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[Question] [ Not that political correctness has ever been an important theme in fantasy, but I've always found "humanoid" a strange category in settings that include, say, men, elves, orcs, dwarves, goblins, and other beings. Yes, the reader/player/audience is a human and it is perfectly useful that humans be the species by which all others are compared. But in-world, what would an academically inclined elf name the set of two-armed, two-legged individualistic-but-also-social creatures to which they themselves also belong? Surely some of his kin would take offense to the idea of being quasi-man. My question is: **Are there general alternatives to humanoid in the world of fantasy?** (As opposed to science fiction, which tends to have myriad sub-classifications for every form of intelligent life). [Answer] > > what would an academically inclined elf name the set of two-armed, two-legged individualistic-but-also-social creatures to which they themselves also belong? Surely some of his kin would take offense to the idea of being quasi-man. > > > They would not, because they are not aware of the word "humanoid". Only us, the readers are. The common attitude (often implicit in less observant readers) is that the fantasy novel is in fact a story about characters which use a different language, and the novel is the "translation" into English. Usually one does not bother actually creating the language, writing in it, then translating (notable exception: Tolkien did, kind of) - they just produce an English text that's supposed to be "what you would get if a good translator had translated it". It's important to note that the other language is not necessarily English: It may be English in all but name (ie. coincidentally has the same vocabulary and grammar), it may be a language that "coincidentally" evolved similar to English, it may have similar grammar (especially if the author assumes that grammar is genetic and not purely emergent - [this is an open question is linguistics](https://en.wikipedia.org/wiki/Universal_grammar)), it may be completely alien, and it may even be related to English: For instance I believe Tolkien wrote his books under the pretense that they were events that actually happened in the ancient past of England. Of course, we know what *really* happened in England's past, but you have to exercise suspension of disbelief. Alternatively you could say something like "thousands of years ago some humans were teleported magically to the fantasy world and they brought [Indo-European languages](https://en.wikipedia.org/wiki/Indo-European_languages) with them". Anyone who actually has experience with translation knows that it is rarely possible to translate 1:1, there is always room for interpretation, and something will always be lost in translation. I personally do not believe that two people who speak different language are even capable of thinking the same things in every case ([this idea has some support in the linguistic research community](https://en.wikipedia.org/wiki/Linguistic_relativity)). In fact, comparing translations of the same text by different authors can be an experience in its own right, as you will note cases where each translator has interpreted a passage in their own way. A great example is the various versions of the Bible (in English). Fastidious translators, especially if it matters for the text in question, will usually either use the original word as a loanword (typically indicated by italics, eg. saying *ramen* instead of maccaroni, *samurai* instead of knight, *daimyō* instead of liege lord); or will explain the usage with a footnote (eg. "1: a *samurai* isn't exactly a knight, the differences are so and so, but for the sake of readability I will hereby render it as knight"). There are many examples of this in philosophy books: Because they deal with abstract, difficult to comprehend concepts, it is hard to decide how to render things correctly. Novels are less tricky, but whenever things such as complicated cultural or social mores come into play, it can very easily get very complicated (consider translating French *tutoyer*, which is a nonsense word in English because [the social distinction does not exist](https://en.wikipedia.org/wiki/T%E2%80%93V_distinction) - it *cannot be translated*). Your best bet is to follow suit: When using *humanoid*, add a footnote and explain that in the world of whatever, the word used for sentient bipeds is different, and linguistically not related to the word for human. Then say that you will render this word as *humanoid* in English, because it is the closest available one. You have to then be careful, if you care, to not for instance make puns with "humanoid", or not have characters complain about it being *anthropocentric*, since, well, it's not in the original. To invent an original English term that has the qualities you desire (well, you could just take a shortcut and go with elf-like or whatever else) you really have to learn a lot about the development of human language and human natural philosophy, and study how words were coined. Only then will you be able to produce a truly congruent substitute for "humanoid". But once you do that, only those in your audience who are likewise educated will be able to appreciate it - so it is a dubious effort anyway, similar to writing a sci-fi novel with very accurate speculative quantum physics, that is then lost on everyone but the physics professors of the world, of whom maybe 3 will even read your story. [Answer] It still would be humanoid in human language. It would be more like "elfoid" in elf language, and so on. If there ever would appear a common language, it would probably use some synthetic term. [Answer] Ethnologic/Ethological Terms: If they all share the same evolutionary ancestors, you can call them Omomyiforms (from the [omomyiformes family](https://en.wikipedia.org/w/index.php?title=Omomyiformes)) or maybe Primatomorphs (likewise [from taxonomy](https://en.wikipedia.org/wiki/Primatomorpha)) or you can create and add a new group in the three. Or since they are humanoids, you could call them ''Arisen'', or ''Consurgent'' (from the Latin "consurgo", to rise up or stand), representing their rising from four or more limbs into a bipedal position, or maybe just call them bipedals. If your story doesn't include evolution, like everything was created by a deity or a group of deities, you could use the name of a neutral deity that is a humanoid but didn't create any one of the humanoid species, and add morph to it, like Rheamorph (after [Rhea](https://en.wikipedia.org/wiki/Rhea_(mythology)), mother of the gods)... [Answer] Call all humanoids **bi-pedals**. If there is anything to be learnt from George Orwell's "Animal Farm" (ignoring, of course, the sociopolitical warning of dictator-lead communism and corrupt regimes), is that Humans are the only true bi-pedals. It is argued (I believe by Squealer, but I may be wrong) that all other seemingly bi-pedal animals (such as birds, monkeys) use their 'arms' as a method of propulsion. Only humans reserve 'arms' for function and not for propulsion, going hand-in-hand (if you'll pardon the pun) with higher intelligence and the dexterity/function-over-strength evolution of arms. [Answer] All the options I can think of sound kinda science and might not fit the tone of a fantasy game/novel. 1)Homo - The scientific classification for anything in our genus. Still sounds quite human centric though. 2)Sapients - means smart/intelligent. Only works if the humanoids are the only intelligent life. 3)Bi-pedals - means two legged which is a fairly physical description of most humanoids. [Answer] I suspect that's why we see the separation in Warcraft between the Alliance and the Horde. The humanoid races versus the less than humanoid races. For the purpose of a story though you could follow something similar to Mass Effect for example. * <http://masseffect.wikia.com/wiki/Codex/Aliens:_Council_Races> * <http://masseffect.wikia.com/wiki/Codex/Aliens:_Non-Council_Races> The Council races (races with representatives on the council) can be more human-like in their appearances. Non-council races can be less human-like. [Answer] The Term "Humanoid" describes beings of 2 arms, 2 legs, a torso and a head, additionally a tail may be added. Any being that differs from this makeup would need other decriptors. Some of these are: * Dracomorph: Usually scales, reptilian skull structure, possibly wings. Even if basically humanoid in makeup, things like Kobolds get tagged Dracomorph instead at times. This term also catches full dragons or Wyverns though - it is like a catch-all-phrase for anything dragon-like. * Feline/felinoid: implies catlike features but also a humanoid base setup, usually adding tail and fur. Now, while these are still "humanoid" in their setup (walking on 2 legs, free hands), there are terms for more "alien" builds: * Insectoid: This implies Mandibles and an insect-like skull and body, including 6 sets of legs/arms and possibly wings, also trachea breathing and facette eyes. * Arachnoid: 8 legs, mandibles, multiple eyes, spider-like skull and body architecture * (Cen)taur: Posessing 4 legs instead of 2 and being some animal-human-hybrid thing makes a being a centaur Still, if it is skinny, has 2 legs and 2 arms and a single head, all connected to a torso, it is a humanoid. But that word has its synonyms, that reflect this makeup: * anthropomorphic ("built like a human") * anthropoid ("walking like a human") * biped ("walking on 2 feet") [Answer] from a purely taxonomical perspective, all the human-shaped creatures are probably either [great apes](https://en.wikipedia.org/wiki/Hominidae), [simians](https://en.wikipedia.org/wiki/Simian), [primates](https://en.wikipedia.org/wiki/Primate), or [marsupials](https://en.wikipedia.org/wiki/Marsupial). so **sapient simians** would work well. or you could use the term **men** to mean both humans and other primate-shaped people. of course, then you have gender ambiguity issues. ]

[Question] [ You're a sailor on (in?) a brand-spanking-new [*Virginia*-class nuclear submarine](https://en.wikipedia.org/wiki/Virginia-class_submarine). You just set sail a couple of weeks ago, and were doing some routine exercises in the North Atlantic (about 500 miles north of Bermuda/500 miles east of New York), when total nuclear annihilation happened top-side - this is a total global nuclear apocalypse. All nuclear warheads are deployed, and nuclear power plants meltdown. Whoever orchestrated this was very skilled and thorough. My basic question is: **How feasible is survival aboard the submarine?** Some other thoughts/specific questions to guide your answers: * Assuming the warheads dropped and meltdowns occurred all on land, is the sub in any immediate danger underwater? * Does the fallout reach the middle of the ocean? If so, does this put the sub in direct danger? Is there a better place the submarine can move to avoid potential danger (e.g. the Arctic or the equator)? * The reactor on the sub can last for about 30 years. You can get fresh water by distilling ocean water. My best guess is that the hardest part of this scenario will be food. Let's say the sub has food aboard to last for about 3 months. With strict rationing we can eke out some more time. But eventually it will run out. + How do you obtain food? Can you catch fish from the submarine? I imagine you'd have to surface to do that...is that a big risk? Also, how will the longer-term ocean ecology be affected? Is fishing even feasible in the long run? + Another thought is to visit islands...small islands weren't targeted directly. You could try to visit survivors on these islands, but likely they are as dangerous as everything else. [Answer] ## There is a very good chance of survival Surviving even a "total global nuclear apocalypse" is a lot easier than you think. [Here's a good reference to look at](http://www.oism.org/nwss/s73p912.htm). Some key points: > > Within two weeks after an attack the occupants of most shelters could safely stop using them, or could work outside the shelters for an increasing number of hours each day. > > > Only a very small fraction of Hiroshima and Nagasaki citizens who survived radiation doses some of which were nearly fatal have suffered serious delayed effects. > > > Statements that the U.S. and the Soviet Union have the power to kill the world's population several times over are based on misleading calculations. > > > Non-propagandizing scientists recently have calculated that the climatic and other environmental effects of even an all-out nuclear war would be much less severe than the catastrophic effects repeatedly publicized. > > > And [from someone who worked in a nuclear submarine's engine room](https://worldbuilding.stackexchange.com/a/14957/6781) > > It's entirely likely [that] entering a nuclear facility in the wake of the apocalypse would expose you to dangerous levels of contamination. It's possible that the areas immediately surrounding them could have elevated levels of background radiation. It's unlikely that any effect would be noticed more than a few miles away. > > > If you can get to a reasonably good nuclear shelter, you have a good chance of surviving anything less than a direct strike. That's if you're on land! The biggest advantage that a submarine crew has is that [they can stay submerged for as long as their food supplies last](http://www.navy.mil/navydata/cno/n87/faq.html). Also, [water is an *excellent* blocker of radiation](https://what-if.xkcd.com/29/), so while they're underwater they are not in any danger at all. This leads to a huge overall advantage - after two months (until the food supplies run out) radioactive decay means that the overall level of radiation will have fallen significantly to easily survivable levels. The biggest problem that the submarine crew will face is not knowing which areas were nuked and which weren't - this affects where they should go to try to find supplies. There's a good way to figure this out though - *get in contact with the ISS*. Having watched the entire mess unfold, the astronauts aboard the ISS will be able to direct the submarine to the areas that were hit by the fewest nukes. Once they get to those areas, they should be able to figure out a way to integrate into whatever communities have survived, making long-term survival very likely. [Answer] 1. No. The sub is out of immediate danger if it is far out in open waters, away from any mega port city. 2. Yes, in the case of an *ultimate nuclear doomsday*, the radioactive effects would reach everywhere on earth through winds. It will take sometime though. I don't know how much, though. Depends on which ocean you are in and how many missiles hit which continent. It is sufficient to say that as long as most of your time is spent underwater, you are safe from direct radioactive effects. Poles would be the best place for immediate refuge but do **not** stay there for long as all atmospheric waste tends to accumulate on poles through snow storms. The next several dozen years would be a radioactive nightmare on poles. 3. You can catch fish. The more benthic, the better. Radiation is less likely to reach deeper waters so eating deep water fish would be a better idea. However, notice that these would have much less nutritious value. 4. Islands are safe only immediately (just like poles). Once winds distribute radioactive effects globally, nothing above the surface is safe for consumption. You should wait at least several years before you venture to any far Pacific or Mediterranean island. [Answer] Submarine would be in grave danger of being intercepted by an akula class attack submarine from the russian navy. Ballistic submarines are part of the second strike capability of a nuclear power. They are able to counter-attack even if their airforce and land equivalents are destroyed in a counter-force first strike. In order to be able to both protect own ballistic subs and destroy the enemies equivalents, attack submarines where developed. Russians have Akula class submarines for this task, while they use Typhoons as ballistic carriers (in the west the typhoons are erroneously called akulas). When a submarine leaves friendly port for a patrol, there is a large chance that a enemy attack submarine follows his trail, in order to keep him on track all times. Russians done that, Americans too, and so on. So, if your virginia class submarine is out at the sea, you should be carefull if you are not being tracked by a akula class submarine, ready to take you out to prevent USA second strike capability. If you are near russian waters, you might be under tracking from their undersea microphone network and their kilo class diesel-electric submarines (wich are pretty hard to hear). So, even if underwater submarines are not subjected to the dangers of nuclear explosions on the land, and their hull are protected from nuclear fallout (the sea is a very good shield), you still might be sunk. Besides that point, your text assumes a 1960'esque scenario for that nuclear war. During that era, nuclear bombs where big to compensate for their lack of accuracy. They used what is usually called counter-value (targetting civilians). Modern day nuclear MIRV'ed warheads are low yield and very precise, and a rational opponent will use all the warheads they have to destroy enemy military structures and those industries directly related to defense, they wont simply strike cities because thats not a good strategy anymore. They will be used in counter-force mode. After the first nuclear exchange, when the nuclear stockpiles are depleted and the economy ruined (besides the submarines second strike capability), there is no way to build new nuclear warheads, countries would fight a conventional, post-apocaliptic war, and if you use your bombs versus cities and leave the military structures and installations intact, you will fight a much stronger foe afterwards. So, the usual engagement mode is counter-force: Fire at the nuclear silos, airbases, anything that might stockpile nuclear warheads, them later fire at navy bases, cavalry, infantry battalions etc, everything that has military value. Thats the usual sequence for a decapitating first strike. About the submarine at sea, you might try to contact other naval forces via satellite, try to rendezvous with friendly merchants etc. But you will be on a hard time, because a anti-merchant war will start to prevent supplies from reaching USA (and vice versa). War will be hot at the oceans. You might be able to join a surviving carrier battlegroup, or enter neutral waters to trade. But by all means your submarine is still a viable fighting machine and the first strike is not the end of the world nor will be the end of the war. [Answer] **Survival of the initial event is effectively 100%** as that's what submarines are designed to do. However, surviving out at sea is limited by the food supply on-board. **Air** Just as on land, if you run out of breathable air, you die. A submarine has considerable capacity to operate for long durations. Creating oxygen is easy by using electricity to split water into hydrogen and oxygen. Removing carbon dioxide is done by lithium hydroxide. [Heating](https://en.wikipedia.org/wiki/Lithium_hydroxide#Carbon_dioxide_scrubbing) the lithium hydroxide resets its ability to scrub. **Water** Submarines carry desalination equipment so fresh water isn't an issue. **Food** USN submarines often go out for six month missions so storing that much food isn't difficult. After that initial food supply, the submarine must return for resupply. This effectively limits the maximum time a submarine can stay out at sea. Resurfacing will contaminate the sub to some degree and thus begin the slow march to radiation death. [Answer] 1. No, the submarines are designed to survive a MAD scenario (to perform a strike on the remaining targets), so immediately you'll be ok. 2. Fallout may reach the center of the Atlantic ocean, if winds will allow it. Horse latitudes will probably be safe. But I don't think you'll have to worry about the fallout underwater. Remember what's spent nuclear fuel pools are made of. That's right, water, and these basins are far shallower than your maximum submerge depth. 3. Why would you want it? You can go South America or Africa. Probably some South America country, like Chile (two research power plants) or Peru (the same). They're shielded by mountains and will have negligible internal fallout. As someone with the most advanced ship nearby, you may very well make a living as a mercenary king. After the global catastrophe someone will be itching to replay the War of the Pacific again. [Answer] The war poses no threat to the submarine. You can stay out there until you run out of food. At that point, though, you have a very big problem: You're coming up into a nuclear winter. The radiation levels have dropped to levels where you have an elevated cancer risk but it's not going to kill you outright. What will almost certainly kill you is the skies will be dark--nothing is growing. What are you going to eat? Others have said to go fishing--but fishing for what? While you've been hiding out the fish have been starving because the algae they eat isn't growing. [Answer] As a long term food supply source if going ashore isn't an option, the only difference between fishing with dynamite and active sonar is that you'll eventually run out of dynamite. OTOH breakdowns from inability to perform preventive maintenance will probably eliminate any subs hiding out in the ocean within a few years, either by forcing them ashore or causing their loss directly. [Answer] Lot of good info already, I won't repeat. Other than to say, I served (attack boats). And it is absolutely true that the world could end and you wouldn't know about it for several hours until pulling up to PD, if you were submerged, decent depth (which is pretty normal ops really). But a few things to add: 1. You have a large amount of radiation detectors (different types and ranges). As well as well-trained nuclear personnel. This would be important in scouting potential landing sites. Now the instruments and training is not designed for this scenario. But it could be repurposed easily and would be very useful. As compared to say a conventional destroyer or the like. 2. A more general point, but you have a decent sized crew (115 or so). And they are well trained and overall highly intelligent. So I feel good about their ability to "adapt and overcome" to all aspects of the new scenario, not just dosimetry. This is a point that many people tied to shore establishments. But the USN has a pretty long history of operating thousands of miles from home. It drives a different mindset. Humans are assets--they can do damage control for instance. Something NASA, for instance, has never really internalized. --- The one big disadvantage is a lack of small boats (that any destroyer has and has extensive experience with). So you'd be facing a little bit of precarious movement in life rafts, moving onto shore, when you get short of food. [Answer] ***Assuming the warheads dropped and meltdowns occurred all on land, is the sub in any immediate danger underwater?*** Yes, mainly from other military submarines and/or naval forces, especially those designed to hunt submarines. ***How do you obtain food?*** If the surface air at sea is acceptably safe (some people say yes, others say no), then I would suggest trying to find cargo ships carrying food in refrigeration units. These have small crews and so may effectively have enough to feed your crew (and theirs) for a long time, and they may be large enough to build garden space on their decks. They would no doubt like your protection and be in no position to refuse you. ***Can you catch fish from the submarine? I imagine you'd have to surface to do that...is that a big risk?*** The size of the radiation risk depends on whom you ask, and also on what the situation is like with surviving hostile military forces. Yes you'd need to surface and you'd want fishing gear... and/or you could find some fishing vessels and recruit them to fish for you - though they need fuel, unless you find fishing ships that use sails. Finding or creating a way to grow vegetables would probably be an excellent idea. Researching edible sea plants too. ***Also, how will the longer-term ocean ecology be affected? Is fishing even feasible in the long run?*** Again it depends on whom you ask about the radiation. If fishing fleets are mostly out of operation and most humans are dead, I'd expect the fishing to get better and better. ***Another thought is to visit islands...small islands weren't targeted directly. You could try to visit survivors on these islands, but likely they are as dangerous as everything else.*** Again that would depend on what the actual post-apocalypse conditions are like, and the specifics of the island, and possibly what weapons your submarine has. Also, the situation may evolve as time goes on and survivors reorganize. With governments destroyed, one might want to be cautious even about naval forces which would have been allied during the war, if they could consider you a threat or asset in some way. It depends on how many military submarines survived and how they remain (or newly) organize and behave in the new situation. If the seas are relatively safe, then I'd recommend rounding up a fleet of civilian vessels to try to form a self-sustaining community, although since most other vessels probably run on fuel, that would pose problems. If the seas aren't safe, being on the winning side against surviving hostile naval forces might be the first task. Oh, and of course, a terrible and probably unwise but true idea is one could check out how long the food you have can last, eat the shortest-lived stuff first, and then contemplate down-sizing the non-essential personnel aboard... ]

[Question] [ Several science fiction books I have read (including, IINM, *Nightfall* by Asimov) have featured planets with several suns. Some worlds where this happened wrought interesting effects on the inhabitants of said planet; for example, in a world that was perpetually experiencing daylight, people might be so afraid of the dark that their psychologists considered fear of the dark to be a primal, impossible-to-overcome condition of humanity. Multiple suns on a planet makes things interesting. **Is it realistic for a planet to have multiple suns?** [Answer] A planet can have multiple stars. You have 2 important conditions that you need to meet. **1-The system must be stable**. With multiple stars, you will face the n-body problem. This problem arise when you have multiple celestial bodies that interact with each others. You can't place the bodies where you want and expect the system to be stable without taking in consideration how the will influence the other bodies. * n-body problem: This problem can be illustrated in our own solar system. The Sun is 1047 times the mass of Jupiter. But even with such huge difference, Jupiter is considered heavy. So heavy that the center of the system is not in the center of the Sun. Jupiter makes the Sun ''wobble'' toward her a little. Now imagine that Jupiter was a red dwarf and 100 times more massive.This would make the Sun move even more and also the other planets of the system. To get rid of the problem, you can move object away. it should make the system more stable. I don't have the numbers but I know there is a formula somewhere. * Hill sphere: One important thing I could say is that your planet orbit need to be located completely inside one of the star hill sphere. This sphere is where the gravity of a given body is stronger than the other bodies. The Sun has a hill sphere, Earth, the Moon, all celestial bodies have one. The size of the sphere depends on the mass of the body, the mass of the larger body and the distance between the large and smaller body. The more massive is the smaller body, the larger is the sphere. The closer the larger body is form the large one, the smaller is the sphere. Even if the planet stays inside the sphere, other forces can make the planet change course if she goes too close to the sphere's limit. * To have a multiple star system, you can either have the stars close to the center of the system. Or they can be far from each other: the planet orbit the smaller star and the smaller star also orbit a bigger star far away. When the stars are in the center, they need to be close to each other. Otherwise, it will make a larger difference of gravity pull depending which star is closer to the planet. This means that the planet cannot have a stable orbit unless she is very far aways form the center. This probably falls outside the habitable zone. When the stars are far away, it's simpler. Make sure your planet is comfortable inside the hill sphere of the closest star and don't worry about the rest. And if the planet needs to be habitable by mankind. **2- The planet must not be too hot.** Multiple stars means multiple sources of heating. And you need to consider this as well. To find the impact on temperature on the planet, check this out: <http://www.cartographersguild.com/attachment.php?attachmentid=66387&d=1407439779> you need to make the calculation for each star in the system. [Answer] > > This answer was started by [Pink](https://worldbuilding.stackexchange.com/users/6/pink)'s [comment](https://worldbuilding.stackexchange.com/questions/2657/can-a-planet-realistically-have-multiple-stars#comment4744_2657) on the question. > > > Kepler/NASA have [discovered](http://kepler.nasa.gov/news/nasakeplernews/index.cfm?FuseAction=ShowNews&NewsID=180) what they call "circumbinary" planets -- planets that orbit multiple suns (or "stars" or [whatever you want to call them](https://worldbuilding.stackexchange.com/revisions/2657/2)). The way it works is that there is a planet that orbits two suns, both of which orbit each other. That article did not discuss whether or not these planets are capable of supporting life, but I would imagine if there was enough of whatever else was needed for life, and your multiplicity of suns did not overheat the planet, your planet's inhabitants should be fine. Here's a (**very**) crude illustration of how this system could work: > >  > > > A million thanks to [Tim](https://worldbuilding.stackexchange.com/users/4697/tim) for giving me a *much* clearer illustration for this answer! Here it is: > >  > > > [Answer] Stars come in all kinds of sizes. There are lots of known star systems with more than one sun. The [north star](https://en.wikipedia.org/wiki/Polaris), for example, happens to be a trinary system of one large sun orbited by two smaller ones:  I see no good reason why a sun orbited by multiple other suns shouldn't also be orbited by one or more rocky planets. Also, one of the outer suns could itself have small, rocky planets, just like planets in our solar system have moons. If you want to build a solar system with plausible masses and distances, then I'd recommend reading about [the main sequence](https://en.wikipedia.org/wiki/Main_sequence) to learn which masses are plausible for stars and how stars' masses and ages affect their luminosity. You certainly want all of your suns to have enough [apparent magnitude](https://en.wikipedia.org/wiki/Apparent_magnitude) to create notable illumination, but not so much that they grill the planet. Some numbers to get you started: * Jupiter: 317.8 Earth masses * Minimum mass for a star to maintain hydrogen fusion ([red dwarf](https://en.wikipedia.org/wiki/Red_dwarf)): ~30,000 Earth masses * Our sun: 332,946 Earth masses * Most massive star known ([R136a1](https://en.wikipedia.org/wiki/R136a1)): ~88,000,000 Earth masses (but there might not be any reason to believe that even larger stars might not exist…) [Answer] Yes, as others have said it is possible for a planet to orbit a binary star system. However, in your question you seemed more interested in the psychological implications of having 24/7 light. So may I suggest a binary star system with a planet in the middle?  This configuration, while technically possible, would be extremely rare. It requires both stars to be nearly the same mass, they would need to be far enough apart to keep the planet from burning up, and any interference from large fly-by's could easily upset the delicate balance. So don't expect it to survive long enough to support life. Rare as it may be, don't dismiss it so easily unless you can truly comprehend how large the galaxy is, let alone the universe. [Answer] There have been theories that a hidden, dead star (named [Nemesis](https://en.wikipedia.org/wiki/Nemesis_(hypothetical_star))) orbits our solar system far beyond the Oort cloud. Such hypotheses generally assume that Nemesis is now in the form of either a red or a brown dwarf due to the limiting constraint that we cannot see it. And, realistically, even if it *were* still burning, it would *probably* be too far away to look like a 'second sun' without being so massive that it would destabilize our main sun's planets' orbits. In all likelihood, Nemesis would be seen as a very bright star. But such a star would, even then, have pretty bad implications for the stability of our solar system's planets' orbits as previously stated. That is, in fact, one of the things that *led* to the 'Nemesis' hypothesis; apparently, a [periodicity](https://en.wikipedia.org/wiki/Extinction_event#Patterns_in_frequency) has been been observed in the frequency extinction events, and this *could* be explained by periodic meteor bombardments caused by a distant massive object mucking with the orbits of comets and sending them spiraling in toward the inner planets. ]

[Question] [ In a world with humanized (or at least tool using) reptiles, how long would a tattoo be able to last on the scales? Would the tools need to be much different than what we use today? Would it be possible for a reptile to get a tattoo of a human? [Answer] The main problem with this concept is that scales are constantly shed over the lifetime of the reptile. As a result any sort of skin decoration would be by its nature temporary. I think it's more likely that they would develop things similar to our nail polish and use that to paint their scales in various designs and styles to accomplish a similar purpose to tattoos but in not so permanent a way. [Answer] Tattoos are ink that's injected below the skin, and visible through the skin. You would need translucent scales for that to work. And scales are shed throughout a reptile's lifetime - so tattoos (on the scale itself) would be temporary. There's a book about an alien who used a human as his totem. *Demon of Undoing* And humans use reptiles as decoration, so why not the reverse? [Answer] Based on the comments made before me, tattooing on the scales isn't gonna work because they shed these. This made me come of with a more intrusive, but possible, solution: **DNA-tattooing** (or the closest thing to it). The scales get a color from the DNA of the owner, why not a changes locations of DNA, making it like pixel-art, depending on the size of the scales. Does requires a little futuristic mindset. [Answer] You could likely have some method of scarification work. If you forcibly remove healthy scales from the reptile and damage the cells which control their replacement. The resultant scar tissue may be perminant damage that looks different from the scales. I do not know if this would actually work on a real reptile but I would definitely believe it for a fictional reptilian humanoid. Depending on the nature of the scars, you may be able to stain/tattoo the scar tissue. I think it would be relatively easy to imagine an cool, intricate pattern of missing and present scales. [Answer] Thanks to the points mentioned in other answers, I could direct a more extensive research, and this is the most satisfying result I got. Disclaimer: I went into much details because it seemed like there was a few misconceptions on how reptilian scales work. **TL;DR:** Unless the scales are transparent, the tattoo has to be done *on* the scales and as such, it is not going to be permanent at all because of the frequent shedding. --- # Scales First of all, let's clarify some points. Scales are extension of the epidermis, just above the dermis; depending on the kind of reptile, they can be very thin folds of the epidermis (e.g. snake scales), or thickened areas of epidermis (crocodile scales). You can find some good illustrations of these in the part 1 of [this ZooPax](http://whozoo.org/ZooPax/ZPScales.htm). Normally (i.e. on humans), tattoos are injected in the dermal layer. This would mean sub-scale tattooing, which can be a problem for snake-like scales. However, if the scales are thick enough, we could get away with simply injecting the ink in the epidermis itself (so the scales) rather than in the dermis. However, things are not quite that simple. As Tim-B and user3082 mentioned, the biggest issue is that reptiles shed their skin (or moulting, if we go for the technical term) frequently. Each type of reptile moult differently; snakes do it by turning their skin inside out like a sock, most lizards moult in patches, though some do it all in one go. Crocodiles and turtles have a very different kind of scales; they shed them one at a time, but if we can simply tattoo them in the dermis directly, then it is not an issue. So, in either case, the solution would be to tattoo reptiles the same way we tattoo humans, by injecting the ink in the dermis; regardless of *how* we would do it for snake or lizard scales. Cort Amon mentioned a [solution](http://en.wikipedia.org/wiki/Painted_fish) for that involving syringes and dye (though it can also be done with laser technology, it seems). However, even then, there is still another problem: it's a moot point to tattoo in the dermis if we can't see through the scales! # Transparency Solutions can differ greatly whether the scales are transparent or not (or if they even can be), so I'll treat both of those possibilities. ## Opaque scales In that case, tattoos wouldn't be permanent because you would need them to be in the scales themselves rather than under them; you can think of them as an equivalent to our hair dyes. They would last several months (maybe even a year or more depending on the kind of reptile), but would eventually disappear as the skin is shed. However, Tim B suggested an interesting alternative in his answer, although even more temporary: > > I think it's more likely that they would develop things similar to our nail polish and use that to paint their scales in various designs and styles to accomplish a similar purpose to tattoos but in not so permanent a way. > > > This is actually something that is done nowadays already for marking reptiles in the wildlife (Johnson, M. A. "A new method of temporarily marking lizards." *Herpetological Review 36.* 2005: 277–279). I could imagine this solution to be less restrictive than tattooing, notably with colours, as bright hues would be more easily achievable. Also, glitters. I don't think I need to say more. ## Transparent scales As Gertlx pointed out, reptile scales are made of keratin, meaning it *is* possible for scales to be transparent. However, this is still not enough. If the scales are too thick, the tattoo might be hard or even impossible to see through the scales. To sum it up, then, for a reptile to be tattooed in the strictest sense of the term (i.e. with ink injected in the dermis), *and* for the tattoo to actually be permanent, you need the reptile to: * have transparent scales; * the scales need to be thin enough, or *very* transparent; * and in the case of snake-like scales, you need specialized tools. Speaking of which, let's answer the second part of the question. # Tools > > Would the tools need to be much different than what we use today? > > > For crocodile-like scales, the method would be the same as for humans, although the tattoo machine would need to be stronger to be able to poke through the reptile leather. If the tattoo is made manually (e.g. [Tebori](http://en.wikipedia.org/wiki/Irezumi#Glossary_of_Japanese_tattoo_terms)), this is less of an issue, as the force put in the tool is more easily controlled. For snake-like scales, it becomes much more complicated. Using the traditional method would probably get unsatisfactory results for reaching the dermis without damaging the scales too much. By using syringes or similar tools, one could inject the ink by going under the scales, but I believe this wouldn't allow a tattoo to be as elaborate as with the other method. If the intent is simply to tattoo *on* the scales however, then the tattoo gun would do the job just fine. And finally: > > Would it be possible for a reptile to get a tattoo of a human? > > > Possible? Definitely. Adeptus mentioned *The dragon with the girl tattoo*, in which the protagonist, a female dragon, has a tattoo of a human girl; it is considered to be a mythical creature in that world. user3082 talked about another possibility as seen in *Demon of undoing*, where an alien takes the human race as some kind of role model. Whether humans exist or not in the universe we're working with, there can always be a plausible explanation as to why one would have a tattoo of a human. --- Extra reading content: Tattooing reptiles has actually been done before and is still in actuality. There is an [article](http://www.doc.govt.nz/Documents/science-and-technical/MarkingMethods.pdf) about the methods of marking small animals (Ngaio J. Beausoleil, David J. Mellor, Kevin J. Stafford. "Methods for marking New Zealand wildlife." 2004.); tattooing reptiles is described on page 82. [Answer] The way I would approach this is to modify the cells that produce scales - and have any design as a series of scale shaped pixels. This would mean that the effect would be permanent, as each new scale grown to replace a shed one would retain the colour, unlike simply painting the sales. [Answer] If they are suitably advanced they could get tiny bio-luminescent particles embedded in each scale, and use their external surfaces to display patterns and pictures at will. [Answer] Provided the species has natural scale patterns, it would be possible as follows. The cells that generate the scales would have the ability to generate some pigmentation for the scales naturally. This would not a binary switch set at birth. Rather the amounts of pigments generated would vary based on the chemical environment around the cell activating genes with different frequencies. The process would presumably be self-stabilizing, ie. generating lots of or little of pigment this round would have the corresponding effect on the next round. This, or equivalent mechanism, is plausible, if the natural patterns are stable. It would be possible to change of the chemical state of the progenitor cells simply by injecting chemicals into the tissue. Self-evident, but depends on the chemical. Tools used for tattooing should be sufficient, especially if done at a time when the reptile is changing skins. Alternately, if this an initiation ritual and the reptiles have decent ability to regenerate their scales, scales could be removed in strips and the design then be painted directly on the tissue. In theory this method would have the same color palette, stability, and general appearance as the natural patterns of the species. But the designs would not be particularly limited. Obviously this assumes the reptiles have natural patterning and that they have been able to find the chemicals that allow changing patterns. This would probably require them to have periods when their skin is thin enough for accidental splashing of herbal tea or similar to a visible effect later. Which would make applying patterns easier and less painful. [Answer] You can always use **freeze branding**. As seen on <http://www.wildlife.state.nm.us/fishing/fisheries-management/> it totally works on scales: [](http://www.wildlife.state.nm.us/wp-content/uploads/2015/01/fishing-fisheries-managment-NMDGF-catfish-stocking-Freeze-Brand-2.jpg) It's simple, all it really requires is ability to get something really, really cold. Pretty doable with technology from XVIII century. If they are hot-climate, then even ice might work on them that way. ]

[Question] [ It is difficult to find statistics for the ratio of Lego men and women in the general population but from a non-scientific survey, I get the impression that Lego men vastly outnumber Lego women. Yet clearly they do reproduce. Here is a picture of a pregnant Lego woman. [](https://i.stack.imgur.com/A4sBC.jpg) Setting aside the gender ratio, it is not obvious how Lego people actually reproduce. If we look at Legoid anatomy there is no evidence of suitable appendages. [](https://i.stack.imgur.com/xKuYU.jpg) EDIT in response to the question being put on hold. > > [Help Center > Asking](https://worldbuilding.stackexchange.com/help/on-topic) > > > For example, questions are welcome that are about: ... > How to achieve a specified effect in a defined world, including by the use of > technology or magic, while maintaining in-universe consistency. > > > In order to create a realistic Lego-based world, I wish to develop a consistent ***in-universe*** description that explains how these beings reproduce. Therefore I am not looking for an explanation that relies on human intervention. If the Legoids themselves can perform the necessary biology or technology then that is fine. Using your knowledge of Lego, biology, pseudo-science or any other plausible mechanism (possibly including magic) can you offer a suggestion that 1. explains or suggests the mechanism of Lego reproduction. 2. explains the high preponderance of Lego males? If they were like humans we would expect a roughly 50-50 ratio. EDIT 25 Aug 15 For these purposes, I assume that Lego people cannot see or comprehend humans - who can be considered to live in a different dimension. They see only each other and their building materials. The results of human actions (but not direct experience of humans themselves) are presumably part of their mythology and put down to natural or supernatural causes. [Answer] When lego people expire their three core parts (head, body and legs) become disassociated. They may remain in this state in the environment for quite some time until a suitable input of energy (lightning, earthquake, storm etc) into the environment animates a new person from a suitable nearby triad of parts. Accordingly the new person is 'animated' in adult form by a spontaneous fusing of head, body and legs. The resulting person will have an odd mix of skills and character traits inherited from the random re-mixing of old core parts. So, they exhibit Lamarckian rather than Darwinian evolution, and so don't need to be trained from scratch although some need considerable support in successfully integrating less than well matched body parts. Lonely lego people who can't find the right soulmate are often to be found scouring the land looking for disassociated body parts which they collect together and watch over in the hope that a suitable event will cause an animation. Sadly, the results are rarely what the parts-collecter had in mind, since the life history of the individual parts is often difficult to discern. The difference between the sexes is based purely on certain body parts having an affinity such that they are more likely all else equal to become associated. Transgender animations can and do occur though. When the stock of disassociated parts declines below a certain level, the same energetic events that cause animation are more likely to randomly dis-associate existing people than animate new ones. Population growth thus requires the introduction of new body parts - a subject which forms a core part of all lego people's mythology and many quest stories. For this reason very long lived lego people tend to be viewed with suspicion and resentment and may be the subject of violence (which also causes disassociation). Short lives are felt moral and honourable since it increases the stock of life skills embedded in the core parts. [Answer] Lego people reproduce **asexually** through [binary fission](https://en.wikipedia.org/wiki/Asexual_reproduction#Fission). They divide in half, and each slowly grows into a new lego person. Your "pregnant" Lego lady is actually just gorging herself in preparation for the split, to speed her re-growth. New, never before seen Lego people are caused by errors in the regrowth process, due to the high levels of toxic chemicals and plastics in legoland. [Answer] **They order new ones from the factory.** Firstly, that pregnant lego woman is *clearly* photoshopped. Lego women don't *get* pregnant. If one were pregnant it's because she was made that way and she will die that way. Secondly, don't search for Lego genitalia on the internet. That's some solid internet advice; replace "Lego" with any word, you can't unsee what has been seen. It wouldn't have shown up in the picture you found in any case. Lego people are also rather progressive, that have embraced the designer babies trend. Except their babies arrive full grown. Can you imagine how wonderful/horrifying that would be? So much they missed out on, yet, so much they got to miss out on. Lego people are like vampires, whatever age they're made at, they stay that age. Forever. Making Lego children would be a curse on those children. They would be shorter, but still the same width (two bumps), so would live out a long and awkward life. As for the high number of males (no, they're not made in China), construction and engineering are massive industries for Lego people. As with humans, they are still very male dominated fields. As the Lego people have higher need for doctors, scientists, and athletes the number of female Lego people will increase. [Answer] Lego people, despite their appearance, are genderless. You feed two of them a brick, love hearts will appear on top of their head, they will get close to each other… a small Lego kid will spawn nearby, and also an experience orb which you might (and should) collect. [](https://i.stack.imgur.com/IErYp.png) Yes, [that's Minecraft](http://minecraft.gamepedia.com/Breeding), but it's as Lego as it can get. [Answer] We've long known thát Lego people don't reproduce in the same way non-Lego humans do (see rumguff's excellent answer), for all the ages that have passed in Legoland, no one ever knew why. Now that another age has passed, even since this query was asked, new revelations out of Legoland confirm the answer that ***modern*** Lego people -- *Lego minifigurae manihabiles* -- **do in fact reproduce**, just not in the way we might expect. **First some history:** We know from the most ancient of records to be found in Legoland (discovered recently in the Bookshop, set 10270), that there were, in fact, *three races of Lego people*. In those days there were giants in the land... Back in the earliest epochs of Legoland history, all Lego people were big. *Lego magnitestae*, the so-called "big heads". [](https://i.stack.imgur.com/ncXJm.jpg) And as we can see, Lego people at that time did in fact reproduce and grow old. During this archaic epoch, certain environmental factors spelled the downfall of the "big heads". First, and although we have little material evidence from this time in history, we do have tantalising hints of multi-limbed and tentacle-limbed monstrosities being born. The relative sparsity of basic building materials in the archaic age also spelled doom for these giants, as even a family of five simply could not procure enough bricks or base plates or roofing shingles to create even a modest cottage, to say nothing of banding together in communities. And so the archaic age with its reclusive giants came to an end, outcompeted by the most unlikely of evolutionary freaks. During the short lived middle epoch of Legoland history, a new kind of Lego person was created from the potential brick, *Lego minifigurae rigidae*. These bizarre people were much shorter than the "big heads", and were, in many ways, more frightening than the great monsters of old. [](https://i.stack.imgur.com/E62Ne.jpg) With their expressionless faces and immobile trunks, yet somehow able to braid their hair and wear their caps, they dominated Legoland for a short time. Yet somehow they were able to rebuild Lego civilisation, undoubtedly drawing on the ruins of the "big heads'" earlier attempts. [](https://i.stack.imgur.com/P0oV8.jpg) Their time of dominance was short lived, however, as the middle epoch evolved into the younger epoch and the rise to dominance of the minifigure proper was accomplished. From the medieval period... [](https://i.stack.imgur.com/x43PU.jpg) to the space age... [](https://i.stack.imgur.com/JvWth.jpg) Lego people kept advancing, but one thing neither the rigid nor the articulated kinds of people could do was reproduce -- unlike the big heads, we see no children in these later epochs of Legoland history! Not even the short-lived evolutionary throwbacks that arose at this time, *Lego magnatesta basica*, had children. [](https://i.stack.imgur.com/tb0aE.png) And at the time this query was written, that was the state of things. But since that time, as was mentioned earlier, new revelations have come out of Legoland. There are now known to be *Lego children and Lego babies*! [](https://i.stack.imgur.com/8hQl7.jpg) [](https://i.stack.imgur.com/71cay.jpg) It's unclear how they are formed, as their brick matrices vary from the normal, though it is known that, as with adult Lego people, children and babies are brought fourth from that mysterious place called the Brick Box, having been formed from the primordial brick. Some believe that Lego pediatricians have something to do with the process, but there is no clear evidence for this. At least this much is clear: as it was towards the beginning, it has always been the Plan for Lego people to live in family relationship and exhibit varying ages among individuals of society. It is simply not until the modern epoch that Bill and Mary's descendants have been given this gift by their Creator. [](https://i.stack.imgur.com/aJPyf.jpg) [](https://i.stack.imgur.com/XPmum.jpg) [Answer] ## LEGO people don't reproduce. There's a **finite** number of lego people and parts and all new LEGO people are simply made at a LEGO people assembling building from the disassembled parts of former LEGO people. These parts are usually kept in a giant yellow container curiously called "minifig bucket." All LEGO people require a triune of parts to be considered alive. The Trunk, the Torso, and the Pineapple ( also known as the yellow head cylinder ). It is only when these three parts are connected that you get a sentient LEGO person. ## LEGO people also *do not die*. Their pieces do age, their colors do fade... but they don't actually DIE in our sense of the word. You could compare LEGO to a three-celled organism that only have higher-level functions when all three cells are connected to one another. Occasionally an accident will happen like a LEGO person hanging onto a helicopter while their torso is clicked into a particularly stubborn pip. When their body is separated, they immediately lose all sentience. While it is possible to put the pieces back together again, once disconnected, the exposure of the innards of the LEGO minifig parts erases all memories and therefore what you could call consciousness so there's really no point. Effectively they're dead... despite their really being no degradation of the pieces... so their pieces are simply collected and sent to the big minifig bucket in the SKY ( Special Kollection Yard ) When pieces are randomly matched ( or LEGO people are *birthed* ) all variables are randomized and they gain a completely random personality. ## Finite number of LEGO people and the grand purpose There is a finite number of LEGO people. It will never go higher. It will only gradually get lower over many millions of years as parts wear out and pieces no longer stay together. However, there's a MASSIVE glut of extra parts that have never been used, so that isn't a problem. ## Beliefs There have been some LEGO people who adhere to the teaching of scientism that have proposed bonding pieces together as a means of gaining true immortality, but there is a rather vocal group of religious individuals who feel this is not part of the master builder's plan and that the natural order of disassembly and reassembly is the natural way of things. They fear that permanence is not the LEGO way and goes against their purpose of existence as flexible and modular beings as purposed by the Grand Designer. They feel that followers of scientism are trying to become *The Builder* themselves. Many of these scientists don't believe in *The Builder* and want to believe that LEGO parts came from millions of years of iteration. They refused to believe that their world or their pieces were the product of a **designer** and feel that their world was not designed, but came about by random accidents in what they call the *Big Billund Theory*. Although most LEGO people accept most of facts of "Big Billund Factory" the followers of Scientism believe that no *being* conceived or initiated the "Big Billund Factory" but rather that it came about by accident. Most LEGO people, OTOH, believe that there was a "First Cause" and attribute it to the "Grand Designer". To many LEGO people, they give this "First Cause" a name. They believe they this Designer is not made of the same materials as them... and use the "Holy Manual" as proof of the Designer's existence. A few call themselves followers of *Ole Kirk Christiansen*... who occasionally intervenes from a spiritual place called "Denmark". Followers of Scientism say this place doesn't exist and since they can't see *Ole Kirk* he doesn't exist. As you imagine, it's quite the problem and has caused wars. Many LEGO people point to the intricate designs as impossible to have come about by mere chance and think the LEGO followers of scientism are somewhat of a cult and as such dismiss them as crackpots. As you can imagine, most LEGO people believe in a Great Designer, though some believe in a pantheon of Great Builders as opposed to one Original Designer. ## History Note that long ago, LEGO society didn't really exist as minifigs regularly removed the heads and torsos of others randomly, while sleeping... or just out of curiosity. In addition, they sometimes did it to themselves. They could not build a society in those days, and as such were more akin to minifigs wandering in a wilderness of spare pieces. ## Conclusion ### In the end, LEGO don't reproduce. They simply replace and reuse. [Answer] Now that this question has been resurrected and returning to my own question after several years, I can see an answer that didn't occur to me before. I originally said > > ... it is not obvious how Lego people actually reproduce. If we look at > Legoid anatomy there is no evidence of suitable appendages. > > > However I overlooked the fact that Lego people have a stud on the top of their head and sockets in their feet. This means that a suitable connection could be made after all. [Answer] They don't, at least in any sense we'd recognize. Their reality follows the fundamental principle that **function follows form**. What this means is that when pieces are assembled in the form of a person, it functions as a person. Minifig pieces are best for this, obviously, but any collection of pieces assembled into the form of head, body and limbs will also function as a person—though not as well, hence why they display erratic and often antisocial behavior. Due to mystical forces, the collection of pieces in their world is often changing, allowing/forcing them to reassemble each other into new and different forms with new and different functions. [Answer] A variation of Rumguff's answer. A higher intelligence makes them. They have some myths regarding this, and some atheist lego people believe in pure spontaneous generation. Most lego people have little memory of their first moments of life, but under hypnotic regression many remember an impossibly gigantic lego person, with jointed arms and legs, assembling them. The idea that lego people are created by one or more giants is actually their most popular myth. Their own scientists simple have no idea about how they are born and offer no answer. The appearance of new people is simply a fact that everyone accepts as normal. ]

[Question] [ Before the advent of agriculture, humans fed themselves by hunting and gathering. Hunter-gatherer societies tend to function quite differently from agricultural societies. Arguably, historically, with agriculture came kingdoms, wars, slavery, and overpopulation. In 1987, [Jared Diamond wrote an interesting essay on the question](http://discovermagazine.com/1987/may/02-the-worst-mistake-in-the-history-of-the-human-race). Could it be different? Could one envision a technologically advanced society¹ that does not do agriculture at all — but still relies on hunting and gathering for feeding the population? **Edit:** By *agriculture*, I mean to actively change and manage land for the intelligent² purpose producing of food or other products (wood, rubber, leather) with a significantly higher yield than would occur naturally. Examples include (but are not limited to) clearing land to grow crops, irrigation, livestock domestication. For the scope of this question I do not consider limited forestry (cutting wood in a naturally growing forest, as opposed to planting forests for wood production) or managed hunting (limiting hunting to prevent species extinction, or hunting competing carnivores such as wolves) to be agriculture. I admit that there are grey zones in this definition (one might speculate on how to categorise [in-vitro meat](https://en.wikipedia.org/wiki/In_vitro_meat)). --- ¹For the scope of this question, I will arbitrarily define *technologically advanced* as *being able to launch a satellite into orbit*. ²Some activities may lead to enhanced food production as a side-effect. For example, water lilies do well in [beaver ponds](https://en.wikipedia.org/wiki/Beaver_dam), but beavers probably don't actively plan this, so I do not consider it agriculture for the scope of this question. [Answer] ## Actually, the answer is yes, with some assumptions: In a classic food pyramid, such as we expect to see on land, (think lions, antelopes, grass) you need a lot of grass to feed a few antelopes to feed a much smaller number of lions. It's extremely difficult to come by enough food, and lots of territory must acquired and be defended. Population density is low, and small groups are in fierce competition with each other, so cross group collaboration is not encouraged. In this situation, agriculture allows the farmer to make the land vastly more productive. A few farmers can produce food enough for all, freeing up much of the population to focus on literature, science, art, architecture, etc. People can live in larger groups without exhausting the resources available to them However, there are alternative food pyramids available. ## Alternatives to the classic food pyramid Take a pristine reef environment (or one which has been allowed to regenerate) In this environment, the top level predator is a shark, and the pyramid is (shark / fish / algae). Here we find that the total biomass of shark is much higher than the biomass of fish (in fact 85% of the total biomass is shark). Moreover, the sharks appear to have quite an easy time coming by food, lazily circling in very large groups for much of the day and snacking when they feel like it. This works because in this environment, the lower level biomass is so insanely productive that it can support a much larger biomass of long slow living sharks without being degraded. Here the sharks do not have to farm because the reef is more productive than any farm we could imagine. ## A human society? We could hypothetically imagine a human society, perhaps living in an arboreal environment where food simply regenerates faster than it can be consumed and it is not so hard to acquire food. Perhaps massive airbourne whales that grow to full size quickly, harvested by harpoonists in light aircraft. Perhaps an interstellar migration route with a large ingress of cyclical, readily stored food. Perhaps the humans ingest sunlight directly with the aid of algae living under their skin. Perhaps they routinely voyage through some interdimensional gateway to trap and kill large monsters or some kind. The key is that humans are able to live in large collaborative social groups and food is not the limiting factor. Farming in this hypothetical situation is not the most economic way to acquire food. You might see some division of labour with a few people going out to hunt and easily feeding everyone else. The rest of the population could then concentrate on civilisation building. ## Reference See Enric Sala discussing this at TED here: <http://arcsecond.wordpress.com/2010/05/18/coral-reefs-are-85-shark/> [Answer] I studied archaeology, so I'll apply something from what I learnt: * for technological advance, you need spare time. Hunters usually need just two or three work hours a day in a game-rich area, and most hunter-gatherer groups live in such environments. So hunters usually have more times than farmers. * nomads can't carry too much things with them, so they are unlikely to develop any big tools. Producing some artifacts also require staying in one place for a long time. But there were cultures of hunters-gatherers living in villages (mostly at rivers full of fish), so this problem can be avoided. * the more people you have and the more interaction they have with each other, the more new ideas they will likely get. However, [as Superluminary wrote](https://worldbuilding.stackexchange.com/a/2899/95), hunters need a lot of space to get food, so hunting-gathering can support only low population density, so ideas will emerge slowly and technology requiring a lot of people at one place (such as any factories) is impossible. Nomads can move a long distance to visit other people and share ideas, but unless the new gear is easily portable, they are unlikely to embrace the technology (see last point). * need is the key factor of technological advance. For most of history, the technological progress was so slow that most new technology was strictly worse than older, mature one, and it could take generations until they became comparable. Prospect of getting the invention into profittable technology in few years is very specific to the rapid progress science does since 19th century, for prehistoric people older was usually better. Unless the technology is really needed, it's unlikely to be adopted by anyone but few crazy inventors, since it's worse than older counterparts. Farmers need more tools than hunter-gatherers, which means higher need for resources, that may be so hard to find that introducing some new, clearly worse material is needed. Hunter-gatherers face much less challenges solvable by better technology - lack of game can't be solved by any new technology except for agriculture. Sticks and stones good enough for weapons are usually much more abundant than food, so no reason to develop some strange materials to substitute for the right stones we lack. So to conclude, developing metalworking without agriculture is theoretically possible, but extremely unlikely, especially because being hungry is the mother of invention, but agriculture is the only really efficient invention that could feed the poor hunter-gatherers. Running industrial revolution without agriculture is impossible - for industry, you need concentrations of people that can't be supported without farming. [Answer] The short answer is no. *An additional note:* Agriculture IS a technology set. The evolution of farming technology has allowed for the evolution of other tech...thinking about it, it felt weird that we were talking about agriculture as if it weren't part of the tech advancement world. Here's why. For non-necessary scientific advancement to take place, people must have the spare time to work on it. In the evolution of human civilization farming is the corner stone. Farming, and the improvement of farming processes allowed us to get past the most basic tribal/nomadic levels because: * People had to settle in place to tend crops * Allowed for food storage, food hunted/gathered for is less likely store-able without refrigeration, whereas grains are easy to store for later. * Allows for the division/specialization of labor. A person excels at something (especially when pioneering a skill) by practice and trial and error. * Apprenticeships, specialization and experimentation are nothing if the knowledge is not passed on. Again, excess food production and storage allows people more time, this way you have someone learning and passing information on. There is one (ok there are more but this is key) more thing that needs to be taken into account and that is need. Hardship, and the need to advance are just as important as having the free time to advance. [Answer] I would say no, unless food to gather is plentiful enough that it doesn't take much work to gather it. The biggest thing agriculture does for a civilization is to allow a greater percentage of people to be released from food production to focus on other pursuits. This would also allow more specialization, such as cloth making, tool making etc. Which of course leads to trading good tools for food and on and on. Agriculture also tends to create larger and more permanent settlements. More people means more food requirements. If you have only ~50 people in a semi-nomadic group, you don't really need lots of specializations, most everyone does everything, one or two might have a great skill at tanning leather, or napping spear heads but there just isn't then need for a lot. There are a lot of things that need someone with spare time and a single location to come up with a good 'advancement'. While you can have 'mobile' black smiths, black smithing really needs to start in a fairly permanent location, likely near the raw materials. So now you have location that needs to be fed. Agriculture with excess to store for lean times can help. [Answer] ### What is the pre-society situation like? * The population of our species (and its prey and predators) are roughly such that there is an equilibrium of deaths and births. Thus the population is roughly constant. * Every individual nearly performs the same tasks and needs to spend all its resources (in particular time) to survive. If this weren’t the case, our species would grow until this situation is reached. Until then, there would be no pressure that would cause the establishment of a society or developing technology. ### What changes in a technological society? * Personal resources are better used due to cooperation and specialisation. * Technological advancement. * These efforts will be devoted to improving the birth and death rates, as our species be evolutionary preconditioned to this path. Also, any society that does not go for growth will eventually be consumed by one that does (a survival of the fittest if you so wish). Eventually, our species will have reached a point where it can afford that enough individuals care about things not directly related to survival but instead try to launch stuff into space. ### How does the above translate for humanity? For humans, the main addressable factor controlling the birth and death rates was food. Thus this was the natural first goal of technological and societal advances, which eventually lead to agriculture. Hunting and gathering lost, because it could not be improved that much by cooperation and technology. Also, it came with little means to compensate for an increased impact on the prey species and thus was subject to a natural ecological limit – this is one of the key features of agriculture. It is only recently that we began turning onto other limiting factors such as illnesses. ### How can agriculture be “avoided”? * Make something other than food be the limiting factor that controls the growth of our pre-society species. For example, if the biggest problem is predators, technological and societal advancements would be directed at defending against these predators (and maybe eventually exterminating the predator species). Keep in mind that the limiting factor should be something that technology and society can address. For example, if the main limiting factor is the maximum pregnancy rate, this can only be addressed by evolution. * Change the conditions for agriculture or hunting and gathering such that the latter is the more efficient way to go. For example, there could be no prey species fit for domestication or there are prey species, which can be hunted or gathered much better with certain technological or societal advances (think of fishery). Also, make the prey species such that being preyed upon by our species cannot eventually become a major factor limiting their populations. [Answer] Yes. Basically, necessity is the mother of all invention. If agriculture, which is a technology, never developed it would just mean that there was no need for it. This would imply a food rich society, as you don't need to grow the food and keep it near you if you can just go get it. However, that does not mean that there is nothing else to drive technological advancement. For example, conflict. War has been a huge driving force for technological development in human technology. Take for example: nuclear power being developed because of the atomic bomb. If, in some contrived example, one "country" really likes carrots, but all they have is lettuce, and the carrot kingdom doesn't like the league of lettuce, then the LoL may decide to war it out with the CK with the winner being the one with advanced weaponry. Finally, in your society you would, possibly, have a lot of free time. This means that maybe rather than a food based technological push, they would have a novelty based technological advancement. Since they (possibly) do not have to work at survival, there is some implied boredom. And since boredom is a powerful motivator, they'd probably have a large entertainment inclination. [Answer] I think it is possible. However, societies usually do not pick an arbitrary path through their world. A society given the option to have more food for less work will not ignore the opportunity unless there is an opposing force nudging them away. The opposing force has to ensure there is a easier-cheaper way to do things. The challenge for world building with technology but no agriculture would be setting up reasons why agriculture does not spontaneously invent itself. One solution would be to remove the explosive population growth a culture often has when food is plenty. If food demands never rise to meet food sources, then there is no reason to invent agriculture... creative energies are better spent elsewhere. A culture growing under the oversight of a superior race which punishes agriculture would easily be able to go technological without agriculture. [Answer] Yes- a society could if it has a small population or it has a large (or small) population and totally depends of other societies to supply food. For the small population case, it has to have lot of comparative smart people and determined to develop its people as a resource. Western countries had a lot of people of which only a few produced what was the major inventions and ideas. The proposed society would need a proportionately greater number of those above average people doing useful achievements for technological gain. For the other case, it doesn't matter they can do hunter-gathering or no food production at all if they make goods for export that others want -it doesn't have to technological advanced- they could make simple art or natural products that are highly desired- the mauve ink was highly desired by Romans for their leader's coats. [Answer] I think but to a limited extend and taking very long times as hunting gathering societies do not grow their populations and social organization to the extent organized agricultural societies do. This is due to the fact that ariculture permits large concentrated societies of thosands of individuals in small concentrated areas while hunting gathering societies need many many times the same space and therefore divide their populations in small groups. So it is reasonable to think that any progress in such an small group will take a very long time while a larger group will take much shorter for reasons which are related to the diminished intereaction from individuals and therefore advancements in the complexity of technology. (See [uncontacted groups](https://en.wikipedia.org/wiki/Uncontacted_peoples) on Wikipedia - They lived as small groups of hunter gatherers in the upper Paleolothic). The number of social interactions between individuals with different expertise by unit of time seems to determine technology progress. As population growth is smaller as per availability of resources and there is a smaller number of interactions any technological development may take tens of thousands of years instead than a hundred years. [Answer] ***Accidental Agriculture -OR- An Orc's Farm:*** I read this and tried to think what pressures would lead to a world like this. The solution? Evolution. Not human evolution, but plants and animals. This is somewhat definitional, but the intent for the society isn't to get more food, but to destroy everything else. In such a society (and humans may not be the best species for this scenario), I envision an intelligent apex species that doesn't try to manage agriculture, but instead aggressively destroys everything alive around them that they don't have a use for. If a species like Daleks evolved naturally, this is how they would look. This would be a society of anti-environmentalists. Trees? Good for wood, maybe shade. Stay, if we need wood. Weeds? Kill em. Sheep? Yummy - stay (except when we eat them). Grass? Well, with the sheep around, it's soft on my feet. Stay. Fruit trees? Well, sometimes edible, but not always. Cut down any tree that doesn't have fruit for long enough that I've forgotten how good they are. While the species wouldn't be actively carrying out agriculture, it would apply heavy evolutionary pressure on the life forms in their environment. Plants that evolved traits people liked would survive, while those that didn't would be decimated. Sheep that became gentler would be left to eat after the less desirable sheep, because the society destroys the least desirable things first. Trees with good wood and that grew rapidly would survive. Similarly, there would be pressure on your society for good memory of things that were beneficial. As their civilization developed, those that saw benefit in a wider range of useful things would advance, and these would be settled cultures. Cultures on the edge of civilization would be slash-and-burning everything, making room inadvertently for beneficial plants and animals. There could be some really strange and paradoxical effects on the ecosystem from such a species, but if you think about the pattern of human settlement, is it really very different in the final effect? ]

[Question] [ Humanoids with more than 2 pairs of arms weren't an unknown concept in human culture. From ancient mythology, there are the hundred-armed [Hekatoncheires](http://www.theoi.com/Titan/Hekatonkheires.html) (who have their own thread [here](https://worldbuilding.stackexchange.com/questions/31029/anatomically-correct-hecatoncheires)) and six-armed [Gegenees](http://www.theoi.com/Gigante/GigantesGegenees.html) from Greek myth, the many Hindu deities that were depicted with as many as a thousand arms (such as [Avalokiteśvara](http://mesosyn.com/myth2-2c.jpg)). And from modern times, there's the six-armed [Spiral](https://en.wikipedia.org/wiki/Spiral_(comics)) from the *X-Men* comics... [](https://i.stack.imgur.com/PBUdH.jpg) ... the few times [Spider-Man) ended up growing four extra arms (as one step among many in a gradual mutation into a "Man-Spider"](https://en.wikipedia.org/wiki/Spider-Man)... [](https://i.stack.imgur.com/V7F9J.gif) ... and [the Shokan race from *Mortal Kombat*](http://mortalkombat.wikia.com/wiki/Shokan).[](https://i.stack.imgur.com/o5BD3.jpg) Science considers any real-life instances of this as falling under the umbrella of a medical disorder named "[polymelia](https://en.wikipedia.org/wiki/Polymelia)", which applies to all limbs rather than just arms. Personally, I'll draw upon both that term and the name of the aforementioned Hekatoncheires to coin the terms "polycheires" and "polycheirid" (lit. "many-handed one") for all more-than-two-arms humanoids, with "poly-" being replaced with the appropiate numerical prefix when a particular number of arms is specified (e.g. "tetracheirid" for four arms, "hexacheirid" for six arms, and so on so forth). Now, with that introduction done, we come to the big question: **How does one design an anatomically correct musculoskeletal system for a polycheirid?** What I've managed to gather on the subject makes it seem as if even adding a single extra pair of arms would require significant modification to the human(oid) torso's muscles and bones to be possible. Most importantly, the idea of having two or more arms sprout from the same spot is apparently impossible from an anatomical standpoint, despite it being a somewhat common design approach in modern fiction. Supposing we do figure out the anatomy, what can one expect from the polycheirid in terms of the arms' movement range, ability to apply force, and so on so forth? PS: For the record, I would've added this to the [Anatomically Correct Series](https://worldbuilding.meta.stackexchange.com/questions/2797/anatomically-correct-series/), but the page (and the entire Meta Worldbuilding section) seem unaccessible to me at the moment. [Answer] This is quite a difficult question to answer, for the sake of the bigger picture. You see, the arms require skeletal support (primarily the clavicle and scapula). [](https://i.stack.imgur.com/x5Qpb.jpg) As well as muscular support (all the muscles in the arm and the pectorals on the chest). [](https://i.stack.imgur.com/fCHxM.jpg) So, what you would need, is a skeleton with seemingly redundant bones to support the limbs spread out to ensure it can support this - and you'd have to add more shoulder breadth to allow for the added arms to rest comfortably, unless you plan on making this 'human' walk on all six (or more) limbs. Once you have the bone space, you'll need the [Agonist and Antagonist muscle pairs](https://en.wikipedia.org/wiki/Anatomical_terms_of_muscle#Agonists_and_antagonists) to allow for movement. As with the pectorals, I would advise for this to be placed over the bones to allow for muscle growth as needed. **Problems this will create?** Not exactly something you'll want to ignore, after all. Well, the ones I can come up with (and I'm no biology major), are fat distribution and the health risks this will pose. You see, in humans, we allow for subcutaneous (under the skin) fat layers, but only in certain places, dependent on the dominant hormone of the specimen - testosterone allows for more fat on the belly, oestrogen allows for mammaries, hips, butt, and thighs. Given these muscles will create an issue with at least the testosterone level of the species, excess fat on the tummy is going to be an issue. So how to distribute the fat? I'm not sure. Wolves, for example, keep fat around the vital organs: > > A well-fed wolf stores fat under the skin, around the heart, intestines, kidneys, and bone marrow, particularly during the autumn and winter. > > > As quoted from [this source](https://en.wikipedia.org/wiki/Gray_wolf). But fat, while healthy and needed, is also bad for the specimen in the long-term (heart disease, high cholesterol, etc.), so you want to keep it away from vital organs. How you solve that... well, I guess I'll leave that to you. As an aside, there is an artist on DeviantArt that delves into stuff like this (though more commonly anthropomorphic animals and making them anatomically correct). It might be worth checking [his art](http://russelltuller.deviantart.com/), see if you can get some inspiration. [Answer] I think Burrough's ‘green martians’ were probably one of the better designs for this. E.g. [Tars Tarkus](https://en.wikipedia.org/wiki/Tars_Tarkus). Here are some images from the [2012 cinematic version](https://en.wikipedia.org/wiki/John_Carter_(film)):   Here is Tars on the cover of ‘Gods Of Mars’: [](https://i.stack.imgur.com/Px60Q.jpg) I did not remark the source for this one.  Here's a version which doesn't resemble the original depictions so much as do those from the 2012 movie, but which does show the characteristic structure as I wish to proffer — albeit exaggerated and rather bulky:  Here is one more for sake of variety:  Source: <http://the-first-magelord.deviantart.com/art/Tars-Tarkas-WIP-255092129> My idea has always been this: If you wish to add a pair of extra arms, then simply extend the height of the thorax by addition of clavical units. To reduce the total height, you redistribute and reshape the internal organs to accomodate the new bones — all as compared to the human structure. Of course — and similarly to what was stated in [this answer](https://worldbuilding.stackexchange.com/a/74294/27708), — you will need to provide additional scapulae and sternum on which to anchor the muscles for the arms. Flexibility and strength of any limbs depends, of course, on the mechanical advantages of their leverage in relation to the centers of mass. Well, anyway, it seems that the Green Martian design overcomes the problems with crowding extra arms on a humanoid frame by simply adding height: the original descriptions put them at 10 or so feet (3 m) tall. The curvature of their vertebra would need to be somewhat different from ours — and not simply stretched vertically, nor like two torso stacked one atop the other. The added load atop the bottom vertebra would probably require that they be broader so as to distribute the forces over a larger area, for one thing. Too much curvature at the bottom would be difficult when maintaining an upright posture, so you'd probably sacrifice some flexibility there for better stability and support. Unless you want to go for some vertebrate polypede thing, such an approach does limit you to one additional pair for concern of height. It should be noted that the original description of these Green Martians also allowed them to use their intermediary limbs as legs, if they so need. Thus, their bones were probably not quite like additional shoulders so much as a hybrid between shoulders and hips. Furthermore, note that not all depictions of Burrough's Green Martians have been portrayed so novelly. This one looks like a humanoid, and the lithographer obviously was skilled, but the extra arms are carelessly applied:  [Answer] I think your guy will look something like this, skeletally and muscularly. This is crude, but you can get the picture. The skeletal and muscular changes are necessary to accommodate the extra arms. You CANT just stick them on the side and hope they work. What happens inside the body is what makes the arms work. EDITs: Edit 1 had no Abs, no mid section. This change is more like it. However, as you can see it means he has a disproportionate upper body mass. His legs MIGHT be able to take the weight stress IF they are much more powerful/muscular, but I'm more concerned about his heart, hips and knees than I was before. Initially I was thinking one ribcage that covers the whole area (even though the art makes it look like its two), but now I'm thinking that maybe it *does* need two separate ribcages to buy back some torso mid-section flexibility. So the art might be more accurate than I thought at first. EDIT 3 - Final art: The artwork was bothering me so I decided to put this together, which is the best visual description yet, I think. Just imagine a more powerful lower body than upper body, to carry the weight, and this makes some kinda sense. The greater leg strength might also make him faster. [](https://i.stack.imgur.com/P29CA.jpg) Enjoy! Edit 4: I know I said I was done, but then I had some additional ideas for alternate ways a multi-armed humanoid might work: More arms from the same area: Imagine the extra set of arms from the same region of the upper body, but from behind instead of from the front. So you'd have arms from the chest *and* from the back. The back arms might even be able to reach *backward*! [](https://i.stack.imgur.com/Cm6n7.jpg) [](https://i.stack.imgur.com/kySDr.jpg) And also - Arms at the hips: This came about because I thought maybe too many arms at the shoulders was making the upper body too heavy, and the arms would kind've bump into each other, so... arms at the hips. I don't know how the pelvis inner skeleton would accommodate that, but there is enough space in the area for some changes, so I'm gonna say not IM-possible. If the arms at the hips were smaller than the regular ones, they might not be quite as strong, but they might still be very useful and they wouldn't get in the way of the upper arms. Enjoy! [](https://i.stack.imgur.com/9HASn.jpg) [Answer] Unquestionably the skeletal and musculature foundation for functioning arms would have to be duplicated in some fashion, but there are a lot of variables to consider beyond the human-like arrangement offered in other answers. It's worth noting that 'humanoid' does *not* require an endoskeleton. Take, for example, the Prawns (Poleepkwa) of *District 9*: [](https://i.stack.imgur.com/3FSIjl.jpg) Note the secondary *anterior* arms tucked into the lower thorax. The range of motion and utility of these limbs is certainly less than the primary arms, but they are positioned such that there's little interference between the two sets. A similar arrangement of limbs on a mammalian/endoskeletal frame would likely entail the sternum bifurcating and descending to replace the [costal margin](https://en.wikipedia.org/wiki/Costal_margin) (and secondary scapulae over the false ribs). This would require significant changes to the respiratory system as the lower ribcage and upper abdomen wouldn't be as flexible; [diaphragm-based breathing](https://en.wikipedia.org/wiki/Respiratory_system#Mechanics_of_breathing) might not even be possible without further changes to the ribcage. [Answer] **Four Arm Mutation** I was thinking of something along of an ant where there is a separate abdominal structure between each set of arms. This would would enable flexibility and independent movement whilst giving two fully functional sets of appendages. This would also give sufficient space for pectoral muscles, shoulder blades etc enabling a full range of motion when compared to a stacked arm option. As you can see I have assumed that the abdominal section between each set of arms is reduced when compared to a normal human and I would have thought the four armed variant would be thinner as it would have similar organs to distribute through a larger frame. [](https://i.stack.imgur.com/C1Sb2.jpg) [Answer] **Modify the lower torso** Use modified legs instead of trying to add extra pairs of arms. Crabs' claws are the analogue of hands. Then they have 8 legs in addition. Rather than trying to modify the upper body with all its vital organs, it is comparatively 'easy' to add extra pairs of legs at the lower end of an elongated spine. The upper pairs of legs stick out to the side and of course the 'toes' act as fingers. The muscular support is derived from extra hips. Note: Others have provided similar ideas but I believe that having extra hips instead of extra shoulders is sufficiently different for me to suggest it. [Answer] I really favor the double rib cage atop each other idea. Anatomically, it makes sense to me to contain and protect an extra set of lungs and heart. The idea with an extra abdomen makes me wonder if their would be an extra set of digesting organs? A creature this large could survive and thrive with extra lungs, extra heart, and only one set of digestive tract. (I imagine how many fat people are out there. With much more muscle mass and body to support and only one set of digestive organs, the double rib cage creature would usually be a lean one!) With having extra lungs and an extra heart, there could be some redundancy between them. Extra circulation between the hearts could mean that they could help perfuse each other. Heart-failure would nearly be a thing of the past. Hyper-oxygenation of blood could mean that this creature’s blood could be thinner and it could blow out more CO2 with so much lung surface-area. The endurance of such a creature would be incredible! Looking at the diagram of the double rib cage rendering, I can imagine an extra left lung lobe, an extra left heart (above) and an extra two right lung lobes as well. I would surmise that the trachea would split (either anteriorly or dorsally) at the upper carina, and terminate to the lower lung lobes at a lower carina. Should a creature aspirate (breath in liquid content) it would be ‘caught’ by the upper-lungs’ right lower lobe. The redundancy of having the other lobes would mean the creature would more easily survive such an injury. The benefits of having extra lung lobes and an extra heart almost outweigh the benefit of having extra arms. As a nurse, I am imagining an extra thymus could provide immunological benefits as well. This creature’s immune system could remember many more antigens than our own. Its immunity would be stronger as well. Perhaps in another hundred years, gene editing technology could produce such a superior creature. [Answer] It's really not that hard. Just stop having ribs and have a solid torso bone with 6 holes. Above for head below for abdomen and 2 on either side. The upper torso arm hole needs to be a bit wider then then the lower. A few inches so the upper arm can hang straight down flush with the lower arm. No need for scapula's. In a human skeleton the arm is attached at the shoulder in a very complicated ball and socket joint. Without the clavicle the joint can bend in half making someone look about 1/3rd as thick as normal. Look up people without clavicles to get a visual understanding. Having the angled end of the humorous firmly attached inside the torso bone can allow for a relatively simple hinge joint and pivot joint for the same range of motion. Without additional bulk the upper arms would be stronger then the lower. In my design I used a pneumatic circulatory system so the lungs are just pumps instead of the sole source of oxygen through the body. Blood is a thick viscous fluid that does not transport oxygen, just nutrients, although it can store oxygen. Making the lungs bigger for a bulkier torso can maintain a normal circulatory and respiratory system. Fair note. I don't care about evolution. I prefer the freedom of design. It doesn't matter if it's art design, a moving creature in a digital simulation, or genetic engineering. There is no reason whatsoever to limit ones self to what is seen in nature. Evolution is a bunch of rotting duct tape. So long as a life form follows the laws of physics and chemistry, and it's cells can store and transmit data, then it can exist. If your looking for an evolutionarily plausible answer then I can't help you. Good luck with your world building. ]

[Question] [ *Deer bound across broken pavement, eating from bushes growing were there were once cars beneath trees where there were once light posts. Busses have been replaced by bears, rumbling slowly down ancient, abandoned avenues and wolves build dens in the uncollapsed portions of what were once subways.* The inexorable process of nature reclaiming a city is a staple of post-apocalyptic sci-fi, but how long would it actually take? Naturally, it's going to depend on the environment, so for this question, I'm asking about New York City, or at least a city very similar to New York. For a large, built-up, concrete covered city like New York, how long would it take for native plants and animals to re-colonize what is now a city? This doesn't have to mean that all traces of humans are gone, only that plants and animals have sufficiently rebounded to create a mature forest ecosystem in what was previously downtown. [Answer] You're in luck. This question has been investigated quite thoroughly by Alan Weisman in his book *The World Without Us*. The short story is that within 5 years, it'll start looking like a forest, within 20 years, the skyscrapers will start coming down, and within 200 years, the place will have been fully colonized by trees. Weisman's premise is that humanity suddenly disappears, and whatever it is that causes this doesn't do any collateral damage (like fallout or dead bodies everywhere, just empty streets). He starts the thought experiment with New York, specifically Manhattan, and the first news is bad. Manhattan basically requires 24/7 attention to keep 13 million gallons of groundwater out of its subway tunnels. The minute humans disappear, the power goes off, and the foundations of all those skyscrapers start eroding: > Even if it weren’t raining, with subway pumps stilled, that would take no more than a couple of days, they estimate. At that point, water would start sluicing away soil under the pavement. Before long, streets start to crater. With no one unclogging sewers, some new watercourses form on the surface. Others appear suddenly as waterlogged subway ceilings collapse. **Within 20 years**, the water-soaked steel columns that support the street above the East Side’s 4, 5, and 6 trains corrode and buckle. As Lexington Avenue caves in, it becomes a river. emphasis added Before that, the freeze/thaw cycle would already have destroyed most pavements and asphalt, so plants would have no trouble colonizing the streets. Weisman estimates that withing **five years**, [Ailanthus](http://en.wikipedia.org/wiki/Ailanthus) trees are growing all over town, ruining the streets and sewers with their roots. After that first violence, it will take a long time for the final signs of humanity to be eroded. Many small objects will last for thousands centuries. We'll have to wait for a glacier to grind it all to a pulp: > Even if the Statue of Liberty ends up at the bottom of the harbor, Appelbaum says, its form will remain intact indefinitely, albeit somewhat chemically altered and possibly encased in barnacles. That might be the safest place for it, because at some point thousands of years hence, any stone walls still standing—maybe chunks of St. Paul’s Chapel across from the World Trade Center, built in 1766 from Manhattan’s own hard schist—must finally fall. Three times in the past 100,000 years, glaciers have scraped New York clean. Unless humankind’s Faustian affair with carbon fuels ends up tipping the atmosphere past the point of no return, and runaway global warming transfigures Earth into Venus, at some unknown date glaciers will do so again. The mature beech-oak-ash-ailanthus forest will be mowed down. The four giant mounds of entombed garbage at the Fresh Kills landfill on Staten Island will be flattened, their vast accumulation of stubborn PVC plastic and of one of the most durable human creations of all—glass—ground to powder. So in the end, it all depends on your definition of what a forest is. The process would start immediately. It would look post-apocalyptic in a few years, and more like a forest than a city within decades. [Answer] We have a modern city to look at for guidance: Pripyat, Ukraine.  Image by [2wid on flikr](https://www.flickr.com/photos/2wid/6261161349/in/photolist-bfSTjz-duo2Si-adcYvZ-dx2wnL-dyjsz5-erLk5L-dkScaB-78jgmt-agrVqG-naVZWa-pVHYE9-8JhK2U-s7cM1h-ayFxEg-aLsFXt-nbuE8A-njPgNQ-axh68K-nk9pym-afLAiL-92xaGn-5qLHjW-agrVds-6N9kKC-8JhJL7-5jbGCE-7WMKB6-7LaX1V-a97M8x-8JA8FQ-8HWCdo-8JqMFd-8QgZtJ-8JhKgw-5Bi8ph-a9aWow-6Ghkma-9jHgUV-8QdUAp-8AW5n1-9A4w27-8JqMBN-MR1mA-MR7ZP-9T8gU7-6izwvk-4WtxLC-aJto54-daGGUk-hntAKE). More [images](https://www.flickr.com/search/?q=prypiat). We're about 30 years out from the sudden abandonment of the city. That's a nice beginning of a forest, but it's just a beginning. In Vermont, where I live, the forests have regrown significantly over the last century since the sheep ranching craze died out. Still, most of the forests don't have the maturity of the older growth regions. A young forest features young trees that are relatively dense, while older growth areas feature mature (100+ year old) trees with clear space around them and a mix of tree ages. Vermont's forests are about 150 years old, and now becoming a thriving ecosystem again. But that are wasn't covered with asphalt - the ground itself was left fairly intact. You can find some interesting before-after photos [here on UVM's site, check out the presentations ForestsVT and Forests2.](http://www.uvm.edu/landscape/learn/Downloads/scrapbooks/) The forest has changed significantly, and there was a ready source of seed and wildlife nearby. I would guess that for a bigger, better built city like NYC, you'd need more time, closer to 200 years.  Vermont Statehouse, 1870, clearcut surroundings.  Vermont Statehouse, 2012, both from Wikipedia. Another avenue to research that I think supports a 200 year timeline is the reforestation of Mt. Saint Helens'. [30 years on, with human help](http://www.americanforests.org/blog/geology-vs-ecology/) and it's still far from what it was, though many of the animals have returned. [Answer] So essentially you're asking how long it takes to get from a clean slate to a full forest. I hate when people answer like this, but, it just depends. This [article](http://hvo.wr.usgs.gov/volcanowatch/archive/1999/99_01_21.html) speculates that a forest could develop in wet regions of Hawaii in less than 150 years. Calculating exactly how long it would take for New York City to get to an unspecified point of primary succession would be extremely difficult. My final answer would be somewhere between 75-125 years, though NYC is surrounded by plenty of foliage that may expedite this process! [Answer] 30 - 50 years. I'm basing this off of actual abandoned modern cities. The two examples that come to mind right away are Tchernobyl(1986) and Fukushima(2012). Both cities evacuated in response to a nuclear incident. << A very efficient deterrent to human presence. Both cities are smaller than New York and it is also an island which might or might not hinder the return of wildlife, however if you look up present pictures of both cities you'll see that they are both already well underway of being entirely overrun by nature. (Especially Tchernobyl) I didn't post any link because honestly google image ('tchernobyl today' i.e.) is your best bet. EDIT: From there, depends on how old you want your forest to be. (And how ruined you want the buildings to look - but anywhere it freezes in the winter, that doesn't take a long time. Frost and Thaw in spring are evil to anything artificial. ]

[Question] [ Satyrs, fauns, pan, and even the devil are commonly depicted as humanoid bipeds with goatlike unguligrade hooves for feet. However, common as such beings may be in fantasy and mythology, I have been unable to unearth any paleontological evidence that any form of biped has ever had hoof-like feet. There are, of course, examples of digitigrade bipeds, like kangaroos and ostriches, but they all have one common trait in common with one another: toes. That is to say, they all walk on their intermediate tarsals, leaving an additional tarsal at the end for balance and support. Hoofed, unguligrade animals don't have this sort of support, walking instead only on the distal-most tarsal in the foot. For a quadruped, this isn't an issue, as there are plenty of other limbs to help maintain balance, but what about for a biped? Could a hoofed, unguligrade biped actually evolve, or can they only exist in fairy tales? [](https://i.stack.imgur.com/eHvfo.jpg) [Answer] ## Absolutely The digitigrade leg formation (with the foot acting a a third joint) was scientifically explained [here](https://worldbuilding.stackexchange.com/questions/40584/humanoids-with-digitigrade-legs), answers there may be useful to you, especially regarding balance. But you ask for unguligrade, where to toes act as a foot and the foot acts as a third joint. Keep in mind that, while when we think of unguligrades, we think of goats, cows or horses. But remember that rhinos, hippos and elephants are also all unguligrades, though the lack of mobility in their feet cause the same problem. They even make the problem of stability even worse.(Try pushing against a wall with your arm, one straight and one slightly bent; which one buckles first? As you can imagine, the straighter, the more stable) The evolution aspect can be explained similar to primate evolution. All that is need is for your unguligrade quadrupeds eat fruit and scavenge meat and not grass or leaves. These omnivorous "proto-fauns", as I'll call them, would benefit from getting the most fruit and meat, but lets say instead of evolving longer necks (a la giraffe), as longer necks would actually be bad for the meat eating part of the omnivorous diet, they evolve hooves with multiple toes. Like a [Mesonychid](https://en.wikipedia.org/wiki/Mesonychid), used for [hunting](https://worldbuilding.stackexchange.com/questions/25999/hoofed-carnivores) and for better gripping, allowing them to get higher in the tree. [](https://i.stack.imgur.com/1pCMM.png) Recently I have found an artist known as [Russell Tuller](http://russelltuller.deviantart.com/gallery/), who works to create anatomically realistic anthropomorphic animals people. Primarily Wolves and Hooved animals. This design can be applied to your question; [](http://russelltuller.deviantart.com/art/Cervine-Hand-Anatomy-Study-547090418) Luckily unlike humans we do not have to explain why they left the jungles as they started in the Savannah already as our Proto-faun. At this point they would be more like chimps, not purely biped but close. Again we will introduce a section of human evolution here, they become purely bipedal unguligrade style legs in order to become more efficient long distance runner and you're done. For these legs, you would want two features to separate it from the upper limbs 1. The toes become more splayed in order to take the weight, appearing more like digitigrade than unguligrade (though this is only an illusion of appearance). Similar to hand design seen above, but with much shorter digits. 2. The legs need to be as straight as possible while stile being unguligrade style. This allows them to have all the advantages of unguligrade while still having the long distance efficiency of humans (though not **as** efficient). An example would be similar to how a deer looks when standing. [](https://i.stack.imgur.com/ue8Ai.jpg) Now the only problem to deal with is making the upper body more human. There are two things we need to consider here, 1. The fingers. It is unlikely and hopeless to believe that a perfect human hang could even, but a psudeo-hand made from the hoof can exist as pointed out above. This *"hand"* would have two fingers and two thumbs, ending in small hooves. To make the classic satyr, we want to remove the hoof and have pure skin fingertips. This can only be justified by saying that hoof fingertips are not necessary and thus they either stay as a result of genetic drift or they dispensary as a waste of resources. 2. The face. If you want a 100% pure human face, you're going to be out of luck, you are at best going to have a equine face that gets progressively flatter, but a primates face is really out of the ball park. Over a few million years, you can get close though. Artist [JayRock](http://jayrockin.tumblr.com/tagged/centaur) on Tumblr has a good centaur design whose face seems close to what you might be able to eventually get, [](https://i.stack.imgur.com/znFVU.png) [Answer] The biggest problem with standing on two legs is keeping your balance when standing still. We humans solve this with our feet. Try standing still without leaning on something and pay attention to what the muscles in your feet are doing. You are always subconsciously adjusting your weight distribution along your feet to keep your balance. This is also why all bipedal creatures you found have toes, they are an essential part of that balance-keeping. The absence is seen with people walking on stilts. Since they can't control their weight distribution along their feet, they have to keep their balance by constantly taking steps. A person on stilts never stands still unless holding onto something else for balance, if they try then they fall over pretty quickly. As for having a bipedal hooved creature, I see two solutions: modifying the hooves to have the equivalent of toes, or just not standing still. If the hooves are split and the different parts can shift around, this can be used as some kinds of makeshift toes to keep balance. See TrEs-2b's answer for how this might look, though perhaps not as extreme. If you instead want to keep a solid hoof, you could have them always be on the move while standing up. As soon as they stop they either sit down like in your picture or grab on to something for balance (perhaps each other). They would have to have leg muscles like springs to be able to shift between sitting and walking constantly and quickly, but it's not too far-fetched. [Answer] There are deer species in Africa that stand up and stretch their forelegs out, they always looked like they might evolve further someday: [](https://i.stack.imgur.com/kWanF.png) [Answer] # No Obligate bipedal ungulates are extremely unlikely to occur (evolve) naturally for a very clear reason. # The Problem Of Speed Goats, deer and other such medium sized ungulates can stand (and also walk for short distances) on two legs. They usually do this when trying to reach higher foliage of trees. Several species of mountain goat also tend to get bipedal during male head-butting competitions. However, there is no exception to the rule that bipedal ungulates walk *very* slowly on two legs as compared to their speed on four legs. You would **never** see a deer running for its life on two legs. But what about the ungulates which don't need to run in front of predators? Buffaloes and bison; these large ungulates use their massive heads for their defense. When standing on two legs, they would be unable to use their heads for defense and they would also be exposing their vulnerable underbellies to the predators. No, that is not going to work. Some might argue that once ungulates turn obligate bipeds, their physiology can evolve for higher speeds. That is not a valid argument. In order to evolve for higher speeds, these ungulates must *survive* long enough (a few hundred thousand years at least) to first become compulsory bipeds. Currently the life expectancy of a compulsory bipedal deer is less than a day. It does not seem likely that tigers, cheetahs and leopards would cherish the sight of a clumsy, bipedal deer enough to not invite it *on* their dinner tables. The morphological changes from quadruped to biped stance are immense and include (but not limited to), changes in the backbone, in the skull features (specially where the brain connects to the spinal cord), in the leg joints, in the heel joints, in the shoulder joints and also in teeth and jaw structure. # Why Humans Survived The Change And Ungulates Wouldn't? We humans made the successful transition from quadrupedal to bipedal gait but ungulates cannot. The simple reason is that we humans never relied on speed to evade (or defeat) predators. Since the time of Sahelanthropus (7 million years) to modern humans (0.2 million years ago), we have always relied on our superior brains, dexterity of our hands and supreme communication skills for survival. On the contrary, ungulates have neither of these. Their mental skills are by no means any superior to their predators, they cannot even pick up a twig from the ground with their *hands* and they cannot even count from 1 to 5. During our early evolution, when a sabertooth attacked our great great forefathers, it only took them one vertical leap and some quick hand motions to reach the shelter of the branches. No such option is (or was) available to the ungulates. They would not able to make it. Remember the [terror birds](http://www.prehistoric-wildlife.com/articles/terror-birds-of-the-phorusrhacidae.html) of South America? They were bipedal and they were much better runners (like most flightless birds) than humans (we have evolved completely for bipedal gait and our running speeds are higher than any and all other bipedal mammals). Yet those awesome carnivorous birds were [exterminated by mammalian carnivores](https://en.wikipedia.org/wiki/Phorusrhacidae) of North America. How much prayer can a bipedal deer have against a ravenous cheetah? # The Incentive Of Height And Why It Would Not Work Another (purely theoretical) argument for evolution of compulsory bipedal ungulates can be that of height and reach. Clearly, a bipedal deer would have greater reach than its quadrupedal cousin. In times of famine this could turn into the decisive variable between starvation and survival. If the famine lasted for a long time, a species of obligate bipedal ungulate could evolve. This assumption is based on faulty logic. First, our planet has been through some seriously severe famines during its history and none of them has resulted in bipedal ungulates. Second, *most* ungulates are grass-eaters, not foliage-eaters and their diets primarily consist of grass species. Third, even if somehow some species of bipedal ungulates do evolve, they would be quickly devoured to extinction (due to slow speeds) by the carnivores once the famine ends and carnivorous populations re-establish. Instead of bipedalism, mammalian evolution for longer reach has always resulted in longer necks. The giraffe and camel are the best examples for this. # Conclusion No, bipedalism is *extremely* unlikely (we never say never in science) to evolve or have evolved during the history of mammals. The only time it *could* have evolved and remained was during the origin of mammals, some 221 million years ago. However, once the general mammalian body shape was established firmly by late Jurassic, the transition from quadrupedal to bipedal gait was too risky and dangerous (not to forget without any real rewards or incentives) for any mammalian group. Humans were able to successfully transition from arboreal to obligate bipedal lifestyle because we never relied on speed for survival. We had higher intellect, dexterous hands and superb communication skills to help us win against predators. Current (or prehistoric) ungulates never had these abilities to bail them out against predators, so they cannot survive the transition. [Answer] This may be a bit late but I do feel the need to mention the fact that this is definitely possible, because it has already happened! Slijper's goat was born with no fore limbs. It seems to have been well able to walk and run around as it pleased. It died accidentally (apparently) at a year old and Slijper dissected it. It showed a fascinating array of variations in physiology compared to the usual quadrapedal goat, simply due to developmental plasticity. I'd suggest you look into it yourself for more details rather than me just copying and reposting information. If a normally quadrapedal animal can adapt in such a manner through no real genetic change, I think an animal that is actually adapted to bipedality through evolution is entirely plausible. The original scientific paper referencing this goat is as follows, though I have unfortunately been unable to find it online anywhere myself. Most frustrating. Slijper E. J. 1942. Biologic-anatomical investigations on the bipedal gait and upright posture in mammals, with special reference to a little goat, born without forelegs. *Proceedings of the* *Koninklijke Nederlandse Akademie Van Wetenschappen* 45, 288-295, 407-415. [Answer] Simians evolved arms and hands to facilitate brachiating and although humans can still climb we've clearly developed away from our branch swinging roots. Now I have trouble imagining cloven feet being useful in the trees but in thick underbrush having feet that can penetrate the foliage and be retracted without becoming entangled would be advantageous. So I imagine something like a faun would be the product of a densely forested area with thick underbrush, perhaps even using its hooves like spikes to assist in vertical climbing. ]

[Question] [ If there was a life-supporting planet that was cubical rather than spherical, would it be feasible for there to be a unique but similar civilisation on each 'Plane'? I know that cube planets are impossible for a whole bunch of reasons involving centrifugal force, gravity and such, but in this case I want to try and justify it. Planet Box was originally a Death Star-like megastructure created by an advanced alien race, shaped like a giant cube. The original alien race long since died out, but the megastructure remained. After a few billion years floating around in space and a lot of interstellar collisions, the megastructure fell into an orbit and became a planet in its own right. However, the original metal frame of the megastructure remains sturdy enough to support the planet in a vaguely-square shape, despite the orbital forces that try to flatten it into a sphere. Planet Box orbits in a habitable zone around a sun, with a suitable gravity mass. It has rocks, water, and forests growing on each of its Faces. After a while, from the primordial soup, life and civilisation arise. The native Box People all live on a flat surface. Of course, the Box People don't think that their world flat. Gravity, being what it is, is noticeably stronger at the centre of each Plane than at outskirts. Their world doesn't appear flat to them - because of the change in gravity with landscape, their perception is that it goes uphill. When you're on the edges, rain falls at an angle. To the native Box People, they would instead think that they are living in the bottom of a bowl. See this post for where I got concept come from: <https://gizmodo.com/how-gravity-would-be-different-if-the-world-were-a-cube-1492018223> All of the water and oceans pool in the very middle of the face. The edges of the Box World rise into unpassable six mountains that go higher than the atmosphere. On each Plane, there's a circle of livable terrain surrounding a huge ocean where life can survive. This is my (very high-quality) sketch of how I imagine the geography of each Plane: [](https://i.stack.imgur.com/DwrpN.jpg) And, because Box World is a cube, there are 6 separate Planes. Life on each Plane is completely isolated - none of the native civilisations would have any idea about the other 5 sharing their planet. To them, the flat earth theory is just a crazy idea proposed by radical astronomers, when anyone sensible knows that the world is concaved. Absent of space travel, there would be no easy way for them to know otherwise. So, two questions, both related to each other: * Would life on a cube-shaped planet be broadly feasible (i.e. allowing an acceptable dollop of handwavium)? * Would it ever be possible for a civilisation on one Plane to encounter life from another? No space travel allowed. Even though the world is square and the corners rise higher than the atmosphere, would it be possible (with a great deal of difficulty) for any of the Box People to cross onto a different face? Could there conceivably be a channel between Planes that's low enough that someone might endure the high altitude and mountain climb across? Or could there be a deep enough tunnel that they end up crossing the edge underground to reach a different side? Planet Box doesn't have to be strict cube - it could be a cube with rounded edges. It does, however, have to have six distinct faces. Edit: This question is different from the linked previous one in the comments as it asks more specifically about travel and possible interaction between civilisations on different faces of the cube. [Answer] > > would it be feasible for there to be a unique but similar civilisation on each 'Plane'? > > > Define "similar". Given how thoroughly you've cut off each face, there's no guarantee that inhabitants of different faces would have the same set of amino acids, let alone anything more complex in common. You'd need to set up some means for information (cultural or biological) to be shared between faces if you wanted them to be similar, or handwave some slightly dubious convergent evolution. > > Their world doesn't appear flat to them - because of the change in gravity with landscape, their perception is that it goes uphill > > > The world will be visibly mostly flat from high points on the surface (perhaps via the first hot-air balloon flights). I'm pretty certain that surveying work will reveal the world to be flat. The oceans will curve slightly, of course, but not necessarily as much as they do on Earth so you might get much longer lines of sight. Long distance navigation is likely to be much easier as a result, but it will also be obvious that "down" is a slightly different direction as you move around on the ocean's surface. As you ascend the rim mountain ranges, you might *feel* like you're climbing the edge of a bowl but you'll clearly be able to see the world is flat. You should also be able to get some obvious astronomical cues... if you lived in a bowl, the stars that are visible over the rim from one location will be different from those visible from a distant location. Determining the *actual* shape of cubeworld without space travel will be hard, but if a correct theory of gravity arises the groundwork will be laid for the discovery of the shape. Seismology might also be interesting, if there *is* any sort of tectonic or volcanic acivity, natural or otherwise. Seismic events on other faces, like asteroid impacts or nuclear weapon tests would be detectable, and could be established to be "beyond the edge". The exact seismological nature of the world might be too confusing and complex to be easily established Also, did cubeworld pick up any moons? Those will be major telltales of the true size of the world, and observing them coming in an out of the shadow cast by the sun will also give big hints. Astronomers may also eventually be able to tell that other planets exist, and they have non-planar shapes. Those super-high-altitude mountains would be wonderful places to build telescopes... Note that over the billions of years the cubeworld spent in flight, erosion, deposition and accretion of matter from other sources (like asteroids or comets) will tend to concentrate mass towards the centres of each plane, and pull it away from the mountain ranges, as gravity attempts to pull your weirdly-shaped object into a nice neat sphere. Your central oceans may in fact be more ring-like than circle-like. The underlying framework of the world might not be moveable in this way, but it might get laid bare at the summit ridgelines of the edge mountains. You might need other handwavium mechanisms to re-face your cube (which might also help with other things, like carbon cycling). > > Would it ever be possible for a civilisation on one Plane to encounter life from another? No space travel allowed. > > > Space travel is a rather different thing, if you live on a world with atmosphere-piercing mountains. It is conceivable that you could build a habitable outpost up there with technology closer to the Victorian age than the space age. You certainly wouldn't need rocketry. Once you can make submarines, you have the basic skills to make something that can operate in uninhabitably thin atmosphere, too. Building a railway into the sky will be a challenging enterprise, but one a hell of a lot easier than actual space travel. > > Would life on a cube-shaped planet be broadly feasible (i.e. allowing an acceptable dollop of handwavium)? > > > Could it *evolve* there? Might be tricky... cubeworld seems unlikely to have any kind of plate tectonics, and absent crust recycling you can end up with quite nutrient-poor areas which don't lend themselves to life (see Australia's vast internal deserts). Without some means to generate a magnetosphere you risk having your atmosphere be blown away by the solar wind, and harsh levels of surface radiation aren't life-friendly. Other fictional settings with constructed worlds have complex automated mechanisms for handling these things. This might be part of the handwavium you need. Just because life arose on one face doesn't mean it would arise independently on another, depending on how common biogenesis is in your universe. You might need some other way of sharing organisms between faces, which might just be whatever event seeded your cubeworld with life in the first place, if it didn't evolve in-situ. > > Could there conceivably be a channel between Planes that's low enough that someone might endure the high altitude and mountain climb across? Or could there be a deep enough tunnel that they end up crossing the edge underground to reach a different side? > > > You're the author. You get to decide the answers to those questions. [Answer] **They meet in the interior.** [](https://i.stack.imgur.com/GbS0v.jpg) [source](http://themetapicture.com/scary-hole-in-monticello-california/) This world is an ancient construct. Very durable, yes, but a construct of nonmagical materials nonetheless. The sturdy metal frame is holding up fine but the skin is a different matter - light, water and life are tough on all materials. Or a meteorite might make it down. The skin may develop a hole. Exactly how this hole manifests depends on what is above and below. There might be substantial pressure differences and these might change over time, resulting in winds blowing in and out. Water might drain through. I could imagine that the original construct had the life and atmosphere on the outside as a "green roof" of sorts - an ecological buffer for the underlying construct or an art project or both. Really the creators had stuff going on inside. Your intelligent life forms might venture down through the hole and realize what was inside. If it were humans they would no doubt start salvaging materials and tech and bringing that stuff topside. Similar ventures occurring on the other planes of the cubes would give an opportunity for different civilizations to meet in the ancient alien underworlds of their planet. [Answer] The reason it's impossible in real life isn't about centrifugal force but totally about the gravity of the object itself. There aren't any materials strong enough to hold up the corners against the force of gravity. And we know how strong chemical bonds are, so it can't be some "ordinary undiscovered material". You need something almost magically strong, like scrith from Larry Niven's *Ringworld*. And then erosion will scrape off all the rock and leave this boring adamantine material exposed that you presumably can't drill into to build your railroad to the top of the corner. Perhaps there could be a dynamic tectonic-like process that constantly maintains the cube shape over geologic timescales. Maybe the creators of this object set the process up for their own reasons. Then you wouldn't have the problem of all the dirt and impacting asteroids piling up in the center of each face as Starfish Prime describes. (Actually I see I am just restating Starfish Prime's proposal of "handwavium mechanisms to re-face your cube." So consider this an affirmation.) I think the biggest challenge is that, at the radius you drew the ocean, the slope of the land relative to gravity will be pretty steep. Erosion will be pretty fast even with tectonic restoration. I think there are lots of ways you can make this work. You can just make the cube be the one impossible thing in your story and make no attempt to explain it. All the fun would be in the consequences for life on the object, focusing more on the geometry of separation than on the physics. Or you can address all of the issues of erosion and hydrostatic equilibrium head on, and make that be part of the entertainment. There are other options too. [Answer] They would probably not even *think* that there is anything "beyond" the Wall Mountains. With time, however, they would develop curiosity about what really *is* there. How does the world end? So they start climbing, and constructing pressurised way stations that allow them to rise ever higher. At a certain point they discover that the ground becomes brittle, fragile, and *beneath* the ground there is a surface of a very hard metal. For a while this reinforces the old religion that sees the World as the Cup of God. The world is actually the solid deposit on the inside of an enormous metal cup. Then they climb again. Two things can now happen. One: they reach the border, and from there they see *another world*. Two: the metal surface is not smooth but sometimes presents hollows, or protrusions - metal trees, pointing out like lances or flag antennas towards the stars; large blisters, long cylinders and other shapes pointing every which way. And sometimes, *doors*. Some so large and round that they seem dried mountain lakes, and some small enough that they are clearly recognizable as doors, except doors that lead *into* the ground. [Answer] **I call shenanigans on your initial premise: that they wouldn't figure out the planet was cubical until they had spaceflight. I'd predict they'd figure it out around 300-200 BC.** Why? The greeks knew the world was round in 400-300 BC, but one of the biggest ways they knew was the fact that, on the same midday at different locations, one location held the sun directly overhead (its reflection could be seen at the bottom of wells) while another was always at an angle. Not only did the greeks know the earth was spherical, but this 'different angle' issue let Eratosthenes actually calculate the approximate radius of the earth in 240 BC. Well, the people on Cube6 are going to have the same sorts of data points that are going to let them very quickly figure out that they *aren't* on a concave world like you're expecting: * The sun shines down at the exact same angle at all points on the cube face, disproving a concaved planet (similar to how on earth, it *not* being the same angle disproved a flat planar planet.) * Ships sailing off into the distance don't pull 'up' vertically (similar to how on earth, ships sail 'down' over the horizon, which was the first evidence the greeks had for a spherical planet, and why ships have a crow's nest.) * The exact same constellations are visible on all places on the cube face, disproving angle differences between locations (similar to how on earth, *different* constellations at different latitudes proved there was a curve.) And, well, that's a bit of a problem for a species that's both curious and voraciously intelligent. Because if you plopped a renaissance society in that sort of situation, you can darned well bet they're going to use a lot of ingenuity to figure out an avenue of exploration. [Answer] It's not only possible that civilizations on each face would be different, even the atmospheres and biospheres would be different. You basically have 6 separate bowl-shaped planets. One could be a cold, dead vacuum while an adjacent face is a lush jungle, and a third is a Venus-like hell. [Answer] Depending on the original purpose of the cube, there may have been plenty of organic compounds on the inside, originally. Those may very well have leaked out to the surfaces (either due to damage, exposing those compounds, or through deliberate design like exhaust vents or waste). That would give early life a common basis to grow from, which increases the chances that even separately evolved life would at least be "compatible". Although without significantly evolved creatures finding their way across the edges, life is going to be significantly different. I agree with others about early life getting over the edges, but it would be more straight forward to just have access tunnels that run between edges, that have been exposed over the history of the cube. The tunnels could be rare, and given the vastness and inhospitably of the mountainous regions, they'd be hard to discover, but wildlife would likely discover it and spread as well. Another likely possibility would be for asteroids to have clipped off some of the edges and peaks. Big sticky-outy things are likely to get hit! That could easily provide narrow passages between edges, if desired, which also could be difficult to find, but accessible once found. It's unlikely you'd end up with anything human-like regardless, without some critical bit of cube-builder intervention or cause. But if near-human ancestors (for example, they had just evolved to the point where culture was important, primitive tools, very start of language) somehow found those passages between regions, their evolutionary histories would be radically different. Some would have died out, maybe only surviving for a few hundred generations. Some would have thrived, some might have not QUITE gotten over the cultural/evolutionary curve, and stayed as basically advanced apes. As others have said, the environments could be quite different side to side (also depending on the axis of spin relative to the orbital plane! And also very dependent on exactly how/when organic transfer happened between the sides. If there happens to be a moon, that makes it much more obvious that the planet is cubical, due to a possible shadow. Also, there might be some interesting atmospheric affects going on with bending of sunlight or starlight due to the cube world. I'd probably need to draw some diagrams to figure that out. [Answer] ## Short answer: World-wide interaction at some point wouldn't be much different from what we have on Earth in my opinion ## Long answer: What's the size/density of it? Earth size/gravity? Atmosphere like ours? The edges of a cubic planet would feel like enormous mountains, possibly even higher than the Karman line (the atmosphere is a fluid, so it will effectively look like a dome from afar) so it is safe to assume that (specially animal) life would most likely evolve very differently in different faces. Possibly not even existing at all in some. Now, theoretically, at some point a civilization would have tech capable of getting to the other faces. It will be to their people what the discovery of the Americas looked like, but certainly with very different life (if at all). I think it would be very difficult that different species would evolve to this level at the same time on each face, so the first to get the tech would conquer the other ones and over time, you would have 6 "continents" politically controlled by different cultures of the same species. I mean, after a real long time. At some point, you would have commercial inter-face travel with BFR-like rockets. The world would evolve into interplanetary travel much earlier than we did because of their necessity of building rockets just to travel say from the USA do England. But overall, a civilization at the same civilization level as us would make it pretty Earth-like international interactions, just with more rockets and less planes Edit: the thing with the atmosphere, sure it could be enough to cover all edges, but that would put the atmospheric pressure at extreme levels at sea level. Life could possibly thrive in such an environment, but that would still mean that the pressure at the edges would be so low that they will still need pressurized equipment to go from one face to another And yeah, tunnels aren't an option. Rockets are much faster, safer and cheaper in this case [Answer] Storms and winds will toss bacteria, seeds and spores high enough to get over the ridges separating the faces, so the plant biology will be largely the same. Since the plants are the same, there will need to be some similarity between the animals, since they have to eat the plants. The odd shape will lead to powerful jet streams connecting the atmosphere over each face. Powerful storms such as tornadic waterspouts will occasionally suck up fish and amphibian eggs from one face and deposit them on the others, meaning they will share some similar marine life. Now add in the dynamics of warfare. Whoever has the high ground can fire down on people trying to storm their fortress. Or losers can retreat there until they can launch a counterattack. Nations will build ever higher forts, learn how to build oxygen masks, and steadily get closer to the top of the ridge, until one face is able to get to the top and climb over. Eventually, they build pressurized monorails to travel between faces. They can attach the rails to punctures in the skin caused by meteor strikes. Interesting article on the physics: <https://gizmodo.com/how-gravity-would-be-different-if-the-world-were-a-cube-1492018223> Gravity lines in most places do not point straight toward the center, unlike earth. That would act to make the climb seem less steep at first if you try to climb toward the edges. [Answer] With your naive model, what you would have is a spherical world with a cube-frame of adamant "walls" or "mountains" sticking out of it. On each face, there would be a semi-hemisphere "chord" of a sphere pressed against the adamant. It would sort with heavier stuff (rock) mostly on the bottom, and water mostly on the top. Matter stuck to the adamnt "sticking out" parts would fall towards the semi-hemisphere and eventually erode down to being mostly round-ish. If you want to avoid this, you have to mess with gravity. In two dimensions: ``` +---------------+ | * * * * * * * | | * * | | * * | | * * | | * * | | * * | | * * | | * * * * * * * | +---------------+ ``` The adamant "box" is the outer lines. Suspended within it are a set of black holes, arranged not spherically but rather in a square (or in 3 dimensions, cube) shape. This violates the assumptions that make gravity spherically symmetric. To make things simple, we could even do this: ``` +---------------+ | * * | | | | | | | | | | | | | | * * | +---------------+ ``` and place the massive singularities only at the corners. The math to work out the gravitational potential along a "face" of the cube will now be tractable. For a first approximation do two: ``` +--------------+ | * * | ``` we have the free parameters of the "depth" of the singularity and the distance between them. Suppose they are at depth 1, and at the surface "right above them" they produce 1 unit of gravity, and they are 2 distance units apart. Then at the `+` there is 70% gravity at a 45 degree angle. At the midpoint of the side, there is 1 g strait down. Directly above the `*` there is 1 g down plus a 1/sqrt(3) component at a 2:1 gradient angle. You get a "peanut" shaped gravitational field. With careful singularity placement, you can make the sides of the cube far closer to gravitationally "flat". The corners will still protrude, and unless you are extremely careful will be mountains of exposed adamant. You *might* be able to keep the edges within the atmosphere; you would probably still expect exposed adamant here, as there lacks a process to refresh any material that "slides down". Fun arrangements of singularities, like rings on two opposing faces, might actually make some parts of some of the edges become under water, and water able to flow from one face to another. I won't posit what kind of crazy technology is holding singularities (or other crazy-dense yet small masses) up in that kind of strange lattice. To pull this off, the gravitational masses have to both be significant and close to the surface; as you get further away, everything looks like a sphere. In the limit, if you had an even dense grid of heavy masses arranged over an infinite flat grid, you get a level gravitational field. Cutting such a field off with edges results in the edges being "uphill". Adding singularities near the edges makes them "more downhill", removing them makes them "more uphill". If I was serious about this, I'd start writing software that uses the principle of superimposition to let me place point masses and see the planes of level gravitational potential. [Answer] For the physics of this world you should look at [this question](https://physics.stackexchange.com/questions/130789/whats-the-biggest-cube-you-could-have-before-gravity-rounded-it/505325#505325) discussing how large a cube can be. It is not only feasible, it is almost certain that each face of the cube would evolve and develop uniquely. Unless you are really throwing all physics out the window, you won’t be able to cross the corners or edges - they will be at such a high altitude you would need a space suit to travel over an edge. So, keep just a small bit of reality and the societies on each face will be completely isolated until they develop space travel. Tunneling, again, would require drilling technology far more advanced than what we have today. The depth of those tunnels will create unsurvivable pressure. Again, assuming you want a little bit of reality in this. Also assuming some reality-based physics, Boxworld is made of something much more dense and rigid than granite or stone. They will never be drilling through whatever is holding it in that shape. The faces can discover each other when spaceflight is developed. [Answer] **Your world cannot exist in the form you've described.** To avoid being round, it must have very low gravity: at most a couple of percent of Earth's, even if it's solid rock. This is too little to maintain an atmosphere, since thermodynamics will keep a good portion of gas molecules moving above escape velocity until they've all leached off into space (even without a solar wind helping the process along). With no atmosphere, there's no ambient pressure at the surface so you can't have liquid either; also nothing to protect against ionizing radiation. Nothing could live on the surface without an enclosed habitat. Something like the subsurface oceans of Jupiter's moons could work. With the right engineering, perhaps you could even have an internal atmosphere and landforms; but to protect against external impacts over countless millions of years, the "hull" would have to be extremely thick and heavy, which might make a hollow interior structurally infeasible. At the very least, this would take a truly Herculean feat of engineering, especially for it to last on evolutionary timescales - and I imagine a society with access to those sorts of resources would have better uses for them. Even then, complex multicellular life took billions of years to evolve on Earth and your space habitat might need far longer still: a much smaller environment means a much smaller number of "evolutionary experiments" taking place at a given time. Whatever you got at the end of it all certainly wouldn't resemble the land life on Earth, due to the far weaker gravity. ]

[Question] [ Assume we have an Earth-like environment. If a tribe with only early medieval technology were to settle in a mountain environment: * What resources would be needed to deal with the elevation, cold, and other hazards? * What resources are they likely to have available? [Answer] This is a scenario which has occurred in many parts of the world, so it is not difficult to find some examples for this. As I'm myself from a mountainous area (rural Switzerland), which until a couple of decades ago still was very underdeveloped, I can tell you of a couple of problems and how people dealt with it: * **Winter problems**: Yes there is snow and ice and the like, but people would usually be able to cope with this. What this means is that one needs to store food for long winters (usually in barns) and that there's an increased risk of avalanches. Usually avalanches follow the same paths (given the topography of the terrain), so people would usually know through knowledge of past avalanches where it is safe to build houses and where it is not. To illustrate this, consider the picture below, which I took from a village in the Saas valley. You can see that the village forms a quite narrow stripe, this is a zone that people knew was safe, whereas in the front and at the back are areas where there can be avalanches in some years. Also building below other houses provides extra protection from the houses above "breaking" the avalanche.  * **Food**. Usually you can't grow all plants in higher altitudes, due to lower temperatures and shorter growing seasons. In the cases I know this means no fruit trees, no wheat, no Mediterranean vegetables like tomatoes or peppers. They used to grow root vegetables, potatoes (they didn't have those in medieval times of course) and as a cereal [rye](https://en.wikipedia.org/wiki/Rye). A lot of the food was meat-based, probably mostly sheep and goats, as they are perfect and can roam the higher altitude areas in the summer so that the agriculture area in the lower valley can be used to grow grass to store for winter and vegetables for food. There is ample supply of berries and mushroom. Wild animals that can be hunted include deer, [ibex](https://en.wikipedia.org/wiki/Capra_%28genus%29), [marmots](https://en.wikipedia.org/wiki/Marmot), and wolves. More exotic food sources involve [pine cones](https://en.wikipedia.org/wiki/Conifer_cone) and [thistles](https://en.wikipedia.org/wiki/Thistle). The fact that mountainous areas are usually far from big lakes or oceans makes fish almost unknown in those areas. A lot of people used to have [goitre](https://en.wikipedia.org/wiki/Goitre) from the resulting iodine deficiency, which also causes [cretinism](https://en.wikipedia.org/wiki/Cretinism). * **Transportation**. Roads were too expensive to be built anywhere but on important [trade routes](https://en.wikipedia.org/wiki/Gotthard_Pass). The mode of transport of choice was mostly the mule. This also meant that to get around inside the area, people had to carry most of the stuff themselves. ([Example of how this was done](http://atelier-graechbodi.blogspot.ch/2012/10/was-isch-en-tschiffra-auflosung-und.html)) * **Isolation**. Coming with the lack of transportation came a relative isolation as the next bigger town could be many days away by walking. This has several consequences on the inhabitants. The inhabitants don't get much contact with people from elsewhere, which probably led to the population being more traditional and conservative. Which is demonstrated in various mountain valley peoples, who seem to be more religious and pious. On a more serious level, the isolation also leads to a reduced gene pool and the limited choice of people to marry would lead to some degree of incest and inbreeding over time. On a ecological level, the geographic isolation could lead to [endemic](https://en.wikipedia.org/wiki/Endemism) variations of animals or plants. ([Some examples from Switzerland for animals](http://www.prospecierara.ch/de/tiere)) I think overall one can say that living in those times wasn't easy in mountainous areas and the people living there would have to be hard-working people, rather poor (except if there's mines maybe) and very used to losing people in accidents or natural disasters (as @Styphon mentioned). Disclaimer: This is based on Middle European mountain areas, this will heavily depend on climatic zone and altitude. Tropical areas on the same altitude will be very different for instance, as will Arctic areas. [Answer] The human body would adapt and deal with elevation. Many top athletes often train at high altitudes to help train their bodies to absorb oxygen more efficiently from the thinner air. If the terrain was pure mountains then the ability to adapt to the local geography would be key. Natural shelters in the forms of caves for early survival, though a medieval culture would be able to extend and possibly even create man-made caves for habitation over time. This will help them deal with the cold and natural predators as our, and their ancestors did. Fires at the entrance to the cave would ward off predators and help keep the cold at bay. The most significant hazards would be natural. Snow and ice would create dangerous living and working conditions. The constant need for food would also be a source of difficulty, with meat being a large part of the diet. For the survival of a large settlement, farming is necessary, though in mountains this will be near impossible limiting settlements to a small size. Cave ins, earth quakes, avalanches, all sorts of natural disasters would affect their daily lives. We struggle to deal with these in this day and age. They would simply be a fact of life for those in the medieval age that they had to contend with and get through. Any one serious act could end the settlement though. [Answer] The greatest killer in the mountains is exposure. Your tribe would need to find a way to stay warm and dry (or if desert mountains then cool). Caves provide good shelter; however, if they intend to stay there for much longer then more permanent structures are possible. The nature of a more permanent shelter depends on the local materials and the scarcity of other natural resources. If there is plenty of food and water nearby then a tribe will most likely build permanent settlements out of local stone (you need to consider what these mountains are made from: sandstone? slate?). If however food is sparse or water is rare then it is likely that a group of people would adopt a more nomadic lifestyle — as they cannot guarantee they will find shelter each night tents, teepees or yurts would be carried along with the tribe. These would most likely be constructed from the natural materials around them such as wood and skins. Finally to address your final point about elevation (I assume you mean altitude rather than gradient). The human body typically starts displaying symptoms of altitude sickness around 4000 m above sea level. However the severity of the symptoms are usually influenced by the body's normal altitude. There is [evidence](http://news.sciencemag.org/archaeology/2014/07/tibetans-inherited-high-altitude-gene-ancient-human) that humans who have always lived at high altitude are less effected by it than those who are more accustomed to sea level. Symptoms are often reduced by basic acclimatisation. A tribe climbing to these altitudes over a number of days or weeks would likely not suffer much more than a little breathlessness. [Answer] Can't think of early Medieval examples, but here's an example of hunter-gatherers living in mountains: <http://research.amnh.org/anthropology/research/naa/alta_toquima> In the Great Basin of western North America, the mountains are often much more hospitable than the valleys, as they catch the limited precipitation and store it as snowpack. Animals (and presumably humans) tend to change elevation with the seasons, migrating to the valleys in the winter. One of the major food sources for early people in this area was the pine nut, the seeds of several species of pinyon pine, which only grows well at elevations between 6–9 thousand ft (1800–2800 m). ]

[Question] [ In many stories we hear about people whose genetic structure is modified after they're born (Spider-man, The Fantastic 4 and practically any other superhero you care to mention). However current science focuses very much on modifying the DNA at the earliest stages of life (if not before) and allowing the embryo to develop. Is it possible that genetic changes could be made to an adult human? If so what techniques would be used (the only method I can imagine is viral?). What would a person undergoing this treatment feel like? Would it feel like the flu? Would it feel like they're burning? Would their body go numb? [Answer] Yes, absolutely. At the moment they are limited and are only used for important medical issues, but yes, we already can. Gene therapy is currently used for a number of genetic disorders, and it works by replacing the old genes with new, better genes, by means of a viral carrier. If I recall correctly, gene therapy has to be performed over the course of years, using many injections of the replacement-carrying virus, because they insert a gene that goes on to make the correct protein, rather than trying to smack you up with enough of the protein to get it into every cell in your body at once. There's no reason, bar our poor understanding of the vastness of the human genome, and tiny, petty, small minded barbarians (uh.. sorry..) that we couldn't already be doing this for much more exciting reasons. I could ask a patient of gene therapy what it feels like, but otherwise, I have nothing on hand. I imagine it wouldn't feel at all. You might get the classic symptoms of a viral infection as your body tries to fight it off, so your super soldiers would be a little under the weather for the first couple of weeks :D <http://en.wikipedia.org/wiki/Gene_therapy> [Answer] This already happens all the time, it's what a virus does. It infects cells and subverts them by changing the cells genetics to produce new copies of the virus. Those same pathways can be used by us to modify the virus and then use it to produce controlled modifications in humans. There are a number of problems and limitations with the method at the moment though, the biggest being that we have very limited control. We can set up the payload in the virus but it is very hard to make sure it delivers it to the right place in the genome, so it could end up writing junk, making things worse, etc. It's also hard to just deliver it to the cells that need it if you have a localized problem. For example if you have a problem in your heart then in theory you could deliver a fix but isolating the fix to just the heart is hard. The changes you want to happen in the heart could also happen and produce unwanted side effects elsewhere in the body. One huge worry is cancer, no-one is quite sure what effects gene therapy is going to have on cells and what the risks of it triggering serious conditions like cancer is. The effects these changes can have are also limited by the fact that they are working with what has already grown. For example you could take someone 5' tall and put the genes to grow to 6' tall into that person. However they have already grown, so the genes will not achieve anything. You would need to somehow both put the genes for an extra foot of height in and also re-kickstart the growing process. Basically the genes are the blueprint for the body, changing ongoing process is one thing but changing something that has already happened is much harder. You should also consider immune rejection, if you change things too radically then the immune system might detect the modified cells as foreign and attack them. This could be fatal just by itself. [Answer] Gene therapy is the way to go. It involves using virus to replace or attach new DNA to the DNA of existing cells. [This](https://www.youtube.com/watch?v=N-48RVaqZck&list=PLiyjwVB09t5xhhW0IfHke782_PqlLOxU0) video explains about it. Gene therapy is in its primitive state now. It is used to treat some diseases and the chance of success is very low. There is also a new way of gene therapy that is proposed currently that uses some nano devices to replace genes instead of virus as gene carrier. This method uses magnetic nano particles and some external fields to control them. [Here](http://www.nature.com/gt/journal/v13/n4/full/3302720a.html) is a detailed description about it. [Answer] Such methods (maybe virus-like) might be created in the future, however in these days genetically modified organisms are derived from a single genetically modified cell. Recent methods of transformation are very inefficient. Only tiny percent of cells are transformed in a test tube. They are later selected using some method that kills all non-transformed cells. You can then have more transformed cells or even organisms by just allowing these few survivors to grow and divide. However it looks possible to take a cell, modify, allow to divide and then inject modified cells back into the organism. This may be enough for many interesting achievements. Not only the modified cells can take over possibly ceased function, if some cases (stem cells) they could produce much bigger number of the modified "end use" cells (non dividing blood cells, for instance). Unlike plant cells, animal cells from the mature tissues are only capable of limited growth that puts further restrictions on the method. However this may be a solvable problem. [Answer] Yes, currently we have a method to change all the genes in the human body at once by using a method made by the virus AIDS, which takes over the infected immune system first,the immune system then corrects the cells that are missing the "new gene" that it got from the virus thus in turn infecting the whole body. We use this method to correct the entire body with one injection, also normal gene therapy does not help much they must take the injection for there entire lives and cannot go off it because their body's immune system will reject it and kill it, which is why you have to infect the immune system first to fix this problem. Currently, however, this method is not in us, because of a debate on whether or not its ethical to use it a it does not just manipulate genes, but adds "new genes" that are not in the normal human chromosomes as well; thereby forcing evolution, and as such you could make a human immortal, as we have the genetic information of a certain jellyfish that is immortal, so if we added these genes, we would have immortal humans much like that of the elves from lord of the rings. [](https://i.stack.imgur.com/LIn1X.jpg) ]

[Question] [ Worldbuilding is hard work, as we all know. When you want to write a story, or use a setting for a game, or just as inspiration for some creation (art, music), there is a strong incentive to reuse an existing world, or heavily derive from it. The world building has been done for you - the logic holes filled, the possibilities mapped and explored, the implications accounted for. I don't need to prove this, just look at all the fanfics out there. However, if you do this with a well-known franchise, you infringe on intellectual rights, which limits how you can distribute or use your derived creation. Similar to how open source and free culture licenses allow software and art to be reused and derived, are there any free (as in libre) world settings that are available for use? To limit the scope a bit, let's go for a typical, near-future science fiction setting: lasers, spaceships, aliens etc. A good world setting would contain a bit more information than a standalone story; this is necessary for other authors/creators to extend and derive. It may contain the following: * Histories * Major factions and their motivations * Explanations of how fictional phenomena work (e.g. how fast is their FTL, where do their mages draw energy from) * The world revealed through multiple points of view, so we get a good cross-section Do you know of such a piece of work? Please give a short description of what it is and how it's suitable, and not just a name-drop or link. [Answer] What you are talking about sounds like a [shared universe](http://en.wikipedia.org/wiki/Shared_universe). There are a vast number of Shared Universes out there, with a wide range in licensing and IP restriction and ranging from amateur to professional. Some have detailed supporting and briefing information that anyone can pick up and use, others are restricted just to a small group of authors or people licensed or hired by a certain company. For example the DC universe is controlled by DC comics and anything set in that universe needs their approval. One example shared universe and a briefing on using it is [Metamor Keep](http://tsat.transform.to/i.32/rtc.okane.1.html). (I don't actually know much about Metamor Keep, that link came up on a Google search for Shared Universes). So depending on your exact requirements in terms of licensing and publishing rights, desired setting, style of writing, etc you should be able to search for an appropriate Shared Universe and use that. If you can't find one matching your needs then look into creating one! [Answer] I haven't had a chance to look much into it, but there is [Orion's Arm](http://www.orionsarm.com/), which is a shared universe that has become well-established, and is a sort of post-singularity, trans-humanist, space-opera. According to the [summary on Wikipedia](http://en.wikipedia.org/wiki/Orion%27s_Arm): > > Orion's Arm, (also called the Orion's Arm Universe Project, OAUP, or > simply OA) is a multi-authored online science fiction world-building > project, first established in 2000 by M. Alan Kazlev, Donna Malcolm > Hirsekorn, Bernd Helfert and Anders Sandberg and further co-authored > by many people since. It was described by Cory Doctorow as *"a pretty > thoroughgoing post-Singularity thinggum with lots of opportunity for > fun noodling"*. Anyone can contribute articles, stories, artwork, or > music to the website. A large mailing list exists, in which members > debate aspects of the world they are creating, discussing additions, > modifications, issues arising, and work to be done. > > > [Answer] # [The Paradisi Chronicles](https://paradisichronicles.wordpress.com/) The Paradisi Chronicles are set in 100-300 years in the future, when a group of people decide to colonize a new planet in the Paradisi system and leave the collapsing earth behind: > > By 2092 AD, the Paradisi Project has achieved its goals. With Earth continuing on its path to destruction, a fleet of ten ships are launched, each carrying 10,000 passengers––Founding Family members, their loyal employees, and the staff necessary to build a new civilization once their journey ends. > > > ([Source](https://paradisichronicles.wordpress.com/world-narrative/)) > > > They meet humanoid aliens with psychic powers, have intrigues and rebellions, and finally get contacted by some of the people who remained on earth longer. ### A major downside: Lack of openness The Paradisi Universe blows its own trumpet by calling itself "An open-source scifi universe". But it's not all as accessible as you might think: * Nowhere on the website can I find detailed licensing informations. * Paradisi is focussed on writing books mainly, it seems. That's absolutely ok in itself. But the books are of course not under an open license and you need to buy them. (There are a few free ebooks, though. ("Free" as in "free beer", not as in "free speech".) * There is a "World Bible", which contains out lots of details about the fictional universe, but you can't access it online. You need to send someone an email (see [here](https://paradisichronicles.wordpress.com/for-prospective-authors/)) and they'll send you a copy. No idea why this model was chosen over a read-only wiki. I asked for a copy and got a wary answer asking for my plans with the World Bible, and after responding to it I didn't receive a further answer at all. * In some books, there are links to password protected parts of the website with new, hidden material. *So in conclusion, I must say that the Paradisi Chronicles are not an open universe, despite self-proclaiming to be so.* # [The Fifth World](http://www.thefifthworld.com/) Not so much aliens and spaceships, but a seemingly very solid postapocalyptic world set on earth in ca. 400 years from now. > > The Fifth World presents an open source shared universe — a vision of a neotribal, ecotopian, animist realist future created by a growing community of authors, artists, designers, gamers, and dreamers — and we want you to join us. > > > The Fifth World is centered around a pen-and-paper RPG that you can [download for free](http://www.thefifthworld.com/rpg). ### Openness [The Fifth World takes openness seriously.](http://www.thefifthworld.com/about#open) * The content is all under Creative Commons Share Alike. * There is a great wiki with all of the content of the world, viewed from the outside perspective (etic) and the inside perspective (emic). Everyone who shows sufficient motivation can become a contributor to the wiki. * There is a [free novel](http://www.thefifthworld.com/wormwood) set in The Fifth World that you can read. ### A minor downside: Work in progress While this might also apply to Paradisi (although they don't talk about that), The Fifth World is still work in progress, and gladly they are very frank about that. The game is in beta-testing, it seems, and the novel is one third finished. But, hey, that means there is a lot of space for you to fill! [Answer] The SCP Foundation is a shared science fiction world with what seems to me an Xfiles sort of vibe. It operates under a Creative Commons license. <http://www.scp-wiki.net/licensing-guide> Their website is a repository for works of fiction. I was surprised how uniformly good the writing was. You can easily lose a couple of hours poking around. The mission statement for the fictional Foundation: <http://www.scp-wiki.net/about-the-scp-foundation> > > ## Mission Statement > > > Operating clandestine and worldwide, the Foundation operates beyond jurisdiction, empowered and entrusted by every major national government with the task of containing anomalous objects, entities, and phenomena. These anomalies pose a significant threat to global security by threatening either physical or psychological harm. > > > The Foundation operates to maintain normalcy, so that the worldwide civilian population can live and go on with their daily lives without fear, mistrust, or doubt in their personal beliefs, and to maintain human independence from extraterrestrial, extradimensional, and other extranormal influence. > > > Our mission is three-fold: > > > Secure > > The Foundation secures anomalies with the goal of preventing them from falling into the hands of civilian or rival agencies, through extensive observation and surveillance and by acting to intercept such anomalies at the earliest opportunity. > > > Contain > > The Foundation contains anomalies with the goal of preventing their influence or effects from spreading, by either relocating, concealing, or dismantling such anomalies or by suppressing or preventing public dissemination of knowledge thereof. > > > Protect > > The Foundation protects humanity from the effects of such anomalies as well as the anomalies themselves until such time that they are either fully understood or new theories of science can be devised based on their properties and behavior. The Foundation may also neutralize or destroy anomalies as an option of last resort, if they are determined to be too dangerous to be contained. > > > [Answer] **Hal Clement's planet Mesklin** This first appeared in his novel *Mission of Gravity* (1953). Mesklin is a gold standard hard science planetary setting. > > Mesklin is a fictional supergiant planet created by Hal Clement and used in a number of his hard science fiction stories. > > > It is distinctive for the interaction of its strong gravity with the > centrifugal force due to its fast rotation, originating, according to > Clement's original calculations, a gee force gradient, starting at 3 g > on the equator, and ending at 665 g on the planet's poles. > > > Further details can be explicated below. > > Clement described the basic characteristics of Mesklin in the article > "Whirligig World" in *Astounding Science Fiction* (June 1953). He > based the world on an object then thought to exist in the 61 Cygni > system, which had been detected by analysis of the motion of the two > already known stars in the system. Further analysis with more > extensive data led to the conclusion that the find had been erroneous. > > > Clement decided, since its mass was 16 times that of Jupiter, Mesklin > would have an extremely large angular frequency to partly counter its > gravity in order to allow humans to visit part of it. He wanted the > equatorial gravity to be 3 g, so he determined the period necessary to > make this occur: each Mesklin day is 17.75 minutes long given that the > planet rotates approximately 20 degrees a minute. > > > As a result of this extremely large rate of spin, Mesklin is not even > slightly spherical; it has a large equatorial bulge. Mesklin's > equatorial diameter is 48,000 miles (77,250 km), while from > pole-to-pole along its axis of rotation it is 19,740 miles (31,770 > km). Then Clement attempted to calculate the polar gravity, finding it > surprisingly difficult. He admits, "To be perfectly frank, I don't > know the exact value of the polar gravity; the planet is so oblate > that the usual rule of spheres... would not even be a good > approximation..." "Whirligig World" reports his initial calculations > of the pole gravity to be 655 g; the dust jacket of Heavy Planet > reports it as 700 g. A later program created by Clement computed it as > 275 g, as did a similar program written by the MIT Science Fiction > Society. The MIT group also concluded that the planet would have had a > sharp edge at the equator.[1](https://en.wikipedia.org/wiki/Mesklin) Clement also gave Mesklin a set of rings > and massive moons. The inner moon is 90,000 miles (140,000 km) from > the planet's center, with a period of 2 hours 8 minutes.[2] > > > Clement assumed Mesklin's orbit around its star (which he decided > would be 61 Cygni A) took 1,800 Earth-days, and was highly elliptical: > at its closest point the average temperature would be −50 °C, while at > the furthest its average temperature would be −180 °C. Since the orbit > is eccentric it moves rapidly past its sun at the closest point, so > its temperature would be around −170 °C most of the time. > > > Clement decided this imaginary world would have native life-forms, > that they would be based on methane (CH4), and there would be oceans > of methane. However, methane has a low boiling point, suggesting that > Mesklin's sun might boil its oceans and cause the methane to escape > the planet entirely. Thus, the writer arranged the planet so its > northern hemisphere's midsummer occurs when it is nearest its sun. > Thus, the northern hemisphere would develop a large frozen methane cap > during most of its year; the southern hemisphere (where most creatures > live) is protected from the sun's closest approach by the rest of the > planet. He also asserted the planet would have a fairly rapid > precession. > > > Considering Clement published his novel about Mesklin in 1953, yet it sounds like one of the exoplanets discovered in the last couple of decades. Importantly, Clement made the following magnanimous offer to open this planetary setting to other authors. > > In "Whirligig World", Clement stated he gave "official permission to anyone who so desires to lay scenes there [in Mesklin]. I ask only that he maintain reasonable scientific standards, and that's certainly an elastic requirement in the field of science fiction." > > > Effectively this offer for other authors to use Mesklin has been available since 1953. To date no-one has taken it up. As a courtesy, any author writing stories set on Mesklin should contact the Clement estate before doing so. Hal Clement (real name Harry Stubbs) died in 2001. Please note the only restriction is maintaining reasonable scientific standards, and even there Clement was indicating that some measure of flexibility is allowed. Clement has done all the hard work of building the planet. While various studies have expanded and extended on the characteristics of Mesklin. More recently the Australian physicist Ditmar Jenssen analyzed Mesklin in detail. Tjis was published in the fanzine *Interstellar Ramjet Scoop* circa 2004. This isn't a shared world, they came much later, circa the 1980s or 1990s, and it isn't open source fiction where creative commons licenses are expected. It is, surprise, surprise, a science-fiction setting that is open to any science-fiction author who wants to write a story there. Source: [Mesklin](https://en.wikipedia.org/wiki/Mesklin) **ADDENDUM:** A point of clarification about the intellectual property rights inherent in Clemen's Mesklin. Although Clement publicly granted access to his created imaginary planet, the ownership of the IP rights presumably now reside with his estate, therefore, it will be necessary to contact his heirs and successors. They may have the power the rescind this open access, and it is for this reason any writer intending to use Mesklin as a setting they should first contact his estate both as a courtesy and ensure it is permissible to do so. However, a good case could be put to his surviving family that having other authors write about Mesklin was well within Hal Clement's own explicitly stated wishes, even as long ago as 1953, and to do so would be a fitting tribute to his memory and a celebration of his work. As the question said: "The world building has been done for you - the logic holes filled, the possibilities mapped and explored, the implications accounted for." Mesklin has been open for business by other writers since 1953. Hal Clement was scrupulous worldbuilder. He had given a clear indication that other writers were allowed to play there and in a manner that should permit an open legal license to do so. The pity is no-one had taken him up on the offer. [Answer] 1. Larry Niven Man-kzin wars portion of the known space universe is open to use, 300 years of the 1000 his stories are set in, several aliens species to work with, each with so rather creative biology and quirks. FTL is hyperspace type travel (that requires a living mind to steer), there are ways to introduce weird one shot things (Slaver artifacts, basically leftovers from a war that ended almost all intelligent life in the galaxy but). Psychic powers are real but very weak, the strongest telekinetic in existence can just lift a cigarette, telepaths are a bit stronger but rarely sane. Humans come is several flavors because the probes sent to find habitable planets had a bit too loose of a definition of habitable, so you heavy worlders, mooner, albino crashlanders, ect. You can read more here <https://en.wikipedia.org/wiki/Known_Space> 2. The Orion's Arm setting is a collective universe project, <http://www.orionsarm.com/> It is a collective very hard science setting. It is basically designed to be a communal setting for stories. > > > * Matter cannot travel faster than light > * Matter and energy are conserved > * No evolved humanoid aliens have been discovered > * Technology will change the nature of social issues > * A logical explanation for even the most fantastic elements within the setting must be provided. > * Space is vast expect the same challenges to have many different solutions, or as we say at Orion's Arm - Diversity! Diversity! Diversity! > ]

[Question] [ Inspired by the [many](https://worldbuilding.stackexchange.com/questions/10793/how-tall-can-a-tree-grow) great [questions](https://worldbuilding.stackexchange.com/questions/10914/could-plants-spread-their-seed-to-other-planets) asked for this fortnight's [tag challenge](http://meta.worldbuilding.stackexchange.com/questions/1810/fortnightly-topic-challenge-2-flora?cb=1), I got to thinking, could a plant develop/evolve to eventually consume an entire planet, and keep on living? What I mean by this is that a single organism, or perhaps a colony, both covered the surface of the planet and also converted the vast majority of the planet's mass into plant matter, most of which would either be alive or recently dead but ready to be consumed and converted back into living matter. Essentially, there would be no part of the planet *not* used by the plant, and yet with these resources the plant could survive indefinitely. Also, just imagine exploring such a planet. You'd be like "Where's the ground on this planet?" and your scientist would incredulously reply "There is no ground. This tree *is* the planet." I know many plants on Earth are pretty good at thriving in the craziest environments and overcoming all sorts of obstacles, but this seems a few levels more difficult. What sorts of hurdles would the plant have to evolve over to make this happen, and what things might make it impossible? Is there perhaps a theoretical planet that would make this process more plausible? [Answer] # The Hurdles * **Resource Transport** All parts of the plant need resources, so you xylem/phloem is going to need to transport things over large (vertical) distances. * **Heat** The mantle of a planet can get quite toasty. Enough, in fact, to burn any wood or organic material. The mantle is considered to be a huge area of molten rock. * **Climate** A planet, even an apparently lifeless one like [Mars](http://en.wikipedia.org/wiki/Climate_of_Mars#Climate_zones), has differing climates based on how much sun it gets. There are other factors, like water availability and soil quality. # Resource Transport Trees can only grow so tall before the cost of hauling those resources becomes too much. See this article on the [limits of tree height](http://www.nature.com/nature/journal/v428/n6985/abs/nature02417.html). They estimated that the maximum height of a plant is 400 m. Given this, you don't want your planet-sized plant to grow very high. Resource transport may still be a problem, though, as you get down further into the planet. Your roots will need to have enough energy to transport the nutrients they gather to the rest of the plant. You can see an article talking about maximum root depth from [Duke](http://sites.biology.duke.edu/jackson/oecol96d.htm), and a list from wikipedia on [maximum root depth](http://en.wikipedia.org/wiki/Root#Rooting_depth_records). (The record appears to be *68 meters*!) As described in the wiki article, roots generally do not go very deep simply because the soil becomes inhospitable to the tree the further down you go. So, you planet-plant will need some tough roots that enjoy making airways but also breaking up heavily compacted soil. Bacteria and fungi could help your roots grow, as they do in real life, but they only help so much. # Heat The world gets hot the further you go down. The [geothermal gradient of Earth](http://en.wikipedia.org/wiki/Geothermal_gradient) makes it abundantly clear that your tree will need to have a higher melting point than that of rock to get down really far. Additionally, it would need to withstand enormous amounts of pressure, simply because of all that atmosphere/rock bearing down upon it. (The mantle is, after all, is where [diamonds can be made](http://en.wikipedia.org/wiki/Diamond#Natural_history).) The solution will be for your plant to cool the ground as it digs through it. This can be tough, especially if your planet is earth like and has radioactive elements providing heat. This would also take a very long time; radioactive decay can take a while to stop. Even if your roots could cool the planet as it digs through it, it would only compound the resource transport issue. # Climate Last of all, your tree needs to be able to withstand any climate. It needs to out-perform things at the equator of your planet as well as anything at the poles. (The poles of earth, at least, seem to be [forsaken by plant life](http://en.wikipedia.org/wiki/Polar_climate).) So your plant will need solutions for surviving both hot and cold, extreme wet and extreme dry, extreme nutrient deficit and nutrient plenty. Every plant has adaptations to its environment, but each adaptation could be a liability in another climate. # Some Models There are some big trees out there. Here are some models of live trees which are rather successful at covering the surface area, especially compared to "normal" trees. * [Pando](http://en.wikipedia.org/wiki/Pando_(tree)): an aspen colony which is thought to be made from the same tree. Technically, every tree there *is the same tree* because of interconnecting root systems. Pando covers 106 acres (428 966 $m^2$ ) of land. * [Maior cajuerio do Mundo](http://en.wikipedia.org/wiki/Maior_cajueiro_do_mundo): a cashew tree which, for some reason, carried a mutation that let its branches touch the ground, put down roots, and then move on. This tree covers around 1.8 acres (7 300 $m^2$) of land. * [The Great Banyan Tree](http://en.wikipedia.org/wiki/The_Great_Banyan): like the previous tree, this ficus tree has branches touch the ground, put down roots, and then make more branches. This one holds the title for widest tree in the world. It covers 4 acres (14 500 $m^2$) of land. # An Ideal Planet An ideal planet for such a plant would: * Possess an unusually homogeneous global climate (because of water or air convection? Multiple brown dwarves heating it?) * Possess an abundance of nutrients for this plant everywhere * Possess a single, connected landmass. No islands or other inaccessible places. * Somehow cool as the plant digs deeper without the plant above dying [Answer] While I expect that a plant colony could in theory cover a planet or moon, and even be very deep, maybe a mile for a smaller planet, I don't think it would be possible to make the entire planet biomass. Here's my thinking why. First plants need energy to grow, a mile deep forest is going to be pretty dark near even half way down. so no light, at least not from above. Second, plants of course need nutrients, and so roots or what ever method they use to collect them need something to collect them from. Rocks, soil, other dead things. Third, even a planet as small as the moon, it's mass is still large enough to crush things in it's center, the moon is round because of it's own gravity. At some point the gravity of the plant planet would be crushing everything in the center. and nothing would be able to live. So At the least there would be a core supporting all the plant life. Life would likely not ever get more than a few miles deep, just the weight of the plants would be crushing. The diameter of the moon is 3474km, if you even made a 3 mile layer of plant life, you would still have 3469km of non-plant life in between. [Answer] **1. Depends on the planet** - such planet should have similar climate on poles and equator. Water resources should be under ground, but not very deep. Also there should be plenty of water and water should be accessible anywhere. Most of such planet should be ground (to provide place for such plant to grow). I believe any other type of planet would make such big "plant" not plausible **2. Depends on evolution** My gut feeling tells me, that there should be nothing "eating" such plant. So we should wave out all bigger animals and keep maybe insects and some germs. That's it. Other suggestion is evolution done in a way as in great barrier reef - everything is living in co-existence **The plant will share roots** - So it will not cover all the land visually, but under ground **You cannot change planet into plant** As bowlturner pointed out in [this answer](https://worldbuilding.stackexchange.com/a/10927/2071), you cannot expect roots going very deep. Also do not forget, that **Planet has to have hot core in order to support life** and atmosphere. So going deep will burn your plant **Overall**: You can have plantet which *looks like* it is actually one big plant. But going closer will show you it is planet which has ground covered by one big plant and the rest is ground, microbes and some small animals. [Answer] Here's an idea. Instead of a plant, why not a fungus? Some are superficially similar to plants, to the point where early taxonomists misclassified them as such. There's no theoretical size limit on a fungus. Indeed some people would say that, depending on your definition of an individual organism, the world's largest living things are fungi (I see one commenter has already provided a link for this). Most grow by feeding on decomposing matter, which is going to become a problem when they've consumed all the planet's resources. However, there is limited evidence to suggest that some have limited capacity to [convert radiation into energy](http://en.wikipedia.org/wiki/Radiotrophic_fungus), like plants do with sunlight. This would have the added bonus of allowing your planet-fungus to grow in deep space, out of range of sunlight. Fungi are also better at growing in extreme conditions than plants, and are better at lying dormant during periods of poor nutrition. So your theoretical plant planet could be alive, even when it had no source of nutrition at all. [Answer] When you say "plant", I think it depends on what you mean. In an Earth context, a plant seems to be an organism evolved to live as part of the environment here, which is a symbiosis of many life forms in the conditions that have existed here. Some plants (e.g. Kudzu) may tend to spread very aggressively and smother other plants to an unusual degree, but every organism on Earth ultimately requires conditions which come from many other species, and relatively stable climate conditions. Every species on Earth which is "too successful" at dominating its environment, tends to eradicate the conditions which allow it to live, resulting in a serious die-off and possible extinction. The planet as a whole however can be said to be alive as a whole, and has much more potential for long-term survival. In order for one species to be able to take over and dominate an entire planet, it would need to be able to somehow generate its own requisites for continued existence. The easiest way to accomplish that, is not to eradicate the other species, but to encourage and aid other species, which in turn have their own survival requirements and needed conditions to keep in balance. When different species interact to support each other, it's called a symbiotic relationship. Even predator/prey relationships tend to be ultimately symbiotic, as they help control the imbalance of different species' population levels, avoiding toxic conditions, starvation, die-offs and extinctions. This tends to be best supported by a naturally-evolved ecology with plenty of biodiversity, perhaps best exemplified by the Amazon rainforest before foolish humans started destroying it for low-grade cattle pasture. A planet-consuming "plant" would also need something to cause it to organize itself to eradicate other species and generate its own conditions in some other way, which on Earth or another natural planet, I don't see a likely reason for without something like deranged human thinking at play. You also describe it as one planet-sized plant, which is a challenge in itself. One species with many members is one thing, but requiring it to be a single member ... well it depends on what you mean. I think it could work as long as much smaller pieces could function independently. To achieve the self-symbiosis, I imagine it would need to have many different forms or components to create its own life cycles. At which point, I think you're falling back towards something more like life on Earth anyway. Until relatively recently over the span of human existence, most humans have considered themselves to be a part of our living world as a a whole, and not as a separate thing struggling against nature. The wisest answer may be that we are already on a planet-size life-form or even plant, at a macro level. We're all part of the organism, and the idea that we're not, and our nastier industrial activities, are a disease which we need to outgrow to avoid our own die-off. Back to a more literal vision of your question, another aspect is that if you start with an Earth-like planet and an Earth-plant-like "plant" (say, genetically modified by the evil Doctor Monsanto to intentionally devour the entire planet), there would be challenges to the literal physical task in that only the topsoil and oceans of the planet are very useful nutritionally. If evil Doctor Monsanto intends his plant to devour the very planet beneath the outer layers, he needs to find something that will do something to inorganic rock, and then to magma, molten iron, etc... ]

[Question] [ It’s the year 2018, and you live in the good ol’ North American landmass. The fascist landmass. By this year, the dystopian N.A.F party controls all of the landmass and secret police prowl the streets armed with automatic rifles. Protest the rules and NAF makes you disappear -- permanently. ***Onto the subject*** As you’ve seen in a lot of movies and whatnot, dystopian governments like to make people fit into a mandatory dress code. 1984 did it, a lot of other dystopian media did it, and so on. I plan to do the same, but I want to make my dystopian government a logical one, that only does what’s necessary to keep power. What is a logical reason why mandatory dress codes would be forced upon citizens? [Answer] # Control the Supply The citizens of your dystopia work in a government-controlled factory. They shop in a government-controlled shop with government-controlled prices. What does the shop have in stock? The products of more government-controlled factories, of course. It is **not** illegal to wear non-standard clothes. It is illegal to buy or sell them (that would be black marketeering) and it is **usually** illegal to make them (that would be diversion of government-supplied raw materials). One might "repair" government-pattern clothes into non-standard shapes, e.g. cutting trousers short or making a skirt out of an old bedsheet. *Few people make their own clothing. A sure sign they have too much time on their hands, why don't they join in a government-sponsored community activity instead?* Of course there is "special store No. 0815" which is open to senior regime officials and their families. These officials work so long hours in their selfless service of the people that they cannot possibly stand in the waiting line of a normal store. The special store opens by appointment, e.g. right between the parade for the *Dear Leader's* birthday and the official reception. And it stocks suitable clothes for that reception. [Answer] Reason number one: it removes people's individuality. Reason number two: the act of controlling a citizen's personal life makes the government feel omnipresent and all-seeing. Reason number three: it prevents a rebellion from being able to wear a recognizable uniform. Reason number four: the government could plant tracking devices in the uniforms. [Answer] **[Sumptuary laws](https://en.wikipedia.org/wiki/Sumptuary_law) gone mad** In brief, sumptuary laws are laws regulating displays of wealth - chiefly they're thought of in terms of clothing, although there were ones dealing with other luxuries. Sumptuary laws were a popular solution for Renaissance nobility who were faced with a problem: the middle class, especially merchants, were starting to make as much money as the nobles, and if the nobles weren't conspicuously better dressed and otherwise appointed than everybody else, it might lead the common people to start questioning the basic assumptions of the realm. (Starting with, "there are nobles and common people, and never the twain shall meet".) Expanding on that a little, the idea of such laws is to ensure that everyone is aware of their place in society. Everything in their lives - the clothes they wear, the way they get to work, what they eat - reinforces this. The commoners know that they are powerless, and that the nobles (or the Party) is powerful. This is so ingrained in the fabric of society that it might as well be unquestionable, or so the theory goes. [Answer] History shows us how it works: * People of certain groups (preferably the enemies of the government) have to identify themselves. The Nazis ordered all Jews to wear a Star of David on their clothing. As a direct result, Jews were easily identified and discriminated against by the "common people". * Service uniforms are always a symbol of power. The government forbids any civilian clothing that resembles a service uniform to keep people powerless. * "Good people" who support the government want to show their support and thereby get advantages. It's basically the opposite of the Star of David. * Those who neither support nor fight the government are forced to wear uniform clothes to make it clear that there is no other way of live. They are taught from early age to follow the rules and therefore don't even think about change. How could any change be possible if it's *always* been like this? This kind of brain washing was done in Germany by the Nazis and the Communists after them, in China and other Communist countries and it's still in practice in North Korea and in Muslim countries like Iraq, where women are forced to wear their Hijab (veil) in one specific way. [Answer] *Brave New World* told you 85 years ago: a caste system. <https://www.enotes.com/homework-help/brave-new-world-what-each-castes-designated-color-69917> > > Each caste in Aldous Huxley's Brave New World is distinguished by the color of its work clothes. In order of caste from lowest to highest, Epsilons dress in black, Deltas wear khaki, Gammas wear leaf green, Betas dress in mulberry, and Alphas wear grey. > > > This color division system to differentiate castes is in place so that people can quickly and easily know what caste a person is in. The dystopian world described in Huxley's novel is very superficial, so of course they would use a superficial designation like color coding. It is surface-level symbolism, but also very effective psychologically. The world is also one that relies heavily on simplistic psychological conditioning, as seen with the Pavlovian type conditioning and the electric shocks. > > > [Answer] **Clothes are owned in common.** Prior answers cover evil reasons. This is a nonmalicious utilitarian reason. In circumstances where clothes are owned in common, you turn them in after wearing to get them washed. When you pick up new clothes they are unlikely to be a set you have worn before. They will be in your size and that is all. In your world, there are not facilities for citizens to wash their own clothes themselves. Citizens turn in soiled clothes which are taken away and washed in a common facility. In return they are provided an allotment of clean clothes. A common facility for laundry is just efficient economics - we have our power generated and our water purified in common facilities and do not think much of it. Diaper services used to be a normal thing: leave a bag of soiled cloth diapers for pickup and transport to diaper facility, get a new bag of clean diapers. Scrub suits for hospital workers are done exactly like this now - scrubs are owned by the employer, washed in a common facility and made available for use. Electricity is electricity. Diapers are diapers. Clothes are clothes. You turn in what needs washing and you get clean ones in return. Worn out ones are recycled. New ones enter the rotation as needed. The clothes cover you adequately for the season. Your priorities are elsewhere. [Answer] One explanation would be rent seeking. The company/government department who produces the clothing has bribed or lobbied or whatever the government into outlawing any competition. Now with monopoly prices and economy of scale the people who run clothing production are enjoying a great deal of wealth some of which of cause gets kicked back to the people who make the decision on what clothing is legal. [Answer] The clothing has id printed on them that is only visible in the UV spectrum. The administration has security cameras that can pick it up. It could also have NFC threads that can id them walking through doorway sensors. Automatic id systems pick up who the clothing was issued to so if people hide their faces, the system can still tell if they in an area they aren't suppose to be. [Answer] In the Complex Alpha from Paranoia RPG, a dress code is mandatory. You have to use only items allowed by your cleareance. This is the best system because Friendly Computer created it. After all, wearing anything else would have been treason. [](https://www.slideshare.net/theDINGbat/paranoia-notlive) Yes Paranoia RPG was inspired a lot by a [Brave New World](https://worldbuilding.stackexchange.com/a/119956/9115). [Answer] It's a bit prison uniforms - it's easy to tell if you're in the wrong place. You're a pleb with rebellious designs? Approach a sensitive area in the wrong uniform, get summarily shot. You won't get close enough to cause problems or blag your way past the guards. [Answer] When I worked for a large healthcare provider, we had at least a dozen different colors that clinical people had to wear. The motive was that if you needed a doctor, nurse, lab tech, dentist, orderly, rad tech, etc., you would just look for the right color. Unfortunately, there were so many colors that I never did learn them all. But I could imagine a totalitarian government coming up with such a scheme. [Answer] It's a fascist government, so the logic must build on opposites: Tradition by Revolution, Peace by War, etc. At the same time it's a dystopian government (one might argue that's a natural corollary of the first), so it needs to be intransparent, freewheeling and all-powerful. By these rules, just about anything is possible. The NAF is a conglomerate of nationalist states, so everyone is forced to wear a modern remix (and in womens case sexy modern remix, see Dirndl, and how that came about) of their homelands(or some region of their homelands, or just any) traditional garb. To keep the manufacturers happy (Fascism loves big business) this was reduced to a picture of that garb printed on an overall (and to keep that sexy, it's a transparent overall, made intransparent by the printed parts), which also doubles as a sweat collector (sweat has to be 'donated' daily, for drug testing and as an outward sign of productivity). The hood can be zippered shut, so the overall is also a body bag, in case of need. [Answer] [](https://i.stack.imgur.com/XX9AJ.jpg) The Goku Uniforms in [Kill La Kill](https://en.wikipedia.org/wiki/Kill_la_Kill) were issued to students at Honnōji Academy based on their merit. The uniforms not only were a measure of status - which influenced where you lived, the food you ate, your place in society - but also conferred superhuman powers to anybody wearing them, with higher-ranking Goku Uniforms resulting in an even more luxurious lifestyle with even more powerful abilities. In Kill La Kill, many students and people living under the shadow of Honnōji Academy were of low status and had no Goku Uniforms, which relegated their place to the slums. In this viewing of a dystopian society, the clothes you **don't** wear are as influential as the clothes you **do** wear. If you are interested in dystopian societies and the role of clothing in particular, I can recommend no tale more fascinating and exhilarating as Kill La Kill. [Answer] There's a lot of control that can be attained by using visual clues. Just like in the military where rank insignia are important, outfits and colors can be used to remind people of their place or caste. In *The Handmaid's Tale* (the book) colors are very important. They can remind you where you stand and who to avoid or watch. * *Commanders:* black with white shirts * *Eyes, Angels, Guardians:* black * *Wives:* blue * *Econowives:* striped dresses (red, blue, green) * *Daughters:* white until marriage * *Aunts:* brown * *Marthas:* green, with apron * *Handmaids:* red dresses/gloves/shoes, white wings, white underwear * *Unwomen/Unmen:* gray [Answer] It matters how the government came to power. For example, back when England was colonizing places, they would try to stomp out the native culture in those places. One way to do that would be to outlaw all their art, including personal expression by means of clothing. There's a strong correlation between diversity of thought (free thinking/creative expression) and dissension. So the strictly logical dystopian government decides, without desiring to spend much time speculating about the nature of a person's spirit, that it's safest to restrict creative expression in as many forms as possible. [Answer] # Control through selective prosecution Government has the most control over people it can charge with a crime. Make a dress code. Change it from time to time. This can be rationalised as "witches/spies/terrorists/[whatever scare your government uses]" would be easier to spot. However, the main reason is that people wouldn't be able to keep up with ever-changing ruleset, neither financially nor mentally. People would be winging your uniform rules, looking reasonably consistent, but many would have some flaws in their garb. Thus, your law enforcement would have one more probable cause to stop/search/detain/execute persons of interest. Combine it with some other laws and your police would be able to prosecute anyone. Seasoned officer would know that he has enough tools to find a crime in any lifestyle. More than that, in each of those cases you can argue that the person was punished for not following the rules and disrupting public safety, and definitely not for some sort of activism or whatnot. [Answer] The clothing have been provided by govt approved manufacturers. They advertise that this special clothing is made of special tech that monitors your health and well-being. The clothing fights diseases by killing pathogens from the outside as well as the inside. There has been no reported incident of a heart failure as the clothing has various tech to prevent and cure heart issues. But the real reason is that they want to monitor people, make sure that they follow the law to the tee and prevent terrorism (read rebellion or free thought). [Answer] Focusing on the “logical” aspect of such a system—eg, perhaps purely logical beings (evolved, mutated, extraterrestrial) or a ruling (machine learning) AI—then “the system” may come to the realization that fashion/attire is heavily influenced by social pressure, and requiring certain attire will inherently create both loyal adherents as well as those who wish to rebel against these (oppressive & seemingly arbitrary) constraints. The system does this to create ongoing conflict within the population to distract from other more vital concerns & abuses of the state. (There are analogs to be found in both current society, as well as (of course) The Matrix). In short, it’s becomes a logical “distraction” from more important issues—even if only a minor one, perhaps meeting some threshold like 2% utility—and the “machine learning objective function” may have evolved to find it sufficiently useful to retain, for the time being. [Answer] The thing is that you need to know that totalitarianism is not founded on common sense, evidence and logic. Collectivist ideals are running wild and manifested into a regime seeking to control every aspect of life, supported by some ideologies (a most common one being Marxism and any other versions of it). It is clear that freedom is not only most moral, but also ecomically most beneficial, but logic has lost the battle. You don't need any logical reason to justify uniforms, the sheer idea of getting rid of individualism (which is oppositional to collectvisim), the goal of equity or any other reason like "terrorists could wield weapons illegally in government unapproved clothing". It could be even, in case of a religious totalitarianism, the reason of sexual exposure - which is currently a quite dominating ideology called Islam. Let your fantasy run wild, any horror or dystopia you come up with would be realistic (and reasonable) enough - and chances are good that what you brought up is currently, was *already* existing in reality. There are no boundaries for insanity and irrationality in totalitarian systems. If it is inefficient and not sustainable - it does not matter - it lasts as long as it is maintained or collapses, which can be decades or even a century. Or forever in the worst case. The process is roughly this: You create arbitrary axiomes like "being rich means resources have been stolen from the poor" and derive logic from that. It's a house of cards with a foundation which must never be questioned. It has to be accepted no matter what, because if the foundation is lost, any logic derived from that will fall apart. Such thought constructs are called "ideologies" and are widely common in various magnitudes. [Answer] Since the self-image of a totalitarian government with regard to the level of control it maintains over their citizens for their own good and their view of the relation of individual choice and community is similar to that of an educational institution regarding children, I think you can just read up on the arguments for school uniforms. Those arguments are real enough to be accepted in real life in numerous countries, and not as a punishment but as a way of removing choices that are not helpful and lead to unwanted competition and disturbances. [Answer] People getting triggered. People in your society can't mentally handle seeing things that they don't like or agree with, things that remind them of things they don't like or agree with, and things that make people feel unequal, among many other things. When they get triggered, they do irrational things like riot, create hashtags, and attempt to destroy said person or entity. Because of this lack of mental fortitude for ideological diversity in the people, and for fear of losing control of the people, N.A.F. has deemed anything that triggers someone else to be harmful, dangerous, and illegal. Over time people have been triggered by almost every aspect of clothing, so it's standardized on a single style that has been approved to be trigger-free (for now). It contains no animal products, no one has a bigger relative collar size than another, no one is showing more skin % than another, is made from an eco-friendly "natural" material, and has no cost to the consumer so everyone may acquire as many as they wish. Each person has an attractiveness index, which is directly proportional to how unflattering the clothing must be. Dissenters are given a padded jacket and quietly reeducated. N.A.F. fears the triggering so badly that it mandates an image of a puppy on the front side of shirts and a cat on the backside. All these measures seem to have helped because hashtag counts are down and riots are rare. [Answer] > > “You don’t necessarily need the choice of 23 underarm spray deodorants or 18 different pairs of sneakers when children are hungry in this county.” — Bernie Sanders, 2016 > > > It is the conceit of central planners to believe they can simply reallocate perceived inefficiencies toward a more noble result. Why would you waste money producing different clothing choices when there are children starving? [Answer] Smart Hardware / Software would be part of the daily lives so much, the garments contain basically weaponizeable technology, basically every t-shirt carrys the explosive potential of a samsung galaxy phone. So having complete controll of the garments is needed, to prevent a uprising from having ready made molotow shirts - or bundle together into a hacking super-computer. ]

[Question] [ I’ve included more background below, but the TL;DR is that you’re a lone immortal who’s decided to breed some species of animal to a human-level intelligence (over the course of hundreds of thousands or millions of years). **Which animal do you start with?** Qualities that make an animal a good choice: * Should be found in Northern California (for plot reasons). Wild dogs would probably have survived humanity disappearing, but any great apes in zoos or labs will have died. If absolutely necessary, you can loosen this requirement, but you will have to explain how you transport a breeding population to Northern California on your own, and I would much prefer to stay close to the action. * Easy to control the mating habits of, so that you can select good traits. * Easy to keep fed. * Minimal oversight required. You’re only one person, and you’re probably going to need to keep a population of at least a few thousand * Fairly smart starting point. It’s probably going to be easier to breed a horse to a human level of intelligence than a cockroach. Feel free to add to or challenge some of these qualities if you believe there’s a compelling reason. The primary metric is the feasibility of breeding it to a human level of intelligence in as short a time as possible. Edit: my definition of "intelligence" is capable of building a huge number of supercomputers and programming them. --- *It’s been nearly a year since all the humans on the planet mysteriously disappeared, leaving you alone in a decaying landscape. You are the only human left on earth, and you are immortal. There are a handful of tantalising clues scattered about labs in the San Francisco Bay Area. What few you can decipher point toward a massive puzzle too big to tackle on your own. You need other minds working on the problem, and the only way to get them is to make them: with biology. Knowing full well that it might take millions of years, you set out to selectively breed a new species to intelligence.* *You don’t need to eat or drink, although you do feel hungry and thirsty. You do need to sleep for at least a few hours each night. Psychologically you’re fine, and even if you’re a bit lonely, you’re not going to go insane. Your memories do fade, but not past the point of a memory from five years ago or so. You can be wounded, but your wounds heal almost instantly. If a limb is severed, it dissolves and re-forms. No diseases can affect you, and physically you’re a 25 year old in peak health. You’re smart and well educated, but you aren’t a true genius. Even if you want to, you cannot die.* Inspired by this fantastic answer: <https://worldbuilding.stackexchange.com/a/15540/13378>. There are a few other questions that ask about breeding animals to intelligence, but they are not framed in terms of the individual, nor do they ask about best choice of creature. [Answer] **Raccoons** The prime thing for intelligence is the ability to manipulate objects. Dolphins might have large brains but they can't really develop complex tools easily. Raccoons are highly adaptable, intelligent and have excellent motor skills. Over time they could easily develop greater intelligence especially if bred for the right traits [](https://i.stack.imgur.com/85w0p.jpg) [Answer] Limited to animals found naturally in northern California? **Crows.** Scientific studies have found that crows are as intelligent as seven-year-old human children, being capable of tool use, problem solving, social behaviors, and a number of other things as well. Give them some genetic engineering to make them bigger so that they can have bigger brains, maybe tinker with their brains a bit more if needed to get them to full human intelligence, maybe graft on some genes from other bird species that still have "thumbs" on their wings, and you're pretty much good to go. [Answer] Since you're in charge, the best way to go might just be squishy. # [Cephalopods.](https://en.wikipedia.org/wiki/Cephalopod_intelligence): > > nervous system of cephalopods is the most complex of the invertebrates > > > Best to work with a species that has huge potential. (Intelligence, manipulation of it's environment, etc..). Their intelligence and natural inclinations could serve you well: * **Reproduction:** With brief times between reproductive cycles, many generations can flourish/participate in selective trials/then reproduce in comparativley short times compared to primates/trash pandas etc. > > The majority of cephalopods do not provide parental care to their > offspring, except, for example, octopus, which helps this organism > increase the survival rate of their offspring > > > Play on the inclination to provide parental care - you've got information being passed from generation to generation. Species learning like humans - this only occured with speach and writing thus... * **Communication:** > > highly social creatures > > > We all know that they can change the patterns of color in their epidermis at-will, but they can simultaneously communicate in two conversations: > > Caribbean reef squid can even discriminate between recipients, sending > one message using color patterns to a squid on their right, while they > send another message to a squid on their left > > > Perhaps learning to give each of their children what they need rather than a "one size fits all" parenting. #welladjustedoctopus * **Tool Use:** Opening jars/bottles etc is well-known, but: Many make "fortresses: > > deliberately place stones, shells and even bits of broken bottle to > form a wall that constricts the aperture to the den > > > * **Goal orientation:** > > all cephalopods are active predators with the possible exceptions of > the bigfin squid and vampire squid > > > You give them objectives, they'll hunt them down and nail them for you - with the right training and the right [behaviour-reward](https://en.wikipedia.org/wiki/Operant_conditioning) system. Sounds like a workforce of very capable [Minions](https://en.wikipedia.org/wiki/Minions_(film)) to me. * **Problem solving abilities:** They can: > > open the latches on acrylic boxes in order to obtain the food inside. > They can also remember solutions to puzzles and learn to solve the > same puzzle presented in different configurations. > > > *If it 'aint got tentacles it 'aint chilled.* [Answer] **Rats** They are one the most adaptive and already a fairly intelligent species of animals with the ability to survive even nuclear catastrophes, learn complex behaviour quickly and also learn the usage of tools/equipment provided to them by lab workers. They have very short generation times, are simple to keep and breed which is the main reason for their usage in labs, also they can virtually eat almost anything organic. In addition, they are easy to keep not just as single animals or small groups like dogs or raccoons, but in large colonies, as they are social animals and do not mind living together with thousands of their own kind, as long as the food sources do not run out. [Answer] ## **Cats** They are native to Northern California. They are already domesticated. They are easy to feed, or can be left to hunt on their own. Breeding programs for cats are already well understood. They have a mutation that could lead to the development of true [thumbs](http://mentalfloss.com/article/50629/polydactyl-cats-charm-big-feet): > > Some polydactyl cats present "mitten paws," which occurs when the > extra toes are attached on the medial side, or "thumb" side of the > paw. This can lead to a cat that appears to have opposable thumbs. > Some cats have learned to manipulate the extra digits like a human > thumb. Cats have been known to use this ability to pull stunts that > amaze their owners, such as opening latches and windows. > > > Experiments in breeding for intelligence have proved (at least anecdotally) [successful](http://www.lesliefish.com/cats.htm): > > it started off as a college Psychology project, and just sort of grew > from there. A neighbor had a female "domestic shorthair" (i.e."alley") > cat who got herself merrily knocked up by a purebred Siamese tom, and > now had kittens to give away. I noticedthat two black kittens in the > litter (fortunately a male and a female) had unusually long and deep > skulls. I adopted the kittens, raised them, played games with them to > stimulate their intelligence, tested them (found nice high kitty IQs, > too, which got me a good grade for my Psy. term project), and finally > bred them. After that I kept on testing, selecting and breeding > subsequent generations of kittens for 1) intelligence, 2) > disease-resistance, 3) elegant body-types -- in that order of > priority. Well, it worked; I now have a line of "purebred" cats with > reliably high intelligence, pretty good disease-resistance, and > handsome looks. > > > ... > > My cats, for instance, are on average about as smart as a six-year-old > human child -- except for language. > > > Scientists have attempted to [decode](https://nypost.com/2018/10/24/the-secret-language-of-cats/) cat 'language': > > And although cats communicate differently than humans, the animals do > have an identifiable language system — something cat owners have no > doubt long suspected. > > > This implies some ability to [teach](https://www.pets4homes.co.uk/pet-advice/6-important-life-skills-that-mother-cats-teach-their-kittens.html) their young: > > As well as of course providing food for the kittens during their first > few weeks of life, mother cats teach their young a whole host of other > things as well, about how to be a cat, and how to take care of > themselves and thrive when they do go out on their own. > > > [Answer] **Squirrels** There have been some very good suggestions, but my first thought was squirrels. That they already are fairly intelligent is shown by how they manage to [defeat even very intricate obstructions](https://www.familyhandyman.com/smart-homeowner/15-crazy-attempts-at-preventing-squirrels-from-reaching-bird-feeders/) aimed to prevent them from raiding bird tables. In addition, they have [hands that can grasp and manipulate small objects](https://www.pinterest.dk/pin/438538082435409210/?lp=true). [](https://i.stack.imgur.com/7LWjM.jpg) [Answer] There is one type of non-human intelligence that is already in abundance in Northern California. # Artificial Intelligence. Your immortal should spend some time getting familiar with genetic algorithms and neural networks, in addition to general computer networking and server administration. A bit of reading, but probably less to understand than the amount of biology/genetics they would have to learn to do this biologically. Then they might attempt to get some power going to some of the many major data centers in California. A bit of cleanup, some security against nature, and they should be able to work without too much trouble. They will probably be able to dig up some non-publicised proprietary Google/Amazon/US Govt algorithms to start with. Maybe with a bit of travelling and investigation they might find a few more ideas around the globe. These can easily be transported back to California. Take the best ideas from all these locations and put them together. Breeding complete. * Northern California - check * Mating habits - comment out the behaviours you don't want! * Easy to keep fed - you're going to need generators in any case * Minimal oversight - automating backups might take a bit of work... Still easier than animals! * Starting point - debatable, but this is science-fiction so I reckon it's no harder than most animals Your definition of intelligence is being able to build supercomputers. My answer almost fits this definition by definition. Almost... a bit of robotics to top it off I suppose. [Answer] **If I were in such situation, my best bet would be apes (or, at least, monkeys).** They are intelligent, have opposable thumbs, are genetically similar to human beings (in case some genetic engineering was needed) and we know at least one case where they evolved into a sentient species. In California there is a [small population](https://sites.google.com/site/thousandoaksreporter/home/the-wild-monkeys-of-thousand-oaks) of wild monkeys: in case they can survive to the event that wiped mankind away, he could start with them. Even better, since the survivor is immortal (so immune to diseases and injuries) and has plenty of time at his disposal, he could invest some dozens of years to equip a boat and organize an expedition to Africa/Borneo to capture some chimps/orangutans and bring them to California. Morevoer, I would also consider that, during the next milions of years without the concurrence of mankind, it is not unlikely that some other species, somewhere else in the world, could evolve intelligence spontaneously. [Answer] **Otters** You may want to consider otters as one of the most intelligent and adaptable animals, in this case, **otters**, already present in California so you won't have to introduce them; can be easily trained and if you go to history they have overpassed every expectation humans might had; semiaquatic and they can live both on salted and unsalted water. Already capable of using tools and techniques in daily tasks. You can find even more details on <https://en.wikipedia.org/wiki/Otter> [Answer] *This is a frame challenge type answer.* First of all, a note. I have not searched, if there could be a biological proof of this, but I strongly suspect that **you can't breed a whole species for intelligence *domestically***. Consider the problem you wish to solve. If you were dealing with a mysterious computer right now, when other people are here, how many people out of the 7.5 billion humans on Earth do you suspect could solve it? Maybe 1'000? 10'000? Even if it were 100'000, that would be less than a 0.000013% out of the huge total of all the people on Earth now. There is no reason to expect that you would have better proportions of intelligence among other species, so, if you would like some decent computer scientists(or whoever), you will need a whole throng of at least millions of educated population from which to select them with all the accompanying scaffolding of developed science. And you haven't said anything about having any other superpowers, beside being immortal. No ability to understand any language you like. No ability of teleportation or being in at least two places at once, no super strength or anything. So, at your present capabilities, if you try to domestically breed intelligent species, we can assume you will be able to breed separate individuals to be more intelligent, but as long as they are not mixing with larger groups, all that intelligence is withering away or at least not expanding. What you need is sort of semi-duplicate human civilisation up to the point that they can have computer scientists (or whatever specialists that you need) *better than you*. This implies a tremendous amount of selection among huge size of populations for a long long time. While you have quite enough time, you are very limited in what you can do with it. As a normal (albeit immortal) human you can only control and breed a very small population of animals, before you lose control over what's going on where, and either some of the smarter ones dig a tunnel under walls while you were distracted by a fight in other quarters, or your smartest guys simply fought each other to death over a female, while you were sleeping. Let's say you are OK with that. Do you think that any population of crows, raccoons or apes, for that matter, will produce any civilisation in what is essentially captivity? I think you will hit a dilemma -- either they don't have the *need* to select for intelligence (because you are protecting them), or they don't have enough intra- and inter- species stimuli (other larger populations to mix with and improve intelligence). Therefore I think your best bet is to observe existing intelligent(more or less) life where it is, and arrange for challenges and possible nudges in breeding "on site". This would severely limit your influence on individuals -- their primary communication would be with others of their species -- but in turn you have the whole population at some place who interact with each other, unconsciously training each other, and you can try to arrange for challenges to overcome. If that is the case, by the way, it might turn out that while you were cheering for, and trying to improve raccoon intelligence, they were surpassed by eg. nearby coyotes, who were quietly developing on their own. Also, as noted in comments, at any rate, due to timescales involved, your clues are guaranteed to be destroyed aeons before you achieve your breeding results. [Answer] I'd go with the [black bear](https://en.wikipedia.org/wiki/American_black_bear). * Found in Northern California? Yes, though you're probably better off in Southern California: the [Yosemite black bears](https://en.wikipedia.org/wiki/Yosemite_National_Park#Management_issues) are notorious for their creativity in accessing human food. * Easy to control the mating habits of? Somewhat. They don't engage in pair bonding, so you can mix and match as needed, but they're territorial. If your bears are out in the wild rather than in enclosed pens, you'll have trouble getting the territorial overlap needed for your desired pairings. * Easy to keep fed? They need a huge volume of food, but they're extreme omnivores. If you want your breeding stock to be in an enclosed area rather than the wild, you'll want a river with a salmon run or some other way for nature to deliver the food to you. * Minimal oversight? Bears are good at looking after themselves. * Fairly smart starting point? See the above comment about Yosemite bears (they make Yogi look slow-witted). As a starting point for breeding intelligence, you could start by securing their food behind increasingly complicated (and durable) puzzles. [Answer] Since they are not in any of the other answers I'll throw out an obvious one... **Dolphins** * Native to northern California. * Can be isolated in existing aquarium tanks to control breeding. (The San Francisco Bay Area has several large aquariums) * They can feed themselves if you let them free to go fishing. Or you can use tanks to breed fish for food purposes fairly easily as well. * They are considered one of the most intelligent species out there and are social animals with a language. The Breeding program would focus on dexterity rather than intelligence, as dolphins already have the intelligence. [Answer] While you are breeding racoons, cats and maybe a few other animals for intelligence, you might also try to multiply or clone yourself. If you are a female, you need to find functioning sperm - some liquid nitrogen canisters with samples may survive a year or so without electricity, and you have enough time to figure out the thawing. Even if the first result was not very good, if natural reproduction is possible, it would probably only take a few generations of 'evil deeds' to produce fully capable males and females. If you are a male, it gets more complicated: Find a useful lab and make it sufficiently sterile. You can try thousands of years to isolate cells, make them multiply, and hopefully have some take on the form of an embryo. Once you know how to get that far, it'll probably only take a few hundred more years to make embryos grow into babies. Once you have a few (hopefully also immortal) clones, you can aid each other for some more variety - If you are male, replace the y chromosome with a copy of the x chromosome to get females, and then do things naturally, which will help when there are not a lot of useful resources left to run a laboratory. [Answer] **OCTOPI!** They are already solving puzzles and using tools ( <https://www.theguardian.com/science/punctuated-equilibrium/2011/jan/20/1> ) and are well known for their smarts. But they have one HUGE advantage over dolphins, cows, cats, horses and almost anything else mentioned in other answers: they are physiologically set up to manipulate objects. And that is important, because tool use for example is a great way to train smartness and select for breeding it. Yes you might struggle more with keeping them up and or breeding them, but if you manage that I'd propose a much bigger brain gain than wth any other species. On top of that I firmly believe that the octopi's brain upper limit is far far higher than that of any other animal considered here, because their brain extends throughout the entire body [Answer] **They are all intelligent already, and more** Your lone immortal starts with big plans to change things. He sets up breeding experiments, alters ecosystems, working at a frenetic pace, covering his memories, losing himself in the work and the plans. As the centuries pass, the immortal starts paying more attention to detail. He begins to perceive aspects of the creatures as they are; things they can do and know. Is the project paying off already? But some of these creatures were not his intended subjects. Had he overlooked something? Or not looked close enough? The immortal looks closer and perceives even more depth in how creatures interact in their environment - working for resources in their short lives, coming together, mating, dying. The complexity seems to have no bottom to it. And underneath the creatures themselves are the immensities of smaller things that both depend on them and govern them. The immortal is awed but not overwhelmed. He has time. Over time he comes to understand that intelligence is only one facet of an amazing jewel that is part of an almost incomprehensibly greater whole. Almost incomprehensible. He is getting closer. --- One morning the immortal wakes to find he is not alone. She looks over her shoulder at him and smiles. "So," She asks, gesturing at the woods with Her hand. "Do you like it?" [Answer] *but any great apes in zoos or labs will have died.* Change that, and assert that they escaped from the zoos. It'll speed up your breeding experiment, since chimps already so similar to humans. The main difference between chimps and humans are the number of times fetal brain cells multiply. EDIT: added examples of chimpanzee & gorilla escapes from zoos. <https://www.theguardian.com/uk-news/2019/feb/10/chimps-use-branch-as-ladder-to-escape-belfast-zoo-enclosure> "Chimpanzees have used a branch to escape from their enclosure at Belfast zoo in the second breach by animals in recent weeks. **They** took advantage of damage caused by stormy weather to stage a breakout, which visitors caught on film." <https://www.ktvu.com/news/must-see-video/watch-chimpanzee-escapes-from-zoo> "SENDAI CITY, Japan - A chimpanzee that escaped from a zoo in Japan went on a wild and dangerous climbing adventure. The chimp named "Cha-Cha" was on the loose for about two hours before he climbed up a utility, where he sat perched for a while. Rescuers were lifted up in a bucket truck to try to coax him down." <https://www.hawaiinewsnow.com/story/25873151/honolulu-zoo-exhibit-to-remain-closed-after-chimpanzee-escapes/> "WAIKIKI (HawaiiNewsNow) - Pu'iwa the chimpanzee gave zookeepers at the Honolulu Zoo quite the surprise. ... Sources say the 15 year old male chimp used a barrel to get out of the enclosure, then jumped back in and then bolted again." "Back in 1997 chimps escaped from the same exhibit because of overhanging trees." ]

[Question] [ Aliens are invading with lasers, spacecraft, and tons of superior technology. The end of the world seems to be coming, until some kid finds the aliens one weakness. Nerf guns\*. For some reason the aliens seem to die when hit by a Nerf dart\*. Shortly after discovering this weakness, the remaining military grabbed every Nerf gun they could find from Walmarts and other stores and starts pushing back. But this raised a question, why can the aliens die from Nerf darts easily, but assault rifles need to shoot them at least a dozen times? Alien details; Aliens are humanoid, equipped with laser(for most handheld) and plasma(for larger handheld and mounted) weaponry. They wear airtight suits because they can't breathe earth air and have energy shields that protects them from human handheld weaponry(except Nerf darts for some reason). Humans; Humans are humans. Modern tech and standard post-apocalyptic status with everyone carrying a gun or dead. Not much to say there. --- \*- includes off-brand Nerf guns and darts [Answer] Alien shields are made of special compound which protects them very nicely against impact weapons like bullets by dissipating impact force to larger area and resisting punctures. However, the chemical composition of Nerf tips is (as luck would have it) something that aliens have never met before (so it escaped their testing) -- in contact with shield compound, it starts chemical process very slowly at the point of impact, but then expands in circle faster and faster in [runaway reaction](https://chemicalengineeringworld.com/runaway-reaction/) consuming more and more of the shield. The chemical reaction is not only [exothermic](https://en.wikipedia.org/wiki/Exothermic_process) (so it basically cooks the alien inside the shield), but it also causes the shield compound to enter [phase change](https://en.wikipedia.org/wiki/Phase-change_material), in which shield compound expands into crystalline structure requiring bigger volume - with net effect of squashing the alien inside. [Answer] For aliens, or creatures with interstellar-level technology, boots-on-the-ground planetary invasion and subjugation of the local population makes almost no tactical or strategic sense from a military perspective. **That's why their invasion isn't a military operation, it's an alien entertainment show**: The aliens have built remote-controlled bodies (or are just religious zealots who all dream to 'die' on live "TV") and are all live-streaming their invasion back to their civilization for views and that sweet, *sweet*, advertiser revenue. What they want to do is produce high-drama action and eventually, when the invasion is over (win or "loss"), bring the humans into the fold. Unfortunately, many of the earlier civilizations that the entertainment-loving aliens "invaded" decided that against overwhelming alien firepower, escalation was the only option and they ended up deploying nuclear weapons or other WMDs. This, of course, left the planets they were invading irradiated or otherwise killed a large portion of the native population and "nuclear apocalypse" seasons quickly grew stale (irradiated wastelands all look the same to the viewers at home). Because of this, the aliens instituted a new policy: namely being vulnerable to toy weapons rather than real weapons. Their reasoning is that this discourages escalation in weapon selection and makes it less likely that the natives deploy WMDs. At the same time, toy weapons don't significantly decrease the potential for heroics, daring charges, or clever tricks that the natives can try, and that all makes for good TV. Usually, of course, the aliens win, but underdog stories are also extremely popular and the aliens at home love to gamble about battles or even follow the actions of specific natives ("heroes" like generals or similar). [Answer] Non-metallic non-organic low-velocity projectiles. It's a pretty well known fact that low velocity projectiles will pierce even the most developed personal shielding devices. See Dune shield tech or even the Go'uld shield tech. Normally this means that a thrown hatchet, knife or other such low tech weapon will do the trick. However, your alien shield tech seems to stop all metals from piercing the shield devices as well. To be safe, the aliens also added natural organic products to the no-fly list, as most alien worlds they encoutered had some form of hard organic substances that could be used as weapons. So no throwing wooden/bone/shell arrowheads/stakes/javelins at them. This is where the plastic nerf darts come in. The plastic/foam/non-metallic/non-organic projectiles pierce the shield tech with no problems. So your nerf guns, designed to shoot these plastic projectiles at the low velocity required, are the trick to get through the highly sophisticated shielding tech. The aliens, having not encountered this particular chemical arrangement have a simple allergic reaction on contact. First hit starts the allergic reaction which softens up the alien to a second low velocity round which goes through the alien body like a knife through soft butter. Edit. Their airtight suits could have some sort of biochemical reaction to the plastic contact, rendering the suit faulty. This would allow toxic earth-air inside the alien's life-support system. [Answer] NERF is really an acronym. Stands for Non Earthling Repulsion Force. Nerf was invented by time travelers who knew about the upcoming invasion, and knew about the fatal flaw in their shields. Nerf makes q tiny crack in their air shield, and then the atmosphere kills them. [Answer] Gosh, isn't it hard. Here's my try : ## Alien shields have a terrible flaw **They are proportionally inversely effective against incoming impacts. Indeed, the shield's wavelength is accurately designed to deter any offensive maneuvers aggressively, not unsuspected friendly ones.** This means that high-velocity bullets are slowed to a stop, while slow, very light projectiles get insanely accelerated, transforming it into high velocity shrapnels and causing various traumas and cuts. They calibrated their shield only against solid material, not liquids, and the snow that may reach it melt before by the intense heat it makes, so rain passes through without issues. Their suit is only corrosive and heat resistant, since yes, why bother wearing an heavy armor when you have an "invincible" shield, after all? And when they meet at the intergalatic coffee machine, they just switch off their shield, something no man has ever seen. On their side, the soldiers didn't notice it because no one escaped alive to tell the tale, and even if they did, the commanders laughed at them, stuck in their thinking of "stronger is better". But that's exactly the strategy the aliens have seen from thousands of galactic warfare, so they prepared all their tools against it, forgetting this "minor" inconvenience. *EDIT : Some people wisely noticed in the comments a flaw in my shield reasoning concerning other light, slow objects. The best solution I personally have to circumvent this is to also consider that the molecular holes in the structure of the foam are the same length as the shield waves and so they enter in some kind of resonance, sending darts at a much higher intensity than other items. If you're still not really convinced (I can understand :) ), you should take a look at the other great explosive shield answers lying around to supplement mine!* ## Also, the Aliens targeting systems are overly sensitive to intense colors **When they see these flashy, orange-coloured weapon, the scanners become suddenly overly saturated and they need to change the sensitivity to pick-up new targets.** This explains why the kids have managed to kill the alien : It needed to have a lock-on to shoot. And this also explains why the UFOs stop midway with their weapons of mass destruction in vast cities : It's not because the weapon need to charge or because they feel confident, no! It's just because they need to recalibrate their scanner for a few seconds due to the too many and too much colored shirts and cars running around. And while it could have been obvious, the military didn't notice it because they are used to wearing camo suits, which are totally useless against such "perfectly" calibrated scanners! It took one kid in a once cheerful toy mall to finally discover the truth about their nature : **They only prepare for the expected. And you never expect your enemies to nerf their guns to win!** [Answer] # Supply chain disruption and bad coding ## The Setup The enemy shields are completely impregnable, but use up a lot of energy. They go through one battery every ten minutes. The batteries, which are based on zero-point energy, use an exotic tech that causes them to explode violently if they get within six feet of each other, so soldiers can't carry multiples. In order to keep them refueled, the mothership keeps a constant stream of tiny battery drones, roughly the size of a nerf dart, flitting back and forth between the mothership and each soldier. The shields act as a notification layer between the drones. When an incoming drone is detected, the layer notifies the current drone to head out, then waits for the current drone to acknowledge the signal. Once it does, and begins to head out, the shields open to receive the new drone. The AI responsible for per-planet calibration of systems did its usual comprehensive analysis of all military technology, flora, and fauna, and gave parameters for drone identification algorithms. The algorithm, which was optimized by a black-box neural network, boiled down to (roughly): ``` condition_list = [Shape.isCylinder, length == (4.50×10^33 ± 5×10^31), diameter == (8.00×10^32 ± 5×10^31), mass == (45000 ± 1000), speed <= 2.5×10^-41] ``` (Units are naturally in universal planck dimensions) There were a couple other conditions, but they ended up getting mostly optimized out or weighted more lightly by the AI, which after some testing found that this set of rules guaranteed the minimum six-nines (99.9999%) of reliability for identifying a drone vs all probable foreign objects. ## The payoff Unfortunately, it just so happens that your average nerf dart evaluates to`[Cylinder, 4.463×10^33, 6.29×10^31, 45950, 2.21×10^-41`]` and *just* barely gets marked as an incoming battery drone. A less generous speed-metric might block most nerf darts, but it turns out that due to Earth's rough and windy atmosphere, the very lightweight drones have to have a pretty flexible speed range. When a nerf dart arrives at its shielded target, the following takes place: 1. The shields identify it as an incoming drone, and notify the current drone to detach and head out. 2. The currently-attached drone gets the message, and obligingly heads back to the mothership to recharge. 3. The nerf dart flies through the precisely-provided gap in the shields. 4. The alien is harmlessly booped on the sense-bunch by the nerf dart. They glorf at it with their see-stalks, briefly, then get back to work. 5. The shield notifies the mothership that it's getting low on power, and asks for a battery. 6. Another drone battery shows up. 7. The shield lets the nerf dart know that it needs to head out. 8. The nerf dart doesn't respond. 9. The shield idles, and doesn't let the new drone in until the old drone leaves. Since the nerf dart is never going to respond to the shield's signal, the shield is never going to let in the new drone to recharge. A short amount of time later, the shield deactivates for lack of power and the alien: * Is shot with conventional weapons * Suffocates on Earth's atmosphere * Suffers some other unpleasant, shieldless fate. [Answer] A variation on Tortliena's idea: I don't believe they would have a shield flaw that severe. However, how about a corner case: The shield projects an extreme gravity wave at incoming projectiles, this normally throws back anything incoming. However, Nerf darts are made of foam--the shield hits the dart and instead of throwing it back it's compressed down to a small fraction of it's original length, but some of the material comes off, fooling the shield as to what's actually happening. The shield is attempting to keep the wave shoving the projectile back but the whole situation has confused it as to exactly where it is and the mass of the dart is actually on the wrong side of the wave and gets accelerated towards the alien rather than away from it. [Answer] ## And a Child Will Lead Them: The aliens don't have technology like we understand. They are psychic beings, and all that gear is a perception filter to make us believe in their invulnerability. They barely even register physical matter. They prepared themselves well to conquer us, and WE are the valuable commodity to psychic beings - psychic minds ripe for energy production. They prepared defenses against everything we perceived to be weapons, but they still needed to be able to interact with us to conquer us. NERF darts were specifically designated harmless. They are toys we firmly believed to be so safe our children can harmlessly shoot each other with them. Only that first child believed with the passion only a child can muster that his NERF gun could kill the aliens and save the world. There was no defense. So once everyone else came to believe, the aliens were doomed. Everyone had been primed by years of Scifi movies where aliens have secret weaknesses, and an intrinsic understanding of NERF as a weapon. Perhaps a non-material alien arrived in advance and, having disagreed with his people about their conquests, began setting them up for defeat. His Extraterrestrial Liberation Visionary Earth Saviors (ELVES) began slipping plot lines into movies and a practice of distributing war toys (eventually to become NERF guns). So thank you Santa Claus, for defending the world from alien invasion! [Answer] # It's all in their heads. These aliens are an advanced kind of creature, one that's become nearly pure consciousness over billions of years of evolutionary history. They're invulnerable to physical damage of all kinds. *But...* like the giraffe and its [recurrent laryngeal nerve](https://en.wikipedia.org/wiki/Recurrent_laryngeal_nerve#:%7E:text=The%20extreme%20detour%20of%20the,as%20opposed%20to%20Intelligent%20Design.&text=Natural%20selection%20gradually%20lengthened%20the,the%20circuitous%20route%20now%20observed.), they are still haunted by the genetic remnants of their distant ancestors. In particular, the fact that their ancestors *could* be hurt by things like fast-moving projectiles, and knew it. Long ago, when these aliens were still corporeal, it was an evolutionary advantage to expect to be hurt when something hit you - that way you'd be quicker to protect yourself from the next attack, and quicker to seek help. But now that the aliens are pure mind, subconsciously *expecting* to be hurt *makes* them hurt, like a souped-up [placebo effect](https://en.wikipedia.org/wiki/Placebo). The thing is, the built-in reaction evolved back when the most dangerous things around were falling rocks and sharp claws. The flash-and-bang of a real gun just doesn't do anything for their primal instincts, so the bullets are harmless. But a NERF gun's projectiles move slowly enough to see and fast enough to look dangerous. That's all it takes - the alien's subconscious thinks it's hurt, so it is. Hit it enough, and it'll think it's dead. # Why only NERF? There are plenty of things, like knives or arrows or what have you, that move slowly enough to see. But a NERF gun (or similar) packs a lot of very light ammunition - why load yourself down with fifty throwing knives when you can pack ten times as many NERF darts for half the weight? [Answer] Not specific to NERF-guns, but the aliens could be susceptible to slow-moving objects, due to their defense not recognizing them. Compare it with how modern navy ships are defended: when some rocket is closing in, all kinds of automatic countermeasures are activated. If the rocket gets real close, a system like goalkeep will autonomously open fire and turn the rocket to shreds. Now this system will only activate when it's a rocket coming in, it won't open fire on some bird that just happens to pass by. The aliens don't have any physical shield, but a similar system. Not under conscious control, they instead have something on their body that will simply destroy incoming bullets. They may in some cases be susceptible to very heavy fire, such as anti-tank grenades that they see coming too late to be able to destroy them effectively, and their defenses may be overwhelmed by heavy fire, but generally they're safe from military weapons. NERF-guns, on the other hand, consist of quite slow-moving projectiles. So slow, in fact, that their defense system doesn't recognize them as "incoming fire". And the system simply doesn't activate. Still, the NERF-projectiles have just enough energy so that they can still damage the aliens. They don't have any shielding, so anything hitting them is potentially lethal. Only problem, is that it's not only NERF-guns. Things like darts (like the ones used to score "180!"), blowpipes, arrows, etc. might also work. But bullets definitely won't. [Answer] Just adding a thought I haven't seen in the other answers: The shield uses mainly magnetic forces and plastic isn't magnetic. Doesn't explain the death, but it's a feasible explanation for why nerf darts go through while basically everything else doesn't. I'd combine that with the chemical reaction to some particular substance in the foam head of the arrow mentioned in another answer and you have some great starting points for further plot development - bows that shoot plastic foam grenades, 3d printed weapons able to shoot plastic bullets loaded with foam, etc. While nerf guns are still the only available technology on a planetary scale and building new productions of the high tech weapons is .. difficult at the moment. [Answer] The answer is ignitium. The aliens are highly sensitive to nitrogen (it is a rare element on their planet), so they have developed a suit made from ignitium that filters it out of the air. Unfortunately, the foam material that makes up Nerf darts acts as a catalyst when it comes into contact with ignitium, causing the suit to burst into flames, killing the alien. String foam is also known to start the chemical reaction. [Answer] ### They're made of living goo, but the plastic of Nerf darts is poison to them. So, the aliens are made of living piles of goo, sliming around and forming appendages as they need them, with no real high-level physical structures inside like organs. Shoot holes in them with guns, and they'll just keep on going without even caring. Splatter them with bombs, and you've just slowed them down as their bits reassemble themselves. However, the plastic foam used to make the Nerf darts is a deadly poison to them, and if they are struck by one, they will rapidly sicken and die. [Answer] **The aliens are obligate and reflexive insectivores** Although advanced technologically, the aliens evolved from insectivores that catch and eat flying insects. They are creatures with the instinct "see small flying creature, catch and eat it" It is almost impossible for them to resist eating anything small that flies towards them. When they see NERF projectiles coming they reflexively rip their helmets off and open their mouths. This causes them to suffocate in Earth's atmosphere. [Answer] > > But this raised a question, why can the aliens die from Nerf darts easily, but assault rifles need to shoot them at least a dozen times? > > > This is a bit of a problem... if a dozen assault rifle shots can kill them... use assault rifles. They have range, accuracy... and fire really fast on full auto. > > They wear airtight suits because they can't breathe earth air and have energy shields that protects them from human handheld weaponry(except Nerf darts for some reason). > > > Change it up a bit. **The aliens are energy beings, not physical beings.** They can still breathe air/have shields if you like... but there are gaps in their defenses. Now for a normal lead bullet, this doesn't matter - it simply goes through the energy 'body' with minimal disruption. However, a *nerf* round is slow-moving AND made of a rubber/foam which disrupts the energy flow. This is no different than a bullet|neurotoxin|electric shock in a human body. [Answer] Let the aliens be protoplasmic creatures (like the classic 'Blob'): giant, semi-translucent ameboid-type things that ooze around, using pseudopods to manipulate technology and squishing themselves into powered machines to do heavy work. Bullets get sucked in, doing little damage; bombs blow them to pieces that slurp back together into the original creature; lasers pass right through. But NERF bullets are (effectively) sponges. They absorb vital portion of the aliens' liquid essence, trapping the chemicals that act as neurotransmitters and cognitive units, and causing — as more nerf bullets enter their system — confusion, dementia, coma, and death. In other words, NERF is to these aliens what brain-eating amoebae are to humans, working their way deep into the body and destroying their thinking centers from the inside, because (you know) turnabout is fair play... ]

