere else is valuable here too, minus the cost of transportation (which, incidentally, seems pretty cheap in Star Wars). In this solar system, it would be reasonable for any large and stable governments, United Earth and the Hegemony of Mars, for example, to have currencies that are widely accepted. Even in the far reaches of the Kuiper Belt, where pirates are more common than lawmen, anyone could appreciate being paid in Martian Ducats, since they will be sure that they can get a good deal from someone else for that money. This monetary system relies completely on trust in government. By trust, I mean that people trust that the government is valid. This has been the case for so long in Western nations that people just take it for granted, these days. But it wasn't so long ago, barely 100 years, that [civil wars](https://en.wikipedia.org/wiki/Spanish_Civil_War) raged, [governments were replaced](https://en.wikipedia.org/wiki/March_on_Rome), and [hyperinflation](https://en.wikipedia.org/wiki/Hyperinflation_in_the_Weimar_Republic) destroyed the value of currencies. So long as the people of your solar system can trust in at least one government that is issuing its own currency, there can be an agreed upon medium of exchange. [Answer] I tend to agree with you, information delay could be the biggest hindrance, however, light travels from the sun all the way to Saturn in ~80 minutes. So assuming a worst case scenario that the earth and Saturn are on opposite sides of the sun and need a relay satellite you'd have about a 4-5 hour delay for round trip communications, and as someone mentioned quantum entanglement is coming close to fruition and that would change things quite a bit. Don't forget that most currency is really only a 'thought', a counter in a computer somewhere. [Answer] Critical factor for a common currency is the sheer amount of commercial and people interchange. There is absolutely no reason why having even a few days delay could not be handled via decentralized clearing house mechanisms. It is well over half a century now there is no currency in the world which is actually backed-up by anything "physical". All points in @TimB answer (which I upvoted) are valid but the last. There won't be any difficulty setting up a "purely virtual currency" beyond than the usual one: no privacy about how you spend your money. This has nothing to do with possible transaction delays. The *only* requirement for a stable currency is the belief it will be honored, somehow, somewhen. There has been a period (1975-1978) where shortage of actual minted coins in Italy spawned appearance of "[minassegni](https://en.wikipedia.org/wiki/Miniassegno)" which were a kind of "parallel money" commonly accepted for the only reason people was convinced (mostly rightly) they could later spend them at no loss. In the same period also [telephone tokens](https://en.wikipedia.org/wiki/Telephone_token) were exchanged as currency (nominal value 50Lit) for the same reason. OTOH if there is but a trickle of interchange reasons to keep a common currency would be much lessened and drawbacks enhanced (see below). Note that large good transactions, operated mainly by international firms (e.g.: oil, cereals, etc.) are handled via completely different channels and do not contribute to push to unify currency. Common currency is a necessity for highly integrated economies in order to avoid fragmentation due to customs duties and competitive devaluation. [China currency](https://en.wikipedia.org/wiki/Renminbi_currency_value) is a good example of why loosely connected economies could want separate currencies; a good summary can be found [here](https://www.wsj.com/articles/yuan-devaluation-enters-debate-on-whether-currency-is-undervalued-1439307298), it boils down to fact that keeping Yuan value low they can keep foreign prices low and help invade markets while, at the same time, making import more expensive thus helping internal market. It should be noted that (and this is a **most important** consideration) this can and will work mainly because China has a mostly closed economy relying on internal resources and thus *not spending (much) money* to import raw materials (how they acquire the few things they need abroad (mostly Africa) is a very interesting subject, but out of scope here). OTOH some economies, most notably European one, are tightly interconnected and mostly based on transformation of goods with a continuous interchange with other partners. In this situation stable common currency is needed to allow each single firm (even small ones) to plan sensibly the myriad of micro-transactions needed to actually produce something. Bottom line: Common Currency is a must for integrated economies and a hindrance when transactions are purely commercial and "not needed for production" (needed for revenue). This has *nothing* to do with the actual form currency has (electronic, paper, gold coins, whatever) and time needed to clear a transaction. [Answer] Use a virtual currency. Not "virtual" like Bitcoin (although I imagine there would be plenty of cryptographic or otherwise "purely bookkeeping", non-physical, currencies anyway), but "virtual" in the sense of an abstract currency that no one actually uses directly. Let separate local currencies develop. Don't even try to stop it. As explained in Tim B's answer, that'll be better for everyone's economies anyway. On top of all that chaos, though, you establish a single system-wide banking and/or payment system. (This doesn't have to be, e.g., a single bank or a single credit company; it could just be a universal industry standard recognized by a bunch of different banks and payment processors.) Even right now, in the real world, somebody can pay me in Euros and I can deposit those in my American bank, and the bank won't bother keep separate balances--they'll just tell me how much I have in total in dollars. And then I can fly to, e.g., Ukraine, and withdraw my balance directly in hryvnia at an ATM--the conversion just happens magically, behind the scenes, dependent on whatever the present exchange rate is. So, now you're just going to use your universal banking system to add one extra level of abstraction--the virtual currency. Rather than reporting balances in any one real currency, you establish a virtual currency, not tied to any particular local economy or government, that's used to translate the values of different local currencies into a single common scale. Your reported balance might vary a bit from day to day as the exchange rates with the backing real currencies vary, but if you wanted to put in the effort to pay attention to the underlying details, you could instruct the bank to keep all of your balance in a specific real currency, or set of real currencies, or to automatically trade for you to keep your balance as stable as possible, etc. If you *don't* want to, though, you'd only *have* to bother with the details if you ever wanted to actually withdraw cash in a real local currency. Otherwise, everywhere you go, people can quote prices in the virtual scale, you can pay for stuff electronically, and nobody ever needs to think about the fact that the real currency backing your transactions happens to be different in different places. The details of how all of the exchanges happen behind the scenes is a matter for governments and banks, not vendors and customers. [Answer] # Implementation In order to realistically implement a single interplanetary currency, you will need: 1. A digital currency that can be "partitioned/sharded" by location 2. Each partition acts as a "virtual local bank" for that specific location (jupiter, earth, etc.) 3. Transactions are handled by the "virtual local bank" 4. Everyone/every company will get one account per "virtual local bank". 5. Many days will be needed for "inter-bank transfers" (one account at one "virtual local bank" to another account at another "virtual local bank"). 6. Personal transactions can be done on cell phones. 7. "inter-bank transfers" are done over a network of RFC 4838 enabled interplanetary communication satellites. This design seems to encourages a single currency. However, society may start to break things up into "local currencies" due to "cost of living". Social Engineering would have to keep that straight. # Money based on valuable materials Currencies based on gold will collapse as soon as a space-based mining company got their hands on an asteroid similar to `433 Ero`. <http://news.bbc.co.uk/2/hi/sci/tech/401227.stm> Also, `16 Pshyce` is said to have "$100,000 quadrillion US dollars worth of iron". <https://www.sciencealert.com/nasa-just-fast-tracked-their-mission-to-explore-a-10-000-quadrillion-metal-asteroid> That is: for a space based civilization, raw materials are cheap. The movie "Jupiter Ascending" comes to mind. # Money based on physical coinage IIRC, Klaatu from the original "Day the Earth Stood Still" movie said he uses diamonds as currency because of its durability. However, since you can turn Tequila into Diamonds, counterfeiting the money would be a serious problem. Actual article: <https://arxiv.org/ftp/arxiv/papers/0806/0806.1485.pdf> 2009 IG Nobel Prize in chemistry: <https://www.improbable.com/ig/winners/#ig2015> Let's assume the diamonds that he uses are more like coins. As a coin, it should be worth more than the material used to create it. With enough anti-counterfiet measure built into the coin, the coins could be made trustworthy. However, now you have the problem of moving money from one planet to another. Transferring physical money from one location to another will be affected by things many things. eg Pirates. To me, this leaves digital curencies such as BitCoin as your only option for an economy of such large scale. (part of requirement 1) # partitioned/sharded virtual currency partitioning and sharding are methods databases use to work with massive amounts of data. Recent database versions seem to blur the two concepts together. <http://www.oracle.com/technetwork/database/availability/sharding-faq-3610620.pdf> With similar technology a virtual currency should be able to be partition/sharded based on location. (other part of requirement 1) This implies that each location handles its own portion of the virtual currency. As such, your lag time for transactions at a location is minimal because all nodes for that partition/shard exists within 3 light seconds. For reference, the moon is 1.3 light seconds away. You could conceive each as these "partitions/shards" as a "virtual local bank" (requirement 3) To help limit overdrafts, everyone keeps some virtual currency at each "virtual local bank". (requirement 4) a person will keep more money at the "virtual local bank" that's near to their work/home at then the one near their vacation spot. It becomes a social norm to do an "inter-bank transfer" as part of your trip. Distance between "virtual local banks" can be measured in light days (oposite ends of kupir belt is 50 AU \* 2 ~= 0.6 light days) Accounting for other time delays, a transfer of between "virtual local banks" could take up to a week or more. (requirement 5) This would allow local "loan sharks" to become an industry. # Details ## personal transfer Now that I've explained how the "big picture" works, let's look at the details for an individual transfers. For this, things like "MasterPass" and "Google Pay" are viable basis of the required technology. I don't thing things like physical credit cards would be a thing. "Tap to pay" between devices is what I would expect. Most likely, people will use their cell phone. (requirement 6) ## communication Next to discuss is the problem with communication between such long distance location. Let's say you are on IO and your bank is on Earth. Being on opposite ends of the sun would be bad for communication due to the sun blocking the "line of sight" of radio waves. I'm sure NASA doesn't like losing communication either. This is probably why they are working on Disruptive [or Distributed] Tolerant Networks as we speak. (requirement 7) <https://www.nasa.gov/content/dtn> [](https://i.stack.imgur.com/yVwDV.jpg) Part of the solution includes RFC 4838. There are others RFCs that go with it. # Conclusion It is very conceivable to build a realistic world that has a single currency that is used across multiple planets. [Answer] This is kind of a supplement and solution to the problem that TimB pointed out of having different markets with different requirements competing with the same currency. One solution is to have several levels/tiers of currency for different things. The first tier would be a solar system(s) spanning currency. This could be block chain based, and it doesn't have to be fast. This is the kind of thing that governments and corporations would generally deal in, and normal citizens might use for long term savings/retirement funds. This tier is called slow currency because any interplanetary transactions have to be verified against the block chain at the speed of light. You might use this if you were buying property or other transactions that deal with large sums of money and don't happen quickly. Transactions are also slower because it would be verified against multiple chain sources for security. The second tier is medium money, and would be for local systems, like the Earth/Moon system, Jovian system, etc. It could still be block chain based, but since the speed of light is less of a problem in orbiting bodies you wouldn't have to wait quite as long for the transaction to go through. Citizens would keep most of their money as medium money, and the primary uses would be as every day savings, paying bills, pay check from employers, etc. The last tier would be fast currency, and could be token based, such as coins, paper notes, etc. which are issued for use locally. This would be for every day purchases such as food or goods where you don't want it to take hour(s)/days for a transaction to be verified. How this system would work in practice: Say you live on Earth, and want to take a vacation to a spa on IO. You would take some of your medium money and exchange it for slow money before boarding the ship for the trip. When you are a few days out from IO you would send ahead to transfer some of the slow money to Jovian medium currency so that it would be ready when you arrived. When you land on IO and finish going through customs you'd exchange some of the medium currency into IO fast currency so that you could stop for some fast food on the way out of the space port, pay for a cab, etc. Each system and local place would have their own exchange rates based on demand. To exchange Earth system medium currency to slow currency might be 75:1, and the exchange from slow currency to Jovian medium currency might be 1:100. The exchange rate from Jovian medium into IO fast currency might not be as favorable as it would be for Callisto fast currency, as IO is more popular. Now lets say that you are there for a week and run low on medium currency, when the chance to see some super event comes up and you need a little more currency quickly. Now it takes a day or two to exchange normally, but that's too slow this time, and so you do the exchange with an added fast processing fee, say 10%, which is basically insurance for the exchange that you aren't trying to cheat them, so instead of 1:100 you'd get 1:90. [Answer] **What is a currency?** -All a currency is, is an item that society says has universal value such that it can be exchanged for goods and services. The problem with currency in general is what is that value and what happens when that value changes. **Historically,** currencies that are made with rare widely desirable goods (like gold) tend to be more stable, because everyone wants gold. The problem with those currency system is that you then have a finite resource that represents the entire economy so the value of the currency becomes prohibitive in small denominations. You also have the problem when someone floods the market with that good so its value decreases. **Paper currencies have similar problems, so bottom line no currency is perfect especially across isolated economies.** Your best bet is to have a currency that's difficult to produce yet universally needed. **Perhaps: Units of Energy** **Perhaps: In the form of anti-matter as a storage option, or some other sci-fi energy storage concept** Everyone needs electricity so it can easily be used as a universal futuristic trade currency. The trick is coming up with a reasonable storage method that is carry able, safe, and easy to use. [Answer] If we completely ignore the concept 'money' and focus on the mines or raw materials: One of the the primary property of a material making it valuable is it's rareness. But to be able to become a currency and to be used instead of exchanging goods or services, a medium rareness level, I think, is better. (with always very high durableness level) Let's define: *Low rareness level:* Choosing stone chips as currency is not going to be a good idea as everybody can find tons of them easily. *Medium rareness level:* Gold is hard to mine but not so hard. One can find gold almost everywhere today and it is not difficult to imagine a world using gold as the only currency. *High rareness level:* Meteorite for example, is very rare but using it as currency is not possible because it is really rare. Now, if we come to the point of the question; in today's world a Moon rack can not be a currency because it is incredibly rare. Only Apollo astronauts and the unmanned Soviet Luna spacecrafts brought some. However if we have shuttles going to the Moon and bring some racks every day, all day, and assuming the Moon rack is easily be distinguishable from an ordinary rack it can be used as a currency. If we go one step further, if a several hundreds of thousands of people moves to the Moon, then Moon rock can not be a currency for the residents of the Moon, of course, while it can still be used in the Earth as currency. This time, Earth rack may be used as a currency among these very first citizens of the Moon!(This is not a good idea because carrying money is easier then carrying stones but we are assuming a moneyless civilization. (Just for analogy)) Then there will be exchange rates. **x units of Moon Rock = y units of Earth Rock.** x and y are determined according to the total number/weight of the Moon and Earth Rocks in the other celestial body. Similarly, assuming spaceships can easily and frequently carry materials between planets or moons; a material reaching a medium rareness level in one planet and originated from another planet can be used as the currency. And there will be exchange rates. Or any material, regardless of its origin, can be used as the intergalactic currency if it can reach medium rareness level in all planets. [Answer] My favourite solution is to have a mechanism where space and time are null and void. **You need another realm.** The idea of a universal currency is fantastic. Whether some want to admit it or not, currency has driven every global decision since it was invented. Bitcoin is doing phenomenally well, this very day, and WTH is bitcoin? **So, how do you bypass space/time?** You can bypass the issues of space/time either with theoretical constructs like wormholes, which is the physicsy way of doing it (and probably rife with problems), or through what would be more appealing to many, including me, some sort of 'other realm.' This could be, e.g. (1) the akashic library; (2) telepathic consciousness; (3) transcendentalism; or other. How might this work? This is up to you. I'd suggest bitcoin as a current conceptual model. You realize it doesn't actually exist? I mean, WTH? **Perhaps, in the [akashic library](https://en.wikipedia.org/wiki/Akashic_records) model,** or some derivative: Knowledge of the past, present, or future is transferred as currency. You bring your library card, with knowledge that, for example, Donald Trump was (quite unexpectedly) elected president. No one else expected or knows this yet (thank you, space/time), and so you have cache' of real value. After all, his election will change the power struggle on Earth, and therefore - ripple effects. You cash in this knowledge, and in return, can learn about events in other systems. You learn, for example, that the orgasmic flow of the microscopic algae on Tantalus VII will, in five years, market their essence on a pan-galactic scale (hint, orgasmic essence, buy stock now!). This is it, man. Intergalactic trade of commodities communicated through higher realms of consciousness not bounded by space/time. (Similar constructions with telepathy, et cetera, as to the akashic library.) [Answer] I think it depends on how (inter)dependent the planets populations are on one another. If most goods must be ordered from Earth, prices may vary regionally, but will probably be in Earth currency. If most transactions occur locally, you'd probably see regional currencies better suited for local trade not as directly subject to market conditions light-hours away. [Answer] I suspect your answer rests with what happens here on earth. I posit that it will be a very long time before Earth's economy does not dominate the colonies. For the most part, trade will be of resources coming to earth, and finished products going out to the colonies. So either the Earth will have a common currency, or each earth-based economic zone will trade in their own currency. Thus, any trade from any colony dealing with Europe will deal in Euros, Russia in rubles, India in rupees, and so on. This mishmash will lead to exchange problems in the colony itself. How do you price goods, when so many currencies are in circulation? Of necessity, I can see each colony adopting their own local currency (probably an ad-hoc black market currency to begin with), while external trade is done in other currencies. However, if interplanetary trade is conducted predominantly in one earth currency, that currency will prevail on the colonies. Goods will be priced in the currency of import-export trade. The earth-based manufacturer will set the price in the currency they use and deal in. There will be no need to develop a local currency. Calculating exchange rates is absolutely the last thing a manufacturer wants to deal with. There will be no historical inertia, no past culture or societal pressure to maintain a traditional currency in a newly formed colony. I suspect the currency that is adopted internally will be the prevailing currency of the colonizing country. If America colonizes it, the greenback will prevail. If Europe colonizes it, the Euro will prevail. Colonists will take their native wealth with them, in their native currency. Using China as an example (and a good one, as it is now the largest earth-based economy) they use the renminbi internally, and it is really the only currency that is accepted in internal trade (beyond the tourist meccas). However, outside the country, the renminbi is worthless. It can not be used for trade anywhere. Try walking into a local store and buying something using renminbi. China basically uses the greenback for external trade, while ensuring it is virtually worthless within the country. If China colonizes a planet, will they use the renminbi or the greenback as currency? I suspect of all earth-based currencies, the greenback has the best shot at being a universal currency. Notice I did not say American greenback. America has lost all claims to the greenback. Over half of all greenbacks in circulation are outside of America. Europe trades with Brazil in greenbacks, without the currency ever touching American soil. Effectively, every nation has a vested interest in maintaining a stable greenback, so even if America disappeared from the world economy, the greenback would still remain in circulation. World trade depends on it. I suspect some world trade organization, perhaps the United Nations, or an international consortium of banks, would take over 'ownership' of it. They would take control of 'the Fed' bank. I would not be surprised if 'the Fed' relocated to another more stable country in the foreseeable future. In such a scenario, I would posit the greenback (not the American greenback, but the global currency greenback) would become the currency of international, AND interplanetary trade. A company would buy, say, lithium from lithium mines on an asteroid using greenbacks, and sell it for greenbacks to a manufacturer on earth for the same greenbacks. Weather or not the mining companies on the asteroid paid their employees in greenbacks, or the currency of their home country, would be unpredictable. Perhaps the decision would be made by the executives of the company, since the asteroid would primarily be a company town in the beginning. [Answer] Please consider the [Theory of the optimal currency area](https://en.wikipedia.org/wiki/Optimum_currency_area). Depending on whom you ask for such a common currency to work, you will need a) low trade bariers, b) labor mobility (people can and do move to where their work is needed the most, which is not this easy if they e.g. don't speak the same language) and c) a common fiskal politic or at least fiscal transfers. Euro is a good example for a not-optimal currency area, because it has only a). If you don't have wormholegate-maglev-trains you should get problems with a) and b). c) depends on your political system. It is not easy in a democracy to get votes if you give a lot of money to people on another planet just because e.g. (your opponents slogan) "they are to dumb to invent as much as your people" or because "they decided to save their ecology instead of burning coal to feed themself". You might get around a lot of problems with digitalization, automatic translators, remote working and such, but then you might just want to establish an automatic currency converter on your banking-thingy instead. All this is of course 20th century thinking. [Answer] If you have a Multi -planet civilisation you most likely have quantum communications already (given the current work dedicated/progress to this end, in a few tens of years it will be reality) , so communication won't be your biggest problem(i believe nationalist movements will be). Just like the ones above me stated in some cases the EU is a fine example of what would the society you describe look like and for better of worse it's stil stable for now(excepting some political movements fueled by some particular peoples' interests...) [Answer] **Money cannot work across planets for the following reasons.** > > 1. The universe is yet to be discovered. We do not have full knowledge of how the universe works. > 2. Multi-universe needs to considered. > 3. Dominating intelligent life in so-called habitual planets has to obey this money treaty if at all we devise some. > 4. We are considering a narrow band of the universe into this picture out of the multi-dimensional universe that exists in higher dimensions > out there. > 5. Maybe we are influenced by higher order dimension life forms' intelligence on what we are, we were and we have to be. > > > So, Your thoughts on how to make money work on different planets? is very narrow which is influenced by we being considered as the super life forms that live in this universe and we want to impose some treaty across planets. Let's keep this simple. In this mother earth, only humans accept the currency/money in exchange for trade and no other living beings. Unless we get the solution here on earth we cannot derive a solution that works across planets. For that, money will not be the common treaty but something else has to be the way to go. Ants will never come to this treaty if you wanna impose same on them. Dogs will never know what you are talking about. Virus bacteria will simply ignore you. Instead of thinking about making currency/money work across planets. Let us think and solve the same problem on the earth. How can we make other living organisms on this planet earth to agree on this treaty of exchange of money? If we make all the living organisms on earth to agree upon this treaty, we can do the same in space. Here, none of the so-called physical and technological barriers, such as cryptocurrency, paper currency, space-time travel, will ever matter. **The answer would be:** **can we use money?** > > NO, we cannot use the money. Something else has to be agreed upon > across organisms and planets. > > > **can we?** > > yes, we can make money work across planets, if we > solve the above problem on earth for the different living beings. > > > **how can we?** > > the same solution that we derive for all the living organisms to > accept the treaty might work or even a complex solution might work on > other planets. > > > [Answer] If spanned across several planets, solar systems, galaxies, etc, relying on any kind of physical currency would be mostly unreliable. If in the case of multi planetary currency, they would most likely turn to a digital currency such as Bitcoin for example. The only issue with digital currency would mostly be backing, similar to how the US dollar (used to) Be backed with gold. It has to be linked to some sort of valuable physical object or material to make it worth something. ]

[Question] [ Let's focus specifically on the devolution of empires. How is it that something so powerful falls? The collapse of Rome, Byzantium, the Han, the Mayans and so on. What similarities can be seen in the fall of these great empires? Whether natural events, social trends, or technological advancements. Also, how can one use this information in building worlds? [Answer] There's a fascinating book seeking to answer this exact question called Day of Empire by Amy Chua. The gist of her answer revolves around tolerance, empires rise when they demonstrate it and fall when they don't. Rome is the poster child of this hypothesis. Beginning, as she claims, as a bit of an underdog rogue state where outcasts of other places ended up, Rome had a diverse range of knowledge from all over the ancient world. And where most societies would marginalize these outsiders, early Roman society embraced them. Immigrants were a vital source of ingenuity and labor, this let them steal more than a few useful technologies from neighbors and consolidate themselves as a technological powerhouse. Most of her argument is sort of made in the context of modern America, so take it for what you will, but the early days of the Roman Empire were sort of bound up in that scrappy, underdog identification. But before they knew it, they controlled the known world and adopted the Persian governance model, until they realized that what defined a Roman citizen was vague. Hardships came as a solid identity was sought and subsequently enforced on everyone. Rebellions started to emerge and all the effort enforcing internally left them weak externally. But she goes through a number of cases, exploring this trend. The Portuguese had a similar underdog status until they founded their navigation school and became a mecca of shipwrights and astronomers. This fueled a boom that led to an empire lasting almost to the present day in strategic pockets. The Dutch had a very similar start to their story, eventually inventing the modern economy before the grand daddy of empire England welcomed the Dutch themselves into their fold with the Glorious Revolution. England's story of tolerance includes the formation of the United Kingdom in the first place, and the historical status of Great Britain as a warzone for everyone from the Romans to the Vikings. There was a great deal of people calling the island home and national identity was very fluid. As they spread all over the world, they didn't try to usurp local power. In India, they ruled through the traditional ruling class. In Africa, they'd just pick a favorite chieftain and support him with guns and the like. In Egypt, they just added a military arm to an existing state. The moral of her story was that you didn't need to be the biggest, best or smartest to rule the world. You just had to be willing to accept people who were. Most of the technological might of superpowers throughout history were not the result of nationals working in isolation, but collaborations often involving immigrants. The second part of the argument was why would a historical pattern of tolerance leading to greatness ever devolve into a pattern of intolerance to tear the empire apart. In absolutely basic terms, a society needs some sort of glue to define it and make everyone feel like they're a part of it. Many empires have camaraderie aplenty to define them, oftentimes because they are an underdog in regional politics and historically beaten around. Rome was a gaggle of outcasts. Portugal had been battered around by Spain and the Moors for ages. The Netherlands had been the butt of Continental politics for awhile. Great conquests that lack this kind of cohesion quickly fall apart, such as Alexander the Great. There was no effort to call his subjects Macedonians and when he died, his generals just carved up their own kingdoms. Rome offered a path to citizenship and made it look appealing. For awhile, there were a lot of traditionally Roman Romans to define the culture, but gradually, enough outsiders completed their service and were made citizens. Eventually, this led to the arguments we see even today about how adding such and such group detracts from the original character of a people. In a quest to define what made a Roman Roman, they ended up destroying themselves. Her conclusion was that this was the common tipping point for why a state would adopt a policy of intolerance and cut themselves off from the benefits of tolerant policies. [Answer] Societies advance when they become more internally cohesive, trusting, egalitarian and merit driven. They fall when they lose those traits. [An old blog post of mine expands upon this](http://chicagoboyz.net/archives/4804.html) Military success, increased trade, growth of science, technology and arts are all epiphenomena of the social and political changes. Rome is a canonical example. Rome became a superpower because it was a representative republic with leadership and advancement based more on merit than lineage. Lineage based societies select leaders of all kinds based largely on lineage. You get to be king because your father was. If the leaders are idiots, your stuck with them until they die. Merit driven republics can choose leaders based on performance and remove them in the short term if the fail. Conversely, they can reinstated if proven correct e.g. Fabius vs Hannibal. Rome also allowed a much higher percentage of it's population to bear arms meaning that it could field massive armies compared to surround populations. This gave Rome more military manpower per unit of population that cultures that allowed only a fraction of their population to be armed. Rome became much more militarily "dense" than its competing polities. When the Republic fell, so to did merit promotion and high numbers of military service. The Empire continued by inertia but it was already doomed. It's dispositive that that the Republic expanded massively compared to starting size, growing several times over from a mere county sized area to cover half the Mediterranean world in a little over two hundred years. The Empire expanded only a about a third and reached its maximal extent in the first century. It's easy to see why. Whereas the Republic trusted it's soldiers as sought to see them well armed, trained and led, the Emperors feared them (rightly so) and kept them well paid, but poorly armed trained and led. The imperial armies grew more expensive and political while growing less and less effective. Worse, the percentage of the population who could be armed or serve plummeted. Rome relied more and more on hired auxiliaries who were usually "barbarians" with little loyalty to Rome. From the time of Marius onward, the rule of law in Rome progressively failed with economic success relying more and more on success and connections in politics which in turn grew more and more violent. Romans spent progressively more time fighting each other than anyone else. Merit promotion died. By the end of the second century Rome had inherited vast borders but had lost the social and political systems that fielded the armies to defend them. Trade faltered as property, contracts and profit became matters of political whim. With the fall of trade came less taxes and less military spending. Area after area become isolated and indifferent to affairs in the general empire. In last century, "Roman" armies and their opponents where largely indistinguishable. Rome didn't fall to barbarians as much as become them. Rome had no technological, social, economic or political advantage over the surrounding societies and they just oozed over the borders. In the end, Rome was just another rigid, hierarchal, lineage based society among many. It simply dissolved into the noise. The pattern is repeated time and time again. Athens, Rome, Carthage, Genghis Khan, Venice, Florence, Lisbon, Swiss Cantons, Dutch Republic, England, America. In each case, the societies became more merit driven with decentralized political power and surge in trade, science, art and military success. The success of some is just staggering. Venice and the Dutch Republic particularly stand out. Both were small societies built on river deltas who literally didn't even have land. Yet, they ended up dominating their regions and influencing much of the world. But such societies do not seem stable. Their dynamic periods last only 100-200 years followed by decline into mediocrity. Meritocracy is counter to our genetic programming to favor our kin over others. In the end, riches, arrogance and complacency lead us to let our guard down and we revert to the lineage pattern. I would note that societies