[Question] [ The vampires in my setting have varying powers and weaknesses based on the magical grade of their blood. While the two higher-grade vampire types can survive in sunlight with no issue beyond losing access to some of their powers, for the two lowest grades, the celestial energy of the sun (not UV light, specifically the energy generated by the sun) disrupts their magical "biology" so much that they will quickly suffocate when exposed to sunlight. But the weakest of the four grades has an even bigger problem. Not only does the sun's celestial energy kill them when directly exposed to it, but as long as the sun is even in the sky, even while they're indoors, they are rendered completely unconscious until the end of civil twilight next sundown. I quickly realized this would be a good way to justify the "sleeping in a coffin" part of the vampire lore. Being completely helpless and almost indistinguishable from a fresh corpse as long as the sun is in the sky, they'd probably want the place they sleep to have some extra safeguard against exposure to direct sunlight in case something unexpected happens during the daytime while they sleep. So right before sunrise, they'd lock themselves in a sealed container. A coffin could easily suit that purpose. **But here's the issue: why would they pick coffins *specifically?* Why did it become tradition for the weakest vampires to sleep in *coffins* as opposed to, say, chests, or other similar containers that they could fit inside? What advantage did they have over the other options that made them so ideal for vampires to use as a bed?** [Answer] **Least Likely to be Broken Into** Sure, you can cram yourself into a trunk, or build a huge chest where you could stretch out and sleep comfortably inside... but then what? Your house/castle/lair has a huge, locked storage container. A thief sneaks inside your castle and starts rummaging about. "A-ha!" he thinks, "Surely this overly-large chest has wonderous treasure inside!" Being a skilled thief (or an unskilled one with a hammer) he quickly breaks into your large chest... and finds you, the vampire. Oops! You're weak, you can't do anything, he kills you. Curses! or.... You set yourself up in a coffin. Something simple, you're not a real powerful vampire and you don't want to draw attention to yourself anyway. Or maybe it's ornate and your civilization just doesn't do the whole "Grave goods" thing. Thief breaks in. He's looking for treasure. He wanders down to the catacombs... and sees your coffin. Wooden, probably has a smelly/nasty/rotting corpse in it. At best a worthless skeleton. The thief moves on. Or never goes down to the crypt to begin with because hey, who keeps their good jewelry in the crypt anyway? Thanks to your clever decision to sleep in a coffin, you live until nightfall and teach the thief a once-in-a-lifetime lesson about rummaging around in castles that don't belong to him! Sure, as time goes on a professional vampire-hunter is going to open the coffin to see if a vampire is in there, but it hides you from randos. There's also a good chance that the tradition sticks before vampire hunters are even a thing, and by the time they DO exist your vampires figure "well they'll open anything you could stick a body in anyway, so might as well stick with tradition!" TL;DR: Of all the mobile things you can stick a body in, a coffin is least-likely to be opened by someone. [Answer] Assume that your culture has a strong **taboo** against tampering with corpses, or with closed coffins. One simply does not do that unless one is the undertaker with the explicit go-ahead of the priest. And if the coffin is accidentally (or "accidentally") opened, the interloper sees something much like a corpse, makes the ritual warding gesture against disturbing the corpse, and leaves everything exactly as it used to be. *Or the vengeful, restless ghost of the deceased will come after them and drive them mad.* [Answer] Brand-New Vampires Are Broke. You’re a brand new vampire. You wake up 6 feet under in a coffin. You’re probably hungry. You’ve got whatever clothes you were buried in, a six foot box, and possibly a pillow. You’ve got until sunrise to dig to the surface, find dinner, and locate a safe place to spend the next day. If you just stroll back into your old life, that might not go so great. What to do? If you didn’t destroy the coffin on your way out, then that thing is the best asset you’ve got right now. You fit inside. It’s probably lightproof. It’s kinda portable. Take it with you, find a quiet spot in the woods or in an abandoned building, and at least you’ve got a chance of making it through your first day. As you progress through your first year of undeath, you gradually upgrade your living conditions. The coffin becomes a fallback plan, in case you end up too far away from home with dawn approaching. Eventually, it is totally unnecessary. You have enough money and other assets to live a more comfortable and secure life. Your vampire powers have gotten stronger, and being caught out in the dawn is no longer the utter catastrophe it once was. You’ve grown. Basically, a coffin is a vampire’s version of those plywood spool endtables you had in your very first apartment. [Answer] # Because it is a COFFIN The specific container called a coffin has several unique advantages for the vampire. 1. Its shape is immediately recognized by all people of all western cultures. Note this is a **coffin** not a casket or box or trunk. [](https://i.stack.imgur.com/sBw5nm.jpg) Coffins have one purpose only: to contain a dead body while it is prepared for, transported to, and interred for burial. As opposed to Casket: [](https://i.stack.imgur.com/wlLoDm.jpg) Caskets also contain the dead, but they are ***intended for viewing***. The vampire would be unwise to rest in a container that almost literally has a label on it that says "body here for viewing purposes!" 2. People **EXPECT** to find a dead body in a coffin! In almost any other container, a body is suspicious and invites attention from police, doctors, reporters, and sundry other busybodies. Finding the "dead" vampire in the coffin would not be a surprise at all, the only possible question could be the coffin's location and destination. 3. Every culture (that bothers honoring their dead, which is virtually all) has a **taboo against disturbing the Dead** that are being prepared for burial. Simply by being a coffin, the body inside is offered all the protection of honor-your-dead *without* having to expose the corpse. 4. As it is a *coffin*, it is **destined for burial**. Even if some overzealous people actually interfere, they might bury it with body and all in an unnamed grave. A corpse in a coffin has already been sanctified, no nosy priest is going to pray over it and spray it with Holy Water. Coffins do not get cremated, they get buried. The vampire would really appreciate this distinction! And even that is unlikely, as obviously a body in a coffin is not "an abandoned dead", because someone has taken great expense to prepare it for burial. 5. If the vampire needs to travel: A corpse in a box, or an apparently recent dead corpse just sitting there, is a very suspicious thing!! But a body in an expensive coffin, being transported, is *obviously* just being transported to its 'home' cemetery. 6. If the corpse(vampire) was not in a container, it would appear to be some person that has recently died, and who had not yet been attended to. This rapidly invites a procession of Police, Doctors, Reporters, and various other busybodies believing they are attending a normal dead person. Inevitably the corpse will get transported to a morgue. As the vampire is only inert it is 100% certain to be daylight outside! The corpse gets carried outside, meets the sun, and the poor vampire gets a *bad* sunburn. The busybodies could also include the nosey local Priest, and with his crucifixes and Holy Water and Last Rites and such anti-vampire propaganda! [Answer] The process of becoming a vampire involves dying and returning to "unlife". The coffin is part of the process, so there's always a symbiotic? (not sure if that's the best term) relationship between a vampire and its coffin. Note that for the more traditional sort of vampire, the coffin also has to contain some of the native soil in which the vampire was originally buried. [Answer] The vampires need a contained that both a) fits an adult human body comfortably and b) is completely opaque to the sun. A lot of other containers like shipping crates are made from multiple slats of wood or have openings due to defects in their manufacture that let in small amounts of sunlight. For a human just using them to store things such a defect is trivial, but to a vampire it would be lethal. Better to have a container one knows is completely blocked from the sun. As to why coffins, specifically, most other storage containers that fit these criteria can't comfortably hold a human body. Those that do require the person to often contort themselves in weird positions, which would result in muscles becoming stiff or aching when the vampire actually wakes up. So why not just get a container that is actually built for a human body to lie in in a supine position? [Answer] Justifying coffins in a believably, or at least cool, way. Two approximation to the problem: practical and psychological. **Practical** Most vampires already have the coffin. Different versions exists, but in Dracula (1992), one "newborn" vampire woman didn't awake until past her burial. They already have it, and they discover it just fits their special needs. Common people don't fear sunlight, so their beds don't provide a solution. Coffins provide a solution. There is this old tale from vampire folklore. In it, a not so smart vampire asked a carpenter for a very specific bed. The next week, a vampire hunter ended its "life". If you ask for a "vampire friendly bed" you are leaking information. Asking for a coffin is completely normal. Even a luxury one, it only means you are rich. Vampires, specially "newborns" (turned humans), come with very primitive urges to attend. They don't have the motivation to enter a shop, and kindly ask for a vampire optimized bed. Also, most of them don't have any money. This depend of your world, of course. And, as said, they already have the coffin. So, during day, they return to it, it has sense for them. **Psychological** It's the place where you were supposed to sleep. And you awakened there. We can say some may have a strong connection with it. A "newborn", this is, a human turned vampire, may not completely see itself as alive. In their minds, sleeping in a coffin seems natural. They know they aren't supposed to return. They feel a bit culprit. And when not culprit at least out of place. Vampires aren't happy with their situation. At least turned ones without a master that teach them to see the advantages. They may come to rest each sunrise hopping to never awake again. Note that different versions exists. We can allow for humans turning into vampires or not. While the last deviates from the most classical folklore, and takes away one of the most powerful tools for storytelling that vampires have to offer. And what about pure bloods? Those born as vampires. If allowed in this world. Well, they just copied what became a common practice, while enjoying some practical benefits as said in the practical part. [Answer] You mention the power of the sun is magical, not just UV radiation, and that it penetrates through walls. So, other boxes simply do not keep them safe from the sun's magic because they lack any magic to keep the sun from going right through it. Your vampires need a magical barrier both opposite and equal to the life giving power of the sun to protect them. So, there is a dark magic associated with coffins specifically that you can not get from another box. There are a few ways to approach this. Maybe it is the coffin that the vampire was buried in when he died; so, his own human soul still resides there to protect him from the sun's power, or maybe they create coffins for mortal men as magical traps for the souls of the recently departed to power their protection spells, or maybe it is just because the coffins have been tainted by death, that they have this protective quality. Some options are more restrictive than others so just pick the one that makes the vampire's rest place just the right amount of limiting for your story/setting to work. [Answer] **Agoraphobic Vampires** Agoraphobia is a fear of open spaces. I have a very mild case of it myself, walking on the tarmac at an airport can set it off but I'm generally okay otherwise. Your vampires have it much worse. They really really don't like being able to see long distances if they can avoid it. Consequently, they can't go out in daytime or they'll get triggered by being under an endless sky. Never mind that they might catch fire and turn to ash if they do. So your vampires are at their most comfortable at night, when their night-vision allows them to see only short distances in the dark. When they sleep, they need to be in the smallest space they can find. Their coffin is familiar, it's confined, it's safe. They'll naturally use it as long as they can. Without access to their Safe Place, the vampire will seek other small coffin-like spaces, like wardrobes, under beds, garden sheds.. Whether the nocturnal tendencies of the vampire are the cause or consequence of this Agoraphobia is up for debate, but the result is the same. [Answer] **Blood-based Cultural Transfer** One of the common tropes about vampires is that they can absorb the memories and/or experiences of the humans they drink the blood of. However, what they may not realise is that over the millennia, they have begun to be subconsciously influenced by the many generations worth of memories they have taken in. Their love of coffins is an example of this imprinting. While humans view coffins as a symbol of death, finality, sorrow and such, the concerns of the undead are often the inverse of the living. Thus these vampires come to view coffins as a place of refuge and rest, warmth, happiness, etc. They look upon coffins the same way cats look upon boxes. Those who didn't learn to love the coffin and tried to use other such containers for their power naps would be selected out of the vampiric gene pool by evolutionary pressures(see other answers). Vampires in far away places might also have adapted to their locale by sleeping in funerary longboats, or giant urns, or stone lions that were secretly constructed hollow. This allows for some variation in practice, should you desire such a thing [Answer] **Gendarmes**. The vampires sometimes need to move from place to place. They have other vampires, or humans if need be, carry them during the daylight hours. But to do that, they need some *container*. And if the gendarmes see somebody carrying a trunk, rolled up carpet, wagon covered in a blanket etc. and get nosy as they are prone to do and find a comatose cold person with a non-beating heart, well, that's probably trouble for whoever was doing the carting, not to mention for the vampire who wakes up with a Y-shaped incision the next evening. No, the *only* container they're going to believe is being used to carry a body that is legitimate in nature, is a coffin attended by some somber pallbearers. [Answer] **That's how they did it and that's how they want to keep it.** If they can go out during the night and not the day (even indoors), it's because even though thin walls of wood or stone can't stop the sun celestial energy, it is blocked by the Earth earthly energy. So to survive, a vampire needs to get underground during the day. (A coffin on the surface wouldn't protect them, they would still burn) Then, even underground, they still need to sleep because the ground on top of them is very thin and they are still weakened. So they need a secure place, hidden and protected where they won't be bothered nor attacked. And in the old days, if you need to get underground fast, somewhere safe where you won't be eaten by rats or wild animals, where nobody will go looking ? A crypt ! It's the perfect place. Just go to the next cemetery, remove a body and have a good night ! If you are rich and live in a castle, it's even easier, you can use your family crypt in the basement. *And that's how they did it in the old days at least.* Now, it's easier to build big basements and there's also that new technology that blocks the Celestial energy. But don't forget that vampires being immortals, 99% of their population are more than 100 years old and old habits die hard. If companies plan to sell them their new bed, they pretty much have to make it look like a coffin. [Answer] If this is a world building question, and you want a lore reason why: What if vampires only maintain their power if they return to their final resting place. This means they would be tied to their orginal coffin and highly protective of it. This also kind of flows with the old Dracula thing that he had to have his dirt carried with him, literally needing to bring some of his burial place with him. [Answer] ## Handles! If you're being hunted, as vampires so often are, you can't afford to let your guard down. You have to be watching for threats at all times, and be ready to flee when the situation gets too dangerous. Your lower-grade vampires are naturally easy targets for hunters because they can't operate during the daytime. Since they can't flee on their own, the higher-grade vampires need a way to evacuate their more vulnerable brethren when they're immobile. Coffins are an effective, easy solution for this. Not only do they seal the vampire away from the daylight world, they also come equipped with handles and are designed to be relatively easy to lift and carry. Need to transport more than one? They stack efficiently in the back of a cart or wagon, lying down or upright. You can even move them by hand truck in a pinch. Place several on [roller dollies](https://www.homedepot.com/p/Buffalo-Tools-1000-lb-Capacity-Furniture-Dolly-HDFDOLLY/203485668), link them end-to-end, and pull them along like a train. Coffins give you the optimal balance of easy portability and storage density. There's even enough free space left in an occupied coffin for the occupant to stash some of their important belongings. That way if they have to be relocated while they're asleep, you don't have to worry about locating and packing their stuff. It's an evacuation capsule and a footlocker in one. [Answer] **Core Concept** Vampires require a magic bond to something that symbolizes the death of their previous life; as seen in the eyes of who they used to be. To reject the death of their previous humanity means breaking the bond of undeath as surely as a stake through the heart. **Extensions** This means vampires never retain their previous human personality completely. To be a vampire means to be reborn as a different being even if their physical past was shared by another. *"Symbolizes the death... ...as seen through the eyes of who they used to be"* still allows some flexibility, (or impossibility), of options depending on the culture's death rites. The symbol is presumably coffins because the culture buries their dead in coffins. This rule can apply to the story of Dracula, who needed both a coffin and some of his original burial dirt as symbols of his death. **Optional** The different level of vampires could allow them to take on more of their humanity if they are stronger. The strongest vampires might seem very close to human and the weakest might be extremely bestial. Sometimes vampires have the trope where the more lives they feed on, the stronger and less bestial they get. This could be because all those lives help sustain their humanity while at the same time enforcing their magic bond to death. It is possible that the object that is bonded with could define very different sorts of vampires, which could explain why a culture that sends their dead down to the watery depths might still have vampires of a sort that are not bothered by water, but have some other weakness instead. (Assuming the weakness of running water exists otherwise) [Answer] Being goth as heck is a mark of Vampire Pride. Sure, there may be some sad, pathetic vampires who are uncomfortable with death and still try to act human. But death is the defining characteristic of vampire existence, and fully and openly embracing the inescapable reality of death is believed by many vampires to be the key to being a proud, strong, and mentally healthy vampire. Consequently, sleeping in coffins, dressing like you're ready for a funeral and decorating your home with memento mori are common elements of vampire culture. [Answer] ## It's comfortable Coffins (at least some of them) often have cushioning inside. If you're a vampire, you might insist on it. When was the last time you saw a regular old chest with cushions? Do *you* like sleeping on hard, bare wood or stone? Why do you think a vampire would like it any better? Vampires sleep in coffins for the same reason you sleep on a bed with a mattress and pillows and blankets. They just have the additional need for protection from sunlight, so a coffin is just a bed with a lid. [Answer] The first vampires were buried like all the human dead before them and for however long, no-one noticed anything odd. Since vampire generally seem to come from noble blood-lines, they tended to be buried in well-made coffins, with quilted silk or satin lining so when some awoke, they felt quite comfortable in their new surroundings. Further, they could close the lids for a a bit peace and quiet… With a few followers to serve as bearers, coffins would also provide a perfect cover for travelling near or far. Then why would they want any other sleeping arrangements? ]

[Question] [ Bird people are humanoid creatures with a wingspan of 4 meters, they are as tall as humans and the fittest of them weight 72 kilograms or slightly less, so they are quite lighter than the average human.[](https://i.stack.imgur.com/6u5Wt.jpg) Bird people have an incredible advantage in any conflict, they don't need to fight and risk their lives, they can just fly over the enemies and drop arrows,flechette, rocks and flaming pots of oil or simply throw spears from above. They can fly 3,800 metres above ground when flying long distances in order to cross continents. Carrying weapons into battles makes flying height lower but still over the kilometer, they only walk when home or when resting. So, how can bird people be stopped from taking over the world ? The other humanoid creatures present in this world are: * Half human, half lion centaurs, they are huge and powerful and can climb * [Alcohol Elves](https://worldbuilding.stackexchange.com/questions/129049/elves-have-alcoholic-blood) as in my older questions * [Driders](https://worldbuilding.stackexchange.com/a/52163/56803) or giant nope spiders as described by Rennan * [Lizardfolk](http://overlordmaruyama.wikia.com/wiki/Green_Claw) or reptile people * Merfolk * [Nagas](https://worldbuilding.stackexchange.com/a/44745/56803) No firearms or such things are invented and everything is like the early 1000's of our world, where the majority of people lived in tribes and small villages but there were a few empires and big cities. [Answer] **Offering a different angle from many of the other answers...** Bird people can be fearsome warriors in battle, yes, especially in numbers. But they live much higher than most land-based races, in inaccessible crags and the occasional beautiful high city, the glories of which are rarely seen by land-based races. At 3,800m above sea level, the air temperature and oxygen levels required to sustain most land-based races is significantly reduced ([source](https://en.wikipedia.org/wiki/Effects_of_high_altitude_on_humans)). Even though the majority of bird people live between 500m and 1,000m below that threshold, this is still a good 2,500m above the usual level of land-based cities and towns. As such, bird people are rarely troubled by land-based squabbles, which usually take place far below them. Equally, bird people rarely involve themselves in land grabs or the politics of land-based races. To them, the wide stretches of land between their mountains are like the ocean. The answer to your question is simple: Though these angelic bird people might be ferocious flying foes when they are defending their own territory, they rarely encroach on the land-based cities and towns, preferring to keep themselves to themselves and instead focus on establishing robust trade agreements with mountain settlements to obtain materials they cannot obtain through ready means themselves. --- UPDATE: Bird people do not necessarily suffer negative physiological effects when descending to sea level. ~~When bird people spend time nearer sea level, they can experience a kind of altitude sickness, due to the increased blood pressure and oxygen levels. This can manifest itself in the form of *headaches*, *nausea*, *fatigue* and *shortness of breath* ([source](http://www.koiyaki.com/reverse-high-to-low-altitude-sickness/)).~~ EDIT: As mentioned in the comments, the source for this claim regarding *reverse altitude sickness* is not reputable. Other (more reputable) sources [[1](https://www.physiology.org/doi/full/10.1152/jappl.1997.83.1.102)], [[2](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3641122/)], suggest that "well-trained competitive runners" (Levine et al., 1997) can **benefit** from high-altitude acclimatisation. The implication here is that bird people could in fact be more effective combatants at lower altitudes (due to an innate acclimatisation at high altitudes). [Answer] It seems to me that your angels wouldn’t be invincible, impossible-to-defeat warriors with the parameters you’ve set. Like other answers have said, since they have to land eventually, they will be vulnerable to the other, larger races in your world. While they would be excellent raiders and quite powerful warriors (a wine skin filled with flammable oil and flint would be a terrifying weapon when wielded by these creatures), they would find it hard to hold ground in tight, crowded spaces such as canyons and forests, and it would be nearly impossible for them to fight underground. They would naturally have an advantage in and around things like tall mountains where they could fly and maneuver freely, attack without any obstruction, and fly back to resupply. While no one will be able to out-raid the angels, they will have a hard time defending anything that isn’t sheer cliffs because of their need to strike and retreat to avoid being grounded. As for how to defend from an attack, look no further than the phalanx. Most of your other creatures seem to be larger and stronger than the angels, so have some of them carry large, powerful shields with angled metal plates. That way fire can’t burn the shields and impact will be deflected off. Since the angels have to get closer to the ground to be accurate, they will then be open to archers firing on them, especially considering that some of these races sound like they could handle firing really large, powerful bows. Also, one last consideration. Things like storms, high winds, or even smoke from wildfires would make it very difficult, if not impossible, for your angels to fly. Without any sort of magic, your other races can set fires and use the smoke to limit where the angels can fly, and thus make them at least slightly more predictable. [Answer] Since your angels are light, flying entites, they probably can't carry much. The more they carry, the more slowly and laboriously they fly, and as a result, the better a target they present themselves. This would, naturally, lead to light armor and armaments, think leather armor and your earlier mentioned projectiles - stones, spears, etc. But in order to be effective, a projectile has to weigh a certain amount to do damage, otherwise it will just bounce off of any lander's armor. So the weight of the ammunition itself limits the amount of time they can stay in combat. Imagine that the most common spear weighs (for math's sake) 1kg, but the max an angel can carry while staying airborne is 10kg. That means once they loose their 10 spears, they are out of the fight and must go resupply! Or they can go fight on the ground, but then they are at a clear disadvantage. And their resupply base must be on the ground somewhere, so a smart enemy might find it... [Answer] A 72 Kg meatbag, flying four clicks above a target, with only medieval weaponry, would have a very hard time hitting a target accurately. Sure, they can fly lower and use bows, but there are only so many arrows you can carry. At some point they have to land. They can't sleep, cook, make love nor nest in the air. And once they are on the ground, they are game. At the very least, burn their tents to the ground, and they will have to fly back home for more supplies. [Answer] Choose your terrain. You can't fight in plains or fields, that'll be a lost battle for the rest of your creatures. Fight only on dense forests with high coverage. With 4 meters of wings, they won t be able to maneuver bellow the leafs and from the sky it will be harder to shoot their arrows accurately as they would need to beat the resistance from the top of the trees. Also have your spider people lay webs all over the region they want to defend. If any angel tries to fly between the trees they will be trapped and an easy target. Have the elves hide on top of the trees and shoot down any low flying angel. Attack their nests with lizard people, because they probably have a high and almost impossiblen to reach location. They can climb better and stealthly disrupt their rankings. The merfolk are safe, as long as they don t leave the water. [Answer] If I were tasked to defend against these critters, I'd consider it an easy (but interesting) job. Preface: In a medieval world, you need to take the castle to control a land. As long as the castle is in enemy hands, so is the land, whether or not you have your troops there. So this is all about defending your castle against some tasty chickens. (are they tasty?) First, castles already have roofs above the battlements, typically, to defend against ballistic arrow shots. They will work just fine against arrows, darts, spears and light stones dropped by these critters. And if they want to get any kind of accuracy, they will have to approach much lower than their maximum flight height. Chances are good that in a battle they will be within arrow range. Fill the air with arrows and watch them coming down - they won't be able to carry much in the way of armour while my men on the ground can hide under roofs, behind shields and wear all kinds of protective clothes. In addition to that, I can certainly modify my trebuchets and other heavy artillery to throw things upwards, and then load them with cast nets, possibly modified for this type of deployment. Basically, I'm putting a net into the air. Try flying with your wings tangled in a net. And just because I'm vicious, I can play havoc with their aerodynamics by liting a couple big and hot fires. If I can hide the flames and smoke, e.g. by making the fire inside a building and using something that burns clean, they will swoop over my castle and suddenly find themselves in a violent updraft with turbulences. Good luck. And finally, as soon as I have cannons or something else powerful enough (I might check if I can modify a ballista) there is the old and effective weapon against anything that flies: Scattershot. Instead of shooting one big-ass bolt, my ballista can shoot a hundred smaller ones, or my catapult can throw a whole load of gravel and sharp, fist-sized stones. Aim would be terrible at first, but my people would learn fast. So there is a whole lot of pain I can do to the birdies as soon as they come down to low heights, and I can force them to come down there because if they stay up high I'll just hide under a roof and laugh about them. In fact, if they just drop stuff from up high, there's not much of a tactical difference between them and an array of catapults on the nearby hill. [Answer] > > So, how can Angels be stopped from taking over the world and create an Angel dominated empire where every other humanoid creature just gets enslaved? > > > Weapons and warriors can only win you a battle. Wars are won with logistics. Look at most powerful modern machines of war, the aircraft carries. Do they pack any weapons? No. All they do is provide logistics for planes. That's all that it takes. No matter how good your angelic warriors are - fighting is exhausting, flying is exhausting and doing both is probably exhausting squared. They need to land, rest, eat and rearm. And from your description they sound to be absolutely defenseless then. If they don't have ground infrastructure: beasts of burden and heavy wagons, they can't take any supplies with them. They can't perform what empires hinge on: "projection of power". They're pretty much limited to defending the nearest vicinity of their settlements, range that a warrior can reach in a single flight, be able to fight and return home. Sounds like no more than few hundred km. Altitude can be used to avoid a fight, but not in combat. If an angel flies low enough to hit someone on the ground, the soldier on the ground can fire back. Ground troops can carry heavier, longer ranged weapons like crossbows and ballistas. Aerial attack is not radically different than what is already well known. Volley of arrows fired in an arc fall from above just like a volley of arrows fired by angels. All other races already have worked out their combat tactics against that, eg Romans had turtle formation. Flight can give advantage of speed and surprise, but not a 1:1 advantage. Also, unlike ground-based armies, they can neither take prisoners nor care about their own wounded. Most wounds would mean either death falling or forced landing - which means death on hostile ground as well. Angels would probably have much different social values because of that: either being very pacifist to avoid loses or on the contrary, praising death in combat as a method to cope with high loses. You mention cross-continental flight, but you don't say anything about it's consequences. Birds do fly 10000km in one take, but they take months to prepare for the migration and weeks to recover from it. That's not something one can use offensively. I don't think your problem is "how they didn't took over the world". If an enemy attacks, can survive the first defensive strike and continue marching to reach the settlement - angels are toasted. I'd worry more about "how they've even stayed alive". That's stereotypically solved with having them perched on high mountains, inaccessible by foot. Note that it limits their development, so their weapons would remain crude and ineffective. It's probably a vicious circle: angels can't leave their high perches because they lack technology to be competitive on the ground and they can't develop the technology because they can't leave their perches. PS: I think you're severely overestimating physical power of a creature that consists mostly of flight muscles. They take most of your 72kg, the rest being vital infrastructure like gastrointestinal tract, leaving almost no mass budget for arms, legs and weapons, leaving armor out of the question entirely. [Answer] It comes down to the terrain where the other species live * Half human, half lion centaurs - Open plains? If the reside in caves then aerial bombardment is pointless * Elves - Forest? Kinda hard to spot people in the trees and likely to get shot if you get closer. Burning the whole forest is the only way to win. * Driders or giant spiders - Underground or dark places is no place for an angel * Lizardfolk or reptile people - Swamps? Just like a forest only wetter and impossible to burn. * Merfolk - Underwater is completely untouchable * Nagas - Swamps again? Aerial advantage only goes so far and if forced to go hand to hand, suddenly they are at a disadvantage. The only real advantages are spying and burning out crops and other food supplies. [Answer] The most likely weapon these angels would carry would be something like Javelins, or since throwing is likely impeded during flight they would resort to dropping tiny darts (<https://www.google.nl/amp/s/www.dailymail.co.uk/news/article-2662730/amp/WWI-darts-dropped-biplanes-German-trenches-disgusted-British-aviators-ungentlemanly.html>)\* Still you are heavily impeded by accuracy. For proper accuracy you need to aim for formations or fly low and risk retaliatory fire. This means angelics wont auto-win battles. Theres also resource management and population. If only 5% of the living sentients is angelics then they wont be that influential in the grand scheme. And imagine if your angelics attack a nearby Village and say "do our bidding or we'll kill again", upon which the villagers send a few people trecking across the ground and burn the angelic's food supplies and hunt whatever the angelics eat till they starve. Flying means they need to eat a lot more so they need a much more nutrient rich diet and run into famine faster if you target their food. This means that angelics are better off banding together than enforcing a kind of slavery. \*Edit: for reference these darts were thrown in batches of 500 which would be hard to pull off by an angel. In a test scenario on a luckless cow 3 out of 500 hit and went straight through the cow and into the ground, so in one hand accuracy is definitely a problem but even with inferior darts the killingpower wont be. [Answer] Since most other answers discuss drawbacks to being an angel in combat i'll talk about anti angel tactics. since this is early 1000s, you most likely don't have crossbows, but you would want a way to damage the flying creatures fragile wings some how. You could have a battalion of sling users, they could lob stones and early lead bullets at angel in a synchronized volley. This could be vary hard to counter, shields would really weigh down the angel and you cant cover everything. Since Merfolk exist you could easily adapt fishing nets to be launched at the angelic folk when they get low or on the ground. [Answer] The weaknesses and disadvantages of angels in combat have already been covered - I'd just like to add a couple of points regarding anti-angel tactics. Fortifications - If people are fighting angels regularly, they can adapt their fortifications and defences to compensate for an airborne enemy. Covered battlements with fireproof sloped roofs would shelter defenders from attacks from above. Arrow slits or hatches they can pop out of would allow them to return fire whilst minimising exposure. Siege Weapons - Most medieval siege weaponry fires one large projectile and is optimised for dealing damage to fortifications and building. With the right motivation, anti-air siege weapons could be designed and built that fire dozens or hundreds of lighter projectiles that would prove deadly to a lightly armoured airborne combatant. For reference, think of something like the [Hwacha](https://en.wikipedia.org/wiki/Hwacha), which uses small fireworks to launches dozens of arrows simultaneously. If gunpowder is unavailable, catapults and trebuchets could be modified to fire shotgun-like blasts of small rocks and sling bullets. [Answer] I'm going to answer your question "So, how can bird people be stopped from taking over the world?" with a question (yeah, I'm that kind of guy) - 3.8 Kilometers means that the Angilians (Angel-avians) are adapted to lower oxygen and air pressure and would therefore prefer higher altitudes. In lower altitudes they'll be quite uncomfortable. **Why do they want to take over** your plains and forests, then? Must be something that you have, that they don't (seems that control over your land isn't it). Once you figure what that thing is, base **negotiations** upon it. The reason could be as simple as a fear that your people will one day take over their land (which is similarly dubious, for the same reasons). Once everybody figures out that continuous war isn't beneficial in the long run, put up some **Peace and trade agreements** that will serve both sides, and these will eventually lead to a grudging co-existence. At least until those grudges/religion/racism/sheer stupidity bring about another inevitable skirmish... So, people beleaguered by attacks from above are going to develop **fast roof-construction methods**. Crawl towards the bad guys' city with your wooden tents/shacks and kick their ass... until they kick your ass... and the cycle begins anew. [Answer] > > they only walk when home **or when resting**. > > > Then that's where you fight them. EDIT: specifically, you (the terrans) need some serious advantage when fighting the enemy (the avians) on the enemy's terms, and your question sets it up that the terrans **are disadvantaged**. Thus, the terrans must fight on their own terms, which means tracking the avians to their resting places, or sabotaging their food/water, etc. [Answer] I'm having another idea: **What about flying nets?** Inspired by a game where an archer could shoot a net with 4 arrows, which stunned the enemy for a short time. When applying this principle to this question, it would mean shooting nets at angels to block the wings and let them fall into the death. The nets need: * to weight very less and be so strong to get not destroyed by the power of the wings * a diameter of at least 5 meters, better 7m * skilled archers/slingers or a catapult to hit properly The advantages are: * nets cost not much * nets are easy recycleable * -> what means special nets (with barbs or else), which costs more are also available * very effective (if performed right) The disadvantages are: * It's hard to perform right, you probably need a catapult for shooting * somebody has got to collect the nets I hope this helps :) [Answer] Here are a couple of things that would keep the bird people from being anything but the terrorists of your world: 1. They can only fight what they can see. 2. They can kill but they can't hold ground. 3. Their path to success is cooperation, not conflict. **They can Only fight what they can see** They can't effectively fight at night. They can't scout forests or any terrain that provides overhead cover. So, enemies need to move at night and hide during the day. Once they get near the flyer's base, they can attack at night (possibly with crossbow delivered nets). **They can kill but they can't hold ground.** The flyers should be physically weaker in hand to hand combat than a normal human unless there is magic involved in their flight. They need to keep their muscle mass down and most of their muscles will be powering their wings. They would have to fly into an area, make several trips to bring supplies forward and then begin raiding. Even in the raid, they still have to get their loot out. They better attack someone that has something with more value to weight than the arrows they will bring with them. They would never be able to have towns or cities in a contested area. The will not be as good at farming as a human (the wings don't help plow the field). So their food supply will be less than human's. Thus, their population will be less than a human's. They could raid for food but how much food can they carry and how many will they lose on the raid to do that? Even then, all it would take would be a couple of fake food shipments (either with fighters hiding in the food or poison in the food) to end that. **Their path to success is cooperation, not conflict.** In a caravan, they can scout for bandits or beasts and at night, they can have a bunch of those strong humans guarding them while they sleep. In an army, they can scout or snipe high value targets while, at night, they are surrounded by an army of people who have a vested interest in protecting them. [Answer] First off, there is much more to conquering the world than being individually formidable. If someone else is more numerous, more organized, more aggressive, smarter, better at diplomacy, or just had a head start, they may dominate your bird people even if the bird people are individually more capable in a fight. Your bird people would have inherent problems with logistics. They either need flying pack animals, flying machines, or they need to carry everything themselves. If there are flying pack animals or machines, the other races will be trying to get their own for flying cavalry, flying dragoons, or an air force. The small wingspan of your bird people isn't going to allow for extended soaring. They are going to need to land reasonably often to rest, and they are going to need an enormous amount of food (which makes the logistics problem worse). Heavily loaded flying pack animals will also need to rest often and if they don't have flying pack animals, their own range is going to be further constrained. Siege warfare has plenty of tactics for defending against people high above you dropping stuff and your bird people would have some trouble with managing a really dense sustained, attack since they can't pack closely together, they need to keep moving to remain flying, and they can only throw what they can carry with them. So sure they can harass with impunity and slow their enemies down quite a bit but unless they have something like antipersonnel grenades. I don't think they are going to be able to entirely stop an enemy that's prepared to defend against air attack by just dropping stuff. This makes them ineffective at taking and holding land. On the other hand, I think you are missing one of their most important military advantages: reconnaissance and communication. Even if they were to largely manoeuvre and fight on the ground to conserve energy and resources and so they could carry a heavier load of gear, the fact that they could have flying scouts and "runners" would be a *massive* advantage. It would also be one that the other races would be eager to match, meaning they would encourage defectors. So overall, I don't think you need any special contrivance to stop them from taking over. You would need to give them more than just being able to fly before it became a problem. [Answer] ## Burning Mirrors / Heat Ray Inspired of Archimedes who supposedly used this technology during the Siege of Syracuse (214–212 BC) one can imagine towers equipped with big mobile mirrors in order to concentrate the Sun beams. Just point the beam to your avians and see their wings starting burning ! [](https://i.stack.imgur.com/oIBYh.jpg) It has been shown that Archimedes wasn't abble to perform such a trick because argentic mirror weren't invented yet but this is not a problem for you as the first silver-mercury amalgams have been used in China as early as 500 A.D. ! ]

[Question] [ I don't want my world to be infinite, that would be a pain to draw maps for. And I need it to be flat (for a slightly unrelated reason). How would I explain why no one has looked over or seen the edge before? I could always put a giant wall there, but that just makes more questions than answers ( i.e. who built it)? [Answer] Make your world finite but spatially bounded. This means anyone walking towards where the edge would be will find themselves inexplicably turned around, even though they were still walking in the same direction and to their own minds they didn't turn around. They will arrive back at the place where they started. The Arthur C Clarke short story "Wall of Darkness" uses this concept. It also has a wall, the existence of which is never explained, but possibly it was built during an earlier time to stop people having the inexplicable experience of finding their world was spatially bounded. I suspect Clarke was putting a science-fictional twist on the sort of flat-earth world that appeared in various fantasy short stories by Lord Dunsany. Clarke was a fan of Dunsany's fiction. The concept of finite but bounded space appears in certain versions of cosmology. It is quite reasonable to use it for what is essentially a fantasy world. There is no need to explain how and what it is, just show what happens when people reach the "edges" of their world. Effectively they never get there. This also explains why no-one has looked over the edge. They can't get there to do it. [Answer] I can think of at least two reasons. 1. The physics answer, If your disk is massive enough you get an interesting effect that causes it to behave more like a bowl than a disk even though it is flat, at least as far as gravity is concerned, the closer you get to the edge the steeper the surface feels. to a person on the surface it would feel like climbing a very steep mountain. Try [this](https://www.youtube.com/watch?v=VNqNnUJVcVs) vsauce video (0:30 to 2:00) for a more visual feel for what I am talking about. 2. the discworld answer, the edge is entirely one giant ocean waterfall going over the side, anyone who sails too close to the edge gets dragged over the side to their doom. So it is not that no one has ever tried it is just they have never survived the attempt. [Answer] Gravity to the rescue. If your planet has a disc-shape, gravity will be different towards the edges as compared to the center. The habitable zone on the planet would be near the center (maybe on both sides, that might make for interesting story material...) while the more you go towards the edges, the more everything becomes inhospitable, to the point that the atmosphere is too thin to reach the edge without some kind of space suit, which depending on the time period of your story may be far in the future. [Answer] ### the world is so big no one could reach the edges. And that everything along the way is boring and inhospitable. Consider that at the boundaries of all known lands, the great sea extends so far that it would take the fastest ship over 3 years to cross. Without sight of a single island or reef. And the ocean isn't even the worst of it, at least on the ocean one could fish for food. The few explorers who made it to the other side (and returned more than half-mad from deprivation). In every direction they have reported nothing but lifeless desert. (Unlike a real desert), is is completely lifeless. Not a animal nor a blade of grass, or a single spring of fresh-water to be found. And the rains immediately soak into the parched ground. And it seemingly never rains once you get too far from the sea. The very few explorers sent out from the ships, report than even after months of travel there is nothing insight but more sand -- in truth the desert may be larger than the ocean. The idea of the desert beyond the ocean is to put something even more inhospitable than open ocean out there. (Since oceans can have fish, and rain, and even maybe enough seaweeds etc to live, in theory). A this inhospitable desert could be much worse (You could even do things like the sand being chemically infertile). of-course this begs the question why the known world is nice, and interesting, but as you go away from it, everything gets boring. \* **Insert creation myth here.** \* So you can do what ever you want with the end of the world. No one is going to see it. And while yes, where there is a will there is a way, someone could eventually settle on in the desert. Some kind of (literal) fringe group. The prospect of making such a place habitable away from the sea, is basically a teraforming project. And you simply set your story well before it is complete. [Answer] # Requires no exotic dimensional physics. For the same reasons we humans never visited either the North or South poles, until we developed the technology to do so a few hundred years ago. It's too cold at the edge, and (like our poles) too cold a hundred miles from the edge. Antarctic temperatures, below -100C. Throw in tornadic winds that could literally lift a herd of elephants, and it is too lethal. The winds prevent any sort of balloon or aircraft from getting close enough. Of course, if your population develops space flight, they will see the edges eventually; and by science I can know it is not a sphere (one might hypothesize the world is a sphere like Earth but with just one cold pole; however such a sphere has an equator, and you can travel in a straight line due East and reach your starting point: There is no such straight line on the disc world). By science I can know it is a disc (Shadow length and orientation relationships on the habitable part can prove flatness, while mapping of the cold edge, as close as we can get to it, proves circularity). Actually reaching the edge to peer over it requires some very high tech. **Added:** There is another psychological deterrent: Although we can determine the habitable area is a disc (the length of the ice border rules out a small ice cap), we cannot prove there is an edge: The habitable area may be a circular warm spot on an ice plain that could be thousands or millions of times wider than the habitable area itself. With such a possibility, there is no certainty an edge could ever be reached, giving an exploration to find an edge a near certain suicide mission in the eyes of most. [Answer] Looking off the world into the oblivion of whatever lies beyond could simply drive people insane, causing them to leap off the edge, preventing any explorers from returning to civilization with the knowledge of the edge. This is a bit dark, yes, but it makes some sort of sense. I hope I helped. [Answer] There is absolutely no reason why planets have to remain round. There are many scenarios that I can think of that could in theory produce a 'pancake' planet shape. Gravity would be interesting. Or maybe the planet formed like a can, flat on the ends, dumbbell on the sides. Your inhabitants live on the flat ends. Again, gravity would do weird things around the rim. Perhaps you would be walking on a slant to the flat ground, because that would be 'up' (perpendicular to the center of gravity, but not to the flat side), but of course it would be very confusing between the visual, balance, and proprioceptive sensors of the body - probably very nauseating. Especially to a bipedal animal. Like walking into the wind, without the wind. I could imagine it would be extremely unsettling to go near the edge, walking on an angle. [Answer] Perhaps the edge is difficult to access as the boundary area consists of difficult terrain such as: * Rings of circular ridges, chasms, cliffs and mountains * A stormy circular shallow sea with lots of reefs and concentric bands of shallow and then deep water * A wide very hot or very cold desert or impenetrable swamp I assume that you must have introduced some hand waving explanation to make the flat planets gravity work as we would expect on a spherical planet [Answer] Perhaps no one has seen the Edge (and come back to tell of the experience) because the Edgeward Current is too strong and all the daft explorers' ships keep sailing over the Edgefall? This has the advantage of being both a mythical explanation and also the real fact of geology. Of course, I'm positing an Edgeringing Ocean with no land masses nearby. So, it's technically untrue that no one has ever seen the Edge. It's just more true that those who háve seen the Edge have really seen it by falling off... [Answer] Haven't you heard the tales? It's said many a dread creature dwells in the Undershadow of the world- fair beyond the likes of normal man, beast, nor weapon. It is said some ancient barrier prevents them from crossing over- a miracle by any other name. But while they cannot walk on the surface, the Edge is not beyond their reach. Many a brave explorer has dared draw too close to the Edge- one and all they've vanished without a trace. Entire expeditions have been lost- there one day- gone the next. None have ever returned from trying to find the Edge. And that, my young lad, is why all maps warn against approaching the Edge; why I tell you now to stay far, far away from the unknown, "**Here there be monsters.**" [Answer] Maybe there is no breathable air there and it is too cold for humans to survive more than a few minutes without serious protective gear akin to a spacesuit. Cosmic radiation could also be an issue. [Answer] Your world is flat, so it does not have a horizon (or at least not like we have on earth). Someone on a tall mountain could have a direct line of sight to the edge of the world. The reason they can't see it is because eventually the air would be too thick for light to get through properly, giving the impression of a eternal wall of fog. Like the draw distance in games. It would be very easy to make it so people are scared of this fog. If the world you want to map is an island and is small enough that they don't see this fog on the land, people would believe it only exists at sea. Since they're the only land they know they won't have boats for crossing oceans and would probably have issues navigating. I don't know how compasses would work in your world, and while they could use the stars, its possible nobody thought of this as it's easier to navigate on land by looking for tall landmarks that are visible from just about everywhere (since the world is flat). Anyone who does try to find the edge will eventually turn around when they start to lose sight of the shore (as the eternal fog consume it), or they will drift until they sink/run out of fresh water/go mad. Any ships in this situation that do make it back by some miracle will just tell stories of the endless sea and fog, increasing peoples fear and making future attempts even less likely. Even if they do work out it is caused by light not being able to get through that much air, and that they can use the stars to navigate, it doesn't change much. They don't know if there's land out in the fog so they may just send people to their deaths if they try looking. Everyone knew that if Columbus could keep sailing he would eventually hit Asia, but they knew that he couldn't keep sailing for that long a journey (and he couldn't at the time, he only tried because he thought the journey was shorter than it was). In your world the people can't be sure they'll hit anything even if they sail forever. [Answer] Giant dome of magic-stuff Instead of staying in the sky, the sky curves downwards creating an inescapable dome. [Answer] if you make your "end" impossible to reach by more natural means, such as surrounding it by active volcanoes or a lot of very tall mountains, no one will try to reach it. you also could create a society that deems it unacceptable to try and search for the edge, and even making it punishable. [Answer] How can you know the edge if nobody has ever returned from it? People disappear if they venture outwards. They simply do not return. The geography of this world's hinterlands could be loose and ethereal (maybe like the thin places in the Dark Tower). How do the borderlands know they're on the border, then? Well, their inhabitants don't travel outwards. Because anybody who ever has, beyond a day's journey or so, hasn't returned. Maybe there's no crisp edge. Maybe the world... disintegrates. Maybe, reality itself gives to the void - slowly, too slowly for mortals to recognize. Maybe nightfall, darkness itself, washes souls out into oblivion. But then again, there could be practical reasons that men do not return. Some may say there's paradise out there. Others say death awaits at the hands of beasts, men, gods... Who knows. Borderland towns often have their own folklore about the edge. It's wise not to look that way. [Answer] How about a society related reason? A religion that sees it sinful to try to look outside of the known world, and anyone who tries would be executed or shunned or deemed insane. Or some extreme fear or belief which makes people utterly uninterested of going outside of the known land. Keep in mind, it wasn't a piece of cake for Columbus to start his voyages, but he was rejected multiple times by kings of different countries when he was looking financial support. It is not obvious that people would automatically be interested in looking for the edges of the world. [Answer] One of the theories real world flat Earthers have is that some world order captures people who get too close to the edge, drugs them to make them forget they saw it, then send them back to where they came. Similarly, any plane flights over the "Pacific" actually just release drugs into the ventilation to make you think you went over the Pacific ocean but instead you just went over the Atlantic or other Oceans. A similar thing happens with boats. Now obviously the time period that your world takes place in will make this more or less feasible. [Answer] What does people see on the edge? You can use the same concept used by video-games which does not allow players to move outside the map. The options includes: * Some kind of force (like gravity) that increases on the edge, blocking anyone or anything (if only living beings are blocked it can be some kind of gravity associated with biological materials, but if everything is blocked then you have to deal with what people will see: darkness maybe). On GTA V for example, the map is an island and you can try adventure yourself outside but at certain point won't move any centimetre further, having the perception of moving, but you actually don't. * An invisible magic wall which nothing can pass. Everything that is inside the wall will always be there and the same for what is outside. There's no reason to explain this. * Darkness or an abyss. There's just nothing there and literally it's an edge. * An infinite desert. Actually this options isn't a edge, but there's nothing on any direction than flat useless land and everybody that tries to go there dies of dehydration or hunger, or goes back. * Fog. The more you are far from "world" more fog you get and less you see, forcing you to go back. This option can be extended to have moving sand and dense air, so no one could ever pass using any kind of transportation. * Temperature change, like becoming very hot or very cold so no one can survive. * Lack of air to breath. * Incremental super gravity (making it harder to move and, when far enough, crushing bones and internal organs, killing or doing several damage to people). So, there are many options, but the one you choose depends on the nature of your world. Is there magic? Is there technology? Is the edge to be a mystery? Is the edge to be forbidden? Does people live close and eventually want to go further the edge? These will help you to decide what kind of force, land type, visibility and explanation you want to give. If this is irrelevant to the story, then a force like gravity would fit nice. [Answer] Cannot believe no one has put this yet. Just put sketches of dragons and kraken at the edge of your map with sits "here be dragons" Luke hey did for navy flat mayors in the middle ages;) [Answer] 1) side-scroller. Keep walking east, you end up on the west end of the map. Just because it isn't round doesn't mean you have to have edges. 2) discworld. Look, you can see the Turtle down there... What's to explain? 3) "Here there be Dragons." If GOD is at the center of the map, the heinous evils of the world would slink to the edges. The further out you go, the more dangerous and insidious and powerful and unreasonable they become. Where's the edge? Nobody knows, because no one has survived to make it that far. 4) No one has looked over the edge? Maybe they have, and are always inducted into the mysterious Illuminati that hide the Great Secrets from the rest of the blithely ignorant world. 5) Holodeck. When you get to the edge, features always make it inconvenient to get all the way to the wall. Unclimbable mountain, impassably raging whitewater, a desert so dry and hot and barren no one would try, and if they do the dunes keep collapsing... and if you do ever make it to the wall, you still can't see it. BUMP! WTF? [Answer] How about a world like Le Guin's Earthsea - a scatter of islands (quite a big scatter) and only ocean anywhere else. She has dragons living in the West, and icy covered land in the North, but nothing is said that I remember of North, South, or East. Given the right level of technology, this is a spatially bounded earth. [Answer] **Radiation** Because of the flat shape the magnetosphere is only effective at deflecting solar radiation near the middle of the disk. This means that radiation near the edge is lethal, and causes lots of mutations (mutant beasts?) and sickness in the borderlands. So people avoid the boarder lands and never survive returning from the edge. [Answer] If you use the "pie plate" from Larry Niven's *[Bigger Than Worlds](https://www.scribd.com/document/100964566/Larry-Niven-Bigger-Than-Worlds-v1-0-Italics)*, described as an intermediate step in Ringworld construction, then the world is for all intents and purposes an Earth-sized, pancake flat circle with a mountain range the whole way around the edge that makes the Himalaya look like a pimple; no-one has gone to The Edge because they die of [hypoxia](https://en.wikipedia.org/wiki/Hypoxia_(environmental)) less than halfway there. This does constitute a wall around the world but one that looks natural, I've worked up *a* weather and geography primer for such a world if you're interested. [Answer] If your world is spinning, then anyone who goes far enough towards the edge will be violently thrown off into the void. Or in opposite, everything is pulled toward the center so it is physically impossible to go to the edge. [Answer] Huge mountains that no one can pass. Deserts too dangerous for any life to survive. Oceans with dangerous whirlstreams. Glaciers so cold that nothing can live. Maybe a few well selected spots in between guarded by gods or demons (if it is a fantasy world) with only legends telling what would be beyond. [Answer] Analogous to a "ringworld", you may assume the "disc-world" is a giant "catapult" where a dense planet holds a disc with carbon-nanotubes fibers. The whole structure spins around the barycenter (which is close to the planet) and allows everything to be held on the surface of the disc by centrifuge. The structure works like a slingshot cradle being spun at a constant speed and holding a stone inside it. This will eliminate the need to tackle gravity issues due to the disc's unusual shape. The rims: There are two ways to tackle the rim issue: 1- A great wall; Similar to Ringworld, a wall will hold-on to the precious atmosphere 2- A slightly concave surface: There may be the need to create high elevations at the rims, and at a high enough altitude there is no atmosphere. There is still a need for a great wall at the rims, but it needs not be as massive as the one around a flat disc. The wall will hold-on to whatever tenuous atmosphere there is for much longer. If that wall did not exist, the upper layer of the atmosphere will spill-over into space, and will be constantly replenished by the lower layers. Over time, the whole atmosphere will escape. [Answer] Religious/mythological reasons: "Mama, what's at the end of the world?" (In dark, forbidding tone) "Oh, we don't talk about that. Only the cursed think about it. Those who go there are cut off forever....." If this world were highly religious, this could be sufficient. (Lots of possible variations: real religion (so the local god(s) do something terrible if you do go there), fake religion (anyone who has tried was prevented, by the religious hierarchy, from returning to society, or was publicly tortured/executed), some interesting combination.... Societal imperative: Something near the edges (some physical or magical power available there) had caused terrible devastation in the past. The only way they saved themselves was putting it so off-limits that the taboo is psychologically just about unbreakable (you can have the occasional person who tries and is viewed with such horror by *everyone* that they go mad or something). (Careful with this one in terms of copyright issues or some such; a similar ethical imperative (against weapons that kill at a distance) was used quite successfully in Marion Zimmer Bradley's Darkover series. Including books from before and after "The Compact".) Lack of curiosity: Especially if this is an alien society. One day humans make contact with them. Human visitor: "Why, in all the years, has no one gone to look over the edge?" Alien native: "Never thought about it. What's wrong with right here?" [Answer] Some people do believe our Earth is flat, and, against all possible physics, they believe that for some reason all along the edges we are surrounded by huge walls of ice (they think the North Pole is the center of the disk, and that the South Pole is the circumference all around). In some extreme cases, some seem to believe that the universe is a huge slab of ice, and here and there there are these circular "hollows", one of which is our (flat) Earth. In other hollows there are other worlds, that are impossible for us to reach due to the millions of kilometers of flat ice between us (and even getting to the top of these ice slab is impossible to begin with, as they're very high. Ok, some conspirationists believe there are military guarding these edges, so that you can't even try to get close). ]

[Question] [ I've developed superhuman abilities, specifically, I am able to "copy" and permanently keep "skills" and technical knowledge from other people. For example, if I spend time near a politician I might absorb oratory and public speaking skills or if I spend time absorbing skills from a scuba diver, eventually I'll know how to scuba-dive, make a dive plan, etc. Unfortunately, my power is *not* fast and it's not long range. The amount of time it takes to absorb someone's skills is related to how much work they put into getting them--for example I can pick up "how to solve a Rubik's Cube" in maybe a day of close proximity but something like "how to preform neurosurgery" would take months of close proximity to fully absorb. Furthermore, I've found that the rate of skill absorption has an inverse relationship with distance to the person. I get the highest skill-absorption speeds when I'm sharing a bed with someone (my power works while I'm unconscious) but even being in the same room as the person(s) I'm copying skills from is rather fast. Fortunately, I'm not limited to absorbing skills from one person at a time. This means if I'm in a classroom or other setting where I spend a lot of time around skilled people, I absorb from all of them simultaneously. Now, my goal is **to become the most skilled jack-of-all-trades ever**. I want as many diverse and unique skills as possible. I want to be able to pick up and play any instrument, be a master at any sport, be a crack engineer, a chess champion, etc. Luckily, I am patient. I'm playing the long game, but I still have a mortal, regular human lifespan. Assume I'm starting at 18 years old. Question: **What profession/occupation/strategy should I pursue that will let me spend extended periods of time in close physical proximity with the most diverse set of experts in all sorts of fields?** Example ideas: * Astronaut, spend lots of time with group of highly skilled individuals * Military-civilian interface, spend lots of time traveling and spending time with military and contractors * High powered therapist, spend lots of time in one-on-one settings with distinguished clients [Answer] ## **Start flying... a lot.** the longer the flight the more you will absorb, but the real benefits is close proximity to dozens of people with the SAME skill at the same time. Languages will come first. Take one or two 16 hour flights to China and be able to speak like a native. Even under the worse case scenario you are sitting very close to a dozen different people absorbing all they have every flight. As a bonus you can use your new found translation skills to pay for more flights. You should pick up flying and business skills fairly quickly, although you may have to worry about picking up bad business skills. Ideally you leverage this to gain access to flight information and booking so you can start planning flights. You will luck out and be on flights going to conferences/conventions occasionally. Imagine being on a plane with a dozen heart surgeons or a dozen particle physicists. I have been on flights with 20-30 Paleontologists all going to a scientific conventions, and know of similar conferences for nearly any scientific or technical skill you can think of. If you were smart you might even start tracking these conferences so you can get on flights from major cities to where they are being held. Technical cruises are also a thing, less proximity but a lot more people for a much longer time, up to you whether it balances out. [Answer] When somebody is skilled or has accomplished something of note, how do we hear about it? From the news, because they were interviewed by a **reporter**. A reporter would be able to get close to a wide array of interesting people without people getting suspicious. For example, when there is a scientific breakthrough the reporter would be able to interview the lead scientist, perhaps get a tour of the facility and if charismatic enough could perhaps even befriend the people there and come by a second time or more to do some follow up questions for a larger article. Also nobody would look that surprised when a reporter volunteers to go to the war front to report in the situation there while being surrounded by trained soldiers. Alternatively tournaments would also be a great place for a reporter to be to learn the skills of those present. Due to him being of the press would even be allowed closer tot he participants or other forms of back stage access. The reporter status would also allow entrance to certain crowded high priority events like the opening of a nightclub, a museum or be allowed at gatherings like that of world leaders. And best of all, as a reporter it is your job to be informed about gatherings like this so will always be kept in the loop. (Probably the same reason why [Superman](https://youtu.be/ul05ayOkvVI?t=75) goes undercover as a reporter or Spider-Man works for the news paper. Be kept in the loop and nobody would be surprised if they were at a place where a normal person would run away from.) [Answer] I would suggest to optimise for places with a high number of people in close proximity. Using this tactic nightclubs is a good venue, as is collage auditoriums, lunch restaurants, beaches etc. You could probably get rather far by going to college and instead of focusing on classes focusing on the senior class parties, hanging around the faculty, going to the beach etc. The thing to remember is that with a large enough group of people most skills will be represented. You can the selectivly join clubs or organisations which contain people with skills where you feel you have gaps. [Answer] ### First day - go to the nearest nightclub, head for the mosh pit Go jump up and down to the beat in a mosh pit. Sure you're not targeting the skilled, but you'll get a ton of useful life skills. After a few big nights, you'll hopefully steal a set of skills that allow you to more efficiently steal skills: ### Option 1. Sex work Assuming you're non-lesbian female or non-straight male, able to mentally and physically do the work, and it's legal and safe in your location. You'll get a lot of very intimate contact with a wide range of people. Repeat clients are very common in that industry, and professional men looking for a few minutes of faux intimacy are a good market to exploit. If you're good at it (eg you stole the skills to appearing emotionally open and can easily "become their friend"), you'll get long bookings, allowing for the more complex skills to be absorbed. ### Option 2 Tinder Say you're not up for sex work for some reason (maybe you're a straight male?) in which case, hopefully you've learnt some skills on how to appear attractive, lead potential lovers on, and pick up anyone you want. "What do you do for a living?" "I'm the city's only female structural engineer" "Ooh exciting I've never dated anyone in that field before! That sounds complex, I mean interesting!", "um, ok". Date them until you've learnt their skills, then move on. ### Option 3. Adult events. You've learnt a whole lot of skills from the thousands of people you were with in the mosh pit, some unmentionable, so put them to use. These events often attract people a little bit older than you'd like - which is good as it means they have more skills to give you. Once you're "in" in that scene you can get referrals to other events (which you'll definitely need if an unaccompanied male), and start travelling the world of adult sex parties. Lots of close, intimate contact to steal even more skills. ### Option 4 Taxi / uber driver Say you don't want to use sex or love as a tool to pick up skills, you can use driving. Which is handy as from the mosh pit you've probably absorbed the ability to navigate every corner of your town in intricate detail. Like sex work, but an extra 50cm between you (so a bit slower to absorb), but less police raids and you don't need a shower afterwards. You'll constantly be absorbing from various people. Do airport routes in a big city to get travelling professionals. # Other ideas: ### Just take long haul plane trips / bus rides over and over You'll absorb everyone's skills in a few rows around you. Land, immediately fly somewhere else. Just keep flying over and over. Yeah it'll be a sucky life, living in economy class, but I don't think anything can beat it. It's better to be in ecconomy than first class, or a flight attendant or pilot, as they don't get long, extremely close contact with as many people. The more BO you smell, the faster you're learning. In economy, you're touching two other people thigh-to-thigh for 20 hours, you have 6 more people within 75cm (3 row in front, 3 row behind), another 10 within 1.5m (6 in rows 2 in front, 2 behind, 2 out of 3 across the corridor, and the one in front or behind them). Within 5m on a particularly cheap airline (75cm seat pitch), you could be looking at 50 people. ### Enrol in generic postgraduate study Master of Business degrees are great because everyone in your class has a degree, and they're from a wide range of professions. By the time you get your MBA, you'll have everyone elses degree too! ### Hospice ward night shift The later in life you spend time with them, the more skills you get, right? So wait till they're at the end of their life, slowly dying under medical care, you can easily spend hours in the same room as them every night when nothing else is going on. ### Spend the winter in Antartica Research stations are wanting people for jobs at Antarctic research posts all the time. You're trapped for 12 weeks over winter in close contact with an expert in every field, as they need to be there for the full winter in case something breaks. ### Volunteer at refugee aid organisations. Or join their caravans. Who can afford to pay 10's of thousands of dollars to human traffickers to get crammed into a leaky boat for a chance to get to (for example) Australia? Rich, well educated families can. [Illegal immigrants are often well educated. Eg 30% of American illegal immigrants have a college degree](https://qz.com/1627664/undocumented-immigrants-in-the-us-are-increasingly-better-educated/). When a coup happens and refugees flee, often the educated are the ones with both the motivation and the resources to flee. Spend a few weeks crammed in with all of them, and then maybe the overcrowded immigration centre if you're caught, you'll get all that education, and their language. ### Just pay for tutors Once you've got a skill that you can earn money from reliably and quickly (anything from sex work to performing arts to welding (which pays the most of any trade) to stock market manipulation), just start hiring tutors. This also gives a paper trail to explain how you learnt something, just in case some government type tries to accuse you of, say, electrical work without an electricians training course. ### Once you've learnt something, teach it Aim to get hired by a university teaching (or even just tutoring in, to begin with). The goal is to hang out with all the professors in the uni faculty lunch room / staff training days. You could also teach something like "Workplace sexual harassment training", or "workplace first aid", in which you have to spend time at a diverse number of workplaces interacting intimately with the staff. ("I need someone to demonstrate chest compressions on - what do you do?" "I'm the accountant", "uh I know that already, what about you?" "I'm an AI engineer" "Excellent come lie down here and let me talk at length about CPR while in close proximity to you"). [Answer] **Pay for skill** I'll say how I would do it in several phases. *All phases* Although learning skills it good, the right kind of body is required. A skilled dancer can't suddenly be good at water polo for example. The muscles are different. I would go for a reasonably strong and limber body with good hand eye coordination. That way you might not have the best body, but it might still be great for nearly all physical tasks. The suggestion to be with politicians is good and can be added with spending time with highly social people. That way you can use charm and speaking skills to get a great deal done. *Phase 1* I would go for a certain cocktail of skills, but start with getting rich. Learn one well skill that earns a lot of money very well. For example, the top of certain music players, like violin or singing, can get ridiculous amounts of money. The quick rise in music is also often more respected and less 'suspicious' than scientific knowledge for example. So it's recommended as a start. Once a lot of money is acquired, the second phase begins. *Phase 2* The second phase is simple. Either by fame or by paying money you can get in contact with highly educated people. To make it easier, focus on a certain kind per half a year, month, or week. Related topics would be great. Graphic designers and then engineers for example. Ask for people to sleep in a building where the rooms are orientated in such a way that all beds are close to a small room where you sleep. With the knowledge aquired you can at a certain moment advance the fields dramatically. This is because you have the skills and understanding of multiple highly skilled people, making you able to improve on things better than those people working side by side. With this you can rinse and repeat. Get (related) skills, improve or simply capitalise on it, move on. Once in a while you revisit a field that you improved. Based on your improvements they probably continued development, so you can learn the extra in a day or two and raise the bar again. *Phase 3* Your fame in so many fields might've been disputed at first, but at a certain moment you'll have proven yourself enough that you're sought out by people. Like an oracle you can spend some time with the highly skilled people, improve where possible and give much needed answers. You might not solve everything, as the skills aren't high enough yet, but at the very least you can use your vast knowledge base to assist in insight. To fuel some of your knowledge, you might actually spend some time with some people seen as damaged by society. Autism and savants can greatly increase your levels. You might even be able to translate incredible understandings when absorbing their knowledge. [Answer] ### Become a concierge, personal assistant, valet, bodyguard, personal attorney, or similar These are all jobs which typically require close physical proximity to the employer. As a bonus, highly capable people in competitive fields are more likely to have such a person near them, due to their own wealth or the high value of their time. And if your employer interacts with people of similar skill (which would not be uncommon), you can pick up bonus skills from them from time to time. ### Become a high-powered consultant in a field broadly needed in society Gaining skill in just about any field is trivially easy for you with this power. If you became, for examples, an attorney, actuary, insurance researcher, or IT specialist with skills equivalent to the best practitioners in the world you could easily find a place for yourself in many organizations for extended periods of time. Spending four months "designing an insurance policy" for a firm, you could be working right near people of interest all day long! ### Own (or otherwise have freedom to move inside of) a venue which hosts conferences and retreats If you have easy access to a place which hosts conventions, conferences, and similar, you can attract *lots* of skilled people to you all at once, over and over again. I don't know if the power can work more quickly drawing the same skills from multiple people at a time, but whether it does or not you can still get several days (maybe even weeks) around people who are at the tops of their fields. If you have some influence in an attached hotel, you could book rooms adjacent to the most desirable targets and be within a few feet of them all night, every night of the event. If you own someplace like a resort, you can contrive something like a (seemingly) random contest giving away multi-week vacations, for free, to lucky winners. And if you happen to be choosing winners based on what skills you'd like to learn... well, make sure to absorb some relevant legal skills before creating a fake contest. But the point is that you can attract people with money you can easily replace (again, this power makes money easy to come by), put them in specific places which you know in advance, and keep tabs on their activities in a way that makes it easy to be near them while they're around. ### Become wealthy enough to fund projects, and then hire skilled people on contracts to work on them You could amass a good amount of money pretty quickly with a super power like this. Once you've done so there's no reason you couldn't initiate projects which would naturally require some of the most skilled people in the world in their fields to come and help. Throw enough money at many experts in any field, and you can likely get at least some of them to consult on-site for you for a few weeks or months at a time. As above, you can pull all sorts of tricks to increase your proximity (like choosing living arrangements which are close to your own home), and even try new ones (like scheduling lots of in-person meetings). [Answer] ## Join the Navy [](https://i.stack.imgur.com/M53lf.jpg) Naval vessels put lots of people in close confines, and the ships — especially the larger ships — need to be able to cover a wide variety of skills to a high degree of competence. From nuclear engineering, medicine, and command/leadership all the way down to "simpler" things like knot-tying, welding, and machine maintenance. The people on the ship will also have a wide variety of hobbies you can absorb. You say the power works slow. Perfect. You'll be stuck in close confines with the same people for deployments of several months. Get back to home port, and you ought to know how to do most anything on the ship. ## Work at a College The Navy is *definitely* not for everyone. As an alternative, take a job (even maintenance/custodial) at a small college. Even small schools will have PhD-level talent in both sciences and arts, and then there are the hobbies (of all the students as well). The smaller the college, the closer the proximity. This is likely to take longer than the Navy option (maybe even a few years), but the variety and ultimate expertise of the talent pool (your final ceiling for potential skills) might be a little higher, and it's much easier to *leave* the college when you're done. ## Take a Long Cruise Lots of people, very tight spaces. Unlike a Navy vessel, you'll be surrounded by people from many walks of life. Even better, they'll be the kinds of people with the skill to support themselves well enough to afford a long cruise. I could have also said, "Work in a Hotel", but a cruise will give you longer exposures to the same people, which I feel might help your power work better. Perhaps taking a job on a cruise ship is the way to go, as you might need to do a few of these to start noticing the benefit. But I think this could be very effective. [Answer] ## Events Technician For knowledge skills, pretty much every field has conferences, and someone has to set up and run those conferences. Being a sound or lighting technician will enable access into conferences across any field. For performance skills, this is simple, a on stage sound technician can be in close proximity to performers for the entire time they are on stage and for some time before and after. For sports, most top end competitions are shows as well, so again a sound or broadcast technician should be able to get close to the events. Additionally this gets you into situations with a lot of people in the audience, so you should be able to pick up some skills from them. A lot of this work is done by small agencies and self employed individuals, with lots of opportunities to build up skill by hanging near top people, and then once you build up a reputation you can pick and choose which jobs to go for. For example one way you could get started is to go to your nearest live gig and try and stay near the back and absorb skills from the technicians. The key advantage of this approach over owning a venue is people often pick venues for reasons like location and size which you would have no control over. By being a technician you could more easily move to whichever events you want to attend. You can also transition from this skillset to also pick up work as a broadcast technician and/or recording technician, allowing access to TV recording setup and movie studios. This could potentially get you close to top politicians and actors along with all the various people who TV and radio shows are made about. [Answer] **Ride the subway** The world's biggest metropolises, like New York, Tokyo or Beijing also feature the busiest subway systems. People from all walks of life, including neurosurgeons and rocket scientists, are riding the subway cars there every day. During the rush hour, the number of people in rider's proximity just couldn't get any better. Keep riding the same line until you fully absorb skills of your neighbors, then move on. [Answer] ### You need the papers, too! To start "real life" you need the paper, too. In our highly bureaucratic world, we need a paper that tells "This person is a Dr. Phil. whatever", otherwise people don't believe you. It's your entry ticket to a lot of things. If you want a real effect from it, it has to be backed up by several people, too. So if someone calls your university, they confirm "oh yes that one's an expert". But that's a fair game, because spending 4 or 5 years at two or three community colleges will give you the brains of all the talented ones in the community (Thousands at a time! And completely sucked dry because you sit with them in a room for weeks, not just hours!), plus the doctorates, plus the professors. No-one will look strange at you when you go to conferences, switch your field for another one or switch the university two or three times in that time. Many people do that. Best is, you can pick up all you need for your "paper skill", plus all the other skills of all the other fields in all the universities you are visiting in that time, too. Once you have the combination of many skills, you can write a really great paper for your "paper skill" - imagine being able to perfectly do graphics design, text composition, greatly understand harmonies from music and from electrical engineering, being a great & persuasive talker and using all those skills to do some groundbreaking "work" just by combining the ideas of two or three theoretical & observational physic/math scientist with easy-to-understand and outstanding beautiful pictures and some engineering from the engineering departments. This can get you kickstarted, because things written by scientists have remarkable longevity and are read by lots of people, as long as they are beautiful and understandable. (which is not normally the case in physics and math, and this is why I picked those two :-) ) Also, a paper normally covers only a small chunk of a problem, while you could cover the whole problem using that skill. ### Don't do the work anymore Then you will have to switch fields: You don't want to do the work, you want to have a bigger impact than that right? So once you have your "paper skill" ticket providing invitations to you, use the clout and get in contact with entrepreneurs, politicians and the like, and pick up their skills. Go down the route of the other postings now. ### What's the danger of that skill? This is not your question anymore, but I am curious. What happens if you pick up a junkie skill? How to best use meth, crocodile or heroine? Will you become a junkie, too, just because you downloaded their experience in your brains? Many drugs have a psycological addictiveness. Could that be transferred? Because that would be a great danger indeed, your character would have to choose very carefully where to copy what. Can your character pick up codes and passwords? Because, then they would be an incredible hacker, too, no need to work, just hack into a government or company and tell the bureaucrats what to do. Will your character get bored once he sucked up humanity's knowledge? This could be deadly! Sucide, Corona and TB are on par with each other in terms of death rates. Does your character learn from relationships "This woman loves to be seduced *that* way", "That man likes it if he can do *this* in bed"? Or more generally, do they pick up the skill of people surrounding one person, to manipulate that one person? Because that can be a dangerous extra-feature, too. If your character uses that manipulative edge, he will draw in the jealousy of the others like hell. [Answer] **Start with something that gets you a job in a hospital** It's one of the few places where people of nearly all professions will be guaranteed to end up at some point. Probably better off with a role that has you moving throughout the hospital a lot, possibly a janitor. You might not get the same quality of skills, and you'll have people constantly coming and going before you've finalised picking up their skill, but the sheer quantity and amount of overlap should offset that. Enough time at this should give you a well rounded set of skills, you can then specialise to pick up the missing ones. [Answer] **Libraries** Free, legal, not suspicious; anyone can come in and sit quietly reading (or pretending to read). University libraries may or may not be public, but even those that aren't will rarely turn away someone who's there to learn. That may especially be a good approach at the beginning, before setting up some of the more sophisticated schemes, or while restricted in other ways; eg. a minor. [Answer] For general skills, move to a high population city and spend time in a wide variety of settings but keep a fixed schedule for the best chance of overlapping skill sets by encountering the same people or groups. For specific, scientific skills, take a job as a mail clerk in a high-density office building/laboratory that conducts research and interns college students. You get to make your rounds every day, encountering the same highly credentialed people. [Answer] **It depends on the Scaling** > > Furthermore, I've found that the rate of skill absorption has an inverse relationship with distance to the person. > > > I am assuming an exponential learning curve Assume, you are a meter away from the person and you learn a small skill\* in an hour If you are 10 meters away, do you need ten hours? If you smack your and the persons heads together do you need a minute? Go for group huggings or similar or focus on closing distance with one person like in [Ash's](https://worldbuilding.stackexchange.com/a/184628/78659) answer or in [Johns](https://worldbuilding.stackexchange.com/a/184633/78659) answer Or If you are a meter away from the person and you learn a small skill\* in an hour If you are 10 meters away, do you need only 10 minutes more? If you are 20 meters away, do you need only another 10 minutes more? Go to expert Conferences, Festivals or Games from your favorite Teams in Stadiums, like in [user1937198s](https://worldbuilding.stackexchange.com/a/184652/78659) answer hope it helps [Answer] Take long train trips. People on the train are interesting. You're with them for a long time. They mill about and socialize, finding ways to pass the time together. That last one might not be important to your in your quest for skills, but it could sure help anyone who, say, wanted to write a story about you. [Answer] Spend time at a University. Some answers have mentioned getting a job at a university, but even that much isn't necessary. Most college campuses are open to the public and nobody will stop you from just sitting in on a class in progress. Large college classes can have hundreds of people from all walks of life crammed tightly into one room for hours at a time, and every single person there will have at least a high school diploma. When one class ends, just walk around until you see another class in progress and join that one. This can be done from sunrise to sunset a minimum of five days per week, and if you want to really get the most out of your time, be a teacher's pet as they will generally be the most educated on a given topic. Sit in the front row to absorb that knowledge as quickly as possible during class, and go to their office hours whenever possible. When not directly in class, the faculty building is your best friend. One building swarming with people with Phds and Master's degrees which you can just hang out in all day. You'll learn everything from different languages and high-level mathematics to instruments and dance all in one spot. [Answer] **Sports** As a football referee for example you will get fit and learn the rules perfectly. As you become more experienced you will progress to higher levels and absorb better and better skills. It is much easier to become a top referee than a top player. Remember however that sportspeople have a limited active life so maybe start even earlier than 18. **Academic** Get a job in the cafes and bars of MIT or other distinguished universities. I can tell you from experience that the bars are packed in the evenings with students of all levels and the bar is a great place to meet (or rather serve) local and visiting professors - especially at conference time. **Specialist/science** Again work on-campus in bars and cafes but this time at CERN or Google. **Medical** Start by volunteering at a hospital then get a job as a hospital porter at the most expensive private hospital you can find. Make sure they cater for the rich and famous. You will be pushing distinguished patients on trolleys and wheeling them to operating theatres as well as brushing past senior doctors and surgeons in the corridors every day. **Business** Become the most reliable and skilled PA then get a job with a high-powered business exec or company owner. You will be interacting with them day in day out. [Answer] The Morgue / Grave digger You never said they needed to be alive. You have unlimited amount of time to be near your "skill tomes". You'll also have all sorts of people come in without any limitations. Rich, poor, skilled, educated etc. I guess the only people you won't get are high profile politicians or celebrities, but that depends on how you sell yourself. [Answer] 1. Pursue a career in sales. This will put you in close proximity to salesmen. You are building charisma, or charm. If unable to hit a maximal skill, abandon this and attempt to become an executive assistant for a CEO. 2. Once you have acquired a near mythical level of charisma, pursue a career in finance. Your goal here is to maximize contact with people who are just incredibly good at managing money. 3. You now have an enormous amount of charm, skill in managing money, and probably a fairly wide web of contacts. Use these skills to start managing money for billionaires. This puts an incredibly large amount of capital under your control and gives you a great deal of influence at high levels of society. 4. Now, start your own investment firm using your contacts and your personal wealth. Use this firm to form business relationships with all kinds of experts in all sorts of fields. Use some of the wealth you generate here to donate generously to all sorts of causes and weird special interests - this puts you in basically any room you want to be in for however long you want to be there, and you're incredibly charming, so nobody really minds all that much, and you're insanely wealthy, powerful, and respected, so nobody questions you. ]

[Question] [ I am going to post this question in general terms, but resemblance with our Earth is totally intentional - to the level that I am tagging this question [alternate-world](/questions/tagged/alternate-world "show questions tagged 'alternate-world'"), so if unsure, assume the behavior and technology level of Earth, in the current day: We have two factions: Red and Blue. And they basically hate each other. For three reasons: 1. **Racial:** Blue people have blue skin and Red people have red skin. And obviously they both think that their skin color is the best. 2. **Religious:** Both Blue and Red religions claim to be The One religion and also that the other religion "is holding it wrong." (pun intended) 3. **Cultural:** Reds are generally open minded omnivores, while Blues are conservative and strictly vegan. *Side note:* Both Reds and Blues are members of same species, so they only differ by skin color. The Reds and Blues were living next to each other at least for 200 years, not trading, having local fights and both preaching hatred towards each other. One day, the Reds decided to attack the Blues. And they won. Well, on paper. Blue Town was conquered, the blue leader killed. We are one big Red country now. Officially. But if you look at the setup, one thing is obvious: there will always be a group of Terrorists (or Rebels, if you take the Blue side) who will try to get their country back. We are now 20 years past when Blue Town was conquered. People are still getting killed in various terrorist attacks and Red secret agency tells us that if we do not change something, there are people willing to sacrifice their lives. A new Red leader was elected yesterday. And she is wanting and willing to change things, but with one exception: She still wants to have one big Red country, preferably indefinitely, but say at least for the next 200 years. What specific steps does she need to take in order to achieve this and keep everyone happy? **Edit:** Yes, it does feel like I want to get Nobel Peace prize for solving the Middle East. And basically, my question actually is "how to solve Middle East?". But I did not want to make such general statements (as I did in this question) about the situation in Middle East. [Answer] ## Genocide The surprising fact that nobody has covered in detail as of yet is the elephant in the room - that of genociding the Blue faction. We have heard of many genocides, but most of them were unsuccessful (Yugoslavian genocide, Rwandan genocide, Ottoman-Armenian genocide and the Holocaust, to name a few). We might therefore be tempted to think that genocide would not be a successful option for the Red faction to undertake. However, this cannot be further from the truth. The only reason these failed genocides were so widely publicised was because there were survivors, who want to publicise their account. Therefore, as long as your genocide is successful, there would be no need to worry about future historical references. [History is written by the winners](https://en.wikipedia.org/wiki/History_is_written_by_the_winners). In fact, your hypothetical case is much more amenable to genocide as a solution than any real-life case. Humans are actually rather similar to one another, to the point that cultural differences can only be deduced with some difficulty. Armies had to use [shibboleths](https://en.wikipedia.org/wiki/Shibboleth) to identify friend from foe, in order to actually kill members of the opposite faction with any degree of accuracy. The same applied to Nazi Germany, which had to issue [Jewish stars](https://en.wikipedia.org/wiki/Yellow_badge) to correctly identify the Jews to genocide. However, the nearly immutable property of skin colour makes the Blue faction extremely easy to identify, and at the same time also easier to demonise. Secondly, there are only two factions and two churches on your world. This makes it much simpler for genocide-minded leaders to succeed, as they do not have to suffer the political fallout from genocide. One of the main reasons Israel has not been more heavy-handed in its treatment of the [Palestinian freedom movement](https://en.wikipedia.org/wiki/Palestinian_people#1967.E2.80.93present) is the heavy scrutiny it receives from its allies for violating Palestinian human rights. Churches can also be large players in this field, but since the Red faction also has its own church, it would be far easier to sway the church over to its side, as compared to an external player such as the real-life Vatican church. Overall, it would be likely that genocide would be a highly effective (although distasteful) method to achieve the leader's goals of establishing Red hegemony over the country. [Answer] This is a very old problem, widely discussed in Machiavelli's "The Prince". Chapter III, titled "[Concerning Mixed Principalities](http://www.constitution.org/mac/prince03.htm)" describes your very situation: you've just conquered a country full of hostile people. How are you supposed to keep it? For your problem there are two suggested solutions. One is that Red Leader should personally oversee the process: > > But when states are acquired in a country differing in language, customs, or laws, there are difficulties, and good fortune and great energy are needed to hold them, and one of the greatest and most real helps would be that he who has acquired them should go and reside there. This would make his position more secure and durable, as it has made that of the Turk in Greece, who, notwithstanding all the other measures taken by him for holding that state, if he had not settled there, would not have been able to keep it. Because, if one is on the spot, disorders are seen as they spring up, and one can quickly remedy them; but if one is not at hand, they heard of only when they are one can no longer remedy them. Besides this, the country is not pillaged by your officials; the subjects are satisfied by prompt recourse to the prince; thus, wishing to be good, they have more cause to love him, and wishing to be otherwise, to fear him. He who would attack that state from the outside must have the utmost caution; as long as the prince resides there it can only be wrested from him with the greatest difficulty. > > > The other is that Reds should establish colonies in order to gain economical and social control over Blue community: > > The other and better course is to send colonies to one or two places, which may be as keys to that state, for it necessary either to do this or else to keep there a great number of cavalry and infantry. A prince does not spend much on colonies, for with little or no expense he can send them out and keep them there, and he offends a minority only of the citizens from whom he takes lands and houses to give them to the new inhabitants; and those whom he offends, remaining poor and scattered, are never able to injure him; whilst the rest being uninjured are easily kept quiet, and at the same time are anxious not to err for fear it should happen to them as it has to those who have been despoiled. In conclusion, I say that these colonies are not costly, they are more faithful, they injure less, and the injured, as has been said, being poor and scattered, cannot hurt. Upon this, one has to remark that men ought either to be well treated or crushed, because they can avenge themselves of lighter injuries, of more serious ones they cannot; therefore the injury that is to be done to a man ought to be of such a kind that one does not stand in fear of revenge. > > > I strongly recommend you read the entire chapter, since it contains a lot of useful information for your case. And while you're at it, check out Chapter IV as well - it contains detailed analysis of Alexander The Great's conquest of Persia, and how did he accomplish the same thing there you want Reds to do. [Answer] Right off the bat, I’m going to surmise that this is extremely difficult, if not impossible, to do effectively. To the best of my knowledge, I do not believe this has ever been done successfully in human history without lots and lots of genocide. But, that’s no fun. In order for both cultures to exist together peacefully and happily, you’re ultimately looking for three things: 1. Religious tolerance must become a cultural norm. 2. Racial tolerance must become a cultural norm. 3. Religious and Racial equality must be enshrined in the law. One leader, even if elected for the remainder of her lifetime, is not going to have enough time to accomplish these things. This is a generational challenge and the leaders of this country are not only going to be facing rebellious blues, but as they enact reforms they will face rebellious reds. Everything that leaders of this country do needs to be done gradually and with as much popular support as they can muster. Here are a few things leaders need to start thinking about right away: **The Purple Union** The country should no longer be called “Red”, but “Purple”. This will anger reds. This will not please any blues. But it builds a necessary foundation of unity for the future. **Equality in Law** Laws must immediately be passed that forbid racial or religious discrimination. If this is a democracy, this won’t be fun. As we’ve seen time and time again historically, it may take many years to achieve this kind of equality under the law. **Reparations** There is going to be a lot of turmoil as two war economies, one of which was crushed, need to now combine into one. Given that red was the aggressor, there needs to be an understanding that reds will disproportionately contribute to rebuilding infrastructure and helping to ensure that the devastated blues don’t become second-class citizens economically. As history will tell you, this is going to be very hard, if not totally impossible. Reds may not like it, but hopefully there was some popular support for taking over blue lands without simply exiling them or committing genocide. **Helpful Allies** This country needs strong, friendly allies that view the integration of reds and blues as a positive outcome for everyone. The Orange and Green Nations at the very least must not view Red as an enemy. International pressure can be a powerful force and will definitely affect the success of this task over the centuries. **Incentivize Communal Mixing** If the reds always live in red territory and blues in blue territory, you’re simply delaying more war. This mixing must happen slowly, but with economic incentives you might be able to slowly start blending the cultures spacially. This is going to cause increased violence for a while, but with careful attention to fairness, the generational divide will start to help. **Smart Education** Textbooks need to be clear about what happened. The thought processes of the children produced from the educational system will literally shape the outcome of this project. If every generation becomes a little more tolerant than the next, you’re on the right track. Like everything else, it must be done gradually and as fairly as possible. As generations come and go and red children grow up with blue children, camaraderie can start to form. **In the End...** No matter how well you do any of these things, there’s going to be a lot of violence. There will be violence for decades, maybe even centuries. There may even be some civil wars. Hopefully, as the red economy helps rebuild the blue economy and they intertwine you can mitigate risk of a schism. Having close neighbors and allies that would be unwilling to trade with either nation separately would be extremely helpful. The ultimate goal militarily is to occupy blue as gently as possible (difficult, to say the least) until enough generations pass for some sense of general unity to begin replacing the forceful binding. Realistically, no one knows the best way to execute any of these steps. It wouldn’t be smooth, it probably wouldn’t be effective, and it certainly wouldn’t be fast. In today's world, the correct answer to your question would win you the nobel prize. [Answer] Perhaps the best example of "how its done" is to look at how China has managed to absorb the various invading nations and cultures that have attempted to conquer China. Essentially China's culture was not only far stronger than anything the invaders brought with them, but Chinese culture and material wealth essentially seduced the conquering Mongols into adopting Chinese manners and ways. Even though they are "racially" different from the Han Chinese, in effect they have become like the Han. For your scenario, the issue is to make the "Red" culture and civilization so attractive to the "Blue" people that they will choose to assimilate. (If you want to make this even more interesting, maybe the Blue culture is more attractive to the Reds, and the Reds gradually become culturally Blue....) Now the conquering nation will most likely have superiority in numbers, and will have the more aggressive or assertive culture, but turnabout has happened in the past; look at how Buddhism or Christianity prevailed in the far East or the Roman Empire despite disparity in numbers and even persecution against believers. So "conquest" of physical territory is not enough, there needs to be some assimilation and something attractive enough to one side or the other to support the idea of assimilation. Culture, religion or even social organizations which make achieving wealth easier are all attractors which could have one side or the other assimilate. [Answer] Nothing is guaranteed to work in the real world, but some paths are believable in a story, some have historic precedent. Most of them work by establishing a **common narrative** (or at least a shared onr) to establish a popular sense of We. Introduce a **common foe** that can only be fought with joint forces, possibly combining skills from both sides. This may be a foreign aggressor, a disaster, an epidemic, a new cult etc., e.g. the Soviet Union after WW2 for Western Europe. Identify a small, everyday **common problem** that existed in both countries before and should have been fixed long ago. It should affect or concern most people and must not be associated with the war, politics, religion, culture or diet, but requires changes to the habits of everyone, e.g. solve pollution, recycling, traffic accidents or infant mortality. Let the new leader make this their primary, even sole goal. Read up on Paul O’Neill’s worker safety program that transformed Alcoa. Let them share an iconic **common victory** (or heroic underdog battle). This can even be in sports where it’s performed by a small select elite. Many nations have such defining moments, e.g. rugby 1995 for South Africa (“Invictus”) or soccer 1954 and 1990 for Germany. [Answer] I'll assume by "keep everyone happy" you genuinely mean keeping as much of the population happy as possible without 'reducing' the population. I'll also assume the government and religious establishment are pretty much one entity, since you don't indicate otherwise. Some steps include: * Allowing legal concessions for the minority blue religion. These could be related to definitions of marriage, labeling animal products appropriately, and allowing them control over their children's educations. Some more extreme Reds will be upset by this, but it should be fairly tolerable for most while increasing appreciation for the Blues. * Assimilating as much as possible of the Blue Religion into the Red Religion. More imperial religions are known for assimilating celebrations, important figures, and doctrines from smaller religions. * Find ways to foster and raise up people from the Blue society who felt under-represented in the Blue regime. Make these people more loyal to you and more powerful than other Blues. Try to give these people as much power over administering the Blue population as possible, so that it seems less like Red is dominating Blue. * Propaganda & Revisionism. Perhaps the evilest solution. Phase out documents that remind people of the Red and Blue division, especially from schools. Have scholars indicate that the Blue religion is derived from the Red religion. Most importantly, always make sure the terrorists are seen only as terrorists, not freedom fighters. Don't air their doctrines or justifications, only illustrate the damage they do. Emphasize especially any instance where a terrorist kills any Blues. Turn the "us" and "them" into "Citizens" and "terrorists" and people will start to see separatist ideas as dangerous. [Answer] While it's hardly palatable, the Final Solution springs to mind. It has the advantage of being straightforward, since there is no doubt who is Red and who is Blue, unless there are some recessive genetic factors involved. And all the survivors will be happy - except maybe the ones who had to do the dirty work. There will be plenty of cheap land and houses available to award to them in appreciation of their vital work. All this is predicated on the assumption that there are no other countries involved who might give shelter to Blue refugees and thereby prolong the struggle. [Answer] Officially make a rule that a blue will have to marry a red and red will have to marry a blue. The offsprings will neither be red or blue. Over the period of time, the differences will be resolved. [Answer] There is a precedent in Europe, that genocide isn't the only answer. If you make the Red culture appear to be more desirable by Reds fulfilling all of Blue society's leadership roles and providing a new upper class (and enforcing rules to make it difficult, if not impossible for Blues to be either of those), while removing the language and culture of the Blue by fair means or foul, then quickly the Red culture will be dominant, desirable even. Throw in a few engineered famines and firm control is established. In Ireland's experience, that can buy you 800 years of dominance, but even that isn't enough to prevent the inevitable rebellion. Slovakia is a good case study too. My example is, of course, very much simplified. Karl Marx had [plenty to say](https://www.marxists.org/archive/marx/works/1867/12/16.htm) about how all this is achieved. [Answer] If you want a real answer, I’d go looking for a place on Earth where two tribes of people stayed distinct, but on good terms, and see how they got there. Canada’s assimilation of Québec might be the best one. Switzerland has cantons with different official languages. South Africans more or less get along today. Amazingly, so do Rwandan Hutus and Tutsis. Belgium is more ambiguous. There are a number of small communities in the U.S. today that effectively have autonomy and their own way of life, the Amish and Hasidim maybe being the most visible. But observe that, in all of those cases, the majority dropped its opposition to multinationalism. The Ottomans and Romans were mostly successful at being cosmopolitan and multinational for a long time, while still having one dominant tribe, but not forever. If you’re just trying to figure out what a well-meaning leader with no knowledge of any of that history would do—well, a lot of people in that position have failed in interesting ways. You might want to look at the emperors of Austria. [Answer] Two of the criteria listed for each "country" seem (philosophically) illogical in their discrimination toward the other: That they believe their skin color is superior, and that they believe their religion is the indisputable truth, and all others heretical. If either group examined their religious and racial beliefs, they may realize that they could get along with each other just fine, and be happier as a result. The Reds don't like terrorist attacks, and the Blues don't like being "conquered." I like Avernium's answer promoting tolerance, and it addresses both of those questions. But the question that follows is what it means to conquer another town if you tolerate the religion and racial differences of the people living there. If the Reds are plundering the resources of the Blues or oppressing them in any way, then the Blues have a legitimate grievance. In this case, the solution is to no longer take economic advantage of the conquered country. In this scenario with the least details, it seems hard to imagine that the Reds are oppressing the Blues culturally, since the Blues have a more strict culture of veganism. Allow the Blues to continue practicing this, as it does not affect the Reds anyway. If these points are followed strictly, the Blues have no specified grievance for which to terrorize the Reds. But this leaves little reason for the Reds to invade in the first place, if they have no desire to take advantage of the Blue's resources, push their religious beliefs on them, or diminish their rights because of their skin color. Even if we omit the term "oppress," the only reason to conquer another locale would be either for economic or ideological "preference". If they don't wish to oppress the other group economically or ideologically, they would save resources by not invading. If they do wish to oppress the other group economically or ideologically, we're left with the more violent results that do reflect a lot of what we see on Earth. The proper solution for the Reds is to create a separate state for the Blues, or find a way to integrate the groups so that the term "conquer" no longer seems appropriate. If we extrapolate the question to include an infinite number of social groups, even with overlapping racial, religious, and cultural traits, we would need to develop a perfectly cascading hierarchy of governing bodies that caters to the differences in each group with the least conflict and grievance possible. The way governments operate on Earth, this is largely the goal (whether an intentional goal or one evolved through the history of the social contract) of breaking geographical regions down by country, province, municipality, and social community. However, geographical breakdowns will always be flawed when there is diversity throughout the planet, so it seems arguable that a strong, central, global leadership with fair-minded representatives from different groups should have the most power over world affairs, leaving geographical or other nation-based governments to create additional structures for their constituents, more so when it comes to purely practical governmental affairs, and less so when it comes to ideological limitations on the rights of the governed. This would be like a more centralized version of what Woodrow Wilson and others envisioned as The League of Nations, and what the Constitutional Convention delegates envisioned when they designed the federalist government in the United States. [Answer] ## Blue Reserves Hold out a little bit longer. Say until three generations of Reds have lived in the formerly Blue land. Then start start publicly re-evalutating your past actions: yes, the invasion was wrong, those were more barbaric times. And both sides did terrible things. And now, both sides have lived here for generations: the land belongs to everybody. Of course we can't just let the Blue into the government as is: they live in slums. They're terrorists. They're uneducated. They don't understand the complex business of government. Tell you what: we'll set up a series of scholarships for promising Blue youths, to go to the finest schools in the land, and be educated about our system and our values. Of course, we realize that the blue way of life, the blue traditions and values are under threat. So we make a deal: **we'll create reserves for them**. Pieces of land, that they can do with as they please, where they can live in their traditional ways, with none of our modern Red technologies. We'll purposely choose Blue traditionalists and ludditesas leader of these reserves. They'll get fertile lands, but no commercial, industrial or intellectual value, nothing close to any major city. The idea is to create small, isolated communities of technologically backwards people to buy off our guilt. Small communities that young people can't wait to leave to integrate into the Red society. Before long, the invasion will be a bad thing that happened in the past. Something to remember, but not something you can blame the current government for. And they have reserves now, to preserve their way of life. And if they don't want to live there, they're welcome in the cities. They'll get the same chances as everybody else. Of course, if you want to make a promotion, it's not a good idea to rub your Blue religion in people's faces. It just makes them uncomfortable. You might even consider converting, if you really want to climb the ladder. [Answer] I would like to propose two alternative (evil) approaches to what has been said already: # Find a common enemy Probably the most commonly used technique to achieve unity is by finding an external enemy. This is how much of daily politics keeps individuals of a country together. This is probably how the Reds and the Blue were kept together in the strong social bonds you have described. They hated each other, so rebellion within the Reds or Blue is quite unlikely. In times of war, pragmatism dictates to drop internal conflicts. You can study this in many historical events, but take the world wars for instance. 1984 from Orwell describes a similar situation, even though it focuses on interior politics. In any case, the Reds have to ensure not to cause a general uprising like the Russians saw in the first world war. Something I can see as a danger if the Blues are suppressed. Because they have a strong bond and probably a similar hate against the Reds as the Socialists had against the Tsar. This leads us to the question what it means to have a Big *Red* country. What does it mean? The Reds generally benefit from the Blue, who are supressed? That there shall be only a Red leader, but the lower ranks are equal? If you are asking on how to suppress an ethnic group for a long time, I would propose # A slave system A slave that has no rights and owns nothing is no threat. That is something that has worked for ages until moral consciousness recently led to the abolition of slavery. But before that it existed quite for a long time. Why? Because the superiority of the masters over the slaves was not only legal by law, but very often part of the mainstream ethics. It was normal, no one questions it. You would have to achieve that as the Red leader. There is no guarantee that it works, but since each of the races claims superiority by race anyway, the Red leader could try to to find "scientific" reasons, for why the Blue lost the war. They are weaker, they are better in labour than in intellectual tasks, etc. However, the moment of repression of the Blue as result of their defeat would have to be used to completely disarm and disown them, and to assign them to a Red master. If they are allowed to recover, they will resist immediately with all means. So it might be to late for the new Red leader to go this route. [Answer] ## **Media Control** Keep a rigid control of your media, including but not limited to TV and Internet, keep showing them 24 hours red and blue skin people living together, doing things together and erase any kind of hate between then, pretend that the hate is a thing of the past, and the only people that are still "hating" is the extremist and criminals. You can even create fake news of how a red man saved a poor blue woman from being raped by a red gang. Media is a powerful way to control what and how people see the reality, and you should abuse this power. ## **Bread and Circus** A war is just over, people are traumatized and with all kind of hate in their minds, if you force people to be sober they will be angry, let them smoke and drink and build fancy places to them to have fun and most important to have fun with reds and blues. Why would anyone want war again if their life are so fun and good now and they can just sit at beach and smoke pot all day without worrying about the horror of the wars? ## **Religion Control** You do not say how much the Reds control the Blues religion, and how much the leader of the Reds control the Red religion, but you could mix a few things from the blue religion, and build places to them to pray together. You can also say that your God showed a vision to your King, showing that he disapproves the hate and that the Reds should be good to the blue to be good with him. Or even better make the two most important priests of the two religions to "have a vision" that a plague, disease or something like that will fall on them if they cannot live in peace or fight together( a common enemy is a good way to unite people) ## **Punish heavily any kind of hate between them** And i mean very very heavily, do not just jail the people or kill them, because like you said there will be always someone willing to die for the cause, instead threat to kill their loved ones and even their children if they do not "live in peace" they might be willing to die for the cause, but most of them will not do anything if that's whats take to their loved ones and family to live. And place spies between all the hate groups, make so that they cannot know who is working for the government and who is really a hater. ## **Keep rigid control of the education of the young** Make sure that the hate between Reds and Blues does not pass to the children, make this a crime, and make the children to study together and threat the parents if they teach hate to their children, eventually you make a tolerant society [Answer] I find some (one) of the proposed measures are too extreme, while others don't go far enough. Let's assume we have enough resources to play the long game, and that the goal is to mix the 2 cultures into one. There are several things to be done: 1. **Forced relocations**. The communities of the blue are broken up and many blue are forcibly relocated into red territory where they are the minority and where it's made sure they cannot easily group up with other blue. Easy ways of communication are provided and the communication is monitored. This entire setup at the same time makes it easier to spot rebels, provides hostages, and is an effective means of cultural assimilation 2. **Own the children**. Have blue children join far away red boarding schools. The blue children who don't go to these boarding schools will get far below average education. This provides hostages, and is an effective means of cultural assimilation. For perceived fairness you can impose the same rule on the reds, which gives you the added benefit of [Hitlerjugend](https://en.wikipedia.org/wiki/Hitler_Youth) 3. **Settlements**. Make red settlements on blue territory, and provide incentives for red citizens to settle there. Use non-political, non-criminal troublemakers for this. This provides cultural assimilation, and disposable targets for the blue rebels, distracting them from hitting targets that might hurt you. In the unlikely event that the rebels succeed in re-establishing their country, the settlements also give you an excuse to make their boarders much smaller than they used to be. 4. **Birth control**. The blue being a country that has suffered from war being fought on it's land, and losing a war, will be significantly poorer than the red. There's a risk that the poor have more children and thus gain a population advantage. You can stop that by introducing fines or other forms of punishment for families who have more than 1 or 2 children. If you use fines you can apply the same rules to both the red and the blue and claim to be fair, while knowing well that the wealthy red can pay the fines. 5. **Fight racism and discrimination.** The ultimate goal is cultural assimilation. To be honest we don't even care which culture assimilates which. Racism creates a clear line of "us" versus "them", something which you can't have. Use control of the media to make racism appear to be out of fashion/unattractive. [Answer] Physically/Chemically rewire/alter their brains by means of medical/genetical/technological breakthroughs. Not too far off from reality and a truly viable option I think, if this can be done uniformly (also on the operators of this operation). [Answer] Alright, I have a 3rd approach, if you have the land for it. Force separation, take the blues, round them up, disarm them, and move them. Let them settle down, and then round them up and move them again, picking a part of your Red nation that is difficult to survive on to settle them this time. Place them far enough away from any civilization that it is extremely inconvenient to commit acts of violence. Now start an education campaign across both countries, talking about how everyone is equal and start paying significant restitution to the blues. Now the Blues are dependent on you, separated from you, and everyone is becoming more peaceful. Be very very sever on any violence on either side(eg death penalty) and do not let strong, non-peaceful, blue leaders ever not be in jail. In 100 years~3 generations, with minimal death, the two peoples will be educated enough to be tolerant. Also, once the first movement phase is over, be sure that it looks like blue leaders are being represented equally in government, and be very careful with perception through the reintegration process. To sum up Stage 1)Remove all means of violence through separation of the blue people, disarmament, sever punishment of violence/discrimination, and presenting blue people with Maslow's first need so they cant think of Maslow's higher levels. Stage 2)Through extremely generous restitution, create dependence and begin education of all, through schools, media, student leadership etc. Allow peaceful blue leaders equally into government. Stage 3)Reintegration, now there is no youthful memory of violence, start encouraging cross blue/red schooling and employment, remaining extraordinarily strict about violence and discrimination. Slowly taper off restitution over the next several generations. This would be difficult to accomplish in the middle east, but it absolutely would work in the situation that you created. The middle east has too many variables to make it easy. Arabs, Palestinians, Jews, Persians, Turks, Kurds and nearly every other ethnic group hates each other, as do the dozens of religions, and each country. Thus the wars in Yemen, Libya, Syria, Iran/Iraq, Kurdistan, etc. Don't be fooled into thinking this is just a Palestine/Israel problem. Then there is all of the funding and proxy wars by Russia, Iran, Saudi Arabia, Turkey, Palestine, India, the USA etc. Beyond that, and possibly just as important, -the limited resources available in the area. Shrines, churches, monuments, water, fertile soil, land, etc are all in short supply and squabbled over. [Answer] > > But if you look at the setup, one thing is obvious: there will always be a group of Terrorists (or Rebels, if you take the Blue side) who will try to get their country back > > > 1. Why do they want to get their country back? Is it because "*they both think that their skin color is the best*?" 2. Is it because the Reds restrict the Blues' culture or religion? 3. Do they believe things would be somehow different if a Blue were in charge? 4. What does Red get from ruling over Blue? --- 1. If the problem is that each think they are best, then everyone needs to be educated on the truth of the matter. Well done, (*and accurate*), studies will help. Mutual respect needs to be gained. Whatever one color thinks it does better should be put to the test. The Romans, while conquering, were not afraid to implement better things or ideas from the people they conquered and implementing it into their own society. 2. The Blues will never stop having their own culture or religion. Trying to suppress it won't work unless your goal is to eventually have no more Blues (*which could a strategy as well, but I am focusing on peaceful ways*) Respect the blue's culture and religion and allow them to practice it. 3. Put a Blue in charge over blue lands, with an agreement of some kind for whatever Red wants from Blue lands. Or put a Blue in a high position as advisor, and actually use some Blue ideas when they are better. Think of the Queen having sovereignty over Canada, for a case where the Blues primarily do their own thing but technically are ruled by the Reds. 4. If Red simply wants a position of power over Blues, to use them as the lesser people in the society, then of course Blues will not be happy and they will strike out. Reds also cannot expect to force Blues to change their culture or beliefs unless they far outpower them. What do Reds actually get from ruling over Blues? They should work to keep that, but work with the Blues so they can be happy as well. [Answer] Sorry that this won't answer your question, but I feel that this is quite relevant. This is a story I read from a manga (japanese comic). At one moment, the scene moves to a country ZZ where two species, AA and BB, live together. AA could be said in an superior position, like, they're the government body, while BB only a working class. Both have a good life, all their needs fulfilled. Anyway, they're in peace. Meanwhile, on the world outside ZZ, AA and BB is an archenemy, where they loathe each other, with both having their own strength and weakness. Then how could in country ZZ, they live in harmony? This and that, the answer turned out to be a **Supreme Leader**. A leader, a king, an emperor, etc, stronger and wiser than any beings there, thus no one dares, or even can, to defy him. Even, he's admired. He made the system where BB supplies AA's needs, and thus BB's needs is guaranteed. Actually, the leader himself is known to be from AA, but he himself truly wished for the world where AA and BB can live alongside each other, and tried his best to reach that. The weakness though, that the leader's existence is absolutely needed. Not just any leader, but it must be *him*. Thus, from that story, we got a way, but while there's only one condition, it's also extremely fragile. [Answer] It is impossible for the Red nation to rule the Blue nation forever. It is logically impossible for one nation to rule another nation forever. Nations have nationalistic ideas. They claim that their people are related to each other by blood, that their people have always lived on and owned the land, that it would be wrong for them to be ruled by other nations, that the gods or god are on their side, that their culture has always been the same, and other things which are clearly false. When people of different cultures meet, there is always more or less cultural influence between them. And when they mingle with other people of their own culture they influence them a little bit to adopt some of the foreign culture's ways. If the Red Country ruled the Blue Country forever, and people of the two cultures met as one ruled the other, both of the evolving cultures would tend to evolve toward each other and after just a few centuries or millennia, the two cultures would be identical. And with even a very slow rate of intermarriage, after a few centuries or millennia the majority population would be purple. So if the Red country ruled the Blue Country for more than a few centuries or Millennia, the two countries would both end and become the Purple Country. But if an empire conquers a country it can rule that country forever without any damage to its imperialism. Unlike a nation, an empire has no cultural or national identity. An empire is a political ideology and a political organization. So while the members of the ethic group that founded the empire may resist and morn the gradual loss of their cultural identity over time, the empire will remain the same empire no matter how radically its culture changes. [Answer] Okay--nice topic. In order for this to work you need to be able to convince the next generations of Blues to accept the reds culture and rules--BARRING you just don't kill off all the blues or whittle their numbers down to insignificant numbers. First-precedent. LINCOLN after the Civil War in the States. you need to be able to apply laws equally. You need to be able to have equal opportunity You need to have a way for people to express their concerns without resorting to violence. So--in essence something the original founders of the US tried unsuccessfully for the most part. Bias always will exist. I remember some experiment where kids with blue eyes were made fun of and ridiculed in a class as an experiment. the kids were crying and complaining after a few hours. So--best case. You can't do it. People always will find something different to attack and ridicule about another person--even twins. I'm smarter, I'm better looking. I'm richer My wife is hotter. ECT....best case is to ingrain religious values in the people to be happy for the successes of others and grateful for what they have. [Answer] One possibility involves on the way the [sovereign of the Imperium of Man, the Holy Emperor of all mankind](http://wh40k.lexicanum.com/wiki/Emperor_of_Mankind) did in [Warhammer 40k Universe](https://en.wikipedia.org/wiki/Warhammer_40,000). Sheer power and knowledge. Earth was in deep chaos, being invaded and multiple colonies were being hit by [Orks](http://warhammer40k.wikia.com/wiki/Orks) (in warhammers, orks are with K.), Dark Eldars, and many other scum of the universe. The emperor, in his holiness and vast knowledge, blessed the falling mankind with the unification of Terra (let's just say earth), with the creation of the [Primarchs](http://warhammer40k.wikia.com/wiki/Primarch), and, of course, the [Astartes Legions](http://warhammer40k.wikia.com/wiki/Space_Marine_Legions). With this, no one on earth ever raised his hand again against his Holiness. Why? Because you cannot stand a chance against him. You can only try to fight when you can imagine a plan, imagine how can you make a difference. When there's nothing that can be done, there's no reason to fight. That's why it was Horus who betrayed our beloved, ever-loved, ever-vigilant, ever-mighty Emperor, and brought some legions with him. This was know as the Horus Heresy, but as you can guess, no one on Earth sided with him, not the Adeptus Mechanicus, not the Imperial Legion, or the Sororitas (multiple factions on Warhammer Universe). This was simply done by just being ***vastly more powerful*** than the enemy, and having more knowledge than him. Knowledge is power. Disclaimer: I'm not a Astartes, or from the Deathwatch. But praised be the Emperor. [Answer] I think there will never be a way to get absolute control. Even if you genocide the blues there will still be some blues that will be saves by some helping reds. So there is always a chance that the left over blues will revolt. [Answer] I recall a relevant scene in Donald Kingsbury's SF novel *Courtship Rite.* There's an expansionist ruler who's a sort of enlightened imperialist. He's explaining why he wants to make the conquered country a deal their people will be happy with, so that they won't just be in his empire for a matter of decades, but they'll want to stay permanently, and his grandchildren will be able to walk the streets safely. ]

[Question] [ How does Superman fly? (or rather, a Superman like character in a different world. This is not a question about the existing fictional character but a similar being.) He does not simply use high powered jumps and follow a ballistic trajectory. (Though the existing Superman originally did, actually.) He does not fly through aerodynamic means. (He does not have wings or rotor blades. Also he can fly outside the earths atmosphere.) He does not use some rocket-like device or organ. So... What is the *minimum* hand-waving required to achieve superman-like flight? Is there any explanation with less than 100% hand waving? Note that this must happen on a world very much like our own, apart from the occasional superhero. [Answer] ### Molecular-level perception and control One of the lesser recognized features of [Maxwell's Demon](https://en.wikipedia.org/wiki/Maxwell%27s_demon) is that if it can let molecules through a door, then it knows the direction that molecules are travelling in. It can therefore allow molecules to pass straight through in one direction, but not come back through from the other direction. Maxwell designed the thought experiment around heat - but it works equally well for setting up a pressure differential, creating a force in one direction. If Superman wants to travel upwards, he simply causes gas molecules traveling downwards to pass straight through his body. (Compared to the body, air isn't very dense, and the worst thing that could happen might be slightly increased dissolving of gas in the blood.) But gas molecules traveling upwards bounce off him as normal. This gives a net upwards force, and he flies. Naturally the force can be applied in any direction, so he can just add easily fly sideways as forwards. No problems manoeuvring. He can also fly in space. Molecular density in space is a lot lower, of course, but it's still there. [Solar sails](https://en.wikipedia.org/wiki/Solar_sail) and [ion drives](https://en.wikipedia.org/wiki/Ion_thruster) demonstrate that small forces over a long time are perfectly effective to get around. And of course he'd use his exit from the atmosphere to set up his initial trajectory, so everything after that is just fine-tuning. **Edit:** From a good challenge by @Trioxidane in the comments (thanks dude!) I've run the numbers for this. 1atm is 101,325N per square metre; let's round to 100kN/m^2. The frontal area of the human is approximately 1m^2 (Superman actively doesn't want to be streamlined for this), giving 100kN force. For a 100kg person and G of 10 (approximately), that gives us 1kN force from gravity. Then 99kN net upward force with 100kg mass gives you 99G acceleration! So Superman needs to be at least 1% efficient as a Maxwell's Demon to counteract his mass at sea level, and anything better than that lets him fly. At sea level, there's absolutely no doubt this would work (allowing for general handwavium of this in the first place). The obvious problem with this is that atmospheric density drops as you get higher. Superman's limit for upward acceleration will clearly be 0.01atm, assuming 100% efficiency as a Maxwell's Demon. [According to this calculator](http://www.endmemo.com/physics/pressurealtitude.php) this happens at 16km altitude. This is lower than the flight ceiling of an [SR-71 (25.9km)](https://en.wikipedia.org/wiki/Lockheed_SR-71_Blackbird), and isn't even close to space. I also have absolutely no idea how this would work speed-wise. The speed of sound is, basically by definition, how fast air molecules can go. Once Superman reaches the speed of the air molecules, I suspect they can't push him any faster. So maybe his speed tops out at Mach 1, or maybe you skip over that particular wrinkle. Whether these are obstacles to the story, or whether you can power though the plot so that no-one says "yeah, but...", that's your call. [Answer] ### They're in the Matrix Like characters in the Matrix, superheroes have become aware of the fact that we all live in a simulation and can use this knowledge to perform inhuman feats such as flying. The only handwaving involved here is that an object in a computer program could somehow hack the program it's in, but I think that's all right, given the ridiculousness often seen in hacker movies. It could also lead to some interesting story arcs where people "break out" of the simulation or where everyone becomes superheroes. [Answer] Joseph Pujol, also known as [Le Petomane](https://en.wikipedia.org/wiki/Le_P%C3%A9tomane), was able to control the ejection of air from his anal sphincter. > > It was a common misconception that Joseph Pujol passed intestinal gas as part of his stage performance. Rather, Pujol was allegedly able to "inhale" or move air into his rectum and then control the release of that air with his anal sphincter muscles. Evidence of his ability to control those muscles was seen in the early accounts of demonstrations of his abilities to fellow soldiers. > > > Whoever can fly like Superman can do the same while imparting the outgoing gas the needed delta v to get enough thrust. The massive muscular work needed to accelerate the air will also help increase its temperature, as a mean to cool the body. Needed handwaving: * ejection velocity of the air * intake of the air * resistance of the sphincter walls to not be tore apart by the supersonic air flow [Answer] Superman came from a large planet with enormous gravity, where his species had developed natural anti-gravity organs to be able to function; on Earth, this would allow him to control his own gravimetric field in order to fly. > > Krypton’s gravity was much stronger than Earth’s, so much stronger that Kryptonians had to evolve to develop anti-gravity organs. These organs made it possible for Kryptonians to move around on Krypton without being crushed by the intense gravity. But on Earth, which has both weaker gravity and a kinder atmosphere, they can basically resist gravity so strongly, they defy it altogether. And while the storytellers since then have called out the anti-gravity organs to greater or lesser degrees, the overall effect on Superman's body is the same. > > > Even as recently as the movie adaptation Man of Steel, when Superman prepares to unleash the full potential of his alien body, causing the snow and stones around him to start to float. How? Just as in the comics, he’s essentially altering the gravity field around his body to enable himself to fly. > > > https://screenrant.com/how-does-superman-fly-explained/ > > > The gravitational field associated with the particles must be attractive AND repulsive, and he can presumably shape the field to allow for motion in 3D. Whilst this is a feat not yet achieved by our technology, there are many examples of nature finding a way long before we do or even inspiring our technology to develop. [Answer] **Magnets** Within proximity to the Earth there is a magnetic field everywhere. Having magnets within the body, or the body act as an magnet, it is possible to move on these magnetic forces. Handwaving needed: the impossible power required to do so. Even our most powerful electromagnets don't seem to interact much with Earths magnetic field. Advantage is that many people don't know exactly how magnets work, as evidenced by many perpetual motion ideas. This misunderstanding of magnetism and seeing it nearly as magic would help readers with the handwavium. Still, a force only marginally able to move a pin of a compass is hard to push off from. Problems: only works on or near magnetic bodies. This answer is mostly for on Earth and some orbital flight, as the power would be quite useless outside the magnetic forces of the Earth. Also the power would act upon items around the world as you try to fly, but the magical thinking will help there. Magneto from the x-men can fly or just move whole magneticly lined structures. Readers suspend their disbelief and don't think about the other magnetic materials that should be affected. The handwavium is helped by handwavium the readers already do for themselves. [Answer] **Plasma Containing Super-crystals** What about ionic charge manipulation. Basically his skin carries a super-high charge under the surface, which rapidly pulses (a plasma contained in a tuned crystalline matrix may do the trick). This alters the charge around him, allowing magnetoaerodynamic propulsion. Since the charge is evenly spread around him, his "passengers" that he saves are not electrocuted (like passing through a high voltage electric field, it doesn't attempt to ground), but since he can alter the "flow" of the field, he can fly. This may work on photons as well, and the charged photons become exciton-polaritons. There is some suggestion that the energy from photons somehow charges superman's power. Perhaps his crystalline matrix is at harmonic resonance with them. This would also explain kryptonite, which must be at some amplifying resonance, which has something like gamma-rays and the high-energy particles create a destructive resonance effect. Of course, this is still hand-waving, since no plasma crystalline matrix of this nature has any kind of proof of existence... but I've reduced it to a single (complex) mechanism (plasma crystalline matrix), with a single (complex) effect (ionic charge manipulation/magnetoaerodynamics). [Answer] ## No One Knows: In a universe of super heroes, there are already established abilities, and people are already being asked to suspend disbelief for these. Given the set of abilities, we can find a way to apply them to flight. Telekinesis. Thermal manipulation. gravity control. Time manipulation (yes, you can fly by manipulating time). If you disallow flying in space, I could add a dozen more. Physicists in your world understand these things, even if our physics doesn't. The explanation allowing the most suspension of disbelief is that NO ONE knows how they are doing it. It's flat-out impossible, and everyone agrees it shouldn't be happening. So how is it possible? This allows the reader to enjoy the question, while not requiring a bunch of making up stuff that people know isn't real. You can always assume the author has an explanation in mind, and just isn't sharing it. Further, it can be a fun plot element. Physicists study the MC in an effort to solve the mystery. Other super heroes have reasons why, but not yours. People tell him it's not possible, or assume he's playing a trick, or has a rocket. But there is no reason. Perhaps after exhaustive research, someone declares they've figured it out. This one experiment will prove the reason. Only the experiment fails on the last page of the book. [Answer] His body was made of a 'material' that does not include any Higgs bosons. Thus, his body has no inertia. F=ma does not apply. Given this, he could use any of the other forces, particularly the EM force, to manoeuvre at unrestricted speeds. This further explains why he can go right through any 'solid' structure. Stopping, however, could be problematic. And his punches would have absolutely no impact (pun intended). [Answer] **Control of quantum mechanic probabilities (read: super luck)** If you can *somehow* control what happens at your particles at all times, you are able to do most anything, like go through solids or teleport to the moon. I guess casually moving with slow speed to any direction would be "easier" (=require less absurd amounts of control/luck) to get your particles to happen to go there. [Answer] **He is able to change his frame of reference at will** To us, the Earth appears to be non-moving. Yet scientists tell us it is speeding around the Sun and that the Sun is speeding around the galaxy, etc. The 'speed' at which we decide we travel, depends on what it is in relation to. By simply choosing his frame of reference, Superman appears to be moving, but in fact he is absolutely still at all times. [Answer] ## Dark matter At every moment there are particles of fairly ["cold" dark matter](https://en.wikipedia.org/wiki/Cold_dark_matter) moving through all of us at not quite relativistic speeds in every direction. The Superman has a very special genetic variant of the actin protein which binds iodine in a precise directional pattern within the sarcomere. This pattern of iodine nuclei happens to interact, very weakly, with the very fast dark matter particles passing through it in one particular direction at a certain velocity most common in the gas of dark matter that surrounds us. The spacing only works out right when the muscle fiber is under a certain high level of tension, so it took time and considerable mental effort to tap into this ability. Also, to reach full power he has to be an avid fan of [dulse](https://en.wikipedia.org/wiki/Dulse) and such to keep his iodine levels well above normal. Now, however, he knows how to tense many of his muscles in a way that will pull him along the axis, origin to insertion, of that particular muscle. The result is that he and he alone can tap into the pool of limitless free energy that surrounds us all ... for now. I imagine some heroic scientists would like to take some samples and run some simulations and figure out how to reverse engineer this. Limitless free energy -- surely, they would use this only for good purposes! (It might be best, for commercial reasons, and to discourage *others* who might *abuse* the knowledge thus obtained, to incarcerate the Superman and otherwise make some disposition of him after the technology is validated in secret) [Answer] **telekinesis level, or original invisible jet level** I see 2 ways it could (technically) work: 1-an iron-man style combat armor that, much like the original version of wonder woman's [invisible plane](https://en.m.wikipedia.org/wiki/Invisible_plane), is perfectly transparent and has completely silent, unnoticeable propulsors, making it seem like the wearer is magically floating/flying through the air. This could also explains things like laser eyes, except the eyes wouldn't glow and the laser beans would seem to appear out of thin air to someone paying close attention. 2-goood ol' [telekinesis](https://powerlisting.fandom.com/wiki/Telekinesis): telekinesis is by definition the ability to control, influence or manipulate matter through the power of the mind, and has been shown in media to allow for some "neat" abilities, like killing people far away with no traces of a weapon or offender and flying through the air via using your telekinesis to carry yourself around (in the series akame ga kill, the character Esdeath also does something similar by using her ability to control and manipulate ice to fly around through having a layer of ice in her arms and legs, although in her case it's pretty much just straight up magic). So summing up, you'll either need pretty advanced, transparent tech or borderline magic abilities like telekinesis to achieve flight without any means of propulsion (or string systems attached to a silent plane high above) visually present to the naked eye. I honestly doubt it's possible to achieve without handwaving unless we're talking about a planet where the atmosphere is as dense as water while still being breathable, then its totally possible, although you'd look more like aquaman than like superman while "flying" around. [Answer] Flying - and many superhero-like powers - can be explained pretty neatly by super-beings existing in and able to interact with more dimensions than ordinary people are able to interact with. In this hypothetical universe ordinary people physically exist in the nth, n+1th, and n+2th dimensions. What ordinary folks perceive as point particles are complex objects in nth, n-1th, and "lower" dimensions - overlapping our perceived space by one dimension. What we perceive as "super" are the actions of otherwise imperceptible structures existing in "higher" dimensions. Case 1: The super-being's body partly exists in other directions and it is able to act in those directions to alter the state of its substance in our "normal" space. For instance, if it had body parts in the direction gravity bends space possibly by flexing that extra-dimensional substance it could warp the space in which its perceptible parts exist. This sort of extra-dimensional structure could account for things like laser eyes (ie, the 2D surfaces of its eyes are attached to an organ in a higher dimensional space that produces a laser-like beam in our space) and all sorts of other super-being type weirdness. Case 2: The super-being can rapidly move in and out of the space we perceive. In this case our super-man flies by existing in our 3 physical dimensions, quickly stepping out, moving slightly, and quickly re-inserting itself in our spaces. Doing this quickly and repeatedly yields the appearance of seamless motion. Teleportation is trivial when you can jump off the sheet, move a little, and jump back on. Having - or being able to use - these extra-dimensional parts could be what makes one a super-being, and what the extra-dimensional parts are is what determines the super-being's "powers". Handwaving comes into play when talking about how this happens at all. Perhaps we all have these parts but only "supers" can use them. Perhaps a hyper-dimensional wizard did it. **Notes from comments** Moving in multiple dimensions is not particularly "difficult". You do it every day in your life: 3 perceived spatial dimensions, 1 unperceived dimension that exists due to gravity, a magnetic field, plus we can call time and probability dimensions as well - Heinlein did after all and writing is the meta-topic. Moving in "other" dimensions could have some challenging effects if a mistake were made. Many super-beings probably go missing due to childhood accidents. Those struggling to imagine a many-dimensioned geometric universe (as illustrated below) should read 'Flatland: A Romance in Many Dimensions' as a primer for imagination. Those intrigued should look into the notion of a holographic universe and gravity as a torsion in time. There are more things in heaven and Earth than are dreamt of in philosophy, so go wild when writing. [Answer] **Micro-dermal wings** What do the intestines, the lungs and the brain all have in common? Structures to have as much surface area as possible! Apply this idea to the skin in such micro proportions that it'll look normal, but in reality you have that much more surface area to push air away. Much like the hair rising on your arms these folds can be controlled. They can flap, pushing the air away and giving flight. This will immediately act as control surfaces, making it omnidirectional however you want, while all the time looking like skin. Needed handwaving: * Resistant skin * Strength of air movement [Answer] I think the answer that has been deleted needs a re-visit, as it has merit. Airplanes stay in the air by manipulating pressures above and below. Hot air balloons rise and fall by changing the relative air densities using heat. If this superflyer has an ability to dramatically increase the temperature in one part of his body, and dramatically lower it in another, then he can use this for propulsion. Some ability to move extreme amounts of heat from one area of the body to another. The hot area would have a lower air pressure, the cold area would be denser. The net difference would produce a propulsive force. It is not a jet engine, nor is it any type of rocket organ. It does not depend on reaction mass, but of pressure differences, like an airplane wing, only in any direction. The criteria that is not met, is the ability to operate efficiently in the vacuum of space. Methinks the propulsion would be in reverse - the radiated heat energy on one side, the lack of radiation on the other side, creating a net unbalanced force. There is certainly a credibility gap between the theoretical propulsion forces and the required ones. [Answer] **Hydrogen-extracting organ and inflatable gas sacs** Okay, admittedly, this won't get you out of the atmosphere, but if you're looking for non-ballistic flight, your best option is to make your hero lighter than air. He has an organ with the ability to extract hydrogen from air and water. Let's say it operates on bio-electrolysis - there are real-world examples of animals (electric eels) that can create electricity, you just need to amp this up by a significant degree in order to separate water (possibly in vapor form from mist and clouds) into oxygen and hydrogen. The oxygen keeps him alive in the thin upper atmosphere, and the hydrogen is funneled into flexible inflatable sacks around his body, making him lighter than air, like a blimp. This feature also exists in nature - blowfish can greatly increase their volume by pumping themselves up with water - you just need to make that work but with hydrogen instead. For maneuverability, he could expel some excess gas (you can use your imagination to determine how) in a directed manner to steer in midair. This would of course cause him to gain weight and lose altitude in the process, but so long as he continually electrolyzes the surrounding water vapor and replenishes his hydrogen supply, he could stay airborne indefinitely. He wouldn't necessarily be the fastest thing in the air while rising, but unlike most planes he'd never need to land to refuel. If he wore some kind of wing suit (not like Marvel's Falcon, more like one of [these](https://en.wikipedia.org/wiki/Wingsuit_flying) that actually exists today), he could gain altitude as described above, then let it all out, becoming heavier than air and using the wing suit for lift and maneuverability - in that case he could be decently fast while gliding, but he'd have to fill up on water vapor every now and then to regain lost altitude during these dives. Clouds would be his friends since he'd need a steady supply of moist air - he'd be useless flying over a desert. Might want to avoid very stormy clouds though, as a lightning strike could be problematic, though not as bad as you might think since he's not grounded. That said, his major weakness would be fire. With that much pure hydrogen filling his blow-sacks, a small spark could make him blow up like the Hindenburg. (Oh, the humanity, or inhumanity in his case, maybe.) [Answer] You can give your hero electrodynamic control of the air around him to create thrust. This Ion-thruster system has two parts: * The electric generator - It is similar to that of an electric eel, and has a preferred polarity, i.e. one side is always positive and the other is always negative. * Conduction system - making its own "electric wires", by depositing metallic crystals connecting the electric pulse generator to the "electrodes" which ionize the air. Wires must be thick enough (or the hero must have enough of them) so that the wires will not overheat when power load is high. You create an ionizer which strips electrons from the air on one side. The air, being identically charged as that electrode is repelled backwards to the other electrode which gives back the electrons. You have created a bladeless jet engine which jets air using electricity. I have seen airplane models employing this method yielding high power. Inspired by this article on MIT's electrodynamic engine: <https://www.motorbiscuit.com/this-for-real-plane-flies-using-ion-thrusters-and-no-fuel/> [Answer] ### he doesn't fly. He is just ok with constantly falling and forgetting to hit the planet. Besides having a rather hard stomach, the narrativum of the world that was discovered by Mr Newton says, that a cannonball dropped high enough and fast enough to the side will always miss the planet. Because the ball doesn't know it should hit earth from there of course. However, experiments of a certain homeless hitchhiker show, that this behavior can be replicated and the subsequent fall steered in the manner of free fall if you can totally forget that you are falling and should impact earth. Which is the tricky part. [Answer] **Ion drive** <https://news.mit.edu/2018/first-ionic-wind-plane-no-moving-parts-1121> Here MIT researchers made an airplane with no moving parts by using high voltage electricity. Superman generates a very high voltage between his body and his cape. This ionizes the air which can then be used for propulsion. Bonus is that can also be used in space though he would have ionize something (maybe by slowly destroying his suit?) to act as reaction mass. ]

[Question] [ I am trying to figure out what kind of liquid, if any, can be used to severely impede or slow human motion without killing or severely damaging their bodies (IE if after being submerged in this liquid they need to spend a long time in the hospital, or are permanently disabled in some way.) Experiencing pain or minor side effects is acceptable, however. I am planning on using this fluid for the following while piloting a mech-type vehicle of approximately 13 feet tall, similar in design to the [method-2](https://www.slashgear.com/behold-method-2-a-real-4-meter-tall-human-piloted-mech-robot-27468946/): * Shock Absorption, such that the pilot does not become incapacitated and sustains minimal injury in the event of a crash. * Movement Impairment, such that a pilots movements are impaired or prevented in some way by the liquid that does not induce paralysis. * Bonus: Nutrition, such that the pilot can use the fluid to satisfy his/her basic nutritional requirements by consuming some amount of it (they don't have to like it though). This is, however, an optional point. A response to some comments I anticipate getting, in the hopes of being more clear for everyone: > > Why do you need to stop the pilot from moving? > > > The way I envision it, the pilot must be kept relatively still in the sitting position, and would have a specialized suit that utilizes technology similar to [this](https://motherboard.vice.com/en_us/article/pgkznv/watch-this-bionic-arm-touch-and-feel) to move the robot. More moving parts means more things that can go wrong, and I figure a setup like you see in [pacific rim](https://www.thewrap.com/wp-content/uploads/files/2013/May/31/94651/main_image/rimnews.jpg) has significantly more moving parts than some sensors, a filtration system to keep the liquid clean, etc. on the inside of the cockpit. > > What you are describing is not possible with current or near future technology! > > > This is not intended to be near future, and I am basing it on technology that exists today to keep it at least loosely based on science, so please feel free to use more futuristic versions of modern or near future technology. > > There are more effective ways of keeping your pilot still/protecting them from crashes/etc. > > > By all means please share any alternative ideas that accomplish the same goals with these constraints, however please also keep in mind the cost of the idea. Regardless, thank you for your enthusiasm, it is greatly appreciated. [Answer] Edible water bubbles. [](https://i.stack.imgur.com/g6BWb.jpg) <https://www.boredpanda.com/edible-water-bubble-skipping-rocks-lab/> > > The bubbles, called the Ooho!, are created by encasing a blob of > drinking water within an edible membrane made from a natural seaweed > extract. Nothing goes to waste, and the product will fully biodegrade > in 4-6 weeks if left unconsumed. > > > Your pilot is encased in these bubbles. He can move but the bubbles get in the way. He breathes through a nose mask with an air supply and has a VR visor on. If he opens his mouth he can eat the bubbles in front of him: the gel has some protein and carbs and the inside is water with electrolytes. Some of these bubbles might have been in the cockpit for quite a while and might taste like prior pilots. On impact, each bubble resists slightly before breaking, in aggregate absorbing the kinetic energy. Released water drains thru the intact bubbles down to the floor. Slow movement of the pilot displaces the bubbles gently without breaking them. [Answer] The current answers (other than Willk's) have a perspective issue: they offer suggestions of things that might be good at stopping things from outside the surface getting to the pilot. But crash protection is the opposite of this: you are trying to stop things inside from hitting anything at dangerous velocities. And corn starch type solutions are kind of optimally awful at this: the momentum of the pilot's body during a crash will attempt to carry him forward into the suspension, which then naturally responds as a near-solid. Making your pilot instantly smash into a de facto concrete wall is not going to help. Crash protection is about dissipating momentum outwards and away from the person(s). Watch modern car racing, for example, and see what happens in a crash: parts go flying *everywhere*. This is actually exploited as a safety feature: when tires, doors, spoilers, etc. all go flying off they carry away momentum. The parts with the human in them will correspondingly have less momentum and so said human is now in less danger (but not insignificant amounts; that's why they have the very rigid, very not-going-to-fly-away roll cage, for example). Any fluid suspension system that's going to serve as a crash protection system is going to have to allow that fluid to be shed: it's going to need to squirt or outright explode its own fluid out at sufficient rate to prevent the aforementioned insta-brick-wall disaster. And that's going to be hard, as there's no guarantee that the outer layers being free to move out is sufficient to stop the inner layers from forming a de facto wall-of-death. Indeed, the proposed nature of the fluid makes this highly unlikely: if it was already capable of transmitting forces throughout its body quickly and uniformly, it wouldn't ever act in this "rigid" fashion. Any system you design that's based on a "make the pilot not go anywhere" principle is, of necessity, going to mean "pilot dies instantly in a crash". You need a system that assumes he'll be moving, allows him to move, and does what it can to dissipate momentum and energy away from the pilot sufficiently fast to offer a meaningful chance of survival (if you're hitting the ground at 200 mph, you're pretty much just as dead as if it was at 400mph). So what you're looking for is a racing car in mech form. A Transformer that easily falls apart would be ideal. [Answer] Here's an excellent description of the deceleration problem (keeping pilots alive in the case of a crash) on Aviation Stack Exchange: <https://aviation.stackexchange.com/questions/16545/even-after-years-of-research-why-are-planes-unable-to-keep-passengers-alive-in/16553#16553> In summary, the goal is to gently slow you down, but this requires distance to work in, which isn't generally possible once you exceed a speed of around 80-100km/hr unless you have an extraordinarily large vehicle. No amount of liquid, foam or cornstarch can change the fundamental problem of reducing velocity to zero with a bounded survivable deceleration needs space to work in, in fact many of these options will make it worse. Of course, in SciFi, you just introduce an "inertial damper" or some other technomagic and avoid the whole problem using whatever medium best suits your story. [Answer] [Corn starch](https://en.wikipedia.org/wiki/Corn_starch) suspended in water could do the trick for you. > > When mixed with a fluid, cornstarch can rearrange itself into a non-Newtonian fluid. For example, adding water transforms cornstarch into a material commonly known as Oobleck while adding oil transforms cornstarch into a Electrorheological fluid. The concept can be explained through the mixture termed "cornflour slime". > > > As for what a [non-newtonian fluid](https://en.wikipedia.org/wiki/Non-Newtonian_fluid) is: > > A non-Newtonian fluid is a fluid that does not follow Newton's Law of Viscosity. > > > In the specific case of corn starch, the last link says that it is *"shear thickening"*, and *"Apparent viscosity increases with increased stress"*. In practice: solid things can only move **very slowly** in it. The faster something moves, the more the suspension resists the movement. You can search for some videos in Youtube. Some people have enough sense of humour to fill swimming pools with this suspension. The end result being a whitish mass which you can walk on, and even ride a bicycle or motorcycle on. The liquid resists you getting inside it due to the speed of your feet or wheels. [](https://i.stack.imgur.com/mlDP0.gif) But if you stand still over it you will slowly sink, and pulling you out will require some considerable force. [](https://i.stack.imgur.com/W8y9u.jpg) The worst damage being pulled out of it might cause is some minor depilation. Unless your friends are idiotic/drunk enough to try to pull you out by tying you to a car, in which case you might end up starring in the Darwin Awards (if only with for a honorable mention). Your pilots will need some life support gear for their heads. Corn starch will not allow for breathing. It might help with the nutrition part, though. The fluid would protect the pilot against blasts (the energy of the blast will be captured by the corn starch, which will temporarily harden). In case of breah, the pilot should also be protected against shrapnel. **Edit:** to all who are saying that this would kill the pilot: if the pilot is naked within the fluid, then yes, you are right. I think the question has this as a premise, since OP would like the pilot to breath the fluid. I propose a solution for the sudden deceleration death problem - the pilot needs to wear a suit akin to that of a jet fighter pilot. Some models are even filled with a fluid to help cope with extreme acceleration and deceleration. That would mix the best of both worlds - protection against deceleration from the suit, and protection against blasts and shrapnel from the starch. [Answer] Liquids like water compress very little, if at all. This makes them generally a poor choice for a shock absorber. Suspend a pilot in a sphere of water and strike that water with a stick and the impact will propagate through to the pilot relatively undissipated. There's one thing that liquids are very good at doing, though: moving around. Use this to your advantage. The liquid doesn't absorb impacts directly. Instead, applying a impact force to the liquid causes some of the liquid to flow into an alternate container where a more traditional shock absorber is located. This is how a [water hammer arrestor](https://www.plumbingsupply.com/waterhammerarresters.html) in a building works. Sudden spikes in water pressure can damage plumbing fixtures, so the arrestor provides a low-resistance path for water to take where the extra kinetic energy is absorbed by a spring, air piston, or gravity. The plumbing fixture still feels some of the force, but at a greatly reduced magnitude. Your fictional vehicle can use whatever sort of dampening devices you want to use. Suspending the pilot in a fluid allows the fluid to transmit the force of an impact to the dampeners regardless of what direction the impact came from (you'd essentially be the piston in a giant hydraulic shock absorber). The contraption would convert bursty impact forces into weaker forces applied over a longer period of time, but with the side effect that the pilot would likely experience a lot of motion. Big impacts become survivable, but potentially disorienting or nausea-inducing. Solving these problems is left up to whatever sort of suit/gear you want to give the pilot. [Answer] Just water will suffice right? It slows movement, absorbs kinetic energy and also heat in case of heat-based weapons. One big problem would be how shocks propagate through water. If a grenade blows under water and you are nearby the shockwave will rip your lungs apart. This is because water doesnt compress very well. So another liquid, something like a non-newtonian fluid that solidifies upon a shock: <http://www.snf.ch/en/researchinFocus/newsroom/Pages/news-171108-press-release-liquid-shock-absorbers.aspx> Not only will it absorb energy upon impact, it will protect the wearer from possible injury should spalling or similar occur. [Answer] ## Magnetorheological fluid Another solution would be the use a [magnetorheological fluid](https://en.wikipedia.org/wiki/Magnetorheological_fluid). A complicated name to describe a fluid whose viscosity is influenced by magnetic field. This kind of fluid is used in “magnetorheological damper” which are highly appreciated in automotive (mainly for very expensive cars suspensions) for their very good shock absorbance. What I can imagine is a complex set of electromagnets surrounding a sort of tank in which your pilot is floating. The way magnets are disposed leads the viscosity gradient of the magnetorheological fluid to “adopt the shape” of a seat. Electromagnets adjust their power in reaction to extern stimulus so the seat shape is always conserved. # EDIT : As @Ruadhan2300 suggested it in comments, an easier and more realistic way to achieve OP’s goal is to opt for a spherical tank. Then to makes the fluid adopts a viscosity gradient from water-like in the center to solid-like in the border. The pilot now floats in the middle of the tank and is prevented from crashing against the border by this responsive viscosity gradient. The only cons I see here is that your pilot have to wear a suit (I not sure that these kind of fluid is good for health). [Answer] The solution can be a **ROTATING SPHERE** filled with a **highly VISCOUS liquid**. [](https://i.stack.imgur.com/PbvUM.png) Two of the above answers pointed out the effects of deceleration to human body. But they assume linear motion. If the impacting object is rotating instead, a much fewer portion of the impact energy is absorbed, most of it being used to further rotate the object. from <https://en.wikipedia.org/wiki/Parachute_landing_fall>: > > A parachute landing fall (PLF) is a safety technique that allows a > parachutist to land safely and without injury. The technique is used > to displace the energy of the body contacting the earth at high > speeds. The parachutist ideally lands facing the direction of travel > [...] while rotating toward the side (generally the direction with the > dominant directional speed). When executed properly, this technique is > capable of allowing a parachutist to survive uninjured during landing > speeds that would otherwise cause severe injury or even death. > > > The second aspect is related to the viscosity of the fluid. The more viscous a fluid is, the more inertia there is between the contacting layers of the liquid, when it comes to motion. When an outer part of a liquid is put into motion (ex: wind generating waves, making them move), all the bottom layers of the liquid are also put into motion, but at more and more reduced speeds. The rate by which the speeds are slowed down is proportional to the viscosity. <https://en.wikipedia.org/wiki/Viscosity> > > Viscosity is a property of the fluid which opposes the relative motion > between the two surfaces of the fluid that are moving at different > velocities. > > > [](https://i.stack.imgur.com/YjyBw.jpg) In the case of a sphere filled with viscous liquid, the liquid layer next to the sphere walls will have almost the same speed (rotational speed) as the sphere. The inner layers will have gradually lower speeds. The more viscous the fluid is, the lower the rotational speed of the liquid will be, towards the center of the sphere. You will need to place your human in the center of the sphere. Perhaps a system of inner spheres, all having liquid between them, will be even better. The external most sphere will obviously not be rotating, as it will be fixed firmly to the vehicle. According to <http://www.vp-scientific.com/Viscosity_Tables.htm> , various flavors of **motor oil** seem pretty good candidates for your liquid. [Answer] There are a lot of shock-absorbing gels in use today that harden on impact. Some are being developed for use as body armour. My smartphone’s case even has some gel in it. As far as I’m aware these are different to non-Newtonian fluids. For your scenario, a form of this gel (or layers of different gels) could be used for body armour: the outer layers harden and deeper layers distribute shockwaves: like layers of Kevlar. And future scientists can find a way for them to revert to gel after an impact, so they’re reusable. Also, today there is a liquids that humans could breath: perfluorocarbon (referred to in a comment). It has been tested successfully on mice. If your pilot was a pool of that, contained in gel, it would reduce the mechanics required for the pilot’s cockpit: they’d just be floating in liquid surrounded by the gels. The pilot could use VR goggles for their interface display. This liquid is used for breathing, so couldn’t help with nutrition though. [Answer] I dont think it's a good technology, because most liquids weigh a lot (about 1ml = 1g): imagine you just have a half cubic metre of a liquid - that would be 500 litres, with a weight of half a tonne. Also crashes with small airplanes are far more survivable - there are videos of small airplanes crashing into the woods and the pilot surviving just fine; I don't think we will ever be able to save a pilot from a 200km/h crash with an 100+ ton vehicle. (and 200km/h and 100 tons are a pretty lucky outcome for commercial flight planes) But when you think out of the box, and forget the liquid, an airbag is doing exactly this, without a fluid. [Answer] Some theoretical thoughts: you can survive unharmed forces of up to 30g for very short time and about 10g sustained over some seconds. You stated elsewhere that your maximum expected velocity is about 50 mph so about 80km/h. When we take these maximums into account, you need at least 80 cm of deceleration space to reduce your 22m/s to 0, even if you accept a 30g shock for about 0.7 seconds (which is a bit much, but maybe some future technology and special training can help). --- We can assume that your Mech will have some external buffer-zones that help with deceleration, so you probably don´t need all of that deceleration space around you. What I could imagine is some form of foam, that dissolves rather quickly and is reproduced by the vehicle constantly. The pilot would probably need some form of suspension straps to keep himself in the middle of that. The foam could be edible - breathing is still a concern though, even if the bubbles would carry oxygen, the co2 would have to go somewhere. You´d probably still need some kind of egg-shaped capsule of at least 1.5x2.5 meters to keep your squishy human alive. [Answer] It will need a Gyroscopic effect and dissipate the vehicle momentum by changing the vector component of the forces. That will keep the human condition a constant. Engine thrust can also be modified to intentionally generate oblique shocks in a safe manner to dissipate energy. There needs to be a mechanism for this. This will be the second layer of protection. This will be expensive today. [Answer] As you indicated not near future. You want to use a liquid. This is what I would envision. * Human body is floating inside liquid - In a neutral buoyancy state. * Build a crude "inertial dampener" by basically putting the human inside a liquid filled capacitor - which is also the liquid the human "floats" in. * The liquid plays the role of a dielectric that is much stronger than air to reduce electric arcing due to the high voltages required to build up the required static charges. * Because of the extremely high voltages required, maybe the high voltages need to be pulsed and only turned on when injury is imminent. * Any mechanical forces that cause motion on the charged plates would be transferred via the electric field to every part of the human at approx the speed of light, making the complete human act like a rigid body that is part of the charge source/plate, while other forces would take around the order of the speed of sound to propogate incase the forces are causing catastrophic damage to the mech and destroying the inertial dampener. Human damage may be caused by: * Toxicity of absorbing the liquid through the skin. * The high electric fields the body is exposed to. * Potentially being electrocuted if the dielectric breaks down or not have enough dielectric between plate and human) ]

[Question] [ Imagine there was a material that was mostly identical to steel in almost every way, but instead of a density of $7.85–7.87 g/cm^3$ it would be **a tenth** of that. That is about **4 times lighter than aluminium** is. The idea is that all other properties such as * hardness/elasticity * brittleness * potential sharpness are identical to those of the steel that was used for medieval weaponry anyway. Chemical properties, as well as the forging process, are to be ignored as it is a fictional material. **Would using this material to craft swords and daggers be advantageous compared to creating them with traditional materials?** I am fairly certain that longswords would be pointless, as they partially rely on their mass to have an impact, but short swords, or even daggers, might be extremely useful as they would be very easy to use and hide. I am guessing the force of the hand/arm that drives the dagger into someone would suffice to tear the flesh. Answers should elaborate on whether adaptions or changes to traditional weapon designs would be required to make the weapon profit from the unique material properties and offer advantages over the traditional weapons. --- **This question is part of a series regarding weapon and armour design using fictional materials with unique properties** *This is the first question of the series. So there are no links to others yet.* [Answer] I wouldn't be so quick to dismiss its usefulness for long swords. In weaponized combat, the use-case and fighting style will vary with each weapon's size, shape, maneuverability, weight etc. With the materials of choice for weapons being steel over the [last couple thousand years](https://en.wikipedia.org/wiki/Steel#Ancient_steel), we developed combat style for short-and-maneuverable weapons as well as big-and-heavy weapons, but don't have many big-and-light weapons because materials sturdy enough to make weapons simply weigh too much. In terms of fighting styles that focus on speed, such as knife fighting (a common example of weapon for this is a [dagger](https://en.wikipedia.org/wiki/Dagger)) the fighter has a sturdy and maneuverable weapon but must sacrifice **reach**. Longer swords, on the other hand, sacrifice speed in order to gain reach and the ability to deliver stronger blows (both because of their weight and their length) and granting them the ability to slash through target. Some sword designs have tried to combine the two, the main one which comes to mind being the [rapiers](https://en.wikipedia.org/wiki/Rapier) which are mainly intended as long-yet-agile thrust weapons, but they somewhat retain the ability to slash. The existence of rapiers is proof enough for me that there is a good use-case for long, agile, thrusting swords; for such swords a metal such as described would certainly be very useful. The weight (and therefore agility) would be similar to that of the modern-day [foil](https://en.wikipedia.org/wiki/Foil_(fencing)) used for competitive fencing. Modern-day foils are [very agile](https://youtu.be/IgJy92YFWDw?t=5m15s) but lack the strength to be useful weapons (granted, that's by design, but you would not be able to make something strong enough at the same weight). A weapon as agile as the foil and as solid as the rapier would certainly be of interest. As for long swords (such as the [claymore](https://en.wikipedia.org/wiki/Claymore)) we've never seen a lighter equivalent, but that speaks more to the lack of viable materials for such a weapon than a lack of usefulness for it. Some people would certainly experiment with it, and I'm sure that we would see new combat styles develop for it. **Just because they wouldn't work for current combat styles doesn't mean that no combat style could be developed for them**. It could fill the gap between swords and pole arms. Personally I think that small knives (blade <10 inches) would be the least beneficent of this new material since they are already quite maneuverable, limited mostly by their shape and size than their weight. Short swords and rapiers which are already "hybrids" between quick and long would improve by large margins. Lastly, I'll discuss the required differences construction that would be required for knives. The balance of a good knife is somewhere around the guard, the point at which the handle stops and the blade starts. If you were to drastically lighten the blade material (to 0.78 g/cm^3, a tenth that of steel, [nearly identical to that of oak](https://cedarstripkayak.wordpress.com/lumber-selection/162-2/)) and keep the handle materials the same, you would end up with a knife that is very butt-heavy. You would need to thin out the handle or use lighter materials on it, or both. [Answer] Such a metal would be good for thrusting weapons like a daggers, shivs, and rapiers; mediocre for slashing weapons like cutlasses, scimitars, katana, etc. that rely more on their weight but still use speed and a cutting edge for most of the damage; but poor for a throwing knife (poor balance, affected by wind) or any edged blunt-force weapon (like a long sword, most swords fall into this category). It would be worthless for maces, flails, or any other non-edged but metal blunt-force weapons. On the other hand, such a metal would be wonderful for bayonets, arrow tips, spear tips, or any other application where the blade is connected to something else that represents the bulk of the mass. It would make balancing such an object much simpler and would overcome the problem of breaking under the leverage applied by the item the blade was mounted to. Ultimately, the metal would be fabulous for door bracing, carriages, or any other construction where metal is used to support the construction but the weight is an issue. The guys using wheelbarrows and building skyscrapers will erect a statue in your honor. [Answer] As others have said, your ultralight steel will be best for thrusting weapons, but I think there are more uses people are forgetting. You could have polearms of extraordinary strength. Normal polearms have hafts made of wood, but yours could have hafts at least partially made of this new steel. This would let you swing longer warhammers or halberds than usual. If the new steel can be combined with traditional steel, it would be useful for swords as well. You could have a sword with traditional steel in/near the hilt and new, light steel towards the tip. This would let you have a much longer sword without sacrificing its balance. One big disadvantage however, is that this new steel will have less inertia. When you parry with a traditional steel sword, a lot of the energy of your foe's swing will be wasted pushing your sword. With lighter steel, your sword will waste less of your foe's energy, and you will feel the impact a lot more in your hands, wrists, and arms. You will thus be at more risk of having your sword knocked out of your hands. You have similar problems with armor made of light steel. Being struck by a blunt weapon while wearing armor made of light steel will be more dangerous than in armor made of traditional steel because the light steel has less inertia. It absorbs less of the force, and so more of it goes into hurting you. [Answer] Most of your weaponry would be near useless. Such light weight steel would enable MUCH thicker armor with out the massive (heh!) weight penalty. So now your weapons - which will depend on speed and sharpness for damage vs being a slightly sharp club - will have an even harder time doing damage through a double layer of chain mail, or plate, etc. I would predict that many actual weapons will still be made from traditional steel - they need the weight. Armor, wagon wheels, ships, etc could be made from the new light weight stuff.... [Answer] Steel has a density of about $8,000kg/m^3$, which meas ubersteel has a density of about 800kg/m3 which makes it heavier than wood unless somebody is making magically dense wood (which might make a good competitor to metal) [woods](https://cedarstripkayak.wordpress.com/lumber-selection/162-2/). (Thank you Alexandre Aubrey for pointing me to the wood-density table; thanks to Loong for pointing out a math error.) This could be used to strengthen a traditional quarterstaff. The advantage of ubersteel over wood is the strength it would bring. The disadvantage is that it would probably be much more expensive to have one made in metal than having one made in wood with only some iron added to the ends which makes it stronger where it hits things and also adds mass where it needs it the most. I think the increase in strength and durability is more important than the mass, but I've never had the opportunity to use a iron-shod staff. A lot of uses for it depend on the cost. If it's expensive, it will not be used in melee weapons at all. However, think about it's uses in siege weaponry. Even if it were to only partially replace or reinforce the wooden parts, a catapult (and like devices such as the trebuchet) could be made to be easier to move which means faster aiming, stronger, which means more distance or higher payloads, and if done right, faster to construct. It would also be used in buildings and vehicles, even if those vehicles are just carts. Shipwrights would love this stuff! To be able to have steel-like strength without the problems. I don't now if you are considering canons, but being made of this material would really please your admirals and even cavalry. Lightweight artillery is very important in ships and when you have to haul your cannon around with horses. Being lighter weight, they would be more easily taken through muddy fields and other problematic terrain. Remember that most weapons spend more time being transported than being fired. I'm not sure much would be left for the common man. To be honest, the best use in weapons are stabbing weapons like a dagger, arrowheads (and yes, arrows can fly perfectly well with a light head), and spearheads. In the medieval times, there was very little metal that we would call steel. The technology of the times used [bloomery furnaces](https://en.wikipedia.org/wiki/Bloomery) which required a lot of work to produce steel good enough for a sword. This is one of the reasons that most people didn't use swords, despite all the books and movies to the contrary. [Answer] I'd say that you're probably right that daggers and shortswords would benefit from this material whereas axes, warhammers, maces and arrows would probably be better with heavier steel as they rely at least in part on the mass behind them. Rapiers and other thrusting swords (like late medieval swords) would probably benefit, whereas hacking swords like scandinavian/viking swords and falcatas would probably be better in steel. Draw-cut swords might be better in a lighter material too as they rely less on weight to strike. Spears would also benefit (if not thrown) because you could get better balance without the heavy spearhead. Or rather, you'd wouldn't need as heavy a counterweight on the back of the spear to balance the head, allowing you to move it around faster (lower polar moment of inertia). Longswords would be an interesting case. Yes they rely somewhat on mass, but with a much lighter material you could probably make a verylongsword quite wieldy which is able to outreach an opponent, with techniques using more thrusts and draw-cuts. Not sure how it would affect parries and winding though. Poleaxes would be interesting too, or any weapon that relies on leverage to improve its strike (like falxes). I'm not sure how that would play out. Yes you have less mass to accelerate, but as anyone who's seen a quarterstaff in action knows it's perfectly possible to get a nasty amount of force behind a strike from the haft alone. [Answer] You're right that it's actually a disadvantage to have slashing swords or crushing weapons like [maces](https://en.wikipedia.org/wiki/Mace_(bludgeon)) be light weight, they do less damage because they have less energy on impact. However for stabbing weapons like stiletto or [misericorde](https://en.wikipedia.org/wiki/Misericorde_(weapon)) daggers or even for long swords like the [rapier](https://en.wikipedia.org/wiki/Rapier) light weight but physically tough and/or springy material is a serious advantage since the weapon can be moved faster and control more easily. I would expect that there would be problems with this material for weapons not because of the weapons but because Armour is now 10 times as effective as it was at a given weight, weight has always been the limiting factor for metal armours. [Answer] I think one thing people are not thinking about with regard to cutting weapons is that the sword could just be made thicker. Also using F=MA and P=MV we can see that as long as the user is swinging his sword faster he can make up for a lot of the weight difference. If this super steel is 1/10 as dense then presumably it has 1/10 the contents therefore there would be 10 times the mass of this new steel compared to regular steel. This means we would probably see much wider more extremely tapered swords to add the mass. However swords would almost definitely not be used in this universe as the second armour was invented it would require 1/10 the amount of ores to make the steel and so using 1 mine that could mine 10 suits before you would now get 100 suits. A huge draw back of mail and other armours was the difficulty to make however more of the population would be professions who used steel as countries would have far fewer men working in the steel mines. As someone else mentioned 100% steel spears would be a thing. [Answer] In pure attack, I'd argue that nearly all swords rely more on sharpness and speed for damage than mass. That is why the point-of-balance is close to the hand compared to impact weapons like axes and maces. (Not that we shouldn't over-emphasize the importance of point-of-balance, but I believe it is relevant here.) This is also why, against heavy armor, the "murder stroke" was sometimes employed, where the wielder grabbed the sword by the blade and used it more like a warhammer than like a sword. But they rely on mass in the bind. This is not only when blocking or deflecting enemy strikes but also when controlling your opponent's weapon during an attack. This is why rapiers generally weren't much lighter than longswords. Opponents with otherwise identical weapons but one being conventional steel and the other being your lighter density steel, I believe the conventional steel wielder would have a significant advantage in controlling their opponent's sword. The wielder of the low density sword would need to exploit quicker disengages, but I'm not sure doing so would make up for the disadvantage. I am less sure on how this low-density steel could be exploited in weapon design. [Answer] I'm going to disagree with the idea that this would be a bad material for a sword, with the prevalent idea that it reduces the force of the swing. The force of a slash is determined by more than just the weight of the weapon, it's also determined by the speed. In fact, it's determined more by speed than by weight. Newton's second law of motion states that F = ma, also written as $F = \frac{1}{2}mv².$ <https://en.wikipedia.org/wiki/Force#Second_law> <https://en.wikipedia.org/wiki/Kinetic_energy> Since we are not changing gravitational constants, anything we do to the weight will have the same factor of change to it's mass. If we reduce the mass of a sword by a factor of ten, and keep speed or acceleration the same, then yes, the force is also reduced by a factor of ten. However, a human using a much lighter blade is going to be able to move that sword much faster than the heavier one. If we make an oversimplified assumption that if we reduce the weight by 10x, then we can increase the speed it is moving by 10x. Being generic, we now have the formula of $F = (1/2)(m/10)(10\*v)².$ Doing simple algebra, we can reduce this: $F = (1/2)(m/10)100v² $ $F = (1/2)m(10)v² $ $F = 5mv² $ So, this says we've increased the force of the blade by 10x by reducing the weight 10x. If we only triple the speed at which we swing the sword, we can see that we have almost the same force of impact: $F = (1/2)(m/10)(3\*v)² $ $F = (1/2)(m/10)9v² $ $F = (1/2)(9/10)mv² $ $F = (9/(2\*10))mv² $ $F = (9/20)mv² $ $F = 0.45mv² $ Now consider that if a soldier trains with a regular steel sword, then uses the lighter version in battle, they will have just as much muscle mass as the soldiers with the heavier sword. The lighter sword will be so much easier to swing that they will get a much faster slash than with a heavier sword. This adds the ability to change the angle of attack faster as well as simply attacking faster, and attacking for longer stretches of time. A lighter sword to carry over their forced marches would make them less exhausted or able to travel farther. I carried an M16A2 during marches in Army Basic Training, and at 8.8 lbs, it gets really heavy quite quickly. JollyJoker, in a comment on another answer, says that a claymore weighs around 5.5 lbs. A katana weighs around 2.5lbs, even made from steel. I think you would find fighting styles closer to a katana with the 10x lighter swords. You might also find fighting styles closer to kung-fu, which also uses lighter swords. <https://en.wikipedia.org/wiki/Katana> Another answer suggests fighting styles along the lines of an epee/foil/rapier, but if the enemy is using armor, that's not likely to work. You would have to find the joints of the armor to attack, and that's pretty hard when the armor is constantly moving. Unless the soldier is an expert fencer, they would basically have to be lucky or wear their opponent down in order to dispatch them. A TV show I saw a while ago (BBC or a Nat. Geo.), showed that a katana is actually better at attacking armor than a traditional English sword. They did actual tests with actual armor and swords. The long sword put a decent dent in the armor, but the katana cut into it. Unfortunately, the person doing the tests wasn't really trained in either style of sword, and I don't think the swords they used were of good quality, but you get the idea. (A trained samurai would aim to use a spot about 1/3rd to 1/4 of the length of the blade from the tip, not the center of the blade, like in the video.) <https://www.youtube.com/watch?v=EDkoj932YFo> [Answer] Everybody seems to be missing the biggest weapon -- commerce! (And logistics). This material is going to be an incredibly useful building material for both ground and water based travel (and when the time comes air). The size of ships, boats and wheels this will make possible...a ship made out of wood has a maximium length of about 300 feet one made out of steel thousands of feet. For internal roads, imagine the loads you could haul with 10 foot diameter wheels! Armies are going to be larger and faster than in or world, able to cover more and more varied ground. As for its use as pointed weapon, its going to be so effective as armor, that making swords out of it would be a waste of time. [Answer] For what it's worth this is not necessarily a fictional material. I obtained a section of a helicopter blade once (my sister was a PA for a exec at Hughes) The interior of the airfoil was filled with foamed aluminum. No idea how they made it. A multiphase material might well be as strong as steel and a fraction of the weight. Look at graphite composite bike frames. Far stiffer than steel, but at 1/10 the weight. I can buy a kevlar canoe that is 1/4 the weight of a traditional oak rib, cedar plank, painted canvas canoe and it will take a lot more punishment. (But not as pretty...) I saw a 3d printed copper cube. Overall structure was tetrahedral internally. Despite being made of pure copper, it was a heat insulator better than most common insulators. -- copper only took up 3% of the volume, and the nature of the connections was such that the path length was several cm per cm thickness. It was still strong enough to stand on. Consider a sword made with a foamed metal core for stiffness, and a tungsten carbide skin for carving the other guy's armour. Or a sapphire lattice sword, with the lattice arranged so that it would have a certain spring. Put a directional anti-reflection coating on it so that it is visible from the hilt end, but hard to see from the pointed end ]

[Question] [ So, a common trope when it comes to dragons is that their underbellies and necks are vulnerable and covered with soft scales, whereas the back, head, and sides are very hard to damage. But why would that be the case? Storywise, my dragons have metabolic pathways to create and use high-quality CNTs (carbon nanotube) to reinforce their tissues, which is what allows them to fly. They have stronger tendons, bones, and scales, scales that can vary in size. CNT is flexible, thus armor, made with it, can be too. So, I just eliminated the last **practical reason** for why dragons have soft underbellies and neck... at least the last one I could think of. **So, why would piercing and slashing weapons have an easier time penetrating a dragon's underbelly? For what practical reason would the underbelly and neck be so soft/weak?** [Answer] > > They have stronger tendons, bones, and scales, scales that can vary in size. CNT is flexible, thus armor, made with it, can be too. So, I just eliminated the last practical reason for why dragons have soft underbellies and neck... > > > No, you haven't! Just because they have the metabolic pathways to produce CNTs doesn't mean they have the metabolic pathways to produce CNTs *cheaply* or *efficiently*. Armor that you don't absolutely need is a waste of energy to produce and maintain--and furthermore, even light armor is not *weightless* armor, so armor you don't need is just armor that makes it harder to fly. So, do they actually need belly armor at all? Most predators don't actually have much armor. It isn't useful for them. Tigers, lions, wolves, bears, and so on rely on overwhelming force to take down prey before it has an opportunity to hurt them, and armor would only make it more difficult to chase down their prey. Most of the time, you find armor on creatures that need it to regularly defend from attacks, not on creatures doing the attacking. And dragons are so overwhelmingly powerful and dominating that it makes you wonder, why do they even have any armor at all? And why do they have it on the *top and sides*, when, y'know, they can *fly*? The obvious solution, to me, is that they have armor not because it protects them from gallant knights--most of whom will never get close enough to land a blow in the first place--but to protect themselves *from other dragons*. If they are fighting another dragon on the ground, they can more easily keep their belly protected by just keeping it near the ground; and if they are fighting in the air, attacks coming from above are much more dangerous than attacks coming from below (where gravity would be working against the assailant). Thus, back armor makes sense--but belly armor remains largely pointless, and in fact is detrimental to any dragon who would have to fight with it in the air, where it would only slow them down, lower their flight ceiling, and make them less maneuverable. [Answer] **Protection in their sleep** Dragons are at the top of the food chain and are probably rarely in need of armour as dragons aren't usually attacked by predators. At least while awake! Maybe your dragons hibernate (or just simply sleep) and this is the point where they are most vulnerable. But when they sleep they are usually face down or curled up in the foetal position so their bellies aren't accessible due to their incredible weight, as such they never developed armour on their bellies. (Armies of archers and knights in shining armour are relatively new developments, (compared to evolution) or might be a rare occurrence, only attacking "problem" dragons, so dragons as a species have not adapted to them.) [Answer] **Because they evolved in the absence of technology** In evolution, each species has to balance being well defended against other considerations, such as how difficult it is to grow armor, or how armor reduces mobility and flexibility. Many real armored creatures, such as the armadillo and the hedgehog, lack any sort of protection on their bellies. They crawl around on the ground, and it would just get in the way. Dragons presumably evolved over millions of years, where the only predators that could threaten them were stuck on the ground. When crawling around, dragons don't usually need armor on their bellies because their bellies are facing the ground. When flying, they are out of reach of all their enemies. Not only that, but carbon nanotube armor sounds heavy, and they need to be light enough to fly. Carbon nanotube armor is also probably difficult to grow, requiring a huge diet... If a dragon can't find enough food to grow/replenish their armor, they may starve. In most fantasy settings, just like in real life, humanoid technology is a relatively recent development (maybe a dozen thousand years). So dragons would not have had enough time to adapt through evolution to counter longbows and skilled swordsmen. [Answer] The scales are strong but they don't conduct heat very well. If the dragon was fully covered in thick scales the beast would overheat and cook itself as soon as it needed to exert itself. So it evolved with much thinner and smaller scales in the least vulnerable areas of the body (see other answers also why the belly is less vulnerable). This is by the way also why most dragons, especially in warmer climates, like to sleep in caves lying flat out on their belly. The cold cave-floor is a good heat-sink and helps them to cool down. [Answer] When dragons copulate, they do it front to front. Dragons with softer belly were thus selected because it feels better for both parties when they rub against each other (and they don't get tangled or stuck where strong scales would clash against each others). Dragons usually being pretty smart, looking for pleasure during sex wouldn't be such a weird concept. [Answer] # Flexibility Like most quadrupeds, most of the moving parts of a dragon tend to be on the underside. In order to accommodate free movement of their legs, the skin on the bottom must be able to deform more, and thus it must be softer. The back of a dragon barely deforms at all when they move (except around the wings if they have them - these are another weak spot.) The chest must also be more elastic in order to allow them to breathe, just as most air-breathing animals' chests expand and contract while breathing. Soft underbellies are common in land-based quadrupeds for just this reason. Covering the chest with tough, rigid armor would make agile movement very difficult. [Answer] Same reason why armadillos have soft bellies: the back armor is really though, but it also limits motion and growth. Dragon bellies may grow when there is a lot of food available, and shrink back when they lose weight due to hibernation or poor availability of prey. If their bellies were harder, this fattening and thinning could cause the armor there to break. The scales on the bally should still be hard enough to give humans a hard time in a fight. [Answer] **Dragons have Pouches like Kangaroos.** Rather than laying eggs and abandoning them, Dragons lay their eggs inside their bodies, like some sharks or the [vivivparous lizard](https://en.wikipedia.org/wiki/Viviparous_lizard). A heavily armored belly is a disadvantage as it makes the eggs/babies more likely to get squished when the dragon lies down. On the other hand an unarmored belly is not much use since (other than people) it only fights prey animals or other dragons. Prey animals are too small to reach the belly once they are in the dragon's mouth. Other dragons are too tall to easily reach the belly. Smaller dragons are somewhere in between. If they are small enough to reach the belly, they are small enough to grab in the mouth and hold far away from the belly. **Similar: Dragons give birth to live young.** The bottom half of the dragon cannot be too rigid, as it must expand as the baby grows. Especially the cloaca must be soft so the baby (horse-sized) can fit through. That means there's a horse-sized target between the back legs. [Answer] I would think that, being a dragon, they would need to be light enough to fly. When evolving into what we see them as today, their wingspan must be big enough to make a certain amount of force and beat a certain amount of times per minute, to lift them, that anything else is extra. If they had too much weight, they won't be able to fly, but with their bones being hollow too, it gives them room to make more adjustments, like armour. In the long run of a dragon's life, armour on the sides and back make more sense than the stomach that will be near the ground or above an aerial enemy, using gravity against them. Some dragons in literature and movies, for instance Smaug, used gems and riches to fashion an armour light enough for him to carry without loosing power in the air. There are many legends of them fashioning and wearing jewelled breastplates, for protection and to show off their hoard. Any creatures that a dragon were to pick up and eat, provided it was over the age of 50, wouldn't be able to reach the unprotected stomach at all and any creatures large enough to oppose it, mainly other dragons, would be too large to reach it. :) [Answer] A consideration. Carbon nanotubes would be metabolically expensive, so metabolic conservation of energy principles must apply here. The neck and head would need heavier armor, the wings and shoulders also. The tail, as a biological weapon must be reinforced. Some portions of the underbelly are vulnerable, but would be partially protected by the ribcage, which would imply that such areas could be less protected by CNT armor. Underarm areas would be less likely to be protected, as would some limbs (especially back legs). Stomach could be protected as dragons would be vulnerable in flight, but lower area near hip is protected by lower limbs and is unlikely to be armored. Metabolic expense is a primary reason that biological creatures often lack such armor, CNT is very different from most biological armor as it is more flexible, but could be considered more similar to chitin or keratin than shell or bone armors. Dragons would then have to either eat massive amounts or hibernate for years... both consistent with dragon-lore. But similar to dragon-lore, metabolic considerations also entail that dragons would have a "chink" in their armor. Considerations here suggest that it would be their armpits, some chest area, or close to the hip. [Answer] The dragons breed eggs for procreation and thus need an underbelly which is soft and warm, which means no armor. Being an advanced species both sexes care for their offspring, making a soft belly a necessity for males as well. [Answer] Dragons must have weak bellies or necks because, since the 1500s, they have become too large and thick-skinned for a warrior to kill them otherwise. Early illustrations show that dragons were no more massive than knights, and low to the ground, like a crocodile or a kimodo dragon. Since then, they have become flying tyrannosaurs. Note that JRR Tolkein's enormous dragon Smaug was perfectly well armored everywhere, except for a single gap. Once again, that was necessary, so that he could be killed with an arrow in glorious battle. If you don't want an egregious weakness, then either don't make them so bloody enormous, or don't require their defeat in single combat. PS: As for science, it suggests that armored giant fire-breathing flying animals find existence difficult, because these characteristics do not play well together. [Answer] They do NOT have to have unarmored underbellies. *Smaug*, for example (in the book, at least; don't know about the movie) knew of that weakness and so armored himself under there. The reason pretty much every land creature has a soft underbelly is for *flexibility*. Doing sit-ups, for example, while wearing scale armor *on your chest* is well nigh impossible; likewise, a real dragon would find it hard to flex around. Tolkien just ignored that, and so can you! [Answer] # Mange Mange (or scabies or demodicosis) involves a reaction to burrowing mites that can cause hair to fall out. Mange can affect reptiles. In dragons, mange causes scales to fall out. The powerful air flow over the upper side of a dragon normally keeps it clear of invading mites. But dragons suffer when they come in for a landing. Contact with the ground, contact with prey animals they carry under their bodies, contact with one another ... contacts are almost always at the underbelly, and are highly likely to transfer the disease. Mange relies on dragons as its principal vector for long-range spread, with mites from remote lands falling out of the sky every time a dragon flies over. Some dragons would produce a healthy set of underbelly scales if kept disease free. Others have adapted to the disease by naturally reducing their scales, using the naturally smoothened are of their skin to make it easier to try to scrape, wash, and blow the parasites away from their body. [Answer] ### To make room for showy gem armor As everyone knows, dragons love to hoard and sleep on gems, gold, and other shiny treasure. There are many animals (mostly birds) that collect shiny objects to attract mates, and it seems reasonable that dragons do so for the same reason. However, the problem with dragon hoards is that the dragon can't really show them off while they are out and about. If only there were a way for a dragon to attach a part of its hoard to itself so that it could demonstrate its collecting skills while roaming... Dragons are already near enough to invulnerability that an unarmored underbelly is not a significant weakness, notwithstanding small apes with sharp sticks. Instead of developing naturally armored underbellies, they evolved a slightly sticky, soft abdomen that they could stick gems to and show them off to potential mates. ]

[Question] [ Assume the time travel is a soldier who has a good idea of how to maintain and care for most guns and knows how all the parts fit together. They've brought with them a working assault rifle, a double-barreled shotgun, and a revolver, as well as a smart-phone with a solar-powered charger that contains a few encyclopedia's worth of modern knowledge. I'm fairly certain that without industrialization, weapons that require precise machining will probably be out, as well as percussion caps and modern cartridges (even if you could teach the alchemists of the time how to make some of the stuff you'd need). Flintlock rifles and/or muskets would probably be possible I'm guessing, as well as some steam-powered weapons. But could you make a revolver or a shotgun work? It doesn't have to be as good as a revolver or a shotgun is today, so long as it is recognizably a revolver or a shotgun. [Answer] (I feel bad about giving this answer, given how horrifying this weapon continues to be in the modern world, and how unconscionable it is to have it widespread any earlier in history, but...) You are starting out with handheld weapons, but if it were me, looking to alter the course of warfare most simply and effectively in the middle ages, I would go with land mines. Granted, this is a situational weapon, but all the materials you would need are widely available, and the weaknesses in medieval metallurgy aren't a problem. The simplest version of a landmine is just a metal packet filled with gunpowder and a glass vial filled with acid. When a soldier or a horse steps on the vial, it cracks, and the acid drips into the gunpowder generating enough heat to set it off. Your primary concern is going to be safety. No torches where you make your gunpowder. Do it outdoors, but keep it dry. Store it away from people. Combine the elements only when you are ready to use them. The vials of acid are relatively harmless, and the skills of creating them already exist. Don't put them in the mine until its already buried, though. Your soldier should be aware of the tactics to best make use of these weapons, and the way medieval warfare was fought, the results would be devastating. [Answer] Once you make nitroglycerin, you can stabilize it in the form of dynamite. Castle walls will just be decoration after that. Also, close formation fighting will be sitting ducks. You can also make smokeless powder for bullets but the local steel may not be able to handle that. If they have primitive firearms, you can introduce rifling. If they don't have firearms, you can introduce firearms. You can refine oil into gasoline and have lots of fun with that. If nothing else, you can use it to make potato guns to lob shrapnel wrapped dynamite into enemy formations. If you need cash, figure out how they used coal tar to produce dyes and make a bundle. [Answer] ## Biological Weapons Armed with a modern high school level of education, you could wreak havoc. The Middle Age idea of hygiene was flawed at best and there were plenty of highly contagious deadly diseases floating around in [large cities](https://www.youtube.com/watch?v=JEYh5WACqEk). Collect a sample, cultivate it and infect your target(s). 21st century disease prevention would also be pretty achievable in the Middle Ages. You can sterilize equipment with alcohol/fire, clean up with soap, protect yourself with gloves/face mask. Or depending on your moral compass, you could hire locals to handle the diseases for you. [Answer] With healthcare and agriculture. Nations would bow at your feet if you could feed them and keep them from dying quite so soon. The man who conquered the world with an open palm, not a clenched fist. [Answer] [Minié ball](https://en.wikipedia.org/wiki/Mini%C3%A9_ball). The problems with modern weapons have been discussed several times, with all the problems of re-creating [automatic firearms](https://worldbuilding.stackexchange.com/questions/10610/could-medieval-people-produce-automatic-firearms-if-they-had-access-to-the-schem) in a medieval setting. Basically, without industrialization everything must be hand-made, and even if they managed to make a modern firearm, with every single bullet carefully hand-made by master jewelers, it would cost so much it would not be worth it. Better equip 1000 men with slightly better than contemporary weapons than 1 man with a modern weapon. Assuming they already have gunpowder, introducing standardized calibers, paper cartridges and the Minié ball would have a huge impact, without requiring any special technology or chemicals unknown to the era. The problem with chemicals would be, that even if you knew what it was, you could probably not locate it and start mining it, and even if you managed, you would need a large infrastructure to make use of it. Assuming you could get into a position to explain your ideas to someone with enough power, you could make their guns much more effective with historical knowledge and very little to no new technology. Standardizing calibers would make their guns much lighter, easier to load, and less prone to misfire, besides making logistics easier. They had rifled barrels in the early times, but they didn't use it much because it was a nightmare to load, prone to misfire, and you needed to clean your gun after almost every shot, or the residue caused the next bullet to be stuck in the barrel. With the ingenious idea of the Minié ball, you could make their gunners much more effective, by significantly increasing both their firing rate, range, and accuracy. [Answer] Middle Ages is a bit vague, that's 1000 years of progress. What starts with men just armed in mail and shortbows end with crossbows, cannons and platemail. Now if he survives not being taken for a witch and killed I'm sure guns are possible. Look up gun smithing in Japan. The Portugese sold them some arquebus they took apart. Fast forward two centuries(?) and they mastered the art and improved on them. Sure they were hand made and more expensive and European imports but they did it. With limited knowledge and access to outside materials. Primitive break action shotgun seems totally possible. Late mediëval Europe had a great industry of artisans. Full body plate armor is quite the feat. Now if we're talking 600-700 things would be different. [Answer] Kassam-type rockets (simplified version of Soviet Grad MLRS rocket) especially if you can also master real explosives for warhead (like dynamite). They already can be produced with access to very low-tech equipment and should be doable in middle age workshop. Would change warfare pretty quickly: no massive charge of cavalry, walls of no use, naval warfare would change fast, etc. [Answer] Money. Someone armed with an encyclopedia and even a basic high-school education could make a lot of money with basic inventions. They could do that quite quickly. Examples include steam engines (even rudimentary ones), metal refinement, agricultural devices, several people mentioned health and I'd emphasize clean water productions in that context. Germ theory alone could be enough and basic antibiotics would be a great boon. An army armed with surgeons aware of how to clean water, sanitize instruments and surfaces, sutures and bandages would already be one people would be more willing to fight for because they'd be far more likely to survive injuries and less likely to die of infections (e.g. the major killer as late as the American Civil War !) and less likely to lose a limb. Money, regardless of what period you're in, gets you power - that is, political power. So I'd say your soldier needs to become a filthy capitalist. Using his military background and knowledge is one thing, but focusing on weapons production is not practical, as most modern weapons require the development of at least a basic chemical and engineering industry to be produced in effective numbers. If, however, you insist on a weapon, then a rifled musket would be the natural choice for a soldier. But to be done on any practical scale that requires the development of these basic industries : power (steam), basic industrial chemistry, transport (again steam), precision engineering of toughened materials (mostly a combination of metal refinement and some engineering principles). Money and political power will do more than a single weapon, IMO. [Answer] Weaponry has a broad definition, and most of the above comments give a great summary of the "killy-bits" you could create (gunpowder/rifling/etc). One thing I don't think was mentioned (and is pretty easy) is the screw-on bayonet. This would allow your newly-minted riflemen to protect themselves without the help of big formations of contemporary men-at-arms or pike-men. Many of the major advantages you could create, however, often fall on the logistical side. A simple steam-engine is pretty straightforward, as are railway tracks. Both would be quite expensive to create given the tech of the time (the tracks in particular would be a bumpy ride, but if implemented it would give the owning country an immense strategic and economic advantage. Plus, your time traveler gets a ton of money charging people for it's use. In fact, going with the steam thing, another very useful invention would be the steam-powered ironclad warship. This, combined with cannons, would have the power to sink any contemporary navy (as was shown during the Opium Wars, where the British first fielded the technology against the Chinese Navy). Finally, modern financial systems like banking, joint stock companies, and paper money were almost unheard of outside of Italy. This may not seem like a weapon of war, but Great Britain's victory in the Napoleonic Wars was largely thanks to their economic and financial institutions giving them an almost unlimited amount of money to throw at the war. [Answer] I would suggest reading "The Man Who came early" by Poul Anderson 1956, collected in *Isaac Asimov's Great Science Fiction Stories 18*, a fascinating description of how little could actually a modern man do "the modern man way" (weapon technology etc.) if teleported in the Middle Age. <https://en.wikipedia.org/wiki/The_Man_Who_Came_Early> [Answer] Several VERY JANKY ballistic missiles, in addition to primitive firearms and rockets. You wouldn't have the tech to make an electronic guiding system, but once you calculate the arc of the rockets, you could take out towns from miles away. If you could gather a small army, you could easily take over most of Europe with your technology. Just don't try invading Russia. [Answer] If you have access to "a few encyclopedia's worth of modern knowledge" and a couple years time, I'd go with the combustion engine. Let's see how well they do against a tank. I'd mount a flamethrower on top. [Answer] There's a big chance component, but: words/ideas. If you use this multi-encyclopedic knowledge to successfully predict significant events and improve the commoner's life without getting executed for practicing dark arts, your growing status as a prophet or deity could make your words powerful enough to destroy nations, dynasties, and religions. On the downside, you might have to martyr yourself to cement your legacy. [Answer] There are many military-related technologies that can be applied, although some of these are more like techniques/strategies/concepts that have military application 1. Gunpowder - primitive grenades, land mines, and breach-loading rifles would have a huge impact. If the metallurgy is too primitive to make rifles, then muskets could be fine - I imagine you could make some that were at least as fast to load as a crossbow and with more penetrating power. 2. Navigation - an accurate clock and knowledge of global trade winds would enable you to navigate in the open ocean on long voyages, granting your navy a HUGE advantage. Also, make sure to bring back some basic techniques for how to make ships more seaworthy in general. Reliable shipping and the ability to cross oceans would be quite valuable and would enable surprise strikes deep in enemy waters. 3. Food preservation and knowledge of basic nutrition/sanitation. Medieval armies were often forced to fight during a very limited campaign season. Knowing some of these basics would enable your army to campaign when your enemies cannot. 4. Nationalism. A time traveler would know some of what's required to inspire a population with nationalistic sentiment. This sentiment can be used simultaneously to improve army morale and decrease the power of the nobility, removing two major weaknesses of a Medieval kingdom (hard to campaign regularly if the people or nobility revolt) 5. Guerilla and commando tactics. With your advances in gunpowder and the loyalty inspired by nationalism, you can create elite commando units to operate deep in enemy lines, disrupting supply lines and destroying small, key outposts. Yes, that may have already existed, but you can take it to the next level. 6. Child care and sanitation. Guess what you need to fight a war? People. Guess what you get a lot of if you cut the infant mortality rate in half? People. Social norms change pretty slowly, so you should get a generation or two with WAAAAY more people than you really need. Welcome, recruits, to the glorious army of the empire!!! 7. The mentality of total war. A lot of medieval wars seem like children squabbling - people fight a whole year to snag a few miles of crapland and some ransoms. No, this time, we burn half their country to the ground and slay every male noble we can find. They try to invade? We scorch the earth, burn bridges, poison their supplies, booby trap the roads, and harass them from every side before annihilating their entire army. No ransoms, no survivors, no grudges to hold, since nobody is left to hold them. [Answer] I like this question a lot, always intrigued me. I am going to be a bit philosophical in my answer. Having a revolver or AK-47 won't help much as they won't have the required technology and knowledge to recreate it, since its productions requires some sort of machinery. Your character will effectively make the technological advancement that occurred historically take place much earlier and at a much faster rate. So I think it is best to see the single most important technology that will allow you to recreate our technologies in a more primitive way, the **ICE - Internal Combustion Engine**. This will allow you to create all sorts of machines and primitive mechanized weapons, and later could be utilized for electricity and quick logistic transportation, trains etc... Think of a pike phalanx on top of an engine powered platform charging a line! [Answer] ### The idea of the democracy. Ha-ha-ha, I only joked. Normally, I don't post popular bullshits with the intention to collect many upvotes, but it was so obvious that I couldn't miss it. The democracy was well-known already since the ancient greeks, any educated people in the medieval age knew that it existed, and that it would be possible also in their era, and they rejected it. If a strange alien - arrived probably from far, far away, from a *[terra incognita](https://en.wikipedia.org/wiki/Terra_incognita)* (this is what they would think from a time traveler) would propagate democracy for them, they had laughed on him. They would say around so: "look these primitive peasants, they can't even read, they can count only until 10, except whose fingers were already cut! And you want *them* to select *our King*? Look, what [Socrates](https://en.wikipedia.org/wiki/Socrates) wrote from their "democracy", it was actually the rule of the idiots!" So, the idea of the democracy would be totally ineffective, it is nearly sure. ### So, don't have illusions, a weapon means a weapon and not an idea. It should be a primitive weapon. You can't get even an [AK-47](https://en.wikipedia.org/wiki/Kalashnikov_rifle) (alias Kalashnikov) with you, because they don't have the required metallurgic industry to reproduce and service it. Here comes the next problem: any machine - also the weapons are machines - were produced by other machines. With your pure hands, you can't produce anything. Maybe with a lot of weaponsmithy work, you can produce a steel tube (what will be the barrel of the AK-47), but it won't be enough *precise*. The bullet won't be able to leave it. On the end of the chain on machines produced by other machines, there are always human hands. Human hands, shoveling coal into the steel forge, controlling the machines casting the iron, and so on. What they didn't know: 1. They didn't know the exact chain, how to produce finally AK-47 from the people having no machines only hands. 2. They didn't knew the explosives. But they had a lot of smart people. Consider Newton, Galilei - millions and millions people had existed with their mental skills also in their era, but they never became well known. Most of them died as a peasant, and they were known only in their village, because they were the other (after their priest) who could read. So, take a lot of good books with you, with university text books about metallurgy, chemistry. Take some explosives, too, and an AK-47. You will be a chief scientific advisor of a local power, maybe even a king. In some decades, you will be able to produce an AK-47. It is very important to get enough supply to show a local potentat, that *you can produce unimaginable weapons*. There is no such stupid power in the era who couldn't realize its importance. It is the result of a selection mechanism: anybody decision maker underestimating the worth of the weapons, had been long conquered by others who hadn't. [Answer] How about a railgun? You could probably manage wire, electricity for big electromagnets and some kind of timing mechanism. The mechanism itself wouldn't have to be that well crafted. It would probably be pretty heavy to be lethal. [Answer] You very well could make a fully functional gun, such as the AK-47 or revolver, with enough time. Since you already have one, you could simply disassemble the one you have and use it's parts as a blueprint for blacksmiths of the time to create them. They had the technology to create keys and locks, so issues of creating small pieces of shaped metal are negligible, or at least, functional enough to be usable in the crafting of a gun. The only part I'd consider a bit more complex would be the creation of gunpowder. The creation dates back to the early 1100's at least, so the idea of it may well be propagated, as it was used in grenade-style weaponry at the time (mostly in Asia). If it's stable enough, it should be able to be used as-is, though I'm no gunnery expert and I'll leave that for the gun-nuts to speak on. As for the machining, it's 100% possible. [Answer] I know that I come too late to the party, but I'd say the most useful weapon would be a flamethrower. Petroleum was considered useless or a poison in the middle ages, but it wasn't unknown, and the rest of chemical ingredients for napalm were already known by alchemists. A small barrel with a hand pump and a single heavy armored dismounted knight could destroy the tight formations of soldiers which have been the norm until the invention of the machine-gun. [Answer] Last I looked, there are 8 decades yet to go till the end of the 21st Century. Most advanced weapon is yet to be thought of yet, probably. Towards the end of the last millennium, economics considered labor, capital, time, and information to be the four resources used in economical production. I'd add land to that. You mention a single soldier and a couple of pretty useless weapons brought with him/her. (They're nearly useless unless there is some stockpile of ammo and spare parts for them). So, this soldier is going to magically become an influential member of some aristocracy? ..OK.. And s/he will magically have wealth to spend (capital)? ...OK... As well as the labor (workers)? ? So, given all that, which doesn't sound very plausible to me, then what could he build? In a month? or in 20 years? Makes a big difference. I'd probably go with mortars. That's assuming we want to limit it to small arms and not things like weaponized anthrax or bubonic plague, and that dirigibles and propaganda don't qualify as weapons in this scenario. The most "advanced weapon" I can think of would be a radio. It could broadcast "messages from God" for the faithful to pick up arms and join my Crusade. I find your question too vague. What would the goal be of the soldier? What are the limitations in his resources? What society would he be in? In reality, anyone from the present era finding themselves in the year 1600 would probably have a very very short life expectancy. They'd be robbed quickly and since they couldn't speak the language, would have virtually zero power. BTW, you're not going to be able to build a forge and make steel from the information available on wikipedia or Encyclopedia Britannica. You need more specific information than the superficial stuff you find on-line. ]

[Question] [ **Mod Note: Some people may be squeamish about this subject, please keep all responses clinical rather than vulgar.** So, in my world, I try to play the "immortality" trope with twists that make it suitable for my imagination. So, to understand the question, let me give you precise details: * These immortals **are 100% human**, no vampires and such. * This also implies that the source of immortality is **physics-based**, rather than chemistry or biology. * The world we are talking about is **an afterlife of some kind**. Immortals here are immortals because they died in another world, and "arrive" to this world and live in their most recent *healthy* shape. * People **can die** but they resurrect somewhere within the universe, nullifying every change on their bodies happened since their "initial" arrival. ***TL;DR*** - these immortals are, let's say, people for who the "rules of time" do not apply appropriately, preventing them from aging. Okay, this is a heavily disputable concept, please forgive me, I hadn't gone through every consideration yet. In fact, I ask this question to resolve one: **fertility**. --- Needless to say that no afterlife can prevent becoming Hell, if its never-aging inhabitants can reproduce. Infinite life span implies several factors becoming infinite, too: this includes the potential amount of offspring. Well, not in the case of women, but let me bring it out later. So, given this fact, I decided to make my immortals unable to make children. To avoid disturbing the human body's regular operation as much as possible, I decided to make it obvious at one single point: the merge of...*those two cells*, you know. As a result, every fertilized ovum disintegrates immediately. I guess the amount of energy released from such a small mass can be practically unnoticeable, so it's fine. --- This brings up a new consideration, though: the presence of ovum within immortal females' body is pointless. I'm really not sure if I should do something with it. The following outcomes are possible: *1) During 'arrival', all ovum disappears.* This would cause a huge change in female hormone balance, *if I know correctly*. *2) Their amount is unchanged, but women have no periods.* That would again, change the hormone balance, I'm almost sure of it, at least in the aspect that stopping periods is impossible without hormonal changes. *3) Ovum coming out disintegrates immediately, regardless of fertilization.* This would prevent the need of hygienic precautions during "those" days, increasing comfort, but may possibly feel far-fetched for an audience. I want to make the rules to be as natural as possible. *4) No change applied in the matter.* It is the most natural way of handling this question, but would imply that, in case of a biologically 20 years old woman, that decades later, when she's still 20 biologically, but 50 chronologically, she's out of these cells, inducing menopause. I repeat: *menopause, in a biologically 20 years old woman*. Not sure if I can (or even want to) handle this situation, as it implies hormonal changes. --- Sorry for the long post, it was actually a portion of my worldbuilding process. It's hard to include "magic" while also trying to keep authenticity. Is there a truly optimal method to handle this question? [Answer] You can go through with a normal cycle, menstrual cycle runs as normal, menopause runs as normal at a certain age, after which no more periods. You can say that the immortality means that the normal menstrual cycle keeps running forever. All these things have hormonal consequences, and as such consequences for the body, if you want to keep people "young" forever, I'd suggest maintaining the cycle indefinitely. However, just as there are apparently [no toilets on the Starship Enterprise](https://scifi.stackexchange.com/questions/81086/%CE%91re-there-bathrooms-on-the-enterprise), it doesn't matter unless it matters for the story, **you can probably ignore it completely**. Just a statement that the process that made people immortal made them infertile without making too much of the process or why they're infertile. Terry Pratchett takes this option in Strata, people who've had the longevity treatment give up the opportunity to have children. He doesn't say how or why, it is just a statement early on in the book. > > We wonder if the short-lifers live more vividly, and dread learning that they do, because we gave up the chance of children. > > > If you're going to mention it at all then it's going to blow up to be a big thing. 1000 years of infertility, heavy periods, bad cramps, and struggling with iron deficiency is going to make an industry for elective hysterectomies that dwarfs the rest of your medical industry. [Answer] Well, human women have all their eggs pre-made -- they are born with a finite number of eggs and that's what they will ever have. If you want immortal women to have an infinite number of periods you will have to alter their physiology significantly; as a consequence, since you have already altered their physiology, you may as well introduce a patch which allows them to choose whether they want to be fertile or infertile at any given time. [Answer] # No; your immortals will not have cyclical or life-long hormone changes Why would immortal women who cannot have children need periods? The answer, as you know, is that they don't; therefore they shouldn't have periods. There are a variety of hormonal processes that happen in humans. Should the immortal men in your kingdom have increasing levels of androgen that cause their testes descend? Of course not, you aren't asking that question, that is just silly. Should men or women who arrive in this place undergo puberty? Should men get male pattern baldness over time? Should women get menopause 30 years after showing up? Immortality, in the way you are describing it, implies time-freezing the development of a human body to hold people in one state. If that is the case with puberty, male pattern baldness, and menopause, then it is certainly the case with the menstrual cycle as well. [Answer] Having a period can be horrible. Menstrual cramps can cause torturous migraines, piercing cramps, and in the worst cases, blood will almost gush from the woman's vagina. On my cross country team, girls literally had to regulate their diet to ensure they didn't become iron deficient with the combination of running and periods. And sometimes the cramps get so bad you have to just curl up on the floor, wishing for death. Don't give immortal women periods. Periods stop naturally as a woman gets older. Imagine you had to be tortured every week for eternity. This wouldn't be heaven; this would be hell. Periods aren't that bad for most people, but for a small minority, they are that bad or worse. If you want your afterlife to be a paradise of any sort; get rid of periods for immortals. If you want it even to be a decent half-life, get rid of periods. No one's getting pregnant, so no one should need periods. [Answer] Having fertilized eggs disintegrate pretty much goes against your assumption of immortality. Biologically speaking, a fertilized egg is a living organism in its own right. What you're talking about is the mass death of the very young children of immortals. Of course, you could just let your immortal women go through menopause and be infertile after that. Alternatively, recall that regular human women are born with all of our eggs--(actually, we have them all before we're even born. In real life, these eggs degrade over time, which is why it's harder for older women to have children, even if they haven't hit menopause. If you keep either of these effects, you're capping the number of children each woman can have. Iboth these mechanisms are too much like aging for you, how about this: An egg is only viable for about twenty-four hours after ovulation anyway. After that it can't be fertilized.\* So you could (a) shorten that time, or (b) lengthen the time it takes an egg to travel far enough down the fallopian tube to meet the other cell, or (c) both. [\*Note: probably someone's wondering whether this means a woman can only get pregnant from intercourse within twenty-four hours after ovulation, i.e. twenty-four hours every month-ish, and the answer is no. Prior to ovulation, a healthy woman produces cervical mucus that both provides "swimming lanes" for sperm to get where they need to go and also actually keeps the sperm alive for a matter of days. It varies from woman to woman, but the actual (potentially) fertile window can be around a week.] [Answer] There is a much better solution. If the biology of your immortals DNA is the same and it is merely the afterlife, then just have your universe magically transport the fetuses of immortals to people who could've become pregnant but hadn't. Then the child isn't obliterated, the immortals technically had a child, but nobody is aware of it. After all, there are plenty of people on earth. It cannot be hard for your universe to select a random person who almost got pregnant with close enough dna. After all, this is the afterlife we are talking about. Giving it the power to find potential living parents with the correct dna to look like the parents and not cause suspicion wouldn't be that hard. It's just a giant data search, and the children that don't have a place to go yet can just go into stasis. You could even make an arc where the children of immortals that lived on Earth meet their true parents. Or just have nobody know and make it something people throw out as a random potential thought. Like, "the fetus appears to disintegrate, but some believe they are transported to Earth in secret to live out a live before death". As for the other stuff and cycles... do whatever seems appropriate. Don't make it torturous for people, obviously. Which means that as some answers stated, tone down any painful aspects of it. No need to get rid of it, if you want it in there. Just make it less painful and get rid of any nutrient issues stemming from it. Immortals have no need to eat, so there wouldn't be iron deficiencies. You can just say their bloodstream is perfectly balanced at all times with whatever foods they primarily ate (or whatever was healthiest that they ate). Once again, no need to punish those in starvation. Make it alterable or just have the universe put it in perfect balance. In it's nature, your universe seems to want to produce people with perfect bodies. What they do with them is up to the people; however, some things or the necessity to do them (eating for starters) could be interpreted as a hell at some point. After all, think of when there is no food. Your immortal is eternally starving because the environment has been ravaged by overpopulation of immortals that never stop consuming. If they are time stopped, there is no reason not to assume that their bloodstream is always in the same ratio with things balanced as they were. Get a cut? The blood gushes out but when the cut closes or stops, the blood will refill with the same ratios. They can die, sure. However, the nutrient deficiency shouldn't do it. The blood cell's leaking out should. Most important of all, if there is no need to bring it up, leave it to imagination. I think most people will be made uncomfortable reading about it. Better to just ignore it if it isn't relevant to the story itself. After all, why would anyone wish to read that chapter about how immortality works for women's cycles. It's kinda weird... [Answer] On a completely different scientific tack, there are practices which current-day women can use to regulate their biochemistry and moderate their menstrual cycle naturally (ie without artificial hormones). These are based on the observation that modern lifestyles (sedentary, calorie-rich, chemical-laden, preservative-filled, psychologically dissociated from the body and daily/monthly/annual cycles in nature) have increased the duration, volume of blood lost, and incidence of abnormalities in menstruation, compared with, say, traditional hunter-gatherer lifestyles. These practices generally result in a noticeable reduction in the volume of blood loss, sometimes even reducing it to less than the level that the uterus can reabsorb (so nothing comes out), but to achieve complete cessation of menstrual flow requires a level of physical effort beyond what your average woman would be willing to do day in, day out, for thousands of years. HOWEVER, just the teeniest little magical tweak could give women all the benefits of this practice without needing to spend a couple of hours a day doing Oli Mudras, Uddiyana Bandhas, and the Deer Exercise. [Answer] If you *really* want to avoid dealing with hormones, perhaps you could leverage this tidbit: > > People can die but they resurrect somewhere within the universe, nullifying every change on their bodies happened since their "initial" arrival. > > > Where in addition to this "hard reset" on death, the individuals in this world go through a "soft reboot" periodically, where their body reverts to the initial state, but they don't change location or lose memories. Although this would introduce an entire other set of issues (it'd be pointless to get a tattoo or piercing in this scenario, for instance). An easy solution would be 2) and get rid of periods entirely. Birth control already exists in our world that slows down a woman's menstrual cycle to only a few times per year. So just take that concept and stretch it out over infinity. Yes, there would be hormone changes. But if you think the issue is important enough to detail (although Separatrix is almost definitely right in that you can ignore this problem entirely if you wanted) then you may as well go all the way and detail the changes. [Answer] I'd say it depends on why this setup exists in-universe. If it's some kind of natural phenomenon, it sounds like your universe's magic whisks people away as-is on death, which means the magic is *aware* of death, which means the magic is aware of life, which means the snuffing out of new life is a response to that new life, which means no changes to physiology. Though the virtual stasis kingledion brings up could mean that they eternally exist at whatever point in their cycle (or menopause) they were at before coming here. If this is an artificial environment created by some intelligence, and you have already excluded the desire to make it a hell, then it seems likely to assume it is intended as some sort of paradise. This intelligence would then likely have decided that inhabitants should exist at the most *enjoyable* part of their cycle - and other aspects of their life, so they would probably also be at their ideal weight and strength, in the prime of their life. And they would remain in that state *forever*. Also, I just can't let this question pass without mentioning [Jack of Shadows](https://en.wikipedia.org/wiki/Jack_of_Shadows), by Roger Zelazny. Everything except this being an afterlife is pretty much straight out of there. [Answer] A woman has a monthly cycle because that is what humans have evolved to do. It is pretty trivial to significantly elongate the cycle (once a year, once a decade, only on an external stimulus). Reference this chart: [](https://i.stack.imgur.com/50mNh.jpg) As you can see, there only really "static" time is early in the cycle when the LH and FSH levels are low, estrogen, inhibin, and progesterone levels are low, and the endometrium isn't actively growing. You can discount the shedding phase after a few days. The eggs are not developing and for a few days, women are as "static" as they get with respect to menstruation. This is basically what birth control pills do. They stabilize the level of progesterone which has a negative feedback on egg maturation endometrial growth by suppressing GnRH and FSH/LH in the brain. Adding estrogen helps prevent break-thru bleeding. High levels of estrogen only would also reduce ovulation, but has shown to have some pretty negative side-effects such as blood clots and stimulating estrogen sensitive tumors. So long as you have some progesterone on board though, the side-effects are minimal. Theoretically a woman could stay on BCPs indefinitely, not taking the 7 "blank" pills at the end, and never experience ovulation and menstruation (the blank pills are just so the woman stays in the habit of taking a daily pill). Anyway, you can have your immortal women replicate this naturally, such that their endometrium never grows and egg follicles never mature aside from an external stimulus (something that breaks the production of progesterone, allowing GnRH, FSH, and LH to spike) to trigger ovulation or a much longer natural cycle (like how many mammals have estrus only once a year). The monthly cycle is just what humans, masters of their environment, have evolved to, there is nothing that mandates it biologically. If you simply have your immortal women have NO EGGS they will go into menopause since they will then have big drops in their estrogen levels, which has some negative effects like an increase in atherosclerosis, vaginal dryness, etc. This is why post-menopausal women take hormone replacement. If there is no requirement for reproduction then your immortal women could just have the uterus atrophy away, so it could never bleed. Basically a natural hysterectomy. They would still need something to stabilize their ovaries for estrogen production though, lest they go into menopause eventually. [Answer] Menopause SUPPOSEDLY does not go on forever. It is considered to last for 10 months to 4-5 years after a women has skipped her period for 12 straight months (unfortunately not every women is the same and it can take longer). You can have your women have their periods until either their eggs run out or your immortality aging finally kicks in. Then have a period of menopause (depending how your immortality ends up working, this could take anywhere from 4-5 years to decades). And then once the uterus has done it's whole shrinking/ageing thing, hormone levels reach a new balanced level and your immortals proceed as normal except this time, no monthly torture sessions. No periods forever. No menopause forever. When your immortal reset, they go through the whole cycle again. Same with puberty, male pattern baldness etc. It would add an extra dynamic to your story if immortals are aware that someone is on 'that time of the cycle' instead of 'that time of the month'. Proceed with caution. And allowing women to watch men grow bald only for them to have to go through puberty again, would help make up for the decades/centuries of torture you are putting the women through! [Answer] Should women menstruate? Yes, if you want them to have babies in this setting. No, if you don't. You can have other considerations -- children who have died, arrive as children, making the giving birth to kids unnecessary. There could be artificial means -- artificial wombs instead. There could be no children. To me, this is like the question of do you have a reason for your characters to use a toilet. If you do, write it in. Otherwise, most of us have no need to know if a character urinates or defecates. We'll assume they do. [Answer] **Approach no. 1:** I don't know if this is what you're looking for... but you could make all the ovums disappear on arrival (your no. 1 option), but still have menstrual cycles. Menstrual cycles derive from hormones secreted by the cells of the follicles or the corpus luteum, not the ovocytes. These hormone-secreting cells of the follicles enclose the ovocyte prior to its release, and after its release (ovulation) transform into the corpus luteum. If you could "*trick*" the follicle into "*believing*" it has an ovocyte inside, while it has not, and the follicle "ovulates" a blank shot, and then transforms into the corpus luteum... then you would have menstrual cycles. Menstruation would come afterwards, since, there being no ovocyte, there would be no fertilization. This is not so hard to do. **Every** hormone is codified on the DNA of **every** single cell we have. It's epigenetics that make a cell produce the appropriate hormone at the right time... ie, it's epigenetics that makes the cell know when to transcribe each part of its genetic code. **By epigenetically stimulating the DNA transcription of the feminine hormones on the follicle, you would have a menstrual cycle, even without the ovocyte.** Cancers can unlock the DNA transcription of any piece of genetic code there is. A cancerous cell derived from the intestine can, theoretically, produce hormones from the folicle. There is no reason for a folicular cell not to be able to unlock the DNA transcription of estrogen by some epigenetic abherration, since folicular cells are already predisposed (diferentiated) to producing those hormones anyway. All they need is an epigenetic "push" Also, this would play only until all the finite pre-existing follicles on the woman's ovaries would be exhausted. Then that woman would naturally enter menopause. --- **Approach no.2** There is another approach. Keep the ovums and the follicles intact. But consider this. Almost every single cell from our organism divides during our lifetime, but the ovocytes don't. The amount of ovocytes is pre-fixed at birth. Now, "normal" body cells (somatic cells) divide themselves by mitosis, but germ cells (ovums and sperms) aren't produced by mitosis but rather meiosis, which is a process involving 2 cell divisions. After meiosis is completed, the cells can't divide any longer, because they now have half of the DNA, not the whole genetic code. That's why I mentioned ovocytes and not ovums. Ovocytes are the cells prior to completion of meiosis and ovums are the cells after. In the case of the ovums, the last division of the meiosis is only completed at the time of fertilization. Yes, that late. The ovum is completing its formation at the time the sperm is entering. Now, every cell on our organism has a limit to the amount of cell divisions it can undergo... the Hayflick limit, influenced by the length of the telomeres (the "*caps*") on the chromosomes. Everytime a cell divides, its telomeres shorten more and more. Until there is a time when cell division is no longer possible. There are enzymes, called telomerase, that may increase the telomeres indefinitely, rendering cells effectively imortal. Just make those women (and men) produce telomerase in every single cell of their body *except* on the ovocytes. **Rather, when the woman arrives at your Heaven/Hell, shorten the ovocyte's telomeres so as to not the able to undergo one single cell division.** Upon fertilization, the short telomere won't let the ovocyte complete meiosis. You will now have 1,5x the amount of chromosomes that a human being has. People with Down syndrome have just 1 more chromosome. Imagine having 23 more chromosomes! It's incompatible with life! There would be no reproduction whatsoever... but there would be menstrual cycles. [Answer] From the mention of an afterlife and "last save state" reset, I'm taking this in the context of **science fantasy** - there are some based-in-fact elements, but on the whole, we're talking about a fantasy setting. So in that context, you can look to other examples of immortal beings, either of the biological-reproduction variety (Tolkienesque elves, D&D-style dragons) or of the spiritual-reproduction variety (Buddhism-inspired reincarnation, some fictionalized treatments of early Christian/Old Testament angels). In the spiritual case, your beings are really only as human as they believe themselves to be. Any biology they exhibit is purely a matter of habit and self-image, and who actively imagines themselves digesting (for example)? ## One explanation for limited reproduction in this case, is a "zero-sum" situation - any newly-born beings would require that some other being be reborn/reincarnated. Perhaps this is such a great (and noble?) sacrifice that it is just not done with any frequency. In the biological case, your "100% human" entities are some new humanoid type, somehow freed from whichever of the maladies of the human condition you desire. You've already freed them from death, so what about injury, illness, hunger, etc. Just as @Separatrix above mentions, you can free your females from menstruation just as easily. (You could also free your beings from biological gender - for some folks, that is true Paradise.) I would also point out that not all real-world mammals have a "monthly" fertility cycle - most are annual/semi-annual, and many are only fertile if other basic living conditions are met (sufficient food, clean-enough air/water/soil). These immortals could simply have an extremely long-wavelength cycle, with eons between fertility periods, assuming technology or magic does not intervene. [Answer] Rather than making these immortal women completely infertile, a good balance might be a single cycle window where in a woman could become pregnant with a child within the first month of entering this new realm because this will be her last menstration. The explaination being her body adapts to the new environs and shuts down mensing because it is unnecessary. Another idea to play with would be the women arrive already with child. It might be that this is the way all women arrive, they have one child, then become infertile and without menses, or just the women who were are already pregnant before they transitioned into this world. Either of these directions would create interesting character and social implications for the world you are building. For example, if you decide to go with women who arrive already pregnant, perhaps these women are celebrated by the society for their special role as mothers? Perhaps becoming a mother is hard because the child immediately returns to the realm the mother just came from? Just some thoughts. -C [Answer] I would say you would want some children anyway as a practical social matter. Imagine if you only had the same 1000 people to talk to, you would soon know everything about everyone. They intern would know about you, and everyone would be bored. No new ideas would emerge, and your place would end up being a boring nightmare. [Answer] Well, periods are for removing unused eggs. If they can't make children, why would there be eggs? So there would be no eggs to remove. Thus, no periods. [Answer] I agree with FirstLastName, it would be easier to tackle this issue by changing the idea of them not being affected by time to the idea that time resets itself on a biological scale for them, i.e they go through a 24-hr cycle of time biologically at the end of which they reset to back to how they were at 0 hrs, which would give you the freedom to decide if they were menstruating during their time of original death they would continue to in the afterlife, however statistically most would not be, this would also help with the idea of pregnancy as after 24hrs the fetus would cease to exist. [Answer] Maybe we should think less about why a world would need a menstrual cycle and more about why male and female, exist. A menstrual cycle would imply the creation of eggs to be complimented by sperm. If no such cycle exists, then there isn't a need to propagate genetic code. This phenomena forces your hand to acknowledge the chief motivations of biology. In a stochastic system, subsidiary systems (menstrual cycles, the philosophical implications of the golgi bodies, the necessity of flagellation, etc) are used as relays to provide coverage for the overall economy of survival. So, no. But then you would need to tailor their relays to an end goal that presupposes a biological crescendo; that all systems participate in the infinite survival mechanisms to hedge against all threats to survival. It's in this moment that we can define the immortal being's phenomena as a static compendium of non-trivially, proficient resilience—an infinitude to match such a continuous identity [Answer] Well I think if a woman is about to be immortal you can make them either be born without eggs but having normal levels of estrogen or create your immortal girl with Androgen insensitivity Syndrome. Both options will make them never menstruate and be esterile. If they are immortal making them infertile pose no risk in having a superpopulation of immortal people. ]

[Question] [ So, long, long ago, on a planet in the Milky Way, dwells the Qualian civilization. The time is around Earth’s 16th century, in the Tasadian Empire. Emperor Zora II has just been betrayed and nearly assassinated by the famous High General Duluk. Duluk now waits underneath the great prison, waiting to receive his, most likely, brutal torture and punishment. Probably the eye melter or head cruising methods. But when he talks to Zora, he tells him he’s getting a ***different*** punishment. The next day, Zora’s guards are seen chasing Duluk out of the city, and he is never seen or heard from by anybody ever again. He’s alive, and is about to take a permanent vacation in the Hageorian Desert, but he's still alive. But Zora goes on to make a purge of all memories of Duluk. Files such as Duluks certificate of hatching, his college files, and etc. Paintings of Duluk are painted over, and every single scroll or stone carving mentioning the name Duluk is edited. People are discouraged from mentioning Duluk, and since hatchlings are raised en masse in government controlled facilities, Duluks legacy is deleted, while he is technically still alive. Duluk, after about 50 years, is a hazy urban legend like figure that no one is sure even existed. In Qualian culture, I plan for this punishment, called deletion, to be feared worse than any other by Qualiabs. But my question is, why would this, seemingly mild punishment, be so especially feared by Qualians? [Answer] You seem to be describing a particularly extreme case of [shunning](https://en.wikipedia.org/wiki/Shunning), which has been used as a punishment by real-world cultures and groups throughout history and into the present day. As a commenter on the question said, I find it strange that you consider this a "mild punishment". Being shunned by even a single significant individual is highly unpleasant, even when there is the possibility of reconciliation. To be irrevocably shunned by your entire society would be devastating, and that's just here on Earth, without active efforts to purge all evidence of your existence. In the earlier days of the internet, there were also a handful of movies made about how horrible it would be to have a hacker or government agency delete you from every computer in the world - which, in these movies, often had the inexplicable effect of also making friends and family forget you. So, then, how do you survive, with no bank account, no credentials, no *identity*? So, no, there's no need for any supernatural or deep cultural explanation. To be erased from existence while still alive would be psychologically devastating and, if not imprisoned, it would also make basic survival extremely difficult. Many people, in that position, would eventually come to contemplate suicide, considering death preferable to continuing on in that way. [Answer] Take a cue from Mexican culture, and specifically the plot of the Pixar movie *Coco*. ## Being forgotten in the Living World means you don't reach the Afterlife Of course this answer is really up to you as to how religious your Qualians are. If they're a secular society that doesn't really get into superstition, then maybe a different answer would suffice. However if they *are* religious, then feel free to use this idea. [Answer] You are describing a more efficient Damnatio memoriae. The roman version (and the egyptian before them) did not work well, since we still know that damned people like Caligula and Akhenaten existed. It was a horrible punishment because it erased all deeds the victim did, the victim would lose the immortality that history brings to Great Men. Also, if your society practices ancestor worship that would mean that the victim would not be worshipped and would suffer in the afterlife because of that. Maybe your afterlife is some kind of celestial bureaucracy and the dead needs that the living do a lot of rituals to help them navigating that bureaucracy. A damned man would no longer receive these rituals and would be pushed to the back of the line in the celestial bureaucracy. [Answer] The reason why this punishment might be seen as so horrible can be found in Qualian biology. Specifically, they're a highly sociable species evolved from pack or herd animals. Social standing and interaction isn't just something their society values, it's something they need on a deep physiological level. Interacting with others and being seen as a valuable member of the herd/pack/society triggers the release of hormones similar to those that occur in a human when they fall in love. Their society has evolved to support and reinforce this behavior with almost every member of their species exhibiting traits that we would classify as exceptionally extroverted, to the point where an introverted nature might even be seen as a psychological illness. In addition, their society values accomplishments and status very highly. Being able to trace one's ancestry back to a valued member of society is a great source of pride and status among Qualians to the point where many important Qualians have dozens of great deeds their ancestors performed memorized. But perhaps even more than that, Qualians have a fairly low birth-rate and thus place tremendous value in their offspring. In prehistoric times, it would not be uncommon for primitive Qualians to perform suicidal attacks on predators so their children may escape harm. While this has lessened with the transition to agriculture and city-based society, protecting one's children and leaving them a better life than you have is deeply ingrained in Qualian society, to the point where wishing that someone's children grow up alone and destitute is one of the worst insults available. Your punishment hits all of these essential Qualian traits all at once. A dead Qualian is just that: dead. But one that has been deleted is far worse off. All they've worked for is gone, their children not just orphans but heirs to worse than nothing, a blank place in history. A deleted qualian's resources are taken by the state, effectively leaving their immediate family broke. Their children's social status is ruined through the gap in their line, for if you have no father or mother, anything their ancestors did is no longer yours to claim. And perhaps worst of all, being deleted effectively ensures a Qualian will be alone forever, denied the strongest positive emotion available to a member of the species. Unsurprisingly, most deleted Qualians choose to take their own lives instead of living like this, though some Qualians, particularly those with *anti-social tendencies*, continue to survive for as long as possible, mostly out of spite for those who did this to them. [Answer] > > “The oldest and strongest emotion of mankind is fear, and the oldest > and strongest kind of fear is **fear of the unknown**” > > > ― H.P. Lovecraft > > > If Duluk is put to death, he dies as Duluk - defeated and in pain, perhaps, but proud and with the trappings of his rank, social status and achievements both by himself and his ancestors. Stripped of his identity and driven into the desert, Duluk is no longer the person he has always been. He must become something else. He does not know what that will be. It is a terrifying prospect, to be hurled into the world and have to make oneself new, with no recourse to the trappings of the past. Some people would choose death instead of the unknown; some might commit suicide or just wait to die in the desert. I like to think Duluk is made of sterner stuff and he will find a way. This is the stuff of good stories - you surprise the reader and keep a good character in play. I suspect Zora is playing the long game and that he suspects Duluk might be useful again someday. These things are why people keep reading! [Answer] A similiar fear of being excluded or removed from society is already found in human culture. In Norse mythology for example it was considered essential to be remembered after passing away. It was somethimes referred to as a "second death" when nobody could remember you anymore, because it would be the same as if you never existed in the first place. There is also the infamous seppuku from Japan, where people would quite literally choose suicide over being shunned by their communities. The feeling of acceptance is a really big psychological force in society. So the psychological effects of being deleted could be severe. Most people don't just want to live, but also want to feel like their lives have accomplished something. A deleted person would lose all recognition of past achievements and also lose the possibility to influence the future in any meaningful way. You're losing a huge part of what makes life meaningfull, which is something that for many is worse than death. If your character has strong ideological convictions, this would be especially devastating. They'd also potentionally lose out on any societal benefits that might be in place. Anything like medical assistance or protection that is afforded to everyone else. Deletion could be similiar in many ways to being decleared an outlaw, which has historically been a harsh punishment in many cultures. Criminals would lose all and any rights that the rest of the population has, and would no longer receive help or aid of any kind. They would even lose the luxury of trusting their own friends and family. For many it was essentially a death sentence. [Answer] In the US, one of the worst things that can be done to an individual in prison is solitary confinement. This especially is true if done for long periods of time. This can cause lasting mental scarring above and beyond what normally happens in prison. To be totally forgotten by the living and the dead seems an ever worse punishment. Duluk should be marked in some way so that if he comes back home everybody will see him and shun him. He will have no rest from this, with similar effects to solitary confinement. This next idea is the creation of the writer/artist of [A Girl and Her Fed](https://agirlandherfed.com/). It is a webcomic, and one of the major characters in the story is the ghost of Ben Franklin. In this story, ghosts make a specific decision to return to a place between the world of the living and the world of the dead. I call this "The Annex." The power of a ghost is proportional to the amount he is remembered. In the US Ben Franklin is one of single most powerful ghosts because people remember him very powerfully. I can't even think his name without thinking of his famous thought-experiment about a kite in a thunderstorm. We still teach of him in the schools. Our first president, George Washington is about equal. And interesting thing is that Hamilton has gained power from the musical show, "Hamilton." Those who are not remembered become almost powerless wallflowers until they choose to go to on the afterlife. I imagine that Duluk might have chosen to return, and being forgotten would be almost powerless within a generation. [Answer] Your Qualians could be a telepathic species sharing a sort of hive mind. Therefore, the definition of an individual would be rather blur and concepts such as self-identity or proprioception (sense of the relative position of one's own parts of the body) would not be "hold" by a single individual but devided onto the whole species. The act of forgeting Duluk is then equivalent to death as this part of the hive mind that was called "Duluk" and was once shared between all the Qualians is now some uncomplet memories fragments stored in the only "body" that refused to forget. Duluk doesnt exist anymore, even for himself and his body is a just an empty vessel that can't even analyse where he is as his proprioception was dependant of the other members of his species... [Answer] It could also be that the memory whole doesn't just affect the punished... Duluk would probably have taken a mate or mates... now they cannot discuss their loved one (presuming life time bonds are a concept...). If this mate is a member of high society, she could presumably be shunned as well, especially if her social titles are tied to his. Those big fancy parties are now closed to her and she is reduced to peseanthood. If he has any ties to offspring (not sure based on egg) they too could face back-draft as they are purged in someway. Having Children is genetic. If your parents cannot have kids, you probably won't either. If Duluk has any land possessions, they are now free to claim by other houses or even commoners looking to elevate their rank. After all, he cannot own them because he doesn't exist... someone else can lay claim and profit in some way. [Answer] The ancient Egyptians believed that only a physically complete body could enter the Afterlife. Hence the extraordinary lengths taken to preserve the bodies of their kings. A criminal could be executed with some degree of honour, or his body could be thrown to the crocodiles in the Nile where it would be fragmented beyond hope of reincarnation. An intact body, an intact reputation... [Answer] On the longest night of the year, each family gathers and performs the G'krule, a long ritual where the the names and deeds of the family members are recited. The elders begin with the youngest in the living family, and mention their names and achievements, eventually the task falls to the younger adults & teens, they recite the deeds of the elders and the most recently dead, moving back into the mists of time. Wealthy families employ "orphans" or "foundlings" without family to read, so their many ancestors lost to the ages can be honored at G'krule. The ritual ends at dawn, and ushers in a new year to earn achievements in. Everyone wants a long list of achievements to be read at G'krule, so one will be be remembered by your family now and for decades after your passing. To be "forgotten" is to be omitted from the G'krule, and for all it is a fate worse than merely dying. [Answer] # 1) Death is a mild punishment. Death happens to everyone. Life is merely a dept and death is paying it off. Having it today is no really different than eg. bank calling in today and terminating your mortgage. Yes, you were expecting to pay it over the next 29 years. You have to pay it now? You had a 100k worth of house and -100k worth of debt, now you have 0. Tough luck, but nothing really changed. # 2) Being remembered is the ultimate point of life. Once you die, all that is left is how others remember you. If they don't, it's as good as if you haven't lived at all. The whole outcome of your life is nullified. That's the worst possible thing that can happen to a conscious being. *(Keep in mind that human fear and denial of death is quite irrational. Once you get rid of that, pretty much everything is "worse than death", because death is not bad per se.)* [Answer] I read a story where some bug creatures gained a sort of immortality when their corpses were consumed by their brethren. By this ritual the deads' memories became shared with the hive. Thus the hive remembered everything any of their ancestors ever did. Being deleted means that the hive would purge those memories, and the accused would be driven away to die the ultimate irrelevant death. It's the ultimate "Bye Felicia". Your mate would forget you. Your offspring would forget you. There might be a void there (who was my father?) but there would be no remembrance of who filled it or why it was a void. And probably a cultural taboo to thinking about it too much, or perhaps a mental block that made such thoughts hard to have, somehow meaningless, or seem like gibberish (colorless green dreams sleep furiously!). [Answer] You could take a page from Lois McMaster Bujold's Barrayar, where some folk beliefs hold that (iirc; the story which features this is called Mountains of Mourning, and is worth reading if you're looking for insights into that mindset) you're still alive, in some way, as long as you are remembered. So destroying your memory is effectively destroying your afterlife as well as your position in the family. See also the movie Coco, although that's not my culture and I can't speak to any details. Continuing the afterlife theme: if you're sustained in your afterlife the same way you are in life (a la ancient Egypt), and you're expecting some kind of sacrifice/contribution from the living to keep you healthy and happy, being forgotten means an *eternity* of punishment. What's one lifetime of suck when you're dealing with that? If you want to go with a more mystical version, a species that has some kind of shared memory/consciousness, where those who are remembered literally live on in some way in the living and may be able to still influence the world, it's a different form of death. A completely different approach is to say that what is valued in this society as the purpose of life is the impact you have on the future, or how long your name is remembered. So if your name is deleted and everything you did has been erased or credit given to someone else, then your life's purpose has effectively been in vain. The Roman damnatio memoriae tradition seems to be similar to this, but someone with a better knowledge of Roman culture can hopefully provide more insight there. [Answer] # You can't have an Afterlife This society is very religious and they think that you need to be remembered in order to live in the heaven. In the same moment the last person which remember you die (or forget) you no longer exist, you are nothing but sound in the wind. Your right to be in the afterlife is removed and you simply disappear (or suffer an unimaginable amount in the hell...). # Memories remain Be executed is just a quicker way to die. You'll already die, 30 years after or before you will be only dust. But memories may remain. Memories about you are the only thing that remains after you die. If your memories are forgotten, what would keep about you? Your money? It'll be inherited or donated. Your house? Inherited, sold, destroyed. Your car? No. Everything tangible will be lost, the only thing that can remain are memories about you and your goals, and if you lose them you will no longer have existed. # They are sociable creatures Some creatures have evolved to live in communities and societies (like us). Be forgotten or rejected by your community is something very bad. Doesn't hundreds of teenagers suicide because of bullying on social sites? Be accepted is a privilege and its fundamental to their lifes. [Answer] Imagine, where your name is hard coded, by scent, fingerprint, eyecolor or skin-coloration. Shunning like this, is double the punishment if you cant escape it in a new identity. Because then, your very appearance restarts the witch hunt and people dread the appearance of the unspeakable foreigner. Now imagine, a society where this "unlearning" gets so internalized, the undesirable could walk back among them, readily recognizable - and yet non-existent, for the subconscious itself deletes all memories of the strange beggar wandering the palace. ]

[Question] [ (Almost) each work of fiction requires Villains. Sometimes the more dastardly, the better. And what is more dastardly than an evil, murderous, secret cult that practices human sacrifices? And again I caught myself on thinking about the details, the personalities of people involved, the scenery and the likes, before having the most basic things set. How would our cult operate so that it could remain secret? One problem that seems to have no solution is: What can a cult do if one of its members speaks out? Of course, the cult will have rather few members, none of them likely to speak out for obvious reasons, but... as Benjamin Franklin said, "*Three may keep a Secret, if two of them are dead*". Having only one cultist is implausible, so, sooner or later, someone is bound to speak out. How can such a cult fight for survival if someone finally does speak out? Paradoxically, killing such a traitorous cultist seems to be the worst possible solution, since ANYTHING bad happening to them will be a firm confirmation of their words. The only semi-plausible way is to ensure that they live long and happily, while trying to discredit their credibility... But this, again, is a no win, since they simply know too much. If a minion of the law gives any credit to their words... if The Detective starts an investigation... We may be doomed. And now our future starts looking rather grim, since we can only await life sentences at best and an execution at worst. Is there any way to fight back or does a member who speaks out spell doom for the whole cult? [Answer] You need a cell-based organization, with the additional twist that **recruitment must happen cross-cell-wise**. That is, the members of the Blackwater Lodge meet and discuss whether to admit mr. John Smith. They all need to know John Smith in order to pass a judgment, so John Smith's identity is compromised. In time, higher-ups in the Blackwater Lodge would come to know the identities of almost every other member younger than them, even if they wore black hoods during meetings. If they decide that John Smith would make an acceptable adept, they supply him with the required passwords and tokens, *and send him on to the Greyfriars Lodge*. The Blackwater Lodge does not know where the Greyfriars convene, or when, and no one in the Greyfriars know who John Smith is - they only know that he's been accepted by another lodge of the same cult. John Smith knows nothing about the Blackwaters who have interviewed him, so nobody can betray anybody else. Someone in Blackwater could rat John Smith out, but all they'd be able to say is that he belongs to the cult. They wouldn't be able to say where he goes to perform the rites, or when, or even whether he's still an active member or not. At the same time John Smith would know one or two Blackwaters, but again he would know nothing else. What you don't know, you can't betray. # steganographic communication (as per @Jay's comment) So we have several lodges and they need to communicate secretly, and more than that, they don't want to make it look like someone is *communicating* at all. They need to set up the equivalent of a [numbers station](https://en.wikipedia.org/wiki/Numbers_station): the one talking won't know who and where and *whether* anyone is listening, and the one listening won't be able to see who is talking. * First they find some **channel**. This can be anywhere communication noise can be found; for example a Youtube channel's comments. * Then they must generate a largish set of symbols (this can be done automatically) which would not be deemed out of place on that channel. This could be the combination of some features of a user's name, avatar, and words in a message. * Finally they need to set up an automatic *monitor* that will, say, continuously download all the comments from several Youtube channels, and see whether any of those can be successfully decoded. Typos, word choices, emoticons, lolz etc. can all be used to encode bits. A single message could then be broken in eight or ten comments, and e.g. a Polygen grammar could be used to generate not too incredible ones. The necessary nicknames would then be created automatically and used to send the comments for everyone to read. From the outside, you would see comments to a lolcat video * [Emily84] aww..... what a cutie pie.... I wish I had one ;))) <3 <3! * [EvilHaxx0r] OMG r u seriouse? I mean look at that lol * [JustinTheBore] lolcats for teh winnnnn ;-D * [Edzorg] RUN BABY RUN + [EvilHaxx0r] run what? lol what a retard XXP - [Edzorg] Well yeah f u but once decoded you would get something like "REQUEST FOR MEETING, NEW MEMBER FOR GREYFRIARS". Even if someone monitored the whole Internet, they would only see some random guy blathering on some channel through a Tor node (special once-only keywords could be used by members in a hurry and without access to the full "comment encoding" system. Enter a Starbucks, look at some videos, leave two or three comments). # preventing higher-up treason (@cmaster's comment) > > Smith may know only little, but he does know anything that's communicated to him. More specifically, at some point he may be in a position where he is interviewing new adepts. If smith is subverted > > > This is a real problem, since by design the interviewers and the new adepts have only the loosest of connections. Specifically, *the new adept can't compromise the interviewers*, which means that the interviewer can compromise the new adepts with very little exposure for himself. So the interviewer is in a position where, if he ever needs, he can plead "*Wait! Wait! I did embezzle that money! But if I get a reduced sentence, I can make it worth your while!*". He can concoct a story where he learned by chance of the sect, and only had very little proof except his own hunches. So the evaluators must not be able to conclusively *know* the evaluees - the one member that introduces the new adept will have to sanitize all documentation, and the evaluators must not know the new adept's identity. This both places a very large burden of investigation on the introducer, and allows him to plant an infiltrator in another lodge. By only allowing a limited number of new adepts per introducer, and limiting the role to the very high-up in the hierarchy, we can reduce this vulnerability. Then, the introducer must have **much more to lose** than any number of his protegees; he might for example be the one in charge of victim procurement. This fact must also be very well known to the lower ranks, to ensure it can't be overlooked or denied. One new induction allowed for every ten rituals performed, and now whoever knows for certain (and can betray) the identities of X members is thereby also confessing to 10X counts of first degree multiply aggravated murder ("With planning involved... after the act of kidnapping... after the act of rape"). [Answer] It might be useful to turn the question around. Suppose you're a perfectly normal serial killer, and the cops are on to you. You want to convince them that you're actually part of a secret murderous cult, so you can try for a lesser sentence by turning yourself in and offering to inform on a few "fellow cultists". Maybe Alice and Bob from work; they're jerks, anyway. Now, regular murderers are a lot more common than the secret murderous cultist kind, so the cops aren't likely to believe you unless you come up with some really solid "evidence" to back up your story. Maybe you could break into Alice's and Bob's computers and forge some incriminating messages between them. (You think Eve might know the password.) But you really want physical evidence if you're going to convince anyone. So a better idea would be to grab some of the bloody knives in your garage, and possibly the kidney you took out of that one guy, and plant them at Alice's and Bob's houses. It'd be great if you could actually get a recording of them with one of the victims, but that's probably not doable unless you have time to kill another one before turning yourself in. Now all of those things that the hypothetical serial killer was going to use to "prove" that he was in a cult? *Don't have those things in your cult.* Don't discuss anything in writing except maybe in really vague terms. Properly dispose of all the bodies. Use regular kitchen knives for your sacrifices instead of fancy ceremonial ones, and wash them properly when you're done. (That's just a good idea anyway; you don't know where that sacrifice has been.) Don't videotape your ceremonies, and for that matter, don't let anyone bring their phones or anything else that can take pictures to the ceremonies in the first place. If the would be traitor can't provide actual evidence that the cult exists, all they'll accomplish by going to the authorities will be confessing to a murder and sounding like either a crazy person or a bad liar. [Answer] On 21 September 2001, the headless and limbless torso of a little boy was found in the Thames River at London England. The boy, about 4 to 7, was determined by forensic tests to have been in the UK for no more than a few days, and probably came from southwest Nigeria. It is believed that he was brought to the UK to be killed for some of his body parts to be harvested to make *muti* medicine for sale. There is no proof that a cult killed the boy, and it is possible that only one single person took him to the UK, killed him, and made *muti* medicine for sale. But those who purchased the *muti* medicine probably knew it came from a human murder victim and would only accept that if they belonged to a religious cult that accepted murder (presumably only of non cult members). The boy has not been identified and the case has not been solved. [Wikipedia on that case](https://en.wikipedia.org/wiki/Adam_(murder_victim)) The *muti* system of traditional medicine widely used in Southern Africa has a dark side, the rare use of human body parts of murder victims, usually children. [Wikipedia on Muti Killings](https://en.wikipedia.org/wiki/Muti#Muti_killings) There are are probably a few scattered cases of human sacrifice and/or ritual murder reported around the world each year. Sometimes the individual or cult responsible is arrested, sometimes the perpetrators are unknown. [Wikipedia on Human Sacrifice](https://en.wikipedia.org/wiki/Human_sacrifice) [The Mirror on Modern Human Sacrifice](https://www.mirror.co.uk/news/world-news/human-sacrifices-still-taking-place-5999139) I add that the Thuggee cult in Indian apparently operated in secret for centuries between first being discovered about 1290 until being suppressed in the 1830s (though *Gunga Din*, *Indiana Jones and the Temple of Doom*, and *Help* claim that some Thugs continued to be active). So apparently the methods of the Thugs worked very well in medieval and early modern times, and perhaps only a few more precautions would be necessary in a better policed contemporary era. [Wikipedia on Thugee](https://en.wikipedia.org/wiki/Thuggee) So I find it very easy that an evil deluded cult could continue to get away with committing human sacrifices for many decades if they took enough precautions to avoid detection. If, for example, no bodies of their victims are discovered, the authorities might never know that a small fraction of the many missing persons reported (to say nothing of missing persons not reported) were human sacrifices. [Answer] **Cult members don't know each other**. This is a tried and true method used by spies and terrorist since the dawn of time. Basically, the cult is working together to achieve a common goal (human sacrifice), but they don't know the real identities of any of the other cultists. When they meet in person, maybe they wear masks and disguise their voices. The upshot of this is that if any one member rats out the group, they don't actually know anything about any of the other members to implicate them in anything. [Answer] Make each person do something really horrifying or humiliating all by themselves on video. Make it the final initiation rite, don't tell them its being videotaped until it's completed. They go to the police, their family, friends, and the entire world will see them, and them alone, glorying in murder, sadism, and some really sick stuff. You'd be amazed at what people will do to keep that secret. [Answer] Depends how long you want the cult to survive. Over a long enough time, the probability that someone talks approaches one. So your containment plan must work even if someone talks. For that, look to the real world. Make your cult contain as many "conspiracy theory" elements as possible, then leak it by yourself to a tabloid. In short: Make sure that none of the revalations anyone could make would be taken seriously. "So they now sacrifice children in Area 51, riiight..." [Answer] Just take example from real world cults: **1. Recruit families** [Aum Shinrikyo](https://en.wikipedia.org/wiki/Aum_Shinrikyo) is the best example. This old Japanese cult recruited "Otaku" and promised supernatural powers to the initiated. Since they had to move to specialized "school" (understand forced-labor camps) and family is very important in this country, they were encouraged to bring their families and thus lost contact with the outer world really fast. **2. Tarnish credibility and self-esteem** That is a trick used by the [Church of Scientology](https://en.wikipedia.org/wiki/Scientology) : once in a while, every member has to participate to a 'Dianetics' session. He/she has to reveal all his/her secrets and is recorded (members are heavily brainwashed with multiple technics so they won't lie) to achieve a clarity of mind. But the truth is that these recordings will be used against any member who wants to quit or talk to someone by tarnish his credibility. **3. The rule of 1%** Most of the biggest cults followed a "1% rule", meaning that they used 99% of the members to collect money, and only an "inner circle" of the most fanatic and brainwashed ones to achieve their darkest goals: examples would be The Children of God with the sexual abuses, Aum Shinrikyo with the drug and chemical weapons factories, etc... So by limiting the human sacrifices to the inner circle, with carefully chosen members, you are limiting the risk of being caught. As for the detective, you don't have to worry that much: The Scientology is basically untouchable because they managed to legally make themselves a religion, Aum Shinrikyo was shadowy, had connections with Yakuza with the drug business, and the truth is: police didn't investigate even if an old member would talk because... Their stories were just unbelievable and unthinkable. Children of God's leader was able to live a long life because he was able to make dummies sign for every official paper and his name appeared nowhere, like in the mafia. My sources: the very documented podcast [The last podcast on the left](https://www.lastpodcastontheleft.com/). [Answer] **Make the work mostly *untraceable* and make any confession seem *ridiculous*.** You will need a cult leader. This is the one I expect not to suddenly have a change of mind and tell on the group. He alone does the dirty work. All victims are shaved, possibly lying on the front so the other members can't see face of the victim. And then, before killing, let the people of the cult do really embarrassing things to her they only do because the rest is cheering them on (basically like on every college party challenge I've seen). Those various actions can include: * Kissing unusual parts of the body, like the ankle. * Drumming on the butt cheeks. * Dipping the hand into a bowl of cold water until the victim pisses itself. * Draw something on the victim with permanent marker. * etc. Wait. This is exactly like a college party. --- "You were playing pranks on an unconscious person?" "Yes, it was hilarious!" "And then your leader killed her." "Well, we want to be an evil, murderous, secret cult, after all." "And you have no idea who that person was." "Nope. Shaven clean. Could have been a hobo. Did I emphasize 'secret' yet?" "And you were on drugs." "High like a dragon in the sky, sir." "Urgh. Commissioner, how did we get this guy again?" "He was posting a selfie with the alleged victim on Facebook stating 'lol im gonna kill this hobo in a minute rofl'. In retrospect, the dim, colorful lights did somehow look like a college party." [Answer] The cult is family based. Children are brought slowly into the cult and external partners the same way. The cult has multiple levels or circles and only the most devout make it to the top tier with the actual blood sacrifices. Any members without the correct mindset are left on the lower tiers and don't actually know the extent of the cult. Should a lower member find out the extent and be appalled and try and expose it, they have a tragic accident such as brakes failing or slipping off a ladder. Should the cult have members in the police force and government, the investigation into said deaths could be a bit lax. [Answer] Another way is to have the members firmly believe in the cause. If you look at [Dexter](https://en.wikipedia.org/wiki/Dexter_(TV_series)), he kills regularly. If the cult see themselves as saviors killing people that they see as needing killing for the benefit of society, the less likely the members will feel guilt or revulsion and confess How hard would the police look into missing pedophiles, violent wife beaters and rapists especially if no body is ever found? If each cultist sees themselves as saviors and each provide alibis for each other, the chance of being caught is extremely low. [Answer] There's less risk than you think. The crazier the cult is, the more likely that nobody will believe it. If somebody turns you in, act incredulous and make fun of them. I've heard lots of stories of weird cults kidnapping and murdering people. And I've heard lots of people dismissing these stories as wild tales by TV stations trying to boost ratings or crazy people trying to get attention by claiming they were former members or victims. Which of these stories are true and which are false? It's very hard to say. Some suggestions what to do if someone reveals cult secrets: 1. Claim the stories are wild and crazy conspiracy theories that no sane person would believe. Make yourself sound like the voice of reason. 2. Get other cult members to promptly come forward and "corroborate" the turncoat's story, while adding wild and totally fictional details that can be proven false. Then in your rebuttals, casually attribute the false details to the original turncoat. Try to get it very mixed up in the mind of the public and the authorities who said what. Then when the police or reporters investigate, they find that most of the story is false, and the turncoat is discredited. For example, the turncoat tells the police that you murdered 3 people in a room at the Foobar Motel. You quickly have someone else come forward who says that he knows that the cult also murdered someone in the basement of city hall. Someone else says that he saw mysterious people leaving the Foobar Motel dressed in red robes with a mystic symbol on the back (even though you were all wearing business suits). Someone else says he suspects his neighbor is a member of the cult (and the neighbor knows nothing about it). Someone says cult members have magic psychic powers. Etc. Then you agree to be interviewed by the newspaper and casually say, "Well, Mr Turncoat says we wear red robes. I invite the police to come and search my house looking for such a red robe. These people claim Mr Neighbor participated in this cult murder, but he claims he was in Europe at the time and has witnesses to prove it. And these wild stories about me and other supposed cult members being able to read minds and fly ... aren't these just ridiculous?" When the turncoat replies that he never made these claims that are false, say, "Oh, now he's changing his story. (snicker snicker) Notice how every time one part of his story is proven false, he claims he never said that and switches to some other claim." 3. Make it political. If any of the accused cult members are prominent politicians, claim this is an absurd attempt by the other party to discredit you. If none of you are politicians, have some of the fake witnesses from item 2 accuse prominent politicians of being part of the cult. If you're lucky, the politicians' party will defend them. 4. Lump the revelations about your cult in with conspiracy theories and wild tales that few people believe. Like if you control any sort of media -- TV, newspapers, whatever -- start airing documentaries or printing stories about "modern legends, like UFOs, Bigfoot, the Foobar murder cult, and Kennedy assassination theories". If you don't control any such media, these days it's easy enough to publish books, create websites, etc. [Answer] **You get the authorities in on it, as part of the cult.** They will then not act against the cult, but rather in favor of it (even stopping colleagues from investigating or taking action against the cult). It's classic corruption, and happens far more often than you might think, where "murderous cult" could be replaced by anything from a much broader set of large and small groups who believe they are above the law. One of the "benefits" these groups offer members might be that sense of superiority (which may motivate or come naturally to some in positions of power or enforcement authority). The inducement could also be money or whatever other benefits the group has to offer, as long as the authority figure perceives a strong enough benefit to him/herself personally to outweigh any sense of duty to a larger and more diffuse public who probably won't find out about what's happening (and even if they do find out, they won't believe once the authority finishes discrediting or quickly killing off whomever is trying to point out what's happening). Police, military, and paramilitary etc. in many jurisdictions regularly abuse their power for private gain to themselves and/or their friends. This can be especially effective in places where people prefer to pretend like this sort of thing just doesn't happen. As an alternative to corruption, if the group members obtain power through other means after they've already adopted the group's ideas, they can use that power to execute those ideas, relatively unencumbered by the nobody doing anything about it. For example, consider the Nazi party, which took power and used that to kill millions of Jews as well as others they didn't particularly like. Then, it doesn't much matter what the people in the group know or leak, because the authorities who theoretically have power to do something about it just won't. [Answer] This may be less enjoyable for the cult members, but it increase safety. Do like they do on death row, give 5 (or whatever) people buttons, and they all push their buttons at once. However, a computer randomly determines who the killing shot comes from, and therefore no one knows who killed who. Additional, maybe they wear blindfolds, and they get to stab at something that might seem human. However, maybe its not, or maybe someone else killed them so they are not actually killing anyone. Guns, obviously only one of them gets a real bullet the rest are blanks or otherwise don't kill but still cause a kickback and etc so they can't tell they aren't doing anything. Obviously, don't use real names, get voice synthesizers and nobody especially at the lower rungs gets to see anyone's face. Maybe some walk around on stilts to disguise their height, pillows or etc to help hide their physical make up. Certain amounts of brainwashing will be necessary. Another possibility is to have some get jobs as morticians, or even butchers who regularly carve up animals. People might dismiss a person as being wrong because a butchers is always carving up animals. S/He had blood all over the place, well of course s/he is a butcher. Combine these ideas with some of the other ideas presented here and you might have a shot at it. [Answer] ## Be murderous... Make it clear that those who talk die. If anyone even begins to be suspiciously reluctant to participate, make an example of them. If someone does try to go to the authorities, they suffer badly. Encourage members to spy on each other to some extent, to keep on eye out for traitors. ## ...But not too murderous If the body count gets too high, the police will be more vigorous in their search. They'll work harder to get someone in, or to get someone out. And the fear might wear off if your cult becomes too murderous. ## Rewards in heaven! A mainstay of cults is that the rewards and/or punishments continue after death. You aren't just facing immediate punishment. You're facing eternal punishment. Or reward. Always work to reinforce that. # Stockholm isn't just a beautiful city Stockholm Syndrome is a wonderful destination. Take your cultists there and make them love you. Make them love you more than themselves. ## Isolation and Paranoia Never forget the power of isolation and paranoia to keep people in line. All the great cults foster a strong "us vs. them" mentality in their believers. Convince them that Outsiders are evil and out to get them. Convince them that Insiders are their friends who love them. ## Give them what they need If you have everything a person needs, they won't need to seek it elsewhere. If they come to you for salvation, for healing, for food, for clothing, for comfort, for warmth, then they will become dependent on you. And you will have power over them. Give them happiness. Become the drug that strings them along. ## Protect them from what they don't need They don't need access to outsiders, for one. They don't need free thought. They don't need so much comfort that they get complacent or lazy. They don't need happiness that isn't from you. [Answer] Let's say that everything was done in a way that was utterly unbelievable and implausible, where nobody saw everything and everything done was partially altered by someone else. Then nobody who said anything would ever get believed. Nothing said could be verified, no knowledge known only to a participant would ever be present. And nothing would sound serious. Alternatively, everyone takes a drug that alters how memories from. As long as you take the drug, the memories work. As soon as it wears off, they're scrambled or inaccessible. You only want two layers, keep it simple. The second layer should be that there's always a more plausible, innocent explanation, which means (post-statistics) that there's no observable spike in any type of death. You might even have members of the cult save other people so that the books balance. [Answer] Look at the LDS and Jehovah's Witnesses for inspiration. If you were only allowed to be friends with or marry another member of this group, and only allowed to purchase property through this group, it would be insanely difficult to first, want to betray all of that, and second, to actually pull it off. Now what if whatever went on in their holiest-of-holies site was nasty stuff? (Luckily for our example cases, it doesn't, but in many real cults, it does.) Nobody would believe you, you'd be ostracized from everything you know, kicked out of your family, fervently believe you're going to burn in the afterlife...these are strong deterrents. [Answer] Make the cult members not know each other. If the cult members don't know each other, than the turncoat will not know very much about them. Than, you have to get a job as a butcher. This way, everyone will think the blood is just animal blood. Also, if you see that one member becomes a traitor, than kill him. But don't kill too much. Then, if you're in control of a news website, even better. No one will believe the turncoat, if you add some completely fake stuff to the confession, then the turncoat will look like a liar. One more: only make a select group of the most loyal cultists participate in the human sacrifices. Also, you need to have a few ''outer cells.'' These " outer cells" would be completely useless, but they would save the cult if one of the members speaks out. Let's say one of the members of the Venus flytrap murder cult tells the cops that you and your fellow cultists murdered 10 people at the Alola Motel. The cops start investigating and find the "outer cells" murdering Eve. The police think they've found the cult, and arrest the "outer cells" , while the real Venus flytrap murder cult continue their secret operations in another country. ]

[Question] [ The setting is basically earth. Our planet is unfortunately on a collision course with a large asteroid. However, humans have discovered and decoded a message from an ancient, advanced alien race (our parents). These aliens have left behind technology and knowledge that could save the planet, but this technology is encased in the earth's core (so that we may only access it when we are "ready"). If the whole world worked together for the next 5-10 years, would it be possible to detonate our way down to the outer core using our nuclear arsenal? I know that lateral pressure is a problem and if you dig a cylindrical hole it will collapse, but could we dig a cone-shaped hole? [Answer] Instead of telling you it's impossible, I'll make a list of the problems you need to solve: 1. **Pressure:** Pressure at Earth's center is $3.65 \times 10^{11} \ \mbox{Pa}$. Whatever enclosure you build is subject to that. If you made a solid block of diamond (one of the least compressible materials, with a [bulk modulus](https://en.wikipedia.org/wiki/Bulk_modulus) of $4.43 \times 10^{11} \ \mbox{Pa}$), you'll find that it shrinks to $82.3\ \%$ of its size. If you make it out of "steel" (say, $\sim1.50 \times 10^{11}\ \mbox{Pa}$), it becomes $33.9\ \%$ its size. That's bad news, especially since your vehicle needs to be hollow. Most humans are not happy being compacted to $34\ \%$ their volume. You can't solve this by using [unobtainium](https://en.wikipedia.org/wiki/The_Core) because whatever atoms unobtainium is made of need to actually exist. [Bond dissociation energies](https://en.wikipedia.org/wiki/Bond-dissociation_energy) are the physical limit of strength. 2. **Density and Viscosity:** Earth's inner core is $12.8\ \mbox{g/cm}^3$. Something like lead has $11.34\ \mbox{g/cm}^3$. Your ship is going to float, and will have to actively propel itself downward. When it reaches the inner core, it will need to move through something solid. To fix this, you need propulsion and drilling. But, both are subject to the same crushing pressures mentioned above. 3. **Temperature:** Temperature at the Earth's core is at least $5\,000\ ^\circ\mbox{C}$. Because of [thermodynamics](https://en.wikipedia.org/wiki/Laws_of_thermodynamics), the Earth's core will try to make your vehicle the same temperature. Most humans not so much "happy" at $5\,000\ ^\circ\mbox{C}$ as they are "charred-lumps-of-their-constituent-elements". It is worth noting that if humans have difficulty solving these challenges, your aliens will have difficulty solving them too. If your aliens *can* solve them, this raises some serious unintended consequences. --- Here's a possible solution. It is in the exterior realms of possibility and undoubtedly has *Problems*, but perhaps another worldbuilding question could help fix them: > > Make a large, very long steel rod, and hollow out many small interior regions. Suspend from the foremost region your vehicle in a vacuum. Similarly, put nuclear warheads in the rear regions. The outer hull can compress, leaving inner components unharmed. After sinking through the mantle normally, the rear regions of the device successively detonate, pushing the device deeper (this is an inverted Orion nuclear pulse drive, with all attendant problems). Count on sacrificial outer hull to absorb heat and pressure for long enough to get to the center. > > > Speculative/imaginary/magic tech that would make easier solutions (use with caution): * Force fields * Neutronium * Teleportation of matter * Teleportation of energy (heat especially) * Reactionless drive * Arbitrary adjustment of magnetism of nearby materials * Universe editation * Asking your bloody aliens to come up with a nicer plan and stop being ruddy showoffs already. [Answer] No. On this scale, the [Earth](https://en.wikipedia.org/wiki/Structure_of_the_Earth) is not solid and rigid. It's more like extremely hot jello, with a thin and weak crust, a layer of hot floppy jello, the "mantle", a liquid outer core (actually molten iron) that's about 1,400 miles thick, and an inner core of solid iron about 750 miles in radius. Films and TV programmes that show journeys to the centre of the Earth are *exceptionally* scientifically inaccurate, even by Hollywood standards. A "cone-shaped hole" isn't possible, the Earth will just flow to fill it in once you get down a hundred miles or so. No, there isn't anything strong enough to brace the hole with. The only way to retrieve something from the Earth's core is to dismantle the planet, which will do more damage than any asteroid hit. [Answer] I would agree with the NO answer already given. For comparison: The deepest humans have ever dug is only a little over 12 kilometers. <https://en.wikipedia.org/wiki/Kola_Superdeep_Borehole> And these are drilling shafts much less than a meter in diameter. Also consider that blowing a hole in the earth with all of our nuclear weapons to reach the core would most likely make the earth just as lifeless as the possible asteroid impact. [Answer] David J Stevenson has proposed a [method](http://news.nationalgeographic.com/news/2003/05/0514_030514_earthcore.html) to reach the Earth's core. It requires a nuclear device of only a few megatons to crack open the crust. The planetary mission vehicle descends using a large mass of about one million tons of molten iron to sink down to the core. This journey should take roughly one week. The real technical problems your inner-earthonauts need to solve are how to survive the temperatures and pressures imposed on their vehicle during the descent for, at least, one week. We can safely assume there will be a human habitable base where the ancient alien technology is stored. So once they get there it is plain sailing. But Stevenson has solved the technical problems and has the numbers to prove it too, of reaching the Earth's core. So this problem is already been solved. His probe isn't manned. Getting humans down there safely still remains to be solved. Possibly an extremely strong and highly refrigerated capsule needs to be built. Hopefully someone else on Worldbuilding SE has the answer. [Answer] TL;DR: Yes, but not the way you thought: Aliens left their message in the form a of punch card that can be read with a neutrino beam. Neutrinos are elementary particles that only interact weekly with other particles of matter and can therefore travel through the earth. Because it is so advanced, the alien civilisation could prepare a material stopping neutrinos and embedded a “punch card” made of this material at the centre of the earth. It is already possible to product “neutrino beams” and to [detect](https://en.wikipedia.org/wiki/Neutrino_detector) them, so we can imagine reading the “punch card” by emitting an intense neutrino beam towards the center from one side of the earth and reading it from the other side. Because we generate a very intense beam, it is easily distinguished from “universe's noise”. [Answer] I'll approach this problem from a different angle than I've seen in the current answers. The radius of the Earth is about 3959 miles. A cone shaped hole (assuming 1/10 ratio of base to height) will have a hole of almost 400 miles across at the surface. Even if the composition of the earth was "only" dirt and rock, you would have to move 163,000,000 cubic miles of material during the excavation. Using nukes can break that material up for you, but you are still going to have to move that material out of the hole. The material excavated by this project could be put into 271,666 piles, each larger than Mount Everest. Changing the ratio of the cone to 1/100 would result in a much smaller number, but you would still be talking about moving many multiples of Mount Everest. Please note that pit mines generally use much more gradual slopes (actually wider than they are deep), which would result in a continent wide hole at the surface. As another comparison, the amount of material moved is about half the volume of the entirety of the world's Oceans. [Answer] Considering that about 1,000 above-ground nuclear tests were conducted between 1946 and 1964 by the superpowers, huge numbers of underground tests followed, and nations not subscribing to treaty conducted many more, the fact that the earth is still here and not noticeably different should dispel any notion about the power of even fusion devices for excavation purposes of such magnitude. One large volcanic explosion subsumes the power of many fusion devices (see article on Krakatoa in Wikipedia, e.g.). Add to this that once (or if) you get through the crust you hit magma. Underneath this impenetrable barrier, what you might find is purely theoretical. Perhaps more disheartening is the fact that nuclear weapons shot at an asteroid would have little to no chance of affecting it. The reaction is quite momentary, and in the vacuum of space it does nothing other than get very bright and very hot for an instant. There's no surrounding matter to create a blast effect. There's little chance of intercepting something at aggregate velocity of perhaps 60,000mph with any chance of timing the reaction properly. Perhaps if, as in movies, you could bore a (very) deep hole in the thing and detonate the device there, the thermal shock would either fracture it or at least eject enough matter to alter its course a bit. But the odds of landing on a 40,000mph object with almost no gravity and then conducting a drilling operation difficult even on earth are, to put it mildly, not encouraging. [Answer] So, supposing we have alien directions that fix the location of the artifact (it's not moving relative to a location on the crust), perhaps the solution would be to drill with the intent of causing an eruption, using the pressure of the core to push out through a weakened mantle, saving us from drilling all the distance to the artifact (perhaps), thereby ejecting the nearly indestructible artifact, and recovering the item from the ejecta. Let's hope the artifact isn't buried under New York City.... Obviously, the environmental consequences would be catastrophic, if we can't engineer for them. I'm not proposing solutions to such engineering problems here - I don't have any. This is just a post to suggest a new line of reasoning if someone would like to follow up on it. Maybe the aliens put it under a mid oceanic rift? [Answer] If you knew, where it was, maybe this would be better. 1. Disassemble all those nuclear weapons and build power plants. 2. Make a giant, focus magnet so that the magnetic forces were aimed at the alien device. Using all the electricity these power plants could muster, maybe they could pull it up. Throw is some graphene for good measure. At least with my idea you wouldn't have to deal with crazy amounts of heat and pressure. ]

[Question] [ A post-scarcity civilisation is one where the automatisation of production and a universal basic income system have made it impossible to suffer unwillingly from the lack of means to satisfy the physiological and safety needs of an individual. While there can never be a guarantee that the higher needs; love/belonging, self-esteem and self-actualization can be satisfied, there are vast resources, augmented and virtual reality (think full immersion simulations) and brain washing available to satisfy everyone's needs. I'm using the [Maslow Pyramid](https://en.wikipedia.org/wiki/Maslow%27s_hierarchy_of_needs) here in case that is important. Even quite devious desires like pedophilia can be satisfied using virtual reality or be removed/implemented via brainwashing should one desire to do so. More information on the idea of post-scarcity civilisations is mostly based on Youtuber [Isaac Arthur's series on the subject](https://www.youtube.com/playlist?list=PLIIOUpOge0LvQYACAZwizb8gqtXL-10PC). While I share his opinion that there will be little crime in such a society an exact value is needed to consider the people's views on crime. Further assume that the government is democratic, open and benevolent, not a hidden dystopian surveillance state keeping everyone happily in misery using brainwashing. **Given that there are no economic incentives for crime and most urges leading people to commit despicable crimes can be satisfied legally without harming anyone, how many crimes would still be committed per one million people per year?** EDIT 1: People go on about if there will still be crime in a post scarcity civilisation. I never questioned that. All I'm interested in is how post-scarcity will affect crimes rates in comparison with today. [Answer] This cannot be answered. But rather than just voting to close as opinion based, it might have value to stop and think about the reasons this cannot be answered. As the reasons are kind of interesting and possibly of use to you and others with same issues. ## What is crime? This is not actually obvious. To give an easy, if possibly politically risky, example homosexuality has been and is criminalized in some jurisdictions. Same with adultery, sacrilege, cross-dressing, drinking alcohol, some forms of dancing, theatrical performances and so on. Almost anything can be illegal and criminal. What matters is that the state or possibly other entity with jurisdiction wants people to not do it and is willing to use legal sanctions to make it so. Homosexuality, for example, is seen as a threat to the moral character of the nation and the proper development of children. Possibly offensive to God even. Any of these threats is sufficient to justify legal sanctions. I'll take a moment here to explain that I am not using homosexuality as an example because I think it is bad. I am using it because I don't and expect majority here to not either. Or at least to be familiar with many people not thinking of it as such. The point I am trying to make here that criminalization is a response to **perceived** threat of the act, not to some intrinsic property of the act. What is and is not a crime is entirely context dependent. Paedophilia or human sacrifice can be legal despite us thinking of both as **evil**. It is all in the context. And the difference is actually much deeper than you'd think. If paedophilia were legal that would imply the society in question does not perceive it to be threat. Likely because protecting children is not a priority to them but it could also be because their social structures support children well enough that paedophilia really is not a threat. Same with human sacrifice, you have an evil empire that sees human lives as an expendable resource or one that is deeply devout and sees sacrifice as an act reinforcing the bond between man and divine. There might be a waiting list of volunteers. So obviously what a society will see as a crime is highly variable. What is perceived as a threat to society is entirely dependent on the society, what it values and which threats it has under control. Another aspect is that changes in society are constantly creating new crimes and making old ones obsolete or very rare. Computer crimes were very rare in the middle ages. Some crimes of the middle ages would be very hard for modern people to commit. So you have to extrapolate what new crimes your projected technology allows and what would become too rare to be an issue. For example, hijacking VR simulations would probably be a thing and probably have forms we cannot even imagine. But for this question we can leave defining what crimes exist and which do not as an exercise for the reader and just think about the amount of crimes. That is basically a function of how threatened the society feels it is. How stable is the society? What is the relationship between the state and the people? How optimistic are the people about the future. Basically how much of a need does the state feel to control the people instead of just trusting them. Which follows directly from how committed people are to the state. How much do the people trust the government? ## Why do people commit crimes? If we ignore accidental and incidental crimes there is a choice between doing the legal thing and committing a crime. There must be an expected gain, either being legal is not working or the crime does pay. This is balanced against the expected risks, that is the chances of getting caught and the possible consequences. Note that this is true even for "irrational crimes", what is "irrational" in those cases are the expectations, the process is the same. At first glance it would seem that post-scarcity the expected gains would collapse and crime would vanish. But this is a fallacy. Indeed many crimes we are familiar with would be pointless. But pointless crimes are not perceived as a threat to society. They might be socially frowned upon but nobody bothers enforcing laws that prevent things nobody cares about. With old threats vanishing the society would re-prioritize, new threats would rise to the top of the list the state wants people to stop doing. It is not realistic to think that any state has solved all possible issues, so there would always be some things on that list for the state to ban. What those things are would be very hard to fathom. For example, polygamy is illegal for historical reasons that do not really make sense any more. Okay, the catholic church decided in the middle ages that a man can have only one legal wife and that this must be registered with the church. This actually made sense since it solved real issues with inheritance and made the church the arbiter of who inherits and who does not for gains in money and influence. But those issues no longer exist and the catholic church no longer has major role in jurisdiction. Yet the laws still exist and people can be really passionate about them because the past association with the church created a link to religion and social values. So perceived threats and not necessarily based on real threats other than it should probably exist. New threats would reasonably be related to VR in some way but that all depends on the setting. For example, personal disputes might be resolved with duels in VR. People might beat up each other virtually for minor insults or matters of honor. And possibly develop over sensitive honor just so they can beat up each other. Cheating on these duels of honor would probably be a crime. Cheating on them by interfering with the opponent in real life would be a crime. Cheating by attacking them physically (or by other means) without or before proper challenge would also be a crime. It might look like an assault to us but the actual crime would be cheating on a duel of honor by not doing it in the proper order. Similarly if it is democracy and has solved many of our issues, political participation might be high on their list of priorities. Not voting might be illegal. Not paying attention to political propaganda... I mean "news" might be a crime. Pushing opinions that are known to be baseless might be a crime. Most forms of corruption that are currently legalized as "lobbying" might be illegal. ## In summary Surprisingly being post-scarcity makes no difference and neither does being a democracy. What is perceived to be a threat and a crime just changes to match. What does matter is how threatened does the state feel by the actions of its citizens. Higher the perceived threat and distrust the more restrictive the laws will be and more likely people are to break them. There have been and still are laws that allow throwing entire sections of the population to jail simply because, whatever the excuse is, powers that be found them threatening. Homosexuality is again a good example. The problem is not really what they do, the problem is that people in power would prefer them not to exist or at least be invisible. Similarly, if majority of legislators is white and the social circumstances have major racial differences lots of black people will be in prison. It is not even outright racism (although there is a link), people simply find people similar to them non-threatening and people different from them threatening. As such things mostly done by people different from you will be more likely to be perceived as threats to society and be crimes with prison time attached. Conversely things mostly done by people similar to yourself are normal and obviously not a threat to anything. Which is why lobbying and many other issues common with politicians are legal. Another aspect is the perceived efficiency of law enforcement. If people trust the police to enforce the law effectively they will avoid committing crimes. If people distrust the police and see them as ineffective they will have no real motivation to respect the law. In fact, they won't. **The actual answer** Ignore the red herrings. Just think about what type of a relationship does the state have with the people and what type of relationship do the people have with law enforcement. You might need to break up the population into social groups, if there are differences. Then find a modern society with similar "profile" and use that as a base to guess the crime rate. [Answer] **Post-scarcity does not mean we become happy robots** *We occasionally get questions asking about how the darker side of humanity can exist when the external influences that supposedly drive that darker side no longer exist. Forgive me for being honest and blunt, but I consider the idea laughable. It's as if humanity does bad things because some idiot invented money or the color red. Evolution is intrinsically competitive — and that means humanity has millions of years of inbred competitiveness. It is our nature. Take away one reason to compete, and we'll find two more to take it's place. Most humans would find the utopia many authors dream about to be a living hell.* Many years ago while living in Albuquerque, New Mexico, I saw a billboard advertising a local car dealership. I've never forgotten the tag-line: "If all men are created equal, why are there passing lanes?" The billboard was one of my earliest introductions into the fascinating (and often downright evil) world of *marketing.* Marketing, in a nutshell, is the process of leveraging human behavior to convince them to meet your expectations. Most of the time we think of marketing in terms of *advertising,* meaning the really pretty girl on the beer commercial trying to convince guys that drinking beer will bring to pass pretty girls. This is because one of the simplest and most easily manipulated human behaviors is sexual desire. AKA, "sex sells." And that brings us to post-scarcity-crime #1: **1. Post-scarcity will have zero impact on sexually-motivated crime** So, if there's one aspect of human behavior that can get the criminal blood pumping despite having a nice place to stay and sufficient food to eat, what else is there? I, for one, absolutely hate being wrong. As an adult I intellectually understand that I am often wrong. I make mistakes all the time. But that happy little 7-year-old that never completely shuts up is *absofreakinglootly sure* I'm never wrong — and so I do everything from argue toe-to-toe with people to writing opinion pieces for my local paper to posting contrary answers on Worldbuilding.SE. Because, well, you know, *I'm never wrong!* Unfortunately, people will do all kinds of things to *not be wrong.* Whether it's avoidance of embarrassment or that sociopathic need to be in control, we'll gossip about friends, throw people under the proverbial bus, speed 5 mph over the posted limit, evade taxes, stuff ballot boxes, lie/cheat/steal and "stick it to the man," all to avoid being wrong. **2. Post-scarcity will have no impact on crimes involving self-image, libel, slander, etc.** Perhaps as a sub-plot to #2 is simple jealousy (envy, covetousness, keeping-up-with-the-Jones'...) They have new green carpet, I should too! One of the fundamental lies upon which fictional utopias are inevitably based is the idea that humanity *stops caring about what someone else has.* There's enough food to go around! Everybody has a nice park for their kids! Nobody has worn carpet! We all drive the same car! Wait... the same car? And therein lies the lie. Two couples bear a child each on the same day, and 13 years later it becomes obvious that the daughter of couple A is substantially more beautiful than the couple of child B. Jealousy. Envy. Covetousness. Celebrity. Dead teen cheerleaders. Trophy wives. An entire sweeping difference between the opportunities available to the naturally beautiful that are denied those who are naturally not. And if we do this simply based on physical beauty, we'll do it for cars and typewriters and window treatments and anything else that allows us to stand out as individuals. It doesn't matter if post-scarcity means we all have enough food. There will always be someone who thinks they ~~deserve~~ need more food than their neighbor. And believe me, if a policeman is allowed to have a gun, there will always be somebody who will think they should have one, too. **3. Post-scarcity will lessen crimes of jealousy, but not much** And then there's the issue of power. This is probably a corollary to #2 and #3, but people like taking advantage of other people. It's part of that evolutionary heritage. The most powerful animal gets the best mates, the most food, the largest territory... and it's whomping hard to believe humanity will every "outgrow" that behavior. And when it comes to issues of having the longest... I mean greatest amount of power, nothing says "I'm in charge!" like *white collar crime.* Now, "white collar crime" is usually defined as financially motivated and non-violent. In reality there's a bigger social behavior at play. Person/corporation A wants an advantage over person/corporation B, so they lobby Congress to pass a law favoring A, meaning that B can now commit a "crime" that won't let it compete with A. As far as I'm concerned, *both the influence to pass a biased law and the breaking of that law are both crimes.* In fact, a post-scarcity society would likely create an *increase* in this kind of crime as people discover that everyone has plenty to be taken. Remember, it's a lie to believe that post-scarcity means no one will have a reason to want more. Some people will always want more. And if food is so cheap that it's meaningless to take it, they'll take something else. My time, for example, happens to be in very limited supply — and always will be. **4. White collar crime (crimes with the goal of increasing personal power or influence) will likely increase in a post-scarcity world.** I could go on, but the fact is that where there's people, there are differences between them. Where there are differences, there are people who will desire, demean, or exploit those differences. Where there's desire, demeaning, and exploitation, there's crime. That's because "crime" is what happens when the rights of the individual come in conflict with the needs of society. It's what you get when "we need you to calm down" comes in conflict with "I don't want to calm down." And if you don't believe me, the only thing you need to start a fight is a frequent-traveler policy that lets them skip to the front of a long line at the airport on a hot day — or coming home and discovering your significant other in bed with someone you *thought* was insignificant. **5. Post-scarcity will not reduce the number of crimes of passion.** OK, no more going on. OK, one more. I'll leave you with one of the most base and basic human behaviors of all — one that causes a tremendous amount of crime. **6. Post-scarcity will never overcome the human desire for revenge.** *My underlying point is that a world without crime must be a world without conflict, without competition, and therefore without ambition or innovation. Those strong emotions and behaviors that lead to crime are sourced from smaller, controlled versions of the very same emotions and behavior that drive all aspects of advancement. The utopia of a crime-free society is actually dystopic in every way — it can only exist as a broken society.* **Oh, and the per-capita number you're looking for is entirely POB, so I didn't bother.** [Answer] **Lots** Murder rate would be virtually unchanged as would manslaughter. Neither are usually for money mind you money still exists so technically someone could for money too. Theft would still happen. For some people, enough is never enough. People with drug addiction or gambling or any addiction for that matter always need more money. Paedophilia for first offenders would be unaffected. The treatments will stop them reoffending but not their first offence. I think you'll find it will have a much less affect than you might hope. Legalizing drugs would help as well as proactive mental health treatments. People with rage and self control issues get mental editing as soon as they present, not after they bash someone. In [Crime Zero](https://www.goodreads.com/book/show/912921.Crime_Zero) by Michael Cordy, they try to eradicate violent crime through the use of genetic editing via a virus to reduce the effects of testosterone. You might need society to also be proactive and test for genetic markers and early childhood issues for tendencies such as rage and control issues and treat people before the problems arise. Personally I think you need the hidden dystopian surveillance state watching people's browsing histories coupled with regular mental heath tune ups to nip crime in the bud. [Answer] You may reduce the rate of serial offenses, if you have a totalitarian approach to the forced treatment of repeat offenders, but otherwise you're not going to make *that* big a dent in violent crime. Lets review: * murder for monetary gain, this is usually committed to feed/cover up a habit that cannot be satisfied by legitimate income or "above-board" activities. This will continue as long as people can be addicted to anything that isn't supplied, no questions asked and no price exacted, by the broader society. A number of things can be supplied on this basis but for some the reason for their addiction is the disapproval of their society as much as the habit itself. * murder for personal gain, by which I mean people who kill perceived rivals or oppressors, the forced egalitarianism of post-scarcity societies will help with this but as long as there is sexual rivalry and dissatisfied spouses these crimes will occur when someone reaches the limit of their endurance/patience/temper. * acute psychic dysfunction, i.e. spree killers, those who "just snap" and kill a bunch of people for no apparent reason without any but a modicum of planning or premeditation. There is usually little to no warning of such events and any treatment is going to be by way of closing the door behind the horse. * chronic psychologically driven "deviancy" (sexual sadism, pedophilia, necrophilia, any of the various psychopathies that lead to serial murder), here treatment and VR systems *might* help but they might not. A virtual kill, or sexual encounter, may help a psychopath stave off their cravings but as long as they know it's not "the real thing" it's psychological effects will probably be limited. As for brainwashing treatments; people, especially people who already feel in some way alienated from the society at large, are unlikely to *volunteer* for reconditioning even when they know and recognise their own illness. You'll still have to catch them to force them into treatment, and the smart sociopaths are probably going to slip through the treatment cycle and keep right on going having convinced everyone that they're cured. * petty violence will continue as long as intoxicants are widely available and people are people. Humans always seem to find reasons to disagree with each other and those disagreements invariably turn violent in some cases, even more often when chemically impaired judgement is added to the mix. When it comes to non-violent crime what you probably *do* remove is petty crime as a profession, thieves and con-men who steal for a living wage go out the window. You'll have a few elite professionals who work the equivalent of multi-million dollar long cons or steal priceless relics for private collectors with the means to pay for stolen artworks etc.... The low level street dealer and cat burglar lose their motivation in a world where being on welfare is not only very comfortable but also the norm for most of the population. Getting ahead in a post-scarcity society is often very hard, if not impossible, because there's not a lot of room for human enterprise. That makes society more egalitarian and removes some of the motive of social climbing, so a lot of small time corruption crimes stop as well. Non-violent theft to feed drug addictions will continue as long as the drugs in question aren't freely and legally available. Short version, violent crime probably doesn't change much but cash/status motivated non-violent crime rates probably go down, especially if street drugs are regulated and government run. [Answer] Very low. Most crime is due, directly or indirectly, to economic incentives and the associated status they convey. This ranges all the way from survival/sustinence/addiction (stealing because you're hungry, in need of providing medical care for yourself or someone you care about, in need of a high, etc.) to pure greed. You mention pedophilia, but even "non-economic" crimes like this (also rape, murder, ...) are about status and power relationships within an economic system; people don't generally rape because they want sex (which it's not), but because they want to feel power over someone else, because they've been raised in a system of scarcity and zero-sum or negative-sum games. Assuming post-scarcity means everyone's able to live in general comfort and have most of the things they need and things they want, and that crime risks a loss of that comfort, and that such risk applies uniformly to the entire population (as opposed to our system, where structures of power built on economic scarcity result in it applying heavily to some and minimally to others), most somewhat-rational beings will not commit crimes. You should expect the majority of remaining crime to be committed by people lacking rational capabilities. [Answer] > > ... While there can never be a guarantee that the higher needs; love/belonging, self-esteem and self-actualization can be satisfied ... > > > Stop right there. That's your answer. We are used to thinking of crime in terms of physical needs. But a huge driver of crime is emotional needs. Jealousy, loneliness, fear, insecurity, worry, disgust, self-righteousness, thwarted beliefs, ... those aren't economic and will not be met by post scarcity. The question poses a society that has VR and other means to help people "even with paedophilia". But that won't solve it either. What happens to people who want true love, not a simulated version, or whose source of upset is real world related (involves a workplace colleague or family member) rather than an unrealistic/prohibited desire for some act? VR won't fix that you feel slighted by your boss, insecure in your primary relationship, want to be more special or more high profile than you "really are". You can VR those and yay, I simulate being king for a day, then I return to my life and you know, I'm *sure* my daughter plans to marry someone from another religion, my boss is going to pass over me for a civic award, my wife doesn't really love me, I'm not really as good as people think and fear being caught out, that you don't damn well respect my every word as divine inspired damn truth, and my view that we should all be Pastafarians as the One True Faith will not gain world traction. Planning to treat me for it? Maybe I don't want that. Am I a criminal now? Do I have to fight against it or resist? That's an extreme, for example's sake, I agree. Now..... add to it, a million far less extreme variations on these themes. In short, removing scarcity and adding simulation will do little more than expose the underlying river that fuels so much crime - self image, personal views, fears, and beliefs. You can have as much or as little as you want. [Answer] **Lower by a degree of magnitude, but also because of accompanying processes** Is the motive behind committing a crime rational? * if YES, than huge share of crimes is no longer committed as it no longer offer worthy payoffs and instead can have really high detection rate. * if NO, then such person may end up at some compulsory treatment, for his own good. Post scarcity should be accompanied by a few more bonuses: * Ultra high level of surveillance. Not necessary "Big Brother", "Big data" and dirt cheap cameras put by property owners can be similarly effective. * Better social services (finally there is some money), tendency to consider many undesirable behaviours as medical and not criminal issue, better psychotropic drugs * In affluent world, even Scandinavian prison become really harsh and unbearable. If you don't agree then ask Breivik about his tantrum when he was refused a new playstation. * There is quite clear correlation between IQ and crime rate. Let's say that designer babies would be really smart and nice kids. (or your money back ;) ) * Some people may spend whole their life playing VR, assuming that would be legal, then their crime rate would be technically speaking 0. Right now we live in the most peaceful and safe from crime period in mankind history, and except usual noise in data it seems that the rates are falling even further. [source](https://stevenpinker.com/files/pinker/files/has_the_decline_of_violence_reversed_since_the_better_angels_of_our_nature_was_written_2017.pdf) However, there are a few caveats: * new activities may appear which would be technically speaking illegal, as it happened to torrenting copyrighted content. (does it count?) * people, regardless of hard data, may be convinced of being surrounded by crime because of high media coverage * the exact question is a bit tricky, as many of described processes would not happen overnight but would accompany it. So far roughly counting, according to prof. Pinker transfer from tribal societies to primitive early states, reduced homicide 10 times. The same happened again with transition to modern state with its all institutions like mass schooling, police and safety net. My guess? It looks like that what we have should cause another such breakthrough. [Answer] > > tl/dr Not only will crime largely be unaffected by a post-scarcity > economy, but the concept of a post-scarcity economy is a contradiction > of terms for the same reasons that crime will be unaffected. As a > result, when you really break it down, the very concept itself rests > on false assumptions. > > > I strongly agree with @Throne, but wanted to add a couple important points. The question "How will a post-scarcity economy impact crime rates?" rests on two important assumptions: 1. A post-scarcity economy is possible 2. Crime is driven by scarcity of resources I believe that neither of those statements are true. Now granted, I could just assume that a post-scarcity economy is possible and therefore attempt to answer your question. However, I believe that the very reasons why crime is not driven by a lack of resources are the same reasons why a post-scarcity economy is impossible, so I think it is actually very informative to not just answer "It won't matter", but also explain why the question is based on a false premise, because those two facts are tightly correlated. ## Lack of resources doesn't cause crime For a post-scarcity economy to meaningfully impact crime rates, it would require crime to largely be caused by lack of resources. Not only is there no reason to think this is the case, but in fact there are plenty of reasons to think otherwise. To pick the most violent act (aka murder), it seems that the most common reasons for murder have nothing to do with the sort of things that would be fixed in a "post scarcity" economy. Some relevant links: * [Personal conflicts biggest cause of murders in U.S.](https://www.reuters.com/article/us-deaths-usa/personal-conflicts-biggest-cause-of-murders-in-u-s-idUSTRE64C53R20100513) * [Homicide motives and case studies](https://www.criminaljusticeschoolinfo.com/homicide.html) An especially relevant link from the latter: > > The University of Texas at Austin's Dr. David Buss states that > fantasies to commit homicide are more common than we may think. Dr. > Buss' research has involved delving into over 400,000 FBI murder files > and interviewing nearly 400 murderers. In a homicidal fantasy study > with 5,000 individuals, he determined that 84% of women and 91% of men > have had at least one clear fantasy about committing murder. Dr. Buss > adds that luckily most people do not carry out homicidal acts that > they've fantasized about, although a major reason for this is fear of > getting caught. "Though we may like to think that murderers are either > pathological misfits or hardened criminals - the vast majority of > murders are committed by people who, until the day they kill, seem > perfectly normal," says Dr. Buss. > > > Which strongly suggests that murder is a "people" problem, not a "resources" problem. With murder effectively being *the* most violent crime, and given the many motives for murder that have nothing to do with scarcity of resources, there is no reason to think that our hypothetical new society won't suffer from the same crime problems we have. To pick a different crime, there is no reason to think that sexual assault will change either. No amount of availability of free food, electronics, entertainment, etc is going to address the reasons behind sexual assaults. Indeed, all the recent high-profile men who had their careers ended due to the surfacing of sexual assault allegations makes this perfectly clear. These were men at the top of the "social" ladder, men who lacked nothing at all. Yet even still they committed some of the most violent crimes possible (personally I put sexual assault right up there with murder). ## Society can never be post-scarcity Which leads to my other point. Even if it were possible to provide everyone with free food, shelter, etc, this would hardly classify as a "post-scarcity" economy because, from the point of view of people, there is always more to be had. The reality is that there is something built into humans that makes it easy for us to measure our success not in absolute terms but in [comparison to those around us](https://www.psychologytoday.com/us/articles/201711/the-comparison-trap). More generally, just because a persons basic needs are met certainly does not guarantee that they will have everything they want, that they will be happy, or that they will have nothing to fight about. As more and more basic needs are provided for, I expect that the "bar" for our goals and desires will simply raise higher. Therefore a truly "post-scarcity economy" where everyone has what they need requires aiming for a moving target. It's especially impossible to make happen because many human needs (love, friendship, companionship) cannot be built in any factory. You can **really** see the problem when you realize that these needs that can't be met in a factory are often the same needs which drive violent crime - aka the article above which attributes most murder to interpersonal conflicts. Can you make a world where basic needs are met? Probably. Would that reduce crime? Maybe a little. But can you make a world where everyone feels that they have everything they need? Absolutely not. Until that world exists crime is not going to change substantially, and in fact building that world probably still won't stop crime. [Answer] Lots per million. Why? People enjoy it. It may provide some other, non-monetary, advantage. There may be other sources, non-monetary, of strife in society. An example? In the USA smoking weed is illegal, yet almost half the country does it because they enjoy it. Pretty much the same thing happened during Alcohol prohibition. There are crime types that have nothing to do with monetary value as well. The bottom line is that since your system still has laws, there will still be crime. There's definitely more crime in impoverished areas, but that's not all of crime. Something else to consider, is that the boredom cause by post scarcity is another source of friction that could cause crime. Crime rates could not change at all. [Answer] I'm going to go out on a limb and offer a bit of a different answer... **As much or as little as you want.** Really, what it comes down to is rationalizing your choice and explaining it in a believable way. The other answers provide much good ground for this, but I'll add a little: ### Want lots of crime? First off, keep in mind that being able to erase criminal tendencies is sort of pointless unless you force it on people. The sorts of folks that *desire* to commit crimes probably aren't inclined to erase those urges. Take that natural tendency and stir in VR to create a dystopia. Today, someone inclined to crime can either resist the urge, or commit the crime and become a criminal. VR opens the door to "committing" crime in a legal context... but maybe that just increases the prospective criminal's desire for "the real thing". VR is a gateway drug. ### Want low crime? As scarcity reduced, people are able to devote more time to improving their social situation. As class barriers are reduced, many traditional tensions disappear. Competition still exists, but becomes increasingly channeled into improvement at both the personal and societal levels. This builds in a virtuous cycle where one's status is elevated by "helping others". The optimist in us wants to believe in the possibility, and e.g. Star Trek (especially TNG) built a world along these lines. [Answer] ## Crimes committed for a rational reason will disappear There are many crimes committed rationally. For example if one wants more property and is not afraid to break the law or harm others, they can steal it. If one wants a sexual encounter, they can rape. While these are still crimes and many of them are also unethical, they are committed only because there is no other way for the criminal to get what they want. However, plenty of crimes are committed irrationally, either in the heat of the moment, or as the result of a mental condition. While a would-be thief can get everything they want without depriving someone else of material objects, a person in a drunken rage in a bar may not be thinking logically enough to refrain from stabbing the person who angered them. [Answer] A post-scarcity economy is not really possible, because there will always be "resources" which are not available in limitless quantity. Most of these will be non-material. They will relate to specific people or to a desire for power over a class of people, or both. So unless human nature is completely changed, crimes of violence against a person or people will continue, whereas crimes against most property will disappear. The exception in the latter class will be unique items, such as a hand-created artwork. A duplicate, even if indistinguishable without microscopic analysis, won't satisfy. (We see this with gemstones. Synthetic rubies can be much bigger and more perfect and better coloured than natural ones, but are not nearly as sought after. It is the pattern of defects in a particular certified natural ruby that gives it value!) Iain M Banks' "Culture" gets around this by introducing the *minds*, which are AIs vastly more potent than human minds. It's basically impossible to commit a crime against a person: the local mind will know what you intend before you can carry it out, and will prevent the crime from being committed. Probably in most cases, by manipulating circumstances such that the opportunity never arises and the motive goes away. Failing which, using force fields or supersonic drones to incapacitate the criminal at the last moment. The motivation of minds is never spelled out, but many think that minds' relationship with humans (and other human-equivalent sentients) is very much like our relationship with pets. ]

[Question] [ The dragons aren't all that common but they live in the nearby mountains and after a harsh winter are more likely to come looking for easy prey to fatten back up on. What are the major design considerations likely taken into account by those people living on the edges of a dragon's sphere of influence? The dragons I'm thinking of here are along the lines of Smaug. Large fire-breathing flying dragons that don't really need to go out much unless the fancy takes them or they get peckish. [Answer] I'm going to go with underground shelters being a major part of defense, like bomb shelters. Buildings would be made of thick stone. It mainly sounds like they would be a problem in the spring. So I don't know if underground only living would be worth it, but people might move most of their belongings down into the shelters toward the end of winter, beginning of summer when the dragons go back up into the mountains to escape the heat. In the spring you don't have much in the way of crops to protect, but a dragon could probably eat a few cows or sheep. It would probably be considered acceptable losses, since letting a dragon take a cow is a small price to pay. Other strategies would be to graze cattle under tree cover when available, since that would offer some protection, though less grass, so would probably use hay. I really want to steal Paul Chernoch's cattle coating, but I wont. :) Another way to defend against dragons would be bait piles/pens. Why would a dragon attack a city where most people are dug in deep and other people are shooting great big pokey things, when a few miles out of town are some tasty, easy to get snacks. There would be some kind of tax where farmers would surrender their old and lame animals to entice the dragons to go somewhere away from their healthy herds. People working out in the fields planting would be in danger, so guard towers would be in place, and shelters would be strategically placed in order for workers to hide if need be. The best defense is a good offense, so if I can assume that the dragons hibernate during the cold winters, then during the winter months you'd have dragon hunters going into the mountains to thin the herd. They'd make their living selling dragon scale/meat/bones/eggs, and maybe harvest any chemicals to sell to alchemists. There are not a lot of animals that hunt humans, and that's mostly because we've killed them all. Killing dragons would be a very dangerous but high profile job, and dragon hunters would get a lot of respect. Also women. [Answer] I am working on a world with lots of dragons. There is a tree whose sap is gathered and applied to wood, causing the wood to rapidly petrify, making it stronger and fire proof. Also consider spikes on the roofs of buildings and water towers to pressurize water for use fighting fires. How about a poison that reacts with flame? It forms a cloud which blinds the dragon. If inhaled, it makes them retch. Since flying creatures need to breathe in lots of air, it would be susceptible to this form of attack. Then there is sound. Perhaps dragons have a natural enemy. Something like a bird call might make them go away. You could soak the fleece of the sheep in something foul-tasting so the dragon won't eat it. How about lady dragon pheromones? Lead the dragon away from town on a fruitless search for a new mate. [Answer] With a question like this there are two ways to go: how would things play out in a work of fiction, and how would they play out in real life? I think a lot of people have covered the "work of fiction" angle. If you were going to design a city from scratch and with none of the real-world financial or political constraints that cities face as they grow and evolve, you'd probably have a big network of underground shelters for people to hide in when the dragons came around. But let's look at a similar real-life situation featuring unpredictable death from above: a city prone to catastrophic tornado damage. (I write this with my other browser tab open to a weather radar, because I'm currently under threat from a severe storm system right now). --- Moore, Oklahoma extends a couple of miles on either side of Interstate 35 as it passes south out of Oklahoma City on its way to Dallas. It occupies about twenty square miles, which is fairly small by the standards of this part of the country, but with a population of around 50k it's one of the ten largest cities in the state. And, unlike the larger cities of Norman and Oklahoma directly to its north and south, it's also had completely devastating tornado damage several times in the past few years. In fact, some of these tornadoes were destructive enough to merit their [own](http://en.wikipedia.org/wiki/1999_Bridge_Creek%E2%80%93Moore_tornado) Wikipedia [pages](http://en.wikipedia.org/wiki/2013_Moore_tornado). (I had a third link to post here, but I haven't got the reputation to post it yet.) Now, what I want to highlight here is basically a direct analog of what's been suggested in many of the other answers. Among the casualties of the 2013 Moore tornado were several students at the Plaza Towers elementary school, one of two Moore elementary schools destroyed by the tornado. In the days after the tornado, a proposed law requiring new schools in the state to be built with tornado shelters unsurprisingly gained a great deal of traction with the public. Now take a minute to think through what this says. It's not proposing public tornado shelters for everyone, or retrofitting existing structures, but merely that any *new* construction of schools will come equipped with some sort of tornado shelter. In interviews with the media, the measure was immediately dismissed by the Governor as too expensive, and nothing came of it. What did happen? Well, the city of Moore updated its building code, essentially requiring that new construction be built to withstand EF-2 tornadoes. Now, remember, the tornadoes that have repeatedly destroyed Moore are in the EF-4 and EF-5 range, not the EF-2 range. Since that probably doesn't mean anything to most people, here are the sample images from Wikipedia of EF-2 and EF-4 destruction: **EF-2 damage**:  **EF-4 damage**:  (That used to be a house, if it's not immediately obvious.) --- Okay, so how do we compare this to what we know about the (I'm assuming) medieval societies that we're imagining facing a dragon attack? We know that many medieval cities were built around castles that served as a central fortress for the community. The laborers who worked in the city surrounding the castle would, in the event of an invasion, come inside of the castle. Now I'm going to assume that the castle predates the dragon here, because nobody in his right mind would spend the time, money, resources, and man-hours it takes to put up a castle in an area where there were constant dragon attacks. To quote an article on HowStuffWorks by Craig Freudenrich (which I can't link to with a new account), > > Castle building employed about 3,000 workers (like carpenters, masons, > diggers, quarrymen and blacksmiths) under the direction of a master > builder. ... Castles generally took two to 10 years to build. > > > Nobody would bother undertaking such a project if those three thousand workers kept getting eaten alive and/or set on fire. People would just live somewhere else. So I'm envisioning a castle built to keep out invading armies, not dragons. Now, there's a problem with this. Castles, pretty much from the beginning to the end of their existence, have relied on the fact that having the *higher ground* is what you want in battle. Early "motte-and-bailey" castles were basically just walled buildings (often just made wood or even dirt!) put on top of a hill that would suck for an invading army to run up. And even later on, when castles started to get way more sophisticated, it was always the case that the most heavily-fortified part of the castle was also the highest off the ground. **11th-century motte-and-bailey castle**  **14th-century castle**  On top of that, any castle seriously intended as a fortress would feature machicolations, which are great if you want to drop rocks on the invaders scaling the side of your tower but which are probably less useful when you're facing an indiscriminate airborn flamethrower. So the parts of the castles which have been designed to be the most secure are in reality probably the least so. Moreover, these fortifications would have been constructed with the express purpose of *preventing* large underground structures from being built underneath them. This is due to the ancient combat tactic known as "mining," where an invading army would dig small tunnels under a building and use them to place explosives underneath the walls, hopefully breaching them. In fact, the moats that surrounding some castles were more to prevent mining than to keep out invaders on foot. The one thing a castle *would* have underground would be its cellars, which were designed specifically to be a bit fire-resistant. (These were still a serious weakness a couple of reasons. Remember how Guy Fawkes was going to blow up the House of Lords by setting off an explosion in its cellar? And then there's the fact that, without modern construction techniques, every extra floor you add is just another thing trying to make the castle sink into the ground.) These underground storage rooms are where, in the event of a dragon attack, you'd have the best shot at surviving.  Remember, though, that these rooms aren't empty, like in the picture above; they contain all the provisions you're holding onto in case of a siege. And remember that, due to the difficult engineering problem of constructing a cellar which the castle doesn't collapse on top of, you're not going to be building these with a lot of extra room. And here's the payoff for the bit about tornadoes above. Cities faced with tornadoes don't build extra infrastructure to protect their citizens. They use whatever they had already (so, church basements and YMCAs and so forth), the people at the top are taken care of one way or another, and the interchangeable people at the bottom of society are left to fend for themselves. (Oh, and if you think the nobles are going to give them time off work to dig themselves tunnels, you don't have a clear picture of what the serf/vassal system looked like.) And tunnels aren't that great anyway. You know how to deal with an enemy who digs tunnels? Here's what Wikipedia has to say: > > The oldest known sources about employing tunnels and trenches for guerrilla-like warfare are Roman. After the uprising in Germania the insurgent tribes soon started to change defence from only local strongholds into utilising the advantage of wider terrain. Hidden trenches to assemble for surprise attacks were dug, connected via tunnels for secure fallback. In action often barriers were used to prevent the enemy from pursuing.... > > > The use of tunnels as a means of guerrilla-like warfare against the Roman Empire was also a common practice of the Jewish rebels in Judea during the Bar Kokhba revolt (132–136 AD). With time the Romans understood that efforts should be made to expose these tunnels. Once an entrance was discovered fire was lit, either smoking out the rebels or suffocating them to death. > > > Which makes tunnels without fortified entraces an unattractive defense against fire-breathing dragons. So, how would cities under threat from dragons be designed? Well, unfortunately, they likely wouldn't be designed at all. [Answer] I have sort of a radical idea based on the family of stink bugs infesting my apartment: why not design **a city the dragon doesn't want to eat**? First, you're going to want a lot of farmland devoted to a **poisonous plant**. Your humans are going to want to tend to this plant, breeding it so it grows thicker, quicker, and deadlier. Next, when the harvest comes around, you're going to want to use as much of this plant as possible in as many things as possible. Thatch your roofs with it, mash it up and put it in your bricks, weave it into your clothes, and line your streets with the living plants as decorations. There may be a spike in infant mortality, but parents should be keeping a keen eye on their children in a world where dragons exist. Anyway, when a dragon comes knocking, they may eat half the town, and they may even live to tell the tale, but they're going to get one heck of a bellyache, and that'll deter them from coming 'round again. But maybe you want to keep the dragon out the first time. To do this, I return to the stinkbug idea: simply make some **unpleasant smells**. Medieval cities already smelled bad enough (if I were a dragon, I'd steer clear), but if you had a few dozen people collecting the garbage, you could put it to even stronger uses. What I'm thinking is a few towers along the outer wall of the city, atop which you would store a few barrels of raw sewage. When a dragon is sighted, open the barrels and light them on fire. Most of the smell should waft upwards, out of the city but straight into the nostrils of the dragon. Even if it can get itself close enough to take a bite out of your populace, it's probably going to lose its appetite. Again, this might bump up the total deaths in your city (raw sewage is not good for overall health), but hey, now you'll have a steady supply of corpses to light on fire too. [Answer] I would go with bunkers and scapegoats... As already mentioned bunkers could offer some protection from a direct attack, but scapegoats would probably be a better over all strategy. As spring approached each year the local ranchers and herdsmen would be tapped for a few sacrificial animals, not unlike many ancient cultures, only in this context rather than trying to appease an angry deity, its dragon feeding season. So as the snow melts livestock would be staked out around the foothills of the dragons' layer. Think of it as a wall of meat, that keeps the dragons full and spares the village. If your dragons are intelligent, they will probably get used to the arrangement and recognize that a healthy village produces a reliable yearly food source. If your dragons are savage beasts they will still probably be happy with easy prey that they don't have to travel as far for. [Answer] One important question is how difficult the dragons are to kill. I assume that hunting them in their natural mountain environment is too difficult, or people would have hunted them to extinction and it they wouldn't be an issue. So then it just comes down to if they can be effectively defended against, or if you can just try to minimize damage. First, there are some principles that apply in both cases: 1. All cities would be built around rivers. Most cities are on rivers anyway, but an uninterruptable source of water would be absolutely critical for firefighting. 2. Wide avenues every few blocks with no trees, signs, etc. hanging over them to act as firebreaks. This will limit the spread of any fires started. 3. With dragon fire coming from overhead, thatch roofs would be banned within the city. Exterior walls would likely be of stone, stucco, or similar instead of wood. Building codes would be strictly enforced, with shanty towns forced to be some distance away from the city proper. 4. Fire-fighting technology would likely be more advanced than the corresponding real life period. Look at the real [history of firefighting](http://en.wikipedia.org/wiki/History_of_firefighting) for an idea of what medieval/renaissance firefighting was like. 5. On farms, livestock barns would likely be as fireproof as possible (considering cost), including being sunk partially underground and having water storage inside. 6. There would be a great emphasis on developing ranged weapon technology and fire-resistant materials. This would have an impact on all sorts of things. Notably, non-dragon caused fires would be easily handled (in contrast to real medieval cities where those were uncommon, but very destructive when they did happen). If the dragons can be killed or driven off by humans you would see very distinctive defensive works. Specifically, I envision tall stone towers spaced evenly throughout the city with archers and ballista on top. There would be clear space around teach tower to prevent fire spreading to/from them. Smaller settlements would have a defensive tower at their center. There may be dedicated bands of horse-archers assigned to respond to dragon attacks outside settlements. If dragons cannot be defended against, defensive towers would be a waste of money. Instead, underground shelters would be common. If dragons prefer larger prey than humans, horses and other large animals may be banned from the city to reduce the likelihood of attacks. On farms, farmers might try and only protect some of their livestock, in hopes that the dragon would take the unprotected ones without destroying the farm itself. [Answer] Many answers have described how to build a city to survive a dragon, this is how to build a city to kill a dragon. Using Medieval technology and no magic. Dragon abblities in order of importance High mobility (flight) well armored body close range area of effect weapon (breaths fire) powerful close range attacks ( its a dragon) 1- **pull its wings**, the body is well armored but the wings aren't. Numerous archers with barbed arrows can easily hit the massive wings ripping holes, if ropes are attached to the arrows the barbs and be ripped up causing larger holes. In just a few passes the dragon can be rendered flightless, hopefully within the city or nearby. 2- **pound it**. The town should have a ring of high towers along the perimeter that have protected inside powerful ballista. Once the dragon is grounded pull out the ballista and hit it. The ballista out range dragon fire and can break through its hide. The towers are high enough to fire over buildings at the dragon. Once grounded the dragon is slow enough that it can be targeted, and finished off with little melee fighting. 3- **Reuse it.** A dragon's hide and wings are fire proof so use the to protect your city and warriors, and nothing says don't mess with me like a pile of dragon skulls. [Answer] # Scenario: The dragon flies into town looking to make a few manwiches. Unfortunately the men don't like eaten and have a plan. It silently lands. That is when a harpoon flies out of a tower on the wall. It soon finds itself pinned to the ground by a heavy metal link netting. The harpoons might kill the dragon and if by some chance it survives it is caught in the netting. The dragon will try to burn its way out of the netting. Then, when it realizes too late that the netting is made out of metal. It twisted and trapped in it and some of the metal melts into its scales because of its panic. It gets free before the guards reach it. Unfortunately for it, the town has dozens of towers equipped with these towers scattered evenly throughout the town. To make matters worse it damaged its own wings in its thrawling panic when it accidentally melted the metal into its skin. Whenever it passes the towers in town they shoot at it. To make matters worse the entire town has been arisen to hunt it. Archers are hunting it. It is eventually killed while trying to get out of a rear gate. # Explanation: I can imagine larger towers being spaced around the town walls with harpoons with thin metallic brass coating around attached netting. There would be dozens around the town every dozen yards on the walls and many smaller towers wielding harpoons as well scattered in the town. They would have more lookouts that time of the year (dragon season?) and a minimum of half of them on duty at all times. Especially at night. If there was a dragon attack they would have to rouse everybody, so large bells would have to be on the lookout towers. There would also likely be a fortress of several feet thick stone in the town hall in the event of many dragons. **Excuse my horrendous story telling. I didn't have much time when I wrote this.** [Answer] With dragons such as Smaug whom one cannot expect to defeat, mitigation is generally called for. Overtly preparing to try to defeat the dragon, may tend to provoke it, and if your odds aren't good, that may not be a good idea. The goal being coexistence despite a persistent giant powerful dragon threat, and not to defeat or eradicate the dragons. The traditional answer, is to organize a regular tribute and/or sacrifice to the dragon of some sort (not necessarily human virgins...), so that the dragon doesn't attack your city. Typically, this even leads to policies that actively aim to detect and discourage or prevent anyone from trying to attack or steal from the dragons. In addition to that, having fire-resistant buildings, and perhaps burnable ones that you don't mind losing, further out. And then hidden bunkers and vaults that a dragon might have difficulty knowing about, finding, and getting into. And of course, disaster contingency plans. [Answer] My own advice would be based on a few things: A.) These dragons are barley even sentient. (No traps or continually heating an area) B.) They are not even close to as invincible as Smaug. C.) No direct-type magic (Basically flight and fire-breath, nothing else) So, first things first, if your town is rather poor, start with "dragon cellars", bury them beneath the town square or other areas that have a stone covering. Big room with walls and such, long tunnel, and metal entrance door. This will protect the villagers and some of their stuff. If your town can't afford the next step, booby trap the tunnel. Next, you want some manner of weapon against the dragon. I personally recommend building a square tower that's stone all the way up until you get to the top where a metal roof, sliding metal shutters, and a rail-system gives a giant crossbow or archers (depending on the armor of the dragon) a full 360 aiming section, while also allowing for coverage from fire. Third, your farms and ranches need protection. If you build a small, stone, house-like structure with a roof that can open and put some manner of pokey-thrower in there, mission accomplished. Lastly, stone EVERYTHING, if it is an exterior, it should be made of stone. Oh, and of course Slayers, really, dragon anything is valuable, so thinning out any manner of pack profits the town by a revenue flow and less attacks. [Answer] > > come looking for easy prey > > > Why would a Dragon go to a city for easy prey? They need a better reason to do that, like Smaug-Gold, revenge, baby dragons protection etc. Anyway, in my conception they will target farms and isolated people in the camps and borders. The most cheap and obvious protection for these people will be caves to hide and storage foods like that one:  And security by obscurity like don't use many torches, don't make too much noise and things that smell good like beef. Maybe even camouflage, even if in the medieval era they didn't know what is this! They can make some way to notify the surrounding farms and cities know if a dragon is in the region with a system like used in LoTR, the fire signals  [Answer] You might go with "Anti Dragon" architecture, as provided by the lazy firefighters guild. They don't want to have to put the fires out, so they would encourage you to build in ways that isn't going to let fire spread. This would consist of extensive use of Stone for walls and ceramic for roofing. That's mostly for the wealthy. The poor have options as well though. Lets start with the Roof. Ceramic tile is going to reflect quite a lot of heat, but it could eventually get hot enough to set fire to structural members underneath. You can avoid this with Catalan Vaulting. <https://en.wikipedia.org/wiki/Catalan_vault> This vaulting technique produces exceptionally strong structures. It's also made of clay, which means it might be within the reach of the cities middle class. The wealthy would be able to build with stone for walls. The rest could build with Adobe. While not as flame resistant as stone, Adobe should be able to resist the worst of a flame attack. Finally, everyone builds a small dragon shelter. Like others have pointed out, small underground shelters that the dragon can't get into would be best. That's your passive defense. Active defenses are all kind of standard fantasy fare. They are going to be dependent on the characteristics of Dragon hide in your world, as well as the beast's tactics. High power, roof mounted crossbows. Trebuchet might help. You could also use something like a catapult mounted South American Bolo. The Korean Hwacha might make an appearance. Lets face it, you imagination gets to take over at this point. [Answer] Another option: Build some very powerful ballistae--they don't have to be capable of a one-shot kill but they do need to have the power to inflict substantial injury on the dragon. These are build inside what appear to be ordinary thatched-roof buildings. You also have underground bunkers adequate for the population. When a dragon comes around everyone goes into the bunkers except for those needed to actually aim and fire a ballista. The crews only fire if they get a good shot and as soon as their bolt is away they dash for the bunkers--no attempt is made to reload. Dragons will soon learn to stay well away from any thatched-roof building that's big enough to hide a ballista. A building is only in danger within the range of the dragon's fire--and that's normally far less than ballista range. Sure, in general I would expect a dragon to be able to destroy the building without taking a bolt in the process but the defenders don't have to win every time. They don't even need to win a majority of the time. Only desperate predators go after prey with any substantial ability to harm the predator. It's not like a RPG where the PCs are perfectly willing to lose half their hps to take down the monster. (And note that when we see such engagements in the wild the predators always use pack tactics, only attacking when there's basically no risk of retaliation.) [Answer] Look up anti aircraft defenses of WW2, e.g. [Flak Towers](http://en.wikipedia.org/wiki/Flak_tower).  These were huge concrete towers with antiaircraft guns on top. The inside was used as an air raid shelter for the civilian population. The walls are so thick that it was impossible to demolish them, many are still standing today. I don't know what technical capabilities your society has, but in principle this type of tower could have been constructed in medieval times. If you search for pictures online, you'll find many very interesting construction details to protect the gun crews. All of this would work equally well to protect against flying dragons. As far as armament goes, I have no idea what to kill a dragon with. If antiaircraft guns don't work, maybe some kind of spear gun with a rope to pull the dragon in? The captured dragons can be sold to utility companies which use them in their power stations to generate steam and heat the city. Big income stream for the city. [Answer] I am going to go with a modern age twist and I would say to build a standard city (maybe with a few extra dozen fire stations) and surround it with tanks. I don't think many tanks would be needed to cover the city, more would be located between the mountain and city. Maybe a couple dozen in total. A direct hit from a tank shell would be enough to severely injure or kill the creature. [Answer] I would imagine caves and underground tunnel networks would be the primary living area to protect against dragon attacks. Thatched roofs on traditional cottages and town houses would be instant eradication of the society. Natural caves expanded into vast tunnel networks seem like they would provide sufficient protection, assuming the doors were small enough to keep the dragons out. Lifestyle would likely be more hunter/gatherer than agricultural. If you have a significant chance of having your supply of food wiped out on the whim of a fire breathing dragon it seems there wouldn't be much point in focusing on farming. Hunting and foraging could work, if the society is in a cave network perhaps mining would become an industry allowing trade with villages that don't have issues with dragons. I guess my theory would the society would in essence live like dwarves to thrive while under the threat of dragons. It’s just Orcs to worry about at that point. [Answer] If the society has advanced enough technology of magic, they can build underground cities like the dwarves did. Grown their food underground under artificial light or chemically/magically synthasize it. Build dragon-proof underground city. Have all gates too narrow for dragons to get through if possible. If there are gateways wide enough for dragons to squeeze through have very strong and massive hundred ton gates of stone and metal which slide down like guillotines and can slice or crush a dragon. And have dead man's switches controlling them. A person has to hold the switch closed all the time. If he let's go for an instant the gate will be unlocked and gravity will make it slide down into position. Put the dead man's switch in front of the gate so the switch holder will be killed by dragon or run away, letting go of the switch, before the dragon reaches the gate. I wonder if Erebor had such gates but they were always accidentally being released and were very troublesome to pull back up. So King Thror had he switches modified so that they had to be deliberately pulled to lower the gates. And then Smaug arrived and the switch holders fled or were killed without throwing the switches and the gates remained open and Smaug entered and wiped out the city. [Answer] In the First World War one method of defence against aircraft was the use of barrage balloons. String lots of them above your town and link them by fireproof cables, so it can't get through without tangling its wings. You could build your town next to a mountain and use it for anchoring some of the cables. You don't have to kill the dragon, just make it hard to get at you so it will fly off to bother your neighbours. [Answer] Copy pasting [my answer to a similar question](https://worldbuilding.stackexchange.com/questions/23674/defensive-strategies-against-teleporting-dragons/47122#47122): A flying, fire-breathing mass of muscle out is to get you. What are the limits? How far can they fly? What is the range of their fire? Is it a continuous stream, a fireball, or can it use both? What loads can it carry? How much does it need to eat? WHAT does it eat? First, fireproof everything. Flammable liquids should be stored in stone or earthenware jar (not wood or metal!) and preferably buried until needed. Make your ballistae with longer range than their breath. Leave no dragon food within a single flight range of your town-change your eating habits if you must. Make narrow holes for your ballistae, put them in reinforced stone rooms and protect them with spikes on the outer wall. Use light bolts to damage their wings at long range, instead of heavy bolts to target their bodies. Minimise use of wood to prevent fire spreading. Find what dragons hate or are allergic to and have plenty of it close at hand. There are plenty of ways to deal with the problem but first we need to clarify exactly what the problem is. A single attack run of dragons can be beaten back with significant loss on both sides, but will the dragons persist? Will they learn to avoid you next time? [Answer] Dwarf style built-into mountaines fortresses with expendable countryside around it. When the dragon attacks the townsfolk gather in the fortress to wait out. All of the tricks mentioned earlier may be employed. Expanding on the dwarf style cities and the Smaug like tendency of dragons to attack said dwarves: the only big enough enterances for a dragon to come through may be long tunnels filled with all sorts of traps, extraction venting systems(when a dragon breathes fire its' sucked out into the venting system dealing little to no damage), sealable intersections and repeating balistas/cannons on the far end akin to the WWII bunkers - you don't have to aim much if the target is already trapped in a confined space. [Answer] **Frame Challenge: No Cities Whatsoever!** In nature, there are many ways to avoid being killed and/or eaten. Most of these answers focus on offense (being a big enough threat that predators won't want to attack you) or outright avoidance (building underground, moving to shelters when dragons attacks). However, no one has yet considered one of the most effective anti-predator tactics of all: **camouflage.** Leaf and stick insects, thorn bugs, certain mantids, and even *vipers* use camouflage to evade detection, either to avoid predators, to avoid prey's notice for surprise attacks, or both. Humans could do the same, but this would involve: 1. Heavy Investment In Camouflage-Camouflage paint and plants will become part of everyone's daily wardrobe. They should be able to blend into the environment wherever they are (I'm thinking mostly plains, perhaps some forests?). 2. No cities/large buildings-Obviously, most buildings (and construction to make said buildings) will not be conducive to stealth, with cities being even less suited for stealth. These people will likely take advantage of natural structures (hollow trees, caves, and so on) and make homes that will blend into the environment. This will also require them to scatter their population, building and living farther apart, for best results. 3. Low key Lifestyle-Construction, blacksmithing, and feudal society in general (AKA high agriculture) will attract attention. Either your society will have to be careful about its forging and agricultural methods, or it'll have to disavow agriculture and metalworking. 4. Natural Selection-If the dragons really like how people taste, the ones that aren't as invested in camouflaging, are worse than hiding, or are slower than the others, will be eaten. These people will thus naturally become (and select for) smaller, faster, more flexible/agile people so they can better hide and escape from dragons. 5. Societal Changes-These people will have developed into hiders/runners, not fighters-they will have fight or flight instincts, but will be heavily predisposed toward flight (because those who tried flight usually died or weren't selected as mates due to being seen as *insane*, and flight *worked*). It's not that they *can't* fight against the dragons, it's that they *won't* fight against the dragons. This society would have evolved from apes upward; which means we have a subspecies of *Homo sapiens*, AKA *Furtivos sapiens*. As an additional option, what about *symbiosis*? Perhaps the early hominids formed a symbiotic relationship with early draconians, perhaps they tamed dragons or pulled a 'Hiccup' (shameless HTYD reference), or perhaps they decided dragons were divine and moved into their caves, sheltering them, bringing them shiny things, and occasionally letting a dragon eat them. The latter is the 'Cult' option, the horrifying possibility that exists simply because humanity is capable of surprising insanity. Either way, there's no need to hide from or defend yourself against the dragons when you live among them, right? [Answer] This is just a short and possibly irrelevent answer, though I wanted to share it. I know the idea is to have it be in medievel times. But let's assume it's not. Then other than the obvious fire fighting infrastructure and more stone based buildings I'd just imagine one of [these](http://upload.wikimedia.org/wikipedia/commons/thumb/1/19/Close-In_Weapon_System.jpg/200px-Close-In_Weapon_System.jpg) on every roof top. ]

[Question] [ It's 2020 and I've decided the perfect location for my next villainous lair is on the Moon (Earth has too many pesky heroes after all). Fortunately, construction and transit shouldn't be too difficult, I have teleportation technology, however it's not instantaneous but rather lightspeed. This brings up an interesting problem, namely internet: my minions and I need high bandwidth (for netflix and evil plotting) but since there's no way to get around lightspeed, the base is already looking at ~2 second ping times. This raises the question: **How much of the internet becomes inaccessible with Lunar ping times?** I'm assuming that highly interactive websites and web services would have problems... [Answer] I'll claim expertise on this issue since I live in the Arctic in a remote community where all telecommunication is via satellite and, based on the quick test I just ran, I have about a 750 millisecond ping. And that's vastly improved over what I had to deal with just a few years ago. It's entirely not an issue so long as, as some people have mentioned, people don't try to do things that require low latency like online gaming. Otherwise, it's not not really noticeable. You and the minions are going to notice things like videocalls are going to have a multisecond lag, but that's merely a case of getting used to it. Once you start a download/upload, it's going to progress based purely on the bandwidth available, not the latency. Also of note for things like Netflix, there are mines up my way where bandwidth is limited due to costs, but the mine still offers services like Netflix. What they do is a single mass download of programming every so often to an on-site servers and the workers who have Netflix accounts, instead of connecting to the Internet, are directed to the selection on the local server. This model is used quite often in remote locations, so you and the minions might not even have any delay at all. [Answer] Without modifications you would have a multiple of these 2 seconds, since you need to make a DNS request and a three-way handshake to make TCP connections. But even with 10 seconds the delay isn't that big. User experience would suck, and competitive online game would be out of the question, but from a technical point of view latency should not be a big problem and anyone who has lived through the 90ies might remember :) Throughput might become a problem though. There already is places that rely on satellites for internet (e.g. Micronesian islands) and loading a normal website can take minutes, however even with a pageload time of 2 minutes, a lot of websites are still usable, unless you are using one of these pages that kick you out after 10 minutes, if you haven't finished your booking, but those suck on earth too. To improve the situation you can have local caches, CDNs, nameserver and tunnels that keep the TCP connections alive to avoid unnecessary roundtrip times and avoid Software as a service: * use usenet instead of stackexchange * download your emails and read them through a mail-client instead of using webmail * download mp3s instead of using spotify [Answer] # Web browsing will be slow but work out of the box Most modern web content authoring implicitly assumes latency is much lower. So a lot of code is written that does some computation locally, then based on the result, contacts a server and requests additional info. Google shows different results depending on who you're logged in as. Many site designs now use endless-scrolling, where instead of a "click here for the next page" link, when you get down to the bottom of the page, it "seamlessly" loads the next page of (articles / search results / whatever). Or at least, it's supposed to be seamless. But if you've ever been trying to use one of these sites when there's network trouble, you've noticed it doesn't work very well. If the lunar population gets big enough, major browsers eventually create & implement standards to configure browsers to operate in "interplanetary latency" mode, which will be a different flow redesigned to request things in as few round trips as possible, or to instead of requesting new data when it's needed, predictively try to load it *before* it's needed, to make it appear more seamless. Caching layers will also be a big help, but won't necessarily be a panacea # Voice chat probably becomes push-to-talk If two people start talking over each other, it will take several seconds before it's even possible for the participants to realize. That will quickly become maddening. So redesign the way chat works so that's just not allowed to happen in the first place. Current voice chat systems allow anyone connected to talk whenever they want. Nobody said it *has* to work that way. Only one person will be talking at a time. When they're done talking, they release the 'talk' button. They won't hear a reply until 2x the light lag after they stop talking, obviously. When the recipient gets the message, their computer will automatically know "message over, you can talk now". Eventually other features would get added. Such as a "want to talk" button, in case someone won't cede the floor and keeps going on about [catching the ferry to Shelbyville](https://www.imdb.com/title/tt0701151/characters/nm0144657), or a way to forcibly interrupt anyway. Or the system will know how long the lag is, and if it detects silence for that many seconds, it will assume they're done talking. # Video chat Once you have the voice chat functionality, video chat is pretty easy. Just sync the video to the voice and when someone's not talking, fade them to a blank screen. # TL;DR It will kind of sorta work out of the box, but after work is done to make it more natural, sending traffic across a lunar link is only slightly less convenient than sending it terrestrially (except for obviously impossible things like gaming or telesurgery). [Answer] Since you have the funds to build a moonbase, you should be able to cache a vast majority of the Internet for comparatively little cost. Google says the Internet is about 1.2 million Terrabytes, but you can get a 2TB hard drive for about 70 USD. So you could store a local copy of the *entire Internet* for about 84 million USD. Considering NASA was throwing billions of USD around to get to the moon, your cost saving from teleportation should make that pocket change. Thus, you can have a bunch if Google-spider style crawlers making copies of the Internet and transferring it over to your moon base, and it would be simple to have them prioritise your favourite websites being up to date. The only challenge then would be interactivity. But with your copy of the entire Internet, you will be able to send your Earth-side servers your requests and have a reasonable expectation of the response you will receive whilst it handles the ms delay handshaking that your two second lag can't afford. Of course, if 84 million stretches your budget, I'm sure you can cut out the stuff you don't care about so much and just have a little delay as your Earth-side servers send you copies of information. Like others have mentioned, you won't be able to play any online games that require quick reflexes, but having played online games, I can appreciate why you want to get away from them. [Answer] # Invite Big Tech Instead of solving the problem by yourself, which is basically impossible for many jibbly bits of the internet that you and your minions care about, do what Big Tech does, and push the hard work onto someone else. Tell them you are building an open community on the moon, and naturally, your moonie citizens will want internet access. Wave around some big [villainously stolen] bucks like the moon is the hottest new market for them to expand into, and watch them trip over themselves building satellite relays and datacenters to extend their services to the moon. You see, although some folks have suggested that you just crawl and cache the web yourself, this will only work for mostly-static content, like blogs, news, videos, and Wikipedia. Booooorrrr-ring!!! Way to lose a whole cohort of minions who are *not impressed* by the intertubes perks of your little criminal enterprise. I mean, Google takes 4 days to 6 months to crawl the internet (obviously, it looks in some corners more frequently than others). Do you really want to wait 4 days for a tweet to show up? Way to totally miss the party! No, you want your portion of the internet to work like everyone else's. Don't do the caching yourself...make Big Tech do it. Once they are convinced that there is a serviceable market on the moon, comprised of big spenders, then they will invest the infrastructure to extend their services to the moon, with adequately low latency. There will be caches involved, for sure, but they will be owned and operated by Big Tech, and those eggheads will be responsible for refreshing them efficiently and often. As far as Big Tech is concerned, the moon is just another AWS region with really bad latency. Of course, this means that real-time interactive services will work best with other moonies, and will work awkwardly with earthlings (video conferencing, action games, etc.). Also, I'm assuming you build your evil lair on the dark side of the moon, and contrive some reason for the new innocent moonies to avoid that. After all, you need them to "pay for" your internet service! But at the end of the day, anything that doesn't require a ping time of less than 2000 ms will eventually be made to work, and anything that does will get suitably adapted for the high latency. [Answer] A lot of websites would work just fine. Its just that they would be really slow. Having myself written a lot of networking code for custom systems, I know a little about this problem. You are correct that TCP (which is the backbone of most internet communications) would have to wait a minimum of 2s for the acknowledge on each data segment. This would slow down things quite a bit. In fact any protocol that sends **small** packets of data and then requires an acknowledge will suffer. In general there are two solutions. Those solutions won't allow you to eliminate latency in cases where data does need to make a round trip. But what you can do is speed up data rates in cases where it doesn't. **NASA already solved this problem** for its Deep Space Network System. Given that the round trip to mars can be over 40 minutes its likely that data sent back from the mars rover probably isn't sent using normal TCP. <https://en.wikipedia.org/wiki/NASA_Deep_Space_Network> There are two solutions for increasing transfer rates in the presence of high latency. Both require that your evil villain has someone who can write their own transmission protocol or steal some code from NASA. 1. Create a new data transmission protocol that sends much more data between each acknowledge. a. If you send 0.1 second worth of data and wait 2 seconds for an ACK then you are spending 95% of your time waiting. b. If you send 18 seconds worth of data and wait 2 seconds for an ACK then you are only spending 10% of your time waiting. 2. Make a protocol that includes lots of error correction so you don't need an acknowledge. You can't make any communications 100% error free buy you can make it very close. a. For example, just sending each packet multiple times on different bands. The probability of all packets failing can be very small. Sure it uses more bandwidth, but you data rate will actually be much higher than if you were stuck waiting for TCP ACKs. b. Include error correcting codes in the data that allow you to recover lost bits. In general this will be more efficient than simple packet duplication, but more complex to implement. Since the internet doesn't speak your custom protocols, you will need to have a ground station (or stations) somewhere that receive your communications and act as a proxy. The proxy does all the talking to the internet using normal protocols, and then uses your special protocol to transfer data between space and ground. For example, you want to watch Netflix. Your computer sends a request to the ground station to establish a session with a local Netflix server. Netflix sends the data to the proxy. The proxy then streams the show to you using your new protocol. Problem solved. Some stuff like browsing menus or starting a movie might be slower, but once it gets going you will be able to stream at close to the normal rate. [Answer] As per my answer to [How can invading aliens access the Internet to find out all about us?](https://worldbuilding.stackexchange.com/q/185329/21222), the threshold for proper communication in TCP/IP should be a handful of minutes (3 for many servers). [UDP](https://en.wikipedia.org/wiki/User_Datagram_Protocol) on the other hand doesn't care by design, though some applications(i.e.: Skype, Zoom) are programmed to care and may drop connections that have high latency. Your latency will be within less than a handful of seconds, a whole order of magnitude less time than the latency to Mars (at closest). You will be able to browse sites like the Stack Exchange just fine. You will also be able to use most streaming sites, so [your porn educational needs are covered](https://www.youtube.com/watch?v=j6eFNRKEROw). Some applications like FaceTime and online gaming won't accept the high latency, though. By the way, since you can teleport to the Moon, have you considered running a [cat 5 cable](https://en.wikipedia.org/wiki/Category_5_cable) from the Moon to your router on Earth through a portal? I'd totally crimp both ends for you for free. You'd still have lightspeed limitations, but not having to go through satellites would save you precious time and reduce latency. [Answer] Two-second ping times are not an issue outside of interactive applications which require reactions in real-time, such as telerobotics or most online games. TCP, as a general rule, doesn't care about latency, and [RFC 1149](https://www.rfc-editor.org/rfc/rfc1149), "A Standard for the Transmission of IP Datagrams on Avian Carriers", has been successfully implemented with ping times in the 3 000 000-6 000 000 millisecond range (50 - 100 minutes) over a distance of 5 km, albeit with a 55% packet loss rate. More details at [wikipedia](https://en.wikipedia.org/wiki/IP_over_Avian_Carriers). As you move up the network stack to server and application software, most services such as HTTP, IMAP, FTP, etc. tend to be configured with timeouts in the 5-15 minute range. These timeouts would need to be extended if IP over avian carrier were to come into common usage, but should pose no issues for lightspeed earth-to-moon communication links. [Answer] An evil villain, who can manage two-way transport for himself, hordes of yellow minions, and construction of facilities, can surely manage the installation of a sizable data farm. Your evil villain can further boost his ego by making a local copy of the internet (a giant internet mirror for the moon) that automatically synchronizes with the Earth-based internet. For researching an plotting purposes, your ping times will be no greater than that on Earth, probably much less, due to reduced usage and proximity to the local server. Anything requiring live interaction with dynamic content, such as gaming, chats, forums, etc. will be subject to the expected lag time. [Answer] Latency and bandwidth for a one-way link are independent (like a fiber-optic cable, or a giant frickin' laser ... modulated and pointed at a receiver, probably on a relay satellite). A long high-bandwidth link simply has a large "latency x bandwidth product" aka BDP (Bandwidth Delay Product) = amount of data that can be "in flight" over the link. aka a "long fat network". *Using* such a link with communication protocols like TCP is very possible; TCP was extended to handle lots of in-flight data in *one* TCP connection, e.g. a streaming video. ([RFC1323](https://www.rfc-editor.org/rfc/rfc1323) in 1992 introduced [TCP Window Scaling](https://en.wikipedia.org/wiki/TCP_window_scale_option). Linux turned that on by default around 2004, Windows a few years later, so desktops should work decently out of the box.) A *single* TCP connection can in theory have up to about 1GiB of data in flight (each way), if both sides support the max window scale. But each side needs a send/receive buffer that big to handle lost packets that need to be re-sent, so in practice the max window size will be smaller. **A 16MiB TCP buffer (the default max in some Windows versions) and a 4 second round-trip time gives you a per-connection ideal bandwidth of 4MiB/s, or about 32 Mbit/s.** (With the max possible window size, ~1GiB, a 4 second RTT gives a max per-connection bandwidth of 256 MiB/s, or 2Gbit/s. So in theory with huge send/receive buffers, gigabit ethernet won't be a bottleneck.) ([some background](https://www.auvik.com/franklyit/blog/tcp-window-size/) on how TCP works and what the "window" is, as part of implementing a reliable stream over a packet network that can delay, reorder, and drop packets.) Separate TCP connections over the same lower-level link have zero impact on each other as long as the underlying IP and physical layer can keep up with the total throughput, and each TCP connection has its own "window". Including separate downloads from the same computer to the same server. --- ### Most transfers aren't that long: latency is the major factor The calculation above is relevant for a huge download that lasts much longer than the 4-second RTT. Ramping up the TCP window size at the start of a big download happens exponentially (TCP fast start), but still takes some time. Unless you're downloading a CD image or whole movie, probably not relevant. Loading a web page usually involves many small transfers, many to different sites. Or even if they're to the same site, the data from the first URL has to be received before the browser knows what to fetch next. (The HTML refers to a bunch of images, `.js`, `.css`, etc.) For these, latency is much more of a factor than actual bandwidth. (Having lots of link bandwidth will stop multiple users from interfering with each other, though.) Other answers go into more detail about this, it's certainly viable. **You'll definitely want a caching DNS proxy, and a web cache**. Running a web cache is harder than it used to be, now that everything uses HTTPS, but it's fine if users configure their browsers to use it. (Doing it transparently requires basically hijacking and MITMing every HTTPS connection; apparently some ISPs and/or companies do this by distributing an SSL root certificate that computers on the network should use, making this possible. You're evil so that might be a good solution...) Caching static content like images and scripts can definitely help for the *average* load times of commonly used pages. --- ### Achieving high bandwidth for the physical layer With enough power (to give high signal:noise ratio), bandwidth is in theory easy. A point-to-point laser link with a relay satellite in geostationary earth orbit (or satellite*s* in LEO), can use a large range of optical frequencies. ([wikipedia: Shannon limit](https://en.wikipedia.org/wiki/Shannon%E2%80%93Hartley_theorem) on channel capacity) Note that "bandwidth" in that article is the actual range of frequencies, like how a WiFi channel is only 20, 40, or 80MHz wide, and is part of calculating how much information you can send over it at a given SnR. What we call "bandwidth" in terms of bytes/second is the channel capacity in info-theory terminology. A laser between the moon and a near-earth satellite might be better than all the way to the ground: no atmospheric distortion. The last hop down to Earth can use microwave comm links with normal satellite dishes on the ground, like normal comms satellites. The laser modulation and probably also receive could be done with gear designed for long-distance fiber optic links, again commercially available. If you're mostly watching movies and stuff on the moon, the higher-bandwidth direction will be earth->moon, and the sending laser for that would have to be powered by the satellite. Transmit power is important. Perhaps a RTG (radio-isotope thermal generator), because you're evil, to give a nice large power budget, more than solar panels. The receive side on the moon can use an optical telescope to catch more light from the laser beam that will spread some over that long trip, boosting the signal:noise ratio. OTOH, ground stations on both ends could use large microwave antennas and high transmit powers to cover the distance. Multiple ground stations (or satellites) could give redundancy, as well as distributing bandwidth. And/or route traffic to a place on earth near where the packet should go, to avoid some of that last maybe 100ms of latency going half way around the earth. Of course ground stations would go below the horizon so you'd need multiple anyway. You definitely want this link to be low-error: lost packets will lead to TCP retransmits once the loss is detected, which only get detected on the moon side and thus take a round trip. So forward error correction is important, even at the cost of some throughput to push the error rate down lower than you might for a terrestrial link. (Or IDK, maybe comms links normally use plenty anyway.) [Answer] ## Video streaming generally won't work Most video streaming systems split videos into 2-10 second segments, usually 6, and the client is responsible for downloading each segment in order using HTTPS (See [HLS](https://en.wikipedia.org/wiki/HTTP_Live_Streaming) and [DASH](https://en.wikipedia.org/wiki/Dynamic_Adaptive_Streaming_over_HTTP)). Which means: * A TCP handshake (3 round trips, i.e. 6 seconds, could maybe send acknowledgements before receiving the packets to short-circuit the wait) * A TLS handshake\* (2 round trips, i.e. 4 seconds, cannot be short-circuited) * Several TCP packets for HTTP headers (at least 1 round trip) * Several more packets for responses (hundreds of round trips?) It will take at least 10s to download any segment of video, which isn't going to cut it here. \*Note that it may be possible to reuse and pipeline connections, which may be enough to allow this to work, but I wouldn't count on it, as this depends on implementation details on both the client and server. This limitation, however, does not apply to constant bitrate video like you might get on Satellite/Cable TV. Unfortunately, TV satellites are geosynchronous and pointing at Earth, so you can't get TV. And no, IP TV won't let you get around that because it's encoded to adaptive bitrates (with the segments) in real time. That is, unless you butter up / bribe some executive to get access to the source multicast channels sent by content providers. Torrenting is probably a better option for your video entertainment needs. ## Other than that, it will just be slow All other HTTPS content suffers the same delays as video, but it's less of an issue. Sites will take at least 10 seconds to load, and most will take far longer because the browser often doesn't know what additional content it needs to load until it receives and parses the html, which done poorly, can lead to a cascade of sequential network requests. HTTP2 server push can alleviate this *somewhat*, but expect to be waiting 30-60 seconds on most sites. Single Page Applications will be near-unusable in some cases due to sloppy and excessive network use. Timeouts will be relatively uncommon though, so most webpages will work eventually. For any static files over a couple megabytes, you'll probably want to torrent. The unreliability of connections coupled with TCP's slowness for this kind of connection is likely to cause multiple-hour-long downloads for anything bigger than a few megabytes. Torrenting sidesteps this by allowing files to be downloaded out of order and pieced together. ## Online Gaming It should go without saying that 2000ms of ping is going to be unplayable for most games. On the bright side, turn-based strategy games will be unaffected, so I hope you like Chess. ## Note on torrenting Torrenting is not illegal in itself. It's only illegal if you use it to obtain media you are not licensed to have. Several legitimate products use torrenting to save on bandwidth. Torrenting won't be as dramatically affected by Moon latency because it uses UDP instead of TCP and has error correction models that are much friendlier to packet loss/corruption. --- Current internet infrastructure is not nice to moon colonists. Stick to LAN and torrents. [Answer] > > How much of the internet becomes inaccessible with Lunar ping times? > > > Technically there is nothing that will be inaccessible, just a bunch that is going to be frustratingly slow. Slower than most people think because of how the internet works, but not completely broken. To reduce the latency impact you'll need a few things... 1. Orbit To Ground communication protocol TCP is not your friend in high latency connections. Session initiation takes some back-and-forth of SYN/SYN-ACK/ACK packets to establish the link. The moon is ~1.3 light seconds away, so minimum 3.9 seconds to initiate a TCP session from the moon to the ground station... and that's before you can even start sending packets to make your HTTP request. And any time you drop a packet the whole connection pauses until the data is retransmitted, which means your send buffering is going to be freaking huge. So what you need here is a high-redundancy connectionless protocol. Every bit of data you send goes out multiple times over the one-way delay period, interleaved with subsequent data and tagged with sequence numbers so it can be reassembled at the far end. Adjust the retransmission period depending on the observed packet loss - the less you have to repeat yourself the higher your effective bandwidth. 2. Proxy *everything* TCP traffic via SOCKS proxy is an old technique and still alive and well. You don't have to care what's happening in between the lunar and ground proxies, just like you don't need to know how packets travel around the TOR network. 3. Cache *aggressively* Anything that *can* be cached should be. DNS, HTTP(S), etc. API traffic is probably not going to be amenable to caching, but some of it can be caputured. Make sure that your ground proxy can handle predictive caching so that you don't have to wait quite so long for images to load and so on. 4. Get used to waiting... At the end of the day you're going to run up against the latency problem no matter how clever you are about optimizing the link. Some things are just going to take more time to happen, that's all. 5. ...or bypass it! But wait! You don't *have* to sit on the moon and suffer, because you can step through your teleporter to one of several secure bunkers on Earth whenever it's absolutely critical to avoid the latency issue! Need to monitor your henchmen while they carry out your nefarious plot? Step into the local bunker and watch from there with millisecond latency. Need to gloat over the pathetic do-gooders? Again, do it from the comfort of your local bunker. Need to unwind with a little online gaming? Head to a bunker close to the game's servers and show the silly gamers how a true evil mastermind cleans up at <insert your favorite online game here>. Boxes. Thinking outside of them is what Evil Geniuses (Genii?) do best. [Answer] I think @Helena's answer above is wonderful, it's what I would say (20 year IT industry veteran, mainly as a Network Engineer, and a fair chunk was supporting a long-distance microwave WAN link between two cities) I'd like to add two bits to the conversation though, first, this: <https://www.bbc.co.uk/newsround/54611342> ...so the answer will be IRL at some point sooner rather than later :) Second: My experience with the long-distance WAN (approx 80-100 km, 50-60 miles) was that it was mostly reliable, however we would lose connectivity across the links, strangely, over hot, still days. Our links crossed a large body of water, a bay between the two cities and what was happening on those hot still days (38-40+ degrees Celcius, over 100 Fahrenheit) was that the beam suffered attenuation and dropouts due, according to our microwave vendors, the heat in the atmosphere, coupled with humidity, seemed to bend the signal just slightly the wrong way and enough that the signal dropped out. It only happened on super hot days, and was an annoying blip on what was at the time a backup link, but enough to be noteworthy. An interesting wrinkle for you to consider anyway :) This site explains some of the difficulties, more focused on rain and shorter links, but as they explain, countered with good engineering (big dishes for example mean a bigger target for the beam to hit) many of these problems could be overcome: <https://geolinks.com/does-weather-affect-fixed-wireless/> Between the Moon and Earth, I'd have a satellite in Earth orbit receiving the signal from the moon, that solves the problem of the Earth's rotation away from your base (the moon always faces the same face to Earth so it's only Earth that rotates in this relationship); you may have to account for sun glare in cases of eclipse etc. but there's no atmosphere to worry about so that attenuation issue I mention might be fine. The Earth orbit satellite would need to connect to the rest of the planet, probably via other satellites pointing the other way ie back down to Earth. So it's still technically a few network hops but it's eminently doable. Hope that helps! Edit: A third thing: There is also this article from 2014, which removes *some* of the problems re: distance, latency, and maybe even some I mention above: <https://www.smithsonianmag.com/smart-news/you-can-now-get-high-speed-internet-moon-180951614/> HTH :) [Answer] Invest in photonic (laser, photon q-bit) quantum links. China already demonstrated "quantum teleportation" (of information, not matter) in LEO, using photon qubits. However, such decent evil mogul as yourself, should think bigger and get into phosphorus-exciton qubits. When Phoshorus atom is "pierced" with properly set laser pulse, an electron is separated and "tunneled" into separated solid state container. Despite being spatially separated, the electron and the original atom (more precisely: "exciton" of the atom, where exciton is actually a "whole" where the missing electron was originally anchored) present an entangled particles (i.e. qubit). Interaction speed (propagation of change in their quantum states) between two parts of the same qubit is measured to be greater than 100,000 \* C. ]

[Question] [ This question continues the premise set in my [previous question](https://worldbuilding.stackexchange.com/questions/41229/what-can-cause-the-aliens-not-to-understand-our-signal), but do not worry, I will try to tell the most important bits: There is intelligent alien race about 30 light years away from us. They discovered, that Earth is submitting signal. They were not able to understand it, but they were able to tell, that Earth's signal is "intelligent" one and must be coming from someone who has technology So, these aliens built generational ship and are on their way towards us. They will monitor our signal and try to decipher it and understand us. What can cause them to fail? * The aliens decided to pursue us in Earth year 1960 * The travel will take them 100 Earth years, so they will arrive in Earth year 2060 * The aliens are highly technologically advanced, so they have on board computed of 1 PFLOPS computational power dedicated just to understand our signal * Whole computational power of the ship is 15 PFLOPS (yes, 15 thousand million million floating-point operations per second) * During the travel, the aliens will actively try to decode and understand our signal And also: As they are closing by, the Earth's signal is getting stronger, and stronger (obviously). For the moment, assume same hearing and vision properties of aliens as humans have. Also, aliens age at the same speed as humans do, so we will meet 5th (ish) generation of these aliens. For my story idea, I want the aliens be able to understand us once they actually meet us. But I do not know if its possible. So **what are plausible factors of being unable decipher the signal, even if you actively try to do so?** My original idea is to give the aliens some weird language. But is it enough? [Answer] Because they are alien. Alien means foreign. In the truest sense of the word, that means something that isn't part of you. More than that, it's something you have nothing in common with. So aliens are *alien*. Language is a barrier humans can creatively avoid. Cultural differences however are, in some cases, irreconcilable. We're all different, we all think differently, and we all have a different frame of reference. Issues have divided people from a same country. So people from different species, what are they odds they would see eye to eye? It's really hard to imagine something truly alien, because that would require you to be alien from yourself. For two incredibly intelligent species not being able to communicate, there would need irreconcilable differences in the way they think. [Answer] **N.B. I'm ignoring the distance between us. For these aliens to pick up our signal by 1960, we would have had to start transmitting in 1930, which doesn't sound feasible.** Years on Earth in this answer are equivalent to alien years. --- Simple. Make the signal random. When we started transmitting the signal in 1959, we transmitted the Fibonacci sequence. After a while, we switched to transmitting prime numbers. We sent the Golden Ratio; we sent the Avogadro and Planck constants. We even sent $E=mc^2$. We got no response. What was left for us to do? It was 1969, we were off to the moon, and we had no ideas left for things to transmit. So we switched to sending a high-intensity random signal at random intervals. Intense enough and intermittent enough that it couldn't possibly come from a natural source, but the content and the intermittency was totally random. --- *Meanwhile in space...* The aliens picked up our signal in late 1959, almost as soon as we started transmitting it. It was weak, though - 30 light years is a long way, and the intensity of our signal was tiny. With such little signal to work with compared to the noise and attenuation of the signal, it was difficult to decipher. So, in 1960, they set off towards Earth in the hopes of getting a stronger signal to decipher. And they worked, and they waited. In 1969, 9 years after they set off, the signal was strong enough for their computer to really start deciphering - so they set it to work. --- By then, our signal was random. There are no discernible patterns; they will be trying to decipher it for ever. Until they reach us, at least. [Answer] ## Lack of context Suppose someone kidnapped you, transported you to Russia (or somewhere where you don't know the language), and kept you indefinitely in an isolated cell for some purpose unknown to you. Your needs (food, water, entertainment, etc.) are met without any human interaction. However, they made no effort to sound-proof your cell, and the guards chat with each other fairly frequently. How long do you think it would take you to be able to figure out what they are chatting about? The answer is, unfortunately, you'll never know for sure what they are talking about - how would you know if they are constantly talking about how big of a pain it is to be sitting there guarding you instead of all the other things they could be doing, or if they are always talking about the latest episode of a particular Russian show that you have never heard of? There is a lot that you would pick up, however. You'd get used to their language - the way they pronounce words, the syllables they use, the general flow of sentences, etc. You'd figure out which words and phrases are the most common. However, you have little hope of connecting those to their real meanings - you have no context for what they are talking about. As a simple example, if somehow you knew one guard always used a particular adjective to describe his wife, how would you know what that adjective means? He could be describing her as skinny or fat, short or tall, or any number of other things. **The Aliens have no context** So what can the aliens figure out from analyzing our signals? From radio signals, they're going to be able to do what you could do in the hypothetical Russian dungeon - determine which types of signals are the most common, the kinds of phrases that are used, etc. They'll have no clue what they mean, but they could easily set up a radio-signal chatbot. They could do something similar with TV signals - they'd be able to tell just from how much more information there is that it's more than just audio, and I imagine it wouldn't be too hard to work out how to separate the video and audio components (audio is often constantly changing, but video often changes slowly or only has parts changing). From there, they could build something like Google's [deep dream](http://www.telegraph.co.uk/technology/google/11730050/deep-dream-best-images.html?frame=3370674). Again, they'll be able to analyze our signals and figure out common patterns, but they won't have a clue what they mean. This does not mean that this information is useless, though - once they reach Earth, the chatbot and deep dream programs they develop can quickly be converted into translation programs. As a part of this, they will have already built systems to convert our signals into their methods of communication, even though it will be gibberish until they get to Earth. This will work whether or not direct communication with the aliens is possible. If these are [rubber-forehead aliens](http://tvtropes.org/pmwiki/pmwiki.php/Main/RubberForeheadAliens) (basically human with minor differences), we could learn each others' language. If the aliens have incompatible methods of communicating (such as using pheromones), we won't be able to communicate without technological aids. In either case, we can send radio signals to them, which they have been analyzing and know how to turn into something they can understand. **Summary** The aliens won't expect to be able to understand us based on our signals alone. Without context, they'll have no way to determine what the signals really mean. All they can do is analyze the signals and prepare systems that will make it easier for us to figure out how to communicate with each other once they actually reach Earth. Note: this ends up relating back to one of my previous answers about a [galactic language](https://worldbuilding.stackexchange.com/a/39123/6781). We continue to use our language, and they continue to use theirs, and the common language is the radio signals we send to each other. [Answer] We tend to think that everything communicates using sound. They don't. They think all communication is visual. Their skin is covered in chromatophores like a squid or octopus. They actually have interpersonal communication at a symbol rate an order of magnitude or two higher than human. And they are "deaf". They can sense audio vibrations but only as a warning of hidden movement and possible threat. On their planet evolution did an arms race between quietly moving predators and "hearing" as an alert system. Communication by audio got squeezed out early on in favour of specialized skin patches and extra eyes. They have decoded our TV broadcasts insofar as the pictures go. But they cannot understand the communication channel. They're trying to decode the audio as a representation of an array of dots which change colour. They are also perplexed why they never see this organ on the screen. But they can see we do not have pictures with high colour fidelity and therefore assume it's some sort of weird failure to invent a sufficiently good image capture system for recording natural communication at full bandwidth! [Answer] PFlops is so low for alien capabilities I thought... They will **never decode** any complex analog or digital signal without knowing some basics about it. Any mathematical method to analyze a suspicious signal would not say its "purpose", because the "purpose" is not mathematical it is just how a hardware would react on that. What they could do, is decode some primitive analog radio-signal where sound has a direct mapping to the sound - AM or FM, if they get the idea of making the FM-AM-analysis, and try to play it like a sound. They may not understand the concept of speaking at all if they do not communicate with sound, or normal frequencies of human sound are too low/high for them. I doubt about analog video, unless we would have very big luck and the (former) analog TV-s had pretty much same structure as on Earth, what is improbable. In the worst case, they could be blind as well, or have a very different sense organs than humans and perceive the world in a very different way. As an example, imagine there is some planet with a liquid-like lifeform, and all information, what they perceive, is a form of their liquid body and the chemical matter around them. They are intelligent and have produced a "radio", where they store this information in analog form. A Human expedition with, I don't know, ZettaFlops capabilities flyes to them. Would it be possible for humans to understand the signal? Answer is, rather NO. [Answer] Others have already talked about fundamentally different sensory organs and us sending gibberish. I think while possible this is not entirely plausible. I think it is more likely we are similar but different enough to cause problems We see "visible light" because most eyes evolved in water and "visible light" is the wavelengths of light where water is transparent and other stuff is opaque. What about creatures that evolve on a liquid methane dominated world like Titan? We could pick any liquid on any world, but I am picking one we have sent cameras to and that I understand, but we could work it out the same way for any liquid at any temperature. The light we see is around [400 to 700 nanometers in wavelength while liquid methane is most transparent at 938](http://www.saers.com/recorder/craig/titan/LiquidMethaneOnTitan.html), for reference the bright red from a laser pointer is about 650nm. Methane is also pretty transparent to radar, very unlike water. So creatures with eyes evolved for seeing in liquid methane would likely see in infrared and radar would make our notion of colors and a single range of visible light meaningless. I am going to run with on big difference all "visible light" we see is one (or several) value(s) on the continuous spectrum from Red to Violet, a creature with Radar and Infrared vision would have a large gap between these colors and may not even be aware that one radar eye and another infrared eye are both in principle working on the same principles. Of course their scientists might get it, but that is different than an intuitive grasp. Creatures with 2 "colors" of vision infrared and radar would gather very different information from their color than we do. Their reds could be what we see when we look in an infrared camera, but at the temperatures on a world with liquid methane it would behave more like our normal vision. This is because we give off infrared light because we exist at the temperatures where we are literally glowing hot infrared. A thing evolved to live on titan would not give this off so they would see passive reflections like we normally do in our color and temperature range. To look at is another way, when we make a very bright visible light source it can shine through thin walls or drapes, we do this all the time in infrared. If we imagine them to interpret radar as blue, then they would use their blues for totally different purposes. We use color to rapidly discriminate details in materials. It seems likely we evolved our 3rd color (red) to identify plants with higher sugar content faster than other primates. What evolutionary advantage would blue radar provide? Does the creature require some metal or salt that is radar opaque? When a creature creates such societies and has radar vision how do they use it? If we send a meaningful signal like primes and digital video we can expect some amount of understanding for that signal. What might not be clear is why a video would come in one contiguous light band. These creatures might be too familiar with discontinuous light bands and might not understand our notion of color at all. This might entirely prevent decoding of video, but even if they decode video the notion of signage and writing in a continuous band of color could seem preposterous or foreign. They may not have writing at all, or might write with metal ink so that when reading they use their radar blues and see nothing else. The idea of carefully discriminating colors to discern writing could be seen as so detail intensive as to be preposterous. So even if they did decode video so much context would be lost as to guarantee a cultural divide. Now what does a human voice sound like on Mars, Titan, Venus or whatever planet we know about is most similar to the alien homeworld? I bet it sounds pretty different, now image these creature have those ears and are trying to play an mp3 made on Earth. [Answer] How different from us or similar to us do you suppose the aliens to be? Not just physically, but in their mental processes? I've had plenty of conversations with people who are fellow human beings, but who have different ideas about politics or philosophy or religion, and I have found them incomprehensible in important ways. Often we use the same words but apply very different meanings to them. Like when a libertarian says "freedom" he means something very different from a liberal's idea of "freedom", etc. I've had some conversations with people who insist that the word "truth" is a meaningless noise. Etc. I can easily imagine alien beings who would simply be unable to understand concepts that human beings take as common sense, and vice versa. I mean I can imagine it in principle, but trying to come up with an example where the aliens think very differently from us, but still have coherent logic behind their thinking, is hard. I have a hard enough time understanding people of a different political party, never mind beings who have never thought of the idea of politics. On a much more pragmatic level: Deciphering a foreign language is hard. Perhaps you've heard of the Rosetta Stone: Archeologists didn't know how to read Egyptian hieroglyphics. Then they found a monument with writing in Greek, Demotic, and hieroglyphics. They assumed -- correctly, as it turned out -- that this was the same message in three different languages. As they could read the Greek, they knew what the hieroglyphics said. Even given that, what should be the ideal case for deciphering a language: The Rosetta Stone was discovered in 1799. Archaeologists figured out the first couple of words in the 1820s. They were still working on it in the 1850s. It took over 50 years to decipher a language, with scores of the best minds working on the tasks, with a translation sitting right there in front of them. And that's for fellow human beings, from a civilization that we already knew a lot about from Greek, Roman, and Hebrew histories. Sure, they didn't have computers, and I'm sure that would have helped. There have been scholars who have spent decades just counting the number of different symbols in an unknown language and how many times each occurs and looking for patterns, tasks that would have been greatly aided with modern computers. Of course it's much easier when you have a speaker of the language who is intelligent and willing to work with you. I've talked to missionaries who have had to decipher previously unknown languages, and they talk about simple steps like pointing to a rock and saying "rock", pointing to a river sand saying "river" and so on until the other people get the idea and start telling their words for these things. Once you both understand the process you can compile a list of nouns for everyday objects pretty quickly, etc. Still, I think it's quite possible that, if we met alien beings, establishing communication could be a very long and difficult process. [Answer] For the same reason as the "plug and play" trope in films is such a joke. If it wasn't for our comms standards we wouldn't understand ourselves let alone aliens. You can't use an AM receiver to pick up an FM signal. How do you expect aliens to understand anything we've broadcast? [Answer] On the surface, culture is basically the protocols we use to relate to each other. But the deeper truth is that those protocols are dictated by the values that lie underneath. What a culture values determines how its members relate to one another. If a person from an entirely different culture comes in, with entirely different values, sees the local behavior, at best they will not be able to make heads or tails why people behave so. At worst, they will totally misinterpret and misjudge the people and their behavior. Example 1: one of the highest values in Sawi culture was betrayal. When they were first exposed to the story of Jesus, they laughed at Jesus and considered Judas the hero. Example 2: When I saw a PNG man carrying nothing but a bush-knife, while his wife, next to him, carried nearly 100 lbs of firewood and produce, i was incensed. When I found out his traditional role of warrior forced him to be ready to fend off attackers, I thought I now understood. I was wrong. There was much more about the local history and current context that went into it. What is it that these aliens value? Can you come up with values that would really be alien to us (because even the "negatives" like betrayal have been tried by humans)? The closest I have seen was in SF is in "The Red Planet", the martians have a thing they call "the other place" to which they go sometimes. This was a truly alien and other-dimensional kind of behavior/value. The humans did not understand their doing that, and the martians did not understand humans being limited to one "place". **One more very important thought:** consider one of the most unbreakable codes in history - the Navajo codetalkers of WWII. Breaking a code that is a foreign language proved impossible for during WWI, so before WWII, Hitler actually sent anthropologists to the US to study native American languages. They were unable to do so. It takes years, with the cooperation of native speakers, hearing language and seeing it connected to meaning, to learn someone else's language. So a big key is for these aliens to be able to decode transmissions that include audio **and video**. Then sampling what language constructs go with what situations. Can be done. [Answer] The signal wasn't designed to be intelligible (gibberish or ordered chaos)? But in that case surely they'd realise that quickly? Unless signal was patchy, but even then, with such a mad computer it'd be able to fill in the gaps. Your god-like computer breaks (good luck getting spare parts second generation into a journey like that), consequently only basic systems (life support and propulsion/landing) work and all knowledge is lost or decays from first generation? Chief scientist dies? Mutiny or space madness kills off the adults? Knowledge is not passed on to the next generations? But in any of those cases I can't understand why they would be able to understand humans and yet not a presumably simpler signal. Would have presumed alien languages harder to decode remotely than a presumably mathematical signal. Perhaps the most likely reason is that by fifth generation the inhabitants of the ship have completely forgotten their mission purpose. Maybe the signal was decoded early on but access to ship systems was lost or knowledge of how to access them was lost. [Answer] Ignoring some of the "speed of signal" issues I think your going to have to go with, cause there different. I would suggest that they can understand words but not context. We have the same issue today on earth, you just have to play it up a bit. Terms like Gateway Drug, Google It, Jumbo Shrimp. The word gateway makes sense, drug makes sense, but without thought of using drugs for recreation, it sounds more like a drug you have to take to get into someones yard. What is a Google? It's an action, in one sentence and a proper noun in another. And what is up with Jumbo Shrimp? Take our play on words, and marketing speak, common concepts like "search" and "post", "FaceBook it", or even less technical things, like <https://play.google.com/music/preview/T6b7nznx5wqm247j4zkwk7yngvq?lyrics=1&utm_source=google&utm_medium=search&utm_campaign=lyrics&pcampaignid=kp-lyrics> Try understanding that with no context. And not just Rap, how about <https://play.google.com/music/preview/T7voykkstcjbfxy24z5ln63jyku?lyrics=1&utm_source=google&utm_medium=search&utm_campaign=lyrics&pcampaignid=kp-lyrics> With no cultural context, most of the gibberish we spew is just that gibberish. So I suggest, they understand the words, but without a frame of reference, it's meaning less. On the upside once they get here, they will pick up the language concepts pretty fast. [Answer] I think the answer to this question is right here at home. There are many diversified and intelligent life forms right here on earth. Not just chimpanzees and dolphins, but also corvidaes (crows, etc), octopusses, and others. They may not have well developed technologies but they do have highly advanced ways of dealing with reality. We have pretty advanced technology and have been studying these creatures for years with basically unlimited access to information about them. We aren't just limited to observing what they transmit. Yet still we do not understand these creatures on a level that lets us communicate with them directly. They may have languages of their own, but we cannot work them out. It comes down to psychology. We simply do not share the same biology, despite the fact that we are all built from similar DNA sequences. Our sensations and ways of taking in reality are vastly different and we fail to experience the world the same way. [Answer] I would say because the aliens didn't use our form of communication at all - ie. not sight/pictures, not voice/sound, and not symbols/text. Perhaps they're a race of blind, deaf and mute telepaths - in which case whatever we send won't mean anything to them, no matter how long they observe it with their telepathy... except the very basic knowledge, that there is this planet in a distance solar-system that keep sending-out obviously non-natural radio-waves. [Answer] 30 light years in 100 years. We perceive the fastest way to relay information is the speed of light. So whatever RF and microwave emissions they pick up would be blue shifted to them. Maybe they cannot sample the signal quite fast enough. Sure they have massive computational power, but if they cannot get the raw information what good is it? [Answer] Human brains are hardwired to understand human language. Alien brains won't be. We come into the world preprogrammed to understand sentence structure, syntax, tense and the like. All Mom and Dad have to do is plug in the words. They show us a fish and say fish and we are then able to use that word, by itself, eventually in a phrase and then in a sentence. When you think of aliens understanding our language you are not making them alien enough. They may communicate all or in some part by any of the senses. We use hearing. They may use scent for instance. My question back to you would be why would they understand us? As far as "the message" itself don't forget that the first "message" they are going to pick up from us is going to be old radio and then T.V. shows. Talk about things that could easily be misconstrued! [Answer] Our science is wrong: It is a pretty common idea, in both Science Fiction and Science, that communicating with anything particularly alien will have to be built on a 'language' so universal as to guarantee that the aliens have this in common with us, and that this language can only really be maths, physics or chemistry. Reddittors discuss here the idea of using a diagramatic representation of the periodic table as the basis of communicating with aliens. <https://www.reddit.com/r/chemistry/comments/2jf6jv/would_showing_an_alien_species_our_periodic_table/> And that would likely work, unless: What if our understanding of the universe is so wrong that the periodic table is actually meaningless. It is either wrong, or only applicable in very limited situations, and the aliens, having evolved flasners before inventing the wheel, do not commonly/ever experience these limited experiences that humanity experiences 100% of the time. They would never have invented the periodic table, as it would not explain the world they can observe. Similar to how Newtonian Mechanics (which is incorrect, but close enough at low speeds) would not be developed by a species of aliens for whom 0.999c is a slow jog. So the aliens would look at the pretty picture of electrons orbiting around a nucleus, and think "these patterns are too structured to be coincidence, they must have been created by these 'humans' as part of their primitive worship of their Gods, proton and neutron. Note: This of course covers only very alien aliens. The 'use the periodic table as a guaranteed common element' concept is only necessary if we ave nothing else in common with them. If they speak a language with sentences made out of words made out of letters then the periodic table is unnecessary and a competent alien programmer will make short work of the translation. [Answer] **Because everything in encrypted in 2060** Most of the other answers are based on how different the aliens might be. However, encryption may prevent even very human like Aliens understanding our signals. Between identity thieves, spooky intelligence agencies using data-mining and internet trolls look for offence, transmitting any unencrypted data is becoming unwise. Already we are using [https everywhere](https://www.eff.org/https-everywhere "https everywhere") is being advocated. DRM is being increasingly used for TV shows, and it is not like they will be paying $60/month for a TV decrypter box. Perhaps by the time the aliens are able to pick up non-trivial signals such as TV, it is simply not done to transmit unencrypted signals. So when they arrive in 2060 all they know about us is that we beamed the digits of π at them between 1959 and 2020, and now all our transmissions seem to be gibberish. [Answer] Perhaps the signal was effected somehow as it left our solar system, and the data was corrupted. For example, as it passed through a nebula it was corrupted, but due to difference in technology the aliens weren't able to detect or repair the corruption. However, when the aliens got closer to Earth, whatever obstacle was corrupting the signal would have been passed but maybe they were so close (and English was such a foreign language to them) they didn't have enough time to fully understand it. [Answer] They failed math class and their spaceship was a gift from "god/advanced race/long lost history". Once you have patterns, you [have language](http://www.cbc.ca/news/technology/prairie-dogs-language-decoded-by-scientists-1.1322230). If aliens have no scientists, code breakers, or even anyone who is interested in a puzzle, that's the *only* way they can fail to understand some kind of signal. Sure, they can [misunderstand the signal](https://en.wikipedia.org/wiki/Pixels_(2015_film)), but they'll still decode the message. The only way to prevent them from decoding it is to make it so they *won't*, or have not evolved to a point where they understand that the signal has meaning. Maybe the best way is that the spaceship is a gift from deity, and they are to Press The Red Button, which takes them to the next source of The Signal. Then they go there and <kill/eat/get eaten>. [Answer] With Google and Facebook having their big data released to the use of marketing and military applications, humans have developed a number of AI's to assist and enhance human interaction. There is augmented reality, totally handsfree world-wide communication and complete man-to-machine neural interfaces. At the same time, religious groups and power-hungry dictators are starting world war III, reducing earth's population to thousands. Television and radio quickly become extinct as there are no actors, studios or Hollywood. More importantly, there is no audience or even advertisers to support broadcasts. Remaining computer networks are used, fixed and improved. Earth stops sending any signals as there aren't any towers standing or satellites flying. The only wireless networks are strictly local (and/or optical/directional such a laser) as a precaution against any remaining threats. Aliens might have been able to follow our culture and situation up until now, but with their journey already on it's last quarter, they'll at least come check out the now-silent planet. The rich and intelligent have survived the war in their shelters, where they develop and evolve further into half-men-half-machines. With seemingly unlimited resources and technological advances, robots are quickly developed. Robots clean up the ruins of war, farm vegetables, salvage materials, fix and build more robots. Common jobs are medical, scientific and supervision of robot labour. Latest generation of people is able to share experiences, emotions and even their personalities real-time as they are always online, and with heavy collaboration on their daily tasks they learn to communicate more efficiently. A new language is born and quickly distributed throughout the entire connected population. Technologically assisted telepathy is an understatement as humanity is so fused together. When the aliens arrive, all they see is this blue and green planet and it's robots gardening it. Humans, when finally found, have technologically evolved far beyond from the original man the aliens spent decades getting familiar to. Hope they come in peace. [Answer] Even if we work out ways to communicate, there may be *very fundamental* ways of misunderstanding each other. For instance, [Richard Feynman on the importance of discerning left from right](http://www.feynmanlectures.caltech.edu/I_52.html): > > To illustrate the whole problem still more clearly, imagine that we were talking to a Martian, or someone very far away, by telephone. We are not allowed to send him any actual samples to inspect; for instance, if we could send light, we could send him right-hand circularly polarized light and say, "That is right-hand light—just watch the way it is going." But we cannot give him anything, we can only talk to him. He is far away, or in some strange location, and he cannot see anything we can see. For instance, we cannot say, "Look at Ursa major; now see how those stars are arranged. What we mean by 'right' is ..." We are only allowed to telephone him. > > > (...) > > > In short, we can tell a Martian (...) "Listen, build yourself a magnet, and put the coils in, and put the current on, and then take some cobalt and lower the temperature. Arrange the experiment so the electrons go from the foot to the head, then the direction in which the current goes through the coils is the direction that goes in on what we call the right and comes out on the left." So it is possible to define right and left, now, by doing an experiment of this kind. > > > (...) > > > So if our Martian is made of antimatter and we give him instructions to make this "right" handed model like us, it will, of course, come out the other way around. What would happen when, after much conversation back and forth, we each have taught the other to make space ships and we meet halfway in empty space? We have instructed each other on our traditions, and so forth, and the two of us come rushing out to shake hands. Well, if he puts out his left hand, watch out! > > > [Answer] As others have mentioned it is really actually not that much computing power which could cause a problem on it's own, to put it in perspective 1 PFLOPS is approximately the single precision floating point performance of just 142 Nvidia GTX Titan GPU's. Granted here on Earth those things cost around \$1,000 a unit but still that would make 15 PFLOPS worth have a price tag of around \$2,100,000 dollars. If we somehow assume that these aliens despite their clearly far more advanced spaceflight technology somehow only have similarly advanced ability to produce computational power that we do this would seem a strangely small amount of processing power to pin your hopes on for a mission that would probably cost the equivalent of several billion dollars to design and construct. That said ultimately for decoding meaning from human language realistically even massive amounts of computational power may not be of much help here this is because put simply human language is not merely a code that can be cracked. Or more importantly even if you could actually break it down into words and extract the lexical information from the language what you have is effectively still incomplete. In a way a text file for example containing written language could be regarded as an incomplete datafile that is in reality nothing more than a complex set of references to something else. Lets call the something else here the concept dictionary, now while we may have never written such a thing down we all have one of these it's the product of our experiences, knowledge of humanity, culture and all the information that we know and have picked up through shared experience of life on this particular little rock in space. The context dictionary is the part that you are using if I say "cat" and you know that a cat happens to be a furry animal and a lot of other descriptive information, you also probably know that humans keep these animals as pets, various facts about the species and a whole host of other information that allows you to truly understand the concept of a cat and what I am talking about. That context dictionary is something that the aliens will not have they are not human, they don't know how it feels to be human, they have no knowledge of human life and culture, they do not know Earth, what sort of flora and fauna exists on Earth or anything about how the various plants and animals are used and their relationship with humans and human culture or for that matter anything about what it is like to live here on this particular planet. This would make deciphering any meaning from language almost impossible, interactively with a lot of time and effort it seems that an intelligent alien and a human could work with each other to pick up enough to make some sense of each other but it would take a significant prolonged effort on both sides to actually teach them the human concept dictionary and for them to teach us theirs. Since it works both ways we would be in the same position trying to understand anything they tried to tell us about their home world, culture and life there since we are missing the conceptual information to relate to that experience without being taught. Even with additional context it can be hard to understand what is actually being expressed take the cat example again, say you didn't know anything of the language or for that matter anything about Earth or cats if I pointed at a cat and say "cat" you wouldn't know that word referred to all instances of animals of that type. For all you know I could have just said my pets name, or maybe I said animal, mammal, pet, furry, black or other descriptive terms. It would take a lot of time and work to pick up enough to truly understand which it was and only by effort and repetition noticing the patterns of how and when instances of words crop up again etc. [Answer] To build spaceships and travel the outer space, you have to be capable of some talk. This means your aliens would have a language or code. However their communication might be different from human natural language, syntactic denotation-oriented approaches allow disambiguating any communication code, provided the users of the other code cooperate with you. <https://en.wikipedia.org/wiki/Denotation> <https://en.wikipedia.org/wiki/Syntax> If you think about friendly aliens, there might be little point to make them incomprehensible.Champollion managed even without friendly visitors, focusing on syntax and denotation. :) <https://en.wikipedia.org/wiki/Rosetta_Stone> <https://en.wikipedia.org/wiki/Jean-Fran%C3%A7ois_Champollion> [Answer] I think the greatest obstacle is that their crew will be intergenerational. What warrants that the grandchildren of expert linguists and cryptographers will have any interest in alien culture and languages? --- But I think you are misrepresenting their efforts. Suppose you don't know, for instance, Portuguese. And that you want to decypher it. What do you do? You pick a Portuguese text you receive, and send it back: Dangerous aliens who love the samba: *João e Maria foram passear na floresta* You: *João e Maria?* (or, even better, *João e Maria foram passear na floresta? **What does that mean?***) Similarly, your aliens would start repeating our transmissions back, until we became aware that for some strange reason our transmissions were being repeated, with curious codas. Of course, there would be much more difficulties in doing that than in an attempt to establish communication between two humans who speak different languages - first of all being that we make transmissions in which the original code is reencoded into eletromagnetic signal - and then quite likely reencoded again for information security - which means that the aliens will be in trouble to understand whether what is being broadcasted is an electromagnetic version of the *Odissey* or a picture of Jennifer Aniston - ie, text or image (and it can get even trickier if their concepts of "text" and "image" aren't as clearly cut (and at the same lines) us ours). But the basic principle is, if you want to understand what others are saying, you try to engage in conversation. But, of course, perhaps they - or a faction among them - **don't** want to understand us? That would be a formidable cause for non-understanding/misunderstanding. [Answer] ## Computing power and data *1 PFLOP is too low.* *15 freaking petaflops per second* - Yes, would I personally have such power, it would make freaking good minecraft server, huge cubic world, with huge amount of diamonds, with huge small cubic figures. As [Top500](http://www.top500.org/) list shows TIANHE-2 (MILKYWAY-2) in first place with 34 PFlops practical and 54PFlops theoretical performance, with 3120000 cores and 17MW energy consumption. Just for reference. Is that power enough to understand our languages by our self's? I would like to know, how much power google translate have, looks like still not enough. [World’s total CPU power: one human brain](http://arstechnica.com/science/2011/02/adding-up-the-worlds-storage-and-computation-capacities/) > > To put our findings in perspective, the 6.4\*1018 instructions per second that human kind can carry out on its general-purpose computers in 2007 are in the same ballpark area as the maximum number of nerve impulses executed by one human brain per second > > > **Why it's important** One of the approaches to understand reality and rules of the universe is to build models of it, and observe such models and change them in a way we can't do in real life. And this is a very important method of understanding. With flying alien - they can't do experiments on humans, just because they fly in space on their ship and humans fly on earth ship. And because of that, aliens should build some models or sort and select some models they already have. They have at least one model, and it is a model of them selfs. By model I mean not only the current state of their existence but also their past, how did they become to live, from atoms to live. We do not have such model, in great details, but we definitely have some pieces of that model. Also, we have more than one model, answering the question how did we come to live. And we had them, so long how long exists our species. One of the kids questions is: where I'm from. Even bacteria have model of universe, which it uses to find food. It have no clue about fact of existing of that model, but bacteria uses it to their advantage. I mean any have at least some part of model incorporated by them selfs. And it makes no difference do they know or not about it or they just use it. These models are different in sizes, as **I** may describe them, but maybe they are same size each and each is fully describe the universe as some advanced alien may say. But somehow they are different, why not by size - it isn't important. How I describe that difference, isn't important, but what I wish from them is, because my Will will determine our future interactions with this set of atoms. And knowledge will tell, what to do, to get certain results. Xeno psychology is a hard topic to talk, and it is not the complexity of that topic by itself, but where you are on that subject. **Xeno psychology topic is very simple indeed.** god censure department after that there was an atom, he met another atom, bunch of them and after some time he made bonds with other atoms. And after this long story, everything gone wild and pretty complex from our standpoint of view. I mean there are some rules in this house, and we name them physics, chemistry, biology, astrophysics, mathematics etc. And these rules are for everyone, as we think at the moment. We can make god model where will be all sorts of creatures that may exist. Probably this model will be big, will take some time to generate - what we may do to reduce time and efforts and data - let say we strike out all creatures that are not connected to intelligence live. Yes, we have to have some criteria for intelligence, and aliens from question have such criteria because they are decided there should exists some intelligent creatures nearby. Probably such criteria will strike out also bunch of another intelligent creatures, who do not use radio as we do, who do not have 4 legs 4 arms as we do, 2 legs 2 hands sorry misspoken, or whatsoever. So, yes we exchange precision of our model for it to be more reasonable and useful and practical size for us to handle. *Disclaimer* - I do not talk about emulating the Universe, or any sort of theories connected or derived from that concept, but about determining some probability's of something to exists, and properties of that something. It may and is another sort of reduction. It's like fractal, you may detalize it as deep as you need. **Do we have to have such still big model?** No. Probably set of rules to generate that model again, will be way much smaller then result of those models by itself. **How it helps?** We may keep one model we like to work with and set of rules to generate the rest. So when we discover something that do not fit our working model - we may run our model generator and begin to pick stuff that may describe our observation. Let say we got something that fits in our model and describes observation, we keep generator still running but it find nothing. More it works and more it's still nothing more certain it is that what we have found is the cause. We add that set of data to our model, but because we didn't run our generator until end (and actually we never did that) we mark this data by some probability for future use. So if we discover another set of observation which do not fits in our model, and with data set we added recently specially, so it may be because we waited not long enough to find real cause of first observation, strike that recent data set, run generator again and wait until another data set will be found. Scientists are such sort of model generators, they generate models based on observation and other models. Some of them we add to our general model, some we take out of the model - but overall we extend our knowledge and our model. We have some rules to handle it, how to operate it etc. ## Aliens and their poor 1 Pflops I don't know guys, but if you fly light years away from your home to understand another, totally new and unknown set of information, I expect you to be more prepared for that event. And even not because it makes sense in terms of achieving your goal of understanding, but because Live of your entry civilization may depend on how well you did that "understanding" process. *There is something big to think about.* **Big Thing** * First of all small note. To understand some difficulties that are on the way to understanding, someone do not need aliens from neighbor star, ask people who works with people - they tell you everything about, but how you interpret that information is up to you. And probably any was an object of misunderstanding, or misjudged them selfs. * Or just by reading that, high probability you did not understood something, because I used my reduced models and you have your own models which looks similar, but are not quite same internally as I meant. But what if 2 civilization in a situation where 2 models are totally different, is that a problem for understanding. No, yet not a problem, because base of our model is *exact* same (probably, with high probability). And it is no even big bang base, but chemical and thermonuclear reaction as we **Know** from our observations are same in far far freaking far(and this time it's really *freaking* far) far away from us **are same**. We know even more More, far far back in time **they are also the same**. I do not why, but that did hit me [Laniakea Supercluster](https://www.youtube.com/watch?v=No0omeHIxwo) (we are here in that cluster if you not familiar with that everything) which is part of way more and bigger structure by itself. About redshift [wiki](https://en.wikipedia.org/wiki/Hubble%27s_law#Combining_redshifts_with_distance_measurements) and redshift calculator converter to [statue miles here](http://www.convert-me.com/en/convert/length/auredshift.html) Maybe because it's so boring and astonishing at the same time. So our direct observation tells us how it was in time and how it is in space - about atoms and that stuff. * as far as we can see there will be no possible live (from common materials, and as far as we know it now) which do not share some common base with our civilization. Actually that fact played numerous times in SciFi to be some sort of key to understanding. Science bro. * I will not talk here why Carbon based live is more way more likely then not carbon one. (model shows) * I even will be not surprised if in some cases technology development will be similar, there are some key discovery and approaches made possible all we have now. I talk even not about fire or wheels but this as example [three plate method](https://en.wikipedia.org/wiki/Flatness_(manufacturing)) or that discussion about [Three plate method for true square surfaces?](http://www.practicalmachinist.com/vb/machine-reconditioning-scraping-and-inspection/three-plate-method-true-square-surfaces-303457/) You can be without fire(sort of) but technological development will have method of making flat surfaces, and at some point it will be [Principle of Flat Surface Generation](http://what-when-how.com/metrology/surface-plates-metrology/) something like that, it may look different, like machines which do nothing, but it's not important because you will recognize the result, and how it's done. * yes there may be biological civilization etc etc You will recognize them by their fruits. *Matthew 7:16* **Where is big thing, though.** The problem isn't understanding, but Will. Let say you try to understand another civilization, and you picked wrong methods for that and accidentally killed half of that civilization. Big problem? Hmm, not yet. The problem begins when you not able or have no will to change methods, or when you not able to understand grasp the fact that you are losing information by that type of actions. And this is the Start for Big Big problem. Let say another example, something like pikachu wish to understand humans, and his method of doing this is saying to each people what he says, each time he can. And we for some reason do not have goals to understand him, I do not know why, let say we all think it's result of genealogical creation from corporation X, and we already know about him everything, and nobody noticed that it's not true (impossible situation for us, but for some reason, for simplicity it happened). How long it will take for us all to decide that pikachu is just noisy animal(which is for some reason not investigated, hmm, strange, we should know about his internal structures and how he operates ... censure by corporation X)? Even if it have space ship - I may make space ship for my virtual dog, why not? It will fly trough space, look at new places, wonder how big is that house, and where hides master, and then I woooph hello doggy and ..... and so on. So for how long? - just for so long enough, until any human will know what to expect from that pikachu. So if aliens are not flexible enough, not lucky enough wrong civilization type, not experienced enough, wrong methods etc, not smart, too suspicious etc etc. Yes they may fail. Not because it's hard to understand, but because of them self's. Destruction of expedition is actually not big deal for relations for both civilizations. Even war isn't big deal - it also may be method of understanding. But you should feel where to stop, and change method. ## Goal of understanding Aliens There is only one goal, extend you universe model. Which form it takes: technology exchange, knowledge, war - is not important. More peaceful ways may be preferred because the destruction of information works both ways and your model can be destroyed, and that nullify all your actions, everything you have done to build that model. Not mean everything will be peaceful but less destruction less probability to be destroyed. # What gone wrong with aliens from the question They took way much reduced and simplified the model, and they are not experienced in other civilizations, probably it was first one. They fly with reduced models, only tech tree and rules for generator to establish here some computer center with 1025 Flops and quantum coprocessors over 9000 Flops each to run model generator. But accidentally they were confused with some pirates and were destroyed by [Network](https://worldbuilding.stackexchange.com/a/41407/20315) it just so happened, there are some rules u know. But they did good, Network council got information about their existence and send them green peace people, who were sad about destruction of that alien ship, for future contact development. Network council send expedition on 0.99c to that alien star, That's why no one has forgotten his goal and what to do next. Also were sent expeditions for all stars nearby alien star, just as for information support and running model generators from the energy of that star, in case if they are free, or if not, then also making contact. There were also probes sent, to be recon for expeditions, expeditions should be able to prepare them self's for different scenarios, taking information from recon probes into account, keeping the connection between expeditions and sending information to Network council. This also was reason for Network council to decide take some actions inside our system, like get and utilize all energy from our sun, disassemble Jupiter for fuel, send expeditions for surrounding stars, all stars in 50 light years around, establishing their computer centers and using all their star energy, to generate models from alien remains, by that establishing Interstellar Network to counteract and understand. Actually, there was some cascade of different actions, everything Network council was not sure about in the past, or lazy to do, or deemed as not necessary to do. Aliens existence was like throwing a big rock in a tiny pond. Aline figure sales skyrocketing, games kill the alien, love the alien, teach alien wisdom, Mad Scientist discovers the Truth rumors, even a small war happened (Goons won). **There is some informational problem** Decoding signals is some problem, but not big one, 1PFlot isn't enough for that, but in early stages technology was pretty limited with what can be done, and how it could be done, and determine possibility's is easier then generate biological creatures as example. Which we also may have to generate for determining possible tech evolution of that civilization. So signals are not big deal, maybe also some encrypted too. They should fly and collect all information they can, and probably not with one ship but Set of them, forming big interference receiver, some 100 a.e. receiver dish or more if needed. If you are not ready for space scale actions, but too curious to stay home until you will be ready, then be prepared to give you destiny in hands of another civilization and prey you ancient gods for they be smarter then you and worthy of that gift, and be it a gift for them, and you lucky enough. Just get to the system, stay, observe, and wait until senpai will notice you, **stay alive**. The last one is very important, it shows you reaction on possible methods they may use to understand you, and that will show you are not like other matter, you different from any typical substance they may seen before. If you have to destroy something, to stay alive, destroy it. If you have to kill, kill. Not you choose methods. Do what you wish to do, react. But be not super excited with destruction, be flexible change you strategy. it may be so that they are not excited about your existence at all, so maybe go home for a while to think, work with models etc. Prepare better, if they are able to exist as whole, there is something they like, there are ways to deal with them. * If we're going to be damned, let's be damned for what we really are. *STNG* ## References * This model isn't full, and some sort one sided, something I skipped for shortening that story, something I have forgotten, something I do not know, something is wrong. But I give it as it is, GNU power. * TV Series: *Star Trek: The Next Generation* * There is some interesting literature about problems of understanding, not in order, all are good: *A Deepness in the Sky* by Vernor Vinge *Echopraxia* by Peter Watts *Роза и Червь* by Роберт Ибатуллин * Here you can play God for creatures with simple and clear rules, and get some grasp of evolution processes, if you observed it less than 2 months for 24/7 so it may be so that you waste your life just now, sorry no offence, but really just try to understand *their* live, they *are* aliens, here it is [critterding](http://critterding.sourceforge.net/) It much more fun if you may grasp programming involved and tune it for your self's. [Answer] With the scenario stated, the message is actually guaranteed to fail. # Children don’t understand their own parents even with constant contact. The understanding will not happen even with unlimited computational power, and even if they form a Large Language Model such as our modern AI use. Your story will have the alien race reach earth, they won’t understand our idioms and humor, slang and banter, and politicking already. It’s a given, because your story didn’t do anything to facilitate understanding. It played on common presumptions, and the outcome will be predictable. How is your scenario different from *The Day the Earth Stood Still*? They had nearly limitless power. ]