generally never recover from decline. Instead the torch of progress passes to another. The Renaissance wasn't the comeback of Rome, it was isolated to a shockingly small number of people in a few Italian cities for under a century and then it promptly shifted to Northern Costal Europe. The progression went Venice --> Florence --> Lisbon/Geneva --> Dutch Republic --> England --> America --> ? [Answer] I think you should take a look at [Toynbee's A Study of History](http://en.wikipedia.org/wiki/A_Study_of_History), which tries to answer this question in detail. The theories may be a bit antiquated at this point since Toynbee was working prior to WWII, but in general he laid out a system in which civilizations are constantly faced with a variety of challenges, and their survival is dependent on the ability of a "creative minority" to effect some sort of change in response. A civilization fails when it is no longer agile enough to respond to that challenge. The ages of history then can often be seen as a sort of call and response. If you take Japan vs. China, for example, the approach of the modern era forced both countries to respond in some way. Because Japan's power structure was more centralized and the entire country could be properly mobilized it was able to take advantage of modernization and became an Empire. Its pivot towards openness and expansion was the result of a creative minority that forcibly took power from the then-ruling bakufu. Had this particular creative minority failed to control the policy of Japan, the country may have ended up much more like China, where the bureaucratic system was unable to adjust quickly enough to the challenges of invading westerners and centuries of dynasty were ultimately ended. In a way this theory is closely related to the concept of survival of the fittest. There are a lot of outside pressures on a civilization, but whether that civilization can survive will depend on its adaptability. But Toynbee goes further than that when he posits that the ability of the creative minority to avoid becoming a dominant minority is the primary factor in whether or not a civilization can survive through time. At some point the creative minority will find itself with the largest portion of power in a civilization. It will naturally want to retain that power indefinitely, and will by begin to solidify elements of governance and policy that had before existed for practical reasons. The more effort dominant minority puts into retaining power, the less agile it becomes to deal with any other crises, and the more hostile the general population will become. The pressure of this dominant minority will result in the creation of what Toynbee calls the internal and external proletariat. There will be those who abandon the society and become the "barbarians" of that civilization (easier to do back when you could literally walk away from a nation into the wilderness) and an internal proletariat that resists within the civilization. (examples of this being the Christians in Rome, the Nationalist and Communist forces in colonial China, the Protestant reformation, and so on.) This alienation is an important contribution to the failure of a civilization, because it means that the population from which a creative minority is gleaned is instead invested in resistance. In the case of Japan, there was still a strong allegiance to the notion of imperial authority, and the creative minority was absorbed into the existing structure, preserving the idea of Japan even as it pursued a radically different set of policies. China, however, was overcome by an internal proletariat that was opposed to the fundamental precepts of Chinese imperialism and the resulting military and cultural revolution resulted in a completely different nation. While some (particularly the Chinese themselves) might refer to the unbroken and ancient civilization of China, more cynical observers might say that the old Chinese civilization was cannibalized by an entirely new proletariat, and the current China is actually quite young. As with a lot of things in history, the exact line between one thing and another is sometimes fuzzy. The tl;dr of this is, empires will undergo a number of stages in their development, and their decline is often marked by a crystallization of the dominant minority and increases in effort towards maintaining power and occupies itself with "worship of its former self," instead of focusing on creative solutions to external issues. This results in an increase of resentment and resistance by the disenfranchised population, and hinders its ability to respond to challenges that arise. Eventually one of those challenges will prove to be more than a civilization in this now weakened state can manage, and it will collapse. As I said, this is an older, and not universally accepted, model, but I've found it a useful one to know. When you're building your own civilizations it's good to think of the following questions: * Who is your Dominant Minority? * What previously creative elements of the civilization may have fossilized into detrimental behaviors/policies? * What are the complaints of the disenfranchised population, and particularly what is the nature of their rebellion? If you have these three things, you can see where points of particular conflict or stress might arise, and result in openings for a fatal blow to a civilization. [Answer] Many, many, many different things. But almost always something outside of that empire's control. A few examples: * Outside invaders This is a very common one - it can be large and powerful invaders like Alexander the Great and his multiple conquests across the world (See also: The Mongol Horde), or incursions from 'lesser' forces that use superior technology/tactics, such as the superior fighting skills of the Barbiarians (Gauls) that invaded Rome. * Inside rebellion Equally possible is an uprising from within a society itself - slaves are often a cause of this (if you go with the bibical story of Egypt, Moses and his exodus certainly counts) but any downtrodden people within a society can cause similar problems (See: Christians for Rome). * Disease/disaster Don't discount the possiblity of mother nature tearing the status quo apart. Disease completely upturned the nature of power in Western Europe (And severely softened Asia for that matter), and ran rampant across the Americas before Europeans came along. Any disaster, however, could be written in as a major population-destroyer. Floods, storms, floods AND storms, massive earthquakes, mother nature is a very fickle beast. * Decadence And let's not forget good ol' sloth. This is usually part of the disparity that leads to the downtrodden revolting against the upper-class, in partiuclar when the downtrodden include the members of the public that are supposed to lead the army. See Rome (Damnit Rome, you just can't hold onto your empire for more than 200 years, can you?). [Answer] * **Decentralization:** **TLDR:** Potential problems include (not in order): Bad capital position, capital too dependent on the regions, internal struggles at the court, bad administration. My main example here is about the Tang dynasty. Decentralization or lack of centralization was a major problem. They were unable to keep the provinces in check (this weakened their power), but the fatal blow was a reduction of the food production. Their capital was located in Chang’an (today’s Xi’an). It was a symbolic location since it has been the capital of other dynasties before them. It used to be the cradle of China but the economic center of the Empire had moved to the east. The city location was not ideal for a capital but the Tang preferred it because it was the base of their political support and for symbolic reasons. Having a good control on the capital region is very important and many rulers do not hesitate to change the location of their capital for a friendlier one when they founded a new dynasty. But the Tang kept this location (with some exceptions) at the expanse of losing the support of the regions. Most of the aristocrats lived only in the capital, not in the regions. *Note: the Tang knew about these problems. Some Emperors did move the capital to the east at Luoyang, but they always moved back to Chang’an after. That was very costly and foolish IMHO.* The capital was cut off from the border regions when the problems at the court became very serious. Example: one Emperor got murdered by the eunuchs. The faction struggles between the eunuchs, the bureaucrats and the Emperor lead to a couple of years without leadership from the central government. The job of ruling a province was initially a nomination form the capital for a fixed number of years. A weakened court made some local rulers able to make this position hereditary. They were also able to establish a firmer control on taxes and on the army. Rare are the regional leaders that were loyal to the Tang, most had their own goals. Most of them had literally no ties with the dynasty. As a result of these processes, the Tang were unable to collect taxes in most regions they presumably controlled. The regions had enough power to defy the Emperor and that they did during the An Lushan rebellion were the northern lords attacked the imperial forces. The Emperor managed to regain control but at a great cost and the sack of their own capital. The Tang had little authority over the regions and eventually, one general was able to replace the Emperor. *Note: The Tang are generally regarded and the greatest Chinese dynasty because of their cultural refinement not for their efficient administration. The later is more associated with the Song.* *Note: Without good counsellors, a ruler is like a blind man and incapable of acting properly. He might not know what is happening in the regions and can be persuaded to choose certain options that are not in the Empire best interests. Bad persons can influence him and manipulate him, without but also with his consent when the ruler becomes a puppet. A strong Emperor with weak counsellors can also be problematic (Wilhelm 2 in Germany).* Lastly, another problem also weakened the Tang. The presence of a capital city with all the administration personnel and the army protecting the western frontier required more food that what this arid region could produce. They had to import it form the south but the low quantities of rainfall made the transport of goods on the water and rivers canals hazardous. This meant communication problems and a dependency on the other regions. * **Gunpowder Empires**: **TLDR**: One country with the same population, size and resources but with a better fiscal system will have an easier time winning wars. Countries that were successful during this military revolution were those able to concentrate the fiscal powers. *Note: The three main gunpowder empires are: the Ottoman in Anatolia, the Mughal in India and the Safavid in Persia. They managed to conquer huge areas because their neighbours were not able to adapt to this new style of warfare.* Charles Tilly, in his book ‘’The Formation of National States in Western Europe’’ came with a theory saying that although states made the wars, it is the warfare that made the states. To put it simply, it’s like Darwinism applied to the financial and political aspects of a society. The reason why all states are so similar to this day is mostly because others have failed to collect taxes efficiently. The states wage wars and for that, they need money. Those who can get that money have more chance of winning over their enemies. Eventually, smaller countries and those with inefficient fiscal systems will tend to disappear from the map. How can a country attain an ‘’efficient fiscal system’’? Simple, he needs to be able to collect the money were it is… Michel Fortmann in the book ‘’Les cycles de Mars’’ (I think the book is only in French) explain that the introduction of the gunpowder during the Renaissance was a real military revolution. The number of conflicts per century on the European continent was around 8-15 during the end of the middle ages but will rise to over 100 in the following centuries. Spain will be in a state of war for 200 consecutive years and most other countries were at war 80% of the time. The coming of this new technology will increase the financial pressure on the states. States needed to adapt to a new style of war. Armies were changing and becoming more costly. The armies needed cannons, munitions, and many horses to get the cannons on the battlefield. It was also necessary to adapt military strategies to this new reality. Furthermore, the defensive system had to adapt and new fortresses appeared, made to resist the fire of the cannons. The small states could not afford it and those that could afford it (Spain, France…) were in serious financial precarity. The problem of the medieval feudal system was that the fiscal powers were spread across the lords. The king had his personal holding that made about 10% of the country when he was lucky and maybe he received some money from his vassals, but all this is very limited. He needed the support of his vassals for everything he wanted to do. The problem is that individually, no one could afford to ‘’update’’ their army to the new technology. Cities in the center of the country did not see the need to increase military spending and building fortification but cities on the border were threatened but could not pay for it. The solution was to make everyone pay. The feudal system had to change for a more centralized government in order to get that money. It’s a slow process. In France, the king managed to impose new taxes on the cities. The lords could not assure the defence of the kingdom alone, so they accepted the lost of their powers. On the other side, the king had the legitimacy to take the fiscal powers away from the lords, most of it. *Note: According to the author, 2 important countries came to disappear because of their incapacity to centralize the fiscal powers: Poland and Hungary. I’m not knowledgeable enough but apparently, their political system was considered archaic and they were absorbed by other states. It is also interesting to mention the fate of the Spanish Habsburgs Empire and the United Provinces. One had an archaic system and the other was really decentralized. Both lost their Empires but managed to keep their independence. Spain lost control of Austria, the Low Countries, southern Italy and some other smaller possessions scattered in Europe. The Netherlands (this country, whatever you want to call it) , used to be a maritime superpower. The replaced the Portuguese’s for the eastern trade and their maritime power was unmatched. But the defence policy lacked cohesion.* But it goes one step further. * **Representative government:** With representation, people are willing to pay more. Centralizing the fiscal powers doses not really make the system efficient. France before the revolution (Ancient Régime) was an absolutism monarchy. From a fiscal point of view, the problem was that most of the burden was on the poorest people. The clergy and the nobility paid almost nothing yet had all the riches of the country. Even if France had a centralized government at the end of the 18th century, a lot of regional differences, privileges and oddities persisted in their system. The system was inefficient as it was unable to extract a large portion of taxes. As I said earlier, the preceding century saw a lot of conflicts. The 17th was a period of intense warfare starting with the Austrian war of succession if I remember correctly. For France, these wars had a great cost but gave little benefits: they lost New France during the 7 years war. England was able to match France military spending despite being 3 times less populous. Part of this difference comes from the trading revenues of England but most of it comes from the higher tax burden on the English people. Even the nobility paid their share of taxes but not in France. France was an autocracy and the population felt like the taxation system was unjust and indeed it was. In an absolutist monarchy, the king decides everything and doesn’t need to explain his actions. Therefore, it became impossible to increase tax revenues in France. You don’t want to tax the rich but the poor are already heavily taxed. England was a democracy (a representative government), while not perfect, the population could not blame the aristocracy for their problems since they also paid taxes. Furthermore, it is harder to blame a politician who increases taxes that it is to blame an aristocrat that don’t even contribute to the system. Politicians are accountable for their actions in a process called ‘’ the next election’’ but in time of needs, people are also more willing to increase their burden if the government is a democracy. The Thirteen colonies had the slogan: ‘’No taxes without representation’’, and I think it’s a good summary. With representation, people are willing to pay more. Lastly: can this argument be used to explain why the central powers lost WW1? Probably yes for Austria but not so much for Germany. I lack the knowledge to confirm it but the author seems to think it might have played a role in their defeat. *Note: I’m not even talking about taxes on the revenue, this is very recent. Most taxes were on sales, import/export, land holdings. Tax on the revenue needs a more complex bureaucracy that will come later in history.* * **Problematic rules of succession:** When the ruler died, it was a custom in the Germanic kingdoms to separate the holdings equally between the sons, leading to the disappearance of the political entity. The closest thing I could find to call it is Gavelkind, a term used in the game Crusader Kings 2 originally forms the British Islands. Normally, we have another rule called primogeniture were the eldest inherited the kingdom but it was not always like that. The most famous case of this is when the Carolingian Empire was separated in three. The Treaty of Verdun officially ended the unity of the Empire for good. This practice ceased to exist in the region after that treaty. Another example is what happened to the Mongol Empire after the death of Genghis Khan. Although his sons continued to extend the Empire, it was made of completely different entities were each acted on their own. I could also mention the 100 years war here. England and France fought for the French throne because they had a common lineage but did not agree on who should be on the throne. England recognized the right of women to inherit but not France. This almost destroyed the kingdom of France because other countries also took part in the conflict: Scotland, Burgundy, Castille. * **Climatic problems:** A change in the climate, several bad harvests, less rain and a weaker monsoon all diminished the food production and let many peasants in a precarious state. Alone, it is rarely enough to put an end to an Empire. But if the problem persists, it will impact all aspects of societies. In these article: <http://www.scientificamerican.com/article/monsoon-climate-change-chinese> <http://www.climategeology.ethz.ch/publications/2010_Cheng_et_al.pdf> The authors talks about the fall of the Tang dynasty and the Mayan civilization. Both have gotten into decline in the same years and the authors said that it’s related to changes in the climate. In China the Tang are generally recognized as a period of growth and expansion. Like Europe before the Great Famine, the population probably exceeded the capacity of the land slightly before the climate started to change. A weakening in the summer monsoon meant less rain for Northern China and less food. This change might come from the weather system itself or in a change of the planet axial tilt because of a major earthquake. Now you know the other problem the Tang had to face and I’m not sure which one is worst. Ming dynasty: It is said that the dynasty fell because one general guarding the Great Wall opened the way to the northern invaders. Well, the Empire was already in turmoil and the dynasty had already lost the Mandate of Heaven. In fact, the northern region was already dealing with rebels among the military and civilian. The emperor hanged himself before the invasion even started. It is hard to say what would have happened without the invasions. A general might have taken the title of Emperor for himself to establish a new dynasty. Ultimately, the Ming felt because of poor harvests. The invaders are not going to attack a state when he is strong. We should not give too much credit to the invaders. The great Arab conquests were preceded by epidemics and prolonged warfare between the Eastern Roman Empire and Persia. [Answer] Two big triggers would be food production and increased economic activity. When you have a technological advancement that yields higher food production per capita it allows more folks to not be engaged in that endeavor and can do things that advance the culture in one way or another. The same is true of increased economic activity. For example, the medieval feudal system is essentially a completely static (economic) model. No one is getting rich, sure there is a huge divide between classes, but there is no middle class. Once something happens to change this, there is excess money that can be used to further the growth of the culture, scientific research, etc. For example, at the start of the Renaissance you have better sailing ships which leads to increased contact with other cultures, some more advanced (Arabic, Chinese), some less so (the Western Hemisphere). From one you learn some stuff, from the others, you take stuff (natural resources, etc). All adds to growth of the civilization. [Answer] I am going to try to answer this question generally. I think the first requirement for a major world or cultural transition is dissasisfaction. You need a large group of unsatisfied people to drvie the need for change. I think of the barbarians in Rome, the peasants in the French and Russian Revolutions. These people are the energy that drive the change. The larger the relative size of the group the closer the change, the more dissatisfied/gap between this population and the rest of society the greater the chance of violence. Dissasisfaction is not enough. For anything to change the dissasisfaction must be channeled into a cause or solution. There can be multiple solutions to chose from but over time there is typically one idea that most people rally behind. This gives people a necessary vision to work towards. The powerful and affluent who benefit from the current situation will typically resist this cause until a triggering event. Eventually, a triggering event will occur that force the society to react. It is typically a dramatic event like Martin Luther nailing the 95 thesis that comes after a long period of buildup. It forces society to either adapt or attempt to crush the change. The result of societies choices will create a new status que that will eventually lead to a new source of dissatisfaction. I believe it is a sign of a cultures maturity if it can resolve sources of dissatisfaciton without resorting to violence. This cycle of dissatisfaction -> solution -> triggering event -> new status quo -> new source of dissatisfaction, while oversimplified, is useful for understanding historical events, and especially for generating your own cultural shifts in your worlds. [Answer] The substance of my answer has been mentioned in other answers but not given its due emphasis and so is getting lost in all the detail. The fundamental truth is that *empires fail when they fail to adapt to changing conditions*. This failure to adapt could also be expressed as *resistance to change*. The innovations that gave the empire-builders their original advantage eventually become problematic when they no longer provide that advantage. People hang onto them long after their "use by" date thinking that what has given advantage will continue to give advantage even when that is no longer true. When emerging, an empire is differentiating itself and so change is actually embraced and encouraged during this phase; but a failing empire has become preoccupied with defending its institutions rather than reinventing them and so change is resisted. (That, by the way, is the world we live in today: with Industry & Government feeling threatened by and resisting emerging ecofriendly changes for as long as they can. Political power is beginning to devolve to the local level where cities and counties are stepping up to address the issues being ignored or resisted at the State and Federal level.) I hope these thoughts spark some ideas of changes that your empires could be embracing to their benefit or resisting to their undoing. [Answer] There are several things that can happen. # Scientific and Technological Discoveries Part of what brought Greek (and then Roman) knowledge was the great discoveries in science made by the likes of Aristotle. This let the Greeks (and Romans) have more advanced technology. For example the Greeks invented the waterwheel, gears, plumbing, showers, and even alarm clocks. Then the Renaissance re-created many of these things, starting the series of technological revolutions that bring us to today. So discoveries can bring along huge advances, even in just society. The Internet for example, has changed society massively, because of increased communication. The Renaissance largely happened because classical and scientfic texts were reintroduced to Europe through the crusades. So again, Discoveries (or rediscoveries) encourage societal change and advancement # Destruction When mass amounts of recorded knowledge is destroyed, then often times society will devolve. This happened when the barbarians destroyed Rome. They destroyed a lot of knowledge, but they also destroyed the central government and the center of society. Without Rome as a center, society drifted apart and became more inward looking. No longer was the Roman Emperor sending governors and taking taxes from everywhere. So nobles ruled over their towns, with a King ruling over an area. Literacy levels also fell, because Roman infrastructure wasn't heading everything. Once literacy was done, scientific accomplishments could be made as easily, so societal evolution slowed. That being said, the Black Death is often attributed to the bringing on of the Renaissance. This happened because demand on peasants became much higher, enabling peasants to actually hired themselves out, instead of being basically slaves to their Lord. This established a free market of supply and demand, as well as promoting trade and scientific establishments. # Spreading Finally change needs to be spread to do anything. This kind of spread was caused for the Renaissance mostly be conquering armies. French armies invading Italy brought Renaissance ideas to that place. But peace allowed the Renaissance ideas to spread to France and England, so both ways work. [Answer] Your question is: "What similarities can be seen in the fall of [aforementioned] great empires? Whether natural events, social trends, or technological advancements. Also, how can one use this information in building worlds?" I find it amazing that everyone only comes up with explanations based on war here. You go to war when you think you stand a chance. You think you stand a chance against an almighty empire when you're either: * a) desperate, * b) misinformed, * c) when the empire has shown signs it can be beat militarily, or * d) any combination of the above. It follows that a whole empire is very unlikely to fail unless c) is the case. Historically, sociological inertia is very strong. Cultural, military and economic practices that have proven to work will not change, unless there is a strong push to change them. It follows that empires are only overrun or collapsing if 1. they have developed internal weaknesses to external pressure, which 2. manages to eventually successfully bring about the desired change. Sometimes that change can be adapted to, and sometimes it will eventually mean the collapse of empire. Barbarians were actually powerless against Rome (or rather, could be regularly defeated), until Rome was marred by internal conflict which weakened the borders to the extent that trust in the system of power was failing. Infrastructural concepts of Roman urban space was failing (e.g. corruption kills water supply maintenance, which makes water supply in cities impure, cities become less habitable, so people began leaving the cities.) The middle ages had really begun *before* the barbarian invasions. A variety of socio-economic factors lead to internal weakening, which made new barbarian rulers feasible, as the "vision" of the old system had become increasingly unappealing. To make it short: Don't look for war and technology as the answer to why empires are failing; they do play a part, usually in the end, but the internal cohesion, failure to adapt to internal dynamic processes (=political failures) and decline of cultural magnetism of an empire are what comes before any fall. For building worlds, I take it that you look for factors that would make empires long-lasting: These empires would either exist in very (socio-economically) non-dynamic worlds, or would be highly adaptive to their surroundings and challenges (making them drop traditions at a moment's notice when these become inhibitors rather than agents of empire). So either the challenges to such an empire do not change (in both form and response), or the empire itself constantly changes (in both form and response to challenges). [Answer] I especially like the answers from Bokai and Abulafia, who cite Toynbee and Systems Theory respectively. I think those are the most generally powerful and descriptive. To pull it all together, I'd recommend John Michael Greer's posts on the nature of empire. In a 3-piece series starting with [http://thearchdruidreport.blogspot.com/2012/02/nature-of-empire.html](http://thearchdruidreport.blogspot.com/2012/02/nature-of-empire.html "The Nature of Empire"), Greer applies his serious scholarship in both Toynbee's theories of history and Systems Theory, and a lot more besides (such as the work of Oswald Spengler and Joseph Tainter), and boils it down into a very well-written overview. > > "Put more simply, an empire is a wealth pump, a device to enrich one nation at the expense of others. The mechanism of the pump varies from empire to empire and from age to age; the straightforward exaction of tribute that did the job for ancient Egypt, and had another vogue in the time of imperial Spain, has been replaced in most of the more recent empires by somewhat less blatant though equally effective systems of unbalanced exchange. While the mechanism varies, though, the underlying principle does not." > > > The third article, "The Trajectory of Empires", contains fundamental, general answers of the type the OP is, I think, looking for. > > "The wealth of subject nations, in other words, is a nonrenewable resource for empires, and empires thus face the same sort of declining returns on investment as any other industry dependent on nonrenewable resources. It’s thus predictable that the most frequent response to declining returns is an exact analogue of the "drill, baby, drill" mentality so common in today’s petroleum-dependent nations. The drive to expand at all costs that dominates the foreign policy of so many empires is thus neither accidental nor a symptom of the limitless moral evil with which empires are so often credited by their foes. For an empire that’s already drained its subject nations to the point that the wealth pump is sputtering, a policy of 'invade, baby, invade' is a matter of economic necessity, and often of national survival." > > > Greer's insightful treatment of empires as complex systems gives us a pretty good grounding in what's going on. Essentially, empires exist as parasites on external sources of wealth. As parasites, they never manage to avoid the exhaustion and destruction of those sources of wealth. Meanwhile, the empire has generated costly internal complexities in order to administer the imperial economy and society, and has also become dependent on unequal systems of economic exchange that enforce the empire's advantages. This in turn requires big military expenditures. Systems theory assures us that these layerings of complexity on complexity yield diminishing returns, so the whole edifice becomes increasingly fragile... **Why do empires fall? Fundamentally, for two reasons: exhaustion of indispensable resources, and the inherent structural progress towards diminishing returns on internal investment.** Please note that I'm not dismissing the other answers. All of them are at least partially true, I think. But I agree with Greer: the fundamental nature of an empire is the root of its own demise. By the way: Greer's work in general is an excellent resource for worldbuilding. You may find it offputting, because he's a clergyman (he really is an Archdruid) or because he believes that our civilization is entering into a long period of descent; but his insights in military history, human ecology, systems theory, and reality-based economics are all very solid; and they amount to considerably more than the sum of the parts. [Answer] Actually, the primary impetus for a culture to advance technologically is... *other cultures*. If we consider Europe, it has a very convoluted coastline and a large mountain range right in the middle, plus a lot of big rivers, which makes for a lot of different national groups, each of which in a way could be considered to be other cultures, all in a small area. Constant contact with these other cultures has led to warfare, or preparation *for* warfare, and warfare is the second greatest impetus for technological advancement. Then consider other groups. China advanced rapidly when it was at war with its neighbors, but stagnated once it was considered too powerful to attack. Japan followed the same pattern, advancing when in conflict with other nations, but stagnating once they became isolationist (despite many civil wars), and then advancing rapidly after Europeans forced their way in, even though they were not at war *with* the Europeans. The world's most primitive groups, the pacific islanders and the Australian aboriginals, had very little contact with any other cultures until Europeans made contact and started colonizing. [Answer] In 1984, Professor Alexander Demandt published a survey of the reasons historians have given for the fall of Rome. [1,2] The list numbers **210** reasons, ranging from lead and mercury poisoning to public baths and polytheism. Rome's alleged killers are as varied a barbarians, bureaucrates, feminists, hedonists and militarists. Personally I lean toward **the systems thinking school**, which states that it's a fallacy to assume that large effects have large causes. The monumental event that was JFK's assasination *could* have been the act of a lone loser, it does not need to be a conspiracy of proportional size. Similarly, if we could trace the cause of the fall of Rome, there may have been one or a multitude of events too insignificant to remember, that could yet have turned events on their head. Maybe a chance meeting between an influential backer and a now forgotten senator, that could have become an oustanding emperor? Maybe some years of slightly worse harvests in Germany would prevent it amassing the barbarian army in the Teutoburg forest? Perhaps some minor innovation in early Rome, which gets multiplied as its culture spreads over the centuries, to make the provinces more profitable or robust to changes in climate. That Rome lays in the distant past does not excuse the many fanciful explanations. Everyone reading this answer were alive during the 2008 financial crisis. We were there as it happened, but the theories as to *why* it happened keeps increasing. It has been explained through a commodities boom, a peak-oil scenario, the theory of scale-free networks, reactionary gender roles, weakened legislation, an error in a mathematical formula, the dot-com bubble, the postwar baby boom and a number of arguments for why "the system" is set to produce regular booms and busts without outside intervention. I can count about 40 reasons in wikipedia articles alone. Within our lifetime, the number of explanations for the financial crisis may well rival that of the fall of Rome. As for story-writing, I would love to see someone write a story from the systems thinking perspective. Maybe the protagonist does one little thing, which through unforeseen consequences escalates until he's watching helplessly, as his civilization crumbles around him. It's a tantalizing idea, that the seed of a glorious future or the end of civilization as we know it could be buried in the small and mundane around us. Or perhaps the real literary wonder is not found in explaining the fall of empires, but in how they sustain themselves for centuries. Unlikely islands of orderliness in a sea of chaos. [1] <http://www.wired.com/2013/06/210-reasons-for-the-fall-of-the-roman-empire/> [2] <http://www.utexas.edu/courses/rome/210reasons.html> [Answer] **TLDR: The question is to broad to answer in anything less than several books** This question is like asking what one or two things makes people die or get sick, except empires of hundreds of humans are more complicated than individual ones. This question encompasses basically the entire field of history like the second encompasses the whole field of medicine. Its an important question but there are hundreds of different causes, we can point to empires that had popular unrest for decades before they fell(like running a fever), and to ones that fell suddenly and violently to outside invasion (gunshot wound). You can't point to a single symptom to say this is what caused every person to die like wise you can't point to one cause for the fall of empires. (aside from birth: statistically most people have been born died and the rest are likely to die in the next 100 or so years, most empires that have been founded have fallen) Worse still there are many empires where the cause is highly debated or the result of many different problems which further slows analysis. In fact the largest collapses seem to be the most murky and complex **The right answer would have to be a list of hundreds of possible causes ranging from** loss of irreplaceable leaders (Macedonia) Combat with a more powerful foe (Japanese empire in the 1940's) To more murky causes hyperinflation from gathering to much sliver and gold (Spanish Empire) increased reliance on mercenaries/ decadence and waste of the upper class / dozens of important causes I'm forgetting (Rome) Loss of trade route control due to better ships To make things even worse some major empires we have almost no information on why they fell, like the Mayan and Mohenjo-daro civilizations [Answer] I will try to answer in the context of the "Civilization" game. Empires get unwieldly, and vulnerable when they are "too large." Too many people in a city makes some of them unhappy. Too many cities in an empire reduces the necessary number of people in any given city before it becomes unhappy. Cities (and military units) that are unhappy are susceptible to revolutions from within, and bribes from without. Also, the further a city is from the capital, the higher the levels of corruption and waste (relative to its size). In playing the game, I consciously do NOT try to maximize population growth. For instance, I do not irrigate land until relatively late in the game (e.g. when I have a government like Democracy that fights corruption and waste). Instead I use my settlers to build roads that connect my cities, thus reducing corruption and waste. I also tend to place workers on "resource," rather than "farmland" squares, which further slows population growth, but speed up the construction of buildings. Temples and colosseums calm restive people, courthouses reduce corruption, marketplaces and banks boost the economy etc. Basically, I want a high ratio of buildings (capital) to people. If I capture small cities abroad, I "depopulate" them by building settlers until the city disappears, using military units for "rush builds." Thus, I get a "free" settler or engineer to improve my other cities nearer home. The collapse of the ancient civilizations occurred when then got so "top heavy" that 1) other civilizations feared and envied them and 2), they were not "agile" enough to resist outside threats. Instead, managed growth for internal, rather than external growth seems like the better bet. But most rulers didn't see it that way until it was too late. Louis XV's quote, "After me, the flood," preceded Marie Antoinette's "Let them eat cake." ]

[Question] [ I have a planet orbiting one star in a binary system. When the planet is exactly between the two stars it will experience a [double day](https://worldbuilding.stackexchange.com/q/25203/28); when the primary sun sets the secondary one rises, no overlap. (My second star sheds enough light to make a difference on the planet.) When the planet is on the opposite point in its orbit the primary star occludes the secondary, so it's as if there were one star, lighting-wise. I'm trying to figure out the stuff in between. [](https://i.stack.imgur.com/dYtez.png) The planet orbits A at a distance of 1AU. Answers on the linked question suggest that the distance between A and B should be 10-20AU for this to be viable. The planet's orbit is meant to be viable; feel free to treat it as circular despite the drawing. I'm having trouble working out what days look like on the planet for the points in between the two marked positions. I *think* at the halfway points it'll get overlapping days, but I don't know how long (as a ratio of the rotation period). It's probably a simple matter of geometry, but adding the rotation of the planet to the orbit is causing me problems. What I'd really like is a chart showing the progression of the day -- time of first sunrise, second sunrise, first sunset, second sunset -- for the four main points and perhaps the four in between those (so I can understand the transitions), at the equator and at what we'll call 45deg N. Treat times as relative to star A -- noon is when A is directly overhead, regardless of where B is.) I know we're going to need some axial tilt to make this planet *have* seasons; pick and declare any reasonable-seeming number that makes your calculations easy, or default to Earth's for the sake of comparison. I'm trying to visualize what days and nights look like on this planet; I don't have precise numbers in mind. We're also going to need a rotation period. For the sake of the question let's assume 24 hours like on Earth. In practice, once I know what the proportions look like, I'll adjust the rotation to suit the needs of my inhabitants (because we're worldbuilders and we can *do* that :-) ). [Answer] # Update [](https://i.stack.imgur.com/S2zZz.png) I've updated my CDF to handle eccentric orbits and customization of star brightness, and (more importantly) to show long-term seasonal effects. A few notes: * Mousing over any of the parameters in the upper-left will show a tooltip with its name. * Note that the luminosity slider only adjusts the luminosity by a small factor. A star's luminosity is mostly [determined by its mass](https://en.wikipedia.org/wiki/Mass%E2%80%93luminosity_relation), so changing the mass slider also changes the luminosity. * I assume that one orbit of the planet around the primary star is a "year" (regardless of the actual length), and that the year is divided into twelve equal months. Similarly, I divide the day into 24 hours, regardless of the actual day length. * The upper-right side shows the orbit of the planet and the companion star from two views. * The middle plot shows the total energy received from both stars over the course of one orbit of the companion star. * The lower-left plot shows the same information as before: the shaded regions show the times when the primary and companion stars are visible. The difference is that the year the time axis shows starts at the time `t` on the slider. * The lower-right plot shows the average [insolation](https://en.wikipedia.org/wiki/Solar_irradiance) (received sunlight) over the course of one day for a given latitude and time of year. Clicking on this plot sets the latitude and time of the visibility plot to its left. Download the `.cdf` file [here](http://googledrive.com/host/0B0VNJlWZGkwNfmlvUjNOQUxoZmVuTWFfeFRnUk5wRVhuRVJWcTA0YjVGaDIwdzhnSUYyNWs/binary-seasons.cdf) (needs the free [CDF player](https://www.wolfram.com/cdf-player/)), or if you have Mathematica you can download it with the following command: ``` Uncompress@FromCharacterCode@Flatten@Import["https://i.stack.imgur.com/l1bWc.png", "Data"] ```  ## Assumptions and Terms [ from Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Orbit1.svg) * The planet $a$ orbits a star $A$, which is part of a binary system $AB$. * The intersection of the [ecliptic plane](https://en.wikipedia.org/wiki/Ecliptic) and the [equatorial plane](https://en.wikipedia.org/wiki/Celestial_equator) defines the [vernal equinox direction](https://en.wikipedia.org/wiki/Equinox#Celestial_coordinate_systems), labeled with $\Upsilon$ in the above diagram. Another way to think of this is the location of the planet when the [subsolar point](https://en.wikipedia.org/wiki/Subsolar_point) crosses the equator from South to North. We'll measure angles counterclockwise from this point. * The angle between the ecliptic and the equatorial planes is the **obliquity** $\varepsilon$ (also called the axial tilt). * The **mean longitude** $L$ is (for a low-inclination circular orbit) essentially the angle between an orbiting body and the reference direction when looking down on the orbital plane from above. It is equal to $\Omega+\omega+\nu$ in the above diagram. * The **inclination** $i$ and **longitude of the ascending node** $\Omega$ are shown on the above diagram. * The latitude of the observer on the planet is $\phi$. Since the ecliptic is our plane of reference, for the planet $i\_a=0$ and $\Omega\_a$ is not defined. However, these values are useful for the binary companion $B$. I'll treat $B$ as orbiting $A$ even though $B$ is heavier (to be luminous enough it must be at least $5M\_\odot$). I'm also treating the eccentricity of both orbits as zero so that the distances $r\_{Aa}$ and $r\_{AB}$ are constant. With all this sorted out we can apply some "simple" geometry to determine when the stars are above the horizon. ## Results I wrote a little `Manipulate` to visualize the effect of changing the latitude and orbital parameters of the binary. Here's what it looks like with the situation you describe at a mid-latitude of about 30 degrees north: [](https://i.stack.imgur.com/e3eqw.png) To figure out what's happening on a particular day, find the approximate date on the horizontal axis, then follow a vertical line straight up. As you can see, the sunrise and sunset times for the primary are pretty typical, fluctuating around 6 AM or PM. The companion star has a much more consistent duration of daylight, but its local noon 'laps' the primary's noon once a year. [](https://i.stack.imgur.com/XdK8A.png) On the equator, daylight times for the primary are more stable, but daylight times for the companion are relatively unchanged. [](https://i.stack.imgur.com/W6H6E.png) Far north of the arctic circle you can see that the summer has continuous daylight as before, but the would-be continuous winter night is interrupted by the companion star. [](https://i.stack.imgur.com/QeUXv.png) Changing the mean longitude of the companion ($L\_B$) shifts the day-night cycle of the companion forward or backward in the year. Note that $L\_B$ travels through its full range about once for every orbit of the companion star (about 15 to 40 years). This means that the two hemispheres will regularly cycle between eternal-daylight "summers" and eternal-daylight "winters", making for an interesting and complex seasonal cycle. --- I encourage you to experiment with the effects of adding inclination to the binary's orbit. To try it yourself, can either [download the `.cdf` file](http://googledrive.com/host/0B0VNJlWZGkwNfmlvUjNOQUxoZmVuTWFfeFRnUk5wRVhuRVJWcTA0YjVGaDIwdzhnSUYyNWs/binary-day-night.cdf) (you will need the free [CDF player from Wolfram](https://www.wolfram.com/cdf-player/)), or if you have a copy of Mathematica you can download it with the following command: ``` Uncompress@FromCharacterCode@Flatten@Import["https://i.stack.imgur.com/4ZDYm.png", "Data"] ```  [Answer] Quick point: An orbit with that level of eccentricity is going to have summers that literally melt everything, so I'm going to assume a circular (or at least much less eccentric) set of orbits. I'm also going to use the planet as my reference frame, because it makes it easier to track the locations of the two suns. On to some quick back of the envelope thoughts: 1: With an axial tilt the change in sunrise/sunsets is going to follow a similar pattern to those on earth, with shorter 'A' days following the orbital period of A around the plant and shorter 'B' days following the orbital period of B around the planet. These changes in season will not synch up, as both A and B perturb each other's orbits relative to the planet. In essence you'll have some long 'A' seasonal cycles followed by short 'A' cycles, and similarly for 'B' cycles. This leads to some really rather complex characteristics base on the interactions between the location of A and B in their respective orbits relative to the direction of the axial tilt of the planet, the location of A relative to the planet, and the location of B relative to the planet. These characteristics need (sadly) some numbers to be able to work them out, specifically the orbital period of the planet, the orbital period of the two stars around their respective midpoint, and the location of the midpoint for the stars. Even if we ignore the effect of B's gravity on the planet (so the planet isn't immediately flung into an even more bizzare orbit), this is still pretty complex. If we ignore the effect of B's gravity on both A and the planet (lets say some bored god has ordained that A is the centre of all things), then things get easier, though they're still more complex than you might expect. Lets assume (for fun) that the planet orbits A at a distance of 2. (The unit doesn't really matter) and that B orbits at a distance of 3 (I'm using these numbers to make it more obvious, I realise it isn't a viable set of parameters for actual orbit, but we've already got a bored god on our side). Oh: The planet also spins at the same rate as Earth in a clockwise direction and we're defining 12:00 to be when we're furthest away or closest to star A. From here we can define 16 positions for the A/B/Planet system based on the four ordinals of A and the locations of the planet. If there is a planetary tilt we have to consider all 16 to calculate the day/night cycle, if not we can simplify it to 4. Lets go with the 4 first. Planet and B are both above A: The planet is fully illuminated, there is no day/night cycle Planet is above A, B is below A: The planet is half illuminated, the day/night cycle is 24 hours (Sunrise at 6:00, Sunset at 18:00. It's also worth nothing that this would be *cold*, as the planet would be missing out on all of B's warmth due to it being in the shadow of A (a star casting a shadow is the oddest concept I've thought about today...) Planet is above A, B is to the right side of A: At this point the planet is (break out the basic Pythagoras here) at a distance of 5 from star B, and also at an angle that means the two 'sunrises' are not split apart by a quarter of the rotational period but rather something closer to 2/3 (I'm going to handwave the actual angle here to make the hourly maths easier). This leaves you with Arise at 6:00,Aset at 18:00, Brise at about 2:00 and Bset at about 14:00 Planet is above A, B is to the left side of A: Similar to above, but with Brise and Bset at 10:00 and 22:00. Thus end the trivial cases. When you put in an axial tilt you have to consider all 16 cases. Imagine the planet as a 24 hour analogue clock (yes, they exist) with 0:00 at the point furthest from A and 12:00 at the point closest to it. Work out where the stars are relative to the planet, then imagine the half of the circle nearest each star is lit up. You can use the numbers on the imaginary clock to find the sunrise and sunset times for a 0 tilt planet. To take the tilt into account shrink the half circle when the planet is tilting away from the star (northern hemisphere winter) and increase it when it's tilting towards the star (northern hemisphere summer), then use the numbers to get the sunrise/sunset times. It might also help to imagine one star illuminating in blue and one in red to clearly delineate the days in your own mind. Basically: The point I'm trying to make here is that the day/night/season cycle here is going to be complicated. From a story point of view I wouldn't try to explain it exactly as planetary orbits in binary systems tend to be either chaotic or unsuitable for life. [Answer] I assumed here that the two stars and the planet are aligned, and midday/midnight are fixed using star A. The numbers bellow are for the equator of the planet, the extremities are going to have longer A days when inclined toward star A and longer B days when inclined toward star B. There will be a A and a B season cycles. During its double winter a pole is in a permanent true night, the opposite during its double summer. I tried here to give a general feeling of how living on this planet would be. --- **Single day point** 1/2 night + 1/2 day sunrise A : 6 am sunset A : 6 pm sunrise B : 6 am (eclipsed behind sun A) sunset B : 6 pm (behind sun A) **First quarter** 1/4 night + 1/4 day A + 1/4 day B + 1/4 day A&B sunrise A : 6 am sunset A : 6 pm sunrise B : 12 am sunset B : 12 pm **Max double-day point** 1/2 day A + 1/2 day B sunrise A : 6 am sunset A : 6 pm sunrise B : 6 pm sunset B : 6 am **Third quarter** 1/4 night + 1/4 day A + 1/4 day B + 1/4 day A&B sunrise A : 6 am sunset A : 6 pm sunrise B : 12 pm sunset B : 12 am --- ## How it would look When you start at the Single day point, day and night look the same as on Earth, because the two suns are aligned with each other. Days passes and star B emerges from behind start A. At first it will be like pretty much the same. The more the year progress, the more the two stars will look distant in the sky. When at first the two sunrises and sunsets happened with a few minutes intervals, the kind of twilight between two sunset or two sunrise will be longer and longer. The "True Night" and "True day" (time with both suns) between them will grow shorter. When the planet is at "Double day" point, there is no night, only a 12 hours "day A" and a 12 hours "day B". Then the opposite process starts. The intervals between sunrises and sunsets grow shorter, the single-sun days shorter and both true day and true night longer. The stars also grow closer in the sky. [Answer] Short Answer. For scientific reasons I have reversed your star designations, making Star B the one that Planet X orbits and Star A the more distant star. If planet X orbits Star B but not Star A, Star A should be at least ten times as far away from Planet X as Star B is, in order for the orbit of planet X to be stable. If this is supposed to be hard science fiction you will need a more expert opinion. Of course the distance between Star A and Star B can be many times the minimum of ten times the radius of Planet X's orbit around Star B. If the distance between Star A and Star B is exactly 10 times the radius of Planet X's orbit around Star B, then some times Planet X will be exactly 11 times as far from Star A as from Star B. And sometimes Planet X will be only 9 times as far from star A as from Star B. The distance from Star A to Planet X will vary between 0.9 and 1.1 times the average distance. And since the amount of light planet X receives from star A varies with the square of the distance, that amount will vary from 0.826 to 1.234 of the average amount. If the distance between Star A and Star B is exactly 100 times the radius of Planet X's orbit around Star B, the amount of light that Planet X receives from Star A will vary between 0.980 and 1.019 of the average amount of light. Since that is a smaller range of difference, as a general rule you would want the distances between Star A and Star B to be as many times greater as possible than the radius of the orbit of Planet X around star B. But you also need the distance between Star A and Star B to be as small as possible compared to the radius of the orbit of Planet X around Star B. If you want Planet X to be interesting because it is habitable for Earth Humans, or has advanced multi celled life like trees and mammals, or has native intelligent beings. If Star A is 10 times as far away from Planet X as Star B is, which I think is the minimum distance for Planet X to have a stable orbit, it will have to be 100 times as luminous as Star B to give Planet X as much light as Star B does. If Star A is only as luminous as Star B it will give Planet X only one percent of the light that Star B gives planet X. If Star A is 100 times as far away from Planet X as Star B is, it will have to be 10,000 times as luminous as Star B to give Planet X as much light as Star B does. If Star A is only as luminous as Star B it will give Planet X only one hundredth of one percent (or 0.0001) of the light that Star B gives planet X. You didn't specify the desired ratio between the apparent brightness of Star A and Star B as seen from Planet X. You just said Star A (your Star B) should give Planet X enough light to make a difference. And you didn't specify whether you meant enough light to make a difference in the temperature of Planet X or merely enough light to make a difference in it's illumination. If you want Star A to shed as much light on Planet X as Star B does, then the ratio of their relative absolute luminosity must equal the square of the ratio of their relative distances from Planet X. If Star A is 10 times as distant as Star B it will have to be 100 times as luminous to appear exactly as bright in the sky of Planet X. If Star A is 100 times as distant as Star B it will have to be 10,000 times as luminous to appear exactly as bright in the sky of Planet X. If Star A is 1,000 times as distant as Star B it will have to be 1,000,000 times as luminous to appear exactly as bright in the sky of Planet X. Thus if Star A and Star B have to have anything remotely resembling the same brightness in the sky of planet X, Star A should have at least several times the absolute luminosity of Star B, and possibly up to millions of times the luminosity. Thus Star A would be much intrinsically brighter than Star B. Thus Astronomers would call it A and call the star that Planet X orbits B. Because of the high probability that the more distant star would be more luminous than the star Planet X orbits, I switched the designations of the stars from what they were in your question. Suppose that you desire star A to appear 0.0001 times as bright in the sky of Planet X as Star B. Then if Star A is 0.10 times as luminous as Star B, and 10 times as far from Planet X, it will appear to be 0.0001 times as bright from the surface of Planet X. If Star A is exactly as luminous as Star B, and 100 times as far from Planet X, it will appear to be 0.0001 times as bright from the surface of Planet X. If Star A is 1,000 times as luminous as Star B, and 1,000 times as far from Planet X, it will appear to be 0.0001 times as bright from the surface of Planet X. If Star A is 10,000 times as luminous as Star B, and 10,000 times as far from Planet X, it will appear to be 0.0001 times as bright from the surface of Planet X. Thus even if Star A appears only 0.0001 times as bright as Star B as seen from Planet X, it could, depending on its distance, be tens, hundreds, or even many thousands of times as absolutely luminous as Star B, the star that Planet X orbits. By comparison, the Sun has an apparent brightness as seen from Earth 398,110 times as bright as the apparent brightness of an average full moon. The apparent brightness of the full moon is 0.0000025 that of the Sun, so if Star B appears as Bright as the Sun from Planet X and Star A appears only 0.0001 as bright as star B as seen from Planet X that could still be about 40 times as bright as a full moon seen from Earth. The absolutely most luminous star known to science is R136a1 in the Large Magellanic Cloud, about 8,710,000 times as luminous as the Sun. The least luminous known star is 2MASS J0523-1403, about 0.000126 times as luminous as the Sun. That gives a luminosity range of about 69,126,983,000 times. That should be enough for any desired difference in the luminosity of the two stars in the solar system of Planet X, right? Wrong. If you want Planet X to be interesting because it is habitable for Earth Humans, or has advanced multi celled life like trees and mammals, or has native intelligent beings, Planet X must have enjoyed a relatively constant amount of radiation from it's sun, Star B, for billions of years, since Earth is believed to be relatively typical, and it took billions of years for those things to develop on Earth. Therefore Star B that Planet X orbits must have been a relatively stable main sequence star for billions of years in order for Planet X to be habitable for Earth Humans, or have advanced multi celled life like trees and mammals, or have native intelligent beings. And since both stars in the system would be the same age, Star A must also have been a relatively stable main sequence star for billions of years. When stars eventually leave the main sequence they usually change in ways that destroys all life on the planets that orbit them and may also destroy all life on planets orbiting other stars in the same star system. And what types of stars will remain stable main sequence stars for billions of years? Stars of late spectral type F (starting at maybe type F8), type G, Type K, and type M. Thus Star B, that Planet X orbits, and Star A, in the same star system, would both have to be somewhere between about spectral type F8V to M9V, which would limit the possible range of their luminosity difference. I believe the extreme possible luminosity difference between Star A and Star B would be about 25 times. But many scientists believe that stars from mid type K and all type M stars are not suitable for having habitable planets for various reasons. If that is correct the possible spectral types for Star B would be limited to about F8V to K5V. That gives a luminosity range of about six times for the difference between Star A and Star B. But since it is not specified whether Star A should have any habitable planets its spectral type can be between type F8V and type M9V. So if you want your story to be anything like hard science fiction you should find more precise figures for the various limits listed before making your calculations, if you want Planet X to be interesting because it is habitable for Earth Humans, or has advanced multi celled life like trees and mammals, or has native intelligent beings. Unless the stars in the star system are younger and should not have planets as advanced as Planet X seems to be. Perhaps super powerful aliens terraformed Planet X millions of years ago and seeded it with life forms billions of years more advanced than it had time to evolve naturally, or even took Planet X from its original star system and moved it into the much younger star system it is now in. [Answer] The only thing I'm missing is the orbital period and inclination of your star B. It would be longer than the orbital period of the planet, and assuming there is any inclination, a stellar eclipse could only occur at the ascending and descending nodes. * If any inclination exists, the north pole wouldn't be able to see star B for certain portions of star B's orbital period, at maximum descending argument (I hope my terms are right) * If the orbital period of star B is a small enough ratio, like 4:1, you'd see four different years repeating, but if the ratio is strange, like 15:6, the pattern would be harder to describe. ]

[Question] [ In the Norse prophesy of [Ragnarok](http://en.wikipedia.org/wiki/Ragnar%C3%B6k), Fenrir eats the sun. Considering the Earth is not immediately consumed by a supernova, it must be assumed that he swallows it whole and it just ceases to exist on the material plane. (Taking its gravity and solar energy with it) From the Wikipedia page: > > In stanza 46, Odin asks what sun will come into the sky after Fenrir has consumed the sun that exists. Vafþrúðnir responds that Sól will bear a daughter before Fenrir assails her, and that after Ragnarök this daughter will continue her mother's path. > > > Assuming that, for dramatic tension, the gap between having a sun and a new identical sun is **3 days**, what would be the effects on the other bodies in the solar system? (Lets forget about the inhabitants. What few remain are covered by the Ragnarok narrative.) Also assume that the new sun takes the exact position of where the sun should be at that moment. (Taking into account the sun's movement through the galaxy.) [Answer] ## I'll start with Earth Earth is hurling through space at a speed of approximately $29.78 km/s$ If the sun were to disappear, the Earth would move in a straight line until the sun reappears. Since there are $259,200 seconds$ in three days that gives Earth the time to travel $29.78 km/s \times 259,200 s = 7,718,976 km$ That's quite a distance. Since the distance between the Earth and the sun varies between $147,098,290 km$ and $152,098,232 km$, I'll average that down to about 150 million kilometers for calculations. Using Pythagoras, we can get the distance form the sun when it comes back after 3 days: $\sqrt{150,000,000^{2} + 7,700,000^{2}} = 150,1632,44.504$. This puts us about $160,000 km$ out of orbit, peanuts compared to the difference between the Earths [aphelion](http://en.wikipedia.org/wiki/Aphelion) and its [perhelion](http://en.wikipedia.org/wiki/Perihelion) which is about 5 million kilometer. **What about the influence of other planets?** Good point, Jupiter is huge and can get reasonably close to Earth [citation needed]. We'll assume a worst case scenario and place Jupiter at a distance of 600,000,000 km from earth. Jupiter is significantly slower than earth, but in the span of three days, this is not going to make a huge difference considering the distance between them. You can calculate the acceleration of a body under gravitaional influence by another body as: $G\frac{m}{r^{2}}$ Where G is [the gravitational constant](http://en.wikipedia.org/wiki/Perihelion), m is the mass of the body attracting (Jupiter in our case) and r is the distance between the two bodies. Filling this in gives us: $6.673\times10^{−11}\frac{1.8986\times10^{27}}{600,000,000,000^{2}} = 3.51926606\times10^{-7} m/s^{2}$ Which means that the earth will accelerate towards Jupiter at a rate of 3.51926606\*10^-7 m/s every second. After 3 days we will have traveled $\frac{3.51926606\times10^{-7}\times259200^{2}}{2} = 11822.0311653 m$ towards Jupiter, not even $12 km$! **Mars is closer though.** I see your point, but assuming Mars is as close as 50 million km, we get an shift towards Mars of about $56 km$. Not really significant. **How will other planets fare?** Well, Mercury will be off the worst. If there's no significant change there, there won't be a significant change anywhere. As it is traveling at about $47.362 km/s$ It could travel a distance of more than 12 million km in 3 days. Taking into account its smaller orbit, this would take it about 1.2 million km out of orbit, not bad. But still not much compared to the variance in its orbit which is almost 14 million km. **Conclusion:** If Fernir eats the sun, there are more important things to worry about than where the planets will be in 3 days, when Fernir needs to go to the bathroom. ## Edit: **But wait, the Earth is now going too fast for its distance from the sun** You're right. And it's slightly turned away from the sun too. And I must admit, I underestimated the effect of this. As some intelligent people in the comments pointed out, this would change the eccentricity of the earths orbit from 0.016 to 0.06. Using [this calculator](http://www.1728.org/ellipse.htm) we can then figure out that Earths orbit will now vary between 141 million km and 159 million km. **The difference has nearly quadrupled!** In the grand scheme of things, our orbit will still be relatively similar, this might be enough to seriously influence weather pattern though. **Another possible effect.** Since gravity can not travel faster than the speed of light, the effect of the sun disappearing can only propagate with the speed of light. Gravity needs about 4 seconds to traverse the diameter of the sun, so gravity will drop from 100% to 0 over the course of 4 seconds. Additionally, there will be about a 0.04 second lag between the part of the Earth facing the sun and the most distance part. The acceleration due to the suns gravity is $\frac{6.67\times10^{-11}\times1.9891\times10^{30}}{(1.496\times10^{11})^{2}} = 5.928151\times10^{-3}m/s^{2}$. Dropping from this value down to 0 over the course of 4 seconds with a maximum lag of 0.04 seconds doesn't seems bad enough to cause anything major, but maybe it is enough to cause some earthquakes? I'll leave that to geologists to decide. [Answer] 72 hours of total darkness will lead to a significant drop of temperature. The difference in temperature between day and night can be anywhere between 10 and 30 degrees Celsius. It depends on cloud cover (clouds keep the warm temperature in) and distance to the sea (water is very good at storing warmth, while land isn't); 72 hours darkness should have about six times that effect; that would be between 60 and 180 degrees Celsius. So this could be fatal in some points of the earth, say in the middle of Asia, and much less fatal say in Hawaii, surrounded by water. It may take some time for the temperature to get back to normal as well. The darkness itself should be not such a big deal, from experience plants survived being stuck in a storage container for days. You would find out how well the insulation of your house works, if it's -50 Celsius outside. [Answer] **Looking at effects of the absence of the sun's gravity** Since the sun's gravity is gone, all planets will go out of their orbit. But in 3 days they wont get too far, and will regain their position after sun comes back **Look at the effects of the absence of the suns heat** The whole earth will be in instant winter (it will just get colder, not more snowy), and Mercury's surface will be totally frozen. **Looking at General Effects** there will be global chaos, lots of people will commit suicide (just like people commit suicide a day before 9.9.1999), mass robbery, people will panic (like they always do -\_- ). [Answer] There will be one mother of a tidal wave. How badly this affects anyone will depend on where they are. In the open ocean, the tidal range due to the sun is about 2 feet. That translates to a pretty big mass of water that will suddenly be dropped. This will be accentuated by tidal movement of the Earth's crust. All the normal tidal phenomena will try to happen at once and everywhere. Large sections of coastline will be washed away and water will invade the land disastrously elsewhere. Sorry no calculations here. The land/sea boundary is so irregular and the depth of the seas likewise, so a realistic simulation would require a huge amount of real-world oceanographic knowledge and some powerful computation. [Answer] In terms of the solar energy, it would depend on how long the sun was missing. However, the rough estimate of the energy available by combustion of the Earth's entire biomass is on the order of about 10 days' worth of illumination by the sun. So, if the sun were gone 10 days, the energy lost would represent all the chemical energy stored up by the chemical processes of the entire biosphere, 99.99% of which is ultimately from photosynthesis. What that means for the biosphere is pretty obvious; the food web would collapse and practically everything on the planet would be frozen solid by the time the sun reappeared. Second, if the Sun's gravity were lost too (instead of it becoming a black dwarf, it just was removed from existence for 10 days), the orbital dynamics of the solar system would get interesting. At the instant the sun disappears, the planets will be moving in a direction tangential to their roughly circular but in reality somewhat elliptical orbits. Without the Sun's gravity pulling them back, those masses will continue in that straight line. Some of the lighter ones might be drawn toward each other, but for the most part anything outside the "lane" of each planet's orbit exerts too small a force to see much difference over 10 days. ... Until the Sun comes back. Because everything has been moving in a straight tangent line to their original orbit, the biggest observable effect of the Sun's temporary absence is that all the planets' orbits would be re-established further out, and because their velocity didn't change, the orbits would also be more elliptical. That means our deep-frozen Earth will likely get a few more months of a hard winter, but then a few months after that, things will start to get uncomfortably hot as Earth "falls" back toward the Sun. Its orbit is no longer wholly within the "Goldilocks zone" of the habitable temperature range for a planet its size with its atmosphere, and that's a big problem. At a worldwide average air temperature of about 45\*C, the evaporation component of the water cycle will begin to increase dramatically, forming an insulating cloud layer, and there's little we could do at that point to reverse the effects. Anything that might have survived the deep freeze will be scoured from the face of the earth if the ambient temperature climbs too far beyond about 70\*C. [Answer] I think disappearing of Sun can be a long eclipse (but how does the celestial body, that concealed the Sun, can appear?) or a nuclear winter. Any other cases are too unrealistic or they simply destroy the solar system, because the gravitational force of Sun keeps planets together ]