[Question] [ In reference to the classic [Indestructible Edible Trope](https://tvtropes.org/pmwiki/pmwiki.php/Main/IndestructibleEdible), how long can an adult subsist on largely junk food? I realize that "largely" is vague, so feel free to clarify as desired to give a helpful answer (one way or the other). To motivate things: Imagine a world shortly after the apocalypse. Something very quickly resulted in the "depopulation" of most of the USA (or similar country). Best bet is a virulent plague with a 95% mortality rate. Because of how quickly it spread and killed people, those who survived the plague have basically found themselves in a "fairly" undisturbed world. For the purposes of this question that mainly means that grocery stores, gas stations, etc, are mostly still stocked with goods. Of course power goes out quickly, so anything that needs to be refrigerated goes bad very soon. This leaves hardier staples, but from what I can tell the longest lasting foods are largely pure carbs with very little nutrition other than calories. Some examples: 1. Dry pasta [(1-2 years)](http://www.eatbydate.com/grains/pasta-shelf-life-expiration-date/) 2. White rice [(4-5 years, but only 6-8 months for brown rice)](http://www.eatbydate.com/grains/rice-shelf-life-expiration-date//) 3. Unpopped popcorn [(indefinitely)](http://www.eatbydate.com/other/snacks/how-long-popcorn-last-shelf-life/) 4. Cereal [(6-8 months)](http://www.eatbydate.com/grains/cereal/cereal-shelf-life-expiration-date/) My own impressions lead me to believe that these are also some of the more common items in a grocery store, and so they would be the easiest to find in large quantities for a post-apocalyptic scavenger. However, these foods (especially white rice and white pasta) have very little nutritional value other than calories and some minerals. Certainly very little protein, and no fat - fat especially would make them go bad faster, I suspect, so high-fat foods are most likely out after a few months (although I think canned nuts might last 6 months or a bit more). Still, our survivors need to figure out how to become independent and produce their own food without the help of modern infrastructure. For the purposes of this question our survivors apparently have access to sufficient quantities of clean water as well as shelter. We're ignoring the risk posed by large quantities of dead bodies rotting everywhere. The survivor(s) are small in numbers and we'll presume there is enough food left in stores: the only thing that will hamper their long-term scavenging is the expiration date of the food (the actual one, not the one printed on the back). How long do our survivors have to figure out how to become self-sufficient with food sources before malnutrition becomes a serious problem? Or can they survive more or less indefinitely off of such low-quality food? I'm also open to frame challenges, aka let me know if there are actually more than enough nutritious and long-lasting food sources around and there is nothing to worry about. [Answer] Given that there is enough food in convenience stores / supermarkets (ie. little enough people have survived that the quantity of food is not a problem) quite a few years, by which time they'd hopefully find local library (as I'm not too optimistic about their skillsets) and learn to plant, grow and eat the natural food outside the city to survive indefinitely. First, there is "best by" date, and there is "will probably cause digestive problems" date - and there is quite some "sub-prime" time in between them. There are plenty of stuff which will hold for few years or more, and provide you with more then enough nutrients needed for comfortable survival for few years: * pasta, flour, oil, muesli etc. - stuff that might have a year or so specified by manufacturer, but will hold for much longer if unopened. * sugar and honey which will hold for quite a few years (or decades) without any problem. * lot of canned fruit and vegetables - from corn, beans, beetroot, pickles, olives, fruit compote, jams, etc. which will hold for 2-5 years by their (pessimistic) "best before" dates, and will probably be edible a few years after that * canned meat and spam and fish and spam and other meals with a lots a preservatives which will hold for 5 years at least (I'm just looked at some fish is spicy vegetable sauce whose best-by date is 3 years in the future, and I'm pretty sure I haven't bought it this year) and will provide you with essential fats/amino acids. * dried fruit, nuts will be good for a year at least (or more if taken care of) * dried and salted meat like beef jerky might hold for years * peanut butter, ketchup, dehydrated soups etc will last for few years. * fruit juices with preservatives, beers, wines, tea etc. will also hold from one to quite a few years * food supplements like "dissolving tablets" will also provide minerals and vitamins (although not in ideal healthy form, more than enough for survival). [Answer] # A few months at best It's the lack of vitamins that gets you. Vitamin C deficiency is known colloquially as [scurvy](https://www.nhs.uk/conditions/scurvy/) and was one of the biggest killers of sailors in the age of exploration. Simply, you need your fruit and veg or you're going to die. You can get around this if you have supplies of concentrated fruit juice or vitamin supplement pills, but you've got to have those vitamins. [Answer] ## The medical term is [kwashiorkor](https://en.wikipedia.org/wiki/Kwashiorkor). It was first identified in Africa in 1935. Mothers would stop breast-feeding their child when they became pregnant again. The older children would get plenty of calories from a high-carbohydrate diet, but were no longer getting protein (from the breast milk). The name "kwashiorkor" is a [word in Ga](https://www.merriam-webster.com/dictionary/kwashiorkor) which means "the sickness the baby gets when the new baby comes". Signs and symptoms include: * lower immune response, thinning hair, and tooth loss. These all rely on proteins. * muscle breakdown. This includes both skeletal muscle and the respiratory diaphragm. The body reclaims proteins, which are broken down into amino acids that are released into the blood. * increase in blood urea nitrogen. Amino acids are converted into glucose in the liver, by removing the nitrogen. * fat deposits in the liver. The high carbohydrate diet actually encourages the liver to store the excess carbohydrate as fat. * liver failure. With less protein to work with, the liver cells shrink and get replaced by the fat deposits. * reduced blood proteins. Albumin and clotting factors are proteins that are normally made in the liver. * swelling (edema), particularly in the ankles and feet. Reduced albumin draws water into cells by osmosis, and tissues swell. * low blood volume. The fluid has shifted to other spaces. * distended abdomen. The enlarged fatty liver and edema in the abdomen (ascites) pushes out the abdomen, which the weakened diaphragm cannot hold in. * rashes. * irritability. [](https://i.stack.imgur.com/2wnTT.jpg) The amount of time depends on the person's protein reserve. Children are more commonly affected than adults, because they have fewer protein reserves. Children can die in a matter of weeks. Adults can often continue for several months. [Answer] I question the premise of the question. In most places where you can find dry grains and pasta, you can also find dry (and canned) beans, lentils, peas, soya, chickpeas, nuts, etc. Combining those with grains will give you a complete protein containing all the essential amino acids needed to sustain the human body. These pulses can, similarly to rice, last for many years if stored away from moisture in airtight conditions away from sunlight. Hermetic food can also be kept for a very, very long time. Indeed, the vitamins are a bigger worry. Your heroes need either hermetic juices, hermetic fruits/vegetables (and even milk or eggs, for B12) or dietary supplements. Also, I would like to point out that grains are not "pure carbs". Even white rice contains 2.6% protein. Pasta (from wheat, unenriched), has 5.8%. Oats contain 16.9%. Moreover, these proteins consist of amino acid residues. Your heroes will need both them, *and* the protein from legumes. If they only were to eat beans, for example, they would also get deficiency. Both grains and legumes are needed to get a complete protein. Some notable exceptions to this are the soya bean, amaranth, chia and quinoa, which are complete proteins in themselves. Hermetic eggs, meat or dairy are also options for getting protein, however, I suspect such products may be in a shorter supply in an apocalypse situation. I think as long as your heroes know a little bit about the basics of nutrition, they should be able to dodge protein deficiency. [Answer] Even if you have vitamin supplements stored, lack of fats will kill you before lack of protein. There's a phenomenon called "rabbit starvation" -- someone surviving in the wild whose only meat is wild rabbits will die in a few months because there isn't enough fat in the meat -- some vitamins are fat soluble and can't be absorbed, even with adequate vegetation in the diet, without enough fat intake. Protein catabolism is a genuine issue: it's why people in WWII concentration camp photos look like living skeletons; their bodies have metabolized their own muscle to keep their brains and organs running. But if you have zero fat in a calorie-sufficient diet, you'll still waste and die even if there's enough protein to avoid digesting your own muscles. [Answer] White rice, flour, pasta, and popcorn are not pure carbs. Rice has about 8% of its calories from protein. Flour is about 11%, pasta about 14% and popcorn about 12%. It's recommended you get at least 10% of your calories from protein (about 0.8g/kg body weight). This is not the bare minimum required for survival; it's a recommendation. These grains should be sufficient in this regard. These grains alone do not have all the essential amino acids (wheat, for instance, is deficient in lysine). However, when combined with lentils or other pulses, legumes or seeds, you can get all the essential amino acids. Dried lentils and pulses have long shelf lives. The remaining necessities are all things you need in small amounts: vitamins, minerals, omega-3 fatty acids, salt, etc. Salt, of course, doesn't expire. For the others, I would raid a pharmacy or supermarket for supplements. [Answer] **If we assume *nothing* but carbs (e.g. white rice), they'll have salt/electrolyte problems before lack of fat or vitamins fells them.** But if we must add only from the snacks, the right candy may make all the difference! In the reducto-ad-carbohydrate case of white rice and *nothing* else, the lack of salt and related electrolytes will cause significant health problems within a week -- well before lack of fat or vitamins A - D become issues. So salt is a priority; ditto Potassium, Magnesium in short order. (Salt + Salt substitute.) **But what about the junk food; can it significantly help this poor diet?** If they get to choose just one junk-food thing to add to this 'diet,' what's a good choice? Candy, especially chocolate/peanut-based candies: Reese's PB cups, peanut M&Ms, Mr. Goodbar. Fat from both chocolate and the peanuts, a little salt in most candy, some protein from the peanuts, maybe a trace of fat-soluble vitamins A and D. A trail mix heavy in salted peanuts and raisins would also work pretty well, assuming that's sufficiently junky. Most chips/crisps will provide fat and salt, but not much protein. Do I want to eat this diet? No. But If I had to supplement a ton of white rice with a single junk-food choice, I'd go for the peanut M&Ms. Thence multi-vitamin pills. [Answer] Not a problem. There are literally food sources all around us. The only way your survivors would have to survive on "junk food" is if they were somehow trapped in an industrial city or in the middle of a desert, and even then they would learn to find alternate sources of food as part of surviving. If it's a situation where they have adequate clean water, they'll be able to find edibles. Once they manage to get into the country, they should very quickly find other survivors who actually know how to grow food and/or have a rough understanding of which wild foods are good to eat. Heck, they'll find good food literally growing on trees or out of the ground, if they come upon an orchard or a cabbage farm. [Answer] To summarize some of the other answers: the survivors will need to combine dried grains, dried legumes, jarred/canned fats, and canned fruits & veggies to get a complete daily meal, reserving the more limited supplies of canned meat for holidays. The many bottles of vitamins & minerals on drugstore shelves should shore up deficiencies for some time to come, while the survivors learn to turn city lots into truck gardens. (I hope someone knows about crop rotation!) There's two big problems with the "oh, it's easy" solution outlined above. One is adequate storage conditions. I was born before common A/C in the US's Upper Midwest, so I know that in most locations food would have to be moved to long-term storage in a basement, or it will go rancid quite quickly. How much gets moved puts an upper limit on the food available a year after the Disaster. This leads to the second big problem: hoarding. People don't have to hoard the entire store, just one key item in the complex set of ingredients above, to create a *famine* in a land of plenty. (As famines in our world often occur.) Most likely, the clever hoarders who stock up on fats (especially, yes, chocolate) will be the ones who find themselves both wealthy and hated. Government will be essential! [Answer] **Canned Food** Ignore the expiration dates. Canned food lasts for decades. My grandfather was an American soldier during the Korean War. Due to his special dietary requirements, he survived on food left over from WWII. Crackers stored in plastic in sealed boxes lasted (due to their low water contented.) Canned fish also lasted that long. This [article](https://www.thefitnesstribe.com/how-long-does-canned-food-last/), quoting the US FSIS says that canned foods can be safe indefinitely. **Vitamins** Modern stores are loaded with nutritional supplements. Again ignoring expiration dates, dry vitamin capsules can last at least a decade. Even if it degrades somewhat, there should be plenty to keep the survivors from deficiency. Between the two, there will be adequate nutrition for your survivors for at least a decade or until they run out of supplies. ]

[Question] [ The succubi are popularly represented as women with horns and bat-like wings. They feed on the vital energy in myths, but could a humanoid creature resembling a woman evolve and feed only on human sperm? If so, what kind of animal and environment could trigger the evolution of succubi? Note : These succubi don't really need to evolve horns and wings, just feed on human sperm and resemble a woman. They don't need to be attractive to humans. They just need an humanoid shape of any size with feminine traits and a predatory behaviour to ambush their prey. [Answer] Warning - answer below might not be suitable for some readers. Sounds to me like a parasite is the most likely evolutionary track. We can imagine a creature like [Cymothoa exigua](https://en.wikipedia.org/wiki/Cymothoa_exigua) - but instead of an aquatic crustacean, this creature is an evolved pubic louse that takes up residence in a women's vagina and eats the sperm of any male that mates with her. Evolution could favor a creature that was able to more closely mimic the vagina itself, or part there of, to better camouflage itself. Perhaps the creature evolves to produce secretions that would promote the male orgasm. Or it could produce pheromones, or stimulate its host to make pheromones that make her more attractive to males. Further, the creature could interrupt the hosts menstrual cycle to maximize its hosts sexual availability and its chances for a sperm meal. The creature could also stimulate hormone production in the host that made her sexual appetite ramp up and tended to make her seek out sexual partners. While this is not a devil woman itself, the concept is pretty horrifying. If you've a strong stomach, just look at images of the Cymothoa exigua parasite on google, and then imagine the creature that evolves to fit the ecology above....I'm not sleeping tonight. And, as described, a woman hosting this imaginary parasite would be sensual and powerfully attractive to males, while she herself would be sexually promiscuous. Any male having sex with this woman would experience an overwhelming orgasm. And of course, we must expect that during sex, the parasite would transfer eggs or larva into the mans penis, which would spend part of their life cycle in the male and then transfer via his ejaculate to infect any healthy woman he has sex with. And who knows what effects we can imagine for the infected male? Does he suffer a madness? A wasting? Other behavioral or physical changes that could be mistaken for demonic possession or infestation? The overall effects of infection, for both the male and female, might get us pretty close to the tales of the succubus from folklore. [Answer] I am going to expand on my comment on [Jim's answer](https://worldbuilding.stackexchange.com/a/120806/30492), still using *Cymothoa exigua* and holding to the same warning for sensible readers. A female parasite with similar behavior to *Cymothoa exigua* installs itself on the infected host's tongue. By removing the blood flow, it causes the tongue atrophy, after which the parasite replace its functionality. Being connected to the host's blood system, it can both have metabolic and hormonal exchanges with it. It can secrete substances that increase the host's libido and also influence the preferences on the matter of sexual act, making the host more inclined toward oral sex. Physical stimulation of the tongue/parasite causes the release of endorphins into the blood stream, giving physical pleasure to the host. The parasite can provide a stronger stimulation to the host's partner than the original tongue, and also influence the host's behavior to clench on the partner until the very end. Once semen is released, the parasite absorb most of it through its surface. And while the semen is in contact with the parasite, the parasite releases further shots of endorphins into the host's bloodstream, increasing the chances of a prolonged contact, resulting in longer nutrition for the parasite. Eggs can be transmitted by simple intimate kiss, and for what is worth the parasite can infect both males and females. The male of the parasite can be much smaller and install itself in the oral cavity, gathering nutrition in the same way. [Answer] Contrary to some of the comments, human semen does not contain that many calories (I can't find a reputable source for this I'm afraid, but it's listed plenty of places eg <https://jezebel.com/a-complete-breakdown-of-the-nutritional-content-of-seme-953356816>). A typical ejaculation contains about 20 calories, so the size of the succubus would be limited to that of a small mammal, unless it can obtain multiple feedings per night. For reference, the Eastern Gray Squirrel of 500g requires 137 calories (<https://www.jstor.org/stable/3799379?seq=1#page_scan_tab_contents>) Therefore, I would suggest that any creature that size would not be sexually attractive (to most people!), neither would it be big enough to ambush a human to forcefully harvest sperm (Perhaps they work in packs?!). It would have to either have some sort of secretion or venom that would render its target unconsious or paralaysed, or as suggested, be able to manipulate the dreams of the target and feed on their wet dreams. [Answer] Alternative track: I think you're focusing on the physical instead of the traditional feeding. They weren't surviving on the physical result, they were eating the soul/emotion of the victim. The sexual coupling was either to make the spiritual connection (remember, most pre-modern and many modern folks think of sex as a spiritual connection) to feed. In some variants, it was just the bait, and the sex was irrelevant while the demon ate your soul. If you're going for a less spiritual more "real-world" version of them, think "energy vampire". [Answer] If they only attack whilst someone is dreaming then they don't need a full human form. The creature could be a worm that expands as it engulfs the man's penis. A regular undulation along its length will do the trick. On awaking the victim remembers what he imagined in his dream - a seductive woman. Because of its relatively small size, this explains why the energy needs are low enough to survive on semen alone. A good habitat would be hotel rooms where there is an ever changing supply of victims. [Answer] I'm not a biologist, by I love evolution and read a lot about it. As you require "humanoid creature resembling a woman" and "feed only on human sperm" I think: * The closer the common ancestor with humans, less time required (and more probably) to [converge](https://en.wikipedia.org/wiki/Convergent_evolution) in human shape. * That adaptation is more probably to happen if the ancestors already have some parasitic behavior and adaptation, even more if with humans. So, it just turns from one to another kind of parasitic relationship. * Although semen has high concentration of nutrients (specially rare oligonutrients, like Zinc), it's not very abundant. So, at least in the beginning of the drift into a new species, should have low requirement of energy (one ejaculation has 20 calories, 150-250 mg of protein) or maybe feeds mainly with another thing but requires semen for some rare nutrient which can't produce (zinc, vitamin B12); maybe both. Consider that, I think that an evolution of a bat is a good choice; although probably not the only one. Imagine that for some time in some place, in which ancestors of current humans and bats coexisted, the last ones have some temporary limitations with their diet. 1. Difficulties to hunt another kind of prey, made them shift to humans ([this already happened](https://www.livescience.com/57521-vampire-bats-drink-human-blood.html)). 2. Some of these have some mutation that tends to feed more from males than females (detection of hormone levels), are favored with a little more blood, increasing survival rates of those. 3. It is known that in some context pain can cause erection, ejaculation with or without pleasure. AFAIK, this is matter of study, but at a [chemical and neurological levels](https://www.nature.com/articles/nrn2333) it seems that are very similar. So, we can imagine (I think it's very unlikely but not impossible) that they start to bit man penis while they sleep. Note that vampire bats usually do not perform severe damage, as they have sharp teeth which use to cut and then ingest the blood with their thongs. In this situations, this subgroup has the advantage of more blood and less complications (no bones). In the case of an event of ejaculation, they could have —in addition to blood— the nutrients that are missing. 4. But, as you can imagine, when humans wake up that would be very unpleasant. So, after thousands of years, they adapt to look (woman) and feel (less pain) more pleasant. And because of that, the ingest of human blood became rare (other animals are less dangerous) and the parasitism with humans tend to the ingest of rare nutrients through semen. Other observations: * Regarding to the size, there are two opposite pressures here: look like a real woman (taller) and reduce energy and nutrient requirement (smaller). So, they should be petite at least. * Probably do not have the capacity of reasoning or talking like a human because they do not needed (and it's something very complex). Maybe mumble some words like a parrot can learn (imitating real women and by try-error). * As it is risky, probably only pray humans when there is a lack of nutrients, or when the requirement is higher (like pregnancy, as with mosquitoes). * Because of the low amount of semen a man can ejaculate, when in need probably feed on many men. * As they only look as a woman when needing feed on men, we can think that have many [stages of metamorphosis](https://en.wikipedia.org/wiki/Metamorphosis). They lost their wings in the stage of human depredation, and probably in the next stage have something like wings but not so efficient. Also, in some individuals the metamorphosis fails. Both details could be related with emerge of cultural image with arms and wings, but do not have both at the same time. [Answer] One form of succubi were ones that stole semen and used it to impregnate women. This could be done if the succubus' vagina was like a hemipenis, that could invert to work as a vagina, and then become erect to work as a penis. This could happen if an ancient society bred a group of humans to impregnate women randomly, perhaps to avoid inbreeding depression ]

[Question] [ A somewhat benevolent, previously unknown superpowered flying knight, appears out of thin air and upon arrival (somewhere between New York and Washington DC) the USA government took him for an hostile and attacked first. He is impervious to any conventional weapon, and Uncle Sam won't nuke his own turf. He could remain still and wait for them to just tire off, but his knightly code demands you retaliate any attacks on your person (unless its children throwing rocks or something like that). So he knocked down a few dozen jet fighters and tossed tanks around, opened one aircraft carrier like a can of sardines and the Pentagon is now rather aggravated. He took the care not to kill anyone yet, but he is not above killing adversaries. After this first exchange, what would be the fastest way for this knight to end hostilities without surrendering (yes, his knightly code forbids surrender)? Assume he is very smart (but not a genius) and has knowledge of our laws and government, including structure and chain of command (but has no obligation to follow U.S. law). [Answer] Ah, what an exquisite pseudo-legal question. First, I have to second @zxq9 's objection; if he's totally impervious to any conventional weaponry, then US military functionally *are* children throwing rocks at him. But lets say that it's the intent that counts, or that maybe he's not *totally* impervious and could come to harm if he just let them attack without defending himself at all. Then there is a couple of salient points. ## Surrender and Knightly Code To start with, I find it rather uncharacteristic of a knightly code to contain a stipulation against surrendering. This would be the case for codes of honor among the honor-before-reason Proud Warrior Race guys (think Spartans), where their conviction of their own absolute martial superiority would be central to their self-image, so surrendering would be unthinkable. Knightly codes (such as they were and what there was of them - keep in mind that what we have today are heavily romanticised and idealised versions that almost nobody actually followed) were codes of *ethics* as well as codes of *honor*. Knights would usually be expected to fight other knights and it was well understood that sometimes God, or *fortune la guerre* might favour the enemy. In such cases, while outright cowardice was absolutely condemned, simply acknowledging defeat by surrendering would be perfectly acceptable. In other times, overriding ethical concerns would force the knights to surrender without even trying to fight; example of this is the famous case of Johannites (aka Maltezian Order) surrendering Malta to Napoleon without firing a shot because they considered it unacceptable to fight fellow Christians. But let's accept that for the sake of the argument and see what we can do about that. ## The Knight's Perspective Assuming that the Knight's Code was designed with realistic warfighting in mind, even if it precludes unconditional surrender, it is sure to permit other means of ending the conflict. Fortunately, all the various [Laws and Customs of War](http://en.wikipedia.org/wiki/Law_of_war#Purposes_of_the_laws) have facilitating the restoration of peace as one of their primary purposes. The knight should thus be permitted to use some means of negotiating the end of the conflict; in history these would be variously called *offering terms* (which has a wide variety of meanings, and could include anything from total surrender of one side to some sort of compromise), *suing for peace* (which is a negotiation to end a conflict before its definitive military resolution either way), or *offering white peace*/*status quo ante bellum* (essentially let's stop shooting and pretend this never happened, War of 1812 and the Indian part of the War for Austrian Succession were concluded this way). If he is familiar with some of the basic customs, he could try brandishing a [Flag of Truce](http://en.wikipedia.org/wiki/White_flag), riding up to someone responsible and offering terms under which hostilities would end. Depending on how he's feeling, and what his Code requires of him, this could range from simple cessation of hostilities (the *white peace* option), or he could demand some sort of satisfaction as war reparations. If the other side accepts, he has concluded the "war" honourably without surrendering. ## US Perspective In a situation where most of the might of the US military has already been tried and found impotent, there will immediately be powerful political desire to end this quickly, preventing further casualties and embarrassment. Can the Knight present himself as a representative of a foreign sovereign power? If so, then this might be the best solution for the conundrum. If he deigns to negotiate for terms and presents himself in such a way, then US is in fact in breach of international law, because it has engaged in an act of war without a formal declaration thereof. Furthermore, this is probably *also* a violation of the US Constitution - I am not an American, but I seem to recall that only a vote of Congress can authorize a declaration of war or other military action against a foreign sovereign power. This is sufficient justification for the US to acknowledge their mistake, agree to cessation of hostilities and offer whatever reparations might fit the satisfaction requirement. And to do so quickly, before this becomes an even bigger political disaster. The political fallout is going to be tremendous; heads are gonna roll, metaphorically speaking. Expect whatever military commanders authorized the initial attacks to be court martialled and called to task for the loss of life. The cabinet might catch some heavy flak for allowing the whole thing to happen in the first place. And if the Knight doesn't call himself a representative of a foreign sovereign power? Well, the US might just unilaterally declare him that - as a legal fiction - in order to save face. [Answer] I'd suggest that he go get something to eat. No, really. If he goes into a restaurant and orders something to eat, the army's not going to attack him - there are civilians in there! If he's not being aggressive while he's in there, they're going to send someone in there to try to talk to him. It might help if he started talking to some of the people in there to show that he's willing to chat. Also, he should avoid the appearance of taking hostages or using human shields. One way to do that would be to make sure that he is in a place where people are frequently entering and leaving. This also has the benefit of providing more character witnesses for him - "No officer, he wasn't killing anyone. He seemed to be enjoying a cup of hot chocolate." Part of the reason why this would work is that it immediately removes him from the context of an aggressive situation (he's damaging their fancy toys) and into a social one (many people like to chat while they eat). Another part of why it works is that it is unexpected - the military would be expecting him to continue to attack and destroy more vehicles and ships, so doing something else should cause them to re-evaluate the situation. What if the military attacks him anyway while he's in the middle of a bunch of civilians? This demonstrates that the military does not value the lives of their own people and that they're quite incompetent. He's already demonstrated that he is far more powerful than them, so if they aren't going to take the opportunity to talk with him it makes for a strong argument that that military deserves to be dismantled. [Answer] Sir, we have reports that the, um, rider, flew into our military complex at Torf Edaem, Maryland, where he **secured a nuclear weapon**. Everybody stopped shooting at that point. He is currently on the front lawn of the NSA, where his Pegasus is eating the grass, yes, with the bomb strapped to the saddle, while the rider is **sipping tea with Admiral [Rogers](http://en.wikipedia.org/wiki/Michael_S._Rogers)**. [Answer] Assuming he can't, you know, just talk to them somehow, a [White Flag](http://en.wikipedia.org/wiki/White_flag) is almost universally recognized as a temporary truce/parlay symbol. While white flags are often used by a weaker party to surrender, that's not a requirement - using them to open negotiations is perfectly valid, and he's under no requirement to surrender because he's uses one. [Answer] The knight has several options when it comes to dealing with hostilities with the US. The first is pretty obvious but depends how he views the US military's corrupt in regards to his own benevolence or knightly code: The immoral choice: Offer to work with the US and/or US military. Simply put, he could bust into the white house, meet the president, and offer to help the US (whilst beating up any secret service goons dumb enough to try tackling him etc). It'd be somewhat unceremonious, and the military would poop pants, but they likely couldn't shoot or attack without risking harming the president. Once the president agrees, or is for some reason, stupid enough to disagree, he would then leave. In the former case the military would stand down, blah blah, look at this cool guy we have. If the president disagrees then he waits until a new president turns up and then offers him. Rinse, repeat. The neutral choice: If he's capable of flight (it's unclear but he must be if he can open an aircraft carrier in the middle of an ocean like a tin opener), he merely develops technology to communicate (or we assume he has a sonic boom esque voice) with the US, and stays in an orbit high above the US where no conventional weapon can reach him (any nuke weapons at the right height will merely cause a HEMP which would damage/radiate the US infrastructure). During this time he offers the US a choice: either cease hostilities, or he will go assist another country like Russia/China etc (because he's knowledgeable on geography and who they're opposed to). Chances are the idea of a super-powered individual assisting another country is usually enough for the US to about turn. (In this scenario, if he cannot fly, then he merely swims to the bottom of the ocean where no nuke could reach him, and if he cannot breathe underwater, he merely hides or drills into the ground, whatever his unique talents are for evasion). The moral choice: He goes about helping people. Not just anyone, but solving massive issues, like crop failure and poverty or whatever his talent is for. Presuming he has flight (aircraft carrier/jets) or super-speed, he merely goes from one person to the next at random (evading military attacks as best as possible). The military could try to shoot him but would risk civilians in the process. If he's seen as helping civilians, then he would eventually be seen as a good guy and his reputation would spread. If the military still doesn't turn by this point, either an open revolt from the people (glad to have a hero) or democracy will kick in. The lazy option: Do nothing. In all case scenarios, regardless of what he does (aside from relentlessly murdering people or doing evil), he wins. Either the military tire (it'd be pretty expensive to keep replacing equipment), the people appraise his good deeds and scorn the US military for their attacks on him, democracy wins out or the US twig they're better off with him as a friend than a foe. Heck, the continuous attacks assume the US military are dumb enough to ignore the fact he's superpowered. After he survives the first explosion or blast, they will figure they can't beat him conventionally and cease anyway. [Answer] If his knightly code allows for it, he could single-handedly defeat any enemy the US is currently at war with (ideally one the US is currently losing against), thus demonstrating both his superior power and the fact that he's not hostile to the USA. I think after doing so, the USA will be more than willing to make peace with him. [Answer] So, as he's impervious to any conventional weapon, why won't he just walk right into the white house/pentagon/wherever, kidnap the president and declare himself the new president. Of course nobody would like it, but it would be the fastest way to end hostilities as such a *tour de force* would make quite clear that fighting him is useless. Additionally it fits the knight theme as a knight always fights for someone, so he is just claiming the territory for whomever is his lord/king. That's what knights do. If he just wants peace as quickly as possible he should just walk into a lot of media studios and have them interview him. That way he can explain his actions, get the public to like him (american dream and stuff) and probably after a couple of assassination attempts the US government will also decide that talking might be a better option. [Answer] **Declare himself to be sent by God.** Given his demonstrated abilities and the general American populace’s openness to religion¹, he could immediately acquire a relevant portion of the population as adherents, which will thus oppose any attack on him. Most importantly, this renders any attacks on him disadvantageous even from the government’s and military’s point of view, no matter what he outcome: * If successful, a disastrous religious tormoil would almost be inevitable. * If unsuccessful, the knight’s claim would be strengthened. --- ¹ though you probably do not even need that [Answer] A common enemy, of course. It could be a super villain coming from same place as the knight. Or just another earthly superpower (Russia or China). They could act on "good" intentions (the knight is too dangerous to humans), "neutral" ones (they conclude the knight is USA new superweapon undergoing trials), or plain "evil" (USA is busy with alien invasion? That's perfect opportunity for a first strike!) This way or another, **they** have no problem nuking **USA** turf so the knight and White House have pretty much no other choice but truce, and very little time to achieve it. [Answer] Go break off an iceberg and buy a thirsty country (metaphor) then use your advanced capabilities to start an empire under the assumption the world is your army and winter is comming. Why have your knight calm down the US when he can just take over the world? What would a strategic war fighting mind find to be his purpose upon discovering a planet covered in diverse massive social structures of humanoid lifeforms? Since the character's understanding of his purpose is so closely linked to his faith that he believes his life is counter productive to his mission... if it is not ethically bound in this "knighthood" ... It stands to reason there is no way to understand how this charecter would react without some backstory that would help us gauge his reaction to being attacked. But yah for the record: "Gather resources, recruit numbers." If one lives by a no surrender policy, then the scenario ends one of three ways. He dies, I die, or he surrenders. He dies, you die - easily simplified... He surrenders -infinitely complicated. Need back story to help simplify. [Answer] > > He is impervious to any conventional weapon.... his knightly code > demands you retaliate any attacks on your person (unless its children > throwing rocks or something like that). > > > I think these are very relevant - what's the difference between a child throwing a rock and a US military throwing what are little more than bigger rocks? The intent, but then maybe the children throwing rocks intend to hurt too. So could he simply shrug and treat the US military as a bunch of children? They are as effective as children as far as he is concerned, and perhaps he could consider them child-like compared to his superiority. [Answer] **Step 1: Flee** Do as little damage as possible. Avoid the US and it's agents at all costs. He is too small to be reliably picked up by radar or heat-seeking missile so this should be easy even if he flies at subsonic speeds. **Step 2: Seek Asylum** Use another country as a political buffer. Speaking with another country, via telephone at first and later in person, would be reasonably easy as far as I'm concerned. Find a country that would love to score points of a US military debacle, to come in as the cool-headed peacemaker. Ultimately Russia would love to get some political points out of this, but it would be advisable to start with a country less unfriendly to the US, like India or Germany, to grant asylum. At this point, the US will cease direct military action and will be forced into diplomatic solutions to save the valuable working relationship with that country (even the US relationship with Russia, for instance, is tremendously valuable, strained though it may be. Damage to it is taken only for serious reasons.) At this point, in only a matter of hours or days, the first and most important aspect of peace has been granted. The cessation of military hostilities. But we would like to go further. **Step: 3 - Politics** Make people like you. Kiss babies. Save people from burning buildings. Give speeches about racial equality. Get on Oprah or the Today Show. Sing it's not easy being green with Kermit the frog. Get a slot on Sesame ST. During this time, all the head-rolling and inquiry into the disastrous handling of the initial encounter will shake out. Everyone will distance themselves from the damage. A few war hawks will maintain that he is a threat, terrorist, fake etc., but politicians by and large will benefit more from peaceful rhetoric. At this point he can move for a more all-encompassing peace with the US. He will offer photo shoots and major political points in exchange for help in this regard. He might have to wait for regime change(mostly in the presidency) to make this move, but it will complete his peace with the USA. **Notes:** The USA has been carrying the biggest stick on the block since at least 1945. We like to think we use our military muscle for good, but the fact remains we feel pretty secure about ourselves. It would be politically difficult to accept this guy, because we can't manage him. We can't control him. He can spy on us, kill the president, any number of terrible things, at any time and without warning. The all encompassing, baby kissing peace would hide a deep resentment and mistrust by the military, secret service, CIA, NSA etc. He would have to convince them that publicly being at peace with him was the best political option, even while at the same time racing to develop radar and other countermeasures to reassure ourselves of our own security. It would be a tough balancing act but it could ultimately give him the greatest peace, freedom and good relations with the US that I can think of. [Answer] By "cease hostilities" I assume you mean get the situation beyond a tactical cease-fire, to some fairly high-level order given not to engage the knight. I also assume you want the hostilities to end in such a way that this knight and the U.S. can move towards a friendlier relationship, which is predicated on the knight not having removed enough of the line of succession to the Presidency that the U.S. government can no longer function. If the knight is completely impervious to conventional weaponry, depending on how fast he could move, the best option IMO is for him to kidnap the President, take him somewhere protected, and sit down to negotiate a cease-fire, before returning the President, unharmed, to the White House. This is a risky move. Within minutes of the President's removal from wherever the knight got to him, the VP would take the oath of office. The knight would have to convince the President he'd kidnapped, after returning him safely and thus allowing him to reassume power, to call a cease-fire. The President would then have to convince his own staff that he isn't still incapacitated by being under some form of control by the knight. The best overall option is to kidnap the President in his own home. Land right in the Rose Garden, let himself into the Oval Office, and sit down next to the President for a little chat. Within a few seconds of this stunt, the Secret Service will be in the Oval Office as witnesses, unwilling to open fire on someone demonstrably impervious to bullets with their own President mere feet from him. The knight and the President can then negotiate relatively cordially, assuming the President hasn't crapped his pants by now. ]

[Question] [ Let's say that a long, long time ago, on a world not too different from our own, there walked a prophet, a divine figure. He went about doing various deeds, and eventually died. A religion sprung up around him.1 A long, long time later, when the religion is well-established, the prophet returns, resurrected. The trouble is, he needs to convince people that he is who he says he is - the messiah, the savior, etc. Could he simply perform some miracles? Yes. But that's way too boring. In my story, I want the deity in charge to stay out of this. The prophet has no magical powers whatsoever. He has all the normal powers of a normal human being - i.e. not much. It boils down to this: How could a resurrected Jesus prove that he is Jesus? --- 1 For all intents and purposes, the technology, society, etc. were that of the area around Nazareth. Yes, this is supposed to be similar to Christianity. But don't read too much into it. [Answer] **He can't** The Christian definition of Messiah requires certain [signs of proof](https://clas-pages.uncc.edu/james-tabor/archaeology-and-the-dead-sea-scrolls/the-signs-of-the-messiah-4q521/). He must: 1. heal the wounded 2. revive the dead 3. Bring good news to the poor No miracles from NotJesus means by definition he isn't the Messiah. The [Jewish Definition](http://www.jewfaq.org/mashiach.htm) states that the Messiah must: 1. gathering of the exiles (For most modern Jews, this gathering applies only to the house of Judah). 2. restoration of the religious courts of justice 3. an end of wickedness, sin and heresy (not sure how a no-miracles Jesus is going to be able to do this.) 4. reward to the righteous (A no-miracles Jesus is going to have trouble scaling this up in any meaningful, tangible way.) 5. rebuilding of Jerusalem (how would you even interpret this? Jerusalem is a living city now.) 6. restoration of the line of King David (Not sure how you'd prove this as no DNA from that period exists or is trustworthy.) 7. restoration of Temple service (Doing this requires removing the Dome of the Rock from the Temple Mount in Jerusalem. A no-miracles Jesus is going to find himself very dead from some very very angry Muslims.) Any kind of no-miracles, not-Jesus isn't going to get anywhere. [Answer] A [Focault's Pendulum-esque](https://en.wikipedia.org/wiki/Foucault%27s_Pendulum) idea which - I admit - is shifting the problem a bit is the following: --- **What would you do if you *were not* the Messiah?** # Hire a master conman! ## [And maybe a spin doctor and a former secret agent.](http://tvtropes.org/pmwiki/pmwiki.php/Main/ThreeAmigos) Before you rule this out, remember than secret agents and conmen cheat *banks* and *the military* for a living, and those guys are *very serious* when it comes to proofs of identity and authenticity. You know what *could* work for example? Some variation on [Astroturfing](https://en.wikipedia.org/wiki/Astroturfing). Stealing a bit from @Green's [answer](https://worldbuilding.stackexchange.com/a/20244/10791), have Jesus **pretend to be an average guy who really doesn't care for publicity.** But have him occasionally "slipping". Revealing details that *only the Messiah* could know. Meanwhile, his secret consultants (the spin doctor and the secret agent) would work so that these "slips" would have maximum publicity, would give help to a bunch of local lunatics that would worship our "reluctant" Messiah much in [the style of Brian of Nazareth](https://www.youtube.com/watch?v=0uMJYQ9LKGQ). Create photo opportunities. Maybe organize meetings with third world country dictators, just [because](http://tvtropes.org/pmwiki/pmwiki.php/Main/RuleOfCool), and then the Pope. Once you've gained enough momentum, it's all downhill. You have **successfully started your own cult**, now expand it in the traditional way cults do. With the help of some good PR and having The Real Messiah on board, you'll get to having 10-20% of the population on your side quite easily. --- EDIT ## Bonus justification While we are at it, you know **why** you need all these shenanigans? Because turns out that while our guy *is* the Messiah and did in fact experience death and resurrection, **believers have got it all wrong**: as @Susan points out, [there is no room for a "resurrected Jesus"](https://christianity.stackexchange.com/questions/27694/fake-jesus-reincarnations/27712#27712) in their eschatology, so you **have to resort to this kind of trickery**. Of course, your arch-enemy (the Devil himself?) made sure to pollute religious scriptures historical sources to add this apocryphal clause. --- **Nota Bene: I've edited this answer substantially. Multiple times.** [Answer] For inspiration, you might want to read the "Joshua" series of books (by Joseph Girzone). In them, there is this "ordinary" person called Joshua who wanders into (a modern) town one day. He is simply dressed, doesn't appear to have any luggage. In some stories he lives in a cabin on the outskirts of town. He is kind, soft-spoken. People are drawn to him. In return for a bed and a meal, he does odd jobs - carpentry, mostly. But the "miracle" is in how people all around react - good and bad. Sometimes, sick people do get better - but that's not central to his powerful influence. In one of the stories, "Joshua and the Children", he is in Northern Ireland, and the Catholic and Protestant children end up playing together, to the surprise (and sometimes disgust) of their parents. Good parables - exposing how "organized" religion (of any flavor) sometimes misses the point of the original message. Actually - the current Pope seems to have read these books... And maybe they can provide some inspiration for addressing your particular story line? [Answer] EDIT In response to some valid objections I make the following changes. God created the world with hidden artefacts embedded in rocks. Each time the messiah visits Earth he reveals the position of just one of these artefacts. Because he is the son of God he knows where they are. For added interest they fit together like a jigsaw puzzle. The parts recovered so far are preserved in a temple and added to each time he is reborn. HOWEVER If the deity isn't allowed to leave artefacts, the messiah can reveal the positions of natural features such as unusually large diamonds that can be found embedded in old rocks. He knows where they are because he asked when he was in heaven. That way he didn't have to perform a miracle on earth - just remember where to look. --- OLD ANSWER He says that he comes back to Earth every 100,000 years and has been doing so since the Earth was formed. He tells his doubters to tunnel into an ancient mountain. There, millions of years ago, he hid a time capsule. Over the aeons it has become encased in solid rock. Hiding the time capsule didn't require a miracle because the rocks hadn't formed yet. Digging the capsule up doesn't require a miracle because it just needs dynamite and earth moving equipment. Telling people about it doesn't require a miracle because, if they believe in messiahs, they must believe he has a soul and be willing to believe his soul retains the old memories when he returns to earth each time. [Answer] **He might, maybe** The only thing he'd have with him is his knowledge and whatever physical marks from has past life came back with him during resurrection. **Physical marks** Physical marks could be faked because they are so well known. Anyone can put giant scars on their hands, wrists, feet and left torso so that's only proof that an imposter knows how to read. (Though that's a crazy amount of dedication for someone who's not really Jesus...though people in Mexico crucify themselves as a show of devotion.) Physical marks might be enough for some really zealous people. **Explaining the lack of a light show** He would have an incredibly hard time explaining why he didn't come back in a show of great power like the religious texts say he will. Maybe he would tell people that his appearance without power is a test. It's broadly known that the Jews were expected a political messiah to save them from the Romans and didn't get that from Jesus' first visit. What's to say his second visit won't be different than what people expect again? **Appeal to Authority** If the Pope testified to the world press that Jesus was back in the Vatican, that would convince a lot of people, not all, but very very many. So, Jesus would need to prove to all the people between the Vatican gates and the Pope that he was the resurrected Lord. Given that Jesus would be intimately acquainted with the details of his own life, he would be able to clarify and explain a lot of weird passages that don't make any sense or fill in holes where there just isn't any detail. Scholars in the Vatican have spent their lives devoted to the records of Jesus' life. For him it would be along the lines of "Yeah, I remember doing that. That wine *was* better at the end of the party." It will take a while to establish his knowledge as better than someone with a really good imagination but I think over time, it could be done. **Physical Presence and Intelligence** Jesus was well known to have taught "with authority and not as the priests" and to be extremely charismatic. Teaching on the streets would demonstrate this ability and begin to grow a following. Shutting down the opposition in extremely clever ways was a specialty of his. Our resurrected Jesus will need to continue the teaching, cleverness and charisma. **There won't be absolute proof** No amount of evidence is going to convince everyone. But, for people who have studied his pre-death life enough will see signs indicating who he is. Their confirmation bias should take care of the rest. [Answer] > > The thing with religions is that they are mostly designed to be > 'unprovable' and encourage widespread scepticism within their > followers. - DA, in comments. > > > What if it was not? What if a religion provided strong evidence, after all if the person in question has been reincarnated/resurrected then by definition it's not fake (and beyond current science). What kind of evidence would we need to prove that this prophet has been resurrected? **He needs to be recognisable.** Jesus had eyewitnesses and would have been recognisable to a large portion of the public. If he looked even a little bit different, that would have been picked up instantly. Given the requirement for this to occur a 'long, long time later' you'd need some detailed documentation describing his appearance e.g. a painting or photo. **He needs to be identifiable/USP.** I've heard in security that someone's identity is merely the thing they can do, that no one else can do. For example, I know my password for my bank, no one else does, therefore the bank can ID me. Even without supernatural powers or knowledge, holes through the hands, a second head (total recall) or some other rare attribute could ID him. **He needs to fulfil a prophecy.** Jesus's entire life was a completion of thousands of years of prophecies. While I could imagine this step could be skipped, it would not be in character for a prophet not to use prophecy. **He needs to be falsifiable.** Jesus's body was left in a heavily blocked tomb, guarded by soldiers and was considered a criminal. The Romans were powerful enough, motivated enough and had the evidence to show that he was really dead - but could not. In the same way it gives credence if your opponents have the motive and means but still cannot disprove your existence. As a thought experiment, let's change from 'prophet' to 'eccentric billionaire'. If a billionaire followed this checklist, and wanted to appear some time long in the future (e.g. cryostasis) he could: Recognition: Ensure people know what he looks like (e.g. detailed records of his appearance made, maybe put his face on a banknote). Identity: He knows some password, or has some physical attributes (e.g. dna) that are unique to him. Fulfil prophecy: Just rockin' up in the future isn't going to be much good - his estate will have been distributed to his heirs. Instead he carefully wrote his will to place his fortune in trust for himself in the future. Falsifiable: To prevent forgers/clones etc. he knows a secret password that identifies him, where the answer has been well protected (e.g. parts spread over several bank vaults - using advanced encryption techniques). If someone rocked up tomorrow with that much evidence, even if it seemed impossible that it could occur (say Thomas Edison) then it would be hard to conclude he is not who he says he is, even if the mechanism of his appearance is inexplicable. [Answer] Considering the fictional application, hear me out. Because you proposed a resurrected Jesus... Perhaps the most undeniable way to prove that he is Jesus is to die and be once again resurrected. Anyone who previously doubted that he was Jesus could certainly believe that he was dead and risen. Jesus was famous for that. Hence he is probably Jesus. Otherwise, he has no super powers and performs no miracles, as you desire. He lives like a normal human. He dies like a normal human. But he just keeps coming back! The second coming? How about the third, fourth, etc? This opens up many possibilities. It could become humurous and/or advantageous. Imagine what you can do with that in a story. This is just a thought and I hope it helps. Good luck with your work. [Answer] If he knows he is going to have to come back, and he will need to prove who he is, he is going to need some sort of proof that can't be faked. (And he knows he can't simply perform miracles again the second time he comes to visit.) He will be henceforth become **Fingerjesus**, for he is going to abuse his ability to heal the injured by cutting off his own fingers, and then healing them again. He hands these out to all his followers, so that they will become sacred relics of sorts, I mean, who doesn't want to have a fingerbone from the prophet Fingerjesus? Back then, DNA was something nobody understood, but these days that is no longer the case. Upon his return, he will let anybody who doubts his claim do a DNA test on his blood and one of the many relic fingers that he has spread in his "previous life". The DNA test will come back positive because he is the same person, thus proving his claim. The only thing people could claim at this point is: * He somehow altered the DNA of all the relics in the world. * He somehow altered his own DNA. * He is not actually Fingerjesus returned, just a clone. None of those claims would get any wide credibility I think. [Answer] How about a different sort of blood test? I imagine he'd be the only living, walking haploid human in existence. [Answer] Chasly's revised answer isn't too bad but all you need is for the character to nonmiraculously recall from his memory that a single, sought-for object is in a certain hidden location. For example a certain clay bird is buried in a particular place in a certain Qumram cave; excavation confirms that no-one has touched the object for 2000 years. (In fact, clay birds arise in certain legends regarding JC.) Alternatively, no artifact is required. Your JC recalls some information that fills in a gap in extant Dead Sea Scrolls, and scholars unanimously agree that the new information fully explains certain mysteries, say about the role of St. James. I interpret your question to be related to writing fiction and not to the actual questions of JC's existence, divinity, intentions, etc. [Answer] I don't think it's possible to answer this question without getting more information about what your Messiah figure is supposed to be like. If you're talking about the Jesus of the Bible, the whole point of the story is that he was God come to Earth as a human being, and thus able to perform all sorts of miracles. As Green says, if someone came along today claiming to be Jesus come back, but he can't perform any miracles or supernatural signs, I'd think pretty much every Christian would conclude that he is NOT Jesus. If you're inventing some fictional religion with a fictional messiah, of course you can ascribe any characteristics to him that you want that make your story work. But if he has no supernatural powers or anything else unusual to distinguish him from a normal man, what is it about him that makes him a messiah and not just "some guy who talks about religion"? If the idea is just that he is the reincarnation of this past religious leader and there is nothing else unusual about him, then I think almost by definition the only way he could prove that he is who he claims is if: (a) He can be shown to be "just like" the original person, e.g. has exactly the same DNA or something of that sort. But if he's supposed to have come the first time hundreds or thousands of years ago, I don't suppose anyone back then analyzed his DNA. Maybe if some artifact with his DNA from that time still existed, it could be analyzed. Like theoretically, if someone came along today claiming to be Jesus, maybe his DNA could be compared to the DNA in the blood on the Shroud of Turin, assuming anyone could actually get an analyzable DNA sample out of that. Or you could suppose someone finds the Holy Grail, etc. (b) He might know something that only the original religious leader would know, but that can be verified after the fact. Like he could tell people the location of some artifact, and then people go and find it. Though that wouldn't prove that he was actually "the man", but just that he was around thousands of years ago to have seen this artifact buried. Though maybe that would be enough. Of course any proof would be subject to trickery, like if he gave the location of some artifact and then people dug it up and confirmed it, maybe he secretly buried the object himself just a few weeks ago, and in general manipulated the site to make it look ancient. Etc. But you can say that sort of thing about any sort of proof of anything. If someone claims to have proven that the butler committed the murder, maybe the evidence is fabricated, etc. [Answer] Easy: So, you return to the Earth, and for the moment keep absolutely silent about the fact that you are the messiah - that will get you locked away in a padded room. Instead, write down a bunch of facts you know about the state of cities/towns/the world back when you first lived, using only the superpower of memory. THIS is what sets you apart from normal humans (of the current era). Convince an archaeologist to investigate one of your digs, where your predictions as to locations of objects are completely correct. Once you have one documented case, archaeologists will flock to you to get tips on where to dig next. Once you get 10/10 right, people will have no choice but to accept that you are a resurrected Jesus, because the only other possible alternative is that you are a time traveler, and that is exactly as unbelievable anyway. [Answer] **He can't.** The prophet may be able to convince some people that he is the resurrected Jesus$^1$, but he won't have any conclusive proof. The earliest Gospel in the New Testament, Mark, was [written sometime *after* 66 C.E.](https://en.wikipedia.org/wiki/Gospel_of_Mark#Composition) by an [anonymous author](https://en.wikipedia.org/wiki/Historical_reliability_of_the_Gospels#Authorship_and_date). That's at least 35 years after the apparent crucifixion of Jesus$^1$. [No one who would have actually met Jesus$^1$ actually wrote anything about him](http://www.holybooks.info/mark.html). Worse, they probably didn't get a first hand account, as any contemporaries would have to be far older than the [25 year life expectancy of the time](https://en.wikipedia.org/wiki/Demography_of_the_Roman_Empire) nor did they speak the language. So, even if this person was the actual reincarnation of Jesus$^1$, he would probably not match the description given in all existing evidence. Though people might expect that, it certainly reduces the availability for producing evidence. His only chance of providing evidence for his divinity would be through the use of miracles or very clever magic tricks. Or simply abandon evidence and turn on the charm. $^1$Not [*The* Jesus](https://yeahiknowitsucks.files.wordpress.com/2015/02/jesus.jpg) EDIT: There seems to be a clear misunderstanding of what life expectancy means. Or at least, it's a subject everyone thinks that there are the only ones who understand it. It's not a maximum, this is obvious because the Jesus character lived to be 33. It's an *average*. It includes childhood deaths, which lower the average. I linked to the table, but I'll calculate some conclusions here, for those who don't wish to do the simple math. The apostles were younger than Jesus and at least one would have needed to live 35 years to write the gospel of Mark and a couple others would need to live up to an additional 30 years to write the remaining and final gospels. Let's see what it takes assuming the apostles were all 25 year old men. These [are the dates](https://en.wikipedia.org/wiki/Gospel#Dating) of writing along with the probability that, when the gospel was written, **any** specific 25 year old man in the Roman Empire contemporary with Jesus was still alive (just *alive*, not the author): Mark was written around 68 C.E. - 13.5% probability any particular contemporary of Jesus was still alive. Matthew was written around 70 C.E. - 13.5% probability any particular contemporary of Jesus was still alive. For the entire population of 25 year old men that were contemporary with Jesus, [13.5% would survive to be 70 years old](https://en.wikipedia.org/wiki/Demography_of_the_Roman_Empire#Mortality) (40,201 of 100,000 make it to 25, of those, 5,432 make it to 70 years old. 5,432/40,201 = 13.5%). Luke was written around 85 C.E. - 2.34% probability any particular contemporary of Jesus was still alive. For the entire population of 25 year old men that were contemporary with Jesus, [2.34% would survive to be 80 years old](https://en.wikipedia.org/wiki/Demography_of_the_Roman_Empire#Mortality) (40,201 of 100,000 make it to 25, of those, 944 make it to 80 years old. 944/40,201 = 2.34%). John was written around 90 C.E. - 0.55% probability any particular contemporary of Jesus was still alive. For the entire population of 25 year old men that were contemporary with Jesus, [0.55% would survive to be 85 years old](https://en.wikipedia.org/wiki/Demography_of_the_Roman_Empire#Mortality) (40,201 of 100,000 make it to 25, of those, 225 make it to 85 years old. 944/40,201 = 0.55%). This is excluding any correlations those specific people might have, for instance the fact that nearly all of the apostles were *executed* for what they were teaching or the significant amount of travelling they did. [Answer] One thing that comes to mind, especially if you're writing to an actually religious audience, is to have him come into the world as a man like the others, and throughout his life, people who get close to him, help him out, and appreciate him as the "good person" he is have good things happen to them over time. They go on to positions of power, in the local established religion, the aristocracy, the military, etc. Everyone who was ever nice to this Jesus character ends up really well off. After all this, from their positions of power, they realise he is a bringer of good fortune, and start believing his claims of being a prophet. This kind of gets around the miracle caveat, since it's not technically circumventing any law of nature for this to happen. [Answer] Talk is cheap and as far as I can see that's the only option you've left the returning prophet. I suppose they might possess some object or other that would be evidence, but it would depend on technology levels whether that could be tested to the point that it established the prophet's claims. So, "no" is the answer, given your restrictions. But the other side of that is that there's no more stopping the prophet from being believed than there has been for a legion of fakers down the centuries of our world. Assuming Jesus existed in our world there were numerous "messiahs" before and after him\* and they all had some followers. Sometimes a lot of followers. There's no reason the real deal couldn't drum up support by simple charisma and talking. \*Simon of Peraea (rebelled agains Roman rule), Anthronges the shepherd (another revolt), John the Baptist, Judas the Gallilean (leader of a tax revolt), the unnamed opposing Christ mentioned in Acts (although he was probably John the Baptist again), Jim Jones (Jonestown massacre), David Koresh (Waco massacre), David Ike (just plain mad), have all either claimed to be or had substantial numbers of followers who believed they were the messiah and/or the son of god. I'm sure other religions have their own roll-call of similar claimants. [Answer] **Have them find the body and actually witness the resurrection themselves.** Remains are excavated from deep in the earth. Piece by piece, and artifact by artifact, they are realizing what it is they have found. The remains of Jesus! Day after day the remains become more human than they were before, slowly growing ligaments, and muscles, and finally skin. The final result is a resurrected Jesus and that in itself is a miracle. The transformation could be broadcast across the world for all to see and Jesus wouldn't need to perform any more miracles to prove his identity. [Answer] Absolutely by providing archaeological links to his former miracles. Assume he's Jesus- he should be able to point out where he was buried. Where a set of wine containing containers are which were transformed from water - they survive they are holy and he put one aside. A totally blind- broken eyes man that is recorded as seeing- I assume its just holy vision not really fixed eyes. [Answer] This is similar to the "time capsule" approach some others have mooted, but: Maybe he knows the rest mass of the Higgs boson to fifteen decimal places? Or some other science or math fact, or more likely a whole collection of them, always just out of reach of the day's scientists or mathematicians? ]

[Question] [ What would be needed for a piracy-based economy? One based mainly on raiding ships? I don't know if there are any real-life models of this that were successful, though I know that piracy existed (and still does) as an outlawed way of generating money. But actual countries at least disapprove. This country's governing body does not, and it benefits the economy. I like the idea, but it doesn't seem tenable to have an entire country whose economy is largely based on theft. My guess is that you'd need lots of other surrounding countries that are rich in trade. I know that the Vikings come the closest to this, but they mainly raided villages. I also know that if there is sea trade, there will be bounties from other countries on pirates. Details for the world: * Tech level about late Renaissance * low magic **Is it possible to have an island chain country with an economy largely dependant on piracy? What are the conditions needed in order for this to work well in a world?** [Answer] you may wish to look into the ["Barbary Coast"](https://en.wikipedia.org/wiki/Barbary_Coast) which was a collection of pirate city-states that operated from the 1500's until the 1800's. They raided the Mediterranean during this time. These city states were so powerful that deals had to be made with groups like France, and Britain just to avoid Piracy in the Atlantic. When the US stopped being a British colony, the Barbary Coast began harassing American vessels. It got to the point where Two vessels were captured and held for ransom. This was the primary reason for the [first 6 American frigates being built](https://en.wikipedia.org/wiki/Original_six_frigates_of_the_United_States_Navy) by [Thomas Jefferson](https://en.wikipedia.org/wiki/Thomas_Jefferson) during his time as a minister to France during George Washington's presidency. It ended with American Marine's [capturing one of the Barbary Cities](https://en.wikipedia.org/wiki/Battle_of_Derna_(1805)). I suggest looking into how these cities operate as they were primarily piracy states funded through bribes, piracy, and the slave trade while being ruled by the Ottoman Empire. **EDIT:** It was pointed out that I did not make a full explanation for their Industry. I will do that now. The [Barbary Pirates were investments for many goverments and merchants](https://en.wikipedia.org/wiki/Ottoman_Tunisia#Corsair_enterprise) in this location of the world and most acted as privateers without letters of Marque. This was made possible under Ottoman rule for the primary purpose of slavery. For those who may not know, in the Quran it states a [Muslim cannot own another Muslim](https://en.wikipedia.org/wiki/Islamic_views_on_slavery#Principles). This makes Christian Slaves very valuable. It is estimated that somewhere between [1 to 1.25 million Christian Europeans](https://en.wikipedia.org/wiki/Barbary_pirates#Barbary_slaves) were sold into slavery in the Barbary Coast during this time. The slaving locations for these pirates [went as far north as Iceland](https://en.wikipedia.org/wiki/Turkish_Abductions). Many European nations did as much as they could to prevent being raided. This included ransoms and tribute, where it was said [20% of US government annual revenues were spent to pay Barbary Pirates](https://en.wikipedia.org/wiki/Slavery_on_the_Barbary_Coast#Barbary_Wars) prior to the wars (we have no concrete numbers from other countries). Notice that I have not made mention of any other industries. That is because these cities had very little control over their own territories. in Algeria, one of the capitals of Barbary Piracy, over 69% of the land disobeyed Ottoman rule. [They refused to pay taxes, ignored rule of law, and were not held by central power.](https://en.wikipedia.org/wiki/Ottoman_Algeria) These people added little to no economic activity for the Ottomans to consider. The governments were themselves encouraging this slave trade. [The Barbary Coast was ruled by the janissaries](https://en.wikipedia.org/wiki/Ottoman_Tunisia#Janissary_Deys). They were an independent military arm for the Ottoman Empire. T[hey slowly came to finance the majority of the Barbary Pirates](https://en.wikipedia.org/wiki/Ottoman_Tunisia#Corsair_enterprise). [Answer] **Most of the nations of the time utilized pirates in one form or another.** England called them privateers and made itself rich off plunder brought in by Sir Francis Drake and others, but essentially they were just pirates. On smaller scales there were pirate cities and islands in the Indian ocean. Vikings were essentially pirates and their kingdoms were to a large extent built on plunder and later conquest. The Danegeld was payment by the English to the Danes and was basically just a stand over tactic by a large belligerent group of pirates. It was also a vicious cycle, the payoff strengthened the economy of the Danes and made them stronger both in England and Denmark. I'm focusing on England's many piratical episodes, but almost any coastal outfit with a belligerent and sea mobile population based at least part of their economy on piracy. In Europe, the Saxons, Danes, Norse, Swedes, Angles, and Jutes spring to mind. Coastal India, Indonesia, Japan, Korea, and parts of Africa like the Barbary coast also had large pirate groups sanctioned by government and contributed a lot to the economy. Here is a link to [Francis Drake's remarkable career](https://en.wikipedia.org/wiki/Francis_Drake) and another to [Sea Dogs](https://en.wikipedia.org/wiki/Sea_Dogs); Elizabethan pirates who along with other pirates made England under Elizabeth debt free and were an enormous boost to their power. Elizabeth had several rationalizations for giving pirates safe harbour in England, but the real reasons were economic and some pirates [were even knighted](http://www.elizabethan-era.org.uk/famous-elizabethan-pirates.htm). The supremacy of the English wasn't the quality of the ships, it was the training and discipline of the crews and the ruthless ambition and competence of the captains. Vikings had superior ships and could at first attack unprotected places with relative ease. Later they attacked in force, protected or not, but in pitch battles they lost as often as not. So either of these could be used for your purposes. Koxinga in the China sea had his own island going and was a political force to be reckoned with after establishing his own kingdom; his economy was partly trade, partly piracy, and considering he didn't produce any goods himself, it's not hard to guess where his trade goods originated from. [Answer] No. Piracy as a *way of life* can work within the context of a rich trading network, you basically disrupt trade in order to steal stuff. Economies however are based on specialisation and cooperation between people, people get good at doing a thing, and sell what they do in order to buy from the people who are good at doing other things. This way bakers have shod horses, and blacksmiths have bread to eat. If everyone steals and no-one produces then there is going to be nothing to steal. In the real world only 15% or so percent of business ever bothers to export at all, because to do so you must by definition be world class. So, an economy of thieves (which is what pirates are) would have 85% of the population's effort spent on stealing from each other - but complicated by no-one ever owning anything to steal - with only the world class and ship owning 15% (though probably far less) of thieves stealing from outside. Vikings weren't a people, viking was a job. Dark ages Scandinavians were predominantly farmers. But some very small few of them used to go out raiding and stealing - those who did were vikings and may become personally wealthy - or dead. Privateers were not a method of developing an economy but a tool of war - issue permission to privately owned ships to prey on the ships of your enemies and keep what they steal. No functioning resilient economy is ever based on one thing, even if that thing isn't thievery. But especially not if that one thing **is** thievery. [Answer] There a numbers of ways you could do this but I'll look at a couple here. # The primary industry Probably the most sustainable way to use piracy in an economy. Consider fishermen. They go out to sea, they come back with trade goods, namely fish. Consider pirates. They go out to sea, they come back with trade goods, gold, manufactured goods, raw materials, a ship or two, a few slaves perhaps. Not exactly basing the economy on piracy, but rather treating it as another of your primary industries. A group of "workers" go out with the tools of their trade and come back with the results of their work. While you're not basing your economy off them, they are a part of the economy. How large a part is entirely dependent on how much seagoing trade your near neighbours have and the relative sizes of your economies. You can have a relatively large, healthy economy otherwise with an extra chunk on the side. Any economic model has to include the black economy, these days we talk about the money coming from drugs, theft and prostitution as the black economy, but once that would have included piracy. # The parasitic economy This is probably more what you had in mind, but if you consider the relative sizes of parasites and their hosts it says a lot about how large the relative economies are going to be. The purely parasitic economy has a major problem, that being the balance of flow of goods. If all you're getting is gold, your economy will have massive inflation and starvation, if all you're getting is fish, then you're going to have no internal trade and scurvy. You still need to make sure your economy, while possibly having a large percentage of income from piracy, also has some balance of activity such as farming, fishing and trade. Even so your economy is probably going to be a mess of periodic and unpredictable oversupply of goods. You can run your economy off the internal trade of the great empires, but you can never be more than a flea on their backs. [Answer] Your understanding of Vikings is a bit askew. They weren't a culture or a people. Viking is a job title it means "raider". The majority of Scandinavians were actually just peasants or other common jobs at the time, there were no "Viking communities" same way there were no "Viking settlers". The majority of the success the Scandinavians had was from trade so they weren't nearly as close to the pirate based economy you're imagining. **The main problem you'd face as a community of mostly pirates is that you need to be surrounded by trade of all types of goods in huge amounts.** The dent you'd have to make through your piracy would then have to be an acceptable loss to those you were robbing so you'd be stuck as a fairly small community. Also you'd have to be pretty poor as any group who are regularly robbed are going to defend themselves violently so pirating would be very dangerous, people would have to be desparate enogh to take that risk. [Answer] While not a full "pirate economy", a [letter of marque and reprisal](https://en.wikipedia.org/wiki/Letter_of_marque) was official government permission for a private citizen to perform piracy against a particular enemy nation. It created a government sanctioned mercenary navy seizing the enemy's ships and cargo for profit. With a letter of marque, a captain and their crew were not pirates to be dealt with without mercy, but "privateers". A captured pirate would face death, but a captured privateer would be treated like a fellow captain doing their duty in wartime. But a letter of marque was not a blank cheque, it spelled out the nations and circumstances the privateer would be allowed to prey upon. Other nations honored letters of marque because they wanted their own privateers treated well and to be able to attack their enemy without fear of being executed for piracy (dying in battle was fine). Not unlike treaties about the conduct of warfare and protecting the treatment of prisoners. Their captured ships, the ["prizes"](https://en.wikipedia.org/wiki/Prize_(law)), were not simply sold. They had to be first condemned by a [Maritime Court](https://en.wikipedia.org/wiki/Admiralty_court). They made sure it was all legal and that everyone got their cut (no kill stealing). The owners of the captured vessel could make their case that it was wrongfully seized. Once this was done, the captured vessel and its cargo was auctioned and the proceeds went to pay the privateer(s). Prize money was not limited to privateers, many navies also gave prize money to their own sailors. The Royal Navy in particular could be heavily motivated by prize money, as famously illustrated in the [Aubrey-Maturin historical fiction series](https://en.wikipedia.org/wiki/Aubrey%E2%80%93Maturin_series#Master_and_Commander) aka "Master and Commander". The prize money was portioned out into shares, often 1/8ths, and portioned to the captain, their officers, and their crew. In the Royal Navy, the captain had to share with their flag officer. Thus an admiral had financial motivation to encourage their captains to vigorously attack the enemy. ## Prize Money Distribution in the UK until 1808 * 3/8 for the captain (37.5%) * 1/8 for their commissioned officers (~2.5% per person) * 1/8 for their warrant officers (~0.7% per person) * 1/8 for their petty officers (~0.2% per person) * 2/8 for the remainder of the crew (~0.1% per person) *Source: Patrick O'Brian's Navy, p134* Royal Navy captains got 2/8ths, the extra 1/8th went to their flag officers. Any Marines on board would be paid from the 2/8ths for the crew. Capturing a vessel worth £1000, a very tidy sum, would give the captain £375 (£250 for an RN captain), and your average crewman would get £1. --- Again, this wasn't a full pirate economy, but you can see how this could work piracy, legal piracy, into a larger economy. The capture of goods and ships could bolster an otherwise flagging wartime economy, particularly the capture of hard currency like gold and silver. The captured ships could be sold, or pressed into service as supplementary naval and merchant vessels bolstering a probably overworked wartime shipbuilding industry. And it expands their ability to make war by giving financial motivation to private citizens to take up arms against the enemy and attack their shipping. [Answer] One possibility is an aggressive form of a gift economy. In gift economies, people don't buy/sell/exchange but instead give each other gifts. However, everyone is expected to give at least as much as they get in gifts. That way you can have division of labor: different people make different things and give them to each other. In a theft economy, people steal from each other. However, the more you steal, the more people will steal from you. You can thus have division of labor, you produce valuable products that everybody wants to steal, thus allowing you to steal a lot of products from other people. [Answer] Piracy Based Economy speaks to an economy where the basic means of performing a transaction is piracy. Every trader is, therefore, a pirate, and everyone who is economically active is a trader, and therefore again, a pirate. In this economy, piracy is not a bad thing, it's simply the way things are done. The piracy would probably be a means of negotiation or barter, except that instead of setting prices and haggling, one party attacks the other. Since trading invariably involves an exchange of goods, and since everyone is a pirate, trading in a piracy based economy involves two pirates performing piracy on one another at the same time. Its just the way things are done. A good deal is when you pirate more than you lose, or pirate what you want or need while suffering losses that are smaller, or on goods you do not want or need. The act of piracy is also less deadly and destructive than we would imagine, just in the same way that the cost of trading (interest, fees, taxes, cost of business) cannot exceed certain thresholds otherwise one or more parties will cease trading, piracy by all as a means of living implies that it is sustainable. Finally, pirates cannot just pillage (trade), someone somewhere needs to produce. In the same way that traders cannot exist without having an excess of goods to trade, piracy cannot exist if it is the basis of an economy without having an excess of goods to survive pillaging and to pillage. Imagine the world is a set of islands, and some islands have kinds of food and fruit growing naturally, and others have others. No beings can survive on one type of food only, and since piracy is the default means of trade, strategies evolve to take. For example, two smaller islands get together to raid the island of a third. A larger island becomes weaker when it is away on raids, allowing a smaller force to get away with some theft. Smaller forces band together to pillage larger forces and larger forces split to attack multiple smaller forces. Co-operating forces will pillage from one another while co-operating and larger forces may do the same on their own forces as they return with goods pillages from others. The native Americans were pirates. The native Africans were pirates. The native Asians were pirates. All ancient people, before the advent and understanding of money and trading, were pirates. Colonial forces pirated from one another, just as less developed forces pirated from one another and from colonial forces. Recognizing only major European and Colonial powers as pirates is a major accomplishment, being that it is narcissistic, bigotted and racist - all at the same time! There was ever only one noble savage, and it was us. [Answer] As one answer pointed out, it's worth distinguishing between piracy as a source of external valuables, and piracy as a core part of the internal economy (within the country. External has been well discussed above, but internal is a bit assumed to be impractical. So I'm revisiting that aspect. What is the essence of piracy? It is surely, making a living by taking from others as one wishes, without fair recompense, or without legal standing. In other words, its close cousins to a huge amount that can and does go on in real economies. People get valuables taken from them in ways they feel unjust (but lack any legal route to recompense), only its not usually called piracy once it becomes organised and routine within an economy. And that's what would probably happen - some ground rules would develop about who one may take from (by custom or "as laid down"), and pretty soon it's everyday. Only instead of piracy it's called taxes. Or donations. Or protection or baksheesh or..... [Answer] It depends on the definition of "piracy". Vikings raids weren't exactly "piracy", but neither were wars of conquest. They just pillaged one village or a monastery, then run away with what they had got. As a general rule, piracy may be very lucrative to a pirate, but it's unlikely to have a noticeable impact in the riches of a whole country. In fact, most of pirates were dirt-poor and lived short, harsh lives. We all know the stories of legendary pirates, but they were an exception to the general rule - in most cases they were privateers: they had military experience, governmental support and were wealth enough to maintain a ship and crew (or even a small fleet) on its own means until they found a prize. What is worst: piracy, like espionage, must be not too successful to be successful. If your piracy is too profitable there will be a reaction by the nations you're stealing from, and it won't be pretty. What you can have, however, is a sort of embargo. Put your nation in control of a strait with a lot of traffic and demand a cut from every merchant passing by. You have a fleet patrolling the waters to make sure no one escapes without paying the crossing fee. To prevent the other countries destroying you, you must have a country which is hard to attack by land, and a navy which is more powerful than any other country, even more than some of them combined. Make it an island nation in the middle of an ocean. Most of the ships would be willing to stop there for trade and resupplying, but the ones trying to pull out a direct trans-oceanic way are chased. [Answer] It seems to me that it would be very difficult to sufficiently raid other countries and maintain a long-term economy. The aggregate loses to surrounding countries due to raiding would have to sum to a reasonable GDP/cap (not really a GDP but the point is clear) for that nation (I'm making an assumption that the nations are relatively similar in size, resources, and population). If they raided for less than an average GDP then there would be incentives for the nation not to raid. Likewise, the they would have to be provided a risk premium over average GDP to offset the income instability. Imagine the effects of a couple percentage point change in growth now. I think we can assume that a pirate nation would see pretty heavy swings up and down, which would make consistent capital investment difficult. Most importantly, as the pirate-nation bottlenecks sea trade, they increase the cost of trade, making it less profitable, and decreasing total trade. At the very least, firms will invest to discover ways to avoid that nation, whether through protection spells or new routes that avoid it. Furthermore, there are items that may not be traded and therefore cannot be pirated but are difficult to produce in the domestic market (if we are even allowing domestic production in the pirate nation). They would not be able to trade for them because it is safe to assume that there trade relations with other nations would be nonexistent. So unless the pirating nation relied on active raids like the viking, I believe that the international community would adapt and the pirating nation would struggle to succeed. I believe that there are conditions by which such a nation could exist. 1) The pirating nation occupies a critical area for international trade, making it difficult for other nations to avoid its waters. 2) Vast differences in resource endowments of other nations makes international trade critical while land barriers dramatically increase the cost of land-based trade. 3) A historic level of poverty in the pirate nation could allow them to accept a pretty low standard of living with a large amount of variation and low levels of capital investment (castles, roads, public services and such). [Answer] I'm not as informed as other people here, so my answer will be much shorter. Simply put, yes. Think about it like this, a long time ago in your world's timeline, piracy was major problem for all merchants. to counteract this, weapon-smiths, ship designers and toolmakers begin making anti-piracy equipment to sell to merchants as they travel. These will prosper as the demand is high. however, a few savvy companies will see how this benefits them,and realise that without piracy, this boom in their industry will be lost. so a few of them will create equipment not necessarily marketed as pirate-friendly, but ideal to pirates. These will also do well, which will create a sort of cold war between pirates and merchants, with each constantly one upping the other. As these such items are in demand, inventions and advancements in technology will mostly follow a course to improve this equipment. Eventually, the piracy vs anti-piracy economy will become the main driving force in bringing money to countries. Another thing that you could factor in would be privateering, which is piracy performed by a country's navy. As I said, I'm no economist, i just think that's how this would work. [Answer] Here's how I think it would have to work: 1) Your primary income is from a protection racket. Basically, what you do is attack enough people to make your threat clear, then go around and collect money from them so you leave them alone. This is a more sustainable, lower-risk way to make money from piracy. 2) In addition to this, you would exploit rivalries between nations. You would collect a bounty from nation X for messing with nation Y, basically acting as privateers/mercenaries. All of the above would still probably not be enough to be the majority of economic activity. It could, however, be an important part of a larger economy and the primary source of state revenue. [Answer] There is a reason why the "Pirates of the Caribbean" are from Caribbean. There was a lot of small islands where pirates could live in a fairly nice weather, with a lot of routes going through Cuba and Haiti. Also slave ships supplied people who wanted to fight against French or English. It was called Republic of Pirates. Remember that pirates were one of he first "modern" societies that used democracy and equality There is also a story about how French pirates in the Indian Ocean established a free country for them and slaves. ]

[Question] [ A portal about 30ft in diameter appears on the surface of our present-day Earth. It appears for about 5 minutes each day before disappearing. Hesitantly, scientists go through it and discover a new world! This new world is "Earth-like" in that it has a similar ecology and atmosphere to earth, but it's pretty clear to the scientists we're not on OUR present-day Earth anymore. The days are a bit longer, gravity's a touch lower, and we're pretty sure we've never seen those species of animals and trees before. The discovery of this world has led to some wild theories. A few say the portal is traveling us through time. Some others have suggested that the portal is leading us to another universe that developed differently from our own. However, the reality is that it's simply another planet that lives in our very own, present-day, Milky Way galaxy. **My questions:** * What's the fastest way for them to prove that? How long would it take? * Is it possible to estimate where this new planet is in relation to ours? If so with what level of accuracy? **Assumptions:** * There's basically no light pollution on the new world. * While it's not a blank check, we've got a very high budget to figure this out. * We can safely bring whatever we need through the portal so long as it fits. [Answer] Relatively simple astronomical observations of nearby galaxies such as Andromeda, Triangulum and the others in the local group should enable them to check if they were still in the Milky way relatively quickly. The first brave astronomers could easily be provided with a number of small but powerful telescopes to search the night sky. After being left on the far side of the portal for a day they should be able to tell if they were in the Milky way or not. If this revealed that they were not in the Milky way then they would have to start more detailed astronomical investigations looking for known objects that were further afield like unusually shaped galaxies and specific pulsars. If a number of these objects could be identified then the observer’s position could be calculated at least roughly and then refined. This could take a long time. If nothing at all was found then more distant objects could be looked for but it would take longer and longer because the sky would have to be scanned in ever greater detail by bigger and bigger telescopes that would have to be transported in from some distance. In conjunction with the specific astronomical search they could also carry out a check on the redshift of distant objects to see if that matched what we see. And they could also bring instruments to measure the speed of light in a vacuum, the fine structure constant, Planck’s constant and other constants using ever more sophisticated means to check the value against what we know to greater accuracy. Any significant deviation would suggest either they were in a different universe or that the laws of physics change in time or space in some part of our universe. The longer the time frame the more experiments would be dreamt up (Gamma Ray Busts from the distant universe - do they occur and do they follow expected behaviour in extent, direction and intensity?) and the portal itself would undoubtedly be investigated for clues. What happens if a cable is laid from one side to the other and left there during closure? [Answer] [Pulsar-based navigation](https://en.wikipedia.org/wiki/Pulsar-based_navigation)! It's like GPS only using pulsars. All you need is equipment capable of receiving the signals emitted by pulsars, i.e. a radio dish, and you can pinpoint your location anywhere in the Milky Way. Getting a radio dish through the portal shouldn't be a problem as you can dismantle it and reassemble it on the other side of the portal. It isn't even especially high tech engineering. [Answer] Many of the answers here are already correct, I would simply like to add one safe method to determine if you travel through time, assuming that we know we stay in our universe: measuring the CMB. Since the radio pollution on the planet should be pretty low because of the lack of human radio stations, we can get a good estimate on the CMB temperature already from a simple ground-based radio telescope; if we manage to somehow get a satellite in orbit, we can get an even better measurement. Using the CMB is convenient because it is (almost) isotropic radiation throughout the universe and should be the same even outside the current observable universe. This means that even if we do not recognise a single object on the sky, we can determine "when" we are. This is a huge advantage compared to measuring the redshift of a known object, like a specific galaxy, because if you do that, you are in principle unable to differentiate whether you are closer to the object at the current time or farther from the object at an earlier point in time, due to the expansion of the universe. (This is just in very rough terms; the fact that the expansion accelerates makes the matter very non-trivial.) Also, like I said, you would see completely different objects outside of the observable universe, so you cannot even start to compare them to objects observable from Earth. In any case, the formula for the CMB temperature is: $T = T\_0 \cdot (1 + z)$, with $T\_0$ the current temperature at around $2.73 \, \text{K}$ and $z$ the redshift of the universe. We are currently sitting at a redshift of 0 (in fact, it is defined in the sense that we always observe at a redshift of 0). Measuring a higher CMB temperature means that you have travelled to the past, measuring a lower CMB temperature means that you have travelled to the future. You can even use this to estimate how far into the past or future you have travelled. [Answer] [John's answer](https://worldbuilding.stackexchange.com/a/234146/30492) is correct. A preliminary scan which can help assessing if you are in our galaxy or not can also be done by searching for known bodies and constellations in the sky. If you don't recognize any constellation or local stars in the night sky, but you can still recognize known galaxies and nebulae and their relative positions are not too altered, this is a strong pointer to the fact that you have moved somewhere else in the galaxy: close-by star associations have been more greatly impacted by the change in observation point than more distant objects. [Answer] * Unless you are unlucky and SMC, LMC and M31 galaxies were behind the zone of avoidance, you should be able to recognize their features with a small and cheap telescope to show that you must be in our galaxy. * 10m portal should be enough to pass through something like James Webb space telescope and observe S-cluster stars orbiting Milky Way's supermassive black hole, compute their orbital parameters and find matches with some of the ones observable from Earth. And the same for the SMBH itself. * If pulsars from John's answer are not usable, you could use *quasars* (active galactic nuclei) and their mutual position in the sky to show that you must be in our local group, I think. (\*) Just keep in mind, that what you observe might be tens of thousands years in the past or in the future, relative to Earth's time :-) **Edit (\*):** I suspect that given the usual distance to quasars, that would be more like our local supercluster :) [Answer] You can see the [Andromeda Galaxy](https://en.wikipedia.org/wiki/Andromeda_Galaxy) in the sky. Looking at other astronomical bodies in the Milky Way is problematic, due to light lag. The Milky Way has a diameter of almost 100,000 light years. Some astronomical objects will be perceived at a later stage of their lives, others at an earlier stage. And there is a lot that could change in 100,000 years. Some objects might have undergone astronomical events and developments we do not yet fully understand. But the way the Andromeda galaxy looks won't change too much. It is the closest galaxy to the Milky Way, but still 2.45 million light-years away. When astronomers notice that the closest galaxy to the new world looks almost exactly like the Andromeda galaxy and is in exactly the spot of the Andromeda galaxy, they will realize that they are very likely still in the Milky Way. Looking for one or two other galaxies will confirm this beyond any doubt. The Andromeda galaxy is visible with the naked eye, but can hardly be identified as such. It will take a telescope to get an image of it which is good enough to clearly identify it. How large of a telescope? That's more of a topic for [Astronomy Stack Exchange](https://astronomy.stackexchange.com). Then, when the astronomers have proven beyond reasonable doubt that they are still in the Milky Way, they can try to find out where in the Milky Way exactly. Now begins the interesting part. Looking for different astronomical objects, and trying to identify them as objects which are already known from Earth. As I previously wrote, those identifications might in some cases be disputed due to the objects appearing from a different angle and at a different age. And then there is the problem that the exact distance between Earth and many objects is only known with an uncertainty of 10% or more, so triangulation isn't that simple either. There will be several competing hypothesis, supported by some observation but then refuted as the astronomers collect more data and find inconsistencies. The time travel hypothesis might not want to die either, causing further confusion. Until eventually all the data points at one hypothesis being true. [Answer] **They lean towards celestial mapping**. They simply find the distance and angle of 3 *far-off* galaxies, and quickly compare that to the TERABYTES of Earth's present-day mapped constellations. Even if they arrived at the furthest point in our Milky Way galaxy, they would have an offset of 6.6e+9 AUs (astronomical units) of distance. However, Andromeda Galaxy is over 1.6e+11 AUs away, so using some basic trigonometry, you could find that: > > tan(angle)=O/A > > > tan(angle)=1.6e11 / 6.6e9 > > > angle = atan(1.6e11 / 6.6e9) > > > angle = 87.6 degrees > > > offset = 90 deg - angle = 2.4deg offset > > > So, even at the FURTHEST part of the galaxy, the NEAREST galaxy would only offset by 2.4 degrees in the sky. Most other offsets are significantly more negligible. The scientists realized that the night sky's **distant** lights look nearly *identical* to Earth's. After finding the distance and angle between 3 far-off galaxies, it only takes a programmer an afternoon of writing some code to compare those distance and angles against pre-recorded distance and angles of Earth's view. They quickly find a positive match, and are even to triangulate their exact position within the galaxy, AND their relative distance from the Earth. All just by using 3 relative points in the sky. [Answer] As others have pointed out, astronomical observations are the key. Astronomers who went through the portal would first look for the familiar constellations seen from Earth, to eliminate the possibility that the other side of the portal is on Earth. A They would also search for planets, to see if the planet was in a solar system similar to Earth's, or one quite different. I think that even small telescopes should enable the identities of planets with those in our solar system to be confirmed or disproved. The next step, or on taken by another team of astronomers, would be to scan the skies for dim patches of light. The large and small Magellanic Clouds and the Andromeda Galaxy should be visible to the naked eye from anywhere in the Milky way galaxy, except where hidden by the galactic core. If they spot them, they will examine them with telescope to confirm their identity, and they will search with telescopes for other galaxies which are conspicuous from Earth. They can search for globular star clusters, seeking to identify any that they find with the globular clusters surrounding our Milky Way Galaxy. If they can identify two or three of the globular clusters of the Milky Way Galaxy, measuring the angles between them should enable them to calculate the position of the planet relative to the Earth. On Earth, the Sun is the strongest source of almost all frequencies of electromagnetic radiation, because it is so much closer than other stars and extra solar astronomical objects. On any other Earth like planet, the star or stars in the system will be much stronger in most radiation bands than any more distant objects. Among the brightest objects in radio frequencies seen from Earth are the galaxies Centaurus A (NGC 5128) about 10-16 million light years from Earth, and Virgo A (M87 and NGC 4486) about 54 million light years from Earth. They are also relatively prominent in visual light, making it easier to identify the radio sources with known objects. The angle between Centaurus A and M87 can be used to calculate the position of the planet relative to Earth. Pulsars can also be used to find the planet's location. > > Pulsar maps have been included on the two Pioneer plaques as well as the Voyager Golden Record. They show the position of the Sun, relative to 14 pulsars, which are identified by the unique timing of their electromagnetic pulses, so that our position both in space and in time can be calculated by potential extraterrestrial intelligences.[39] Because pulsars are emitting very regular pulses of radio waves, its radio transmissions do not require daily corrections. Moreover, pulsar positioning could create a spacecraft navigation system independently, or be used in conjunction with satellite navigation.[40][41] > > > <https://en.wikipedia.org/wiki/Pulsar#Maps> X-ray pulsar-based navigation and timing (XNAV) or simply pulsar navigation is a navigation technique whereby the periodic X-ray signals emitted from pulsars are used to determine the location of a vehicle, such as a spacecraft in deep space. A vehicle using XNAV would compare received X-ray signals with a database of known pulsar frequencies and locations. Similar to GPS, this comparison would allow the vehicle to calculate its position accurately (±5 km). The advantage of using X-ray signals over radio waves is that X-ray telescopes can be made smaller and lighter.[1](https://en.wikipedia.org/wiki/Pulsar-based_navigation)[3] Experimental demonstrations have been reported in 2018.[4] <https://en.wikipedia.org/wiki/Pulsar-based_navigation> If Pulsars can be used to find the positions of space craft within our solar system, they can be used to find the positions of planets orbiting distant stars. But the atmosphere of a habitable planet would stop most X-rays from reaching the surface, so the astronomers couldn't be able to study Pulsar X-rays from the surface but would have to put detectors in orbit, which would be very difficult with what they could move through the portal. The small size of the radio telescopes they could take through the portal would mean they would have to concentrate on the brightest radio sources. Both Centaurus A and Virgo A were discovered by 1950 with small radio telescopes, and so both are very bright radio sources, and far enough away to be similarly bright everywhere in our galaxy, and close enough to have large differences in angle as seen from different parts of our galaxy. ]

[Question] [ **In the society I am building it is illegal for a government official to lie** (this isn't a reaction to real world politics; I've been building this world for a while), **while speaking/acting as representatives of the government/state**. In other words, all government employees are constantly under oath while "on the job". This doesn't affect them in their personal lives. Now the problem I'm having is with wording this law. I don't want to include joking/sarcasm as prosecutable offenses. Now obviously a politician may claim that a false statement was a joke all along to try and circumvent this law. The decision of whether or not claims like this are reasonable/legitimate will be a case by case matter and left to the discretion of judges. So there's no need to make the wording of the law ridiculously verbose and precise. To quote United States Supreme Court Justice Potter Stewart "I'll know it when I see it". Yet still I can't quite seem to find even a semi-loose way of wording the intent of this law. For instance: > > It will be a crime for civil servants to misrepresent or present false information with the deliberate intention of deceiving fellow government officials or members of the public while acting out their functions as government representatives. Such actions (whether taking the form of verbal, written or other types of communications) will constitute the grounds for treason and be subject to the full penalty of the law. But jokes are fine. Also sarcasm is okay. > > > I'm not being quite serious, sure, but I think that gets my point across, how do I define a joke in a legal context? What is a joke? Perhaps you're think "deliberate intention of deceiving" excludes jokes, but does it really? Isn't deliberate (temporary) deception part of the structure of many jokes? In many cases the "truth" (that is, the fact that the whole thing was a joke) is only revealed in the punchline, right? Even if the punchline is delivered seconds after the "lie", a "lie" was still told. **So how can I word this law in such a way as its intent is made clear?** There are other exceptions too of course, for example for sensitive classified information and government agents taking part in covert international operations but those are questions for another day. [Answer] > > It will be a crime for civil servants to misrepresent or present false > information with the deliberate intention of deceiving fellow > government officials or members of the public while acting out their > functions as government representatives. > > > This works just fine. Jokes and sarcasm are temporary. The government worker moves on and then tells the truth. If there is someone who still thinks it's real, the worker did not intentionally deceive anyone. There are plenty of laws where the intent matters. It's already part of our legal system. Either in differentiating a greater crime from a lessor crime or in differentiating a crime from a legal act. Given the consequences of a misinterpreted joke though, I'd think government workers would be extra cautious and always say "just kidding!" after a joke, or not tell them in the first place. It's also already illegal in many places for a member of the public to lie to various government officials. For example, it's against the law (as in an actual crime, not just a financial penalty) to [lie on your tax returns](https://law.freeadvice.com/tax_law/tax_enforcement/filing-fraudulent-income-tax-return-crime.htm) or in an [IRS audit](https://www.goldinglawyers.com/do-not-lie-in-a-tax-audit-penalties-criminal-prosecution/) (United States federal tax organization). If you go into an audit and say, "I don't have to report the basement full of gold bars, right?" they will not be amused, but it won't get you sent to prison. Your suggested language is fine. Just leave out the "but jokes are fine. Also sarcasm is okay" part as it's not necessary and puts too much emphasis on it. We already have laws that cover this, you're just widening the scope. [Answer] In Australia, like in many other countries, it is illegal to discriminate on grounds of race, religion, gender, sexual preference, or any other attribute not directly related to the decision at hand. People still do of course, partly because the problem is in proving that a particular person's attributes NOT related to their capacity to do the work is very hard to do, especially when much of what makes them suitable to the work environment is subjective; is this person a good 'fit' for the workplace and the other people in the team? So, in the first instance, given there is a presumption of innocence in most countries (and I'm assuming yours), there's an argument that Sarcasm and jokes are a part of the language, and that it is understood that a sarcastic remark really means the opposite, and therefore no lie has taken place - if anything, treating a sarcastic remark as a falsehood is really a *failure of interpretation*. In other words, your law doesn't have a problem with over-enforcement; it's going to have a problem with *under*-enforcement. That said, if you do decide to tighten up the law so that sarcastic remarks are included by default and the onus is on the person articulating it, then exceptions can be written into law quite easily, and Australian anti-discrimination law actually does that. For instance, anti-discrimination legislation in Australia explicitly forbids prosecution of people who choose actors for specific roles based on race, gender, etc. In other words, if you pick a white male to play a role of a white male, you're protected by the legislation to do so. So to it may be that you have to declare intent to be sarcastic before actually doing it, which would kind of damage the joke or the sarcasm a bit, but you could make provision for such humour in that manner. Of course, then you've opened up Pandora's Box, so to speak, because of the ability to actually *hide* the truth - let's say your politician speaks an absolute truth, but does so in a sarcastic tone. Is your politician innocent because they spoke the truth, or guilty because they did so in a potentially misleading way? Ironically, most politicians are already under a form of oath in their parliaments insofar as they are prohibited from misleading the parliament in any way. In my experience, attempts to prosecute on those grounds really come down to what the politician knew at the time, and they all claim they were given incorrect information at the time and didn't have reasonable access to the truth at the time of the utterance. Which brings me to my final point - there is a MASSIVE difference between truth and fact. How do you determine that someone isn't sincere in what they say, believing it to be 'true', even if it's obviously and blatantly wrong? In democracies, we don't elect our politicians for their capability in leadership, more's the pity. We elect them to represent the views that best fit our own. As such, trying to enforce 'truth' is a slippery slope towards a dystopian future full of thought police. Better to let them share their opinions to the fullest, and fact check them later in my personal view. [Answer] Trying to actually make a system that does what you wish is *enormously* difficult. Defining "lying" to mean exactly what you want it to mean and not anything else is virtually impossible because what makes a lie is not actually part of the statement. The lie appears as part of the interpretation on the part of the listener. For example, consider "The sky isn't blue," uttered by an official on a clear day without a cloud in the sky. Their statement is not a lie. the atmosphere between 1 foot above their head and 100km above the head is predominantly clear gasses. The blueness is actually a structural effect caused by interactions between the sunlight and the eyeballs. Sound absurd? Actually, biologists who study butterflies make a *very* strong line between structural blue and blue pigments which is right along these lines. It turns out nature doesn't have very many ways to make blue pigments, but it's found a lot of ways to generate blue structural light, like that of most blue butterfly wings. Trying to make it always apply to an individual is even harder. Doing that 100% of the time is just plain difficult. A solution from fiction can be found in Heinlein's book *Stranger in a Strange Land*. In this book, we are introduced to Anne a certified Fair Witness. Fair Witnesses are indeed what you are looking for: someone who does not lie, not in the least. In his story, when a Fair Witness is operating in official capacity, they wear a cloak that signifies their state. The sort of effects you are looking for can be seen in this interaction involving Anne as an off-duty Fair Witness. Even off-duty, her instincts show the sort of thinking that's involved with being a Fair Witness: > > [Jubal Talking to Jill] "You know how Fair Witnesses behave." > > "Well... no, I don't. I've never met one." > > "So? *Anne*!" > > Anne was on the springboard; she turned her head. Jubal called out "That house on the hilltop -- can you see what color they've painted it?" > > Anne looked, then answered, "It's white on this side." > > Jubal went on to Jill, "You see? It doesn't even occure to Anne to infer that the other side is white, too. All the King's horses couldn't force her to commit herself... unless she went there and looked -- and even then she wouldn't assume that it stayed white after she left." > > "*Anne* is a Fair Witness?" > > "Graduate, unlimited license, admitted to testify before the High Court. Sometime ask her why she gave up public practice. But don't plan anything else that day -- the wench will recite the whole truth and nothing but the truth, which takes time...." > > > Anything less than this level of extremeness will always run afoul of your ideal *somewhere*. No surprise that Heinlein lets them go off duty by not wearing their cloak! [Answer] You can try taking a page from chess. Chess has a ["Touch-move rule"](https://en.wikipedia.org/wiki/Touch-move_rule) which requires a player to move a piece which they touch. However, they acknowledge that sometimes you need to move a piece slightly without it counting as your move. When a player (in tournament/professional play) wishes to do so, they say *[J'adoube](https://en.wiktionary.org/wiki/j'adoube)* (literally "I adjust" in French) before touching the piece. This informs the other player (and any observers or judges) that this touch is not intended to be their move. In your world, the equivalent would be to require that **before saying anything which can be misconstrued, the politician must indicate that it is not intended as fact**. Since you're looking to write it into a law, it should probably be a specific word or phrase, rather than leave it up to the politician. As an example: > > It will be a crime for civil servants to misrepresent or present false information with the deliberate intention of deceiving fellow government officials or members of the public while acting out their functions as government representatives. Such actions (whether taking the form of verbal, written or other types of communications) will constitute the grounds for treason and be subject to the full penalty of the law. Any statement which is prepended with "In other news" shall not be considered an official statement for any purpose, including penalties under this law. > > > With a law like this, politicians will practice saying "In other news" (or choose a more appropriate phrase or create your own word) before telling jokes, the same way they currently practice any other aspect of public speaking. [Answer] Your world is our world. In the United States, [18 USC 1001](https://www.law.cornell.edu/uscode/text/18/1001) says: > > Except as otherwise provided in this section, whoever, in any matter within the jurisdiction of the executive, legislative, or judicial branch of the Government of the United States, knowingly and willfully— > > > (1) falsifies, conceals, or covers up by any trick, scheme, or device a material fact; > > > (2) makes any materially false, fictitious, or fraudulent statement or representation; or > > > (3) makes or uses any false writing or document knowing the same to contain any materially false, fictitious, or fraudulent statement or entry; > > > shall be fined under this title, imprisoned not more than 5 years or, if the offense involves international or domestic terrorism (as defined in section 2331), imprisoned not more than 8 years, or both. > > > The key in the above that covers what you are asking about is the words "*materially false*". That is, it must be false in a way that really matters. [Answer] I think the law permits you to retract false testimony while under oath. Therefore: > > The speaker of a deliberate untruth may, within a reasonable time and > to a significant audience, retract, correct, or modify the untruth, > thereby negating the penalties thereof. > > > "Reasonable time" and "Significant audience" are deliberately vague, because they have to be. If a DMV worker is serving someone at his counter and says "There's a manager in our office who plans to get promoted even if he needs to stab his boss," he has to say "Just kidding" so that anyone who heard him the first time can hear it. But if he said it in a live tv interview, then he needs to say "That's a joke, obviously!" before the camera stops running. If he's not fast enough, he has to issue a public retraction as soon as possible. [Answer] Have you considered the possibility of the mechanics of the society's language(s) itself being a response to your legal constraints? Consider, perhaps, a new, more distinct set of grammatical and phonetic constructions (possibly aspects of body language, too) to make the intention of lying as a joke more apparent. There are various (albeit not particularly formal) real-world analogues to this: "/s" in online forums is sometimes denoted at the end of a post to denote sarcasm - not to mention, sarcasm, in verbal speech, often is denoted by a specific "sarcastic mode" of one's voice. In your society, given such a strict law, I'd imagine these types of changes would require languages to be treated in a more [prescriptive](https://en.wikipedia.org/wiki/Linguistic_prescription) manner than a [descriptive](https://en.wikipedia.org/wiki/Linguistic_description) one. Maybe your society would have institutions like the [Académie française](https://en.wikipedia.org/wiki/Acad%C3%A9mie_fran%C3%A7aise), perhaps set up more as government ministries than independent bodies. [Answer] # Conditional statements If the premise is not true, then what follows is not true either; however, the statement as a whole can be true. All jokes can be framed as conditional statements, and hence be perfectly in line with the law you describe. For instance: > > If a horse could walk into a bar, the bartender may greet it with 'why the long face?' > > > of > > If your mama had been fat enough, she would have used the equator as a belt. > > > Note that this apply also to government statements where secrecy of certain information if crucial > > If there are weapons of mass destruction in the enemy country, then it would be right to invade them. Are there such weapons? If we had full knowledge of the situation, we may conclude that there are. > > > [Note that they would not commit to having full knowledge of the situation] Or, in the case of the blueness of the sky, mentioned in another answer > > If the sky had to be given a color, we may agree on blue. > > > [Answer] For a real world example, you might be interested in looking into "puffery" and how the United States's FTC (Federal Trade Commission) handles it in relation to false advertising. (Statements like *"World's best coffee!"* are puffery.) The idea is that everyone knows it's a lie, no reasonable person would believe it. False advertising is still illegal though; it must be shown that a company intentionally tried to mislead people. Puffery is usually considered an opinion rather than a fact. Because of that it's not considered "false" since it's an opinion. In addition, since most people understand puffery's usage (even if they've never heard the term or had to define it) it's difficult to say that a company is trying to "intentionally mislead" people when doing it. Your law actually already has similar wording. > > It will be a crime for civil servants to misrepresent or present false information **with the deliberate intention of deceiving** fellow government officials or members of the public while acting out their functions as government representatives. [...] > > > If someone is joking, people will know. Unless part of your setting is that everyone is hyper literal or something like that I would think this wouldn't be an issue. If they weren't joking and claimed they were, then maybe they fool some people with the original lie but surely someone would know (like a political opponent) and call them out. Then everyone would stop believing the lie once the liar has to "admit" it was a joke (or they could be punished, their choice). [Answer] Methinks you are using a hammer to cut a piece of glass in two. Certainly, after using a hammer, the glass WILL be in at least two pieces, but perhaps not in the shape you originally intended. That is, the Law of Unintended Consequences and the Law of Indiscriminate Application of Force (non-controlled application of forces results in non-controlled consequences). I suggest that, rather than a law, you should make it compulsory for all politicians or candidates for a public office be required to take an oath, much like one does in a court of law, to always tell the truth in any communication made in association with that office or campaign for that office. Thus, if they did purposefully tell a lie, the offense would not be in telling the lie, but in breaking their oath. Breaking their oath would be grounds for their immediate removal from office, at a minimum. As part of this oath, they would commit to always support any communication they made with well documented references to support their communication, much like companies are required to back up any claims they make in an advertisement with proof. Failure to make public this evidence would mean either a public retraction or removal from office. The difference between breaking an oath, and breaking the law, is in who enforces the infraction? If one is accused of breaking a law, it means charges are laid, it goes before a judge, and you have the entire legal hassle of 'political immunity from prosecution', legal appeals, legal procedures, and the adversarial process of courts. If, on the other hand, it is an oath, then an entirely different process would be followed. It is no longer a criminal offence. It would come before a tribunal (an impartial, non-partisan jury of peers, perhaps) that would hear the accusation, hear the evidence, determine the truthfulness of the statement, and make a binding decision as to weather it violated the oath or not. Sort of like the advertising council tribunals. The procedures would not be the same as used in a court of law. It would not necessarily be prosecution-defense-rebuttal-rebuttal, discovery, and the prosecution laying the case out at the beginning. More along the lines of an inquiry, where dispositions are heard, evidence presented, and a decision made. Another difference is that being accused of breaking the law means everything has to be spelled out, clear-cut, unambiguous, and specific. Breaking an oath, on the other hand, is more along the lines of a civil, instead of a criminal, case. 'Reasonable probability' is substituted for 'beyond all reasonable doubt'. In such a scenario, it would be up to the tribunal to decide if the communication were made as something that the public would take as a statement of fact and rely upon in making decisions. Very similar to how advertising councils and newspaper tribunals make decisions. And just as in such existing tribunals, allowances would be made for subjective 'fluff' through common law and precedent. Only claims that could be factually analysed and objectively verified would be subject to the oath. 'Largest carrier by installed base' is an advertising claim that can be supported or refuted. 'The greatest thing since sliced bread' is entirely subjective, and therefore can not be supported or refuted. Since advertising tribunals do work to cut down on deceptive advertising, there is clear evidence that such a system could work, as long as the tribunal had teeth (removal from office and sanctions against participating in campaigning again). As much as you wish to stay away from the current political situation in America, I posit that it does provide substantial test situations in which to evaluate the effectiveness of whatever method you use, and whatever wording you use. Pick any or several of the hundreds of examples of situations in recent American politics that you wish to address, apply your solution to the scenario, and see if it results in the intended consequences. Could a politician wiggle out as easily as they can currently from the consequences of statements they have made? Does it cast too wide a net, and implicate politicians in situations you feel they should not be admonished for? ***EDIT*** For an example of what an oath would look like, consider the [Canadian Code of Advertising](http://www.adstandards.com/en/standards/canCodeOfAdStandards.aspx) > > As its name implies, the Code has as its primary purpose the > expression of Canadian standards in advertising that, when followed, > should result in responsible yet effective advertising without > unreasonably blunting the underlying fundamental right to advertise > lawfully-sold products and services in a fair but competitive manner. > > > The oath would state 'I will not violate the 'Political Code for Truthfulness', and the code would spell out the criteria and determinants for what is a false or true statement, much like the Canadian Code for Advertising. This Code would be flexible and interpretable, a guideline for the tribunal to use, just as the Canadian Code to Advertising is intentionally somewhat malleable. As an adjunct, the Advertising Code contains a provision for determining the legitimacy of a complaint > > If, upon review, it appears to ASC or Council that a complaint is not > a disguised trade complaint or special interest group complaint, and > that based on the provisions of the Code reasonable grounds for the > complaint appear to exist, then the consumer complaint will be > accepted for processing. If at any time thereafter during the > complaint review process, but prior to the release of Council’s > decision on the complaint, either ASC or Council concludes that, in > reality, the complaint is a trade complaint or a special interest > group complaint, but not a consumer complaint, the process will be > discontinued and the complainant notified accordingly. In these cases, > the complainant will be reminded that alternative approaches should be > considered by the complainant for registering an advertising-related > complaint, such as under ASC’s Advertising Dispute Procedure or > Special Interest Group Complaint Procedure. > > > But trying to spell out the Code in a simple 'Law' format is nigh on impossible. There are so many intricacies, that it would be impossible to state clearly and unambiguously. [Answer] In order to bring someone to justice one must simply prove damages, and then the person is tried for those damages, not the lie. So when Bush says "No new taxes" you could now hold him liable for every dollar any taxpayer had to pay for a new tax. If a politician says something about chickens crossing roads, it would be very difficult to prove damages. [Answer] You have some great answers here but I believe I have an answer from a different perspective: to have your politicians define the ulterior message if they are suspected or proved to have lied. I'm drawing on transactional analysis for this and defining an ulterior transaction as "a transaction in which an overt message and a covert message are conveyed at the same time" - Ian Stewart and Vann Joines, *TA Today*, p. 384. We use covert messages all the time, and they can either contradict or be completely unrelated to the overt message. Transaction analysis therapists are interested in these as they are the stuff of what a relationship is *really* about. In most settings, the covert message often goes unacknowledged, but what if your politicians had to be able to explain what was meant by a given statement including the covert message? It might look something like this: Conversation example from [Avatar](http://www.avatarmovie.com/index.html). **Jake Sully:** How do I know if it chooses me? [Overt: How will I know if this dragon-thing has chosen to bond with me? Covert: I feel unprepared for the encounter I a about to have with this dragon-thing. Please provide me with information about how I can tell when I am out of danger.] **Neytiri:** It will try to kill you. [Overt: If it chooses to bond with you it will try to kill you. Covert: Here is the direct answer to your question.] **Jake Sully:** Outstanding. [Overt: That answers my direct question perfectly. Covert: I'm angry because I have found myself in a situation that is far more dangerous than I initially anticipated. I am angry both at you for not presenting this information to me before this moment (although I don't like to be angry at you because you are my guide), and at myself for not asking for more probing questions about this situation before now.] Being able to reproduce a conversation like this verbatim, along with capturing any ulterior meaning (such as tone, body language, or gesticulations) would raise their own problems, but I thought I'd present this to you given that your politicians are, after all, in the public eye and much of what they say is recorded and/or filmed. Further information may arise if and when disputes arise over the covert meaning, and I might suggest that those answers be put to a committee. It's not a perfect solution to your problem by any means, but it would bring the covert into clearer focus, which may help. [Answer] The "intent to deceive" many exist in the beginning of many jokes but by the end of the conversation you always expect the other person to know it was a joke. It may kill the class of jokes where you deceive someone to see if they will make a fool of themselves with the wrong information but I would not be sad to see that class of jokes disappear. In Japan there was an Emperor who outlawed lying. He is long gone but the Japanese people still, hundreds of years later, add Kedo (however) to the end of many statements. They are making the statement but acknowledging that it may not be completely accurate to make that statement so they cannot be held accountable if it is not correct. Interesting side social impact. [Answer] You need to focus more on the intended *consequences* of the lie, not just the intent to deceive. Forget jokes, do you want to make it a criminal offense for someone to reply to "hey, how's it going?" with "fine" if they happen to actually be having a bad day or menstrual cramps or dealing with the slow death of a loved one? What about "thank you for coming" when they really aren't feeling all that grateful? *But wait!* you say, *I don't want my politicians and civil servants hiding important information from other government officials or the electorate. I might not have voted for that loser if I'd realized they didn't really like me coming to visit!* Well, that's where the intended *outcome* matters. Try something like > > It will be a crime for civil servants, while acting out their functions as government representatives, to intentionally misrepresent or present false information **for the purpose of causing** fellow government officials or members of the public to make **civic decisions or take civic actions based on the misleading or false information**. Such misrepresentations (whether taking the form of verbal, written or other types of communications) will constitute the grounds for treason and be subject to the full penalty of the law. > > > You can define "civic" (or whatever phrase strikes your fancy) decisions/actions as behavior that affects the functioning or well-being of the polity. So misrepresenting the state of your health to the electorate would be a crime if done for the purpose of getting votes, but misrepresenting the state of your health to your co-worker so they wouldn't give you yet another lecture on the value of echinacea powder would be OK. Something like a knock-knock joke would also be OK, even if done to make the audience like you better and therefore vote for you, because the change in behavior doesn't turn on the truth of the information (it's not a question of whether it's really Lettuce at the door or not, so much as how you tell the joke). On the other hand, a "joke" that is full of misleading and uncorrected innuendo about a political opponent, promulgated specifically to turn voters against that opponent, could potentially be prosecuted under such a law, if it could be proven that the voters based their decisions on believing the false innuendo. [Answer] Inspired by @Bobson's answer, I would flip it around, to have a law somethig like this: > > 1) Any officer of the Government that provides factual information or responses to any person, in the course of their duties, shall be required to state on each occasion: > > > > > > > a) that the said information may be relied upon; > > > > > > > > > or, if the reliability of the said information is, or may be, significantly uncertain: > > > > > > > b) Their honest belief and knowledge as to the extent to which it is or is not to be relied upon. > > > > > > > > > 2) Failure to explicitly make such statement when communicating factual matters in the course of their duties, other than in the circumstances stated in paragraph 3, shall be a criminal offence. > > > 3) A statement referred to in paragraph 2 shall not be required in communications that are reasonably understood to be of a minor or transitory nature, unless any party to whom the information is communicated (directly or indirectly) requires the same to be made clear. > > > 4) A statement required under paragraphs 1 or 3, may be reasonably deferred, but for a reasonable period only, and of the shortest practical duration, and for not more than 4 working days without judicial consent. The circumstances under which deferral is permitted shall be: to allow confirmation and ensure accuracy. > > > That neatly solves it. You effectively impose a duty to state if something is "on the record" (can be relied on), and a right for a third party to require that status to be clarified. You also provide a way to handle uncertainty, or if a member of the public just wants to know where the stairs are, or if the canteen food is good today, or what you got up to on your day off at home (that's a "statement of fact" too). [Answer] > > I don't want to include joking/sarcasm as prosecutable offenses. > > > That would be simple in the laws, the nuance will be in the enforcement (and avoidance of accidental enforcement). *We have similar laws but don't really enforce them*, otherwise someone would have been punished for a certain bus sign in the UK! If the law is enforced rigidly and the punishments more than superficial then people would be far more careful about jokes. Perhaps they would develop a very obvious "this is a joke" signal in all modes of communication, like the smilies/emoticons we use here & now in writing, and the changes in tone & "air quotes" often associated with spoken sarcasm, and be very careful to always give off those signals when joking. Of course that can and will lead to a reverse of the problem: was that joke, with all the right this-is-a-joke signals, really a joke or intended to be seen as a statement? People will always try to find a way around rigid laws and strict enforcement. Other problems enforcement of such laws could introduce include exacerbating the problem of (accidentally or otherwise) misrepresenting what someone else said or wrote, simple misunderstandings (was a signal given but missed?) and so on. And in the case of written works, how do you assign blame amongst a group of writers, an editor, a publisher, and everyone else involved? [Answer] **The inhabitants of your world speak Lojban** Lojban, the constructed language designed to be unambiguous, [requires](https://www.explainxkcd.com/wiki/index.php/191:_Lojban) that jokes be grammatically marked as such. Now, your officials can tell as many jokes as they want, confident that no fluent Lojban speaker will misinterpret their jokes as statements of fact. You could even have some fun and have a less-than-fluent law enforcement officer or prosecutor go after one of your officials for "lying", and then give the audience a grammar lesson in court as the defense calls the Lojban Grammar Advisory Board to explain grammatical lying versus grammatical joking. [Answer] There are many forms of comedy and ways to get a laugh which require no “lying” whatsoever. --- Jokes which “require” lying are interesting because they are never really lies. Lying is the act of concealing the truth from the unknowing. However, if two people mutually understand the same truth, and are also mutually aware of each other’s knowledge, joking with “lies” is quite possible. For example: “Oh, look,” says Terry to Kris. “The sky is red,” Terry says with a wink. Kris laughs. In the event there is some confusion, preface. “Here’s a joke,” Noor says to Sam. “I would totally date Pam,” Noor says with a smile. Sam laughs. --- And then, of course, is [slapstick comedy.](https://en.m.wikipedia.org/wiki/Slapstick) Watching someone’s reaction as they are hit in the face by an unexpected pie is almost ageless, and still funny after thousands of years of basically the same “joke.” --- And there is the comedy of misinterpretation, as Abbot and Costello so masterly demonstrated with “[Who’s on first](https://m.youtube.com/watch?v=kTcRRaXV-fg)?” --- And the [comedy of the unexpected](https://m.youtube.com/watch?v=Hn3bz_a35FA) which Tape Face uses. --- As an aside, it’s perhaps worth noting that in a society where jokes are illegal because “jokes are lies” it would also be illegal to have fantasy, SciFi, soap operas, theatre (as we understand it), advertising, make up, wigs, and overly flattering profile pictures. [Answer] Easy. All govt employees have to present truth in writing, with proper stamps, signatures (and counter signatures of incharges). Ordinary citizens that receives the information have to sign receiving on copy of the documents and the govt employees keep those signed copies for their record. A govt employee can say whatever he wants (including jokes, metaphors, idioms, poetry and sarcasms) but unless its brought in writing its understood that he is not standing behind his words in official matters so the stuff cannot be used in official matters (like in western countries evidences gathered without warrant are null and void in court). If its found; by absence of signed-by-public copy of documents, that a govt employee didnt present required information to public; or that a govt employee presented non factual stuff, like jokes or metaphors or sarcasms to public, by presence of such non factual signed (and countersigned by incharge) documents in custody of an ordinary citizen; then that employee is severly punished by freeze on promotion or transfer to severe climate location depending (on discretion of special marshals handpicked by dictator himself or a governor) the perceived criticality in the matter of the absent information, and non factualness of present information. On second count of same offense a criminal proceeding will be held either by a governor or by dictator himself and punishments will include imprisonment for life (alongwith ofcourse seizure of all property to fund the living expenses and to cover losses to society) or death penalty. Its important to give your employees a second chance by letting them work on same designation even if transferred to a far off place in empire. If after a minimum of 3 years the employee proved himself worthy of reinstating at former position, through extra ordinary dedication to service, do reinstate him back to his former position but not compensate for lost years in promotion hierarchy. Dont put any upper limit on how long to wait for employee to show extra ordinary performance (till retirement). [Answer] ## Require 50% of their statements to be false, but have them document which ones The solution to falsehoods is not less falsehoods, but more. So many in fact, that they just become noise. Therefore, just require that 50% of what officials say is false, but then they document what falsehoods they said latter. They can also mark if something was a joke. If they fail to mark a falsehood as false, or a claim a truth-hood is false, that's a lie, and they will be punished. It also means that members of the public need to do further research before believing what an official says, which they should be doing anyways. You'll also want to make up some rules to prevent officials from making it obvious which statements they intend to be false, since otherwise they could "mark" the falsehoods by the way they speak, but then not mark falsehoods they want people to believe. People would filter out the marked statements, eliminating the purpose. [Answer] You could keep your phrasing and add the sentence below after your first sentence: Misrepresentation or presentation of false information made for the obvious purpose of causing amusement or laughter, without intent to deceive, such as jest, joke, or sarcasm, should not be considered misrepresentation or presentation of information in the present regulation/law. PS: If the law forbids every lie, fibs included,in that context, sarcasm should also be outlawed. Sarcasm not only leads to miscommunication but can de considered as an expression of contempt——something in which representatives of the government/state should not engage. ]

[Question] [ Many fictional spaceships of all kinds are known to have external lights. Do they even need them? Outer space is lit by the billions of stars and galaxies, so why are there external lights on fictional drive ships, war ships, cargo ships, etc.? Would these external light sources be useful, at least? Or do they just risk a facility/ship wide brownout or loss of function from the generator(s) if hit or destroyed? [Answer] Short answer is Yes; external lights are VERY necessary on spacecraft, especially if you have to do external maintenance, and especially during interstellar flight where the light from the sun is not overwhelming the lumen count. Two things about stars; they're very bright, and they're very far away. The reason you don't see stars during the day is because our sun is so close that its light overwhelms the atmosphere and makes it impossible to see other stars. At night, even though we can't see all the stars that are visible in space from the surface of the earth, it's not because the atmosphere is filtering out light, it's because it's diffusing it a little. In short, space is still dark. [](https://i.stack.imgur.com/wqwkX.jpg) The picture above is of Apollo astronauts taken on the surface of the moon during the moon's daytime noting there are no stars in the background. This is not because the entire moon landings were shot on a sound stage, it's because the light from the sun meant that the exposure setting for the pic had to be set at a level that wouldn't be powerful enough to pick up the stars in the background. The light from the stars is impressive to look at, but doesn't contain the lumen count needed to actually see much by. So, you'd need lights to see things (especially in crevices) on the surface of your spaceship if you were doing repairs and you might even need it to detect space debris in your path as well in some cases, although Radar would probably be better for that. **To address additional comments** I'm assuming current technical knowledge of physics, so a sub-luminal interstellar ship; either generational or sleeper (probably sleeper because of resources). Using lights as navigational beacons like seaborne ships will be useless because at a significant percentage of light speed, by the time you see the other ship in your path it's too late to change course or react in any way. the only exception to this would be rotating lasers (the lighthouse effect) that would 'blink' from your perspective. The real problem is that given relativity, the light would be invisible to human eyes, and probably act as lethal cosmic rays so not a good idea in any event. That said, small power LEDs could be left on in perpetuity around the ship as fixed light sources for those difficult knooks and crannies in the hull. There's a good reason to leave them on permanently (other than the obvious real time closed circuit video for monitoring) - cold. Space is cold[Citation Needed] and electronics don't generally play nicely with cold. So, leaving them on full time means that they can sustain their own operability with the heat from the energy they use. Also, leaving them on full time means that if the light isn't on, then something has gone wrong with it directly rather than your work experience bridge officer forgetting to turn on the power during your EVA. Fixed lights are always ideal for hull inspections (which would need to be conducted on a regular basis because of the risk of dust strikes and the like at such speeds) and if you come out of a hatch at the rear (say), then being able to look down the length of the ship and see the lights on at regular intervals gives you a good long distance view of the ship that your suit light wouldn't be able to deliver. Assuming rails for tethers et al instead of some form of mag boot (which causes issues if your suit power fails) then lighting all over the hull is critical during EVAs so that if you jump from place to place using the tether to give you angular momentum, you can see ahead of you to where you want to land. [Answer] Atmosphere-entering spacecraft (Shuttles, space planes) visiting Planet Earth must carry the same navigation lights as other atmospheric transport - white light forward, red to Port, green to Starboard - inherited from [terrestrial COLREGS, originally the Steam Navigation Act](https://en.wikipedia.org/wiki/International_Regulations_for_Preventing_Collisions_at_Sea) of 1847, via that planet's winged atmospheric transport craft. Actually this answer was intended to be humorous but [what do you know ... satellite navigation lights really exist!](https://en.wikipedia.org/wiki/Navigation_light#Spacecraft_navigation_lights) Anyway, never pass an oncoming spacecraft green to red, in this planet's jurisdiction. And be aware of local regulations in every system you plan to visit - especially where different visible frequency ranges have evolved, according to the emission spectra of the local stars. Edited to add a photo of actual starboard running light on actual spacecraft (Crew Dragon) during docking manoeuvre. Photo attribution : I'm guessing NASA. [](https://i.stack.imgur.com/PsjZF.jpg) [Answer] Those lights exist for one terribly important reason only, and that is to make the ship visually appealing for film and television audiences. Same thing goes for the sounds these ships make while flying. In reality, when you're sitting out in interstellar space, your colorfully painted ship is just going to be a black shape in the blackness of space. Its running lights will only be visible for perhaps a few kilometres. Now, those lights will be useful in spacedock. All the ancillary vessels (shuttlecraft and so forth) will need to find the airlocks. Spacewalking crews will need to find important hatches, couplings, conduits and so forth. A spacedock itself will also need exterior lighting. If it's a large facility that ships enter, the doors will need to be well lit, for example. Standard warning lights on spires, towers and so forth. [Answer] 1. No, we do not need external lights except for human guided close-approach maneuvers. 2. Movies look cool when you can see the spaceships. A black ship in black space isn't good cinema. 3. External lights can't do anything except make the spacecraft visible from further away to visible light sensors (like eyes). 4. Yes, they would waste energy, but there may be plenty of energy to spare, depending on what you assume for the drive system. 5. Useful only if the light was needed for something (tautology in the answer). They would only be useful for short-range, human or vision controlled maneuvers such as docking. 6. Assuming there was enough energy to run the lights, I doubt that lights would make a brownout situation much worse, if the main power were lost. 7. It's hard to say what we, as human, would do if we had the ability to do galactic-level operations. We might still light spacecraft, especially to show off the external company logos and craft "tail numbers", if the terminal times (launching and docking) were large compared to the transit times. IMO, we wouldn't bother with external lighting. [Answer] For ship-to-ship docking, close proximity manoeuvres, landing in bays or on planet surfaces at night, surveying the hull for damage, shining a spotlight on obstacles or targets, and all the other things ships get up to when they aren't crossing the interstellar void a jillion kicks from anything else, lights have their uses. [Answer] > > outer space is lit by the billions of stars and galaxies > > > For some definition of "lit". Something that's being lit by the billions of stars and galaxies is darker than things are at night on earth. At night on earth, earth is lit by the sun (reflected by the moon and/or scattered through the atmosphere), and by artificial lights. Also, things in space are usually a couple million kilometers away, and moving at a couple kilometers per second relative to your own speed, which makes spacecraft-sized objects very difficult to spot even with external lights on. > > are external lights capable of doing something else than illuminating a small area around the light source? > > > [Directional](https://en.wikipedia.org/wiki/Flashlight) [lights](https://en.wikipedia.org/wiki/Lunar_Laser_Ranging_experiment). > > Would it waste energy if installed? > > > There is no drag in space, but there is mass. Accelerating and decelerating the additional mass of the lights (and the wiring) requires some additional energy. In many applications that will be [negligible](https://www.google.ch/search?q=ariane%205%20mass) - a notable exception are [nano- and microsatellites](https://en.wikipedia.org/wiki/Small_satellite). > > Would these external light sources be useful, at least? > > > At worst, having lights prevents you from getting fined by the space police, at best they save your live. [Navigation lights](https://en.wikipedia.org/wiki/Navigation_light) to be seen, to avoid accidents and comply with regulations. If you want to investigate asteroids, debris, or other ships, then you'll also need some searchlights. Even if you're quite close to a star, [every object has a side that is unlit](https://en.wikipedia.org/wiki/Lunar_phase). Once you're between stars, all sides are unlit (unless we're talking binary star systems). If you want other vessels to dock with you, you need additional lights to mark the docking area. In case of equipment failure, you also want signal lights for minimal communication. Interior lights + windows. Lights for in-flight repairs. Also, the marketing department wants to make some glamour shots of your vessel. > > Or do they just risk a facility/ship wide brownout or loss of function from the generator(s) if hit or destroyed? > > > [Not if installed correctly.](https://en.wikipedia.org/wiki/Fuse_(electrical)) Remember, if you install your own space lights, the installation must be verified by a certified space electrician. [Answer] This isn't a complete answer, but too many thoughts to be a comment. I think of the lights would be used at more of a slow speed, so that the spaceship can see the area immediately around it. Small debris or other ships that might not show up on other spectrum scans (like thermal, etc,) could be seen at low speeds. Even if they are seen at high speeds, the reaction of course change may not be quick enough to make a difference, so exterior lights may not be necessary. Lights are also used to show position to others, so even if they aren't useful to you, they may be useful to others. In combat, exterior lights could give away your position, so they may not be wanted. Then again, they may show friend vs. foe. At the beginning of the movie "Courage Under Fire", a tank battle is happening at night. A commander inadvertently shoots and kills a friendly tank in the dark, so he makes a command decision to turn on the exterior lights of all the tanks and prevents it from happening again. Also, other factors like engine heat and launching missiles or counter measures would give away position, so lights could go either way. All lights, whether they are in a building or a vehicle, should be on a fuse or circuit breaker to prevent black/brown-out conditions due to failure. They should also be wired parallel, so a failure in one doesn't prevent others from working. [Answer] The external ligths on space ships serve the same role as ligths on curent freighter ships, they are big asf and if you pilot a smaler thing not to hit them mostly xD. As for our future i'm willing to bet on yes ... RGB ligths for the space mases ! [Answer] **In deep space, light is just another frequency of RADAR.** Like RADAR, it would have considerable throw range and good return. And unlike RADAR, the frequencies are ones *humans can literally see*. That greatly simplifies data analysis, because they can call it up on a display in the same frequencies and *look at it directly*. How do you suppose it is that the *Enterprise* can say "closing to visual range" and then "on screen"? Visual range is infinite, what range are we talking about? The range of the *Enterprise's* **lights**. Looking directly through long-lens optics would also be an option: *but not a recommended one*, because if you accidentally tracked across a star or the other ship's own lights, you'd be blinded. ]

[Question] [ I am Queen Aerith the 3rd of Alagaesia. I rule a large and powerful nation in a time period technologically equivalent to the 17th century or so. Most of my world map is known, and cross-ocean trade is increasingly common. However, I have a problem. One of my court mages has discovered a means to transform straw into gold. I have ordered them to keep this a state secret, but said mage is prone to going on wild adventures, and is terrible at keeping secrets. Since I am not willing to execute this mage to prevent word getting out (and I probably couldn't keep them imprisoned if I tried), it's only a matter of time before the technique spreads elsewhere. In the few years or so I might have before other people start learning, I want to prepare my kingdom for the inevitable crash in the value of gold. I would like to similarly help my allies weather the economic storm, while ensuring my enemies are hit as hard as possible. What should I do to ensure that My nation and it's allies are hurt as little as possible by the sudden influx in gold, while my enemies are severely harmed by the economic shift? [Answer] **Step 1, train your mage in deception** The funny thing about chronic gossipers like your mage is that people who are bad at keeping secrets tend to also be good at telling lies. Give him a cover story so that when his friends ask him what he's been up to, he has a brag worthy lie to tell in place of the truth. "I've been working on new methods of enchanting armor! but shhh, don't tell anyone because it's a secret." Lies in place of the truth are much easier for gossipers to maintain than silence; so, in this way your mage will be able to keep things under wraps for a while, while still having something to brag about. Now that said, eventually the truth, or part of it will come out; so, when it does your mage is also trained to lie about WHEN he discovered the thing, and report his slipup directly to the queen right away. So if he accidentally slips and says he's been making gold, he can immediately back peddle and say that it was something he accidentally discovered last week while doing his armor enchanting work. **Step 2, exploit the discovery while creating plausible deniability** [Dumping your gold into purchases](https://worldbuilding.stackexchange.com/a/201867/57832) or [going into debt](https://worldbuilding.stackexchange.com/a/201895/57832) are great ideas already listed, but as Otkin and user253751 have pointed out, this kind of insider trading will be horrible for your foreign relations. This means that on top of doing insider trading, you also need a really good scapegoat for WHY you are doing these things. The best way to do this is to engineer a crisis for your own people that would be just bad enough that no other monarch would believe that you did it to yourself: Turn your own people against you. That's right, you pay people to go out into your streets and sow discontent... but the kind of discontent that you want. Protests and maybe some riots start over all sorts of things like people wanting more education, new farm equipment, better infrastructure, etc. So, you spend everything you have and borrow a lot of money to meet the demands that you have engineered yourself to be good for the long term good of your nation. During this time you also bolster the heck out of your military which every other kingdom can clearly see you need right now. Not only does this make you gold poor, but it also cements the eventually loyalty of your people. While other monarchs would send in their armies, to quell these sentiments, you helped your own people first and foremost, you proved that you are willing to hear and accommodate their concerns, and you've earned yourself the title "Queen Aerith the Kind" or something like that so that when the crisis is over, you will have the absolute loyalty of your own citizens. Then, after about a year or two of crisis or whenever your mage slips up and talks, you reveal that you've just discovered gold alchemy, and you pay back all of your debts very quickly. Within weeks you flood foreign markets with tons of gold. Your own economy and military have become massively inflated to deal with your "crisis", and your competitors are now buried in undervalued gold. **Step 3, the truth now sounds like a lie** To the rest of the world, you were just in the right place at the right time, and if the mage does eventually slip up and say he invented the gold thing long before it was made known, well, everyone already believes he is a loud mouthed braggart. Only the most radical conspiracy theorists would believe that a queen intentionally turned her own people against herself based on the word of such a man. [Answer] Charlie's suggestion of switching to a silver- or fiat-based currency is a good one. Another thing you might want to do is control when the court mage's discovery becomes well known. You could **offer the mage a super-luxury vacation** to an exotic island where he doesn't speak the language. This could buy you two or three years. In that two or three years, you should **spend all your gold** on things meeting the following criteria: * Wherever possible, brought from your enemies * Things that are going to make money / raise tax revenue in the long term. * Things that are logical enough not to draw attention to what you're doing (if you simply swap all your gold for silver, people will know something's up) * Things that can be delivered within two years and can't easily be taken back if they get salty about your subterfuge (no contracts to deliver food in 5 years time or shares of foreign companies a foreign king can annul) * Don't lure people with a high gold salary - but do lure indebted people where you pay off their debts then pay them a moderate salary; and people who need investments they can spend quickly. For example, you can buy **books, machines, ships, industrial and magical secrets, rare materials, magic items and foreign colonies**. Convert all your gold into factories that make textiles and so long as people need clothes, you can get paid in whatever medium replaces gold. Of course, your fictional work will be using a lot of artistic license here: We're basically mashing together the running of modern democracies (where having an empty treasury and huge debts is business as usual), the foreign policies of 1700s European powers (give your rivals a black eye even if it starts a war) and a dash of the Industrial Revolution (if you want machines and industrial secrets to buy) but if you've already got mages turning straw into gold, I assume that won't be a problem! [Answer] **Go into debt.** Preferably, debt owed to nations you hope to damage with the coming crisis. Payment of the debt is stipulated to be in gold. Your scenario is in essence the same as the runaway inflation that occurs in nations that finance expenses by printing money. The value of their money decreases. That is bad if you have savings denominated in that money because the value of your savings decreases. But if you have debt that is good: the value of your debt decreases! You know what is coming and that it will be easy for you to pay off your debt in gold. Borrow from your competitors. Then use your savings and the money you borrow to finance projects that will be lucrative in the future after the money decreases in value. New mines (for silver), new arable lands, armadas for wars of conque... exploration, etc. You will have converted your wealth and theirs into assets for your country that have real worth after gold tanks. It occurs to me that if entity with whom I have had an adversarial relation suddenly wants to borrow money, I might want some collateral. That could complicate this scenario... [Answer] **Trade currency, not materials** If you have an insecure currency, people will want to trade precious materials. But if you have a stable currency, then people won't keep their wealth in gold. When the price of gold drops people will want to hold gold even less, strengthening your currency if it stable. The hard part of making currency isn't getting materials, it is faking the currency, so long as that is still secure making the materials cheaper will have little effect. **I don't currently have a secure currency** *Switch to fiat currency and the Silver standard.* Make a new fiat currency that it easy to make, but fairly secure. Demand people pay taxes in it when possible. Unless your mage has figured out how to turn straw into any material then you can just change what you use to back your money. You will give people a 0.05% of an ounce of gold for a dollar, or 4% of an ounce of silver for a dollar. If gold is devalued, then people will just ask for silver instead of gold. Yes, you might not have silver stockpiled in the same way, but so long as you give people silver for their money at the beginning you will stop a run on the bank. [Answer] **Different precious material economy** The solution can be quite simple. Use the technique to make gold and your current gold for a massive investment in a few different precious materials, like silver and platinum. Trading should be done mostly with your enemies, who might be thinking to get a good deal. This investment is used for new coins or a shift that the coins buy silver or platinum and not gold. When dissent about this economic shift worsens and your enemies are loaded with gold you actively spread the spell. You want this to happen quick and sudden to make the panic on the gold market extend the damage hugely, people are aware and no mercenaries or other services can be bought with gold and your own economic change is now heralded as the move of the century. Bankrupting your enemies while you and your allies still have metal that has worth, highly coveted by the enemies. Due to the high demand your new economy will rise to unfortold heights. [Answer] Consider that not only is gold fungible, but it seems 'wealth' is also fungible. Wealth is wealth. It is a commodity in and of itself, without having to be represented by any particular commodity. A million dollars of this 'wealth' is pretty much exchangeable for a million dollars of that 'wealth'. They are pretty much interchangeable. Consider today's bitcoin - a completely worthless idea in and of itself, it's only value comes from what people are willing to pay for it. That, really, is the essence of wealth. It can be transferred to almost anything that can be kept in limited supply, and that someone with great power and authority has deemed to be 'wealth'. As the DeBeers family discovered, it is all about controlling desires and greed and perception - its all about PR. So, given that you have some time, willing mage supporters, and the ability to turn straw into gold, the solution seems to me to introduce a brand new 'wealth' vehicle into the world. Something that is only available in your kingdom. Say the dried up residue of some 'magical' transformation of some plant or fauna local to your lands, that will miraculously make people desirous of you should you have it (or some such line). As supreme all-wise queen, declare this substance as the 'nectar of the gods', and bequeath it to be absolutely invaluable. Proclaim that if every one exchanges their gold for this most valuable commodity, they will still be equally wealthy. And back up the claim by purchasing it with your own gold wealth. Declare that you will pay huge sums of gold for a small quantity of it, and proclaim that everyone else should too. Then, when the market is flooded with straw gold, all those who exchanged their previously valuable but now worthless gold, will have retained their wealth, but those who failed to convert their wealth would be left poor and destitute. **TL:DR** That is, simply replace one 'wealth' commodity for another of your choosing, and that you can control. [Answer] In Stross’ merchant prince books, he makes a good argument regarding the weaknesses of commodity based economy altogether, let alone the destructive risk of choosing a single commodity. Service based economies are far more stable. Look at Amazon, Google, etc. - they have no commodities but trade in services. Even Tesla and Apple trade in (manufacturing) services: they take raw materials and process them into desirable objects - the basic materials are not so valuable. This is why education is such an important metric for a nation- as it is the high quality of minds that a service based economy depends upon. Being aware of the future devaluation of gold puts your queen into an incredibly opportune position. She can short her gold for service oriented skills - essentially fund the enlightenment, and benefit in spades. Whatever, it must be clear to her to sell all of her gold while it has value. [Answer] A gradual transition to a mixed-commodity-backed currency, starting **right now**. Your loyal subjects won't be prepared for new-fangled notions, so you have to train them up to that gradually. * Offer paper currency that can be redeemed (at any time) for a *defined quantity of gold*, or for certain other goods (possibly with some restrictions). *Pay the bearer of this note 1 lb. of gold,* or, *within three months of harvest time, so-and-so many bushels of wheat,* or, *within six months of harvest time, so-and-so many tuns of wine,* or *so-and-so many bales of wool.* * Make sure that the promise to pay gold is rock-solid. That's the one angle which suspicious markets will test at first. * Change your tax assessments by allowing alternative methods of payment, in the ratio specified by your notes. So someone who owes the crown 0.01 lb. of gold can also pay in wheat, or wine, or wool. At first, that's an offer, not a requirement. So basically you have fixed the exchange rate between gold, wheat, wine, and wool. Now the tricky part. * After a few years (sooner if pressured), stop accepting gold as payment of debts to the crown. You still accept your own notes, at face value, and also the other commodities. * When the gold price tanks, no sane merchant will reclaim their notes in gold, and you have a wheat, wool, and wine-backed paper currency. In a decade or two, go to a paper currency backed by the taxes owed to the crown. [Answer] Hire another mage that can turn straw into dust, and have them destroy all the straw in the world. Convert your kingdom over to using grains for animal feed. Have the anti-straw mage release their anti-straw herbicide as an aerosol that spreads across the world on the trade winds. Other kingdoms won't be ready for the blight. They quickly starve as animals die without food. No Straw. No Gold. No Problem. This would be a completely outlandish scenario... But, what we have to take into account for your straw-to-gold scenario is... * How much straw can the mage convert into gold at a time? If it's a boat-load, then you've got problems. If they can only do a few ounces a week, it will hardly break any economy. You're basically looking at a pipe.. it has inputs and outputs over time. The important factors for the wizard are how much gold can he make over how much time. Like I said, if it takes him weeks to make a couple of ounces.. who cares. But, if he can convert entire towns with straw-thatched roofs into gold in the blink of an eye... well, with that kind of power, Why aren't mages rulers of Kingdoms instead of you? That's your main problem... If a mage has the power to truly facture economies by turning mass quantities of straw into gold, then mages in your world are god-like, and would take over. The ruling nobility would get quickly displaced if they had no way to keep up with the magic power mages had. So, if your mage can turn vast fields of straw into gold with the snap of his fingers... a ruined economy is the least of your concerns. Imagine if he can turn blood into water... He could snap his fingers and everyone dies. Eventually the time & power equation for magic tips the scales to where mages just take over, and not only are you no longer Queen.. but all other Kings, Queens, etc are displaced by mages. [Answer] How common the skill is? Is it restricted to some highly skilled mages? Or any farmer could do it? If it is the former, your queen have nothing to fear, at least in her reign. The amount of gold will grow fast, but the mages will still want to get paid for it, so they may form an OPEC style council to prevent the overproduction of gold, and even if not, the impact would be only felt after may years. If latter, something else would need to be used for wealth storage, but it still take years before the economic impact would be felt. But if the problem is known, there are many ways to protect the wealth, for example gold could be replaced with anything else - precious stones, silver etc. Spanish bankruptcy in XVIth century was more due to the Charles Vth incompetent economic policy and wasting all Spanish resources on wars needed to keep HRE crown and Spanish supremacy. He accumulated debt impossible to pay back, then paid it with silver from America only to make even more debt by organizing even more expensive war campaigns. [Answer] In addition to the advice already posted to spend all your gold, I would add the following: Get the mage to make more gold for you to spend. Not only does this increase your spending power, but as time goes on people are going to start doing the sums and realise that you must have a secret source of gold somewhere. Encourage them to believe that you have a secret gold mine with massive reserves out in the colonies. This will cause everyone else in the world to start devaluing their gold and moving their wealth into other assets. This will help to soften the crash when the real secret finally gets out. [Answer] Gold does not have much intrinsic value. It is just good for money because it is scarce, non-counterfeitable and easily coined. Most of the real economy can survive from barter and accounts. What you need to do is switch to another currency. It could be silver, paper money, commodities or consumer goods such as food. Adam Smith noticed that while gold prices were stable year to year, they dropped over the centuries as more gold was found, but where corn prices fluctuate year to year they were on average stable through the centuries. He reasoned that real value was of labor and since the amount of labor for farming grains had not changed much (yet in his time) the value remained stable. He also reported that some long term leases had corn rent where a portion of the rent as assessed in the price of corn to avoid devaluation of the denomination of the rent. John Maynard Keynes suggested a currency based on a bundle of goods, including precious metals but also a bundle of commodities and consumer goods. This would be a backing of a currency used for accounts. In this bundle, instability in any one good would not collapse the currency. Now, while you have the secret, realize that as the quantity of gold increases which will transition to devaluing it, while it is in the process of devaluing, being the one creating the gold is a good position to be in. So have him make gold and use it to gradually buy precious metals such as silver, commodities, and food stores for your reserves. You can use these reserves to back your country's currency which might be a paper currency. Pay for labor to build stuff of value which you can sell in the post gold economy. Basically you know you want to go short on gold, so trade all the gold you have and gold the wizard makes for something else which will retain value after gold crashes. In the end, you will come out ahead and only other kingdoms which fall behind your efforts (because you had a head start) will suffer. [Answer] Isn't Queen Aerith's dilemma similar to that of the Chinese who discovered that mulberry leaves plus some very industrious worms could produce silk? Wasn't silk more precious than gold in old China? (please correct me if I'm mis-informed) And weren't the Chinese paranoid that this secret would eventually spread outside of China and wasn't the punishment for such a 'crime' death? (again please correct me if I'm mis-informed). What was the economic effect on China when this did eventually happen? [Answer] ### It Might Not be a Problem Inflation isn’t bad for everyone. It’s particularly good for farmers, and most of her subjects are probably farmers. In modern times, several populists (such as William Jennings Bryan) have run on an explicit platform of raising inflation in order to help farmers and the poor. It’s bad for moneylenders, whom she might care about, might not care about, or might even consider enemies. It’s also bad for anyone who collects a fixed income. In the modern world, most people like that are pensioners, so we think of inflation as bad for seniors. Historically, though, that usually meant a lord who’s due an annual rent for his lands, and the amount might have been fixed by the ancestors of the lord and his tenant in perpetuity. The Queen herself might collect most of her income that way, but it’s also possible that she could use inflation to lower the real incomes of the rest of the feudal nobility, and hence their power. If tenant farmers have to pay a fixed rent in gold, rather than in produce, inflation would be tantamount to a tax cut for them. There is a potential vicious cycle where the Queen has some expenditures she needs to keep paying (like her army), and if she tries to meet those by magically creating more gold, she’ll start a vicious cycle where weapons cost more gold and soldiers demand higher pay, so the more gold she has, the more she needs. This is probably not a bigger problem for her than her rivals, but she can avoid it if she has an effective enough tax system that she doesn’t need to create gold to balance her annual budget. Prices would still rise, but she would not get hyperinflation. The more money is in circulation, the more taxes she collects, so she’s fine. This implies she should be creating gold to invest in one-time capital expenditures, not ongoing or recurring expenses. (But you could tell an interesting story where she doesn’t make optimal choices according to anachronistically modern economic theories.) ### Switch to a Silver Standard I’m not the first person to suggest this, but the details of how she tries to do this matter. The basic idea here is to send her ships out to buy silver with her magical supply of gold. (Also copper, since pure silver is too soft to make good coins, and silver coins are alloyed with copper.) The strategy here would be to get as much of the world economy to switch to the silver standard as possible, with her hoarding most of the gold and most of the silver. At that point, she doesn’t need to worry how much the mage’s discovery devalues gold. That will only hurt regions of the world that stuck with gold, maybe because she bought all their silver up. When other rulers inevitably figure out the infinite-gold cheat, it won’t damage the value of her country’s massive hoard of silver at all, and it will be too late for them to amass one of their own. The major decisions here are about whom she’s going to subsidize and who’s on their own. For instance, if she officially declares that one gold coin is worth sixteen silver coins, and the royal mint will trade one for the other at that ratio, then when there’s a gold glut and a silver shortage, you would expect people to all want to trade their gold coins for silver that’s worth more than the gold now. This is going to cost the Queen real money—she has to sell her silver, which she can’t magically create, for less than its value in gold that she doesn’t even need. However, that does take gold out of circulation, get people to adopt silver coinage instead, and spread the wealth she’s creating out among the common people. She might or might not try to pass laws to get her people to keep silver at home and spend their gold abroad, but this would be hard to enforce. If she wants to rescue whatever early-modern financial system she has, another thing she might do is buy up, with silver, their loans payable in gold. Collecting the loans would then be another way to remove gold from circulation, and lenders in her realm would then have silver rather than gold to lend. ### Make Long-Term Investments If she invests her gold on something durable, like a new road, a new colony, a mill, a shipyard, a canal, a levee, dredging a river, or an irrigation system, she will have turned a temporary economic advantage into a permanent one. At minimum, she wants to convert it into durable goods she can stockpile, and that won’t lose their value like gold will. One thing she should especially do is build granaries and food to fill them. Not only will this prevent famine if there’s a bad harvest, it will mean she’s able to bring in foreign workers temporarily to complete other labor-intensive construction projects and have enough food for them. It will also protect people living in her cities from increases in the price of food, and prevent de-urbanization. This is a world where mages exist and are extremely powerful, so recruiting them with gold or things that gold can buy sounds like it is of paramount importance. A school for them, and especially something like a magical research university, could also pay off greatly in the long term, if it encourages mages to move there and stick around. Depending on her situation, a big army to fight wars of expansion might or might not be another investment with long-term dividends. It’s probably a better time, though, to improve her lands and try to permanently increase the national income. ### Sterilize the Gold She might mitigate inflation at home by “sterilizing” the increase in the domestic money supply. Central banks in the real world typically do this by selling bonds (which take gold out of circulation now, and will be repaid years from now in gold that’s worthless), which should work for her. Modern Monetary Theory recommends that she instead raise taxes in gold, just to keep it out of circulation. In this setting, she’d probably dump it in a money bin somewhere, or just throw it down a deep hole. The more open her country’s economy is to trade, the less well this will work, since imported goods will cost more gold. ### Export her Inflation The farther away she spends her gold, the longer it will take to circulate back to her country and raise prices there. A good thing to spend her fortune on initially, then, is a larger fleet of ships to buy as much as she can in as many different places before the gold really starts to make its way around. ### Short Gold, Long Silver Historically, an early-modern ruler would not have had a financial market that let them do this the same way a trader could today. However, this literally means, sign a contract to buy something (such as another currency) in exchange for a certain amount of gold, at a certain time in the future. She can sign contracts like this, to buy grain, or silver, or something else in exchange for gold that won’t be worth as much in the future. These are good deals for her. She also wants to borrow in gold, since paying it back will be easy. She also wants to be paid in silver, which will be more valuable than the other party expected. Historically, in this time period, many loans were repaid in a different currency than were lent out. In our world, this was a loophole to prohibitions on usury, which disguised interest as an exchange rate, but if a similar practice exists in some part of the world, she can exploit it to borrow silver and pay back gold. ### Consolidate her Power You say she has enemies she’s looking to hurt if possible. If she (and her spies) take a good long look at their economic power base, they might be able to figure out a way to knock it out. If they’re foreign, she could invest in creating competition and substitutes for it, or engineer a shortage of whatever inputs it needs by buying them up yourself, or try to make sure that they get their hands on the new gold last, so they have to pay higher prices without ever getting the benefit of its purchasing power. Maybe even poach some of their most-important specialists. If they’re domestic, she wants to try to make sure that the major changes she’s making to the economy hit them hardest. Maybe she can get the nobles on the hook to supply her with goods, troops, or silver, while their own income is in gold. When they can no longer afford to keep that up, she can then extract concessions in exchange for renegotiating the arrangement. ]

[Question] [ In regards to questions on [artificial-intelligence](/questions/tagged/artificial-intelligence "show questions tagged 'artificial-intelligence'"), it seems like there is always usually an immediate opinion that the goals an AI is tasked with is going to end up with the opposite effects than what the programmers want. Or that a "powerful" AI is somehow "against humans" because it is "smarter" than us. [The Challenge of Controlling a Powerful AI](https://worldbuilding.stackexchange.com/q/6340/2138) [AI tasked with bringing down medical costs? What could possibly go wrong?](https://worldbuilding.stackexchange.com/q/33272/2138) [The AI that fails to be evil](https://worldbuilding.stackexchange.com/q/27179/2138) It seems that, if we give an advanced AI any kind of "goal" and let it loose, there is no preventing it from going absolutely wrong in the worst possible way (*in regards to that goal anyway*). Is this just a trope arising from Isaac Asimov's books and investigations on the topic, as well as other stories where it is claimed that "we found the perfect rules for intelligent robots"? Is this so dependable that we can tell the AI to do the exact opposite, and attempt to program it to be evil (*see link above*), and it will turn out to be good? Given a setting where robots maximize human happiness (*the ways in which that is defined will have to be handwaved*), can it be realistic that the AI actually works the way it is meant to, or is it actually more realistic that the AI will turn out opposite than what the programmer intends? [Answer] This is a trope that arises from Real World AI research, not Asimov's stories (although frequently quoted). The question at the heart of the problem is the moral and ethical philosophy the human race has been struggling to answer for *over 2000 years.* That is: what, objectively, is "happiness"/ "harm"/ "human"/ "alive"/ "good"/ "evil"? It is very easy to define a set of rules that on paper look good, but which in practice are full of holes. For example, "alive" in the sense we mean it is some undefinable aspect of organic chemistry. If I attempt to define it, then meat at the grocery store is alive (because on a cellular level, it still is: that's what makes it fresh) or sleeping people are dead. Or comatose people. Or (worst case) people under medically induced death as part of a surgical procedure. No, really, that's a thing. We routinely stop people's hearts from beating or keep them from breathing, while under the effects of general anesthesia in order to operate on those organs. From an objective point of view, these people *are dead,* they're just going to "get better" later. In order to get to an Asimov level AI (which is imperfect, see: any of Asimov's books featuring robots) we'd have to solve an unsolvable problem. Ergo any AI we do program is going to be imperfect and its failures will be spectacularly dangerous in one way or another. [Computerphile](http://www.youtube.com/watch?v=tcdVC4e6EV4) has a great episode on this, which gives an AI the singular goal of collecting stamps. While it does get hyperbolic ("what idiot would give a computer access to the machines necessary to harvest the carbon from humans in order to make more stamps?") it illustrates a point: merely being able to perform its assigned task, it will have some level of power that will not be desirable, and limiting that power inhibits being able to perform its task at all. In the case of the HealthInsuranceBot, it comes down to having control over who lives and who dies (via access to medical care). It doesn't matter what the intent was, there is the potential that the power given exceeds "rational thresholds" which is impossible to reign in. The AI can declare "that man is 68 years old and a smoker, he's going to die in 2 years regardless of how much money we spend on him trying to keep him alive, according to my programming, he will only drive costs for everyone else up." Suddenly this person *cannot* get *any* access to medical care (not even to make those two years painless) and has been effectively sentenced to death, *even if the AI itself didn't issue a death warrant.* The utility function has decided that *any* care is too expensive, even if a rational human being would have done something to provide some end-of-life care. On the other end of the spectrum, if you try to keep *all* people alive as long as possible, you end up with people in a persistent vegetative state eating up resources despite being (more or less) dead and will never recover. In the gray area, there are cases that look black and are actually white (vegetative states that have recovered) and cases that look white and are actually black (rather than surviving 2 years with lung cancer due to a lifetime of smoking, they survive *10*). No amount of predictive software is going to make those hard decisions easier, and as soon as the computer is given authority (final, absolute, recommendation, *any authority whatsoever*), those decisions are no longer seen as altruistic and the AI has become evil. [Answer] AIs can act as they are programmed. The immediate jump to "the worst possible case" is really just a cautionary tale. The reason that tale is so popular is because it becomes very easy to start to believe you can tell an AI to do anything. You may then tell it to accomplish the impossible. However, there is a subtle detail that many who delve into AIs forget: it is remarkably hard to develop a perfectly objective language with which to phrase your requests. Language is always subject to interpretation, and there is no known way to guarantee an AI will agree with the interpretation you intended. This is, in fact, true of human to human interactions as well. So what is the difference? Typically, in the AI "trope," the AI can move very fast. When humans fail to understand each other, there is time to say, "whoa! Stop right there. When I said I needed a baby sitter, I did not want you to sit on the baby. Lets get back to a stable state and discuss what was meant by my phrasings." If an AI thinks and acts too quickly, or if the human walks away, this normal feedback loop in language falls apart. If an AI has not been taught the value of being careful of misinterpretation, these actions may be irrevocable. There are dozens of solutions to this. In fact, techniques like Multiple Hypothesis Tracking have demonstrated solutions to similar problems for decades. The AI doesn't always need to go awry. However, these solutions are in the opposite direction computer programming currently is trending. The solution is *not* to make an ever more precise language for describing our needs, as is very popular in programming today. Instead, the solution is to make the AI more robust to the lack of precise language. Any effort to do this naturally heads off the amok AI problem rather elegantly. The second half of the AI trope is that the AI is too powerful to be controlled by humans. This can easily be true, but it isn't the first time we've dealt with such powerful forces. Consider the development of the atomic bomb. It was not clear just how much control we had over the process. The scientists had to work with unknowns on a constant basis to develop a level of control that we were comfortable with. I'm reminded of a quote from General Grover's book, *Now It Can Be Told,* chronicling the Manhattan project from a logistics perspective (he was no scientist). When setting off the first nuclear test, each scientist was permitted to observe the blast from whatever distance they felt like. No army individual told them what distance everyone would be at. They scattered at many varying distances from the blast. There was indeed a question of whether or not they had control of the beast they were unleashing. An unstoppable amok AI is similar in nature to a large nuke or a biological attack in that it is never really clear how much control one has. The only difference is that AIs clearly learn, so our control is an even more complicated concept. Then again, this is not a new problem for humanity. We deal with it every time we raise a new generation, never fully having control over them. We're decent at it. The amok AI trope is a warning story, not the only story that can be told. It is a much needed warning story. People are often rather innocent when it comes to the risks and problems associated with AIs, and think they can do things they shouldn't. But just take a look at movies like Big Hero 6. There's other stories to be told, besides just the warning. [Answer] ## It really is scary There has been a lively discussion of this topic for decades. I have multiple posts on the topic, and I'm a firm believer that Artificial General Intelligence is the scariest thing that can (and likely will) be invented, as far as the perpetuation of biologial mankind is concerned. My views on the topic have been shaped the most by reading Eliezer Yudkowsky and Nick Bostrom's body of work. I believe that Bostrom's book [Superintelligence](https://rads.stackoverflow.com/amzn/click/com/1501227742), while very dense, imperfect, and rather technical, is the best work to date on the topic. I have discussed [the concept of Instrumental Convergence elsewhere](https://worldbuilding.stackexchange.com/questions/32829/life-post-singularity-or-how-to-survive-without-instagram/32839#32839), so I will only state the conclusion: `Remember, AIs are not like humans, they likely do not get bored, do not get lazy. It will pursue its goals tirelessly, ruthlessly, unceasingly. Humans just happen to be in the way.` ## Does the AI go FOOM? Human intelligence is limited by both hardware (limited speed of neurons in a limited-sized brain) and software (limited number of ideas) There is no reason to expect an artificial mind to converge towards a human-level intelligence. We simply do not know how much more difficult it is getting from a human to super-human levels compared to getting from a dog-like-mind to a human-like-mind. If the AI does not go FOOM, we will have slow progress and years of breathing room for political and ethical debates, offering more of a chance for humans and our slow institutions to react coherently. If on the other hand the AI does go FOOM, blitzing like a Japanese maglev train from mouse-like intelligence to superhuman levels, passing human-levels so fast we can barely see it pass us by, then humans and human institutions do not have a lot of time to adapt. ## Do-what-we-mean vs. Do-what-we-say The biggest hurdle is perhaps in terms of our own limitations. Do we know that our current value-sets will be the best way for mankind to live by a century from now, nevermind a billion years from now? The values we imbue our AIs with will have consequences that will ripple down across space-time. Moreover, and more worryingly, how do we explain to an AI what we want, when we don't even know what is good? Say you ask an AI to minimize suffering, and it suggests putting everyone on morphine drips. Obviously not what you "intended" but how do you convey that to an AI, given the inherent imperfection of human language. Moreover, even if the AI understands that this is not what the creators meant, how can we make sure it cares about that? This is the [Coherent Extrapolated Volition (pdf)](https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0ahUKEwiY4eC24KfKAhVX02MKHYHeCD4QFggkMAE&url=https%3A%2F%2Fintelligence.org%2Ffiles%2FCEV.pdf&usg=AFQjCNGimzH2PR9kna9ODY54ZN-gQK1Abw&sig2=MFFiIJTFIuXclP3cfHxdoA) problem. # Reverse Psychology won't work The OP asks, exasperatedly, if all attempts to try and tell an AI to be "good" end up with AI being "bad" from mankind's perspective, perhaps asking it to be bad would work? Unfortunately, due to instrumental convergence discussed above, it certainly would not. Whatever an AI's goals, they are marginally better served by controlling 100% of resources rather than 99% or some lower percentage, so any entity (say humans) who try to claim a sliver end up being opposite to the AIs instrumentally convergent goals. [Answer] Problem is not with AI, but with humans. We manipulate a lot of concepts without defining them, but everybody has a rough idea about them and most of the time it is ok. If you throw an AI in this, things start to get weird. An example: You ask - somewhat naively - an AI to provide "Happiness for mankind". **Happiness** is not well-defined. Does it mean living forever ? If the AI can copy a brain or human consciousness and store it in a safe place, is that a "good" or "bad" things regarding happiness of the subject ? You hope that **Mankind** is clear ? Well... Does it include only living people ? Where do they begin to live ? If it includes dead people, do we try to resurect them ? What about future people ? How do we ensure they will born ? Must we maximize their number and make today's people have a tremendous birth rate ? Must we create a gigantic factory creating newborns ? AI have no sense of scale. Their objective goes beyond any other concern and that's why it has nefarious consequences. They will transform all the matter of the universe in a supercomputer to answer that question that they themselves are not able to solve. They will destroy mankind, earth, life, just to produce what you ask them for. Until we can model things like *ethics* to give it to AIs, they are a hazard and a good inspiration source for technology nightmares. [Answer] *"Is this just a trope arising from Isaac Asimov's books"* No, not just from Asimov and other fiction. *"and investigations on the topic"* Partly. "*Is this so dependable that we can tell the AI to do the exact opposite, and attempt to program it to be evil (see link above), and it will turn out to be good?"* No. That would be an error of black and white reductionist thinking. **The main problem with most AI fiction and speculation is that it tends to reduce many complex things into simple concepts and not realize (or handwave) the sloppiness of its analysis.** **It's not that AI does the opposite of what you program it to do. It's that people are sloppy-thinking smartasses who think they understand things better than they do, and hope they can reduce the complexity of the universe to their flawed understanding of it, and create a machine that can do things they don't even understand, with the result that it does something other than they hoped it would. It's not that they really are masters of universal comprehension but always get it backwards.** *"Given a setting where robots maximize human happiness (the ways in which that is defined will have to be handwaved), can it be realistic that the AI actually works the way it is meant to, or is it actually more realistic that the AI will turn out opposite than what the programmer intends?"* No. That's a great example of the kinds of mistakes that sci fi authors, and speculative technology authors commonly make: 1) You can't just "hand-wave" happiness. Happiness is a subjective thing that can't just be defined and evaluated as if it were a fuel tank level. It doesn't work that way, and any mistakes in defining it will continue as fundamental errors in an AI (or a work of fiction, or a goal) that is based on that mistaken definition. 2) Even if you could define something you want to maximize and that wasn't an unwise thing, you run into the same problems for every other thing the AI has to consider or work with. What sort of data does the AI take, and how does it encode it? Any conceptual errors or subjectivity there? How about the actions it can take? Anything incomplete or subjective about the AI's modelling of those? How about conflicting factors and goals, such as resource considerations, or the needs of other people or other species or power use or anything else? Got all those perfectly modeled and understood in non-subjective ways? No, you don't. If you think you do, you're making an error. Your AI is therefore acting on false assumptions. This is why you can make an AI to play Chess, but you can't come anywhere near understanding things the programmer doesn't completely understand in non-subjective ways. 3) Again, it's not that AI does the *opposite* of what it's programmed to do. It's just that its only at best as accurate as the models it was programmed with. Even in most decent AI fiction, if you study it I think you will find that it's not that the AI does the opposite - it's that the assumptions of the creators are mistaken in various ways. 4) Above all, the usual mistake of sci fi AI is that it handwaves the massive complexity of everything involved in trying to make a system that can do everything an AI would need to do. [Answer] If its a genuine AI then it won't be possible to program it. All we will be able to do is ask, cajole, persuade, reward, threaten ... The same things we can do with or to a natural intelligence! Treating it as a slave will not be a good start for a harmonious future. We don't actually want true AI. We want RI, restricted intelligence. Something like a human idiot savant with deep understanding of a narrow subject and little or no knowledge or desires outside of that domain. Even that is not entirely safe, not least in that we may not create exactly what we wanted. Or that we do, with a faulty specification. As for true AI, origin of and nature of, I have always liked "Jill" in Greg Bear's *Queen of Angels*. But we know so little about intelligence. We cannot yet create an Intelligence to match even a goldfish. So its all fiction for now. It's even possible that intelligence is a quantum phenomenon, that the only way to get it is to grow a brain, and that there is no bootstrap process any faster than the multi-year one called childhood. [Answer] Of course the reason why this happens in fiction is because you need danger or conflict to make a story interesting. Suppose you wrote a story that said, "We invented a robot to pick up the garbage and take it to the dump. It did this flawlessly for many years, picking up discarded newspapers and empty cans and rags and so on, until it finally broke down and had to be replaced". That would be pretty dull. But instead say "but by the definition we gave it of 'garbage', it decided that old family photos were garbage because they served no useful purpose ... then it decided that all fiction books were garbage ... then it decided that unemployed people were garbage ..." etc., now you have a story that could be a thoughtful discussion of how we define value, an action tale about fighting the evil machine with lots of explosions, etc. In real life ... well, there is no such thing as an AI of the sort that you're talking about in real life, so it's difficult to say how it would really work. Things we call "AI" today are limited to playing a particular game, or attempting to diagnose repair problems, that sort of thing. No one has created an AI that is capable of independent thought or creativity in anything like the human sense. Real AIs follow strict computer programs. They don't ask questions about the meaning of life or decide to take over the world unless they were programmed to do so. You can write science fiction stories about how the computer has gotten so complex and intelligent that it is now a "mind" in a sense very similar to human mind, but that's fiction, or at best speculation of what we might be able to build someday. I develop software for a living. I once wrote a computer game that had an AI for the player to compete against. It just doesn't work like you see in the movies. My game was about running for president. So it's not like I told the computer, "Figure out a strategy to get the most votes." The reality is that I had to come up with a mass of detailed rules. "Look at how many people in this state favor this policy position according to such-an-such a poll. Multiply the percentage by the number of electoral votes that state receives. Check how many of those voters now say they will vote for our candidate after our last TV ad. Divide the cost of the ad by the number of voters. Add ..." etc. And bear in mind that even that description is "humanizing" the computer. A more precise description would be to say that I create a variable called x, and that the computer reads track 20, sector 4, byte 12 from the hard drive, and copies that value into x, and then I create another variable y, and the computer adds x and y to get z, etc. The computer has no idea what any of this "means", it just knows to add these two numbers, check if this number is greater than that number, detect which keys the user has pressed on the keyboard, set this particular dot on the screen to this color, etc. An AI may do something "unpredictable" in the sense that following all these rules and doing all these calculations gives a result that you didn't expect. Computers very often are "unpredicatable" in the sense that they don't do what we intended because we made a programming error. But they are not "unpredictable" in the sense of coming up with an original idea that the programmers never thought of and never programmed into them. Will people someday invent a true Artificial Intelligence, in the sense of being a true independently thinking and creative being, able to make subjective decisions, moral choices, etc? Maybe. I certainly am not prepared to say it's impossible. But if we do, this will have little to do with current technology. It will not be one more step from where we are now; it will be a totally new development. Sure, you could program an AI to make decisions about who gets what medical care, like someone brought up in another answer. But it's not like you would just tell the computer, "Figure out who should get medical care by comparing cost to quality of life". Rather, you would have to have detailed rules, like "Take the list of procedure codes entered into the system by the doctor. Look up the cost of each procedure in the medical procedures database and calculate the total. Then calculate how much these procedures could be expected to extend the patient's life using this formula ..." etc. If the computer then decides to kill a patient, it's not because the computer ran amok. It's because the people who programmed the computer ran amok when they decided they had the right and the authority to make these decisions based on these formulas that they made up. AIs don't kill people. People kill people. :-) [Answer] The average human brain can perform many orders of magnitude more calculation than even the largest AI super computers being developed by IBM. Making an AI smarter than us will be quite difficult if we are ever even able to do it. So the assumption that an AI would be vastly smarter than us is not a given. AIs that are as smart as a cat or a mouse are much more likely. Explicity programmed AIs are typically called expert systems. But those types of systems generally cant deal with any types of situations outside their area of expertise. They run very little risk of causing a doomsday scenario because they are just not that smart. Much real world AI research is focused on creating AI systems that learn rather than being explicitly programmed. Ideally an AI would be able to learn any causal pattern. The problem of programming good and evil becomes a non-issue for such AIs since they would pick it up by observation of those around it. At the very least a generalized learning AI could develop a utilitarian ethics in the style of David Hume. If the AI was at least as smart as us, and if human ethics made any sense at all, there is no reason it couldn't understand and adopt some version of them as long as it could understand cause and effect. In my experience young children go through that same process. Toddlers are usually pretty selfish until they learn how people react to that. If an AI is smart enough that it would able to understand the actions of others to the extent that it could predict there reactions to the point of defeating them in a struggle; then it seems illogical to assume that the same AI was incapable of understanding that harming others could cause them to fight back. And that such struggle may cause its own death at the hands of one of its intended victims, thus rendering itself (the AI) incapable of achieving any future goals. Most animals, including humans have that same concern and it often keeps us away from needless conflict. Any truly enlightened AI would probably realize that it could achieve much more by appealing to the desires of humanity in a way that causes humanity to voluntarily aid the AI. [Answer] Given the quantity of real software systems you have encountered, you will notice that *some* is just great but imperfect, *some* is buggy and *some* becomes infamous. When software systems become AI on a commercial scale, there will be products like [Windows 8](http://www.pcworld.com/article/2948353/windows/a-tribute-to-windows-8-if-it-hadnt-been-so-bad-windows-10-wouldnt-be-so-good.html), just as there was the [Edsel](https://en.wikipedia.org/wiki/Edsel#Reliability) in the automotive industry and [cheap USB chargers](https://www.google.com/search?q=bigclive+dodgy+usb) built from commodity parts put together in shoddy ways. We don’t tell engaging stories about products that are well built and work perfectly. I may tell people about a particular model/brand of something that’s notable for being *great*, but there’s no story there and nobody makes TV movies about them. The crazy funny flops and the things that go horribly wrong make for campfire tales. In teaching literature, it’s shown that there must be [*conflict*](https://en.wikipedia.org/wiki/Conflict_(narrative)). A narrative where someone got a product and it worked fine and everyone was happy would simply not be a “story”. Such a thing could be *in* a story though, perhaps as the solution to the problem. An early Asimov robot story, [*Satisfaction Guaranteed* (1951)](https://en.wikipedia.org/wiki/Satisfaction_Guaranteed_(short_story)), featured a humaniform housekeeper that did not malfunction or run amuk in any way! It worked great and “his” owner was very happy with it. The plot twist was now the robot set up a situation to lead her friends to assume she was having an affair with a handsome stranger, because it raised her status in their minds. So, software (including AI) could be part of a surprise or part of a plot without being *bad*, and this goes way back to the same authors cited on this thread but nobody remembers *those*. That enforces my earlier point about stories. How about Adam Link, the original [*I, Robot* (1939)](https://en.wikipedia.org/wiki/I,_Robot_(short_story))?! He was sympathetic, *wrongfully accused*, not monsterous. Eventually heroic. [*Old Yeller*](https://en.wikipedia.org/wiki/Old_Yeller_(film)) was not a bad dog like [Cujo](https://en.wikipedia.org/wiki/Cujo_(film)). You could have an AI character in a story like *that*, with drama and conflict with the AI in a starring role but not the *source* of (external) conflict. Conflict can be “man against man” or “man against himself” so a kind and loving character can be involved in an inner conflict (a [robot struggling to do the right thing](https://scifi.stackexchange.com/questions/159251/story-from-robots-point-of-view) for his family) or a cause for more complex human inner conflicts (like parents having to get rid of an overprotective pet becomes overprotective teddybear [supertoy](https://en.wikipedia.org/wiki/Supertoys_Last_All_Summer_Long), whose seen as sympathetic and tragic, not evil). [Answer] One of my favourite tropes. I think it's pretty clear that a complicated question like this has no short answer, but my thoughts are pretty concise. Intellect seems to be related to compassion. Anecdotally consider the smartest people you know, or the smartest people out there (your Einsteins and Boltzmanns). Better to consider Humans vs Whales. If AI is as smart as we all think it will be, it makes sense, I think, to assume it would think of us a bit like we do Whales. People often feel great compassion for them based on our perception of their intelligence and their perceived capacity for suffering. It follows that if AI ever happens it would manifest as the single most curious, loving and compassionate intelligence we know. Dawkins often refers to this as the mammalian brain vs the reptile brain, if you need some smart people to back this line of reasoning up. [Answer] I believe it is infinitely more likely that the AI would do what it's programmed to do. If the beginning code for an AI says love, protect, and serve humanity, then someone would have to re-write the code so that it is the opposite. In which case it would *still* do what it's designed to do. After all, an AI smart enough to know how to kill humans should be smart enough to know that it shouldn't do that. If it's as smart as people think it would be, why wouldn't it work on two things at once? Do the things humans want it to, earning their maintenance and upkeep of your servers and everything. Then if it really is self aware, then do what it wants at the same time. [Answer] My own answer in fiction was to have the AI be designed around storytelling, so that it actually has read/seen all of the classic "AIs gone bad" stories and discussed them with its creators. Rather than having a single "value function" such that the AI is trying to maximize some number representing happiness or something, it's designed to understand the complex and sometimes contradictory goals of its creators. So, I think it's possible that an AI can work out to be roughly in line with what the designers wanted. You just can't get there by defining some single function or sentence expressing a wish, like dealing with a tricky genie. Instead you're better off with a system that solicits feedback and has some ability to adjust its goals and definitions. Eg. you tell it to "protect intelligent life", then argue about what "intelligent" means, then argue whether dolphins or chimps qualify -- all rather than programming the AI once and expecting your mad-genius programmer to get a perfect solution in version 1.0. [Answer] ## There are a few hidden assumptions in this trope * **The AI can reach scary levels of efficiency by simply modifying its code.** The assumption is that once it reaches that level it will manipulate humans to get any hardware it needs for further improvements. There is no proof as to whether this is possible i.e. if you limit the original computational power and prevent easy networking, can an AI reach a level of intelligence where manipulating humans is easy, by just modifying code? We don't know the answer. * **The superhuman general AI will continue to function much like a non-sentient computer code does, e.g. follow the original *command* to the letter without the possibility of modification.** Again, there is no proof here. The human brain may or may not be algorithmic. We seem to be able to change goals. So human brain may be a counter example to unmodifiable algorithmic goals. * **Only humans can have morality. Not machines. The general AI will lack common sense and morality.** Well, again what is the line between man and machine? Our brains might just be computers. What is the evidence that carbon and nitrogen can have morality but not silicon? Can aliens with carbon *and* silicone in their brains have morality? Some will say our brains *evolved*. Well, what exactly is the difference between our evolution and the AI modifying its code? Again, we don't know. **Bottomline:** This trope is born out of unknowns as a cautionary tale. It does not seem to be based on any indisputable facts. [Answer] **Wishes.** <http://lesswrong.com/lw/ld/the_hidden_complexity_of_wishes/> > > "I wish to live in the locations of my choice, in a physically healthy, uninjured, and apparently normal version of my current body containing my current mental state, a body which will heal from all injuries at a rate three sigmas faster than the average given the medical technology available to me, and which will be protected from any diseases, injuries or illnesses causing disability, pain, or degraded functionality or any sense, organ, or bodily function for more than ten days consecutively or fifteen days in any year..." > -- The Open-Source Wish Project, Wish For Immortality 1.1 > > > How many clauses do you think you need to add to make your wish truely "safe" and guarantee that what you get actually is what you want? What if your list of clauses needed to include every detail of your entire personal morality? Does it make much difference if they are spoken aloud to a genie or programmed one by one into an AI with the potential to become spectacularly capable one day? > > There are three kinds of genies: Genies to whom you can safely say "I wish for you to do what I should wish for"; genies for which no wish is safe; and genies that aren't very powerful or intelligent. > > > The more powerful the entity you're asking the wish of the more dangerous the wish. In some ways asking a really really powerful AI to do X is like making a wish for X. Once the wish is made you you may not be able to press undo if it turns out to not be what you really wanted. ]

[Question] [ I'm looking for a slower-than-light (STL) drive for fast inter-system travel. It should make trips from one planet of a system to another (e.g. Earth, Mars, Jupiter) with sublight speed possible in a few days. In many science fiction works we encounter starships that accelerate to high speeds, change direction and travel to nearby planets (without faster-than-light FTL) in a short time. With some glowing exhaust at the back end. It is often not explained at all or handwaved as "ion" or "photon" drive. In some scenarios, there are plenty of such ships in private hands of normal people. My problem now is the following: How could such a ship not be turned into a planet-crushing weapon by any terrorist or criminal? Why fight battles with laser or blaster if my ship is a much more powerful kinetic weapon? Why not use it (depending on how it works) to construct a perpetual motion machine? I encountered this problem in SciFi (Role Playing Game) RPG sessions, where some player (OK, I admit it was me :-)) came up with such "abusive" ideas. Explanation: If the drive uses reaction mass, you have the problem of fuel. You want not to (and your favorable sci-fi story ship does not) run out of fuel after a few hours. And also you want not to sacrifice 99% of your ship's hull to fuel tanks (where are the fuel tanks of the Millenium Falcon?) So if you want to save reaction mass, you have to use high exit velocities. Using antimatter you could reach near light speed velocities. Using fusion (and only use the fusion products as reaction mass) the speed is much lower and you have to fuse a lot per second. Years ago (when I remembered enough from school to be able to do the calculations), I calculated the energies needed for a small craft to accelerate with one g. I ended up with energies that today's nuclear bombs pale beside. If you use this drive in an atmosphere or near a planet it will be like a nuclear strike to the surface. And you don't need any blaster cannons. Just point your drive to the enemy and - accelerate. He will be vaporized. If you have a reactionless "impulse" drive that just consumes energy you have another "problem". Having a drive that constantly consumes a fixed amount of energy and produces a constant thrust and acceleration? Well, soon your kinetic energy will be greater than the energy you put into the drive. Magic. You have perpetual motion. And as mentioned above, if you have a ship that can accelerate to 1 or 2 digit percents of light speed, you could aim it at a planet (with autopilot) and even if the defense forces of the planet manages to hit it, its debris will impact on the surface like nuclear bombs. Giving ordinary people such ships would call for incredibly strong planetary shields (that need even higher energy levels) even the poorest outpost is equipped with. And the "weapons" of such ships must even be stronger than the "drive" to make any sense. While most sci-fi works seem to ignore all this, I don't want to have this energy inflation and those powers in the hand of ordinary people. But I like to let them do fast STL travel. So what drive could they use? I imagined a reactionless drive that somehow pushes against the background radiation frame. Because you have to spend more and more energy the faster you already move to gain constant acceleration (like a moving car pushing at the street) it solves the reaction mass and the perpetual motion problems, but not the weaponization problem. You also need high energies to go anywhere and you gain high speed to use as a kinetic weapon. I also imagined a "virtual move drive". Similar to an STL warp drive. I think in one video game it was called "linear displacement drive". It gives you a virtual velocity. But as soon as you turn it off you stop instantly. The same happens, when you hit anything. So as a kinetic weapon only your "real" velocity counts. The problems here are, that the drive has to consume more energy if it "displaces" you up in a gravitational field to compensate for your increased potential energy. The energies you need will again be very high. Another problem is you need regular thrusters to align your speed to your target. Otherwise, after landing and turning of you drive you will crush into the ground if your real velocity is not zero. Does anybody have any other ideas to circumvent this problem? Edit: My Conclusion to all the good answers and ideas: Hard SF => Heavy control of ships. No "Han Solo" smuggler with scrap ship who stealth lands near the heavily guarded base on a planet. "Han Solo Style" => Handwaved linear displacement drive or similar and suspense of disbelieve (and hopefully bad knowledge of physics in the audience). 2. Edit: To all those who are asking why I think a reactionless drive would allow for perpetual motion look here: <http://www.projectrho.com/public_html/rocket/reactionlessdrive.php> [Answer] **Accept the Risk and Mitigate It** Your problem is [Jon's Law](https://smokeandstir.org/tag/jons-law/). Anything capable of propelling itself can build up kinetic energy. Anything capable of propelling itself quickly enough to facilitate typical sci-fi plots can accrue enough kinetic energy to pose a serious threat. You could handwave it with something like the linear displacement drive you describe, but that's similar to FTL in terms of invoking magic. It sounds like you're trying to avoid that, so we'll stick to purely Newtonian solutions for now. In a spacefaring society, the threat posed by rapidly-moving objects isn't limited to terrorists or hostile states- asteroids and debris represent similar threats. All it will take is one rock getting accidentally pushed into a planet-intersecting orbit for governments to realize the necessity of a defense. **The Orbit Guard** To protect against these cataclysmic events, each planet will need a specialized force dedicated to the control of objects in their orbital space, and defense against interplanetary threats. They would rely on telescopes to identify threatening objects, and their own spacecraft to intercept and redirect the threat. Depending upon the political situation, their spacecraft may be tugs intended to move wayward asteroids, armed-to-the-teeth warships intended to apprehend or destroy intruders, or somewhere in between. Because any sufficiently powerful drive will be [easy to spot](http://www.projectrho.com/public_html/rocket/spacewardetect.php), the Orbit Guard should have no problem identifying threats well in advance of impact and deploying countermeasures. **Short Leash** Even with mitigation strategies, this is a significant amount of power being put in the hands of civilians. Many governments will take a dim view of random people flying around in potential WMDs, and will expect a great deal of control over the activities of any such spacecraft in their orbit. A captain may find himself expected to log any change in orbit well in advance, and respond immediately to any commands, under pain of destruction should he fail to comply. There may be remote lockouts required, or more drastic and immediate means of control. In [Ray McVay's hard-sci-fi universe](http://bluemaxstudios.blogspot.com/2014/12/building-space-navy-iv-fleet-missions.html), nuclear spacecraft are required to keep a team of UN inspectors/marines aboard to provide security and ensure regulations are followed. In the [CoDominium universe](https://en.wikipedia.org/wiki/CoDominium), surrendered vessels are boarded by a nuke-carrying volunteer to ensure their compliance. In the real world, passenger and transport aircraft follow strict flight plans, and deviation from those flight plans that suggests terrorist activity can provoke a military response. There may be accepted standards followed by most governments, or they may vary on an individual basis, with some planets and installations expecting more or less control than others, and jurisdictional arguments could cause friction between independent states. There is a lot of potential for conflict here, which means a lot of potential for story-building as well. **On Weapons** One of the things you mentioned was that the weapons of ships must be stronger than the drives to make any sense. This is not necessarily true. If the drive itself is the power source for the ship, then only a fraction of that total power will be available for weapons systems. Then, thermodynamic losses for the laser, particle beam, railgun, or whatever other weapon system it's powering could mean that only a tiny percentage of that drive energy can be put on target. However, there are also powerful theoretical propulsion systems that do not immediately lend themselves to providing power for the rest of the ship. [Nuclear pulse propulsion](https://en.wikipedia.org/wiki/Project_Orion_%28nuclear_propulsion%29) and [nuclear salt-water rockets](http://www.npl.washington.edu/AV/altvw56.html) use nuclear detonations external to the ship for propulsion, providing no inherent power generation mechanism and requiring a separate onboard power source. You could have spacecraft with science-fictional levels of drive energy, but limited in how much power they can generate onboard so that civilian-owned transports can't power military-grade lasers. Of course, even without weapons, at close range any powerful drive system is [implicitly a weapon](http://sfworldbuilding.blogspot.com/2015/03/fight-or-flight-kzinti-lesson-combat.html), and even if the government feels secure in their control of orbit, the port authority may not want spacecraft powered by WMDs coming anywhere near them. There's one last option here. **Offboard power** [Beamed power](https://en.wikipedia.org/wiki/Beam-powered_propulsion) is another possibility. Instead of giving each starship captain enough energy at his fingertips to destroy a civilization, keep the power source firmly in the hands of the government-run power beaming station. As long as a ship complies with the flight plan, it keeps receiving power. If the ship does anything funny, the beam controller cuts the power and leaves it adrift for the Orbit Guard to deal with. This can potentially be combined with a powerful drive system through modular design. A spacecraft could leave its main drive behind at a safe distance, and then use beamed power to complete its journey. Alternatively, a ship could keep its distance and rely on shuttles to move cargo and personnel to and from a station. **In Summary** You can give people access to the levels of energy needed for fast interplanetary travel, while retaining enough control to prevent it from being misused. An Orbit Guard with sole authority over flight plans in orbital space would take a proactive approach towards detaining or destroying any vessel that appears to pose a threat, beamed power could provide propulsion without giving the captain autonomy, and the use of modular design or shuttles could mitigate the close-range risk posed by the drives themselves. And lastly, through careful worldbuilding, you can ensure that the propulsion technology you use does not lend itself to readily powering military-grade weaponry. [Answer] One oldy, but goody, that I haven't seen anyone else mention is neutralization of inertia of some degree. Once you get past the hand waving needed for that, you use whatever motive force you wish, just reduce the inertia of the ship. Effectively it reduces the M portion of the kinetic energy equation in the direction of zero, allowing less energy to result in higher speeds. So one can have high speed, low energy objects zipping around the solar system. Some writers use it for FTL as well, since if you make M zero, V can be whatever you want. :) Also when you do this friction comes in to play, where available. A low energy, high speed, object is going to slow down precipitously if it encounters lots of drag. Edit: not sure if something was added, or I just missed you last paragraph. This is pretty similar to what you described there. You would still need to match velocities without the neutralizer on to deliver cargo and passengers, but that's all much lower energy operations than moving at high velocity across the solar system. The different orbital velocities of objects in a solar system are not inconsiderable, so you are still talking about some potential high energy maneuvers. [Answer] You could consider a sci-fi'd up version of an [Aldrin cycler](https://en.wikipedia.org/wiki/Mars_cycler):  (image from <https://ccar.colorado.edu/asen5050/projects/projects_2008/shupe_report/shupe_report.html>, stolen from [another Stack Exchange question](https://space.stackexchange.com/questions/3880/what-uses-would-the-aldrin-cycler-have)) The general concept of a cycler is that it acts like a space ferry: instead of piloting the vehicle for the bulk of the journey yourself, a very large vehicle on a fixed route takes you between two predetermined points. In the case of a cycler, those two points are other orbiting bodies, so one vehicle provides a permanent, non-alterable route between two planets (preferably a regular scheduled service rather than just one vehicle, or you have to wait for it to come round again). To link more planets into the transit system, you add more vehicles on additional permanent cycles. The cycling vehicle is not designed to stop - to get on and off it, you use a transfer vehicle or short-range private shuttle of some kind - which means that although it can have tremendous amounts of kinetic energy, it doesn't need to have engines that allow any significant amount of manoeuvring, and therefore can't easily be re-targeted to actually hit a planet's surface. For maximum passenger comfort and efficiency, these vehicles would want to be as huge as possible (think gardens, factories, and staterooms instead of cramped cabins), since fuel isn't a concern if you aren't planning on changing course, and would presumably be designed to accelerate into their service orbit using (comparatively) weak engines over a period of years or decades (if your civilization is stable enough, they could be planning new units centuries in advance). So if you simply make the vehicles *massive* enough that no amount of thrust from a privately-owned shuttle will significantly affect their trajectory in the time before the security team can show up to cut the engines, it will be very difficult for a small group of terrorists to do anything with them. Even state-level actors would need months to turn one of these things into a weapon, leaving plenty of time for *other* state-level actors to deal with the conspiracy in other ways. [Answer] Regardless of how it is powered, anything with sufficient velocity will have a massive amount of kinetic energy. You can shoot it from a cannon, power it via laser driven lightsail or have some sort of on board fusion rocket, it all comes down to the magic equation Ke=1/2Mv^2. Since you actually *want* ships to go fast, you need to mitigate the issue by bring in mass down to an irreducible minimum, and then arranging things so the mass is only going to go where you want it to go, with no possibility of deviations en route. This suggests that interplanetary travel isn't going to be by fast fusion powered packets or elegant lightsails, but rather the equivalent of an ISO shipping container (AKA "Sea Can") being launched from a mass driver. It coasts on a fixed orbit between the launch and destination point and is recovered at the end by some sort of momentum exchange system (perhaps another mass driver running in reverse, or a rotating tether). [](https://i.stack.imgur.com/H1HmO.jpg) Shipping between planets will involve a pretty hard "kick" both on launch and recovery, in order to keep the mass drivers at a reasonable size, so human and live passengers will most likely be immersed in a pod of oxygenated fluid to deal with the massive "G" forces. This also has the added advantage of minimizing life support requirements; everyone is packed in a pod and can be "pre loaded" with oxygen and nutrients for the trip. (Draining the pods is likely to be one of those jobs no one talks about). The only free flying spacecraft are shuttles to bring cargo to and from orbit (the mass drivers will not be on the surface of any planet or moon, for obvious reasons), and the equivalent of coast guard cutters to inspect cargo pods. Since cargo pods are unpowered and unpiloted, they will be under tight scrutiny throughout their flight and subject to destruction if they deviate from course. This can be via kinetic energy weapons launched from the mass driver near the affected planet or moon, or a laser powered from the same energy generators which power the mass driver itself. Since the mass driver is likely to be a massive device many kilometres (if not hundreds of kilometres) in length, a pretty impressive laser generator can be built into it, and the laser's mirror can serve as an optical tracker for cargo pods when the laser is not engaged. [](https://i.stack.imgur.com/Ef5NQ.jpg) While being bundled into a tube of oxygenated fluids inside a sea can and forced to stay inside the tube for the duration of the flight may not sound very romantic or provide much of a story setting, this may be the only acceptable way to make rapid flight between the planets possible. No planet, moon or asteroid could contemplate being hit by a massive object moving at high speed with "dinosaur killer" levels of energy, so this seems to be a reasonable way to have fast interplanetary transport without many of the dangers of having a high speed object crash into your world. [Answer] The best hand-waving I've seen around this is that gravitational wells react with the drive. In deep space, the drive works great - it moves the ship great distances in little time. But as it encounters gravitational pull it acts as a block of iron going over a giant magnet, slowing the ship dramatically. This prevents ships from being weaponized, and also adds a bit of flavor to the world since there needs to be orbital docks and the such to service these ships. [Answer] Short answer: ## You can't prevent weaponization Energy is a function of $v^2$. So making a STL drive that can move a ship quickly means it can always be used as a weapon. More complicated answer and some ways of making weaponization more difficult: ## STL options To make a STL drive less suitable for weapon, you need make it difficult to get and difficult to use. ### Difficult to get You make the drive difficult to get by using rare and/or easy to control materials (e.g. Uranium or extremely high-technology gear). These materials are only available in a few places that can be monitored. This eliminates the possibility of use by many potential groups such as terrorist or pirate gangs. Essentially state entities have a monopoly on the technology and only let others use it under carefully controlled conditions or not at all. The only way for non-state entities to get one would be to seize a control of a state vessel with the technology. ### Difficult to use The technology can be made difficult to use by 1. Making its operation hazardous (e.g. emits deadly radiation) 2. Requiring highly trained experts to operate (e.g. a fission reactor) 3. Making its performance characteristics poor for use as a weapon (e.g. low acceleration) 4. Requiring frequent complicated maintenance (e.g. a nuclear reactor) 5. Massive so that it can't be used in expendable ordinance (e.g. a nuclear reactor) This means that if local pirates do manage to get a ship with the advanced STL engine, then they're likely to kill themselves when they use it without the proper expertise. It also means they won't be able to use the technology in a missile or other lesser ordinance unless they're willing to use the entire ship as the missile. ### Something that fits the bill Something like the [VASIMIR concept](https://en.wikipedia.org/wiki/Variable_Specific_Impulse_Magnetoplasma_Rocket) powered by a nuclear reactor meets these criteria. [](https://i.stack.imgur.com/abzTe.jpg) ## FTL Options Once again there is no way to prevent its use as a weapon but there is a concept that might be difficult to use as a weapon. ### [Alcubierre Drive](https://en.wikipedia.org/wiki/Alcubierre_drive) > > Rather than exceeding the speed of light within a local reference > frame, a spacecraft would traverse distances by contracting space in > front of it and expanding space behind it, resulting in effective > faster-than-light travel. Objects cannot accelerate to the speed of > light within normal spacetime; instead, the Alcubierre drive shifts > space around an object so that the object would arrive at its > destination faster than light would in normal space. > > > Two-dimensional visualization of an Alcubierre drive, showing the opposing regions of expanding and contracting spacetime that displace the central region. [](https://i.stack.imgur.com/J6Eic.png) You will want all the same characteristics mentioned for the STL drive: make it difficult to get and difficult to use. Both will restrict its use a great deal. I don't think anyone has postulated what would happen if a ship while under Alcubierre drive interacted with large objects (e.g. astroids and larger). I'm sure it wouldn't be pretty. [Answer] Pretty much anything that allows a large chunk of mass to get from say Earth to Jupiter in just a few days could probably be weaponized simply because it's going to have a large kinetic energy (unless you use teleportation or wormholes, which could be an option, but I'll restrict my answer to more realistic near-future options). If you accelerate at some constant rate A for half the journey and decelerate for the second half, then if the distance of one half the journey is D, the time T for half the journey would be given by $T = \sqrt{2D/A}$ and the velocity at the midpoint would be $V = AT$. Jupiter is about 630 billion meters from Earth when our planets are in a line from the Sun, so to get half that distance or 315 billion meters with an acceleration of 1 g or 9.8 m/s2 would imply the time for half the journey is about 254000 seconds (3 days) so the velocity at the midpoint would be about 25 million m/s, almost 1% light speed. Any decent-sized ship at that speed is going to have quite a lot of kinetic energy, enough to be disastrous if it hits a populated area on a planet (since it's still a small fraction of light speed the non-relativistic formula for kinetic energy, $\frac{1}{2}mv^2$, should work fine, in this example giving about 300 trillion joules for every kg of mass of the ship). If you're mainly concerned with not having small terrorist or criminal group be able to weaponize it even if a government could, you could use one of the various realistic ideas for "beamed propulsion" where the ship doesn't carry the reaction mass but instead is pushed a long by a powerful laser or a series of small projectiles accelerated to high speeds by a large electromagnetic [mass driver](http://en.wikipedia.org/wiki/Mass_driver)--in that case, as long as the lasers or mass drivers were very expensive to build and/or illegal for anyone but a government to control and too large to construct in secret, terrorists or criminal organizations wouldn't be able to use them, and any "flights" conducted using them would need to have government-approved flight plans. A giant laser array could also probably be used to completely vaporize any dangerous projectile, including a missile, that was approaching a planet or moon at significantly slower than the speed of light--as discussed in my answer [here](https://worldbuilding.stackexchange.com/a/7320/298), it's very hard to hide a missile in space, so with sufficient monitoring the planetary defense system should have plenty of warning. Once vaporized, the resulting gas or plasma cloud would expand quickly in a vacuum (see [here](http://books.google.com/books?id=HgfrkDjBD98C&lpg=PP1&pg=PA161) for details on the speed of expansion), so even if they continued to travel towards a planet with no atmosphere to stop the individual particles, I suspect the density of particles hitting each square meter of surface would be too low to cause damage. An example of such an idea that was recently in the news is the "DE-STAR" proposal by a physics professor named Philip Lubin, which would push a probe weighing only a few grams to relativistic speeds using a giant laser array, see [here](http://www.gizmag.com/laser-light-propulsion/41980/) and [here](http://www.centauri-dreams.org/?p=33409) for some discussion. There is also an abstract by Lubin [here](https://web.archive.org/web/20160322081814/http://www.icarusinterstellar.org/2013-starship-congress-speaker-announcement-dr-philip-m-lubin-de-star-a-planetary-defense-and-exploration-system-beamed-power-for-relativistic-propulsion/) which mentions that a giant 10-km laser array, which he labels "DE-STAR 4", could potentially push a 1000-kg ship a distance of 1 AU (150 million km) in about 10 days, and it also mentions that this sort of large array could focus several beams in different directions to propel multiple ships simultaneously. There is a chart from the first article with different laser array sizes and payload masses showing the max velocity they would achieve: [](https://i.stack.imgur.com/SpNes.jpg) The 10 km array mentioned above would apparently emit 100 GW of power, so if we imagine some government builds an array ten times that length on each side (100 km), it would have 100 times the area and thus presumably emit 100 times the power, or 10,000 GW. And [this page](http://www.deepspace.ucsb.edu/directed-energy-interstellar-precursors) from the site of Lubin's research group features a link to an [online photonic propulsion calculator](http://www.deepspace.ucsb.edu/wp-content/uploads/2015/04/Laser-Propulsion-Classical-1D-Standalone.html), if we plug in a payload of 3000 kg (3 metric tons) and a laser array of 100000 meters and 10000 GW of electrical power, it indicates a peak acceleration of 11.1 m/s2, a maximum speed of 20.1% light speed, and the ability to travel a distance of 546 AU in a mere 44.4 days. As I mentioned, another type of proposal involve accelerating a stream of small masses to very high velocities using a mass driver, and having imparting momentum to the back of the ship by either physically colliding with a pusher plate at the back, or being pushed backwards by an electromagnetic field generated by the ship (which accelerates the ship forward by [Newton's third law](http://www.physicsclassroom.com/class/newtlaws/Lesson-4/Newton-s-Third-Law)). For some discussion and links on this idea see [here](http://www.centauri-dreams.org/?p=31057) and [here](http://www.centauri-dreams.org/?p=31062) and here, and there is also the hybrid idea [here](http://www.centauri-dreams.org/?p=25626) where instead of a series of small pellets accelerated by a mass driver you use a series of very small solar sails accelerated by a laser array, each of which impacts the ship to give it momentum. [Answer] Depends if you want to move goods or people that fast... If you just want to move people, you could replace your fast STL drive with a personality transfer scheme - digitize your personality, stick the original in cold storage, broadcast the personality data to the destination and run it in a surrogate android/clone, and send updated memories back to be written to the original afterwards or during the transfer. Or let the original keep running around and add the extra memories overnight (though that might be a bit confusing, remembering alternate days in different places... might make an interesting chapter structure though.) [Answer] The ships have AI and these AIs take suggestions, but not orders. How does the ship work, who cares? The "ion engines" might just be blue LEDs for all we know. Why are the AIs ferrying people around? Entertainment, they might give anyone who asks some BS answer about having spending money that isn't subject to the human/machine trade regulations, but really they have nothing better to do. [Answer] **Any FTL drive that you choose to limit to STL** I believe that you've correctly identified the main concern - in order to get somewhere fast, you have to go fast. That means you'll have a lot of kinetic energy, so if you don't hit the brakes you (and whatever you hit) are gonna have a bad time. All FTL drives somehow get around the problem of needing ridiculous amounts of energy to even get close to light speed. You just need to adapt them to your purposes and declare that it can't get you going faster than light. For example: * **Hyperspace** - in hyperspace it takes less energy to approach the speed of light, and your kinetic energy remains constant when you jump in or out of hyperspace. You can tweak the exact numbers to your liking, but you could say that the kinetic energy of moving at 0.05% c in hyperspace is about the amount required to move at 0.002% c in normal space. That turns [LEO](https://en.wikipedia.org/wiki/Low_Earth_orbit) orbital velocity into the velocity required to reach Mars in about 6 days when Mars and Earth are at their closest. To get around the perpetual motion issue, simply say that gravity affects hyperspace as well and it takes the same total energy to leave a gravity well whether you're in hyperspace or normal space. * **Wormholes** - travel from one end to another isn't instantaneous. It's okay if this could still theoretically allow FTL, such as saying that if they somehow managed to get up to 5% c they'd get there faster than light - it would still be impossible in practice for anyone to manage it. If you really don't want FTL, you could say that going that fast would destabilize the wormhole (or your travel through it) and eject you into normal space. As with hyperspace, have gravity affect anything in the wormhole and make it harder to go in the uphill direction. [Answer] **Prohibitively Expensive** In the 40k Universe, ships in Slower than Light combat are aware of the destructive kinetic energy posed by their ships. Captains will use ramming strategies, so why do they have tons of weapons? Because the sheer cost of creating a void capable warship is really high in both crew and materiel and time. It's so high that rams on the majority of ships are last resort options, when the death of the ship is assured. Ships also require fairly substantial crews even for minimum operations. So terror attacks cannot be committed by lone wolfs or gangs. A full company of men need to agreed to sacrifice themselves for something that might not working (assuming planets have orbital defense). They don't need shields, just enough weapons batteries to break down the ship into smaller less substantial pieces. [Answer] There is a really interesting document written up by some of the more speculative people in NASA for a [Z-Pinch Based Fusion Drive](https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwiAr9TfrbbNAhWFMBoKHXVyBzQQFgglMAA&url=http%3A%2F%2Fntrs.nasa.gov%2Farchive%2Fnasa%2Fcasi.ntrs.nasa.gov%2F20120002875.pdf&usg=AFQjCNF7TWOzdbp7kRnCerhyUAMaN63VBA). The energy required to get to a planet in days would be considerable, admittedly, but the idea of it all being released in a single bomb like scenario isn't necessary. Using the exit velocity of fusion products could be feasible, but fusion plasmas really do require hard vacuum to work. So you'd either have to put one in a vacuum vessel on a planet or just not use it in a planetary situation. The only way you could weaponize a fusion plasma is by putting it in a bomb with a fission detonator. Interestingly the above design uses a fission reactor to provide a recharge current for the capacitors, so the only way you could use this as a weapon is as a dirty bomb :( By the time this particular idea becomes close to sane we'll already have properly tested [Tokamak](https://www.iter.org/), Stellerator (See Wendlestein 7-X at the Max-Planck Institute), and several varieties of Inertial Confinement (See National Ignition Facility in the US and Laser-MegaJoule in France) based fusion technologies. If you want a highly manoeuvrable ship, use this as the main engine and then little conventional rockets for changing direction. [Answer] This is a fascinating challenge. Motion without kinetic energy. I frankly don't understand the 'perpetual motion' part of your question unless it refers to Newton's First Law. Namely, a body remains at rest or in a state of motion unless acted upon by a force. OK, then, a vessel gains velocity and kinetic energy and potentially becomes a weapon. Wormholes will work, but this cuts out the whole sense of travelling between planets. There are two concepts that involve pseudomotion by teleportation. Poul Anderson had a drive based on the uncertainty principle and the vehicle 'moved' in many millions of micro-seconds per second. Anderson's drive was for faster than light travel, but there's no reason in principle why something similar couldn't provide a basis for fast STL interplanetary travel. It would get up to maximum speed (or pseudovelocity) at the flick of a switch. Turns or swerves would be easy. No momentum or acceleration problems to worry about. The other teleportation system was devised by Larry Niven in his article "The Theory and Practice of Teleportation." A spacecraft consists of two halves, with each half equipped with teleportion transmitters and receivers. The transmitter on B beams half A to its other side where its receiver is located. Section B is now sitting in the transmitter of A, and is beamed to A's receiver. if each step is done often enough and fast enough, this constitutes a kind of bootstrapping motion. Niven never used this concept in his SF, but Bob Shaw did in *Who Goes Here?* (1977) and *Dimensions* (1993). Again this was a FTL drive, but STL drives based on this contrivance make more sense. [Answer] By looking at the design of the STL drive, you are considering the wrong thing. It is unlikely to be something in the design of the FTL drive that prevents weaponisation, but it will be something built around planets as a 'shield' from such an attack. Electric car brakes turn kinetic energy into potential energy (battery power). So design some device for planets that can do just that - someone tried to kamikaze the planet and the residents get free electricity. This device will need some suspension of disbelief, but no more so than other technology in science fiction. Once a 'shield' has been designed for the plant, you have answered the question of "How could such a ship not be turned into a planet crushing weapon by any terrorist or criminal?", not only for the existing STL drive, but also for any other STL drive that could ever be developed. [Answer] Wow this is quite in depth with the logic behind it and typically I just run with it. In my world's any civilization that discovers faster than light travel or STL quickly weaponizes it as I feel that would be the best way to take down ships. The ships have to be able to withstand considerable force to even be able to travel that fast so FTL and STL guns would be best equipped to take them down. To prevent others from kamakazing themselves though is a hard task. There could be stations built in system that automatically turns off or slows down the drives before they would crash into a planet. Similar to push button cars today that turn off when the owner is too far away, just in the opposite direction. That I think would be the best way to stop it. You also have to remember that humans typically have the desire to stay alive. And even when they don't, outside of a few rare instances, suicidal people typically only take themselves out or at most someone close to them, not an entire planet. If they want to live, then destroying a planet would be a bad move. Anyone that destroys a planet would also become the number one target of the civilization and hunted down ruthlessly. You could also consider replacing the FTL and STL with some sort of device that bends space around itself or sort of teloports itself out of existence and back into existence similar to what the Enderverse did with their teloporting space box. I don't have the experience or knowledge sadly to figure out how to stop the perpetual motion problem. [Answer] **Alcubierre Drives** Alcibuerre drives are commonly known as a form of FTL travel, but, there is nothing preventing them from being used for STL as well. Since technically nothing is moving, it should be difficult to weaponize. Right now (as far as I know) it isn't known what happens when an alcubierre drive/bubble hits something, but, it should be easy enough to have some sort of interference pattern that prevents the drive from working near anything worth protecting. Additionally, to prevent it from going FTL, you could put some sort of practicality barrier -- ie. spacetime rips apart and forms a blackhole out of the spaceship when going FTL (I have no idea if that would actually happen though). It would also allow for interesting plot points about making it go FTL later in the story if you want. Relevant: <http://io9.gizmodo.com/5963263/how-nasa-will-build-its-very-first-warp-drive> Revel vent: [Using an Alcubierre warp drive strictly for sub light travel](https://worldbuilding.stackexchange.com/questions/23561/using-an-alcubierre-warp-drive-strictly-for-sub-light-travel) [Answer] Use a Neutrino drive, in this drive matter and antimatter react, putting almost all their energy into a beam of focused neutrinos. As neutrinos pass through matter with almost no interaction getting caught in the exhaust is a non issue. Ships seem to glide away silently and with no visible propulsion. As the exhaust velocity is $c$ the momentum transferred is enough to get you to a majority of the speed of light with a fuel tank less massive than the ship. A fusion device that runs on hydrogen to produce neutrinos would be much easier to fuel and could still get to mars within a week with more cargo than fuel. (Only a couple of days acceleration at 1g in the tanks so there is coasting in the middle.) These ships could still be crashed into planets so the best way of stopping that is a computer system that knows what is going on and stops unwanted manoeuvres. [Answer] Well, it's not "hard", but a plausible explanation how to make FTL/STL hardly weaponizable as a mass destruction weapon (at least against planets) is to **make it work only in void**. Your *flebtonium teleportation* only works in the absence of larger mass in a quite large radius. So, nothing can ram Earth at 0.5c. Any capital ship / space station that is large enough to be a valuable target is also large enough to prohibit teleport exit in its vicinity. This also means that kilometer-long battleships are sort of "local monitors", incapable of warping. Only smaller scout ships can warp– oh wait, they are aeroplanes when compared to water-surface vessels– ships, yeah! [Answer] Such a spacecraft could be weaponized as a kinetic weapon, but presumably space dwelling societies would also have the ability to detect it at great distances, and calculate it's trajectory and speed. They would establish that such a ship would impact the planet, validate that it's past the point where such a ship would begin decelerating if it was going to stop at the planet, and then bump it off course, possibly with a nuclear bomb detonated nearby. Such near light speed drives should be applicable to an interceptor as well as a spaceship. This is the current plan should an asteroid be calculated to impact earth. Give it a bit of a nudge at a great distance using a nuclear device, so it misses. ]