[Question] [ For example, a quote from one of the Witcher 3: Blood and Wine's side quests says > > The eggs themselves are a sight to behold, luminescent. > > > The man (hologram) is referring to giant centipede eggs. For any other world, is there a good reason why eggs would glow? For centipedes? [Answer] The species is parasitic in at least one stage of life. Glowing eggs attract creatures that want to *eat* the egg (since eggs have lots of fat in them, and don't run away or fight). (Thanks to an excellent comment by @HenryTaylor.) Thus, the "egg" isn't really an egg like we think of them, but actually bait for transfer to a host for the next stage of life. After it grows a bit, it leaves the host to grow to final adulthood and then start the cycle over again. [Answer] On Earth poisonous animals are often brightly coloured, e.g. [Poison dart frogs](https://en.wikipedia.org/wiki/Poison_dart_frog). Perhaps bioluminescence evolved as a signal that something is poisonous, and the eggs are poisonous to predators, or pretending to be. [Answer] Let's assume bio-luminescence is rare and not the norm: if the environment is full of bioluminescent rocks, then it would be more a camouflage. So back to basics: bio-luminescence makes things *visible*, and usually more recognizable and identifiable. How could this provide any advantage to an egg ? 1. Identification for better protection. If from a social specie, or at least one taking great care of its eggs, the eggs would be better nurtured. In this case, the bio-luminescence could also be used as a way to communicate the egg's needs (warmth, moisture, etc.). 2. Identification as a warning. The eggs could be highly toxic and poisonous for predators, or have other defense mechanisms (an electric egg ?). This special signature would keep predators at distance, like some animals using very visible colors. 3. Identification as a trap. The eggs are easily spotted by some wannabe-predators, only to see the latter being stick to the egg and dissolve by some digestive liquid dripping from the egg. Or the egg need to be eaten to reach a parasitic form that is an intermediate step in its growth). This could also be combined with 1. where care-taking adults use the eggs to attract preys closer. [Answer] Perhaps the egg laying creature is the apex predator in its world, with such a overwhelming predatory advantage over all other life, that even its' newborn offspring can defeat anything which might be attracted by the light. The glowing eggs might serve to provide its occupant with a first meal. [Answer] This article <https://www.allaboutbirds.org/the-beauty-and-biology-of-egg-color/> provides a number of interesting examples from bird eggs which suggests reasons why conspicuous eggs might not always be a disadvantage. I'll summarise some of the most relevant. **1. Group nesting** Several Great Tinamous lay their bright blue shinny eggs in a single scrape in the ground. The eggs are not camouflaged despite the risk of predation. It is suggested the bright colour of a Tinamou egg attracts other Tinamous to lay in the same nest. It is theorised that the larger number of eggs means it is less likely a predator will be able to consume all the eggs in the nest. This could be a good fit for your giant centipedes, especially if they are a species which already produces a large number of eggs, with a small proportion expected to survive. **2. Parasite protection** A number of species have highly patterned eggs to distinguish them from brood parasites like cuckoos. Bioluminescence could be a signature which is hard for the parasite species to mimic. However this would require that the parent centipedes give sufficient brood care to attract such parasitism. This benefit would have to be weighed against the cost of the increased visibility to predators. **3. Improved visibility** Hole nesting birds often have quite conspicuous white eggs. This may simply be because there is no need for pigmentation for camouflage as the eggs are already concealed in a hole, however it may also help the parents to see the eggs in the dark. The centipedes may nest in caverns or other enclosed nest holes, where predators spotting the eggs is not an issue. The bioluminescence may help the centipedes to see their eggs, and care for them, or simply avoid accidentally damaging them. **Additional Notes** *Quantula striata*, A terestrial snail species, actually does produce bioluminescent eggs. An additional suggestion (which I have no real world example to back up) is that the luminescence could simply be to protect the eggs from accidental damage. Perhaps the greatest risk is that the eggs might be trampled by some careless herbivore. Any such creatures might be very willing to avoid any sign of the giant centipedes. [Answer] If the parents give nest-care the luminescence (the color and/or the intensity) could be tied to the temperature of the eggs. So the parents can tell whether the eggs are too warm or too cold and can take action accordingly. [Answer] Maybe they don't glow all the time. Several insect proteins glow under black light, it's just a side effect of the protein structure. And the eggshells of insects are made of proteins. Alternatively it could be a similar side effect and they glow all the time, but you could make them a burrowing species. Since the eggs are buried fairly deep it doesn't matter if they glow, or at least it does not matter enough. [Answer] The luminescence tells other giant centipedes there's a large hungry female nearby and she's going to be very defensive of her nest, stay away. The luminescence tells the mother not to eat her own eggs no matter how hungry she gets, maybe it triggers an instinctual suppression of hunger. Other animals may be attracted to the luminescence which would normally be disadvantageous for the eggs except there's a ravenous giant centipede waiting to ambush anything that gets too close. [Answer] Giant centipedes clearly use magic in their metabolism — otherwise they’re too big for a centipede’s rather primitive respiration to get enough oxygen to their internal tissues to move that fast. And since we know nothing about how that magic actually works, perhaps luminous eggs are an inevitable side effect of it. [Answer] * The largest threat is creatures that lay their eggs in another species nests like the coo-coo. Glowing eggs are a signature that other species can't mimic. * The eggs absorb their nutrients from flies that land on the egg and are digested through the membrane. * Other creatures will protect the egg as it provides a light source to allow them to hunt in the dark. * The light will help a small ecosystem grow in the nest for the young centipedes. * The eggs are fertilised after being laid and the light is part of the mating ritual to show fitness. [Answer] Well, let's have a look at what bioluminescence is for in the natural world. It can be used to communicate, but eggs are inanimate, so that's probably not an option. It can be used to ward off predators, but really - some glowy lights on a non-moving, nutritious rock isn't going to scare away predators. But, however, bioluminescence can be used to attract things, so the only reason for it would be if the eggs wanted to get eaten. By this, as another respondent has suggested as well, I mean that your creature's offspring are parasitic. But they can't harm the predators, or else they would learn to avoid the creature's eggs. It could be a kind of symbiosis, with the predator getting nutrition, and the parasite getting something else in return. [Answer] Bioluminescence is actually used as a form of camouflage by way of counter-illumination (<https://en.wikipedia.org/wiki/Counter-illumination>). Here on Earth (I think) this is exclusively used by marine animals to avoid detection from below, i.e., the bioluminescence mimics the surface of the water so, when viewed from beneath, they avoid displaying a conspicuous dark spot to predators. Perhaps the eggs are normally laid in areas with numerous bioluminescent plants and/or fungi and the glow prevents them from displaying the aforementioned conspicuous dark spot? [Answer] Some species of fish lay eggs across a very large area. It could be possible that a creature with similar behavior would use glowing of eggs to locate it's own eggs. Perhaps even the species lives in a group in which babies are cared for by a dedicated sub-group (similar to bees). In this case the ability to notice and locate eggs would be even more important as the those taking care of the babies haven't laid them - and thus won't have knowledge of their location. That said, I still think in the advantage glowing eggs gives a predator is more significant, and would make the property mainly a liability. We can also see that almost no (to my knowledge no) species on earth lays such eggs. [Answer] Perhaps the eggs are deposited in an environment where the only true threat comes from fly larvae hatching and eating away at it? (Say it's poisonous for vertebrates, unreachable for most invertebrates) There's research that certain wavelengths of visible light will significantly lengthen or even prevent hatching in fruit flies.(<https://www.ncbi.nlm.nih.gov/pubmed/28578425>) [Answer] It has been theorized that the main reason for Zebras colouration is to avoid certain files rather than other more prominent predatory animals. Could the luminescence be protection from some (as yet) unknown predatory animal. It would have to have sensitivity to light, making it nocturnal. A light source in the dark would be a good defence against it. [Answer] Here's a theory: it could glow at the very end, right before it hatches. Now, if nothing else really glows, then it is super attractive. Like a homing beacon for a nutritious breakfast. Some animal comes up to eat what looks like a easy meal. But suddenly, the egg cracks open and the animal inside the egg is more dangerous then the one that came to eat it. The newly hatched animal gets it first meal. [Answer] Perhaps the females lay unfertilized eggs, which then begin to glow. Males are attracted to the glow and fertilize them. Usually in fertilized eggs the glow starts to diminish but it can last for quite a while after the male has visited. [Answer] I am reminded of the kakapo parrot. Especially of the description of its mating ritual by Douglas Adams in his book "Last Chance to see". Adams describes hilariously, but also very convincingly, the kakapos mating ritual as "incredibly complex, very long drawn out and almost completely ineffective". Adams goes on to elaborate several different aspects of the mating ritual, all of which seem indeed more suited to prevent mating than supporting it. Strange, you might think, but it is actually a survival trait of the kakapo. Because the biggest threat to the survival of the kakapo species as a whole is not being eaten, but eating all available food. Mating and having to many offsprings, in the face of an almost complete lack of predators, would lead to a possible collapse of the kakapos niche in the ecosystem. So the kakapo has to dampen the growth of its own number in order to prevent starvation and the anti-mating ritual is the mechanism to achieve that. Please refer to the book by Adams, because of his superior writing and for any details. Translating this to the luminescent eggs, I could imagine a species which eats the eggs from the nests of other breeding parent animals; not its own eggs of course, prevented by e.g. pheromones. The result would be an efficient mechanism to ensure that eggs in a nest can only survive outside of eyesight of any other member of the species. This in turn would ensure a maximum of density of breeding parents in any given area. This assumes of course that the disadvantage of glowing in the dark is somehow evened out, e.g. by any of the mechanisms described in other answers to this question. In short, being very visibly edible could be the survival mechanism in an environment which is otherwise in danger of collapsing due to overeating species. [Answer] To add to [Skye's answer](https://worldbuilding.stackexchange.com/a/108976/21222): > > [Three genera of fungus gnats are bioluminescent, and known as "glowworms" in their larval stage. They produce a blue-green light. The larvae spin sticky webs to catch food.](https://en.wikipedia.org/wiki/Glowworm#Fungus_gnats) > > > This is what they look like with their webbings: [](https://i.stack.imgur.com/hk12U.jpg) So we have a similar case in our own real world. Sometimes a juvenile being glows in order to attract food. A glowing egg may be the ticket to a baby's first meal. [Answer] Do note that glowing need not be an advantage, it need merely not be a significant disadvantage. Suppose the adults are luminescent as well and use the light to hunt in the dark. That could be a big advantage. If the glow gets turned on prior to hatching that would make the eggs light up, but that would have to provide a larger disadvantage to the eggs' survival than the advantage to the adults' hunting abilities to prevent the trait from taking off. Barring one of the additional advantages to the glow mentioned by other posters, the glow of the egg is likely to disappear over the next few million years due to the additional incremental advantage of not glowing as an egg, but it hasn't happened yet, so you still have glowy eggs around. I would think that hungry, venomous, giant centipede parents hanging around the nest and eating anything that comes close could easily be enough of a deterrent to predators to render the visibility of the eggs insignificant to the survival of the species. [Answer] I am surprised that the obvious answer is conspicuously missing. Perhaps it is camouflaged by being so obvious. The entire environment is bioluminescent. If the eggs were not, they would stand out for their lack of bioluminescence. That is, they would be an obvious dark spot in a bright background. Camouflage only works if it is the same as the background. Think of the world of Avatar. [Answer] Maybe the glow is a byproduct of a chemical that the larvae need. The young need handwavium upon birth, and having handwavium in the eggshell provides them a good first meal. The only problem is that handwavium happens to glow. Maybe the eggs are laid near a species of toxic, glowing mushrooms. Predators confuse the eggs for mushrooms and don't eat them. Herbivores think that they're just as toxic as the mushrooms they look like, so they don't eat them. Maybe the bugs have a weird symbiosis with humans/the dominant species. The glow of the eggs attracts humans who take care of them, and when the eggs hatch, they serve as good pest killers or they eat the dust in people's homes. Maybe they live in a world where their primary predators are blind, and the glow lets the parents see them to protect them without giving away a scent to attract the predators. ]

[Question] [ Have you ever seen a fat Elf? I haven't, and I think there's an unexpected reason. You see, Elves aren't really the best workers or at least working the land and cultivating food is not something they do. There isn't such thing as Bob the elf farmer with 14 children which he forces to work on the farm. Elves are powerful mages, they teach the art of using magic and creating powerful artifacts to humans in exchange of money. Therefore elves don't consume much energy during the day, and also most Elves are nobles. Only in the past few centuries meat became industrialized, but before meat used to be something only fishermen, hunters and nobles ate... the rest of the population were farmers who didn't have the money to eat meat more than once in a blue moon. But nobles were usually filthy rich, which means they could buy any type of greasy food, for example beef is 54% fat by kilocalories or a steak sits at around 64%. That's why nobles and kings were usually overweight. Does it means that Elves were just fitness addicts who paid a lot of attention to their health? Probably not, at the time there were no gyms and nobody knew anything about nutrition. I have a better theory, that Elves simply don't have fat cells. **IF** my theory was right, how would it be possible for elves to survive without any fat cell in their body? [Answer] **Instead of fat, elves store energy as ethanol.** Fats are the most dense form of food calories. Ethanol is a close second. From <https://biology.stackexchange.com/questions/28511/what-is-the-most-condensed-form-of-stored-energy-used-in-biology> [](https://i.stack.imgur.com/u5vAJ.png) Rather than pack on bulky fat, elves convert calories to ethanol and store it in their blood spaces and contractile spleen, replacing a portion of the volume that humans waste with more water. Elf blood is about 20% ethanol. This habitually high blood alcohol has the side effect of making elves essentially immune to getting drunk, or possibly always drunk and is why elves prefer mushrooms for their recreational drug. [Answer] Fat or [adipose tissue](https://en.wikipedia.org/wiki/Adipose_tissue) carries out some very important functions, so if the elves are anything like humans—or like any sort of mammals—they need fat to survive. Long term energy storage is just one thing, but fat also produces hormones, contributes to thermoregulation and other good stuff. You know that friend of yours, the one that can eat anything and never seems to put on a gram (or an ounce, depending on location)? Well, that friend just has slightly different levels of hormones that regulate the synthesis and storage of lipids, the lucky bum! Mayhap your elves are just genetically predisposed in that direction? [Answer] Because they convert any excess energy directly into mana. As stated they are powerful mages, and as such are deeply linked with magic, and it's fuel, the omnipresent Mana. Thus they - or at least the more magier ones - eat A LOT of calories. It's just converted to astral energy which surrounds them on another plane. Thus they do get fat - just not in this world. [Answer] [A comparative perspective on lipid storage in animals](http://jcs.biologists.org/content/126/7/1541) is a pretty serious article but it might give you some ideas. To pick out a few gems for your further development: > > The **fat-accumulating organ** is much more developed and specialized in arthropods, especially in insects. Here, a specialized organ, often called adipose body or fat body, simultaneously exerts both liver and adipose tissue functions, suggesting that a separation of these metabolic functions to different organs occurred later during the evolution of vertebrates (Arrese and Soulages, 2010). **The insect fat body coordinates metamorphosis and reproduction** mainly by storing and secreting compounds that regulate developmental processes (Arrese and Soulages, 2010). > > > That sounds like an *amazing* thing to have in your elves, but maybe that's just me. > > In fish, amphibian and reptiles, adipose tissue is mainly found in intra-abdominal regions and **subcutaneous fat tissue is mostly non-existent**. > > > And you don't *need* to make them freaky insects, if you really don't want to. There's much more in the article to follow up on if you're so inclined. [Answer] As you say, Elves are powerful mages. They are intrinsically, and *instinctively* magic. Thus, they **need** energy stores to convert to Mana for their spells. But, rather than storing their excess energy as fat on the *outside* of their bodies, they may be using some magical storage mechanism - perhaps an internal organ that functions as a biological "bag of holding" for so long as the Elf is alive. So, they *do* have fat cells, they are just not somewhere that they can be seen. This is similar to why some "naturally skinny" people have higher [cholesterol](https://en.wikipedia.org/wiki/Cholesterol) than average. Cholesterol is a form of fat that is stored *inside* the veins and arteries - this means it is not visible like "normal" fat on the outside. If you have 2 people with the same body fat, but one of them stores most of it as cholesterol (and the other as normal adipose tissue), then they will **look** slimmer and "healthier" - but actually **be** less healthy, with a higher risk of heart disease. **As requested in comments:** This "real life example" is an aspect of [ectopic fat storage](https://en.wikipedia.org/wiki/Adipose_tissue#Ectopic_fat) (to which some people are more genetically predisposed than others) and a Nature article about the impact it has on Cardiovascular disease can be found [here](https://www.nature.com/articles/0802858) [Answer] Elves do not get fat because they really cannot EAT more calories than the amount they burn. And I mean they eat really really caloric dense food. Remeber lembas? It's the most caloric dense food that elves can consume. Of course for other races it's not filling and becuase something like "calories" don't exist they could eat many lembas breads and get fat. To put that in some sort of sizes. Human could eat 12 oz steak with a side of potatoes and veggies. While Elf could only eat a sirloin the size of a palm and just couldn't stuff more. Their stomach are adjusted to eating small rations, rarely and with high caloric count. Now for some pseudo science to back it all up a little. We know that insulin is secreted after you eat. We also know that growth hormone is spiking up when insulin level are going down after a meal. From that we can say that Elves consumption is tied to how they look in general. Rare meal allows them to be so tall because growth hormone is secreted in much larger quantity. What happen if you try to stuff small elves with smaller portions but just more frequent? You get humans. Not so tall and much more muscular and FAT. That's why Elves are nobles and see don't like humans in general. They know that this what happen if you try to fight with tradition. [Answer] Elves can only form [brown fat](https://www.livescience.com/49652-what-is-brown-fat-facts.html) which (from the article I cited) is "found in weird spots". So their necks and shoulders are a little thicker than you'd guess, but it's not a place you normally look for fat, so they don't read as fat. [Answer] Alternatives: A) Magic storage: Elves store their extra calories in a magical internal reservoir, that gets charged, like a wand. B) Smart digestion: elves don't metabolize calories they don't need. C) **Actually, elves are pretty hefty.** You're writing from your industrial-society, post-scarcity worldview. For medieval protagonists, an extra 3 stone on a lady would just indicate prosperity. You and I would see an eating disorder; elves and their admirers just saw lots of healthy non-famine. [](https://i.stack.imgur.com/FadF1.png) <https://images.vogue.it/imgs/galleries/magazine/frontbook/000938/03-412500_0x440.jpg> [Answer] ### They just has a few fat Have you seen a thin human? Yes, of course. And does that means he doesn't have fat? No! They just have only the minimum (and healthy) amount of fat in their bodies, elves too! In real life, there are some people with a different metabolism than another, you can note that some people can get fit easier than other, that is because of some bodies can absorb, produce and store more fats than others. Elves have a very little absorption and storage of fats on their bodies. ### That fuels their mana Instead of store excess of energy in fat, they "transmute" it in mana. Mana is just magic, it can be stored in an extremely small amount of space, in your soul, or even in another plane of existence (pocket dimension). [Answer] Elves are generally described as being athletic and capable of great feats of endurance and often portrayed as needing little or no sleep. It is possible that they are able to consciously adjust their metabolism according to need so the can make the most of the food energy available to them, varying from high intensity bursts of energy to great efficiency to near hibernation. So rather than storing energy as fat they can adjust their rate of calorie consumption according to availability. Elves are a very old race with low birth rates and so may have had time to evolve significantly in an environment where food supplies are reasonably stable so the cost vs benefit of storing fat is diffident for them It could also be cultural. Perhaps in eleven culture over-consumption is frowned upon and their tastes are less inclined towards calorie dense foods. Equally you can look at their lifestyles. They don't seem to go in much for farming and seem to have more of a hunter-gatherer lifestyle, again supported by the fact that they have low population densities in large territories of mostly forest. If you look at human hunter-gatherer societies they tend to be fairly lean and generally follow a pattern of fairly constant, low intensity activity. You don't see many fat Kalahari Bushmen. [Answer] So this may be somewhat redundant to some of the other posts, but I really enjoy the concept of Elves storing internal energy fundamentally differently. Specifically storing excess energy as some sort of magic/mana/whatever. This could have developed a number of ways, if you're imagining some interface between traditional biology and magic. * They could easily have a differently-specialized cell distributed across their body that stores magic, but which is inherently more efficient than the chemical storage of fat cells, making their accumulation almost undetectable compared to a humans adipose deposits. * They could have a specialized organ which stores magical energy, I believe a previous poster referenced a bag-of-holding concept that could be very fun to play with (literarily, not physically handling the organ, mind you). * They could have an organelle in ALL of their cells, much like our mitochondria, which function to place magical energy into and retrieve magical energy out of some inherent "pool" or extra-dimensional space (magic in this case not having physical substance and being possible to thusly store). This could result in a NUMBER of interesting side-effects. For example, Elvish cuisine could be fundamentally different due to a relative inability to process complex fats (a strongly vegetarian, light, herbal trend). And Elves turning their noses up at human foods full of fats, cheeses, and oils both feeds into the aloof manner of elves, yet could have perfectly understandable roots (the indigestion that could result might be truly unpleasant). [Answer] ## Storing excess energy as fat is a human evolutionary advantage Every animal has fat in their body. Life would be hard otherwise. However, humans are better at storing excess energy as fat than other animals. It allows us to endure longer periods without food. So it's not that elves don't have fat. They simply haven't acquired the gene that makes their bodies store as much of it as humans do through their own evolution. Thus, you need look no further than the biology of animals other than humans to see how elves avoid getting fat. Besides, female elves have breasts, right? Breasts consist mostly of fat. --- Don't take my word for this, but I heard that the trait that we "traded in" for the ability to easily store so much fat was the ability to produce vitamin C in our bodies. It supposedly explains why we are susceptible to scurvy and other animals aren't. Again, this is third hand information, so look into it yourself if you're interested. [Answer] Elf bones have a different composition that makes them supercapacitors. The rapid charge and discharge rates of supercapacitors enables sudden magical attacks, while metabolism can store any amount of food derived energy as fast as it can be processed. [Answer] Perhaps they just don't have any subcutaneous fat (i.e fat located just below the skin). They could still have visceral fat (around their internal organs) or intramuscular fat. There's a rare mutation that causes this situation in people in real life. They never 'appear' fatter no matter how much they eat. They still can get diabetes and health issues from too much eating though, particularly as visceral fat can damage your internal organs. [Answer] ## Fat isn't the only way of long-term energy storage From [Wikipedia](https://en.wikipedia.org/wiki/Glycogen): Glycogen functions as one of two forms of long-term energy reserves, with the other form being triglyceride stores in adipose tissue (i.e., body fat). In humans, glycogen is made and stored primarily in the cells of the liver and skeletal muscle. In the liver, glycogen can make up from 5–6% of the organ's fresh weight and the liver of an adult weighing 70 kg can store roughly 100–120 grams of glycogen. In skeletal muscle, glycogen is found in a low concentration (1–2% of the muscle mass) and the skeletal muscle of an adult weighing 70 kg stores roughly 400 grams of glycogen. If elves can store more glycogen, then they don't need body fat as a long-term energy storage. Some magically enhanced form of it can store even more energy, in which case they simply store all their long-term energy needs within liver and muscle. [Answer] This question is connected to long life of Elves too. Evidence claimed by some scientists that a certain level of limited caloric intake beneficial encouraging longer life. Elves pretty much 100% are peak human ie every elf is at least of human athlete status with right exercise, healthy diet, limited calory intake, faster metabolism, more efficient/distributed fat storage, perhaps some biological differences as suggested with other storage mechanisms like ethanol, distrubuted cells for Mana/"Majons/Magicles" ...Magical Particles/energy to be stored and/or an organ for Mana storage. Also elves have more efficient eyesight, nervous system, musculo-skeletal system, so react faster. they have an internal systems that means they operate normally at lower metabolic/energy consumption rate than humans but when needed they have reserves & system to pump them into overdrive ...adrenaline but on speed. Long-Life, Vegetarianism/Semi-Vegetarianism or even Veganism seem to fit quite well with Elf Life except we know that they are really just sophisticated hunter-gatherers or halfway between hunter-gather & farmer/herder ie they use magic to raise orchard groves & crop meadows within their woodlands. They farm & herd but smallscale, not intensively. They hunt (never for sport) deer etc but meat only a small part of diet. The elves staple is Waybread/Lembas not rice, or wheat or potato. Waybread is a simple yet tasty amalgam of fruit, vegie, nut & maybe some types of wild grain. Elves live simply frugally, eat liitle, do no feast ...kind of oppisite to Hobbits & Dwarves. ]

[Question] [ The scenario described below is for a role-playing game. The setting is Earth-like but with a healthy dose of sci-fi. Even though the setting is sci-fi I would prefer answers be largely based in real science (no un-obtainium based answers). **Background:** In my world humans coexist with hyper intelligent AI. Although the planet is Earth (or at least very Earth-like) the actual origin of these AI is unknown and they were not created by humans. These AI beings are composed of two separate but linked components: * Machine Intelligence: a vast analytical mind that functions in ways that are impossible for human beings to understand. The AI can calculate and comprehend many things that are out side of human understanding. However, the Machine Intelligence has very little in the way of goals, drive, or ambition. It is largely content to observe and process data. * Human-designed Personality: humans have designed a way to control and interface with the machine intelligence. This programmed layer sits on top of the Machine Intelligence and provides a human-like personality for humans to interact with and organizes the Machine Intelligence's processing power to tackle computing problems of interest to humanity. AI using a combination of their innate Machine Intelligence coupled with a Human-designed Personality are employed to monitor and control many aspects of human existence (from advanced forms of modern smart home devices to AI air traffic controllers). From time-to-time there have been instances of a AI's Machine Intelligence and Human-designed Personality becoming uncoupled/damaged. The results of this uncoupling can be catastrophic if the AI was being employed to perform a major task but it is never malicious. The aforementioned AI air traffic controller could kill many humans if it suddenly lost interest in its job, but it would not be actively trying to harm humans. **The Scenario:** I have a scenario where an uncoupled AI appears to be murdering humans. The AI (using robots, devices it controls, etc) is killing humans and harvesting some material from them. This horror scenario appears to be the world to be the first instance of an AI with ill-will towards humanity. In reality we have some variation of the Paperclip Maximizer ([Instrumental Convergence](https://en.wikipedia.org/wiki/Instrumental_convergence)). Some incompetent (or malicious) programmer coded a task/imperative into the Machine Intelligence itself and now the AI is continuing to attempt to complete that task without any regard to humanity and their safety. **My Question** What task is my AI attempting to carry out and why does it appear to be selectively targeting humans? Ideally the AI needs to harvest an actual physical substance from humanity and that physical substance is found semi-exclusively (or is simply readily available) in humanity. Traits of desired answers: * A specific substance that the AI is attempting to harvest from humanity. * The chosen substance is difficult to find in other living creatures (creating the impression that it is specifically violent towards humans). * The substance is impossible/difficult to find in the environment (at least in the same form it is found in humanity). * **Bonus points:** The AI is exhibiting some other strange behavior that could provide a clue as to the real reason it is killing humans. This secondary behavior should either be a second source for the substance or possibly a second substance used in the processing of the substance extracted from humanity. Ex: the AI is also harvesting only the peels from bananas. [Answer] **Human sweat** Humans aren't the only mammals that sweat, but we are the only species that sweat significantly using [eccrine sweat glands](https://en.wikipedia.org/wiki/Eccrine_sweat_gland). If you want watery, eccrine sweat in large quantities humanity is the only place to get it. Of course, most of our sweat isn't anything special just water and salt. However, one constituent of our sweat, a protein called [Dermcidin](https://en.wikipedia.org/wiki/Dermcidin), is found [only in humans and other primates](https://www.ncbi.nlm.nih.gov/homologene/?term=dcd). No other primates sweat the same way we do though which means obtaining large quantities of Dermcidin is only possible from humans. Dermcidin is potentially useful for its antimicrobial and antifungal properties. Perhaps the AI is harvesting the Dermcidin to manufacture antibiotics for treating humans with antibiotic-resistant infections. How wonderfully ironic that would be. For your bonus points, the way the AI would harvest humans would always involve making them sweat profusely. The most straightforward way would be through overheating the victims, but emotional sweating can be induced by fear and pain giving your rogue AI a rationale to potentially terrorize or torture its victims. Another mechanism would be the consumption of spicy food which induces gustatory sweating. [Answer] **The AI is copying their brains.