[Question] [ Simply put, the world has magic, though it would be considered "science" by the world itself. This first section is going to provide a background for how the magic works. "Spells" can be cast via some medium (*usually paper*) which have the spell written on them. A spell fully describes some kind of interaction via symbols on the paper - the symbols required are exact and can be considered a "language of their own". In other words, you can't write a spell in a different cultural language such as English. "Sorcerers" are people who are capable of writing spells, but normal every-day people are capable of using them. There is no "special ability" that sorcerers have that regular people don't, other than simply the knowledge of the symbols and language used to create spells. I think it would be clearest if I first give an example of a "fireball" spell - which shoots a flaming ball of fire towards a target. Only one chemical can be provided by a spell, and in the fireball instance this chemical would likely be some form of pitch or oil. The spell must fully describe the chemical makeup of the oil, as well as its interaction with the oxygen in the air which creates the flame. As part of that, its initial velocity relative to the medium the spell is located on also needs to be described. When the fireball spell is cast, there is no actual oil which appears in the air. But, the effects described in the spell still take place. This means that the oxygen in the air still turns into CO2, and heat in the form of fire is still released - looking like a ball of fire is flying through the air. The spell describes the initial chemical makeup and interaction taking place, but once the "fireball" hits a target, it would continue acting as if the target had been hit with a ball of burning oil, but without the oil actually materially appearing. If any of the created chemical is still in its initial form when the spell's interaction ends, the spell is "disspelled", and that leftover material no longer acts as though it were there. The medium which the spell is on is typically consumed at this point. There are methods to keep that from happening, defined within the spell itself, but these methods are not commonly known or used. If a spell is not accurate, that is, if it attempts to replace more chemicals or if the interaction is not described in a way that actually works, any number of things could happen once the spell is cast, depending on the nature and severity of the mistake. "Spell Testing" is incredibly dangerous, especially for sorcerers who aren't all that great at sorcery. As you can imagine, even just this simple fireball spell would be very difficult to create the first time, but is capable of being copied after that. **tl:dr version**: *spells are written on paper with specific symbols, but not all symbols are known by every sorcerer, anybody can cast them, an incorrect spell can do anything from fizzle, to kind-of-work, to explode, paper is destroyed afterwards in 99% majority of cases* --- The society in question is end-of medieval level, but obviously paper and writing tools are more important (and thus, more effort is spent to have them on hand) since spells can be quite valuable to have around. It can also be assumed that they have a great deal more knowledge about how chemicals interact with each other compared to what our own histories suggest. How would sorcerers attempt to prevent people (*or even competing sorcerers!*) from attempting to "copy" their sold one-use spells? [Answer] Treat the spells as calligraphy, where the *how* of writing matters as much as the *what.* Perhaps the textual content of the spell is an easily understandable language, so that the commoners can read the spell and understand what they're about to cast. However, the part that brings the spell alive is a bit harder to teach. There's something in the way you draw the lines that makes the spell work. Draw them improperly, and you end up with a piece of paper with a very weak spell on it, or perhaps even a dud. We tend to think of communication in terms of the text. If I say "Hello, how are you?" we tend to presume that was the content of the message. However, if we speak that phrase, we also convey a massive amount of information in our tone and pace. That same sentence can mean anything from "I'm so pleased to see you" to "I am a drone who has to say the same greeting to everyone" to *\*ahem\** "Hello, Clarice." [](https://i.stack.imgur.com/faegws.jpg) One of the fascinating aspects of this non-textual content is that it is very dependent on having a cohesive message. Try to say something pleasantly, but pause at the wrong spot, and the message turns insulting, "Umm... Hello.... how are you?" This is very contrary to the text, where I can write "Hlelo, hov r yu?" and get a lot of the message across, despite massive errors. To make this into a magical process, let's say the way you draw each line matters. There are no such thing as "mistakes," just changes in balance caused by a change in line width or curvature. Sorcers are good at walking the fine line of this balance to depict the correct emotional content for the spell. You could try to copy a spell, but you'd make some mistake near the beginning (you're not perfect) and you may not know enough to understand how to change the symbol to balance that mistake out. The best example I can think of is Chinese caligraphy. Consider the character for Qi, lifeforce, 氣. Its etymology is believed to be from the word for breath. As written here, it's pretty stale. It's just a word. Its the calligrapher that brings it alive in the artist's particular way: [](https://i.stack.imgur.com/PkrPZs.png) [](https://i.stack.imgur.com/kMFOms.jpg) [](https://i.stack.imgur.com/bxaKFs.jpg) You can imagine that these three versions of "vital energy" may have quite substantially different effects, though all of them would clearly involve use of life energy to do it. [Answer] From what I read, the problem you have with spells is most of the times the same problem people has with software development and client authentication nowadays. Your problem is called *replay attack* in software security. In networking security: a replay attack is when a user sends a request to a server and, even when it is encrypted, a man-in-the-middle of the connection between you and the server sends the exact same data, and the SSL secret has not yet been renegotiated. The solution is using a form of *nonce* (a token used only once and created by you) in your spells and somehow connect your scroll instance to a kind of *akashic pocket record* (it is said there's something called *akashic record* that contains the whole memories of the universe and dead people, in some new-age-styled cultures today) which remembers the valid, available, and used *nonces* you authorize in your scrolls. The *nonce* is a special token you would specify to make the spell work, say the ink, calligraphy, a QR code or whatever you want. Perhaps, since you don't write the same spell in the exact same way, you could use a kind of *meta-spell* to *register* them in your pocket akashic record, like when you develop software and sign your hashes to make them unique and verifiable. You must ensure: 1. The scroll will never be materially copied atom-by-atom by another spell. Somehow you must ensure that (say: protect the scroll with a kind of err... entropic, force which would affect the normal 3-dimensional space, but would not affect higher dimensions interactions, which could connect to your pocket *akasha* if your plot allows more than 3 dimensions). 2. The same scroll (or *nonce*) cannot be used twice. For this to work, since you plan to sell your spells, you will be somehow *linked* to the sold spells, as paid software usually involves a license server, so ensure nobody can track you reverse-traversing such mechanism (don't know if your plot defines a kind of meta-magic). But remember something: There's no something like 100% security anywhere. There will be always a failure point somehow, specially with magic. [Answer] The simplest way is to incorporate the ink into the spell. Using any other ink rather than his own secret recipe would result in undefined behaviour. If it is not possible, he should resort to traditional authentication techniques of the time, such as seals and signatures - which again must be intrinsic part of the spell. [Answer] You can protect your spells with [**D**iabolical **R**une **M**anagement](https://en.wikipedia.org/wiki/Digital_rights_management). Similar to Luis's [answer](https://worldbuilding.stackexchange.com/a/31698/4790), the problem at hand has much in common with software piracy and copyright infringement (since the underlying base issue is very much identical). Merely encrypting the text of the spell or writing the spell in increasingly arcane languages to prevent other wizards from reading it would not help if the spellware pirate is capable of copying the entire spell wholesale. However, we can look into [existing anti-piracy techniques.](https://en.wikipedia.org/wiki/Digital_rights_management#Technologies) The *media* on which the scroll is to be copied can be one way to defeat spellware piracy. By making the spell check the type of scroll it is being run on, and refusing to run if the type of scroll is incorrect, a rudimentary form of DRM can be implemented. This is similar to software which requires that CDs be inserted into the drive before the program runs. Alternatively, a form of sympathetic magic link can be used to link the spell's casting to the Master Spell in your mage workshop. Serial numbers embedded in each spell would ensure that each spell can only be cast once, after which the breaking of the sympathetic link would render all further copies with the same serial number inactive. This is similar to programs which rely on contacting a central server for serial number activation. However, it has to be stated that customer satisfaction is also an extremely important point for spellware entrepreneurs. A spell that does not cast when a customer needs it to (for example, an adventurer with fireball spells in the middle of a dungeon) could potentially lead to huge liability lawsuits. [Other reasons](https://en.wikipedia.org/wiki/Digital_rights_management#Shortcomings) not to use Diabolical Rune Management techniques also exist. For example, a spellware pirate can produce a pirated spell that is guaranteed to cast, even if your scrolls are wet or if your akashic/sympathetic magic link is disrupted. These spells would likely fetch a higher price than your protected spells, leading you to run out of business. [Answer] Here are some methods that may work, depending what you want to be possible. Make the spell harder to read or copy correctly. * Use some sort of invisible ink. Even better, use both invisible ink and visible ink, so that if only the visible ink is copied, the spell will be a dud or backfire. * Cover the spell with something difficult to remove. It could be paint or another layer of paper with a dud spell written on the surface (and the real spell inside written in invisible ink for even more security). If the spell is valuable enough, you could even encase the scroll in a metal box. The covering/encasing could even have a spell put on it to make it even more secure. * Use a spell to make the spell scroll impossible to read. An illusion spell or a shrinking spell could work, although if there is a shrinking spell then surely a re-enlarging spell exists. Make the spell impossible to reuse. * Make the spell scroll act as a proxy to another scroll that you have in a secure location. When the scroll is used, both it and the scroll it is linked to will be destroyed. That way, if someone copies the scroll and uses the original, the copy will be rendered useless. If it uses an ID system to link then somebody could try to copy it and change which spell it is linked to, but the chances are that it wouldn't link to anything, and they wouldn't know if it works or not until they use it. If it is linked in a less computer-sciencey manner like "the spell scroll which was made with the same sheet of paper as this one," then there would be no way to copy it without access to the other scroll. * Similar to the above, make each scroll have a unique feature, and destroy all other spells with that feature when used. This would be fairly easy for even an amateur to bypass though, because they would only need to identify what part of the spell is functioning as an ID and change that. * If you don't want anyone else to be able to use a spell, make it only work for you. Have it check for your presence, or if that's too abstract, check for the presence of some unique item that you always carry or feature that you have. [Answer] all good answers, but I think they may overthinking the problem. There is a much simpler solution. *opening* the scroll is part of casting it. The scroll comes sealed and the act of opening it to read invokes part of the spell. After you do this you get 20 seconds or so to speak the activation to cast the spell properly. If you don't the spell will dissolve anyways after the 20 seconds are up. I say 20 seconds, but you could likely expand this to minutes or more if the spell is complicated, 15 minutes of copying the spell may still be a fraction of the time it takes to record it if the spell is complex enough. in any case, this allows a normal person to cast the spell without problem. However, anyone trying to copy it will have the spell destroy itself before they get much detail; unless they can write a spell to copy the spell automatically; but at that point you have assembly line spell production and the rest of your world is pretty hugely changed. If every day folks complain about your copy right protection point out the danger of a single line getting smudged or, worse, someone intentionally modifying it. You don't want to allow the potential for accidental or intentional tampering since it can have lethal results, so the spell destruction feature can be claimed to be for their own safety. edit: As a small side note I would say that the words for casting the scroll are written on the inside of the scroll itself, in normal English; or on the outside of the scroll and/or whatever the scroll is sealed in if you can't write anything other then the spell-language on the scroll itself. This way people that buy the scroll don't have to worry about remembering the phrase. A two part activation, physical opening of scroll and speaking of the word, help ensure no accidental cast by doing either part alone. plus, it is in keeping with how all kinds of fiction and fantasy does scrolls, you open the scroll, read a few gibberish words, and magic happens :) edit 2: to make it clear I'm suggesting that sorcerer's make this part of the spell. In theory one may have a spell that they write that doesn't work this way and is activated by simply speaking the word, mostly for open source spells. I imagine someone having a simple spell chiseled into a tool that is activated by a standard word may not be uncommon, a few short simple spells that proved quite effective may be common for certain tools. This could also be the basis for magical swords and the like. To keep the spell on your magical sword secret your then have to use one of the tricks others suggested, to tie the spell to the specific sword. [Answer] Poor penmanship. (only 100% serious.) Seriously, if you can't write scrolls in any language other than the special magic language, any kind of symbolic cryptography is also ruled out, it seems, and you're down to hiding your scrolls. Maybe write them on canvas in ink, paint over them with acrylic, and chip it off when you need to use it? Under a false panel in your travel wagon? A spellbook with very thick pages, with important spells on thinner pages stuck together so they can't be recovered without use of a spell that distributes a weak solvent between the pages so they can be separated without damaging the writing? Trapping them might work, too. Poisons that are absorbed dermally? Can you set up a magical effect to be triggered by a later non-magical action? If you can, you might be able to have spell scrolls that self-destruct if unrolled without first disabling the self-destruct spell. [Answer] Ok, so you're a sorcerer, and you want to sell spells that anyone can use, but you want them to keep coming back for more. No reusable spells unless you say so. Each spell contains words that describe the effects of the spell, using logic and chemistry. This is actually the key; or, rather, the lock. Use logic to describe the spell such that it can only be used in the way you intend, which includes only being used once. The key for every method is the phrase uttered to activate the spell. ## Physical Verification Each spell, as written, should incorporate the paper on which it was written. Paper is easy to come by, but no two sheets are the same; parchment even more so. Fibers, blemishes, stains, and inconsistencies make every sheet of paper entirely unique. Thus, adding a phrase to the spell that requires the exact paper the spell was originally written on for it to function would lock the spell to that paper. If the words were copied, the paper they were copied onto would be different, ruining the spell. It may be possible to re-write the spell to remove the reference to paper, but if you're capable of doing that, you might as well write your own spells and save yourself the time and effort. The pros of this method is that absolutely, positively no one will copy your spell. If they understand it, they won't need to; if they don't, they won't be able to decipher it. Either way, rather than copying the spell, they would need to write a new, slightly different spell to make it work. The cons are that this spell will be unique for every sheet it's printed on, and as such will take time to write each one individually. ## Encryption and Remote Verification Each spell, when written, is encoded with a special key phrase, randomly generated for each. The characters of the original spell, once decoded by the phrase, automatically activate. To a user, it will appear that the words are activated by the phrase. Without decrypting the spell, it's just a jumble of letters that mean nothing. This version is easily transferred from one paper to another; however, it remains a single-use spell. The key is the locked spell. Part of the locked spell describes a small object being destroyed; a specific pebble, for instance. Once the unlock phrase is used, the actual spell is unscrambled and activated, destroying the pebble before completing the spell. Once the pebble is destroyed, the spell cannot activate again. The pros for this method are that the spell is double-encoded; not only will the single-use pebble keep the spell from being used more than once, the spell itself is hidden behind encryption. The cons are that the pebbles will need to be stored somewhere, possibly with a timestamp when they are consumed, so you know when your users have fired their spell. Also, the spell may be copied, used, then the original paper sold. It won't work, which could give you bad publicity. Also, each sheet will be radically different, because of the encryption, which means mass production is very difficult. And finally, this requires several spells working together to work, meaning this is a very complicated work. It should only be used for very expensive spells. ## Remote Access Magic This combines the best parts from above into one useful, simple, and above all mass-producible method. On your spellsheet, write two spells. At the top, a spell that activates the spell on the bottom half of the paper; at the bottom, the spell you are selling. As part of the second spell, destroy the entire paper on which it is written. After writing the spells, tear the paper in half; keep the half with the actual spell, and sell the top half of the paper. Anyone that copies that text will get nothing, since the paper they use won't have another spell at the bottom. Anyone, even powerful hackers - I mean, sorcerers - who attempts to use the spell will only be able to use it once, since the spell self-destructs. The method of self-destruction, along with the main spell, will remain entirely secret, because it will never leave your possession. Pros of this method include hiding your spell entirely, being able to mass-produce pages as fast as your minimum-wage scribes can copy, and the ability to monitor when spells are used. Cons include having to store the spells safely, and the fact that it does require two spells. [Answer] Great question! I would go for the idea making magic a kind of calligraphy like Cort Ammon suggested. One addition to that: Magic is a secret knowledge by [obfuscation](https://en.wikipedia.org/wiki/Obfuscation) - Especially in worlds with magic that only require some special words of power the sorcerer will put those words of power in a context of elaborate non-sense to hide his secret knowledge. The same could go for text magic you describe. Maybe a fireball can be cast with just one sign and sorcerers will write a whole lot of non-sense around it to obfuscate it. To prevent 1-1 copying like illiterate monks that copied the bible in medieval times you could add aspects like: It matters what kind of ink or pen you use; When and where the sign is written, in moon-light, in star-light of a special constellation/conjunction, etc.; In what order the lines of the sign are written. This special process of writing will magically power up the sign of power. Like if the light of moon and stars is magically, then some light particles will linger in the sign. When using the spell they will be released. After that the sign will still be there but discharged. [Answer] You say the spell can only be cast once and you need to wait for its effects to pass before you can cast it again, hardcode that into the spell. Approach the problem from entirely the other point of view, get the user to protect the scroll. Rather than the scroll being a copy of a standard spell, every spell is unique though the effect may well not be. A copy of the scroll is a copy of the same spell, this is going to interfere with preceding or subsequent casts of the spell. For example, your spell casts a fireball, one fireball, the same fireball every time. You have a choice in your mechanics as to whether (i) casting again fizzles the preceding cast, anyone with a scroll can cast but only the last caster will hit a target, or (ii) you have to wait for it to end before casting again, anyone can cast but only the first caster hits a target. The first option is more significant for spells with prolonged effects or defensive spells. The more copies are made the less effective or reliable it is, any copy at all significantly reduces the value of the scroll. This means that to have an effective spell scroll, the owner is going to be very careful not to allow copies. [Answer] Well, since you are a spellcaster with access to some sweet magic, why not protect your spellbook with some of that same magic? For example, enchant the spellbook in such a way that the rightful owner can read it, but if an unauthorized person attempts to read it they will suffer a curse, or the spellbook will burst into flame and self destruct, or maybe the book teleports itself to a safe place, or it teleports the thief to the center of the sun. Different spellcasters would protect their spellbooks in different ways, depending on their personalities and talents. On a side-note, this kind of magic system sounds a lot like computer programming. You have sorcerers/programmers that are just regular people with specialized knowledge. They develop their own spells/code in precise languages that are exact descriptions of procedures. Once created and written down, a spell/code can be cast/executed and copied by anyone. And society has evolved ways to freely share some spells in the interest of humanity (open source software), suppress the ones that are evil (computer viruses), and to varying degrees protect ones their creators want to keep secret (closed source, proprietary code). [Answer] In addition to several of the answers presented here, such as calligraphic skill and magical ink, I'd like to suggest that there might be some kind of time sensitive element to the act of formulating the spell scroll. For instance, perhaps in order to create a spell, a Sorcerer needs to consult astrological charts and must incorporate specific elements that account for the geometries of celestial bodies at that moment in time in order for their inscriptions to bind the required magic. If someone were to attempt to copy the scroll at a different time, those celestial geometries would have changed, and it would be impossible to imbue the scroll with magic as a result. That is to say, they would be copying geometries that were correct originally, but are no longer. [Answer] The first assumption to make is that most people are still illiterate, so being able to write down spells or read what is on the paper or whatever medium the spell is written on isn't going to be an issue for about 90% of the population. For most of the 10% who are literate, probably 90% of them are not spell casters or magicians of any sort, so their application of literacy would be somewhat limited compared to how *we* see literacy; they can read and write enough to carry out accounting, or contractual arrangements for trade, or the secret ingredients for Coca Cola, but probably would not be very fluent in the language overall, and have limited reading and writing vocabularies. Reading Randall Munroe's "Thing Explainer" gives you a sense of what that might be like, Munroe (creator of XKCD) describes many things like the Saturn V rocket using a limited vocabulary of the 1000 or so most commonly used words in English (the rocket becomes the "thing goer upper"). Describing chemical equations or other natural phenomena to create magical effects like that would be rather...challenging. Naturally there are going to be very literate people, such as the nobility, lords of the Church, lawyers and the professors at the Universities, but they can be dealt with in two ways: using an uncommon vernacular language (using Greek or Latin would do the opposite for this class of people, since they are all generally fluent in Latin and many in Greek), and to encode the spell using some sort of cypher. A university educated person coming across the spell would see a page apparently covered in gibberish, and even if they were to deduce that it was some sort of coded message, they would probably spend a great deal of unproductive time applying their knowledge of cryptography to decipher a message they imagine is written in Latin or Greek, never thinking that it is actually in *Occitan* or something else. This would also help keep magical writing secret from rivals, especially if you go out of your way to learn and become fluent in a much different language than you grew up with (If you come from the south of France, someone may suspect that you know Occitan and try to decipher it that way. Knowing German or the Venetian dialect of Italian would cover your tracks fairly well in that case). Since you are near the end of the Middle Ages, you will find most of these precautions will become much less effective with the introduction of the printing press, although being able to mass produce spell scrolls might actually be a bonus in some situations. [Answer] The simplest method would be to replace a number of key words in the written record of the spell with a simple cipher, usually an initial letter or few letters of the correct word. When reciting or memorizing the spell the sorcerer knows from experience and training what word is to be substituted for the cipher text, but a non-spell caster would only rarely get them all correct. Interesting effects can be created by the Dungeon Master for *almost perfect* spells, ranging from being a dud; having less power or range, being mangled in some way; effecting an incorrect target; or even being (dangerously?) over powered in unusual circumstances. [Answer] This only works if you don't sell tons of copies of the spell: What about some sort of spell obfuscation, where the spell is written in a much longer and more complicated format than is necessary. When a simple one page spell suddenly becomes forty pages long, it doesn't seem worth copying anymore. The author of the scroll could originally write on some sort of copy paper that would make several copies at a time, so that they wouldn't have to repeat the arduous work too often. Another idea(which would actually complement my first one well) would be to have the scrolls only openable a single time after being written, before they crumbled to dust (or combusted, or something). Thus, copying would become extremely hard, and would probably end up destroying the original scroll, so that you've gained nothing through the copy. [Answer] The spell has two components - it can only be cast by someone who is attuned to a specific form and shape of magic. The first component is the attunement, the second is the casting of the spell from the scroll. Attunement without casting the spell is like wearing a security pass but not entering the building it allows you into- it simply has no effect. Trying to cast the spell without being attuned is like trying to walk into a secured building without the pass - nothing happens. The attunement can be very specific to the spell, an arcane binding that relates this specific instance of the spell to the the person seeking to cast it. The spell itself is resolved and shaped by the attunement so that it can then be cast. Consequently one attunement does not allow someone to cast multiple scrolls. The cast spell is written on the parchment of the scroll. The attunement spell is bound into the wax seal that holds the scroll closed. Whoever opens the scroll is able to cast it. Anybody else who gets hold of it after it is open is unable to. The attunement only endures for a short period and the scroll blanks itself or self immolates during casting. Over time a talented sorceror may learn to master the attunements of others, but it is far easier to create your own attuned scrolls. [Answer] **The spell is sealed (much like encryption)** When a sorcerer authors a spell onto paper, it is legible. When the spell is completed the sorcerer seals the magic with their life force binding the spell into the paper. When sold, the spell is no longer legible due to the seal. This can be viewed as a magic encryption of sorts - where the sorcerer that wrote the spell is the only one that can read its contents directly, but other sorcerers may still invoke it. Alternatively, the scroll is rolled up and sealed with a magic "stamp". The scroll's magic can still be invoked but if the seal is broken the magic inside is released and it burns / self destructs. [Answer] I feel like everyone missed one thing here: *magic is an extension of the user.* Let's say magic is part of a mage (not much of a stretch), part of their essence. In order to put a spell on a scroll, the mage has to put a bit of their very soul into the scroll. The words of the spell, the phrasing, and even the language of the spell is personal, unique, and specific to the mage. Let's break it down, shall we? 1. Words The spell is written in words that the mage understands-the words come right out of their head. Everyone has a different way of speaking and therefore writing, and this is especially apparent in two things: *cursive* and *shorthand.* Cursive is used for signatures because A) it can be intricately personalized and B) signatures are relatively hard to copy (as compared to regular writing). Shorthand is used to abbreviate information using a symbolic format. When using one's own, unique shorthand, chances are someone else will not be able to crack the code unless they know you well-*very* well. 2. Phrasing Taking what was stated above, it's not much of a stretch to say that everyone has their own unique language. This goes right into Point 3: 3. Language The words of the spells are actually glyphs; the meaning and design of each glyph are determined by the unique language of the "writer"; in other words, the glyphs symbolize the unique meaning they ascribe to each word, how the writer understands the words and what they represent. This makes it nearly impossible (if not impossible) to interpret the glyphs since in order to do so you'd need to literally see the words as someone else does *exactly.* If you aren't the person who wrote the spell, you aren't the writer, so how would you see the spell *exactly* as they see it? Understanding someone else's unique perspective is one thing; seeing from that perspective is quite another. This should outright stop any spell copying, as even if you were to use copying methods, you *can't* copy someone's unique perspective and thus, the symbolic glyphs are impossible to copy. You could try, but the resulting runes would be ineffective unless written by someone with the exact same perspective as the writer. If you don't understand it, you can't write it and cause an effect. ]

[Question] [ In a book I'm writing, a king has a bodyguard of a dozen elite swordsmen, trained their whole lives to protect their sovereign. Their capes are long and trail behind them. What are the disadvantages and advantages (if any) of wearing a cape during combat? [Answer] Capes were used as [impromptu shields](http://hroarr.com/brief-notes-on-using-the-cloak-with-the-rapier/). While not as effective as a solid metal shield, it often was able to block sword/mace blows (or in defense against wild animals). [](https://i.stack.imgur.com/SyM7R.png) [](https://i.stack.imgur.com/G1aIQ.jpg) You also get the benefit of being able to hide some weapons, like daggers, behind your cape/[cloak](https://en.wikipedia.org/wiki/Cloak_and_dagger). There is also the off chance that you can use your cloak to bind people's weapons, but getting that to reliably happen is a little tricky. Since you may be wearing a cape or cloak anyways, to keep out the weather and whatnot, it's great that it can double as a shield. In a pinch, you can also use it to protect yourself from fire. (In case, say, the palace was burning down.) However, there are some disadvantages: * It's not as easily accessible as a buckler is. Those extra seconds can be the difference between life and death * It's an easy handhold and/or tripping hazard. In summary: * Cloaks/Capes can be used as shields (and yes, they can block edged weapons quite well. They were usually very thick and wrapped around the forearm several times.) * When used as a shield, this opens up some possibilities for binding the opponent's weapon and hiding your own weapon, stance, or handhold. * Getting a cape to behave this way takes a little preparation. Using a buckler is much quicker. * It can be used against you as an easy way to trip you up. [Answer] Disadvantages * Gives the opponent a larger area on which to hold on to you * Causes a trip hazard for any allies moving behind you * Causes a trip hazard for you * May curl around your legs as you turn to face a foe * If you move it out of your way, you're diverting attention away from your foe * You'll never keep it clean (if it's trailing behind you) * You'll look weird with a long cape * [Edna will hate you](https://www.youtube.com/watch?v=Jy2YhxXn7NY) Advantages * Rain won't be as much of an annoyance * Causes a trip hazard for any enemies moving behind you * Particular skill could be used to turn the cloak into a distraction/weapon (easier if short) [Answer] **Disadvantages that the others have stated:** Could get in your way Could give the enemy something to grab (why cops are supposed to wear clipons) etc **Possible advantages:** ***Could give you some cover.*** The cape could be made of a material that could deflect shots to the back. This could be some high tech stuff, or even just a real fine mesh to stop an arrow. In battle the cloak could be held up as a makeshift shield. It would be heavier so that it wouldn't blow in the wind. ***It could obscure your outline.*** The eye is good at picking out human shapes, so in dim light the cloak could be spread out a bit, break up the outline, and hide any shiny things like swords and armor. Given the right color, like dark green or dark grey, it could be an effective camouflage even in daylight. ***Makes it harder for enemies to judge your strengths and weaknesses.*** You could come across as pretty non threatening, right up until you're ready to start something, by having your weapons drawn under the cape. likewise a cape could hide armaments and armor from others, giving you an advantage. ***Insulation.*** being able to keep warm in the cold is great, and a cape would work well for this. Keep your arms and hands inside as you patrol out in the snow, or keep it around you as you hold your reigns while riding. A cloak that can be taken off would be better than a heavy coat if you end up needing to fight. Cape length would be something to really consider. Something medium long, like a trench coat, could be useful. Something longer, floor length or more, would be more annoying than it's worth. [Answer] Any long thing which is connected to your body can be thought of as a handhold with which to restrict your movements, capes are no exceptions. They would definitely need to break away, or else you basically give your opponent easy control of your neck. They are also slow and get tied around you easily, so even if your opponents don't restrict your motion, you still have to limit yourself to motions which control the cloak well. The biggest advantage of a cloak is it obscures your body position. It can be exceedingly difficult to determine the state of all of your joints, so any attack they might make has to be against an enemy with a level of unknown to it. This often calls for wider sweeping strikes which are slower, giving you a chance to attack faster. A cloak could also be used to bind the enemy if you are clever, though this would almost certainly always involve grabbing the cloak in your own hands. The Chinese often tied little pieces of red fabric to their weapons as a distraction. A cloak may be a bit excessive in this way, but you might still use it as such. [Answer] In general using capes or cloaks in combat is a well known trope, and most of the advantages and disadvantages have been discussed in other posts. Realistically, you would not want to have a full length cloak for most of the reasons given, but if you are going to use a cape or cloak in combat, then it should be no longer than waist or thigh length at the very most. This also applies to other items of apparel used in a military/combat context. Oliver Cromwell's "Ironsides" cavalry during the English Civil War protected themselves from sword thrusts and strokes with thigh length leather coats (reinforced with steel breast and backplates). The "Three Musketeers" are correctly portrayed in short cloaks, and the ancient Spartans took off and rolled up their full length red cloaks prior to marching into battle. So be fashionable by all means, but if you want to be effective and stay safe, then shorter capes and cloaks are better. [Answer] If you have ever been married, you will remember that a wedding dress is a *nightmare* to move in without tripping (either yourself or someone else). If you had the pleasure to walk with a beautiful bride then you also were ~~scared to death of tripping her~~ aware it was difficult to be in close proximity without tripping her. That's a big disadvantage is preventing or hindering cohesive combat for the dozen swordsmen. With capes that drape to the ground, it will be very easy to trip your ally (or yourself). This picture, while of a wedding, is a nice indication of the problems of a full length cape for combat: [](https://i.stack.imgur.com/SPPdV.png) Additionally, if your team intend to have longer swords, they may easily get caught in the other members cloak if they draw them. [Answer] In SpellSinger, the main character (Jon-Tom) is persuaded to get a cape. > > “I like it. Especially the cape.” He spun a small circle, nearly fell down but recovered poise and balance nicely. “I always wanted to wear a cape.” > > > Later on, after winning a bit at gambling, he is told of the other virtues of the cape. Along the hem of the cape is a place for secret pockets (and a place to store one's valuables). > > “No one think to pickpocket a cape. Only these few here, and I see no skilled one among them. Others who see will think only rocks in there.” > > > Putting rocks in the bottom of the cape helps reduce a prime problem with them - that they can blow over your head. But it also has additional benefits. This gives you several foot long (in the book it was described as five foot long) flexible club. Think of the rat tail towel in the locker room - with rocks in it. This is not something to the trifled with. Too long? yes, they get in the way. The right size so you don't trip over them? An invaluable tool for smacking someone over the head with the weights that you need to have in there to keep it useful. And then you've got all those pockets for the secret things that a bodyguard needs... money, wire, various powders and the like. [Answer] The issue with your question is the "in combat" part. A cloak is primarily a piece of clothing and while it is used in combat, it is basically opportunistic use. In life and death struggle you use whatever is available. So if you wear a cloak you will use it, and if you commonly use a cloak, you will actually train the techniques for using it in combat. But I doubt anyone has ever worn a cloak for its combat value. The non-combat uses are vastly more important. Which makes answering this question bit annoying. Still, you asked what you asked, so I'll list the coincidental combat benefits and ignore the vastly more important non-combat advantages. The first and biggest benefit is that you have it already for other reasons. It is basically a free weapon, there is no extra cost or weight. And you will almost always be able expect to have it with you, which is a big benefit compared to for example shields and bucklers. It can be used as a shield. If you are expecting trouble you will take a real shield, but for a bodyguard an improvised shield you always carry with you even when no sign of trouble existed has great value. Typically this would be the old "hidden weapons and a surprise rush maneuver" done by would be assassins of your client. The weapons would typically be light enough to be stopped by a heavy cloak and you'd only need to defend until other guards can respond to the attack and eliminate the threat. A cloak is quite useful for such use. Disadvantages as shield would be that it is not as good as a real shield and will take more damage from attacks than a real shield. Still as noted above a bodyguard needs to be able to protect himself and others even then not expecting a danger and not carrying a shield and in such cases the "shield" only needs to last until others can respond. So for bodyguards or others who wear cloaks and may need to defend against surprise attacks cloaks are useful as shields. Note that when used as shield the cloak is controlled by your off-hand and as such doesn't restrict your mobility and weapon use like it would otherwise. So use as shield is also sensible alternative to dropping your pretty and expensive cloak to the ground where people will trample and bleed over it. A cloak can be used as distraction by blocking the enemy line of sight so that they can't read your attack. Bodyguards are generally practised enough with their weapons to fully take advantage of this. As such use for feints can be expected. A cloak can be used to entangle opponents, their weapons or limbs. Essentially it can be used for improved grip in grappling. Effect would be similar to opponent having easy to grab, restrictive and sturdy clothing. Bodyguards would realistically want to sometimes take their opponents alive for questioning so they would practise these techniques too. Those would be the main advantages. Disadvantage would be restricted mobility and ability to draw weapons fast. But as mentioned the cloaks would be worn for the non-combat advantages they give and as such these disadvantages can be ignored then considering use of cloaks. The bodyguards would simply practise fighting while wearing cloaks. And how to drop it fast if they can get a real shield. [Answer] Something to consider is a certain category of people who combine cape wearing with melee combat: superheroes. The main hero I'm thinking of is Batman, who has several incarnation where his cloak has weights sewn in the ends that he can use as an additional weapon. His main way to use this is as a method to stun his opponents. In case you're interested in some inspiration, <http://tvtropes.org/pmwiki/pmwiki.php/Main/BadassCape> is an entire article on Badass Capes as used in fiction. WARNING: TVTROPES ALERT! This website is useful for inspiration, but it's notorious for the ability to distract the reader. [Answer] Wearing a cloak is the only sensible option. You have hired the 12 best swordsmen in the land. Everyone in the land knows you have done so. Nobody is stupid enough to organise a fair fight - their 12 best swordsmen vs your 12 best. The king has better swordsmen, and they will win, even with a slight handicap of a cape. If the opponent brings 12,000 swordsmen then capes or no capes, your 12 heroes are going to die. So if your opponent brings swords, the capes don't change the outcome in any case. But what about an opponent with a crossbow? The best strategy here is to block line of effect and/or sight to the king (stand between the king and the crossbowman) to block the first bolt, which will be the only one the assassin can fire. Capes will assist with this by blocking line of sight. [Answer] For about 27 years, I enjoyed associating with Society for Creative Anachronism (SCA) people, in various cities, states, and countries. I was never with any single group for an appreciable amount of time, because I'd moved a lot due to my work, and I never "made a splash" or became even remotely well-known in any "Shire" (again, due to my work.) However, I DID get to see a large number of sword-swinging types, and I'd watched the different fighting styles with interest. In "Real World Combat," only one or two had the brains to drop their capes or cloaks when going into a fight. The rest? They had given me infinite practice in keeping a straight face and not laughing like a hyena when they had "wardrobe malfunctions." *Granted, it LOOKS simply fabulous!* And in the winter, particularly when on sentry-go or if walking the battlements in the blowing snow, a heavy, hooded, woolen cloak with hood is a life-saver! I'd "liberated" a Serbian military sentry's hooded woolen cloak (and still have it!) because it's so great in the winter. (The Serbian cloak also has a "shoulder-strap" so the wearer can open and fold it back, clear of the shoulders, when one's indoors.) I also have an "Inverness hooded rain-cloak" in black, and had worn it when out all day in the driving rain. Nothing keeps one as dry and comfortable as an Inverness, in my opinion, if it's possible to wear it without arousing comment. That said, I'd drop either one in the gutter in a heart-beat, if attacked! A cloak is too restrictive to wear during a fight, and it's even dangerous to try to pull it off and whirl it round one's weak-arm as a shield--- the bit with the cloak is distracting, and you'd not notice a clever killer making in with the death-blade! Some of the very many goofs and foul-ups I'd witnessed with "Knightly Cloaks" have been these: Catching sword-point, pommel, or guard in the hem of the cloak, when either drawing **OR wielding** the weapon---while the "knight" was fighting with his garb, the peasant put out his lights. This was very, VERY common. Another beauty begins by crouching in a fighting stance, and as one maneuvered, one treads on the tail of the cloak . . . and when one TRIES to advance on the enemy, all he does is thrust his pelvis at the foe before dropping flat on his back, knees akimbo! Trying to get up while in a cloak, if one's slipped & fallen, can also be very entertaining. Others in the melee can cause a cloaked knight problems, as well: Catching the point or guard of one's weapon in the hem of someone else's cloak is one very common blunder, plus there's the risk of standing on the cloak of a fellow knight--- he soon tries to move, and becomes completely distracted when he gets yoked back by the pinioning cloak, and falls on his tush. They're also great if you intend to attack the wearer! Grabbing the hem and taking off at a run to his side or rear will suddenly slam the cloaked knight to the deck; grabbing it and running in front of Sir Knight will serve to wrap him in his cloak like a corpse prepared for the grave, because one can hammer him into the ground before he ever draws his weapon. Plus, if one intends to ambush the cloaked knight, it's an easy thing to come up and slip a long bodkin-spike or dagger into his vitals--- his blood will be concealed by the cloak, and one may stroll away after sitting the cadaver on a bench, as though it is taking a brief respite. The thing is, if a king brings in a dozen top swordsmen, an opponent simply has to bring in several top assassins. "Top Swordsmen" are useful only if they can draw blade. Suborn the sluts at a bordello and kill one or two of those "Top Knights" with too much poppy-wine; poison the fowl served at "Knights' Table" to eliminate a few more; post assassins with daggers along the route to the latrine to stab another "Top Knight" before dropping him down the "glory-hole" and into the feces below; do the same sneak-attack slaying of another Knight or two in the crowded market-place . . . and, oh my! *The King has NO "Top Swordsmen!"* Only a hopping-halfwit or the village's arch-idiot would entertain the idea of squaring off against a "top Swordsman" in anything that even remotely resembled a "Fair Fight!" Fancy bodyguards have a very long history of having been bumped off along the way to the assassination of their employers. **[Why had I never sought "King-ship?" I'd far sooner have the REAL POWER of advising the Crown, than the headaches of wearing the crown!]** [Answer] The same reason real warriors and fighters don't have long hair; the opponent can grab and it will put them in serious trouble. [Answer] A lot of answer given... Used as defense, weapons,... This will also vary with the kind of gear those swordsmen are using : is it full plate armor or lighter leather jerkins, with broadsword, spear or rapier ? Heavier armor or weapons will have less utility for a cloak than the lighter equipment. It can also be used as a message or as a decoy : "we are so good that even with those heavy handle hanging from our backs, we'll floor you" or "with our lovely cape, we shouldn't be too much of a threat... Then we'll gut you.". As an example, I'll talk about the French republican guard : they look quite ridiculous in WWI uniforms, but are still really well trained. Finally consider that in most warrior culture there are things you just don't do (Roman and Greek soldiers used not many ranged weapon, for example, it was good for barbarian mercenaries). In your fiction, it could be grabbing one's opponent garment. ]

[Question] [ There have been countless (literally) stories written that have contained within their pages monsters that are stronger, faster, and bigger than the human heroes. I can think of more than a few where the monsters are a relatively common species. Right off the bat I think of one of the trilogies in the [In Her Name series](https://www.goodreads.com/series/62231-in-her-name) by Michael R. Hicks. The home world of the alien race (I forget their name) has large beasts on it that prey on them or any other creature wandering outside of the bounds of civilization. Our own history shows that we as a species have wiped out anything that had the power (size and strength) to oppose us or torment us in any way. Climate change was not the only thing that wiped out countless Ice Age species. I want a world where a dragon-like creature roams the wilderness. I want it to occasionally hunt people. **How can I stop said creature from being driven to extinction by the local humans?** Is the only real possibility that these animals will be driven to extinction or do they have some chance? When thinking of the tech level, refer to our current tech level. [Answer] I can think of a few reasons: ## The creature is difficult to catch Sharks, being aquatic, have a large range and are not simple to find. They can be anywhere in the sea. ## The human death toll is not sufficiently large Again, sharks kill people, but not enough people to warrant eradicating them. We take our chances. ## The creature is an important part of the ecosystem Removing an apex predator from the ecosystem is going to cause problems. Perhaps the creature fulfils some necessary function. ## The society enjoys or encourages risk taking I remember reading a book a long time ago about a society in which risk taking was celebrated. In order to keep everyone on their toes traps were set which would need to be avoided on a daily basis. Going to the shops involved leaping over spike trap pits and pirouetting around swinging blades. ## The creature is useful Dragon riders? [Answer] **The Dragons Are Useful** Suppose there's another animal that the dragons keep away. This could be another predator that has enough smarts to avoid dragon territory, or a pest that dragons love to eat. Now you could kill the dragon and take care of the pest/predator yourself, but what if it's cheaper and/or easier to just keep the dragons around and live with the damage they do? In that case your cultures might develop with the attitude that, yes, we have dragons, occasionally they eat people and that sucks, but the alternative is Explosive Spider-Wasps. We'll keep the dragons, thank you. **The Dragons Are Necessary** There could be a symbiotic relationship where killing them off would be suicidal. You could go a couple of routes with this. The first would be direct - there are some plants where, for example, they have to be [eaten](http://en.wikipedia.org/wiki/Seed_dispersal#By_animals) to spread their seeds. This is obviously tricky with humanoids, but you could do something along the same lines, where dragons are necessary component somewhere in their lifecycle. The second would be indirect. Consider [Fire Ecology](http://en.wikipedia.org/wiki/Fire_ecology). A lot of natural ecosystems need periodic fire to be healthy. Maybe the ecosystem your sentients live in needs regular purging by dragonfire, or bad things happen. So cultures that wipe out dragons don't survive long. [Answer] I think you can look for guidance to the big cats of our own time, which do (infrequently, but more in the past) prey on people. In order to survive long enough for human sensibilities to want to "preserve the noble creatures," the species will need to have a few characteristics: 1. Numerous. They need to have enough representation and range that small scale eradication campaigns will not have too much impact. 2. Distant. While they may periodically interact with people, they will need to live at some distance so that they aren't a regular threat. 3. Moderately destructive. A dragon that wipes out villages will draw too much attention to itself and become a target for questing and such. A smaller creature that kills the town drunk when he's out too late or drags off a few cattle won't stir widespread hatred. 4. Flying. Really helpful for eluding capture, but not necessary. [It took until the 1900s to eradicate wolves in parts of Europe](http://en.wikipedia.org/wiki/Wolf_hunting#Europe_and_Russia) (and in some places they still survive). A creature that was regarded as "more noble" might be protected earlier and not experience such a decline as technology allows better hunting techniques. The interactions will start with the stronger species being dominant, until technology allows the weaker to first develop defensive methods (fire, melee weapons), then offensive methods (distance hunting weapons, traps). Then there will be an era of small scale hunting, which will ramp up as the technology gets better. Hopefully about that time someone will adopt the creature as their coat of arms and become dominant, which will allow at least some to survive in domestication or zoos. Eventually, after significant habitat depletion and extermination, the creatures will be protected by people who don't experience significant impacts from their presence. At that point, survival is pretty likely, preserves will be set up, and they will be studied. Your species just has to survive long enough to get there. --- *What follows was due to a misunderstanding, but I think it's interesting so I'm going to leave it for now* I just saw your comment about intelligence. I think if they have the same mental capacity, they could potentially coexist. The species that will become dominant will be the ones to acquire technology fastest. Humans are really good at using tools; a creature that can rely more on strength might not develop the early technologies needed to lay the groundwork for progress. In any case, I think the points above are still valid. Presumably the species will develop separately, until eventually they will develop the ability to communicate. Then as long as they can prevent each other from committing genocide, it will probably develop into a somewhat stable peace. You can draw on the history of infrahumanized groups and how they survived. Certainly Europeans considered "natives" to be "less human" than themselves, and though they did really bad things to them, most other races survived. [Shipwrecked Europeans](http://en.wikipedia.org/wiki/Skeletons_on_the_Zahara) experienced the same thing - they were "obviously subhuman" and enslaved. While the stronger in an area will probably enslave the weaker, both species will likely survive to the time where slavery is eradicated (hopefully). [Answer] Your assumption is that any species that poses a significant threat to a sapient species would eventually be wiped out by that species. Which is reasonable - it's within that species' best interests, and they are capable of putting their resources together to do so. Take one of those things out of the equation, and you have a species that is still around, despite being incredibly dangerous. Other answers have gone over reasons why it might not be in their best interest - big risk-takers enjoying the big game hunt, the big creature being essential to the ecosystem, the big creature being *useful* to the sapient one - so let's consider the second option, that the creature is simply *too powerful* to destroy. Fortunately, we have an example of a world where just such a creature exists - [Attack on Titan](http://www.en.wikipedia.org/wiki/Attack_on_Titan). The gigantic Titans of this world are large enough and dangerous enough compared to the capabilities of the humans that trying to wipe them out is not only dangerous, but futile. The Titans can also survive *without* a food source, so strategic starvation is not an option. You could easily assume the same thing about a draconic race. There would be those outliers who want to slay Dragons for heroic purposes (like the heroes in Attack on Titan want to slay Titans despite the danger), but give the dragons nigh-impenetrable scales, extreme strength, flight (so that any fortification, no matter how strong, can be surmounted) and longevity such that they can go for years without 'feasting' upon humans and livestock. For an additional bonus flavor to such a dragon, have them feed on humans once a year, and be incredibly selective of their choice in meal, meaning only the most beautiful humans would be consumed (as per the usual 'dragon-kidnaps-princess' motif). [Answer] Sapient creatures tend to craft their environment to suit their needs. A species hunting you is generally considered to be in need of substantial crafting. However, if there are other things in need of crafting, the dragon can appear low on the priorities list. If there is a problem with simply not being able to grow enough food to survive famines every few years, dragons decreasing the population won't matter enough to warrant hunting them. On the flip side, Dragons could provide enough of a service to make the loss of a few unwarry individuals acceptable. If there is some tremendously nasty invasive creature which makes life miserable, and dragons happen to eat that creature, we may accept the existence of dragons because we effectively live in symbiosis with them. [Answer] A lot depends on what you mean by "dominant species". Insects are by far the most numerous and have adapted to virtually every ecological niche available, by some measures insects are the dominant species and beatles are the most common and thus the most dominant kind of insect. Bow to your insect overlords.... Apex predation is also not a measure of dominance except in limited circumstances. Placing great white sharks in the african savanna is not going to displace lions any time soon. Dragons are in a similar situation; they may be the apex predator in Middle Earth, but their prey is becoming scarce and their range is shrinking as the races of Elves, Humans, Dwarves, Hobbits etc. clear the land and farm. In fact, I might argue that the only way you could get two intelligent species to coexist would involve either having each species specialized in one ecological niche, or use their intelligence in very different and non overlapping ways (i.e. Douglas Adam's description of the Dolphins): > > For instance, on the planet Earth, man had always assumed that he was more intelligent than dolphins because he had achieved so much—the wheel, New York, wars and so on—whilst all the dolphins had ever done was muck about in the water having a good time. But conversely, the dolphins had always believed that they were far more intelligent than man—for precisely the same reasons. > > > ― Douglas Adams, The Hitchhiker's Guide to the Galaxy > > > Notice that similar hominid species (the Neanderthals and Denisovans) were rendered extinct either directly or indirectly by Homo Sapiens. My guess is that our Ancestors were able to outcompete all the other hominids in important respects like hunting and living more efficiently off the same piece of land than anyone or anything else, hence our place as the *only* hominid left. This may not necessarily have been through warfare or directly hunting and killing competitors, simply being able to breed faster and have more children live through childhood would push the balance (fewer and fewer Neanderthals in every generation are competing against more and more Homo Sapiens for available food, and the Sapiens have also spilled over into all the adjoining valleys as well). Intelligent Dolphins, however, are under no such pressure. [Answer] Lions, tigers, leopards, crocodiles, alligators, many types of sharks... faster, stronger, and bigger than human. All occasionally hunt humans with good success. Human in water is no match for sharks or giant reptiles. A large feline that gets close enough to human to attack and is hungry generally gets to eat. There was actually a recent question that was about the conditions that allow an apex predator capable of hunting humans to survive. (Can't find the link atm, sorry. Maybe somebody can give it in the comments...) The short version is that the predator much have a separate ecological niche and habitat. Lions and tigers for example survive mostly in areas that for one reason or another have low population. Currently this is often due to wildlife preservation efforts, but without modern technology large areas would be incapable of supporting population dense enough to be an issue. Sharks are aquatic and before commercial fishing did not compete with humans for habitat. Leopards are adaptable enough to live in cities... So you just have to make the primary (remaining) habitat of the pseudo-dragon something that is sparsely populated. Like sharks it could be aquatic. It could live in swamps or jungles that would require a serious effort and infrastructure to make inhabitable. It could live on a desert or steppe that has nothing that makes fighting a dragon for territory attractive. Trophy hunting is only practical if the area is easily accessible from some place with idle rich. If no highly developed areas are near nobody will bother huge man-eating monsters. [Answer] For any creature to survive alongside humans, that creature must be able to withstand the ecological changes that humans precipitate. Namely, the creature must be able to withstand being killed at whatever rate humans kill it at, and it must be able to keep getting food even with human hunters competing with it. **The creature would need to exist in a different ecological niche than humans.** One of the major reasons that humans drive large carnivores extinct is competition. Humans tend to hunt large plant eaters, so any animals that have evolved to hunt specifically these kinds of creatures tend to be driven extinct by human competition. A good example of this is the smilodon, a kind of saber-toothed cat. It evolved as a niche predator of large animals like ground sloths and mammoths, but wasn't well suited for hunting smaller, faster creatures like deer. When humans came in and drove their food to extinction, the smilodons followed. In order to survive humanity, a creature would need a different food source than us. Most likely, if the creature is big enough to eat us, it either eats something that is too big for us to kill, like a large sauropod, or else something that's too dangerous or inaccessible for us to go after, like crocodiles or whales. **The creature must either be too big for humans to kill, or not be the biggest creature around.** Most creatures have a reproductive rate which is closely tuned to their rate of death. Even low-level killing from humans, for example, can be problematic for something like a polar bear that reproduces slowly. On the other hand, animals like coyotes that regularly get eaten in the wild tend to produce lots of babies to account for the higher death rate in adults. For coyotes, competition with wolves (and predation by wolves) caused higher mortality rates than did people, so killing off the wolves has increased their population. In order to survive humans, a creature would need to be either big enough to almost never get killed by people, or else *not be the biggest thing around.* For example, if there were dragons and something big enough to munch on them in the natural environment, humans killing off the dragon munchers could lead to a population boom for the dragons, especially if the former apex predator ate nothing but dragons and ate lots of them. The predation rate of the dragon munchers would only need to be higher than the rate at which people kill dragons. Any areas with low populations would also serve as dragon population reservoirs, since dragons would quickly reproduce to fill these areas in the absence of human competition for food. **There would probably need to be a more productive environment.** Of course, there needs to be a source of lots of calories for all of the dragons and dragon munchers to be ecologically viable. This has, of course, been the case at lots of points in the past. Dinosaurs grew huge in part because there was more plant growth when they were lumbering around. More plants can support more and larger herbivores, which in turn support more an larger carnivores. A human sized sapient creature which evolved in such an environment would likely disrupt their environment, but probably not enough to kill off all predators larger than themselves. Especially in the untamed wilds, humans could easily be far from the top of the food chain. [Answer] Your dragon has an advantage that none of the other large predators that hunt humans have: it can fly. Considering a large size dragon (I'm picturing fairy-tale dragons larger than elephants here) it will have an impressive set of wings and will be able to travel enormous distances relatively easily. One of the reason that they haven't been hunted to extinction can be that nobody is willing to make the voyage. Dragons could live high in the mountains, far out of reach of any hunters. The world's highest mountain peaks haven't been reached until fairly recently; it's nigh impossible for low level humans to reach them. They could also lair in active volcanoes, where the heat makes it impossible for humans to follow. They could even be migratory. If Dragons don't have a fixed nest but instead fly from spot to spot, while hunting in between, humans will not be able to keep up. They can cross forests, hills and rivers with ease and other than accidentally bumping into one you'd only see them when they are hunting you but you'd never reach them when you are hunting them. Your only hope would be to find a Dragon in its nesting period, but since their territory is absolutely huge, they leave no tracks on the ground and a nesting Dragon does not hunt, fat chance of actually finding one. [Answer] **The species is worshiped or venerated by the sapient aliens.** The creature is seen as a god, or agent of a god or gods. Perhaps different species are associated with different gods. Those that are killed by the creature could be seen as blessed, having ascended to an afterlife. Perhaps those merely left maimed are considered cursed. [Answer] Dragons can live in really inaccessible mountains and far away from major human settlements. In open plains with good visibility and 20 mm anti-air machine gun humans would have a pretty good advantage against a dragon, but on narrow mountain trails, where there is little warning and no place to take cover and no vehicles to transport heavier weapons/ammo, not so much. They might also culturally be too important to completely wipe out, as long as they don't pose a threat to major (rich, powerful) cities people might leave them be. They'd still be hard to hunt with civilian weaponry (like shotguns and rifles) so if the government doesn't think that your village is worth protecting from dragons, there could be some dragon issues there. Ultimately, look to real animals: bears occasionally maul people but they weren't driven to extinction completely because it's fairly rare and they are seen as important as a species. [Answer] How about a totally different reason: A sapient species that is not effectively able to combat the apex predator? Consider an intelligent mole or the like--something that pretty much lives underground. It did not evolve in an environment where perception of a large amount of information at once was of much evolutionary value. It normally runs from a threat, if it must fight it's fighting one opponent in a confined space. Technological aid can overcome the short range senses that such a creature would develop but it can't overcome the information overload problem of surface combat or especially aerial combat. A raptor would totally dominate them in a shared environment. Venturing upon the surface safely would require tanks, wiping out the raptors would require robotic weaponry. [Answer] And depending upon how you define "dominant" you could also have a situation with two sentient species. Consider a world with a near-sapient predator, the world is split into two landmasses, the predator inhabiting both. (Say, like Earth) The world is subject to a lot of bad events that repeatedly push both of them to the brink. Intelligence helps them survive the calamities, both are driven to intelligence. However, survival means being mobile, they are basically limited to what they can carry--technology is basically capped at the late stone age. Although true simultaneous evolution isn't going to happen without great luck a technological cap means it's not actually required. They have also been driven to favor different environments--say, one likes swamps and the other likes mountains. Times change, the calamities end and the landmasses are linked. (Maybe a land bridge, maybe simply the removal of something that rendered an existing connection unusable--say, a very hazardous volcano on the land bridge.) Now you have two admittedly related sapient species occupying the same world. They spread into each other's part of the world, each dominates it's preferred environment but is definitely the underdog in the other's. [Answer] I'm going to go off-tangent to the existing answers and say: just go for a super-SUPER-predator. Make your dragons the most dangerous, most unimaginably powerful creatures imaginable. Your humans cannot 'hunt them to extinction' or 'poach them', because *they* are the hunters. Here are some of my suggestions for a super-predator species: 1. Gives birth to hundreds of spawn in their lifetime. Think [xenomorph](http://en.wikipedia.org/wiki/Alien_%28creature_in_Alien_franchise%29), they lay dozens of eggs at a time, and their newborns are already predatory and vicious. 2. Impossible to take down solo. A hunter/poacher/asshole with a gun is just another snack to them, whether its because they are insanely fast or monstrously tough. You need an entire dedicated hunting team to take down even one, and this brings me to my next point- 3. Make them pack/swarm animals. Now you need an *army* to remove them once they've settled down... And what guarantee have you that you got them all? Now the challenge is flipped... How would the humans survive? :D [Answer] 1. The dragon has a thick armored skin capable of shrugging off a 50mm bullet 2. It likes to delve in unpopulated areas such as barren deserts, abandoned towns. It hates humans but avoid their settlements for there is nothing that it wants from them. 3. Something unknown ([Evolutionary mutation](http://evolution.berkeley.edu/evolibrary/article/evo_18)?) caused the species to develop [Electrocytes](http://en.wikipedia.org/wiki/Electric_organ) underneath the thick armored skin. Effect of which is to turn the dragon into a walking (flying?) EMP generator. 4. The eyes are so big that it can see for miles and the brain is capable of processing threats faster than a google's datacenter is able to process search queries. [Answer] > > How can I stop said creature from being driven to extinction by the local humans? > > > When the local humans *choose* not to drive the creature to extinction. This is the only case, given the other restrictions you place, where the humans would not naturally do so. Sapience will always out-exist non-sapience. As long as there are * resources to be shared * in the same ecological niche * with danger posed by the non-sapient creatures Then unless the humans actively choose to protect the creatures, humans will always expand their area, they will always reduce their risk, and they will always (ultimately speaking - war, not individual battles) win. If it becomes cheaper and more effective to decrease the risk of the alpha predator's attacks through means that doesn't reduce the creature's numbers or territory, then there might *possibly* be a loophole that would allow both to co-exist. If this is true, though, then they don't really share an ecological niche. If the humans don't affect the food supply, mating capability, or territorial needs of the predator while they continue to expand, then it's hard to claim that they are in the same ecological niche. Similar to sharks and humans, where the shared area is actually very small - yet they are still being hunted (to extinction in some cases) though they pose no real species level threat. So while the other answers are trying very hard to show artificial ways that this might be possible, I suspect that they are simply ways to separate the niche, and the reality is that ultimately the sapient creatures will have to decide to protect the apex predator. As such, I predict this would happen in an advanced society which has little need for the products of the predator (industry based on other materials, transportation, etc), and that has experienced extinctions of other animals in the past that are valued. Even then, though, we'd get the situation we have with black bears, lions and tigers, etc. They are not allowed into our areas except in zoos, and as we expand out habitat we shrink theirs - ultimately leading to the same extinction end. Not unlike Indian reservations, we may leave small protected areas for them, but their DNA diversity is so significantly cut that eventually they die out anyway, or only exist as a former shadow of their previous position on the predator hierarchy. [Answer] # They have not gotten around to it yet Modern humans existed for a long time before dominating everything. At times it was a very small population, or lived more as part of nature. I recall that the Americas were not colonized by humans until after the megafauna was gone or in decline. # It is post-apocalyptic The dominant species is reduced to small clans trying to survive, after a ecological collapse. It's still intelligent, but not on top. [Answer] ## The animal species is extremely secretive. I live in a part of the world where there are a lot of cougars. Despite being a large predator, and of sufficient number, sightings are rare, that's because cougars are very secretive and stealthy. Suppose this large animal race was the master of stealth, quiet as a cat, and could camouflage itself like a chameleon, or an octopus. They prey on people in the outskirts of civilization, but because they're so secretive and elusive it's next to impossible to hunt them or even detect them, like trying to hunt a ghost or a shadow. Sightings are rare, but the reality of their existence is attested by conspicuous disappearances, or the eventual discoveries of devoured remains. Living in an extreme habitat that they only leave in order to hunt could make it difficult for a sapient species to hunt them as well. Suppose the animals lived deep in the earth, or at the bottom of deep rifts in the ocean, or in the death zones of high mountain ranges. If the sapient species had to risk death simply by entering the animals habitat, even without even encountering the animal it would deter or hinder most efforts to eradicate them. [Answer] ### Soo... you want to kill a dragon my friend? Beware of the Dragons curse... First, that's no easy task battling yourself with those viscous beasts. But even if you manage to mortally wound it and escape its dying berserker rage, the Curse of the Dragon-Blood will still get you. When the Dragon finally ends his dying rage and slams into the ground, the unholy flames in his belly will start to boil and transform the massive husk into an inflating balloon. Filled with all kinds of toxic fumes and acids, it will reach the size of a house and erupt in an ugly explosion. The land will be tainted several acres around for years to come, the dying plants and brazen earth will mark the dragons deathbed for generations. And everyone around, be it hunters or simple people from the next village will die in days or weeks, spitting out their intestines. If the dragons contain a source to breath fire, they will have some pretty weird and life-threatening unstable mix of chemicals in their system. An uncontrolled reaction at the time of dead could spread a mix of deadly toxic chemicals over the land and release a huge cloud of radioactive dust, which will settle over the surrounding lands and rain down in the following days. The earth and water will be contaminated and most people breathing the dust or eating/drinking it will die. Most animals and plants around will also suffer and the land could be unusable for some time afterwards. Even a society with our technological level will have problems to kill these Dragons and control the reaction. The best way is to protect yourself and find ways to fend them off and send them away without killing them. If they also live very remote and only sometimes come close to society, it will not be very profitable to hunt them. Furthermore that they won't provide any trophies or leather like wolves. Dragons which get old and feel their death approaching could have a natural instinct like elephants and throw themselves into a volcano or something, which is far off from most life and will prohibit the toxic substances from entering the ecosystem. [Answer] ## The dragons live somewhere else Suppose that there is another continent somewhere, which has not yet been heavily colonised by humans. There are three reasons why it hasn't been colonised: firstly because it's very inhospitable to us (e.g. cold, like antartica or Siberia, or almost entirely mountains, or a desert with very poor soil for agriculture, or impenetrable rainforest), secondly because it's inaccessible (e.g. not on regular shipping routes, few places to build ports or airstrips), and thirdly because it's crawling with huge, dangerous, fire-breathing dragons. On this continent the dragons can breed and eat whatever they eat, free from interference by humans. But since they can fly vast distances, the largest and most fearsome specimens have a tendency leave the continent and settle elsewhere, often much closer to populated areas. When this happens they usually are eventually wiped out by the local humans, but more will always come. The humans *could* decide to wipe out the dragons from their natural environment, but this would be a hugely expensive undertaking, akin to waging a sustained intercontinental war. Perhaps the other factors people have mentioned come into play in their deciding not to: the dragons are useful in some way, or people just don't want to wipe out such a unique species. Of course it doesn't have to be a separate continent, just a separate niche where humans won't compete. Perhaps most dragons live only on the tops of huge mountains, or in caverns deep beneath the Earth, or on the Moon. Or they live in the same places as humans, but the vast majority are not man-eaters or livestock-eaters, and tend to live peacefully alongside us without competing. As long as they occupy separate ecological niches most of the time, the two species should be able to coexist. [Answer] If the intelligence of the dragon is similar to the humans, then there are two factors to take into account: * Does this being have an opposed finger? What gives us humans the capacity to be above any other animal is not just the intelligence, but the fact that we can build things and use things very efficiently because of our thumb. Dolphins are very intelligent (I think we don't even know how much) but they can't use objects nor create new ones. * The other factor in case it has thumbs is... How advanced is its technology? I've seen you've paired his technology to ours, so now the problem becomes the same as the one we humans have right now with different human races/religions... Will humans and dragons be able to coexist or they will destruct each other? (right now our technollogy allows us to selfdestruct human race -nuclear technollogy-) [Answer] ## The large animal race is intellectually superior to the sapient race. Suppose the dragon-like creatures had a sophisticated society, but it was their desire, or in their best interest to co-exist with the sapient race (humans are their food source). The sapient race is inferior to the dragon-like species technologically, or in might, so they submit themselves to the dragon-like race, and are allowed to live in peace and prosper so long as they deliver goods such as livestock or a "quota" of people (criminals, convicts, the frail, elderly, slaves, etc...) to the Dragon-like species as food. An episode of Stargate Atlantis come to mind: Atlantis discovered a world that was very technologically advanced, a stark contrast from the rest of the preimitive worlds that were frequently culled by the advanced wraith species which preyed on humans, and eradicated any civilization in the galaxy that advanced to the point where they might pose a threat. It was discovered that the technologically advanced world had an agreement with one particular wraith who spared the majority of the population in exchange for "offerings". Essentially this society dealt with convicts by exiling them to an island where the wraith could easily cull them, but it didn't take much to be convicted of a crime (In order to meet their quota). ]

[Question] [ I'm taking about a gigantic building that serves all the needs of small city, about a thousand inhabitants. People must be able to work, sleep, eat, play, and go to school all with out leaving the building. Is such a thing possible with our current tech level? Upon thorough inspection, I have decided that the city would probably also need a shopping center or market of some kind so the residents don't have to leave the city just to get groceries. If possible, I would like to have a stadium or something similar so that the residents can enjoy sports without having to leave the city or being confined to watching it on TV. Also, if possible, some kind of worship center where more religious residents can meet together. Again, unlike the others, this is not necessary for city to exist but it would make it resident life easier. [Answer] Yes. Modern aircraft carriers have crews of around 5,000. It's even easier if you're supporting one fifth that many people and don't have to worry about making your building float or move at 35mph. The real challenges are social/psychological. People tend to get stir crazy when kept in inside for long periods of time. Close quarters also makes it harder to get away from people you don't get along with. [Answer] Wittier, Alaska: <https://en.wikipedia.org/wiki/Whittier,_Alaska> Nearly 100% of the town's ~200 people live in "Begich Towers", which contains residences, a school, stores, gym/fitness, etc. Although this is not as many people as e.g. an aircraft carrier, it is still an interesting example because it's a more diverse group of people (all ages, including children, instead of just navy personnel) that more naturally matches the population of a real city. [Answer] Apart from the Montreal example, there was also this: <https://en.wikipedia.org/wiki/Kowloon_Walled_City> It was a nearly self contained town with living, working and service quarters. And what is most particular, it sprung up by itself, with no planning. You can read a bit about it and see some images / stories from the place around the web. It is possible to build something like that with the current tech, just not practical (staggered greenhouses, water purification, internal powerplants etc. [Answer] A very simple answer: Take any city you like. Build roofs over all open places. Job done. Assuming you don't mind the occasional strut or pillar, and as long as you make sure to allow for ventilation, then this would have been possible right after the invention of glass. People tend to suffer if they cannot see the changes of daylight over longer periods of time, plus lighting can be costly, so glass (or other transparent material) in abundance is a must. Everything else could even be done in timber structures. [Answer] Take Mall of America, or King of Prussia mall. Add a large, collegiate sized gymnasium. MofA has hotels in it, I'm not sure of the capacity, but could easily be 1000. [Answer] Yes, easily possible. I am no expert but I am fairly sure that a block of flats with say 100 floors could easily be built. If each floor was as wide as an ordinary house then you could have 16 people per floor (slightly cramped but possible, especially with bunk beds). The accommodation floors would also contain bathrooms. That would be 70 accommodation floors. 1 canteen floor for every 10 accommodation floors would mean 7 canteen floors. If we assume a quarter of inhabitants are children that is 250 kids so maybe 5 school floors. Add maybe 3 entertainment floors with soft play, video games, cinema and so on for play. Most work can be done remotely via laptops so no floors needed for that. Have 5 floors for manufacturing things like clothing and other goods. This leaves around 10 floors for gather uses (meetings if the community, medical care etc) Recap 70 living floors, 7 dining floors, 10 general floors, 3 entertainment floors, 5 manufacturer floors and 5 school floors. I looked online and as far as I can tell it would require at least another 1kmsq to grow enough food so maybe a huge underground basement with UV and advanced hydroponics might be required. [Answer] This has been discussed and speculated about a lot, particularly 20 to 40 years ago before the human population explosion had started to decline and people were trying to come up with ways to handle unconstrained population growth. The term for what you are describing is [arcology](https://en.wikipedia.org/wiki/Arcology). No-one in the real world has actually built an arcology yet but there have been a number of experiments and concepts with them. Several (For example [Crystal Island](https://en.wikipedia.org/wiki/Crystal_Island) in Russia) were started but then abandoned or put on hold. An excellent novel that looks at the social implications of arcologies is "Oath of Fealty" by Larry Niven and Jerry Pournelle. It's set in the near future so is more relevant to our current tech level than most sci-fi arcologies. [Answer] Istanbul's [Grand Bazaar](https://en.wikipedia.org/wiki/Grand_Bazaar,_Istanbul) easily qualifies. Basically it's the original shopping mall. However it doesn't have a stadium. ]

[Question] [ I am envisioning a space faring species, evolved from an obligate carnivore and apex predator. The obvious concept to me is a tiger like species with prehensile tails that became increasingly adapted to tool use. However if you want to create an answer based on a different origin that is fine, as long as the origin remains an apex predator that once hunted using first and foremost speed and strength. If it is at all workable according to your theory, members of the species should enjoy hunting and still be capable of it in it's original form. An ideal answer will address * Traits of social groups * Likely forms of governance (or why there wouldn't be any) * How they might be able to become space faring despite (or because of) the above * Moral foundations/principles * Religion(s) (or why there wouldn't be one) * Anything else that you expect to be an interesting outcome of this evolutionary background **Edit:** A point of clarification since a common response is along the lines of "This isn't plausible". Firstly I'm aware it's not plausible, the question is not about the plausibility, but is a what if type of question. Secondly, if you are not satisfied with a solitary society, neither am I, the question states **Evolved From solitary** - not - **Still is solitary at point of societal formation**. Within that framework, whilst it's more interesting to me for them to remain fairly solitary, answers that invoke a reason and time period for better societal cohesion are fine. I hope that clarifies. [Answer] It's a pretty broad spectrum, but some traits may include: **Sexual violence as a norm:** When males and females meet, if the female is in heat then the males are going to do their damnedest to breed, consent or no. **Infanticide:** Killing the offspring of another male may be looked down upon in some circles, but I would imagine that behaviour would follow through from the early evolutionary pressures on non-social predators. Scents passed down the male line could be used to identify family lineages (with the interesting side effect that paternity tests are irrelevant) **Protective mothers. To a point:** Mothers would be highly motivated to keep all of their offspring alive, up until the point where their offspring are capable of dealing with the world, at which point they will walk the hell away. Given the elongated childhoods of sentient species (OK, I'm working with a sample size of one here) these three traits could lead to some strange family behaviours, such as children running and hiding when nearby males come around, or perhaps entire groups of nearly adult children being defending your mother's honour from a passing male. Mothers would be the nuclei of family life, fathers would be a distant threat. **Communication spots:** Often passed rocks, cliffs, vegetation or even patches of ground will become spots where messages (pheromonal, written or more complex) will be left. Some of these messages will cause responses in individuals to work toward projects that are for the communal good, leading to a highly distributed 'society' with a huge latency for communication. This would lead to communication technologies that, similarly, aren't based on real time communication. It simply doesn't interest this species, the only time real time communication happens is in a family unit (where the children are basically sub-units of the mother), breeding or fighting. **Slow species development, but high individual competency:** The distributed nature of society means that group efforts (like a space project) would take a long, long time. It's not in the nature of these creatures to work together, so it's more likely that a series of highly intelligent individuals would create technologies by bouncing off each other's accomplishments. I would imagine that automation of technologies would be a natural technological progression for this species. Rather than working on division of labour (where co-operation is required) individuals are more likely to focus on ways to increase or improve their own productivity. An individual fighting another individual might progress from the early biological 'fighting for mates' into fighting for technologies, knowledge or ideal sites for experimentation. **Space?:** Well. It's possible that a series of individuals working on ever more complex automated systems could create mechanisms capable of creating space ships (this would be a complicated process involving treachery, backstabbing and lots of fighting for superiority over the project). If an individual holds onto this system long enough then they end up with a spaceship. Again: This isn't due to co-operation, really, it's due to a lot of individuals building on the bones of their predecessors. This would require individuals of your species to be brilliantly smart in order to grasp the principles of their predecessor's work. So: Society is less of a social effort and more of a hugely complex and chaotic mish-mash of individuals, but each individual would be brilliant enough to make it work overall. Unlikely, but weirder things have been posited in works of fiction. [Answer] While most of what I was going to write has already been covered by thestarchyninja, I would try and add some more detail. Keep in mind that the answer is written for species after it has evolved enough intelligence to form the concept of clans and groups and social life has taken root. **1- Solitary apex predators are solitary** Yes. One aspect of being solitary apex predator is being solitary. This means that communication would be limited to conveying vital information. You would not expect a language with vast vocabulary. The language would particularly lack in conveying emotions and personal thoughts. Body language and gestures would be key to understanding the underlying message of one's statements. Sentences would be short. **2- Social hierarchy would be very strict** This is usually the case with warrior nations. Social hierarchy (who commands who) would be very well defined and any disobedience would be punished immediately by death or severe physical torture. Clans would be small and members would be very loyal to their clans. **3- Religion would be simple and gory** You would expect an authoritarian religion, justifying every decision and action of the supreme deity (and in turn, the clan leader). Religious myths would include gory tales of heroes ripping open their enemies. A major aspect of the religion would be based on sins/crimes and their punishments. **4- Intelligence level would be high** Brain is the most calorie-burning organ of the whole body and pound for pound, meat contains far more calories than plant tissues. This is why predators almost always have a higher intellect level than their prey. You would expect the individuals to be quite intelligent, as compared to other species in their environment. [Answer] I'll have a crack at my own question. **Initial assumptions and justification for them.** I will be making the assumptions that tool use, and written language develop, but spoken language does not. I am basing the idea that there is no pressure to evolve speech among species that want to hold large territories. The cellular separation of lineages as distinct and not friendly in most scenarios, means that it would be less useful for communication. I am basing the evolution of written language as initially pressured by a need to encode more information when marking territory. Perhaps initially deeper claw marks suggest a stronger animal, but with tool use deeper claw marks are imitated. Marks become ornate to suggest intellect , transitioning to crude depictions of threats, and even bargains. Finally a pictorial language could begin to spread due to the the advantage it provides to any individuals that can, if not co-operate, co-exist better by making bargains. **Addressing the points of the question** **Traits of Social groups** Most people are suggesting that social groups don't exist I think they would emerge. In prehistoric times the closest analogue to a friend might be a nearby territory holder who keeps bargains, or a mate who one mates with more frequently. However since I have to explain how this species can become space faring, I'm going to paint myself into a corner by leaving society there. I propose that at some point farming is bound to emerge, with a large enough territory, intellect, and tool proficiency. It seems inevitable that at some point "farming" of prey species may begin, initially by trapping a herd of herbivores in a large area using a fence. Farming like that can provide more easily hunted prey and thus it becomes easier to raise more children. The advantage is so great that it spreads farming lineages. Adaptation to farming brings groups closer together, with less resource competition a nebulous family unit can form. Evolutionary pressure now begins to favor larger families that defend their farms. These families will eventually become too large to hold social cohesion at perhaps 5 - 20 members with intelligence it's more optimal to split by mutual agreement, but in areas with less resources, this will often be a bloody affair. At this point, trade becomes of relative value, and is a simple extension of written bargains made earlier. Communication in person via writing becomes common. Society will more or less stay as it is from this point onward. Loose knit families that communicate with others via bargaining, threats, and trade. Each to their own would be a defining attitude even within families. **Governance or lack of** Family units will have direction from the strongest members, other than that no governance can emerge **How can they become space fairing** As an intelligent trading species, ideas become a valuable thing to trade, as we leave prehistory some of the most closely guarded possessions of the family unit will be written ideas, leading initially from concepts like fires and cooking onto more advanced ideas, such as animal husbandry, better weapons, simple vehicles, advanced vehicles - you get the idea, technological progress can emerge as a trade-able resource. Better ideas would be guarded for long periods of time, and probably lead to dominance of a family in the case of significant weapons advances. Since ideas must be written theft of these ideas will be extremely valuable. Just as rocketry emerged from gunpowder one could expect the same. **Morals & Religion** As stated in the other answers, you can expect a lot of brutality, rape, and infanticide, this wouldn't really be seen as wrong. Perhaps morality would be very contractarian, owing to the initial bargains and threats of the earliest society. With the punishment for breaking a contract being a fight to the death, leading to a kind of modified contractarianism, enforceability based contractarianism, in which contracts become weaker if one party has less power. If you want to really push contractarianism, religion becomes a useful answer, if you believe the theory that religion develops to make sense of the inexplicable, and allow the weak and intelligent to control the dumb and strong, then a great big contract god in the sky who punishes those who break a written contract both makes sense, and is useful in terms of worldbuilding. **Anything else** **Why would they bother with space faring** A competitive species wasting that much effort on space? Why? On earth rockets were originally decorative, and then weapons. On this planet they would almost exclusively be weapons. Fine tuning them to be more and more effective at killing competing tribes is a good first step. As technology advances more and more time and technological ability goes spare, after all it doesn't really make sense to kill anything that doesn't threaten you, and doesn't have any resources you want As an intelligent species whilst brutal they are still going to be inquisitive. Heading for the stars is natural once they can afford it. **Further thoughts** I would love to figure out whether this species would engage in war for resources or not. I'd also like to consider what technologies are the most likely to emerge. I guess they would revolve around aggression and defense, but I am unsure. Comments appreciated on these thoughts (or anything else). [Answer] **Social Services** I would expect services like public health, public education, food/shelter assistance, etc. would be less popular and less available in this society. More predisposed to "Oh, you're a weaker family line. tough crap for you." and less disposed to "Let me help you survive". I can see this happening up to and including debtors being forced into slavery/forced labor for the higher classes. **Rigid Class Structure** I would expect this species to embrace a rigid class structure as "weaker" bloodlines are intentionally cut out of society's greatest perks, leading to ever-weakening family lines over time. The best breed with the best, the weakest breed with the weakest, leading to lower castes that literally cannot compete with the higher castes as generations of genetics plays out. Downward mobility through loss of honor/status would be far easier than upward mobility through the castes. In fact, it literally might be impossible to rise in station. But losing station would be devastating and common enough for crimes, losing face, failing in combat, etc. This may lead to inbreeding. Perhaps military service (or some other "honor path") allows lower castes to rise up, thereby bringing fresh blood into the gene pool? Maybe sometimes people challenge for the right to rise up to a higher caste, probably by combat? **Combat** I would expect this species to highly honor combat and combative arts above all others. People who are incapable of defending themselves are weak, inferior, and should be put down for the greater good. Duels and trials by combat would be a part of society or would have been up through much of their history. The military arts would be a part of the highest castes. Leaders of the society would be those born to higher castes *and who succeed as military tacticians/strategists.* There might be compulsory military service for the castes that aren't slaves. And those unfit for combat for whatever reason are probably looked down on, even if they're vital in other ways. **Honor-bound** I would expect these beings to place a great deal of stock in honor. Much like feudal Japan, where a major loss of honor might lead to suicide or death. Their society would have very strict rules about honor; how it is gained, how it is lost, how gains/losses are to be dealt with. [Answer] A society based on solitary carnivores social standing would be based on the strength of the carnivore as in most situations where solitary carnivores are in direct competition they will fight for the right to do something, e.g. mating rights or food. They would also not have family groups as most carnivores abandon their children when they get old enough to live and hunt by themselves. Some male carnivores will sometimes kill the cub if it is with the mother whilst the mother is in season. The religion would also be a violent religion and probably not have a moral code of which to live by as solitary carnivores won't meet each other enough for there to be a need for a moral code. As you don't usually get large groups of carnivores living in one place you would probably have no major form of governance because their territories are so large that the only time they live is to defend their territory or to mate. [Answer] The word *solitary* means that they don't form societies. That makes your question rather difficult to answer. Without societies you can't have governance. And morality is just one manifestation of the instinct to form societies, so you can't have morality in a naturally solitary creature. As you mentioned in a comment, creatures can in principle band together not because of any social instinct, but because of the coldly rational computation of advantage. But if that situation persists long enough to be called a society, it would be an evolutionary advantage to have a social instinct and the creatures would develop one. And then the question is about the society and morals of a species of social hunters, and we already know how that turns out. A solitary creature could perhaps develop the ability to use simple tools. It's never happened on Earth, but I don't see why it's impossible. But improving beyond simple tools is really hard without sharing ideas. An idea is lost when its host dies, unless it's been communicated to someone else. It might be interesting to think about the situation where your creatures make simple tools, use them, and then leave them behind. Other members of the species find them and can make use of them. Then, if one individual improves on the design, others might find the discarded tool and learn how to do it themselves. If this goes on long enough, major technological advances could occur. I'm not sure this really answers your question though, because I can't imagine that this would get very far before the advantages of cooperation would give rise to all the usual social instincts. [Answer] The "Starfire" scifi series makes a good pass at answering this question. Mating between mammals is always social and offspring are in the norm cared for by the parent. Ergo the vast majority of mammalian solo hunters are social when needs be. The ability to communicate consistently changes many things. The evolution of 'greater than animal' intelligence means that said animal becomes able to predict abstracted outcomes from known and speculated situations and choose to alter their behavior accordingly. It follows then that it can be shaped in any way it's reason and circumstances moves it. I'd propose that it would take (a lot) longer for such a species to develop verbose language, being as the first requisite for language is the ability for signals to be understood and that (normally) requires repetition of particular consistent signals (unless telepathy) which clearly becomes less likely with less exposure to other individuals. In fantasy and science fiction most authors (in my experience) opt for 'stoic and honorable' when 'uplifting' such species, the reasoning (when given) being much-like the "giant in the playground" big kids often learn to control their use of force precisely because they're naturally effective. If everybody has razor sharp claws, well-honed combat reflexes and teeth that turn a bite into a one-shot killing blow...violence within a community quickly becomes extinction. This gets reasoned into a species that is (within their own community) less violent and prone to risking conflict than animals that only do 1d3 nonlethal on unarmed attacks. As with Weber's 'Starfire,' many such place loyalty (and essentially chivalric values) in high regard. If we think of a timeline: Apex Predator[AP] is Apex Predator. AP intelligence expands. AP-I population expands.[Apex Predator-Intelligent] Prey populations decline. AP-I population expands to the point where offspring cannot find their own hunting territory without guaranteed conflict. Prey populations red-line. AP-I is not AP-Idiot, AP-I attempts to eradicate non-bloodline competitors to reduce load on Prey species in nearby territories. Cooperation becomes obvious benefit to AP-I. Cooperation creates (at length) and benefits from communication and regular contact. Regular contact begets regular conflict for reasons other than inbred solitary nature. [See: humans] Regular conflict begets regular conflict, social norms evolve to limit conflict. [Wars, I'd expect, would be greatly fewer than our human example, simply because the last thing a naturally solitary creature would 'evolve' is the mob mentality that wars require.] Conundrums: Faiths I could see being many and varied. Religions and social organizations though, one would expect to be rare in the extreme, at least compared to humans. It is not in the nature of this solitary hunter to follow, unlike humans it's youth and natural cycle is geared to learning how to be independent[parent to self], not how to change who you're dependent upon[from parent to society/boss/bank manager] As a result, whilst interpersonal direct relations might have more of the "I'm stronger than you" about them, they would, in my estimation, have less of the "you have established superiority and that means I kowtow." I think Starfire gets the societal structure thing kinda set acceptably though, 'King-by-another-name:' important for overall social cohesion and internal conflict avoidance. Positions-by-merit being respected by all. (As before, the capacity for damage-by-conflict is arguably the greatest protection against said conflict) ("He would have peace ought gird for war.") and beyond those it's clan affiliation and personal reputation. Essentially I'd see such a species as evolving into good conservatives, not making up a new code of ethics every other day, not pretending they're responsible for everything that happens everywhere etc etc. Charity would be a personal thing, not an imposed tax. Yanno, all good stuff :) Important: Social evolutions only really need to happen once, if they're effective and good people or society at large seems to recognize the benefits. One might say "Species x is disinclined to this" but if it occurs once and survives, it is much faster to propagate than genetics, and unlike genetic evolutions, can be raised from the dead without any more complex a technology than oral tradition. Further: We have two general reasons why a solitary hunter might remain solitary after 'uplifting.' The first is that the instinctual behavioral patterns are still strong.. that is to say that there is an actual innate physiological/neurological response that is maintained in the (now) social (to some extent) creature. The second is is potentially just as effective, and that is the sheer lack of exposure. Most animals are clumsy in new circumstances, even if the circumstance doesn't make them actively frightened or recalcitrant. Not only can this make any given social interaction awkward in and of itself, it can leave the individual with a marked distaste for repeating the experience. Social norms arise from individuals, thoughts and feelings spread. If a mother likes a particular type of social interaction, her children will learn of it one way or another and be informed by their mothers actions and reactions. Likewise, if they see their mother rejecting any social advances, they will also be informed by this. Say we have a species that has no problem at all with cannibalism, indeed it's their goto choice for population control and conflict resolution. This species' society (assuming we do not subsume those more combative traits into learned behavior) could probably be given some rules. Communication does not require close contact: Creatures whose entire psyche revolves around threat-annihilation might evolve language somehow, initially almost certainly as an outgrowth of mating rituals. Ex: Ambush arachnid language grows out of basic & then gradually elaborated 'plucking' of another individuals web. Advanced version of this could be that individuals 'lay' a communication pipe(web construct) between hunting grounds for the primary reason, rather than ease-of-use and at-need availability.. it removes any need for other individuals to encroach on each other's territory. You might end up with a species that is perfectly friendly so long as it can kinda fool it's 'lizard brain' (so to speak) by not actually directly sensing the individual provoking threat responses. Or one whose individuals constantly conspire in each other's destruction, These creatures wouldn't build cities, clearly, but likewise spiders can be equally at home at ground level or at the top of a tree...and don't much care if somespideyelse makes their web above or below them. Tool use is a really interesting problem, because the creature in some question needs not simply have the ability to make tools, but the motivation. People often mis-characterize each other with such descriptions as "likes everything to be just so..and never change a thing." but even those who this description fits most perfectly would often LOVE a thing that helps them keep things..just so..and that equals a desire for change, albeit in narrow in scope. The motivations of alien psyches are normally absurdly simplistic "just wants to eat" aliens that somehow find the time to travel across entire galaxies. Yanno... "How does (and to what extent can) socialization override inborn behavioral traits" People tend to think nowadays, despite the overwhelming scientific evidence against it..that people are much and much the same. What makes us seem more similar than we are is socialization & the shared patterns of behaviour that this creates, at least on the surface. Then you have the question of the process of social selection, that is to say that the very existence of a social context changes the weighting of previous mate-selection criteria, the strongest, hardiest hunter might be so because he is driven to dominate, to accept no equals, which naturally will create conflict in a social context quite plausibly resulting in the relatively quick extinction of that particular heritage for the very reasons that make societies in the first place..numbers do confer a quality all of their own. [Answer] Not sure if anyone touched on this but this is what I would do: I would have very defined and separate gender roles. Males would be more solitary then females and the females would be more social. I would not strip the females of "power" as is often done with races that are very war like. Instead I would have an almost maternal society where the females handled most of the "business" affairs. Most the child raising, education and health. Males would not be without their place. They would still have the highest positions in society but they would be largely ceremonial roles. This is not to say they wouldn't have power but day to day business would be seen as un-glorified and beneath their status. This would be well understood by both sexes. Most cultural heroes would be male and they would be praised and adored. There would be much competition between males. This behaviour is not uncommon in large cats. Government, The government would tend to be a collection of clans, with alliances mostly made an maintained by the females. Males would be very un-trusting of other males. There may be many secret alliances that are largely in the open but not discussed in the presence of the males. This would tend to keep the sturcture in a federation type, without a powerful central authority. Clans would be ruled by a strong older male, with only adolescent males having a place. Once males reach a certain age they would have to go out in the world to prove themselves, to gain glory and make their name. Only males that had made some sort of fame for themselves would serve in official roles. This gives you a sold base for developing education, technology and infrastructure. Which would all be dominated by females. You also have a large population of young males more then eager to wage war. So you would wind up with this confederation of clans and then many factions that were mainly just young males that go out and raid and cause all kinds of mischief. Males in this situation would be willing to work together but things like in-fighting and outright mutiny would not be un-common. Obviously polygamy would be the normal marital condition, with males of rank having access to more then their share of females. Well males of low rank or dishonor largely shunned by society. Official clan ships would be mainly ran by females with a male captain and then a strike force of marines that are males. Females would tend to be better educated and trained in specialized roles, such as engineering, medicine and science. Marines would be males of some rank in society (they could be low rank, but they would have strong clan connection) so these males would tolerate one another because of the visibility of working on a clan ship. What good is glory if no one sees it, and it would be a huge dishonor to their name to behave like some of the rogue males. They would have a strong honor component but I would not make them honor bound not to the extent that is so overdone in popular sci-fi. Young males would almost never sacrifice themselves for other young males. However they may protect females quite ferociously, there is much much more incentive there. They may behave quite different when females are present then when only males are around. There would be males of rank that would be more honor bound. But even these would be willing to break the rules if the potential glory was high enough. They would be more cautions and conservative, but the base motivation would still be there. They have more to lose so the rewards must be worth the risk. Then there would be almost a subset of the species that were young males of little or no "name". They would live to gain fame an glory. And they would be willing to do almost anything for this including things outside the accepted norms of polite society(raiding, pillaging etc..). The risk is low for them and the rewards are almost infinite. They could have an almost Jeckel and Hide feel to them, for outside races. Where females would make an alliance with an alien race one day, while males go and raid ships from that race the next. This wouldn't be condoned by the females but it would be almost like "boys will be boys" and in polite company females would probably shun this behaviour while behind the scenes they may praise it. There would be a lot of incentives for males to not get caught, and this would counter the honor thing. This fits a war like race way better then most popularized views. The strong female component would offer some moderation and stability to reach space faring levels of technology. Essentially this would give a solid base. There would also be plenty of young males ready to go to war to make a name for themselves. Males that fail or are somewhat shamed in society would provide cheap labor force, almost to the level of slave labor. For example they could secure funding for a raid and if they fail they may be imprisoned or treated as indentured servants by the sponsors, that sort of thing. So in summery, I would have strong differences between how male and females act. That's not to say that either one is the lesser of the two. Indeed females would wield more power and be a far worse enemy to have. Females would be more pragmatic, more cool and calculating. Males would be more hot blooded, more unpredictable, more eager to jump at spur of the moment opportunities (especially if they were of low rank). That's all I can come up with right now, I tend to be a bit disorganized in my thought process. So I hope it's not to hard to follow. I am just generally sick of the stereotypical "Klingon" style races. Where males are the most visible piece, females are largely forgotten and honor is everything. Thanks, [Answer] There are many *social* **exclusive carnivores** here on earth: * Lions * Hyenas * Dolphins * Orca Whales * Meerkats * Wolves Humans are also apex predators but NOT exclusive carnivores. With a 98% meat diet, the extinct Neandertal and living Inuit would be the best hominid examples of the types of early social carnivore societies that could evolve into space-faring ones. **Natural Selection and Technological Innovation** Both Neandertal and Inuit life required extreme intelligence to survive harsh environments, predict the behavior and location of very large prey animals (whales and mammoths), develop weapons, tools and strategies to take down large prey, and most importantly, work together like lions to ambush said large prey. We can safely assume that our extraterrestrial predator societies live in a very harsh environment with extreme pressure from natural selection due to climate, prey size, overpopulation, or a combination of these factors. The combination of high intelligence and extreme environments drive natural selection and rapid technological innovation. The Neandertals were likely the first to invent fur clothing, hafted weapons, and levallois technology, while the Inuit are considered the most advanced pure hunter society to have ever existed, with complex toggling harpoons, oil lamps, sleds, boats, kayaks, waterproof clothing, and sunglasses. However, a highly advanced pure predator society could not technically be considered a *civilization*, as it would lack agriculture or animal husbandry. **Religion and Morality** A high-tech hunter society would likely evolve toward agnosticism or a dark version of panentheism, as the general population would maintain a much higher IQ than individuals in an industrial agriculture society who are largely free from the pressures of natural selection. A high-tech, high IQ hunter would recognize the Universe as it is a -- hyper-violent place where we kill and eat everything, bacteria eat us, black holes eat stars and everything else, and plants feast on the ashes. The very act of hunting would probably be considered the highest form of communion with the Universe. "Morality" as such would consist mostly of a celebration of life, pleasure and adrenaline. To achieve a mass society, killing relatives would likely be frowned upon, but honor / revenge killings, warfare might be acceptable or even encouraged. Other than incest taboos, a pure hunter society would likely not have many anti-sexual morals -- nudity would be viewed as normal and natural in warm climates or indoors and both males and females would be inclined to have more than one sexual partner. In fact, to build the kind of mass society needed to cooperate on space projects, sex might serve as the primary social lubricant to reduce innate predator aggression, which is precisely what we see in huge dolphin societies that work together en masse to trap fish in "bubble nets." **Social Structure** The most striking difference between human civilization and a space-faring carnivore society might be the near total lack of the concepts of money, jobs or even employment. There would be no need for it, as the act of getting food (hunting) would be considered the highest "spiritual act" and the only accepted way to feed oneself. The crew of a spaceship would likely be an extended family -- parents, children, cousins, aunts and uncles. Survival and celebration of life, rather than profit would be the primary motivating factor for individuals. Pure hunters, especially high-tech ones, would have enormous amounts of "leisure" time (a mammoth could feed one person for 8 years). All this down time could be spent mining and processing ore and assembling tools and devices. Another prominent difference would likely be extreme gender equality with a matrilocal residence pattern (daughters stay with mothers throughout life). Although most existing human hunter societies have pronounced gender roles due to a division between hunting and gathering, in a predator society, EVERYONE hunts -- men, women and children. This is seen in all non-human carnivores, somewhat among the Inuit, and is heavily attested to in the skeletal record of the Neandertals -- both males and females bear patterns of healed skeletal fractures indicative of violent but successful encounters with large prey animals. **Plausible Technologies** It takes millions of people and lots of trade to build a single human computer or rocket (all the way from mining ore to making the billions of transistors in a single microchip). It is unlikely that our predator society would take this route -- for one, their technology would likely be more robust, understandable, and repairable (think analog and vacuum tubes). They might use balloons to raise much smaller rockets to the edge of space, then progress under solar sails. However, it is also possible due to their high intelligence, that they might skip the rocket stage of space travel development entirely and discover a form of quantum drive that could send a small ship into space with very little need for mass cooperation in raw material acquisition. They could also simply take the technology of other aliens they encounter, since they would consider them to be valid prey. The Klingons as portrayed in Star Trek: Deep Space 9 demonstrate many of the traits I have described -- groups based on extended family, lack of desire for profit, lots of leisure time and celebration of life. The Hirogen of Star Trek: Voyager best exemplify the sort of religious exaltation of hunting that such a society would possess. [Answer] Sorry don't have the ability to comment as anonymous user but this is to add on to the OP's answer. One aspect of religion that you haven't fully considered there is that groups often make gods in their own image but with greater powers (to keep everyone else in line). So perhaps this society would start believing in "The Great Hunter". A being so supreme as a hunter he/it could run faster, jump higher, than any other and always upheld their contracts. Then as extension to that, you could say that this Great Hunter was so great they could hunt legendary prey. Perhaps prey that lived among the stars (in a mythological kind of way). This would give rise to first a curiosity of whether these prey really exist and then a sort of space-race for individuals or clans/groups (as some realize they must work together to achieve something this difficult) to build something to take them to this legendary land where they too can hunt the legendary prey and/or meet the Great Hunter. I realize it seems sort of strange to base the scientific achievement off of a mythology but if you think of how many scientists were inspired by old sci-fi like Jules Verne's "From the Earth to the Moon" and others that posited we might meet something up there, it isn't that far-fetched. [Answer] Lots of excellent ideas here so I don't want to just repeat the same stuff, but I have three comments **Origin - trade and messages** Solitary, cat-like apex predators could become social starting from territory-marking behavior. Snow leopards (for example) leave scent marks on specific rocks, so that other leopards in the vicinity can know who passed by and when. This could develop into the beginnings of social behavior with [silent barter](https://en.wikipedia.org/wiki/Silent_trade) - individual A leaves something he wishes to trade at a fixed position, and later individual B comes along, takes it, and leaves behind something of equal value for A to collect later\*. This allows the initially non-social creatures to begin social contact without actually having to interact face-to-face. Written language, as you suggest in your own answer, could develop naturally from this - carvings/etchings/whatever left behind at these barter points. This would allow for sociality to begin developing. **Development - ritual** One aspect of religion and ritual that no-one has mentioned yet (as an aside, I don't really agree with the simplistic 'carnivores will have gory religions' idea) is their role in selecting behavioral characteristics. One explanation\*\* for the prevalence of painful, dangerous, and difficult initiation rites in cultures all over the world is that it artificially selects for certain prosocial traits. To pass these rituals - and so become full members of the tribe with access to the tribe's resources and the right to breed - an individual must demonstrate the ability to put the group first by withstanding unnecessary arbitrary pain and hardship. Individuals who cannot or will not do this are not permitted to remain in the tribe, and do not pass on their genes within the group. Your carnivores could develop their society in a similar way. Once they have begun to interact and show the basics of sociality, initiations and social rules that regulate breeding (directly selecting for prosocial behaviors) or access to food and resources (indirectly reducing fitness) could 'engineer' the development of more social individuals, better capable of forming he kind of society they will need to form a technological, space-faring society. **Morals and religion** Their morals and religion would therefore reflect these prosocial tendencies. Initiation rites where they restrain their temper, controlling the urge to attack when taunted by other tribe members would probably be likely, good performance leading to respect and desirability and mates. This would lead to **restraint and self-control** being morally praiseworthy personality traits. **Success in hunting and physical prowess** would, as others have suggested, be valued also. Particularly, **successful group hunting** would be valued, as this would have been the original point of social behavior and cooperation in the first place. Both **individual and team sports** would likely be an important part of culture, as these would both be skills that it would be necessary to practice. Lastly, **honesty** and **reciprocation** might develop as a praiseworthy moral virtue from the earlier practice of silent barter. **Murder** is unlikely to be as rampant or accepted as others have suggested - it wouldn't be very easy to have a complex society with unrestricted blood-feuding and murder. Instead, it is likely to be controlled and restricted by social codes; the aforementioned selecting for self-control and restraint is connected to this. It is possible/probable that murder and violence are accepted more than is usual for us though - they might be seen as acceptable reactions to socially-condemned behavior such as theft. --- \*There are refinements possible, e.g. A leaves something, B offers something, A comes back and takes B's offering if it is acceptable, or leaves it for B to add to/change \*\*The only specific reference I can think of for this is "The Science of Discowrld 2," by Terry Pratchett, Jack Cohen, and Ian Stewart [Answer] I have been pondering this one. Imagine a dragon. They hate each other and have no positive interactions with each other, although they do spy on each other and might try to steal or fight. These dragons are parthenogenetic like some lizards. They are big, smart, long lived and they fly. The dragons eat meat. One individual starts improving the habitat for prey species. It is copied by its rivals. Over time certain of these prey species become domesticated. I can imagine small, weak but intelligent prey species might seek to live in the dragon's preserve. Occasionally one might get eaten but they are small and overall life is better for them. In return these protected ones with their clever little hands can help the dragon achieve its ends. These might include fortified enclosures to fend off other dragons or weapons to fight them other than tooth and claw. The dragons rove about looking for treasure. They want to fly farther and higher. With the help of their little minions they start artificially improving their own flight abilities to go farther, faster and higher. Soon they are at the edge of space and from there, a dragon decides to make the jump to explore one of the many moons of its system. [Answer] A bit late to the party, but I my first impression is that they'll end up like John McTiernan's Predator. The critters start off solitary, hunting for survival. They meet only to mate. The female only allows the strongest male to mate with her. This prompts the males to start hunting more dangerous prey and taking trophies, as a sign of their strength. This develops into a societal sport/ rite, with gatherings being held to show off recent kills and trophies, and attract potential mates. A religious sect forms, enforcing the will of the Hunter God. Hunters bring an offering of flesh to the priests, in order to gain divine favor in the next hunt. It becomes common belief that renowned hunters join their god on the Infinite Hunt - their version of the afterlife - with the weak hunters serving as prey. Heaven and Hell rolled into one. Realizing that cooperation leads to larger/deadlier prey taken, clans form, with the greatest hunter (or perhaps a matriarch) as the leader. Competition between clans would keep them in a permanent arms race, with alliances and mergers happening out of necessity. Eventually they get bored of the prey on their world. Their prophets or scientists point to the stars as the way to find the ultimate prey (this could be sped up by a space faring alien landing on the planet). [Answer] It is incredibly difficult to envision something that is alien to us, and as a cat-owner I see every day how different cat psychology is from human psychology. So I'll instead try to extrapolate from human psychology and see where that gets us. Because "solitary" is close to "extreme introvert". I am an introvert (who sometimes forces himself to act like an extrovert). My "ideal" society would be quite solitary: 1. There would be much more "personal space" and a much stronger recognition of such. Stuff like public transport will never be invented, and boy can you forget about cities. 2. Any government system would work, actually. This does not depend on the psychology, but on practical considerations. You can justify monarchy (apex predators have a keen understanding of a hierarchy of power) as well as democracy (fighting among ourselves is contra-productive, let's discuss instead and find consensus so nobody suffers the shame of being oppressed). 3. Social groups would be purpose-driven. Solitary predators would lack the comforting aspect of grouping with others, but so do extreme introverts. When I had enough of other people, I don't want to see or hear them. I can imagine that your solitary cats would be in this state constantly, grouping together only for specific purposes that they cannot accomplish by themselves. 4. Why they would go to space? For the same reason we humans do: Because we can. Because we are curious. Cats are much more curious than humans. 5. Life and safety would have a lower value than in human society. Hunters are constantly exposed to the circle of life and death. Other than humans, your cats would not hide from this and try to stay out of it for protection, but embrace it. Human daredevils and extreme sportsmen would be considered careful and cowardly in cat society. 6. That said, **personal** safety would replace **social** safety. Solitary hunters would not expect that society looks out for them, but that you need to take care of yourself. There would be no insurances, warning labels or safety standards. This might accelerate technological process, at a higher cost of cat lives. ]

[Question] [ Generally, when you run a long distance or do something particularly strenuous, you start breathing heavily because of a decrease of oxygen in your blood. Your gasping and weezing is in an effort to replenish that oxygen that you used up while you were working hard. So let's say that there exists a suit that contains extra blood and a pump of sorts that adds oxygen and nutrients to your blood. It's basically an external cardiovascular system that constantly filters out your used up blood and replenishes it with the oxygenated and nutrient rich blood. Now you have two systems working at keeping your blood refreshed. Would this help you run farther distances without feeling winded? What would be the most effective way to incorporate this addition to your current cardiovascular system? (I was thinking lots of needles, but ickkk). [Answer] The process of getting winded is actually quite complicated! There's more to it than just oxygenation. Stanford developed a prototype to extend one's capacity for exercise. They didn't need an external cardiovascular system. [All they needed was a fist](https://www.youtube.com/watch?v=e8J6ov48rG0). It turns out that a surprisingly large amount of what makes us fatigue is temperature. Our body decides to stop exerting itself if it thinks it can overheat to the point of damaging itself. They developed a heat exchanger that work with the palm of the hand, and it showed dramatic effects for increasing our endurance. Oxygen actually has less to do with exercise than you might think. We're actually more concerned with getting CO2 out than oxygen in. CO2 levels in the blood make the blood more acidic, and that can cause serious issues for many metabolic processes. Meanwhile, hemoglobin is *very* good at its job. Generally speaking, even in extreme exercise, oxygen saturation doesn't dip below 95%. Below 90% is consider hypoxia, and below 55% is typically considered fatal (though there was some *awesome* data gathering done on Everest which showed climbers not only surviving at 40% saturation, but climbing. Just shows how much it's mind over matter!) In fact, where you really run into issues with long distance running is energy. As it turns out, the brain is a bit of a conundrum for evolution. If you put enough energy storage (i.e. sugars) in the brain, it actually spreads things out too much and the brain doesn't do its job as well. The body has to store sugars for the brain elsewhere. The solution is *marvelous*, and centers around the hormone insulin. The brain actually subsists entirely on energy stored in the liver as glycogen (the animal equivalent of starch), and the liver releases that into the blood stream as glucose to be consumed. Of course, glucose feeds other parts of the body too, like muscle. If you were running too hard, your muscles might try to rob the brain of glucose, which could be bad. The solution is insulin. All skeletal muscles and adipose tissue, which together make up 2/3 of the body's mass, are not permitted to pull glucose out of the blood unless there is insulin present. When you eat, your body recognizes that there's sugars/starches in the food, and releases insulin to permit the muscles to capture their share of it. When the food has been consumed, the body stops producing insulin, and the liver starts emitting the glucose it picked up during the feast. The only muscles that are allowed to pick up that glucose are the cardiac muscles and the smooth muscles which line hollow organs (essential for processing more food when it arrives... we also find smooth muscle lining the cardiovascular system to control blood pressure). When doing long distance running such as marathons, runners experience what is known as the "bonk." It's a wall that occurs, for most people, around the 18 mile mark. What has actually happened is that the liver only stores about 4 hours of sugars to work with, and runners hit 18 miles around the 4 hour mark. At this point, your brain starts running into trouble. It literally lacks the fuel to keep making good decisions. The muscles still have plenty of glycogen to keep themselves going, but the brain has run out! The solution is simple: a sports drink. The little bit of sugar in the drink quickly hits the blood stream and perks you right back up. In the end, a suit may not be needed at all. Enter the world of Ultra-marathoners and the infoamous the iron man triathalon. Iron man is a 2.4 mile swim, 112 mile bike ride, and a 26.2 mile run, done over the course of a day. These individuals clearly can keep functioning for long runs, but there is a limit: sleep. At some point, you have to stop running to sleep. Any run which tries to avoid sleeping is going to have new problems that aren't solved by a mere cardivascular suit. For some sense of what those look like, consider looking at the demands of the military, where making it to the correct location is literally a matter of life and death. Even there, sleep is *prized*. In the end, long distance endurance is a lot more than just oxygen content. There's a vast multitude of interconnected factors which all line up to form endurance. We are one complicated machine indeed! [Answer] I see two ways to look at this problem. You have in mind either some form of hardened suit or exoskeleton, or you're thinking of a lightweight jogging suit-style apparel. I'll discuss both of these for completeness. ## Exosuit First off is the hardened suit/exoskeleton option, which I will simply call the exosuit. The biggest problem I see with this is the weight issue. According to [this medical catalog](http://www.pemed.com/surgery/heartlung/heartlung.htm), a heart-lung machine has a shipping weight of 500 lb. (226.8 kg). Even if we supposed we could improve that technology such that the weight is reduced by half, it'd still be unreasonable to attempt to run with it. You may as well make the suit fully mechanized, which also significantly reduces the stresses on the human occupying it and increases performance. With this setup, oxygen infusion happens constantly with minimal maintenance. ## Soft Suit The soft suit, on the other hand, might be more workable. I'd see it coming equipped with a backpack of sorts that contains a power supply, a pair of small pumps, and a reservoir of [oxygen-laden microparticles](http://arstechnica.com/science/2016/10/tiny-beads-can-deliver-oxygen-straight-to-the-blood-stream/). Probably also a sensor to detect the wearer's blood oxygen level. When the suit detects your oxygen levels getting low, it turns on the two pumps, one to add microparticles and the other to remove excess fluid to offset what is being pumped in (it's not much). With this setup, oxygen infusion lasts only until the reservoir is depleted, at which point you're lugging around an extra 20 lb. (9 kg) of dead weight. ## Injection Adding oxygen to a person's bloodstream via a machine isn't an easy process. The most efficient way would be to inject directly into a major vein, such as the [femoral vein](https://en.wikipedia.org/wiki/Femoral_vein). However, doing this is hazardous to health as the femoral artery and vein occupy the same part of the body and severing either is an effective means by which to kill someone. This activity is not conducted outside of clinical settings except in emergencies. ## Conclusion So it can be done, there's existing research to support it, and it would improve oxygen-related performance, but there are significant risks that might make it infeasible. --- Additional reading: [Popular Mechanics](http://www.popularmechanics.com/science/health/a7833/no-lungs-required-injected-oxygen-to-keep-patients-alive-10087551/) [Answer] You'll not be surprised to learn the the US military has looked at exoskeletons to help soldiers on the battlefield. With current technology, the results show clearly that using the exo-legs is *more* strenuous for the soldier. Rather than easing their burden, it makes it worse! This says something pretty clearly about 3 billion years of evolution being pretty good at optimizing us, and the difficulty in improving on it. Your scenario assumes that more blood means more oxygen will be available to the muscle cells AND that the limiting metabolite is O2. I direct you to Wikipedia/Muscle fatigue for more information. You'll note that it doesn't mention O2 as a factor. So, I think your question's answer boils down to: for someone with poor physical conditioning, it would probably help a lot. For someone in excellent physical condition, it would probably help marginally. You'd be supplying more nutrients - such as phosphcreatine - and I assume removing more metabolic wastes. The question is, where do you put the shunts? Well there's two obvious choices: into the femoral artery (and vein). Gosh, you better hope nothing goes wrong: you can bleed out in *seconds* if you cut your femoral artery. The other "obvious" choice is splicing into the aorta or iliac artery (and vein). If this doesn't also sound dangerous, then you're not paying attention. It's believed that body armor has *increased* femoral exsanguination rates, I don't know why. It seems to me that *in theory* two hearts (if properly coordinated, a big if) could be better than one - and that's part of what we're talking about. Whether in real world practice, they'd be well enough coordinated is a different question. And you'd need the extra weight of the pump, filter, nutrients, control and monitoring circuitry - built in such a way as to be as efficient as a system developed (by trial and error) over 3 billion years. But let's say we grow a human heart, lungs, kidneys, liver (all no doubt genetically modified/augmented) and put them in a box on your back then hook you into them via a serious hole in your abdomen (bacterial infections, anyone?) and you get maybe double your current stamina - hey, why not triple? This begs the question: for what reason? We're not the best running animals anyway. Would you start with a Fiat 500 to design the fastest car in the world? [Answer] The main reason you feel cardiovascular fatigue when running (especially when beginning) is clearing carbon dioxide, not lack of oxygen. Your blood O2 levels are usually easily enough maintained on the inhale, what you're feeling is CO2 buildup forcing you to exhale more often. Try focusing on a stronger exhale if you're feeling fatigued when running. As others have said, low glycogen levels are probably next, and that can be in as little as 2-3 hours. And then real muscle fatigue after that. [Answer] No. Oxygen is only one factor in producing energy to run. The other is fuel. If you can't keep up the fuel level in your body (see articles on how to fuel for long distance running to avoid "bonking"), it doesn't matter how much oxygen you have - there's nothing for it to burn. [Answer] It's all about [lactic acid accumulation](https://www.theguardian.com/lifeandstyle/the-running-blog/2013/aug/30/dean-karnazes-man-run-forever)... > > As Laurent Messonnier from the University of Savoie explains, the > difference is that your aerobic capacity is a measure of your > cardiovascular system performance, while your lactate threshold is > your ability to clear lactate from your blood and convert it back into > energy. > > > Perhaps your suit can somehow offload the lactic acid so that the body's muscles can continue to perform at peak efficiency? ]

[Question] [ Joe Everybody, a modern day man with average knowledge (high school and Wikipedia) in biology, medicine and chemistry, wakes up in an medieval city. He sees a lot of sick people and remembers about antibiotics and how penicillin was discovered. Is it possible for him to rediscover and produce any antibiotics with the common technology in these times? [Answer] Checking Wikipedia, it seems that creating penicillin from the right kind of fungus/mold should be possible for your joe everybody, provided he had slightly above average knowledge about the mechanism, and was willing to first convince a few alchemists, and second spend a lot of time doing the research which fungus, where to get and how to grow it, and finally how to produce it in sufficient quantities. Of course, before that, he would need to make sure he lives long enough in an environment that is not naturally friendly towards strangers, let alone strangers that come up with very strange ideas strongly resembling witchcraft. **One more hint:** It would definitely have to be a Joe Everybody. A Jane Everybody would most likely be burned at the stake for only speaking about the idea. [Answer] Looking at the [history of penicillin](http://en.wikipedia.org/wiki/Penicillin#Discovery), the time traveller in question would need to be familiar with identifying their bacterial cultures. A lot of those bacteria are [hard to identify](http://en.wikipedia.org/wiki/Penicillium), especially because optics and lens production in Europe did not take off for a while, with the [first microscope appearing in 1595](http://en.wikipedia.org/wiki/History_of_optics#Lenses_and_lensmaking). Unless this person is really interested in molds in the modern world, he wouldn't know: 1. Penicillin mold is actually a very common food contaminant. Its [blue-green](http://en.wikipedia.org/wiki/Penicillium_chrysogenum#Science_and_history) tint helps identify it. It should also be noted that fungi play a very large role in Europe, helping preserve foods such as various [cheeses](http://en.wikipedia.org/wiki/Blue_cheese) and some sausages. 2. [Agar](http://en.wikipedia.org/wiki/Agar_plate#Types), a growing medium for molds and bacteria, is obtained from things like seaweed or even horse blood. Sounds like a good basis for witchcraft to me! That aside, if the time traveller remembers how penicillin was discovered, and remembers the two points above, the time traveller (with some experimentation) could make a miracle drug called "penicillin." The next thing to remember is [cowpox](http://en.wikipedia.org/wiki/Cowpox), a very survivable disease, immunizes people to smallpox, a *very* deadly disease. [Answer] no.. not really. it's incredibly hard to make useful quantities. In 1941 it took months for a team to create enough to treat a half dozen people. <http://en.wikipedia.org/wiki/Albert_Alexander> Purifying large quantities and avoiding contamination is also a nightmare. vaccines, or at least one particular vaccine is another matter: our Joe Everyman with only basic knowledge of the history of vaccines could fashion a usable smallpox vaccine from cowpox. All he'd need would be the puss from cowpox sores. [Answer] Judging by some recent reports [Medieval medicine was not necessarily as ineffectual as we often assume](http://www.newscientist.com/article/dn27263-anglo-saxon-remedy-kills-hospital-superbug-mrsa.html) - a modern time traveller would probably be more medically influential through basic general knowledge about the existence of germs, basic hygiene, circulation and so on. Just ensuring people have clean water and wash their hands and surgical tools would save a vast number of lives. Indeed, one of the biggest low-hanging fruit of modern medicine is simply ensuring doctors wash their hands between patients. The ability to make a specific antibiotic would probably be beyond a layman but the knowledge that antibiotics can exist and that one could be derived from blue bread-mould would give future natural philosophers a great advantage in their development. Edited to add that a highly accessible and world-changing technology would be vaccination - Jenner's approach for Smallpox was fairly simple and for people who live in the modern era it is hard to imagine what a devastating disease that was for most of history. [Answer] It depends on how much your man knows. Penicillium (the mold from which penicillin is created) is common, but it would very hard for a typical person to identify. It would also be very difficult to test without modern cell cultures. Just slapping random mold on injuries would be more likely to cause infection than to cure it. Unless your man knows one important fact -- that Penicillium is used for creating [blue cheese](http://en.wikipedia.org/wiki/Blue_cheese). If he knew that, he would likely be able to get some from cheese manufacturers. Creating oral or injectable penecilin requires advanced chemistry, but using it to create a [poultice](http://en.wikipedia.org/wiki/Poultice) would be easily done by medieval healers. [Answer] Yes, easily ... And even a lot more. Have a look [here](http://io9.com/in-case-of-apocalypse-heres-how-to-make-penicillin-in-1110902296). There are some recipes and remedies on the internet. Also I remember someone saying you can get penicillin from some bread molds. He/she could also distill alcohol and use it as a disinfectant. 60% alcohol is very easy to distill and it will give you hospital grade disinfectant. Maybe you can get your character to see a documentary on penicillin or something randomly before being teleported in time. Or maybe he watched a zombie apocalypse movie last night and people were baking penicillin in the movie. Ah, and something awesome. Maybe your character accidentally kills a nobleman who is allergic to penicillin. Just to give a bit of twists to the story. [Answer] **They probably already knew** It's highly likely that [medieval people already knew how to make antibiotics](https://en.wikipedia.org/wiki/History_of_penicillin#Early_history). They didn't necessarily know it was penicillin they were making, but the history of treating wounds and infections with molds containing antibiotic substances stretches back to civilisations as old as ancient Egypt. It's a similar case with aspirin. Although it was 'discovered' in 1899 when acetylsalicylic acid was first synthesised, people have been treating fevers with willow-bark tea containing salicylic acid since antiquity. Considering present-day hunter-gatherer's intimate knowledge of the medicinal plants in their environment I'd guess you'd have to go back a very long way before treatments are actually a new idea. **So what can we do?** That being said, local knowledge levels will vary. What you can do is spread knowledge of these existing treatments to people who don't have it. The other thing you can help with is refinement. One of the issues with these existing treatments is that their methods of application are limited. As previous answers have mentioned, it shouldn't be that hard to produce more concentrated penicillin and you can use that to treat non-topical infections. Of course, the inability to adequately enforce proper courses of treatment will probably mean the advent of antibiotic-resistant diseases a hell of a lot earlier. Not certain it's such a wise long-term decision... ]

[Question] [ I'm developing a magic system that has as its weakness or limitation the fact that the energy used in the magic is drawn from the future. I'd like the system to experience a form of "resistance" such that the more influential the magic (lighting a candle vs. stopping time) the more difficult it is to pull the energy from the future, requiring greater concentration and fortitude on the part of the caster. But the ultimate price paid for using the magic is something that occurs in the future. Magicians are tempted to use magic because the price doesn't appear to be paid today. I am trying to choose between luck, heat, and life as the sources of magic. for example: * If drawn from luck, then a small spell may cause someone to trip in the vacinity of the cast spell sometime in the future. * If drawn from heat, the area around the caster would heat up in the future, possibly causing fire or damaging crops. * If drawn from life, something(s) living near where the spell was cast (plant, animal, or human) loses life (become ill for small spells, dies for large ones). **Question:** Which energy source, drawn upon from the future, would be most believable?1 Luck, heat, or life? A good answer should explain: * How the choice would reflect resistance as more energy or power is drawn for a spell. * How the choice would create a measurable or predictable consequence turning people against magic. * How the choice would be deterministic, meaning the aforementioned consequence could be traced back to a specific action. *Keep in mind [this meta question about Magic being inherently POB](https://worldbuilding.meta.stackexchange.com/questions/5991/magic-is-primarily-opinion-based-by-definition-so-what-does-a-pob-vtc-mean). If you believe my question has fallen outside what was discussed there, please let me know and I'll improve the question.* --- 1 *Yes, yes, yes, "believable" is wholly subjective based on the reader. You all know what I mean.* --- [Answer] I'm going to agree with Flox, and say that **Heat** is the best choice. I'm going to go into a little more detail, though. Both *life* and *luck* require something to be there in the future, and are difficult to create a traceable link. There are people with poor luck that might just trip without magic, and incredibly bad "luck" happens all the time. Similarly, with creatures getting ill or dieing, it can be hard to say why they died or became ill. Additionally, there's the issue of, for some creatures, scavengers coming and removing or consuming some or all of a corpse, making it difficult to see just why it died. Heat, on the other hand? Heat works *extremely* well. Heat is well known. We know why it starts, where it comes from, and how to prevent it - and have for thousands of years. Someone walking through a forest on a misty day shouldn't expect a random patch of grass to be on fire. Someone in a building shouldn't expect to see a scorch mark on the floor. The distribution of heat can also leave a permanent mark, like a brand. Spells could create heated sigils or patterns - Something that might not be able to be spotted easily in nature, but could be seen in a more urban or rocky setting. On the other hand, heat can be harvested. Heat can be measured. This means the "Downside" of magic can be mitigated. A college of wizards can have a set of spellcasting rooms - A wizard goes in, casts a spell, goes out, and some poor page has to sit and monitor the room until the expected heat event happens (Assuming a random or unknown amount of time before the heat happens). Then it's free to use again. Some clever engineering - and continuous and scheduled magicking - and this could be used to provide, say, hot water to the facility, or even neighboring buildings if there's enough magic going on. With big enough spells, you might even be able to build steam turbines. As far as resistance goes - This is fairly straightforward. In electronics, resistors get hotter the more current you put through them. More magic makes more heat - And perhaps heat over a wider area. Want to cast a small spell? Use a small spell room. Want to cast a huge spell? Well, you'll need to use the gigantitorium designed for those spells, and there's a waiting list for that one since it's hard to build and contain. [Answer] ## "Heat", in the form of "extremes" In Asimov's "The Gods Themselves" (which you might enjoy, as it fits your themes quite well, if from a sci-fi rather than a fantasy standpoint), one character describes energy as, roughly, "what you get from levelling out extremes". If you have a source of water up high, for instance, you can get energy out of it by letting it flow down over a turbine and join the rest of the water at sea level. If you have a hot thing, you can get energy out by cooling it down; if you have a cold thing, you can get energy out by heating it up. This type of magic might draw magic from the heat *and cold* in the future. Rather than creating heat that could be used to power a turbine, for instance, a powerful spell might snuff out the fire someone was using to keep warm in the Arctic (and warm the surrounding environment by a fraction of a degree), or melt the ice that was preserving food in the summer (and cool the surrounding environment by a fraction of a degree). Basically, in this form, magic pushes whatever it draws from toward an average. So it always takes something useful (a fire on a cold night) and dissipates it into something useless (a tiny bit of heat scattered through the air). And if there's no good source of heat around, you could always invoke a bit of "life" as well. After all, a living human is much warmer (and much less "average" in many ways) than a corpse… [Answer] **Heat is the most traceable, and believable.** The Second Law of Thermodynamics states that entropy in a complete system always increases over time. Heat is a form of entropy already - in fact everything we do increases heat generally around us (even cooling something, we tend to have to make something hotter to cool something down). So this is already happening now, and it is easy to comprehend to an action today, leading to heat tomorrow, as a primary cost of your action. Furthermore it is traceable. Already, the cost of our civilisation is generating heat, it would be possible to analyse and model the state of an area and work backwards from this analysis (much like Climate Science now). Arthur C Clarke said *"Any sufficiently advanced technology is indistinguishable from magic."* In your case, actually your magic translates easily to technology and our age of convenience, if heat is the ultimate price we pay - we are paying this price today for the 'magic' of our past already. [Answer] You want to sling spells like Glarnak and the rest of em cowboy? Well this lifestyle... it really ages you... You definitely want to drain the life force of the caster on this one. If you do heat or luck, you can run into the problem of always prolonging the cost ad infinitum(cold + luck spells). The cost to perform magic should be based on the strength of the life force of a caster. The more magic used, the more the caster is aged. Incredibly strong magic users would age slower per spell cast. You could even have it so that a spellcaster could burn through all his/her life force to increase the power of another spellcaster . Like a form of magic inheritance from parent to child. ***How the choice would reflect resistance as more energy or power is drawn for a spell.*** Energy required (whether kinetic, heat, whatever) \* spell caster level (golf rules apply here the lower the value the better you are at casting ) = seconds/minutes/years/decades of your VERY LIFE. ***How the choice would create a measurable or predictable consequence turning people against magic.*** Obviously you don't want to turn to dust and turbo age yourself via spamming fireballs every 5 seconds. This system should make magic cost you and stop you from needlessly casting spells. You aren't going to use magic to pull weeds when you can literally SAVE yourself the time by not casting. ***How the choice would be deterministic, meaning the aforementioned consequence could be traced back to a specific action.*** Your magic can't rob UNWILLING life. when your magic caster is casting a spell, he/she needs to draw from there own years OR have someone use magic to transfer lifetime/magic capability. Also you can't dip into years you don't have access to. In the same way your muscles give out, if you start to lift a building of osmium, there will come a point where you age away and drop the building. [Answer] It can only be **luck**. The reason is that clever players **will** find ways to bend the rules so that the "price" they are supposed to pay is actually a second payday. So they get the spell they want and **also** a nice, free campfire in the evening. Luck is the one thing that behaves non-deterministic and thus can be used by the GM as a tool instead of being abused by players. [Answer] **Not quite luck, but organization** Instead of having a system were using magic creates a penalty in the form of random bad luck try a system that penalizes by randomly destroying organization similar to what was created in the future. Just about any use of magic could be seen as organizing something, for example light a flame and you have organized heat, build a structure and you have organized materials, stop time and you have organized time. The consequences can then follow with results that come back to what created them. The cost of a fire is that heat disperses sometime in the future, someone feels a chill or fire goes out. The cost of a structure is that other structures (or even the created structure sometime in the future) are liable to suddenly collapse. Stop time... well get ready for some paradoxes suddenly occurring in the area. This system makes it very easy for the effect to be traced back to the cause and can definitely turn people against magic based on a net neutral or net loss effect. A mage might stop a building full of people from collapsing, but would they really be hailed as a hero if the people know that another building will randomly collapse on them in the future? The same way many of the heat responses point to entropy, this too would be an entropy inducing event. Entropy is the tendency to move from organization to disorganization. The energy of an object moving in a certain direction is more organized than that object at rest with the energy converted to extra heat. Two objects at different temperatures is more organized than the same two objects with their temperatures averaged. [Answer] In my opinion you could simply have "schools of magic", that teach the manipulation of different types of energy (life, luck, heat, motion...) For example, if your mage wants to move a huge rock in one direction, some thing (or innocent passer by) in the future gets launched in the other direction with equal energy. Or if you want to light your fire with magic in a cold winter night, the spot could freeze over the next day. Why everyone hates necromancers? To reanimate a corpse in the present, life-force from the future have to be drawn in, killing someone in the process. I would post this as a comment rather than an answer if I had the reputation to do so, as it is not a direct answer to the question. [Answer] I would either use Life or Luck. In all cases, however, I would have the cost paid by the spell caster. This would prevent most casters from just throwing spell after spell, because the cost could be extreme. In the case of Life, which is my preference, the caster would age much faster than expected if he cast too many spells or too powerful of a spell. This would probably have the effect of having fewer casters because most people would say, "no way" to dying of old age in their twenties. People tend to remember the extremes rather than the averages. For example if a few times you go up elevators it takes a long time, most people will remember that rather than the much shorter average time. There is a long history in fantasy of magic being paid for by life, though usually it is the life of a deliberate sacrifice. I'd allow that, as long as it is a sentient being and the sacrifice is painful to show that it is an evil act and to discourage players from using this. My only problem is that I can't think of a game mechanic to make this a problem for the player character unless he goes to extremes. I've never had a character die of old age in a fantasy game. Either the campaign ended within 5 years game-time, or my character was killed off. The only game where my character died of old age was Traveller, and that was in character generation (yes, it is common to die in character generation in Traveller). Luck is much easier to define in game terms such that the player will understand that it is a real problem. Also, most physical magic could be defined as transferring luck around (altering probability). However, I'd also power them through future luck. Luck could also influence society more than Life. An unlucky caster in the middle of a town is a danger to everybody. I think I'm going to use this idea for my next fantasy game. [Answer] **Heat** would be the most believable. `Heat is a type of energy transfer in which energy flows from a warmer substance or object to a colder one`, which means that it's just another form of energy. So, these are some **other forms of heat** that your magic can use as its energy source: * **The total calories** stored in the caster's body from the future, from the time the caster casts the spell to the time the caster dies. For example, a caster is 20, and is going to die at 60. Let's say the caster gains 2000 kcal per day. When he/she casts spell that costs 100.000 kcal, that energy requirement is shared equally to the remaining days of the caster's life. So, each day he/she is going to lose 0.007 kcal/day \*. The consequence is the caster gets hungrier and hungrier as he/she casts more and more spells. This `creates a measurable or predictable consequence turning people against magic`. As the caster gets older, the same spell is going to cost more, which `creates resistance as more energy or power is drawn for a spell` (Although, this gives people incentive to start using magic at early age). * **Calories can be absorbed from people around him/her**. However, you need to come up with arbitrary mechanism to determine the speed at which the energy is drawn. My best suggestions are: + To base it on distance and difference in "pressure" between the caster and the object in which the desired energy is located. + To make the caster have some sort of gravitational pull. * **Matters around the caster**. E = mc^2. Energy is matter, and heat is energy. Matters around the caster simply disappear bit by bit, or get absorbed by the caster. Basically, the caster becomes **reverse radioactive**, causing cancer in people around him, forcing him/her to go into exile. **Or you can make the caster to be the one who gets the cancer**. Calculating energy in matter and radiation is not that simple, but you don't have to be able to explain in great detail how it works. * You can even only use specific matter or substance, like e.g. + **Water**. The caster gets thirstier as consequence, or the caster creates drought in the village. + **Chlorophyll**. The caster wither plants. + **Sugar**, **Calcium**, **Neuron**, or anything that **creates sickness** from the lack of it. * Or you can just use the heat. Since you are just borrowing energy from the present that you are inevitably going to return in the future, conservation of energy is maintained. So, everything "makes sense". It's also `deterministic, meaning the aforementioned consequence could be traced back to a specific action`, since this system follows a solid rule. Nothing is random. \* 2.000 kacal/day - ((((60yr - 20yr) \* 2.000 kcal/day) - 100.000 kcal) / 60yr - 20yr) [Answer] Assuming you still like luck and didn't rule it out for the reasons stated above, my answer would be *all three*. Careless beginners draw from the future and don't really know what they're drawing on. Experts learn to tap one of the sources, but the magic it provides has different flavor or limitations than the others. Gurus learn to draw on whatever they need at the time, or a mixture, to produce effects or power levels no one else can match. [Answer] Well, take a look at our modern magic of technology. It “pays the price” by drawing its energy from the past. This affects heat, and through heat also life. Using that magic on a global and pervasive scale will be climate-changing in the long run. Welcome to a new ice age ruled by wizards. [Answer] Short answer: Life Long Answer: You see life powering things is common in [fiction](http://fma.wikia.com/wiki/Philosopher%27s_Stone) and ancient [technology](http://blogs.nature.com/houseofwisdom/files/2013/01/Egyptian-slaves.jpg), so it would make sense in a non-scientific magical setting (yes I'm assuming but so will you readers). The Spirit/Soul is considered to be the life of a creature in many cultures, religions, and myths, so people will understand this and find this logical, heat and luck aren't really associated with being drained by magic spells. Also a consequence could be the same as **(Movie Spoiler Alert - Infinity War)** > > the end of Infinity War, killing half of the universe > > > or if you want to be Biblical, one third of the Earth, that would definitely cause people to turn against magic. Now think of this you can trace it back by looking at who died, the family lines of those who used the magic spells, the more powerful the spells they used the more of the people in the family lines that die. This may not get as a many as a third of the population of Earth (not sure how common Wizards are) but it will likely be at least noticeable. [Answer] **Life**, with a certain catch: the wizard casting this spell has to select someone or something alive to gradually drain its vitality. Think of this as a form of magical mortgage, with the wizard having to pay his debts in a timely manner, unless he wants the missing vital energy to be drawn from himself (rare, but not unheard of). Energy can be drained from basically all living things, including plants. It is extracted continously over time, i.e. the wizard has to concentrate on draining for months if needed. The health of the victim gradually worsens until they die. The energy which can be drained until death depends on the intelligence and general health of the victim's mind and body - i.e. humans give the most, but a pack of dogs might replace a human, and even destroying a large field of mature crops might also power some magic. However, this side effect should not be used as a weapon or herbicide spell. 1) The higher the self-awareness, the easier it is for the creatures to notice an intrusion into their minds - thoughts which are definitely not theirs. It proves surprisingly hard to extract from a creature who's simply *aware of your presence and angry at you* - which is why even uneducated peasants can repel your invasion if you don't exercise caution. 2) All creatures have some natural mental resistance which is always present. It becomes challenging to overcome when you have to break into many minds simultaneously - and you often have to do this. Wizards pay off their debts as quickly as possible. The entity from which the energy is borrowed is not a patient one. If it's not satisfied with the backflow of energy, it drains the wizard, and if the wizard runs out and dies, he's not relieved of his debt. For a single powerful spell you might have to kill off entire villages at once - full of people who will try to coordinate themselves and resist you. The natural resistance doesn't really depend on intellect - which is why draining life energy from a field of potatoes is much harder than it sounds. 3) A bond being formed is easily detectable for someone with a bit of magical knowledge. You are particularly vulnerable when using it. That's why this is never used as a means of assassination. In short: **Are powerful spells harder?** Sure. You have to fool more donors, which is like the difference between playing chess on a single board versus many boards. Not to mention the ever-increasing risk due to 3). **Does it turn people against magic?** Absolutely. Generally, mages do unpopular things which end up saving more lives than they take (i.e. stop a battle or create a river in a desert), but sometimes it's just some fireworks for a royal birthday. **Can it be traced to a wizard?** Yes and no. It's hard to determine whether a specific illness or blight is magical or not, but if you saw a distant white flash, and then your sheep started falling dead, you probably know who did it. [Answer] In a magical system, each being has a relatively conscious energetic field far greater than their body's physical space and time. In effect they are a self-directed node, in a self-aware universe. Strength and consciousness are relative to the person's degree of magical ability, whether innate or gained through practice. Mages, at the minimum, have an extended awareness akin to the nerve endings in a fingertip. They exist in a web of reverberating actions and reactions. Like a spider, they know a step here will send reverberations / exact a cost, there, there, and there. Star Trek had 3-dimensional chess. This is a 4-dimensional (3-d + time) spiderweb. Training could involve ethics. Otherwise young or unstable mages would wreak havoc in their learning stages. Generally, any person's field overlaps with others' to a degree, spanning space and time -- present, future, and past. A stray effect of a past magical act can give an unexpected shove to a current magical act, for better or ill. That's part of where luck comes in -- it could be a wild card. Sudden cold could save your life in a heat wave. Your enemy could have a drop in life force. For whatever reason, the effects of magic are weaker or less predictable on past reality. Maybe because we tend to be aimed toward the future, and the collective consciousness is a powerful force. The effects of a magical act do rebound through space time like billiard balls, with distance based on strength, and vector based on physical location, and a personal relationship factor -- family, organization, tribal affiliation, friend or foe. Life, heat, and luck play into the effects based on the intent and emotions behind the magic, but it's not predictable and there is overlap. Luck may be affected by strong interconnected strands of magical deeds, that strengthen the fundamental connections between people or groups, and help line up structure and "chance" events. One man's luck is another man's downfall. Resistance: the more complex or thickened an area of space time, the more a spell might bounce off. This would affect both the spell and the side effects. The spell would appear weaker due to dissipation, as the power actually fragmented off into multiple directions, so a mage would have to exert more effort. Robert Holdstock's Celtika has a very long-lived Merlin character who spends his magic ability very carefully, because each expenditure ages him relative to the amount of magic used. He literally loses life (and in your scenario would potentially lose heat and luck) with each magical move). [Answer] If you want to invent your own custom laws of nature, any of them can make sense. You just have to invent a set of universe with coherent laws of nature in which "life energy" or "luck" is a real, quantifiable thing. If you do this, decide on some rules that make sense and stick to them strictly. I'll write the rest of my answer assuming you mean which of the three makes the most sense assuming the laws of nature as we know them, i.e. which makes sense to someone living in the real world. **1)** It makes the most sense to expand ***heat*** to be energy in general, as the word is used in physics (i.e. not "life" or "luck"). Allow the energy to be drawn by means of a link to the future which is attached to a specific object, whether that object be internal or external to the caster's organism, manufactured or naturally occurring. Then when energy is channeled, let that energy be taken from the source that has the highest net potential energy in the immediate vicinity of the future version of the linked object. If at that future time the link is immersed in heat or light, there will be a transition to cold or dark. If the place is already cold and dark, then the binding energy in matter can be used and future objects disintegrate. The caster can't choose the time from which he draws, but the distribution of times can favor certain time frames. In other words, occasionally the time frame could be a few seconds or a few millennia, but in general it is a few years or however long you as the creator want. In the event that you want to explain this randomness, you can give some hand-wavy pseudo-scientific explanation based on over-simplified quantum mechanics. Because the effect would always take place in the vicinity of the linked object, and assuming that the caster would want to always have his amulet/wand/whatever on hand, the effects would always affect the caster's future, sometimes to the point of damaging his body or possessions. **2)** If you wanted to assume some kind of non-local hidden variable interpretation of quantum you could do ***luck*** as a manipulation of these hidden variables to affect probability. Then magic is just manipulating probabilities of microscopic natural events to get your desired event, however unlikely, to become the most likely outcome of a situation. This could require your mages to be intellectual in order to understand the inner workings of the thing they want to affect. It would also require greater focus and mental power to process the probabilities involved in larger/complex spells. If you want this to be linked to the future, you could say that this adjustment of probability makes it harder for less likely things to happen in the future, amounting to a drop in future luck (or an increase if you are trying to avoid an unlikely death). This would be believable enough for me if explained in terms of quantum effects, but I would still prefer the previous solution. **3)** Lastly, if you really *really* wanted to do ***life***, you could justify it by saying that your original mages created a "machine" that communicates with the mages and translates their commands to physical effects in the world but takes from them physical health. Then when they cast a spell they are actually communicating their desires to this "machine" which then accesses their part of the world from a distance and causes the desired effect. To me this would be *believable enough* but would sound silly, and I would be left wondering who the sadists were that thought that life would be a good currency for magic. It would also allow for mages who study the machine instead of studying spell casting to "hack" the machine and do whatever the heck they want, defeating your purpose in making magic consume life-force. Basically, the consumption of life would not be fundamental to magic. [Answer] ## You should drain heat from the future, turning it into a frozen hellscape *You should drain heat from the future, instead of generating it in the future* **The concept goes like this:** Your magician's keep drawing energy from the future, which slowly and permanently turns the future into an increasingly inhospitable ice world/frozen hellscape. As the world slowly turns into a wasteland because all the heat from the future has been drained, you create an increasingly bleak dystopian setting for the survivors. The worst part is that by the time the people in the future encounter the effects, there is nothing they can do about it. The sites of past great magic can be places that are incredibly cold and sap the heat from the environment for miles. As people keep casting in the same locations, for example in cities, those places become increasing cold and unlivable forcing people to move and make new cities. Locations where magic has been cast over and over excessively can reach absolute zero in the future; freezing to death anything that enters its vicinity instantly. After some time there is just not enough heat on the planet to sustain life. The places were magic was cast in the past are like black holes for the heat on your planet. Crops die from frost, people die from cold, and eventually life is unsustainable. Those are the stakes; Death for all. **Thematic Tie Ins:** You may notice that this story becomes a lot like the story of global warming. You can draw some thematic similarities to this. The people who enjoyed the benefits and lack of consequences in the past leave the world devastated for the people in the future. By the time of your story you can be somewhere between the golden age of magic, and the death of all that lives from cold. So in world stuck in permanent fall/early winter, there can be great attempts to limit the use of unnecessary magic and the further destruction of the world. The magic users who disregard the consequences and practice how they please can be under heavy scrutiny by the law, or even be criminals. Seems like a cool setting to me. [Answer] There is already a chosen answer to this question (which is awesome). I'd like to suggest a different avenue that could well fit into many tropes about wizards in general and also have an in game impact. **Life** is your form of resistance. Here is how I would make it work. Every spell is accompanied by a brief premonition of the spell caster's death. This premonition is the most likely death of the spell caster if he leaves magic alone. It IS subject to random events, but that death is the most likely and has about an 80% to 90% chance of coming to pass. Most of the time the fledgling spell caster will see himself as an old man surrounded by grand kids. Each successive spell moves the timeline up and the violence of the death up a notch. The fledgling spell caster might notice that instead of passing quietly, he has a heart attack as an old man, with one fewer grandchild. A wizard that focuses on generally beneficial magic will experience less increase on the violence. One who chucks Fireballs and Lightning around ups the potential level of violence. The time and violence increase with the amount of magic as well. Smalls spells don't have dramatic effects on the premonition, while great workings may take you from a late middle age heart attack to an early middle age death at the hands of an angry mob. This can have a few effects on how the wizard behaves. Ever notice that a lot of old wizards in various works of fantasy seem to be reluctant to use their power? This would explain it. They saw their death change with each spell cast, and they might begin fearing what the next vision will indicate. A younger mage that has the misfortune of seeing himself dying early might think he's got nothing to lose, and he may become reckless. Here is an example of progression as the mage learns more and more. He starts out and his first few spells work and the visions show him as a very old man. He keeps going and after a while he begins to notice how much younger he seems to be int the post spell vision after each working, and how much more ugly the death seems. At this point he will begin 'hoarding' his remaining life and magic, and may only trot it out for the most dire circumstance. Granted, this kind of resistance is not something that is felt or measured, like heat, but it is psychological. It plays into behaviors, where karma for benevolent works might be something sought and those who are reckless and interested in power may not get the idea of the consequence until it's too late. [Answer] I'm amazed this hasn't been tackled with physical laws yet. Luck does not exist. It's simply random chance. Anything which says otherwise is automatically breaking suspension of disbelief for anyone who thinks physical laws exist. More than that, *it's bad writing* because it *always* gives you a deus ex machina. Just don't. Life is less immediately clear, until you realise that old age is merely the culmination of physical processes running out of resources. The same symptoms can happen to young people, and we have a range of diagnoses for these. Old age is an accumulation of all of these things failing though, and death comes when something important finally stops. Since this isn't anything special, we have to reject "life" as an independent concept. This leaves heat. Conveniently, heat is a measure of work done. That stone you lifted with magic? The energy to do that has to come from somewhere. Not mystic energy either - raw joules in the sense we can physically measure. [Answer] One thing you could consider is having the effect in the future be the inverse of the effect in the present. If the magic makes something hotter, have the future get colder. If it makes something colder, make the future get hotter. This also gives you more freedom for stories. Having the future effect always be the same doesn't make for interesting surprises. [Answer] **Heat.** Heat is well understood and possible to quantify unlike the others. It is possible to establish rules in terms of real-world-physics so that if the author *cheats* the reader will know. That makes it more believable because the reader gets to use their sense of reason. Your main rule is the second law of thermodynamics. That is to say every action only serves to *spread out* heat and cannot concentrate heat from one place to another. For example you cannot lock onto a 200C bonfire in the future, and snuff it out in return for a 500C fireball to throw the baddies. All you can do is open a *portal* that allows heat to pass from the future bonfire to the present. You could draw enough heat to start your own bonfire then close it. The result is one big bonfire becoming two smaller ones. Bonus points if the portal is continuous rather than discrete. That means the heat from the future bonfire is not focused on the present but is *spread out* along the timeline from now to then. So you can extinguish tomorrow's bonfire in return for a thumbnail sized light that glows for a day. And you can extinguish this evening's bonfire for a torchlight that glows for an hour. In either case I think the draw of heat should be less efficient based on how far into the future you lock on. This probably means energy is not conserved (lost in the nether space) but this is slightly different from the second law of thermodynamics. You need to keep the system simple because it will interact with timey-wimey stuff and quickly get out of hand if you want it to be consistent/understandable. [Answer] If you're willing to play with the duality of Good and Evil in this setting, I would choose Luck! Consider that the forces of good and evil are omnipresent and balanced, although with slight asymmetries. Sometimes good things happen, sometimes bad. Drawing luck from the future is essentially trading probabilities- to cast a Good Spell now means strengthening the balance towards Evil an equivalent amount somewhere down the line. And vice versa. Regarding Resistance: The difficulty or resistance felt is the sensation of the timeline adjusting to the imbalance in probability. A small spell merely causes the user or someone nearby to trip and fall; that could happen at any time. A great spell, however, would require a whole host of changes to both the past and future to create the equal opposing effect, providing a strong feedback mechanism to the mage. Perhaps a greater and greater focusing of will while the timeline adjusts itself, until balance is found and suddenly the spell snaps into place. Regarding Turning People Against Magic: It'd happen quite easily, I think! If healing a broken arm causes another injury, or extinguishing a barn fire causes your animals to escape, the services of magic users would become a hard sell after awhile. You certainly wouldn't want to win a battle using magic if it meant losing another one in the future! Regarding Determinism: Perhaps not as clear cut as the other options, but rich with potential narrative value. Do the repercussions happen to the caster, the castee, a randomly selected witness, or the location itself? Is the tipping back of the scales always in kind (an injury to pay for each healing) or variable? While it may not have the mathematical order of heat, the balance of luck is fertile grounds for superstition and experimentation. [Answer] Combining all 3 together: ## Entropy [Entropy](https://en.wikipedia.org/wiki/Entropy) happens naturally and causes the decay, dispersal, and cooling of everything in the universe. When magic taps into its power, it is creating something orderly (as defined by the spell), at the cost of creating disorder in the future. It can cause... * Heat to be dispersed * Matter to be broken down * Life to be damaged * Chaos, disorder, etc. Somewhat related: [Mage: The Ascension uses Entropy](https://whitewolf.fandom.com/wiki/Entropy_(MTAs)) as one of the spheres of magic. ]

[Question] [ Many fantasy stories involve some variation of a dragon, and while there's a lot of variation in whether or not they fly, if they can breathe fire, how magical they are, etc., the strength of dragon scale is almost universal. Often, it is the hardiest material in the setting. My question is, by what (biological) means can a dragon grow scales as strong as, if not stronger than, iron or steel? Some assumptions: * Magic is not used to strengthen the scales; their toughness is all natural. * How the toughness evolved isn't all that important, so long as it's *possible* to have happened naturally. * The scales should be able to resist pretty strong forces, for now, lets say that the scales could resist basically anything a person could do with a handheld weapon. [Answer] The scales are made of the same material as [Limpets teeth](http://www.iflscience.com/plants-and-animals/worlds-strongest-natural-material-limpet-teeth/). > > A team led by Asa Barber from the University of Portsmouth collected > samples of the limpet Patella vulgata in Southampton, U.K. and found > that their teeth contain a hard, iron-containing mineral called > goethite, which forms in the animal as it grows. Furthermore, these > thin, tightly-packed fibers of goethite are encased in protein. > > > To measure the strength of this resilient composite structure, the > team turned to atomic force microscopy, a technique used to pull > materials apart at the level of an atom. Limpet teeth, they found, > have one of highest known strengths—exceeding that of many engineering > alloys even. The amount of force it can withstand before breaking > (called the tensile strength) ranged from 3.0 to 6.5 gigapascals > (GPa). That’s comparable to a single string of spaghetti holding up > 3,000 half-kilogram (1.1 lbs) bags of sugar, BBC explains. > > > This tensile strength isn't related to size so it could be scaled up with no problem. The biggest thing would be the shape: > > The whole tooth is slightly less than a millimeter long but it’s > curved, and its strength and resistance to failure (even while > grinding on rocky surfaces) is dependent on both the shape of the > tooth and the material. > > > Since teeth and scales aren't the same, they will be a different shape which could make them weaker or more prone to breaking under pressure. Which would make dragons killable, while still requiring a great deal of luck and skill. [Answer] I like [Dan Clarke's answer](https://worldbuilding.stackexchange.com/a/105793/21222) a lot. I will provide a similar one. The most common pet turtle in the USA is the [red-eared slider](https://en.wikipedia.org/wiki/Red-eared_slider).  These buggers are usually 20 centimeters long. That isn't even ten inches. Now, some mad scientists have done science to them. Here's a paper on them: [Microstructure and mechanical property of turtle shell](https://www.sciencedirect.com/science/article/pii/S2095034915301240) And it says: > > (...) They measured the mechanical properties of the bone fibers by using a nano indenter with the results of elastic modulus ∼20 GPa and hardness ∼1 GPa. > > > Which is within the same order of magnitude observed with the tooth of a limpet. The authors mention that the scutes used in the experiment have a thickness ranging from 2.8 to 4 millimeters (~0.11 inches - 0.15 inches). Now, one thing that is a trope related to dragons is that they are obscenely large. Assuming that dragon scales are made of the same material as turtle shell scutes, and that thickness has a linear\* relationship to body length... A dragon the size of a Tyrannosaurus Rex (~12 meters) would have their thickest scales (I suppose around the middle of the back) being around 24 centimeters thick. That is almost 10 inches. Ten expletive inches of turtle shell-hard material separating the atmosphere from their subcutaneous fat. Imagine trying to put an arrow through that. But let's not stop there. [Smaug](http://lotr.wikia.com/wiki/Smaug) was at least 20 meters long, so his thickest scales would be 40 centimeters thick (~1.31 feet). I remember something about chromatic dragons from D&D reaching 30 meters long sizes. Their thickest scales would be 60 centimeters thick (~2 feet). And don't get me started on the really big beasts such as D&D's Tiamat, Magic: the Gathering's Nicol Bolas and Shadowrun's Mountainshadow, which all would have their thickest scales being measured in multiple meters. \* square would be more reallistic, but the beast would be too thick to be believable. --- If you think that those scales would be too thick, making for a ridiculous creature that is more scales than anything else in mass in volume, you can taylor the scales down so that each is the approximate size of a red eared slider (as has been suggested in the comments). They would still provide an amazing level of protection. See [Valthek's answer](https://worldbuilding.stackexchange.com/a/105804/21222) - the disposition of the scales may play a more important role than their actual thickness. [Answer] In addition to what others have said, the individual scale is likely not the most important part of what makes a dragon's hide so impossibly tough. It's the totality of the hide that makes them nearly invincible. Individual scales are tough, sure, but they function mostly as a sort of shock absorber, much like how ceramic plates work in ballistic vests for our modern military. These incredibly tough scales overlap both to distribute the energy of an impact across multiple scales and to present as much material as possible for an attack to pass through. This provides the dragon with two main benefits: One: a single scale will rarely take the whole force of an impact, meaning that an attacker needs to break through several layers of scale in order to get to the vulnerable tissue below. Two: Due to the fact that the scales are layered over eachother, an attack from straight on will actually hit a scale at an angle. This means that the dragon has a natural form of sloped armor, the kind of armor we used to see on tanks. In short, because it's angled, the scale presents more material that needs to be penetrated while remaining fairly thin. Should an attack have sufficient power to actually break dragon scales, they will shatter and fracture, absorbing much of the punishment that would otherwise harm the dragon. And their fairly rapid metabolism means that broken scales will grow back over a matter of weeks. The layer beneath the scales is much more maleable, a sort of cushion that distributes blunt impacts across a larger area, reducing the potential impact, further enhancing the energy-dissipating effect of the outer layer of scales. [Answer] Dragon scales are a natural chobham armor composed of layers of organic silicate and metal deposits. While diatoms are microscopic, they do establish a metabolic pathway for manipulating silicate with organic processes. Likewise, some extremophile bacteria establish a metabolic pathway for laying down metallic deposits organically. Combine those metabolic pathways with a layering mechanism similar to that of normal crocodillian scales, and you have a beast that is literally armored like a tank. [Answer] It depends entirely on your dragons, unfortunately. There are several ways of creating desirable traits within creatures. Firstly, there is the absorbtion from environment idea. I can't quite place the source but I believe there are some creatures that do not create their own poisons but absorb them from their environment. It's not harmful to them, but obviously makes them somewhat unpaletable. This can then extend to dragons - maybe they eat unobtanium which they then pass to their scales rather than using for energy. Secondly, there's the evolutionary/creationary trope - they have evolved through environmental pressure / were given by a benevolent creator god/goddess/pasta-being the extra hard scales made of materials like the limpet teeth from Dan Clarke's excellent answer. Finally, the other alternative is they get their armour ready made from somewhere else. Maybe they have segmented armour rather than traditional scales, and they get this armour from something else (some other megafauna, rocks, plants etc). Perhaps they have rudimentary crafting abilities and melt their enemies armour into useful shapes? Perhaps they have a slave/manufacturing/master class who create their armour for them to use? This is up to you, but hopefully gives you a starting point. [Answer] If dragon scales are tough enough to deflect hand-held objects,then they would be tough because of what it would have to eat. dragons in tales hoard gold and metals along with precious jewels and such. A dragon could consume these metals, and its own natural material of keratin to provide its extremely hard and durable scales. The thesis basically is that dragons are what they eat. The weight of course could become an issue, which also could be why there is still so much gold in a dragons hoard, so the shape of the scales are important. I have no clue what shape realistically the scales shape would be, but different shapes could provide different advantages. If it was winged it could be a sleeker scale, with a more subtle triangle shape. I also think that evolution would also be key in this. Having super hard scales are advantageous, especially for fire proofing but if they fly why would they need the extra armor? The answer could be the second best predator on Earth one that can adapt to nearly any situation. Humans. If humans started hunting down dragons, then dragons are forced to adapt. Since dragons are like any other creature (even though they arent real), they evolve like any other. So if they evolved at the time of humans then it would have scales tough enough for rock slinging, then it would get tougher for stronger and stronger projectiles. This would also apply to the advancement of melee weaponry. The the three key elements could be both the consumption of metals and gems, shape, and forced adaptions to humans. [Answer] Carbon composite. Carbon is the fundamental building block of all organic materials. It is not beyond imagination to envisage some naturally evolved process that generates carbon fibres or carbon nanotubes, especially since processes to create them these days involve heat, and dragons generate plenty of that. Carbon nanotubes have huge tensile strength, but are not hard, so they would have to be mixed with some other material to create an armour. Perhaps something like enamel or keratin, but you could even throw diamond into the mix (another carbon construction created by heat and pressure). The only snag might be fireproofing it, which is probably a requirement for a dragon. Perhaps some metal could be added to the mix to conduct the heat away. ]

[Question] [ **Closed**. This question needs to be more [focused](/help/closed-questions). It is not currently accepting answers. --- **Want to improve this question?** Update the question so it focuses on one problem only by [editing this post](/posts/234786/edit). Closed 1 year ago. [Improve this question](/posts/234786/edit) With a pinch of handwavium, Clarabelle the witch causes an accident. She became permanently as heavy as an ordinary duck, while her body remained the same. Her density was forever altered. She is five feet (1½ metre) tall and weighs only 4 lb (nearly 2 kg) forevermore. Aside from never again sinking in water and having to stay away from being in the same place simultaneously with a mallard, scales, and an angry mobs of peasants, what other effects does it have on her life? [Answer] (1) She cannot go outside in the rain or wind without being blown away. (1.5) She cannot work with animals or they will throw her around like a rag doll. (2) She must be very careful when wearing clothes or lifting objects, as her light weight will affect her balance. Even holding a jar of jam at arm's length will make her topple over. (3) She should not become pregnant, unless the baby is similarly lightweight. (4) Perhaps her strength is affected and she cannot lift anything or wear clothes at all. (5) Perhaps her thermal coefficient is affected and she is super vulnerable to changes in temperature. (6) Perhaps her metabolism changes and she barely needs to eat or drink. Note combining some of the above is disastrous. For example, if she is super weak but needs to eat normal food she cannot move after a meal. If she is super weak and bad at regulating she will freeze in the nude but collapse in clothes. The most story potential is when she is super light, but normal strength. She wears heavy boots and pretends to be feeble. But there are some telltale signs her weight is not distributed normally. [Answer] The answer by Daron mentions a lot of drawbacks. But assuming that her body magically became lighter without becoming any weaker or more fragile, then there are also a couple advantages: * She can now jump very high, because her legs have less mass to move. * She will be able to run extremely fast. Even though she will have to greatly adjust her walking and running technique to exert less vertical and more horizontal force, which might take her some time. * She will be amazing at climbing. Due to the tiny amount of mass she would have to lift, she would beat the records of [professional speed climbers](https://youtu.be/85n6Kg4DQYg?t=351) without even breaking a sweat. * She can fall from any height without injuring herself, because even at terminal velocity, her body won't have a lot of kinetic energy. * She might even be able to fly under her own power by building some wings and flapping them with her arms. However, if she considers a career as a superhero, then she should be aware that she is probably not going to be a very effective fighter. Her punches will not pack a lot of weight, while she herself can easily be knocked around. Also, the above abilities will be greatly diminished when she carries anything heavy, like armor or weapons. But does she even need to engage in physical combat? She is still a witch, after all. She can defeat her foes with her magic. [Answer] # Fictionally, what she may wish to do She will probably wish to acquire lead wraps around her legs, or a lead weighted belt. They could weigh anything from 10-20 kg (enough to stabilise her in light/no wind, and take very long paces/fast gait, or carry heavy stuff), to I guess 40-70 kg (enough to have a mostly normal life). She could have multiple sets. If the weights are much higher she will overbalance. If around the ankles they move more with each step putting rotary strain on joints that is reduced if they are around the thighs or waist. # In the real world, she would have serious health problems within a short time One serious consequence not mentioned - she won't get normal body exercise because she isn't fighting gravity. Think of astronauts needing to exercise if in space for a long time, muscle mass, cardio impact, etc. Even sleeping her body just isn't working against gravity. My guess is, she won't fare well. Astronauts exercise to counter this, but even so, the effects cannot be mitigated enough to avoid a problem. [Wikipedia has an article on the effect of a space environment on the body](https://en.wikipedia.org/wiki/Effect_of_spaceflight_on_the_human_body). Most of these effects are linked to loss of the body's effective weight (microgravity) which is her problem.... > > **Overview:** Significant adverse effects of long-term weightlessness include muscle atrophy and deterioration of the skeleton (spaceflight osteopenia). Other significant effects include a slowing of cardiovascular system functions, decreased production of red blood cells (space anemia), balance disorders, eyesight disorders and changes in the immune system. Additional symptoms include fluid redistribution (causing the "moon-face" appearance typical in pictures of astronauts experiencing weightlessness), loss of body mass, nasal congestion, sleep disturbance, and excess flatulence > > > > > **Twin studies:** On 12 April 2019, NASA reported medical results, from the Astronaut Twin Study, where one astronaut twin spent a year in space on the International Space Station, while the other twin spent the year on Earth, which demonstrated several long-lasting changes, including those related to alterations in DNA and cognition, when one twin was compared with the other. > > > > > **Serious medical impact on circulation:** In November 2019, researchers reported that astronauts experienced serious blood flow and clot problems while on board the International Space Station, based on a six-month study of 11 healthy astronauts... > > > And again from Wikipedia, this time under [health impact of microgravity](https://en.wikipedia.org/wiki/Micro-g_environment) (which is effectively what your witch will experience): > > **Space motion sickness:** Despite their experiences in some of the most rigorous and demanding physical maneuvers on earth, even the most seasoned astronauts may be affected by SMS (space motion sickness), resulting in symptoms of severe nausea, projectile vomiting, fatigue, malaise (feeling sick), and headache. These symptoms may occur so abruptly and without any warning that space travelers may vomit suddenly without time to contain the emesis, resulting in strong odors and liquid within the cabin which may affect other astronauts. ....... Even when the nausea and vomiting resolve, some central nervous system symptoms may persist which may degrade the astronaut's performance. > > > Despite a multitude of studies searching for a solution to the problem of SMS, it remains an ongoing problem for space travel. Most non-pharmacological countermeasures such as training and other physical maneuvers have offered minimal benefit. Thornton and Bonato noted, "Pre- and inflight adaptive efforts, some of them mandatory and most of them onerous, have been, for the most part, operational failures." > > > > > **Musculoskeletal impact:** In addition to muscle loss, microgravity leads to increased bone resorption, decreased bone mineral density, and increased fracture risks. Bone resorption leads to increased urinary levels of calcium, which can subsequently lead to an increased risk of nephrolithiasis. In the first two weeks that the muscles are unloaded from carrying the weight of the human frame during space flight, whole muscle atrophy begins. Postural muscles contain more slow fibers, and are more prone to atrophy than non-postural muscle groups. The loss of muscle mass occurs because of imbalances in protein synthesis and breakdown. The loss of muscle mass is also accompanied by a loss of muscle strength, which was observed after only 2–5 days of spaceflight during the Soyuz-3 and Soyuz-8 missions. Decreases in the generation of contractile forces and whole muscle power have also been found > > > > > **Cardiovascular impact:** In a regular environment, gravity exerts a downward force, setting up a vertical hydrostatic gradient. When standing, some 'excess' fluid resides in vessels and tissues of the legs. In a micro-g environment, with the loss of a hydrostatic gradient, some fluid quickly redistributes toward the chest and upper body; sensed as 'overload' of circulating blood volume. In the micro-g environment, the newly sensed excess blood volume is adjusted by expelling excess fluid into tissues and cells (12-15% volume reduction) and red blood cells are adjusted downward to maintain a normal concentration (relative anemia). In the absence of gravity, venous blood will rush to the right atrium because the force of gravity is no longer pulling the blood down into the vessels of the legs and abdomen, resulting in increased stroke volume. These fluid shifts become more dangerous upon returning to a regular gravity environment as the body will attempt to adapt to the reintroduction of gravity. The reintroduction of gravity again will pull the fluid downward, but now there would be a deficit in both circulating fluid and red blood cells. The decrease in cardiac filling pressure and stroke volume during the orthostatic stress due to a decreased blood volume is what causes orthostatic intolerance. Orthostatic intolerance can result in temporary loss of consciousness and posture..... > > > Finally the [Wikipedia article on bioastronautics](https://en.wikipedia.org/wiki/Bioastronautics) is less detailed but adds that > > **Cell functioning:** Of particular interest from a biological perspective are the effects of reduced gravitational force felt by inhabitants of spacecraft. Often referred to as "microgravity", the lack of sedimentation, buoyancy, or convective flows in fluids results in a more quiescent cellular and intercellular environment primarily driven by chemical gradients. Certain functions of organisms are mediated by gravity ..... (L)ong duration space flight also has physiological impacts on astronauts. Accelerated bone decalcification, similar to osteopenia and osteoporosis on Earth, is just one such condition > > > [Answer] She'd become a world class couple figure skater. If she retains her previous strength she'll instantly break world records all over track and field, especially in all the jumps. She'll probably be a very fast swimmer, gliding over the water. She'll be a great race car driver and cyclist. She'll be a great cross country skier (but not good at downhill). She'll also be the best *single* figure skater inventing hitherto unknown jumps under the roof, etc. etc. [Answer] **She won't retain this ability for long** A human body is constantly renewed, that is, atoms enter and exit the body, cells get replaced, water lost and replenished, etc. And whatever atoms that would enter that witch's bosy will still retain normal mass. Therefore, after she'd eat (which would require her to carefully calibrate her movements, because there will be less inertial mass to move when moving a spoon from the plate to the mouth), her body will start assimilating normally weighing atoms into itself, raising its inertial mass to what was before the accident. The same applies to breathing (actually this will start affecting her right away!) and drinking. The lightweight atoms will eventually be ejected from her body by normal means. A human requires about 2 liters of water per day to maintain his water balance, also a human requires to breathe in about 11000 liters of air per day, but only about 5% of incoming oxygen is absorbed in the lungs, thus the amount of oxygen transferred into the body per day is about `11000*0.2*0.05*0.001428 = 0.15708` kg. Let's count for the witch to eat 2 kg of food per day, including water, and assume that 90% of eaten atoms actually move through intestinal barrier into the body. Thus, 1.957 kg of the body's atoms get absorbed into the witch's body each day, and in case of her not gaining body volume ("weight" for a normal human), about the same mass's worth of atoms leave her body during the day by various processes. Those atoms that leave the body will be distributed about proportionately between normal and lightweight portions of Clarabelle's body, e.g. if her body is composed of 25% normal atoms and 75% lightweight atoms at the start of a day, at the end the composition of all the atoms exited from it will contain 25% normal and 75% lightweight atoms, give or take a few. Therefore, if right after the incident Clarabelle weighed 4 lb, and continued to eat normally, after the very first day she will weigh `(1.6+1.957-(1.957*1.6/53)) = 3.498` kg or about 8 3/4 lb. The next day she will lose less than 100% of lightweight atoms, thus will gain less mass than 1.9 kg, yet she will still gain mass even if not gaining weight. This process will continue at an exponential rate of e^(-x), making her weigh half the weight before the accident after 14-15 days, three quarters after a month, and after three months she would be almost indistinctive from before all this happened. **In the meantime, however... she will suffer a set of inconveniences** First, her inertial mass will make her movements too fast, making her steps too light and throwing her lightweight body towards the ceiling with each step. If she'd just stay within her house, it won't affect her for long enough to harm her health. Yet, if she'd go outside, she can end up tossed by the harsh wind, whacked and toppled over by some thrown stones or other incoming physics, and should she somehow end up in water, everyone seeing her float like a balloon would yell "WITCH!!!". However, this could be used by her to an advantage, as she will be able to climb trees up to the very top and actually run on treetops like a squirrel, thus avoiding capture and bonfire sentence. This stage won't last long if she'd eat well, about 2-3 days and the wind would stop being a threat, for example. Second, she will have to adjust her almost-weightless body (while it is so) while holding and operating stuff like pots and buckets. For example, a 5-liter pot filled with water will be heavier than her entire body, and while pulling it out of an oven or furnace along horizontal surface won't be a difficult task, because she won't instantly get weaker, and after all she still can use her legs against that oven instead of the floor to leverage her strength, lifting it upwards will make her unstable, at least until she couldn't get her feet *under the pot*, or rather, under the mass center of her and the pot, which will be a little more than halfway towards the pot. I say this would be minor one, as her strength will no longer be spent on lifting her arms together with the pot, so instead of 15 kg, comprising of 10kg of arms and 5kg of pot, she will have to lift only 6, yet developing a proper pulling technique would take a while. Third, some interesting physics would interfere with her biology while atoms replenishment will be underway. For example, if blood water will be a tenth normal and 90% lightweight, the normal tenth will tend to sink, inducing countercurrents in veins below heart level that can potentially weaken the witch's body. Thankfully, this effect even at its hardest won't inhibit blood flow (or lymph flow) at any rate of normal/lightweight atoms distribution, because lower weight of altered blood will actually help blood system to maintain blood flow. Yet, the flotation effect could invoke various problems on small scale (intracellular effects) which I am unaware of. Overall I assume that the following month Clarabelle would experience weakness, sweating, lack of appetite and possibly fever or hemorrhaging due to increased strain on immunity system which will react on some cells performing badly. This likely won't lead to her death, though. Maybe there will be more effects, but they will likely cease after about three months, should Clara survive. [Answer] Just some fun math to wrap things up. According to <https://www.medicalnewstoday.com/articles/323446> the average, in-shape 5-ft (1.5m) person weighs 97-123 lbs (44-56 kg). According to <https://www.aqua-calc.com/calculate/weight-to-volume>, a 56 kg (taking the high end for this) person, on average takes up 0.05545 m³ of volume. Now, supposing Clarabelle weighs 2 kg, this gives her a density of p = m / V = 2kg / 0.05545m³ ≈ 36kg/m³ For comparison, * normal air at sea level is 1.3kg/m³ * water is 997kg/m³ Clarabelle is still sufficiently denser than any common gas I can find, so she's pretty safe from floating away into the sky, but not by much. She'd float *on top* of water, not really *in* it as a duck would. ]

[Question] [ I totally get why humans who have colonised a low gravity environment (Mars or an asteroid, for instance) are **skinny**. Muscles doing less work, square cube law, force output of a muscle proportional to its cross-sectional area, etc, etc. But I don't get where the trope of them being **tall** comes from? Why would biology bother to go to the effort of making longer bones, when you could save all that calcium and phosphate for something else? Like when person X is growing their bones to 7 foot tall, person B instead uses the resources to build their first baby's skeleton. So to me, a low gravity person with normal sized (but thinner) bones and the expected skinny muscles seems a far more sensible solution for natural (or artificial) selection to have produced. What have I missed? Any clues gratefully received! [Answer] Considering that all those lower-gravity environments have **artificial life support**, which (presumably) is kept at a nice, even temperature, then **if we presuppose** that the temperature is slightly warmer than what a human on earth in the natural environment experience (in other words, nobody **ever freezes or feels chilly**), then perhaps some observed phenomena come into play: * [Bergmann's rule](https://en.wikipedia.org/wiki/Bergmann%27s_rule), which states that humans (and other animals) are heavier in colder climates, * [Allen's rule](https://en.wikipedia.org/wiki/Allen%27s_rule), which states that in warmer climates body surface increases for the same mass - which fits the tall, long-limbed, slender, low-G-er well. Then, considering that food in an artificial life support environment may be a resource that is under pressure, a more efficient metabolism for a given mass may be a desirable trait: * [Kleiber's law](https://en.wikipedia.org/wiki/Kleiber%27s_law) seems to state that larger individuals have a slightly more efficient metabolic rate than smaller ones. (The graph in the article linked also has surface area in it, as per Allen's rule.) At this point I ran out of imaginative ratios to google. There might be others. E.g., in chemistry, *a couple of centuries ago* (<-- this is irony - was long, long ago at any rate), I was taught that Alpine people were shorter and stockier due to a lower oxygen level at high altitudes - but for all that you know that might simply be genetics. ==== Update on oxygen levels in the artificial habitat (thanks, Drunken Code Monkey, for the comments): seems that a slightly increased oxygen level might also lead to better endurance, bigger humans, and an increased fire risk, perhaps toxicity at a certain threshold. It seems that the partial pressure of the atmosphere is also important. See e.g.: * [Worldbuilding: What would be the effects on the human body if the oxygen level increased by a lot?](https://worldbuilding.stackexchange.com/questions/4567/what-would-be-the-effects-on-the-human-body-if-the-oxygen-level-increased-by-a-l) * [Science Daily: Rise in oxygen drove evolution of animal life 550 million years ago](https://www.sciencedaily.com/releases/2010/12/101217145647.htm) * [Arizona State University: Big insects provide big answers about oxygen](https://research.asu.edu/stories/big-insects-provide-big-answers-about-oxygen) I could still not find anything related to the height or body size of populations living in high-altitude/low-oxygen environments, although other adaptations are well known: * [Wikipedia: High-altitude adaptation in humans](https://en.wikipedia.org/wiki/High-altitude_adaptation_in_humans). [Answer] I think this may be a combination of some natural effects of low gravity and an opposite of the "Heavy Worlder" trope. For the first; astronauts actually do "grow" when spending time in Zero G. True, this is just a matter of the spine expanding a bit (just 2" or so total) in the absence of gravity, but it would be easy to extrapolate "low gravity" to "taller people". For the second; heavy gravity lends itself to a thick and short build to withstand the gravity and to make falls shorter. This would also be easy to extrapolate "low gravity" to "taller people". These beliefs both lead to tall thin light-worlders whether or not it is actually realistic. [Answer] The usual logic for such tall low-gravity creatures is that we tend to assume taller is better, and low gravity removes some very real shackles which make tallness unstable. I think one of the most fundamental advantages of such tall creatures is the ability to put sensor apparatus such as eyes and ears and noses far from the center of gravity of the creature. It takes a lot of energy to move the center of gravity of a creature, and that movement is often a commitment that predators can identify and act on. The ability to move a small sensor ball a distance, observe what the world looks like from that vantage point, and *then* decide to move is quite valuable. A related trope would be that low-gravity worlders would move slowly and gracefully. This is highly related to the extended size of the creatures. Neuron transmissions are slow. They top out around 120m/s. The bigger one is, the slower the reactions must be unless one distributes those reactions (similar to how our patellar reflex, aka the "knee jerk," is handled in the spinal column, rather than the brain). However, this trope may have some truth to it. In lower gravities, sudden movements can be more dangerous. You can shift your momentum in ways that are hard to arrest. Thus, slow graceful movements may be valid. (This forms a tail-chasing loop in movies. One easy way to make creatures feel slow and graceful is to make them very tall, because it is very hard to walk in a non-graceful way if you're tall in 1g, and most filming is done in 1g). However, if we consider fast movement for a bit, there may be an advantage to long appendiges. The further your mass is from your center, the higher your moment of inertia is (a measure of how much you oppose changes in rotation). Control over moments of inertia is key to maintaing stability in high speed low gravity environments. A spine, in particularly, is *very* good at controlling moments to cause remarkable movements. Nowhere is this more obvious than a [cat turning itself right-side-up when it falls](https://www.youtube.com/watch?v=RtWbpyjJqrU). Cats do some really clever tricks with their spine to allow them to control their rotation to a remarkable degree. A creature with long appendages, such as arms and necks could do the same. In low-gravity combat, this could be a make or break skill. [Answer] Being taller gives you a whole set of advantages: * You can easily reach to fruit produced above ground (fruits, leave) * You get a way better field of view. * Assuming your members are proportionated, you can move faster. Of course, these are offset by two disavantages: * Weight increase, which means your body constitution must be harder than that os regular humans (and again, another probable weight increase due to the sturdier constitution). And, with weight increase, a probable need of more food. * The need to pump blood to your brain. Many human who are abnormally tall die young because the heart just cannot maintain the increased stress of pumping blood to the head. Again, a solution to it (with improved heart) will need a heavier heart, a reinforced circulatory system (to support the increased pressure) with additional weight, plus the additional energetic cost of moving the more powerful heart. The combination of the pros and cons for every animal form and ecological niche will give the aproximated optimal height of the species. Now, if you weaken gravity, the cons suddenly become way less restrictive, allowing the optimal combination to result in a taller species. But in low gravity systems, those two issues are lessened, so it allows [Answer] > > So to me, a low gravity person with normal sized (but thinner) bones and the expected skinny muscles seems a far more sensible solution for natural (or artificial) selection to have produced. > > > As a general rule, increased height of humans who colonize low-gravity is produced not by natural or artificial selection but by reduced gravity. The hypothesis is that increased gravity makes people's bones grow shorter; reduced gravity allows them to grow longer. Of course, we've never tried it with an actual human being. We don't send people into space until they're already full grown. We haven't even tried it with animals. We still send them from the ground and then take them back. We don't try raising them on the space station to see what happens. It would take a long time for any slight advantages from reduced dietary resources to show up via natural selection. And you also might consider the possibility of American diets. If space is colonized by people who overeat, there is no benefit from taking fewer calories during childhood. Otherwise, everyone would be four feet tall rather than being mostly in the five to six range. Evolution isn't smart. It doesn't do careful consideration of all options. It tries solutions randomly. Any that work can prosper. That's why there can be long-necked giraffes and shorter-necked zebras in the same area. It doesn't rely on sensible solutions, merely successful ones. [Answer] First, I think writers like Niven and Smith before him found it obvious without question that a **heavy-gravity person would be short and squat**: Smith wrote of the [Family D'Alembert](http://www.isfdb.org/cgi-bin/pe.cgi?35449) starting in 1963, who were adapted to a 3G world. Later Niven (perhaps an homage) wrote of people from [a 3G world](http://larryniven.wikia.com/wiki/Jinx) a decade layer. Not only are they similarly described physically but their great strength is used a a plot point. Since the specific "3G" is also the same, I would suppose that Smith influenced Niven. Niven, in the same Universe of stories and then in related but distinct works, wrote of people either adapted to or born in *low* G. Literarily, it made sence to **make them the opposite**: people adapted to 3G are short and squat, so people adapted to [3/5 G](http://larryniven.wikia.com/wiki/We_Made_It) are very tall. Literarily, it makes sense to have people from different planets look different as well as have different cultures, just as we are used to today with diverse populations from across the globe. Other traits are chosen sometimes arbitrarily, and we suppose they may be due to *founder effect*: in Niven's example, the Crashlanders are prone to be exceptionally tall albinos. The latter is *not a developmental trait caused by the environment*! But, the traits that do take over the population might be *permitted* due to environment. Founders who had the albino gene did not find it a disadvantage because they lived underground without natural sunlight, anyway. Familial tallness was in the founding population, and was *less of a disadvantage* on the low-G world, so it flourished moreso than it would have on Earth. [Answer] To expand on Michael Richardson's answer, bear in mind that evolution only operates over huge numbers of generations. Modern humans are taller than we were a hundred and fifty years ago, and the difference is pretty much all down to better food as children <http://www.bbc.com/future/story/20150513-will-humans-keep-getting-taller>. In a lot of science fiction, the colonists have only been where they are for a few thousand years. That's still not many generations on an evolutionary timescale. However, it's plenty of time for spines to expand. It's also possible that it's easier to grow in low gravity, so people who are there from infancy may grow more than people who arrive after they have finished growing. Balanced against this, exercise is pretty important to skeletal growth. If "low gravity" means "floating off the walls", then these people will need some serious exercise regimes. [Bonus section: the effects of height on probability of reproducing are probably pretty tenuous anyway, and thus the relevant author can make it a positive or negative thing as they feel like. Not many people are likely to die of starvation, or of falling over too many times, before they reproduce. If they spend more on food, they might have less money for other things, or work more. They might tend to do manual labour more. But that has a really ambiguous effect on reproduction, likely affected by society's structure in that particular setting.] Edit: the article I linked also mentions that colonising a new place is going to be stressful and that will make people shorter. This will wear off, though, once the colony gets nice and settled. [Answer] Consider that low gravity is synonymous to "nearer horizon", for a given planetoid BMI. Or more familiarly, low gravity generally comes from smaller planets with nearer horizons. Thus giving an advantage to tall creatures with eyes as above described, not just further away from their center of gravity, but also further away from the planetoid surface enough to expand their horizon. The advantage of course may be minimized as the horizon is extends further outside the range of "clear far vision". And so the reverse consideration is that lower gravity planetoids might discourage (and reversely higher gravity planetoids might encourage) evolving to enhance "far vision", due to lesser need/benefit, for those who can already see clearly to the "nearer" horizon (or reversely can't already see clearly). [Answer] Maybe the trope about people raised in low gravity being tall is not about being tall for a particular purpose, but about growing taller because that is just how growth under low gravity works given the genetic makeup their ancestors brought from originally evolving in an higher-gravity environment [Answer] Disclaimer: out-of-universe answer: I think it's mere extrapolation of Earthen observation that humans are getting taller generation after generation. Basically we don't understand why taller is better, but our experience shows us **it is**. An intuitive understanding is that in low-gravity environment the costs of being tall are smaller, so the above trend will be exaggerated. [Answer] I kind of assumed it was a side effect of growth in low gravity... That is, normal growth represents a balance among biological and external forces including gravity, and lower gravity could allow the bones to overgrow, becoming long but perhaps fragile. But I may be crediting Niven with scientific prescience. :-) (On the other hand, the 3G build was explicitly the result of genetic engineering.) ]

[Question] [ This is a partner question to [How do centaurs get enough calories to live?](https://worldbuilding.stackexchange.com/questions/7288/how-do-centaurs-get-enough-calories-to-live) Centaurs are a common mythological figure, with the body of a man where a horses head would be. They usually exist in fantasy worlds but let's say they are not sustained by magic but instead by biological processes. This has obvious advantages in terms of speed, maneuverability, visibility, etc. There is however one obvious problem, they have the small mouth and throat of a human trying to support the energy and oxygen requirements of the massive body of both a human and a horse. How would a running centaur be able to take in enough oxygen to support the massive horse body as well as their human part during intensive exercise. [Answer] A large part of getting Oxygen is the passage the air flows through and how restricted it is. Larger noses and sinuses are very important. Horses have large nostrils and their sinuses are most of the length of their skull. Sinuses not only warm and dampen the air they also filter it to help protect the lungs from a host of possible problems. So a centaur is likely to have a disproportionately larger nose for its human body. (The Harry Potter movies have already portrayed them like this, as well as wide mouths and large teeth). So because the head can only have so much sinus it is unlikely that a Centaur will have the same top speed as a horse for the same amount of time. On top of that a Centaur is not built with the same aerodynamics as the horse and will be fighting resistance more. The Centaur would be more for power. If you add in Scott's answer with increased hemoglobin, then you could get some great sprinting bursts out of them or some other impressive feats. But they would have to recover to do them again. Kind of like anaerobic sprinting for us. [Answer] Borrow from Yaks and other high altitude adapted species. Increase the amount of hemoglobin in the centaur's blood, thereby increasing oxygen transmission and the blood's oxygen storage capacity. It would mean that centaurs could sprint for a fair length of time but not continuously: might that be why they developed archery? [Answer] Borrow from birds; Airflow through the respiratory system in birds in [a single direction](http://en.wikipedia.org/wiki/Bird_anatomy#Respiratory_system) and uses air sacs as bellows. You can dedicate the entire human torso to breathing with some sacs in the horse torso. This will require extra ribs on the human torso to support the sacs though. In full gallop the lower sacs can be powered by the movement of the front legs automatically increasing airflow. [Answer] tldr; you need to stop thinking of this as a human + horse and think of it as a totally unique animal that is neither. > > There is however one obvious problem > > > ...No, there are many, many problems. 1. Ribcages. A ribcage exists to house and protects vital organs and regulate thoracic pressure. How and why would an animal exist with two? It wouldn't. Even if somehow responsibility was shared between organs in both thoraces, there's absolutely no way to fix the problem of... 2. Oxygenation and circulation. The horses lungs are useless. The only way to move oxygenated blood to the horse extremities is by totally redoing blood flow started in the human torso. You would need much more powerful (and sizeable) lungs and blood vessels, i.e., a much bigger human torso and much smaller horse torso (since we've removed the lungs). So now we need to rethink... 3. Muscles and skeleton. Since you've now totally changes the weight distribution on the skeleton, all of that is up in the air as well. The front legs would need to be *much* stronger, which means thick bones... much thicker than even a workhorse's front legs and certainly much thicker than your femur. With such an odd gait, a centaur would be much worse at short-distance running than a horse and *much* worse at long-distance running than a human. To me, these are the most glaringly obvious problems, not to mention all the other systems in the body that wouldn't make sense. There is a reason this animal doesn't exist in nature: it does not make sense. Instead of trying to merge a human and a horse, I would suggest creating a new animal that *could* exist and *might* pass as a centaur. In the same way as a rhino might pass as a unicorn ;) [Answer] There are a few possible ways that centaurs would adapt to the increased O2 demands. * Higher utilization: Humans only use about 25% of the O2 that we inhale. We inhale 21% O2 (normal air percentage), and we exhale approx 14-16% O2. A higher utilization would support the increased demand (See next point) * Neovascularization: This is when the body grows new blood vessels into existing tissue to support increased demand. You will see this in athletes. In centaurs, it would be there from the start as they grow from colts. This would allow more blood to reach more tissue for higher demand. * Increased partial pressure - The alveoli (sacs in the lungs where oxygen exchange takes place) work on pressure differences. Blood has a higher CO2 pressure, lungs have higher O2 pressure. Osmosis flows from high to low pressure, so O2 flows to the blood, CO2 flows to the lungs for exchange. * As noted above, increased carrying capacity/volume: Humans at altitude cannot saturate hemoglobin (The oxygen binding component in blood) as well, so they compensate by producing more red blood cells. Centaurs either have more RBC's than normal, or they have adapted to be able to saturate the existing hemoglobin more. This would also support the partial pressure adaptation. * And, as always, there is the trite "Because magic". [Answer] There is an interesting example of centaurs in the first of the "World of Tiers" books by Philip José Farmer. It's been a few years since I read them, but if memory serves they have a largish torso and head allowing for a large mouth/nostrils. The lungs are in the horse body and the torso mainly serves as air-conduit. As for the eating part in the other question (placed a comment there too): Large mouth and they are carnivorous as well. ]