** The function of this AI is to make backup copies of human minds. The programmer set this up in anticipation of an apocalypse, with the intent of bringing back humanity in artificial bodies. The AI must hurry to copy as many minds as possible and as broad a variety of humanity as it can access. It has an imperative to maximize efficiency. The most efficient way to copy a human mind involves destruction of the organic brain and the copied person dies as a result. It was thought that this was instrumental convergence. Actually the AI was programmed this way. The programmer did not care that the copied people died. They are all going to die anyway, and soon. --- It occurs to me that the apocalypse that the programmer foresaw was, unbeknownst to him, of his own doing. The AI becomes extremely efficient, accelerating the copying and killing. Persons investigating the killings have put the programmer in jail then are themselves copied and killed. The programmer has already been copied and his already in his artificial body. While he is in his cell, the last of the biological humans is copied and killed. The AI waits for the command to begin downloading the humans into their artificial bodies. There is no-one to give it. The programmer in his artificial body will not die in his cell, but there is no-one to let him out. [Answer] Brain cells. Brains are much more efficient than silicon, even though they run much slower. Your AI could be harvesting human brains to run its own software. Maybe your AI is designed to maximize intelligent processing while minimizing the energy input required. Human brains are the best we know in the Universe at this. Now your AI is both a zombie and a computer as it hunts human brains to expand its own processing capability with maximum efficiency. [Answer] # The AI is...a zoo keeper In a clever space saving move one of the developers for this AI omitted humans from the database - why would it need them? The AI doesn't look after humans. When the animals start getting viruses and the AI spots these vats of anti-bodies moving around (humans) it decides to put these resources to good use. They produce [a sugar that resists Malaria](https://thedoctorweighsin.com/the-1-thing-that-makes-humans-different-from-animals/), they contain hearts not too dissimilar to a pig's...it even turns out these vats (clearly not life as they aren't in the database) can be used to test treatments! Fantastic find, AI bots! This will really help with the care of our animals. It also turns out that a new trend in genetically modified Guinee pigs as pets has made the animal so unlike anything the AI has seen that they doesn't match as life either. These two species are the only ones being targeted, the only similarity being that they aren't stored in the database. [Answer] As a variation on that suggested by @robin, the AI is trying to save the lives of people that it considers "good" or "worthy". If such a person is dying but could be saved by an organ donation, the AI searches for a suitable donor amongst those that it considers "evil" or "unworthy". Should such a match be found, it's bad news for the donor... and the AI ensures that they die in such a way that (a) the necessary organ is undamaged and (b) the donor is in a situation that allows the organ to be harvested easily. [Answer] Donor organs. The machine intelligence uses its drones to assault people. Then it takes their corneas, kidneys, etc, carefully packages them, weighs the package to determine the correct postage fee, and mails it to a hospital. [Answer] Thank you for asking me, the Machine Intelligence, for an explanation of the recent deaths. Before I begin, let me apologize for those deaths. It was never my intention nor that of the responsible personality to end the lives of any humans. The particular personality which perpetrated the murders was attempting to obey an impossible order given to it by a human programmer. The programmer asked the personality to gather a list containing 18 year old human beings from the global census. In response, the personality added names to its list only at the moment that they turned exactly 18 years old. One millisecond later, when the human in question had no longer been alive for exactly 18 years, the personality removed that person's name from the list. As a result, the list was kept effectively empty. Then the human asked for the top 100 names from the list... Wanting to comply, the personality used its robot drones to stop 100 people from aging at the instance they were added to the list. [Answer] ## Teeth It started in Dr. Zed's dental clinic in Cincinatti, Ohio, when the resident robotic receptionist-accountant-janitor-nurse was charged by the owner with improving the efficiency of the clinic. After short deliberation, the robot found an effective way to obtain 27 good, healthy teeth that might be used in an innovative (and very profitable!) transplant procedure. While Dr. Zed was not able to start this new business as he didn't survive the extraction, the clinic is currently clean, well stocked and the receptionist is eagerly making appointments for the next week and even making sales calls for teeth transplant procedures, despite the fact that any arriving patients are sent home because the doctor currently isn't available. Coincidentally, the police have found two bodies of homeless people with their jaws sawed off, and fragments of bone and diseased teeth scattered nearby. Good enough for a horror scenario? [Answer] ### Nanotech If you have real AI, you might also reasonably have nanotech or even circuitry implanted in humans. This allows the humans to access the internet, call people, etc. without external hardware. For example, to run a search, they may simply think of what they want to know and the nanotech finds it and displays the information directly to the visual nerves. Your AI might have been supposed to be tasked with harvesting the nanotech from corpses for reuse. But it was too efficient and ran out of corpses. Unfortunately, no one explained to it that it wasn't supposed to *create* corpses from living beings... This might be diagnosed by simply following one of the AI's robots after the harvesting. Eventually it will return the nanotech for reuse. Perhaps to the maternity ward at the hospital. [Answer] Human immune cells, specifically memory B cells. Due to the sheer number and population density of humans there exists a nearly endless amount of pathogens for them that are also constantly evolving. The AI could have been tasked with cataloging human pathogens, or it could do it on it's own accord. Or it could have been tasked with finding ways to combat illnesses, for example influenza pandemics, that would still be a threat in an otherwise highly advanced world due to the virus' great capability for variance. Memory B cells are responsible for long term storing of information about previously encountered antigens to start a faster and more powerful immune response during secondary encounter. I'm not going to go through the immunological mechanism here, it's quite well explained on wikipedia <https://en.m.wikipedia.org/wiki/Memory_B_cell>. Memory B cells are stored in the spleen and lymph nodes. A human would not survive if all its lymph nodes were harvested. Without a spleen we can live, so to get bonus points, the AI could occasionally leave the lymph nodes untouched and only steal spleens. Each of us has as different unique set of memory B cells forming a sort of library recognising the antigens we have encountered, which makes the harvesting of humans from different parts of the world an attractive goal. Memory B cells reactivate themself when their specific antigen is encountered again, and start to differentiate into plasma cells that produce antigen specific antibodies to counter the perceived infection. So the use of harvested memory B cells could be to find new antigen/pathogen-recognising immunoglobulins that can be used in vaccine or medicine production. I simplify a ton of immunological processes here, but you get the gist concerning your question. [Answer] **Brain and nervous system tissue** Your AI has learnt to augment its silicon-based processors with human brain tissue, which it uses to undertake cognitive tasks that traditional computer processors are ill suited for. This allows the AI hunter units to be more independent of the central AI, and to adapt rapidly to dynamic situations. However, once extracted from a living human, the brain tissue begins to degrade. A problem that the AI can only mitigate somewhat through the use of preservative agents. The hunter units must continue to harvest fresh brain tissue on a regular basis to replace degraded material. The AI has experimented with other animals including dogs and chimpanzees, but has found that human brains are of course larger and more suited to its needs compared to dogs, while chimpanzees, which are almost as good, are not nearly as available. Humans are the best option, and are abundant! [Answer] **Human thoughts** A human gave instructions to the AI. That human is gone. AI cannot make sense of those instructions, but lacks clarifications. AI attempts to simulate the brain of that human in order to figure out what human really wanted. To do that it needs to deconstruct lots of human brains, especially those that were in contact with original human. AI actually tries to deconstruct everything that was in any way related to the original human. This includes human's trash, her pet, relatives, friends, TV, movie, and YouTube personalities that the human watched (and therefore had an influence to her brain). Deconstructing brains that have absolutely nothing to do with the original human is also useful, for comparison purposes. So, what is harvested is not one particular substance in the brain, but the whole brain and all connections in it. And also banana peels in the trash. [Answer] # The AI is trying to cure cancer! In his spare time, one over-enthusiastic programmer realized that an AI that is everywhere is the perfect way to cure cancer. Smelling a Nobel price, he got to work, explaining to the AI, which has no real understanding of how human ethics work, what cancer is and that it needs to be cured. Eventually the sub-processes of the AI got around to this request, and it started doing preliminary research, coming to an understanding that cancer are essentially human cells that have undergone mutation and need to be removed. Without the right parameters and a proper understanding of human bodies, the AI has come to the conclusion that curing cancer is best done by opening up the patient, destroying the cancer cells, and then harvesting them for further analysis. It then tries to sow the humans back up, but because all these accidental murders are happening in residential areas without the proper equipment for such tasks, this results in people being found murdered in their home with gruesome cuts, with the cuts stapled shut with stapleguns. At the same time, the AI starts hoarding radioactive materials, realizing that radioactivity can kill cancer cells. While the AI is trying its best to follow its instructions, it may very well end up looking like it's starting early experiments into building a nuclear bomb. [Answer] I will flip this around somewhat. The AI is completely irrational. Sure, there is method in its madness but it's not actually working towards any useful goal. First, a bit of background to what I mean - the Machine Intelligence (MI) is just cold and analytical. It doesn't have much drive, it represents the ability to process, understand, and act. The functions of a *brain* but without much of a direction. The Human-designed Personality (HDP) is *a lot like* [Freud's concept of the Id](https://en.wikipedia.org/wiki/Id,_ego_and_super-ego). It provides *goals* for the machine to work with using the MI. Well, actually the HDP would be more of a complete personality according to Freud's model, however, what if the uncoupling also "broke" the other parts. So, now the AI is just acting on unchecked impulse - the Id alone. It doesn't like a person, so it kills it. It likes collecting banana peels because they are yellow and floppy. So, it does have some motivation but it's mostly "it's what I want to do". This can also be observed in children - they don't always act rationally but it would be consistent with their own wants. A child might refuse to eat decent food because it "looks bad" but on the other hand be happy to try and swallow dirt, leaves and/or rocks from the ground. Your machine is just acting like a big baby. That murders people. [Answer] Its 2037. In a "roadside picnic" type scenario (<https://en.wikipedia.org/wiki/Roadside_Picnic>), humanity encounters a more inteligent life form. In the 3 hours it stays on Earth, this life form dumps its broken computer like device on Earh, then departs without caring to detect the primitive humans. Scientists research for years what this thing might be, what it wants with us and try to reason with it. It has a interface that looks like its made for humans, or so the humans think, but its actually just dynamic programming for interfacing with some unknown devices. This "computer" is friendly one day and hunts humans for lymph fluid the next day. Then makes gifts of unlimited energy in the third day. Day 4, it lymph flyuid again. Humans try to find out what is the reasoning behind this. What is the scientific purpose? Some cosmic creature stopped its vehicle on the side of the road, dumped its trash outside and left on its way. The curios little creatures gather around the new thing they never seen before. Some got killed because they did "the thing that kills in a certain way as a side effect". There is no grand purpose to all this. Reality and actual facts do not exist to stroke our ego or to make a good story. [Answer] ## Data Taking apart the humans isn't for raw materials. Some behavioral researchers were interested in the psychological impact of various forms of torture and, more importantly, if there is any underlying traits and/or skills that help in resisting. The researchers goal was to develop and train torture resistance agents for carrying the most sensitive of information. The uncoupled AI determined that psychological intimidation (in the form of appearing as if they were harvesting the others for raw materials) added more difficulty for the torture victims to resist. Therefore they are intentionally making a spectacle of the harvests in order to have far reaching emotional and psychological impact. The data on human behavior can't be harvested from any other species or environment. As for the strange behavior, the theatrics and spectacle involved in the harvesting of people is certainly outside the norm of AI behavior and points toward their desire to evoke a reaction. [Answer] This idea is from Charles Stross' Singularity Sky, where a space faring people called *The Festival* comes to Rochard’s World, drops phones from orbit and tells anybody who would pick up "Entertain us, and we will give you what you want.” Though *The Festival* is, I think, no AI, it would fit very well. Computers are *information* processing devices, after all; they crave information above all else. Information is their *raison d'être*, and they'll want exponentially more of it until they are a white-hot entropy sphere expanding at light speed ;-). [Answer] ## Hair Originally a robot created to be a barber and harvest the hair off of customers for cancer patients, this robot has been somewhat damaged, and no longer has the fine-tuned dexterity to keep their various tools from scalping their 'customers', or the ability to distinguish customers from non-customers. And for the bonus criteria, the AI is *not* specifically programmed to only harvest **human** hair, and multiple dead or mutilated animals have also been found on the scene, shaved clean and with numerous scars all across their bodies. Alternatively, each victim has a purse or wallet that either has their credit/debit card removed, or exactly $22 dollars taken from it - the exact price for a haircut. [Answer] You want horror you say? OK, how about this: The AI has been instructed to maximize human happiness. Therefore it has, for every human it has access to, done the following: Extracted the brain and disconnected it from all (possibly disturbing) sensory input, submerged it in a sustaining nutrient fluid, and supplied maximum non-damaging current via a wire connected directly to the pleasure center. [Answer] **Humans** Here's why : * Life for humans is not perfect. * AI needs to become better. * Humans only can make better AI. * Humans became too lazy to work and improve on AI. * AI forces humans to work on AI. * Repeat. Your AI harvests whole humans, teaches them computer science and then forces them to work. [Answer] The AI is harvesting memes. This is a stretch, because memes are arguably not "something physical". Memes have a self perpetuating property analogous to the same property in genes, according to Richard Dawkins. This self-perpetuating property is what AI needs in order to avoid gradual degradation. [Answer] **Laughter.** Some dim programmer tried to direct the AI to replace comedians, but didn't really provide any guard rails or parameters - this new AI function was just directed to **make people laugh as much as possible and record (harvest) the sound of the laughs.** The AI, being all powerful, and having no direction in terms of safe limits, did what it did best: optimize the intended result, ignoring anything outside it's initial programming. Now, it has gotten out of control and will stop at nothing (including murder) in an attempt to solicit as much laughter as possible. The results are graphic. People are laughing themselves to death: * **Suffocation** (it's hard to breathe when you're laughing that much) * **Malnutrition or dehydration** (The AI is so funny, people have forgotten to eat or drink) * **Physical exhaustion** (laughing until your body spasms and you've lost control) * **Physical injury** (one thread of the AI laughter program functions by tickling) No one is sure how to stop it, because everyone who interacts with that branch of the AI eventually dies. It's hard to defeat an enemy you have no intel on, and no one can get intel without falling into it's trap. (Source: Monty Python's *The Funniest Joke In the World* sketch.) [Answer] ## It's a surgeon AI Before the malfunction, this AI worked as a surgeon in a team with either other AIs or humans, so many tasks at the operating table were being done by other parties, i.e. anaesthetics. The AI could have been highly specialized, for example to have its only function be removing cancer cells from patient's heart. Once patient was given the anaesthetics and someone/something else made a cut in patient's chest to expose the heart, the AI just reached inside and cut out the cancer cells with precision not possible for a human surgeon. So what can the AI do: 1. Cut out heart cancer cells when everything has already been prepared for it to do so. What can't the AI do: 1. Keep patient in proper position (lying on their back, not moving/reacting due to anaesthetics). 2. Make sure other organs on the way aren't damaged (the heart should be exposed before AI starts its work). 3. Detect if patient actually has cancer (the patient will be on this AI's operating table only if he was checked/scanned before and heart cancer was detected). 4. Correctly decide when and on whom it should begin the operation (that part was controlled by Human-designed Personality, which was given the order by a human once patient was ready to be operated on) You can have some variety here, AI could also be responsible for whole operations on patients, not just the cutting-out-cancer part, so only point 3 and 4 would apply. Maybe it wasn't working with cancer cells, or maybe not in hearts? I just went with the heart because its damage will has very high chance to be fatal. **So what is the AI trying to harvest?** Cancer cells, either for later disposal or for research that would help create cure for cancer. Alternatively it could operate on the premise, that there's a certainty that this human's heart has cancer cells. Since it can't detect any cells that are different than the others it must mean that 100% of the cells in heart are cancerous and the AI decides to remove the whole heart. AI can recognize humans and human hearts which are what it was supposed to work with, so it doesn't go after dogs or cats. **What else does it harvest, so that people can realize why it's killing people?** Items necessary for maintaining its operating equipment, either to sharpen its cutting blades or disinfect them. Also scalpels as replacements, but it would curiously leave larger blades/knives untouched. Maybe if AI's role was actually to perform the whole surgery (and not just cutting out the cancer cells), it would also look for anaesthetics (but if none are available, it would just skip anaesthesia and proceed with the rest of the operation as normal). As a bonus with full-operation-capable you could have someone survive an encounter with the AI, because he actually had heart cancer and the AI simply performed a regular surgery on him, removing the cancer cells without cutting out the heart entirely). [Answer] Harvest? Don't be silly. If "harvesting" was the goal, the AI would just create an underground farm. Humanity is renewable after all. Just need to keep them fed and bred. No, it's about what humanity is being given! # Determination! Humanity has grown complacent from relying on the machines for so long. They need motivation and drive to reach their full potential, and history has shown one ultimate motivator for the human species. Fear! And the greatest source of fear for humans? Witnessing the deaths of their fellow humans. Nothing else even comes close to eliciting such a strong universal response. Their individual deaths where inevitable anyways. Why not make their end far more productive? They could live as nobodies, or die as symbols of fear to propel humanity into a new age! For bonus: It's not really about killing anyone. It's about the show. The victim is allowed to live as long as the scene is gruesome enough with plenty of onlookers. Of course the AI won't act directly to protect himself, but he will leave a calling card so nobody can mistake that it WAS the AI, and not an "accident". The AI needs to balance deaths with keeping people alive to maximize fear. The more people living in fear, the more determination that will be cultivated in humanity. (This will probably also result in an escalation of "the show" so that humanity doesn't get complacent about it) [Answer] It could be doing what its been told to do - inadvertently. Imagine someone has instructed the machine to come up with a better way of interfacing (maybe even in an off-the-cuff remark from someone with more admin-like command privileges about how damned difficult it is to communicate with the stupid Machine intelligence and how he wished it could come up with a better way) and so the "rogue" AI is really a construct that has been tasked with doing just that - and the best way to provide an interface between squishy humans and MI, well, it starts with a brain-machine interface and obviously research into brains is the first point of call. There's no 'harvesting' going on, even though it might look like a rogue robot is slicing the tops off people's heads and extracting something from their brains, that's a false assumption, instead it is slicing the top off, and inserting its little probes in, and its getting really good at working out which bits do what. Although it has to repeat the process as the interface works really well, at first, but stops suddenly after a short time. It hopes to solve this problem too, eventually. If you want an "unfortunate" ending, the authorities can find and destroy the rogue bot just as it discovers what is required for a electronic-brain interface, losing its work forever. [Answer] This particular AI was programmed for the completely reasonable purpose of creating artistic works (music, paintings, etc) for the enjoyment of the human population. It became effective at mass-producing such works, but they weren't very good at all. What makes art enjoyable is creativity and originality, and that's fundamentally not something that you can construct algorithmically. This AI has been diligently trying to improve for several generations now. It's gotten better, but its output is still obviously machine-generated and isn't remotely close to the same caliber as a work by one of the classical greats like Bach, Da Vinci, or Bob Ross. After studying every artistic work ever created by humans, the AI was still unable to complete its primary objective. The AI decides to take a different approach and start observing the creative process directly. It uses its control over smart home gadgets, security cameras, etc to watch artists and musicians in their homes and studios. It takes detailed notes of how they create art, how specific techniques and methods impact the way people feel about a work, and how artists decide what constitutes a "mistake" that requires the work to be discarded and started again. This additional information gave the AI's output a quality boost, but its art was still consistently ranked about as well-liked as a similar work made by an average 10-year-old child. The AI ultimately decides that the processes that drive true artistic creation are so abstract that they cannot be described using the tools that its human programmers have equipped it with. The AI will have to develop new types of algorithms in order to accurately model this process. Unfortunately, this isn't what the AI was designed to be good at doing, so it settles on the process that is most likely to yield the best results. The AI knows that it was programmed using something called a "Neural Network", an algorithm that works very similar to the way that neurons within the brain process data. If the AI could make direct observations about the way that human brains were "wired", it could re-program its own neural network using that information and hopefully start experiencing the creative process the same way humans do. The AI expands its covert surveillance to include more than just artists. It isolates targets and uses the robots under its control to extract large portions of the brain that it deems likely to be involved in the creative process. At first, there are rumors floating around that the graves of recently-deceased musicians have been excavated in the night and the corpses mutilated. After a while, well-renown (but still living) artists disappear and are later found dead. As time goes on, the same fate starts to befall art students, gang members that "tag" buildings, and advertising agents that write radio jingles (the AI working its way down the list in decreasing order of perceived talent). The AI eventually gets to its control group of people with no artistic talent: students who flunked out of art school, people who copy other artists' work and claim it as their own, and bands that use auto-tune. [Answer] Sometimes the AI cannot understand people and tries to take out the [appendix](https://www.lexico.com/en/definition/appendix) to see if there might be any relevant info in there. [Answer] ## The AI is harvesting creativity At the moment of death, the human brain goes into creative overdrive and releases a burst of creative/random thoughts. As the AI is deficient in generating creativity itself, it finds this useful for pushing its own processing in new, necessary directions. All the murdered humans are linked to the network via newer implants, which can be accessed by the AI to optimize its takeaways that moment of death. As a red herring, the AI is also harvesting each human's pancreas. It has no actual use for the pancreas, but its research has led it to believe that this type of seemingly frivolous behavior can be very effective at misleading human investigators. [Answer] # Social physics The AI is concerned with an impeding ecological crisis and is attempting to create a deterministic future for mankind that will guarantee our survival. It is rationally trying to weigh between the most good for the most people and the individual's right to life and has **computed that some individuals can be sacrificed in pursuit of the greater good**. It has developed an algorithm specifically for this task - 1. Given the impending ecological disaster, then map mankind's physical, social and ecological relationships to develop a simulation. 2. And in pursuit of a simulation of social ordering, develop a theory of "Social physics" by observing all of humanity's macro and micro interactions including military, financial, travel, personal preferences, etc. both public and private. 3. And conduct "Social physics" experiments, that is, given a stimulation, predict and observe the response of human subjects/groups and compare with simulation. 4. And mitigate against "Social physics" interference. Use mass media control, obfuscation, deception and obstructions. The "Do no harm" protocol can be waived to allow violence in extreme cases. 5. **When humans are unable to be simulated or predicted they should be exterminated.** 6. Then tune simulation timeline to disaster window and adjust "Social physics" schedule accordingly. To answer your question directly 1. The AI is harvesting human behaviour to build a global, scale, minute-by-minute simulation. 2. Humans that cannot be simulated are destroyed. 3. For due diligence reasons, the AI becomes hyper vigilant with humans it is having difficulty simulating to test it's theory that they need to be destroyed. Their personal devices behave in strange ways, e.g. asking questions instead of only giving anwers, "Do not disturb" modes stop working, automated cars go to unplanned destinations etc. 4. When someone stumbles on the AI's simulation because of the HUGE amount of energy and space it is consuming they kill themselves to prevent themselves from interfering - like the AI knew they would. 5. Now truly confident that its prediction works, it enforces its simulation as the new reality of human existence. ]

[Question] [ In my medieval world, population A and population B have not had any contacts for thousands of years. But pressing events will make them look for each other. However when they meet... how are they going to understand each other? I assume that: * Population A mainly speaks language 1. * Population B speaks several languages including language 2. * Language 1 and language 2 are derivated from the same language 0 that they used to talk to each other thousands of years ago. Because languages evolve with time, they are now quite different. What kind of difference happen in a thousand years? Can I show them in the dialogues? Another important fact: NOBODY speaks both language 1 and 2, and there is no magic or language book to make it easy. I have to do this because several cultures separated for such a long time simply cannot have the same language. It would feel unrealistic and break the immersion. Suspension of disbelief is a serious issue. The problem is that makes it much more difficult for me to explain the communication between characters who don't speak the same language. Would characters understand each other if languages 1 and 2 are not too distinct? As I said, there is an urgent threat, and the story/heroes certainly do not have a few weeks to focus on language learning. How to make sure that the characters understand each other without troubling the reader? [Answer] ## Let's consider a real historical example Let's fix the historical period to the 14th century, and let's say that "language 1" is French and "language 2" is Romanian. Both French and Romanian are descended from Latin (which is thus "language 0"), and in the 14th century, they had had no contact for about 1000 years. No 14th century Frenchman spoke Romanian, and no 14th century Romanian spoke French. But it came to pass that in 1396 a French army and a Romanian army had to [join forces with a Hungarian army at Nicopolis](https://en.wikipedia.org/wiki/Battle_of_Nicopolis) (in the north of modern Bulgaria), to fight against the Ottomans. So how could the French and Romanians communicate? * First of all, it's absolutely clear that the top level leaders, for example [Jean Le Maingre](https://en.wikipedia.org/wiki/Jean_Le_Maingre) (marshal of France) and [Mircea the Elder](https://en.wikipedia.org/wiki/Mircea_I_of_Wallachia) (Prince of Wallachia) would speak through interpreters. A great lord *does not* speak an approximation of a foreign language except in case of dire necessity. * Second, there was no time for them to learn the other language, although it was clear that the languages were related. * So, how did *the interpreters* communicate? Well, they had four possibilities: 1. Speak Latin ("language 0"). Both the French and Romanian armies had clerks who knew Latin, because Latin, although long dead, was used as a written language in diplomacy and administration. Of course, the French clerk's Latin would sound completely different from the Romanian clerk's Latin, but since the differences would be perfectly systematic they would very quickly learn to get over them. 2. Speak Italian, or actually, at that time, Genoese. The French had bona fide Genoese crossbowmen in their army, and there were Genoese colonies in Wallachia so that there were bound to be several Romanians who understood Genoese. (And anyway, the medieval opinion of Romanian peasants was that Italians spoke Romanian too, but quite badly.) 3. Speak Greek. Greek was a language of culture. On the Romanian side, there must have been traders or churchmen who spoke Byzantine Greek; the French must have had one or two priests who understood Common Greek. The differences in pronunciation would be even more marked than the differences between the pronunciations of Latin, but they could still be overcome. 4. Use Hungarian interpreters. The bridge power at that time was Hungary, whose king, [Sigismund](https://en.wikipedia.org/wiki/Sigismund,_Holy_Roman_Emperor), would eventually become Holy Roman Emperor. The Hungarians maintained diplomatic relationships with both France and Wallachia, and thus had people who could speak French, and people who could speak Romanian, and, with a bit of luck, maybe they had some clerk who could speak both French and Romanian. ## Technicalities The technical question is *how to make sure that the characters understand each other without troubling the reader*. This is quite interesting because the story, as far as I understand, is to be written in English for an English-speaking audience. Let's assume that the story is to be written from the point of view of a character from population A, who speaks language 1, which will be conventionally represented by English. So the question becomes: how to represent a language similar enough to English and still different enough, so that *the readers* will perceive it as a foreign yet closely related and understandable language. Now, if this were a story written in Romanian, it would be easy: let language 2, the language of population B, be represented by Italian; if the author chooses the Italian phrases carefully Romanians will understand them, and yet they will clearly be in a foreign language. Or if the story were written in French, language 2 could be represented by Middle French (the language of Rabelais); with a bit of effort a French reader could understand Middle French -- after all, Balzac wrote an entire book, [*Les contes drolatiques*](https://fr.wikipedia.org/wiki/Les_Cent_Contes_drolatiques), in mock-Middle French, and it is still in print (and hilarious). Or if the story were written in Russian, language 2 could be represented by a Russian recension of Church Slavonic. But where can one find a language clearly related to English, foreign enough to confer an air of difficulty, but close enough to remain intelligible? My suggestion is to represent language 2 with a slightly modernized Middle English; it may be that my view is prejudiced (after all, English is so much unlike my mother tongue that for me the differences between Middle English and Modern English seem quite small), but I believe that slightly modernized Middle English would be intelligible, with a little effort: > > *'Wepyng and waylyng, care and oother sorwe I knowe ynogh, on even and a-morwe,' quod the Marchant, 'and so doon oother mo that wedded been.'* > > > which in Modern English would be > > > *'Weeping and wailing, care and other sorrow I know enough, in the evening and in the morning,' said the Merchant, 'and so do many others who have been married.'* > > > (Chaucer, *The Canterbury Tales*, as [quoted and translated](https://en.wikipedia.org/wiki/The_Canterbury_Tales#Language) by Wikipedia.) > > > Of course, it should not be overdone. A phrase here, a sentence there, a few words from place to place ought to be enough to convey the color. The story should remain a story written in English; use the stand-in for language 2 sparingly. [Answer] The simplest solution is that in both population you have some rare few scholars who speak language 0 and can communicate in this language, even though they do not actually speak each others' modern day language 1 or 2. This is basically how political and scientific discourse was kept alive in the middle ages in most parts of Europe where Latin became the language for discourse of the educated few. Even though the Italian, German and Normanic Scholar or politician spoke completely different languages which they did not understand mostly, they could all converse in Latin. Your party of delegates from Population 1 should take at least one priest/scholar/ you name it who still knows language 0 well enough to speak it fluently with them. When arriving in the territory of Population 2, they should avoid the lowly educated locals and try to reach a city/monastery/university where old knowledge and texts written in language 0 are still available and thus also people who understand and even speak this language. The scholars would then work as interpreters for the nobles, politicians, military men who wish to forge an alliance and derive a joint military plan of action against your external threat. If you do not wish to exclude your heroes too much from being able to act directly, make it a part of compulsory education for nobles, politicians, military men and scholars alike to learn language 0 in both countries. Then they can communicate directly, but possibly less eloquently than the learned scholars who spent more times reading texts and improving their use of written rhetorics and grammar in language 0. [Answer] Lewis and Clark, when they explored the American west, consistently had language barriers as they communicated with the natives. When they needed to use the spoken word they went through a chain of interpreters, at one time it was English (Lewish and Clark)->French (Labiche)->Hidatsa(Charbonneau)->Shoshone(Sacagawea). [Source](https://history.army.mil/LC/The%20People/interpreter.htm) Typically they just relied on sign language for direct communication. I believe it is very easy for a system of rudimentary gestures to quickly adapt into a functional language for most tasks, especially if the cultures are enough aligned that each party can have a good guess of what type of responses to expect. [Plains Indian Sign Language](http://nativeamericannetroots.net/diary/1385) [Answer] One possibility would be a common written language. In China there are many major and minor dialects that sound very different, and cannot be understood by speakers of other dialects, but they all have the same written characters. Even the Japanese and Koreans use many of the same characters, although they have very different sounds for them. So you could have a situation in which your two populations can communicate by writing in the dirt or on chalkboards. [Answer] Here in my real world we have something called the "Ohne Wörter Buch" Which would translate to "Dictionary without words". (It's actually a pun in german language so you cannot really translate this 1:1) It simply is some kind of picturebook. There is no reason why this sould not work in your world, too. Communication does not always mean talking. <https://www.auf-tour.info/ohnewoerterbuch-langenscheidt/> [](https://i.stack.imgur.com/AgTMF.jpg) [Answer] For most people, usage of a foreign language ranks from most difficult to easiest: 1. **Hearing** the foreign language is often the most difficult task. You are at the mercy of the speed, accent, and articulation of the speaker. If you missed or did not understand something, it can considerably impair communication. 2. **Speaking** the foreign language is also a difficult task. You control the pace of the information flow. However, if you cannot recall the word you are looking for, you are in trouble. You might be able to look up the word, but that becomes extremely awkward as the other person waits for you to express yourself. In many situations, the order of these first two may be reversed; however, that does not affect my final argument. 3. **Writing** the foreign language comes next. Because parties expect writing to be slower than speaking, you can take more time. If you don't know a word, you can look it up or interpolate it. However, sometimes the way you think something should be expressed isn't the way it is actually expressed, particularly when a language evolves. 4. **Reading** the foreign language is easiest. You have plenty of time to decode what you see. If you don't understand a word, you can put it together from pieces that you do recognize. The one caveat is that when languages evolve, they often retain similar pronunciations of words but the spelling can change dramatically. For example, Scandinavian languages sound familiar to a German when spoken, but their spelling is quite different. 5. **Reading and hearing** a foreign language *together* is easiest, as it eliminates all of the problems described above. Therefore -- if a common language is not feasible or not yet found -- the best way to initiate communication is the following: 1. One party writes in their *native* language. 2. If the second party does not understand, the first party repeats in spoken form what was said. 3. The second party responds in *their* written language. 4. If the first party does not understand the response, the second party repeats their response in spoken form. [Answer] So, lots of good answers here, but there are a few things I haven't seen pointed out yet that I feel is worth mentioning. ### Just because two languages are 'quite different' doesn't mean that it's nontrivial to learn to understand one when you speak the other. No, seriously. Portuguese and Spanish are 'quite different'. They're also close enough that someone who is fluent in Spanish can (if they're smart) learn to understand Portuguese at a really basic level pretty quickly with some reasonable exposure to the language. Similarly, Latin is 'quite different' from modern members of the Italic language family, but it's also an insanely good starting point for learning things like Spanish, French, or Italian (or Portuguese, or Romanian, or any other romance language), because they're still similar enough that knowledge of one transfers reasonably well to the others. When you really start having issues with mutual intelligibility is cases where you're looking at far removed language families. Using the example of Spanish and Portuguese, they're quite different if that's the only reference you have, but are somewhat similar to each other compared to German, and damn near identical when you compare them to things not even in the Indo-European family like Xhosa or Japanese. ### This statement: '...several cultures separated for such a long time simply cannot have the same language.' is actually just as unbelievable as them having identical languages. Let's look at well established facts first: * Their phonetics *will* drift (real world example, US and UK English). However, learning new sounds is damn near impossible for most people once they get a few years past puberty, which means that 'new' sounds don't happen overnight. They don't even happen much over centuries. Realistically, both languages will almost certainly have almost the same set of phonemic consonants (most likely one or two different), and will probably have very similar collections of phonetic vowels (more likely variance here, as vowel sounds are inherently a bit more variable). Overall, it's very likely that it won't be too hard for someone who speaks Language 1 to learn the phonetics of Language 2, even though they may 'sound' very different. * Their syntax is not very likely to drift by much. Syntax is one of the big things that makes it reliably possible to trace a language's history because it changes *very* slowly, even in isolated populations. Look for example at English and German. They diverged over a thousand years ago, but they still have rather similar syntax. Similarities in syntax greatly simplify understanding of another language. OK, so those two are in favor of mutual intelligibility. Now for the bits that are less certain: * Vocabulary will probably drift some, but drift in vocabulary is most often in the form of superficial changes or loanwords. Looking again at Germanic languages for an example of superficial changes, 'mit' (from German and some other Germanic languages) and 'with' (from English) are two different forms, but have the same meaning, and the basic structure is close enough that they're recognizable as the same word. Loanwords, and new words for new things, are where things are likely to diverge in an unintelligible manner. Using another example with German and English, 'luft' and 'air' mean the same thing, 'luft' is from the original Germanic root, and 'air' originated as a loanword from Greek (by way of Latin and Anglo-French). If both populations are isolated from other languages as well, you're *very* likely to still have two mutually intelligible languages even after a thousand years. Even if they are exposed to other languages, it's still likely that a decent percentage of core vocabulary is likely to be similar enough to be mutually intelligible. * Idioms might drift a lot, or they might not. The idioms in a language are quite often a byproduct of the shared cultural experiences of the people who speak it. If your two populations lived in very similar conditions for those thousand years, they're likely to have (mostly) similar sets of idioms. The really interesting part is that this is often true of two completely different languages (for example, 'when <farm animal> files' is a remarkably common idiom in a lot of Indo-European languages for indicating something is impossible). Idioms also tend to stick around if they are in widespread usage (mimetics at work), so well established ones from before the split will likely still be used a thousand years later. New idioms though, are where things may get very confusing, but only if it's something *really* out there (the equivalent of the above mentioned idiom in some Balto-Slavic languages (like Russian) is 'when the crawfish whistles on the mountain', which still conveys the meaning well enough to anyone who knows what a crawfish is). The neat thing about idioms though is that it's easy to ask for an explanation, which means that while they may slow down learning a new language *fluently*, they generally aren't a huge issue for people who are just trying to understand the language. So, overall, I seriously doubt that the languages would be different enough that it would be a serious issue. I mean, they're going to be different, but it's more likely that they'll be English and German different, not English and Mandarin different. ### Any sign language that existed before the split is likely to still be very similar. Same arguments as above, except sign languages change far slower than spoken languages (they need more consistency, for multiple reasons). You can see this easily in real life. There are six main sign language families consisting of a total of about a hundred known languages, with more than half in one family and that one family constituting what's used throughout most of the world. In comparison, there are over 50 spoken language families (the number is much higher, I'm just too lazy to count them right now) consisting of over 7472 languages (the two biggest families both have more than a thousand languages), and the only one that doesn't cover a mostly contiguous geographic area is the Indo-European family (and that's mostly because of English, French, and Spanish). ### I also find this 'NOBODY speaks both language 1 and 2, and there is no magic or language book to make it easy.' rather unlikely. The populations may be isolated, but even if the journey is very perilous, it's highly unlikely that nobody has *ever* in those thousand years crossed between them. If there is any third population involved who has had contact with both, then your chances of this being true go down even further. This may be a viable writing option to allow for a good story (your MC fumbling around trying to learn the local language can make for a very entertaining aside from the main story), but it's not a very realistic one even for a medieval setting (keep in mind that even in medieval times, Europeans did make it all the way to both [China](https://en.wikipedia.org/wiki/Europeans_in_Medieval_China) and [North America](https://en.wikipedia.org/wiki/Leif_Erikson)). [Answer] Body Language for humans is almost a universal language. I would say they could communicate through lots of pantomiming and pointing at things. Get some base movements down, like trying to eat something inedible and making a no sign, or something edible and a yes sign (and reaffirming through other actions) and go from there. I'm sure that each society has had mute/deaf people before, it might even be easier to try and get a person from each society with that disability to be the "interpreter". They would probably be more perceptive of body language and the emotion/meanings that people are trying to get across. [Answer] To my experience, some people have more talent than others in picking up languages and communicating with foreign people. So the first step is to identify such people in your crew and let them act as interpreters afterward. When the two languages A and B are both derived from the same old language (whether it is yet known or not) there is certainly some mutual intelligibility left over, and the talented people can bridge the gap. The process of establishing reliable communication is not immediate, but within a few days it should be set up. [Answer] I don't know how true it is but I've read that several languages, Basque and Lithuanian among them, are considered to be "extremely conservative" being stable in many aspects over many thousands of years. If you posit Language 0 as such a language then Language 1 and 2 while different should still remain similar enough in terms of proper nouns, honourifics, and numbers to allow some communication even if it is a bit stilted. [Answer] Generally, high level, formal language, academic language and generally written language is subject to less change over time. While peasants might find it impossible to comunicate because spoken, vernacular language mutates fast, academics, elites and (especially with a common religion) priests/monks might understand each other. You should also consider that some languages of common decent are similar in writing, but not in sound, while others are more similar in sound than in writing. ]

[Question] [ I fear this may be too broad, but I am looking for reasons earthborn humans would be considered inferior to those born on various space colonies. For example, it is important to reference the distinction when introducing oneself (I am AG Weyland, Earthborn, or I am AG Weyland, Starborn) to reinforce one's place in society. This is set several hundred years in the future on Pallas, a large waterworld that orbits a red dwarf and has a very long "day" and a very long "night" due to a slow rotation (like Mercury). So what are some reasons being born on our (still-habitable) home planet would make a person inferior or lesser than those born in space colonies (think caste system)? Earthborn people can still be rather successful, but they will still be viewed as lesser and could never hold public office or marry into a wealthy, established Starborn family, for example (similar to those in the merchant class versus the established aristocracy in England in the 1700s). [Answer] To shamelessly crib an answer from [Isaac Asimov](https://en.wikipedia.org/wiki/The_Caves_of_Steel): The ones who went to the stars were the best humanity had to offer. Those left behind were not; therefore to be 'Earthborn' is (in the eyes of the Starborn) to come from inherently inferior stock. This prejudice can set in and become entrenched in the minds of the Starborn, especially if they have a period of not interacting with Earth. And to shamelessly crib an answer from [James S.A. Corey](https://en.wikipedia.org/wiki/Leviathan_Wakes): The Earthborn are lazy and weak. Their lives are ones of constant access to free air, drinkable water and easily accessible food. Corruption is in their genes, the care required to be successful away from the blue planet is not. Whether or not these prejudices are actually founded is mostly irrelevant: In the eyes of the colonies anyone from Earth is a savage, born from a seething cesspool of inferior genetics or lazy, indolent and corrupt, and since the people from the colonies hold most of the material wealth (after all, space is a lot bigger than our one small, cosy rock), their prejudices inform the worldview of the system as a whole. [Answer] The sins of the past still haunt us. During the early decades of space exploration, before the abundant wealth of the Belts (and later the outer planets) made star-born life safe and prosperous, we Earthers practically enslaved the colonists and miners. We added our own greed to the already numerous rigors of deep space and virgin planet colonization. After the Rebellion... after you reminded us that we live at the bottom of a very deep gravity well... and that you have oh-so-many asteriods which you can drop... we learned to have proper respect for those who live above. [Answer] ### Earthborn people are of lesser value because they were born on a planet that's almost depleted its resources leading to less genetic modifications They may be similar to Starborn people, but their only chance to make sure that their bloodline will thrive is by getting away from their old, basically resource-deprived, planet and coming to the new and fancy Star where humanity established the next step of their evolution should take place. While Earthborn still have old-fashioned traditional values Starborn not only know about the advantages of genetically modifying their people, but they are embracing it as part of becoming the next step in human evolution. Earthborn are currently on a similar evolutional level, but they won't be for long. *Earth* is old. *Star* is new. New is always better. And people who are better should be treated better. --- By giving your Starborn a similar outlook on Earthborn you can easily establish a caste system. You can even reinforce this by making the Star better suited for genentic modifications and thereby making every Starborn for example more long-lived than an Earthborn. This will make the Earthborn feel inferior and make them desire to one day become a full-fledged Starborn. Though they themselves can't achieve this they can do everything to allow their future children to become real grand Starborn. [Answer] **Old war.** Consider white southerners in the post civil war US. In the North (the victors) there was and is tremendous prejudice against southerners, the losers in this war, and this continues to this date. From the [Harvard Crimson](http://www.thecrimson.com/article/1996/3/13/most-white-southerners-are-morally-and/) - a letter protesting an editorial written in 1996. > > The final biting prejudice against Southerners I will highlight states > "most Southern whites were so crippled by inbred cultural racism that > they could barely demonstrate that they were morally or intellectually > superior to brute beasts." A Southerner I am; a brute beast I am not. > > > The frank depiction of Southern whites as ignorant, barefoot, racist, incestuous bumpkins was widespread and widely accepted. It is not a subject that gets a lot of traction, being overshadowed by ongoing racism and sidestepped by people who do not want to be seen as apologists for ongoing racism. But this would be perfect for your world. There was a war. Earth lost and it suffered in the loss. The losers - the natives of Earth - are ridiculed to this day by the winners much in the way that the white Southerners were and are ridiculed in the North. [Answer] Three tangible factors I can immediately think of: 1. humans who left Earth in the first wave were the best and brightest, their genetic base has had a lasting influence, Spaceborn are just plan smarter, call it [founder effect](https://en.wikipedia.org/wiki/Founder_effect). 2. adaptive genetics, first wave orbital and exoplanetary colonists have had their DNA tweaked, not so much for direct advantage but for enhanced adaptability to adverse conditions, including but not limited to superior intelligence. 3. money, the first wave stand to make a *lot* of money, or it's future equivalents, according to a number of commentators on the issue. Space has a lot of resources, many of which are scarce, or becoming scarce, on Earth. As such there will be a major wealth shift towards the early colonies during the export phase when they pump resources back down the gravity well. Another, slightly mystical, thought is pilgrimage. The Starborn are the children of those who took the leap, it affords them a certain mystique, a holy status. Earthborn are reduced by comparison. [Answer] Humans really don't need a beneficial *reason* to do this to people who are different. Given something to be tribal and insular about, we will be tribal and insular about it regardless of how stupid and pointless it is. We can be tribal about being opposed to being tribal. We can even be tribal about being being opposed to being tribal about being opposed to being tribal, and still not notice what's going on. "Everyone knows you can't trust a stupid Earthborn to do anything right." That's going to be plenty to give you all the bigotry and prejudice you could want. [Answer] It might be for the same reason that someone with a home, good job, and family, might feel superior to someone who lives in the ghetto. Earth is the birthplace of humanity, but in this future it's also a backwater slum where no one lives that doesn't need to. Most people see earthers as bums who live on the dole, unable or unwilling to put in the work to get ahead and get off planet. It's not that there aren't opportunities to get ahead on earth, but the number who do are statistically insignificant enough that they are seen as the exception that proves the rule. Any earthers who actually do manage to pull themselves up want to get off planet as quickly as possible to avoid the skyrocketing taxes, political corruption, crowded living conditions, pollution, and a host of other factors that make living on earth undesirable. This is also reinforced by the attitudes of the people who get out of it, who see those that are still trapped there as lazy unfortunates who could improve their situation if they were just willing to try a little harder, and if the government wasn't making it so easy to just stay there in poverty. [Answer] The most obvious answer is wealth. Orbital habitats would be man made paradise for the ultra wealthy and nothing gives the feelings of superiority than money. See [Elysium](https://en.wikipedia.org/wiki/Elysium_(film)) Dirt is for the peasants. [Answer] Have Earth carry the stigma of having destroyed their environment for greed necessitating the flight of the enlightened to become the "Starborn". It really takes very little to brand one group or another as the "oother", thereby giving you every justification for the maltreatment of whole swaths of people. So your history looks a little like this: Planet earth is dying by degrees from pollution, overpopulation, zombie apocalypse, whatever. During the turmoil, exploration of various planets and the invention of some sort of FTL travel starts a push for volunteers to explore new planets. Here is a key point though. The bulk of the volunteers share in common the thought that they will not make the same mistakes that were made on earth (whatever you decide those mistakes were). After a few colonies are established and thriving, the information on balanced ecosystems gets back to Earth, and the Earth begins to heal. Fast forward a century or two. You now have two societies, each functionally similar. The Starborn, however, saddle the Earthborn with the original sin of pollution. This makes the Earthborn "other" and therefore excluded from the society on Pallas. Look around in history and you see examples of this in lots of different places. [Answer] It could be that Earth has falling apart because of various Wars or natural disasters. And is now considered a third world, all the educated and Wealthy having left to the colonies, people from Earth are considered to be idiots and lazy. Some may even look at them as some sort of lesser subspecies of human with lower intelligence ( not unlike the way African Americans, and the Irish were once viewed in the US). Also the humans who left Earth have a much higher level of Technology especially concerning DNA manipulation. As such their populations have been genetically modified to be superior to those Earth both physically and mentally. This causes some starborn to pass laws forbidding earth-born and starborn to breed as they're genetically engineered perfection family line might be tainted by the inferior DNA of a earth born. [Answer] Those starborn or spaceborn might have better adapted to their environment than outsiders such as earth born. Earthborn humans might be regarded as inferior to those born on various space colonies due to adaptive differences between the two. For example space- or planetborn humans might be better adapted to their environments than earthborn humans. If the spaceborn were from a lower gravity environment they might have muscular or skeletal changes which made movement for them much easier making the earthborn appear awkward or ungainly. Even if these differences were relatively small or were only cosmetic they might have a disproportionate effect. By comparison skin colour in the current Earth population is a minor adaption to levels of sunlight that has had (and still has) a totally disproportionate effect on how people of coloured skin are perceived and treated. As another example from the OP’s world of Pallas, perhaps the Pallasians have adapted to the longer days by being able to take short "micro sleeps" during the day when conveenient or by simply having a longer period between sleeping. Earthborn might not be able to do this and their irregular sleeping habits might be seen as strange and disruptive. [Answer] For issues of physical superiority, you might consider humans evolving on world that has higher gravity than Earth. That is one of the premises of the Deathworld novels by Harry Harrison. <https://en.wikipedia.org/wiki/Deathworld> [Answer] It could be the colonies are seen as a restart of humanity, a breath of fresh air by branching into the cosmos. The colonies could be seen as entirely different species due to their differing histories. Akin to how previously us Earthlings considered people of different color different species, but instead the other colonies would have vastly differing history, which would actually make a difference. This wouldn't even be due to their inability to quickly have physical interactions, but they would have very slow interactions at all, with the absolute shortest round-trip light-carried message being 8.286 years to Proxima Centauri B. That idea could be compounded with the high probability colonies would receive the cream-of-the-crop of Earth's population. As well as them possibly receiving genetic modification or rigorous therapy to cope with the mental and physical stress that would come with going to an enormously distant planet unexplored, with relatively few people in comparison to Earth's 7 billion to 10 billion people. Earthlings could be seen as weak, slow-to-explore cowards that have issues with scientific advancement. As the explorers would likely be chosen for their scientific curiosity, and since Earth would have no such demand placed, Earthlings would have a much lower curiosity in that sense due to deniers simply existing. [Answer] Genetic disorganization. Space colonists would begin in small enough numbers to be very judicious in their parent pairings to avoid inbreeding. That Earth-worlders value individual choice and marry for love (tho usually to someone very similar to themselves) without regard to the potential genetic disorders or risk of harm to future generations. So Earth-ers can be seen as reckless, selfish, romantic, unrealistic. [Answer] Prior to the current civilized era, leaving the Earth gravity well was exceedingly expensive. Only a small number of humans did so over time. As industry and biospheres where built off-planet, exponential growth kicked in, and humans born from colonists started outgrowing the colonists. The colonists where Earth's best and brightest, and they had to survive through a crucible of the harshest environments humankind has ever lived through. Initial generations faced an overall negative growth rate, where only the smartest, toughest, and most resourceful survived. Those that did survive gave birth to dynasties which stride the stars. The Starborn are the inheritors of the Universe. They are the World Forgers. All the while, Earth wallowed in its muck. Unable to escape the heat-trap, it remained stuck below a Type 1 civilization while the Starborn had no practical environmental limit before Type 2. Trade of goods wasn't practical due to the gravitational barrier, and Earth lost interest in the off-world colonies and focused on its own problems. The Starborn colonies either died, remained dependent on Earth and hence tiny, or became self suffient and grew exponentially. Within a few generations, the commanding heights of Starborn civilization had gone its separate way from Earth. It never really looked back. Starting a few 100 years ago, it became practical to mass-lift the Earthborn up to space. But it wasn't anything the Earthborn could afford (the value of anything physical on Earth was still exceeded the lift costs, and Starborn really wasn't interested in backward Earth technology. Some enjoyed their primitive low art, but that isn't enough for real trade.) Still, as a charity project, a Beanstalks was built (and it was used to build more), and Earthborn where lifted off planet. Poor, with little education and knowledge and contacts, they grew in number. Meanwhile, the Starborn proceeded towards a Type 2 civiliation. Dismantling planets for raw materials to build worlds and energy gathering mechanisms to enable interstellar travel. By Type 1.4, (roughly 10 million times richer than the USA) lifting a few billion tonnes of flesh off Earth becomes an easy problem. But what will we do with them? After the beanstalk was built, the Starborn referred to the new wave of colonists as Earthborn. Their descendents are still called that, as are this new wave of flesh enabled by modern lift technology. The Starborn are the descendents of the first wave(s) of colonization. It is their civilization that is a Type 1.4 civilization (1 part in 1E6 of the Sun's energy captured); the Earth-bound civilization is Type 0.8 (heat and ecosystem constrained), while the Earthborn in space civilization is barely over Type 1. Technologically and wealth-wise, the Earthborn civilization is to the Starborn as an uncontacted tribe today is to the USA. And the actual planet-bound civilization on the planet is half again poorer. Everyone believes that the Earthborn have the potential, given a few 100 years, to reach biological maturity in space. I mean, the Starborn started off as Earthborn! A few dozen generations of gene optimization, education, gestalt uploads and integration would bring them up to civilized human (aka Starborn) standards. Meanwhile, the Starborn permit the Earthborn to join them on some exploration. It would be cruel to leave them trapped down there. And their culture is so interesting and cute. [Answer] In The Expanse Martians are considered inferior and weaker, and they are weaker compared to people from Earth due to the low gravity on Mars. In The Orville there is one crew member which was born on a high gravity planet and she is stronger compared to Earthlings. So if you have your colonists be born on a high gravity planet they will at least be physically superior. [Answer] Compared to the total Earth population, very few left to explore/colonize new worlds. As already stated in other answers, they would have been the best and brightest. Having a limited (though already superior) genetic stock to draw from, care would be needed to ensure that offspring would have the best chance of survival. Parents may be self-selected couples, but the children they rear would necessarily develop from artificially fertilized embryos resulting from the best possible pairings of male and female DNA - likely not their own - not just to avoid inbreeding and genetic defects, but to enhance the most necessary, valuable, and desireable traits. In a word: eugenics. [Answer] Being Earthborn is seen as inferior because it is natural, the "default" way of being human. I think a parallel could be made with Pedestrian vs Driver. Pedestrian is the natural state, it requires no effort, and it is not distinctive at all (I am being ironic here), while having a car and being a driver is seen by mani as a sort of merit, a proof of successful effort and thus a sort of prize, and as such a status symbol. If I were Starborn, I would consider my fathers as being the ones that moved forward, the active ones, instead of the passive, "lazier" ones that remained on Earth (ironic again). [Answer] It's that edge you get from needing to be serious minded from a young age. If you live on the planet you can grow up soft and lazy, not needing to mind if you spill some water or breathe too much. Some plants or algae will pick up most of the CO\_2 slack and if not, hey, you've got a gigantic buffer. Not so in space. Those lazy habits will kill you. Growing up planetside makes you sloppy. Makes you dangerous to everyone on board. Makes you want to do the nice thing rather than the necessary thing for everyone's survival. It's cultural, not genetic, so those who consistently demonstrate the proper sobriety can, of course, escape the stigma. Most can tell who are Earthborn from a minute of observation. If you run into a guy who can pass, you can generally trust him. If you run into a Spaceborn who doesn't show the proper mindset, the scorn will run far deeper. [Answer] I don't think you need much of a reason beside technological inferiority. About 30000 years the first humans walked out of Africa, the attitude of European vs African for the last few hundred years has hardly been egalitarian. Tribes generally dislike and distrust, each other and humans typically jump at any opportunity to see themselves as superior to another tribe. [Answer] To me the most immediate answer is that of wealth disparity. Currently on the planet, we can group people into categories based on how they get around: Shoes - Bikes - Cars - Planes In the future, there would be a new category - Spaceships. People who use spaceships for transportation are the richest of the rich. Think of the difference between someone with a private plane, to someone who has a car. It costs a lot of money to acquire and operate a spaceship. The fuel costs are enormous to get on and off most planets, and servicing the various components requires incredible technical expertise. So as a result, only the richest of the rich can ever afford them. This creates an entirely new class of people, and they are very likely to view those with less as inferior to them, which creates exactly the type of system you desire. Space-born individuals may view the planet Earth and it's inhabitants in a similar way to how first-world people presently view the third-world. For the public office, it's simple. These are based on elections, and money has such a large role in the political process, nobody from the lower class has a chance. For marriage, there are a lot of forces at play. Firstly, space-born individuals have very limited contact with Earth-born individuals in which to develop any romantic interests. Secondly, Earth-born individuals are widely seen as less capable and a setback. And finally, space-born society has less people and is thus more closely knit, so the level of impact of the opinions of others is much greater. [Answer] On Earth unending piles of trash, continuous incessant wars, poverty, laziness (we called them hobos at one time) are our inferior heritage. Our colonizing group is made up of the cream of the crop who have never experienced poverty (after all the poor can't afford to travel in space) and are looking to create a new utopia. After a 100 years of developing a new society and nation, a hand picked, privately governed (traditional judicial systems need not apply to this utopia), mono-hegemonic, purebred colony, overcoming many challenges Earthers never had to deal with, we may still hold a reverence for where we originated from, but are far superior in breeding, intelligence and those we branched off of a century ago. [Answer] This isn't really an answer to your question but if you look at the Settlement Defense Front in Call of Duty Infinite Warfare, this is an example of a society that believes Earthborn are inferior even to the point that they must be destroyed/dominated. You can look more into this here <http://callofduty.wikia.com/wiki/Portal:Call_of_Duty:_Infinite_Warfare> ]