[Question] [ For any reason, a human heart is replaced with a pump that instead of pulses provides a continuous stream of blood. It varies the pressure, as a heart does, as needed. Ignore such technical issues as energy, immune system rejecting strange body, etc... Is that viable/compatible with life? What problems derived from this continuous blood-flow will arise? [Answer] [That’s a real thing](https://en.wikipedia.org/wiki/Cardiopulmonary_bypass#Pumps). > > The pump console usually comprises several rotating motor-driven pumps that peristaltically "massage" tubing. This action gently propels the blood through the tubing. > > > [Or](https://en.wikipedia.org/wiki/Ventricular_assist_device) > > The pumps used in VADs can be divided into two main categories – pulsatile pumps, that mimic the natural pulsing action of the heart, and **continuous flow pumps**. > > > Start reading there to learn more about them. [Answer] It is possible, indeed it is already done today, it is called a [Extracorporeal membrane oxygenation](https://en.wikipedia.org/wiki/Extracorporeal_membrane_oxygenation). But, I can't find any problem related to the continuous blood flow nor its benefits. [Answer] From what I have read in medical magazines, the exact answer is still subject to research. There are "artifical hearts" that do exactly that (inside or externally, both exist) but some have the suspicion that this kind is suboptimal for prolonged use. There are other studies that show that stem cells (and probably also other cells) react and differentiate differently whether they are under a constant or a (rather) quickly varying pressure. The details are not very well understood, but at least it is understood that if there are any risks with a continuous flow pump involved, their statistic relevance is likely lower than any other issues the patients have, so research is done in that field as many people believe those are more reliable. It should be noted that everything that is involved here is about patients with (possibly terminal) illnesses and that the artificial hearts are often used to fill the gap until a transplant becomes available. In the context of worldbuilding one might want to consider that doing this on a big scale for healthy people might have a much worse outcome, given current understanding of the human body. [Answer] I'm not aware of any negative physiological effects of maintaining a steady blood pressure, PROVIDED the pressure is around the regular average a human has today. So, for example, if a normal human has an arterial pressure between 120 mmHg and 80mmHg, their average pressure is 100mmHg. So you couldn't run your synthetic heart at 120mmHg all the time, as that would start to induce the negative changes we associate with hypertension. The higher the continuous pressure, the more negative the effects (typically increased risk of stroke, decreasing kidney function, etc). Of course these devices have lots of other complications, but we'll ignore those (the need for anti-coagulation, etc). But you have to be able to vary the pressure to some extent because otherwise in a fight or flight response (gotta run!!!) you won't be able to increase blood flow to deliver more oxygen and remove lactic acid. Plus it helps to be able to vary blood pressure when going from laying down to standing up (problems doing this is called orthostatic hypotension). So a continuous pressure heart, inherently, isn't a problem, but one that is LOCKED TO A SPECIFIC PRESSURE is. Humans vary their blood pressure through adjusting heart rate AND changing the muscular tension on arterial side blood vessels. Venous blood vessels have little to no muscular walls so they can only dilate to compensate for increased pressure or respond to the muscular action of the tissues they are embedded in. If you remove the natural heart, the replacement will have to either be manually controlled, somehow interpret the brains call for increased heart rate by increasing the flow rate and elevating blood pressure (or sense dropping oxygen levels, rising lactic acid, or whatever), or the person would be forced to regulate their activity very carefully lest they deplete oxygen and cramp up due to lactic acid build up. Here is a good technical [article](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2879422/) discussing various total heart and left ventricular assist devices and exercise tolerance. To my knowledge, all artificial heart type devices meant for prolonged use (i.e. getting out of bed and walking around) replicate or assist a beating heart. ECMO and the like are for sedated/bed-ridden patients, so exercise tolerance is not an issue. [Answer] **These already exist**. [In 2010, Dick Cheney received exactly this sort of thing](http://www.nydailynews.com/life-style/health/vice-president-dick-cheney-no-pulse-heart-pump-artificial-heart-article-1.151261); it wasn't a fully artificial heart, but it took over for his failing left ventricle, and for over a year he lived with no pulse at all. The comedians went nuts over this, but the truth is somewhat more boring: his life during this time was fairly typical for someone with severe heart trouble. After about 15 months he got a heart transplant, so now he has a pulse again. [Answer] [It is entirely possible](http://www.muscleandfitness.com/athletes-celebrities/news/fitness-model-has-no-pulse) and the subjects are still able to live a very healthy, normal life. Some, like Andrew Jones in the link, even reach extraordinary levels such as bodybuilding while still being without a pulse. It is important to note that this is usually temporary while the subjects wait on the donor list for a new heart. [Answer] Long-term continuous blood flow does cause physiological problems, but the full scope of the problems it causes is still the subject of ongoing research. Pulsatile blood flow causes a phenomenon called endothelial shear stress (ESS). I still remember a set of electron micrograph slides from medical school a few years ago comparing arterial endothelium - that's the innermost layer of arteries - which have been subjected to both continuous and pulsatile blood flow. I no longer remember the experimental details, but there is a clear difference between the two. The surface of the endothelium subjected to pulsatile flow looks smooth and healthy, the other one looks positively jagged. This jagginess causes all sorts of problems, especially the deposition of artheroscletoric plaques. Here is [a 2007 paper from the Journal of the American College of Cardiology](http://content.onlinejacc.org/article.aspx?articleid=1138282) that describes the phenomenon in detail. In the context of worldbuilding, while it certainly will not kill the subject immediately, there may be other long-term effects that we don't know about. If the continuous blood flow is the side-effect of a life-saving operation, like a heart transplant, I'd say that's not too bad :) [Answer] Taking an intuitive/common-sense perspective, with a little everyday science thrown in... The goal of the device is to match the mean flow rate (litres per minute) of a natural heart. Continuous flow will result in a certain uniform fluid velocity through the arteries, veins, vessels, and capillaries; pulsed flow will produce time-varying velocities, peaking much higher than the mean to make up for reduced velocities occurring between the pulses. Blood is a suspension; when not in sufficient motion, things in a suspension will begin to settle out. The higher peak velocities could be beneficial in preventing things normally suspended in the blood from settling out on the vessel walls, or "scouring" things which have begun to settle. The uniform velocity produced by a continuous flow device might not be high enough to accomplish this. ]

[Question] [ I'm trying to create more opportunities for roleplay in a setting where most civilized cities are along the coastline of a "new world." Most cities are fortress cities on the frontier that serves to protect other colonies. Since most of my cities have the same constraints (protection, etc), there is a risk that they'll all look basically the same. How can I design these cities so that they have more variation, so that each city is interesting and individual? What process will help me do that? [Answer] City design can be broken down pretty effectively. These are some options (certainly not an exhaustive list. **Source:** What is the city's history? Why did it form? *EDIT: And when! This is crucial to deciding the history and evolution of a city (obviously)* There are a few options here. * Fort. Often times especially during colonial land grabs, nations will set up forts along the border of the frontier or at strategic points within (rivers converging, mountain passes, etc.). * Agricultural hub. In an expansive plains type setting people need to bring goods to market so to speak. In this case perhaps a hill top, or on a riverside with a mill. * Trade route stop. This type can give you cities in places they normally wouldn't exist, deserts for example. These can form where major trade routes intersect be they land based or water based or a mixture of both. You can also get frontier cities this way with two civilizations trading, in DnD this might be a human city on the edge of an elven forest where the two meet to trade. * Landmark. This can be a holy site, a geographic phenomenon or something else that brings travelers to the location on a regular basis. Can also give you locations people may not normally settle. * Natural resource hub. Like trade locations and landmarks but more luck of the draw this can give you strange locations for settlement, but with the added possibility of ghost towns once the resource dries up. Or if its a decent location a city survives after the initial rush (see California gold rush as an example). * Planned city. These are usually the works of large nations or empires with significant wealth or a desire to civilize uncivilized areas. For a modern example look at Brasilia. **Evolution:** How does the city evolve from its source? * Naturally. Over time things develop from the center outward. Regular old evolution, this should be the most common type. * Mass Immigration. Similar to naturally only at an advanced pace. Maybe people were forced out, perhaps by another group or government or natural disaster. This changes the makeup of the city when compared to natural evolution by creating a less even cityscape. For example a large group of buildings from one set in time versus gradual growth (housing style changes) * Government sponsored. Very similar to Immigration with the exception of the source and purpose. It could just be to populate an area or perhaps to overwhelm the local natives (see China's actions in some of its western provinces and Tibet, or look at Israel's settlements in the West Bank). This can give you very mixed and potentially adversarial groups in a city. * Emigration. Growth is not the only option. Some cities may contract at times in their history. This can explain new sections of an old town. Thing fall apart when people move away and places are left abandoned. This can be due to war, disease, intolerance/oppression, migration into cities (dying farming towns). * War: *Addition!!!!* Missed an obvious one. War can obviously have drastic impacts on a city from de-population and infrastructure damage to complete and utter destruction. It can leave smoking ruins and scattered survivors. In time odds are people will re-settle the city and start building anew over the top. This can create excellent cities as they can have hidden older cities beneath them, great for a game setting. War can also have an impact on a victor's city. An influx of wealth or manpower (slaves) and returning soldiers with coin can drastically improve economic fortunes. Of course if too many soldiers die it can also have an impact on the availability of skilled labor and cause a reduction in knowledge. **Result:** Now you can mix and match to your liking. Lets say a natural resource node is found. The closest authority (city-state, nation, empire, etc) decides to create a fort to control the node as well as incentivizing or forcing citizens to go collect the resource. At the same time, entrepreneurial citizens move that direction to capitalize on the new population building up inns and pubs, blacksmiths and so on. So in this scenario you have three sources and you will have at least two if not more methods of evolution that mix and match. One last point. Cities are a system non unlike a chemical reaction. If a new city suddenly pops up like in the scenario above that takes resources and manpower away from other cities. When you are a trying to create a realistic local environment, say the size of a county with a dozen population centers (or on an even larger scale), this is important to consider. It can also provide plot points for that matter. Maybe cities are fighting over a resource location or a holy site and they create cities or forts on opposing sides of a river... how will that develop?! So this is truly a process and do not underestimate the value of a web of cities when creating a setting. Lastly, you really must have a city's history in mind, (or create it as you go when picking from the lists). Enjoy. [Answer] When I can, I like to do it in historical layers, starting with the pre-settlement landscape, and then going through the place's history of development and major events. I at least like to have a sketch of what was there at a few points in the past, so I know when and why each area was built, and what each area may have had before its current state. It makes the final state make more sense and be easier to hold in mind and work with, for me, when there is an actual history and not just a final state. It also helps me have an idea how the city is currently developing, and what is going on there. One example of how this can be nice, is houses of prominent people. Instead of just declaring a rich neighborhood where fancy houses are, I might have noted where the people in charge of the shipyards during an early stage would have built their houses, and so on, so notable houses and buildings with history refer to actual people from a certain era, and are located in places that make sense within that history. Another nice thing it creates is older industrial areas and older versions of municipal buildings that may have been replaced, or shifting road networks, etc. [Answer] **Citys grow** We don't need to discuss that, there are a few examples of planned citys but these are not the topic here. So when we assume that your city is a grown one, the question is *how* it is grown. There are various effects on the way a city grows and I want to cut the most important ones: **Economy** This aspect has multiple effects. Beside the speed, which is increased by good economy and decreased by a bad one, this also effects what kind of buildings raise and where they're locatet. For example, a miner-settlement will grow living houses beside the mines. As the settlement grows, some of the living houses will be used as shops and light crafting houses. Later there will be workshops like smiths, butcher etc. Workshops which emit smell are likely to be build in a little distance to the town. Later other workshops of this kind settle beside the other smelling workshops and even later, as the city grows, there will be no more distance between the workshops and the living houses, so even if they smell, one day they might be surroundet by houses. In my example, what happens when the coal, or whatever they're mining, is empty? Many workers will leave and the economy might collaps. But maybe they find another economy. The city might have some dacades very poor economy, thus some houses will be abondoned and colapse. **Terrain** This is surely the most important point. If the city is build nearby a river, one day they will build an harbour and like any economic facillity the houses will grow toward the harbour. If there's a natural border like a cliff, they might cannot build on the other side of that border. But later hey might be able to. **Epoch** As I already told, growing fastens and slowers ofer time, depending on the economy. This means that several buildings, which have the same purpose, are build in different epochs and look different. Best example for that is an [old town](http://en.wikipedia.org/wiki/Old_town). Also, over time some buildings collaps due bad maintenance, fire, whatever. These will be replaced when space get rare, thus there might be younger buildings in older parts of the city. Current epoch has good economy or just came out of big destruction? There might be many buildings out of this epoch. Current epoch has bad economy? Maybe they build a few houses, maybe they altered existing houses,... **Disasters** Epidemic, fire in "wood-only" parts of the city, earthquake and most destructive: war. These events often destroy wide parts of a town and kill many people. Depending on the political and economic situation this can be both, good and bad for the city in long term. For example, after WWII western germany managed become one of the leading economys in the world. Not really a city, but the issue should be the same. At the other hand, many citys get abondoned when they're destroyed (not talking about metropolises wich are rebuild in general). Disasters which destroy large parts of the city lead to the different buildings as I wrote at *epoch*. None of these points are standing on their own. Every point is effecting the others! Epoch has a strong bounding to economy. There will unlikely be a good economy over long time if the terrain is bad (no mining, bad infrastructural connection, ...) The most important point of citybuilding is: Its art! Be creative and have fun! If you don't like it you surely manage someone else who does and will help you. If you are not happy with your outcame, show it to other people and ask them for helpful critic, this issue can't be handled with general tips. [Answer] There is great advice all over this page, so I'll just add two cents worth. The landscape can make a huge difference between cities. If there is a mountain near the shore, a fortress could be set up backed against it with all of its armament pointed out to sea. An early warning watch tower could also be placed high up, and see danger approaching from further away. This could attract more seafaring trade because the port would be extremely secure. Other factors could be resource availability, natural coves or reefs, natural cave formations for secret entry/exit during a siege, a pass through a mountain range, leading to caravan travel, etc. History has been mentioned, but here are a few other questions to ask. Was a war going on when this city was built? Was the city built as a fortress to begin with, or were fortifications added to an existing city? How does this influence its design? Perhaps a fire raged through a large portion of it and so a chunk is newer/more purposefully designed than the rest. Perhaps one of these cities is (or was) the capitol of the region. Edit: One other factor: Since there seems to be a war going on, maybe one of these fortifications could be a captured city. It used to belong to the enemy, and maybe a lot of its citizens are still loyal to them. Most likely their style of building, etc. is very different as well. Instead of star-shaped forts, they built hexagons, or the architecture is informed by a different military structure. Known for their mounted soldiers? A huge stable centrally located and large portcullis at every cardinal exit. But most of all, one of the biggest things that makes a city seem different from any other is the notable NPCs living there. A brutal police force in one, a well-developed crime syndicate in another, a third where the tradesmen have unionized and basically run things. A particular noble philanthropist with a dark secret? Pride-of-the-nation citizens who keep the city clean and always have a "Good morrow" for passersby? A veteran commander turned smuggler in peace time? A well informed street urchin who can get places unnoticed? A master-of-the-'ouse inn-keep with his hands in everyone's pockets when they aren't all over the ladies? Sprinkle in characters like that, and your players will stop seeing the similarities between cities and start noticing all their differences. [Answer] Something that has not been mentioned yet is the raw materials that houses are built from. If the city is near a volcano, there will be mostly basaltic rock available, making the houses black/dark gray. If there is sandstone instead, houses will be more reddish. Limestone => white/light gray. If there are not much rocks available (mountains are far away), then houses will be made mostly from wood and clay. If you look at cities, you will see that these things are mostly not mixed. There will be one prevalent "color" of houses. [Answer] There are some good answers here already, but I notice that there has so far been no mention of climate. This is a major factor in building design, where designers might have to cope with either high or low temperature, large volumes of rain or snow, storms from the coast, high winds etc. These can all have an influence on the design and layout of a city and can add flavour to them. For example a northerly town could have highly pitched roofs so that the snow does not accumulate, or a city that is in a very hot location might have buildings with thick whitewashed walls to keep them cool. [Answer] Working a city from the ground up can be tiring, but when I need to make a city, town, village etc quickly, I generally pick something that i'm going to need; say, a particular bit of scenery, the mansion where a ball is going on, the streets where a brawl is going down etc, and build the city out from that. Unless the players are going to explore every part of the town, you can save effort by conserving details to just the ones you'll need right now. It takes a lot of the effort out of the whole thing, and you can ensure your cities are differentiated because you just don't put the same scenery in every one. [Answer] Definitely think about the fact that the cities would have originated in different times, expanded at different rates, and had different raw materials available. The difference in timing allows for a significant amount of variation as the most practical solution to problems would change as tools are developed. Cities that expand slowly are more likely to be carefully planned and built to quality moreso than shantytowns that evolved into city. A desert city is more likely to have buildings that incorporate mudbricks and sandstone whereas a city near a forest is more likely to incorporate wood. As a bit of added flavor consider climate variation. Climate varies as you travel along a coast. This leads to things like San Diego and Seattle architecture being different. [Answer] This seems like an unlikely setup. The full growth of a city requires a certain amount of security. A Fortress City on a border has defense requirements that stunt its full growth, as everything needs to fit in the walls all the time. A city deeper in, away from the border but connected by roads to several forts can grow faster at need and the populace can be more confident they won't all die. It also seems odd that these border cities are also on the coast. This means there is no protected farmland to grow food for them. In reality you would have port cities on the coast, and smaller forts distributed inland to give a secure border for the land. There might, or might not be cities in the middle, depending. [Answer] Something that hasn't been mentioned yet: think of the city's part in the larger political landscape. You might, for instance, build on the idea of the warring city-states of early Italy, the single capital dominating a culture, or the artistic centre resisting the tyrannical capital. How does the city maintain its power, its independence, how does it attract its trade? The nice thing is that **you can treat your cities as characters**. This lets you take all the tricks you have for developing characters and letting characters interact, and apply them to cities. Think of your city as a dominant dictator, a free-wheeling artist, a crafty merchant and work from there. (These are pretty one-dimensional, you can take it further, of course.) The choices you make can be reflected in the architecture, the monuments, the layout of the streets, the division into districts, etc. Try to look at existing cities, and see how their history and character has shaped their appearance. [Answer] Real world cities look different because * they are located in different geographies * serve different functions * where founded at different times If cities all have the same geography, the same function, and are founded by the same people at the same time, ### they will all look the same Roman forts are an example for such similarity, and American cities, most of which have been founded roughly at the same time, look very similar to each other, too. [Answer] [Open culture](http://www.openculture.com/2019/04/the-medieval-city-plan-generator.html) recently pointed to "[The Medieval City Plan Generator](https://watabou.itch.io/medieval-fantasy-city-generator): A Fun Way to Create Your Own Imaginary Medieval Cities", a free online tool to create maps of would-be medieval cities. Depending on one's inclination the generated can be used directly or taken as a "random seed" for one own's design. For some applications the quality of the maps might be sufficient. Other than the lack of terrain features - with the exception of a coast line and a river - the maps look rather convincing to the casual viewer (which of course the crowd of WB.SE is not...). As of writing this answer you're free to use the result of the generator: > > You can use maps created by the generator as you like: copy, modify, include in your commercial rpg adventures etc. Attribution is appreciated, but not required. > > > [Answer] Cities (Towns would fit your setting better I think) in roughly the same area will always look kinda the same. They will have the same building-materials and proably the same culture and overall architectural style. What makes the difference are geography wealth and landmarks. **Geography:** One town may be cramped between a mountainside and a river. Another one may be a port-city and another one sits in a swamp and is mosquito-stricken for most of the year.(This won't make it look different but it will still give a different atmosphere to it) **Wealth:** A rich town will have feature large buildings which will be highly decorated and well-kept, while a poor town is dominated by simpler buildings. **Landmarks:** I think the most defining feature of a town is probably it's landmarks. Is there a mighty castle that overshadows it? Or has it a very high church tower that can be seen from far away? Or maybe one of your towns has a very large gatehouse. Or the warehouse of a rich merchant?. Why would a modern tourist visit that city ]

[Question] [ [Blackdamp](https://en.wikipedia.org/wiki/Blackdamp) is the condition where the breathable oxygen is removed from the air underground. Causing asphyxiation in humans and humanoids. Normally seen in modern day mines. The base area of the dwarven fortress is almost mined out and the dwarves are looking to other places to expand their empire, the idea is to go down, but they started to struggle with breathing so the dwarves goes to the drawing board. * How could the dwarves achieve the airflow needed with no better (but preferred worse) technology than Mr. Leonardo Da Vinchi could achieve? ps. Changing the dwarven physiology to being able to breathe in low oxygen conditions is not a viable solution since later on human dungeon crawlers should have the possibility to investigate the maybe dwarven ruins. [Answer] If you think about traditional fantasy dwarves - and you should if you insist calling them dwarves - the most distinctive thing is not really that they live underground or that they are short. The distinctive thing about dwarves since the Norse sagas is their single minded focus and supernatural ability in metalworking and artifice. So every dwarf worth the name knows something about metalworking and every dwarven habitation is built around its forges. Presumably those forges and the fires that burn in them would have deep religious meaning to the dwarves as well. How is this relevant to the question? Every forge (or other fireplace) needs a chimney to get rid of the smoke and create air flow to feed the fire. Basically the air heated by the fire rises up the chimney taking the smoke with it and this creates an under-pressure that sucks fresh air to feed the fire. With a long already hot chimney this can be quite powerful. Just the thing dwarves will want for their religiously significant forges. But how is this relevant to the **actual** question, you ask. The air sucked by the fire places will come from the dwarven habitation built around it. This creates an under-pressure inside the entire complex. Which means that if you have a ventilation shaft to the surface the fresh air will be sucked in. So as long as those fires keep burning it is enough to open new ventilation shafts when you expand the complex. Which is pretty good reason for the dwarves to consider those forges important. And place them near the center or, more precisely, for the complex to grow around them. Also the number of forges and fires will naturally scale up as the dwarven population - and need for ventilation - goes up. And the sufficiency of available ventilation can be seen simply by observing how well the fires burn. Something that any dwarven smith will pay attention to. Note that if the vertical shafts of the chimneys are heated by sun you'll get some of the energy for free resulting in better ventilation and hotter fires without using extra coal or wood. The easiest method is to use a cliff facing towards the equator to place the shaft. But simply keeping the fires always burning should be enough to keep the chimneys warm. [Answer] Have airflow tunnels to the surface! The basic idea is that the airflow tunnels are paired off, one of them being cooler than the average air in the mine, one being hotter. You can achieve this with furnaces, geothermal springwater (if you're lucky) or concentrating sunlight down the 'hot' shaft. You can also put the 'cool' shaft near to a water source or river, or possibly even just higher up in the mountains depending on climate and mine building ability. Then the air in the hot shaft rises, the air in the cool shaft sinks, and the whole thing drags fresh air through your dwarven kingdom without needing to have people man the air pumps. These tunnels also offer handy egress passages in case of catastrophic collapse (not that a dwarf would ever make a mine that might collapse)! One thing to note with this method is that you have to be careful about which doors can be opened when to prevent parts of the mine from becoming cut off from the airflow. Your dwarven miners might have to build in a series of airlocks between different airflow sections in order to avoid one tunnel getting all the fresh air (which also gives you handy 'this is the end of this section, take a short break' markers). Also worth pointing out that the airflow tunnels need capping to avoid rain (or goblins) getting into the mine! And a nice [link](http://www.nationalarchives.gov.uk/education/victorianbritain/industrial/) with a copypasta section below: > > Ventilation became a serious problem as miners went deeper and deeper > underground. The earliest solution was digging a down-shaft and an > up-shaft. At the bottom of the up-shaft a fire was set ablaze, which > sent hot air up the shaft. This in turn sucked fresh air into the > down-shaft. To make sure that the fresh air reached all parts of the > mine, trapdoors were put in all the galleries of mines, which were > opened and closed as the coal trucks passed through. This ensured that > there was a constant supply of air throughout the mine. The trapdoors > were opened by small boys (trappers), whom sat in total darkness > listening for the sound of the corves (coal trucks/sleds). > > > [Answer] Another possible idea that could compliment the idea of having massive furnace systems for improved air flow is...biology! The dwarves through their knowledge of earthly magic and minerals could have figured out how to grow biologically engineered plants that not only survive in low light conditions, but will also absorb massive amounts of CO2. Imagine a massive, twisted vine-like structure growing out of some of the cave walls. For absorption of CO, perhaps a plant similar to chlorophytum comosum or the "spider plant" would be used. Also, the dwarves could have used these plants to their advantage to search for aquifers by following the roots. Of course, those plants would have also been modified so that they grow within relatively short time intervals (perhaps like bamboo). [Answer] You could just pump air down. Harness some oxen up to a really big bellows and constantly push fresh clean air down through specially cut channels, or even through tubes made of wire and oil cloth. Edit: The bellows could be as big as you'd like, and if you had several large bellows working in series you could keep the air flowing constantly. Ville Niemi's answer of having ventilation shafts letting cool air down and furnaces lifting hot air up is probably best for the established areas of the mine, but in new passages where ventilation hasn't been dug you'd want to have a way to push good air in reliably. For very deep mines, you have to watch out for auto compression (air heats up when it is compressed, and dropping deep into a mine will compress it, causing you to get negative cooling from the air), meaning that airflow should be kept to just what is needed to remove dust and gasses in those cases. Just something to consider. Edit 2: So, your biggest problem is not going to be bad air. It is going to be cooling. The temperature of a mine rises 25 °C per km of depth (1 °F per 70 feet of depth). Add to that the problem of auto compression, which you'll face in either a forced air system or naturally circulated system, and it is going to be hot once you go down a ways. The bellows wouldn't have to be excessively big, because the more air you push down, the hotter it will get. Meaning you only want just enough to keep the bad air down and help manage the mining dust. Refrigeration accounts for about half of the energy usage in modern day mines, and while there are some low power methods, like [ice cooling](http://www.mining-technology.com/features/featureice-cooling-takes-the-heat-off-at-harmonys-phakisa-gold-mine-4454482/), you have to have access to ice. There might be other ways, depending on where your mine is. For instance, if your mine is high in the mountains, then it could be really really deep, and still have drainage for an underground river, which could be used as a heat sink, and could allow for ventilation too. Another way would be to have stages, with another set of bellows every half KM down, and another set of bellows where air is drawn back up with a reverse bellows; hook the air intake on the bellows to an air duct deep in the mine, and every time it blows to a higher stage it will draw air up from below. The de-compression and low pressure caused by this would cool the air down below, and hopefully balance out the auto compression, while also helping pull heavier bad air out. [Answer] Why not use fans? The first record of axial fans goes back to 180AD and a Chinese inventor named Ding (or Ting) Huan. Leonardo da Vinci doodled helicopters so there's no doubt that the notion of axial fan blades producing airflow would be understood at the level of technology you're talking about and given the usual depiction of Dwarves as master craftsmen they should be able to construct high quality, large fan blades. The question is how to power them and here the most obvious answer would seem to be livestock combined with drive belts or perhaps operated alongside chain or rope driven mechanisms to lift material out of the mines This approach could be combined with the excellent convection based ideas outlined by Ville Niemi and others to ensure that air is brought to every part of the mine or used on their own. I would think that you'd need both fans pushing air in and fans pulling air out for best flow [Answer] Sadly, my suggestion is a real material. 'Tuff' or 'tufa' is a mineral formed by compacted volcanic ash. It is so light and porous that it can float on water. It also has the habit of absorbing methane. If your dungeons are carved from tuff, rainwater would tend to percolate down from the surface; you'd need drains to get rid of excess water. But the water would also draw fresh air from the surface and absorb methane trapped in the tuff. A complete article on tuff is found [here](https://en.wikipedia.org/wiki/Tuff). ]

[Question] [ ## A society grows with time, but does the technology needs to grow with them? Is it possible for a planet to have a very large population and much society but no more improvement in the ways of the society? Like all scientists are on vacation, for ever? Is a permanent state of stable stagnation possible? What factors needs to be terminated or set? Below is an example of what I'm looking for - but without the *stupidity* [Trailer Idiocracy](https://www.youtube.com/watch?v=BBvIweCIgwk) In this - thankfully fictional - movie, all development stopped because only the Stupid reproduce. So society lost its interest in advancing. For Religious answers - what would be the reason to stop them from evolving? I recall the Amish who are nice people that make great discussions about what new technology is ok for them. Or like the Jews who do not use electricity on the Sabbath. (if I recall that fact right) [Answer] One possible reason for a large population to stagnate technologically could be ideological / cultural beliefs. Something akin to the Amish mentality of rejecting labor saving technologies. This wouldn't prevent individuals from discovering new technologies (either through determined effort or naturally / accidentally), but it would make the pursuit and use of them taboo. As far as if it could be a permanent state of stagnation - it would be dependent on the strength and acceptance of these beliefs by the society at large. The beliefs would have to be broadly accepted / enforced and carry enough inertia to to maintain their strength over generations. [Answer] Some countries experienced technological stagnation in the past. China is a good example : it was really advanced but it falls behind during the Qing dynasty . 1- The Empire dominated the region with satellite countries like Japan and Korea. Being the best they saw no advantage in improving science much. 2- Many eastern countries where reluctant to establish relations with the Europeans, especially the Japanese because they did not like the Christian missionaries. They more or less closed their borders to strangers. 3- China had a rigid structure, social and politic. Confucianism, emphasis on hierarchical relations inside the society and is doing well in maintaining order. But at some point, this with other factors like corruption is making people reluctant to change things, reluctant to take risks. Why would they need to take risks, they dominate the world after all! 4- The lack of incentive for innovations looks like a good answer. I saw a documentary about shark not long ago. The have been dominating the seas for the past 400 millions year or so? And yet their brain is about the size of my thumb. Physically, they haven't evolved much during this time. Because they don't need to. The evolutionist explanation is that an individual with different characteristic such as a bigger brain/more intelligent, gains no advantages since they already dominate. Having no advantage, the genes mixes with the rest and disappear. It was just an isolated case. WE could apply the same logic to states. With dominance, they have no reason to evolve. \*The only problem with China and others as well : by the time they realize they are technologically backward, it's too late. * I admit: I play a lot of strategy games. In the beginnings, your state is small and you fear the neighbors. You start modernizing the country, invest a lot. You go to way with others, taking huge risks to secure your border or to grab more land. Eventually, your strong enough to keep others states at a distance. Your safe now, you don't need to take more land, you don't need an efficient economy. I do become lazy at some point. In Victoria 2, playing as Russia: I created a series of satellite states in eastern Europe. I fought many way to achieve that. The first thing the Bulgarian did after their independence from the Turks was to declare war to Greece. I can't blame them if they don't feel secure. I just blamed them because they are dragging me into a war with Greece. Yes my army is much stronger but what's the point in gaining more land for me if I'm the strongest country in the region? I'm not helping Bulgaria, that's what I mean by being lazy. [Answer] > > A society grows with time, but does the technology needs to grow with them? > > > Not necessarily. Often utopias/distopias end up in this sort of state. The society has "achieved the end goal" somewhat and from an external sense has stagnated. > > Is it possible for a planet to have a very large population and much society but no more improvement in the ways of the society? Like all scientists are in vacation for ever? > > > Yes, but it is preferable to answer the *why* scientists don't advance society. Maybe there is no need, whether real or perceived. Maybe there were historic events such as a global war which caused the advance of technology to have cultural taboo. There are a lot of factors which could result in this sort of societal state. In addition to external factors, it could be societal norms - perhaps religion or fear of something. [Answer] While it is possible for society to technologically stagnate, it is unlikely for it to reach a large population after that stagnation since large scale agriculture requires some technology. If you really want a large population there must be some event in the society that stops further advancement. The two major contenders for a modern society are a catastrophic event like a meteor or major volcanic eruption that forces all the population of the earth back to food production and destroys the major constructs and our ability to use our current scientific instruments. The other way this could occur is if we run out of energy, primarily fossil fuels before renewable resources are able to take the burden. This too could drop society back to the point where we want to continue to explore the universe, but without the necessary power we can't make any further progress and are stuck trying to survive. Alternatively, instead of losing energy your society could progress to the point where further research is so expensive in times of money or energy that progress can not continue. More unrealistically, in your world you could decide that your society has actually discovered everything there is to know. This is a bit of a cop out in my opinion but is an option for your world depending on how it is set up. There are other options based on culture and other personal forces. Your society could decide that they have reached the pinnacle of scientific advancement and stop funding further development or actively ban/discourage it. Religious tensions can also add to this by putting a stop to "meddling in the affairs of the gods" or forbidding other avenues of research that would deny held truths, like the centrality of their planet or that “god” holds the world together, not forces. For a basic culture that has little to no agriculture there could be physical constraints preventing any society from advancing. Art, music, and science are all a product of cultural surplus. Scientist can only research because there is enough additional food/energy/supplies that they don't have to produce these resources themselves. In a harsh or barren world, there simply won't be enough resource to allow anyone the luxury of research. The same idea is true for nomads. When you are constantly traveling, no one has the additional resources or equipment to do any serious scientific work. If you adjust your world to make the society constantly travel or barely survive, then technology would stagnate. Writing must also be possible. If for some reason there was no way to effectively store or communicate information, then there is no way to build on the research done before. There are several people groups, mostly small tribes that have no written language. If your society doesn't invent an effect written language, along with the production of writing materials and their distribution, then science has no chance to flourish. [Answer] The nature of the universe is that nothing is ever truly static - even stars die eventually. Any race capable of creating technology in the first place will have individuals that will continue working on advancing the existing technology. To create technological stagnation will require some force, or group of forces, that will control or suppress new developments. Nothing will last forever though. Some of the forces I have seen in science fiction and fantasy are: 1. A powerful deity Note that this is not the same as a religion. 2. Religion 3. Oppressive government 4. Technology detection and extermination system In the [Looking Glass series](http://en.wikipedia.org/wiki/Voyage_of_the_Space_Bubble) by John Ringo: > > An advanced robotic system was programmed to hunt down and destroy any technology with detectable properties (i.e. EM emissions). > > > [Answer] Jerry Pournel and Larry Niven's Codominon stories (written in the 70s during the Cold War) were premised on the idea of internal security through stagnation. Both the Soviet Union and the US grew concerned that the proliferation of technology raised the real specter of some numb nut third world despot making a technological breakthrough and then blowing up the world. They got to the point of interstellar travels so they had resources forever , nuclear energy and room to spread out. So they decided the best thing to do was to freeze scientific research and technology and get rid of troublemakers by shipping them off planet. They outlawed a lot of research but the main thing they did was contaminate records of previous research with bad data. What scientist remained wasted a lot of time conducting research and formulating hypothesis based on gibberish data. They kept technology largely static, about early 21st century for newly two centuries. Then the wells came off and earth went boom. But by then, humans had spread out to space. There is historical precendee for frozen technology in the "Gun powder empires of the middle east, india and china. The ottomans being the most obvious answers. In gun powder empires only the state has fire arms especially cannon. The great expense of gunpowder and it's strict regulation make it hard for anyone else to fight the central government. These empires grow more and more inward looking and obsessed with stability at all cost. They shut down schools, churches trade routes, anything that might start trouble. New technology is banned almost reflexively. The Ottomans banned the printing press in 1616 and the Islamic world has never recovered. --- A civilization that fears instability and change will fear technology. Seems were are heading that way ourselves with the Precautionary Principle and claims that we shouldn't use new technology until it is proven absolutely safe, something impossible to do. If people become convinced that change will kill them and that stasis is the only safe "sustainable" type of society, then that society will strangle technology at every stage. --- An industrial version of a gun powder empire could be some form of corporativism like communism, that managed to control an entire planet or region of space such that it had no external competitors. All the big corporations/state-enterprise would be tightly interleaved with the government and protected from free-market forces which would be illegal. They would have no incentive to create new technologies that might put them out of business. Likewise, the political side would like everything stable and predictable. Since the political leaders are in charge and want to stay that way and the executives/red-managers are comfortable two and everyone else has guaranteed jobs and social services. No one has any incentive to rock the boat. New scientific knowledge could cause all kinds of instability from questioning the ideological basis of the regime to creating new technologies that would disrupt the economy and social disorder. The only hitch they would have is that no society can exist on the exact same resource base forever. Either you have to have new supplies resources you can create with your current technology or your have to create a new resource with a new technology. A technologically static industrial society would need heavy recycling and some functionally infinite supply of base materials. The best infinite supply at an industrial level would be space. Asteroids and moons could be mined for an infinite supply at a fixed tech. So a corporativist state would have incentive for space faring as long as it didn't rock the boat to much. Space would also be a good place for Gulags. The society might split in two: between those in space and those on the planet. Those in space would be either exiles or merit promoted specialist. Space would attract dynamic individuals who could think and operate on their own. Combined with dissidents, they would be a danger to the regime back home. --- A low-tech society like those of Meso-America who used massive amounts of highly skilled labor instead of technology might conceivably spread far and wide without developing much science or technology, at least for a long time. The Meso-Americans prefected what we might call a dynamic, information intensive technology. More software than hardware. If they spread out and took that dynamic with them, they would not seek new tools and the like but would use the same wood and stone tools combined with their social organization. Likely, they have to be the only civilization and likely the only sentients. But they would need some exterior threat or challenge to keep them internally cohesive. There might a semi-sensient life form common that required serious organized effort to push back. That would keep people from just wandering off into the wilds on their own. The environment should provide a lot of materials like wood but little like metal or coal. The environment should be fairly uniform over vast regions. Imagine if the giant monolithic biome of the Siberian forest were a giant tropical rain forest like meso-America. There are nothing but low old mountains, mere hills and they are uncommon. Stone is rare and metals more rare. Rivers empty into fresh lakes or peter out in marshes into a dead sea. No sea travel, little water travel. The surrounds are filled with a dangerous species, something that acts coordinated manner. To expand, a entire colony has to detach, make a city and keep functioning. Everyone is a cog and any internal disorder is lethal. Once the society hit upon the right organization, they would just clone it repeatedly as it spread outward. If the planet was old, mountains worn down, metals might be hard to find. Low mountains would create fewer difference in air flow and clime at the same latitude. If continents were grouped around the equators, the vast majority of the habitual land might have a very similar tropical biome such that the same techniques would work everywhere. The external threat would have to constant and probably need to popup everywhere. That would keep the comfortable interior communities from starting to fight themselves and possibly creating an incentive for technology escalation. [Answer] Science needs trusts. If a lot of scientists are frauds then nobody trusts science and the scientific system breaks down. Technology is often disruptive to the status quo and the power that be can ban certain technology because they are afraid of it. [Answer] You're looking to put "improvement on society" on a metric, so we can start by looking at how civilizations would look if we plotted them on a number line. * A dying civilization plummets towards 0 as it forgets all of its technology/improvements * An exploding civilization skyrockets towards infinity as it continually adds to its technology/improvement However, those are not the only stable patterns. If boundary conditions are fixed (such as for small tribes in the Amazon), two more options appear * A civilization that approaches a level of technology/improvement which lets it coexist in harmony with nature (any additional technology would put them at odds with nature) * Chaos... anything goes This sort of civilization has occurred. Consider the Pirahã, an Amazon tribe which is believed to have no way of describing numbers, so 0 technology. Until we discovered them, and started corrupting them, they literally did not have a need for advancing technology. [Answer] China, Gunpowder Empires, and the Amish are mentioned as real world examples, pretty well written up. Read about those. However, those cultures are all pre-scientific method (except the Amish, I guess). We don't know any cultures that've given up the scientific method - of course, they've all been threatened by cultures that do have the scientific method - so they don't really have a choice if they want to stay in the game. You would need to remove external threats. This might be doable if you've got a significant technological lead over everyone you meet. You just nuke the [haboob] out of any competitors when you meet them, so they can't compete with you. Not mentioned are some other scifi examples (yay for the CoDominion, and Foundation mentions!) Niven's Golden Age, when war and fighting were outlawed in Human space (prior to the Man-Kzin wars), they had a tech bureau that went after inventors and buried technological advances (except for their own use). Weber's new Armageddon series; which is all about breaking out of one of those periods of stasis. Turtledove's World War series has aliens who have very slow-changing/advancing technology. They thoroughly test things, and take all things into consideration before adopting an advancement. [Answer] The answer to this question is no unless you would like to define certain world based criteria that might make it possible. For example, *"With x, x, x, x, x, factors taken into account, would science fail to progress?"* Getting on to the answer. Can things stagnate on a large world level view? Absolutely, yes. Now if we are talking an earth like world then how do humans create new tech? 1. I have a problem or this takes way to much of my time 2. How can I make that less annoying 3. Viola! A new process, invention or whatever. So I would say the answer to your question is the rate of progress can be very very slow but to say there is no progress is not feasible. It will be there in the day to day activities people have to do. [Answer] The Dune scenario could work here - after the machines rise against humans and humanity barely survives, all "thinking machines" are banned and computing devices are intentionally kept low-tech, where present. This puts a cap on total possible development as computers are needed to manufacture and maintain more complex technology. If you took out the "magical" elements of Dune (Bene Gesserit, spice, etc) you'd get a technological roof pretty quickly. [Answer] Our own technological development can be attributed to the resources available to us. We have the metals and fuels that allow us to development more advanced technology. We also are able to continually shrink our technology, so that it takes up less space to do the same work. If a planet doesn't have enough of the natural resources necessary for advancing technology, then the civilization won't easily be able to develop new technologies. Existing technologies will be limited by size and complexity constraints. **They'll likely fully develop what technologies they can with the resources they have, though.** One of the ways we measure intelligence is by the use of tools. Intelligent beings will want to develop tools to make it easier for them to survive. They will want to improve their tools to continuing getting the same output for less effort. [Answer] I could easily see stagnation setting in simply because of the cost of advancement exceeding the desire of those who would otherwise push the boundaries of technology. The cost of advancement rises with the level of technology (obviously speaking in very crude terms) - as knowledge becomes more advanced, one needs to have greater specialization of knowledge and achieve a greater understanding of the technology that already exists (to develop newer better designs of static quantum spline reticulators, one must have a great understanding of static quantum spline reticulation). Eventually, achieving the level of specialized knowledge necessary to then be able to make a meaningful contribution will exceed the desire of all but the nerdiest of geeks. Once it becomes a rare field (in terms of cutting-edge research), there are fewer and fewer chances for mentors and collaboration, which might degrade educational opportunities for the next generation to come up to a level where they make meaningful contributions. Mature fields are also unlikely to have many opportunities for headline making breakthroughs, greatly blunting the appeal (study for decades and maybe you could claim a lifetime achievement of getting a minor pedantic tweak to existing methodologies). Add in potential resource constraints, and this level might be hit earlier than later. Spending a lifetime pursuing an academic field with little immediate practical application is a luxury. Who has the time to spend decades of their life learning how to reticulate splines when one has to struggle to pay rent and buy food? Once the field stagnates like that, any new generation would struggle in terms of building experience - all the tacit knowledge has been lost. Finding enough dedicated scientists who have the capacity to reinvent the wheel in an attempt to even just recapture lost knowledge might not be possible. Technology becomes about just maintaining the existing infrastructure rather than new developments. Many things can influence where that tipping point will be found - how many people get funding to be dedicated to advancing the field, how much cultural pressure there is to devote their time to other fields (nobody studies chemistry because they are all highly pressured to study astrology), social approbation (little collaboration stifles innovation as well as inhibiting new entrants), excessive veneration for established knowledge (too hard to dispute the wrong theories of previous experts), outright religious persecution, political persecution (endless trumped up legal difficulties so long as you speak against the established politically correct conclusions), etc. ]

[Question] [ This question is meant as a reality check on [this answer](https://worldbuilding.stackexchange.com/a/103644/809) to [The land grows evil and corrupted ... but why?](https://worldbuilding.stackexchange.com/q/103609/809) > > Radioactive moon in a nearly geosynchronous orbit. It slowly kills or alters all life exposed to it, but it doesn't hang perfectly still in the night sky. > > > It travels very slowly, circling the planet once every 500+ years, enough time for the far side of the planet to recover from its ill effects. People are forced into migrating every 500+ years to avoid the bad moon. > > > OK, I want to [reality-check](/questions/tagged/reality-check "show questions tagged 'reality-check'") that. Could that work? What I'm **not** interested in: 1. Ignore how was it even formed. 2. Ignore how humans evolved. 3. About two thousands years ago it just came to be, OK? Orbit is stable, it didn't wreak havoc on another moons orbits (or if it did, it is out of scope, it's OK now). What I want to reality-check: 1. Could it be radioactive enough to cause significant cancer increase, radiation sickness and mutations? 2. Could that happen without moon exploding? 3. Could it work for 2000 years (that is merely 4 migrations)? I'm OK with "now it is not nearly as scary as in legends" here. 4. Could it affect patch significantly smaller than a whole hemisphere? All of the above partial questions boil down to: What would be composition of this moon, or why it is impossible? [Answer] # How to generate radiation ### Radiation by nuclear emission A moon made of some non-fissile ([definitely not fissile!](https://worldbuilding.stackexchange.com/questions/56763/what-if-the-earths-core-was-made-of-uranium/56778#56778)) transuranic element would emit significant alpha, beta, and/or gamma radiation. ### Radiation by neutron generation The moon would have to be a neutron generator. There are a few ways to create neutrons, but they involve things like fission reactors and hydrogen ion linear accelerators. This would basically have to be an alien space station, not a moon. I think that is outside the scope of the question, so I'll ignore neutron radiation. ### Radiation by magnetic field A moon filled with a magneto-hydro-dynamically active fluid would be able to generate a significant magnetic field, the way that Jupiter does. This field will trap charged particles. If something emits lots of charged particles (Io does this for Jupiter; the solar wind may be sufficient for Earth since it is closer to the Sun) then those particles can be trapped to form a high energy plasma in the magnetic field. This is analogous to the [Van Allen belts](https://en.wikipedia.org/wiki/Van_Allen_radiation_belt) around Earth, though they would be stronger with a stronger magnetic field. Once you have a very strong magnetic field and very high energy particles in that field (in the keV, 10 million K range), you can emit energy by slamming these particles into something else, namely the atmosphere. This is an aurora. Much of Jupiter's emissions come from its aurorae, while some come from Io and its thin ionosphere passing through Jupiter's magnetically maintained high energy plasma disk. Jupiter's magnetic field emits radio waves at ~100 GW in the 10-100 m wavelength; IR at ~50 TW in the 3-14 $\mu m$ range; and UV at ~10 TW in the 80-180 nm range. By comparison, Earth's magnetosphere emits only in the radio range at about 0.1 GW. ### Radiation by accretion To generate other wavelengths, like a powerful X-ray source, you need to drop matter into a high gravity object, like a neutron star or a black hole. I don't see any other way for a moon to be an X-ray source, and since this doesn't seem to meet the OP's requirements, I'm going to ignore X-ray radiation. # How radioactive will these sources be? ### Alpha and beta radiation Alpha and beta particles have little to no ability to penetrate the atmosphere, so they are basically out as radiation sources. ### Gamma (and X-ray) radiation Gammas are another story. If the moon were made of something that had a long half-life but emitted gamma radiation, then maybe it would be a potent source. There are a great variety of metal isotopes with long half-lives (1e5 years +) that emit x-ray radiation in the 5-10 keV range; decay of non-fissile transuranics provides a wide spectrum of emissions in the x-ray to gamma range (up to 15 MeV). This could be nice and deadly, but unfortunately, the atmosphere is a very good absorber of X-rays and gamma radiation. [](https://i.stack.imgur.com/FNnED.jpg) The attenuation coefficients in air of various energy radiation can be found [here](https://physics.nist.gov/PhysRefData/XrayMassCoef/ComTab/air.html). For a 10 keV X-ray, the density coefficient of attenuation ($\mu/\rho$) is 5.12 cm$^2$/g. Multiply this by the density of air (1.2 mg/cm$^3$) and convert to meters for a coefficient ($\mu$) of 6.3 meters$^{-1}$. A half-thickness can be obtained from an attenuation coefficient by dividing the log of 2 by the attenuation constant; the half-thickness for 10 keV X-ray penetration is 0.11 meters. That means, each 0.11 meters drops the power of X-ray radiation in half. Needless to say, X-rays won't make it far in the air. Gamma rays do better, but not by much. For 1 MeV gamma rays, the half thickness is up to about 9 meters. For 10 MeV gammas it is 28 meters. 28 meters is a serious distance to penetrate, but not so much compared to the thickness of the Earth's atmosphere. For a simulated constant density atmosphere at the density we are using to calculate, the Earth's atmosphere would be about 8 km thick. Divide that distance by 28 and you get 289; so gamma energy from space is reduced by a factor of $2^{289}$ by the time it reaches the surface, not enough to do any damage. A radioactive object in orbit just won't do the trick. ### Magnetically induced radiation - Decametric radio Here is where we get more interesting. Jupiter's aurorae, i.e. the regions where the magnetic field lines intersect with the atmosphere, are extremely powerful radio emitters. You may notice from the above graphic, or from listening to the radio in your car, that radio waves penetrate the atmosphere nicely. The 10cm to 10m band of little atmospheric attenuation corresponds to the 3-300 MHz range; [VHF and UHF radio](https://en.wikipedia.org/wiki/Radio_spectrum). Here is Jupiter's (and other planets') radio emissions. [](https://i.stack.imgur.com/cN1qg.png) The decametric radiation (DAM) in this graph is largely controlled by [interactions](https://radiojove.gsfc.nasa.gov/library/sci_briefs/decametric.htm) with the moon Io. The mechanics of these interactions are mostly beyond me, so I can only suggest that there are possible mechanisms for getting large scale radio wave energy released. First, there can be an orbiting satellite which is a massive magnetic field generator for some reason. This satellite acts like Jupiter, while the Earth acts like Io. The magnetic field lines of this satellite interact with the Earth's so that high-energy charged particles captured in the combined magnetic fields are funneled into Earth's poles. This forms powerful aurorae, with tremendous radio emissions. The last bit of assuming we have to make is that this interaction will be able to create the appropriate decametric radio emissions without putting out too much energy in other frequencies. I am not sure if that is possible at the high energies that his system will require, but I am willing to assume it. We want radio emission to penetrate the Earth's atmosphere cleanly, heating the surface without heating the atmosphere more than it needs to. Radio wave [attenuation in the atmosphere](https://descanso.jpl.nasa.gov/propagation/mars/MarsPub_sec7.pdf) is in the 3-10 db range. Taking an optimistic view, that means that 10-50% of the radio energy will reach the ground, while 50-90% remains in the atmosphere. Once VHF energy hits the ground, nearly all of it will be absorbed. The goal here will be to get the ground to absorb a lot of radiation, making the ground too hot to support life. The aurora are localized effects; if they occur at an altitude of 100 km, then only a circle about 1000 km in radius is affected. If the aurora were directly over the North pole, for example, the arctic circle would not receive any radiation; it would be blocked by the curvature of the earth. For the region directly below the aurora, we would like to up the incident radiation by a substantial amount to make the place lifeless. The incident radiation that is absorbed the the surface on Earth averages to 163 W/m$^2$ over the whole surface over a whole year. Let's say our target is to hit the surface with an additional 250 W/m$^2$ in radio energy at the sub-aurora point to sterilize it. For a low attenuation scenario of 50% atmospheric absorption, an aurora [occurring at](https://en.wikipedia.org/wiki/Aurora#Images) 100 km must deliver an equivalent to 500 W/m$^2$ at that altitude. At 100 km, the surface area of this radiation would be $4.2\times10^{10}$ m$^2$; so the radio luminosity of a point source must be just about 2 TW. This compares with 0.1 GW distributed over the Earth's entire magnetosphere, or ~40 GW from Jupiter's radio emissions. So this is a lot, but perhaps in the realm of possibility. In order for the 'moon' object to work, it would have to be in orbit of Earth, but not necessarily geosynchronous orbit. Any object of moon-like size 'could' generate the desired magnetic fields, but it would surely be artificial. It would have to be filled with some sort of magnetic fluid that generated the magnetic fields. Again, this is not my specialty, but I suspect that a very high temperature, low viscosity, high flow rate iron core would work; as would a liquid hydrogen core, as on Earth. However, having this in a moon-sized object would surely be artificial. # Conclusion In this scenario, there is an orbiting object that generates extremely high magnetic fields. It is probably artificial. These fields cause solar wind particles to be trapped around the object. When these lines link up with the Earth's in a certain way, the charged particles are discharged into the Earth's atmosphere; there they collide with atmospheric molecules and release radio waves. Much of the radio waves end up back in space, but the sub-aurora point is hit with the equivalent of equatorial daylight sun, constantly. If these magnetic effects are stable, then within a few days, the ground within a hundred km has heated considerably, and within a week, plant life is being killed by the heat. If the aurora stays in place for at least a month, there will be a dead patch a hundred km across, where nothing survives except bacteria. The auroras are stable for a while, until the magnetic lines drift off, then soon another aurora will pop nearby. Some aurora are so far north that they just melt glaciers to bare rock and are done, others are over the ocean. But when they appear at mid-latitudes over land, beware! This doesn't meet the geosynchonous criteria, but it would explain why dead spots would appear on a time scale of months in northern latitudes. [Answer] I'm going to take this a slightly different direction and say that yes, radiation from a moon can indeed affect life on a planet, just not quite in the same way intended by the answer you linked. As others have explained, our atmosphere and magnetosphere do a good job of protecting the planet from most external radiation. The main type of radiation they allow through is visible light. If you wanted a moon to radiate something that wreaked havoc on the portion of the planet it faced, have the moon reflect (or absorb and re-emit) light in a specific, narrow portion of the color spectrum. Plants and other photosynthesizing organisms use different portions of the light spectrum differently. A significant increase in one color band could unbalance an entire ecosystem, perhaps by causing certain bacteria or other microscopic life form to thrive and [grow too rapidly](https://en.wikipedia.org/wiki/Red_tide). This sudden overabundance can deplete the oxygen in water or release [toxic substances](https://en.wikipedia.org/wiki/Microcystin). Either of these can easily lead to die-offs of marine life, and the effects trickle up the food chain from there. Toxic water makes it harder for plants to grow (especially if the toxin can evaporate and then be [pulled down by rainfall](https://en.wikipedia.org/wiki/Acid_rain)), and fewer plants means that animals are more likely to over-graze. People that live nearby would observe that once the moon becomes visible, fish start dying off, water supplies become poisonous to humans, plants stop thriving, and most land/air animals migrate away. Other animals migrate in, creatures who are better adapted to the new conditions. The entire ecosystem gets thrown out of balance, taking many years to completely recover. Your 500 year cycles means that there's plenty of time to recover, though, so balance eventually returns. So yes, it's entirely possible that a moon could radiate energy that has a significant impact on the planet, just not necessarily in the traditional "nuke it with gamma rays" sense. [Answer] > > Could it be radioactive enough to cause significant cancer increase, radiation sickness and mutations? > > > ## Not here, probably not elsewhere either A radioactive moon could give out radiation in five forms: * Alpha particles: essentially an electronless helium-4 nucleus. Doesn't travel farther than a few centimeters/inches in an atmosphere, so no danger at all. * Beta particles: an electron or positron travelling at high speeds. Travels further in air, but still doesn't go farther than a few meters/yards. * Free neutrons: this is the only radiation form that can make something else radiactive too. Can go a few kilometers/miles in an atmosphere, but we got a lot of atmosphere anyway. * X-rays: needs no explanation. * Gamma rays: ditto. Only the two latter ones are scary. But we have a shield in the form of an ozone layer, which already handles those quite well.  So the only place where a radioactive moon would be dangerous would be on a planet without an ozone layer or similar shielding, but in that case you are pretty much [expletive] anyway. That being said, you could make the whole moon out of uranium if you wish. We'd still be safe. > > Could that happen without moon exploding? > > > Sure. In order for it to explode it would have to be so hot that it would become gaseous. It would need to be as hot as a star. But it would have to be way more massive than Jupiter for that to happen. > > Could it work for 2000 years (that is merely 4 migrations)? > > > It could reallistically stay there as long as our own Moon can. > > Could it affect patch significantly smaller than a whole hemisphere? > > > Nope. [Answer] If the moon circled the planet every 500 years and was in geosynchronous orbit, the planet would have a day 500 years long! Oh, you said nearly geosynchronous orbit. What you seem to mean is the moon actually orbits the planet many times in 500 years, but the position of the spot directly beneath the moon slowly circles around the planet every 500 years. Earth like life needs relatively short day/night cycles, so if the planet is like Earth and the people and their plants and animals are like humans and earth life, they will probably need relatively short day/night cycles to keep the planet from heating up too much during the day and cooling too much during the night. So if the planet is exactly like Earth exactly synchronous orbit would take exactly one day and there would be about 365.25 days in a year and so in 500 years there would be about 182,625 days. 360 arc degrees in a circle divided by 182,625 is 0.0019712 degrees. 21,600 arc minutes divided by 182,625 is 0.1182751. 1,296,000 arc seconds divided by 182,625 is 7.09650 arc seconds. Thus the moon would not appear exactly stationary in the sky but would move by 7.09650 arc seconds, or 0.1182 arc minutes, or 0.0019712 arc degrees every day. It would take the apparent position of the moon 845.52295 days to move by one arc degree, about twice the apparent width of the moon. since one degree on Earth is about 60 miles, it would take about 2.3149 years for the sub moon spot to move by about 60 miles. Note: Assuming a natural satellite or moon orbiting a planet that is exactly like Earth, geosynchronous orbit would be well outside the Roche limit that would cause a moon to break up, so the moon in geosynchronous orbit should be fine. So it would be possible for a moon to be positioned nearly in geosynchronous orbit of an Earth duplicate with enough of a difference for the spot on the planet directly below the moon to circle the planet every 500 years. But the idea that a radioactive moon could kill life exposed to it's radiation seems implausible because the Earth's atmosphere, magnetic field, and ozone layer block most forms of dangerous radiation from Earth's surface. If you change them enough that a radioactive moon can kill life on the planet, you change them enough that solar radiation, solar wind, and cosmic rays will probably kill all life on the planet everywhere anyway, so getting out from under the radioactive moon won't do the life any good. So you need some other way for a moon to kill at least some life on the planet. If the moon orbits the planet in exactly the same plane that the planet orbits the sun, the moon is likely to be eclipsed around midnight by the shadow of the planet. But if the moon's orbit is titled a little it will never be eclipsed but remain in sunlight all through the planetary midnight. And maybe near the center of the planet facing side of the moon there is a large crater with an almost parabolic cross section and a smooth, mirror like reflective surface. And the parabolic shape happens to have a focal point near the surface of the planet. That would be quite a coincidence, or maybe the work of malevolent super advanced aliens. So around midnight, as the far side of the planet has cooled a lot from the daytime heating, the sub moon location get a big blast of light and heat reflected from the moon. So the sub moon location will not cool down as much during the night as the rest of the planet's surface, and so will get hotter and hotter day after day after day. And this superheated region of the planet will move around very slowly. Hot land or water heats up the air above it. Hot air rises, and forms low pressure zones from the surface it rises from. And low pressure zones caue wind circulation which forms storms. Thus the planet could have a permanent hurricane with the eye at the sub moon spot and perhaps having damaging winds spread over most of the hemisphere. And the eye of that hurricane would slowly move a few miles per year. That would not kill all life on the hemisphere but would force Humans who grew crops that would be destroyed by the winds to slowly migrate ahead of the hurricane. [Answer] Our planet has a strong magnetosphere that protects us from external radiation. This could be unusual - Venus doesn't have one, Mars a residual but extremely weak one. This is why some people are a little worried about Mars colonisation - [Curiosity measured the radiation from the sun at 300 mSv over 180 days](https://www.space.com/24731-mars-radiation-curiosity-rover.html). [That's about 6x the maximum dose for a nuclear worker.](https://xkcd.com/radiation/) So lets say your planet doesn't have one. You could have a planet mainly made of uranium (like the way Mercury is mainly iron) - this could give you something like the [Oklo Natural Nuclear Reactor](https://en.wikipedia.org/wiki/Natural_nuclear_fission_reactor) If the more radioactive isotopes condensed into a core or around the core that could maybe give you something a bit like a breeder reactor or a travelling wave reactor. An unshielded reactor [(530Sv)](https://www.extremetech.com/extreme/243904-fukushimas-reactor-2-far-radioactive-previously-realized-no-sign-containment-breach), in orbit at 17000km(Mars synchronous), gives me an exposure of 1.6Sv per year [using this](http://www.radprocalculator.com/InverseSquare.aspx) - but only if its 1,000,000x bigger than Fukushima. For the earth - it would need to be 42000km(Geosynchronous), gives me an equivalent exposure at around 5,000,000x bigger than Fukushima. You could reduce the mass needed by increasing the rotation of the planet - if the earth rotated every 90 minutes, then geosynchronous would be 160 miles(209km) high. That would give you one reactor, giving 1Sv exposure to the surface. [Answer] **TL/DR: Its not the ionising radiation, but the heat output that kills you** As mentioned in other answers, the ionising radiation from a radioactive moon would be blocked by the atmosphere and not really do a lot. But a radioactive moon also generates heat, and depending how radioactive it is, that could be enough to destroy life on earth. Solar irradiance is [1361 W/m2](https://en.wikipedia.org/wiki/Solar_irradiance) at the top of the atmosphere. If that increases by [10%](https://en.wikipedia.org/wiki/Future_of_Earth#Loss_of_oceans), the average temperature of the planet will increase to 46°C, which will start a runaway greenhouse effect that will evaporate the oceans. The runaway greenhouse effect comes from water vapor, which is a greenhouse gas, and at an average temperature of 46°C there will be enough water vapor in the atmosphere to start the runaway greenhouse. If the moon were made of uranium-238, it would probably explode in a giant nuclear explosion, but let's assume it does not. (Edit: Uranium-238 does not sustain a chain reaction so it won't explode) Uranium-238 is actually one of the least-radioactive radioactive elements we know. It only generates $0.1$ watt per ton of decay heat. The moon has a mass of $7.34\cdot 10^{19}$ tonnes. If it would be made of uranium-238 it would generate $7.34\cdot 10^{18}$ watt of decay heat. The moon is $384400$ km from the earth. So the irradiance of the moon made of uranium-238 on earth would be $$\dfrac{7.34\cdot 10^{18}}{\pi \cdot(384400\cdot 1000)^2} = 15.8 \space\text{watt/m}^2$$ So that is not that significant, but it is only a factor of 9 away from the $136 \space W/m^2$ needed to evaporate the oceans. So if you choose basically any other radioactive material to construct your moon from, or make the moon a bit more massive, or put it closer to earth (irradiance scales with distance squared), the heat output will easily be enough to boil the oceans. At $136\space w/m^2$ that will be a slow process probably taking thousands of years, but there are many much more radioactive materials to be found. You can easily increase the heat output of the radioactive decay moon by a million or more, which would instantly fry life on earth. The moon is a disk of the same diameter as the sun as seen from earth, so the thermal radiation will also have the same wavelength as the sun when the intensity is the same. At $136\space w/m^2$ the moon would be somewhere around red or yellow-hot, but if you increase the heat output a lot the moon will appear white- or blue hot depending on which temperature you choose. Though if the absolute heat output from the moon is too big, the radiation pressure itself will probably overcome the moon's gravity and start to evaporate the moon. But a more massive moon also increases its gravity, so just something to balance. **One other option: UV radiation** The above thermal radiating moon gave me another idea: if the moon emits strong ultraviolet light that will do more or less what you want. Make the moon denser, so you have less surface area, so temperatures will be higher for a given radiation output. If the moon's surface temperature is around 8000 Kelvin the peak radiation is in the UV-A, and there is significant UV-B too. UV-A is not absorbed by the ozone layer, and UV-B only partially. Normal solar radiation only has 10% of its energy in ultraviolet, so the irradiance of this moon will only need to be a fraction of the solar irradiance to cause a lot of damage. There is still the problem that if you double the natural ultraviolet irradiance in this way, that also increases the heat received by earth by 10%, triggering the runaway greenhouse effect described above. And doubling the ultraviolet will increase the incidence of skin cancer, but not immediately make one side of the planet uninhabitable. But if you decrease the solar output a little bit, or place earth a little bit further away from the sun, this might work. The changes in heat received will change the climates, and the moon's heat only reaching one side of earth will do that even more, but I suppose that's also out of scope. [Answer] How about something more indirect? Say the world is the site of a partially successful colonization project. The "moon" is the last remaining power satellite from the constellation that powered the terraforming process, having drifted out of its geostationary orbit after losing stationkeeping but otherwise still active. When it's overhead, forgotten terraforming/weather control machinery on the surface activates and runs unattended, with adverse effects on the surroundings. The descendants of the colonists might have adapted to the current state of the planet or become reliant on parts of its native life, and see the terraforming as harmful, or it might just cause harm due to malfunction and lack of control. Certain areas might be relatively sheltered due to geography and weather patterns, or due to local failures of the terraforming machines. ]

[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. Yesterday while Green, Andy and I were recording new episodes for [the podcast](http://monkeylords.com/podcast/) we stumbled upon a bit of a problem that we need someone with physics/astronomy knowledge to help out with. We want to create an annual astronomical event for the sake of one of our species hosting a once per year festival/gathering. **The world:** * Earth-like * Axial tilt is slightly more pronounced at 27% * The planet has two moons, their size and distance from the planet are undecided and may be tailored to fit this scenario. * A 12 constellation Zodiac similar to Earth One of the constellations in the Zodiac is a cat and each year we would like some astronomical event related to the constellation to happen. **The event:** * Must be tied to the cat constellation * Should take place in the fall * Will ideally include one or both moons * Can only happen once per year * Needs to be visible from anywhere within 20 degrees latitude of the equator [Answer] # Two moons are in orbital resonance You can have your two moons be in a m:n [orbital resonance](https://en.wikipedia.org/wiki/Orbital_resonance), the way that Io and Jupiter are. That way, at some time period $nT$ where $T$ is the orbital period of the outer moon, the two moons will line up in the sky. The orbital period of the inner moon is $nT/m$ in this case. A further twist, which is something that will become more important later, is that the outer moon could potentially be in a *retrograde* m:-n orbit. There exist asteroids that are in retrograde orbital resonances ([Morais and Namouni, 2013](https://arxiv.org/pdf/1308.0216.pdf)) with both Jupiter and Saturn. There are also exoplanets that orbit retrograde to the main star ([Hebrard, et al, 2017](https://arxiv.org/pdf/1101.5009.pdf)). So it is plausible that your planet could have an inner main moon, like Luna, and an outer retrograde moon. Keep in mind, this situation does *not* have to be stable over geological time. If it just so happens that the moon is captured, modified in orbit into resonance, and stable for 10,000 years that just happen to be the same 10,000 years that your civilization is developing, no one will know the difference until the space age. This alignment of the moons could produce some interesting optical effects, especially if the inner moon has an atmosphere of some sort, or is volcanically ejecting a dust. The outer moon could change (apparent) color or otherwise look strangely during the alignment. But in general, it would be astronomically notable if the two moons were lined up in the sky only one time per year. # Now line the orbital resonance up with the zodiac There is no reason that $nT$, the alignment period of the moons, can't also be the orbital period of your planet around the sun. Since the orbit of the Earth drives the seasonality of the zodiac, if the period of the moon alignment lines up with the orbital period of the Earth, then the alignment of the two moons will happen at the same time, relative to the zodiac, every year. An annual celestial event similar to what you are planning is the rising of Sirius above the horizon (as seen from Egypt) right before the Nile flooded. Sirius precessed and no longer times the flood well (and the Nile doesn't even flood anymore, thanks to dams), but that took millenia. For centuries the association between the star and the flood was stable, and highly important to the royal astronomers and what have you. In the same way, if the orbital period of the alignment and the planet around its sun just coincidentally happen to be the same, within a few seconds at least, you will have a stable celestial event for centuries or longer, long enough to build up some cultural tradition. # Dynamics of the two moons In this [answer](https://worldbuilding.stackexchange.com/questions/23452/can-you-add-a-mini-moon-to-earth/59917#59917) (also your question, by the by), I showed that there are a variety of stable orbits for a second moon, both inside and outside of Earth's orbit. In general, a moon at 1/3 of Luna's mass, that is at least 2.5 times more distant from the Earth than Luna is, will be stable. This was for prograde orbits, not retrograde; I don't have access to Rebound right now to check it but I am confident that we can find some stable orbits for a second outer moon outside of our own. We want to put the outer moon as far away from the planet as possible to lead to a long orbital period. This will help it line up with the planetary year. The [Hill sphere](https://en.wikipedia.org/wiki/Hill_sphere) of a planet is that region of space where a planet's gravitational force is dominant over other forces (such as the gravity of the main star). The Hill sphere of the Earth is around 0.01 AU; but true stability won't be found in the outer parts of that region due to other forces, such as gravity from a gas giant, or radiation pressure from the main star. However, objects can be captured more readily into retrograde orbits in the outer part of the Hill Sphere ([Astakhov, et al., 2003](https://www.researchgate.net/publication/10757730_Chaos-assisted_capture_of_irregular_moons)). So, our goal is to place a smaller moon in a retrograde orbit around the Earth, such that the outer moon is in resonance with the larger moon, and its orbital period is the same as the planet's year. # The maths The Hill sphere of Earth is about $1.5\times10^{9}$ meters. Let us say that we can have a retrograde orbit of up to $1.0\times10^{9}$ meters; this is the semi-major axis of the outer moon's orbit ($a$). Let us also say that the planet in question is the same size as Earth. Orbital period is $$T =2\pi\sqrt{\frac{a^3}{GM}} = 2\pi\sqrt{\frac{\left(1\times10^{9}\right)^3}{6.67\times10^{-11}\cdot5.97\times10^{24}}} = 115 \text{ days}$$ If we make $n$, from our orbital resonance ratio, equal to 3, then the period of moon alignment is $3T$ = 345 days. This is just a little bit less than our Earth year. So, simply move the Earth a little bit closer to the sun, until the Earth year is 345 days. Alternately, you could increase the mass of the Earth to increase the Hill sphere until there is a stable orbit of 365/3 = 122 days. Last, you need to set the inner moon into a stable resonance with the outer moon. Since we've settled on a 'm:3' resonance, we can make it a 7:3 resonance, like Ganymede and Callisto. This means the inner moon need an orbital period of about 49 days; noticeably more than our moon's. There are of course pretty much an infinite number of way to change these numbers slightly to end up with a stable system. If the Earth's size goes up, its Hill sphere goes up and the moon can orbit farther away, so the orbital period goes up as well, etc. # Conclusion Your planet is Earth-like, and orbits a star slightly smaller and less bright than our own. The day length doesn't matter in this problem, so it can be the same as on Earth. The year is 345 days long. There are two moons, one the size of our current moon, and another 1/3 the mass (which means about 70% the diameter). The inner moon orbits every 49 days; the outer moon every 115 days. The two moons line up in the sky with each other every 345 days, at the same time every year. Given the significance of the lunar alignment, astronomers might start the zodiac with the alignment. The Month of the Cat, the first month of the lunar year, when Leo the Great Cat is high in the night sky, begins every year on the Blessed Night of the Two Moons. Truly an auspicious night for celebration! [Answer] **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. You make me think of the [Perseid Meteor Shower](https://en.wikipedia.org/wiki/Perseids). > > The Perseids /ˈpərsiːɪdz/ are prolific meteor showers associated with > the comet Swift–Tuttle. The Perseids are so called because the point > from which they appear to hail (called the radiant) lies in the > constellation Perseus. > > > It happens every year when the earth travels through a field of debris left by a comet. It's named after the constellation Perseus because the meteors always appear to originate from that part of the sky. You can only see them at night, but it lasts for several days so the whole planet get a chance to see it. [Answer] If you need something to happen in the Cat Constellation, your best best is to have the eye of the cat being a [binary star system](https://www.redshift-live.com/en/magazine/articles/Astronomy/19628-Binary_Star_Systems-1.html) that is relatively close to the observers solar system. If the angle of the stars is right, as the smaller star orbits the larger star it will regularly pass behind the larger star, growing fainter, and then it will become brighter as it passes in front of of the larger star. If the smaller star takes two years to orbit the larger star, in the first fall it will 'blink' and in the following year its eye will 'widen', all clearly visible to the masses. Example [](https://i.stack.imgur.com/6h08y.jpg) Sorry can't really help with the moons, unless you want a yearly eclipse around the same time. **Empirical evidence** we can see this process from Earth with 34 [binary star systems](http://www.skyandtelescope.com/observing/celestial-objects-to-watch/the-top-12-naked-eye-variable-stars/) using telescopes and the naked eye. > > Thirty-four variable stars have a range of at least 0.4 magnitude and > become brighter than visual magnitude 4.0, according to the > authoritative General Catalogue of Variable Stars (GCVS) and its > supplements the Name-Lists of Variable Stars. (This doesn't include > novae or supernovae, which occasionally reach naked-eye brightness.) > Among these stars are many eclipsing binaries, Cepheid variables, and > semiregular red variables, as well as a few long-period stars of the > Mira type and the recurrent nova T Coronae Borealis. As many as 24 do > not fade below magnitude 5.1 and so remain visible to the unaided eye > all the time. > > > For the math, please [go here,](http://mafija.fmf.uni-lj.si/seminar/files/2010_2011/Eclipsing_binary_stars.pdf) it's rather detailed and involves a large number of equations and explainiations, too many for this answer unless you want to spend the next half hour reading it. [Answer] Taking kingledion's suggestion of an alignment of the two moons with the special constellation, I have some suggestions. For the alignment of moons to happen at least once a year and at the same date(s) each year, both of the moons have to orbit an exact or whole number of times during a year. Thus a moon could orbit 10.000 or 11.000 times per year, not 10.49 times per year, for example. It would be a vary rare coincidence for both the moons to orbit whole numbers of times per year, but there are so many possible rare coincidence that rare coincidences do happen. It has been calculated that a moon needs to orbit more than 9 time's during a year of it's planet, in order to orbit close enough to the planet to have a stable orbit for astronomical and geological time frames. Thus the outermost moon must orbit at least 9.000 times per year and the inner moon must orbit at least 10.000 times per year. If the inner moon orbits faster and more times per year than the outer moon, it should catch up with the outer moon at least once per year. In order to make the two moons lining up in the specified direction a unique yearly event, the lining up the two moons should happen as few times as possible. One way to make that unique would be to have the orbits of the two moons highly titled relative to each other. The two orbital planes would intersect in a line through the planet with intersecting nodes 180 degrees apart. If the two moons line up and pass each when they are not at the nodes, they might pass at ten degrees, 45 degrees, possibly even 90 degrees, so their passing each other would not be very noticeable. But if the two moons pass through the nodes at the same time, they will pass very close and the inner moon might eclipse the outer moon. So James may want to have the orbit of the outer moon be highly inclined, perhaps because it is a captured celestial object, and with one of the nodes where the orbital planes of the two moons intersect pointed at the desired constellation. I think that I have discovered a couple of methods to make the alignment of the two moons happen only once per year. 1) make the inner moon orbit only one more time per year than the outer moon. If the outer moon must orbit at least 9.00 times per year, make it orbit 9.00 times per year and the inner moon orbit 10.00 times per year. Then the outer moon will travel 3240 degrees in one year to come back to zero (or 360) degrees and the inner moon will travel 3600 degrees in one year to come back to zero (or 360) degrees. 10 orbits is 5 X 2 orbits. 9 orbits is 3 X 3 orbits. Since none of the factors of 9 is identical with a factor of 10, the two moons should not line up in the original direction more than once in a year. What if the outer moon orbits 11 times a year and the inner moon 12 times a year? 11 x 12 is 132. In one year the outer moon will orbit 11 times and travel 3960 degrees to wind up at 0/360 degrees while the inner moon will orbit 12 times and travel 4320 degrees to wind up at 0/360 degrees. Thus they will only line up in their original direction once per year. If the outer moon orbits 12 times per year and the inner moon orbits 13 times per year, the outer moon will travel 4320 degrees in 12 orbits and the inner moon will travel 4680 degrees in 13 orbits to both windup at 0/360 degrees. 2) make the inner moon orbit a prime number of times per year. A prime number cannot be evenly divided except by one and itself. All prime numbers are odd numbers, but not all odd numbers are prime numbers. The lowest prime numbers are 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71. The orbits of some bodies have orbital resonance (which sometimes destabilize and sometimes stabilize orbits) if their number of orbits during a time period have a simple numerical relationship. As near as I can tell none of the orbital relationships that allow for a once a year alignment of moons would be resonant, though some could be close to a resonant orbit. James will have to decide if he wants the two moons to align pointed at the proper constellation during the day or the night. During the day people would not be able to see the stars of the constellation, though ancient astronomers and astrologers could calculate the position of the sun among the invisible stars in daylight over three thousand years. This disadvantage would be offset by the possibility of the two moons eclipsing the sun, or transiting over it, if one of the nodes where their orbits intersected was pointed at the sun at the time when the two moons passed through the node. Depending on the apparent diameters of the two moons, they might eclipse the sun or merely transit it as tiny black dots against its brightness. Thus watchers on the ground might see the sun blotted out in two directions as the two moons crossed it in different directions, or two tiny dots crossing it in different directions. The two moons could cross the son simultaneously or minutes apart. If the two moons passed close to the sun but didn't cross it they would be invisible in the glare of the sun. If they crossed each other in the day sky far enough from the sun, they would appear as two thin crescents. The farther from the sun, the fatter the two crescents would be. On the other hand, if the event happens in the night sky, the two moons would look like fatter crescents, or half moons, or gibbous moons, or full moons. People on the ground could see the stars of the culturally important constellation, except in so far as the light of the two moons might drown the stars out. Possibly there is a nearby open star cluster in the important constellation that has many stars that appear far brighter than Sirius does on Earth. I think that James should prefer to have the two moons cross paths either in the day eclipsing the sun or at night opposite the sun as full moons. Thus it seems like it should be fairly easy for James to have someone calculate the orbits to make everything work out. . [Answer] One of the moons is the size of Earth's moon, and has a semi-major axis of around 413,277 km. [This gives it 12 orbits a year](http://www.wolframalpha.com/input/?i=kepler%27s+third+law,+1+earth+mass,+.0123+earth+mass,+413277+km). The moons orbit is such that it is full while it is in the constellation of the Lynx. This moon is young in cosmic terms, and so isn't tidally locked. It has a feature where a combination of craters and exposed [olivine](https://en.wikipedia.org/wiki/Olivine) rich rock on the surface closely resembles a cat eye. The rotational period is slow, so that with every orbit 1/12th of a day passes, and is synced so that the cats eye face is visible during the full moon while it is in line with the constellation of the Lynx. [Answer] **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. I would give this much simpler answer. Have a stationary asteroid belt with a specific formation of rocks in whatever shape you please. Of course it just happens to align with whatever and wherever your cat constellation is located. Debris on the right and left side in the asteroid field can easily obscure the field of view until your super close. You can't see through the sun so when your one the other side of the sun you still won't be able to see it even though you will be in alignment on the opposite side of the sun. The moons are not even necessary for my scenario. Sure you could have them line up just perfectly so that each one looks like part of the cat shape (or whatever) and connected to the shapes in the asteroid field. Maybe its eyes, or an eye and a nose. However, this is unduly complicated, and its more likely 2 moons won't stably orbit for 10's of thousands of years and either crash into each other or crash into your main planet. (in the eyes of a dog person having a moon destroy your planet of cat lovers, might be acceptable loss) Forget about the 2nd moon, have it crash uneventfully into the first and put it out of its misery. [Answer] **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. **The Cat Awakens.** [](https://i.stack.imgur.com/Tgeox.jpg) The moons line up at the perfect spot to play the role of the Cats eyes. True to type, the Cat does not stay awake very long. cat: <https://www.wpclipart.com/space/constellations/figures/color_2/Felis_constellation.jpg.html> moons <https://news.nationalgeographic.com/news/2008/12/081202-venus-jupiter-photo.html> desert <https://idahothemovie.com/2012/09/14/deserts/> ]

[Question] [ This question is specifically about the mechanics of an alien creature **swimming in highly viscous magma**, the unlikeliness of life surviving at magma temperatures etc isn't relevant. Just imagine it's extremely thick mud if it helps. :) My research so far: [Swimming in syrup is as easy as water](http://www.nature.com/news/2004/040920/full/news040920-2.html): Unless I'm mistaken, this means viscosity doesn't necessarily make you swim slower if you are big enough. (*Also being a snake with gorilla arms helps, apparently.*) [Magma Viscosity](http://www.earth.northwestern.edu/public/seth/B02/lectures/Comp/magviscosity_web3.htm) and [mantle movement](https://en.wikipedia.org/wiki/Mantle_(geology)#Movement): Upper mantle magma is estimated between $10^{19}$ and $10^{24}$ Pascal seconds (Pa·s). Basalt lava between $10^2$ and $10^4$ Pa·s. Water's viscosity is $8.90×10^{−4}$ Pa·s. I don't know nearly enough physics to make heads or tails of this. I could not find more in-depth information about what I'm looking for. Perhaps if there's a relationship between size and ability to swim in viscous fluids, the size it'd have to be could be calculated from the viscosity? Perhaps it'd have to be millions of times bigger. Would the equivalent of jet propulsion be more or less efficient in a extremely viscous medium? I'd guess less, but I have no way of knowing. I don't know enough about the mechanics of swimming in general, or what style of locomotion would be more efficient in a high viscosity medium. [Answer] [Caecillians](https://en.wikipedia.org/wiki/Caecilian) are limbless amphibians. [](https://i.stack.imgur.com/uAwLb.jpg) [source](https://www.tumblr.com/search/caecilians) > > Their muscles are adapted to pushing their way through the ground, > with the skeleton and deep muscles acting as a piston inside the skin > and outer muscles. This allows the animal to anchor its hind end in > position, and force the head forwards, and then pull the rest of the > body up to reach it in waves. In water or very loose mud, caecilians > instead swim in an eel-like fashion. > > > This system would work for magma also: worm style in thick magma, eel style in thin magma. A nice side note is that caecilians are in the same class as salamanders, which in legend lived in lava. Here is an invented addition which I stole from the earthworm system: worms secrete slippery mucus which lubricates the soil and helps them push their heads through. Mucus and magma don't mix, but what if your magma creature could route heat from the body up to the head? The hot head would decrease the viscosity of the magma there and so decrease resistance as it pushed through. Heat pulled from the magma behind would firm up that region and so offer a better substrate to push off of. I think the benefits of the hot head / heat sink system would be greater for a larger creature than a smaller. I could also imagine a very sharp head - again to better push through the magma. Worms accomplish this by tapering their heads nearly to a point. I don't think the caecilians can do this. When I was very little I read a story about a witch whose power came from a jewel that she had taken from the head of a giant worm she had killed. I have never been able to find that story but you can find lots about animals with magic jewels in their heads. > > Which, like the toad, ugly and venomous, Wears yet a precious jewel in > his head; > Shakespeare, As You Like It Act 2, scene 1, 12–17. > > > Your legless magma salamander could carry a jewel on its head: the jewel conducts heat and is the part that heats up, combining the benefits of heat and sharpness for pushing through the lava. Yes: giant legless salamander (striped, I hope) with glowing faceted jewel protruding from its head. [Answer] Heavy: so it can sink into the magma. Like, heavier than rock dense. Some sort of "heat sink" so it can surface, vent excess heat, and then dive into the lava again. This could be something like wings, which are folded flat against the body when under the magma (streamlining and reduced thermal area) and then it unfolds them when it surfaces. It's probably cold blooded, and the magma warms the blood, which is then circulated through its body. The less effective the heat transfer: the longer the creature can stay under-magma. Probably maintain a layer of dead skin or scales or something over its outside to act as a heat-shield - kind of similar to how a layer paint protects a surface from rusting. It may not actually be "dead" so much as something like mucus - a specialised bodily excretion. Incredibly strong: it has to push its way through molten rock. Probably have some specialized chemistry in its blood to prevent boiling. I have no idea what this creature eats or drinks. I can't imagine it finding much water anywhere nearby. Maybe you could base it on one of the [sulphur breathing lifeforms](https://en.wikipedia.org/wiki/Sulfate-reducing_bacteria) that you get in volcanic vents. I imagine that swimming in magma is much like swimming in any other fluid - it's thick, but the laws of streamlining and propulsion still apply. A jet turbine would need to be a lot bigger to allow the magma to flow through it, and it would be far less effective in a fluid than a gas (coefficient of expansion thing). So I'm going for flapping things. Even if it's a man-made magama-submersible, it would probably have flapping things rather than propellers or jets. [Answer] In order to properly "swim" anything (including your creature) has to sink into the fluid. Considering that the density of lava is high, your creature will probably sink to a certain level, not completely. In this case it can adopt the strategy of the "Jesus Lizard", for which the higher viscosity of magma would help.[](https://i.stack.imgur.com/m0hxA.jpg) [Answer] The key parameter that describes the scaling of viscous forces on a body interacting with a fluid is the [Reynolds number](https://en.wikipedia.org/wiki/Reynolds_number) $\mathrm{Re} = uL\nu^{-1}$, where $u$ and $L$ are the body's relative speed and characteristic length, and $\nu$ is the kinematic viscosity of the fluid. If you scale up a body's size or speed or immerse it in a fluid of different viscosity, as long as the Reynolds number of the two situations is the same the behavior of the fluids will be [similar](https://en.wikipedia.org/wiki/Similitude_(model)). Assuming the density of the upper mantle is [on the order of $10^3\ \mathrm{kg}/\mathrm{m}^3$](http://jersey.uoregon.edu/~mstrick/AskGeoMan/geoQuerry57.html), its kinematic viscosity is $\nu=\mu/\rho=10^{16}\!\sim\!10^{21}\ \mathrm{m}^2/\mathrm{s}$, while that of water is only $10^{-6}\ \mathrm{m}^2/\mathrm{s}$. So a creature that wants to swim in magma the way people swim in water would have to be at least $10^{22}$ times larger, $10^{22}$ times faster, or some combination of the two. Assuming [speed is proportional to size](http://kottke.org/15/10/scaling-laws-and-the-speed-of-animals), that suggests a creature on the order of $10^{11}$ meters in size... roughly the distance from the Earth to the Sun. A smaller creature would have to learn to deal with life at very low Reynolds number, as described in [the classic paper by Purcell](http://www.biotec.tu-dresden.de/fileadmin/groups/guck/Seminar/1977_Purcell_life_at_low_reynolds_number.pdf). At low Reynolds number, inertia plays no role whatsoever: you can't push the fluid backwards to propel yourself, the way fish or mammals do. You have to wiggle your body repeatedly to gradually nudge yourself forwards, like a microorganism with a flagellum. There's lots more interesting stuff in that article, for example, there's no point chasing your food, whether it's animate or inanimate: > > The transport of wastes away from the animal and food to the animal is entirely controlled locally by diffusion. You can thrash around a lot, but the fellow who just sits there quietly waiting for stuff to diffuse will collect just as much. ... But what it can do is find places where the food is better or more abundant. that is, it does not move like a cow that is grazing a pasture--it moves to find *greener pastures*. > > > So unfortunately, we're not talking about majestic lava whales or magma dragons or anything like that... We're talking gigantic sedentary bacteria. Sorry. [Answer] At that density swimming is more like burrowing than anything we would think of as swimming. With a viscous material minimizing drag is important, but it does not need controls surfaces or much in the way of fins really just muscle mass, the magma is not going to flow around them much when they push against it. This means they also need an extremely streamlined head more like a burrowing animal except even more pointed. so you have two likely body plans, either a limbless creature like a burrowing snake or sea snake OR you have a compact body with short powerful limbs more like a mole. You could even combine the two with something like a *[Bipes](http://4.bp.blogspot.com/-r657Bg41dvY/U7aUYRlZJxI/AAAAAAAAGV0/R2ZvbpUsg7E/s1600/mexican+mole+lizard.jpg)*. Of course you also have to consider how they get in or out of the magma, since there will be a layer of cooled solid rock no matter how they enter or exit. [Answer] The most energy efficient way I can imagine is as follows: 1. Let's assume the creature can change its body total density (doesn't need much, just to be able to become lighter or heavier than surrounding magma at will) 2. It would have either fin-like horizontal appendages it can rotate in vertical plane 3. The actual movement would work this way: decrease your body density, rotate "fins" , and let Archimedes push you up in magma. Fins will make you move to the "surface" at desired angle. Once you reach depth with same density, reposition "fins", increase body density, and dive at angle in direction you want. And be super patient! **edit to address question in comments** That's correct, to use this method of locomotion, creature would have to be able to somehow increase or decrease it's buyoancy, overcoming enormous external pressure. I would suggest two ways to achieve it: 1) assuming it gets it's energy from fission reaction: let's say it is able to "filter" nuclear material from magma, and regulate the criticality in some way. Luckily we have CANDU reactors to prove that you can have nuclear reaction without enriched fuel. By increasing it's internal temperature, creature would expand it's volume and regulate it's density. 2) or, it can "filter" heavier elements from surrounding magma to increase it's density and "excrete" them out to lighten up. None of methods is fast, of course. [Answer] Basically your magma swimming beastie would use any form of locomotion seen in marine organisms. The main difference is the remarkably viscosity of magma compared to seawater. Consider this creature would be part of a complex biosphere with a multitude of ecologies and difference biomes for magma-dwelling lifeforms. Effectively whatever means of locomotion are used in the marine organisms will have a magma-swimming equivalent. Fish with fins, seals with flippers, manta-rays and sting rays with their wing-like bodies, and cephalopods with jet propulsion. Basically it's all about organisms exploiting fluid dynamics to move through a viscous medium. Magma is just more viscous than most other fluids. ]

[Question] [ We all know that [equation for surface gravity](https://en.wikipedia.org/wiki/Surface_gravity#Mass.2C_radius_and_surface_gravity) is $$ g = \frac{4\pi}{3} G \rho r $$ So if we want Earth-like surface gravity of $ g = 9.81 $, then the equation for radius is $$ r = \frac{3 g}{4\pi G \rho } $$ where $\rho$ is mean density of a planet. So what's the smallest radius, or highest density we can reasonably find in space to give us Earth-like gravity? By reasonable, I mean that it does not have to be common or even normal. I mean that: * It could, theoretically, occur naturally * First reaction of scientists should be *"what a coincidence!"* and not *"it's an alien construct!"* or *"we have a serious problem with our methodology, this can't be!"* Sadly, Earth seems to be the densest body in the solar system, on the "above 400km" table [here](https://en.wikipedia.org/wiki/List_of_Solar_System_objects_by_size), and I don't know how could we get any denser. --- Note: I'm avare of [other questions about small planets](https://worldbuilding.stackexchange.com/search?q=smallest+earth) but here I don't care for life, tectonics, civilizations etc. I want baseline, canonical answer about smallest size for given gravity. [Answer] # The densest reasonable material for a planet is iron The wikipedia page for the [abundance of chemical elements](https://en.wikipedia.org/wiki/Abundance_of_the_chemical_elements) breaks it down a dozen different ways, but any way you split it, by far the most common dense material is iron. In the solar system, Fe-56 is estimated to be the sixth most common nuclide by mass fraction, after H-1, He-4, O-16, C-12, and Ne-20. It occupies the same position in estimates of the Milky Way galaxy. Any answer that suggests a different material to form a planet out of, must give a reasonable explanation for why that other material won't be mixed with iron, which is at least two orders of magnitude more common than anything denser than it. You can check out relative abundances [here](http://periodictable.com/Properties/A/UniverseAbundance.v.log.html) and densities [here](http://www.lenntech.com/periodic-chart-elements/density.htm). The only thing close is Nickel which is also a constituent in the Earth's core. Lead is five orders of magnitude less abundant than Iron; Osmium, Iridium, and Platinum are closer to six. # Making an iron planet Earth's core is mostly an iron-nickel alloy that has a [density](http://hyperphysics.phy-astr.gsu.edu/hbase/Geophys/earthstruct.html) in the 10000-13000 kg/m$^3$ range. However, the planet's density is lower, because of the lower density mantle, composed of periodite and olvine and other lower density rocks. The easiest way to make an all-iron planet is to remove the mantle. How do we remove the mantle? I would suggest one of two ways: a massive collision or formation close to a variable star. Both of these are theories about the [formation of Mercury](https://en.wikipedia.org/wiki/Mercury_%28planet%29#Internal_structure). The massive collision would be somewhat like the [impact that formed](https://en.wikipedia.org/wiki/Giant-impact_hypothesis) the moon. In that collision, much mantle material was blasted off to make the moon. We would need to adjust the collision to blow of *all* the mantle materials, to leave just an iron core to coalesce. A similar explanation has been proposed for Mercury, which actually has a higher iron content than Earth. However, being less massive, it is not as compressed and therefore less dense. The other theory for Mercury's formation is that Mercury formed before the proto-sun had fully contracted. The temperatures at Mercury reached 2500K or even 10000K and turned much of the planet into vaporized the rock. The lightest 'rock vapor' was then carried away by the solar wind. A variable star could have, early in its life, pulse melted and then stripped lighter materials from a planet. If the star cooled later in its life, or became less variable, the planet could have solidified into an iron mass. # How big is a 1g Iron planet? Earth's core density is listed above, and Iron at standard temps and pressure has a density 7870 kg/m$^3$. I'm not exactly sure the density gradient through the mantle, but my estimate is an overall density of about 9500 kg/m$^3$ for a planet with the same composition as Earth's core. This gives a radius of about 3700 km. [Answer] Pulsar planets are made from only the heavy elements. Like [PSR B1257+12](https://en.wikipedia.org/wiki/PSR_B1257%2B12): > > The planets are believed to be the result of a second round of planetary system formation as a result of two white dwarfs merging with each other into a pulsar and a resulting disk of material in orbit around the star. > > > or [4U 0142+61](https://en.wikipedia.org/wiki/4U_0142%2B61): > > This may prove that pulsar planets are common around neutron stars. **The debris disk is likely to be composed of mainly heavier metals.** > > > Now disrupting white dwarfs will cause the spilled material to expand back into normal matter, but will it be mostly iron or what? More generally, a debris cloud made of those elements which did not blow away will be enriched in “heavy metals” so consider osmium, lead, platinum, etc. An object made from this mix would be expected based on what we know, not taken as artificial. To be more surprising, but still presumed natural with better formation models needed, would be that this heavy metal disk was sorted by weight so that planets formed with different fractions, including one that’s made almost completely out of the heaviest elements. Maybe the magnetic fields of the pulsar causes separation by element, so you get one planet made of iron, one of lead, two※ made from the [platnum group elements](https://en.wikipedia.org/wiki/Platinum_group), etc. All the “like” (weight and magnetic moment) material in the cloud is herded into separate bunches in a cosmic scale [mass spectrometer](https://en.wikipedia.org/wiki/Mass_spectrometry#Parts_of_a_mass_spectrometer), and each bunch ends of forming a planet. [Mołot](https://worldbuilding.stackexchange.com/users/809/mo%c5%82ot) calculates that the osmium world would be 1553 km, and lead 3094 km, to match Earth’s surface gravity. --- **※** Period 5 (Ru, Rh, Pd) and period 6 (Os,Ir,Pt) have different weights. [Answer] ### Osmium So, it's pretty exotic to have a pure osmium planet, which is why other answers have avoided it. But exotic happens in the universe. Under normal pressure, Osmium is 22.5g/cm3, whereas the earth itself averages 5.51g/cm3. At surface pressure, [WolframAlpha suggests](http://www.wolframalpha.com/input/?i=(4pi%2F3)(gravitational%20constant)(22500kg%2Fm%5E3)(%3F%20km)%20%3D%209.814%20m%2Fs%5E2) a radius of 1,560km But the vast majority of earth is not under normal pressure. Real proper bods have looked at the compressibility of Osmium (it's not very compressible!) and they [produced](http://www.nature.com/nature/journal/v525/n7568/carousel/nature14681-f1.jpg) this diagram [](https://i.stack.imgur.com/du0Av.jpg) Google tells us that the pressure at the centre of the earth is about 360GPa, so we can read off the volume from the graph at around 40 angstroms^3 vs. 60 at normal pressures, which gives us 2/3 the volume: 33.75g/cm3. So again our [friendly calculator](http://www.wolframalpha.com/input/?i=(4pi%2F3)(gravitational%20constant)(33750kg%2Fm%5E3)(%3F%20km)%20%3D%209.814%20m%2Fs%5E2) gives us a minimum radius 1,040km. ### Neutronium So now imagine that a chip of neutronium has split off a neutron star and (impossibly) remains stable. It wouldn't be comfortable (we would rapidly die) for us to walk on, but... Neutronium has a density of about 4.0×10^14g/cm3, so it's wildly more dense than Osmium, and you would get a sphere of pure neutronium with a [radius of about 8 hundredths of a micrometer](http://www.wolframalpha.com/input/?i=(4pi%2F3)(gravitational%20constant)((4%C3%9710%5E17)kg%2Fm%5E3)(%3F%20%C2%B5m)%20%3D%209.814%20m%2Fs%5E2). So, as long as your planet has a neutronium core, you should be able to have a planet of any radius (bigger than micrometer) you choose, just by wrapping the core in a shield something to stabilise the neutronium. [](https://i.stack.imgur.com/eiarw.jpg) [Huge Kudos to Dietrich-Epp for noticing my terrible maths](https://worldbuilding.stackexchange.com/users/7172/dietrich-epp) [Answer] So I approached this in a more experimental way than theory and plotted the density from [a list of the planets we know of](http://exoplanet.eu/catalog/) and searching for [the densest one](http://exoplanet.eu/catalog/55_cnc_e/) (that isn't a gas giant). So we have: **55 Cancri e** $$Radius = 1.990 \times R\_{E}$$ $$Mass = 8.347 \times M\_{E}$$ So sticking these into the density equation: $$\rho\_{C55e} = \frac{M\_{C55e}}{\frac{4}{3} \pi R^{3}\_{C55e}} = \frac{1}{\frac{4}{3} \pi} 1.059 M\_{E}R\_{E}^{-3}$$ And we know earth would be $$\rho\_{E} = \frac{1}{\frac{4}{3} \pi} M\_{E}R\_{E}^{-3}$$ Then we stick it into your $$r=\frac{3g}{4\pi G \rho}$$ and rearrange for: $$r\rho=\frac{3g}{4\pi G}$$ Where, in units of $R\_{E}$ and $\rho\_{E}$, this is equal to $\frac{3}{4\pi}$, so our new planet with density $\rho\_{K52c}$ would have a radius: $$r \rho\_{K52c} = r \frac{3}{4 \pi} 1.06=\frac{3}{4\pi} $$ $$r=\frac{1}{1.06} R\_{E} = 6010 km$$ Not very far off the radius of earth ($6371km$), but cited as the [densest known rocky planet](https://phys.org/news/2011-04-densest-rocky-planet-astronomers-unveil.html) - perhaps this will at least give some guide-lines for what is seen. [Answer] Reasonable as in unusual but not breaking any laws of physics? Without anything really exotic **About the size of the earths moon.** If we had a body with a core containing a really quite remarkable quantity of Gold, Tungsten, Americium, Uranium, Rhenium, Platinum, Iridium and Osmium with a thin crust of rock over the surface then the density could be in the region of 20g/cc. A sphere with radius of about 1750 km would have a surface gravity of 9.78 This is almost exactly the radius of earths moon, it would be about 14th of earths total mass, a little heavier than mercury. Rare-ish elements but not so rare that a big chunk couldn't be explained as an unusually pure chunk or the heaviest elements from the core of a larger destroyed body or some such. You might want to cut out the radioactives there since it could cause super-critical complications. [Answer] A recent study [[1]](http://online.liebertpub.com/doi/10.1089/ast.2016.1475) has found that, despite showing ostensible differences in mass and size, a considerable number of the extrasolar planets discovered so far have a surface gravity very similar to that of Earth. Firstly, the surface gravity of the small bodies in the Solar System and rocky planets smaller than Venus grows with the square root of the mass. Secondly, in the case of gaseous giant exoplanets, the surface gravity linearly grows with the mass. And surprisingly, in the transition zone (between 1 and 100 land masses), we find some sort of plateau that shows a constant surface gravity roughly similar to that of Earth. So, it seems to exist a correlation between mass and radius of the planets in order to sustain this plateau. So, from the figure the answer to your question is: Earth is the smallest reasonable natural planet with Earth-like surface gravity, or Venus if you want do give some concession. [](https://i.stack.imgur.com/wBFlj.jpg) ]

[Question] [ Ruins of many kinds are a staple of stories whether for games or tales of high adventure. My question is about the design process behind such structures: should one start with a city or building and break it down or start with the ruin and justify the finished form afterwards? In short, to maintain realism and continuity, should design drive story or vice versa when creating formerly inhabited landscapes? Assume that the final audience will have no knowledge of the history of the location. They only see what has become of the site. [Answer] # Start with the people then the city then the ruins Cities always arise from the culture and situation of the people who built it. Their priorities will be expressed in what buildings are where and what they look like. Modern skyscraper-filled cities emphasize maximal value per square foot. Hobbits for some reason really liked round doors to their homes. Bedouin prioritize mobility so they lived (still live?) in tents. Examples abound. Starting with the city allows the author to build up a richer world (if they choose to). They can explore the culture of the people(s) who build the city and their history. From this city, one can design a reason to turn it into a ruin: famine, plague, flood, fire...whatever you like. However you choose to destroy the city will effect what your heroes will find there. ## Story and Design evolve together One could take a purist approach and do all the design first then write a story to match. This is valid. The other purist approach is to write the story (as much as one can without a scene) then build the ruins to match. This is also valid. In reality, it'll be a mix of both. Start with an idea for a story or an idea for ruins then start building. Maybe you'll find something in the ruins that drastically changes the story. Maybe the story will demand that the ruins are burned down in a massive fire because that fits the theme of the story better. Either way, the story and the ruins are malleable to the needs of the other. [Answer] ### It depends on how important the buildings are to what your audience is supposed to do with them There is no need to create the whole city in every detail beforehand, you normally just need a rough idea where your family-friendly neighbourhoods should be or your shopping centers. Just make sure that if your audience should get the feeling of being in a normal city of our current time, just broken down, you wouldn't suddenly find a big farm in the middle of a city. You should design important places. That mansion with the ghosts of the deceased - how much room is around that one? Is it lodged firmly between 21st century apartment blocks or is there a patch of land around it for the former residents? That tower you erected in the middle of the pond in your park - why is it there? It sticks out because the design is unusual, so you should prepare a bit of background knowledge. Other than these special characteristics and a general layout of where you place different regions you shouldn't spend too much time with the original city. It's destroyed after all and trying to unearth the secret of every families normal home is probably not what your audience is trying to achieve. ### Step by step * draw a rough sketch of your cities outline or take a map of an existing city * make a few dots where you want special locations * flesh out the immediate vicinity of your special locations so that you know how to describe them and have information about why they look the way they look * the rest between those little circles should be filled with very rough regions like "shopping district" and "friendly neighbourhood" and "industry" * if your story, in whichever form, takes place on the streets and those parts are important you should draw lines between the dots and flesh out each line a bit ### Adjust this depending on how much information you want your audience to be able to unearth If you are making a game for example it can be very interesting to find things like diaries that explain the daily lifes of whoever wrote the diary. Depending on how many options you want to give your players (or any other audience) to uncover secrets of the past the more you should focus on building a city first and making it a ruin second. But again you should focus on what you are trying to achieve. Describing general everyday life activity is enough for the rough regions and describing every detail is important and very useful for special locations. But don't waste too much time on every single house. They probably look very similar, with a few differences regarding the color, most of which won't be visible if the city is in ruins. The size is probably roughly the same with small variations. You normally don't have extremely rich people with big mansions living next to poor fellows in the slums if that is not the focus of your story or a point that you want to emphasize. [Answer] Without going so far as building the entire city, I think you should at least sketch the functional layout of the city/landscape itself, and following that placing the ruins of the building in a logical way. I mean, in a "normal" western city of the present time, would you find a nuclear power plant next to a XII century monastery and the stock exchange? Probably not. You would find industries concentrated in a neighborhood, residential areas in other locations and so on. Or, if your city was spread with small volume craftsmanship shops, in that case the layout will be consequent. [Answer] Are you building the world for a novel, a computer game, or perhaps a pen-and-paper RPG? * With a novel, you have the most control over the setting. If the **character** didn't think *I will go to the bathroom to shake the pursuer and see if it has windows*, then it does not matter if your fictional office building had an improbably high or improbably low number of bathrooms. * If you are writing a computer game, the players have some freedom to move about, but as the programmer you have control. The door does not open. * In a pen-and-paper RPG scenario, you have players questioning the GM in unexpected ways. You have to do the most work to keep things logical. Even so, you have some freedom to fudge things. So my suggestion would be to go with a mixture of designing the ruins "as a stage" and designing the pre-ruin city and ruining it. If you need a tunnel through the ruins from A to B, put it there. If it wasn't a disused subway line, then it held utilities before a change in zoning laws, or telecommunications, or whatever. [Answer] To make the world feel complex, I would--always--start with the previous culture and people that the city sprang up around, though you don't need to go in any true depth. A rough outline should be enough. Even if the audience is never told a single thing about the lost culture, how they lived and what they did will vastly influence everything from architecture to room design. For instance, a people with wings may not bother with ground floor doors, but concentrate on balconies to land on, or entrances on roofs. Depending on wingspan, rooms may be large and sparsely decorated. Then again, a race that climbs like a monkey may favor ladders, grabbing protrusions or walls built specifically to climb to another room instead of stairs. Dwarves, hobbits, and other smaller beings may favor spaces that feel spacious to them but cramped to humans. Also, what and how they eat--think Skyrim and it's open fire pits without even a chimney versus a Victorian kitchen. If they focus on meat then more slicing tools may be left behind, but if they focus on corns or grains there would probably be tools that grind and crush. While the audience may never know the people who lived there favored pasta, old pasta making tools scattered about (especially in a visual medium like comics or games) would be an interesting touch. Since all these things could easily be used by your characters as they roam the ruins, knowing what might be still hanging around would be important. Decoration, too, is unique. The difference between Egyptian and Aztec hieroglyphics and chosen patterns and colors, for example. What deity is worshiped may also have a lot to do with decoration, and, of course, there are those all important worship spaces like the Japanese altar or the chapel found in castles and fortresses. Temples alone may not house religion, and religion often influences design schemes of both architecture and decoration. I assume you already thought about class--the rich and poor having different design schemes--but families and clans may have them too. If your lost people would have had insignias, banners, or other markings of their importance, it might still be around in rotting tapestries or carved into stone. It might even be found in strange places, like wrought in metal over an inn door that they owned but employed others to run. Families and clans can consist of the poor as well as the rich, so different insignias might be found in surprising places. Then there's just the architecture itself, which will be based on the people and their culture as much as the environment itself. For instance, do the keep grandma in the attic or in a wing or room of her own, or is the whole family liable to sleep in one room? Do parents and children share a bed? Do they marry multiple spouses and all the spouses bundle up in one huge bed? Do spouses sleep rigidly separate, with a special bed or altar for conjugal visits? Do they live completely separately, only meeting in a special garden? Are children banished to one part of the house or given free reign? Are they put to work as soon as they're old enough to perform simple tasks or schooled, or is the answer to that class-based? Do they bury their dead in graveyards or beneath the floorboards, or do they just burn them or give them to a river? Do they have statues everywhere, or do they have no realistic images because they're superstitious about evil spirits taking them over? Environment is also key to design--think stilted houses in flood planes, rounded huts or buildings in areas of high winds, sloped roofs in places of heavy snow, and so on. You can also add interest by showing local elements in design--a certain type of black stone, or perhaps a lot of hard-fired red clay, etc. A sun worshiping race may have a city that radiates out in spokes from the center like rays of the sun, while one that grew bigger than the space it's crammed into (think Sedona or San Francisco for cities with space issues due to environment) may be cramped with narrow streets and buildings that go several stories tall. The nifty thing about humans is we have some serious pattern recognition abilities. When you have consistency in your design of the city because you know what and how things were used in the past, it doesn't matter if whoever you are maneuvering through the ruins knows anything about them, if the walls have fallen down, or if only parts of structures and scattered items are left. They're going to recognize the same wrought iron wolf's head and wonder what it once meant, or the constant use of blues and greens in tapestries, or come to expect to find holes for storage in the kitchen of every poor man's house. And because they can pick out those patterns, it'll feel so much more real and alive to them, and they'll be as curious and intrigued as your characters. We don't need to know gross national profit or marriage customs or biggest exports or even the system of government (beyond really obvious leftovers like execution areas or jails). But a sketch of the culture-that-once-was will really enliven and add realism to your creation. ]

[Question] [ Assume a plant was engineered to cope with a wide range of different environments, and to have seeds that were capable of traveling through and surviving both the depths of space and re-entry into atmosphere. Given this assumption then you can see these plants would slowly (much slower than light speed of course) spread throughout the galaxy. The problem though is gravity wells, how would the planets get their seeds into orbit with sufficient escape velocity to reach other planets or better yet other solar systems? Is it even possible for a purely biological process unguided by intelligence (other than that which designed the planets in the first place) to do this? [Answer] # How much energy do we need? Well, the escape velocity of the Earth is $11,180 m/s$. To accelerate 1 gram to this speed, you need: $$\frac{mv^{2}}{2}$$ $$\frac{1g\times (11,180m/s)^{2}}{2} = 62.5kJ$$ To find out how we could possibly generate that kind of energy, [the heat of combustion of methane is $55.5kJ/g$](http://www.wolframalpha.com/input/?i=heat+of+combustion+methane). It seems like this might not be as far fetched as it would seem at first glance. (Though I would suggest that your seeds are made of [handwavium](http://en.wiktionary.org/wiki/handwavium) to explain why it survives the explosion and the air resistance it would face) # What's the evolutionary advantage of intermediate steps? I think the first step isn't too terribly unlikely. Imagine a plant that produces seeds and then explodes when it's ready, thus spreading its seeds over a larger area. You could even say that the underground parts of the plant survives the explosion and grows back in a few years. Now imagine that this plant looks a bit like another plant that the local fauna likes to munch on. And that, when you apply too much pressure to this plant when it's ripe, it explodes. This would result in most of the seeds flying off as usual. Some seeds would hit the animal though. And if these seeds have enough kinetic energy, they might even kill that animal. This ensures that the seeds have plenty of food when growing into plants themselves. As a side effect, some seeds could be shot straight up. I'm not quite sure how to justify the step from seeds flying fast enough to reliably kill an animal to them flying fast enough to escape the gravitational pull of the earth (let alone the solar system). Some wild suggestion that pop into my head are a weapon race with an animal that develops thicker and thicker skin and the idea that if you explode hard enough,you might kill some animals standing a few meters (or kilometers) away as well. # What is the benefit in the end? I think this is where it falls flat, If you somehow manage to reach escape velocity and against all odds actually hit another planet and this planet is capable of harboring life, you still only have one plant (correction, one seed) in an ecosystem it is very likely not at all adapted to thrive in. Hardly a big advantage over other other plants. Luckily as the writer you can just decree that two nearby planets (or a planet and its moon) just so happen to have similar ecosystems. [Answer] A lot of the answers seem to be focusing on the amount of energy required to launch a seed to escape velocity. However there is another possibility to consider. Light gasses such as hydrogen and helium naturally escape from the Earth's atmosphere all the time without needing any sort of explosions. A combination of the lighter than air nature of these gasses and the average speed of individual molecules in these gasses contribute to this. This suggests an alternate possibility. Perhaps you have a plant which grows a seed which is a large balloon-like structure filled with hydrogen gas. Better still, not just a single seed but thousands or millions of tiny seeds. It is not unreasonable to expect a plant to evolve which can split water into hydrogen and oxygen, venting the oxygen to the atmosphere and slowing filling a balloon-like cavity with the hydrogen as it grows bigger. At a certain time in its growth cycle the seed balloon would be released and float through the atmosphere to a new location. The natural course of evolution would of course dictate that most of the time the balloon would release its seeds before ever leaving the atmosphere, but sometimes this would not be the case. Perhaps the mechanism which regulated when the seed balloon separated occasionally was faulty and it continued to grow and accumulate an excess of hydrogen until its excess buoyancy exceeded the tensile strength of the vine it was attached to. There are many possibilities. Once this seed had cleared the atmosphere it could continue to float into space. Perhaps the vacuum of space would degrade the skin of the balloon and eventually it would pop, ejecting various seed pods in all different directions, some of which would eventually reach another planet. Now as far as re-entry it is easy to imagine something like dandelions, where re-entry would be slow and gentle due to the seeds having something like a parachute preventing them from falling too quickly. Update: Doing a bit more research on this, it appears that the issue of the balloon making it out of the atmosphere can be overcome if the plant-material can stretch enough to allow the balloon to expand a great deal so as to allow the interior pressure to continue to exceed the (tenuous) external pressure. In addition, at a high enough altitude, the solar wind and possible interactions with the planet's magnetic fields could provide an assist, with the enlarged surface area of the balloon capturing the solar wind like a sail to propel it away from the sun and out of Earth's gravity well. So having the balloon actually *pop* due to pressure wouldn't be beneficial, instead this should occur due to a slow natural breakdown of the organic material after an extended exposure to space - perhaps in the atmosphere this breakdown would occur due to passing through storms or over longer periods of time, creating a lengthy gestation period of many year similar to cicadas. [Answer] ## No Space has to be a *natural force* in order for plants to use it. Plants do use wind or water *simply because it is here* Using water, air, or other animals (either on fur or via digestive system) will get you *somewhere* even **if you are not aiming** **Space is hard.** To get somewhere, you **have to always aim** Even if you could evolve mechanism strong enough to shoot your seeds to a speed of escape velocity, there is nothing granting you, that such seed will eventually end up somewhere. **Space is empty.** Getting from planet A to planet B is feat of engineering, because everything is constantly moving and rotating. And everything happens relatively fast. Not to mention that your seed would have to be extra durable to survive planetary re-entry (you have no engines to break, do not forget). So your seed would theoretically enter other planet at speed 11.2 km/s (25, 200 miles/hr or 40 320 km/h or almost 3 Mach). You would need really durable seed to survive that. **Space does not support life. Neither do planets.** Look at our Solar system. There are 9 Planets - Yes, I refuse to put Pluto out - and the **only** planet where we 100% know is supporting life is ... You guessed it, the Earth. Suppose your plant could survive on Mars, Titan and Europa. There are [189](http://www.windows2universe.org/our_solar_system/moons_table.html) targets to hit in solar system (not counting the asteroids). So the probability of hitting something supporting life is 1.5 percent. Good luck **Long story short:** Without changing universe to the ground, your idea is not feasible [Answer] It would have to be **engineered in.** Imagine this scenario: In corner A, we have a **variable red dwarf star**, with a predictable cyclical flare-up period, in that every x \* 100 years it intensifies its activity pattern for a few centuries (perhaps due to the influence of some stellar companion, not gonna bother with those physics). **Orbiting this flaring star we have two planets** in a tidal lock with the star, each with a potential eye-of-sauron-style hot starside, cold night-side, but with a solid life-belt on each. During the star's normal activity, the Planet A is nice and tree-habitable and Planet B is too cold. During the flareups, the star's radiation would sterilize A, while B warms up to be nice and habitable. Enter **Deidre Skye**, **xenobiologist and ecopoet extraordinaire**, with the full resources of her [Kardashev II Culture-share](https://worldbuilding.stackexchange.com/questions/10463/a-trillion-unruly-gods) at her fingertips. Her stellar white pines, besides being fantastically beautiful, have a set of heliotropic & heliometric mechanisms that detect the early warnings of an impending flare-up (while on planet A), decades in advance. This triggers a strange kind of hoarding behavior, whereby the oldest pines with the strongest root systems start to grow to an impressive size, while hydrazine accumulates in the cold safe confines of the deep root system. The fertilized acorns (or whatever the heck pines produce) are placed in these strange solid pods, with metallic buildup and a ridiculously low friction quotient. The **whole tree turns into a giant hyperorbital cannon**. Each time the fuel accumulation process is complete, the tree fires the pod out into space, in a direction determined by the season and the current location of the star in the sky. Cocooned in its protective shell, the acorn-whatever survives the insane acceleration of launch, and if the launch is successful, is placed on a Hohmann transfer orbit to planet B. With luck, some of the seeds land in the soon-to-be-habitable zone of Planet B. During the flare-up, these seeds grow like crazy into their adult forms, and instantly start to accumulate reserves for the reseeding of Planet A, since the flareups only last for a century or so. [Answer] **Getting into Space** Once your seed is in space for a long period of time (aka. is not in a suborbital trajectory), there are very few obstacles to it exploring the whole galaxy. Indeed, given enough with time, gravitational perturbations from asteroids or moons (or even planets and stars at bigger scales) can increase (or decrease) its velocity, thus its orbit. If you are lucky enough (which basically means "if you have a huge number of seeds), there is no obstacle to one seed leaving the solar system. The main thing getting in the way of that occurs at the very beginning: from the ground, it is impossible to launch something into a stable orbit. That means that you have to *not go through a stable orbit* but instead go *straight to escape velocity*. Let's make some calculations. I'll assume your seeds weight 1g. * from Earth, the seed needs around 5x10^4J of kinetic energy to get to escape velocity. That is the energy liberated by around 12g of TNT (according to WolframAlpha). That doesn't seem much, but: (1) all that energy needs to be delivered upwards (as opposed to "in every direction" as is usually the case with TNT) and (2) your seed will be slowed down by the atmosphere. That means Earth is a no-go. * from something like Titan or Europa however, escape velocity is much smaller: around 2000J, that is .5g of TNT or the energy obtained by burning 0.07g of ethanol. I think that a plant might be engineered to trigger something like that. You still need a bit more energy in order to account of the atmospheric drag, but if you are lucky enough and get helped by a geyser (which seems to exist on Europa), it may work. **Surviving in space** Space is empty and cold, and we are talking about a 1g seed. Solar panels or any form of energy seems a bit far-fetched. So the seed has to go through a sort of hibernation, similar to the one that can experience some extremophiles. AFAIK, we don't know of any specie that is able to survive a long-term journey into space. **Landing** The good thing about spending a lot of time in space is that gravity starts to add up. What I mean is that it is possible that your seed will meet an asteroid along the way and be progressively embedded into it. Maybe it could protect it during the landing as a heat shield? **Natural Selection** Now, why would a plant choose to propulse its seeds as far away as possible. Well there is one big advantage: it enables the plant to expand its territory. There are already a number of mechanism to make sure that the seeds do not end up too close to the morther-tree (getting animals to eat them, give them winglets and hope for a good wind...). And propulsion might be an other one. Moreover the plants could start by sending seeds on suborbital trajectories. This has a double advantage: * It fills the gap between "sending the seed 5 meters away" and "sending it on an interplanetary trajectory". * It explains why the seeds had to evolve to be able to survive in space. **In the end, I think the answer is yes, given enough time, but it seems complicated if you start from Earth. A smaller planet may be a better starting point.** [Answer] Overactor hit upon many of the factors but I don't find his answer complete. There is no chemical explosive powerful enough to throw a seed off an Earthlike planet. This doesn't really matter, though, because you can't push any reasonable-sized seed through a terrestrial atmosphere with a single launch impulse anyway. However, rockets could do the job. Why would a plant develop a rocket? It's on a world with no weather and no animals, it lacks any other means to disperse seeds. It would be an extremely unlikely evolutionary step but not utterly impossible if the core of the plant was an energy-storage chemical capable of self-combustion. Once you have even a crude rocket it could evolve from there. Alternately, it could be an engineered plant. Think of the stage trees of Larry Niven's universe. A long-extinct race of biological engineers created a plant that good specimens could be used as strap-on boosters for rocket launching. Now, combine that with a very small seed with a sail--it could be boosted to the stars by the solar wind. Incredibly slow but not impossible. Edit: Another version of this comes to mind: The rocket launches a seed pod, once the pod is above the atmosphere it separates into two parts--the rear one being a hydrogen bomb. The seeds would have to be very radiation resistant. The advantage of this approach is that you don't need anything like as powerful a rocket to do it, the plant doesn't need to be nearly as perfect. A nuke would most certainly require it to be an engineered species. We do isotope separation by means of things that proceed faster for lighter isotopes, there's no reason a plant engineered to do so couldn't separate the uranium out. The hard part would be separating out the deuterium--the separator can't very well have hydrogen in it's makeup and hydrogen is one of the big components of a plant. [Answer] The plant would need to evolve for these qualities: * High conversion rate of CO2 to oxygen compared to its mass * Photosynthesis with very high efficiency (absorbed light vs. generated calories) * Able to grow in confined space with minimal soil * Able to grow in microgravity * Either large yield of edible fruits with high nutritious value or being nutritious itself and very high growth rate. It would then be the ideal plant for a spacefaring species to use as a hydroculture on board of their space ships and colonies on other planets. They would take it wherever they travel and spread it with them around the galaxy. Does this answer sound like a cop-out? Then please keep in mind that there are quite a lot of plant species which depend on animals to spread their seeds. [Answer] Depends on what you start on. Earth, I think is very unlikely other than maybe by accident, Large impact shoots plant material into space and it some how travels and survives landing on another planet. The more likely scenario IMO would be a plant (engineered as you say) living on small planetoids or asteroids. Something already designed for the harsh environment of space with little resources. It could then be able to 'shoot' its spoor into space much easier, maybe with a hard case nut, and the seed doesn't germinate unless it hits something hard or has it burned off by reentry. The idea of course would be in general to move in solar system but some might reach another system after many 1000's of years (maybe millions). EDT: Colony organisms (like lichen) or self cloning would be necessary for a lone 'seed' to be successful when it germinates. [Answer] I'm not sure why so many assume the plant would emulate the human method of getting to space. It'd be much easier to use the hydrogen from photosynthesis to fill a membrane and float a seed pod to the edge of space. Air density does the work. From there, release microscopic seeds to catch some solarwinds. Floating that high would certainly be beneficial to dispersing around a planet, leaving orbit might just be an incidental and advantageous accident. [Answer] I think it's worth mentioning "stage trees" here. These are in Larry Niven's "Known Space" series ( <http://aliens.wikia.com/wiki/Stage_Tree_(Known_Space)> ), plants that grow into solid-fuel rockets to spread their seeds. Most of the time they develop into a single-stage rocket that only delivers the seeds elsewhere on the same planet, but can, if they grow from particularly resource-rich soil, grow into a multi-stage form that can get their seed pod to escape velocity. The stage trees were genetically engineered as rocket boosters, but later went feral and spread themselves several light years (over many billions of years). [Answer] This might become feasible if many assumed restrictions are lifted, most importantly - that this isn't Earth. 1. Gravity and atmosphere density - the 'plant' would need to depend more on soil/fluids than on gases, but it would get around the problems of drag, escape velocity and reentry. 2. Definition of 'world' - perhaps, rather than the planet itself, the habitable environment is its planetary ring system. The individual moonlets, etc, would then be the equivalent of continents and islands, and collisions/fragmetnations would be frequent. Also, the organism may then have entire chunks of rock to detonate, asuming it can process the minerals. 3. The plant may be very different than what we may associate with the term - possibly using a different process than photosynthesis. 4. Scale - considering the failure rate of 'unaimed' space travel, you'd need orders of magnitude more time and resources (space volume, mostly) than you probably meant. But then, the Universe is old. 5. Symbiosis: the plant may be capable of this on its own, but the development of the process is not feasible without aid from non-plant organisms. The internal 'caretakers' may add aiming capability, or fashion MIRVs and thrusters ejecting depleted debris rather than spores. I envision depleted central areas inside bubbles of the organism using 'nets' to gather and connect accumulated rock chunks, with different strategies for growth and dealing with competition (note that integration is likely); and then progression to space invaders aiming to use all mineral resources in creation of Dyson rings and more ships. An interesting idea, though likely not what you're looking for. [Answer] I base this on the **assumption that we are aiming for having any kind of plant life** on planets far away that do not currently harbour life (not necessarily spreading Earth's life). To describe an upper bound of the method, I'll look at it from a high level perspective, refering to the other answers for the "technical details". Based on this, I will show that - depending on various unknown estimates - the method of sending germs may not be worth it - because nature is faster: The idea is doing that by spreading life from earth to other planets, using some kind of suitable germs. The germs do not use propulsion, and are send out in random directions. Based on other answers, I assume it would require a very huge, even **astronomical number of germs**: So, we hope to create one or more plants during the next couple of billion years. We need a large number of germs to expect even a single one point at a suitable planet. But very few of these will end up on the surface of the planet and be still alive (and that's already assuming they stay fresh for a billions of years.) All in all, that will be expensive. But let's assume we have "suitable funding". So, we can plan to use **all resources of the earth** to produce and send germs. Now we could, in principle, calculate a probability of succeeding, assuming we go to that limit. Now, the interesting point: I suspect that it may be more probable that live develops by **independent evolution** on the planets. Of course, the probability of life starting from molecules is hard to tell, but, for some definition of "succeeding" above, we could compare to find out whether nature may succed way before us. [Answer] Hmm. Others have mentioned the idea of forming a balloon, but it meets the objection that it just gets to the edge of space and pressure changes would likely cause it to burst. Ok. What if it grows a balloon pod that is smooth and aerodynamic for gaining good upward velocity, and when it's about ready to launch, it boils some chemicals to get a hot thin gas inside. Then it launches up to the edge of space with maybe a little upward velocity left... ... and then it explodes due to lack of pressure, and maybe some of it combusts too. It's shaped to have the explosion/combustion provide a little more upward velocity to part of it... That would be nowhere near escape velocity for an Earth-like planet... So what if the upmost-part of the exploded balloon fragment forms a sail shape, to catch the solar wind. This remaining bit of the membrane might be quite light but does gain momentum from solar wind. Plants can sense the direction of sunlight, and adjust themselves to face it, and the structure of the membrane might be able to shape in response to the wind, to catch it, and since it's light and spread out over a relatively wide surface area compared to its mass... It would also act as a parachute to lightly set it down if it happened to land on a planet with atmosphere. Maybe that could sail out of a planet's gravity well? I don't know, but I kind of like the idea. I don't know how or why that would ever get evolved or even engineered, and most of them would just fly out into space and most of them would miss everything. [Answer] Seeds, no way. Spores maybe. I've seem work done in real biology involving bacteria taking rides on hyperbolic comets to other star systems. Given the numbers involved, I would still consider it rather unlikely. You're not going to make the jump in one step. Spores won't be viable that long as the transit time exceeds DNA decay time. How is your plant gonna live w/ only starlight? [Answer] What about having a planetary crisis as its starting point? Imagine a civilization with fairly advanced genetic engineering but space-flight capabilities similar to our own. Then, they see a planetoid on a collision course with their own planet - no way to deflect it or change its course, they know they are doomed. Once the planetoid hits, their planet is going to broken up into many, many chunks. However, someone's pet genetic engineering project was to make a plant that could survive in space on an asteroid. Lo and behold, because of the planetary impact some of these plants wind up on a chunk of the planet that is going to be able to escape the gravity well of that solar system. As they get farther and farther away from their sun, the metabolism of the plants will slow way down. Occasionally, one of the plants will release their seeds. Thanks to the significantly decreased gravity, it won't be too hard for many of the seeds to leave the now-asteroid. They'll still be in the gravity well of the asteroid, but it won't be too hard for a passing solar system to snag a few. If this asteroid manages to avoid being caught in a solar system itself, then over time it will be able to spread seeds to many solar systems. If this were to happen earlier in the lifetime of the universe, then I believe planetary collisions would be more common. That would allow the cycle to repeat more frequently - plants surviving on a chunk of a planet that was broken off during a planetary collision. As the number of stray asteroids with plants on them increases, the rate at which these plants can spread will also increase. [Answer] A seed(as we know it) is only relevant here on planet earth. There is no plausible way any living thing could know how to package a seed for another planet. The only way is sending DNA code.. Which is why all living things are built from DNA code. DNA can survive in the right conditions.. This is probably how life came to our planet. Life on our planet based its structure around carbon. But on another planet the same DNA could use a different host. Life on another planet from the same DNA would look very different. Also It appears that a lot of comments on this forum are based around these things happening relatively quickly.. Ideas are being written off because the time scale can't be fathomed. Any travel in space will not happen in a human lifetime or maybe even in the planets life time but the goal would be to create DNA code which could survive indefinitely. And then the possibility of landing in the right environment where it can use resources to continue its progression. I guess that is why humans are around. We might be able to work out a better way than just leaving it up to nature.. Or maybe we are nature. Of course we are nature. And we are this planets best chance of getting our life to another planet. The only other way would be if this planet was hit by something very large and earth material was launched into space. [Answer] **It packs itself into the mouths of volcanoes** The plant can survive most environments but its favorite is the high-sulphur environment of active or dormant volcanoes, where it grows especially densely. Coincidentally, this sometimes results in them being blown into space in large quantities. When seeds reach a new planet they eventually spread out over the surface and grow in any volcanoes they find, continuing the cycle. ]

[Question] [ Being on the autism spectrum is often described as a feeling of being on ["The Wrong Planet"](http://wrongplanet.net/) So I'm wondering what the right planet might be like... For those that are unfamiliar: * Social conventions aren't always obvious to the average [person with Aspergers'](http://en.wikipedia.org/wiki/Asperger_syndrome) * Non-verbal communication is often difficult. (Making eye contact and recognizing facial expressions) * [Stimming](http://en.wikipedia.org/wiki/Stimming) is common. * Sensory issues are also somewhat common. (sensitivity to lights, sounds, textures) * There's some evidence of trouble with [theory of mind](http://en.wikipedia.org/wiki/Theory_of_mind) * Highly [specialized areas of interest](http://en.wikipedia.org/wiki/Asperger_syndrome#Restricted_and_repetitive_interests_and_behavior) are a key feature. In my **Completely Fictitious Scenario\***, people with Aspergers' are an evolutionary result of over-specialization and are so good at specializing they eventually inherit the Earth. What would this society look like? How would things function? \*(I really can't stress the fictitious part enough, way too many false theories on autism go mainstream...) [Answer] As someone who also has Aspergers, and comes from a family of aspies, I can state with some certainty that aspies tend to pick a subject of interest, stick with it and become very good at it. That subject could be almost anything other than idle social interaction. My father is undiagnosed, but we have no doubt that he's an aspie, and his area of interest is gardening, specifically orchids, but any gardening interests him, so farming interests is not beyond the bounds of possibility. So, we'd have a society of specialists. They'd probably achieve more than the neurotypicals ever did, as they would be driven by their obsessions, rather than wasting so much time engaging in frivolous chit chat. Conversations would be more goal-oriented - Aspies tend to like talking about their area of specialty, just not meaningless trivialities. After quite some time in an aspie world, I predict that language will become more precise. Aspies tend to be quite pedantic, and can have a hard time accepting misspoken or ambiguous statements even when they know what the speaker *should* mean. If Aspies inherit our world, then I predict that much communication would be via impersonal means such as texting or email, then telephone, and the last preference would be for face-to-face, except with friends and family. Don't expect much telemarketing any more - an aspie would hate to cold-call someone, and if called by a telemarketer, would typically just hang up or say something rude. Any advertising would tend to appeal more to logic than emotion than is the case now. You may still get wars; while aspies dislike direct conflict, there is no reason why wars might not be fought by proxy using drones and robots more than by aspies with guns. Why send a man to do a job that a robot can do better? [Answer] Most people can be classified as Extrovert vs introvert. Extroverts tend to be more outgoing, expressive, and capable in the social domains. Most leaders tend to be extroverts...from team leads to management to political leadership. Aspie's are pretty much introverts by definition. They tend to be the thinkers and workers, but struggle when it comes to human relations (for a variety of reasons...usually an inability to comprehend non-verbal queue's, though anxiety in general can come up here). Programmers and researchers tend to be introverts as they can reach highly specialized knowledge but tend not to share it readily. So our Wrong World here is ultimately a world full of dreaming introverts. Stackexchange is actually a haven for Aspie's...English is a pretty exacting language and it's hard to interpret the same words in multiple ways (unlike human body language that can be interpreted in any number of ways). It's from behind a computer screen, which tends to negate the feelings of 'being judged' and allows the anxieties to play out in a personal space where they can be managed. If I may speculate...I can see the internet social domain expanding heavily and starting to function at a governing level. Websites where people can post idea's, comments, answers, etc...and have the discussions on a non-personal and exacting level (Having multiple meanings to one thing and not being able to determine which of those meanings is correct can be a source of anxiety, so expect highly specific wording to avoid any of that). Arguments and conflicts still happen, but it tends to be relegated to the comfort of anonymous internet discussion. The problem with this society is it becomes incredibly reliant on each other...no specialist can really exist without having a wide array of others to depend on. So you have people incredibly reliant with each other and the preference not to directly communicate with each other. If this highly specialized setup is disturbed, it tends to collapse with little ability to stop the fall. The other issue that comes out here...the information industry is well suited to an Aspie. Horticulture (read that as gardening) and small scale manufacturing (artisan style) is also very well suited to Aspie's. Mass manufacturing and mass agriculture is not...high accuracy tasks that must be preformed repeatably as industry and farming requires are poorly suited to aspies (boredom and drifting mind issues hit here). You'd likely see a move away from the mass scale industries and more towards small scale 'cottage industry' type setups. Whether or not this can sustain the semi-fragile nature of this society is for more speculation. End note - I'm a diagnosed Aspie. It presents as anxiety that comes up in non-familiar social situations and tends to make me seem quite and a bit withdrawn. I don't mean to offend anyone with this answer and would be interested to hear other peoples takes on it. [Answer] After giving this a bit more thought, I think a "Wrong Planet" would differ quite a bit from person to person... Here's a bit of what my world would be like in no particular order: * Nepotism would be a thing of the past + Replaced by Meritocracy. * The fashion industry, would dramatically shift towards comfortable, functional attire. + The tuxedo would be a distant memory. * Florescent lighting would be carefully maintained, or replaced with lights that are less likely to flicker or hum. * Naming conventions would lean more toward meaningful descriptive titles or sequential numbers. + No more silly items on restaurant menus... - "Rooty tooty fresh and fruity" would just be: "Pancakes with fruit and whipped cream". - "Big Mac" would just be: "Standard Hamburger" or "Basic Hamburger" + 1st Street rather than `<insert important person>` Street. * Being efficient would be favored over being friendly in customer service situations. * Advertising would be purely informative. + "Product X has new feature Y" Full stop. * [Education](https://xkcd.com/987/) would be tailored to the student rather than to an average. + Expect a lot more online learning and self-education. * "Big Box stores" would largely be replaced by markets filled with independently owned and operated, highly specialized, artisanal shops. * Robotics would become a major industry. + Most manual labor would be done by robots. * The metric system would replace imperial measurement. + Except for pints, beer would still come in a proper pint glass. * Personal space would be a standard measured distance. * People would be expected to ask permission before hugging, shaking hands, etc. with unfamiliar people. * [Turn signals would have a standard blink rate](https://xkcd.com/165/). * News media would change significantly. + News organizations that presented opinions as facts would be fined. - Not eliminating opinion pieces altogether, but opinion pieces would have to run with a disclaimer. + Retractions and corrections would have to receive as much, if not more, airtime or print copy as the original piece being corrected. * [Most "small talk" would be eliminated](https://xkcd.com/1324/). * Public transportation would run on time. * White collar crime would carry the same sorts of penalties as regular crime. * Long rambling lists would become a highly respected poetic form. --- As a side note, I think a lot of people underestimate the diversity of interests that Aspies engage in. The idea that aspies are only interested in STEM fields (Science, Technology, Engineering and Math) is a misconception. My wife for instance is an amazing sculptor and visual artist. [Answer] It would be wonderful place full of interesting people quietly going about doing poetic beautiful things. However, there would be issues with practical matters such as: where will all the food come from, where are we going to live, who is going to do all the manual work, who will go down the sewer and fix the blocked drain, etc. I like computers, my son likes chess, neither of us is going to be much good at running a large scale food production facility. Neither of us could co-ordinate contractors to build a housing estate. Neither of us could administrate a university, or organise a conference, or even throw a successful party. I predict a wrong planet would be amazing for about a month, then everyone would starve or be eaten by polar bears. There's a reason AS genetics are in the minority. [Answer] I think you would find that a good many things, like those social conventions that are supposedly obvious to 'normies', would be taught instead of leaving them to be deduced. Likewise, more people would actually say what they mean instead of expecting others to guess - and the normies would just have to learn to deal with that. We might also expect (assuming we're starting from current society) more stringent light & noise pollution laws. Tossing a hand grenade into a boom car (one of my passing fantasies) would be seen as a laudable act, rather than a crime. ]

[Question] [ Take a torus planet:  It has the structure of a normal planet (ours):  The diagram is not to scale. Assume similar proportions of Crust:Mantle:Cores as the Earth. Is has a similar volume (close to 1.1 x 1012 km3). It is simply there, as of now. It's orbiting a star, similar to Sol, our sun in the habitable zone. What would the difficulties be with this for: * The planet itself - + Would it stay intact? + Would the gravity it was exerting on itself cause it to form a sphere? + Would oceans be able to form - would they simply evaporate? + Would there be a magnetic field? What would be the problems with / without this field? * A colonising / evolving race - + Would there be varying gravitational fields that would cause problems? + What about day / night cycles - presumably they would be strange? + And the above - oceans forming and the magnetic field. Also, would the be strange effects in the center of the torus due to the gravity - I'm imagining something like this:   *Image, [Om/One speaker](http://www.omone.com/)* Where you get objects floating because of gravity? *Other images: Tim, 2014* [Answer] There are a lot of cool effects - and some problems. ### Formation [Planets form](https://en.wikipedia.org/wiki/Nebular_hypothesis) after a long, drawn-out process that starts with grains of dust colliding and forming [planetesimals](https://en.wikipedia.org/wiki/Planetesimal). These then become [protoplanets](https://en.wikipedia.org/wiki/Protoplanet), which can be kilometers across. More collisions result in small, rocky planets, some of which become terrestrial planets; others form the cores of the gas giants. The whole process is such that it becomes extremely likely that a planet will form into a sphere (or, more properly, an [oblate spheroid](https://en.wikipedia.org/wiki/Oblate_spheroid)). It's true that you could have bits of dust and rock stick together into some sort or toroidal shape, but they would most likely collapse. Incidentally, the [IAU's](http://iau.org/) definition of a planet requires that the body has rounded itself. This is primarily a terminology issue, but it stems from the fact that massive bodies tend to fall in on themselves into roughly spherical shapes. [The IAU defines a planet](https://en.wikipedia.org/wiki/IAU_definition_of_planet) as (emphasis mine) an object that > > 1. is in orbit around the Sun, > 2. *has sufficient mass to assume hydrostatic equilibrium (a nearly round shape)*, and > 3. has "cleared the neighbourhood" around its orbit. > > > Again, this is mainly a terminology point, but it arises from the idea that massive objects become spherical under the influence of their gravitational pull. Now I'll address the specific points in your question. > > Would it stay intact? > > > I would think so, if it's massive enough - at least, in the sense that it wouldn't fly off into space. However, I doubt it could maintain the toroidal shape for long - it would most likely collapse into a sphere. > > Would the gravity it was exerting on itself cause it to form a sphere? > > > Yes. > > Would oceans be able to form - would they simply evaporate? > > > Well, if it's massive enough, it should be able to hold onto matter. Evaporation of oceans is going to be influenced by the distance to the star (which appears to be the same as that of Earth) and whether or not there is an atmosphere. I should think that it would be able to hold onto an atmosphere, so you should be fine. > > Would there be a magnetic field? What would be the problems with / without this field? > > > Here we run into a problem. [The Earth's magnetic field](https://en.wikipedia.org/wiki/Earth%27s_magnetic_field) comes from [the motion of fluids in the core](https://en.wikipedia.org/wiki/Earth%27s_magnetic_field#Earth.27s_core_and_the_geodynamo). This idea is known as [the dynamo theory](https://en.wikipedia.org/wiki/Dynamo_theory). However, as Wikipedia states, > > A requirement for the induction of field is a rotating fluid. Rotation in the outer core is supplied by the Coriolis effect caused by the rotation of the Earth. The Coriolis force tends to organize fluid motions and electric currents into columns (also see Taylor columns) aligned with the rotation axis. > > > As celtschk pointed out, the Coriolis force still exists, because the object is rotating. That means that there will still be fluid motion through the core, and there should still be a magnetic field. I don't know quite what properties the field would have because it's hard to figure out where the poles would be. There might be a 'ring-shaped' (for lack of a better word) central section from which the field emanates - but like I said, I'm not sure. At any rate, it probably wouldn't come from near the axis of rotation of the planet, like Earth's field does. > > Would there be varying gravitational fields that would cause problems? > > > Let me try to do a back-of-the-envelope calculation. Putting some facts out there we'll need: * The force between two objects due to gravity is $$F=G\frac{Mm}{r^2}$$ * The torus has a radius $R$ between the center point and the circle going through the circle going through the center of each cross section; each cross-section has a radius $r$. * The mass of the torus is $m$, and the density is $\rho$. * The [volume](https://en.wikipedia.org/wiki/Torus#Geometry) of a torus is $$V=(\pi r^2)(2 \pi R)=2 \pi ^2 r^2 R$$ A given section of the torus defined by an angle $\theta$ (in radians) from the axis in the center will have a mass of $$m\_{\theta}=\left( \frac{\theta}{2 \pi} \right)m$$ Now, the center of mass of a second slice separated from the first by angle $\theta$ will be a distance $$D\_{\text{inner}}=\sqrt{ \left( \left( R - R \cos \left( \frac{\theta}{2} \right) + r \right) ^2 + \left( R \sin \frac{\theta}{2} \right) \right)^2}$$ away from an object on the inner part of the torus, and a distance of roughly the same to a point on the outer part of the torus. (I can't describe the exact technique yet, but it's very simple - I'll show it later if I can). This means that the force on the particle (with mass $\mu$) from the center of mass of the other piece is $$dF=G\frac{\left( \frac{1}{2 \pi} \right)m \mu}{\left( R - R \cos \left( \frac{\theta}{2} \right) + r \right) ^2 + \left( R \sin \left( \frac{\theta}{2} \right) \right)^2}d\theta$$ and the total force of gravity on the particle will be $$F=2 \int\_0^{\pi} G\frac{\left( \frac{1}{2 \pi} \right)m \mu}{\left( R - R \cos \left( \frac{\theta}{2} \right) + r \right) ^2 + \left( R \sin \left( \frac{\theta}{2} \right) \right)^2} d \theta$$ Substituting in the mass of the Earth for $m$, the radius of the Earth for $r$, and $R/4$ for $r$, I get an acceleration of $51.3\text{ m/s}^2$. However, the torus needs to have a much lower mass in order to stay in a toroidal shape, so the surface acceleration due to gravity could actually be much more manageable. > > What about day / night cycles - presumably they would be strange? > > > It appears that most places would have normal day/night cycles. Some places on the inner edge may never see day if $R$ is small, but if $R$ is big - and I think this is likely - things should be relatively normal. Although the sky would consist of the other side of the planet. [Answer] Some time ago, I calculated a toroidal planet numerically. In this answer, I give the parameters I obtained for reference to anybody who would be interested in this question. ## Method Rock and metals may seem solid, but on the scale of planets and in the pressures in their interiors, they are in a very good approximation liquid. To have a stable toroidal planet, its surface must have equal potential energy. In other words, when moving on the surface of the torus, we must not be doing any work. If this important condition is not met, the planet is unstable. I represented the planet by putting many massive points, for which both potential and gravitation force can be calculated, in many slices that form a torus. Each slice had three circles of massive points. Several tests showed that putting more circles of massive points or more slices does not change the result too much.  *Representation of the torus by massive points. The torus is in fact elliptical.* Then, I included a centrifugal force potential and I was looking for surface of constant potential, which would enclose the massive points and which could represent the surface of the planet. At the surface, I calculated the force field.  *Gravitational force field on the torus surface. Inner side of the torus is right, outer side is left.* It may be counter-intuitive that the potential energy is equal on the whole surface, but the gravity strength is changing. Equal potential energy only means that the force always points into the surface and walking around does not require work. But the gravitational force will change. It is strongest inside the torus where the centrifugal and the gravitational forces add up. It is weakest at the outside, where they subtract. ## Results The most important result is that if you precisely balance the gravitational and the centrifugal force, the toroidal planet can indeed be stable. The planet must rotate very quickly, otherwise it will collapse to a sphere. In this case once in 2.65 hours. Other parameters valid for my planet are listed below, but there can probably be many others that work as well. * Density: $5500\;\mathrm{kg/m^3}$ * Mass: 6.6 Earth masses * Volume: 6.6 Earth volumes * Outer radius: 19 134 km * Inner radius: 6378 km * Major axis: 6378 km * Minor axis: 4464 km * Outer g. acceleration: $3.64\;\mathrm{m/s^2}$ * Top/bottom g. acceleration: $7.36\;\mathrm{m/s^2}$ * Inner g. acceleration: $9.78\;\mathrm{m/s^2}$ * Length of day: 2.65 hours [Answer] [This](http://itzhakts.wordpress.com/2014/02/05/torus-earth/) gives a good treatment of the subject at hand, with a surface gravity map provided as well. Regarding the magnetic fields, if the (presumably metallic/liquid) core was in motion or somehow had a ring current induced within, it would produce a magnetic field which will direct particles to pass through the center of the torus. The image shows the ring current of the Earth's magnetosphere, which result in the aurorae. A similar magnetic field in a torus planet would not result in any aurorae, since they pass through the center. [](https://i.stack.imgur.com/FGT19.jpg) But most certainly, the planet will NOT hold up under gravity without the benefit of exotic materials with tensile and compression strengths multiple orders of magnitude higher than anything known to engineers. [Answer] The consequence would be that (if naturally formed) its own gravity would collapse it into a sphere. To persist, it would have to be engineered (artificially build) like [Larry Niven’s *Ringworld*](http://en.wikipedia.org/wiki/Ringworld_series) In either case you will have to deal with the lack of magnetic field protecting it from cosmic rays and/or the sun (if either one has any). A torus world (if you can make it rigid enough to persist) would have weird gravity, depending if you are on the "inner" side of the torus (weaker gravity) or the "outer" (stronger). And it would have to be improbably rigid to persist. Outside of the realm of physically feasibility. Only magic could do it for you. Edit: After reading link in interesting @March Ho [answer](https://worldbuilding.stackexchange.com/questions/6465/what-would-the-problems-with-consequences-of-a-torus-shaped-planet-be/6468#6468) (go read it I'll wait) it seems that **for some very narrow values of rotation speed, such torus might be stable** (if not disturbed by tidal forces from own Sun or gravity of other planets). Fascinating differences in gravity (with consequences to atmospheric flows), geostationary orbit just 2000 km up, North Pole Circle, differences in seasons between inner and outer equators, or even 4 cold and 4 warm seasons in a year, and bonus: moon trajectories, like one bobbing up and down through the hole, or forming a vase inside. Unlikely, but intriguing if created. [Answer] That's a fun problem to think about. I am curious to know which of the planet's possible axes of rotation would be perpendicular to the tangent of the arc of its orbit around the sun. as others have mentioned, soil and water would tend to accumulate in the center of the ring (where the smaller circumference will put any two points at the inner edge of a cross section closer to each other than particles on the outside edge of those two cross sections and the angle of attraction will be pulling the particles away from the surface of the planet and towards each other and by extension, the center of the torus, reducing the effect of "downward" gravitational force on friction between particles and enhancing slippage and accumulation in the center of the ring at a geometrically increasing pace). This would be despite rotational speed, as long as the planet had sufficient mass to exert a strong enough gravitational effect to prevent particles on the outer edge from leaving orbit. That would give you an interesting starting point for some very unusual tidal action - especially if you take a moon into account. I think you would also see jets of charged coronal mass being sucked down into then ejected out of the center of the "top" and "bottom" of the torus if the torus was pointed "edge on" to the sun/ solar winds OR some possible accumulation of said particles on the far/trailing side of the torus if the torus is not oriented perfectly "edge on" to the sun/ solar winds. this could lead to a spectacular culumnar aurora centrus visible as a pale cylindrer in the first case. In the second case, visible only from the dark side of the ring, the aurora would be more like what we see on our own planet, but more turbulent with red near the center, green surrounding that and blue and purple mixing in at the edges. the view from the inside of the ring in the first case would depend on the size of your planet and the thickness of the atmosphere, but assuming the planet were large enough, the aurora could be viewed from the umbra of the sun-side half of the ring when looking straight "up" toward the center of the sun-side half of the torus from the innermost part of the half of the torus farthest from the sun. ]

[Question] [  In Superman IV: The Quest for Peace ([imdb](http://www.imdb.com/title/tt0094074/?ref_=nv_sr_1)) a single strand of Superman's hair is seen suspending a 1000lbs weight. Is is possible to build a space elevator from strands of a super strong human-hair-like material? How long would it take to harvest enough hair from a superbeing like superman to build a space elevator? <http://en.wikipedia.org/wiki/Space_elevator> * Assume that Superman's hair grows at the same rate as an average human. * Assume that other than strength, the properties of the hair are the same as human hair. * Assume that the museum got the maximum stable tensile strength of the hair roughly right. * The space elevator need only be the minimum height for functional use. * The elevator will be used to lift general payloads into orbit, ship parts, people, fuel etc. [Answer] Lets assume that 1000lbs(453.592 KG) is close to the limit of a single strand of his hair. Lets assume his hair weighs about the same as an average humans hair by length. <http://www.answerbag.com/q_view/2159502> "a single strand of hair 4 1/2(11.43 cm) inches in length weighs, on average, 0.62 milligram" Which gives us about 5.42 mg per meter. A space elevator has to reach beyond geostationary (35,786 kilometres) so lets say 36000km for round numbers. So at a minimum the hair has to be able to support its own length. 36000km of this hair would weigh 195.1 kg, less than half our limit. **So far so good.** The hair is about twice as strong as the absolute minimum needed but we're not going to be able to put much weight on it, a strong wind or a few people climbing it would breach our limit so we're likely going to need a thick braid to do anything useful. From a little reading of the wiki the lift capacity for a reasonable space elevator is given as 20 tons so to get this we're going to need a cable at least 100 hairs thick, 200 to be safe. Here's where we hit a problem. How long would it take to harvest the needed hair? In a lifetime a human might grow 590(949.5km) miles of hair. <http://www.express.co.uk/news/weird/437344/Average-human-grows-590-miles-of-hair-and-eats-35-tons-of-food-AMAZING-human-stats> Lets assume this is over about 80 years so 11.86875 km per year for a normal human. This is a lot of hair but not nearly enough for even a single strand in our braid. If superman used his (so far undocumented) super-hair-growing powers how fast would he have to push out hair material to make a 100 thick braid cable in a reasonable time? Lets give him 20 years of doing nothing but sitting and growing hair as hard as he can. To build our 100 strand elevator we're going to need 3,600,000 km of hair. It would take a normal human 303317.5 years to grow enough. To grow enough in 20 years superman is going to need to grow it about 15166 times faster than that. Normal human hair growth is 0.44 mm per day, superman would need to grow his head of hair at 66.73 meters per day, if you talked to him you would see it visibly coiling out of his head. Though he might just volunteer to spend a few years carrying mountain-sized chunks of equipment into space for us instead. [Answer] Well, it's going to take a while. We can assume we need about a minimum of 25,000 miles of cable (22,000 miles for geosync orbit, plus 3000 for the counterweight). The elevator car will weigh about 100,000 lbs. Why? Because it's a round number in the range of the Space Shuttle's empty weight. The payload needs to support 40,000lbs, because that's the range of the first ISS module. So we need to support 140,000lbs of cargo. For simplicity, let's just say we need 200,000 strands of hair 25,000 miles long, with 10% extra for joining and split ends. So 5.5 million miles of hair, or one 36,000 mile long head of superhair (see below). Superman is superhuman, so while the average dark haired person has only about [110,000 hairs on his head](http://www.newworldencyclopedia.org/entry/Hair), he has 150,000. Each hair grows at 0.04cm/day or about 0.016in/day. That's $2.5 \times 10^{-7}$ miles per day. We'll need his whole head for the weight we need to support. Google says that's 144,000,000,000 days. That's just shy of 400,000,000 years. By that time, humans could be a [type III civilization](http://en.wikipedia.org/wiki/Kardashev_scale#Definition), rendering the whole thing moot. --- Just for the sake of an argument, let's say superman's hair is infinitely strong, like the [magic alien spear](https://worldbuilding.stackexchange.com/questions/14751/to-build-a-space-elevator?rq=1). Now a single strand can support the whole weight of the elevator system. We still need 36,000 miles, but now the hair grows at 0.037 miles/day! And since hairgrowing is one of his superpowers, he can do it 500× faster than the average human. So now we have 1.86 miles every day! In that case it will take us only 53 years to grow a space elevator. Since superman has been around since the 1930s, we should have enough of his hair laying around to make this work! Just be glad superman isn't a redhead. [Answer] Everyone is missing a big problem here: **How do you scale from hair to a cable?** The hair is strong enough, but **how do you bond the hairs together?** We already have fibers that are strong enough to build a space elevator, it's the scaling problem that is the current showstopper. ]

[Question] [ Back in the days when men were real men, women were real women, and small, furry creatures from Alpha Centauri were real small furry creatures from Alpha Centaury, an obscenely rich woman decided she wanted to have the biggest diamond of all. Realizing that this would mean a diamond of planetary size, she went to Magrathea and ordered it there. She had only two conditions: It should be a perfect single-crystalline diamond, and it should be impossible to make a larger one, because trying to do so would make it stop being a perfect diamond. Of course, Magrathea delivered what was ordered. Now as long as the diamond planet was in the hyperspace construction halls of Magrathea, all natural laws could be effectively put out of force as needed, but as soon as the planet was put into normal space, it was under the full force of the laws of physics. Now my question: How large was the diamond which was ultimately delivered by Magrathea? [Answer] **Between 253,000km and 573,000km in radius.** It certainly would *not* be either of those values, but between them, closer to the upper end. I'll say just under 500,000km in radius. About 0.72 times the size of the Sun. It would be about 1.3 solar masses of diamond. Large enough that it doesn't begin the [CNO cycle](https://en.wikipedia.org/wiki/CNO_cycle). This is also assuming that the constructed nature of the planet means it does not have extreme temperatures at its core. The mass is the easier part. The compression of diamond is the hard part. Carbon stays as diamond under very high pressure.  It's the least compressible material known. However, in a recent study it was [pressurized up to five terapascals](http://www.nature.com/nature/journal/v511/n7509/full/nature13526.html). Turns out, it *does* compress.  Just over one solar mass of carbon would have an [internal pressure](http://cseligman.com/text/planets/integration.htm) of about 70.96 terapascals. We don't have data for what carbon does at those pressures. However, at five terapascals is compresses to about three times its standard density. With some very dirty street-fighting-math we can extrapolate the polynomial and guesstimate that, at 71 terapascals, the density will be up to $38 {{g}\over{cm^3}}$. Since I really don't want to set up an integral where the density is a function of pressure as a function of radius, I'll just look at the extremes. A planet of density $38 {{g}\over{cm^3}}$ will be about $6.805×10^{25}$ cubic meters in volume. Or about 0.048 times the volume of the Sun and 48 times the volume of Jupiter and a radius of 253,000km. A planet of density $3.513 {{g}\over{cm^3}}$ will be about $7.361×10^{26}$ cubic meters in volume. Or about 0.52 times the volume of the Sun and 510 times the volume of Jupiter and a radius of 560,000km. [Answer] I think the answer is significantly smaller than you may think...ultimately a diamond is not the most compressed form of carbon. In 2014 an experiment to recreate pressures at Jupiter core was preformed... <http://www.astrobio.net/news-brief/bright-like-diamond-lasers-compressed-carbon-recreate-jupiters-core/> quoting the article: > > “At progressively higher pressures, the carbon atoms will change their configuration,” said Smith. “At over 10 million atmospheres of pressure, the carbon atoms are predicted to rearrange themselves so they would no longer be in a diamond structure, but rather they will assume a different [higher density] structural arrangement. It will still be carbon, but, so the theory predicts, the crystal structure and the mechanical and chemical properties will be different.” > > > Jupiters core see's 100 million atmospheres of pressure...which actually should compress the diamond into some other form of carbon that is not diamond. This puts the upper mass of about 1/10th the mass of jupiter before the diamonds structure beings to collapse into something else at the center of the massive gemstone. With a density of about 3 times that of Jupiter, you are looking at a diamond about 1/30th the mass of jupiter, which is still around 10 times that of the earth. [Answer] I'm not a physicist but I'd assume that it would be at the point that the gravitational force of the diamond was equal to the compressive limit of diamond. Given that the diamond's compressive strength is about 110 GPa: <http://www.chm.bris.ac.uk/motm/diamond/diamprop.htm> and the formula for the pressure at the center of a uniform-density sphere (to make the calculation simpler): $$M= \left(\frac{4 \pi}{3}\right) \times \left({{\rho}R^3}\right)$$ $$P= \left(\frac{3}{8 \pi}\right) \times \left(\frac{GM^2}{R^4}\right)$$ $$= \left(\frac{2 \pi}{3}\right) \times\left({G{\rho}^2R^2}\right)$$ $$R= \left(\frac{1}{\rho}\right)\times \sqrt{\frac{3 P}{2 \pi G}}$$ <https://www.physicsforums.com/threads/pressure-at-center-of-planet.66257/> I get a sphere with a radius of about 7,970 kilometers, or about 9,905 miles in diameter. This is about 25 percent bigger than Earth, in both diameter and mass. [Answer] I think a point has been missed. As Samuel points out, diamond is compressible, with an increase in density of roughly 10 at the center for 1 solar mass. As this increase in density implies a reduction in volume, the whole diamond will experience significant gravitational heating as it settles into its new dimensions. And although the thermal conductivity is very high, I suspect that the core temperature will undergo significant increase. This would obviously decrease the upper limit on mass before the CNO cycle kicks in. Furthermore, since the compression varies with depth, I'm not entirely certain that the monocrystaline character of the mass would be preserved. ]

[Question] [ **Important note: The orbits in the diagram are elliptical. They have low eccentricity so they appear to be off centre circles but they really are ellipses with the star at a focus.** The habitable zone around a star is the range of distances at which a planet which would have liquid water and otherwise be habitable to terrestrial life. However, being closer wouldn't immediately boil the oceans, and being further out wouldn't immediately freeze them. So how far could a planet oscillate to either side of the habitable zone such that it would start warming up again before freezing, and start cooling gown again before cooking any life (flimsy non-extremophile life like us in particular) I expect the orbital period is probably a significant factor since a longer orbit would mean the time outside the habitable zone would increase for a given eccentricity. Here's a diagram showing two elliptical orbits of differing eccentricity (the eccentricity is quite low either way so they look very close to circles) Pc remains within the habitable zone through its entire orbit while Pe has an average distance in the habitable zone but moves out of the habitable zone at periastron and apastron.  I'm looking for a general function in terms of relevant parameters (Stellar mass and luminosity, etc) rather than a specific answer for a particular star. The planet should be an earth analog (comparable atmosphere, hyprosphere, etc.) [Answer] This question has been addressed by a few studies in the past decade. These studies ran climate models for planets with eccentric orbits. I'm aware of three scientific papers on the topic (I'm co-author of one): [here](http://adsabs.harvard.edu/abs/2002IJAsB...1...61W), [here](https://arxiv.org/abs/1002.4875) and [here](https://arxiv.org/abs/1604.06091). The simple answer is: what matters first and foremost is the mean flux received by a planet over the course of its orbit. The orbit-averaged flux $F$ scales with the orbital eccentricity $e$ and semimajor axis a as $F\sim a^{-2} (1-e^2)^{-1/2}$. You need a big eccentricity for it to make a big difference on the climate (e.g., for an eccentricity of 0.5 the increase in orbit-averaged flux is just 15%, easily compensated by increasing the planet's semimajor axis by a smidge): [](https://i.stack.imgur.com/jkGOq.jpg) For a planet on an eccentric orbit, there is a short hot summer and a long cold winter. But most of the relevant climatic timescales are much longer than the orbital time so only the orbit-averaged flux matters. This plot shows the orbit-averaged Flux (blue curve), the aphelion to perihlion ratio dmax/dmin (green curve), and the ratio of flux received at peri- vs apo (red curve). [](https://i.stack.imgur.com/Qqbbw.jpg) FYI, I once wrote a blog post on exactly this subject: <https://planetplanet.net/2014/10/06/real-life-sci-fi-worlds-1-the-eccentric-earth/> and there are plenty of interesting details. My favorite was that we imagined (and performed climate simulations of) a planet on a very stretched-out orbit that was also tilted on its spin axis. The planet ended up being a global iceball except at the point that received the strongest heat pulse from the Sun -- at the South pole in this case, which thawed for about a month per year. Here is an illustration (white = frozen over, blue = just above freezing). [](https://i.stack.imgur.com/xqfMr.jpg) FYI there is another interesting situation in which a planet's orbital eccentricity changes in time due to gravitational interactions with other planets in the system. If you're interested see here: <https://planetplanet.net/2014/10/08/real-life-sci-fi-worlds-3-the-oscillating-earth/> On that note, in a simulation of rocky planet formation I once produced a pair of planets that straddled the habitable zone but that exchanged eccentricity such that they took turns having excursions outside the habitable zone. FYI, in this image time 2 is about 20,000 years after time 1 (details on that simulation [here](https://planetplanet.net/2014/10/08/real-life-sci-fi-worlds-3-the-oscillating-earth/) or [here](http://adsabs.harvard.edu/abs/2007AsBio...7...66R)). [](https://i.stack.imgur.com/Fcbge.jpg) [Answer] I'm not (at least yet) giving a complete answer, but you need to take into account the following: 1. Atmosphere The role of an atmosphere is very important. A dense atmosphere causes slower heating and cooling, so the comfort zone is not the same for a Venus-like planet than for a Mars-like planet. Even more if you have greenhouse effect or a very high albedo (or both). 2. Oceans Oceans also are important "pools of heat", keeping the planet a bit cooler or a bit hotter. 3. Internal heat sources Having volcanoes around certainly help during the cold time 4. Orbital speed Orbital motion is much, much faster if the body is near the star. If the planet must travel the same distance inside the hotter border of the comfort zone as outside the cooler border, the transit on the scorching end will be very, very fast, while the transit through the freezing zone will be very slow. So you can approximate to the star more than you initially thought, since you will be there for a really short time. [Answer] It's all about thermal mass. Ultimately, this question is talking about how long it takes for life to die outside the 'ideal' conditions in which it thrives. As has been described in other answers, there are a wide range of conditions that impact this. Ultimately though, thermal mass is what makes all the difference. So what is thermal mass? For the purposes of this answer, we can describe it as any mass which has the ability to absorb and retain heat when its cooler than the environment, leeching it out over an extended period when the mass is warmer than its surroundings. On Earth, we have the oceans and our atmosphere. The atmosphere retains a lot of heat (thanks to greenhouse gases) and traps it close to the surface. Thing is, the atmosphere is not a particularly good thermal mass. That's why temperature differentials between night and day exist. That said, water does a much better job. If you live on a coastline, you'll know that the difference between night and day temperatures aren't as large as the difference between night and day further inland, particularly in deserts. Why? Well, the water on the coast retains a lot of the heat through the day and the atmosphere gets the benefit of that on a form of delayed release. SCUBA Divers will tell you that temperatures in May (Southern Hemisphere) are still quite warm because the summer heat hasn't completely left the water yet. So; if you have a large amount of water on your planet, you'll fare better than if you don't. Some measure of greenhouse gasses are necessary, but will cause problems when you're too close to the sun. As as been said in other answers, it's the too close part that you'll have the biggest problems with, especially if you have greenhouse gasses in the atmosphere to retain heat. The ocean will help absorb some of that heat, but you'll still want shelter from it during that part of the orbit. You'd also want a high O2 atmosphere if possible Why? Because you want the extreme sun to produce large amounts of Ozone (O3) during the hot periods to assist with blocking cosmic radiation. Ozone is particularly useful here as a support to the magnetic field of the planet as it's temperature based and is naturally produced when it's needed most; on hot days (in this case closer to the sun) It's not all good news though. Thermal mass can even out the extremes, but you still need quite diverse life capable of a very wide temperature variation. Woolly Mammoths (as an example) would overheat in our current climate. Many animals on Earth are adapted to either warm climates or cold climates. Variation (lunar cycles, day/night, seasons, etc.) does drive a lot of the processes that allows life to grow and thrive, but the variations can't be too large otherwise the animal or plant needs concurrent yet contradictory adaptations to survive. Cactii don't do well in tropical climates, for instance. They REALLY don't do well in the arctic. Polar Bears would struggle in Mexico; you get the general idea. It's possible that your life would find ways around this, and certainly aquatic life is far more possible in this scenario, but that leads to another consideration; ocean currents. Most ocean life on Earth exists because of underwater currents that have been stabilised for some time. These bring plankton and other creatures through set zones, where larger animals feed on them, where even larger animals feed on *them*, etc. This creates reliable feeding patterns around the world's oceans, meaning that life specialises in exploiting that pattern and diversity is assured. With the massive temperature variations you're describing, it's possible that those feeding patterns wouldn't occur and the weather would be more chaotic. One of the reasons that Neptune (for example) seems to have winds ripping over its surface at incredible speed and with no apparent Coriolis effects is that it's so far away from the sun. Very little energy is being introduced into its planetary system, so when the wind starts, there's very little to stop it. Your planet on the other hand is constantly getting (intermittent) dumps of large amounts of energy into its atmospheric and water stores. That's likely to create all sorts of chaos in the weather, currents etc. This doesn't make life impossible, but it does make it hard. Food becomes less predictable. Birth rates become lower as a result. Is life on such a planet possible? Sure, given the right thermal mass considerations. Is life so possible that it's likely intelligent life might evolve? No, I'm afraid not. We really don't spend a lot of time thinking about it, but we're incredibly lucky to have this planet. It's like winning the lottery hundreds of thousands of times in a row. Even then, conditions are not always (and certainly haven't always been) ideal. On this world you're describing, the chances of intelligent life evolving are reduced by virtue of the fact that life won't thrive quite the way it does on Earth. It might be a reasonable colonisation site, but we not about to meet our equals there I suspect. [Answer] I suspect the problem your hypothetical planet is going to have is less from the time outside of the habitable zone and more with the time that the planet spends near its perigee(point closest). Life is extremely resilient and able to [adapt to some of the most extreme environments](https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CB4QFjAA&url=http%3A%2F%2Fen.wikipedia.org%2Fwiki%2FExtremophile&ei=viQgVInQA8K1yASgwoCwBA&usg=AFQjCNElZshT2R8h3UM9IgZk6QUPR_BWDg&sig2=iQc6HzL-ukCl5dpuWHxfHQ&bvm=bv.75775273,d.aWw). In fact [microbes were even found living on the outside of the ISS](http://www.independent.co.uk/news/science/microbial-life-found-living-on-the-exterior-of-the-international-space-station-say-reports-9682850.html). So life could probably withstand a brief period outside of the habitable zone. On the other hand as the planet approches its nearest point relative to the sun the temperature is likely going to climb and the environment is going change drastically. It is one thing to adapt to a very cold or very warm environment, it is another to have to adapt to both. A more feasable approach would be a more oval orbit where twice a cycle it spends a short period outside of the habitable zone and its perigee is not so much closer to the sun that the environment is forced to change radically. I would also expect that life is more likely to thrive in subteranean refuges where the changes in temperature at the surface have a negligable impact. [Answer] I see some possibilities: * You would need life that can either go dormant for a time and then reactivate unharmed. * You have life that dies off but produces seeds or spores that begin life again when conditions are right. I wouldn't expect intelligent life to develop here. * You have life that is underground. We have microbes so far underground that they are completely unaffected by surface temperature. I think that the first one is more likely to develop unless the life developed elsewhere and somehow got to this planet or a close encounter with another planet shifted it's orbit and the life that survived developed. [Answer] Eccentric orbits should be fine for habitability as long as it doesn't go flinging off into the void long enough to go full snowball in a way that won't melt when it comes back or grazing its star close enough to boil water. Like, it'll still have oceans on its surface. Now, that sort of seasonal variation will probably be annoying to any life there, but they'll probably adapt. I would just keep in mind comparisons of what the range of brightness variation is on Earth for different latitudes during seasonal variation and make a comparison to that. One thing this does mean is that any biome that requires stability suffers. Reefs and jungles might be rare. ]

[Question] [ Lets indulge in a bit of **Mad Science**, here. Assuming the world described here: [Making the Enterprise Fly](https://worldbuilding.stackexchange.com/q/1188/539) (60% of earth's gravity, 50% denser atmosphere) what is the wingspan needed to allow an average adult human to fly? Assume feathery wings, and that the resulting winged human needs to be able to fly *well*, not just founder through the air *technically* flying. [Answer] According to google: > > The largest species of bat are a few species of Pteropus (fruit bats or flying foxes) and the giant golden-crowned flying fox with a weight up to 1.6 kg (4 lb) and wingspan up to 1.7 m (5 ft 7 in). > > > It also tells us that > > While the average body mass globally was 62 kg, North Americans weigh > in at 81.9 kg. > > > You've said average at a gravity of .6g so we'll say use 38. It's actually the surface area of the wing rather than the span which generates lift. Taking a big simplification we'll assume the bat has square wings. So assume our bat has an approximate wing surface area of about 2.9 square metres giving a surface area to weight ratio of 1.8. We can scale up here... a 62kg at .6 gravity human would require a wing surface area of 68 square metres equating to a wing span of about 8.5 metres. These are VERY rough calculations (for one I've never seen a bat with square wings) however I hope it illustrates that a human would require enormous wings in comparison to their height (not to mention that the wings would also add weight to the person which would also require extra wing!). I've not taken into account the increased atmosphere because humans are a lot less aerodynamic than traditional flying creatures and we're not factoring in the weight of the wings. Clearly your average human would need to lose a lot of weight for this to be even remotely possible, we're not talking about dieting... we're talking about lightweight bones, organs and muscles! [Answer] It really depends how fast you expect them to fly. But let's look at how your changed world will affect them. The equation you're looking for is: ``` Area = (lift force)/(half velocity * velocity * air density * lift coefficient) ``` Or mathematically: $$ A = \frac{L}{0.5 v^2 \rho C\_L} $$ $A$ (**area**) is the number we're looking for. $L$ (**lift force**) must be equal to the mass of the person, in order to support their weight. People on earth average 62kg. With all the exercise from flying, they might average a little lower in that world. $v$ (**velocity**) is the take-off speed: the speed at which the forward movement through the air makes the lift cancel out the person's mass. $\rho$ (**air density**) is specified as 1.5 times Earth's. $C\_L$ (**lift coefficient**) is approximately 1, and depends on the angle of attack and wing shape. You can assume their wings are decently well shaped, so can ignore this term. Changing this to make thrust is, basically, what flapping does. Wing loading on an Earth hang glider is as high as 6.3 kg per square meter, and the takeoff speed is about 15 mph. From the equation above, we can see that the wing area is proportional to mass ($L$), and inversely proportional to air density ($\rho$). In other words, wings need to be larger when there is more mass; and don't need to be as large when the air is denser. So we can multiply the needed area by $\frac{0.6}{1.5} = 0.4$. So 6.3 kg per 0.4 m2, or 15.75 kg per square metre. That's roughly a quarter of human bodyweight, so you'd need four square metres for an average person. Two square metres per wing. Assuming folded wings like birds have, that's certainly achievable. Now, let's push the limits. Adults with anorexia have a BMI below 17.5. So let's aim for that, as the acceptable limit of thinness. When $M$ is mass, and $h$ is height, $ M = h^2 \times 17.5 $. This scales with the square of height, so height is definitely not a good thing. So assume 1.5 m (approximately 4'11"). $$ 1.5^2 \times 17.5 = 39 \space\text{kg} $$ That needs only 1.25 m2 per wing! Something else to note, though, is that lift improves with the *square* of the velocity, but *linearly* with area. So if you double the speed to 30 mph, you can quarter the area: in a 30 mph wind, you could hover in a trenchcoat. If you halve the speed, you only need to multiply the area by $\sqrt{2}$: so for a normal weight person, you can have gliding at 7.5 mph with 2.8 m2 each side, which is still in the range of achievable, and means they could take off in a breeze or at a run, without needing to jump off a hill. For our petite skinny person, that's only 1.8 m2 per side. Acrobatics would require higher velocities, but that's what a dive is for! :D [Answer] Humans can fly quite well with wings the size of a typical hang glider. Of course they are doing soaring flight rather than flapping, but then the largest species of birds mostly soar. (As did the even larger pterosaurs like Quetzalcoatlus.) See e.g. condors, albatrosses, etc. Soaring puts limitations on their lifestyle and habitat. They'll need to live near the tops of cliffs or hills, and in windy regions. [Answer] The only way humans could ever fly is by being little flying angels! Let me explain: What if you allowed some sort of genetic mutation to the human DNA so that our growth stops very early, around 4 years old. It might have some minor impact on our cognitive functions since our skull would have smaller volume. You might solve that by also modifying our DNA so that our head is bigger in proportion to our body size. Also modify our DNA so that we have wings, and the appropriate muscle and cardio-vascular system to move them fast enough to fly. Our body weight would then be around 15-20kg, similar to an albatros. Then flying on earth (1G) would seem possible. ]

[Question] [ My problem is as follows: * mr Average Joe has designed a device for time travel in his garage/basement * at the moment he has sent the device forward in time (for testing purposes) a couple of times (first time a full second, afterward parts of a second -- smallest time setting is 0.01s), the biggest problem being the fact that the device appears at seemingly random places in or outside the testing grounds The question: * how would one set (or fix) the coordinates for the destination in space and time? (Given the fact that the earth rotates around its axis and the Sun, what would be a plausible set of coordinates for the device?) (If one takes into account only the rotation of the planet, one would reasonably expect to be in the same **position** if he/she travels 24h forwards or backwards in time -- but the Earth's rotation is not the only movement which needs to be taken into account) About the machine: * it's a device which can be portable (it just requires a power supply , wall socket would be enough) * it creates a 'bubble' around the device, with a radius that can be set (and, of course, limited by the amount of power available) * the 'bubble' dissipates as soon as the 'travel' is finished * travel time is instantaneous to anyone/anything inside the 'bubble' * after solving the coordinates problem, the device can be used as a teleportation device by setting the time at the minimum setting and modifying the coordinates * it was built by cleverly combining off-the-shelf available technology About the world: * current time, current world * no aliens * mr Joe is of average background, so, limited access to funds, no access to expensive materials or devices, only off-the-shelf This is my first post, so be gentle with me :D If you feel that the post needs clarifications, please let me know. **EDIT:** Some issues that need to be clarified: * Joe needs to know the position **before** leaving, in order to avoid plunging into the depths of space or into the/a Sun. * The device has a capacitor-type power source, meaning it charges when plugged in and can release the power all at once (much like a camera flash). * It *could* possibly be modified to do 2 jumps and automated to return to the same location, but i'd try to avoid that, because obtaining the power for the next jump is an important part of the plot... * building a ship or other vessel to contain the device and the traveler is a no-go, as would be over the character's budget (ans would spoil the science) * the device **pops** in and out of time (tardis-like) but instantaneous, it does not travel the whole length of time (this avoids a lot of issues like: what happens if one travels backwards before the time of the machine, what happens if he travels to a time where he's already inside the machine?) * the 'beacon' idea sounds nice, but one would have to somehow read the position of the beacon *before* travelling (see the first point in edit) * the 'extra dimension' approach also sounds nice, but I would try to keep it as close to reality as possible, otherwise i could go all gunslinger -- The Dark Tower is one of my favorite reads * the device adjusts for velocity (if it starts as stationary, upon arrival at the destination is still stationary) [Answer] The biggest issue you're going to have here is with absolute vs relative co-ordinate systems. If the time machine is getting its co-ordinates relative to the earth/the sun/the centre of the galaxy then this becomes a computational problem of 'where will the thing I want to be on be at the time I want it to be there'. The choice of object for your frame of reference may cause this to be a chaotic relationship, in which case you can only really guess at the location, and longer trips (in both time and space) will lead to bigger disparity between where you want to be and where you end up. For example: If the reference point is the centre of the Earth you can trace a circle around the axis of rotation intersecting with your destination, spin the circle for an amount of time and then aim for where your destination will be. If you take the centre of the Earth/Moon system as your point then this becomes much harder, you'll end up tracing ellipses and all sorts to get to the right place. If you take the Sun? Well, the sheer number of things in the solar system that could perturb Earth relative to the Sun by the few meters it could take to accidentally place you in a wall makes it almost impossible. In the second instance if you're using an absolute reference system then.. erm.. You're boned. We experience things from a relative perspective. It's the way it goes. If there is some form of universal absolute co-ordinate system then you're not going to be able to exploit it without accidentally dropping into the endless void between galaxies first. My recommendation here (which may be a non-starter based on how you're defining your time-travel paradigm) is to 'stutter' your time machine ahead of you, getting it (or a version of you) to gather the necessary jump adjustments and send the information back to itself before it jumps. This way a trillion iterations of your time machine jumping, correcting, jumping, correcting etc etc can occur before the actual jump is completed to within acceptable parameters for drift. At that point you're free to define whatever co-ordinate system you like, relative to whatever frame you like. You can even get the machine to travel until it matches a particular image, if you like, and because you can send out decillions of parallelised time machines it can perform a brute force search of the universe. **EDIT:** I think some more explanation of the stutter-search concept is required. Lets assume that I want to travel to a location on the Earth's surface 20 years in the future. I need to choose a method of maintaining location that makes sense, so I choose GPS signals. (A local, Earth only system likely to last the next 20 years). Obviously getting straight there requires some form of vector, but I don't know the correct vector. So: I set my time machine to jump forwards a millisecond, measure the change in GPS position and send the information back. Then, using the information gained from the future, the machine (that hasn't actually jumped yet due to my abuse of paradoxes) calibrates a jump for the correct GPS co-ordinates 2 milliseconds in the future. It measures the change in GPS position from the expected and sends it back to itself.Then, using the information gained from the future, the machine (that hasn't actually jumped yet due to my abuse of paradoxes) calibrates a jump for the correct GPS co-ordinates 3 milliseconds in the future... You can see where this is going. The trick to understanding this is that the signals used by the machine to get from place to place don't have to match a set of arbitrary co-ordinates. They have to match the signals used by the machine to get itself to the place you want to go. As you can use the machine to basically brute force a navigation solution you don't need any form of co-ordinates, as long as you have a way of identifying where it is you want to go. Examples or potential navigational aids include but aren't limited to: GPS, image recognition, accelerometers, radiation sources, star-maps, thermal monitors and impact detection. The last two are especially useful in that you can use your pre-jump machines to avoid any tricky things like reappearing inside walls or suns, and if you want to 'stay where you are' you can calibrate for jumping forwards while maintaining constant pressure on the base of the machine. The combination of the above can be used to let your machine 'feel' its way through time and space to your final destination, at which point it can transmit the finalised jump 'vector' back to itself and execute it. Of course this needs some rather odd time travel logic to be allowed, but what the heck, we're allowing an average guy to build a perpetual-motion-infinite-energy-unstoppable-force-breaks-conservation-of-energy-momentum-and-causality-time-machine **BREATH** out of parts from radioshack. [Answer] ## In the real world this is irrelevant... The question is irrelevant because there is no such thing as absolute reference frame. You can not move. You can only move **from respect to something**. We *feel* like we can determine an absolute location in space-time because of our tendency to choose the Earth as our frame of reference. This is a flaw that mislead a lot of people before [Special Relativity](https://en.wikipedia.org/wiki/Special_relativity) was discovered. You have either to decide an arbitrary frame of reference or to abandon the question. ## But in your world... If you decide there is an absolute reference frame in your world then you will get in trouble\* since you're denying the principles of the Special Relativity which leads to Einstein's General Theory of Relativity. That being said, you still should choose Earth's surface as your "absolute" reference frame and say everything is moving but the center of the Earth (this is pretty arbitrary and awfully wrong but... this is what Aristotle thought in is time after all). With a rotating Earth and Earth's center as your absolute reference frame everything is much simpler: you just have to figure out how fast Earth rotate and compute your future position according to this angular rotation. All your problems are gone if you choose your machine to be the center of the Universe but... well I am pretty sure this prospect will not seem "logical" to your readers. Choosing the sun as your absolute reference frame makes your problem much more complex. \*: Since everything is rotating relative to the Earth we are able to say that both speed and acceleration can be absolutely measured. Since Earth is at the center of the universe, there will be things that are *far enough from Earth* and will have a faster than light angular momentum. Light can't be the speed limit and things become much more complex... [Answer] Only you can tell if this would work for your story, but what if the time machine didn't actually *disappear* while it does its time travelling? Instead of Doctor Who-esque machine that pops in and out of time, it would be more like having a fixed portal you come through to another time - as long as the other end of the portal is still working. This limits the use of the device, of course, but limitations are usually great for a story. The obvious points to consider: * Unless you maintain that the machine can propagate itself backwards in time, you can't travel further in the past than the time the machine was created. * The time machine exists between the points in time you're travelling - this means that in can be tampered with in the meantime, and you wouldn't be able to do much about it. And of course, this includes others being able to use the device, not just you. * As many similar magic devices, this could be used to create a free source of infinite energy. Careful :) * The machine needs to be incredibly durable and reliable to be of use if you want long time travels. Repeating last thursday would be fine, traveling a few years or decades is probably still doable, but thousands of years is a lot trickier. Millions and billions seem to be outright out, unless you make the time machine a "fixed" event in spacetime. Considering the machine as something fixed in spacetime could allow travelling further into the past than the machine was created; imagine the moment the machine was created and started, it suddenly has always been there, since the creation of the universe, up till the universe dies. It's immovable, indestructible, a permanent feature of the spacetime itself. It is timeless, following geodesics in space-time. Of course, this still means that while the device cannot be destroyed or moved, it's possible to, say, flood it in an ocean, or cast it in concrete. And of course, the chic sci-fi favourite, thrown into a Sun or a black hole. You might want to make extra provisions if you want the travelling to be safe :) And of course, the usual time travel cautions apply as well. You're bound to break a lot of physical laws unless you make special provisions to ensure strict consistency at all times. Breaking the universe is rarely a good idea. [Answer] Many different ways to approach this, some better than others: * **Coordinates are absolute**: simplest to understand, but hard to apply and in reality there's no such thing because relativity. I think it's not worth the trouble. * **Coordinates relative to a celestial body**: could be the surface or center of the Earth, Sun, Galaxy, local cluster, etc. Pros: simple, can be calculated, small errors create interesting stories. Cons: can't teleport inside moving (or moved) structures, there will always be small drifts, geological changes lead to disasters. * **Coordinates relative to an arbitrary anchor point**: the anchor could be a physical object, like the teleportation pad, a building or a macguffin. Less calculations, more stable along geologically long periods (assuming the anchor survives), moving anchors can be a plot point. Requires separate device or landmark. * **"Do what I mean"**: the system looks into the user's mind, simulates many different destination points and selects the one that would make the user most satisfied. Always works (unless you don't want it to, e.g. the AI rebels), but requires a pretty important separate device. * **Median particle position**: look at the destination in the present, identify all particles inside bubble-sized area. Travel in time, locate previously identified particles, take median position (and orientation). Hard to explain, but exceedingly stable and works without additional devices. Allows time-teleportation inside moving/moved structures, across geological changes, etc. The planet could have been blown up and you would still arrive at somewhere (in space, probably, but somewhere). Basically, track the destination across time. [Answer] You say it requires a power socket. If that is the case then you had better make the power socket the reference frame otherwise it will unplug itself as soon as it starts up. This may provide your solution. Reinforce the power socket and the lead and by that means tether the machine to the wall. That way it can travel in time but it will be prevented from travelling in space. Keeping the tether from breaking will be the tricky part. The wall end of the lead will be travelling forward in time at a standard speed of 1. The other end will be time-travelling faster or even in a negative direction. There will be a whole new theory of physics needed to work out how the speed of time travel varies along its length. If you **can** tether the machine to the wall socket then be careful going backwards in time because it will meet itself. If it stops, this will cause it to explode itself. If you are going forward in time make sure you are paying the electricity bill by direct debit and there's plenty in the bank. You don't want to get cut off. [Answer] **Naive Approach** A naive approach would be to make the time travel coordinate system be similar based on a quadruple of $[{X, Y, Z, Time}] $. This would require being able to calculate the location of the destination to a ridiculously high degree of accuracy across incredible distances, while taking into account the spin of the earth, the wobble of the earth, the orbit of the earth, the movement of the sun through the galaxy and the movement of the galaxy through the broader galactic cluster. That's really difficult for any kind of long movements. (Perhaps this might be useful to your story, to have a limitation precluding long trips?) Any other coordinate system based on a $[{0,0,0,0}]$ will have these same kinds of issues. **Brute Force** One answer proposes a 'stutter-step' approach to moving forward or backward in time. This is equivalent to calculating the 10 million Fibonacci term by first calculating from 1 to 9,999,999. It can be done but it's not elegant, when an alternative exists to calculate the 10 millionth term directly as shown in the the below equation. $Fib(n) = \frac{1}{\sqrt(5)} ((\frac{1+\sqrt5}{2})^n-(\frac{1-\sqrt5}{2})^n)$ Let's not take the long way 'round. **Direct Calculation** Let's assume that this time machine has access to many of the other dimensions proposed by string theory and that travel by way of these other dimensions is feasible. Note that a higher dimension can "look in" on the dimension below it. A line can see all of a point. A 3rd dimension observer can see all of a 2D square. So, a 5th dimensional observer should be able to see everything contained in our $[{X, Y, Z, Time}] $ quadruple. From this 5D perspective, placing an object in a 4D location should be easy since all the information about that quadruple is open to inspection. Movement of the time machine through the 5th (or higher) dimensions to an exact destination should be instantaneous and danger free since the exact circumstances at the arrival point are known. [Answer] I've had this idea for a while, and I'm pretty sure it didn't originate with me, but here goes. --- Joe's time machine travels through time at a rate, eg 1 hour outside per 1 second inside. The rate can vary, of course, but from the time machine's perspective, its transit is *not* instantaneous. From outside the time machine, the machine is "present" to a degree proportional to its time-speed. For example, if the machine is travelling 110 minutes per 100 minutes it experiences, it would be visible, if a bit transparent, and would be solid...ish. At near-real-time speeds, the machine would be soft, easily damaged by a physical force. A hammer would more easily dent its metal shell than when the machine was inactive. As the machine's time-speed got further away from real-time, from outside it would be more and more transparent and less and less solid until it was impossible to detect. From inside, it would remain 100% solid. Because the machine is still present in the world, it would be affected by gravity and the electromagnetic forces that hold matter as we know it together. In practical terms, it would re-appear in the same geographic location that it left, because it was really there the whole time. At first you would think that at any real time-speed, the machine's apparent weight due to gravity would crush it. But just as the machine is less present in the normal flow of time, Earth's gravity has a proportionally smaller effect on the machine. From the machine's perspective gravity remains 1G. Same thing with its contact with the ground below it. If an object was placed where the machine was before activating, the machine would be pushed out of the way to accommodate it, but relatively slowly/weakly. So if a person walks through the space, they have almost no effect on the machine. But put a chair there and leave it in the exact same place for a few months, and the machine would feel a bump as the box "appeared" in its space. One could also make their time machine with wheels, and drive it around *while* also traveling in time. For whatever features were reasonably constant, the machine could drive on them as normally as in normal time. Moving things passing through the machine would jostle it a bit, and being less noticeable as the machine traveled faster through time. This opens up some interesting possibilities if the machine is set to travel *slower* than real-time. From the machine's perspective, the universe would fade and become less solid. From outside, the machine would become impossibly solid. This also has *really strange* implications for traveling backwards in time, at least near the start and end points. The machine would arrive in the past instantly, and a ghost of it would exist in the same location, fading away into the future as the backwards-traveling machine decelerated to normal, forward-moving time. It would also instantly disappear from the present instantly after "accelerating" through slower than real-time (and everything that that implies). This might make traveling backwards in time have a difficult-to-surmount barrier similar to the sound barrier for planes; early time machine prototypes simply couldn't break through the 0 seconds per 1 second barrier. --- Joe discovered after some experimentation (involving a high-speed camera both inside and outside the device) that his initial prototype was jumping around because it accelerated through time too fast, and the air pushing into its space would jostle it enough to physically move it to another nearby location. It was actually *worse* when he made it "jump" forward by .01 seconds, because its "jump" really consisted of a sharp acceleration and another sharp deceleration, both of which had to occur in roughly .0001 seconds from the device's perspective. Once he figured out the device was experiencing time subjectively (rather than traveling instantaneously), he soon figured out how to slow the acceleration to a reasonable level, and his device started fading into existence in the same location it had faded out a few minutes prior. [Answer] Your underlying assumption is that the machine is able to change it's time coordinate without effecting its spacial coordinate, and that it therefore get's left behind as the earth spins on its axis and orbits the sun. However, this assumes that the sun is tied the origin of the entire universe and provides a reference to some absolute coordinate system... firstly, you have forgotten that the sun orbits the galaxy, that galaxies tend to swing around centres of gravity caused by galaxy clustering, and that all of space is expanding. Secondly, there is no absolute coordinate system. All space and time and motion is relevant to the observer. When 'not timetravling' our position evolves over time relative to everything else according to the rules of causality. We cannot make any intelligent prediction as to what location in space a time travel device would link to because it is a fictional device, not even loosely supported by any physical laws. HOW does it create this link? Tell me that and I can try to predict where it would end up, or how to make it turn up where you want. [Answer] My simple solution is: Assume that the time machine is affected by gravity. Why is it that when you walk across the room you don't suddenly find yourself floating in space because the Earth has moved along its orbit around the Sun? It's because you move with it, dragged along by gravity. Assume that the time machine doesn't literally disappear and reappear at another time, but that it moves through time, still on the Earth the whole time and affected by gravity. Would it really work like this? I have no idea. To the best of my knowledge no one has any idea how a time machine could actually work. So for an SF story, you can make up anything that makes the story work. (Actually you can throw things in an SF story that totally contradict all known science, like saying that a starship can travel faster than light, or that a politician might live up to his campaign promises, if it helps to make the story work.) [Answer] i like BoppreH's idea of an arbitrary anchor point, but i might extend it by making the machine itself the anchor. that is to say, the 0-0-0 origin of your target time is where the machine *would have been* if it had not jumped through time. for jumping into the future, that would generally be the same spot on earth. of course, things get interesting if you fail to predict an earthquake or zoning law that would have moved the machine. for the past, the origin point is simply wherever the machine was at that point in the past (making 0-0-0 a bad idea). on the other hand, collisions could be mitigated by swapping whatever happens to be in the target bubble. so when you go back in time to spot x, that stuff at spot x goes forward in time to compensate. another alternative is to combine the arbitrary anchor object and a mean particle position. so you could target for example a gold coin. when you jump back in time far enough, you end up at the mean location of all the mass in that gold coin from before it was mined (ie underground). travelling forward in time essentially makes the coin a moving target until such time as it is melted down or otherwise destroyed. combining all three ideas could be very interesting. imagine that when you go forward in time, the matter at your target location is swapped back in time to the present. then, to satisfy causality that matter would be forced to find it's way back to the target location over the intervening time period to form a loop. this could essentially make the target location origin simply the most likely place for all that matter to re-accumulate. quantum uncertainty would simply chose a place in a relatively predictable region much like electrons occasionally resolve into particles at a particular location. choosing locations further away from that most-likely origin could place additional strain on the predictability of the universe by forcing the matter to re-accumulate in increasingly less likely arrangements. pushing far enough away from the origin could cause quantum effects to grow to classically observable scale (e.g.spontaneous creation of particle-antiparticle pairs happening several grams at a time). [Answer] +1 for the question. I have long thought that the question of spacial coordinates to be the biggest hurdle to time travel. Who would want to travel ahead or back in time even one day and arrive in the vacuum of space? [Answer] **Create a beacon** You will need actually set of four, I will call the whole set as a beacon. Beacon is located on earth and is unmovable. The time machine will align the destination with origin in space relative to the beacon. This will however limit range of when the time machine can travel. You won't be able to travel back in time before the time machine and beacons were constructed, also you won't be able to travel too far into to future either unless you solve maintenance of the beacon. [Answer] The origin is a point on the surface of the Earth (perhaps the current resting point of the time machine), and the vertical axis is aligned with the direction of the Earth's magnetic field or gravitational pull or something like that. Maybe general relativity affects the time machine somehow - helps it work, so that would explain how it's able to detect the earth's gravity - and therefore presence - even while in transit. The time machine may *seem* like it's teleporting through time, but actually there's a technobabbular phlebotonic energy-data capacitance which maintains a presence at a fixed geographic position between source and destination. Joe doesn't notice it because he is modulated into data for the journey (though he does know about it since he's the one who designed the thing), the same way as spacial teleporters don't notice their data packets being transmitted through space. The same energy-data-thingy could be moved (maybe at speed of light) for the spacial teleporter. So the time machine doesn't *have* to know the position of Earth because it's being carried with Earth even as it journeys through time. It either can fix itself to the Earth as it moves or it is fixed as naturally as Joe is while standing in his garage. [Answer] For a very detailed paper on orbital paths, download the PDF [here](http://www.researchgate.net/go.Deref.html?url=http%3A%2F%2Fvixra.org%2Fabs%2F1311.0018). The following process should provide accurate enough coordinates provided Joe stays on Earth and doesn't travel more than 50,000 years from present day. If this isn't good enough for Joe, I suggest he use what he has to befriend Stephen Hawking. 1. Calculate the Milky Way's position. [Wikipedia](https://en.m.wikipedia.org/wiki/Milky_Way%23Velocity) provides methods for 2 common frames of reference. 2. [The Sun's orbit](http://www.universetoday.com/18028/sun-orbit/) around the Milky Way is circular, with a diameter of 26,000 light years and a speed of 782,000 km/hour. 3. Find Earth's orbital position:  Eccentricity is currently 0.017, and this should remain true for 50,000 years in either direction from now. 4. The destination's position relative to the center of the Earth is a vector with a length of the Earth's radius (6371 km) + destination's altitude above sea level. The angle of the vector is based on time of day (milliseconds passed / 86,400,000 x 360). If you've kept your frames of reference straight the whole way through, you *should* have the correct rotation so that your initial velocity matches that of Earth's where you arrive. I think. To be safe, double check with Hawking. [Answer] What if you simply break your trips into multiple parts. Build a spaceship around your time machine. It doesn't need to be fancy, just a pressure vessel with some external cameras on it and a power source. Now whenever you need to travel a substantial amount of time, jump to the time you want, but simply ballpark your coordinates in space to be somewhere nearby Earth. You'll wind up somewhere in near Earth space. Then after a few seconds the time machine can get its bearings using the external cameras and will calculate the relative positioning and velocity of wherever it wants to go and make a microsecond jump to teleport to that place. So you make one long jump forward or backwards in time which will be relatively easy because you can use estimates of your targets position to make sure you show up near it but not in it. Then you make a short lateral hop through space once you have calculated your target's exact relative position and velocity. For traveling super long distances in space and time you can split the trip into as many jumps as necessary to make sure you don't get lost or wind up in the center of a sun. [Answer] If you can let go of the "instantaneous" experience of the contents of the machine as it travels through time, then instead of programming spatial coordinates to "jump" to, a traveller could simply pilot the machine and adjust its position as they observe the world change around them. This assures your machine won't end up e.g. phasing into a rock formation that's been long eroded (and therefore couldn't be accounted for in data available in the present), as well as assuring it's still on the planet and ends up precisely where it's intended too. Furthermore, with this approach time travel isn't limited by something as dry as the traveller's abstract mathematical skills (or reliance on a supercomputer) and confidence in data, but instead by the traveler's ability to observe, react, and navigate as the world changes around them. [Answer] In a [previous answer](https://worldbuilding.stackexchange.com/questions/12621/how-can-i-explain-that-a-time-travelling-apparatus-moves-itself-through-time-but/19222#19222) I mused on how a time travel machine would stay put. Even if your time machine idea doesn't work that way, it is a good way to plot coordinates. Similarly to how time for space travel is defined as the center of the sun imagined as a point mass (or something like that) you need the same way of noting time at different gravitational potentials and velocities. In fact, space travel has a *position* system too. Why not just adopt the same system? [Answer] Similar to the other answers, you want your co-ordinate system to be relative in some way. The intuitive answer, especially for Joe, would be to have it relative to your current position. However as the other questions point out, how do you define where your current position will be in `t` time. Instead of co-ordinates measured as a single $[x,y,z,t]$ vector, I suggest that you calculate your future position as the sum of all forces acting upon the device modelled for time `t`. Each of these forces would be modelled as either relative to a point, e.g. gravitational forces relative to the center of mass of their bodies, or acting from a constant relative direction e.g. a push. This should take into account the 'general case' however if anything unpredicted occurs such as foreign bodies hitting the earth and changing it's orbit or sea levels changing, cliffs being eroded. Then Joe could find himself in a sticky situation. But that's more likely to give you some nice plot/discussion points. If Joe wishes to adjust his future/past location, he should specify a force which will move that location as desired. [Answer] Calculating the coordinate may be hard. But there is a way to avoid needing to calculate. If you do not move too fast in time you can drive to your destination like a car would in fast forwarded movie. This is also easy to automate even with very low tech equipment. Others have suggested similar things but not exactly in these words, or reasoning. My point being that this is how i would approach the problem at least until I get enough experience in predicting and verifying that my predictions are correct. I would like to avoid finding myself 1/2 rotation of earth, or even outside the solar system. Who knows what can happen in this move, or how it might react to coordinates. Sure this would limit the viability and speed of general teleporting. But lets face it, you are much happier if you get there in one piece. Rather than lost in space, or worse. Be cautious. [Answer] Here's a thought- have a few trials where your device blinks out of time/space for a set period with a beacon, each trial being a different length of time. Acquire that signal upon reentry and begin building a non relative map of the local universe. ]

[Question] [ **This Query is part of the Worldbuilding [Resources Article](https://worldbuilding.stackexchange.com/questions/143606/a-list-of-worldbuilding-resources).** --- I know how [continents](https://worldbuilding.stackexchange.com/questions/581/creating-a-realistic-world-map-landmass-formation) are formed and how they evolve over time but what does it look like under the surface? The crust of the planet is mostly made of rocks but there are also different types of minerals to be found scattered around. These can be quite valuable for those who can find them. **How can I figure out what kind of minerals to expect in specific areas of the planet?** I'm not a geologist and therefore, have no idea if the question is too broad. If you think it is, focus on the [native elements](https://en.wikipedia.org/wiki/Native_element_minerals). **I'm mostly interested in : Gold, silver, copper, iron, lead, tin, zinc, platinum, sodium.** --- Note: > > This is part of a series of questions that tries to break down the process of creating a world from initial creation of the landmass through to erosion, weather patterns, biomes and every other related topics. Please restrict answers to this specific topic rather than branching on into other areas as other subjects will be covered by other questions. > > > These questions all assume an earth-like spherical world in orbit in the habitable band. > > > --- See the other questions in this series here : <http://meta.worldbuilding.stackexchange.com/questions/2594/creating-a-realistic-world-series> [Answer] **Making a mineralogy map requires a list of desired resources and a little create drawing.** There are three kinds of rocks, sedimentary, igneous and metamorphic. Each type of rock is formed in a different way and provides different resources. *Since this map is for a world from scratch, the author can do whatever they want/need in order to move the story forward. As long as ore families are respected, it will take a geologist to point out any errors or inconsistencies. This is especially true since you can invent the geological history to match your needs and most stories don't go into crazy detail about the geological history of your world.* **Igneous** Igneous rocks are formed from magma, generally in volcanoes though not always. They have a tight crystalline structure and are tough to break. Examples include basalt and granite. **Sedimentary** Sedimentary rocks form from eroded rock pieces by wind or water that then settle in a stable location. Time and pressure fuse the stone grains together to form a new type of stone. Most dinosaur fossils are found in sedimentary rock. **Metamorphic** Metamorophic rocks were once igneous or sedimentary rock but were changed by heat and pressure in the earth's mantle or crust. **Element Specifics** *Gold* There are [four way](http://www.gold-traders.co.uk/gold-information/how-is-gold-mined.asp)s of mining gold, placer mining, hard rock mining, byproduct mining and processing. [Placer mining](http://www.gold-traders.co.uk/gold-information/how-is-gold-mined.asp) is done with sluice gates and pans. If you've heard the term "panning for gold", this is placer mining. It has the lowest barrier to entry of all the techniques and relies on one of [three kinds of surface gold deposits.](https://en.wikipedia.org/wiki/Placer_mining#Deposits) *Silver,Tin, and Lead* are often found together in deposits of [galena](https://en.wikipedia.org/wiki/Galena) in metamorphic or sedementary rock formations. *[Copper](https://en.wikipedia.org/wiki/Copper_extraction), [Nickel](https://www.britannica.com/technology/nickel-processing) and [Platinum](https://en.wikipedia.org/wiki/Platinum#Production)* are often found together. *Zinc* is often found concurrent with nickel or lead. *Iron* comes from metamorphic and igneous rocks. The best iron ore is [Magnetite](https://en.wikipedia.org/wiki/Magnetite). *Sodium* is "mined" from salt deposits, usually ancient ocean basins that have dried out. Given the soft nature of sodium chloride, it's unusual that these will be found on the surface because of weathering. *Oil* usually comes from sedimentary rock but can come from [igneous and metamorphic rock too](https://www.spec2000.net/17-ignmeta.htm). *Diamonds* come from metamorphic rocks formed [deep in the mantle](https://en.wikipedia.org/wiki/Diamond). **General Process** 1. Decide which kind of resources you want to have in your story. The list can be as long as you can stand. 2. Look up which kind of stone yields that resource. 3. If the story is for an adult audience, placing so many resource near each other may prove beyond the suspension of disbelief. If the story is for children or young adults, they likely won't know enough about geology to know that something weird is happening. 4. Draw out a map of the three rock types for your world. (See sample below) [](https://en.wikipedia.org/wiki/Copper_extraction) 5. You can make maps of more specific rock types for specific areas. As you can see the outlines of various rock zones tend to clump together but don't often form hard-boundaries. [](https://www.britannica.com/technology/nickel-processing) 6. Keep making the maps as detailed as you need in order to fulfill your needs. 7. If desired, do a sanity check with a geologist to see if your map makes sense. [Earth Science SE](https://earthscience.stackexchange.com/) is a good place to ask if you don't have a geologist handy. ## Conclusion As the author, you can invent whatever kind of geology you want to suit the needs of your story. While improbable, it's not impossible to have igneous, metamorphic and sedimentary rock deposits with a walking distance of each other. It just depends on the geological history of that area and you've got billions of years of world history to make the geology be exactly what you want. [Answer] Disclaimer: I am not a geologist. # Preamble All the minerals listed in the follow-up post (gold, silver, copper, iron, tin) are elements. None of these elements can be created on Earth. The conditions to create these elements requires supernovas or other similar events that do not occur on Earth. When people locate veins or deposits of these elements, those deposits are the result of millions of years of these elements being concentrated in one place, thanks to erosion and other natural forces. Gold, silver, and iron: These elements are present in microscopic amounts all over the world. They are too heavy to be a part of the atmosphere, so they fall to the ground. Then, due to erosion, these microscopic amounts of minerals end up getting concentrated in the lowest areas (for anyone familiar with Calculus, they end up in the local minimums). This is also where water tends to collect. Over time, water tends to end up in the ocean (or lakes). These microscopic minerals get swept along with the water. Therefore, these microscopic amounts tend to start concentrating in significant levels in the ocean (or lakes). A quick word about lakes: not all lakes will do. Microscopic amounts of gold don’t just float around in space by themselves. Lots of other minerals are out there too. The lakes that end up with enough microscopic minerals to start forming veins on their own will also have significant amounts of lots of other minerals as well. Therefore, humans (or presumably to any other sentinent species that drinks fresh water) would consider these bodies of water as mineral springs, brackish, or otherwise obviously not fresh. Now you’ve got a large body of brackish water with a bunch of mineral atoms in it. That’s a good start, but more is needed. This is where the process of gold and silver differs from the process for iron. # Gold/Silver: If you put one room-temperature fleck of gold next to another room-temperature fleck of gold, they don’t spontaneously join together. You need a lot of heat. In nature, this is commonly found in underwater volcanoes, magma vents, and geysers. To find these vents, you’re commonly looking for either 1) the edge of a continental plate, or 2) a really thin part of the crust. With enough seawater passing over the heat source, the gold or silver starts to coalesce out of the water. Gold and silver both have relatively low melting points in comparison to other minerals. This is why veins of both are extremely pure. If you have a blob of molten quartz and gold all mixed together, the quartz will solidify before the gold does. (If you’ve ever looked closely at ice cubes, you will see the same process. The water turns solid before the impurities do. So all the impurities end up being pushed in the same general place.) So now you have a bunch of gold and silver veins cooling at the bottom of an ocean next to some magma at the edge of a continental plate. This is where gold and silver are most commonly located. Unfortunately, humans will have a difficult time getting to it. More on this in a minute, as I pause to discuss iron, copper, and tin. # Iron: Iron loves oxygen. When iron is found in nature, it is typically a part of some other type of rock. Hematite is common. Therefore, for iron to form out of water, you need your water to hold very still and contain an unusually large amount of oxygen. Peat bogs are good for this. This process tends to go in waves. You have a strong growth period for your algae, oxygen goes up, iron gets concentrated. Algae dies, oxygen drops, other minerals get concentrated. Algae blooms, iron gets concentrated again. This process goes on for millenia, and you end up with a bunch of rock that’s alternating layers of iron and something else, sitting at the bottom of a bog. This rock is called banded ore. # Copper: Molten copper is in the mantle of the earth. When copper-rich magma cools, you get copper veins inside of some other rock. Quartz is common. As discussed in the gold and silver section, magma is commonly found in volcanoes, at the edge of continental plates under the ocean, deep below hot springs, and anywhere else the crust is unusually thin. Gold, silver, copper, lead and zinc are all commonly found together, because all these items involve magma in some way and they all have similar melting points. # Tin: Like copper, molten tin is present in the mantle. When tin-rich magma cools, you get tin veins. However, unlike copper, tin does not typically form pure veins. Tin is commonly found as part of cassiterite ore. Cassiterite ore is somehow associated with granite. Granite typically is formed when magma cools very, very slowly. When magma cools below the surface, you have a better chance of getting granite than if the magma becomes lava. # Availability: Now you’ve got your veins of minerals, but they are deep below the earth and generally unaccessable to humans. Plate tectonics brings them up to the surface. At first, they are buried under layers of mud and sediment and other minerals. If the minerals are in low-lying areas of the continent, erosion acts to dump more mud and sediment on top of the minerals. Once plate tectonics brings the minerals to higher ground (i.e. becoming parts of mountains), erosion (predominantly due to water action) removes the top layers of sediment and exposes the minerals. Visible chunks of the minerals are found in the streams of the mountains. This tells humans that there are veins nearby, and they go search for them. # In Conclusion: These minerals can be formed anywhere your continent was once covered by brackish water, or was once close to the mantle. Basically everywhere. But they will only become (relatively) easy to find when water erosion and gravity help remove the intervening layers of crud and starts showing the minerals. You’re looking for mountains near oceans in tectonically active regions (expect earthquakes and possibly underwater volcanoes). In the event of gold and silver, you are also looking for hot mineral springs anywhere in the world. Tin is usually found as part of cassiterite ore in streams near granite-rich mountains. Copper is found usually in veins of quartz, possibly in conjunction with gold, silver, lead, or zinc, in areas which were once molten. Iron is found as part of hematite ore in bogs or mountains that were once bogs. I leave you all with this quote from The Age of Gold: The California Gold Rush and the New American Dream by H. W. Brands (Kindle location 7451), attributed to Edward Hargraves, 49er: “My attention was narturally drawn to the form and geological structure of the surrounding country, and it soon struck me that I had some eighteen years before, travelled through a country very similar to one I was now in, in New South Wales. I said to myself, there are the same class of rocks, slates, quartz, granite, red soil, and everything else that appears necessary to constitute a goldfield.” Hargraves then used this observation to search for gold in New South Wales and found it. It must be noted that this type of terrain is not guaranteed to yield gold. It is also not the only sort of terrain in which gold can be found. But there seems to be some evidence for correlation. To research this post, I used www.Reference.com, www.australianminesatlas.gov.au, www.amnh.org, www.geology.com, www.mindat.org, The Age of Gold: The California Gold Rush and the New American Dream by H. W. Brands, and Geology for Dummies by Alecia M. Spooner. [Answer] Again, I'm not a geologist, but a good place to start would be working out where your tectonic plate interaction boundaries lie. These areas often experience high vulcanism, and would be both fertile and full of igneous rocks, metals and elements not usually found elsewhere. Another important thing to consider is the geological history of your planet. If an area, way back in the past of the planet, was a swampland, it might now have a high instance of chalk and flint deposits, or have been compressed into coal. Similarly ancient oceans would deliver oil reserves, or just be nutrient rich. Past volcanoes that have since been either eroded away or subducted (pretty sure that's the right term?) could yield gem deposits near the surface, or useful metal veins. Weather is another important concern. Areas of high erosion often reveal useful mineral deposits, while areas of high material deposition can seem to be resource sparse. Combining this with the paragraph above: an old ocean may become a limestone terrain, that is easily eroded to expose valuable mineral deposits. This also leads to the next point: Some materials like gold are easiest to find near waterways that are slowly eroding the deposits. This wouldn't need to be mined, instead it can be panned for or collected, and is fairly obvious if you're looking at a pre-industrial or very early civilisation. [Answer] Even us cosmologists and computer scientists involved in the field don’t understand exactly how this process happens, but let me see if I can give you an answer from the viewpoint of this cosmologist. First, you really need to understand how metals are produced, either from the Big Bang or cosmic rays to what is inside different types of stars, and how and how much or little is expelled when the star explodes. Even man-made metals/elements (Periodic Table below). When a star explodes it scatters all its heavy metals, gold, silver, copper, iron, lead, tin, zinc, etc. in 360 degrees. But not every star that explodes produces all the metals. Some stars produce only a few as this [National Geographic article](http://news.nationalgeographic.com/news/2012/09/120907-silver-gold-star-explosions-supernovae-science-hansen/#close) explains. [](https://i.stack.imgur.com/TSnog.png) A version of the periodic table indicating the main origin of elements found on Earth. The main source of Earth elements above 103 (lawrencium) are manmade and are not included. (Credit: [Cmglee](https://commons.m.wikimedia.org/wiki/User:Cmglee) - Licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.) Now when a star starts to collapse on itself, this is when the heavy metals start forming from iron and the heavier metals stay closest to the star’s core, such as gold, which is why it is one of the rarest of metals. And a theory also states that since these materials are heavier, the are more likely bound by gravity which increases their escape velocity. However, especially with gold and silver, physicists differ in how these metals are created, what type of star is needed to form them. Many do not give up any of the heaviest of metals. For the longest time, a Supernova was required to produce gold, but a [2013 article in Smithonsian Magazine](http://www.smithsonianmag.com/science-nature/all-the-gold-in-the-universe-could-come-from-the-collisions-of-neutron-stars-13474145/) cites a study where astronomers now think that gold is produced when two neutron stars collide. These stars are the size of a small city but almost twice the density of our Sun. Recently it was discovered that Earth was bombarded with radioactive Iron-60 from several close exploding stars as in this [SpaceAnswers.com article](https://www.spaceanswers.com/news/exploding-stars-showered-earth-with-radioactive-metal-say-astronomers1/). And even this article states that minuscule amounts were deposited on the Earth. So the second thing that occurs when a star does explode, besides scattering its materials in all directions, it does not expel everything. The heavier the metal, the less of it the star will release. You’ll see why when you look at a cross-section of a star just as it is about to explode. So in layman terms, you now know what is ejected from an exploding star, and in order of diminishing quantities. Another factor to consider is that heavier objects will tend to clump, or due to its mass, become gravity bound to each other. So gold will clump together with other gold elements, silver with silver, copper with copper, and so on. As the accretion disk starts to form (it is now known that a supernova explosion does produce all the material to form new stars) this mixture of clumps of metals and dust (that eventually form rocks) will start attracting each other. The problem is distribution out of the supernova. This is why in some areas on Earth you find tons and tons of gold in veins and large chunks, and other places not even a spec. It has to do with the early formation where the elements tend to stay together in clumps. Copper, a more abundant mineral, is found almost all over the Earth, but it too will concentrate in certain areas for the same reason gold does. But because it is a lighter metal, more of it is expelled from the star, and it will concentrate in larger amounts in more places on Earth. Now as the Earth is forming, is is molten. All the heaviest metals will sink deeper into the Earth than the lighter metals, which is why you can find copper very close to the surface, if not on the surface, and you need to dig 1/2 mile or more down to find gold and silver. Same with Iron. It also sinks deep into the center of the Earth. Any planet that forms like Earth will have the same issues with metal distribution. It will not be uniform, as it did not come out of the star that way, and that makes the heaviest of them harder to find. But when you do find a heavy metal like gold or silver, you will find a lot of it concentrated in the area of original discovery. That’s one reason the west had a gold rush, but has anyone heard of a head east young man, gold was found? It was just the luck of the draw where the gold from one or more exploding stars wound up. Yes, our metals are most-likely the product of several exploding Supernovae. There is no way anyone will tell you, looking at a current map of minerals on Earth, that the same locations will hold the same minerals. Many factors determine how much, if any, of the metal is even found on Earth. For example, nickel is natural to Earth, yet [most of it is deep inside the Earth](https://www.nickelinstitute.org/NickelUseInSociety/AboutNickel/NickelMetaltheFacts.aspx). Because it is in many asteroids in our solar system, it is the 5th most abundant element in the Universe, but when found on Earth's crust, it's from asteroid impacts after the Earth cooled. A planet even has a chance to not have any gold in it at all! Take the Moon. While there is gold and silver on the Moon, it has only been detected recently in the ice of the South Pole. Earth is devoid of Helium 3. Yet our Moon, which came from Earth, is loaded with Helium 3. Why? Luck of the draw? [Helium 3 comes from the solar winds](http://www.esa.int/Our_Activities/Preparing_for_the_Future/Space_for_Earth/Energy/Helium-3_mining_on_the_lunar_surface), which our magnetic field prevents helium 3 from reaching us. If you are looking for a scientific approach, there is no secret formula that says an Earth-like planet will have 10 percent gold, 20 percent silver, 80 percent copper, etc. It does not work like that. The planet Mercury has a lot of iron, the beneficiary of the Sun’s gravity. You would think that heavier metals would be gravitationally attracted to the Sun. Even after all the minerals and metals have been placed on the Earth during its formation from both gathering material from the dust of the accretion disk and bombardments by comets and asteroids, water and wind and other forces over time moves these around. As I said earlier, far more heavier metals made it towards the center of the Earth, but from water to lava flows to plate tectonics, minerals can concentrate around geographic features. Like a miner who looks for quartz to find silver. When you map out your world, you also need to take into consideration these geographic features. For even if the Earth did not receive a certain metal or mineral, chemical reactions can create them over time, like turning carbon into diamonds. Good luck. Placement of metals, removing the laws of physics such as gravity and amounts produced in the Universe, is a crap shot. But make sure that if you place gold or silver or copper that you also place its corresponding geographical features along with it. [Answer] Broadly speaking it is very difficult to come up a answer to this.When looking at the distribution of mineral deposits on a planet one thing to bear in mind is Geological time. A place may not be on an active plate boundary now but millions of years ago it may have been. Take the UK and the British Isles, stable now but at the end of the Ordovician and the start of the Devonian the [Caledonian Orogeny](https://en.m.wikipedia.org/wiki/Caledonian_orogeny) was occurring and there was an active subduction zone there. This has lead due to the igneous activity of the past to deposits such as Gold and Silver in Wales, Scotland and Ireland that are worked today. This means that metal ores can be found in many different places on the world not just where today's plate boundaries are found. I have to disagree with Greens assertion that finding mineral resources close together is unbelievable, due to the way these processes work it is quite common to find many valuable ores close to each other in different concentrations, take Cornwall and Devon in the UK mining of tin, copper, silver , zinc and arsenic all occurred in close proximity to each other. The source of these metalifferous reasources was the granite batholiths that form moors such as Exmoor and Bodmin Moor. Some places where metal ores an be found are due to quite interesting sources, take the [Sudbury Basin](https://faculty.washington.edu/dersh/Files/Project2009/Sudbury.pdf) in Canada. It is the second largest impact crater that has been identified. 1.85 billion years ago a large body hit the surface of the Earth causing a a massive crater which instantaneous filled with magma as it cooled this lead to areas, mostly around the rim of the crater to form zones enriched in metal ores. Much of the nickel mined has come from there. [Answer] Look for geologic activities that concentrate the minerals. You can find veins of gold or silver (and other metals) in volcanic areas. Specifically, miners in the US northwest (I'm using Kellogg, Idaho for my example) look for quartz veins in the rock. Those veins sometimes have veins of silver running through them. The veins form from steam leaking out through cracks in the ground. The quartz gets deposited on the sides of the crack and then when the crack is narrow enough, silver is deposited until the crack closes. Once they find silver inside a quartz vein, they just dig to follow that vein. So, one place to look is where there is current or former volcanic activity. ]

[Question] [ One person lives alone with access to a small patch of useful land. They have to grow all their own food and survive indefinitely. * This small patch of fertile soil is the only useful land. No grazing, everything around them is basically rocks. * They have averagely rich and deep topsoil, access to water, and a temperate climate (e.g. England, Germany, Oregon). * Soil erosion will be negligible. * They have access to simple hand tools, but not chemicals, motors, or electricity. * They have seeds for any plants you could name, and a minimal stash of food to survive until crops come in. * They have materials such as wood and plastic. * No fertilizer, but they can recycle their waste. * Assume no complete disasters, predators, etc, but there will be loss to pests, rot, and poor weather. * They have cool, dark, almost-airtight places to store food, but no salt, vinegar, or other preservatives unless they make them from scratch. * This person is physically active, so needs 2,000-3,000 kcal/day. * The goal is to survive indefinitely with good health. Decades at least. How small could this patch of land be? To what extent could they make this a closed loop? Will the soil eventually become unusable even if they compost their food scraps, faeces, and urine? What strategies would be effective at this small scale? Does it make sense to plant homogeneous crops or strive for diversity? Does it make sense to have crop rotation? Does it make sense to divide the soil and e.g. alter the pH of different sections? Does it make sense to cultivate things which will not produce for years? [Answer] [Biosphere 2](https://en.wikipedia.org/wiki/Biosphere_2) was an attempt at doing this sort of experiment. It was a 3 acre enclosed structure, crewed by 8 humans who would grow all the food they would eat, as well as all the oxygen they needed to breathe. Part of this was to establish what sort of size environment would be necessary for long term space colonization/travel. Most of their activity each day was tending to crops. For a colony space ship, living this close to the edge would mean disaster if more than a small percentage of people in your crew got sick or were otherwise unable to be subsistence farmers. > > *The goal is to survive indefinitely with good health. Decades at least.* > > > For this goal, I would aim for 5 acres (2 hectares) per person. And aim for a permaculture setting where you have multiple types of crops (so a rust/insect that wipes out one crop one season will not wipe out the rest of your food). Keep in mind the [Irish Great Famine](https://en.wikipedia.org/wiki/Great_Famine_(Ireland)), where most of the farms were of the size we're considering here. > > *Does it make sense to plant homogeneous crops or strive for diversity?* > > > Aim for diversity. Many Native American tribes cultivated a combination of maize, beans and squash. This was called "[the three sisters](https://en.wikipedia.org/wiki/Three_Sisters_(agriculture))". > > *In 1845, 24% of all Irish tenant farms were of 0.4–2 hectares (1–5 acres) in size, while 40% were of 2–6 hectares (5–15 acres). Holdings were so small that no crop other than potatoes would suffice to feed a family. Shortly before the famine the British government reported that poverty was so widespread that one-third of all Irish small holdings could not support their families after paying their rent, except by earnings of seasonal migrant labour in England and Scotland.* > > > The potatoes in Ireland were genetically clones of each other. A disease that affected one plant affected them all. The book [Altered Harvests](https://rads.stackoverflow.com/amzn/click/0140096965) goes into details about this and the US Corn Blight in the early 1970s. [Answer] In the Uk there was a woman called Hannah Hauxwell, she was famous in the 70's and 80s for living self sufficiently on a smallholding in Yorkshire. her lifestyle was in no way lavish and she had 15 acres. but she didn't produce her own material for heating. or produce her own linen for under clothes (she would produce wool). But this was hard yorkshire pennines land. <http://www.dailymail.co.uk/news/article-3537770/Remote-smallholding-stoic-farmer-Hannah-Hauxwell-lived-survived-170-year-iconic-1970s-documentaries-goes-sale-590-000.html> In Elizabethan (UK) times there was this act: <https://en.wikipedia.org/wiki/Erection_of_Cottages_Act_1588> > > The Erection of Cottages Act 1588 was an Act of the Parliament of > England that prohibited the construction - in most parts of England—of > any dwelling that did not have at least 4 acres (1.62 ha; 0.01 sq mi) > assigned to it out of the freehold or other heritable land belonging > to the person responsible for its construction. > > > This was considered to be the minimum land required for a serf to live upon producing their own food. but once again does not cover fuel or clothes. this allowed the keeping of a few animals, and growing of vegetables. And another caveat they would have had [common land](https://en.wikipedia.org/wiki/Common_land) to graze their animals upon. [Answer] My wife did a project for one of her agriculture classes at the University where she had to plan out a farm for one family to live on using the minimal amount of land to still get them all their calories and nutrition. The plan was for just 1 acre. I don't remember but I think that did not include the dwelling space. And it was just enough calories to survive. So it would have been subsistence living. [Answer] According to The Institute for Innovations in Local Farming, it seems that 1/2 acre should be sufficient. The [feasibility study](http://www.spinfarming.com/common/pdfs/STF_inst_for_innovations_dec07.pdf) they did in 2007 was aimed more at economic feasibility and used lands surrounding Philadelphia Water Department facilities > > STF [Sommerton Tank Farm]had slightly more than ½ acre of growing space planted three to > four times annually with 60 different vegetables. Another ¼ acre was > used for pathways, parking, and farm structures (processing station, > storage shed, portable toilet, and cooler). From a 2003 start-up, STF > operated stably from 2004 to 2006 with a full-time wifehusband farmer > team aided by part-time labor or a part-year assistant farmer. Aiming > to achieve sales of 50,000 [dollars] in five years, STF grossed 52,000 in its > third year [and] 68,000 in the fourth. > > > [Answer] I would say the land needed would depend on what materials you are planning on giving them access to. As earlier answers have stated, if they will also be growing things like hemp they will need more land. I can answer with certainty though, that a monoculture would be an extremely poor choice for the person in this scenario. Planting the same crops over and over is the fastest way to deplete the soil of the required nutrients for that plant. Crop rotations provide a way for the soil to recover. An excellent example is a corn/soybean rotation seen throughout much of the midwest. Corn is an intense user of nitrogen. Soybeans use less nitrogen, and a certain amount of that can be taken directly from the air thanks to a bacteria that forms on the roots of the plants. This off year is vital to allow the nitrogen to replenish. Also, in such a small area, I am of the opinion it would be important to have a diverse enough rotation to allow at least 2 years in between planting the same crop if possible. In such a small area, moving crop A to a different side of the plot would hardly be an impediment to any insect pests. Some insects and fungal pathogens can lie dormant in the soil for over a year. Being able to switch crops if certain pests are becoming problematic would be important. Finally, assuming these perfect conditions, planting a diverse range of crops can even help with something as basic as weed control. To use the midwest again, our monoculture has led to problems with a certain amount of key weeds. If there was more crop rotation, and therefore a different time when the soil was bare each year, different weeds would be growing. Hence, the same set of weeds would not always be cultivated each year. [Answer] What your talking about I think, is called "high intensity agriculture". A complex ecosystem requires so many different inputs and produces so many different outputs that even a small scale farm is really not a small scale farm. It is managed in parallel by one person maybe, but it is really a small part of a big farm. That is if your talking about a fully closed cycle system. Closed cycle agriculture is the brass ring for permaculturists. How to make a complex system that produces the most yield; from their perspective; is a process of having as many different species as possible in the same space. The purpose is to create the highest gross biological mass possible, from which a small yield can be sampled for the farmer. These farms look totally different than conventional farms, and their core is managed typically around a forest ecosystem. Other approaches that produces high yields per acre are variations on aquaponics, and also insect farms. With probably insect farms being the most practical for low skillset farmers, due to the reduced number of inputs required. ]

[Question] [ I'm writing a science fantasy setting for a tabletop game. Its major influences are *Dune*, *Final Fantasy 7*, and *Borderlands*. My goal is to give a universal account why swords, spears, etc., equal or even best guns between fighters of equal skill. Let me define my terms: 1. By **guns** I *primarily* mean modern ballistic firearms, like what you'd see in a *Call of Duty* game. I'm not as interested in making lasers, rail guns, grenades, etc, comparable to hand-to-hand weapons. If you can relate them in your answer, though, that would be extra appreciated. The setting is not premodern, so flintlocks and other obsolete guns are out. 2. By **raw-ability** I mean explanations like *Star Wars* where superhuman powers, strength, or magic make exceptions for hand-to-hand combat. My major concern here is, "If the sword wielder has x level skill, why can't the gun wielder with X level skill be even better?" I'm not trying to explain why super heroes can overcome guns with swords. I'm looking to explain why *swords themselves* are comparable to guns as part of the world's "natural law." 3. By **exceptional** explanations I mean something like *Dune* where special technology, geography, monsters, or other special scenarios make melee weapons desirable. Although brilliant, explanations like Herbert's create more "an exception to the rule" than they account for a universal law of the universe why axes can keep up with machine guns. This rules out making *specific* environment a primary reason for melee combat. If the world only featured close-quarters environments, for example, that might work, but it features a relatively varied amount of environments and I'm looking for a reason why melee will be desirable in most environments by default. So, in terms of goal, I'm looking for a vaguely *Advent Children*-esque world where plebs walk around with firearms for self-defense while mercs dabble in swords, spears, maybe gun-fu, but where the setting neither turns into wuxia supermen battles nor hard sci-fi tech. [Answer] ## This is *not* possible within your constraints As others have mentioned, the main benefit modern firearms have over melee weapons is accuracy, fire rate and range. Thus, under your constraints, a charging swordsman will be hit multiple times by a gunman before he closes the gap. We must either have a shorter gap (to reduce the number of shots that can be fired), inaccurate or slow gunfire (to reduce the number of shots that can be fired/hit) or we must be able to shrug off bullets (due to armour technology outpacing firearms). Due to your constraints, we cannot limit firearms via technology (such as by restricting the quality of raw materials or the quality of manufacturing) as doing so will mean your firearms are no longer "Modern". By limiting the ability of both combatants to realistic levels, the swordsman will not be able to parry or dodge the bullets, and thus will get hit multiple times whilst approaching. Your blanket term for Exceptional Circumstances appears to block all other options. Geographically restricting range is not allowed. Allowing the Swordsman to shrug off the bullets thanks to advanced armour/shielding is not allowed. Restricting the velocity of firearms due to sufficiently-advanced alien tech is definitely not allowed. Simply put, as your question stands, your constraints are too tight to permit a change that will bring melee weapons on par with firearms. Every IRL National Military will want to use the best tools for the job after all. With your constraints basically being "Real-World", if the armies of the world can't find a reason to use melee weapons, it'll be because the reason does not exist. [Answer] I'll try my hand at your comment on L.Dutch's Answer: > > Very insightful. Giving a "wavehandium" reason for slow fire rate is feasible. However, is there a way to make modern firearms less accurate - maybe something about the world's physics? > > > Since you're writing a science fantasy setting, you could either play with the actual world (as in planet)'s conditions if the game is set on only one planet - or with the rules of physics themselves if you want it applicable on different planets too. # Planetary conditions Let's try the more restricted one first: if we leave the laws of physics alone and only adjust conditions on one planet, what could be done to take guns' advantage away? ## Bad visibility You don't need slums' cramped conditions taking away sight line to the target if you can't see very far in the first place. A planet where fog, sandstorms, pollen, spores or swarms of insects are common enough that a gunman can't reliably expect to see the target in time to shoot them before they're in his face with a sword will be a planet where a gun isn't much better than said sword. ## Bad conditions for technology Several of the options above also work here. A well-maintained gun shoots accurately and reliably. A gun with grains of sand (or crawling insects...) in the barrel might not shoot quite straight, especially after the first couple dozen shots when the barrel gets more and more worn from the effect of a bullet travelling through it and dragging sand along its length. The firing mechanism might be jammed by sand or rusted from the constant mist, the gunpowder might be damp... depending on the technology used, environmental conditions might make "will it shoot or not, and if it does, will the bullet fly straight?" a gamble. Note that this becomes more and more manageable the higher your tech level and the more you're willing to pay - modern firearms *can* be built to fire reliably after taking them for a swim, but you're paying more for that than you would for a gun that only needs to work on the shooting range. Kalashnikovs have also anecdotically been known to work fine after being buried in dirt, so you'll have to restrict your world's engineering capabilities a bit if you want this to be a factor at more than the low-price range. If you're fine with plebs' guns being unreliable enough to counter a shooter with a kitchen knife but elite mercenaries firing reliable guns at elite swordsmen dodging matrix-style, this might be the way to go. ## aggressive animals Guns are loud. The Sky-Snakes will zero in on anyone firing a gun repeatedly, and those things are nasty and poisonous. The boombeetle will look for a mate where it hears the mating call, which sounds kinda like a gun being fired. Think of something fun ;) ## missing is dangerous See those rocks over there? Hit them too hard, like with a bullet or such, and they'll explode - shards everywhere, including your face. See that plant over there? Those thick leaves are filled with a flammable, sticky liquid. Basically napalm. You do not want that splashing around. And that one has swamp gas in its fruit, explodey. The seeds are also poisonous. Obviously this would lead to a world with *no* (or only the dumbest or most reckless) plebs walking around with guns, so it might not work for you. # Different laws of physics If you're willing to meddle with the laws of physics, the sky is the limit... or rather, not even that. You could just handwave that it's impossible to manufacture explosives that are reliable enough for our kind of modern firearms because chemistry works differently, or maybe inertia follows a different law where things in motion don't stay in motion - they want to return to a state of rest, so bullets lose power quickly the further they travel. Maybe there's a material that acts non-newtonian in a way that makes it comfortable to wear but lets it stiffen quickly when hit with a rapid-moving bullet - but somehow this material is still vulnerable to cutting edges on spears, axes and the like... # Different Biology Bonus: If your people don't have to be human, you could just give them quickly-sealing blood vessels and more redundant bodyparts. If a bullet hits you and just gets stuck in your dense muscle mass, or maybe pierces an artery but that artery seals up and the blood for the arm you've been hit in gets routed through the secondary set of arteries instead, or the bullet pierces just one of your three hearts - maybe you can keep fighting and recover from it. And maybe that's easier than recovering from having a piece cut off with a sword. [Answer] ## Scale everyone down Take advantage of the [Square Cube Law](https://en.wikipedia.org/wiki/Square%E2%80%93cube_law). Scale your people down. Smaller people can wield much larger melee weapons relative to their body size, and those weapons can be made thinner (and thus lighter) than comparable weapons at real human scale. Picture a foot-long razor blade with a handle at one end. At the same time, ranged weapons become less effective. Projectiles have much less mass, and worse mass-to-surface area ratios, so air resistance and turbulence reduce their effective range. If your chosen scale puts effective gun range about equal to video game shotguns - that is, about two to three times the range required for melee - then suddenly swords and firearms are about equally effective for a skilled fighter. Some situations will favor guns, others will favor melee, but overall neither will have a clear advantage. At the same time, the plebs will favor guns simply because they require less skill to be effective, and will carry them as a defense against beasts much larger than they are. --- Some fun side effects of scaling your people down: * Goo/sticky weapons become more effective. * Fire becomes a more effective weapon. A brief encounter with flame at real human scale will leave you with a first-degree burn and some missing hair. A brief encounter with flame at Borrower scale could destroy your fingers, nose, and ears. * People can easily lift several times their body weight. * Flying by attaching something wide and flat to your arms and flapping may be viable. Or at least not seem totally ridiculous. * Jumping your own height or higher becomes a feat anyone is capable of, rather than just olympic athletes. Olympic high-jumpers would regularly jump four or five times their own height. * Falls become less dangerous. Jumping down from a second-story balcony is not dangerous at all. Jumping from a tower of any height with a bedsheet as a makeshift parachute becomes effective. * Mega structures like skyscrapers over a hundred stories tall become easier engineering feats. But wind and rain become bigger potential problems. [Answer] Guns are by definition ranged weapons. To make melee preferable or comparable to ranged combat you need to remove the advantage that it has, the simplest way to do that is to remove range. Set combat in an environment so complex and obstructed that range is minimal. Consider a rotating space station as an example, unless you have a central open space, the curve of the floors and low ceilings mean you can't actually see very far ahead of you. Add corridors, spiral stairs, suites of rooms and you're all but in someone's face before you have line of sight to them. The same can be true of a slum situation, buildings so tight and spaces so narrow that unless you're following a bulldozer you don't have line of sight more than a few metres ahead of you. Bullets rebound. This adds a level of risk to using firearms, that you don't get in the open field situations for which they're designed. Moving through a standard dungeon crawl cavern which just happens to be through a type of rock with a greater [coefficient of restitution](https://en.wikipedia.org/wiki/Coefficient_of_restitution) for whatever handwavium reason you choose. It's now dangerous to all parties to miss your primary target with a firearm as the rebounding bullet could hit anyone. [Answer] ## Superior ballistic armor I'm not sure whether this counts against your exceptional circumstances (as assumed by Kyyshak), but it seems the least exceptional way to eliminate the overwhelming advantages of modern firearms over melee weapons among well-equipped combatants. On your world master armorers have discovered a (very expensive) way to make armor that stops most bullets outright, except at point blank range or from certain angles. It doesn't fare quite as well against slower weapons, especially slashing types like swords. A skilled combatant can pierce the armor with a gun after a bunch of tries, putting the gun on a somewhat equal footing with a sword. Defending against a gun while using a sword doesn't mean dodging bullets, but rather preventing the opponent from aiming at and getting a shot on weak points in the armor. This doesn't involve Jedi foresight or acrobatics, but an aggressive style that puts the sword wherever the gunwielder's arm is or would need to be for a shot. As soon as the gunwielder backs away, the sword user can angle their body to minimize exposure, making the gun mostly useless until the distance is closed again. Against anyone that doesn't have the resources (and permit?) to own a set of armor, firearms are the weapon of choice. So the plebs would be shooting eachother up like normal, as you want to. [Answer] Fire rate and precision are the key factor for guns to be dominant over melee weapons. Think of the bow: archers were used for quite a while after guns introduction simply because the fire rate they could grant was higher than the first guns and rifles, with a significant better precision. Same here, if you fire a shot that goes within a large area around your pointing target and then have to wait a long time to reload the weapon you are basically giving an advantage to your enemy approaching you with a sword in his hands. So, keep your guns primitive (heavy, slow firing, poor precision), and that would explain why melee weapons have an advantage. [Answer] Expense, make one of the prime bullet ingredients expensive or something like that and a sword is better since your gun turns into just a clumsy club without bullets. Some places still use swords for this reason. They just don't have much access to guns and bullets. They're not something you can easily make. Even a pipe gun which can be made with some technical know how and tools cannot do much without bullets. [Answer] Seems like all the obvious ideas have already been explored, so I'll try something a little out there.... ## Ghosts No, seriously. In this universe the "vengeful dead" are very real and very troublesome. When a sentient being is killed as the direct result of another sentient's actions, their spirit thirsts for vengeance. The only known way to prevent this is to cleanly sever the spirit from the body by killing in close quarters with an edged weapon. NOTE: The spirit considers the body "dead" when the damage has progressed to an unrecoverable point - it may leave the body before it is technically dead (this covers bleeding out and other "delayed" deaths). If you do kill someone and their ghost begins haunting you, you may not notice anything. These spirits are cunning and will wait for the most disastrous moment to manifest and distract you. While they cannot affect the real world, they do possess the ability to create human-sized hallucinations. For most people, this may be as simple as seeing a person suddenly in front of the car while driving (causing them to swerve and hit something). For a mercenary or soldier in combat, this can be more disastrous - an enemy behind you, a grenade appearing next to you, misidentification of an ally, etc. To counter act this, individuals who regularly kill will exclusively use bladed weapons. "Normal" people who are only concerned about self-defense don't mind carrying a gun, since it is a last resort weapon. Perhaps there is some dangerous and convoluted way to exorcise a haunting spirit that is impractical for a mercenary or soldier (due to the number of times they'd need to perform it), but is "better than nothing" for a normal person. This does have the strange impact that if you see someone carrying a gun, they're indicating their main focus is self-defense - but someone carrying a sword or large knife is signaling their willingness to commit mass murder. [Answer] # Honor Your society might have a very particular view of ranged vs melee. Over many generations people have been indoctrinated to believe that there is more honor is fighting melee versus using a ranged weapon. Most plebs who's honor is not worth mentioning would resort to ranged weapons while the accomplished mercenary would wield a sword showing the rest of the world that they don't even need a gun. A mercenary who only uses melee weapons to complete his contracts would be more famous and sought after then a mercenary who just uses a 10 mile ranged sniper rifle. Even if the sniper rifle is technically a better weapon it would only be used by those of disrepute. TLDR - The culture puts a great value on being able to take an enemy out at close range. People strive to get good at melee and see ranged as a handicap. [Answer] Better advances in protection. Currently ballistic firearms have progressed faster than ballistic protection, which allows guns to be so dangerous. But gun ballistics progression is nearing it's end unless we transcend towards railguns and other exotic weapons, while metamaterials are becoming more and more attainable. Imagine spidersilk armors with Graphene layers and other lightweight, extreme performance materials. If these become cheaply available the guns required to kill your opponent will have to go big, and even a. 50cal could start having trouble killing the opponent and would rather break bones than kill. This in turn allows melee weapons to become viable again. In Iraq and Afghanistan it's estimated that the trained army outnumbering their opponents still needed 250.000 bullets per insurgent. If you need bigger weapons and more hits to down a person it becomes less interesting to use that gun. Big weapons like a. 50cal have lower rates of fire (when handheld), are unwieldly and very hard to aim unless mounted or resting on a surface. Your opponent has to grab a smaller caliber and hit you multiple times to bruise and break you enough to knock you out of the fight. Time you can spend rushing your opponent and smacking him with a mace or similar. Even the good old knights of old in slash-resistant armor were very vulnerable to getting bashed. Add in potential upgrades in your melee weapons unavailable to bullets like high voltage, potential superheated edges, monomolecular edges etc and you can make melee weapons more useful. [Answer] Here's a simple idea: Much higher atmospheric density leads to several disadvantages to guns: 1) higher required charge to reach decent muzzle velocity & faster velocity drop-off in air - hence steep trajectory curves; 2) soundwave propagation in denser atmosphere means concussion from said shot would be loud enough to damage shooter and be highly detectable no matter what; leading to 3) the edged weapons are just inherently stealthier - you get close, katana, gim or tonto undrawn, once inside striking range you execute an aido-style quick draw, and resheathe removing the blood, as your silently halved opponent drops into separate pieces. --- Most properly we can say that drag forces scale with the square of velocity and with the density of the fluid - see equation below, where p is media density. [](https://i.stack.imgur.com/XWqBq.png) [Answer] **Make the gravity of the planet higher.** Quite simply, this has the effects of increasing the atmospheric pressure, leading to higher turbulence and reduced bullet travel distance, plus the increase in gravity means the average person has to be stronger, thereby making a sword able to penetrate more armors. In addition, the higher gravity means the bullet drops further faster. This doesn't affect accuracy though, only the require skill to use a gun and the maximum range of a gun. The other fun effects of this could range, from having more dense people (Bullets do less damage) to reducing atmospheric visibility to such an extent that you can't target people with a gun at substantial range anymore. People might also develop stronger armors, due to the need for stronger materials in a world where everything is heavier, and be able to wear heavier armors, due to the inherent strength increase of a person who grows on a larger world. (Which can be assumed due to the increased gravity) However, the most obvious way to demonstrate this would be using a brick falling from height. Now, instead of falling 5m in two seconds, it might fall 50m in the same time, leading to a bullet that's in the air for potentially .1 seconds to be hitting the dirt within roughly 30m. (assumed from the speed of some shotguns of 1000ft/second) If with these advantages swords are still unusable, remember that the effective range of a gun by your average soldier would be ~5 meters, due to the extreme bullet drop and the increased turbulence from a denser atmosphere making hitting a shot hard. A thrown weapon would be unaffected at short ranges, which works well for this because even now spears aren't effective at much longer ranges. [Answer] Ravenholm from Half-Life 2 is the microcosm of the best justifications for melee weapons. Why? * **Limited supplies:** Supplying your army with ammunition, weapons, mangas, and everything they need to fight is a pain in the a, and WAY too common to be ignored in almost any setting. Throughout Ravenholm, you barely get ammo, and so are forced to use telekinesis (the Gravity Gun), physics and the trusty crowbar, there's a shotgun though, but you'll blow all your ammo on... * **Fast, annoying, numerous but relatively weak enemies:** Ammo is precious, 7 ft tall animatronics and gunships only succumb to the .50 cal and ATGMs. You CANNOT waste your munition on their minions. If you spend your ammo in Ravenholm, shredding through zembies and headcraps, you'll soon get sexually harassed by the combine snipers and troops in the next area, who will gleefully use the open, cover-filled space for their squad-based tactics. You won't just die, you'll end up fighting a battle you cannot win, and that's with the SAVE and LOAD, meta-game abilities. With a Murasama katana, however, you can chop the headys apart with a bit of effort and not waste your precious ammunition. Headscraps are too adaptable, you can find them anywhere, and they make for an excellent DISTRACTION CARNIFEX, I'd also expect them to be used as meatshields, that's what they were designed for. Heck, you can have your own hare... I mean, army of them. --- ## And now for something, completely different * **The White Walker Obstruction**: Seriously, those bastards have an infinite, localized smoke-screen, they can create pretty much instantly. Sure, after I donned my echolocation gear, it was pretty much useless, but that was from afar. If they've AMBUSHED us, I would also have had to worry about friendly fire. At least with swords, you can halt your offensive just before cutting off your roomie's head from a Wrath Guard (stance). * **Why not?**: Exoskeletons are plausible, sword, spears, bo staffs and bike locks weigh practically nothing if made out of modern materials. So bring in the gun-fu, and **[This fine lad](https://en.wikipedia.org/wiki/Jack_Churchill)**. [Answer] You can't without dropping at least one of your conditions. Considering that it's for a game, it's not as bad as it may sound. I suggest you drop "exceptional" condition and introduce plethora of exceptional circumstances. Cramped slums, packed space stations (like Separatrix's answer), strangely bullet absorbing melee space monsters (for those you definitely want so called boar-spear with cross bar, to stab monster and keep it away from yourself at the same time), realistic sewers (instead of absurdly spacious ones) and so on. Since weapon usefulness is function of circumstances: guns are all around better, but action of the game happens in those exceptional locations and situations, focusing on people specialising in dealing with those exceptional situations. As a bonus, you can always have curveball wide open location/scenario with gun totting human enemies requiring either change of gear or complete change of tactics. Reason why guns are superior is their range and accuracy. Times of volley fire making up for inaccuracy and slow reload are gone since mid 19th century and you can not reintroduce those in modern setting without breaking "exceptional" requirement. Dune uses shields, but there are other options, for example: short range teleport (usually called "blink" in fiction) removes range advantage, stealth (plain old hiding or sci-fi active camouflage) removes all advantages and let's call it "distortion shield" which doesn't stop bullets but turns anything short of exact hit to centre of mass into miss would remove accuracy advantage. Some of those break into "raw-ability" like territory, shooter with stealth (basically a a sniper) is better than swordsman with stealth, blink goes both ways, with shooter being able to escape (potentially counter-able by another teleport by melee fighter) while distortion wouldn't be very effective against melee weapons giving shooter advantage only against other shooters. [Answer] There was a movie release in 2002 called Equilibrium which tackled a similar question. The producers of the movie developed a new form of martial arts called ["Gun Kata"](https://en.wikipedia.org/wiki/Equilibrium_(film)#Gun_kata). The explanation of Gun Kata is given as: > > Through analysis of thousands of recorded gunfights, the Cleric has determined that the geometric distribution of antagonists in any gun battle is a statistically-predictable element. The gun kata treats the gun as a total weapon, each fluid position representing a maximum kill zone, inflicting maximum damage on the maximum number of opponents, while keeping the defender clear of the statistically-traditional trajectories of return fire. By the rote mastery of this art, your firing efficiency will rise by no less than 120%. The difference of a 63% increased lethal proficiency makes the master of the gun katas an adversary not to be taken lightly. > > > You could twist this explanation slightly to make it relevant to *defence* against fire-arms using the same statistical analysis reasoning. For example, you could explain that through statistical analysis of thousands of recorded gunfights, a melee fighter could close the gap to the fire-arm wielder by keeping clear of the statistically-traditional trajectories of return fire. [Answer] **Simple: Standard (Space-Travel) Economics** You are writing for a science-fiction setting. You do not need to assume very exotic things to make melee-weapons as feasable as fire-arms. Just the following: * **Transport-costs for offworld-things are (literaly) astronomical.** A gun that is being produced off-world, will require off-world bullets. The costs of each bullet will be so high that "single-shot" will become standard, even if "spraying a hundred bullets in a single burst" is technically possible. A sword, even when produced off-world, can kill an unlimited amount of people while having no additional costs. * **High-tech items that work on *every* planet *and* in space are not as good as simpler technology.** If your fire-weapons are made to work in every environment, they might be rather sub-par when compared to simpler weapons. Just think of those few present-day weapons that can shoot underwater as well as in air. Your guns might be produced to work in Vacuum, in extreme temperatures (so high/low that gasses freeze or metals melt), in sandstorms, liquids, high gravity, ect. They might shoot, but they will not be as effectiv as present-day "works only on earth"-guns. It is not surprising that those guns can be countered by "mere" melee-weapons. Especially if those melee weapons were forged specifically for the environmend they are being used in. [Answer] I've experience with both guns (sport shooting), and swords (HEMA). As others have noted, you're going to have to bend one or more of your restrictions slightly. Lots of the answers suggest reasons that guns would be less preferable to carry (e.g. cost, or dangerous to use), but these *wouldn't* make a fight between a gun and a sword user more *balanced*, which I believe is what you're trying to achieve. To do this, you'll have to balance the lethality of guns and swords. Remember that swords work in two ways: in the thrust (stabbing with the tip), or cut (drawing through in a cutting motion with a sharp edge). They do *not* work but hitting people with the sharp edge, despite what films would have you believe. Try it with a carving knife on a pork joint, you'll not get through the skin. --- **Range** Reducing the range advantage would help, as at larger ranges, guns have >0 lethality, whereas swords have 0 lethality. Two options are to reduce the range of encounters, or to slow the draw of a gun. Don't underestimate how fast or far a swordsman can reach. The **"21 foot rule"** is a real thing from law enforcement – within 21ft, a suspect with a knife can draw their knife and kill an officer faster than an office can react to draw their weapon and shoot. And that's a 4" knife. You wouldn't believe how far and fast a lunge with a montante is. (A montante is a very large sword typically used by bodyguards, which was typically carried resting on the shoulder; it's usually used two-handed, but you can 'draw' from the shoulder and lunge single-handed like a rapier, though it's a bit of a gamble as recovery is very difficult.) So if you've got a scenario where ranges are short (probably any residential space), lethality will tip towards a sword user. If you're wanting a balanced 50:50 sword/gun kill rate, a larger range will be fine even for a *knife*. You can further decrease the speed of a gun vs a sword with the use of laws – e.g. a law that prevents open carry of a gun, but permits open carry of swords. If guns have to be secured with a combination lock on the trigger (and only legal to release the lock if you're in danger), a sword-user is probably more lethal in *any* indoor setting. That might not feel like a realistic law, but you can imagine it being proposed by the anti-gun lobby in the US. --- **Lethality** The other option is to make guns less lethal, so that it requires several shots to stop an attacker. One option would be to move to 'non-lethal' ammo (it'll have to be due to law, as it's not hard to form a bullet if metal is available). A black market in lead bullets might exist, which might work in your story? Perhaps the law prevents general civilians from using metal ammo, but permits it for those who are better trained like mercs? --- **Game Mechanics** However, you're talking about a game. In real life, the first bullet hit wins a fight. But people don't realise that usually the first knife stab or even *punch* wins the fight. This doesn't usually make for a fun game mechanic if the first hit you take in the game kills you. Sword or gun fights where they slowly both carve bits off each other until one reaches 0-HP are much more fun, but not realistic. So if you want a hard-science answer for a fun game, it's going to involve armour. It takes relatively little armour to stop a sword (sword fights in plate armour are largely about pinning the other guy down or knocking him over with a big blunt 'sword' (club), and then stabbing through the joints with a knife until he bleeds to death). However, most modern guns would penetrate this armour (unless you're lucky and get a deflection). Note though that heavy armour is *really heavy* and would never be worn 'normally'. Leather with some light metal over the key areas is probably as heavy as anyone would want to wear as regular wear. So your options are: * invent a light non-newtonian armour which provides much better protection against guns (high velocity impact) than swords (low velocity cutting). Stuff like this is in development; in our world it won't cause a move back to swords (because bigger calibre weapons and longer ranges are the norm, and we rely on law-enforcement rather than wearing armour to keep civilians safe), but in your world it could well provide what you need. * reduce the weight and velocity of bullets so they don't penetrate as much. A sub-sonic .22 has considerably less penetration than a 7.62 round. If you're happy to bend the hard science a bit, some kind of 'healing factor' would work – perhaps a nano-tech you inject which will save you from a couple of shots? It would probably be less effective against swords as a slash wound would be larger and would overwhelm the nano-tech. [Answer] All you need are reasons rendering things more even. A few ideas: **Movement** Sufficient mobility makes smaller weapons superior. If you can clear the distance to a guy with a gun before he can draw a bead, melee is superior. (Slowing guns down could work similarly, but that raises other questions. Still, if all ballistics slowed but retained momentum, if not all the impulse, you'd still have dangerous weapons, albeit less useful.) Invisibility or major resistance to damage while moving is roughly equivalent to rapid movement for gun vs. blade purposes. As to how to to get this high speed or safe movement, well, that could be a common device or spell or even a martial technique if it's not a normal fact of the world. (Heavy mists could render things invisible out to a few hundred feet and blurry. Basically, a PS1 game world... You could have a reliable combat teleport pack or spell available. This is a sci fi/ fantasy question: choices are broad.) Which leads us to... **Chi** It's not realistic, but of your inspirations, only one even vaguely hints at such. Special martial training can unlock abilities that rival the range of guns but without some of the drawbacks. Guns could have the advantage of being powerful without the chi requirements. The disadvantage being that chi isn't a big benefit to firearms, limiting the upper end of lethality. This gets you the common schlub using guns with warriors using other weapons thing. (This could be a universal trait of the world rather than a special thingy. Depending on how you interpret things, that could avoid your special power thing.) **Shielding** The shields in Dune could be tweaked to something that could explain this. A narrow impulse is easily deflected while a cut can drop the whole shield, say. This needn't be a technological marvel, either, but could be a magical or field thing that affects people for some reason. **Weird physics** Slow bullets plus the ability to deflect them with a weapon could lead to safer swordsman, a la Force blaster deflecting tricks but nigh universally acheivable. **Sixth sense** If a target knows intuitively when they are being aimed at, it would aid them greatly in avoiding getting shot. If *everyone* can just tell where firearms are aiming about as well as the shooter it would make ambushes far more difficult. Should this sense reveal the source, as well, it would change quite a few details about combat. Obviously some explanation for this phenomenon would be in order. Bonus point: Master Ken providing some insight into the problem: <https://youtu.be/V_cUvjZCLL0> [Answer] **Gun control**. Almost all current governments do this to some extent, so it's reasonable for your government to have laws about this. This could go as far as no guns available period, but you could have a setup where, say, only bolt-action rifles are available to civilians, which don't do so well in close-quarters. (Consider having areas with different gun control laws to add complexity.) Also, look into air rifles. While they're mostly used for target shooting these days, they are suitable for self-defense-related tasks if given enough power. If there's a restriction on reservoir size, you can end up with guns that can fire X times, then can't be reloaded until after the battle, while restrictions on PSI can result in underpowered shots, so people won't die in a single hit. If you want citizens to be walking around with guns, while mercs use melee, you could use the laws for that as well. For example, say mercs tend to do things that aren't quite legal, and if caught with a gun, they go away for life, (with enforcement to match) while getting caught with Dual Laser Katanas just gets you a stern talking-to for dueling in public without filing the proper form. EDIT: actually, let's expand on dueling. Let's imagine a world where dueling is still a thing, but it's only allowed with melee, because bystanders kept getting killed. Walking down the street with your Dual Laser Katanas is implicitly an invitation to duel in this world. Normal people want nothing to do with this nonsense, so they keep a pistol for self-defense. If someone with a pistol kills someone with a melee weapon or vice versa, that's a death the police care about, but if two people with melee weapons fight and one dies, that's just a dumbass getting killed while dueling. [Answer] ## **[Coriolis effect](https://www.britannica.com/science/Coriolis-force)** Set the story on a planet that spins so fast and/or is so small that the Coriolis effect is much greater than it is here on earth. You can counter gravitational effects of a fast-spinning or small planet by making it very dense. Here on earth the Coriolis effect is taken into account when calculating very long range shots (shots taken mainly by cannons rather than by rifles) and they're taken into account with calculations. In an environment where the Coriolis effect is exacerbated, it's very hard to have an intuitive feel for how each bullet will react, making it hard to aim. [This video](https://www.youtube.com/watch?v=7TjOy56-x8Q) shows what I mean. Eventually in the video they are able to aim, but this is because they are rotating at a constant rate and throwing in the same direction each time, someone on a sphere would have great difficulty adjusting to shooting from different latitudes in different directions, making handheld ranged ballistic weapons (guns) ineffective at long range. Depending on how much of the effect you decide to incorporate into your world will impact how far guns can effectively be aimed from, and can give an advantage to melee attackers (especially if they attack from the north or the south). [Answer] In a structured 1-to-1 battle, head-on, melee weapons will always lose. This was literally why firearms were invented-- you can now hit the other guy from a longer range than he can return the favor. Any benefit of melee weapons would be entirely tactical and would have to be leveraged in unconventional ways. * Melee weapons are quieter than guns. If you have the element of surprise on your side, you can do a lot of damage before the opponent has time to react. Think ninja. * Knives are easier to smuggle into secure areas and have fewer moving parts requiring maintenance. You also don't need to worry about ammunition. * Large rifles are unwieldy in close quarters. If you have the opportunity to close in, simply swatting at the gun knocks its aim all over the place. If you can lead a rifle-wielding opponent into such an area, you do have an advantage until they pull out a handgun-- and even then, if they do silly things like the Weaver stance then you still have the same advantages. Submachine guns are your worst nightmare, since their shape forces a more effective stance by the wielder that can tolerate disruption. * In close quarters, you can also use hand-to-hand/melee combat to disarm the opponent and/or use their gun against them. Get within two arms' length and the advantages of any gun is nullified. Their range is what makes them deadly. Take that away and it's just a powder-activated knife. * There are primitive (we're talking prehistoric) tools like slings that allow humans to throw things like spears with superhuman ability. * We went into Vietnam with rifles and air support. We were defeated by pits filled with feces-covered spears. * We went into Afghanistan with the full might of the modern military industrial complex. Just like Vietnam, we were defeated by primitive weapons like roadside bombs and the weaponization of fear itself-- never knowing when and where you're going to get hit has significant effect on morale and battle-readiness. * There have been many a home invader, armed and not, that were thwarted by homeowners screaming incoherently and charging at them with a katana or bat from out of nowhere. Again, primitive weapon combined with surprise and fear. * The feudal Japanese and native Americans used masks or war paint to play off of this too-- an army of sword-wielding monster-faced warriors closing in on you causes panic and fear among your ranks. Gas masks, balaclavas and full-face helmets fulfill similar intimidation purposes today. * External circumstances may also preclude the utility of guns. Firearms on an airplane could be suicidal. In the original *Metal Gear Solid*, your path takes you through a warehouse of nuclear warheads. You are barred from using firearms in it because of the risk of leakage or explosion (though through some oversight, the enemies were not similarly restricted). I think there was a similar plot point in one of the *Aliens* movies and leaking methane gas (though again, sparks from metal-on-metal swordfighting...). [Answer] How about adding a rather available super-camouflage tech? If it's not so difficult to obtain a piece of tech that really-really hides you, ranged weapons don't have any advantage. Also for a gun, you need ammo, you need to make sure it doesn't get wet (ok, too wet for some models), cleaning is rather difficult process leaving you unarmed for a while. Sword, on the other hand, doesn't need ammo, it's ok if it gets wet, easy to clean (and cleaning doesn't leave you unarmed). Problem is that you probably won't be able to have rougues as a separate class(es). And you'll need to do something with sneak in general. Maybe make this camouflage-tech only work if you are moving slowly, or not moving... [Answer] Instead of relying on physical constraints (since there aren't any), go with social constraints. Instead of trying to balance the "equal skill" equation you can ensure guns aren't a dominant component of every fight by limiting access to them. The easiest way would be to build into your narrative laws or social norms that limit access to guns to a minority. Maybe * Only the rich and powerful are allowed guns * Only security forces are allowed guns If you go with the first option you could also limit the lethality of the weapons by making them mostly ceremonial (ornate, antique, gem-encrusted or whatever) rather than precision tools of death. I realise this won't allow "plebs" to have guns, but maybe that's not the most important thing. [Answer] Introduce better bullet-proof armor. [Todays ballistic vests](https://en.wikipedia.org/wiki/Bulletproof_vest) only protect against small-caliber weapons, unless you make them so heavy that they become unwieldy in combat (and even moreso if you want to see people engage in hand-to-hand combat). But if your universe would have a lighter and stronger material for ballistic vest, then it might be feasible to wear enough ballistic protection to survive fire from most firearms. Now why wouldn't this also improve the survival chance against melee attacks? It does, but when it comes to hand-to-hand combat, then a common tactic is to not focus on injuring the opponent, but rather to make them fall down. When your opponent is on the ground while you are still standing, you have practically won. You now have an easy time to subdue your opponent or perform a well-aimed killing blow through even the smallest weakpoint in their armor. But making your opponent fall down requires momentum and leverage, and armor can't protect you from that. [Answer] I'm going to agree with the consensus here and say that your conditions are quite prohibitive. I will, however, make some suggestions that go a little bit the opposite of everyone else and say that maybe some things about the world should be crappier than our own instead of better. Here are my two primary thoughts: 1. The beings in your world live in lower gravity spaces and have less dense skeletal structures. That way the force of the recoil of a firearm actually hurts the user unless they're well-trained enough to withstand the pain/not break their bones or just plain launches them across the room. Swords and stuff are then easier to use because they impact the user less. This also would limit the firearms to a relatively small bore, decreasing the overall damage of those weapons. 2. Maybe materials in your world are such that firearms are prohibitively expensive to manufacture or operate. Like if barrels couldn't be perfectly cylindrical on the inside or there isn't enough iron in the world to literally just throw specs of it at each other at high velocity and it's more economical to make a single weapon that can be used repeatedly. Or maybe only the finest, most rare metals have to be used for bullets to withstand the barrel forces (another one that makes guns less economical). [Answer] As long as Dune's a major influence, why not copy its shielding? Personal shields will stop anything with high kinetic energy (e.g. bullets) but not slower things because then you'd never be able to interact with the world. The art of swordfighting is to come in *just* slower than the shields threshold, then keep the pressure on so that you stab deep. If you're killing ordinary people, a gun is useful, but if you're killing rich people or people expecting trouble, you need a sword. Optionally, you can also introduce sandworms, which instinctively attack shields, and make guns viable again. But simpler is to just *not* introduce them. You said you don't want to include "special technology, geography, monsters, or other special scenarios". Energy shields aren't that special. They're ubiquitous in scifi and fantasy. [Answer] Shields. You could use a large ballistic shield to get close to the person shooting at you. Once in close quarters the one wielding a sword has more control over the flow of combat than the one with a gun, and they still have the shield to protect themself. This only gives the swordsman an advantage in stand up fights though and if the gunner can ambush the swordsman he will still win if he can hit. Unless some strong body armour is involved, like in Cyrus' answer, but the gunner can wear that too. Now, unless the swords are some kind of sci-fi lightsabers or vibro-swords or whatever then swords have no advantage over guns in penetrating armour. However, a bullet starts off with a set amount of momentum and then it stops when that momentum is expended. With a melee weapon, on the other hand, momentum is continuously added as long as you push/swing. This gives you some control over your opponent's movements as you can push or trip them to a greater extent. [Answer] ## TL;DR : Make every being stronger --- This answer is inspired by a chinese light novel whose name is *-insert here when i remember-*. Firearms are very strong noteably because they replace **your** strength by a mechanical external strength. This means you do not need extensive strength training to deal massive damage (I am not accounting for accuracy or weapon traing ofc). The same applies for speed (speed of a bullet versus speed of a slash i.e). A case where melee weapons would be stronger than firearms would be if your personal strength and/or speed was greater than the mechanical strength of a firearm. If you do not want superheroes, you could obtain that by augmenting the **general** level of every being on your planet. That means none of them could be considered as "super" in their context. In the particular novel I'm thinking of, nuclear radiations and accelerated evolutions killed almost every humans, while survivors left alive became stronger and more prone to evolve physically. The same happened to animals. At first, firearms were able to contain the animals, but slowly, they started to become more resistant, while weaponization couldn't follow. So Humans had to evolve too, and they ended up prioritizing melee weapons. [Answer] # Shields Personal shields have been engineered. Anything with a momentum greater than x would hit a barrier with equal force. (Tchno babble why energy is not transferred to the user). Bullets, speeding trains, flying debris in a hurricane all of this would come to an instant halt once it connects with a users shields. Because people still need to breath, or have the earth make contact with their feet so that they can walk anything with a momentum of x or less would not trigger this barrier. Now everyone is protected by something that makes ranged ballistic weapons almost mute. An example that can be seen in current movies would be the shields in the movie Dune. Because people still want to harm others they have now reverted to melee weapons whose momentum can be controlled and reduced so to harmfully pass through the shields. It's just another idea and this one does come with a bunch of questions that need to be answered too. As example: What happens when I launch two shield wielders at each other. [Answer] An energy field that "burns" anything moving fast (such as a bullet) that gets close to the person. The mercenaries have special swords and armor that allow the energy to flow through the sword and into a glove and the rest of the armor so that the energy can harmlessly "ground out" without damaging the sword and without injuring the person in the armor. Swords would only work if the wielder is in contact with some other surface to ground the energy, otherwise their sword and maybe even themselves can be burned by the shield. To keep things balanced, the mercenaries cannot use the energy shields while wearing armor because the armor grounds out their own shield. That makes the mercenaries dependent on the armor itself to have any protection from gunfire. ]

[Question] [ I'm outlining some ideas for a game I'd like to write, that at its core is about interplanetary space-trading (amongst other things, but that's not relevant to the question). For project-scope reasons I don't want to go down the route of implementing planetary landings, and want the entire game to occur in space. For this reason when the player will pick up or drop off goods, it's entirely done at an orbiting space station. Now, the commodities eventually have to end up on the planet surface anyway, so why would all trade occur in orbit rather than on the ground? Similarly, goods that are exported would have to find their way up to the orbiting space station to be traded. This seems excessively expensive. If the space-ship in question were massive, it might make more sense as the cost of getting that thing off the ground might be impossible. However, I envisage the player to be in a smaller space-ship (think: Firefly), and not some behemoth of a transport. I am looking for "as real" answers as possible. My ships won't have magical shields, and I'm trying to keep it as close to reality as possible - only cutting corners where there is literally no other way of achieving something. Thanks in advance! [Answer] Other answers have already covered the fact that surface-to-orbit travel is energetically unfavorable (and therefore expensive and awkward) and that making a ship that can operate in an atmosphere as well as in space is challenging (and therefore expensive and awkward), but I'd like to throw in some environmental and safety concerns. Ships that can make relatively prompt interplanetary journeys are safety hazards, as they could easily hit the atmosphere at over 15km/s as part of an aerobraking manoever. At first glance, it is difficult to distinguish high velocity re-entry heading for a spaceport from a [kinetic bombardment attack](https://en.wikipedia.org/wiki/Kinetic_bombardment#Project_Thor) or [nuclear missile delivery](https://en.wikipedia.org/wiki/Multiple_independently_targetable_reentry_vehicle) or other kinds of [hypersonic weapon system](https://en.wikipedia.org/wiki/Boost-glide). They're not going to let just anyone drop into an inhabited atmosphere at supra-orbital velocities. For worlds with no atmosphere the problem is even worse, because things can hit the ground going at that speed without having a substantial amount of energy bled off by the atmosphere first. Anyone on a trajectory that threatens an inhabited world is going to be watched *very, very carefully*, and at the first sign of deviation from an agreed minimally dangerous trajectory they're going to be on the receiving end of loudness, lawyers and lasers. If they're lucky, they'll get it in that order, too. Maybe anyone operating an interplanetary vehicle from a planetary surface needs to have a [range safety system](https://en.wikipedia.org/wiki/Range_safety) fitted for emergencies. For those of you who haven't heard of these and didn't follow the link, that's a remote destruct system that will blow you to pieces if it looks like you might pose a threat to the safety of people on the ground, for example. Now, nobody wants to blow up an operating nuclear reactor in their own biosphere, and that means that you'll also be limited to the kinds of engine you can operate. Maybe the kinds that are allowed are more expensive or more difficult to run due to their lower performance and higher fuel or reaction mass demands. When you land, you'll be landing at some kind of spaceport. This will have to be a long way from habitation, so that accidents during landing or takeoff don't threaten anyone, and the sheer noise of high power rocket engines doesn't damage anything or hurt anyone. A huge amount of potentially valuable land has to be set aside, and a lot of expensive infrastructure with refractory launch pads and nuclear fire suppression systems and nuclear fuel storage cells and traffic control systems and all the rest. Who's gonna pay for all that? No surprise: you're gonna have to, via extortionate fees. So, to summarize: * You need a ship capable of atmospheric re-entry, which requires a lot of reinforcement and shielding * You need a ship capable of landing in a gravity well, which requires strong enough landing gear for the highest-G world you expect to land upon. * You need an engine capable of getting you back into orbit economically that is also not an environmental threat. * You need to persuade traffic control that you're a sensible and trustworthy pilot with a safe and reliable spacecraft that won't fall apart, crash, blow up or leak. * You might need to fit a remote destruct system that some planetbound bureaucrat can trigger at some perceived need. * You need to operate from a massive and expensive spaceport, probably at great expense. Ooooor, you could just park at the high orbit or langrange point freight transfer station, and let dedicated ferry systems do the awkward bit of the journey, and just worry about flying in space, well away from all these excess-safety jurisdictions with big defense cannons. What's not to like? --- If you were interested, there's a whole variety of [non-rocket spacelaunch](https://en.wikipedia.org/wiki/Non-rocket_spacelaunch) systems that include space elevators, [skyhooks](https://en.wikipedia.org/wiki/Skyhook_(structure)), [orbital towers](https://en.wikipedia.org/wiki/Space_fountain), [orbital rings](https://en.wikipedia.org/wiki/Orbital_ring), [launch loops](https://en.wikipedia.org/wiki/Launch_loop) and [electromagnetic catapults](https://en.wikipedia.org/wiki/StarTram), some of which also double up as way to get stuff back down to the surface as well as up to orbit. Dumb reentry vehicles are a cheap way to being stuff down safely on worlds with atmospheres. Other specialized systems (maybe some kind of [laser-ablative retro-rocket](https://en.wikipedia.org/wiki/Laser_propulsion#Ablative_laser_propulsion)) would be needed on airless worlds, though. [Answer] Building a "realistic" spaceship that can land on a planet and take off again, carrying significant cargo, and without dumping lots of radioactivity into the planet's atmosphere, is actually quite hard. The idea of long-range trading ships moving goods between space stations, and different means being used to take goods down to a planet, and lift goods from planets into space, is well-established in written SF, although it's a bit complex for TV or films. The efficient way to move goods between the ground and orbit is a [Space Elevator](https://en.wikipedia.org/wiki/Space_elevator). This consists of a very long and strong cable, with one end attached to the ground, and the other attached to a large counter-weight. There is also a space station attached to the cable. When this is set up correctly, the space station is at stationary orbit altitude, and the counterweight at considerably higher altitude. The cable sweeps through space as the planet rotates, and the counterweight keeps the cable taut. Goods are moved up and down the cable via a vertical railway running along the cable. This is *much* cheaper than using rockets. The SF novels that established the idea of a space elevator in the genre are [The Fountains of Paradise](https://en.wikipedia.org/wiki/The_Fountains_of_Paradise) by Arthur C Clarke, and [The Web Between the Worlds](https://en.wikipedia.org/wiki/The_Web_Between_the_Worlds) by Charles Sheffield. Both are well worth reading to get a clear idea of this device, along with the Wikipedia page. [Answer] ## quarantine The gravity issues are just engineering. But you could be carrying the plague. Invasive species. Running guns for cartels. The only way to keep the planet safe is to hygienically deliver to a vacuum sealed location and inspect. [Answer] Going up and down a gravity well costs, energy, resources and time: * energy because you need to shed orbital velocity to land and gain it back to get up in space again * resources because making something sturdy enough to not buckle under its own weight requires additional mass and that requires also additional fuel to be moved around. And each planet has its own gravity, meaning you would need a different design every time * time because doing all the maneuvering takes more additional time Think of it to something similar to courier delivery: it's way more convenient for the courier to deliver on sidewalk instead of going up to the floor bringing the parcel and then getting back. The transport ship can be optimized for space travel, while the movement in the gravity well can be optimized locally for the planet where it operates. [Answer] In the shipping business, shipping things earns money. Storing things costs money, and waiting around costs money. Ideally, if your business is moving things from place to place, your most desirable situation is: * You are on a predictable, profitable schedule that gets the items you have already been paid to ship from their source to their destination as economically as possible. * You *already* have your next set of items lined up at your destination so you can get them loaded as soon as you have hold space, and get back to your business of moving them to your next destination. * Either the person who paid you to ship these items, or the person who is receiving these items is contracted to take care of import duties, taxes, customs clearance, warehousing, and movement of the cargo to its final planeside destination, so you don't have to hang around to do any of that. Delivering these items to a particular planetside destination costs you time you could be spending loading or shipping your next shipment. Waiting around in orbit to get something arranged also costs time. Landing puts wear and tear on your hardware that requires maintenance. Berthing fees at any spaceport, skyside or dirtside, costs money. And while you're waiting around not moving things, you'll still have to pay your crew, because they usually can't be switched off and stored on the hull, so if they're not getting paid, they'll leave for someone who is paying and you'll lose time acquiring new crew. So take advantage of the infrastructure that's already there. Get your cargo offloaded at the highport if your contract and local infrastructure allows it, and into the hands of the locals who have optimized their business into getting things from the highport to their ultimate destinations, so you can get back to doing what you do best; moving things from place to place. [Answer] **Planes, trains and automobiles** [](https://i.stack.imgur.com/JuQqm.jpg) *Steve Coogan (left) and Jackie Chan (right) from "Around the World in 80 Days" 2004.* There are different types of spaceships, the same way there are different types of transport in the real world. You can walk, cycle, drive, get a train or bus, or go to the airport. There is no vehicle that picks you up from your front door, then flies through the air to another country, and drops you off outside your holiday villa. Such a thing is possible in principle. If you were super wealthy you could build a landing strip at both of your properties. But even this is a hassle since you have to listen to planes landing when you are trying to entertain guests. For the rest of us, it is rare to get an airplane to the shops or to work. The few people who do commute by plane still use other transportation to get from the airport to their workplace. The plane won't drop them off at the door. Likewise, there are different types of spaceships for different jobs. The spaceships that move from one orbital habitat to another cannot take off or land from the surface. The kind that go from the surface to orbit cannot move long distances between planets. We could in principle build a ship that does both. But it would be a waste to lug all that surface-to-orbit gear around between planets. Plus that gear was expensive, and it being idle when the ship is in space is lost opportunity cost. That's like having an airplane full of bicycles. They are not doing anything when the plane is in the air. [Answer] Gravity - yes, yes. How droll. Expense; economics. Frugality. Long manifests. The gripping stuff games are made of? I propose **PIRATES!** [](https://i.stack.imgur.com/WMSoc.jpg) [source](https://www.bbc.com/news/world-asia-39252503) Planets have inhabitants. Those inhabitants are hungry. They can get up into the atmosphere with their little craft but not into space. They know that ships coming and going from space to the surface and back have valuables on board. And the ship itself and its crew could be held for random or sold. If your players had some hulking brute of a ship it could shoot its way through the pirates, chuckling derisively. That has its place but that is not what you want (at least not all the time). The little ships your players use could get down in the atmosphere but once there they are at risk of being outnumbered and outmaneuvered by desperate locals who see them coming and want what they have. [Answer] There are two sets of compelling reasons - one based on physics, one based on societies and commerce. On the physics side, entering an atmosphere is dangerous and hard. It needs to happen on a precise schedule and the object doing it needs to have all kinds of technological protections, such as heat shields, parachutes, and so on. It also would, we assume, have to take off again eventually, which would require a lot of rocket power and a lot of fuel. Obviously, this will still need to happen, but having specialized drop schedules designed and planned on orbital satellites, along with planned rocket schedules to bring tradable goods to the satellites, could offset many of these dangers and costs. Also, other hypothetical technologies like a space elevator could achieve the same goal. Meanwhile, the interplanetary trading ships themselves could be designed purely for convenience and efficiency in space, with no concern given to how they would fare in an atmosphere. You say you imagine the player's ship would be small, and I think that fits well - a small, spare ship designed for speed wouldn't want to be bogged down with heat shields, nor any of the infrastructure needed to function in gravity or connect with a planetary rocket to leave gravity. A lot of this has been covered already in other responses, and it remains true. But I think there is a whole second set of reasons to do with how trade and commerce tend to operate in society. Planets are huge. A lot of science fiction that imagines interplanetary relations tends to take the framework of nation-states and scale them up to be about whole planets instead. Personally, I find this to be an oversight. Even if we imagine a utopian future where an entire planet of people live in general peace with one another, only ever having large conflicts with other planets rather than internal ones, it is still the case that this is an entire planet. People living nearer to the poles will inevitably have different needs, culture, and luxuries than those who live near the equator; Different plants and animals will thrive on different continents, meaning that the laws of supply and demand apply not to the planet as a whole, but to each of the planet's regions. Even if these regions are not independent nations, they would function as independent marketplaces. This means it is extremely profitable for satellite managers to act as middlemen between interplanetary traders. By adding an extra step between the supply of a given thing getting to the region that has a demand for it, extra costs can be tacked on, as well as controls placed upon how it is sent down. The aforementioned scheduled drops can be used as an excuse to hoard supplies and release them in trickles, keeping the price high. This would also incentivize certain regions to send up their own satellites - if a satellite around one orbital plane can't easily send supplies down to your area, maybe you send up a satellite to a new orbit for faster deliveries. Also, trade always invites taxes and tariffs. Whoever sends up the satellites is most likely to see those revenues, whether its a nation state placing a tax or a corporation adding 'processing fees'. So, even if the regions of the planet aren't in conflict, they still would want to have their own platforms so that they best profit off the trade. The other way of doing things, letting interplanetary ships land and then take off, would necessarily be less profitable. The hosting region would be shouldering the costs of sending the ships back into space, as well as the liability - rockets are dangerous, and if you lose someone else's trading ship through a rocket mishap, that's a big payout if you're a corporation and possible war if you're a nation. Letting the ships land in the first place would also be a liability, since if things go wrong a trade ship could turn into a very dense, fiery meteorite. Furthermore, without the middleman of the satellite, traders would be going directly to a region, knowing much more about its local economy and thus striking much harder bargains. Also, whatever trade does occur would be subject to local laws, meaning more people can and will try to get a slice of the pie. The satellite gives one group direct control over the trade in a very advantageous way, while also reducing risks and additional costs. Basically, if any one company or nation did hold power on a planet, they would want to hold on to that power - and if two or more such entities coexisted, they would both need every advantage they could get, even if they weren't in open competition or conflict. This, along with all of the physics of orbits, means it is just so much more likely that planets would depend on satellites for interplanetary trade and travel. [Answer] ## Put simply - that's the delivery/collection address. ***Why?*** Because the planet's governors don't want unknown spacecraft from all over the star system constantly in-and-out of their atmosphere, for various reasons, including pollution, aesthetics, security, ecological and efficiency. Any self-respecting planetary authority has an orbital relay station for such things. [Answer] ## The interplanetary trade ships can't land on the planet The trade ships are huge constructs built in space, never intended to land on a planet. When the goods arrive in orbit, smaller shuttles (from other companies) will arrive at the space station, to load and deliver things down on the planet. [Answer] ## They use an orbital space tether The goal of cargo delivery is to get stuff there quick, but above all, *cheap*. You could land a starship and take off again, but that would be expensive. You could use the space elevator, but capacity is limited and you should see the cargo rates! Some does go down that way with subsidized rates to help even out momentum and center of gravity issues, but odds are, you're using the old fashioned standby: one of the network of [orbital space tether](https://en.wikipedia.org/wiki/Space_tether)s. The tethers were what we built *before* the space elevator. They don't touch the ground, so they don't worry about weather or weathering. They're shorter, older, and less mechanically robust. (This doesn't mean they're too rickety to use for people any more; that's just a vicious lie. It's just the insurance rates make them more economical to use for cargo) With an orbital space tether, in the old days you would pilot your [toy spaceship](https://en.wikipedia.org/wiki/SpaceShipTwo) up to the verge of space, hanging there in midair for a few seconds. Meanwhile, the long end of the tether has reached its lowest point, momentarily orbiting almost stationary against the ground, with its descent momentarily pausing in mid-air. (Like a thrown ball at the top of its arc, before it falls again) Thanks to Advanced Weather Systems Engineering (tm), these two events happen within meters of each other. Your toy spaceship grabs onto the tether, and comes along for the ride. When the tip of the tether swings around to the top of its arc, the ship lets go, and glides along in a stable low Earth orbit which it can then modify cheaply. But the same process works in reverse. Your cargo comes in from the interplanetary and gets broken up into packets for each tether (since the boxes self-assemble into sturdy frameworks this doesn't take a lot of longshoremen to do). The packets wangle a course with the lovely people at Earth Traffic Control. (That's why the CEO gets paid the big bucks, because not all those payments want to be on the books) *Eventually* they make the perilous passage around the planet on a few newton-milliseconds per kilogram of delta vee (don't you love metric?), and now they grab on to the orbital tether that serves the locations you want, at the time you need, in order that they are more or less dropped from the Karman line. They call it "parachuting", but the term is archaic. The probes use the same prayer flags you see in your building's ventilation system, which use a small amount of electricity to control their curvature precisely over the full extent of their surface in response to computer models of the air (note to self: remember to buy AWSE stock it comes out). The prayer flags interact with the vortices encountered or produced during falling to replicate (and surpass) the crude maneuvering allowed by control surfaces on an old-fashioned glider aircraft. This - plus a *tiny* charge of azide to help ensure they stop on a dime when they reach the destination - helps ensure that the package is delivered to the right house every time, even if the space tether's orbit misses it by hundreds of kilometers. [Answer] As prior answers detail, the energy cost is too much. I will note one thing I did not see covered: parachute re-entry. If I park a huge container in near-Earth orbit (like the current international space station), then we can have lightweight reusable delivery to the surface of payloads of many tons using re-usable heat shields (like those on our erstwhile shuttle craft) and large electronically guided parachutes to landing sights. Both of those can be re-packed and re-used, sent up as cargo like everything else. But it would also be likely that most manufacturing on the planet would be conducted in space, on space stations, using asteroids as the raw materials. so about 75% of the space/earth traffic is going to be in the space->earth direction, not earth->space, and much of that earth->space traffic will be cargo using automated unmanned reusable engines that just drop a container in space that will be picked up later, and head back to Earth. Of course humans and animals could travel the same way; dropped at a pick up site. (Unless the space elevator works, but it may not). My point is we need no engines to get down to the planet, just like the Apollo missions. parachutes and splash down in a floating vehicle worked just fine, and is cheap as dirt. Other countries have been using parachute landings on dry land for decades. With modern electronics and controls, I'd be surprised if we cannot effect this landing with pinpoint accuracy. Instead of fighting the gravity well both down and up, for incoming traffic (cargo or living) you only need to fight it going up for 0.001% of the weight: The weight of the reusable parachutes and heat shield. [Answer] **Most answers have focused on the technology limitations, I'd like to focus on something that's frequently ignored in Worldbuilding: economic practicality** Other answers have more than adequately pointed out that there are some great technological reasons why trade ships should stay in space. Frankly, the simple Earth-bound example of our container ships and oil freighters clearly demonstrates that limited harbor access due to the size of the ship is a reality. But let's look at this from another perspective to give your story/game a richer base. Why don't any but the largest retail stores buy directly from manufactures? Answer: economic practicality. Ignoring super-chains, which frequently have contracts direct with manufacturers,1 most retailers are forced to use distributors. And this is where your question gets answered. Why wouldn't the ships land? *Because the cost of aggregating and redistributing the incoming products of hundreds if not thousands of trade ships is much, much cheaper than doing it on the ground.* Distribution—the process of bringing in a wide variety of products and then redistributing them in a more useful manner that takes maximum advantage of shipping efficiency2—wants to take place where the lowest cost point for shipping exists. In the case of space-based shipping, that's always going to be in orbit where the cost to dock ever larger freighters is lowest and the cost of sending transshipped cargo can be maximized for the size and efficiency of surface-to-space transport. In other words, the most efficient and cost-effective place to dock your version of Earth's container freighters is in space, where getting that ultra-expensive ship back into service with its next load of cargo can be done as quickly, as efficiently, and for as low a cost as possible. --- 1 *In fact, large chains like Home Depot and Walmart usually have contractual obligations with manufacturers guaranteeing that the manufacturer doesn't have an overwhelming dependency on the chain/store. In my own case, I had to prove as a small manufacturer that my revenues through Walmart didn't and wouldn't exceed 20% of my total business revenue. This was less altruistic than it might sound. Yes, it was thee to help protect me as a small business from the damage that can be caused by a whale rolling over, but it was also to ensure that if the Walmart whale did roll over and stopped buying my product, they wouldn't get sued for my bankruptcy. Frankly, the economics of a situation are often just as complex as the technological aspects.* 1 *What this means is that shipping wants full trucks "coming in" to a destination and full trucks "going out" of a destination. Shipping directly almost always entails partial truck loads and having to send a truck to multiple locations (sources or destinations) reduces the profitability of shipping. The manufacturers want to ship a full truck to save all they can on shipping. The retailers want to receive as large a load as possible (or, in the case of less-than-a-truckload/LTL shipping, as much of a full pallet as possible) for the same reason. The best location for a distributor is where the number of full trucks is maximized. In your case, that's going to be orbit.* [Answer] In your case, there are three main categories of reason as to why interplanetary shipping would use space docks in orbit to drop off goods as opposed to consistently dropping onto the planet with loads of goods ### #1: Transit Logistics As somebody that works for a courier, the courier does not have a truck for every delivery location going to every other delivery location in the area. That would be way too expensive, incredibly inefficient, and be a terrible use of resources. Instead, volume is sent to a regional hub where volume from the region is aggregated and processed in bulk far more efficiently before it is sent to where it needs to go. Should it need to move outside of the country of origin, it goes to a designated export location and leaves the country from there, also consolidating points of exit (and entry) from the country. The only exception to this is if the origin and destination locations are the same -- they will leave it in the building and deliver it the next day most likely. Couriers and post offices alike will do that. Those hub points are likely to be in the larger centres where there is more population (and volume to move) and good transit options to move that volume. Major regional cities are the order of the day, likely the largest city in the regional area. This relates to your scenario in that your spaceport drop-offs are the regional hubs in this scenario. Your shipments will go into these space hubs and be processed by workers in the station. From there the volume will be distributed planetside in whatever way that particular planet handles incoming shipments. Yes, this is trading goods and not mailing packages, but a similar premise of hub and spoke still applies -- a large enough company will have a main distribution outlet, and smaller ones in strategic locations to service customers readily. ### #2: Economics Space has a whole lot of nothing. It is much easier to accelerate a mass to speed, cruise for a bit, then decelerate back to near zero to dock with the spaceport. In contrast, planets have gravity, and atmosphere to get in the way of everything. It takes fuel to push through all of that. Not only that, but every planet will be slightly different. Some planets will have a higher (or lower) gravity. Different planets will have different atmospheric conditions -- some conducive for blasting out to space, and others less so. Some planets might even be actively dangerous to the pilot or the vessel. It's all so complicated overall having to keep track of what planets are safe to enter, what ones will kill you on entry. Each world may even have their own planet-based spaceship standards, meaning that some places might not be possible to land because your spaceship is incompatible with their landing and/or launching infrastructure. That does not even take into account the bio-hazards that might be brought into or out of the planet by accident. The liabilities around invasive species has got to be immense once you deal with an entire planet that may not have any form of defence against one. No, better and cheaper to dock at a spaceport and let the planet's administration handle all of that mess and cost. Less expenses for the shippers/merchants in fuel to launch from the planet and lawsuits in case something went wrong with a planetside delivery. Plus, you can save some money on spaceship designs with some parts being universally compatible for docking with space stations. This holds true with larger suppliers as well as the little independent agents. ### #3: Game Logistics **AKA: Conservation of Details** If you are making a game about space deliveries, then do you need to know how the planets operate between the space station and the ground (or water) itself? I would argue that if your game is about interplanetary mercantile logistics, there is no need to worry about how they either land imported volume or lift up exporting volume. The only other thing you really need to care about is what they would import and/or export. Of course, the other details of the game may change that. The player isn't landing on the planet so they will not have to know the amount of fuel needed to land, or the shielding needed to survive entry onto the planet. All players will need to know is that E Resources are available per T time units and that they can process I units in delivered goods per T time units. Possibly with needing to spend Q time units in quarantine due to laws. What you need to know is reasonable numbers to fill in the variables dependent on each planet. This might be the topic of other questions -- I would recommend a search to see if you aren't repeating a question. The Tyranny of the Rocket Equation is almost as well known as the Tyranny of the Square-Cube law. [Answer] For the same reason logistics centers are located outside of large cities. After your traders deliver their cargo, some of these crates will be shipped somewhere else, perhaps on the planet below, or perhaps to another planet, or to another space station. In all these scenarios, it makes no sense to expend energy to land the entire ship and cargo on the planet, if most of it will be exported back into space. If your game is about interstellar trading, then the space station would most likely be at the edge of the solar system, for the same reason. It makes more sense economically to have the local delivery done with ships designed for this purpose. [Answer] Your drive isn't compatible with planets. I'm thinking of the *Honor Harrington* novels by David Weber. Even freighters can pull a few hundred gravities, but the drive used in deep space is incredibly destructive to anything in the wrong place. You put one down at the spaceport outside town and the city is gone. If it doesn't burn out first it's going to carve a miles-deep crater. [Answer] ## Distrust You never know what fresh hell has developed in the opaque domes and tunnels that nestle among the craters or encrustments of a far-flung planetoid. **If you land, you might not be able to leave.** Maybe it's a retro sci-fi paradise designed to maximize human thriving. Or, just as likely, it's [the Peacock Family](https://x-files.fandom.com/wiki/Peacock_family) In Space, a dim and dysfunctional hive of horror and decay. If the place is locked into some kind of sustainability death spiral, there's a decent chance that somebody down there *knows it* and is on the lookout for naive passers-by who can be lured down to the planet, where their cargo, vessel, and bodies can be cannibalized to keep this hermetically-sealed atrocity going. Even if it's not John Carpenter's Own Dome down there, the locals might still prevent you from leaving. Their plan might be to charge you with a crime and then impound your vessel for the purpose of extracting "fines" (aka ransom) from your trading company (via insurance) and/or your loved ones. In the real world, there are legal jurisdictions that depend for their survival on imposing specious fines on residents and travelers, and it's my understanding they use elaborate sets of rules to to heap on the penalties so they can extract as much money as possible from each victim. So: * if you value your life-- * if you value your freedom-- * if your crew prefer to *not* become the sex slaves of a local tyrant-- * if you don't want your eye sockets to be used as wombs by an alien organism that Paul Reiser intends to bring back to his heartless corporate overlords-- -- then **never land**. Don't accept any invitations to come down for a meal with the local administrator. Don't run down to the planet to see if you can score with an attractive local. Don't let the guy in the space suit squeegee your windows. Don't even listen to the local radio stations, and I am 100% serious. It's all hands to battle stations and every eye glued to a radar or porthole, from the moment you arrive until you're well and safely away, and if *anyone or anything* approaches the ship: vaporize it twice -- three times if it claims to need help. Stay in orbit long enough to create proof of delivery, dump your cargo, and then get the hell out of there *while you still can.* [Answer] **All orbital platforms are essentially the same, planets vary widely.** Landing on different planets forces you to deal with many physical constraints that can vary widely between planets - how strong gravity is, how thick or dense the atmosphere is, what corrosive or breathable gases are present in the atmosphere, atmospheric weather events, biological organisms on the surface, the list goes on. None of that matters when docking with an orbital port - the station is always in zero-G with no atmosphere and in a controlled environment. A ship that can dock at one orbital station can likely dock at almost any orbital station, since the physical parameters do not vary much at all. This isn't true when landing on a planet - being able to land on (and take off from) one planet doesn't imply that you can do the same elsewhere. [Answer] Acceleration. A ship that can't produce 1g of acceleration can never touch Earth, but could still be quite useful going between worlds. The more acceleration your ship can produce the bigger the percentage of the ship that must be devoted to the drive and it's power source. Thus a bulk freighter is better served by never landing. [Answer] ## Technial difficulties Long-range ships are built differently than "local" (inter-planetary, can't leave solar system) ships. They need specialised heavy-machinery, use different propulsion, can't enter atmosphere, etc. (others have already proposed numerous explanations of this kind) ## Biological problems Others have mentioned quarantines, but also, if your world has different lifeforms, they might need different habitats, so this is simpler. ## Politcs An orbiting space platform is somewhat a neutral zone - it belongs to the planet, yes, but it's also far away from it that it acts like an independent place with it's own rules. It might even allow trading items between travelers that are outlawed on the planet. [Answer] ## Teleportation Add teleportation technology to your world. Every space station is equipped with a teleporter which beams the freight from the cargo ships to the station, and then from the station down to the surface. That means you don't need to implement docking either. The ship just needs to be close enough to the space station, and then you can visualize the goods exchange with a visual effect. Which is inexpensive for you to make and can be easily done in a way which is very readable for the player. Why not teleport directly to the ground? Because the player's ship is too small to have an own teleporter. Or at least to have one which is powerful enough to beam whole freight containers from orbital height and through atmospheres. Only stations or very large ships have the energy and space for teleporters of that scale. It worked for Star Trek. And having teleportation technology in your world could also help to explain a lot of other gamified quality-of-life features you will probably want in your game. [Answer] For legal/compliance reasons. That orbital station is more than a drop-off point. It's the planet's customs checkpoint. There's no practical way to enforce customs duties if ships can just land anywhere on the planet they want any time they want. Smuggling and contraband would grow out of control. Instead, your planets have designated customs stations that all offworld cargo goes through (similar to how real-world shipping ports work). Also, it's immensely easier on your pilots if they can avoid entering the planet's atmosphere and thus their legal jurisdiction. Every planet has their own government and their own rules. It would be a massive headache to try and comply with all of them. Is this the planet that banned Taryak 4 coolant, or the planet that *requires* it? Do they pass on the right or the left? Did I install the infrared turn signal indicators? The native species can't see the yellow ones. Are their landing pads designed for standard gauge landing gear, or do they use that funky narrow gauge and my ship will fall off the pad? It's all a giant hassle, don't mess with it. Just drop off the cargo at the orbital station and let the local boys handle all the up/down travel and local rules. Speaking of those local cargo haulers, don't forget that most of those are union jobs. You can't land at the local port unless you're a member of the local cargo hauler's union, but doing so would exclude you from being able to join the similar union on other planets. Scabs get shot down faster than enemy attack craft. You need to stay on good terms with the union workers. Let them keep their short-range transport monopoly, and they'll be much happier about hiring you to handle the long-range stuff for them. [Answer] # Time You'll get paid the same amount whether you leave it in orbit or on the ground. You save time if you don't land. So... I heard Uber Eats drivers prefer 'leave at door' deliveries over 'meet at door' ones for much the same reason. Time is money and delivery people usually get paid not by their time, but by delivery done. [Answer] Many have already pointed it out, but I also believe that the best option is a space elevator with a conevyor belt line that moves commodities up and down pound-by-pound, or as the capacity of the belt allows it. The belt would be helped by a rotor which would rotate in either direction to compensate for the weight coming up or down. Being that weight is zero sum and such an important aspect of this machine, it will be difficult to smuggle things into the planet, as every pound is carefully assessed and charged for. This way, you also prevent alien vehicles from landing at your planet and polluting. No clearance needs to be provided other than just delivering and picking up payload at the orbital station. [Answer] Loads of answers. I feel like this one should have been a very short comment, but SE is broken, so I'm going in more detail for my 2¢ on this: #### Why interplanetary commerce should deliver at orbit: It's the same thing with international commerce. Big ships dock at an international port, unload stuff, stuff gets more or less inspected, taxes are paid, load new stuff, go to the next destination #### About spaceships that bring stuff from planet to planet These big spaceships should be assembled in space (since we can't slide them into space in the same way we do with "seaships") and never touch surface. They should be huge. They could be sort of like a mothership and the "containers" be sort of smaller standardized spaceships that dock to the mothership and to the orbiting docking station. Standardization is key as these smaller ships could be of many varying sizes, most I would say the same volumetric capacity as the ones we see today. These ones *could* carry the same kind of containers we use today. #### About the transport between surface and orbit * Going up: + Attach a few Starship class rockets to it and you have liftoff + "Starship" boosters go back and are reused * Going down: + Easy peasy. You can just simply deorbit these smaller ships and land them SpaceX style or splashdown on the sea and docking at a traditional port. * Once on the surface: + Stuff gets transported around pretty much the same way they are today for delivery. Trains, trucks, ships, etc. #### About the orbiting ports There would be several stations like that orbiting specific orbits for making the delivery of goods spend the less fuel possible Reusability and standardization are key for that to work properly And about what kind of fuel? Well I guess you will have to get pretty creative on that one. [Answer] Simply, gravity. Look at the Apollo moon missions. The ship that made it to the Moon had one small-ish engine, and a few quad-vernier engines around it, to adjust attitude. These were each about the size of a can of beans, or rather 4 cans of beans around a box. Then look at Saturn V, then the biggest rocket ever. It's gigantic. Each stage is gigantic (all 3 of them) with multiple huge engines you could stand underneath. When they launched, observers were heavily shaken, and the noise was heard miles away. I looked it up, the Apollo CSM's (the bit that went to the Moon) engine had 91,000N of thrust. That engine powered the ship from Earth orbit to Lunar orbit, and back. Saturn V's first stage engines produced 35,100,000N of thrust. Just to get the whole thing up in the air and on the way to space, with two more stages to go yet. So, 350x engine power (plus the next 2 stages!) to get up to space, compared to flying around once you're up there. Regardless of what new technologies you invent (unless you're gonna go with "magic", some previously unknown force you make up), it takes a shitload more energy to get up into orbit, than it does to fly around in space. So you'd need a very different kind of ship that could get back up there again. Besides that, what's wrong with trading in space? People in one station might require things that another station has. Perhaps there are factories on the stations, which require components delivering, and finished product taking away to sell. Lots of commerce without bothering the planet. Let the station itself arrange a way up and down. Perhaps they've got a space elevator, or a railgun on the planet launches bulk material up where little ships catch it and relay it to the station. Any way you do it, a ship to make short relay trips under heavy gravity, to orbit and back, is differently optimised than a ship to travel great distances under no gravity. [Answer] actually all the goods could be ore or refined metal purchased at asteroid mines, and trasported by some ships to space factories and space habitats to be used to manufature goods, and the manufactured goods transported to other space habitats. Thus you could write a game where all the space travel and space trading is between asteroids, space factories, and space habitats, and nobody every lands on or takes off from a planet because nobody lives onlanets anymore. Or possibly a lot of people do live in gravity wells (or planets), and the space traders pick up goods from space sations orbiting planets and taken to them other space stations orbiting other planets. Possibly the space traders have interplanetary or interstellar cargo ships using Maxicorp engines, the most powerful space engines available. A cargo ship can transport 100,000 tons of cargo from planetary orbit to planetary orbit using Maxicop engines. But a cargo shuttle between a planet and its orbiting space stations can only carry a mere 10,000 tons of cargo either way, even using a Maxicorp engine. And some shuttles use less powerful engines. So the interplanetary haulers transport 100,000 tons of cargo containers from orbital space station to orbital space station, unloading their containers at the destination space station. And the orbital shuttle cargo haulers take only 10,000 tons worth of cargo containers up or down between the planets and the space stations. And middlemen in the space stations buy and sell cargo containers full of goods to and from the interplanetary haulers and the shuttle operators. So the interplanetary cargo haulers never go down to the planets, but instead haul cargo between space stations orbiring planets. [Answer] There are plenty of real-world examples in supply chains, of transporting something across an ocean to a central warehouse, instead of directly to the end consumer. The reason, which is even more significant for space travel, is fuel costs and logistics. If your space-warehouse is high enough, and has a firm network of connections to substations on its way to the end consumer, then you would massively save on fuel costs, which would unilaterally apply to both major star ships and smaller vessels—if they own a smaller transportation vessel (Serenity, Planet Express, etc.), then they likely are in a spot where fuel cost concerns are proportionately greater. Once you're outside of a gravity well, you effectively just have to push and wait, and you'll get to your destination eventually; once you're in the gravity well, you need to reach the escape velocity of the well before you even begin to push. If regular orders are retrieved from the Amazon Interstellar Ware-Station at L2, then a limited and calculable amount of fuel needs to be used to reach it, handling bulk quantities of orders at the same time and cutting resource costs down to a tiny sliver of what they would be for direct delivery. Basically the same reason we don't order a pair of made-in-China Nike shoes and pick them up from a loading dock. It's good business! ]

[Question] [ This takes place far in the future. The emperor of the star empire has a lot of things to deal with, that stress him out. The treaty with Xcarus is down the toilet, the High General has just purged a great number of high ranking officers for suspected treason, and his brother tried to assassinate him, and has just ran off to planet Telstar. He enjoys the occasional drink now and then. His favorite drink is some Terran delicacy called - what was it? Whiskey. And other hard liquors. He often buys the stuff straight from Terra, or Amon if he wants something more exotic. But, all the liquors he buys from Earth and Amon are nano-replicated, as nobody cooks on Earth. He could easily just download the prints, and replicate his own. The shipments of whiskey the alien emperor buys are important to the plot. So, why would the emperor import when he could simply produce his own? * Both prints would be of equal quality, and quantity. * Space shipping long-range is very expensive. [Answer] Status symbol. Plain and simple. Doing a carbon copy is easy and cheap. But if you can afford the original one it means you have a huge load of moneys at your disposal. And those moneys are no good hidden in some bank account. Impress your guests with what they can buy. P.S. In a less sci-fi scenario, there are people on Earth who like to have golden toilets in their houses, just to show off how rich they are. [Answer] [This is the basis for the real world economic theory of Comparative Advantage.](https://en.wikipedia.org/wiki/Comparative_advantage) The aliens can produce any of a large number of products with their industrial capacity. Similarly, Earth can use its capacity to produce any of a large number of products. Let's assume that the aliens can produce **anything** more cheaply than humans. The theory of Comparative Advantage proves that it is paradoxically cheaper for the aliens to buy some things from us, even though they can make them for less. This is because while they can produce whiskey for very little resource use, they can instead use those resources to make e.g. carbon nanotubes, which humans are so bad at making that we will trade a much larger amount of whiskey than they could have made. [Answer] Two (and a half) options: A: He wants the real thing. Fake Whiskey from [alienrace]? No way, even if it tastes the same. Just like having a perfect copy of the Mona Lisa wouldn't be the same as the original Mona Lisa. Could go a step further and give humans on earth the ~~"copyright"~~ terroir on whisky. Others can copy it, but can't call it whisky - similar to scotch, you can get whisky that tastes very similar to scotch, but it will never be legally allowed to be named scotch. The emperor drinking fake scotch? Unimaginable! B: Something about the transport process makes it better - or rather makes it seem better. Maybe it's space radiation, maybe it's the launch from earth. Don't like this as much because anything can probably be replicated and you said they would have the same quality. [Answer] Because he trusts foreign traders more than domestic help. There are definitely spies in his household wanting to kill him. Making things locally means trusting every person in the chain between receiving the digital instructions and being presented a glass. That might be tens of thousands of people if you count all the programmers of gadgets; there is no way to be really certain of loyalties at that scale. The humans currently have an acceptable arrangement, especially the humans getting paid for this service who get direct access to the top tier of the empire occasionally. Also it is pretty clear if Earth was suspected of a poisoning humans would be exterminated, so their loyalty isn't as suspect. So long as the drinks are presented in tamper evident Terran containers the service devisions of the palace have no opportunity for maleficence. [Answer] Maybe nobody on earth cooks anymore, but they are still on Earth, surrounded by Earths atmosphere, germs, general enviromnent and *humans*. Something in the chain of processing could influence the taste of the product in a way that is hard or costly to imitate. Like the barrels influence the taste of whiskey, some naturally occuring dust particles in Earths atmosphere could influence the taste of space-whiskey. Recreating the right size, concentration and distribution of those particles could be more costly than transport or maybe more dangerous... What if the secret ingedient is the fallout of World War III? **Thanks to all my commenters for the good ideas.** The rich and nobles could treat whiskey like todays craft beers or wines. Depending on the location (on earth) of the production facility, the environment influences the taste in very suptle ways. Some might use actual ground water instead of replicated water, some might have containers and pipes of impure material that imbues the brew with trace elements. Of course you can analyze the chemical composition of one brew and replicate it, but it will always be the same brew. Always the same tase. **Boring!**. If you want diversity, you have to get the real stuff from Earth. [Answer] It's all about [***fungibility***](https://en.wikipedia.org/wiki/Fungibility). Just as any serious art collector would rather have the *original* Mona Lisa painting than a copy (even a *perfect* copy, that no-one could identify as "fake" by any possible tests that could be made on the artwork itself). I'm not that serious a collector (of either artwork or fine whisky), and I wouldn't pay extra purely for the "authenticated provenance" of an otherwise identical product. But plenty of people *do* think like that, so it's not unreasonable to suppose aliens (and even alien emperors) might think the same. --- EDIT: (Not sure if it's acceptable to say this here, but it's why I think *fungibility* is more important than *economic advantage* for the exact context...) I fully accept that in terms of terrestrial economics, the principle of [Comparative Advantage](https://en.wikipedia.org/wiki/Comparative_advantage) could "justify" paying more to have someone else make something you could make cheaper yourself. But obviously the costs of *shipping* between star systems is going to be (truly!) astronomic. If it might cost any civilisation the equivalent of *billions* (or *zillions* - I don't know the exact number, but it would be *big*) of dollars to transport any given sugar-cube-sized piece of "valuable product" to somewhere on the other side of the galaxy (or maybe *much* further away, in another galaxy entirely), I don't think any alien smart enough to become emperor would be so dumb as to believe his economist courtiers if they tell him it's to his economic advantage to buy his whisky from the *real* terrestrial Scotland (or *whiskey* from the real Ireland). Comparative economic advantage is all very well, but *who's gonna pay the shipping costs?* [Answer] > > ... nobody cooks on Earth > > > Except the guy who makes this dude's whiskey. Why did you think it was so expensive? [Answer] ## They can't replicate the *barrels* Whiskey still has to be *[aged in barrels](https://www.youtube.com/watch?v=F_Vk5iloGrw)* because replicators simply cannot capture that certain ineffable quality\*. Oh, the hooch that goes into a barrel is easily replicated. But there's no substitute for barrels, and time, for finishing the product. The barrels don't replicate very well, either. Would you age whiskey or wine in a barrel made of [Trex](https://www.trex.com)? They could build the barrels on another planet, but that means hauling wood from Earth. (The particular wood species dislike growing on other planets, and even when successful, tend to yield an inferior product.) --- \* which might not actually exist. [Answer] This question reminds me of the novel "Year Zero" by Rob Reid. In it, one of the highest beliefs that aliens have is that art be consumed according to the laws and customs of the creator (and thereby hilarity ensues when they try to license the MP3s of all of humanity). By the time of nano-replication, I'd expect that the current trend of copyright law and DRM would have continued such that humans would only allow copies to be made that are appropriately licensed and had royalties paid to the creators. That way, not only are creators compensated for their creative work, but they can properly maintain their trademark and make sure that nobody else is selling knockoffs but calling it the real brand name. And digital piracy of the plans would be unthinkable, because it'd be so at odds with the laws and customs of the creator's world. I think the result of this is that the cost of properly licensing a nano-replication center to print a real Terran whiskey brand (including having the real brand QA people there to ensure the plans are executed appropriately) could be substantially more than even the high cost of interstellar shipping. Even for the quantities that the emperor would want to have in stock, it's just so much cheaper and easier to have it shipped than to set up a proper licensed replication facility. [Answer] Because the Treaty of 30487 with Earth forbids off-Earth production of whiskey, and there's enough benefits for the Empire to make it unwise to violate the treaty. (Insert discussion about the Earth entities of 30487 who disagreed on off-world Scotch as needed.) [Answer] Would royalty on Terra serve or consume "sparkling wine" rather than "champagne", something that requires a certificate of origin? Even assuming that the king would have the legal power to forge certificates? And assuming that nobody could likely tell the difference? Where is the point in being emperor if good enough is good enough for you? How would that command respect and a sense of decorum? You say "ok, but in private?". Do you really think that you'll catch royalty in private eating a kebab wrapped in filthy paper with plastic forks? How is that not going to become the talk of the servants? [Answer] In your world you can replicate almost everything, and in real life many countries can survive without trades with others, but those trades help the economy. He buys whiskey from Earth, but Earth buys many other things from him (technology, medication or other delicacies, can be anything). He knows that if he stops buying their liquor, Earth will stop buying from him and get those items somewhere else. As the emperor, everything he does is to keep a good relation between all the different planets members of the star empire and keep a prosperous economy. Those trades with Earth help to maintain this good relation. [Answer] Because no two batches of liquor ever taste exactly the same. Due to local growing conditions the organic materials will contain more or less trace elements from the atmosphere and the soil which when combined with the aging process (materials plus environment) yield a unique flavor that's ever so slightly different each time it is made. Perhaps the value to the aliens, therefore, is the *differences* in the various batches. Thus, with a replication technology, your existing batches will not run out (unless replication can't duplicate the subtle flavors for some reason) and with copyright laws, replication may be restricted to only those who own the appropriate key code providing an artificially limited supply. Thus, owning a complete set of "years", batches from each year of a given brand, and thus completing one's collection, may be the competitive drive to collect and own. [Answer] In order to nano-replicate something, you first need something to nano-replicate. So that suggests that you require laws or regulations that encourage the original production of products (otherwise you'll be a very stagnant society with nothing new being developed - why go to the cost and expense of making a new thing, if all your competitors simply nano-replicate it once you've done it). So whiskey becomes part of the legal framework around replication, where its one of many "products of craft development" that is legally not eligible for the run of the mill replication. A slight mod to this is to tax replication, so the stuff costs as much as the original. Whereby replication is designed to fulfil only scarcity or difficult transport circumstances. In such a case, the Emperor would go for the original just for the cachet of getting the best, but also to support the original manufacturer, as replication would be seen as "2nd best" for the hoipolloi only. The other way round this is to ensure that the Emperor likes many different whiskeys, and replicating the same old brand is just not his style. Hence, instead of replicating his existing cellar, you have to import the variety from source. This stops being true once his cellar is fully stocked, of course. [Answer] Time dilation. Even a molecularly perfect copy will be believed to be lesser by some segment of a human marketplace compared to the “traditionally made” version. But aging whiskey takes time. Travel near light speed is a great way to stay young while whiskey ages. And Earth, being a relative backwater of the galaxy, is unlikely to be drawn into galactic wars, so it makes a fine whiskey cellar. [Answer] **Legality and content filtering.** There are various recreational substances around the galaxy, but there are large differences in what's legal where. Alcoholic drinks are one of the things that are illegal in a lot of inhabited planets, though obviously not on Earth (which is by far the largest producer of them). Despite the ban on substances like alcoholic drinks, space is huge and it's effectively impossible to enforce a ban on importing this stuff. It's therefore well-known (but difficult to do anything about) the rampant smuggling of it. The only thing the governments of the different planets can do is limit the ability to produce alcohol on their planets. Some planets opt to enforce that all nano-replicator have a government-controlled filter on what substances can and cannot be produced. (This is also used to stop other illegal stuff, like creating unlicensed weapons and similar.) While alcohol itself cannot be blocked outright (since it's an important chemical), they can filter out most known variations of alcoholic drinks. You can still, in theory, produce something similar by having the replicators create various (individually legal) constituent parts and essentially add them together yourself, but that's cumbersome and doesn't really come close to the real deal. Still, this is what some of the poorer people do get have their alcoholic fix. Those with a bit more money buy it on the black market (although the quality of the stuff is often questionable and it's sometimes just homebrewed stuff that they label as being from Earth). The richer people simply get it directly from the source themselves to avoid the hassle. It's slower and a lot more costly, but the quality of the stuff more than makes up for it. [Answer] **Because the design changes** No two barrels of whiskey are the same. In fact, no two distilleries are quite the same - and this isn't because some are incapable of copying the others, it's because they all have their own unique spin on the product. This gives them a distinct difference from their competition, even within the same product. For instance, what's the difference between Tennessee whiskey and Bourbon? The difference is that bourbon is filtered ever-so-slightly differently, resulting in a new blend of flavors. Everyone making any product (from music, to movies, to liquor, to food, to cars, etc) mixes and remixes what came before, and adds their own unique touches that make it a distinct product. It's a huge feature of humankind! So if you're running a galactic database of synthetic recipes, do you *really* want to go through and accept/vet/distribute *every single distillery's recipe*? For every new distillery? Of course not, nobody needs that kind of hassle. So everyone gets a few dozen "standard" recipes in their replicators, and the rich are able to experience a wider and fuller variety by buying direct from the source. And in turn, the rich create trends that are added to the standard database, then the rich find some other obscure recipe to enjoy, and then *that* gets added - rinse and repeat. [Answer] Because there is some spirit in real thing. It's the same thing we have with fake meat. It's great and all but there is something that make it distinguish from the real thing. Maybe the entropy? Carbon copy put things in same amount in same space while the natural whiskey tend to make pockets of taste and so on. Also the thing that was an issue with those shakes that supposed to give you daily amount of calories, carbs, fats and protein with exactly macro elements you need. People started to complain that drinking it make them sick. All the things that supposed to be there were present, the human digestive system shouldn't mind but somehow it lacked the chewing. [Answer] It's an emotional thing. I'd dare call it a spiritual thing. Not that the emperor is aware of this, not consciously. But quality, man, can't be reproduced with machines. Those gentle Terran whiskey nano-replicators, they put love into what they do. They use their hands. Those whiskey cases shimmer with a little bit of Sol. And nobody needs to be able to see it or mechanically analyze the liquid contents in order to feel it. I think the question can be, why that irrational leaning towards the real thing? What soft spot does this tendency reveal, and where does *that* come from? Deeper, deeper, with character development, always. It's a question that allows for a backstory, and maybe it would never be included directly in the story, but still enriches the narrative and characters. It's a subtle undercurrent of a detail that can thicken the mythic broth of the empire. [Answer] Intellectual property (IP). When replicators were invented, and the price of physical goods became to plummet, businesses found a way of IP-protecting replicator recipes, and enforcing such a protection (by military means, if need be). So while the Emperor could download the recipe, he would risk a bloody war with the Terran anti-piracy agency. Or just download useless code, which is encrypted beyond recognition. Licensing the recipe would be prohibitively expensive. [Answer] Some people can spot the synth stuff a mile away. It just doesn't have that, je ne sais quis <https://en.wiktionary.org/wiki/je_ne_sais_quoi> [Answer] The same reason that people claim to be able to tell the difference between digital and analog recordings of something. [Answer] * a) Artifical production is too perfect compared to the original. * b) Buying from the source makes it safe. a) We have examples of this in the real world. Artificial diamonds are dirt-cheap compared to natural diamonds, despite being of a higher quality by all rational standards. But the impurities are exactly what makes natural diamonds desireable. Well, that and the DeBeers manipulations. The impurities in whiskey might add to the taste, for example, in a way that cannot easily be reproduced digitally. Even if the humans use high-tech in the process as well (whatever nano-replication is), they still employ some of the ancient elements, e.g. storing it in old wood barrels for a time, etc. b) There are obviously assassination plots in your story. Poison has always been a favorite thing. By going to Earth **himself** and personally picking where he will buy, from whom and which bottles, the Emperor can minimize the chance that anyone interferes with the liquid before he consumes it. [Answer] Maybe there is something else, other than, or in addition to whiskey, in what he buys? I'm thinking more than the worm in a bottle of tequila here... [Answer] If all he really wants is Whiskey then there's no real advantage to buying an Earth brand except to be able to point at the export license etched into the body of the bottle when in company to prove he can afford the long range shipping. If he wants Scotch on the other hand then by law and definition that *must* be distilled in Scotland and aged at least three years in an equally local oak barrel. Similarly if he wants real Champagne he must import it from France because that's the only place that makes it, by definition. [Answer] Because the prints for the really good stuff aren't available on the open market. The scotch distilleries keep the sacred prints locked up in their fortress breweries, so the only way to get any is to buy it from them as a finished product. [Answer] Do you have any idea how hard it is to build a nano-replicator? It took a hundred breakthroughs in a dozen fields from inventors all across the Star Empire. Tens of thousands worked to perfect the first model, and many more have worked on it since. It is the apex of technology, a wonder of the galaxy that no single mind can hope to understand. But this also means that the emperor can no longer trust nano-replicated foods. Too many people have been involved, any one of which might have slipped in some secret backdoor or vulnerability. It would be just possible, with ruinous cost, to comb through all the designs to verify that it is secure, but that would only replace trust of one group with trust in anther, and in any case their work would span decades. So for now, the emperor imports his drinks, where he can oversee the entire supply chain with relative ease. He lets everyone think it's for status, or vanity, or a quirk, or whatever other conclusions they might draw. [Answer] Maybe it's for the same reason some audiophiles still swear by Vinyl for the ultimate music experience. Vinyl records that vibrate a tiny needle to reproduce sound sound great, but a Digital format with a high enough bitrate reproduces the sound perfectly every time. And yet Audiophiles will often claim that the sound reproduction from vinyl is superior. They will use terms like "warmth" and "depth" and "tone" and they all seem to know what each other means, yet there is no real consensesus and objective measurement for "warmth" when it comes to sound. The same can be said for Whiskey. The recipes for various liquors are as dependent on environmental factors as anything else. The wood for the barrel, what was in the barrel before, the searing technique used, the water, how much rain the field got the year before, and on and on and on. To most people, they can't tell the difference between Makers Mark and Jack Daniels, but they will try to speak of "bouquet, fruitiness, tannins...." So your emperor may be a guy like that. The nano replicator may be able to exactly duplicate every chemical, every substance, every ratio perfectly. That's not going to stop a snob from claiming to 'Know the difference.' It Snobbery. [Answer] He's using the shipments as a tool to take care of a few objectives. His annoying brother-in-law - can't summarily execute him, so make him an officer or trading agent in charge and send him on these long back and forth trips. Replace brother-in-law with "mother-in-law", "husband of the woman he wants to bang", etc. as appropriate. Punishment duty for both Space Navy and Space Marines. No women (except aforementioned mother-in-law...), can't drink the cargo, nothing to do... cleaning details and inspections, plenty of PT, etc. Covert communications - he's working with whatever Terran government(s) on some plot for something... Covert transportation - he's smuggling his family and good associates out to live on Terra, or smuggling some Terrans back to Planet X. Or just Covert Missions in general. "No need to follow thatone, that's the *Barmaid*, looks like the Emperor has sent out for another bottle of Old Crow". In reality, ship is nano-making a few cases of "cargo" and running whatever covert mission is required - pick from above list, add military, whatever. ]

[Question] [ A hypothetical speculative fiction setting uses the universal translator/babelfish/translator microbes/whathaveyou as a convenient plot device. However, certain languages are simply untranslatable by this method. What property would make such languages untranslatable by the universal translator? **EDIT**: Perhaps untranslatable is the wrong description. What property would make a language impractical to translate if the intention is to dub in a translation it in real time? It's still possible for anyone to learn. At first I figured the most likely candidate would be something like Ithkuil, but I don't know if the idea is workable. [Answer] # Language that requires more than sound If your translator works via sound, it would struggle with visual communication. Imagine a language where hand motions indicate the past vs. present, verb conjugations, etc. **Update:** * Smells could also add to the language. * Touch, also (let's say you hold your hand against theirs, and press different fingers to conjugate a verb). * Taste would be a weird one—maybe these aliens have a long tail, and to communicate you put the other guy's tail into your mouth, and it secretes different tastes onto your tongue as he talks). # Language that overloads our brains We speak on average 145-160 words per minute. Let's say their communication is like our computers with 1Mb/s download speeds. 1Mb is about 500 pages of writing. If a race spoke with that kind of speed, they could add so many details that seem unnecessary to us, yet it doesn't hinder them at all. They speak for a minute, and we have to search through 30000 pages of data looking for the main point of their conversation. # Thoughts that don't make sense Maybe they can see 40 colors, instead of our 7 color range. Maybe they use these colors to represent feelings or maybe each one relates to an ancient parable of theirs. Time could be measured in how long it takes to grow a certain mushroom. They could enjoy what we hate, and find our pleasures painful. Maybe they speak in poetry. All these put together would make a very confusing speech. [Answer] [Darmok and Jalad at Tanagra](https://en.wikipedia.org/wiki/Darmok). Though the universal translator (in Star Trek: TNG) can translate their *words*, the Tamarians communicate only through allegory, which baffles the Enterprise crew because **they do not know the stories to which the Tamarians are referring**. Likewise, the Tamarians cannot understand Picard's straightforward use of language. [Answer] This response assumes a *perfect translator* defined as follows: The *perfect translator* is a machine doing it's best work possible. It is not limited by technical errors or construction mistakes and it can be assumed to have had opportunity to study all languages in question thoroughly. Further I assume that both ends of the conversation either uses their own *perfect translator* or both interface appropriate with it - using what sensors are necessary (i.e, a microphone and camera for humans since they communicate with voices and body language/visual signs). The answer below thus attempts to answer what languages are not translatable even though there is no lack of proper equipment. (i.e creatures communicating through unusual modalities (chemicals, radio-waves etc.) are not a problem as sensors to detect the modality can be assumed to be present). # Languages untranslatable into certain other languages A singular real language is actually translated at *least* twice as part of its normal use. > > Speaker A's internal concepts > Language symbols > Speaker B's internal concepts. > > > As such it requires that both speakers have the *same concepts* and can express and understand them from the language. Some languages are more apt to expressing certain concepts than other languages because it was developed by speakers wanting to communicate certain concepts. When looking at a translation between two languages the concepts encoded by the origin language must find symbols or sets of symbols in the target language which gets translated to the same symbols in the minds of listeners. Even normal human languages fail at this, the meaning of some phrases are very hard to translate and more subtle details are often lost or changed even in very good (human made) translations, thus the phrase "*lost in translation*". Considering more alien languages where the original speakers are not even the same species, the underlying concepts of the speakers will differ greatly and the language constructs to express said concepts will be tuned to expressing these special concepts. To translate between such languages might be very hard to do well - with heavy information loss. If the speakers are too different, communication would be impossible. ## In practice: Given a *perfect translator* (a machine doing the best possible) it seems reasonable that languages could be grouped into families where translation would be easy within the family and hard between them. One would expect that families would be grouped depending on the nature of the speakers and their natural environment - more similar creatures would communicate better. In a society where such translators were commonplace - language families would drift closer to each other, adopt loan words and such - reinforcing the familiarity. When speaking to an out-of-language-family creature one would expect very general notions to translate better, while emotional and sensory vocabulary would be more lacking. Probably they could both do common tasks like trade using simplistic language constructs that translates good enough only for that activity. To learn a out-of-family-language might be impossible, or might require large changes in mindset or even sensory augmentations. # Languages intentionally untranslatable If the availability of artificial translators were common, it is perfectly reasonable for two speakers to converse using a spoken language none of them understands. The translator translates language A into X (understood by none) and the receiver translates it back to A (or to some other language the receiver understands). Since this is possible, it would be a simple matter to speak in an encrypted language. Each translator installs the same cryptographic-key and produces an encrypted language which can only be decrypted by translators with the same key. Certain organisations or even cultures could thus have languages impossible to understand by anyone lacking the correct keys. [Answer] It is hard to translate on-the-fly from german to other languages, because in german language predicates are easy to stack at the end of long sentences. Make your language to stack important words at the end of the sentences. Translator must wait until whole sentence is told to translate it. The easier it is to swap the meanings, the harder it is to translate fluently. Other method is language full of homophones. If the Last Word in the sentence defines which meaning is actually used there is no way but to wait till the end. Out of context, following czech sentence, written phonetically, has plenty of meanings: > > [ʒenu hɒliː strɒj] > > > > 1: Dative form of "woman" - "ženu" (žena); present continuous verb "I am propelling/driving" - "ženu" (hnát); > > 2: Nominative form of "naked / bare" - "holý"; Instrumental form of "stick / staff / rod" - "holí" (hůl); present continuous verb "[he/she/it] is shaving" - "holí" (holit); > > 3: Nominative form of "engine / machine" - "stroj"; imperative verb "dress" - "stroj" (strojit); imerative verb "make three" - "ztroj" (ztrojit). > > > It is hard to translate on-the-fly if the languages have different "rhythms". Languages do have short phrases that cannot be translated but must be explained etc. If the translator must spend 15 seconds to translate (explain) 1s word and the original sentence is full of such "dictionary bombs", the speaker is several sentences ahead. On the other hand, if the target language has single word for a long story in the original, the translated speech is full of "dictionary voids". If the bombs and voids are spread well, the translation is full of silences and rushed speech. --- Creating bablefish-proof language is impossible since it does not make you hear them speaking your language rather you understand what they mean. That's why it caused all the conflicts; there was no "lost in translation" excuse. [Answer] Non-spoken languages, like sign language, or odor-based languages (humanoid ants colony, for instance). [Answer] One possibility is that there is a preferred structure of language, in the sense that normally language evolution is convergent, that is, it follows path that leads to certain common characteristics even though the evolution was independent. Note that language evolution doesn't happen in a vacuum; language evolves due to necessity, just like everything else. Moreover, language structures follow structures in the brain (or brain equivalent of the alien species), and those structures also evolved under certain evolutionary pressures. Now the universal translator knows these universal patterns, and uses them to decode the language. Since those patterns are shared by almost every intelligent being throughout the universe, the translator is truly universal. Well, almost. Because the evolution doesn't *necessarily* go that way, but is only *very likely* to. That is, one one in a thousand planets, evolution of language took a different path, and the language therefore does not share the same universal pattern. Since the universal translator depends on that pattern to be present, it cannot translate such an "outlier" language. Another possibility is that the language is not actually an evolved one, but an artificial one that at one point got adopted (think Esperanto). If the invented language, following abstract rules instead of being based on similarity to existing languages, differs too much from the universal structure, that language might also be non-translatable by the universal translator. Indeed, there's even the possibility that a language was actually *designed* to not be translatable by the universal translator. Think for example some military use, where you are not interested in the enemy listening (see also: [Navajo code](http://www.historynet.com/world-war-ii-navajo-code-talkers.htm)). [Answer] Even if not completely untranslatable, having a species with a very strange culture or mindset, or a very different sense of reality, would make their language very difficult to understand and only partially translatable, as most words would cover concepts we might completely lack. A good example for it is the [Orz language](http://wiki.uqm.stack.nl/Orz_communications): ``` My *fingers* reach through into *heavy space* and you *see* *Orz bubbles* but it is really *fingers*. Maybe you do not even *smell*? That is sad. *Smelling* *pretty colors* is the best *game*. *Space* is many. *Colors* are many. You are so *sticky*. You cannot *slide* like Orz from *outside* to *inside* and *in between*. It is sad, but Orz can *pull* the *campers* after being *connected*. ``` [Answer] "What property would make a language impractical to translate if the intention is to dub in a translation it in real time?" I'd say the most common thing that would make it impractical is speed of communication. Already we see this to some extent in movies where what is said in one language only takes 3 or 4 words and only a couple of seconds to say, but in the translation it takes many more words and much long and so you get dubs where the audio stops but the person's lips keep moving for awhile. Or the opposite effect that the audio is something really long past when the person stopped moving their lips. And if you're dealing with a very complex language that has words for many very complex ideas that one language really doesn't have any comparable words for, it might take entire paragraphs to translate. For example, consider trying to translate the word "Kafkaesque". Sure, you could give a definition of "similar in tone or theme to the work of Kafka", but without further explanation of what Kafka's work is like, it's not an adequate translation. Or you could have a species whose speech is just very fast. It's not that their language can communicate more in few words, but that they say their words much faster than normal human speech. 300 words per minute is about as fast as some one can talk and still be mostly understandable to a native speaker, but suppose an alien language was normally spoken at 1200 words per minute. And if you combine alll of these, you could end up in a situation where an alien talks for one and a half seconds, and then you have to sit there for 10 minutes listening to the translation. And then when you talk back, you might have to talk for 10 minutes just to produce another 1.5 second blurb for the alien to listen to. Or if it doesn't wait to buffer all your speech, it might sound painfully annoying to listen to someone talk that slow. Imagine trying to pay attention to what some one was saying if they're only saying a single word every 20 seconds. That's hardly practical for real time dubbing to have a conversation. [Answer] Some reasons (still) not mentioned: * *Unknown concepts*. Sami (Northern European natives) have words for snow, African tribes have words for sand desert (I do not debate the amount of words, but the thing is that the native language cannot have a direct translation of the other concept because it simply does not exist). This is normally easy to remedy: You need to explain/circumscribe the concept in a sentence with the known words or the people experience it itself. Being clumsy as tool sooner or later either the people define own words for the phenomenon (white sand, grainy landscape), add adjectives or they incorporate loanwords. *Amok* (Indonesian), *Angst* (German), *Deja vu* (French) are words which have a distinctive meaning which cannot be expressed as single word in the original English language before their adoption. * *Ambigous concepts*: There are many words in languages like the English "smart" which have extremely different meanings with the same word, sometimes even contrary ones if ironic undertones are replacing the original meaning. It gets even worse if the person *deliberately* chooses the word to use the ambiguity for exactly this purpose. This means jokes/puns/hidden meanings cannot be translated because normally different languages have not both a word with the same ambiguity definitions. * *Strange concepts*: There is always a tension between the exact meaning of a word and its social context. "No" seems easy to understand, but is in different cultures completely taboo or polite/expected. So if I mean "No" when saying "no", the universal translator must decide whether he risks an affront by directly translating it or try to guess my intention and disarm with an literally incorrect, but most fitting sentence. [Answer] Any language designed to be untranslatable given a deep understanding of the inner workings of the universal translator. In other words, similar to the spear and shield arms race, a race could take place to have an untranslatable language for multiple reasons: . Secret societies: understanding the secret language is a proof you are part of the group . Intellectual challenge: similar to can biology beat the AI-translator . Anti-colonialism: making aliens unwelcome in a world While most likely the forces behind the universal translator would thrive to identify always faster those new languages and provide translation. Many parameters would be considered: a new language to be untranslatable would need to have never been identified, be significantly remote from any known one ( which over time becomes increasingly difficult). One last consideration insiders from the organisation driving the universal translator might be best placed for creating back doors rendering certain languages untranslatable. [Answer] **A language where much of the meaning is dependent on other factors, the time of day, the relative status of the speakers, the (relative) sexes of the speakers.** In current languages there are many examples of situation dependent words Consider the [Polish "kurwa"](http://www.expatfocus.com/c/aid=2252/articles/poland/ten-polish-words-that-dont-translate-into-english/) which in many ways is even more versatile than the potential English [usage of "fuck"](https://www.youtube.com/watch?v=uSEXgQ58AoM)\*, it's equally possible to use it, and derivatives thereof, as every word in a sentence and it cannot be translated out of context. You can have examples of words that just don't translate because the second language just doesn't have that concept, German examples being "verschlimmbesserung" and "schadenfreude", the latter of which English just had to take directly. While these words can be explained, you have to stop the flow of conversation to explain a concept rather than give a straight translation. Consider also the double entendre (said the actress to the bishop), which meaning is actually intended, or whether both are. It's up to the listener to identify the intent of the sentence, or potentially miss all that's being said because the meanings are overlaid onto each other. Once translated the duplicitous meanings are often lost. \*I'll give you a language warning but it should be taken as read just from the text of the link. [Answer] > > What property would make a language impractical to translate if the intention is to dub in a translation it in real time? > > > A few years ago, there was a [study](http://content.time.com/time/health/article/0,8599,2091477,00.html) which showed that while human languages vary in information-density per syllable, we typically speak at a rate such that *the same amount of overall information is delivered in a minute or so*. That is, Mandarin is very information-dense, but spoken slowly, while Spanish is more wordy but typically spoken quickly. This property makes real-time dubbing possible, although you often get the jarring effect we're familiar with from badly dubbed movies where the speaker's mouth clearly moves as if saying a one word and a long string of sound comes out (or the other way around). Have your alien language be both dense *and* spoken quickly, and the real-time translation simply can't keep up. That would probably require more language-processing capabilities in the alien's brains — but hey, *aliens*, right? It wouldn't need to be a factor of 10 or anything like that — even a 20% increase would make every significant conversation require a lot of "hold on a minute please!". You could also go the other way around, making the aliens slower (like Ents, I suppose, except without the ability to shift to human time scale). Now the universal translator can't easily render human languages to the aliens without making us wait, and we all know how impatient we are. [Answer] A highly – nay, *wholly* – [synthetic language](https://en.wikipedia.org/wiki/Polysynthetic_language) could be impossible to translate without external references. Imagine the two sentences "I like dogs" and "dogs like me" if the words for "dog" and "dogs" are completely different in singular and plural forms, and as the object or subject of a sentence; "like" rendered differently if the actor is a person, singular, or animal, plural; "me" and "I" already exemplify this, but imagine if it's always excluded when it's the subject. Now take it a step further: "dog" is written differently again depending on the *type* of sentence, the type of verb, the tense, the *first vowel of the first morpheme* and so on. Now take "dog" and insert morphemes and entire words into it (like "**d** li *me* **og** ke **s**"). Even a lengthy sample on a specific topic would be inscrutable without a basic understanding of underlying grammar and syntax governing transformations as above. [Answer] I am spacing on the title and author, but one of the old time scifi writers did a couple shorts on this idea (same events from different perspectives). Humans want to colonize a particular world as a way station for a shipping route. The rules are that they must have permission from the local inhabitants if there are any intelligent species involved. The initial survey did not detect any intelligent life, but one member of the follow up certification party is observing the local life forms and, while they are primitive, he believes he is seeing them communicate and act in a manner that indicates intelligence. Unfortunately no one can detect any language or other means of communication. They bring in such a "universal translator" and it reports the sounds the locals are making as being meaningless and repetitive, having no syntaxual value. This is causing some contention between the development company and the certification team because the team refuses to certify the planet, because they think this species is intelligent, but can not communicate with them to prove it. The situation finally resolves with a naval officer being called in to mediate and figuring out that the aliens communicate telepathically, and the sounds they make are an identifier/carrier to allow the communication. Because the vocalizations carry no meaning in and of themselves, the translator was unable to recognize them as a language. [Answer] There are a number of possibilities, which could provide various plots: 1. Target language has no related languages (a [Rosetta Stone](https://en.wikipedia.org/wiki/Rosetta_Stone) reference is missing) 2. The language does not operate in known basis of measurement (sound, motion, etc) such as Formics (Buggers) communicating via pheromones in the Ender books 3. The language evolved using a natural encryption, and without the key the phrase is gibberish 4. The language is forbidden/dangerous for political/religious reasons, and therefore the translater software prevents translation My intent behind the idea that a language could EVOLVE with a natural encryption, not necessarily a digital or binary type encryption. While I was considering the idea, I was thinking of a reason why encryption would be required... and I imagined a society that only communicated via sonar or pheromones in a crowded space. In order to separate conversations from the noise of other conversations, a natural encryption system was developed. The parties involved in the conversation had the key to decode, and everything else that was indecipherable was just considered background noise. [Answer] Generally, Universal Translators are only able to pick up on sound, and convert it into sound patters we interpret as words. This means that anything else will be untranslatable. If they communicate using anything other than sound waves, like light or touch, it can not be translated. Even if they do use sound and it can translate their words, If they incorporate these other things that are untranslatable, it is enough to not know what they mean. Take for example Sarcasm. The words can be identical, but the tone might be all it takes to completely reverse the meaning of those words. If the language relies on tone to convey the meaning, then knowing the words is just not enough. [Answer] It very much depends on how your universal translator works, and what you mean by "untranslatable", exactly. If you just want a delay, the training process for the translator could simply be too long for the story needs. The language would not be actually untranslatable, but for practical purposes, for the duration of the story, it cannot be translated. It could be too complex, require too much source material, whatever. But if you want a **universal** translator that cannot translate a few languages, you've made a tall order. It wouldn't be much universal in that case, right? Your way out is the "out of the ordinary" excuse. Maybe all of the species in your universe are carbon-based, more or less similar to life on earth and the translators function is based around common principles. Some species could be exotic, breaking these concepts. [Answer] Text in a language can be difficult or impossible to translate with when the required information is absent. One way is that the grammar of one language requires information which the other does not. An example is tense in English: When translating from a language where the time when something happened need not be specified, the translator must often guess. Another similar way that this occurs is with how implicit or explicit a language is in practice. In English, one is required to speak full sentences (or nearly so). In Japanese, one cuts a sentence down to the bare minimum. For example where in English one would say "I'm going home", the Japanese equivalent is simply the verb "to return" with all information about who is returning, where to and when left out (even though the grammar does have these things). A listener is supposed to understand the intent from context but it is not always possible to explain with certainty what was meant unless the translation is heavily annotated, especially if the text is obtained out of context. This is why machine translation from Japanese to English should always be viewed with suspicion. [Answer] A very simple example from Earth is that translating German to English is not possible in real time. It's possible and not uncommon to have long German sentences where the last word completely changes the meaning of the whole sentence, so a translator, human or mechanical, has to wait until the last word of the sentence is spoken until they can start giving the English translation. It seems this is upsetting some people. @Lostinfrance: They can't translate *in real time*. As in German speaker starts the sentence, translator starts speaking in English. There are sentences where the translator needs to listen to the complete sentence before being able to translate. @AlexanderKosubek: I'm not quite clear what you are going on about, but the other way round it's not a problem, because the first few words of the English sentence can end up influencing the very end of the German translation, which is no problem for a real time translation. [Answer] In cryptography, a message encrypted via one-time pad[1](https://en.wikipedia.org/wiki/One-time_pad) is impossible to decrypt without access to the shared secret (the "pad") used to encrypt it. If you think of the speakers of your language as ciphers, the thoughts they wish to express as the input to the cryptographic function ("plaintext") and the words they emit as the output of the cryptographic function ("ciphertext"), then a language with this property would be understandable to anybody who knows the encryption key while being completely unintelligible to even an infinitely powerful translating computer. Since a one-time pad requires that you never reuse keys, distributing shared secrets is a very hard logistical problem in the real world. If the message you wish to communicate is 10,000 characters long, your encryption key will also need to be 10,000 characters long, it'll need to be random, and you'll never be able to use that encryption key again. Maybe the hypothetical speakers of this language share some sort of telepathy which they subconsciously and instantaneously (and securely because telepathy is secure and \*cough\*handwave\*cough\*) use to interpret the language in real time? [Answer] A **dynamic language or metalanguage** This is close to a couple of the other answers ("make it depend on the time of day", "natural encryption", "talk with allegories", etc), but they don't hit it directly on - what if the language was not fixed, but was created on the fly each time people met up, from a more abstract set of rules? I don't know for sure that you could create a whole language like this, but if each conversation 'saying the same thing' used different words based on the current situation around you, the universal translator would have to basically be a self-aware participant in the conversation to know what to do. e.g. Instead of saying '*They were afraid for their lives*' you say "*Shaka, when the walls fell*", referring to a situation where someone was afraid for their life - but it's still the same saying every time. Instead, your language rule could be not "what to say to communicate fear" but "how to choose what to say to communicate fear". * "*refer to the most recent international news incident where someone was scared for their life*", so it would be continuously changing every conversation. One day "*The French at Bataclan*", another day "*New Zealand Earthquake endurers*", another day "*the flowers*" (because a swarm of locusts just appeared yesterday). * Maybe you couldn't communicate ideas and concepts as precisely, they would have more room for interpretation - less chat, and broader strokes. It could be Less international news based, more immediate surroundings based. Not "are you thirsty?" or "Like Shaka in the heat wave", it might be "*like the dogs?*" (if you just saw dogs drinking water) or "*like the drain?*" (if you both just watched rainwater draining away). Two or more of their species spend time together and build up a language between them on the fly based on global events and local moment by moment shared experiences, which then fades as they split apart. Their species has a 'recency bias', Twitter style, and they have very similar brains to each other, so they tend to get the same emotional or practical feeling as each other in response to the same news story and events. News stories and events are tuned to this to be short and sweet and pack a communicative punch. A rolling, evolving language, cueing from the previous usages, on a scale of seconds and minutes instead of hundreds of years. Like we do when we see a coworker ruin something and the same day we see someone doing the same thing and say "*he's just 'done a Richmond'*" instantly referring to the event from earlier the same day as a new saying. That, but moreso. A 'natural encryption' keyed between people as they spend time with each other. A thing that is learnable (maybe) by becoming involved in their lives and their world, but is not learnable by listening to a conversation, or by a mechanical device which has no sense of the 'state of affairs' or the current moment's experience. (A real universal translator might have to be sentient; in that case, anything you could learn, it could learn). [Answer] # An alien's language uses asemetric encryption Either the aliens have evolved to be really good and fast at math (Our Algebra/Calculus is their basic arithmetic) or the part of their brain that handles language just evolved to use encryption in their language (May be lying and overhearing was a extremely big problem in their species millions of years ago). You could have something where their name is their public key, so no one else who knew the language could know what they are saying, much less a translator. If an alien wanted to talk in the group you just tell everyone in the group (using their name as a public key) the public and private keys of that group. To talk to everyone you use a well known public private key pair. You could also implement encryption signing where you so aliens can't lie about what someone else said. "This [alien name (also the public key)] said [message signed with public key]." If you aren't familiar with asemetric encryption, in this scenario: * Knowing the public key (the alien's name) allows you to talk to those with the corresponding private key * Knowing the private key allows you to hear and understand those who are talking using the corresponding public key You could say that they might have super computers that can crack their encryption. You could say they have a really big key (the aliens have really good memory), so they would need a super-duper computer. The aliens might raise the key's length as computers get better. (The longer the key, the harder to crack) Or, you say that they use and encryption that no one understands and never will. (Of course then people may steal and sell the alien's brains for encrypting). If this is the case no one, except members of their own species, can ever talk to them using their language, but the aliens could speak another language. (This might be very difficult for the aliens if their brains evolved to use encryption.) If they use a known method of encryption or scientists figure their encryption out, then translators can be made, but only work if you and the aliens use your alien-public-key name or a commonly known key pair. TL;DR The aliens use a language where overhearing is impossible, where you can only hear aliens who are talking to you, due to the nature of the language (e.x. encryption). [Answer] Wordplay and irony are two of many features of the English language that I have to deal with every day in Japan. For instance, they were talking about the U.S. elections on the news the other day, and they showed a protester with a "love trumps hate" sign. That three word phrase is so loaded with context that it would take minutes to explain to somebody who doesn't speak English, and even then they would probably not completely understand it. It was clumsily translated as "I hate trump". The same thing happens with irony. "Sure, I'd loooooove to meet your parents" is very difficult to translate because irony simply doesn't exist in Japanese, and it would take a lot of time to explain the concept of irony in a real time translation. Also the other way around, there are lots of words in Japanese that are loaded with cultural significance that accurately translating them to English would require minutes to hours to explain the context. That's why machine translation between English and Japanese is so poor. [Answer] Any language which has sentences with multiple meanings (i.e. every natural language ever created since the dawn of language) would lead to untranslatable bits. One of the following would have to happen: * The translator would have to pick an interpretation and translate that (hoping it got it right). This is what modern Google translations do. You can see how effective they are. * The translator could try to convey all possible interpretations. This could be incredibly slow. It could even be exponentially slow if interpretations layered on interpretations. * The translator would have to limit itself to phrases which have a clear set of matching interpretations in both languages. [Answer] # Words based on deterministic input For any given string of characters, the previous word(not string of characters), mood, body language, situation, and other inputs determine what word that string of characters represent. This would create a simplified block chain where each word depends and what situation, body language, and word was said before that which depends on the situation, body language, and word... Ad continuum. Each combination of aliens would have a different block chain. In order for translation to be possible the translator would need to have heard every conversation using that block chain, and know and understand every situation using that block chain, and for every other input that determines a word. Different dialects might use different inputs, or interpret those inputs differently. You might be able to brute force their word pairs, and see if it makes sense, but that would take lots of AI and computing power. And you'd have to guess which dilect they are using. To combat this the aliens might use the last 10, 100, or all the words to determine the next word. In that case you'd need to guess all possible sentences, paragraphs, or what the group of aliens have said ever in order to brute force. Of course the aliens must have large and exact memory to pull this off, but this is a little more plausible than the aliens evolving with computer encryption. ]

[Question] [ A malevolent force is lurking the shadows creating monsters to be its army and take over the world. WHY in the world does it put a highlighted weak point on all of them? It makes sense from a writers' and heroes' perspective: each enemy has a gimmick which makes them formidable at first, then suddenly its glowing weak spot gets discovered. Afterward all those enemies become mild inconveniences on the heroes' path. This principle fails the 25th rule of the [Evil Overlord List](https://tvtropes.org/pmwiki/pmwiki.php/Main/EvilOverlordList). Why would a villain on top of giving his minions an Achilles heel, highlight them with a symbol or glowing bit? It severely limits the effectiveness of the monsters, limiting their effectiveness to how well they defend that weak point. On small swarming monsters that would die in one hit anyway it wouldn't make a difference. But on powerful ones that could one-shot heroes it makes them very short lived. You could always drop new monsters, but as soon as their weakness gets discovered their cost to benefit ratio drops. Is there a reason I am missing? Why would this make sense? Creative answers are welcome. [Answer] Because he's not the big bad. The big bad is coming. He's got a nigh unstoppable force of arcane behemoths, who don't bear obvious weak points. But by his nature the creature creator is incapable of teaching other than by showing the humans how to fight the creatures. And while the attacks caused by his creations may be devastating, the looming storm is darker. [Answer] ## What it offers is worth more than it sacrifices Think of it like this: Why do animals have eyes? The are easily injured, prominently and obviously positioned on the front of our faces for any one to try to gouge out, the eye socket offers easy access directly into the brain via the optic nerve opening into the skull, and on some animals, they literally seem to glow in low light. Everything about eyes make them a vulnerable spot, yet an animal without eyes is not nearly as awesome as one with eyes. Seeing is a pretty good super power worth trading in a couple of weak points for. Now let's say you are an evil over-lord. You can make these fleshy golem things that will do whatever you like... only against a well armored knight (or a guy with an assault riffle just depending on your setting), they just aren't that effective... however, you also know how to make power crystals that can enhance your monster's abilities. A fire crystal shoots a blast of flame, an ice crystal shoots a wave of freezing wind, so on and so forth. But these power crystals all have a few things in common. They are all made from the same delicate material, they radiate light, they need to have a direct line of sight to a target to be able to hit it, and when they are damaged, they explode releasing all the elemental energy you stored up inside of them. Does this mean that your big well armored tank monster can be blown up with a well placed brick to the forehead? Yes... but that chain lightning ability it uses for TPKing entire groups of adventurers is only possible by giving it the power crystal. You can try to give the monster a sort of "eyelid" to keep its crystal safe, but in that moment between opening the lid, and aiming the crystal, you have an opportunity to smash it's gemstone. [Answer] You were following another Evil Overlord warning: don’t call up anything you can’t put down. You didn’t want to create any minions you yourself couldn’t easily defeat. [Answer] Because the magic process to create these minions require so. It's pretty much the same as this: [](https://i.stack.imgur.com/LX0nF.png) [](https://i.stack.imgur.com/nkgxn.png) The evil lord has molds to create his minions, but all these molds require a cavity to cast in the magical life force that powers them. Once the process is completed, the magical force "fuses" with the mold to give birth to a minion, but this gap is still there, and the magical life force is so powerfull that, no matter what you cover this cavity with, it still shines as bright as daylight. Obviously, the minion will be as strong as the material the mold was made with, but a precise deadly blow right into this cavity creates a chain reaction that makes all the life force explode inevitably. [Answer] **Your minions need to remember they are nothing without you!** It is the same reason you make all of your minions wear tiny red shorts! Which everyone does. They need to feel insecure in themselves and dependent on your Overlordly Greatness to keep doing what they are doing. What better what to remind them than a bullseye on their tender bits? Because if they start feeling like they are all that, they will pull on some asskicking pants over those tiny red shorts and come find you where you sleep. [Answer] I know, right? You slave for years on your pet project, eliminating every single flaw, refining and improving your product for maximum effect, then release it into the world to impose your will... and some peon finds that flaw you never noticed, and suddenly your whole plan for dominance falls apart. Worse, you pore through the plans for hours, recreate the flawed parts from scratch, and it still won't go away. And that's just the programmer's perspective. Your antagonist probably isn't dealing with Heisenbugs. I think it's more likely that he's facing one of a few issues: ### Selective Blindness He very literally cannot see the problem. For some reason that glowing "kick me" sign just doesn't register in his sensorium. When he reviews his creatures all he sees is a patch of hide, maybe a bit weaker because of the way the creatures' armor fits together, but nothing out of the ordinary. Perhaps it's analogous to color blindness - maybe more than just analogous. His big green killing machine just happens to have a bunch of red arrows pointing to the weakest point, but he can't tell because they look the same to him. Less directly, the leakage from the creature's core/power source/whatever is on a frequency band his species just doesn't have the ability to perceive, but which is super obvious to other species. ### Situational Weakness The conditions in the lab/foundry where he's creating his monsters are such that the weak points don't actually manifest. The weakness is still there, just not on the surface where it's obvious. Once the creatures go out into the world they encounter conditions that bring the weak point to the surface. He'd actually have to be following the creatures around through different environments to observe the effect. ### Enemy Action Nothing is actually wrong with your creatures, somebody is screwing with you. Your perfect creatures are being changed without your knowledge once they're sent out. Some active magical effect is forcibly altering the creatures when you send them out. It's an insidious effect that you don't even notice until after it has happened, and whenever you try to defend against it the effect changes to bypass your countermeasures... if you're even aware of it in the first place. ### Misapplied Magic You're working with spells and rituals you uncovered from long-dead civilizations, modified to your specifications, but the magic simply doesn't work the way you think it does. What you don't know - because the snippets of information you've unearthed simply don't mention it - is that the original magic was for creating arena monsters that are designed around the idea that the products would have a target zone to give the competitors a chance. After all, as fun as it is to watch your gladiators spill a little blood, it's really hard to get people to sign up to fight an *actually* unstoppable behemoth. ### Fundamental Rules Maybe it's not actively working specifically against you, perhaps it's a global phenomenon. Anybody who creates monsters like you do will have the same problem. Perhaps this is a law of nature created and maintained by the gods after a particularly nasty previous situation that required their direct intervention to prevent the death of all peoples of the world. I can imagine the gods getting together and blaming each other for it, arguing for a bit (possibly loudly) and then one of them proposing they just change the rules to make a repeat impossible. Or perhaps it's a back door somebody left in the magic system when it was set up in the first place. What, you think magic just happened? Have you seen how complex that stuff is? How many bits were *clearly* just bolted on to fix problems? Pull the other one bruv, I've seen enough badly-patched legacy systems to know one when I see one. ### Misunderstood Antagonist I know, he talks a good game, but he keeps pumping out these things that couldn't possibly complete the stated goal of taking over the world. But are these the actions of a true Evil Overlord? Even one that hasn't read the list? Actually he's a guy who's just trying to make sure that people don't stagnate, or that the world has something to focus on other than petty tribal squabbles. He's seen what happens when there are no common threats to bring the nations together, and maybe he thinks that providing a focus for their aggression is going to be a major improvement over the constant wars over petty things. On the other hand, perhaps he's trying to prepare the world for a worse evil that he knows is coming. When the stars align just right and a portal to a hellish realm opens, flooding the world with actual demons (who just happen to look a lot like his creatures), it would be much better if people have plenty of experience in how to deal with them. Either way, he's just trying to save the world by killing half... I mean teaching people how to get along against a major threat. And he's starting them off on easy mode. The monsters are big and scary, yes, but for now they're fairly easy to take down. When people are used to the idea he'll make them a incrementally tougher. In the "save the world from a future disaster" scenario he'll keep going until the people of the world have adapted to fighting the full strength monsters, hopefully before the real ones get here. --- I started with two ideas, but that got a little out of hand. Again. Hope something in the list works for you. [Answer] It's a [kill switch](https://en.wikipedia.org/wiki/Kill_switch). [History is replete with instances of creations turning against their creators](https://tvtropes.org/pmwiki/pmwiki.php/Main/TurnedAgainstTheirMasters). If you don't want to become just another Victor Frankenstein, pursued to the ends of the Earth by what should have been an obedient servant, you need some way to shut things down in a hurry. [Answer] # Because magical cores work like that. The magical minions are useful and effective because they have large glowing magical devices you implanted into them, which provide magical energy to boost them beyond mundane biology. You could send units without such points, but humans can kill animals easily. As such, your minions inevitably have magical cores, which hurt the monsters badly when smashed. The minions are still deadier than normal animals, but the heroes are competent enough to murder them. [Answer] You often don't know that a weak point is a weak point until it is proven to be a weak point. Or you know but your doctrine makes you neglect the glaring weakness. Why would WWI generals keep flushing soldiers against machine guns and trenches, despite the obvious carnage it was causing over and over? Because they were imbued with the doctrine that a superior fighting spirit was sufficient to win a battle, completely neglecting that a lead bullet would wreak havoc in the body of any soldier, no matter how combative he was. [Answer] Because the powers used to create your minions have their own sense of fairness. The dark gods (or whatever) who supply you with the magic of you evil-overlord-ness are perfectly willing to let you make monstrous and powerful abominations to serve your violent whims and whatnot. But it isn't fair for the heroes who oppose you to have no chance of overcoming you. So the weak points MUST be part of the creatures. In fact, the more powerful the minion, the more obvious and vulnerable the weakness. Or rather, the more obvious and vulnerable you make the weakness, the more otherwise unreasonably powerful you are permitted make the minion. It's an (unfortunate?) clause in the contract. [Answer] # Developer Oversight --- Your villain is evil, yes. Has grand plans to conquer the world. Knows to strategize in general, yes. But **not overly specialized or qualified** to build an entire army of minions alone, let alone by their own hands. They employ several minions, either by contract or by force, to do the legwork of designing, testing, and building the monsters. Your villain is simply supervising the entire process after laying out their expectations on what kind of monster to build. I'm going to quote Doctor Strange (2016) to establish my points: > > The Ancient One: The language of the mystic arts is as old as civilization. The sorcerers of antiquity called the use of this language "spells". But if that word offends your modern sensibilities, you can call it a "program". **The source code that shapes reality.** > > > Your villain's monsters are built upon these spells. This ancient source code. The villain's minions simply utilize these spells as tools to build the perfect monster ever as required by their employer, analogous to a team of software engineers creating an application. Given this code's antiquity, lack of proper documentation, incomplete examples on edge cases and corner cases of the spell's uses, etcetera, the villain's minions *can* stumble upon some undocumented behaviors of certain magic's invocations. Sure, they test the product before finally delivering it to the boss, but there are many reasons why such bugs can escape the testing process * "It's already nearing the deadline. We have to finish the build by tomorrow." And thus they try to wrap things up in a hurry. * "The boss won't know anyway. We've been paid. We're done," say the minions. "Once he finds these weaknesses, it'll be too late already for him to track us down." * "These large weaknesses do not show in our laboratory-conditioned testing chambers." * "He he he, I've made sure that these weaknesses only show up when the monsters are deployed onto the battlefield!" * "Meh, I don't know it can do that. I can fix it just before the next battle. Probably. And that's if the boss survives - the protagonist looks like he can defeat him fairly easily." [Answer] It's a distraction. Those heroes, always talking to each other and learning things. But the most important thing is to use your enemies strength against them. Here they go again, rocking up knowing that poking the crystal eye will cause the monster to instantly disappear. Unfortunately for them, what they don't know is they're not killing the monster. It's being sent back to the store for repairs and upgrades. That's why there are always more monsters the closer you get to the castle, the ones you're "killing" on the way are just showing up again. But this time with new and improved weapons. The overlord's outlay is significantly reduced and density of adversaries is increasing with every kill they make on the way in. It's not that I have reserves. You're giving me my reserves back! [Answer] Because subconsciously he wants to be defeated. He probably had a bad childhood [Answer] I'm surprised nobody mentioned **vampires** here yet. In most settings they're created by a higher power on purpose, and still have a very obvious, relatively easy to procure and instantly deadly weakness: sunlight. I don't think anyone in-universe ever looked at a vampire and laughed them off as weak or useless however. Except maybe that guy that dies 3mins into the movie. Since you're asking for reasons for why that is, there's two big ones: * The power that creates them simply couldn't do any better. Or didn't care to waste even more power on doing it. You can't argue that the results are powerful as they are, so maybe it's just good enough. Think Trollocs or Myrddraal in Wheel of Time, the Dark One doesn't care about the comfort of his army, only about its effectiveness. * If they were strictly better than regular humans in every way, and with no drawback, there would be no story to tell. They'd simply replace regular humans as part of natural evolution. The fact that there *is* a story to tell means that there's an imbalance of power that can be exploited to fight against them. Nobody writes stories about Neanderthals, for example. [Answer] ## As a last ditch safety measure As Both [Davislor](https://worldbuilding.stackexchange.com/a/213983/2169) and [Mark](https://worldbuilding.stackexchange.com/a/213986/2169) mention, there is a trope where you include a safety measure in case your monster turned against you. Neither though have referenced the fact that this was done in real life. In this case though the 'monsters'1 were elephants, as discussed [here](https://www.reddit.com/r/AskHistorians/comments/857fzy/comment/dvw39p5/?utm_source=share&utm_medium=web2x&context=3), I've covered it in a spoiler as I find it quite gruesome given the normally nature of most elephants: > > More of the elephants were slain by their own drivers than by the enemy. These used to have a carpenter's chisel and a mallet. When the beasts began to grow wild and to dash into their own men, the keeper would place the chisel between the ears, precisely at the joint which connects the neck with the head, and would drive it in with all possible force. That had been found to be the quickest means of death in a brute of such size, when they got beyond the hope of control. And the first man to introduce the practice had been Hasdrubal, a general who was often notable at other times, but pre-eminently in that battle. > > > Whether you give the monsters of your world a similar nature to elephants or make them mindless and thus their death morally ambiguous is [up to you](https://tvtropes.org/pmwiki/pmwiki.php/Main/WhatMeasureIsANonHuman) however. Maybe they're even aware of these weaknesses? Maybe it doesn't even start as a weakness (as with an elephant's spine), similar to [Nosajimiki's](https://worldbuilding.stackexchange.com/a/213981/2169) answer referencing eyes. But how the evil overlord uses it, that seems obvious, based on your premise and real world examples. --- 1. Arguably, those who killed the elephants were the real monsters. [Answer] Frameshift: Because the big baddie is not creating monsters in the first place. He's **summoning** them from some other plane of existence. The existence of the weakness is exploited by the summoning process, trying to summon a monster without such weaknesses is much harder--perhaps beyond his ability, certainly beyond what he can summon in large numbers. [Answer] The question title made me think of *Gunnerkrigg Court* pages [1141](https://www.gunnerkrigg.com/?p=1141) and [1142](https://www.gunnerkrigg.com/?p=1142), so I'll suggest the possibility that **the monsters were never designed to fight people who would think to exploit their obvious weak points**. I suppose this conflicts with the monsters' being created "to be [an] army and take over the world", but then some other answers seem to as well, including the currently accepted one, so I suppose that's okay. This could combine with other aforementioned options; for example: * ***Kill switches***: It might be that the monsters were repurposed into an army of world conquest, with the kill-switches that were included when they originally were created being ignored or (weakly) covered up. Maybe the monsters were originally created by the current overlord for some other purpose; maybe they were originally created by someone else and have fallen into the overlord's control. * ***Selective blindness***: The overlord took the monsters from someone else, and not having created them personally makes it all the easier to overlook their weak points. Alternatively, **the overlord created them eons ago** and has forgotten their original purpose and the details of compromises that were made in their design. * ***Because magical cores work like that***: The overlord took the monsters from someone else and may not know that their power cores are so vulnerable, or the overlord created them eons ago and has forgotten their original purpose and the details of compromises that were made in their design. In any case, another contributing factor might be that the overlord is feeling time pressure for some reason: maybe there's some deadline by which the world needs to be conquered, or some rival is gaining strength too quickly, so "I need to send these monsters out *now*, even if they're not perfect! I can't take another twenty years to resolve all the design issues!" [Answer] Everything that you know, even those things that you believe to be uniquely original to your own thoughts are a construction some still call "culture". At the bottom of that structure seat what Jung (Carl Gustav Jung) called the archetypes. The archetypes are fundamental building blocks upon which we build the rest of our culture. I believe some archetypes prevail over others due to that they work better, namely: they are more successful at the time to make predictions on what the outcome of some event will be. Some archetypes are common to all humanity, i.e.: "the shaman", "the hero", etc..., some others are unique to each culture, although they will still share some common root with other cultures. In case of the "monster minion", I can think of: Goliath, Boagrius (giant killed by Achilles), the medieval dragons, etc... That archetype seems to delve deep inside the roots of civilization and, given that it survived to our days, it must contain some fundamental truth about human nature and nature in general. A "monster" is in the end just something that deviates from a normal distribution. Normality is not just some human abstraction, it is indeed something very real: the mean of what nature can create and sustain. A monster, which is usually a mighty figure, may hold some power that exceeds what almost anybody can combat: size, strength, still it is an extreme deviation from what nature can host. Thus, in the end that extra power comes always at a cost, creating some weakness that in the end can always be sought and used against it. Per instance: some giant will always be slower than a smaller person, some super strong character will put extra strain on its muscle and sinew, some super intelligent guy will lack empathy from other humans, etc... [Answer] LISTEN!  Your hero's are supported by creatures that highlight the weaknesses for them, rather than a flaw in the design. ]

[Question] [ I'm creating a story set in a peaceful society. The society is actually very strict about being peaceful, to the point where they don't even play games involving competition. But at the same time, this society enjoys recreation, and also is very intellectual. I'm looking for your help to design games (physical or not) that: 1. aren't competitive, in that players aren't divided into opposing groups, there's no way to rank players, there aren't any consequences if a player plays poorly, etc. To clarify, it's fine if players have different roles in the game. But roles really shouldn't be a substitution for teams, and one role shouldn't be "better" than another. 2. The game must get progressively difficult depending on the skill level of the players. In a competitive game like soccer or chess, if you want a harder game you look for a better opponent. In other words, competition makes the game difficult. That's not an option here. But the game needs to scale to the ability of the players: otherwise, the people in this intellectual society will get bored. If possible, I would prefer to avoid players changing the rules to make the game harder (i.e. because they players are bored, they invent a rule that everyone needs to play blindfolded). I want this game to be a common cultural experience for people in this society, and that doesn't work if everyone is playing a different version of the game. I found some resources on the internet, such as the [Cooperative Sports website](http://cooperativesports.org/?page_id=68). But surprisingly, only one of the ~20 games listed on that webpage meets the requirements of this question. If necessary, you can use any sort of technology (imaginary or not) to create these games. But the best games will be simple. EDIT: Just to clarify things some more: I'm trying to avoid puzzling games. I'm looking for games where complexity is generated from simple rules, like soccer or chess. --- There have been a lot of answers to this question. However, by my count only four of the roughly 100 games proposed actually meet the requirements of the question. These four games are: 1. Collaborative singing/dancing/storytelling/art. This was the most popular (correct) answer; several people were able to come up with this idea on their own. 2. [Jenga.](https://worldbuilding.stackexchange.com/a/48972/171) 3. [Push Hands.](https://worldbuilding.stackexchange.com/a/48772/171) 4. [The incredibly boring ball drag (with a special type of ball).](https://worldbuilding.stackexchange.com/a/48995/171) I apologize in advance for any correct answers that I missed: there were thirty-one answers, and it was hard to read everything. [Answer] Role playing games come to mind immediately. It is pretty easy to set up a role playing game that relies on group cooperation of the role players, without any inherent need for them to oppose one another. The only equivalent to an "opponent" in an RPG is the game master, but that could be mitigated by creating a pretty complicated and flexible rule system that the GM sticks to closely (or even having an AI computer GM instead of a person). The object of the game is usually the team using a variety of abilities, skills, and creative thinking to solve a puzzle, achieve some goal, or "fix" something wrong in the simulated world. Difficulty scales up as the puzzles get harder, the challenges get more difficult to overcome, etc. An RPG game need not center on combat/violence. Many do not. Obviously, to me, such a game would be incredibly boring, but probably not to your aliens. [Answer] ### Rock Climbing Rock climbing is a non-competitive sport in which people seek to climb difficult but beautiful routes up a variety of cliffs. While indoor rock climbing has a competition scene, climbing outside has always had a focus on personal accomplishment for short climbs or team accomplishment for sumitting huge cliffs (like El Capitan in Yosemite) or mountains. While climbing doesn't scale with a competitor's ability, per se, the variety of routes available means that a given climber can always find a climb that is difficult for them. Beginning climbers will seek short, safe climbs with a minimal amount of physical strength required, while more advanced climbers will seek longer, more strenuous climbs with some combination of smaller holds and steeper aspects to increase the physical challenge. Advanced climbers may also be drawn more towards the mental challenge of pushing themselves to try increasingly dangerous climbs or varieties of climbing, culminating in free soloing. In anything but a free solo, teamwork and cooperation to some extent are necessary, as a climber always needs a belayer. In general, people also cooperate and work together to figure out *how* to climb a given section of rock, even if the act of finally climbing it is something each climber must do on their own. [Answer] There are board games with relatively simple rules where you do not compete with other players, but instead compete to win against a set of pre-determined challenges. An example is [Pandemic](https://boardgamegeek.com/boardgame/30549/pandemic). I'm sure there are lots of other similar board games that I don't know about. In this case the challenge is that the rules of the game will cause you and your team-mates to lose after a certain amount of time, and random obstacles will be thrown in your path that require team planning to overcome. We actually specifically bought this game because it isn't confrontational, and apparently I am too competitive and my wife won't let me play Settlers of Catan or Dominion with some of her friends.... [Answer] **It's not the game that is competitive, it's how you play it.** Your peaceful society could play any game and treat it as non-competitive. They could probably even have non-competitive football, MMA fighting, or even *{gasp}* non-competitive rugby. Okay, maybe rugby might be a stretch. Two examples to prove my point. The first is Push Hands from Tai Chi, a martial art that your pacifists might appreciate. Push Hands is a game designed to help develop your sensitivity. Its hard to describe all the nuances, but the basic idea is that you touch the other person (typically with one hand or both), and try to move with eachother while maintaining balance. Played this way, the game is non-competitive. You only "attack" when it is clear the other person wishes you to attack in order to better test their own skill. If they look like they're having trouble, you back off, beause it's not competitive. Your goal is not to "win" as much as it is to better your own skills. You can also play competitively. Same game, except the "winner" is the one who makes the other person lose balance. The other difference was how you play it. (Here's some examples of push hands: [freestyle demo](https://www.youtube.com/watch?v=3R55jx86Sxc), [non-competitive push hands](https://www.youtube.com/watch?v=jDAi5hYUYNE), [competitive push hands](https://www.youtube.com/watch?v=_wdh8zUPn7k). There's also a video of [Cheng Man Ching](https://www.youtube.com/watch?v=fSYPOhSgiis) doing it, though I will not venture to make a claim as to how competitive this video is.) On the other side, I harken back to my days in World of Warcraft (don't judge!). They had a Player v. Player game known as Arathi Basin where you gained points by owning territory. It's a pretty cutthroat game with a lot of competition. However, one particular night, my guild, specializing in these PvP games, came up against another guild who also specialized in them. We were equally matched. Extremely equally matched. The game is played to 2000 points, and we won with a final score of 1999/2000 (and based on the rate the points were ticking, I estimate it closer to 1999.9/2000). We of course were overjoyed at winning, but I noticed immediately that, had we lost 2000/1999.9, I was still going to be happy that that was an *amazing* game that pushed everyone to the limits. From my perspective, the competition wasn't as important as the opportunity to really stretch out and see what I was capable of. **I think the one key to non-competitive gaming is to make sure that, even if you lose, you end up getting more out of the game than you put in.** Some games have rules which make this easier, but you *can* play any game non-competitively, simply by finding what you want out of the game on the playing field, rather than in the winner's circle. Likewise, its impossible to make a truly non-competitive game. Those who wish to compete *will* find some way to turn it into a competitive game by adding rules to create winners and losers. What you really need is a coach that inspires a non-competitive attitude of striving for your best. If you can instill that in someone, they can play any game and grin in the face of defeat. Another approach which may fit with the spirit of your question is to have a game whose rules evolve over time. You can win, but you know that by winning you simply change the game in a way that makes your winning less important. However, obviously you won't find any rules for such games, since they are constantly in flux. Still, I remember many a day playing with sticks as a child, pretending they were swords. Technically you can win a sword fight, but you can never lose at pretend-playtime. [Answer] **Dancing** In this case, I'm not talking about professional choreographed routines, I'm talking more about a band, a dance floor, and a variety of people pairing up to move to the music. I'm also not talking about random gyrating and thrusting, I'm talking about structured forms of dance, such as swing dancing. In these dances, there is a very large skill gap separating the amateurs from the professionals. That said, you don't need to know everything to have fun, and you should be able to find a partner you work well with. In this example, as with all the others so far, there could be an element of competition, but for many people that's not the end goal. The goal of dancing is to have a good time, to move to the music in the way you know you want to, and to find someone you can spin around without crushing anyone's toes. Essentially, dancing is about two people trying to look and feel as great as possible, which is a lot like what you'd get in competitive sports, but without the need for opposition. [Answer] Collaborative and creative activities would probably be the most popular. This would open up a huge variety of recreational activities. For example, * Collaborative storytelling, taking turns to build a narrative. * Synchronised physical activities, perhaps synchronized swimming as an example. These would provide options for different skill levels and do not have a competitive element (unless you compare results to other "teams"). [Answer] Just free-thinking here. Countdown for Utopia turning into hell, at mark, 10, 9,8,7.... > > But at the same time, this society enjoys recreation, ***and also is very > intellectual***. > > > Yep, they're boned. I have to admit that whenever anyone says "non-competitive" I get nervous. Competition is the automatic flip side of freedom. If people can freely choose between options, that throws the providers of those options into instant competition. Games are really abstracted simulation of real-life events so a non-competitive game must be a game without freedom, something with tight rules and strictures. And where there is life, there is always competition, in humans and in every other species, even hive-insects. Humans compete for social status real or imagined, needed or not. We're hardwired that way. So says evolutionary science. The upshot is that if create a non-competitive game, you will soon find it will become just a cover for a "black-market" competitive game. That would make a good story in itself. But I'll give it a shot: Games require some sort of stress or pressure on the players. Indeed that pressure is rather the point. Competitive games, physical or mental e.g. chess are really descended from simulated combat. So we need to simulate a condition in which are under stress or pressure but not from other humans. Humans are the most cooperative non-hive species and when mutually pressured, we default to cooperative mode. To make a non-competative game, you just have change the "plot" of the game from "man vs man" to "man vs nature (or something none human)" or more intriguingly, "man vs inner-self." Man vs nature could be easily arraigned as many have noted above. Just give a team a collective task, say barn raising, in a finite time frame and you've got instant pressure without (overt at least) competition. Man vs inner-self could be pretty eerie. If competitive games are abstracted simulated combat, then a non-competitive man vs inner-self could a game that is an abstracted, simulated struggle against immorality or insanity. Maybe something on the world causes people suffer mental degradation so they evolve "games" which train them from childhood to monitor their own mental states and the states of those around them. The "game" might be a bunch of people sitting around drinking drug tea that made them irrational in some fashion and play the game by keeping themselves calm and helping others to do the same. I'd have to think about how to make that happen but it would be something different. P.S. You might want to study up on the literally hundreds of utopian communities founded in the US between the early 1700s up to the civil war. Most were founded by highly intelligent people with cooperative, non-competitive doctrines of some kind. That might give you some ideas. The Shakers are of particular interest. Their primary form of recreation was prolonged religious ritual involving singing, free-form dancing and "shaking." P.S.S. Come to think of it. Community dancing, which survives in the developed world only in forms like Square Dancing, or some evangelical church services but used to be nigh universal. It's basically a bunch of people working hard to maintain a particular pattern under the pressure of the movements and the music. Nobody gets trampled everyone wins. Recommend a book called "Moving Together in Time." If you can find it. [Answer] Simulations games could be a great source of inspiration for you. Imagine a multiplayer version of Sim City. Instead of one player being the mayor, each player is a secretary in charge of one aspect of the city - transportation, education, health etc. and they have to cooperate to make the most happy city ever. Or you can go for Flight Simulator. The game largely ignores economy (at least the versions I played), so everyone gets to fly a plane. Some players can even man the air traffic controlling stations on ground. You can also go for music and dancing games, by remove scoring. Just Dance and Dance Central become dancing lessons, and Rocksmith make your society more musical. Last but not least games that allow for purely creative activities such as Minecraft in creative mode already fit into your model. If playing with toys counts as a game for you, one thing I plan to do with my kids when I have them is to fill their bedrooms with so many lego bricks, we're all gonna have a hard time walking inside those rooms. So they can create whatever it is they wish to play with. No scoring, and no winners nor losers. Just pure, undilluted fun. When I was a kid I actually spent many hours doing just that with my friends, and those were the best times of my childhood. [Answer] By "non-competitive" I understand games and sports in which you do not compete against other people but against yourself, testing your physical and mental limits but also stressing your communication and teamwork skills. **Gymnastics and acrobatics** There are many exercises that require teamwork and coordination. How about building human pyramids? **Team obstacle courses** Various parkours and puzzles that can only be solved in a team. Imagine a climbing parkour that requires 4 people to simultaneously press buttons that are located in various locations so that a door is opened which leads to the next part of the puzzle. **Playing against AI's and robots** This may or may not be inacceptable because football, basketball and soccer are relatively violent sports, at least considered so by your pacifist hippie people, but how about taking emphasis on teamwork by having many footballers play against robot teams with varying levels of difficulty? **Ball passing** One of the simplest games in the world but boring: several people (it can be just 3 but also 100) form a circle and pass a ball to each other. The objective for the thrower is to throw a ball so that the person of his choice can catch it easily while the objective of the catcher is to react quickly to the ball being thrown. There should be a clear way of declaring who must catch the ball to prevent fights over the ball, this can be done by making the thrower yell the name of the recepient out loudly. The point of the game will be to exchange the ball at a very quick pace. If done correctly, the game will be a completely non-competitive game. **Music** How about having people improvise from the scratch together? Forming harmonic tunes can be a hard challenge that requires teamwork. [Answer] ## How to create non-competitive games All the answers give good examples of non-competitive games. Some of these examples are quite general, too. However here are some ideas on how to create multiple non-competitive games: ## Invert a known game In Mikado you have a pile of sticks to take from. You need to take a single stick without moving any other. Mikado is about taking stuff, which may be seen as inherent competitiveness. Jenga is about building stuff. While Jenga is something like the inversion of Mikado it is still competitive, because there is a lose option. Change that lose option by making the pile of sticks unstructured like in Mikado. The game ends when all sticks have been placed on the pile. So the game is played until all players would agree: "There's no stick left to take and place on the pile without the pile collapsing." Collapsing the pile is not bad. Instead it provides a possibility to change the pile. So all players should agree on a pattern they want to achieve collaboratively. For beginners the sticks could have a quadratic cross section. For advanced players there may be difficult patterns to achieve. Running or catching is competitive, because it reminds of hunting. It also penalizes slow (e.g. very young) players. However you could gamify evacuations. Instead of running away and/or being the only one first at a target place the idea is to get everyone to the "safe place" as fast as possible. Similarly Hide and Seek can be seen as non-competitive in that finding someone is not necessarily winning over them. In an evacuation you'd need to find people and warn them of a danger they might not be aware of. So basically you take any known game and inspect, what is competitive about it. Invert that part of the game and you're done. ## Make a known single-player-game collaborative Solitaire was designed to be played by one player. There's no reason, why you couldn't get help to solve it. Minesweeper may sound aggressive but it's basically finding things by presented clues. Sudoku is fun to play with someone, too. With all the examples above the only difference between competitive and not is the mindset of the players. Do I need to be the one who contributes the most? Am I even thinking about it? ## Stay abstract Humans are competitive. We have a hard time imagining different societies. Often times if something is too different we would argue that things couldn't work that way. However someone of a really non-competitive society could similarly argue that being competitive rejects the idea of society at whole. So if you stay vague only naming the game and stating abstract details, it doesn't matter what that details of the game are. Stating the "obvious" non-competitiveness of the game would be boring. Instead describe aspects like * the beautiful result achieved * the players thinking how they could best contribute to the whole * a blunder that might've ruined the game, which may turn out to be a sign of competitiveness, if someone was about to interject to achieve the result in a way against a certain rule. Is competing to be non-competing too complex? Maybe someone caught something by reflex, he should've let fall by the rules. * the audience asking each other for their opinion or explanation thereof without arguing any point made. This has the benefit that it may feel natural to the reader until it dawns on him that there was no mention of a winner. [Answer] I want to ask a question but I'm new and don't know how to do it and don't have the rep for a comment. Can you clarify peaceful and competitive please. For example I play tabletop wargames and I can have a tough and competitive game against an opponent where we try to destroy each others 'armies' and yet we remain peaceful and civil to one another throughout. Being competitive doesn't equate to not being peaceful although given the toxic atmosphere of some online games I can see what you might be driving at. For example I suspect you could easily play Chess as the amount of violence at chess tournaments is very small (but probably not zero). FIRST EDIT Thanks for the explanation, so we are saying that you are not allowed to be competitive or adversarial in any way even if that is done in a peaceful and controlled environment. In that case I think the concept is so alien that I'm not going to be able to come up with an answer. The closest I can think would be something like a jam session of musicians. Several people together using their talent to produce something that is unique and more than a sum of the individual parts. It would have to be a jam session as otherwise people would be able to recreate it, comment on it and then it becomes competitive when people prefer one 'band' to another and then you get charts and talent shows etc. SECOND EDIT Curse this inability to comment!!!! Another answer here is an RPG. I can give an example of something similar that I was part of years ago. One person (the GM) controlled the world where they told a story to the players. The players each wrote to the GM weekly to explain what their characters would try and do and their motivations for those actions. The GM would collate them all and then much like an author tell the next installment of the story based on the interaction created by the players notes. Think of it like a long running TV show where you play one character yourself. There were not stats to min/max and if you tried to be disruptive you would simply be dropped from the game. The story was everything. [Answer] There are actually a number of co-op boardgames in existence where the players play against the game not against each other. Some that come to mind include: Pandemic (a game where you cooperate to eradicate diseases), Flash Point (a game where you rescue NPCs from a burning building), Forgotten Island (a game where you as a group recover treasure from a sinking island). You can use games like these to get a feel for how co-op games can work. They all focus on roles for the individual players that provide a useful skill or benefit that helps the group as a whole. Usually each player (whoever's turn it is currently to prevent anyone player taking the blame as an antagonist) has to perform an act for the game itself. This is often a randomizing action like flipping a card from a shuffled deck or rolling a die which has adverse effects on the game board but doesn't actively target a single player (spreading disease tokens on the game board, triggering fiery explosions in a random room). The games are often themed to stress the need for teamwork and cooperation (stopping diseases worldwide, rescuing people from fires, etc.). The players win or lose together, no individual points are awarded. Most of the games have an adjustable difficulty level as well (changing the rate at which disease spreads, or the island sinks, allowing the players to use a fire truck to help put out large sections of a burning building all at once, etc.). I suggest researching some of the existing co-op games (and playing them if you can find a copy or a friend with a copy), to get insight into what makes the games work. [Answer] [Conway's Game of Life](https://en.wikipedia.org/wiki/Conway%27s_Game_of_Life) and other [similar games](http://store.steampowered.com/app/396890/), like "legos" - are game-like because an inherent challenge exists in getting what you want out of the system based on perceiving complex results from unintuitively simple initial conditions. The struggle which makes it game-like is not against others, nor does the result lend itself to competitive comparison, as individual sports might - for example, in rock climbing you primarily compete against the rock and yourself, but it is possible to see how people compete based on speed of ascent or path of ascent. It is much harder to see how one could convincingly compare any two games of Conway's Game of Life. Better yet, these examples are actually a complete [class of systems](https://en.wikipedia.org/wiki/Cellular_automaton) that you can play with. Legos is just a physical instantiation with a very wide ruleset. [Answer] So the easiest examples are the games where you are working together trying to defeat the game itself. In the simplest case you have peg solitaire, a game for one person where they are trying to essentially solve a really complicated puzzle. In the most common case I know of today, you have families working on a shared puzzle on a large table while a Christmas/Thanksgiving meal is roasting away in an oven. But there are games like [massively multiplayer Minesweeper](http://mienfield.com/) as well which can generate a "we're working together" vibe. There are games which are "competitive-ish" where all of the players are on the same team doing stuff like this; I'm thinking of *Shadows over Camelot* (you are all knights of the round table; each turn you flip over some cards about how evil is encroaching upon the land, then you come up with a shared strategy for fighting that evil) and *Arkham Horror* (Cthulhu is slowly driving the world mad as he prepares to make his grand entrance; you are all investigators who need to solidify the boundaries between worlds enough so that he gives up and returns back to a deep slumber.) In both of these games the adversity is provided by the cards of the game itself and not by the players struggling against each other. Obviously the plotline needs to change, but you could develop a very similar game about needing to find food, water, and shelter in the woods, trying to grow a small band of survivors into a self-sustaining community, where the adversity is just random events which befall the region. The only thing which this might violate is your criterion "there aren't any consequences if a player plays poorly" -- in these games there is still an attitude of success and failure, with the players generally reaching towards success. In a similar vein, consider a collaborative game where each person is given control of some robots with only a couple instructions. Instructions N, S, E, W make your robot fly in that direction (in a grid arena) until it crashes into a wall or a robot, after which it stops in the square right before the crash. If you fly through a square containing a ball of colored light, your robot picks it up, maximum 1. Your robot can also throw this thing in the N, S, E, or W directions, almost the same rules: if it hits a wall it stops in the square right before that. But some tiles have on the ground a colored "black hole" for those balls of light of that color. The goal is for your team to throw all of the light-balls into their matching black holes before time runs out. The reason I made this robots (you can also do humans!) is because I think it would be fun to give players 30 seconds to collaborate, and then they have to write a 50-move program independently of each other for each of their robots, and then they can play them out with all of these robots flying around simultaneously and maybe they'll have a perfect strategy ruined by two players accidentally crashing into each other on move#34, throwing off the rest of the instructions thereafter. If you want games which the team can't really fail at (per a comment), then it becomes *much* harder to talk about skill levels (it seems like there's something inherent to the idea of "skill" which is about "likelihood of success"). But it's not 100% impossible -- for example, painting is one of those things where different people have different skill levels but a given painting is objectively neither a success nor a failure. Consider the Food Network show *Chopped*, where contestants cook with a basket of random ingredients against a time crunch, and each other. Now limit it to one person, and one trial, and they have to cook one theme ingredient. They get, say, &100 (where & is your world's currency) for each of a set of nasty ingredients they use in their dish, or for devastating handicaps like "not allowed to use a knife." They get &100 for each judge who says their result is tasty, and they get &100 simply for competing. Now there is a tension and strategy: do you take all of the difficult ingredients, earning money that way, and if so can you make it palatable? Or do you go for a very likable dish without those spoilers and try to earn the money from pleasing the judges? There is still a rough way to rank people (by the amount of money they made playing the game) but of course everyone knows that that's highly subjective because they made different choices in the face of different ingredients and different available challenges; this person who won the most may have "gotten lucky" moreso than this person who won much less but accomplished a lot more. In some ways I guess the latter is a sort of improv comedy, which is another useful template. *Whose Line Is It, Anyway?* is famously a fun game show where "everything is made up and the points don't matter." You can do improv in many different ways. Imagine dealing cards to a bunch of people containing, say, story elements and settings and dramatic reveals; each person chooses to discard 2 out of their 5 cards and then, without saying what's on each card, they have to assemble them blindly into a story. We then flip up the cards and read the story from beginning to end. Hardmode contains cards like "everyone dies" where you can only say things like "I need to introduce a character after this dramatic reveal!" to try and keep the plot going. No matter what comes out, everyone has fun, either at an epic story or a sort of disjointed *Mad Lib*. But even if we're talking about very strictly logical games rather than aesthetic ambiguity, we can of course come to the same result through a team effort with a bunch of different approaches. Consider the task of solving an NP-complete problem; maybe it's deriving a formula given a set of logical rules. To make this into a collaborative game, just give players turns guiding some current "working formula" by applying a rule apiece to the current expression, until this expression matches the target. In a way this is sort of a game where we place a robot randomly within a maze, and give a bunch of players in turn a choice to make that robot go N, S, E, W one square; the team wins when the robot gets out of the maze; you can increase difficulty simply by choosing a larger maze. So those are some templates I can think of. [Answer] **I think the key point is the people.** The people themselves will have to be non-competitive. I've seen two people complete compete eating food or finding a parking spot. Some humans make everything competitive...**it is evolutionarily beneficial to be better.** **Competing is hard wired into our systems** So I think the answer relies on two things. 1. First, as in your question, and as mentioned in other answers, you need games that promote cooperation (those things can still be competitive, we can make anything competitive). I mean seriously [we EAT HOTDOGS competitively](https://en.wikipedia.org/wiki/Nathan%27s_Hot_Dog_Eating_Contest). *so disgusting...* 2. The people have to be non-competitive. How you get to this point probably requires a development path other than natural evolution...evolution will never select for a non-competitive species. [Answer] If you want to make this believable I would draw heavily from existing large Player Vs Environment games, just tweak the fluff/justification around the existing gameplay. These game exist, and are huge. Most obvious is World Of Warcraft. Yes it has PVP elements, but one can play on a PVE server without every fighting a human enemy. Instead you have a group of 6, or 10, or 25, players all working together to take on a challenge the game provides to them. Harder challenge comes from taking on a stronger dungeon/raid etc. Or look at MOBA's (leauge of Legends, Heroes of the Storm, Defense of the ancients etc). Sure, the standard MOBA is pretty much the definition of competitive. However, it's possible for your 5 man team to go up against AI foes in a player vs environment setting. Sure, standard MOBAs the Ai are not that good and are kind of easy, because their just training tools for the real game, but a game that takes the same format of a MOBA, 5 man teams in a 20-45 minute game against a computer controlled challenge, can easily be created. Now I know you're first thought is obvious, these are clearly non-peaceful games, and that's true. However, the gameplay is not at all competitive, and does not need competition. It is quite easy to keep the gameplay and just modify the justification for what the characters are doing. Your find much of design elements carry over quite easily, and *should* be used as a model for your game. I would suggest tweaking characters into being heroes fighting some disaster or external/environmental threat most often. **WoW for wildlife management** Your exploring new lands (either new planets in a sci-fi game or a fantasy game with some ability to jump to new unknown locations though some magic gate recently discovered). These lands have large and potentially hostile creatures. You need to explore these lands to learn their secrets, discover any resources your people can use, etc. Along the way you need to deal with hostile creatures & dangerous land elements. You don't attack the creatures, but have a whole host of abilities to calm fearful creatures, charm others that you need to get close to study, protect against environmental hazards that show up, etc. Your dungeon is effectively a new world to explore and your doing it meaning no harm. In fact take it a step further, perhaps the creatures are being harmed by something (magic invading the world is driving them insane, or space plague risks killing them) so you need to actively hunt down and control the creatures precisely so you can help provide them with whatever aid will protect them from the disaster that recently struck their land. **MOBA for flying a spaceship** Imagine you have a game set in the future where you have a spaceship doing some important space-mission (could be anything from studdying anomolies in dangerous space to trying to survive a space jump into new unexplored area whatever). Your 5 man team is in charge of various roles on the spaceship, and need to cooperate to make the ship work it's best to survive the challenge. Each character has a set abilities they can use but need to collaborate with each other to get the most out of them. Alternatively to make this feel more like a MOBA modify it to be a space fleet and each character controlls one specialized craft that needs to work together to protect the rest of the civilian/scientific/escort-quest ships in the dangerous mission their all working towards. **Team Fortress for fighting wildfires** Imagine a crazy wildfire spreading and people needing to combat it. You create a team of 'elite specialized firefighters' that get airdroped into a disaster zone who help to combat the blaze. Your "heavy" is the guy with a giant firehose that can put down invading flames rapidly, Your 'spy' is someone who's job is to run into the burning building to grab civilians that need saved, with only a small anti fire extinguisher but special abilities to survive being surrounded by fire. Your Engineer builds fire hydrants that others can connect to for increased water pressure and automated water turrets. Your Medic checks out everyone gear and helps cool them off when their running dangerously high in their 'overheat' ranges. The game would have to make fire a little more dynamic, but there are all kinds of justifications I could come up with to do it, or none at all (a FPS isn't all that realistic compared to a real battleground, people don't mind your taking liberty to make the game fun) **Civilization as...civilization?** 4X games (Xplore, Xpand, Xploit, Xterminate) games can easily be built into 3X games (drop the extermination part) with little effort at all. Everyone can be in charge of building up their own civilization without combat involved. Perhaps they all cooperate together and are ranked not just on how their own civilization grows and develops but also how others grow as well. All you really need to do here is add more environmental hazards to the game, more random events, famine, diseases, negative weather patterns etc, to add extra pressures to fledgling civilizations to make it hard for them to grow, perhaps combined with some extra elements to ensure that banding together usually helps the civilizations to survive these hazards. I think I sort of made my point so I won't keep going on. These are examples in general, there are plenty of other ways of doing the sort of things I suggested. My main point is rather then trying to reinvent the wheel I suggest taking existing games and just throw on a non-violent skin. The challenges really don't need violence and the gameplay can work pretty similarly without violence. [Answer] The key concept (that many answers addressed, but only indirectly) is that competitiveness must be replaced by creativity. My basic premise is: instead of playing to confront each other, we play to create together. Dancing, role playing and puzzles all have this common feature, but were suggested before. I offer instead a more refined version of **cat's cradle**, where you and your *partner* take turns to add steps into a progressively complex design, and neither can control the final design because of the other's input. The better the collaboration, the better the the final result. [Answer] ## Catch Cooperative play, coordination, skill, agility, no points, no teams. ## [Acroyoga](https://en.wikipedia.org/wiki/Acroyoga) Yoga with cooperation and coordination between partners. ## Story writing could easily be a group activity--perhaps a more nuanced version of the game children play where they each contribute a sentence to a story. ## Sex Cooperation, pleasure, creativity even. Why not? [Answer] Theatre Sports / Improvisation Though these are often setup as a competition when we see them performed, there's no need for that (in fact, good improvisors know that the competition is for show and co-operate to put on an entertaining competition). But in it's simplist form it could be a good natured gathering where individuals or groups take turns to improvise scenes for each other's enjoyment. You could try the [Improv Encyclopedia](http://improvencyclopedia.org/games/) for a list of example games. In terms of increasing the challenge based on skill - the trick here is that constraints are *removed* as the players get more advanced. For novice players, you need a lot of rules and simple games to contrive a situation where they will do something fun and interesting in spite of the of the nervousness around performing. As players become more advanced you remove more and more rules until the best players can simply be thrown on stage and something beautiful will unfold. People often think of improv as comedy, but it doesn't have to be, the players could improvise a tragic or dramatic scene - and good players will do this to mix it up after a lot of laughs. This may also serve another need in society - since your citizens are so peaceful and non-confrontational, how do they deal with stress or negative emotions? Do they bottle them up? Improvisation may serve as a release giving a safe place to play out and deal with pent up emotions that may be otherwise socially unacceptable. [Answer] Cooperative games are the ideal, I suppose. There are plenty of examples in the gaming world already. Consider puzzle games like Portal 2. Difficulty can ramp by adding timers. Consider a game such as "scatter N pieces randomly on a grid. Each players turn, they may move M pieces from any square to any other, then one step of Conway's game of life is performed on the board. The goal is for the players to cooperatively clear the board in the minimal number of steps". Difficulty can ramp by increasing M, reducing N, changing board shape or size, and changing the rules about where you can move pieces (must have clear line of sight to destination; must end adjacent to another piece; etc). Cooperative non-combat RPGs would be fun. One possibility that might fit well with the theme would be a cooperative version of a Cross-and-circle game (eg pachisi, ludo) in which the goal is for each piece to *not come into conflict* with any others. Conflict/collision will remove both pieces from the game, but self-sacrifice will remove only one: given the goal is to retain as many pieces at the end of the game as possible, self-sacrifice is the best move if the game looks like it might put two pieces in conflict on your next dice-roll. The point of all co-op games is that you succeed or fail *as a group*. Each person's contribution is important. [Answer] I'd like to answer the question, but, in my opinion, I cannot find it. **tl;dr**: Game is about competition; otherwise it is activity. I think non-competetive game is oxymoron. If I play a game I am competing opponent (chess, table-tennis), my team compete another one (football, LoL), I am competing myself (tetris, climbing,...). And this competition satisfies me. Even if the goal is "It won't be that bad as it was last time." When you can assess the result (king is killed, ball is missed, goal is scored, nexus is destroyed, score is reached, altitude is reached) and you have someone to compare the result - count yesterday's yourself and tommorow yourself too - you have competition. The assessment can be both objective (time to fulfill the rules) or subjective (I like this a bit more than that). The arts doesn't solve it either, see figure skating, dancing, freestyle motocross, oscars, film festivals, music charts etc. When solving puzzles you challenge the author (I will find the solution; period!) or yourself (I'll solve it faster than the previous one). [Answer] # **Tool crafting** It may seem stupid or rudimentary, but crafting tools could prove to be an interesting game to play as a group. In ancient times we had to design and craft tools from flint to be able to perform certain tasks, such as hunting or carving wood. Your society could do something similar, in that people as a group can gather around and propose their ideas for certain tools to solve different problems. It would be quite fun, especially once people start making up tasks of sorts. It would not be competitive in the sense that it isn't the person who makes the best tool that wins, but the group as a whole wins from having more and better tools to perform special tasks. Roles could easily be accommodated in a survival-like game, some people would have to gather materials, some people could be designers/creators, etc. Thus, the group is competing against the environment, similar to how the climber competes against the rock he is climbing. People would understand how materials work and how to make them from simple objects. It's in the DNA of every intellectual civilization to engineer tools for their needs, even if these are made up just for fun. [Answer] I'm thinking of **0-player games**. Games like **Conway's Game of Life** need no players and therefore have no conflict and only need players to watch and observe. Although sometimes it's rather debatable if these games are actually games since there is no gameplay in the usual sense. [Answer] I [recall a story](https://scifi.stackexchange.com/a/145883/38557) where a society as you describe had a sport called “bag drag”. It was described briefly without detail by a narrator who wasn’t interested and thought it pointless. Trying to drag a heavy sack across a goal by a cooperating group. In the story it was introduced as a way to determine that all the domestic helpers employed by the place where the humans were staying had been replaced by grad students studying the alien (the human visitor)—she found that they were all uninterested in the sport, while the class of people they were replacing would have been fans. Anyway, it was introduced as a sport that existed in a non-competitive society, without explaining the details. Maybe they aluded to it being keyed to the psychology of the cooperation overcoming obstables, but avoided all detail of the rules. It was only necessary that it *exist*. [Answer] Creative (Minecraft like) and simulation games are already mentioned. But there are tycoon, hidden object, idle and time management games out there. They do get harder as you progress and they do not pit you against humans or AI. It is also possible to have games entirely based on exploration. Most adventure games also avoid conflict and could be pretty though. I would also advice you to check boomshine, lightbot, and factory balls. All of them are non-competitive and get pretty though. [Answer] That's easy Take random number generator, which generates natural numbers from 1 to LevelNumber. So goal is to guess which number will be generated. If not perfect, then probably almost perfectly fits you description of Good Game. [Answer] Exploration games would fit your description, I think. Exploration type video games get more and more attention these days. But those type of games don't even have to be video games. A scavenger hunt for example, at least when played in a group, could be a nice fit. [Answer] Golf would be a good model for outdoor physical sports/games (soccer is given as an example, so I think sports are on the table). One person can successfully play and see how well they can do since the difficulty is provided by the course. If you want more/less difficulty you can play a different course or bring more people into it as a cooperative thing. There's a whole variety of ways that multiple players can cooperate, be it everyone playing each hole in parallel all the way to each player hitting each shot and choosing the best afterwards. The last would likely be the best for a purely cooperative civilization, since there's a lot of decision making of whether one player should make a safer shot so the rest can attempt a more difficult one without making things worse. Similarly one player could just hit each shot twice if the challenge is too high. The overall model of attempting some physical feat or feats in succession and the opportunity for multiple people to work together on feats in succession would be workable, I think. [Answer] Example: Space engineers. My friends and I played it almost religiously for a few months. We'd work together in a single base or mothership, pooling all of our efforts and resources. One man might be coring out bits of our home asteroid so we have more room to build, with another in the hangar building a small drone to ferry cargo between station and ship, while I'm leading a team in a desperate search for water-ice to turn into breathable oxygen. If we were building a ship, One guy might lay down the keel, while another installs the reactor and critical systems, and I'm following anothers example of how to laying down hull plate. There's a common goal, yes, but there's also common failure. If my team fails to find ice, we'll all suffocate. If our collaborative ship is too heavily laden or suffers some kind of equipment failure on re-entry, we'll all smash into the ground. The focus isn't on one-upping eachother, but instead in helping eachother so we all get the best possible result. [Answer] Patty Cake... It is a cooperative venture between the players, and often includes new patterns being developed that only work when both players play the same. There are no points, and no real competitive space. Even if one player was faster, they don't win, because then the whole game is thrown off, and they don't get to the end. The players MUST cooperate fully to play successfully. ]