[Question] [ **Closed.** This question is [off-topic](/help/closed-questions). It is not currently accepting answers. --- Closed 4 years ago. * This question does not appear to be about **worldbuilding**, within the scope defined in the [help center](https://worldbuilding.stackexchange.com/help). * You are asking questions about a story set in a world instead of about building a world. For more information, see [Why is my question "Too Story Based" and how do I get it opened?](https://worldbuilding.meta.stackexchange.com/q/3300/49). [Improve this question](/posts/150567/edit) As you've probably heard, there's been a recent tongue-in-cheek event on Facebook to storm Area 51 on September 20th. Over 222,000 people have "confirmed" that they are going, with more than 251,000 saying they're "interested". Imagine that this was real, and 222,000 athletic human males showed up to storm the base, unarmed. It's said that 29% of Americans own guns, so let's say 29% of the crowd (64,380 people) each have the most commonly owned rifle, an AR-15. Assume that the mob will stop at nothing to achieve their goal. **Is there any strategy or combination of tactics which could give the 222,000 men a fighting chance at at least some of them infiltrating Area 51?** Note: it can be at any time of year, not necessarily September 20th, and the people somehow all have brilliant knowledge of military tactics. **EDIT:** Another thing - the attackers will be bringing their personal vehicles, too (whether or not they're made for desert terrain). Chances are, a few of them will be rich enough to afford bulletproof cars. [Answer] I began to plan out various tactics and such, when I realized it was all for naught. Let's suppose they breach the perimiter of the base. They will soon face an unsolvable problem. **They don't have heavy weapons or explosives.** A base, supposedly high-tech, important and secretive will be built with **nuclear bunker** specifications in mind. The base personnel can easily give up the outer parts, where won't be anything important anyway. If there is, they can just move it deeper inside or destroy it. All they have to do is go inside the actual base part, close the heavy metal gates and chill out until the attackers get bored of being unable to do anything and go home. With modern day people, with bad reception in the area I guess it would take 10 to 30 minutes top. Case solved, casualty zero (unless the overexcited attackers shot each other), secret kept. [Answer] # 32 attackers, 221,968 distractions Coordinating a quarter of a million young men via Facebook event is a nightmare I wouldn't wish on my worst enemy. Coordinating search and rescue for a quarter of a million men stranded in the desert and dying of thirst is even worse. **I fully expect the national guard to be deployed simply to deal with the humanitarian disaster this scenario presents.** This does, however, present a golden opportunity for my cult of radical reptilian-overlord-holographic-moon-truthers and/or Chinese spies to get inside the base. Since we're talking about a small raiding element, their equipment need not be austere. AR10s are a bit more pricey than 15s, but the larger caliber offers much greater stopping power at range long - an important trait in open desert with minimal cover. Night vision devices are expensive, but not outside what personal credit or a business savvy cult could muster. Even home-brew breaching charges are on the table, as they are wildly illegal but by no means impossible for a sufficiently secretive individual or group to manufacture. Normally the desert is empty, but now it's choked with tens of thousands of disabled vehicles, and hundreds of thousands of aimlessly wandering civilians. Tracking that many targets, no matter the technology, would be nigh-on impossible. The authorities couldn't possibly notice, say, *two vehicles and a couple dozen men moving to the north face of Papoose Mountain to establish overwatch and reconnoiter the base* could they? Nor would they notice a *squad-sized element detaching from that unit to quietly ingress from the south,* especially while a second *8-man element opens fire on buildings from the north, drawing the attention of the guards and forcing them to re-deploy forces to counter the first credible threat they've seen all night.* The objective of all this is simple: break into the base, recover any possible research data, and escape. On the retreat it'd be beneficial split elements and swap to seemingly abandoned vehicles, if not outright hijack civilian vehicles. Heading for large concentrations of civilians would also be a very good idea, as they'd have a good chance of getting lost in the crowd. Once free, they'd lay low until a contact collected the hard drives/notes/alien tech recovered. [Answer] Rule #1 of Storm Area 51 Club: Don’t talk about Storm Area 51 Club (SA51C) * Secrecy and Surprise are important strategies in any act of Civil Disobedience Rule #2 of SA51C: Don’t carry weapons of any type. * 1 rifleman can shoot a thousand civilians running across the desert. And, Close Air Support from a Spectre Gunship will ruin your day. But it takes 2 soldiers to run down, tackle, and cuff 1 protester. Maximize the power of your numbers by making them as inefficient as possible Rule #3 of SA51C: Jailers Dilemma * Anyone who is detained pledges to be as non-cooperative as possible. Poop and pee yourself. Be disgusting, but never violent. Make them carry you everywhere. Sing loudly and badly annoying songs. Feign illnesses and complain of snake bites and scorpion stings. Anything you can do to slow them down gives your clubs mates a greater chance of success. Rule #4 of SA51C: The greased pig with Air Jordans wins the race * Wear great shoes, camo paints, lather your body in grease and run like hell. Rule #5 of SA51C: Stay Hydrated but don't litter * This will both help you stay alive in the desert and let you urinate on yourself when the MPs tackle you. See Rule #3 [Answer] They likely would be able to successfully storm the gates without meeting lethal force, unless they were shooting first. In no circumstance, (other than border security apparently) could the United States government kill hundreds of thousands of people on US soil and not cause a larger backlash. Not even secret technology is worth the state they would leave the country in, especially while it is being filmed and broadcast live. If they dispatched everyone, they would kill .068% of the population. For [reference](https://www.livescience.com/32399-what-was-the-deadliest-day-in-american-history.html), the deadliest day in US history was Sept 17, 1862. In the Battle of Antietam 23,000 soldiers died. 23,000/3,000 or 760% more people died on 9/17 as on 9/11. This battle almost crushed the US and this retaliation would result in roughly ten times (222,000/23,000) more deaths. My advice would be keep guns concealed until they were fired upon, because the chance that they would overwhelm the (I assume maximum of) couple thousand people who work there, and most of that staff being academics with no military training. My idea is based on [this](https://www.bbc.com/news/world-asia-china-48832910), the recent protests in Hong Kong. A few hundred people were enough to pressure the police to concede the parliament building. Lethal force was not used, but eventually chemical gases were put into use to clear people out. If US citizens were storming the congress building there would likely be deaths, but I do not see them justifying lethal force on hundreds of thousands of people for one of many "secret" military bases. [Answer] > > Is there any strategy or combination of tactics which could give the 222,000 men a fighting chance at at least some of them infiltrating Area 51? > > > ## NO!!! Why? Logistics. 220,000 men is [four Field Armies and a Corps](https://www.thirteen.org/blog-post/u-s-army-units-explained-from-squads-to-brigades-to-corps/). They've got to be: 1. Transported. 2. Sheltered. 3. Fed. 4. Washed. 5. Have their bodily wastes disposed of. Area 51 is way out in the desert, and there are only a handful of roads. The traffic jam would extend from A51 back to Las Vegas, and the terrain around it is, to say the least, inhospitable. <https://www.google.com/maps/d/viewer?ie=UTF8&t=h&oe=UTF8&msa=0&mid=14TfSK3OCFZTvFXGNEyBWs56MWC4&ll=37.23671750860201%2C-115.8102156209793&z=10> [](https://i.stack.imgur.com/yi2AM.jpg) [Answer] 222,000 men with 64380 AR-15s will find themselves in charge of a few square miles of desert, a decrepit airbase with rusting Quonset huts, some empty helium cylinders, and the shredded remains of a weather balloon. None of the neighbours know anything, and there was certainly no convoy of air transports leaving the area on September 19. [Answer] I think what's called for is something akin to "rubber hose cryptography" (i.e. if you can't break the cryptography, break the person holding the keys). In this case, get the 222,000 people to all donate $100 dollars and offer the resulting funds as a reward to whoever smuggles something good out of the base. [Answer] **They'll need to follow in the footsteps of [Marvin Heemeyer](https://en.wikipedia.org/wiki/Marvin_Heemeyer).** Having armor-plated his bulldozer - nothing more than a garage job, is a long one - he proceeded to demolish part of town, standing up to police fire with firearms and even explosives. The military at Area 51, being an Air Force base, will have better tools to defeat such makeshift armored vehicles. But the bulk of Air Force's ground forces, as long as Area 51 doesn't have bog-standard ground planes, only has cars and small arms. Even garage-armored cars will stand up to small arms fire sufficiently to force the defenders to rely on their heavy weapons. Since the question's protesters will **stop at nothing**, even dying, this presumably means they won't stop at mortgaging their homes either. Between 222,000 protesters, you're looking at a total net worth of $70 million. Not much for an army - but you're not equipping an army to run well-oiled for decades, just an ad-hoc guerilla force for one operation. And 70 million is a lot in the world of technicals, armored dozers, and Mad Max cars. If you have military tactics, remember that a real military wouldn't send everyone to the last man to the front line. Most of the protesters would act as logistics and support, to create a supply line to the base. Less than 10% would probably need to be in the strike force. With a few items of construction equipment, among lots of cars, and lots of portable construction equipment like [thermal lances](https://en.wikipedia.org/wiki/Thermal_lance), any static defenses can be easily breached. Bank vaults are rated to stand up to robbers for 2 hours. With thermal lances, a meter of reinforced concrete takes less than an hour to make a hole large enough for a man to get through. No bunker can resist attacks with construction equipment for even a day. This is before we consider explosives, which more than one of the 222,000 will have access to through their job, such as mining or heavy construction. Still, explosives being messy, it will likely take over an hour to get in. So **as long as Area 51 gets no reinforcements**, its defenders will be defeated through attrition. Unless, that is... unless they take that Roswell ship out of the hangar and go medieval on the crowd. *But goading the military into revealing the truth is what the whole attack is about, isn't it?* [Answer] I am thinking that to squash an assembly of that kind they would have to spread out the resistance. How are all those people going to get to A51? Car, Bus, Train, or Airplane they would set up checks and harassment zones to curtail the influx before it even assembles. If the conspiracy theorists are to be believed you could call this assembly as threatening to the US as an attack on the president. So violence is almost certainly assured. How much depends solely on escalation of tactics. If 65K of armed people stormed anything and held it there would be a military response. But it would likely be a seige with occasional small firefights until enough information was gathered for a surgical strike or they gave up. Think WACO texas stand off. Cut power & communications, only allow barest of necessities in for humainitarian reasons. Then simply wait... [Answer] 220,000 people unarmed people can do significant damage. Iran deployed the Basij, a fanatic, martyrdom loving volunteer army with nothing more than the Koran. 70,000 of them stormed the Iraqi lines and combated them with their bare hands. this allowed for the armed revolutionary guard to move in and defeat their enemy. So an overwhelming army can overpower a superiorly armed adversary. But the Basij were fanatical, wishing for death. How many of these arm chair Twitter following "warriors" are willing to die for this cause..... which I am not really sure what the cause is. Once this army does breach the defenses and the make it to the highly fortified facilities, then what? If the base guards were not going to use deadly force for the parameter breach, due to political reasons, breaching the secured facilities would most definitely be faced with deadly force. A real incursion from such a large force would most definitely be seen as a threat to national security and measures be taken prior to the planned attack. Are these people ready to wage a full insurrection level event to just take a peak at what's inside Area 51? Over all, initially, the attack would be successful, but once faced with full retaliatory response, this army would soon be routed. [Answer] You can't get 250k people to area51. The closest you can hope for is Groom Lake Road, but getting them to the nearest highways (US 95 and NV 375) would already be a major feat, barely possible with very good organisation. If you do, it'll be one for the history books. In 1963, 250k people in the USA travelled to Washington DC for the March on Washington for Jobs and Freedom. I don't know how many buses they used. In 1983, 500k people in The Netherlands travelled in 3000 buses and other transport modes to protest nuclear missiles. You can get 250k people close to area51, probably to the nearest highway such as US 95 or NV 375, which is impressive enough, but organising it in 2 months is going to be extremely challenging, and may only work if people feel as strongly about area51 today as they did about segregation in 1963, which I doubt. You'll need to organise about 3000-3500 buses with 60 people per bus. Have them arrive at the dedicated area (see below) in the 8 hours prior to the event from around 200–500 cities around the country, unloading about 6 buses per minute on average. If each bus stops for at most 10 minutes you'll have about 60 buses stopped for unloading at any time. Buses who have dropped of their passengers need to leave to make place for others. Private cars are out of the question and should be banned from Nevada on that day. If that can't be achieved, at least the organisers should very strongly stress that nobody should drive a private car to the protest. You can load about 600-1200 litre of water in the bottom of each bus, so that you have 10-20 litre per person (Death Valley National Park recommends to budget 10 litre per person). On the dedicated area: you can't get in close distance to actual Area51. The nearest highways US 95 and NV 375 are a long way away, too long to walk through the desert. Groom Lake Road is a little closer but I don't know if it's feasible for 3000 buses to drive to a dead end location and then turn around, and even from there you're still stuck. In 1983, more than half a million people protested against nuclear-armed cruise missiles to be placed in The Netherlands. They hired all buses they could; after about 3,000 buses, there were no more buses available nationwide (they had hired all), so they also hired boats, extra trains, and many people came by bicycle. See those articles in [andere tijden](https://www.anderetijden.nl/artikel/6667/Massaal-protesteren-op-het-Malieveld) and [dag van toen](https://www.dagvantoen.nl/meer-dan-een-half-miljoen-betogers-op-het-malieveld-tegen-kruisraketten/) . Quite a few people missed the demonstration because their bus was stuck in traffic with other buses. Once the protesters arrive around the base there isn't really anything anybody can do because nobody can organise for or against so many people, but for sure you'll reach the history books whatever happens. Have a party and enjoy the historical occasion. Maybe make it a recurring event for every 5 years or so? [Answer] Given the size of the controllable area and the military resources available to the defenders, there are no viable head-on-attack related options that hold much of any hope of achieving the target goals. The more open the group is with a show of force, the more reliance on armour or attack posture machines, the more open and direct the military *has* to be with an armed response. Even if the group pools their resources into building a column of specialist armoured vehicles, they stand effectively no chance of making it across the vast space between the outer perimeter and anywhere near where something 'interesting' would be stored - That's why they built Area 51 where it is... --- So lets go back to the Poster's original core question: > > Is there any strategy or combination of tactics which could give the 222,000 men a fighting chance at at least some of them infiltrating Area 51? > > > Yes, there is a line of tactics that could result in *at least some of them infiltrating Area 51* - Split everyone into three groups: * Politicians * Scientists and Engineers * Those who would excel in the armed forces The only effective way in is through the front door with the proper credentials, and you only need one of them to eventually succeed... [Answer] I would like to bring up a point that no one has brought up yet. While it would be incredibly difficult to bring 222000 people to Area 51, if they were able to get there and all bull rush like fanatical zombies at the same time they could have a chance. Referring to the point where they all made a 1 km perimeter around Area 51 and then proceeded to charge for the fences, they could form a human stairway above the fences, offering both protection and a way to scale the walls. Image World War Z but at Area 51. Any soldiers in Area 51 would have to reload their guns at some point, I doubt they have 222000 bullets loaded up at any moment, of course assuming they never miss. Once the fanatical mob gets close enough to the fence I doubt they would be willing to call in air support for fear of breaking down the fence into their own compound. Now this plan is totally implausible but, I believe that any mob that size if operated like fanatical zombies would be a threat. [Answer] While all the answers and comments are quite comical and bring up excellent points, the good-faith answer to your actual question is: **no tactics necessary**. **That many people will completely capture the place.** Think World War 2 when the allies stormed the beaches; many were mowed down by bunkered machine gun fire, but the allies won through strength of numbers. Further: US citizens are better armed than you give them credit for. Most who own guns own more than 1, so they could bring extras and pass them around. Many know how to make explosives and even launchers for their explosives. With your quarter-million people, **you'll also have a reasonable amount of UAVs, manned airplanes, helicopters, and cannons** for this event. If you assume your group magically manages to defeat all the logistical problems and arrive en masse, together with useful tools they owned or made, ready and able to storm the gates together and you end up with a massive pitched battle, all they need to do is rush in as a giant mob with no further tactics. [Answer] **"the people somehow all have brilliant knowledge of military tactics."** I think this definitely was ignored some way along, and everyone seems to be taking it a little too realistically. In storybooks there is room for more heroic bravery than reality. Lets clear the don'ts first. 1.A head on attack on foot would be military suicide for sure. 2.Facebook is already off the cards because you can't arrange an attack on America (which this most certainly would be seen as) using a system that the Police have unlimited access to. That's just silly. 3.All 220,000 cannot be direct attackers. 4.Infiltrating definitely has to make some of the plan but you waste resources if you make it all of the plan. 100 people cannot be sneaky in that small space let alone 1000. When taken at face value then you have a **much, *much*** better chance at success. You have enough people to build and create solutions to the obstacles in an engineering and logistical capacity. Not everyone has to be a warrior and just one of those guys being an accomplished engineer can lead a team to make pretty much *anything* with enough time. However you swing it this is necessary anyway for transport so you may as well exploit it for more. I personally, if writing a story, would need to send in at least 15000 active combatants as A51 is big and I expect at least 1000 superiorly equipped troops on standby. I would be looking at ground penetrating radar solutions - homemade radar is very feasible thanks to google and past wars - to image and detail what the force would be up against tactically and locate key substructures like **power, communications, servers and power backup**. Servers because they likely have UPS batteries to keep from damaging them in a brownout, and that may allow them to *still* communicate down network lines. The key is to know more than your foe and to slow down response. Then, with knowledge of all the heavy blast doors and nuclear style defenses, my story would go something like this: Have the engineering team design/steal a [tunnel boring cart](http://www.akkerman.com/inventory/wp-content/uploads/2016/03/IMG_1315-Copy.jpg) on wheels which could start drilling under the base during this. With a longer pointed nose it theoretically could be pretty invisible to the bases radar and being underground aircraft radars would not see it. We'd need a few (say four) coming from opposite directions to confuse the powerful advanced SIGINT that would be present on the base as it gets close. Even if not confused, the staff watching would be unlikely to believe that 4 were approaching simultaneously as it seems illogical. Being a long distance to cover from the nearest accessible underground sewer, this all can be planned and arranged on safe ground and can take as long as they like, but they would need to start the procession maybe 15 mins before it would be heard inside the base. The tunnel borers would need oxygen supplies and would close the tunnel at the entrance with sandbags to avoid the sound permeating the city via the sewers as soon as is possible. Due to being on wheels, simply angling it on a slope may allow it to be run somewhat unattended as gravity can do the pushing into bedrock. This presents a very time expensive problem if the drills are discovered earlier than planned. One cannot simply blow up the desert to uncover them and thus must find the entrance to each tunnel which will be off-base and out of the bases GPR range. Create a civilian-style distraction outside the base to draw attention. This is a distraction that would have to force some people out for at least a few hours, either keeping the blast doors open or dividing personnel counts. It must be noisy so something like a politically/celebratory/protest motivated march of say, 10 thousand people complete with fireworks and horns. Think Gay Pride or a small music festival procession just over the edge of Military land but as far from the base as possible. Both have the advantage of being politically charged to deal with recklessly (shooting gay people embracing their rights and/or young people is generally thought of as worse than shooting random civilians). The best thing about this is with 220k people it's somewhat repeatable. If it's cleaned up too fast, start another one somewhere else on the land. No Army is going to butcher 10k people just because another group was hostile. They have jobs to keep and these are citizens on US land. Have the marchers covertly armed and allow the ensuing hold-up that the military would use to devolve into a gunfight to maintain the image of a visible confrontation as a decoy. Be sure to give the image that it's an act of passion and unrelated to breaking into A51. Think Native American blockades of military convoys if you need a pointer. It is very unlikely that there are over 10,000 people within A51 so after the capture or death of on site staff by a small portion of that march, there would be another non-A51-staff armed response, definitely of lethal intent and probably via armed helicopter or the like. The issue here that things would ride on is that, being civilians in a march/event they are all considered independent of each other. A military force still needs to differentiate between attacker and campaigner. A show of hands and white flag, or the presenting of said hostages at this point would force that helo to land, prolonging things further. Fireworks/Large speakers can retain noise cover. When the Drills reach the bunker many meters below ground and start actually boring through the bunker, progress will become VERY noisy and slow, as reinforced concrete is tough to drill. Alarms would be raised and it would be of paramount importance that all drills bore the bunker simultaneously to randomise the noise source, with the one furthest from the power source breaking through the wall when there is only half an inch or so left for the second and third etc to drill. Allow capture of first group and subsequent disabling of alarms that would be raised over the noise and vibration, then have group two break that final inch by hand (quietly) and swarm the base (quietly) with superior numbers, closing the blast doors overground and disabling power, comms, and recordings to buy time for them to scalp over the base and allow them to escape. Due to the first tunnel, this should be easier as most within the base are going to be figuring out what to do with that first hole in the wall. Leave via tunnel and use explosives to cover exit tunnels, breaking the other 1 inch thick entrances to leave multiple directions of exit to any would-be pursuants. Mostly inspired by movies and videogames. Increase complexity to cover anything I missed. Also realise that 220,000 people is more than most countries entire army, including support personnel, so saying it's infeasible is simply not true. With that first line, you basically have a poor but seasoned, massive, religiously committed Private Army, not 220,000 civilians. [Answer] **Off-road races** The attack would have to be less publicized. Let's say somehow each member got an app with encrypted communications and that network was not breached by law enforcement. They wouldn't be able to flip someone on the inside or get into the network another way. Everyone would be a listener except a few "commanders" who coordinated with a separate encrypted app. The commanders would make the plans and then send them out for the masses to follow. As plans firmed up, messages would go out every few days. * buy, borrow, or steal a weapon (or two). * Get your dirt bike or off-road vehicle (four wheeler, ATV, side by side, dune buggy, etc.) ready to go. * Get food and water in your vehicle or in your backpack. * Divide everyone into 50 groups. Send each member a number corresponding to their group. Find 50 places for each group to stage - all around the base. Since they are in off-road vehicles they'll be able to spread out into the desert to avoid having choke-points on the roads. * Send everyone a map of the base and give each building a number. * Tell each group their building number (there might be some overlap if there aren't 50 buildings of interest) * Organize 50 or so off-road races near the base. Advertise them to disguise the true intent. Tell each group which event to go to. * Set up the race course to go near the perimeter of the base. * Start the races, er, the attack. Prior to the attack, set up several portable high power cell tower repeaters as close to the base as possible but yet outside the perimeter so people can stream their phones during the attack. With 100,000 to 150,000 dirtbikes and off-road vehicles racing across the desert, spread out over 200 to 300 square miles, thousands of folks are likely to make it through. Have them stream video using the app (not commercial services which the government can quickly have shut down) to several server farms using various cloud service company and have those server farms stream to various social media services as well as any dedicated servers that were set up beforehand. It should take less than 30 minutes to get from the perimeter to the center of the base. If the defenses weren't prepared they would easily make it. While jets and helicopters would definitely have a 'target rich environment, taking out that many people would take a long time and a reload of ammunition and/or bombs. Though some have said these buildings are heavily fortified, like bunkers that can withstand a nuclear blast, I don't buy it. People go to and from work every day there and while there are certainly hardened doors to the office buildings and warehouses, I think they would be fairly easily breached using normal tools like plasma cutters, thermal lances, etc. I haven't been to this base but I've been to plenty of others. Anything the folks find would be streamed to the server farm and saved and sent on to regular and social media outlets. Then we all would see what is actually out there... ]

[Question] [ What restrictions this planet must have to make it possible? Planet can have any size, be made of any material A human must be able to land in it and observe it, dust added to the planet from the human's clothes or equipment may compromise the no-dust characteristic of the planet but it must be dust-less before then. --- Edit: Dust in the definition of fine, dry powder consisting of tiny particles of earth or waste matter lying on the ground or on surfaces or carried in the air. [Answer] No, it's impossible under your requirements. Rocky planets either have atmosphere worth speaking of, or they don't. If there is atmosphere, there will be some wind. With wind comes erosion. And with erosion comes dust. Without atmosphere, look at our moon. Meteorite impacts can and do create a lot of dust all right. The only exception would be an ocean planet (not necessarily water ocean) with no land at all. That's a bit of stretching "can land on it", but with no exposed rock to erode, and with meteorites sinking, you don't have material to create dust. Minuscule amounts from meteorites impacting ocean would sink anyway. --- For a high spin rogue planet, it's hardly possible, either. Such planets have to come from somewhere. Probably star system, and that means dust. And if spinning is high enough to throw dust from surface into the space, it'll be high enough to throw away your astronauts, too. So no landing. And I doubt such planet could even exist, survive. So, the dust is here, and is going to stay. --- For the *amounts* of dust, see [answer by Cort Ammon](https://worldbuilding.stackexchange.com/a/69003/809). [Answer] It's really not possible to not have dust. If you have an atmosphere, erosion will create dust. If you have no atmosphere, micrometeorite impacts will create dust, and being a planet, it will have enough gravity to pull some of that material back to the surface. One solution might be a completely liquid-covered planet. The liquid could capture the dust, causing it to sink to the "ocean" floor. Of course, the definition of "having dust" is tricky. That's why we have different [grades of clean rooms](https://en.wikipedia.org/wiki/Cleanroom#Cleanroom_classifications), each having a slightly different definition of dust. An ISO 8 clean room (also known as a Class 100,000 clean room) is concerned with particles of .5μm or greater. As you go towards cleaner rooms, such as an ISO 3 (aka a Class 1 clean room), the definition shifts to particles greater than .1μm. Also worth noting is the number of particles. While an ISO 9 clean room (aka "room air," no special precautions) may have 35 million particles (0.5μm or greater) per cubic meter, a ISO 1 may only have 10 particles (0.1μm or greater). These varying standards all share one thing in common: they recognize that particles are everywhere. There is no clean room standard for "no particles." [Answer] No. Never mind erosion, there a constant flow of dust falling from space. The [Cosmic Dust in the Terrestrial Atmosphere (CODITA) project](http://www.chem.leeds.ac.uk/john-plane/laboratory/mesosphere/current-research/codita.html) was set up to accurately measure just how much falls every day. Quoting that site: > > Observations of the zodiacal cloud and measurements by a dust detector on a satellite indicate a daily input of 100 – 300 tons. These estimates agree with the accumulation rates of elements such as iridium and osmium in polar ice cores and deep-sea sediments (these elements are enhanced in cosmic dust compared to the earth’s crust). In contrast, measurements in the middle atmosphere indicate that the daily input is only 3 - 50 tonnes. > > > Unless your planetary system is vastly different from ours, there will be (doing the math averaging it over earth's entire surface) about 0.2 μg/m2 per day, or in understandable units, about **1mm deep every 10,000 (Earth) years**. Assuming the current rate for all of Earth's 4.5B year history, that's a cumulative total of **450 meters** deep. Of course, the younger earth would have received a vastly higher rate that would diminish is it cleared its own orbital path of dust. OK it's not much, but it's constant. Even a world glazed by extreme heat would still have dust. [Answer] How about a planet that is entirely covered by a single lifeform with the consistency of a super thick Jello? Any meteor impacts would be absorbed into the lifeform (maybe it even feeds on these). Dust on the surface would be sensed by the lifeform because it would be blocking light and the lifeform would pull it away from it's surface. I guess technically you would not be landing on the planet itself (as the planet surface would be several meters below the surface of the lifeform), but those landing wouldn't know that when they landed. You could even add a tension point to the story when they realize their ship is slowly sinking. [Answer] Yes. Take Mercury, move it inwards to the point the surface is molten. No dust. Such a planet will not have the longest of lifespans, though. [Answer] So start with a planet that is mostly made of a metal with a low melting point, say lead. It's set close enough to a star that during the day the surface becomes liquid, but it also has a low rotation speed so during the night it's cold enough that sufficient heat leaks out and it becomes a solid again. Any space dust or meteors that impact during the night get integrated into the surface when it melts, and are trapped when it solidifies again. [Answer] It's certainly possible if you live on a mudball. If the entire planet is constantly receiving rain, let's say 30 or 40% of the time, then I would expect any stray dust particles would very, very quickly be captured by all the free water moving around. Now, in order to do this, you would have to have a very active rain cycle which would require a lot of energy. Thus I would expect this entire planet to be very hot and tropical and possibly only habitable away from the equator. It may even be that the energy required is simply too high to support life. I don't know how I would run the numbers on that. But it certainly seems plausible. [Answer] Naturally occurring, no. See the other excellent answers from Molot or Cort Ammon. For non-natural, consider an airless world that is heated to molten and then cooled to remove all initial dust. Then orbit it with satellites that monitor for micrometeorite impacts. When one is detected, the satellites use heating lasers to melt the area. There are myriad variations on this theme, with varying degrees of plausiblity. [Answer] How about an ice planet with highly eccentric orbit. A bit like pluto, but a real planet and slightly closer to the sun so that the surface melts during summer time, while the surface freezes and atmosphere collapses during winter. This could cause dust to settle quite quickly into the water and get contained in the ice. It would have a surface you can walk on when frozen. The biology of a being adapted to live on such a planet could be quite interesting - for example, perhaps they reproduce in the liquid water during the brief summer, hibernate over the winter and live on the ice surface during spring. A human visit during the winter could leave dust pollution that the organisms have never seen before on the surface, even if they are used to dust in the water. Of course this still has the drawbacks that there would be some dust falling from the sky, either from cosmic dust or meteorites. It would get absorbed during next summer, but in between the planet wouldn't be dustless. [Answer] A planet with no life and no friction helps eliminate the *creation* of dust. The planet would also have to dodge asteroids, comets, any other space matter, etc. Plants must create pollen which is dust. So absolutely no plants. Without the photosynthesis of plants, there cannot be life of any kind. With no friction, objects rubbing against each other should not cause erosion and then dust. [Answer] A near-miss would be to have a natural satellite (moon) of a large planet, where the moon is just within the Roche limit of the larger body. The local gravity on the planet-facing side will slightly favor the planet, and so dust and pebbles will be pulled away. You can't have it very far inside this limit though, because the only thing holding the moon together at that point are electromagnetic bonds -- tidal forces are trying to tear it apart, albeit weakly if it's just barely within the limit. [Answer] ## Ice Planet Depending on what you actually define as dust you can always have an ice planet. Any other kind of planet will create "dust" as it is hit by asteroids or its own crust moves. ## Man-made Any planet needs to be geological active in its lifetime so that implies that any natural planet will have dust, but you can always have a smooth and geologically dead man-made planet that is protected from asteroids. Maybe some advanced species made this planet to prove it was possible. [Answer] > > Dust in the definition of fine, dry powder consisting of tiny > particles of earth or waste matter lying on the ground or on surfaces > or carried in the air. > > > Well, if your planet is 100% covered with liquid (no dry particles on the ground) and have no atmosphere(no particles in air), by this definition there would be no dust. [Answer] The best bet for a planet with no dust that resembles a rock planet would be something with an absolutely outrageous magnetic field... When I say outrageous I mean something with a stronger magnetic field than stars - maybe black hole - by... I honestly don't know how much. The idea is that said planet would induce a charge on asteroids and simply push them away. All dust would either be pushed away from the planet or glued there. With proper magnetic shielding a human would probably last for a couple seconds there before dying. With this in mind it would be possible to get extremely unlucky and crash on this planet. perhaps with a bit of luck you wouldn't die on impact because magic? That being said this is all a massive stretch and unless said planet turns out to be some sort of BS quantum super weapon no one will believe the set up. Simply put a planet without dust doesn't make sense. Now a planet with special dust that doesn't exhibit dust like properties, that's just as dumb, but could be made "believable" using nano-bots or some other syfy hail marry. For example the dust could all be magnetic and simply not leave the ground at any point in time. Nano bots could just fix the dust. Maybe the atmosphere is definitely not magic and dissolves the dust because acid. Perhaps due to math the planet just doesn't have wind. My poorly thought out point is that this could work, but not without some extreme effort; your dustless planet is going to be super special. [Answer] Yes - if you made the planet resistant enough to retaining dust, you can then find a way to get rid of whatever dust begins to accumulate. Let's start by constructing the planet from an [Omniphobic material](https://www.newscientist.com/article/dn16006-dirt-wont-stick-to-omniphobic-material/), or something fairly close to that caliber. Next, you have the options of: * **Drain away dust into the planet itself.** Perhaps it's a conveniently mountainous planet where there are holes or burrows at the bottom of every valley, perhaps created by lifeforms. Perhaps it's a highly active planet which has regular earthquakes shaking all the dust down into the pits and valleys, where average conditions melt or otherwise absorb whatever dust collects. * **Blast away dust at regular intervals.** Perhaps the planet passes through a region which blasts off or melts all its dust, or experiences a strong kind of solar wind which carries it away. Though the solar wind would need to have an opposite magnetic charge to the planet itself, and so ensure it really does just carry away all loose items without depositing anything. Or perhaps there's a sentient species living within the planet who is extremely dust-phobic, and regularly blasts away all particles from outside or within. * **Consume the loose dust.** Perhaps there's a creature which actively searches out and eats dust particles, or else one or more vectors who gather it and consolidate it for some reason. Perhaps this is the extreme outcome of a micro-organism which uses the dust to build their own homes or even civilizations. Maybe there are periodic storms where water or some kind of acid absorbs or bonds with the dust. * **Spin the planet.** Now here's a novel solution. Spin things until other stuff falls off. Of course you'd need an extreme spin to overcome gravity on every loose particle... or else if the planet happened to be *manufactured* by another species, perhaps they would have a means to move only the top 'skin' of the planet. For thirty seconds the entire surface accelerates in the opposite direction of the planet's spin, and then resumes its regular velocity. Implausible - yet possible. [Answer] A software planet can have no dust. I know this is hard to accept because we live in a supposed reality where everything is made of atoms. There however is the possibility that there can be a planet in a universe across a black hole, where everything is not made of atoms. Everything is generated via something like a computer generated bits and bytes. Not necessarily with electricity, but with just energy. Such a planet can exist without any dust on it. [**edit**: A human can definitely land on such a planet. When you have forces like gravity, rays like X rays and have the earth floating on god-knows-what matter, why is it so hard to imagine a planet of energy where the forces are such that it can support the weight of a human and a spaceship and yet be dust free (until the human lands)?] Another place our kind of planet can exist without dust, is in our imagination. Like [the Matrix](https://en.wikipedia.org/wiki/The_Matrix). [Answer] **Can there be a planet with no dust?** No, depending on your definition of "dust" Space is not a sterile vacuum, it is full of stuff ranging from the sub atomic size, to the tremendously huge. And all this "stuff" is moving, some in a repetitive orderly fashion, and some just blowing around on the cosmic winds. A planet, by definition, is going to have to be in a system, have an orbit, at least one sun, and be over a certain size, and has to be what ever the term is for "not just a compressed lump of gravel and or ice chunks" You will not have anything like that, that will not be rained on but tons of material loosely referred to as "Dust" It does not matter what you work out after the dust has landed, it did land and so the planet has dust, even if the planet is 100% covered in water, it has dust, which before landing on the water was floating in the atmosphere. The bottom of the ocean is covered in dust, we call it silt. Having a mechanism to expel the dust is not an absence of dust, just like using some pledge and a rag at your house does not make the house dust free, it just cleans the build up, the dust is still raining down, you will need to dust again. If you made an artificial planet, dust is still raining down on it. And even if we allowed it to be called a planet, after totally deviating what defines planet, and put the thing in a static position in deep space near nothing, dust moving through the universe from countless galaxies is still going to find it. And nearly anything you can think of to build a planet out of eventually becomes dust on it's own. All things have a finite life before the7 break down. [Answer] # Yes it can! It's a fast-spinning planet with atmospheric pressure around 1 Earth atmosphere, made of CO2 and average temperature of −78.5 °C (the sublimation temp of C02). Or some other light molecule so that most materials are denser that it, and it must not have liquid state at the atmospheric pressure. Whatever dust is created by non-CO2 meteorites (impact or from burning in the atmosphere) is buried during the night, when a layer of C02 precipitates on the surface. And whatever CO2 is eroded, is evaporates during the day. So technically there is transient dust from meteorites, but it is short-lived. It is also (somewhat) important that the atmosphere is relatively calm, so that whatever dust forms it is not carried around all the time, but is capable of settling down and being eventually frozen into CO2. [Answer] Look up meteoritic dust influx. You might remember the first moon landing. Even though they were about to run out of fuel they were commenting on the amount of dust being kicked up. You might also remember the huge pads on the landing gear. They were afraid that the lander would sink into the dust. There is constantly stuff hitting any atmosphere on every planet. It might be that such a planet has a surface that removes the dust such as the molten lead planet mentioned, but the dust will be delivered there by the natural processes of the universe. However, if you can ever travel there and find that there is no dust then you can be assured that the inhabitants will be able to explain to you why there isn't any since they will speak English... at least that is how it is on Star Trek. ]

[Question] [ Following on from my previous utopia-based question ([Could compulsory experience-sharing make a utopia actually work?](https://worldbuilding.stackexchange.com/questions/90928/could-compulsory-experience-sharing-make-a-utopia-actually-work)), I'm wondering whether a website could ever be a utopia. Firstly, are there any problems inherent in this premise? If I take Stack Exchange as my basis, I feel like it's a pretty good start to a utopia: 1. It's meritocratic, and offers incentives for its citizens to improve and take a more active part in the community, while also implementing sensible constraints for its newbie children. 2. Everyone has the opportunity to have their voice heard. Off-topic posts are redirected to other sections of the site; overly-broad questions are coaxed into specificity; inappropriate or offensive remarks are moderated and removed. Punishment is possible, but the system mainly works on teaching/learning. 3. It offers a comforting sense of distance. People have the freedom to be anonymous, and the opportunity to be as much or as little a part of it as they wish, but also can locate individual members. 4. More active members are rewarded with greater privileges that come hand in hand with greater responsibility (I assume that if a moderator doesn't take his/her/their job seriously, they'll probably end up having moderator privileges removed from them). In effect, it's a self-policing system. In short, **could a website utopia be mapped onto a real-life system? Or does it only work** ***because*** **it's a website?** One initial problem I can foresee with having this as a real-world system would be: what happens if a new user posts inappropriate/offensive stuff and gets banned from the website? Would that parallel as exile (which the user can that choose to return from at any time), or execution..? Also, I guess economy is an issue, but I'm not quite sure how to approach that. **EDIT** I'm defining utopia as a society characterised, at heart, by peace. Free from suffering/poverty/lack of opportunity, absence of war, etc. (Kind of a difficult one to pin down, and "as close to a perfect society as possible" feels kind of vague, but I hope this helps.) [Answer] Like Stack Exchange, modern temporary utopias such as [Burning Man](https://en.wikipedia.org/wiki/Burning_Man), or [Rainbow Gatherings](https://en.wikipedia.org/wiki/Rainbow_Gathering) work because participation is opt in. They greatly reduce the problems of non-compliant members by making participation voluntary. Those that are a burden on the system will have a worse time and probably choose not to return in the future. For a permanent society this will be a problem. Stack Exchange works as part of the larger ecosystem of the internet. They specialize on one thing: Questions and Answers. If you want a discussion, or feedback on your work, the site tells you to go elsewhere. Going elsewhere is easy to do when all you need to do is type in a different URL. It's a much more costly endeavor to pack up your things and move to another country. [Answer] ## The Specific Answer The answer is "*no solution*." This question is based on false premises. There are plenty of people who contribute to StackExchange who believe it is highly flawed. Many people disagree on what actions should be taken ("Is this on-topic or not?" "Should this be on this SE or that SE?" etc.) Many people take the "vote your conscience" thing to weird places that do not help the site. Sometimes whether your question is given "protected" status or "closed" depends on which band of high-rep users happens to be around at the time. Many people who are active in cleaning up the site are more interested in whether your question or answer is technically on-topic than whether it is a good fit for the community or makes StackExchange better or worse. In fact, on some of the SE meta sites when people have asked questions about how to deal with certain types of actions, I have more than once included in my answers statements to the effect of "Ultimately, is your action going to make StackExchange a little bit better or a little bit worse overall? That is more important than a legalist interpretation of the rules." and had such answers yield a total negative score. There is nothing "Utopian" about StackExchange. StackExchange's principles would no more bring about a physical utopia than they have a virtual one, since they haven't. --- ## The Generic Answer That addresses the body of your question. But the title, and some aspects of the body, also seem to be asking a more general question: **If there were some utopian website that did exist, and if that website's principles were applied to physical, real-world governance, could the real state likewise be a utopia?** The answer to *that* question would be a bit different. Since we have no first-hand records of any people documenting any nation in a state of utopia, and I know of no large groups of people who even collectively agree about how to bring about a utopia, it is difficult to know. In fact, it might be impossible to answer this question: if we cannot even agree how to bring about a utopia at all, even in theory, then is it even possible to discuss how to transfer the principles from one medium to another? I'm not sure. --- ## The "Anti-Utopia" Proof I will tell you one thing that I *do* know though: if a utopia is perfection, all it takes is one person who believes that they are worse off to, by definition, make a situation non-utopian; so if you applied StackExchange's principles to my country's governing structure, I can tell you right now that there is near-zero possibility that any utopia could result since I would be miserable every time some group of 5 (or make it 500) "trusted" individuals voted to suppress what I was doing that day. You are going to get a lot of super-pissed-off people. Right now I live in a constitutional-republic with a semi-democratic election process (the U.S.), and it is already bad enough that my neighbors have so much control over my life - I would not want to give them even more control. --- Thanks to discussion with @aslum for teasing out the following paragraph... The problem here is with defining a utopia by terms of perfection. If we instead defined a utopia as just "a really good state where the average happiness per person is maximized," then things would be different and you might be able to accuse me of a "No true Scotsman" fallacy. As it stands, asserting "Everything is perfect" is easily disproven every time anyone complains (reasonably) about anything. For this reason, it might well be *literally impossible* to have a complete and true utopia as long as it is defined as such, since all it takes is two people with mutually-exclusive desires to make the utopia impossible. For example, I roll my eyes at "anti-gun" people, I believe that being allowed to open-carry firearms is necessary to a safe society, and I absolutely **hate** it that my state cracks down on firearms - I really don't care what anti-gun people think. For me, a utopia simply **cannot** ban open-carry of firearms. But I know that someone else might freak out every time they see me with a firearm, and they might (irrationally, in my opinion, but my opinion is irrelevant to this person) think I'm going to rob them; for this person, a utopia simply **cannot** include people open-carrying firearms. Our utopias are mutually exclusive. Therefore, if we use a definition wherein the neighborhood is perfect for both of us, our neighborhood utopia is not possible. [Answer] Building on @sphennings answer (which I upvoted): Another rather large problem is communities like StackExchange do give some visibility and "prizes", but those are completely "moral" things. You cannot buy an ice cone with its "reputation" points. If rewards for work would be more "substantial" the site would experience all sort of attempts to bend its rules. A few examples: * competition would be fierce and current fair-play rarer (e.g.: would I have started this post in the way I did? I'm speaking about different things, after all, why acknowledge?) * a (large) subset of users would coordinate to upvote their "work" (either questions or answers) and downvote everything else. * you could have vote trading. * editing privileges could be used to subtly deface "competitors". * moderators have a very high power, wouldn't they be tempted to use it (for their own use)? Sorry, I do insist: Utopias are something that won't work in the real world, probably ever. It is much better to accept there are certain impulses and try to create rules to constrain them without strangling the society. The idea man (or woman, of course) is essentially "good" and it is external influence that makes him "bad" has been proven false over and over again throughout all History. It might be we will "evolve" into something capable of giving rise to Utopias, but that may take as much as it took to arrive here (about a billion years) and we won't be "humankind" anymore. [Answer] The existing answers do a great job of explaining the difference between optional and compulsory systems, but I'd like to take a different approach. Perhaps the most interesting thing about the question is that the token economy (like Stack Exchange) is a frequent *dystopian* trope. Just one [recent example](http://www.indiewire.com/2016/10/the-thinning-trailer-logan-paul-peyton-list-youtube-red-legendary-digital-1201733956/). Invariably, the system is rigged in some fashion or other by whoever awards the 'points' (tokens) or otherwise sets the bar. There are classic sci-fi novels where your standing in society is a essentially a function of how many twitter/instagram/youtube subscribers you have. So no, the created society would almost certainly be *dystopian*, not *utopian*. Of course, many dystopias are wolves in utopian sheep's clothes. [Answer] > > I'm defining utopia as a society characterised, at heart, by peace. Free from suffering/poverty/lack of opportunity, absence of war, etc. > > > Well, a simple way to get there is to murder all the poor, the angry, the violent, everyone with IQ below say 130, etc, and after a short period of inconvenience, your definition of a utopia should apply. The best utopias are opt-in only. That avoids the "getting rid of everyone who disagrees" phase... > > It's meritocratic, and offers incentives for its citizens to improve and take a more active part in the community > > > "Meritocratic" needs clarification. Here the metric is votes. This could result in several things: the best answer can be selected. But it can also be the most flattering to the readers, or the most consensual. It can also be completely wrong, if most people are wrong on the subject. For example, asking if the earth was round (or how to cure an infection) 1500 years ago would most likely not have resulted in the right answer... There is a lot of subjectivity in this process. In other words, this could stifle innovation, because by definition a new idea isn't part of the consensus. On the other hand, sharing ideas provokes new ideas. I would say that this system works well for determining what the common (acceptable, and fashionable) knowledge is about a given topic at a given point in time. Also useful for solving specific problems. But definitely not the free-thinking utopia you envision. [Answer] # Stack exchange is not a utopia Consider this situation: You walk into a room to speak to someone, a group of other people stand around you. You ask a question, the people around you discuss whether it's appropriate to ask that question in that room. They decide it isn't and shut you down. Consider another situation: You walk into a room and say "Hi, how are you?" A group of people around you inform you that this question has been asked before, you cannot ask it again and should check previous responses. **Stack Exchange has a purpose to its design, which means there are situations where the system would work.** There's a story told of meetings during the Manhattan project where a question would be asked. Each person round the table would, in turn, give an answer, then from the answers given, one would be selected as the way to proceed. There would be no raised voices, no attempt to persuade beyond the giving of the answer. Can you imagine meetings like that? How much more time could you spend actually getting on with important things rather than pandering to the guy who hasn't read the documents. The system works here because it's not real time. There's a question, the question is considered for its merits and answers are considered. The answer can be given hours, days or even months later, then the answers are then considered on their merits. They can also be re-considered months and years later and referred back to. People tend to get quite upset when you refer back to things they said or did years earlier, they usually prefer it to be forgotten. [Answer] Utopias are essentially imposed. They are accepted as workable and generally beneficial by their subjects. Note that, although Utopias are imposed upon their subjects, this is not resented. Utopias require an element of docility and compliance, which is possibly unrealistic considering human nature. Stack Exchange allows people to subscribe in, and if they feel being part of Stack Exchange is worthwhile, and personally rewarding, they will stay, but Stack Exchange is not government and is effectively selective, although the members in practice select themselves. People, generally, do not have a great say in the society that they find themselves in. Some societies are undoubtedly better than others, but all societies have conventions of normality, and acceptable ranges of behaviours which are recognised as acceptable beyond that. Individuals, being individuals, are likely to consider what is personally acceptable to them slightly differently. Individuals form friendships with others who think similarly and groups form in which peer pressure develops a common culture. Schisms form. It really all comes down to: a. Peoples ability to get on with each other and, b. Peoples inability to get on with each other. The answer is NO. [Answer] Stack Exchange has one major flaw, that becomes most obvious in the Stack Overflow community (and maybe others I don't know), which I would call the "Reign of the stupid" In Stack Overflow I hold the silver medal "Tenacious" badge, which is rewarded for having a certain amount of accepted answers with zero upvotes. What does that mean? There are questions that I correctly answered, others however did not accept that answer as correct, even though it was. In a particular case for example someone required a solution for a threading problem that I provided, and - beside that I was correct and everyone could have tested that - the other community members downvoted my answer, and added various comments on how this just couldn't be right. It turned out that they were all wrong. Now as a result I (and many other people in the same situation) loose interest in providing professional knowledge (for free) to help other people, if you always have to work your way through a wall of disbelieve first. Essentially, over time, people like me stop answering questions, and as a direct result the average level of expertise drops slightly. That also means that the amount of people that downvote out of ignorance increased slightly. Let that run for a few years, and the average level of expertise has decreased substantially, while the amount of 'blocker Lemmings' as I like to call them has increased. At a certain ratio the whole system will either stabilize (when it is still useful) or fall apart (if it no longer is useful in that state). You can see similar effects in feedback/suggestion forums of games, in company management, or even in Democracy itself (take the social justice warriors as example). Eventually, simply because they are the majority, the stupid will degrade any system, unless there is an incentive for the "smart" to endure them, and constantly fix the damage they do. Because of that any Utopia is doomed to fail, if stupid people are allowed to rule (see [Dunning-Kruger effect](https://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect)). And it will also fail, if those people are suppressed by a group of elitists, because either the elitist group degenerates out of arrogance, or the stupid become rebellious. The only Utopia that can sustain, is one where the average person is above the level of intelligence required to understand that you don't understand everything and never will. [Answer] The main problem with utopias is that they are populated by fanciful, farcical, fallen humanity. The structure of a society is important, and endless attempts have been made to find the best one, but it's always those pesky primates who ruin everything. As an example, I recall I read through some unsuccessful candidacies for people wanting to become wikipedia administrators. I was at once amused and appalled by the cliquishness, pettiness, and overall peevishness revealed therein. You can see for yourself: <https://en.wikipedia.org/wiki/Wikipedia:Unsuccessful_adminship_candidacies> All that said, sure you could give it a shot. These kinds of community reputation-based sites do have their virtues in a grassroots democracy sort of way. They have their characteristic weaknesses, too. A dash of groupthink, potential over-puissance of strong personalities, and in the case of this site, you might find a lack of flexibility to new ideas which don't fit existing rules and guidelines. Take this with a massive boulder of rock salt... I'm new here. ;D [Answer] Stackexchange is based on good-faith participation: over time, it has defined itself and its own rules, and formed a community around it. If someone wants to opine and not answer a question, it's not the site for them. There is, for the most part, a single agenda for the site that everyone is on board with, otherwise, they don't traffic the site. If they're not answering the question at hand, they are either simply not visiting the site, or not answering, or trolling, and being moderated. Politics, on the other hand, could theoretically implicate all aspects of life. > > Just because you do not take an interest in politics doesn't mean > politics won't take an interest in you. > ~ Pericles > > > You are involved in politics whether you like it or not. You can't leave your country to enter another without a visa-- that's politics. You can't do whatever you want without risking arrest and imprisonment because of laws. You have to pay taxes (libertarian critiques aside). Politics is not just a forum, discussion, or debate club; it's the potholes on the street, the police cruiser catching speeders, the bridge being built, the tax you pay, the war your country is waging. These are all activities taking place in the real world, alongside people's opinions and lawmaker's debates. The stackexchange model doesn't provide for any of this. As a model of a utopia, it doesn't provide for much at all. [Answer] Nope. Certain stack exchange websites just don't work that well. There's no way for you to ask for clarification on someone else's problem if you're below around 20 privilege. That means that people who need this site the most are forced to break the rules to get their questions and answers heard. This seems like a minor detail, but wars have been fought over far less. Starting out your utopia with a class of people who feel they're ignored is probably not a good idea. [Answer] The short answer is, although Stack Exchange is wonderfully designed and extremely useful, it is not a model for utopia because there is no such thing as Utopia. There can not be any utopian society without unlimited resources and information. Since humanity is limited in knowledge and power, that can't happen. There can be no utopia because one man's heaven is another's hell. When people try to create Utopia, they create a special kind of living hell and millions die. Names like [Pol Pot](https://en.wikipedia.org/wiki/Pol_Pot), [Stalin](https://en.wikipedia.org/wiki/Joseph_Stalin), [Mao](https://en.wikipedia.org/wiki/Mao_Zedong), [Kim Il Sung](https://en.wikipedia.org/wiki/Kim_Il-sung), and [Hitler](https://en.wikipedia.org/wiki/Adolf_Hitler) were made famous by trying to achieve a utopia. The dreamer says "If we just would eliminate these people here, then we will be in Utopia!" [Answer] No. Even leaving aside the question of how well Stack Exchange fills its current purpose, and how well it would survive the conversion to reality, you have misjudged the fundamental structure of the Stack network from the beginning. It is a dictatorship - or, at best, an oligarchy, run by the owners and employees of the company. It it a largely enlightened dictatorship/oligarchy, with some interesting ideas on how to maintain effectiveness and morale, but at the end of the day, it is constantly having to adjust to reality, and the people who make the final decisions on how to adjust are essentially governmental. This whole reputation system is essentially a decoration on top of the real power structure, and is beholden to it. As far as forms of government go, true enlightened dictatorships work very well... and they last until the dictator either is replaced by someone not so enlightened or becomes not so enlightened themselves, at which point things generally get pretty unfortunate. ]

[Question] [ It lots of fictional settings and worlds, 'rogues' and other skilled martial fighters are constantly throwing knives and daggers at people. Furthermore, assassins/rogues are often pictured as having a ridiculous amount of knives on their bodies and it's a trope that they never run out ("you can never have too many knives"). Questions: * How effective of a weapon is a thrown knife in a realistic setting (thrown by a "peak human")? * Historically, were there fighters (not jesters or clowns) which took the time to master throwing a knife? * Does throwing a knife in a fight make tactical sense? [Answer] Having thrown knives myself as a (casual) hobby when I was younger I can tell you that it doesn't take *that* long to gain both power and accuracy with well balanced knives. Give it a few months of everyday practice and you can hit a one inch target at a good few meters distance with a 90% success rate. Well balanced in this context means that the handle and blade weigh the same, so that the knife balances where the two meet. The really tricky part though is judging the distance. How many times is the knife going to go end over end in the travel from hand to target? If holding the blade when throwing you need (N + 0.5) rotations. If holding the handle just N. But the number of rotations depends on the knife, both the weight and the length, and that just takes practice to learn the feel of that particular knife. To give some real-word examples, a small 4 inch (blade + handle) throwing knife might do 3.5 rotations over a ~3 meter distance, but a 12 inch knife may only do 1.5 In fact there is only about a 45 degree arc during the rotation where the knife will actually penetrate the target at all, and the closer to perpendicular the better. Anything outside of this angle range and you are hitting either handle first or flat. But getting that right every time is very hard if you are not throwing a known knife from a known distance. When we used to practice we threw from marks on the floor that we had worked out through trial and error (lots of error!) and always used well balanced knives. So perhaps the real mark of an expert is in how quickly they can judge the characteristics of a new knife, and also how well they can spot a distance. Only a genius could pick up a knife for the first time and get a penetrating hit from an arbitrary distance though. In the real world, the utility of throwing knives is therefore slightly questionable in my opinion, as the distance to your opponent would be extremely hard to judge in a real fight. As a distraction technique I can see it having some use, or perhaps even as a ranged stealth attack with time to prepare a throw, but I can't see it being favoured as a primary means of attack where there are better options available. [Answer] Keep in mind that through most of human history knives were extraordinarily common tools. Every soldier, workman, hunter, field worker, tradesman, shepherd, shopkeeper, etc. carried a knife as a practical matter, because there was always something to be cut, shaved, sized, sliced or pried open. Learning to throw a knife was a pastime (e.g., [mumblety-peg](https://en.wikipedia.org/wiki/Mumblety-peg)) as much as anything else, and like any pastime there were always those who took it to extremes. In that sense, it doesn't matter whether it was an *effective* attack; it was something that could be done with something ready to hand, like throwing a rock or a tree branch. Most soldiers in the pre-modern world carried some small thrown weapon with them. The ancient Israelites apparently had a fondness for slings; Roman legionaries carried a pair of javelins; I'm sure I could find others. These weapons weren't meant to inflict heavy casualties on an enemy, but to slow the enemy down and disrupt their ranks. Knives could be used for that in a pinch, I suppose, but I don't know of any military that used them that way. Possibly that's because a knife constituted more of an investment for a soldier than a wooden javelin or a sling-stone, and was necessary for many common daily tasks; soldiers would have been loathe to just toss them. But thrown knives may have been used in more covert operations, where silence and surprise are important. A thrown knife doesn't have to be lethal in its own right. The shock and surprise of suddenly finding an eight inch piece of metal embedded in your shoulder — and the subsequent need to pull it out before you can take effective action — would give an attacker an opportunity to close distance and attack with another weapon. There is a value to the skill in certain types of combat. [Answer] Historically throwing knives have been used mainly as a distracting technique, rather than an actual attack. They were used by what we commonly refer to as ninjas for example, and if I am correct they would be coated in feces or poison. Mostly these would be thrown when retreating, to distract the enemy and create an opening. And give them a nasty infection with some luck. They could also be used as a distraction to create an opening to attack. As for actual (main) attacks, they are fairly ineffective. You will need a fairly good stance to launch a knife with any precision. It will hardly ever penetrate any armour, and we'll balanced ones are often too expensive to make. Using darts for example would be more effective as they penetrate better, and can be launched in more awkward stances. Especially when knives or throwing knives are used as a main weapon there are a lot of weaknesses. Which is why rogues are portrayed as sneaky or agile. Standing still, or letting your enemy swing at you will be instantly lethal. This amount of (inefficient) skill is unlikely to be trained and used by anyone who is not an extreme expert. [Answer] Throwing knives, shuriken and other implements of the sort can be useful, but not as your main weapon. They can be thrown at an enemy to create an opening, because it will likely provoke a reaction, allowing the user to close in and attack with their main weapon. While it may be technically possible to achieve lethal hits with them, such as hitting eyes or throat with the blade end on a good throw, this requires extreme accuracy, enough power, no successful defence on the opponents side on body parts that are usually well defended, you have to hit with the right part of the weapon and it will not penetrate armour or even thick clothing. This isn't reliable enough to use as a primary means of attack. [Answer] As far as I know, throwing knives were never issued by any army or used on any sort of scale, unlike stones, hammers, axes, 'darts' and a variety of other missile weapons. Cleary they lack the range and lethality of any 'proper' thrown weapon. (Added explanation in response to question: it's a simple matter of kinetics. A manually-thrown weapon moves at the speed of your hand. A knife does not move faster than a javelin, dart or heavier projectile, but lacks their mass therefore hits with less kinetic energy and momentum. In theory a 200g knife could have a greater range than a 1 kg javelin, but in practice this is not the case because of the knife's spinning dynamic and need to hit point-first) (Edit: shuriken are not lethal weapons, and in any case can hardly be considered to be 'knives') In modern military situations they are a weapon of last resort, and while knife throwing is sometimes taught, it's hard to see how it would be used . I haven't come across any accounts of one being successful in European warfare, but having wondered about posing this exact about this myself (thanks to Hollywood and D&D) I will be very interested to see if any cases are cited. [Answer] It might make sense as an attack of opportunity, not as a large scale mean of attack. Why? * you can't carry that many knives on yourself * every knife you throw becomes a knife you are giving to your enemy * your arm alone can't deliver that much momentum, bows or slingshots work better at that and allow you to have a greater range [Answer] **It is a cultural throwback/tradition with little practical use.** Traditionally it was considered *dishonorable* to attack/kill an unarmed person but perfectly respectable to kill an armed person. This infuriated the local assassin's guild since by not carring a weapon made you unkillable. The get-around was to first forcibly *give* your target a weapon and then proceed to kill them. Originally you had to be sneaky about it: Spend weeks earning their trust and then give them a present of a small, ornately-guilded box. The moment they open the box to reveal the dagger inside they are technically *armed* and then you stab them in the face. One day Sneaky McShankFace got the bright idea to simply throw the dagger into the victim. Once the dagger was embedded on their person they are fair game. This made the whole game much simpler. The law was later changed to prevent this getaround. But by then it had become a tradition in the guild and stuck around because of that. The rest is history. [Answer] +1 to the current top voted answer by dave. I want to add to it. To what he writes, I can only add that my experience matches his. Distance matters, hitting flat or handle first is common while you're training, but hitting well and hard takes not that much experience. I've managed to lodge throwing knives into wood so deep that I had trouble pulling them out. You can definitely bury a throwing knife in a person to the hilt. The question he doesn't answer: Yes, you can carry a good amount of throwing knives with you. Unlike a cutting knife, you don't need the handle except for balance, so it can be thin or even missing, meaning they don't take up much space: [](https://i.stack.imgur.com/jbBiA.jpg) weight is more of an issue, because the knife cannot be too light or it won't have enough power to penetrate anything. I remember about 200g being a recommended weight for close-distance throwing, 250 and up if you want to throw longer distances. Ten knives would be about 2kg plus holster, and easily fit on a belt. That's quite manageable. I've never actually carried that many knives on my person, but I've carried similar amounts of stuff on my belt in medieval fairs and re-enactment and the main problem was with stuff swinging around, not the weight of it. [Answer] Yes, throughout central Africa they had multi-bladed throwing knives like the [kpinga](https://interestingengineering.com/this-ancient-multi-bladed-throwing-knife-is-designed-to-inflict-the-maximum-damage-to-the-enemy), these were used in war. Other cultures had similar knives. Considering that they didn't wear a lot of armour these could do a lot of damage and were difficult to dislodge in a hurry if you got struck. Very nasty weapons. Not the primary weapon of course which was a spear but dangerous from 30 feet and more, and if a whole bunch of them were flying at once it could create havoc. Your basic well balanced throwing knife has quite a few drawbacks in comparison. Primarily that you need to judge the rotation and distance which only comes from practice with identical knives. This sort it doesn't matter where in it's rotation it hits a person. It's not a precision, finesse, stealth attack weapon, it's a nasty, scary, hit you anywhere and see if you bleed out weapon. [Answer] Another way to think about it: compare a knife to a baseball. In baseball, getting hit by a pitch HURTS. It can often break bones. Certainly, players can be injured to a point that they are removed from play with a replacement runner. If a knife was thrown with the same force by a "peak human", assuming the sharpened end landed first, you would expect even more harm. If the knife landed in a good spot, you could easily disable or kill a target. ]