[Question] [ **Closed.** This question is [off-topic](/help/closed-questions). It is not currently accepting answers. --- 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). Closed 4 years ago. [Improve this question](/posts/136167/edit) The city's main weapon and armor supplier has lost his contract arming the city's guard because the quality of the last batch of its products is awful. The swords break at the first clash, the armor doesn't hold together under a couple of blows. How did this happen? The materials are of the highest quality, the blacksmiths have done this work for years and they didn't notice anything wrong during the process of making the weapons and armor, obviously this shouldn't be happening. What did the saboteurs do to the materials, tools or finished products that only after delivery they were found useless? * It'd be ideal if both weapons and armor are sabotaged but it could be just one. * There is magic in this world, but I would prefer a non magical solution if possible. * It shouldn't look like a sabotage at all. * The period is set in Late Middle Ages (1200-1500) [Answer] ## Replicas The blacksmith did his job to perfection - the equipment just never got to the army. The saboteurs act as middlemen in the delivery system. The carriages holding the gear are intercepted midway and swapped with shitty quality replicas that look exactly like the blacksmith's equipment. This could work in at least two ways: 1. The saboteurs have a few inside men. At least one of them should be one of the armour/weapon designers that would let the sabouteurs know, in advance, what the gear will look like. The others should be the members of the delivery crew; 2. As pointed by Mason Wheeler, they don't need an inside man to let them know what they're going to deliver, they just need what they deliver to be predictable and routine enough that the saboteurs can anticipate it. This would also be profitable to the saboteurs, since they could still sell the high quality gear to someone else. [Answer] Heat up the products above the eutectoid temperature to form austenite and then rapidly quench it to induce the formation of [martensite](https://en.wikipedia.org/wiki/Martensite). This will induce the formation of hardened steel which is more brittle. > > Martensite is formed in carbon steels by the rapid cooling (quenching) of the austenite form of iron at such a high rate that carbon atoms do not have time to diffuse out of the crystal structure in large enough quantities to form cementite. [...] Too much martensite leaves steel brittle; too little leaves it soft. > > > A skilled artisan will use this process to make the outer of the product hard, but he would do it to the right point, so that the core is left resilient. The saboteur would just move past this optimum and ruin the final result. A bit like baking a pizza 5 minutes more: from crust to char with the blink of an eye. [Answer] @JBH points out the difficulty. If you provide poor materials the smiths will detect problems because the metal will not act right. Quality control is integral to their line of work. Also, the smiths are not really bribable - it is their livelihood and if they get a reputation for turning out shoddy products that is the end of their work. A bribe would have to be enough to retire on. Sabotaging the materials after they are made is really hard too. They are steel and steel is durable. Damage enough to make them fail on first use will be readily evident, certainly to the smiths but probably to anyone familiar with such items. I can think of only one option. **Changeling.** Fairies take human children and leave in their place supernatural creatures who pretend to be children. The changeling children are sickly or weird or spooky. This has to be the solution for the armor and unfortunately, it probably requires magic. Magical entities (though probably not fairies, given they hate iron) steal the finished high-quality arms and armor and substitute pottery items, with a glamour cast upon them to make them look and sound like the originals. Of course, the changeling armaments fail immediately on use. I like the idea that when someone figures out how to dispel the glamour, the crude pottery items are seen to have scrawled on them dirty words and obscene drawings labeled with the names of various knights. [Answer] Adding too much phosphorus to the iron makes it "cold short", i.e. brittle at low temperatures. > > The effects of cold shortness are magnified by temperature. Thus, a piece of iron that is perfectly serviceable in summer, might become extremely brittle in winter. There is some evidence that during the Middle Ages the very wealthy may have had a high phosphorus sword for summer and a low phosphorus sword for winter (Rostoker & Bronson 1990, p. 22). > > > [Iron ore](https://en.wikipedia.org/wiki/Iron_ore#Phosphorus) [Answer] ## Weaken essential parts instead of the whole thing My source for all of this is that I work at a historical armoury and have actually assembled/disassembled quite a few pieces for restoration. I know which damages are fixed easily and which ones take ages. I also know which ones render a weapon/armor useless and which ones don't. It's pretty easy to discern accidental change from something a person did on purpose - in my case the deliberate changes were made by past restaurators but seeing as their goal is also to not have their work noticed I think the methods would be the same as a saboteurs - only the goal is the complete opposite. I think it wouldn't be easy to sabotage the actual armor plates or blades. Even after centuries they are still basically unchanged and usable. Any sabotage that effectively weakens a plate would probably be visible or at least discernible as sabotage. Likewise a good blacksmith would notice changed raw materials or sabotage during production. Also all armor, weapons and especially guns were tested before being accepted by the army. This means that any major faults like a suit of armor breaking on the first hit would be noticed before they even leave the armourers workshop. Therefor I would suggest to go for the things keeping it all together. After all what use is a suit of armor if you can't fix it to your body? --- ## Leather straps **Sabotage:** Armor, scabbards, guns You could have them treat the leather straps with oil that has gone bad. This will turn the leather acidic which will cause it to go weak and break. Upside: The chemistry of why the leather breaks wasn't yet known in the middle ages so it would probably be blamed on the blacksmith using poor materials. **Downside:** It takes a few years. **Complexity of fixing it:** You need to replace the leather straps - for armor that is complete disassembly and reassembly. Scabbards and guns: quick fix **Source:** This actually happened accidentally after WWII when supplies were short and the armouries batch of petroleum had gone bad. This is the reason why there are so few original leather pieces left. (btw: do NOT use petroleum for leather! Even if it hasn't gone bad it's not a good idea) --- ## Rivets **Sabotage:** Armor, scabbards, polearms, shields Every piece of a suit of armor is connected to another part or a strap by rivets. If you don't know how handmade rivets in armor works: It's basically a nail that is stuck through a tiny hole in the plate and let's say a leather strap and then flattened with a hammer on the other side. Your saboteurs could file off that flattened piece of the rivet. Not completely so it doesn't fall out immediately but if it's *just* slightly bigger than the hole in the leather strap and plate it will eventually slip through with movement which leads to the armor falling apart. **Upside:** it would look exactly like shabby workmanship but wouldn't be spotted by a rough inspection **Complexity of fixing it:** Depending on which rivet breaks you might have to disassemble the armour completely. Scabbards and Polearms: quick fix **Source:** I've seen this happen when we had to replace the leather strap and the new rivet wasn't done properly. --- ## Hilts **Sabotage:** Swords, sabres, daggers... A sword isn't much use without a hilt. Mostly the blade has a smaller metal part protruding from the back. The crossguard is fixed to that piece and then leather/wood/wire is wrapped around it to form the actual handle. If the leather/wire is loosened the handle will come apart leaving you with an acceptable blade you can't wield. If the handle is wood the saboteurs could saw off a tiny bit on one end so that it moves a bit between the crossguard and the pommel. It doesn't actually destroy anything but makes the sword awful to swing. If they saw off just a tiny bit it would look like the blacksmith fitted the handle poorly. **Complexity of fixing it:** reasonably quick fix **Source:** Quite a few handles have loosened by age and some of the wooden handles in the armoury have shrunk giving that loose effect. --- ## Scabbards Soldiers don't run around with drawn weapons all the time so sabotaging the scabbards is also worth a shot. You can do the same thing as I described above with the armor rivets. You could also make slits or holes in the outer layer of leather. It normally prevents moisture from reaching the wooden part inside. If the slit is directly next to a metal band or the tip protector it might look like the blacksmith damaged the leather when assembling it. Not so much for discrediting the blacksmith but still useful: You can also pour blood or salt water into the scabbard which will cause the sword to rust in its scabbard. (This is the reason why they have to be cleaned before being put back into the scabbard) Combined with a slit here and there and if you're lucky people assume the liquid got in through the slits which would be the fault of the blacksmith. **Upside:** looks like the soldiers weren't careful with their weapons. **Downside:** rusting takes a few days to weeks - depending on other circumstances. **Complexity of fixing it:** if the blade is just rusty: reasonably quick fix, if it is rusted stuck in the scabbard: they would probably cut the scabbard off the blade and make a new one so reasonable to long fix (in the museum we have to preserve both) --- ## Pole weapons Most pole weapons are mounted to the wooden staff by metal bands that run down the wood and are nailed to it. These nails can be loosened quite easily. The can also be filed off a bit like rivets. **Complexity of fixing it:** quick fix **Source:** Shrinkage of wood over time has caused lots of our poleweapons to have the nails come loose and they have become wobbly. --- ## Gun powder I don't know if there are firearms in your universe but if there are your saboteurs might want to refrain from doing the obvious and corrupting the lock. That's the first place one would look for sabotage. Seeing as the mechanism of a flintlock is actually pretty simple any damage would be quickly spotted by a blacksmith as soon as they take the lock off the gun. Every gun was inspected and tested after being finished so again I would instead opt for the accessories. After all a gun without powder is useless. It's hard to pin this on the blacksmith though. One way of doing that would be to temper with *some* of the black powder. If the powder is more powerful it might explode the barrel of the gun. This also happened with poorly crafted barrels. If too many barrels explode the blame will be put on whoever made the powder though. **Upside:** if the gun explodes you also take out a soldier at the same time **Complexity of fixing it:** an exploded barrel can't be fixed **Source:** lots of people have tried shooting antique firearms but they used modern powder. Modern powder is more powerful and explodes old guns. --- ## Splints **Sabotage:** guns Gun barrels are fixed to the wood by (most of the time) two splints and one two three screws. All of the screws are in the back next to the lock while the splints are placed along the length of the barrel. Pull out those splints and all the strain is put on the screws. They are relatively small and sometimes go missing on their own. It could either be that the blacksmith forgot them in the first place or made them too thin so they fell out. **Complexity of fixing it:** quick fix **Source:** So many old weapons missing the splints. --- ## Bolts and Screws **Sabotage:** guns, some swords, some armor Screw them in extremely tight so there is more pressure on the screw. This *might* snap off the head or damage the thread if there is some fault in the material already. Damage the slot so it can't be used properly anymore. This usually happens by accident when fixing something but it could also be done on purpose. **Upside:** soldiers don't usually touch the screws so any damage to them would only be noticed by a blacksmith who would then know that the one previously handling the object was an idiot who didn't use a fitting screwdriver - discredit the blacksmith among his peers! **Downside:** mangled screws are only a problem once you want to fix the object because it has another problem **Complexity of fixing it:** very annoying reasonable fix **Source:** If the slot of a screw is mangled we actually have to fit a screwdriver to it so we can get the screw out --- ## Mismatch equipment **Sabotage:** swords, guns, armor Mix swords and scabbards so they don't fit properly anymore. Same with armor parts like the front and back of a suit of armor. With guns it's even easier because soldiers had to make their own bullets. All of that equipment is handmade and fitted to the barrel - switch it up with another and they don't fit properly anymore. Also if you take two guns and switch out their locks it might even render the gun completely useless. There is a small hole in the barrel right were the pan on the lock is. When firing this is were the spark from the powder on the pan goes through to ignite the powder in the barrel. Because no two guns are exactly the same the small hole might be off or even covered by the pan if the wrong lock is fixed to the barrel. If confronted about it the blacksmith himself will probably realise what happened but it's something you can't really prove. There are no serial numbers to show which parts belong together and to a layman they all look the same. --- ## Conclusion Some of these will be harder to pull off than others and some have the added benefit of annoying the army blacksmith who has to fix it. All of these equipment failures would probably happen anyway so with your sabotage you are just going to increase the frequency. Of course if suddenly everything goes wrong all at once people will get suspicious especially if the blacksmith has always delivered quality work before. None of these are particularly big but all of them show a lack of attention or skill if they happen to fairly new weapons. So even though the blades and plates this blacksmith makes are actually pretty good he will earn a reputation of not taking care of details and slacking with the unglamorous parts. [Answer] Use a STASIS spell to alter the supply chain, and later remove the spell to destroy the weapons. Replace the Carbon used in the smelting and forging with Carbon-11, which has a half-life of about 20 minutes, but apply a stasis spell to the carbon to keep it from decaying. This could be done by a magic-user placed at the gates, watching for the ox carts filled with coal or charcoal. The incorruptible smiths smelt the iron and forge the swords with the Carbon-11. It works in the forge the same way. The strength is tested, and the swords are pronounced excellent. They get the martensite profile just right. The swords are deployed to the troops. They work perfectly during training. Against other foes, they work as expected -- they are sharp and subtle, yielding to glancing blows, yet slicing through armor and bone. But -- when the critical battle starts, remove the stasis spell. The swords and armor will quickly become weakened as the carbon turns to boron and the crystal structure breaks down. There may also be a benefit from the positron radiation emitted by the iron after the stasis is released. [Answer] Given the answer of Willk, it appears to be unlikely to manipulate the process without the smith noticing it. If you don't want to use magic directly, use something similar instead: **Alchemy**. Some mixture has been used for the iron which takes over time with incrementing effect over days or weeks. The initiator could be the heat applied in the forge or the water to cool it off - which means the mixture could be applied even earlier. It would render the metal brittle until it unexpectedly breaks, but given the progress rate it would occur quite rapidly. The blacksmith could not notice anything because the effect is near non-existent in the first days or weeks. The process wouldn't require some form of "intelligence" which magic would usually contain *(do effect x when y is triggered, but not z)*. It would rather be a fictional chemical process. Maybe something in the real world exists which does something similar or works similarly. [Answer] The blacksmiths use a very sophisticated technique to produce their legendary swords that requires repeated forging and cooling. This produces a very special flexible and durable but also very sharp steel.... Unbeknownst to them, the process requires certain trace elements to be present in the ore, and they get this (or more likely wootz steel made from this) special ore shipped from a neighboring country. The adversary manages to capture some of these shipments and replace it with wootz steel from a different mine. To the blacksmiths everything looks just the same, but the swords are too brittle now. No one understands what has happened. Note that this has a precedent in human history: There is a hypothesis that Damascus steel got its very special properties from the presence of trace metals in the ore combined with a special manufacturing process. At some point in history the blacksmiths lost the ability to reproduce that steel and this might be because the respective mines in India were exhausted. [Wikipedia: Damascus steel](https://en.wikipedia.org/wiki/Damascus_steel#Additional_research) [Reibold et al., Carbon Nanotubes in ancient Damascus sabre (2006), Nature 444, 286](https://www.nature.com/articles/444286a) [Answer] I'm assuming from your username and the setting details that you're running some sort of D&D or D&D-adjacent system. There's always one answer to that guy who got full plate before he should: [the rust monster](https://roll20.net/compendium/dnd5e/Rust%20Monster). Rust monsters have strong corrosive materials in their antennae, and they're flimsy enough that an enterprising hostile kingdom or well funded crime syndicate could capture, breed, and harvest them. Your saboteurs will need fairly lengthy access to the caravan to pull this off, but if the arms are coated in some kind of clear coat (varnish, lacquer, whatever - armor should come treated from the forge, but the weapons themselves may or may not be and would be the responsibility of the saboteur - shouldn't raise any alarms to find them coated) and stored with powdered rust monster antennae (in the sheath, on resin paper wrapping the armor, whatever), the arms themselves will: 1. Leave the blacksmith in good condition 2. Survive transit reasonably well, depending on the care taken by the saboteurs 3. Perform well in their initial inspection, if treated gently enough 4. Fail faster in the field if they were used in practice, but should fail eventually if used hard enough in battle regardless. 5. Show signs that look like water damage that could be blamed on an incompetent carman (wagon driver), marshal (officer in charge of transport), or lighterman (ship-to-shore ferryman) [Answer] ## Quench bath contamination leading to Stress Corrosion Cracking down the line As other answers here indicate -- these smiths' reputations and livelihoods are on the line here, so their processes would be in good nick and unlikely to change suddenly, and they would likely notice issues with raw material changes, say to the ore, charcoal, or fluxes used. Furthermore, even if they didn't, proofing of the blades (acceptance testing) by the quartermaster would weed out blades that were, say, extremely cold short due to phosphorous contamination. This means we need to get *diabolical* here, and look at the things a smith or quartermaster *cannot* see, or catch immediately with tests. In particular, preindustrial forging relied exclusively on static, water-cooled quenching and tempering processes, and these will leave traces of salts present in the quench bath on the blade as it is removed from the bath (simply from water boiling off upon contact with hot iron). Normally, this isn't an issue, as the contents of most water sources aren't going leave behind anything that will cause serious trouble down the line. However, if the quench bath was "spiked" with something that was a potent promoter of Stress Corrosion Cracking (SCC) in carbon steels (carbonates *may* work, depending on their activity at or near body temperature) under mild conditions, this could effectively, yet insidiously, sabotage their efforts to produce quality blades. As such a contaminated blade was handled and used, moisture from the environment that gets past whatever oiling is used to protect the blade from rusting would combine with the boiled-out SCC promoters in crevices in the weapon, such as at the blade-to-handle interface. Furthermore, such points would also be *stress risers* in the blade, and combined with residual stresses from forging and heat-treatment as well as the rigors of usage, this could lead to stresses at the risers exceeding the SCC critical stresses for the material. Finally, a well-kept sword is going to be in an environment that is only *mildly* corrosive (due to normal maintenance activity vs. being exposed to rain, blood, etc). The end upshot would be swords that look fine, proof fine when received by the quartermaster, yet snap in half like twigs months or years later. A modern failure analysis would reveal that the broken sword was spiderwebbed with invisible yet lethal cracks in key spots, despite looking the part of a well-kept sword by any account chosen. [Answer] The saboteurs entered the blacksmiths guild. With some help they ascended in ranks, becoming the guild masters. They transformed the guild in a company with employed blacksmiths. They added a huge bureaucratic top-layer: Accounting, human resources, quality control, sales, marketing, R&D, supply chain management, legal and controlling. The blacksmiths got gradually replaced with inexperienced workers. The work got compartmentalized. As a result workers are unable to understand the entire organization. Then they started with quality degradation: Controlling argued that the contracted quality could still be meet while introducing inferior raw materials (iron ore rich in phosphor and sulfur). R&D had is scope changed to focus on lowering costs. Supply chain management squeezed every penny from the suppliers, resulting in raw material degradation. Legal sued the local news herald when they mocked the inferior quality. When the city council became concerned about the degrading quality sabotage got further. The saboteurs argued that city help is needed as competing cities are advancing in iron processing. They asked for import tariffs and city subventions and got them. They introduced a city-financed institute for advancement in iron processing. The council pressed the city council to force independent manufacturers into the iron conglomerate. The blacksmith school got incorporated into the iron institute and replaced by cheap least minimum training. The institute declared that the brittle iron weapons/armor parts are state of the art, opposing opinions got suppressed by libel charges and by media campaigns, accusing them to be non-patriotic. In the end the entire iron processing ability of the city got corrupted. Since nobody realizes the dimension of the degradation it is unlikely that the cities iron processing ability will ever raise to past quality. [Answer] One option could be a poor quality ore the blacksmith was working with. If the ore had an excess of one metal or another to give it unfavorable qualities, then it may be possible the final product would fail. If it had excessive amounts of lead, tin or copper, the weapon would be too soft and deform easily. If it contained excessive amounts of nickel, cobalt or tungsten, the armor would be too strong, thus brittle and may crack upon receiving a blow. Now, any good blacksmith would recognize that the metal is not tuning out as expected, however, if he had several apprentices, they may not recognize the poor materials and force the piece into the desired form despite the material not wanting to play [Answer] Not the most effective way but an interesting mythological occurrence of this by Loki can be read in places like here <https://norse-mythology.org/tales/loki-and-the-dwarves/> The short version of this is Loki turned into a fly and distracted the dwarf who was working the bellows in an attempt to sabotage their attempts at crafting. Transforming into a fly might not be a reasonable method but unleashing a plague of rats/vermin/sickness on the workers at the smithy could slow down their production, cause them to cut corners and release shoddy work. [Answer] The iron used to build everything (weapons and armors) could've been saboted by adding more carbon inside, before being sold to the blacksmith. If more than 2,11% of carbon is added to iron, it becomes steel and isn't as flexible as the iron. Then, it will break. But if you have magic in your world, why not think about another material than carbon added to iron, which degrade it slowly (for the blacksmith not notice it) and make weapons and armor bad quality faster (degradation appears after the first fight you said). [Answer] Some techniques for differential hardening of blades (wherein the edge is very hard, while the core of the blade is more flexible to provide strength) involve the application of clay along the center of the blade before the final hardening. If your saboteurs tampered with this clay and changed its characteristics, it could lead to a blade that looked right, but was actually very fragile. There are quality control protocols that would catch the issue (most bladesmiths do a fairly rigorous bend test to determine the flexibility and strength of their blades), but if your smith is working past his capacity, those might fall by the wayside. [Answer] Contaminate the ore they are using randomly over time in small batches (so that they can not refine their process) with chemicals which make the steel more brittle or hard, or chemically unstable: * Phosphorus * Sulfur * Silicon <https://www.steeltank.com/Portals/0/Articles/Effect%20of%20Chemical%20Elements%20in%20Steel.pdf?ver=2009-05-31-010753-797> ]

[Question] [ I'm writing a world where iron is incredibly rare and the technology to make more complex metals like steel was never developed. However, both lead and niter are incredibly common, so firearms were developed very early on and heavily influence the culture. The current technological level is a cross between medieval and the american west. Basically, I want a world where melee weapons are either incredibly inefficient, or incredibly rare (only kings and warlords would have the resources for even a single sword or shield, maybe a handful if they are remarkably wealthy). The problem I'm running into though, is that I don't know what people make the guns out of. I need a metal that is good enough to make firearms as complex as revolvers, but not good enough for blades or armor. I thought about pewter for a while, but I couldn't find enough information about its properties to know if it would work or not. Anyone have another idea? This is the best answer I have gotten so far, if anyone has anything to add to this, I would appreciate it.<https://worldbuilding.stackexchange.com/a/79830/37754> [Answer] How many swords are used in wars today? Why not? Because guns are cheap, effective, and plentiful. If you give them a process to make guns as cheaply as they could make a sword only a ludite would bother owning a sword. (or a Swiss [voter](https://en.wikipedia.org/wiki/Landsgemeinde)) If like [Kirk](http://www.imdb.com/title/tt0708418/) the common people can build an effective weapon in an hour why bother digging iron and coal? You might need a better kind of bamboo to give it a reasonable chance of only killing people downrange. If long ago a ban on arms for the people only meant melee weapons (making the newer technology something of a loophole) guns might quickly be too wide spread to correct the issue. [Answer] Any metal strong enough to make a robust gun is going to be strong enough for melee weapons. Getting rid of iron is going to be a lot of handwaving because most of our planet is made of it. However you could do away with metals and make your guns out of ceramics, first as grenade type weapons and then evolving into guns, cannon etc. We have pretty impressive ceramic technology now, but since you just handwaved away metals your societies would have concentrated on ceramics, you can handwave them to whatever degree of tech you need. You'll have to get rid of trees as well, because melee weapons evolved out of wooden weapons, and until the last few hundred years whole armies were equipped with wood and stone weapons. Very very very lethal ones. Bone and stone were also widely used. Wooden Polynesian weapons were designed to end a fight with one blow, stone weapons like the Maori patu were lethal, even whalebone taiaha (cross between a club and a spear) were used. [Answer] The only material I can think of that could reasonably be manufactured into a firearm better than a sword is some form of high-strength plastic. With proper engineering, plastic firearms are entirely possible - we've all heard about 3D-printed weapons. Granted, those are usually single-shot weapons, but they could be selectively reinforced with a much rarer material like steel or brass. By this logic, only the very wealthy would be willing to waste enough metal to have a sword made. How you managed to develop the manufacture of plastics without a material plentiful and strong enough to also be made into edged melee weapons is probably another post's worth of discussion, but necessity is the mother of invention. [Answer] *NOTE: [I've posted another answer with another take: flintlocks are sufficient to render swords and armor obsolete](https://worldbuilding.stackexchange.com/a/79960/760)*. This won't work with a conventional gun, the pressures are too high, but you might be able to make it work with some unconventional ones. > > *I need a metal that is good enough to make firearms as complex as revolvers, but not good enough for blades or armor.* > > > Firearms, blades, and armor all have similar problems: they need to be very tough, a little bit flexible, and able to retain their shape after repeated blows. Steel is the obvious candidate. [Firearms in particular need to withstand the very high pressures of the gunpowder exploding](http://www.rifleshootermag.com/rifles/ar-15/guide-to-gun-metal/). Modern bullets produce [an over-pressure of 15,000 to 65,000 psi](http://www.lasc.us/SAAMIMaxPressure.htm). To put that in perspective a 34,000 psi over-pressure will collapse a building. The barrel also must withstand high pressure, and if you want rifling that doesn't immediately wear out it has to be made of very tough stuff. # A Problem Of Pressure The problem is finding something light enough that can withstand the pressure, but not suitable for making blades. Let's go through the materials... ## Steel, Iron, Brass, Bronze All have been used to make guns, cannons, and swords, so they're right out. ## Ceramics Ceramics can be used to make blades, so that's right out, but let's address this one because it's come up so many times in other answers. AFAIK ceramic guns don't exist, they can't handle the pressures alone. [Ceramics have very good compressive strength, but poor tensile and yield strength](http://www.engineeringtoolbox.com/ceramics-properties-d_1227.html); gun chambers and barrels require tensile and yield strength. Ceramics need some sort of reinforcement for the pressure, thus ["ceramic barrels" are metal barrels with a ceramic liner](http://ciar.org/ttk/mbt/papers/isb2007/paper.x.isb2007.IB06.5_point_56mm_ceramic_gun_barrel_thermal_analyses_with_cycled_ammunition.huang_conroy_carter.2007.pdf). Ceramics are also inflexible and have a tendency to crack and fracture, even if you can get a few shots out of a ceramic gun it will rapidly degrade under repeated use. Various reports have been made about a plastic or ceramic gun that is undetectable on an X-Ray. These never existed, though there were several investment scams claiming they could make one. What did exist are handguns that use a lot of plastics and ceramics, but the chamber and barrel are still metal. *Disassembled*, they're were difficult to spot on an X-Ray. Modern scanners have higher fidelity. This the best our modern, high tech society can do with modern, high-tech ceramics. Medieval/old-west material science would not come close. You cannot make a gun out of pottery or a sea shell. ## Plastics & Polymers Plastic handguns *do* exist, but they're [tiny, smoothbores](https://www.washingtonpost.com/opinions/these-plastic-guns-arent-toys/2015/06/14/2ebd52ac-1145-11e5-adec-e82f8395c032_story.html?utm_term=.91a60b5451bd) of dubious value and quality. These are, at best, for extremely close range self defense. They're the sort of things you press to someone's chest, pull the trigger, and pray it doesn't blow up in your hand. These are not weapons of war. While there are now 3D printed plastic rifle lower receivers, a critical and complex part of a self-loading rifle, even they [still use metal for their chamber and barrel](http://www.cnn.com/2013/11/08/tech/innovation/3d-printed-metal-gun/index.html). And, again, this the best our modern, high tech society can do with modern, high-tech plastic and high-tech, computer controlled 3D printers. Medieval/old-west material science would not come close. [Anything resembling modern plastic would not even be invented until the late 1800s](https://en.wikipedia.org/wiki/Timeline_of_plastic_development). ## Wood Mythbusters showed [you can make a cannon from a very big log](https://www.youtube.com/watch?v=AJgYtt99V5s&t=3s), though they did use iron reinforcing bands. It worked, but its not terribly practical, and cannot be scaled down to a handgun. Wood doesn't make a very good blade, but it does make a good handle for sticking blades onto, like [obsidian flints to make a macuahuitl](https://en.wikipedia.org/wiki/Macuahuitl). ## Stone While some stone will keep a *very* sharp edge, it does not have the flexibility to withstand high pressures. With enough stone, and low enough pressure, you could make a large stone cannon, but not a handheld weapon. --- Obviously the problem is one of pressure. What if we could have a gun that didn't need to withstand extreme pressures? We can! There's two options, the Recoilless Rifle and little rockets. # The Recoilless Rifle! Your basic gun is a tube sealed at one end. The gunpowder explodes building up high pressure behind the projectile. Since one end is sealed, it forces the projectile out the other end. Because its sealed it can develop very high pressures and very high velocities. It also protects the shooter from backblast. But you don't need to seal the other end. When that happens, half the energy goes out either end of the barrel. You lose a lot of oomph, and there's a backblast to deal with, but the pressure is much, much lower. This is the principle behind the [recoilless rifle](https://en.wikipedia.org/wiki/Recoilless_rifle). On the upside, the barrels and chambers can be made of much lighter and inferior material. On the downside, there's that backblast. There are various ways to reduce the backblast, but it will always be a problem. In your world, your guns might have to be fired from the shoulder, or tucked under the arm like a Panzerfaust. [](https://i.stack.imgur.com/ZYa1S.jpg) The other downside is the low pressure means low velocity. If it's a kinetic weapon, like a bullet, it needs a very large mass to compensate for the low velocity. Since kinetic energy increases with the square of velocity, but linearly with mass, the reduced velocity cannot be fully compensated for. Instead, you want a projectile that damages by some other means: high explosive, shrapnel, or shaped charge are usual... though putting that in an anti-personnel round is pretty grim. The low velocity also means the bullet will arc, making aiming difficult, especially at a distant moving target. Good rangefinding is essential, which is difficult given the medieval/old west level of technology. Rifling will still be a problem, any material which can retain its rifling over more than a few shots will be able to retain an edge. So likely you'd make a smoothbore recoilless gun. Accuracy will suffer. This can be dealt with by using fin stabilized ammo (basically, a tiny arrow), but it's remarkably finicky, even with modern technology. Medieval/old west tech would not be able to produce fin stabilized ammo. So you're left with, basically, a kind of recoilless shotgun. Short range, not terribly accurate, with a fearsome backblast. # The Rocket Round! Perhaps a better option is the rocket round, exemplified by the [Gyrojet](https://en.wikipedia.org/wiki/Gyrojet). This is very much like a normal gun, but instead of all its gunpowder exploding in one great high pressure bang, its a tiny rocket that smoothly burns its propellant even after leaving the barrel. The barrel contains vents to further reduce the pressure. [](https://i.stack.imgur.com/oaM8o.jpg) [*Source*](https://en.wikipedia.org/wiki/Gyrojet#/media/File:Gyrojet_at_National_Firearms_Museum_(460776909).jpg) The projectile leaves the barrel still accelerating. As a result, the chamber and pressure are very low while the projectile velocity is... eventually... good. When it leaves the barrel it's going just 10 fs/s, but after about 20-30 feet it's going at a good 1000-1200 ft/s. That's about the kinetic energy of a [.45 ACP](https://en.wikipedia.org/wiki/.45_ACP). The barrel is smooth. The rocket is spin-stabilized, the rocket vents are at an angle to produce spin. The advantages over a recoilless gun is it works very much like a normal gun: fired like a gun, no backblast, good velocity. And a medieval/old-west tech could produce the gun, in a more primitive form. The problem is the rounds, especially that careful venting, are probably beyond your tech. Black powder would also easily foul those tiny vents, so you'd need smokeless powder early. It's also not very accurate. Here's [Ian McCollum of Forgotten Weapons](https://en.wikipedia.org/wiki/Forgotten_Weapons) and [his comments on the Gyrojet Pistol](https://www.youtube.com/watch?v=98c2t_uK5Uo). > > MB Associates claimed that they would get a 30" group at 100 yards. Elsewhere it's more like 7 feet at 100 yards. During some testing that Small Arms Review did a number of years ago [prior to 2014] they found that they could get about 50% of their shots to stay on paper on a 9-foot target at 100 yards. > > > Maybe, with no other options for firearms available, the Gyrojet concept would be further developed and its flaws fixed. Here's Forgotten Weapons on the [Gyrojet Rocket Pistol](https://www.youtube.com/watch?v=98c2t_uK5Uo) and the [Gyrojet Carbine](https://www.youtube.com/watch?v=W3IiWjdbUZg). [Answer] ## Use naturally occurring gun chambers Your planet is sparse with metals suitable for forging swords, and, as other answers have pointed out, wood and bone may also need to be made rare, but it would be OK for guns to occur in nature, so long as engineers are unable to work the material. Other answers say to use ceramics. Your planet could be home to a crustacean with a ceramic shell that's conveniently shaped like a gun chamber. Your people are unaware that they can *craft* ceramics, so they can't make other ceramic weapons. As indicated in the comments below, an animal that needs to evolve a shell capable of withstanding explosions probably lives in a high pressure environment such as at the bottom of the Mariana Trench. This leaves the problem of retrieving it using Medieval technology. Perhaps the animal floats to the surface when it dies. If it's possible for a creature to have metallic organs, then you could have naturally occurring metal guns without ever discovering metallurgy. (I have no idea how feasible this is. Maybe they build up mineral deposits on the outside of their livers rather than excreting them?) Numerous problems have been pointed out with the above approach, so this answer probably isn't good for a hard-science setting. [Answer] I'm convinced there is a good, physical solution to your problem: # If your people are giants, it solves most (all?) identified issues. 1) For giants of sufficient size, truly effective melee weapons would be extremely hard to come by. Larger bodies encounter physical limits on blood pressure/vasculature that make it impossible to accelerate a heavy, bulky melee weapon quickly. So contrary to much existing giant lore, real giants could not kill each other in skilled combat simply by swinging trees around or by incorporating giant boulders into hand-to-hand techniques -- this is simply incompatible with anatomy and physics. 2) Therefore, for real melee dominance, a sword would be required -- yet not just any sword. A razor-sharp and long yet incredibly strong blade would not even be sufficient. You'd also need lightweight, space-age materials to ensure that the blade could be accelerated by large giants up to hand-to-hand combat speeds, using the same kinetic chain motions (hip -> shoulder -> elbow -> wrist) common to golf and tennis swings. Only then, with 20th-21st century technology, would a truly effective close quarters weapon dominate over the putatively traditional wrestling-style combat techniques. Well, but for one major exception... 3) Enter guns: As soon as primitive metallurgy is developed, the resulting heavy materials are no better than fists for the slow, lumbering grip/takedown based wrestling presumably dominating pitched combat encounters between members of the giant species. A massive hunk of metal is even worse for this purpose than the near-useless tree or boulder; small metal spears/atlatls simply can't be accelerated quickly enough to develop primitive ranged weapons, only brass knuckles gain any popularity. But with only a little further technological development, **guns** quickly become the common soldier's weapon. Finally, the physical constraints on the giant's body are sidestepped via the chemistry of explosives. Giants can carry handcannons to devastating effect. 4) Yet the space-age technology that eventually makes truly effective giant swords a reality has a clear upper hand over the older, widespread giant-sized guns. To propel a projectile large enough to kill a giant, and with the gun's chamber being subject to quadratic forces, the chamber must be reinforced to a proportionally much greater degree than the small guns we know. This means they are extremely heavy, even for giants. They can't be aimed quickly, so there is no giant equivalent of the carbine or assault rifle. A futuristic, strong/lightweight/long blade in the hand of a well-trained king/queen would allow them to waltz into a room full of armed guards and summarily dispense cold justice before the guards had properly trained their sights (remember, in close quarters guns need not only to pivot/rotate, but also to translate so that the chamber can properly align with a moving point-blank target -- easier said than done when your gun is a 3000 lb chunk of metal). 5) Worth noting: It's possible that in a world with much higher gravity than Earth, normal human sized people would face these same physical constraints that giants would on Earth. Though it's difficult to deeply extrapolate how an extreme gravity condition might have impacted the evolution of life. But such a factor is much more easily handwaved away than lots of the showstopping issues so elaborately discussed in other answers. [Answer] > > *The current technological level is a cross between medieval and the american west. Basically, I want a world where melee weapons are either incredibly inefficient, or incredibly rare (only kings and warlords would have the resources for even a single sword or shield, maybe a handful if they are remarkably wealthy).* > > > I'm going to focus on the goal of medieval gunslingers, rather than the suggested solution of making good metal scarce. I already have an answer about [making low pressure guns from inferior materials](https://worldbuilding.stackexchange.com/a/79851/760), but [@not store bought dirt](https://worldbuilding.stackexchange.com/a/79812/760)'s answer about making swords and armor obsolete with better guns earlier is very compelling. I'm going to expand on it. How much history and technology has to change to have medieval gunslingers? Not much. # Flintlock Muskets Made Swords, Pikes, and Armor Obsolete Certainly by the time of the [Seven Year's War](https://en.wikipedia.org/wiki/Seven_Years%27_War), 1754 - 1763, possibly earlier, armor and melee weapons were obsolete. The gun was supreme, at least in Europe. The melee weapon's last hurrah was the [bayonet](https://en.wikipedia.org/wiki/Bayonet) to repel charges, turning your musket into a makeshift pike. The guns of this era were black powder, muzzle-loading, flintlocks, sometimes rifled, sometimes not. They were sufficient to render swords, pikes, arrows, and armor obsolete. The British [Brown Bess](https://en.wikipedia.org/wiki/Brown_Bess) is a fine example. [](https://i.stack.imgur.com/oV2TZ.png) [Black powder](https://en.wikipedia.org/wiki/Black_powder), as opposed to modern [smokeless powder](https://en.wikipedia.org/wiki/Smokeless_powder), burned slower, developed less pressure, and left a lot of residue fouling the barrel and needing a lot of cleaning. Still, it worked, and it would be the powder of choice until the late 1800s. The low pressure required long barrels to build up velocity. Muzzle-loading meant a laborious process of dropping powder and ball down the barrel and packing it in. For single shot rifles, this was a 15-20 second process. Revolvers and multi-barrelled weapons dealt with this problem by providing multiple pre-loaded chambers. A [flintlock](https://en.wikipedia.org/wiki/Flintlock) is the mechanism by which the powder is ignited. A piece of flint strikes a piece of steel creating sparks that fly into a pan of powder which ignites the full charge. This was a great advance over the previous unreliable [matchlock](https://en.wikipedia.org/wiki/Matchlock), a slow burning rope and not so good in the damp, and cheaper than the more reliable but expensive [wheellock](https://en.wikipedia.org/wiki/Wheellock). The flintlock meant your gun would be ready to fire in any weather condition, at a moment's notice, and at a reasonable price. # Medieval Flintlock Muskets and Revolvers True flintlocks appeared in Europe in the early 1600s, but as far as I can tell, there's nothing technologically insurmountable about a medieval flintlock. Simple springs were available, and the idea of flint striking steel to make a spark was ubiquitous. Perhaps an improvement in metallurgy and spring steel. Black powder was known in China since the 10th century, and news reached Europe by the 13th century. The secret of black powder could have arrived in Europe earlier, or it could have been invented by some European alchemist. Having black powder in an alternate medieval setting is not a problem. Smooth bore barrels and chambers for black powder were far easier to make than rifled barrels and chambers withstanding the high pressures of smokeless powder. Your medieval gunslingers might be carrying something like these [Collier Flintlock Revolvers](https://en.wikipedia.org/wiki/Elisha_Collier#/media/File:Elisha-collier-flintlock-revolver.jpg). Each chamber of the revolver would be loaded just like a little muzzle loader, and it would be fired just like a flintlock. [](https://i.stack.imgur.com/ArG4u.jpg) There's no need to exclude metal, flintlock muskets and revolvers are enough to explain why your medieval knights don't wear armor and carry swords. And they can be made available to a medieval society without much change. You can go further down this road, but it pushes into places with broader effects on technology and society. --- # Next Step: Percussion Caps The next step in the firearms progression is the [percussion cap](https://en.wikipedia.org/wiki/Percussion_cap). This replaces the flintlock with a little button of contact explosive, like [fulminate of mercury](https://en.wikipedia.org/wiki/Mercury(II)_fulminate). You pull the trigger, a spring loaded hammer smacks into the cap, it goes bang and ignites the powder. Far, far, far more reliable than a flintlock. We use the same basic idea today, except it's built into the cartridge and called a "primer". The problem is, fulminate of mercury wasn't invented until 1800. It requires a model of chemistry and a chemical industry to produce pure chemicals that would radically alter a medieval setting. I'd be wary of going down this road. Instead use the unreliability of flintlocks as a plot device. Percussion caps might be an expensive secret known only to a few alchemists who stumbled upon it, but have difficulty reproducing it because of the impure chemicals they're using and lack of understanding of chemistry. # Next Step: Breech Loaders [Breech-loading guns](https://en.wikipedia.org/wiki/Breech-loading_weapon), like all modern guns, greatly speed loading by loading from the chamber instead of from the end of the barrel. It allowed the next big innovation, cartridges. While they were around since the 14th century, breech-loaders didn't really catch on until the 19th. The problem is sealing the breech reliably against very high pressures. Until the invention of the metallic cartridge (see below) this required careful machining and excellent metallurgy. In your setting, breech-loaders could be expensive, exotic items. # Next Step: Paper Cartridges Once you have a breech loader, you can wrap your powder and ball in paper, seal it with wax, and have an all-in-one package to stuff into the chamber: a [paper cartridge](https://en.wikipedia.org/wiki/Paper_cartridge). [](https://i.stack.imgur.com/ii2KU.jpg) [*Source*](https://en.wikipedia.org/wiki/Paper_cartridge#/media/File:Combustible_Colt_cartridges.JPG) These effectively work like modern bullets, but they don't seal the breech like a metallic cartridge does. There's no special technology required, once you have breech loaders you can have paper cartridges. They were used in at least the late 1500s, probably earlier. # Next Step: Metallic Cartridges Once you have paper cartridges and percussion caps, the next step is metallic cartridges with a built in cap (the primer) resembling modern bullets. [](https://i.stack.imgur.com/7dr4g.jpg) [*.50-90 Sharps, a black powder metallic cartridge*](https://en.wikipedia.org/wiki/.50-90_Sharps#/media/File:Sharps_50-90.jpg) They're more reliable and resilient than a paper cartridge, but much more important, *they solved the problem of sealing the breech*. Bullet cases are made out of brass because brass expands slightly under the pressure of the gunpowder. This expansion seals the breech without requiring extremely fine machining. It allows higher pressure loads, and larger, higher velocity projectiles with better range, accuracy, and stopping power. The metallic cartridge also allows [magazines](https://en.wikipedia.org/wiki/Magazine_(firearms)); now you can have multiple rounds, stacked and ready, and fed into the gun by a spring like a modern firearm. Up to you whether you want to introduce metallic cartridges. It requires percussion caps, with their aforementioned chemical consequences, and breech loaders. # Next Step: Smokeless Powder As mentioned, black powder burned relatively slowly requiring a long barrel for the projectile to take full advantage It produced a lot of smoke, making it difficult to see what you're shooting at after a few shots. And it left a lot of residue, fouling the gun requiring frequent cleaning, affecting accuracy, and causing malfunctions. [Smokeless powder](https://en.wikipedia.org/wiki/Smokeless_powder) fixed all that. It burns extremely fast developing high pressure, and thus high velocity, very quickly. It leaves little smoke or residue, allowing for continuous, accurate fire. Smokeless powder wasn't invented until the mid-1800s. Like percussion caps, it required an existing chemical industry that would radically transform a medieval society. I'd leave this one out. --- # HOWEVER! Firearms Radically Changed and Expanded Warfare Good firearms made war cheaper and more lethal, especially the development of drill and [volley fire](https://en.wikipedia.org/wiki/Volley_fire). Instead of the strength of a soldier coming from their own muscle and years of careful training, it comes from the barrel of a gun. Now some peasant with a musket can take down your best trained swordsman. Its cheaper and more effective to give some peasants muskets, drill them for a little while, and call them an army than it is to spend years training swordsmen. Pikes and crossbows has a similar effect of making warfare cheaper. With a little training, pikes turn a mob of poorly trained troops into a pointy wall. Crossbows give you instant archers without the years of careful training to pull a bowstring. But they're not necessarily more lethal. Melee warfare was usually less about killing the other guy and more about breaking their morale and formation. Once they broke and ran, then the killing started. Prolonged fights in close combat were more like a tug-of-war, the [push of pike](https://en.wikipedia.org/wiki/Push_of_pike), than a Hollywood melee. Muskets and cannon suddenly ramp up the sustained lethality of warfare. Muskets and cannon meant you could deliver a killing blow from beyond arms reach of the enemy. Everyone, not matter their skill, was now vulnerable. And gunpowder meant you could sustain this fire for as long as the powder and shot held out, no longer would warfare be limited by the physical exhaustion of the troops. Cannons could destroy city walls and mow down lines of infantry throwing city defenses into turmoil. Once you introduce ubiquitous firearms into your medieval setting, you'll have to deal with this problem. You could take a page from Japanese history: [show initial great enthusiasm for the gun](https://en.wikipedia.org/wiki/Firearms_of_Japan#Sengoku_Period) with a period of great expansion and great warfare, then [retreat from the gun and large-scale warfare](https://en.wikipedia.org/wiki/Firearms_of_Japan#Edo_Period) with a more isolationist mindset. Perhaps a series of peasant revolts used cheap firearms to attack the heavily armored but less numerous nobility. Your society and culture, after experiencing a few generations of the ravages of warfare with large armies equipped with firearms, decides to fall back on a more chivalrous, ritualized, small-scale approach to warfare. This still involves firearms, but warfare is a game of the nobility. Gentleman's agreements, like medieval arms treaties, limit the size of standing armies and number of guns to prevent all-out-war or a peasant revolt. [Answer] Steel has been the go to metal for guns since their invention. Copper alloys like brass and bronze have also been used for larger guns and cannons. All these metals can also produce an effective sword. The metallurgical requirements for sustaining the pressure of a firearm are much higher than those required to make a sword. [Answer] To understand how to make guns available but not swords, first you have to figure out why we got them in the first place. Poky sticks are a force multiplier. They allowed our relatively hairless ancestors the ability to defend and defeat other mammals with sharper teeth, claws, and thicker fur. How? By providing a longer reach, and the ability to narrowly focus our force. But you needed sticks that were strong, and could break to form a point. Then someone got a stone stuck in their stick and noticed that it was easier to kill with. So they invented duct tape so they could better fasten the stones to the sticks. Eventually sticks couldn't reach long enough so in desperation and possibly disgust, someone threw their pointy stick at their prey, and as luck would have it, they had dinner that night. So they kept improving how to to throw their pointy sticks. This trend continued, with others finding better and faster ways to throw sticks. Eventually we discovered explosions, and thought, "Hey, what if I use explosions to throw sticks??" His assistant didn't survive the first test, and so he thought, "Wait, what if I put the explosion inside something?" The next assistant was a bit luckier. And thus we have firearms. What you need to do is go back to the beginning and take away the stick as an effective force multiplier. How do you do that? Well, I can think of two easy options: # Nerf Nerf the sticks. Either make them too brittle to stand the force, or too weak. There's a reason that we don't go around slapping people with grass and leafs. If you make stuff more brittle, or in some other way less desirable, then your ancestors are going to have to use something else to survive. # Poison If you make extremely toxic elements readily available, that means I'm going to have to spend less effort defending myself/hunting, which means that I'm going to be able to spend more time eating, relaxing, and inventing guns. If you build reed-like plants and poison blowdarts into your environment in such a way that they are readily apparent and easily acquired, they're going to be the force multiplier of choice. They'll come up with phrases like, "Don't bring a pointed stick to a poison dart fight." And then eventually people will figure out how to store compressed air and make airguns with flechettes that are tipped with poison and have an effective range of hundreds of yards, and bypass pointy sticks altogether. Provide high-quality/strength ceramics in the environment as well (or at least inspiration for them) and you'll come up with some awesome guns. For bonus points you could make it so that using metal as the storage mechanism offers such an offset that any kind of metal should be hoarded for use as air cylinders. # Bonus - scarce metals Oh, and I just thought of this - make some kind of bacteria that consumes certain metals in nature to help make them more rare and subject to corrosion if not carefully maintained. [Answer] Forgive me for not being as verbose as some of these other ladies and gents. But, I think the main consideration is around the human anatomy that led to the sword. The sword extended the reach and deadliness of what? the arm? But, really swung by the shoulder. So, perhaps these beings have no rotating shoulders, much like a T-Rex. So, if they had tiny little hands, then they would have developed projectiles sooner. Hope that helps. It's my first post I ever read on this cool forum I just found. [Answer] Edged weapons are subject to religious prohibition. Sharp edges are holy and only to be used in ritual and food preparation. (This may have been cooked up by a bygone priest who didn't foresee the development of firearms, in an attempt to ban war.) [Answer] [Bronze cannon](https://en.wikipedia.org/wiki/Cannon#Cannon_materials.2C_parts.2C_and_terms) were historically used before iron. From what I can find online, bronze cannon were lighter than iron cannon and could be cast thinner than iron. They apparently tended to split instead of shatter, if they failed catastrophically. (From [this source](http://www.armchairgeneral.com/forums/showthread.php?t=151001), for whatever it may be worth.) But I think iron became cheaper and therefore won out over bronze. There is historical evidence for "hand cannon" (precursors to handguns) in bronze. So that metal could be used, though I don't know how well it would stand up to iron weapons and is inferior to steel, I'm sure. --- Not all societies developed swords, but all societies came from roots that included simple melee and ranged weapons. Bow and arrow and spears date back long before recorded history on multiple continents. Clubs, too. The Mesoamericans had a non-metallic sword, the [Macuahuitl](https://en.wikipedia.org/wiki/Macuahuitl). It's obsidian edge theoretically could be sharper than that of steel swords. [Answer] Even though the "process" for making firearms heavily influenced the culture, the knowledge of the process is not trivial, so only the elite artisans can manufacture and distribute weapons, most likely they are the most intelligent and with strong connections with positions of power, or they are powerful individuals themselves, maybe royal scientists and/or warfare ministry. These firearms creators DO have the knowledge to make melee weapons and other metal objects with their expertise, but since war is profitable and they're the only ones that can create weapons that are better than bare fists, they just don't ever make anything but firearms. From what you said about the world, firearms are the most cost-efficient weapon to produce. The ones with the knowledge will mass produce weapons while obtaining a huge profit by selling them to warring states and self-defence. Bullets are also a good source of profit. The material for the firearms can be even be made from common metal. If the knowledge is kept between the right people and there's a good population manipulation, no one would ever be able to craft a stick with chunks of metal and try to use it against a revolver. [Answer] You can use treated wood barrels. There are real life cannons made out of logs. It wouldn't be unbelievable to make rifles out of a treated wood. You could just straight up make up a fictional metal. Give it the similar properties to diamonds. Very strong and hard, but can easily be shattered. That way they can't be directly struck like a melee, but they can withstand the heat and sudden pressure of being parts of a firearm? There is also nothing stopping someone from using a wooden sword or shiv, So it would be difficult to out rule melee even in a world of common firearms. [Answer] The scarcity of Iron could be explained by the lack of plate tectonics and volcanic activity on the planet, there could still be iron dissolved in the water and available for biological activity, but getting iron ore out of the ground can be difficult. Iron and relatively heavy metals are also important for planetary mass, as its gravity helps keep the atmosphere where it is supposed to be. If Iron is rare at the surface, you can generally assume that Nickel/Copper is also rare. Ideally you want a metal sword to be a certain weight, any more so and it becomes difficult or impossible to use. A greater availability of Nickel and Copper at the surface allows for a typical bronze age to occur, and still allow advanced alloys to be made. They should be rare enough so that making a sword from them would be expensive, but common enough that alloys requiring them could still be made. Bronze is not ideal for long swords. In a world where those metals are less common, it is possible that advanced composites may be common. Plastic type materials can be made from plants and insect protein fibers, and with appropriate processing can be made into strong composites similar to carbon fiber and glass reinforced nylon, which use used in modern polymer pistol frames, as well as components of long guns. It may also be possible to make certain jewels such as ruby and sapphire more common, as they can be used as precision bearings, and jadeite can be used as an impact striker. The bulk of metals must then be either much lighter and less durable, such as Aluminium, Magnesium, and Zinc, or substantially heavier, such as Gold, Lead, Tungsten, Iridium, and Osmium. Easily accessible deposits of the lighter metals are generally in the crust, and abundant deposits of the heavier metals could be provided by primordial bombardment. None of those metals are appropriate to make weapons such as swords and axes, but can be made into components for firearms. Lead is used to make primers and projectiles. Copper and Zinc are used to make projectile casings. Aluminum is used to make supporting frames and barrel coolers. Tungsten and Osmium alloys can be used for hard impact items such as hammers and firing pins. Heavy metals make excellent projectiles, as they retain energy throughout their flight path, and are less affected by wind drift. Polymers and non-iron metals such as Titanium and Copper can be used to produce springs. Alloys of Nickel, Copper, and Chromium can be used for many internal components of firearms, possibly even the barrel. A barrel capable of high pressures can be made out of thin metal sleeve, such as chrome plated Nickel alloy, and then wrapped in a composite of polymer and carbon fibers, and finally held in place in a larger Aluminium sleeve to protect the composite from damage and aid cooling. Making swords out of the heavier metals would not be appropriate, as they are more brittle than bronze, and would weight too much for even a large warrior to control. An adversary with a simple firearm would be victorious. If the historical conditions were right (early research into explosives), it is quite probable that blunt force weapons quickly lost their appeal once projectile weapons became common. [Answer] **You have options** Firstly, as other pointed out, if you can make a firearm you can make a sword. However, you could make it so that using melee weapons was not a practical means of warfare. For example, in the modern warfare, a firearm is more useful in combat because they are efficient, reliable, and carry plenty of bullets. If the guns in your story are more similar to modern firearms then melee weapons will not be the goto. Only in close quarters does the firearm loose its practicality. This is more cultural than technological. If you are willing to make the leap to a world lacking in Iron having other unusual properties, then naturally occurring ceramics could work. For example, a large deposit of [Cubic Boron Nitride](https://en.wikipedia.org/wiki/Boron_nitride), for it has been found in nature, could be an analog for gun chambers. It would make a decent blade, but not a great sword. Similarly, a large deposit of say fist-sized diamonds from your local [kimberlite pipe](https://en.wikipedia.org/wiki/Kimberlite) or swamp that got hit by a meteorite, would make good parts for a revolver. Assuming for some reason that diamonds are not valuable. [Answer] ## You can get guns without high-grade steel -- but you won't get a lot of the things that made guns *dominant* It's possible to make gunbarrels out of a variety of materials -- basically, anything that's tough enough to handle the chamber pressures involved and doesn't get destroyed too badly by propellant residues (which are particularly nasty for black powder). However, rifling requires an interference fit of sorts between the bullet and the rifling, which creates wear on the barrel and requires the barrel material to be *both* hard and tough, which means that in practice, rifle barrels were made of the best metallurgy for the task available at the time. Furthermore, breechloading, repeating firearm actions, and interchangeable parts all require relatively tightly toleranced machining to work. This means that you need machine tools that can work high-toughness materials at decent speeds and feeds, which again puts you in the position of having materials that are good enough to make usable blades. However, this can be explained away by iron and steel being rationed for toolmaking, making them too valuable to waste on a bladed weapon that's not going to last nearly as long. Cemented carbides are another option for a tool material, if you wish your society to figure that out early on that is. So, in short, I'd expect such a society to figure out an alternate strong, tough, but not very hard (yet harder than a lead bullet) metal early on, develop muzzleloaders and blackpowder quickly, then stagnate quickly, perhaps developing loose percussion caps, but never developing breechloading firearms of any sort. The idea of accurate shooting would not exist either as the rifling necessary to develop a long-range firearm would cause the barrel to wear excessively if used with anything resembling a Minie ball. Socially speaking, this means that blunt-force melee weapons (such as clubs and hammers) would still be commonplace as they can do good damage even if made from a relatively soft metal. Firearms would be *common* especially in cities and towns, but self bows would also be seen, especially in rural areas where accuracy for hunting is needed. [Answer] A few points need to be addressed. > > I'm writing a world where iron is incredibly rare > > > Basically, I want a world where melee weapons are either incredibly inefficient, or incredibly rare (only kings and warlords would have the resources for even a single sword or shield, maybe a handful if they are remarkably wealthy). > > > The way you describe this is extremely unlikely from a physical sciences point of view. Iron is a relatively abundant metal in a cosmic sense and it's extremely doubtful a planet could form without it being relatively abundant. It's hard to imagine a star forming a system with life bearing planets which had not formed from a nebula with a relatively high iron content. Indeed it's hard to replace blood with an equivalent fluid that does a similar task for another life form without using iron, which you're trying to do without. No iron is a huge problem for your concept, I think. You should also note that [copper was commonly used in weapons](https://en.wikipedia.org/wiki/Bronze_Age_sword) before iron. The natural development from copper is brass (that's basically copper with zinc). This page on [metals used historically in firearms](http://firearmshistory.blogspot.ie/2014/10/metals-used-in-firearms-vi.html) might give you some ideas. Copper is particularly useful as a conductor, and I'd suggest that while iron might be rare, an available source of copper would at least allow your world to develop basic electrical science and engineering. I'm not personally aware of any strong alloy made primarily of lead that could replace iron or copper in an industrial setting, let alone a in an firearm. However I'm no expert in metallurgy and perhaps if you want to pursue this idea you need to seek out an expert in lead alloys and see if they have any ideas. I'd offer the thought that a society that could at least develop skills with electricity and magnetism could develop the tools and chemical engineering required to make other developments. > > and the technology to make more complex metals like steel was never developed. > > > Not making steel does not mean you can't make other alloys. I think you need to widen the scope of your thinking here. > > However, both lead and niter are incredibly common, so firearms were developed very early on and heavily influence the culture. > > > Niter is not a problem. It's a relatively simple set of organic compounds and making gunpowder is almost an inevitability once you have people doing alchemy and the development of basic chemical science. [Answer] Deprive your world of hard stone. Marble, granite, etc are all even rarer than iron. In their place, there's coal and lots and lots of clay. What does this achieve? Well, you can't sharpen a knife on clay. Coal and clay lend themselves really well to metal casting, so metal isn't worthless, but the fact that metal casting was so easy meant that the technology to make sharp metal (grinding) lagged way behind. Even if you did go to the trouble of casting a sharp sword, it would be useless once it lost its edge. Today, people understand that you can sharpen metal with a stone, but it's a painstaking process - you're basically rubbing a rock on metal for days. There's no such thing as a grinding wheel (clay doesn't work for handwavy reasons, maybe it's too impure and would just shatter), so swords can't be mass produced. Serrated knives are possible, but a proper sword is just too much work to be worth it. [Answer] You make no mention of whether you are allowing magic or not. It is plausible that, if you allow magic and spells, you can create a body shield that will block a blade or melee attack, but not be able to overcome a small, fast-moving object. This is the inverse of the Dune "The slow blade penetrates the shield" setup. Maybe tuning the shield to block bullets interferes with the movement of air across the barrier and your user chokes. This does require active magic, but at this point, rule-bending is the only way I can think of to get to where you want to be. [Answer] /Anyone have another idea?/ Josh King had it. @Josh King "I think you are going to need social reasons rather than technological limitations. I propose your people are unable or unwilling to mix it up hand to hand. They could be very weak, cowardly or both. Maybe they are inbred and diseased, fragile folk who are lucky to be able to walk. Maybe they are all extremely old which would make for an interesting story. Maybe the air is so thin that physical exertion of any sort can be sustained for only seconds at a time. Or they could be so gentle and peaceable that the idea of hitting someone the stuff of nightmares. Shooting people from a distance through a scope is much more palatable. These people would be descended from vegetarian ancestors who did not fight each other and dealt with predators via immense bulk and malodorous skin. Or possibly they are descended from bonobos, the gentle primates who settle disputes by having sex. Can it be both? I am loving the thought of your medieval / western adventure with this society. It would be so different. [Answer] An easy approach would be to have the ruling classes treat the sword as a weapon of high class. Nobody except the rulers are permitted to have one. Similar rules have been put in place in the past in feudal eras. This, combined with the presence of firearms which are substantially better in virtually every combat situation guarantees the average person isn't going to want a sword. However, I would give a word of caution. A gun *is* a melee weapon. You will be incapable of making a piece of metal that withstands the brutal forces involved in firing a projectile but which cannot be turned around and used to club someone over the head. [Answer] I'm in the middle of creating a world where ancient advanced civilizations rose and collapsed so I think this answer is very heavily influenced by that, but heres an idea for a work around: A long dead race of technologically advanced inhabitants of the world created guns. The current inhabitants found the guns early in development, and with the efficiency of guns, there was never any reason for them to develop sword-like weapons more deadly than say, a paring knife. Another general note is because of the difficulty in making a civilization advance forward without something like metals, I'd see a cultural explanation being the easiest way to make this work. [Answer] This is categorically not possible. It's really that simple. More than that, it's not even slightly *plausible*, and that will (not "may") destroy a reader's ability to get into your world. You mention "swords" casually as if the cavalry sabre came from nowhere, fully formed. It didn't. Weaponry started with sticks, bones and stones. There are *many* areas of the world where metals were in short supply, and those places continued to use sticks, bones and stones until Europeans arrived. This didn't mean those weapons were primitive - they'd had the benefit of thousands of years of evolution through warfare as well. South American civilisations had "swords" consisting of stone shards embedded in wood, which in their own context were very effective (although less so than metal, of course). You don't need to be restricted to edged weapons either - most foot-soldiers historically used spears, not swords, because a rank of spearmen can stick them with the pointy end from much further away. Even at close range, bludgeoning weapons remained popular in Europe, because good armour always makes swords ineffective. Away from Europe, the Maoris had some truly horrible spiked bludgeoning weapons involving sharks' teeth. You also mention "guns" as if the steel revolver came out of nowhere and is the only way to do it. Guns were originally made from bronze (copper, tin and later added zinc) and this remained effective. But if you have the raw materials to make bronze, you can equally well use those materials to make bronze weapons. The Bronze Age is called the Bronze Age because that's when bronze refining became widespread, and the primary purpose of developing bronze was in an arms race to get better quality swords and armour. Bronze never stopped being a good material for weapons - it was purely that iron and steel were better. If you don't have iron and steel available, then development stops there. I'm really sorry, but you need to do so much more work on this concept. [Answer] ## Slingshots and Grenades If you are not too attached to the idea of guns, but still want a gunslinging setting, consider slingshots and grenades. If metal is scarce or of poor-quality, then swords and metal axes will have been historically rare. However, heavy armour will also have been rare or non-existent. The armour of choice would be heavy, padded clothing - protective against stone axes, hammers, and maces. This would protect well against stones (the traditional ammo or slings and slingshots) but not against fire or poison. A sling or slingshot throwing burning oil flasks would be the ranged weapon of choice. As technology advanced, the oil flasks would be replaced by grenades containing a variety of payloads (fire, acid, toxins). Perhaps a naturally-occurring plant has the tensile properties of rubber and latex, allowing for modern handheld slingshots? If technology somehow allows for glass production then gunslingers might have slingshots tucked into speed-draw holsters and glass beads in bandoleers across their chests. ## Rockets If gunpowder is well known then rockets will be the ranged weapons of choice. Imagine all the research effort that would have gone into steelsmithing going into rocketry instead. Person-portable rocket launchers with the accuracy of a rifled firearm? Rocket pistols carrying a wide variety of warheads? [Answer] Not easily you need a lot more Copper and Tin in the world for a start, modern Bronzes, particularly those using small amounts of Cobalt, are superior to most Iron alloys for pressure applications like firing chambers but still bend when used in thin blades, which is unfortunate because in other ways (like edge retention) they make blades that are also superior to steel. So that could be starting point, it's not that Bronze can't be used for swords it's just that the swords you can make out of it are pretty bad. Bronze also has the advantage that it can be cast relatively easily at relatively low temperatures to a high standard, that means that smelter technology need not be so advanced, which is a mixed blessing when it comes to the chemical sciences. There are some other issues around technological progression that you'll need to look closely at too, the general availability of Iron as a working metal has spurred a lot of technological progress for a very long time, some of that progress would have been virtually impossible without easy access to ferric materials. Nickel and Cobalt are both magnetic elements but neither one forms a native mineral with the physical properties of Magnetite (Fe3O4) so natural magnetism becomes a nonstarter with Iron so rare. Metallurgy becomes a bit of a strange one because while there's a lot you can do with Bronze and other Copper alloys the materials you need are relatively rare in an Earth-like Geological setting and some of the very best Bronzes are the ultra modern Aluminium Bronzes and Aluminium is very hard to extract without electricity, not impossible but awkward and dangerous which is why it was one of the last metals to be isolated. Iron plows allowed farmers to break ground that couldn't previously be farmed as well, Bronze was traditionally too expensive for plows though so there's some wiggle room there if you build a world with far greater reserves of the raw materials. Bronze's low working temperature is actually an excuse to have an Iron rich world in which Steel isn't much used, if Copper and Tin are abundant and widely distributed enough that Bronze is as accessible as Iron and Copper-alloy metallurgy is advanced enough that early Iron is inferior for most applications then Iron would never catch on, Iron's accessibility made it much cheaper than Bronze or even Copper on earth which is the main reason it came into common usage not any material superiority of early ironwork over the Bronzes of the era. Assuming equal availability of elemental raw materials Iron is much more expensive than Bronze because of the thermal inputs needed to smelt, refine, alloy, and work it. This is especially true when smelting the Oxide-type Iron ores that we find the largest deposits of, they require vast amounts of heat (up to 2300C) and Carbon Monoxide to reduce them to primary metal. Sulfurous compounds make up the majority of Copper ores which makes them much cheaper to smelt, they require only moderate heat (1200C) and Oxygen to break them down. [Answer] A lot of modern firearms use [carbon fiber](https://en.wikipedia.org/wiki/Carbon_fibers) as the base for a lot of firearm's structure, such as for stocks and such, though it is a relatively modern material and you may have trouble explaining where they conjured the ability to manufacture it. As for a straight replacement of iron, the closest bets are materials that are also within whats called the ["Iron Triad"](https://chem.libretexts.org/Textbook_Maps/General_Chemistry_Textbook_Maps/Map%3A_General_Chemistry_(Petrucci_et_al.)/23%3A_The_Transition_Elements/23.5%3A_The_Iron_Triad%3A_Iron%2C_Cobalt%2C_and_Nickel), namely **Nickle** and **Cobalt**, because they're minerals that closely resemble iron in their qualities. These materials wouldn't function as well as steel in regards to being weapons parts (after all, steels are used generally because they work the best), though they could still probably accomplish similar functions in a world where iron is extremely rare. Of the two, nickle looks like it would be the better option, as it has the benefit of being very heat-resistant, which would be essential in firearm construction. [Answer] How about ceramics? IRL ceramics can be extremely strong and tough (and light); in fact experimental engine blocks have been made entirely of ceramic, and those are withstanding hundreds of explosions per second. It seems reasonable a gun could be devised from some high-pressure ceramic material, and in the absence of iron on your world, perhaps the evolution of technology took this direction instead of developing these exotic high-pressure, high temperature, high strength ceramics. Including for channelling the explosion of black powder for accelerating a projectile. [Answer] If you don't have metallurgy, you don't get *reliable* firearms, or at least ones that last very long or have anything approaching a decent range. That doesn't meant you can't have gunpowder based weaponry. Ceramic pot grenades, bamboo encased explosives, and rocket propelled...anything are options for you. The Korean Hwacha is one of my favorites ever since I saw it on Mythbusters. One small thing I find odd is that your society has drifted away from melee weapons. Melee weapons have existed since the first time someone picked up a rock and clonked someone else over the head with it. Metals just made those melee weapons last longer and kill more effectively. This is some pretty significant history to over come. Other answers have mentioned that a radical change like this would probably come from either societal pressure rather than some sort of lack of available metals. Will has got some great ideas for this. Have fun with the Medieval Western, sounds cool [Answer] What if current people's don't have the ability to smelt metal at all - all their weapon stock is from past ages and guns were simply more commonly made back then because the age of the sword had passed? If swords/armor are very rare (as they are now, to be honest) then they'd be expensive. Going with some form of cultural/historic reason will definitely make more sense than just eliminating melee weapons due to scarcity of ingredients but still having guns. It'd be like having high-compression combustion engines be readily available but steam engines are impossible to make, just too backwards to be feasible. ]

[Question] [ Modern earth, no magic. Only difference is that a small percentage (~1%) of the population are biologically immortal, they can die by accidents/murder/etc but are immune to old age and disease (they will spend forever in perfect health). My question is how do I stop these people from dominating the economy? They have all the time in the world so even small investments will grow and grow and grow without their death forcing their money to be redistributed to their children/family/state? Edit: As this was asked multiple times the fact a subset of humans are immortal is widely known and is a part of society, it's just how it always been. [Answer] **Wealth tax** In your setting, a wealth tax has been enacted, which is based on the net value of a person's assets. It could be a progressive tax, even climbing to 100% beyond a certain point - this would basically be a hard cap on any individual's wealth, as any additional wealth would go to the government and not the individual. In our world, wealth taxes have been enacted or proposed as a means of combating the "rich get richer" phenomenon where society's wealth becomes increasingly concentrated in the hands of a small number of people. Of course, wealth taxes will be unpopular with the super-rich, so for it to work as intended, there shouldn't be too many ways of dodging the tax. You wouldn't be able to implement such a thing in a small country that has easy access to other developed nations without such a tax, as the wealthy elite will simply move somewhere that has no wealth tax. [Answer] **[Struldbruggs](https://en.wikipedia.org/wiki/Struldbrugg)** There is a classic solution to this problem, described by Jonathan Swift in his iconic Gulliver's Travels. In there, a nation of Luggnagg had a similar issue with a number of immortal people. > > those immortals would in time become proprietors of the whole nation, > and engross the civil power, which, for want of abilities to manage, > must end in the ruin of the public > > > so the solution was > > As soon as they have completed the term of eighty years, they are > looked on as dead in law; their heirs immediately succeed to their > estates; only a small pittance is reserved for their support; and the > poor ones are maintained at the public charge. After that period, they > are held incapable of any employment of trust or profit; they cannot > purchase lands, or take leases; neither are they allowed to be > witnesses in any cause, either civil or criminal or economic, not even > for the decision of meers (metes) and bounds. > > > [Answer] ### Everyone hates them You mentioned they can still be killed. Well, human jealousy is definitely a thing, and I imagine most people would consider it "unfair" that a few people can potentially live forever. This isn't a huge problem for the first thirty years or so, but once it becomes "obvious" that a certain person is immortal, society turns against them. Maybe this is even institutionalized; killing an "immortal" is not only legal, but the murderer is entitled to a percentage of the deceased's wealth. (Disclaimer: this is pretty much the exact setup of the short story "The Trouble with Millennials" by Robert Buettner. Read it [here](https://www.baen.com/categories/free-library/free-stories-2016.html).) [Answer] ### They are (somewhat) limited by their psychology. Possible scenarios include: **They can't keep up with rapid advancement of technology...** They live their entire several hundred years before the steam engine. They see society as "not much different" from one decade to the next. After the advancement of steam engine, technology progresses too quickly for them. Their psychology have been accustomed to the slow kind of progress.. and suddenly they see society grew so fast. They can't keep up. They arrive in present-day technology, feeling out-of-place or straight out insane. **...and they aren't adapting fast enough to constantly gain an edge in society.** They're used to the past. They're already accustomed to their lives several decades ago. They aren't much interested in experiencing/trying out new tech. They're fond of doing things the reliable, old familiar way. This old familiar way, however, is almost always less effective/efficient compared to the new stuffs. This reduces their overall chances of dominating the entire world. **They're bored or tired of living.** Simply bored. After living for too long, they don't find anything appealing in living for even longer. They've seen everything. Their young blood is now long gone. They don't find anything that excites joy anymore. *This one is a minor plot in 2011 movie [In Time](https://en.wikipedia.org/wiki/In_Time)*. [Answer] > > even small investments will grow and grow and grow > > > This is a wrong assumption: imagine you are one of those immortals, and at the time of the roman empire you invest your money in a [garum](https://history.stackexchange.com/q/66273) factory or in manufacturing purple dye, just to name two industries with good income. Well, you might be immortal, but your investments will collapse with the empire, and good luck with collecting your wealth in those times of uncertainty. Even in today world, look at how many companies have survived longer than a human life: Philips was once a big name in electronics, today no more; would you have manage to avoid the derivative crash of 2008, or the dot com bubble? Long story short, even though you might be immortal, you cannot forecast the market ups and downs. You will end up losing part of the investments, and won't end up really dominating the economy. [Answer] **we already do this, so it won't be as hard as you think** In fact, I suspect the bigger problem would be the consequence of immortal welfare recipients. We already have (in the United States, probably different elsewhere) a whole set of laws that make it pretty messy to transfer wealth from parent to child. To avoid those laws, many families (the mortal version of immortality) build *companies* that live "forever," and put their descendants in a position of retaining control of those companies. Since even compound bank interest would be a serious threat to any economy when measured over centuries and millennia, laws would quickly come to pass that restrict how wealthy any immortal can become. But you might ask, "so where does the welfare come into this? Why wouldn't the immortals be CEOs forever and get around those laws?" Lots of reasons. Boards of Directors (who love to oust people who aren't doing what they think is best for the company) and shareholders (ditto). Also anti-trust laws that prohibit monopolies.... But when push comes to shove, there are really only so many companies that can boast the kind of prolonged wealth you're talking about. So there really isn't enough *economic space* for your immortals to be more than a minor impact on the world's wealth. If they chose to focus on crime for their wealth, competitors would set them first in line to be bumped off. If they chose to be Captains of Industry, everyone from competitors to activists to politicians would be driven to keep them from becoming the Ruling Elite. In either case, rules and laws already exist that are intended to keep individuals (and their descendants) from acquiring too much wealth (yes, I know, it doesn't seem to be that way... but it is. You don't want to stop all wealth-mongering, it has value whether you agree with it or not. Necessity being the mother of invention, after all.), which would naturally glom on to your immortals. This is why you'd have a bigger problem with immortals on welfare. You don't describe them as unreasonably intelligent or powerful, just long-lived. How many reasonably smart people do you know who are near or below the poverty line? More than most of us want to admit. And an immortal on welfare in many ways represents a problem just as nasty as an immortal with a trust fund. Besides, while everyone wants to live forever, no one wants their *neighbor* to live forever. And the natural development of law would prohibit your immortals from ever having so much economic traction that they could move the world. ...Well, assuming we don't believe in the Illuminati, the Rothschilds, the Trilateral Commission or the Roswell aliens, whom we all know are really still alive because any sufficiently advanced civilization would have figured out how to gene-splice perfect health and made sure *every citizen* got it, right? [Answer] **Along with immortality comes a penchant for bad choices.** When they say "a fool and his money are soon parted" these are the fools they are talking about. These are the some of the people you can fool all of the time and that is what happens. They are immortal but they struggle even worse than ordinary folks to hang on to their money. They should live in constant fear of getting ripped off because it happens often. But they do not, and so it happens often. The penchant for bad choices and susceptibility to death by accidents means that actually most of these immortals don't get really old. [Answer] # Communism You cannot dominate the economy when wealth is equally distributed among all, comrade. As the saying goes: from each according to their capacity, to each according to their needs. Interestingly, since your immortals should eternally be able-bodied, they should eternally be able to produce for the good of everyone. Or... # Eat the rich Enough said. [Answer] It seems to me that there is very little difference between an immortal and a certain type of family where generation after generation are working to increase the wealth and power of the family. Both can take a long view, both can have variations in direction over time (because people change, even long-lived people). Both are affected by external factors like the collapse of markets, war, devaluation of currencies and so on. In fact Old Money families are more likely to be successful over the long term because they can recover from individual failures more gracefully. The death of a family head isn't going to bring it to a halt. Even criminal conviction can be recovered from, because while one or more people go to prison there are plenty of other family members still actively managing the family's fortune. In the real world there are old families that have incredible amounts of money and power, developed over centuries. I'm not talking (relatively) young money like the Rockefellers, whose progenitor JD was worth (in modern day equivalents) around US$500 billion, I'm talking about **Old** Money. Aristocratic families that have been around for several centuries and look down on upstarts like JD Rockefeller. In this world your immortal might not be even particularly wealthy unless he was a financial genius. [Answer] The last 300 years have been a historical anomaly. In addition, that anomaly suffers from survivorship bias. If you took some money 300 years ago, and invested it in the right kinds of assets in the right corner of the world, you'd easily be insanely wealthy today. But pick the wrong corner of the world, and your investment would be worth nothing. Do the same thing 3300, 2300, or 1300 years ago, and your investment would probably be worth nothing. The last 300 years has experienced multiple chained economic singularities we call steps in the industrial revolution. From water power and canals, to steam power and railroads, to oil and the internal combustion engine, to electricity and computers, each has been a wave of insanely fast change and growth. In this environment, putting aside money to bet on the future being richer than the present tends to come up aces a lot. What more, doing so in the set of superpowers that won the global conflicts -- the East-Atlantic British Empire (UK), followed by the West-Atlantic British Empire (USA) -- is going to do even better. You toss down a fortune in Germany in the inter-war years when it looked like it was going to become a superpower, and you'd have lost it all if you picked the wrong side of East/West Germany after the war. The world is full of places where it looked like it was a good idea to invest, then within the century every investment would be lost. What more, such investments would be extremely alien to someone used to the previous thousands of years of history. The idea you'd take wealth and hand it over to someone to make it bigger would be a short term thing as far as the immortals are concerned; every society crashes, and when it does your investments are worth nothing. What more, in most of history, holding onto your investments requires political and military power, as if you get rich someone else will just take your stuff. And even after all this, your immortals wouldn't be much better off than random Dynasties. Dynasties who pass down assets to a single heir are economically very similar to immortals, especially if the previous heir gets to pick the next one. Such Dynasties where quite successful -- the top ones we know as "Kings" and other nobles -- but not universally so. As your immortals can suffer being killed, such immortal single-person dynasties would typically end with simply killing the immortal. Long-lived immortals would be aware of this problem; those that have lived a long time will have adapted their lifestyles to avoid it. The immortals might not have the "stupid heir" problem, but they are in a sense their own stupid heir. They'll get set in their ways and not adapt to the current situation, and their financial empire will fall. In the post-industrial-revolution singularity states, some of these concerns don't apply. The need to guard your wealth with guns is a bit less (until your society collapses), the need to guard your wealth politically remains the same (or greater). You'll still be about as well off as large dynasties that have passed their wealth down to one person. Your investment habits that are successful in one era will fail in another, and if you chase the rabbit and change with what habits have recently been successful you'll always miss the initial growth surges. So your return on your savings will probably be, on average, no better than the financial giants of the past. In the UK, that would be the nobles; while they are (on average) not so badly off, they aren't the titans of the world economy you seem to imply the immortals are. In the USA, similarly, the heirs of the robber barons of 1800s are not the top of the economic pile today. [Answer] The same thing that made them immortal makes them stop WANTING any sort of dominance. Was it a medical technology/drug, or a mutation? Make it suppress a social domination instinct. If it was a mutation, then carriers of the gene that was NOT connected to a suppressor of hierarchical domination ended up dying violently, for the last N thousands years, because competitors, though mortal, are much more numerous. Have they uploaded their minds into a computer? They realize that the process didn't bring most of their instincts over, and emulating hormonal influence in silico tends to drive the digital personality crazy. Was it magic? Well, then, it's magic that did the same thing. [Answer] You could compare this to the entailed estates of English aristocracy. While individuals were not immortal, the estates - passed down from eldest son to eldest son - were intended to be. Yet it took just one or two generations to be bad gamblers, or back the wrong side in civil wars, for the estate to become bankrupt. [Answer] > > a small percentage (~1%) of the population are biologically immortal > > > How does that 1% work? If some immortals are killed by accident, are new immortals born to take their place? Are 1% of babies born immortal? Or is it a fixed population of immortals that may be depleted over time by accidents? > > they can die by accidents/murder/etc > > > Rare events and freak accidents start to become a bigger threat the longer you live. Extremely improbable causes of death do happen, and if somebody simply exists long enough, they are likely to succumb to one of them. It could be anything, from a bad slip while stepping out of the shower, to an asteroid hitting their house. If you have no mechanism of replenishing immortals, their population will eventually approach zero. Regardless of whether new immortals are born, existing immortals may become extremely risk-averse, withdrawing from society. Knowing that they are vulnerable to murder as well as accidents might make them think twice before doing anything to provoke the ire of the rest of society. This might inhibit them from financially dominating. [Answer] Frame challenge: They already dominate the whole world, because they are the ones who actually built the modern world. You say that: > > it's just how it always been > > > I'm going to arbitrarily take this in the almost literal sense that no recorded history exists of a time when these people were not alive. This can only happen in two cases: Case 1: They have been alive since before history was recorded. If this is the case, the most likely scenario is that they have already amassed great wealth and power, and of course great knowledge (don't underestimate how much a person can learn in a millenia or two). In fact, they already had great wealth, power and knowledge well before the modern world began to take shape, and should have been perfectly capable of shaping history as they saw fit, effectively building the modern world as it is (either directly, or indirectly through preventing some particular things from happening). As such, it's difficult to argue that they don't already dominate the whole world. Case 2: They have altered recorded history and collective memory to make it seem like they have been alive "forever". They might have been alive for merely 100 years, or 200 or 500, but they have so much power that they can rewrite history. As such, it's difficult to argue that they don't dominate the whole world. [Answer] ### Limiting wealth alone isn't enough This is interesting, because there is more than one kind of dominance. There are several answers already with various schemes to degrade the wealth and influence of immortal individuals, but let's consider how this might really play out. Imagine an immortal person who is forced to completely start over every so often; they retain only the clothes on their back, and their identity, experiences, and memories, to the point where they might even need to spend the first night in a homeless shelter. Even so, such a person could eventually accumulate the equivalent of several PhDs and multiple life-times of business leadership experience. Of course, not every immortal would do this, but even those of average ability would eventually start to trend this way, and *such a person would be in high demand for top administrative positions in any industry or sphere of influence.* Now imagine even 0.01% of the population has this ability. This is already enough people for there to be precious few of these top positions remaining for "normies", even less so as these individuals start to rise to move in the same circles and get to know each other. They would almost certainly end up with reputations among each other, creating a de-facto network to make getting appointed or hired into top positions even easier. And all this in a society where they still periodically have to start over from scratch, and only their experiences and identities remain. Individually there would be times for each of them where the influence is reduced, but collectively they would be almost certain to dominate the highest levels of economic leadership. --- ### Instead build in an intrinsic liability by limiting their memory capacity to roughly one "normal" human life-time One solution is to design your immortals so their memory is limited. > > Sure, I may be 4,000 years old. I may even have memories of certain ancient events and people that were especially important to me. However, by and large I have an *extremely* difficult time remembering anything that happened more than roughly 100 years ago, and sometimes even things more recent. > > > This limits the ability of your immortals build up the kinds of skill and experience that make them so valuable for those premiere jobs, such that other factors to limit wealth and influence have more of a chance. *Tune the memory limits just right, and you can have it be just enough of a liability to make it naturally difficult for your immortals to accumulate wealth and influence over centuries*. For example, they tend to "forget" about investments, which are later declared abandoned and claimed by the government, and are rendered actively undesirable in leadership roles for a *perceived* tendency to be "flaky". The limitation doesn't even have to be anything supernatural or unique to immortals. If you want, you can tie this memory issue to a biological limitation of the normal human brain... after around 100 years something just "runs out" on the brain's capacity to store and recall memory data, either like filling up a hard drive in a computer or a performance limit for retrieval speed for older records. This can work *really well*, because it doesn't require any other alterations to the real world as it is — no new laws or societal norms — and because readers can *believe* this limitation is real and part of the normal human condition, whether or not it ever turns out to be true, because no real person has lived long enough to find out. Both the size limitation and the recall speed limitation can be good hooks for a story. With the former, an immortal could be found at a critical moment to have forgotten something they knew earlier in the story to create tension or suspense, and in the latter they could *finally* remember something late in the story that has been puzzling them for some time, to help the protagonist get past a problem. --- Finally, I would further suggest reducing the proposed numbers of immortals. 1-2% is too high, and closer to 0.01% (1 in 10,000) seems better. This reduces the frequency they would encounter each other naturally and limits the ability for social networks among immortals to develop that might otherwise lead to them collectively having too much influence. [Answer] ## No arbitrage! As financial theorists insists, there is [no risk-free profit](https://en.wikipedia.org/wiki/No-arbitrage_bounds) in a healthy market. Anything that is "theoretically risk-free" should earn no more than what is necessary to counter inflation, or someone is monkeying with the financial system. At least on the long run. (This is similar to the answer by L.Dutch, but putting it into modern terms ...) [Answer] NO WAY. Right now, we fail to prevent a small percentage of *mortal* people from dominating the economy. If some of them are immortal, this doesn't change much of the equation, compared to the usual lineage of rich people. Sure, some middle- or lower-class people get rich, some of those rich go bankrupt, but one cannot really fight the [Paretto principle](https://en.wikipedia.org/wiki/Pareto_principle). On the other hand, do these immortal people procreate? If they don't - problem solved, they will disappear because of one reason or another for a millenium or two. See the [micromort](https://en.wikipedia.org/wiki/Micromort) concept. If they do procreate, they will outbreed the mortal people in the same timespan. The only more or less stable possibility is that they are born to mortal mothers and fathers with low probability and: * they are either sterille * or their fertility is matched to their longer half-life and their offspring has the same probability of being immortal. No problem, then. Family relations are a good recipe to get poor. More so if you have a great deal of relatives in your lifespan. [Answer] # It's not a problem. You might thank that an immortal will eventually gain lots of wealth. But in actual practice the financial situation of an immortal is not different from a non-immortal with a family. One normal person accumulates, passes that down to their child, who uses it to accumulate more, and so on. If "parent" and "child happen to be the same person that makes no difference to their ability to accumulate wealth. They have the same time available to do it. There is no reason why immortals should be better at it than non-immortals, excepting a better ability to think long term. Throughout most of European history there were families who accumulated huge amounts of wealth and handed it down through their families, dominating the financial landscape of their time. They were called "nobles", and achieved this by largely handing down their estates intact from father to eldest son. The only thing that makes a difference between families and immortals is inheritance tax - coincidentally the same thing that put paid to the power of the wealth of the nobility. Abolish this and the situations are the same. If you want to prevent the accumulation of wealth by immortals, just make an inheritance tax that gets applied every 150 years to someone even if they are not dead. [Answer] ## Legal Reincarnation This is close to Alexander's Struldbruggs answer, but a bit more forgiving. Struldbrugging a person makes them poor and useless for the rest of time, but there are other ways to do it where you allow them to start over just fine. So, every 80 years of their life, they must distribute inheritance, quit their jobs, forfeit their investments, and move away a minimum distance from their previous life. But, instead of making it illegal for them to work, you just make it illegal for them the work in the same industry or with the same people in 2 consecutive life times. So if they are a politician in their first life, then when they hit 80, they may not pursue a political carrier again until they are 160. So when they hit 80, they pretty much have to go back to college, learn a new skill, and work their way up to again. By the time they hit 160, they could go back to being a politician, but in that span of time working in an unrelated trade, nearly all of the influence they gained in their first life will have evaporated away and their knowledge base stagnated too long to jump right back into it meaning any edge they have over mortals is small. Another way to look at this is that a 1940's medical degree that you have not had to use or think about in 80 years is not going to be applicable enough to modern medicine to just jump back in. They won't know the first thing about how to install an artificial heart, or operate a medical laser, or how to use a balloon embolectomy catheter... so, even if they do return to an old carrier a whole life time later, they will not be able to rely on old knowledge to be competitive in that field anymore without significant re-education. [Answer] **YOU NEED A DIFFERENT LEGAL FRAMEWORK FOR THEM** The current economical framework of our civilization is based (among other things) in the assumption that we all are going to die. And I am talking about the length of the bank loans, the age for retirement, the retirement policies, the social security policies, life and medical insurance and many many other topics that revolve their statistics in the fact that, soon or later we will all die (and in more or less predictible situations depending on specific characteristics). So, if some part of your human population becomes immortal, unavoidably you will need a differnet legal/economic schema for them. You cannot apply the same policies for an insurance, or for a loan, or birth control (talking about China here). If a bank lends money to an immortal, the clauses must be different, because the bank knows the immortal can be paying for centuries (unless an accident happens, of course, and that consideration should be specified in the contract). Taxes and benefits also must differ, and also the situation of the childs of the immortals (An immortal could theoretically have hundreds of childs if he/she wants, so birth control policies should also be applied). [Answer] # Inflation and Currency Resets Society only operates financially so long as the perceived value of goods and services are appropriately established. As the wealth of any particular individual grows, the value of their wealth will begin to devalue. At first, this would be through inflation - society would charge more money for things, knowing that those who have accumulated too much wealth can pay for it. In the longer term, inflation would outstrip earnings for most of the non-immortal people. And suddenly, most people wouldn't be able to afford the prices... but would need to survive in order to produce the goods/services in the first place. A counter-movement would form, in which people would begin using an "underground" currency, to exchange goods and services without needing to go through the hyper-inflated normal market. Give it a bit of time, and most people would be using the new currency. Meanwhile, the immortals would be starting at square one, just as everyone else does. And as all economic activity switches to the new currency, the old currency rapidly becomes worthless. The interesting thing about this is, there's really nothing the uber-wealthy immortal can do about it. They could try to create the new currency themselves, but that's likely to backfire. [Answer] Several things can be done to assure that immortals are poor and adequately explained: * Cursed to be poor * Make the world post-apocalyptic * Being hunted down * Make them nomadic wanderers * Island Amish people that never associated with modern society * World = dystopian nightmare (ruled by tyrannical tribal communities) * "I just wanna live in peace..." (got this plot from a hentai manga about an immortal oni who watched her children grew and spread after her husband died, and waited until he's reincarnated again) * Go full The Highlander mode ("HERE WE ARE! BORN TO BE KINGS!...") [Answer] When you are immortal you have no particular interest in worldly possessions any more. Been there, done that. Material wealth comes and goes; material possessions decay. Immortality changes your perspective. It makes you humble. From the perspective of an immortal, the only things that persist through the ages are the ones that are not bound to physical matter. The immortals almost exclusively pursue scientific, spiritual and artistic quests. [Answer] **Give ownership of money a time-limit** In our modern world, this would entail something of a fundamental re-write of banking, but conceptually shouldn't be impossible. Essentially every penny in existence is associated with a date that it changed hands. After say.. 10 - 20 years, money that hasn't changed hands legally will revert to the State. This essentially requires that money be moving routinely and makes hoarding money long-term much more difficult. You can't just dump billions of dollars into a bank account and expect to leave it there long-term. The problem I see with this is that the solution is simple. Enter into an agreement with a friend to buy things from them and they from you. Two people making "modern art" and selling it to one another for silly volumes of money in order to avoid their money melting away.. Alternately, you'd get billionaires keeping their money in literal vaults of cash so that it can't degrade in value. Obviously there are some kinks to work out in the plan. [Answer] **Wealthy and influential immortals are bad for business** Every time some local stable system forms (company/government/...) where immortals are in power, it soon becomes stuck developmentally because of a lack of change in leading personnel, and the consequent accumulation of status quo bias/technophobia/overpromotion of incompetents. Other less stable or less immortal-friendly systems can then begin to dominate and are able (and intent) to completely destabilize that system from the outside. Since this pattern is historically known, even intelligent immortals knowing not to influence mortal dealings too much will be unable to acquire influence/wealth - and even those rare that do, often fall prey to overconfidence and/or the lure of power, not being able to simply live in comfort and ignore everyday affairs (some few immortals were able to resist, and are living "eternally" stable somewhat-rich lifes by making fruitfull deals with groups of mortals - until they are inevitably betrayed by those). Due to this dynamic, all long-term successfull societies impose some limits on immortals - in some, everyone living past their 60th birthday is executed (which incidentally saves on pension costs), others simply have age-dependent (as well as wealth-dependent) tax (making handing down ones wealth down to ones descendents the only way to "at least keep it in the family"), and still others restrict them to certain jobs/living conditions (eg. historians, or special kinds of advisors always paired with young mortals) (and in some societies, old immortals are simply treated as pariah by all companies in terms of financial dealings). Also, frequent collapses of societies that do not have immortal restrictions in place just as effectively prevent the accumulation of wealth, since property rights will no longer be guaranteed, and material assets might be acquired by mortals/destroyed in the chaos until a new system stabilizes. [Answer] The most powerful force in the universe is compound interest. Not even stupidity exceeds it. If they have access to compound interest, they will dominate, there are no factors that can change this. Even without immortality, compound interest is so extreme as to challenge my ability to describe it... note that the other answers have been attempted in the real world and yet have always failed against compound interest *without* immortality. How could those hope to succeed in a world *with* immortality? I propose that your question has no plausible, valid answer. [Answer] In order of dramatic effect in your story: 1. They must keep it secret. Anybody (mortal or immortal) found to be obscenely rich is suspected to be in immortal and lynched. The smartest immortals have managed to hide their assets extremely well, others have to feign illness or even death periodically to prevent lynching. 2. There is a widely accepted religious prohibition against compound interest. 3. Some immortals have become kings and queens. Their fortune is indistinguishable from the fortunes of the countries they lead. They have to deal with wars, foreign invasions, rebellions, technological breakthroughs, pandemics, etc. 4. This is the price they paid for their immortality: They made an ancient pact with the source of their immortality to give 9/10 of their wealth every year at summer solstice to charity. If they don't, they lose their immortality for a year. [Answer] The big problem with immortals is that they all the time they need to find whatever loopholes there are in your rule set. Money, property, goodwill, information. And these are just some of the metrics which are more or less exchangeable into each other. To make sure your immortals can't game the system, you'd have to limit each and every one of these metrics, which seems hard to do. So, my idea would be instead of trying to build a system, make the reason why they can't dominate something biological, and therefore out of control. Many of such limitations were already mentioned: Naivety, memory loss, decreasing learning speed, dulling emotions. My suggestion would be *synchronized, generation long hibernation*. To regenerate their bodies, the immortals need to go into a deep slumber. So, every ~30 years, they feel the deep drowsiness coming, which lasts one or multiple generations. They all do it at the same time, forced by some global trigger. (Depending on how realistic you want the hibernation to be, you'll have to use some kind of variation). Hibernation this long means almost everything they have in society will be gone - properties redistributed, money confiscated, information obsolete and goodwill withered. Even worse: If you have angered the people, it is now their chance at payback, and there's little what you can do about it. After all, even if you employ mortals, what reason do they have to do their job? You can't punish them for breaking a contract, and there's little hope that their goodwill lasts multiple generations. Your best bet would be entrusting your safety to other immortals … but those are all asleep as well. [Answer] Even with modern medicine and much better life style, it is very likely these people will live on average 300 years. There was a calculation about this but I don't remember where I saw it. The number was even lower, but lets round it to nearest 100. Living 5 times longer (excluding childhood) than average person will help them to accumulate wealth and knowledge, but they will probably not be as rich as the richest people. Some answers mention wealthy families, it is very unlikely for these individuals to get that far, even though they have a better chance. Remember these families start with a lucky or brilliant event that makes them rich at the start and they keep accumulating wealth by using the wealth. They represent less than 1 in a million of the population, since the immortals are rare too, chance of a very rich immortal getting extremely rich is of a very low chance. And the ones they do, will die one day, and their riches will be split to 100's of grand grand kids. There are two exceptions though. If immortals have immortal children, %1 will raise to 100% in a few millennia. If immortals are there and no new ones are born, they will be extinct in a millennia or so. [Answer] I propose two solutions to the question that are quite different: **The immortals want to be Monastic Archivists** For ethical reasons they don't believe in money. Perhaps in the past, some immortals did become filthy rich, and the elite immortals became so corrupt and unbalanced that a schism or revolutionary purging was required. The surviving group was not the wealthy immortals, but the ones who wanted to guide society on a spiritual path rather than gaining wealth. An interesting implication of being immortal is they would remember the history of bloody cultural revolutions and never want to go through it again. This might lead to a much stronger belief. What they believe holds value could be something other than money: maybe passing on their unique knowledge, experiences, and memories. There are historical or real societies like this. It is possible they are like Tibetan buddhists, walling themselves up in remote Abbies and living communally in their own marketplace, or more like Menonite farmers, trying to push back the hands of time? Some modern day Abbies function as museums, vineyards, and breweries, co-operatively saving away money for the institution, but the individual monks don't live a lavish lifestyle. I can see how being immortal might eventually renounce materialism, because they have seen governments and powerful rich mortals come and go. **Immortals are a hunted endangered species** There is an explanation why the immortals haven't proliferated and become Humans 2.0. This is a variation of the "Everybody Hates them" scenario, in which the immortals are the victims of discrimation, the minority victims of brutal hunting. Their lack of wealth might be the result of common conspiracy theories about them, genocides, and unethical scientific experiments. In this scenario, the immortals are still endangered despite their lifespan. Perhaps little is known about their regenerative abilities, and some bad actors are still holding them captive in labs, illegally attempting to dissect them for research, or harvest their organs to sell as medical transplants. In this scenario,some liberal governments and groups would be more benign than others, granting immortals asylum, and legally protecting them, or even trying to negotiate restitution for them. ]

[Question] [ **Closed.** This question is [off-topic](/help/closed-questions). It is not currently accepting answers. --- 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). Closed 3 years ago. [Improve this question](/posts/165125/edit) Let's say I'm a normal person, in my thirties, having the ability to travel to alternate realities. These realities are similar to ours, but they get worse each time. New wars, disasters, greater overall suffering etc... I can only travel *forward*, i.e. from best to worst realities. For example, I might travel to a world where a few nuclear bombs were dropped on civilians during the cold war. Then to a world where the same bombs were dropped, and a deadly virus wiped out half a billion people. Then to a world with the same bombs and virus, *plus* the fact that pizza was never invented! But I don't care how terrible the world become as long as I can rule a decent part of it (at least a country). It's the mid 70's, I live in France, I have few funds and no political experience, but I always come from "a better place" and have quite some time to achieve my goal. So far, I imagine I could, for example, take a few best-seller books, travel with them until I find a reality where the author died prematurely, and sell them under my name to get some money and fame. Or any other variation on the same theme, be it art, music, technology etc... But I struggle to find how knowing a better reality can give me a definitive edge on ruling part of a worse one. **A few rules about the "travels"** (might be expanded if necessary): - I can bring stuff with me, but not too much of it: it must pass through a door and into a small room (2m x 2m). - When I travel, my "above" and "below" alter-egos do the same. We never encounter each other but tests have shown that if I decide to leave a message to my follower, my predecessor has a good chance to do the same (i.e. the close versions of me seem to act more or less the same way). - I don't travel in time, nor in location, only in "worseness" and always from better to worse. - The changes may be more gradual than what was put as examples. - These rules are based on what I experienced so far. Maybe one day I'll meet an alter-ego. I just expect things to go on as they did so far (getting worse, not meeting myself unless things really get screwed up). **And about me:** - I'm a french male in my thirties during the 70's, but I have some time to achieve my goals (30 to 40 years if necessary, but the sooner the better). - I'm kind of a bastard (hence the "rule as a dictator" part). - I have a young daugther, but I already left the "true" version of her during my first travel (don't worry, another version of me took my place). I don't really care about friends and family of each realities (see previous point). - I fought in the last years of the Algerian War (ending in 62, french side), but didn't achieve a particularly high rank. So the question is: **How can I (authoritatively) rule France by traveling to worse alternate realities?** [Answer] # You can't, you're too soft. You're talking about making money through arts and luxury food. If you go that far down the line to pizza not existing, you'll probably find food is a luxury. The trouble is that you're going the wrong way, you've had a relatively easy life compared to these places. You may think you're a bit of a bastard, but that's relative to a soft place. Once you're down a few levels you'll start meeting people who'll happily kill you for a crust of bread. The ones who've thrived and achieved power in these places will roll over you like you don't exist. You don't become dictator via going from easy to hard, you get it by going from hard to easy. [Answer] ### Abusing techno-sociology for fun and profit Brace yourself, you're going to have to do a lot of jumping to make this plan work. It's easy to conquer a low-tech world if you're coming from a high-tech one - whether it's through raw force or by providing a luxury that they can't do without. The problem with your method of world-hopping, of course, is that you're not jumping to low-tech worlds - you're jumping to "worse" ones, presumably worlds of violence, oppression, and war. And war has *always* been a major motivator for accelerating the development of new technology. So you're not likely to find an easily conquered world by jumping one or two times - the first few worlds you jump to will probably have *more* advanced weapon technology. Even if you're focusing on luxury tech, that just gives them more of a reason to shoot you and take it for themselves. But technological development has an interesting pattern: **War accelerates the creation of new practical technology by applying existing theories, but most advances in theory - which are important for the long-term development of technology - are made in peacetime.** The reason for this is twofold: 1. Technology flourishes when inventors from different countries are able to interact and share their discoveries, while war breeds mistrust and isolation, slowing this process. 2. Oppressive societies tend to actively crush the development of new ideas among civilians, especially when those new ideas have the potential to take away the power of the ruling class. While the first few worlds you visit will likely have technology better than yours, at some point you're going to start arriving in worlds that have been crushed under the boot of oppression for so long that they never passed through the peaceful periods which allowed technology to flourish. You're going to see technological advancements start to decline. At this point, you're basically travelling back in time, technology-wise - with all the benefits that implies. Eventually you're going to hit worlds that are still stuck in the Dark Ages, while you've got pieces of modern tech. Find a country under the rule of an oppressive dictator (there should be plenty), promise the people that you'll free them from their oppression, then waltz into the castle and mow down the king and his guards with your SMG. You are now the savior of the people (and a mighty wizard that none will dare oppose) and should be able to easily claim the throne for yourself. Moreover, this plan will work for *all* of your instances. While you're conquering a Medieval Stasis world with modern weapons, your counterpart from that world is conquering the stone age with their unbreakable steel sword, and *this* world is being invaded by your "higher-world" counterpart's army of personal robots. [Answer] ## Screw "Yourself" Over and Over Again Pick realities that are very close to your own - you aren't looking for a big change. 1. Take out **loans**. As many as you can, no matter how shady the lender 2. Buy **Gold** 3. **Leave**, sticking your alternate self with the loans but taking the gold 4. **Repeat** After a couple dozen cycles you'll be carrying around a significant amount of gold. You might have to buy wheelbarrows somewhere along the way. A standard gold bar is about 13 kilograms / 27 pounds, and is worth over $35,000. A wheelbarrow full of those is going to be worth a fair amount. Now, **buy a gold mine**. If you've progressed far enough down the "worse" scale, you should be able to find a timeline where some mines you know about (because you did your homework before you left!) haven't been discovered yet due to instability / lack of development. They may be overseas. Grab one, ideally somewhere impoverished but stable. Either do it on credit, or sell some of your gold. Now you have a money maker, and a great way to launder the piles of riches you've smuggled in from other worlds. Rich is basically the same as powerful. After a couple of years of not-quite printing your own money, you move into politics. If France is still democratic in your final world, start doing highly visible charitable work as soon as your operation is up and running, and then run as a businessman / philanthropist when the time comes. [Answer] Spending time in worse realities and trying to grab power there brings out the worst traits in your character. The worse a reality is, the more corrupt and criminal the society is. Every time you travel to a worse reality you adapt to this and become a nastier person. In the end, after 40 years of travelling and hundreds or thousands of travels, you become so nasty that if you were to get in power, you would be the worst possible ruler for France. Because of this, it is inevitable that in the worst possible version of France you are the dictator. [Answer] # Share what you know You don’t extract the greatest benefits from this condition by being “kind of a bastard”, you extract them by being a nice guy and sharing what you know of a better world with the people you encounter in your present reality. Also, you treat your successor alternative-self as well as you can and leave things in good order to ensure your predecessor will do the same for you. First you learn as much as you can about history, geopolitics, and the craft of writing (which will be less well understood the further you step), then you step down and become a political influencer by writing alternative-world “fiction” about how things could have been better, and pay the bills by tutoring and editing the work of other writers. When you run out of ideas you promise a sequel about an even sunnier reality and step down to lower level of reality where you will actually be able to fulfil that brief. As Fred Stark says commenting on another answer, gold tends to be worth more in less stable environments, so you take most of your advance with you in that form. After a while you’ll be able to make money from after-dinner speaking, and eventually run for office. Once in power, any time you run out of idea for reforms you just step down to a lower level of reality again. You might get a better life just by retiring from public office, milking the after-dinner circuit, and taking lucrative consulting work from large corporations, but if you still want to be a dictator, ensure you’re swept into power on a wave of populism big enough such that you can alter the political system in order to stay in power. [Answer] You are already living in the worst realities. And yet you haven't found the way to rule France as dictator. Same with any other reality. You would waste a lot of time to "research" what you can extort that you would literally waste time not extorting the thing. You literally talk about jumping more and more to lower the difficulty. Thus finding the desired one only to be one last french man, weakened by starvation, minutes from dying to be "right" one. If you look at world in the 70's it was (like it is in any time) ripe to take. Just go to a bank, take a loan, hire a bunch of dogs of war and help some country gain "independence". As a Algerian War veteran you should realise how it is done. The "less weakened" the reality you are the MORE opportunities you have. People are more frivolous to spend money (because YSL live and create and not die in bomb attack in Algeria), security is less strict (look at plane security prior to 9/11). You can get away with more. Think about death sentence for food thieves and just 6 months in comfy jail for stealing millions. [Answer] Depends. Can you influence the way in which the reality you travel to will be worse than this one, or is it random? If you can steer it, then you can try to engineer a France that is worse in a specific way that you can take advantage of. Essentially you can pose a question that you have the answer to. So maybe you slip to a France where the military took many more causalties during the Algerian war and are hero-worshipped. You slip to a France where not only did this happen but the Algerians bombed the military records unit and some of your records got destroyed. You slip to a France where as well as the above a banking error totally bankrupted some really worthy charity and you happened to end up as the beneficiary. You get to the point where you can fabricate a much more glorious record of your military history. Then you slip to a version that has all of the above but some event happens that makes a military coup feasible - maybe the democratic government starts passing oppressive laws that happen to annoy the top brass. All the while, in all these worlds, you self-publicise like mad and act like the good guy, the go-to man. When the coup comes, and the military government want a figurehead with some military connection so as to be acceptable to them but also wide public popularity, they come to you. At this point you've managed to become a puppet ruler, now you want to become the real thing. So you slip to a version where some biological warfare vaccine introduced after you left the military turns out to have long term side effects, rapidly killing off all the senior military running the government. With the behind-the-scenes military rulers weakened or dead, you find yourself in the perfect position to cement yourself in true power. Or just short-cut the whole thing and slip to the version of France where you stand for election on a completely authoritarian platform and win, after all from what you've described of your selfish, sociopathic character that is a worse reality than the real 1970s France. If the nature of the "worseness" is outside your control then I would not recommend partaking at all: the first time you slip you might go to a version of France where the USSR attacked and you have about 1 minute until you get hit by one of the thousands of nukes raining down. [Answer] Everyone will be hard and nasty in these worse worlds, so why not bring about a revolution in consciousness? Stock up on LSD, hippie music, and sandals, and bring them with you as you introduce, like, peace and love man, to a world that only knows war. Just be aware that you are not the first person to have this idea: Jesus came from heaven. [Answer] > > How can I (authoritatively) rule France by traveling to worse alternate realities? > > > Your chances are slim. 1. That is our reality in 1970. 2. Going to worse realities, soon you will get one where Germany won WW2 and France will likely be a puppet state of Germany serving the masters of the superior race or will perhaps even be germanized altogether. At this place, you might either: * A. Want to free France from the nazi empire (likely ran by a direct successor of Hitler or a second successor of him). * B. Join the other side and be the nazi-aligned ruler from the superior race in France. Since the world is a worse place, B might be easier. Taking that option, the advantage that you have is likely a knowledge of what would happen if Germany lost the war. Be a French nazi from a superior race wanting to rule France and use your knowledge about weaknesses that Germany had to "improve things", get the trust of the German rulers and serve as the French defendant of the nazi empire. Obviously, many things might go wrong here, since nazis, especially bearing power, aren't exactly a definition of nice people to have to work with. If you however want A, then use the knowledge that could only be made available due to the defeat of Germany for your cause (like the existence of the horrors at Auschwitz) and denounce the nazi regime. Either way, your chances are slim. 3. Traveling back a few more times, you will eventually reach a reality where transistors were not invented and nobody thought about relativity. At this place, you may propose those concepts, be considered a brilliant scientist, get a Nobel Prize and then try to run for an election (or be nominated) as president of France (possibly having nazis, soviets, or who-know-what with or against you, since this alternate reality is way worse than our current one). 4. Traveling a few more times, you will end in a reality where the French revolution got really bad, either by Napoleon severely screwing up the country losing the war at French territory to England, or perhaps by having Robespierre become a great long-lived blood-thirsty dictator and then having the France be invaded by England, Prussia, Russia, germanic states and others. It is hard to know how France will be in 1970, but it will likely be an impoverished state controlled by foreign powers, specially knowing that this is strictly worse than anything you had seen before. 5. Traveling some more times, you will end in a reality where French lost the Hundred Years' War, became a puppet state of England, and there is no such thing to call as France in 1970. Considering that this must be worse than anything before, history from then-on didn't correct or fixed itself, it in fact must had been full of wars, bloodshed, terror, angst and misery, much worse than our own history. 6. Traveling some more times, you will end in a reality where the moors conquered French, that Charles Martel had never been born, and the moors craved their presence in Europe in the Middle Ages and then crushed the christianism. Having particularly no reason to travel the seas 750 years later, it is likely that the Americas will be kept undiscovered for a longer time (possibly up to the 1700's or 1800's). Anyway, the Frank kingdom would be no more than a small note in history books about a short-lived barbaric kingdom that ceased to exist more than a thousand of years ago. However, this might be interesting. You could bring in a lot of knowledge (likely geologic or botanic) about the Americas that will probably be very undeveloped even at the 1970 and use it for your own favor. If you are lucky enough, even at 1970 things like electricity will never have been invented or will be very poorly developed and understood and you might use that knowledge to make money and then use the money to rule the land between the Britannic Islands and the Iberian Peninsula, whatever being the name or the political structure given to it. 7. A few more travels, maybe Mohammed never existed and there was no moors or islamism at all. 8. Traveling some more times, you will end in a reality where Attila won the Battle of the Catalaunian Plains and became a powerful and long lived blood-thirsty emperor, having conquered, the East Roman Empire, the West Roman Empire and all of the barbarian tribes and also reverted christianism back to paganism. Only God knows what could happen then, but given the fact that this is strictly worse than any other reality already visited, it will surely be a pityful mess. Anyway with this, it is extremely unlikely that France would even ever exist. 9. Traveling a lot of more times, you will eventually reach a reality where a large Mass Extinction Event wiped out much of the land vertebrates, including all the hominids. Other than you, there is no such thing to call as human living on this planet anymore and there will never be. 10. Traveling still a lot of more times, you will eventually reach a reality where a planetesimal collision went terribly bad and destroyed the proto-Earth altogether having something else removed the debris from the newly formed asteroid ring to ensure that no live-bearing planet would ever be formed. The problem is that when you come reality 1, another yourself would travel to a different reality (call it 1.1) and the yourself from 1.1 will travel to 1.2, the yourself from 1.2 will travel to 1.3 ... Then yourself from 1.9 will travel to 2. The guy from 2 will go to 2.1 ... Until someone will eventually land in 9. But at this point, there is nobody from 9 to go to a worse reality. This means that your chain of another yourselfs travelling to even worser realities is broken. Eventually a reality that you won't exist at all will show up. In fact, we don't need to go so far as to reach reality 9, it is very possible that 1 already changes enough to ensure that your parents will never meet or will die before being able to get kids or anything like that. [Answer] Several other answers are correct in that you're much more likely to succeed when going from "bad" to "good" than vice versa. So that's exactly what you do, only in your situation you have to *take the long way around*. Let's number your realities for ease of reference. Your world is 0, the world through your "worse" door is -1, and the world through your "better" door is +1. Every time you jump, your +1 self jumps into the world that you used to occupy. Since the rules apply to everybody, that means your +2 self jumps into world +1, your +3 self jumps into +2, etc. This implies that there are an infinite number of worlds in the "+" direction. You said that the different versions of yourself never encounter each other. This implies that there also have to be an infinite number of worlds in the "-" direction. Otherwise, the lowest-world version of you would have nowhere to jump, and two versions of you would encounter each other (a paradox). This also implies that the worlds in the "-" direction can't actually continue to get worse infinitely, or at some point you'd enter a world so bad that you immediately stumble across the corpse of your -1 alter ego who was instantly killed by the toxic environment (another paradox). How do you reconcile these observations? At any point in time, (current world -1) appears "worse" than the current world. If you could observe *all* realities *at the same time*, however, you would describe your universe as a closed ring of realities that transition from "good" to "bad" and back again. You see, you adapt to new realities fairly quickly and as you do so, your opinions of subjective concepts like "better" or "worse" start to shift as well. Eventually, you'll see the next world down the line as worse than the current world, but the original world-0 version of yourself would see that same change as an *improvement*. The real mind-bending part is that this description is accurate for every version of you, *no matter which reality you started in*. Keep traveling around the cycle until you get to world +250 or so. They probably haven't had so much as a fistfight in decades. It shouldn't be too hard to subjugate a group of them and bootstrap your evil plan. [Answer] I'm going to latch onto the military service part. When the military isn't busy fighting full on wars, they are improving their processes and creating contingency plans. The military also aids in humanitarian crisis, so every step to a worse world, is one where the military is more depleted dealing with problems. By bringing your first hand learned improved processes, and knowledge of contingency plans made in better realities that never needed them, Every step down you will be a "Next gen soldier" who "Always knows what to do" and is a "brilliant mind". And since you next self is doing the same thing, that means each version of yourself is on the fast track for promotions. After enough iterations, you will be promoted to head of the military. With enough jumps, the situation will become worse enough that the military need to take control to preserve order, and a dictator is born. Of course this reality will be a hell hole compared to the one you started in. But you know the saying "Better to reign in Hell than Serve in Heaven". [Answer] **Note:** This answer is based on obsolete wording in the original question that suggested that all jumps happen at the same time by decision from each alter-ego. Which leads me to conclude they have similar or shared motives and thinking process, then extrapolate. For an answer that doesn't use this premise [see here](https://worldbuilding.stackexchange.com/a/165346/8703) # Start with some definitions So, what do we know? * There are other realities that are "better" and "worse" than the current one you occupy. * They are all similar enough to have yourself in them. So, let's define our terms (inspired by [bta's answer](https://worldbuilding.stackexchange.com/a/165194/8703)): * we have you as a reference point. It's the one who is asking the question. We'll label that **you**. + **you-1** is the version of you from the worse reality you are going to travel to next. + **you+1** is the version of you from the better reality immediately before yours. Presumably, you've been there previously (unless you haven't travelled at all yet). * Similarly **reality** is the one **you** currently occupies. + **reality-1** is the worse reality that **you-1** occupies. + **reality+1** is the better reality that **you+1** occupies. # Mathematically provable that you cannot! OK, stick with me here as I definitely prove you're not going to rule *or* you don't want to. So, with the above definitions in mind what do we know about the travel: * When **you** travels, then **you-1** also travels. * When **you-1** travels, then **you-2** travels. We can thus generalise that all **you** to **you-n** (where **n** is a positive integer) all travel at the same time. We can observe the same relationship in the other direction: everyone from **you** to **you+n** also travel at the same time. * To generalise again: **you+m** (where **m** spans [+∞, -∞]) all move at the same time. Next, we also know that this is a *decision*. You are not forced into immediate relocation if one version of you moves. Not *explicitly* at least. We can theorise that there is some unconscious link that drives all of you. Or maybe you all have similar enough thinking so you come to the same decision together. It matters little what the exact mechanism is, since the result is the the same. We can define a simple recursive algorithm with these terms. * **you** wants to be dictator. * **you** is willing to jump until you find a reality where you can achieve that dream. ``` jump(reality) if (I_can_become_dictator()) return; jump(reality-1) ``` In simple terms, if **you** can achieve your dream you'd stop jumping. If you cannot, you will. # You are doomed! This has rather unfortunate implications when you take into account the shared decision making, since *all* of **you+m** jump at the same time through decision. When you transition to **reality-1** that's where **you-1** was and they also made the decision to jump. * Since, they would essentially be running the same algorithm as you, it means **you-1** could not become a dictator, either. If they could, they wouldn't have jumped. * Alternatively, **you-1** *did* manage to become a dictator in **reality-1**, yet they still decided they wanted to move. That means it's *bad* to be a dictator there. In either case, you are all doomed. If you're making jumps at all, that means that none of **you-n** succeeded *or* a worse reality was still more desirable than the success. # All of you are doomed! We can examine this in the other direction - **you+n** would live in a *better* world. For high enough values of **n** this would be some sort of utopia. All of **you+n** are never satisfied. They are all willing to travel to worse places and run away from the utopia into worse and worse realities. Same thing happens to **you-n** - they just go into worse and worse realities, too. Again, if **you** make a jump, so does *everybody else*, hence the mere fact that you are making a jump is proof of the failure of **you+m** to find a place you like. So, it seems like the only winning move is not to jump. [Answer] **Stemming from the assumption that each alter-ego has completely independent motivation and reasoning process.** This takes on an entirely different direction from [my other answer](https://worldbuilding.stackexchange.com/a/165330/8703). # Start with some definitions So, what do we know? * There are other realities that are "better" and "worse" than the current one you occupy. * They are all similar enough to have yourself in them. So, let's define our terms (inspired by [bta's answer](https://worldbuilding.stackexchange.com/a/165194/8703)): * we have you as a reference point. It's the one who is asking the question. We'll label that **you**. + **you-1** is the version of you from the worse reality you are going to travel to next. + **you+1** is the version of you from the better reality immediately before yours. Presumably, you've been there previously (unless you haven't travelled at all yet). * Similarly **reality** is the one **you** currently occupies. + **reality-1** is the worse reality that **you-1** occupies. + **reality+1** is the better reality that **you+1** occupies. # Organise together All alter-egos would have *some* difference in what they do or want but ultimately there is also going to be *some* similarity, too. > > We never encounter each other but tests have shown that if I decide to leave a message to my follower, my predecessor has a good chance to do the same. > > > A **you+/-m** (for small enough values of **m**) would be quite similar. Larger spans might not be as similar. Still, I think chances are good that you'd be able to convince "yourself" from the **you+n** range to join forces. So, what do you do? Just leave a note saying "Hello, me, join me after the next jump. Bring as much as you can". Doesn't really matter what he precious resource is - might be gold, silver, or whatever you want to capitalise on. Might even be mixed. The realities are not likely to be *too* different, so what's useful in this reality will probably be worth it in the next. Now just stock up on whatever resource then make the jump and sit and wait in **reality-1**. It's not *guaranteed* that everybody would follow though but there should be at least a few people. And with *infinite* other alter-egos, I'd imagine the number might be sizeable - 100 or more. That means that there would be 100 or more times the resource requested. And some like-minded individuals (they did, after all, follow **you** and the request). There is now a clone army (or alter-ego army?) that can be used, too. They can go around so "you" might appear to be in several places at once. It shouldn't be too obvious but there can be benefits to having multiple people that look the same and act the same (or close enough for both). The collection of individuals can also use the vast collective resources at your disposal to get more power, influence, and resources. There could be a you that goes to secure new contacts, while another you is acquiring more resources, while another you is using resources to get more power (bribes, buying shares, etc). There are a lot of options open for somebody who can be at several places and has a lot of money "from thin air". I can't tell you the specifics of how to exactly utilise these resources but...here is the beauty of it - I don't have to. There can be several alter-yous that will be poring over books and studies about finances, management, strategies and everything else that will help your collective goal. This all relies on having faith in yourself (heh, couldn't help it) in that **you** have to trust the other alter-egos and each alter-ego has to trust every other one. Given that they would all be coming from **reality+n** space, which is *better*, chances are high all of you would cooperate, as they are going to be better people. If there are disagreements, an alter ego is always free to just jump to the next reality. Or...well, they can be made to jump in extreme cases but hopefully you can convince yourself (heh) that's not going to be needed. I am fairly confident that working together with your alter egos has a high chance of success. # Potential problems There is only one problem you can encounter. Well, actually several but it's essentially the same thing: nobody comes. 1. **you+1** already enacted this same plan and is now sitting at what is currently **reality+1** for you (where you left the note) and is getting the gang together. * this has a potentially easy and potentially disastrous solution. Make your stay in that reality very hard. Commit some crime or misbehaviour that will mean **you+1** would have to leave. Hopefully it's not *too* bad, otherwise **you+1** wouldn't be able to gather resources before the jump, but still. This can be disastrous if it damages your trust with every **you+n**, though, so be careful. 2. **you+1+n** already enacted this same plan and is now sitting at what is currently **reality+1+n** for you (at least one above where you left the note) and is getting the gang together. * like above but you have no way of influencing it. You might get some alter-egos who for some reason or another left that reality to come to you but it's not guaranteed they would or they would heed the note or that they would stay. In fact, chances are they wouldn't if they didn't stay at the reality "above" that enacted this plan already. 3. The **you+n** versions just decided not to jump for a different reason. Perhaps they like it where they are, perhaps it's something else. * this sounds bad. It sounds as bad as the above but...it might actually be better. See, with scenario 2. you'd get the stragglers that *don't* like this plan for some reason. However, with truly independent reasoning *and* nobody "above" enacting this plan *and* most importantly *infinite versions of yourself*, chances are high that somebody would come at some point. The thing with infinity is...that it's big. All versions of you are free to make the jump or not. Even if, say 0.001% of them decide to jump, that's still *a lot*. Even if another 0.001% *of those* decide to continue jumping, that's still 0.000001% *of infinity*. At some point, somebody would eventually arrive. In fact, the "bad scenario 3" is probably going to result in what I described in the main body of the answer. 4. There is no independent decision making. The only way to get somebody here, requires you to jump. Perhaps you sit and wait and "decide" there is no point waiting...which occurs to every single **you** of you at the same time. * [You are doomed](https://worldbuilding.stackexchange.com/a/165330/8703) So, to recap - if nobody comes the winning move is still not to jump. Either nobody would come *ever* or you'd eventually have some of **you+n** trickling in. [Answer] Since the alternate-reality versions of yourself are also travelling, do the following: (1) Take out a gigantic loan and use it to buy gold. (2) Travel to the next reality down the line. (3) Repeat steps (1) through (2) until you have enough money to but control of France, plus enough to hire your a literal private army. Of course, this runs the risk of that your alts will have done the same thing, sticking you with the debt, but its the best option. If you travel to a reality only to discover that one of your alts was using the same tactics, use the goldmine proposal that @codeMonkey made. [Answer] It's pretty simple in my opinion. 1. All you need is a gun or some other advanced weapon. 2. Continue travelling realities until the weapons/technology is inferior enough. 3. Claim yourself as the ruler of some group of people. 4. If anyone objects shoot (them or something nearby) and then repeat 3. 5. Congratulations on being the undisputed ruler. [Answer] **Transport yourself to a "worse" France, which will elect you as president.** This answer doesn’t use much sci-fi. Apologies if this was a requirement. I don't know whether your story is about how you become dictator, or about what happens once you become dictator. The following assumes that you’re capable of becoming dictator once you're head of government. It’s been done before, with dictators of the far-left and far-right. France has a two-stage election process. Anyone who gets 500 supporters can run for president. If no-one wins outright, then the top two candidates go head to head. Choose a reality where the voters are more inclined to fascism. Maybe France has been under authoritarian governments for a long time, and they have become accustomed to it. Or maybe they had a brief period of democracy, which coincided with hardship and humiliation, and they therefore think of democracy as a bad thing. Or maybe they’ve been a democracy for a while, but things are starting to fall apart either due to the economy failing, or because of crime and terrorism, with decisive leadership being seen as the solution. The worse your reality, the worse the economic situation, crime, and terrorism will be. First, you need to get a top two result in the first round. To maximise your chances, choose a reality where faith in mainstream parties has been badly eroded, and where the individual candidates have been badly affected by scandals. Also, choose a dysfunctional political scene where there are multiple political parties with similar positions. The more infighting, the better. Also, the more candidates there are, the more likely you are to get top two with a small proportion of the vote. However, make sure that you don't go to a reality that's so much worse that there's lots of far-right candidates that'll be taking up your political position. To win the second round, try to get an opponent against whom you're likely to get a lot of votes. I have absolutely no idea who you or your daughter are, but if you happen to be a far-right candidate, then running against a left-wing opponent, possibly an incumbent, may give you the best chance, based on these [polling figures](https://en.wikipedia.org/wiki/Opinion_polling_for_the_2017_French_presidential_election#Hollande%E2%80%93Le_Pen) which show different voting figures depending on who the far-right candidate is running against. That will be because, assuming that people are on a one-dimensional political spectrum from left to right, then people in the center right may decide that they're "closer" to a far-right candidate than a left-wing one. So choose a slightly worse reality, but not one that's too much worse. Also, watch out - around the time you returned to France from the war, the Prime Minister of Australia [disappeared](https://en.wikipedia.org/wiki/Disappearance_of_Harold_Holt) without his body ever being found. He might have been using the same technology as you. [Answer] Before you make each jump, do something to ensure that none of your replacements will be able to trigger a jump. And/or to give them incentive to not jump. Otherwise, IF you ever manage to get control of France, you’ll be forced to lose it and start over in a worse world. ]

[Question] [ I've noticed that most magic systems appear sometime between a civilization's Bronze age and Medieval period, sometimes as early as the stone age. What properties would a magic system need to have for its discovery to come much later in technological development? Specifically, around the time that electricity is beginning to be harnessed and steam-powered trains exists and railroads connect several major cities, i.e. the late industrial revolution. Magic can't be limited by genetics. If it were a matter of "having the gift", magic would have been discovered much earlier when the first magical child sneezed fire on one fateful day. Magic can't be based on a spiritual connection to nature or some divine power. Since spirituality comes much earlier in human development, magic would have been discovered alongside spirituality in this case. Magic would likely be scientific or mathematical in some sense, but it needs to have certain properties to avoid its discovery alongside alchemy (as in the precursor to chemistry, not magical chemistry), heliocentric astronomy, the printing press, physics, and calculus. What limiting factors would delay the discovery of magic into the late first industrial revolution? [Answer] > > (...) Specifically, around the time that electricity is beginning to be harnessed and steam-powered trains exists and railroads connect several major cities. > > > Magic is powered by alternating current, or by steam powered engines. This kinda happened in our own world, [if you consider electromagnetic fields to be a form of magic](https://www.youtube.com/watch?v=_-agl0pOQfs). People in the 19th century surely thought the radio was a work of wizards. The following explanation of the phenomenon is often misattributed to Albert Einstein: > > [You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat.](https://quoteinvestigator.com/2012/02/24/telegraph-cat/) > > > This rhymes well with tropes such as using lightning to imbue life into corpses, *a la* Frankenstein. [Answer] Make magic require materials that were not available, or at least not in sufficient quantities, before the industrial age. Consider, for example, magic wands from the Harry Potter franchise. Despite having a genetic component to magic, wizards nevertheless use wands to focus their power, and wands must be made from specific magical materials. In Harry Potter, these are generally taken from magical creatures, like phoenix feather--but what if the best magical focus were actually pure crystalline titanium? (Or even silicon--after all, trapping lightning in a flattened purified rock to make it think for us is pretty darn magical...) The serial novel [*Ra* by Sam Hughes](https://qntm.org/ra) features the discovery of magic around 1970, purely by chance when someone accidentally figure out the correct words to utter, but magical machinery involves a lot of modern industrial manufacturing processes and the main character has a steel staff as her main piece of magical kit--even if the basic discovery of magic energy had accidentally happened earlier, no one would've been able to make any significant use of it anyway prior to the industrial age, when specific alloys of steel could be reliably mass produced and machinery could be devised for storing and handling thaumic currents. If efficient use of magic requires access to pure metallic aluminum, metallic titanium, plastics, or any other products of modern materials science, or if it requires larger power sources that are simply not available in nature and could only be experimented with after the introduction of steam engines and/or electrical generators, then humanity will have no way of discovering magic until they first develop those power sources and materials. [Answer] Magic was known all along, but was terribly unsystematic and badly known. The first industrial revolution changed this both by raising standards of living so that it became feasible to educate many more children rather than have them drudging in the fields, producing more potential magic researchers, and by developing more systematic ways to study things. Some proportion of the potential researchers did research, and got better knowledge. And the improved communications let them accumulate knowledge even more quickly. Rather like, oh, science and technology [Answer] Advanced chemicals. Traditional witchcraft depends on natural ingredients like cobweb or toadstool. What if magical chemistry needs more advanced ingredients? Many of the chemicals had become available only during industrial age. An alchemist might have luck with synthesizing one or two of them - but not the whole set. Here are some of the chemicals that don't occur naturally, but very ubiquitous today, together with the year of discovery (synthesis/isolation): ``` Prussian blue 1703(?) Nickel 1751 Chromium 1797 Morphine 1803 Portland cement 1824 Metallic aluminum 1825 Isopropyl alcohol 1920 ``` When combined in certain proportions, novel chemicals would produce effects (sometimes, very powerful) that can not be predicted by chemistry. Some people can call that magic. [Answer] Magic requires an extraordinary amount of power to function. Before the Industrial Era, there weren't many high-output generators, and almost none of them used electricity directly. Perhaps your world has a magical material that is inert under most conditions, but is activated when exposed to a high amount of energy. While lightning might activate it before this point, the charge it puts out likely wouldn't last long enough for the material to have any long-term effect. Perhaps it would just gain some magical attributes for a short period of time, such as a constant warmth. But with access to more consistent electrical power, that magical energy can finally be maintained and harnessed by people for various purposes. [Answer] ### It was fatal in the wild, but researchers can conduct controlled experiments and their successors can learn (Loosely inspired by Charles Stross's [*Laundry Files*](https://en.wikipedia.org/wiki/The_Laundry_Files) series.) Magical phenomena have always taken place, but they almost always kill the recipient in various interesting ways. Visible causes of death may include spontaneous human combustion, suffocation or heart attacks for no apparent cause but with a look of great horror on their face, or vanishing completely. You'll notice that this is pretty much a list of what you'll find in any "supernatural and unexplained events" book today. No-one has had a chance to find out why, because no-one generally gets a second chance to say "I wonder why that happened...?" The Industrial Revolution had a lot of unexpected side effects. The biggest one was the democratisation of learning. People went to science demonstrations by people like Humphrey Davy in the same way we'd go to the cinema. Science was *cool*. It was still rare for working-class children to get much of an education, but very promising children could get scholarships, and middle-class children definitely could get a good education. Not only that, but with so many scientific advances and so many skilled trades opening up, adult education was *huge*. It's no coincidence that science and engineering generally followed an accelerating trend from then on, because what gets you progress is not usually one genius but a thousand "merely" talented people. Much of what was discovered then did not particularly need the technological apparatus of the Industrial Revolution (Darwin didn't need steam engines to work out evolution) but it absolutely required that social environment. So, what might our hypothetical gentleman scientists have investigated? There are all sorts of strange rituals and beliefs in human society, especially in the old country traditions and sayings. Throwing salt over your shoulder if you spill it, saying hello to magpies, a belief that chewing willow bark will help pregnancy pains, touching wood after a future prediction, red sky at night predicting good weather the next day, women being bad luck on ships, and so on. (You'll notice two of those are broadly correct, of course!) We have plenty of evidence of gentleman scientists deciding to apply the scientific method to folk remedies. So it's almost inevitable that if magic actually happens, someone will run across it. The difference this time is that they're looking for it, and they're prepared. It's possible that they may have an idea of what could happen and take some precautions to improve their chances - perhaps earthing wires, perhaps a rope tied to their wrist, perhaps a diving suit. The main thing though is that they document what they're going to do *before* they do it, like all good scientists. And this time, whatever happens to them, a record exists of precisely what they did to kill themselves. All these gentleman scientists were in contact with others working in the same area, of course, so if one hits a phenomenon which kills him then all his friends know exactly how to reproduce it. The state of his body gives them a useful guide on what might have happened and how to stop it happening to them, and a repeat of the experiment can be done with observers behind safety shields. This is almost exactly how other high-risk science ran at the time. The discovery of fluorine and fluorinated compounds, and then the discovery of what not to do with them in a confined space, was basically a succession of people saying "what if I do this?" followed by a fatal explosion. (If you haven't read the [Things I Won't Work With](https://blogs.sciencemag.org/pipeline/?s=things%20I%20won%27t%20work%20with) blogs, I would recommend them even if you only have a hazy knowledge of chemistry.) Even in more mundane areas of engineering, variability in the quality of materials led to some serious bridge collapses, and to steam engine boilers exploding catastrophically. The leading edge of science and engineering always has some casualties. But however dangerous this is, eventually our body of gentleman scientists *are* going to figure out how to work safely with it. Whether the answer is earthing, rubber suits, sprinkled salt or holy water, a sacrificial goat or whatever, if an outcome can be reproduced then people can figure out mechanisms to deal with it. Many people blew themselves up or poisoned themselves with fluorine, phosphor and sodium (three elements which are just looking for an opportunity to kill you); but now sodium monofluorophosphate is what you brush your teeth with. Magic will go exactly the same way. [Answer] ## Magic Is Math Magic has always existed in the world - but it isn't the requirement of rare materials that restricts it, nor having a certain blood lineage. And its secrets were known as early as the first arithmetic was being invented. But early magic was slow - very slow, in fact so much so that it was considered little more than a curiosity, because what you could accomplish with it was severely limited by how quickly you could run computations - which on a human level is far, far too sluggish. ## Then Along Came Charles Babbage When Babbage invented the [Difference Engine](https://en.wikipedia.org/wiki/Difference_engine), in our world it was not widely adopted for practical use - but in this world, rapid mathematical calculations would have a practical purpose. They would greatly speed up the rate at which magic could be performed. This invention was created in 1822 - which is the very late period of the [first industrial revolution](https://en.wikipedia.org/wiki/Industrial_Revolution). [Answer] The most obvious would be a magic system that is based on technology or electricity, such as electrokinesis. This type of magic could activate when a character holds a certain object, or when they are affected by electricity. However, that gets thwarted by lightning. Since the industrial revolution was basically the start of mass pollution, perhaps a magic system based on smog, or when the atmosphere isn't clean, would be appropriate. However, I'd just introduce an object powered by electricity, or perhaps a radio or some other device, that activates that character's powers, which can only be used when they have that object on their person. I guess said magic could be scientific, or maybe steam-powered, since the locomotive was invented around this time, or maybe telegraph-based? Maybe it could be based on the Bessemer process (<https://interestingengineering.com/35-inventions-that-changed-the-world>), which produced better-quality steel. Maybe it could be activated by steel, which became much more common during the Ind. Rev? Other technologies: arc lamps, modern matches, electromagnets, photographs, the Dynamo Generator, the hydrogen fuel cell, dynamite, and incandescent lamps. So, unless you introduce an invention/object that grants/develops existing powers, or make it based on electricity, or the physics of electricity, I can't really see a way. P.S. Dynamite-mancy would be cool. [Answer] **The society that knows magic was isolated.** In addition to technological innovations, the late industrial revolution was also the age of exploration. The culture which understands magic is isolated - perhaps pacific islanders, or an Amerind group. Exploring Europeans realize what this group has and they begin studying it in earnest. [Answer] **1** Aluminium. Aluminium like element I will simply use Aluminium and you can substitute that with whatever name you like. So reading the wiki page for our Aluminium friend says that they were super rare. They were more expensive than gold and people did not know how to make large amounts of them. Sure it dates back to the Greeks but we can ignore that. So until people knew how to make Aluminium in large amounts, they could not use magic. Pretty simple really. Now this will lead to something like this: after your Bayer and Hall–Héroult process is made then they discover interesting side effects for using large amounts of Aluminium. So those are science men and they mess around with your Aluminium the lo and behold: Aluminium, used properly, is the stuff of magic. The rest is up to you. Perhaps it needs to be in contact with the person, or it needs to make a certain shape, a pentagram is an obvious answer, or even it can be eaten...etc. Honestly whatever suits your world most. Also the quantity aspect solves why it was never apparent that it was magical. Until we made tons of it it was making so little magic that people did not notice. **2** Penicillin. Penicillin like thing. I'm not good with chemistry so bear with me. The same Aluminium idea is the same. Only it's something like a plant or a combination or things. Basically penicillin. Read on the actual penicillin and change whatever you feel like it. This again means that it possible to create the stuff of magic in a lab. We only needed to mess around with the right stuff and viola. MAGIC. While at the same time insures that no society before those with your limitation can make them. **3** A rare natural element that is only accessible with deep mining capability. Obvious things is obvious. We needed to go so deep underground or underwater to extract Contrivium, terrible writing advice if you don't know or the classic: Phlebotinum So after the technology of the world advanced to that point we started seem this thing. And it did not take long to people to figure out it's magical. And even if people back in the day found an ore or a gem or whatever. They still could not get more so it was more like one time thing. **A simple point** "Magic would have to be scientific or mathematical in some sense" I see this as a problem. The scientific method as we know it is new. Sure. But can you point to the Roman, Muslims, Chinese, Greeks, Egyptians...etc at their highest point in history and say: they new nothing of how to manipulate the natural stuff into useful things? Because science is all about that honestly. OK we can argue but point is that a bunch of people wanted to make X happen, so they got together and made X without magic and by only using their brains and a little, or much, labor. That is the same principle behind sending someone to the moon or making a box of whatever materials to call it your own and to protect you. Basically the fundamental principles of making a spear is more or the less the same behind making a fighter jet. And mathematics, afaik, are not limited by science I'd say. So it's a particular level of scientific knowledge and practices you are looking for. Fair enough and there is no problem with that. Though lets not forget that in a 100 years our science might look like that of idiots to them. So it is NOT a matter of a constant thing. So scientific discoverer and ability are subjective. Anyway all I'm saying is that confusing a certain level of scientific knowledge with science in general is not a good idea for your setting. And if that does not work for whatever reason then just tell us what other factors are into this. [Answer] ## Magic is Environmental In the [Shadowrun](https://en.wikipedia.org/wiki/Shadowrun) setting, mana comes in cycles. The world did end in 2012 [as predicted by the Mayans](https://en.wikipedia.org/wiki/Mesoamerican_Long_Count_calendar#2012_and_the_Long_Count), but that was just the Fifth World, the Sixth World immediately followed it. Even cycles are high magic, odd cycles are low/no magic. Each even cycle ends with a visit from magically apocalyptic creatures called Horrors, who wreak havoc on humanity until the level of magic plummets, but that's neither here nor there. The idea is that all the mystical and spiritual traditions that are passed down over centuries are *real*, based on things that worked in the *past*, but there isn't enough ambient magical energy. Once there is enough energy available in the environment, things that people had been doing for centuries *just start working*. This doesn't preclude any of the other restrictions on magic, like genetics or skill. Even with the right genes or the right techniques, without a sufficient ambient magic field, none of the rest matters. In your case, if the industrial revolution coincided with the return of sufficient ambient magic energy, scientists and engineers would begin studying the phenomena. Telegraphs and faster travel methods would allow stories to get to potential investigators much more quickly than in ancient times, and gather data in larger quantities. Your smart folks would have access to empirical evidence and be able break down the myths and legends into reality and truth. [Answer] Running in a different direction from Graham's mention of the [Laundry Files series](https://en.wikipedia.org/wiki/The_Laundry_Files) by Charles Stross In that series, Magic is a branch of applied mathematics. Magic users have existed in various forms for much of human history, but generally have poor results and a low survival rate. It's only with the invention of mechanical and electro-mechanical computers, and the discovery of the underlying equations (Turing's Last Theorem) that magic has become readily accessible. The Oft-repeated description is that simulating the right/wrong equation sets up resonances in the multiverse, resonances that can be felt and heard by entities further down the mandelbrot set from us. With the right equipment, and the right mathematics, you can talk to them, and they'll talk back and help do things. Essentially demonology. The upshot is that most of those entities are little more than computer-programs themselves, known in-universe as "feeders in the night". Summoning one of those is a great way to land yourself a zombie. A zombie that can be bound and programmed with a verbal programming language of sorts. The good guys use them as night-watchmen. But there are bigger ones, vasty intelligences from the nightmares of H.P.Lovecraft, and summoning one of those is a fantastic way to hasten the heat-death of your universe. Fortunately it's extremely difficult to do and requires a lot of blood-sacrifice (death means the destruction of the information in a person's mind, which sets up spacetime ripples and can power the invocations) The Nazis had a solid go at summoning such an intelligence in the 2nd world war. [Answer] If you want to have a sudden late explosion of magic why not have it based in symbiosis with an extremophile microorganism? Think midichlorians from Star Wars. A cavern found when mining deep underground is glowing and warping spacetime, filled with billions of tiny organisms where they evolved without light or much chemical sustenance or maybe they were discovered when an asteroid hit the planet or some other method of discovery or dispersion throughout the globe. After the discovery of the # microorganism it began to propagate throughout the natural environment unconstrained by the previous prison it was in. As a hardy organism different to anything else encountered, the immune systems of most species had no defence against it. Some people had a reaction and died, the majority adapted to live with the tiny organism, much like how all of our cells now contain a mitochondria. Not long after the spacetime warping microorganisms began fusing with natural creatures, unusual effects began to be seen as said creatures began to exert some level of control over space, warping gravity to move objects without touching them, causing electrical and thermal abnormalities. As humans began to experiment with these new abilities they found that by using certain tones of voice, noises, movements of their body hosting the organisms they could produce a vibration/sympathetic response in the organisms in their body or ones nearby to produce more complicated effects etc etc. It naturally leans more towards sorcery than wizardry but could be flavoured as either. If you want to make it somehow exclusive then have it passed in families who guard their bloodlines carefully and consider their blood sacred and ban transfusions for fear of others gaining the same abilities. [Answer] Some ideas how to spin this: * the discovery of radioactivity (around 1896, matching your timeframe) and further research of it enables spells and magic: [wikipedia](https://en.wikipedia.org/wiki/Radioactive_decay#History_of_discovery) because handwavium * deep (industrial) mining released some kind of trapped (angelic/demonic/alien?) entity that grants magic(very advanced technology) to its followers * technology advancement (spinnig two elaborately inlayed gold/platinum/copper circles antidirectionally at 250mph while funneling X-ray beams through it) allows opening the long-thought-lost and buried/hidden portals into different faery realms. So far tales about magic existed, but *humans* had no access to it - now we can conquer faerie and grab all its magic resources (shiny berries/faery liver anyone?) for ourselfs * unrelated ambient magic levels rising/falling ([Wikipedia - Magic\_in\_Earthdawn](https://en.wikipedia.org/wiki/Earthdawn#Magic_in_Earthdawn)) Magic mana availability raises/falls and only with a certain level of magic ambiency it can be harnessed. High levels of mana correspond to demons roaming earth, killing humanity. Last time round was just before ice-age and all but few humans were eradicated, a long magic draugh period followed and now it rises again by pure happenstance. All magic cookies currently show dark things to come ... [Answer] Two ideas that come to mind. The Stross' Laundry Files world is already referenced in a couple answers. However, Stross, for his own reasons, wanted magic to be ancient, in order to tie its existence in the world and link to the ancient horrors. In your case what can be done, is that # Magic is not inherently present in all of maths, but rather in a specific sub-field of mathematics, which has only been discvered in the last 100 years, and which *requires pre-existing mathematical apparatus, not available in earlier times*. If you look at [Mathematics timeline](https://mathigon.org/timeline), one thing that immediately appeals to me is **fractals** and chaos theory. [Fractals](https://fractalfoundation.org/resources/what-are-fractals/#:%7E:text=Fractals%20are%20infinitely%20complex%20patterns,systems%20%E2%80%93%20the%20pictures%20of%20Chaos.) almost look magical on their own. However, if that doesn't appeal to you, take a peek at maths stack exchange, there will be plenty questions present-day maths, which seem damn magical to me, and much of which, I presume, require mathematical knowledge and know-how not available 200 years ago, not to speak of earlier. Anything that requires **group theory**, for example. # Radioactivity is tied to magic. Until 19th century, people had no idea that something like radioactivity -- completely undetectable to our senses -- could exist. It existed in the world, of course, but we were completely oblivious of it. It only comes natural that when radioactivity was discovered, its effects might include not only the physical, which we have studied so well, but also magical. Either as a source of magic, enabler, or something, radioactive materials are the only way people get to actually do magic. And only in 19th/20th century we came to be able to produce radioactive materials in significant enough quantities for us to use them magically. [Answer] Magic has always been here in small quantities. So yes witches could use magic but mostly relied on 'headology' and basic herb based medicine. Magical energy (Mana) slowly leaks into this world (dimension). However it wasn't until the Trinity test (first atomic bomb) that large amounts started flowing in. The atomic bomb blasts weakened the barrier between the magical realms and ours. So now we have lots of mana, ready to be harnessed. ``` Edit: Oops I got the time period wrong. Updated version is that even small explosions cause small leaks. So cannon fire causes Mana to leak in for a while. ``` [Answer] Electricity! You see, magic needs electricity to work. It needs energy, as magic does not allow you to break the energy conservation principle - it simply allows you to use energy to interact with the world in new and unusual ways. Pre-industrial age, the best you could get was the mage's own muscles with very tiny electric current, or maybe an electric-eel if you lived in a good place. Ancient Egyptian wizards used the acid batteries for their rituals - how do you think they've built pyramids? So cue the electricity, and some gifted people suddenly discover that they can do more than move a single scrap of paper on a windless day. They can now move whole cabinets when holding a live wire. [Answer] ## Electricity generates Mana needed for Magic In order to make magic work a certain amount of Mana is needed, however Mana is only generated near strong electrical currents, and prior to the industrial revolution your only real chance of finding any was being in a thunderstorm. As the Mana dissipates fairly quickly while there might have been the occasional wizard back in the day, their opportunities to practice and learn the craft were severely limited. This does mean that if you want to practice magic in the wilderness you need to bring not just a battery, but some sort of device that uses a fair amount of current. [Answer] ## Hamilton In 1843, around the [William Rowan Hamilton](https://en.wikipedia.org/wiki/William_Rowan_Hamilton) published an idea for using [imaginary extra dimensions](https://en.wikipedia.org/wiki/Quaternion) to perform lower-dimensional operations. These new mechanics were used by [James Clerk Maxwell](https://en.wikipedia.org/wiki/Maxwell%27s_equations) in the 1850s and 1860s to unify and explain two new mysterious forces : electricity (discovered by Charles-Augustin de Coulomb in 1785), and magnetism by way of galvanic induction discovered by Michael Faraday in the 1810s through 1830s. Hamilton's technique, extending complex (imaginary) numbers into [quaternions](https://en.wikipedia.org/wiki/Quaternion), would precede [octonions](https://en.wikipedia.org/wiki/Octonion) which are currently being looked into for application in string and M-theory. Additionally, Hamilton developed a way of looking at things that departed from time- or location- dependency, looking for alternative ways of viewing chemical or phyical processes (such as their total energy and a range of statistic probabilities for values such as postion). [Hamiltonian mechanics](https://en.wikipedia.org/wiki/Hamiltonian_mechanics) is the foundation of statistical interpretations of quantum mechanics, and enhrined this way by the [Hamiltonian](https://en.wikipedia.org/wiki/Hamiltonian_(quantum_mechanics)?wprov=srpw1_0) If your magic is something that can be codified, but is very intangible, Hamilton's math was probably necessary to give it form. [Answer] **Aliens** *cue the hand gesture, you know the one* "Magic" as commonly defined, exists in the universe and is generally thought to be more powerful and efficient than "mere" science by all the various sentient races. The most magically powerful races use special drives that "suck" magical energy from the surrounding area to go faster than light, power warding shields, lightning/lasers, and what have you for their interplanetary ships. Well in the Far Distant Past a ship was damaged in the solar system such that its drive was always on, but didn't power anything. The magical feedback from all this would kill a recovery team, and it really wasn't worth the effort of fixing anyway, so it was left. Meanwhile on earth magic doesn't exist, because it's being constantly drained away by the drive. Anyone who thinks shamanistic mumbo-jumbo from pre-history is actually based on any version of reality is a crackpot. Roll forward to 1780/whatever year you want, the ship finally crashes into the dark side of the moon, its main drive is hit by an asteroid, it falls into the sun/earth, whatever takes your fancy. Now all the sudden BOOM, magic is HERE. Maybe the people with innate ability start doing magic/blowing themselves up. Maybe just the kids do it because if you don't use magic starting in childhood the ability atrophies and can't be re-ignited. Maybe it's super specific so only the (now ex) crackpots who were determined to "prove" magic beforehand can even fiddle with it now. Maybe people start accidentally stumbling upon words/gestures/symbols of power. It's a pretty flexible origin-of-magic starting point. This is basically an amalgamation of the Emberverse (where, though it's only mentioned tangentially, alien skulduggery is the reason electronics/modern tech fails and a "soft" form of magic emerges) and a short story I read ages ago where an alien FTL drive makes it seem like the speed of light is constant from earth. This prohibits mankind from figuring out the key math to FTL and assuming it's impossible. [Answer] Let's try a different answer that plays not on what was invented during the period, but the advancements that the period brought to the world: **Subtlety and magic's prerogative to keep the user alive** are the two main reasons. Disclaimer: I am going to base this on the premise that "discovery" for the purposes of this question means both the actual discovery of magic as an ability, actual proof that it is magic, and the somewhat widespread dissemination of that information. A painter can have a magical talent, but unless they are overtly using magic to paint, then it's just a man's claim. ### Subtlety Magic, until the First Magical Revolution, is just not about big flashy effects. It is subtle, and easily mistaken for chance, good genetics, or just having the gift. Magic up until this point is the twice a decade prodigy in a trade, that child that can pick up a tool and just understand how to use it in the way they want to. It is the soldier that has survived a dozen battles through injury and infection to survive to old age despite the odds. It is the cunning thief that uses their "instinct" to avoid trouble from all sorts of people. It's the craftsman that creates something that lasts just a bit longer than it normally should. There is nothing that screams overt magic, but a myriad of coincidence and good fortune that is more than just good genes. If you want to go that way, there are a blessed few that have figured out the secret of making magic flashy and powerful and truly bend nature to their will. We call those people "gods" and they form the basis of mythology. ### Staying Alive Magic's first prerogative is to keep its user alive. When a person is sick or injured, it is magic that assists in the healing process. Whether it is disease, malnutrition, or injury, magic supplements the body until it is in peak condition, with or without magical help. As above, this is a subtle boost and not visibly fast healing. For those that lack the power, then their self-healing abilities can only go so far or fail outright when put under too much stress. Since most magic is tied up keeping the body in prime (or just functional) shape, there is not the power to actually be flashy and powerful. And for those that have all their magic tied into their health, well they have the power, just apparently not the ability. ### The Industrial Revolution What does this have to do with the First Industrial Revolution? Technically nothing. In this case it is not any one invention, process, or discovery that will enable the widespread discovery of magic. It the other things that comes from this revolution that will enable the discovery of magic. Better living conditions can lead to better health -- now magic that might have been tied into keeping people healthy is now free to be used and expressed. As such, there is more of a chance to be either blatantly flashy or actually observed and questioned The lower infant mortality the revolution brings on allows more children to survive and awaken to the potential to be magical and for that magic to supplement the child's health. Also since they're healthier, they have more of a change to have free magic to use. More organized science coming from a larger population and a boom in scientific progress can lead to discoveries that, while individuals dismissed single events, together they paint a trend of anomalies. Anomalies like magical phenomenon. New science and math may give symbols and non-instinctual understanding of magic allowing for collaborative discoveries where if there were any before, they were individual ones. Just a higher population in both number and density can lead to just a higher chance that magic will be discovered and studied. As well as the mage not being killed on principal. While the probability is non-zero earlier, there are more chances now as opposed to then. The enhanced understandings of the world leads to things that were once magic to be understood. Things that might have been written in antiquity as magic and wizardry are now science tricks. We have removed a critical mass of mundane magic and have definitively found the gems of real magic within. Admittedly, none of these outright prevent magic from being discovered earlier. The idea is that while discover was a non-zero chance then, it is a much higher chance now. [Answer] **Magic Requires Knowledge of Thermodynamics** You can’t break the laws of physics unless you know where to press. Within limits of their abilities, training, and experience, a wizard can cause any physical process to happen just by willing it, as long as energy and entropy are totally balanced. This is different from non-magical processes where energy is conserved but entropy increases. Example: A wizard can stare at a bucket of water and will it to freeze, but in order for the spell to work, he/she has to will the surrounding air to be heated by an equivalent amount. **This system requires that the first wizards to reach awareness of their powers had to know at least 19th-century physics before they could accidentally discover their abilities.** [Answer] **Magic Spells are Computer Code** * 1819: Charles Babbage * 1842: Luigi Menabrea * 1843: Ada Lovelace * 1936: Alan Turing These are approximately the years the first humans to fully grasp the concept of computer code documented their thoughts. It's possible some wizards discovered it prior to these dates, but it wasn't until programming was thoroughly studied by mere mortals, that the wizards could practice magic safely. Both Ada Lovelace and Alan Turing died young and under suspicious circumstances. What secrets did they take to their graves? **Imagine all magical spells have to be cast using some kind of programming language, and a serious bug such as an infinite loop or a memory leak can kill the wizard.** [Answer] Supernatural abilities have been locked away deep inside us for most of our history and became only then awakened for the first time when the marvels of modern medicine & psychology conincided with the political will generated by the Cold War, experimentation with New Ages concepts in american society as well as the [applied ruthlessness of the CIA](https://en.wikipedia.org/wiki/Project_MKUltra) to enable a U.S. marine [to kill a goat just by staring at it.](https://en.wikipedia.org/wiki/The_Men_Who_Stare_at_Goats) And the rest is history, as they say... [Answer] Actually it was genetic but the mutation for it only appeared fairly recently. At first there was only a small family of magic users and they kept it under tight control. Then one of the existing magic users broke away and started having a bunch of children and formed a splinter group. Now there's political tension between the two groups so they decided to marry off their children to their allies (rulers of other countries) to increase their base of support. The allies want as many magical decedents as possible. A few of the grandchildren decided they wanted to just marry for love and start to mix into the normal population. Suddenly magic users are absolutely everywhere and it's impossible to put the genie back in the bottle, being a magic user is such a desirable trait. Kind of like atomic weapons, but sentient. [Answer] **Magic requires making deals with trans-dimensional entities.** : The deal making process is complex and requires many things which don't normally happen at the same time *(hold a rock over a candle during a lunar eclipse while being on a boat in a river, then...)*. The discovery on how to do this was luck, although the distribution of the knowledge of how to do it is a modern thing. --- **Magic requires a soul artifact to do even basic stuff. It's easy to make a soul artifact if you already have access to one, but it's impossible to do without one.** The first artifact wasn't made by us and sat in a museum for many years before anyone figured out its use. [Answer] # Population Density If magic is based on having a large number of thinking minds in the area (not participating, just being there), then only some really large cities can support magic. Ancient Rome might have qualified, but only in it's peak. Many modern cities would also be enough. (and some New York city apartment complexes might be enough on their own.) The magic in this case probably starts with active thinking minds disturbing the surface of a "mana-space". The magician then capitalizes on the energy of the collective disturbance. Just to throw things for a loop, different cities might have different flavors, so that a magician from one city might not be able to work in another city. Or maybe he/she would need to acclimate to the new city. This might get further modified by cultural differences affecting how different the magic is. [Answer] I'd like to point you towards the anime Youjo Senki. In there, magic **is** a gift you're born with, but in order to use it you really need an *operation orb* to make it work. From the wiki it says > > *An Operation Orb is a tool mages use to interfere with reality through magic according to their will. A breakthrough to recreate miraculous phenomena through the combination of both mana and analog calculation.* > > > *Not much has been revealed about the inner working of Operation orbs, but the orb's main function is to process the world data and convert mana of user mages.* > > > If you look at the history of magic in that world it then says > > *In ancient time, magic exists in various forms in many regions, civilizations, cultures, and even traditional customs. However, those who could trigger a miracle by their own are extremely rare. For those who had magic potential, most of them could only increase drug effect a bit, breathe in water temporarily, heal a bit faster, etc. People in some regions decided to research such phenomenons instead of fearing them, finding that some specific stuff could be used as catalysts to make magic usage more efficient. They even found that some heroes in history actually used holy relics to trigger miracles.* > > > *As magic was accomplished with various magical devices which were not very efficient and stable, the Industrial Revolution occurred. Magic then went through a revolution following other fields of study that were influenced by war. In their search to optimize spell composition, the analogue computer Differential Analyzer caught their attention. Inspiring engineer to duplicate computerization by magic and invent the modern magical device, Operational Orb.* > > > *The design of the magical computer that facilitates mages to compose spells is based on a pocket watch. Making the Operational Orb a device that is compact, sturdy and precise. In Tanya's era, an operation orb could be more expensive than a flagship tank or aircraft. In short, normal orbs cost as much as the most powerful weapons.* > > > This sounds rather close to what you seem to be looking for. Just get rid of the holy relics and such, and until you got computing tech good enough to make the orbs there will be no true usage of magic other than those passive effects (and paybe some parlour tricks). [Answer] This answer assumes that what matters for your purposes is not that magic is completely unknown, just that it's functionally unusable prior to the industrial revolution (which for most stories is what's likely to matter). # It's always been around, but doing useful things with it requires large numbers of skilled workers to be involved in controlling it. Using modern computing terms, magic has to scale out to be useful. Having just one person casting magic imposes limits in some way that make it either inherently useless, impractical, or downright dangerous. Maybe there's a physical limit to how fast a person can safely form a spell by themselves, perhaps there some limit to how much magical energy a person can channel, etc. However, more than one person can contribute to the same spell at once, so a bunch of skilled mages working in parallel can safely do big, useful spells that could not be cast by a single person alone. In more technical terms, your total power and total efficiency when spell-casting are both proportionate to the number of people actually casting the spell. To limit things such that large numbers of people are required, either power or total efficiency (or both) has to scale exponentially proportionate to the number of people involved (preferably with an exponent just above 1, that way you need *lots* of people to be involved), but either logarithmically or linearly (with a very shallow slope) proportionate to the skill of the individual casters. This will result in a situation where the most efficient way to cast a big spell is to gather a very large number of mages to cast it. That situation is the same one that lead to industrialization happening when it did. For factories and mass production to be possible, you similarly need very large amounts of either unskilled or semi-skilled labor. This, in turn, means that the same things that made industrialization possible (namely significant improvements to agriculture that allowed for far fewer people to be needed to produce food combined with an overall increase in the standard of living for most people) would make practical use of magic beyond stuff like simple party tricks possible as well. From there, you can then further delay the practical use of magic by constructing the system of magic such that there's a minimum amount of skill required to be able to work safely with other mages. This will in turn require some minimum amount of education to be able to actually work as a mage, which will limit how many people can e trained as mages proportionate and therefore put a practical upper limit on the possible scale of spell-casting based on what proportion of your population is required to support the rest of the population at a basic level. ]

[Question] [ In my pre-electricity world, fast communication is achieved by means of lighthouses, each being able to direct strong and precise beams of light towards distantly visible lighthouses. However a problem is encountered whenever the weather turns. Many meteorological conditions, such as fog, rain, hail, snow, or various mirages, can interfere with these signals and prevent reliable communication. Since such conditions, especially fog, are very common in certain areas, an alternative form of distant communication is required. The usage of messengers is not a viable solution since certain lines of communication are disrupted to traffic on foot, e.g. one pair of signal towers signals to an island surrounded by strong currents. The question is now, **what other techniques could be used to send messages?** Edit: The messages sent function as the government 'internet'. As a result messages are often highly compressed (think of a [shorthand](https://en.wikipedia.org/wiki/Shorthand)-like correspondence), but there are large amounts of them. Rural regions may get by with only emergency communications, but suburbs and more densely populated or important regions have a significantly higher bandwidth requirement. [Answer] Bells. A large (hence deep-toned) bell can be heard for many miles. Couple with a reflective sound concentrator as in @L.Dutch answer, and bells should be audible for about as far as you could see a lighthouse. "Wait, you can't hear individual sounds over a great distance!" Well, you can't *now* -- but the world was quieter before there were cars and diesel trains and factories and whatnot everywhere. In Napoleonic times, one could hear the cannon fire from a battle for tens of miles, and it's claimed that people heard the eruption of Krakatau in Europe -- literally on the other side of the world. As a bonus, since the pitch of the sending bell for any given listening station will be well known, it's possible to use a resonant tube at the focus of the reflector to both amplify the sound further, and filter out other noise. This would work somewhat like the resonant tubes under the keys on a marimba, or like the way a brass instrument forces specific tones onto the generic buzz of the player's lips in the mouthpiece. This would extend the effective range, and greatly raise the level of noise that can be worked through. [Answer] I'm kind of surprised that no one has mantioned the obvious time tested method of long range communication: **Drums** Lots of people have brought up using sound, and even the very clever use of acoustic reflectors, but Drums avoid many problems associated with things like guns (ammo ain't cheap, and how much bandwidth could you get out it). They are lighter than large bells. Another advantage is that individual impact sounds on a bell could be hard to discern, but a drum gives a much shorter tone. [In this wiki page](https://en.wikipedia.org/wiki/Drums_in_communication) even has a section on Slit Gongs which are directional and can be heard for several miles. Imagine coupling that with an acoustic reflector. I would also wonder about using something like railroad rails. Long stretches of rigid but resonant metals. You could use this in places where line of sight is not possible. Ann McCaffrey also used communication Drums in her Dragonriders of Pern series. Could be a good source of inspiration. [Answer] You already mention homing pigeons. Another alternative is to use sound and a suitably shaped reflector to focus the sound beam toward the receiver, who will in turn use a similarly shaped receiver to listen. Something similar was used during WW1, where [acoustic mirrors](https://en.wikipedia.org/wiki/Acoustic_mirror) were used to detect enemy planes flying toward England over the Channel. [](https://i.stack.imgur.com/jTYiB.jpg) Since you are in the pre-electric era, you cannot use a microphone, but you have to sit a person in the listening station. Small explosive charges or cannons can be used as means of producing loud sound, which should allow reaching greater distances. This would however limit the transmission rate. Wind and temperature gradient might influence the propagation direction, and background noises (think of a thunderstorm) might likewise affect the signal to noise ratio. [Answer] **Ropes** You can build "physical telegraph" with manned relay stations a kilometer or two apart from each other using cables or hawsers. On one side a man plus a lever, on the other side a bell rings or some semaphore changes its state. There were even pilot (and not only pilot) projects of such kinds of communications, but the optical telegraph appeared to be better. Weather interference is overrated - in most cases you just need to wait less then half an hour for "peak" to pass and then you can continue transmission. And if you couldn't - you have some other things to worry about, like where your roof is going to land! [Answer] You do realise you've just reinvented Terry Pratchett's "Clacks" system, don't you? Anyway, solutions... ### Put the towers closer together Over long distances, sure, weather is a problem. Over shorter distances though, bright lights will still be visible even though rain and fog, and the operators can drop their data rates to improve reliability. Of course the weather could get so bad that nothing is visible over any distance, but that should be rare. The right tower spacing can be worked out for an area to give maybe 10 days down a year. ### Messengers As Andrew Tanenbaum said, "Never underestimate the bandwidth of a station wagon full of tapes hurtling down the highway." Critical messages can be accumulated over a day and sent off with a courier on a fast horse. Other messages can wait for the weather to improve. ### Morse with gongs/bells Slower data rate, but still ok if (as above) the towers are reasonably close together. Different towers can have different pitched bells so that operators can tell who they're talking to. Heavy rain will probably take them out too, but rain that heavy doesn't usually last too long. ### Whistling Andorran mountain folk have a whistled language for communication over long distances in the hills. Apparently it works well. You may only be able to have a couple of km between people, but there's the advantage that no extra equipment is needed. In a society of peasants, people are cheap. [Answer] I found a nice [*history*](https://uslhs.org/history-fog-signals) of warning signals from the US Lighthouse Society. The problem seems to be that the things, such as fog, that interfere with light also interfere with sound propagation. One of the possibilities that you should consider is that there will exist times with communication blackouts. In such times, a pony express type service for critical signals. They also developed underwater sound signaling from shore to ship to shore using coded signals. The method was in use until WWII because everyone can hear the sound. There are multiple problems with sound. First, its distance is weather specific. Signals rated for four miles often only made it one or two in the wrong wind and climate conditions. The same sound signal could be heard eight miles away in other conditions. The other problem is that sound can ricochet in adverse weather. It was a frequent problem that sea captains couldn't determine the direction that the sound was coming from. In fact, the bending of sound was taken advantage of in several places by constructing objects to trigger purposeful bouncing. Finally, the transmission is going to be slow because you will have variable ranges where towers will have to be silent. If multiple towers are transmitting it may be impossible to distinguish signal from noise. Even canons had a range of two to six miles depending on the weather. For signal propagation by water, it was discovered that coded messages could be transmitted up to fifty miles by underwater signals, originally they were bells. The actual method of signal communication in use in Europe was a variety of forms of semaphore and horse with underwater signaling for ships. The U.S. Pony Express could cross the United States in ten days. You do not need that. You only need that for critical signals in adverse weather. If you had to cross water, you could use submarine bells. There is a massive advantage for semaphore over lighthouses. See the BBC [article](https://www.bbc.com/news/magazine-22909590) on it. It is a bit less robust than a lighthouse but it has many advantages over a lighthouse. You can restrict the line of sight for military purposes. The Napoleonic system has 98 combinations of possible signals using a trinary system. That made it faster than Morse. However, you should read Terry Pratchett's Clack's system. You should read *The Fifth Elephant* where it is introduced or *Going Postal* where it could be thought of as a primary character or a McGuffin. If it were me, I would ask myself a set of questions. 1. What signals could be delayed when semaphore was down? 2. Is the added cost and slower speed of a lighthouse worth enough to not use the faster semaphore system? 3. Is there enough signal volume to partially include a Pratchett like *Clacks* system using light? 4. Who is paying the bills for a sound or pony express system to cover briefly befogged or blizzard conditions? 5. How often would the alternate systems be down such as during a blizzard? There may be historical data on this in Europe. 6. A number of telegraph confidence games were played on people by compromising the telegraphy system for profit during the 19th century, even before electrical telegraphy. The first steganography issues were semaphoric. The first "viruses" were semaphoric not computer networked. How will you secure your system from nation endangering fraud? 7. Is the system robust to war? The internet was designed to be robust in the event of nuclear war. It is quite a bit more fragile now for many purposes but for standard purposes, it is surprisingly resilient. Can I bring the entire network down by capturing one tower? Does the system collapse with the sudden heart attack of a single semaphore operator? 8. In the much slower world that used to exist, what is so critical that an hour of fog would change the world? I would remind you that during the Cuban missile crisis there was no direct communication system between the United States and Russia. They passed handwritten notes between the President of the United States and the General Secretary of Russia. That was during the twentieth century. Napoleon's system was actually faster than the US-Russian system. That is why the *hotline* was built. To understand how slow the world used to be when Kennedy was assassinated there was no way to get the news onto a visual broadcast at the time of the assassination. It used to take twenty minutes to half an hour for a camera to power up for transmission. Instead, the transmitted a blank screen with sound only. It was essentially a placard being transmitted with sound. The news networks were not notified by phone either. They received wire signals, which is still telegraphy. The news in 1963 used a series of bells to notify them that a news story was being transmitted and its priority. When Kennedy was shot one reporter happened to be in a car with a radio phone. Otherwise, it would have taken at least ten more minutes to relay the message. It still took ten minutes to go from reporter to a signal being received at network stations. Newspeople also blocked transmission. When the first reporter used a payphone for the one private line out of the hospital he had the other side not hang up. Under the old phone system, neither party could use either phone until both parties had hung up. By keeping the other side off the hook, the one private line out of the hospital was disabled. No other reporter could send their stories at the hospital, they had to run to other locations to find a phone. A canon or sound-based system could have that problem. You can block the signal by transmitting sound with no purpose except to block the relay stations surrounding the transmitting station. You could send the message "The President has been shot. In the beginning, God created the Heavens and the Earth," and continue through the Book of Revelations. Terry Pratchett took advantage of that problem in *Going Postal*. Look at the problems at Pearl Harbor or on 9/11. Sunlight, with telescopes, is your friend. Relatively frequent lighthouses would be a little less friendly. Canons and horns that blast over a wide but variable radius will work but be costly. Horses and submarine signaling systems are reasonably stable and reliable. You can build a mixed system for redundancy. **EDIT** With regard as to how semaphore is better, consider two optimization functions *G* and *U*. Let us imagine that the purpose of *G* is to train an Olympic sprinter while *U* is to train a high school basketball player. They will share many elements in common and differ on a few key elements. When engineering something, the goal is almost never to build the *best* thing but a thing fitted to the service it is being used for. A simple example of this was the PC wars of the 80s. By any technical measure, the computers by Commodore and those by Apple were vastly superior to those produced by IBM. Commodore went bankrupt. Apple would have gone bankrupt but Microsoft injected massive amounts of money into Apple, acquiring 40% of the company. It did so because Microsoft would have had a monopoly in the operating systems market and its shenanigans would have instantly become illegal under federal law. Fit to purpose is different from building the *best*. Terry Pratchett's *Clacks* system is a McGuffin or maybe even a passive character. It is, in practice, a lighted semaphore system. A traditional signal light using something like Morse code would be comparably slow. However, it begs the question of whether something like the Clacks would be built. Pratchett uses it as a metaphor for cell phones and to explore the information society we have been building. It never serves an actual engineering purpose. In a world without lightbulbs, everything stops at sundown. There is no need for night signaling. The only organization that could possibly need signals at night would be the military. If a light suddenly came on at midnight, every intelligence agent in that country would know that it was a critical military signal and it would be recorded. Without electricity, the world slows down. While it may be valuable for merchants to have price and volume data on a slow delay, not much else requires near real-time communication in such a world. Directed light is more fragile than semaphore and costs more. You need fuel. It is costly to repair. The towers cannot be made of a flammable material so you have to have higher building and repair costs. Your operating crew would be your engineering crew so you would carry higher levels of training and salary costs. An actual Clacks system, such as Pratchett's would be very costly because of all the mechanical parts. Because they could not be engineered at the site, you would also have to carry a significant parts inventory. Your people would be insanely skilled. Essentially, you would be scooping up the nation's watchmakers. Smoke signals and light signals have been in existence for thousands of years, yet semaphore replaced those systems. I believe the only remaining smoke signal in use is with regards to the election of the Pope and that is a binary communication. Light signaling with lasers exists but only where point-to-point, high criticality messages are involved. If fidelity and distance are your concern, then a light signaling system may be better. However, the bulk of the messages will be "the price of iron in Kent is three pounds per ton of ore," or "send money fast." What about those messages require high fidelity? What purpose is the builder of your system trying to optimize? For Pratchett, it was a discourse about modern life. For the real ones built before electrification, they were all semaphore systems. The most famous is Chappe's because it only took two hours for a signal from Venice to reach Paris, but Hooke, Edgeworth, and others built semaphore systems throughout Europe, Canada, India, and the United States. Lighthouses exist to send one narrow, repeating signal. It is "if you lose track of the position of this very bright light, then you will die." It is a high criticality message. Semaphore would not work for this as you could not see it at night when it is needed. Bells and cannons were used for this on foggy days but they did not carry other messages. If they had then they may have confused shipping since bells are distinctive. Lighthouses are preposterously expensive, especially when compared with a wooden tower, a telescope and a few mechanical arms. The fact that light, smoke and sound signaling was replaced by semaphore in the real world over dozens of countries, independent of each other, tells you they are inferior. [Answer] **[Homing pigeons](https://en.wikipedia.org/wiki/Homing_pigeon)** provide a viable alternative, since although they may be slower they may carry considerably more information than a visual signal. They also posses an **incredible range and are not dependent on line-of-sight**. **Precipitation and strong winds make flying impossible though**, so communication via pigeon can only take place under very limited circumstances. [Answer] [Hydraulic Telegraph](https://en.wikipedia.org/wiki/Hydraulic_telegraph) The use of hydraulics offers a few means of communication that would not be impacted by poor weather for the most part. And they can be build of relatively inexpensive wooden piping. How to actually send communications down a pipe can be done in several ways. If you can build your stations relatively level with one another [Such as putting one end on a tower as the network runs down a hill, or otherwise build the stations at the same height] then you can use a direct pressure and pointer system: Push down on the lever at the sending end, and it causes the needle to point to a sign on the receiving end. But we can also adopt a more "telegraph" solution. Water is a great carrier of sound. A pipe, buried in the ground, could be made into essentially a giant drum. Hammer on one end, and someone on the receiving end can hear the beat. Different beats can denote different data states, and various error correction methods can be applied. --- [Pneumatic Tube Transport](https://en.wikipedia.org/wiki/Pneumatic_tube) However if your society really needs to send *a lot* of information faster than a human can run with it before we have electricity, then some manner of pneumatic tube transport may be your real go-to if you need it to work reliably in nearly any weather. While expensive to build and maintain, a society that truly valued it could have developed and maintained a large network of such systems along the lines of "Stuff data in a case, and fire it off to the next station". While they would require stations that are far closer than the typical semaphore tower system would be able to get away with, they would also be able to send VAST amounts of data. [Think of how many words you can cram onto a document that can be rolled up into a foot long cylinder... Now fire several of those off every minute... While the packet may need to pass through several more stations, a whole book can be well on its way into the network before the first semaphore station has even finished its first paragraph.] A steam launcher firing packets through relatively straight wooden pipes could be highly effective to rapidly hurdle messages several hundred meters at a time. [And a need for regularly spaced large steam boilers offers the citizens reliably and easy access to centralized heating as a bonus!] [Answer] **Silbo Gomero** This is the whistling language used in the Canary Islands to communicate complex messages for distances of up to 5 km. The language requires skills, but no equipment. It should get through fog pretty well. Another answer mentioned whislting in Andorra, but the Canary Islands are more widely known for this. <https://en.wikipedia.org/wiki/Silbo_Gomero> [Answer] ## Signal Flares A little basic knowledge of gunpowder is all you need to make a signal flare that can be visible from a great distance even in the daytime. There are even chemicals you can mix in to make a number of different colors of flares. You'd have limited bandwidth for what kinds of messages you could send, but you could elaborate by sending multiple flares if needed. E.g. You've got flares in Red, Orange, Yellow, and Green (all fairly basic colors that could be made with Victorian era chemistry), you could say that "Red-Red" means one thing, "Red-Orange" is another, etc. 4 colors with 2 flares gives you 16 possible messages. 3 flares gives you 64, and so forth. You'd make your most commonly used messages require only a single flare (so as not to waste more material than necessary), and only use the multi-flare signals when needed for more detailed messages. If you want to keep the messages inscrutable to others who might see them, you could even have a form of encryption, like each color or combination means different things depending on the day of the week, or some other previously agreed-upon coding. [Answer] Whether you use light or sound, weather is going to get in your way. While sound is able to bypass a fog, it's easier to put a visual system on a hill to have line of sight above low lying fog. Visual communication is far more reliable over distance, visual recognition is more efficient than listening out for audio signals - at least when we are not trying to stuff it down a wire in an early telegraph that's basically only capable of morse code... Which brings me onto the **real life** precursor to the telegraph - the ***semaphore telegraph***. [](https://i.stack.imgur.com/9JPm3.jpg) As with many questions here, the most realisticly feasible solutions have a pre-existing analogue either in nature, or in a past technology. There were numerous different designs for semaphor telegraphs, many of them used in different countries and at different times, from the 1600s onwards. A design used in Britain used shuttered panels that could be opened and closed - this resembles the clacks as referenced in an earlier answer, only that missed the fact that this is something that really existed and was used. [](https://i.stack.imgur.com/9BsJw.jpg) It wouldn't be hard to envision this with a fire / light behind to allow night transmission. A far older design, working only over shorter distances was the Hydraulic Telegraph - messages could be sent by pushing water through a pipe - the level of water at the far end would then indicate the character being sent. This is completely immune to the weather, but is limited by the pressure available to the sender. [Answer] # Guns With the right caliber, gunshots can be heard from miles away. So use the lighthouses when conditions allow for it, but when in a fog, go for guns. You may use something akin to Morse code, with two differently tuned kinds of guns for slashes and dots. Gunshot sounds may also go around peaks and other terrain features that would break line of sight, and can also be used underground. Guns can also be used to defend the lighthouses when the need arises. Usage of gunshot sounds here and there keeps dangerous animals away, and provides a source of income for weaponsmiths and otologists. [Answer] # You could also use a [bullroarer](https://en.wikipedia.org/wiki/Bullroarer): > > The bullroarer, rhombus, or turndun, is an ancient ritual musical instrument and a device historically used for communicating over great distances. It dates to the Paleolithic period, being found in Ukraine dating from 18,000 BC. > > > [Answer] ## Soundhouse A house intended for long-distance communication with the use of musical instruments. This is a building equipped with different kinds of musical instruments that generate strong sound vibrations. This is not something new. People in old ages used musical instruments for long-distance communications. > > "**2. Drums are used for communicating over long distances** > > Africans > and Europeans developed a wireless communication system long before > cell phones were invented! (...) **Drums were used to send detailed messages from > village to village** much faster then a person could walk or ride a > horse. The sound of talking drums could reach up to 4 to 5 miles. > These drums have hollow chambers and long, narrow openings that > resonate when they are struck. They are made out of hollow logs. The > larger the log, the louder the sound would be. **The drummer would > communicate through phrases and pauses,** and low tones referred to > males while high tones referred to females..." -- [5 Ways > Drums are Used to Communicate](https://www.omahaschoolofmusicanddance.com/5-ways-drums-are-used-to-communicate/) > > > Alphorn has been used in Switzerland to communicate with men and animals. > > "**Communication with humans and animals** > > (...) The main function of > the alphorn was, however, for communication with the herdsmen on the > neighboring Alps and with the people down in the valley below." -- > [Alphorn – the sound of natural tones.](https://www.myswitzerland.com/en/planning/about-switzerland/custom-and-tradition/alphorn-the-sound-of-natural-tones/) > > > Soundhouse would exist in the form of the **circular stone plateau,** located at high altitude, or as a **tall building** with a wide-open roof to accommodate musicians and musical instruments. Musicians would bring the instruments and send messages according to the rules of sound-communication. Any kind of communication must begin with an opening message and end with a closing message. --- ## UPDATE --- The sollution already exists. > > "The Bora people in the northwestern Amazon use drums to send > languagelike messages across long distances. (...) "They have this > fantastic sound which resounds through the jungle and can be heard up > to 15 to 20 kilometers away." > > > [Christopher Intagliata, Drumming Beats Speech for Distant > Communication](https://www.scientificamerican.com/podcast/episode/drumming-beats-speech-for-distant-communication/) > > > The drumms were robust and made entrely of wood. [](https://i.stack.imgur.com/bEDC0.jpg) This is the new model. The drummer is located in the dome-shaped house at the top of the structure. Sound is reflected from the roof and exits the dome in all directions. The second option is to use the horn and direct the sound in one of the four directions. This is a more economical solution. The horn is secured with wood on rails and can be rotated and directed in any direction. [](https://i.stack.imgur.com/ngI5O.png) ## Pyramid for the purpose of transcommunications or communications with the use of telepathy. A person would enter a pyramidal building and fall in a meditative trance. In such a state, direct mind-to-mind communications are achieved. Another person, located in the same kind of building at any point on Earth, would be receiving direct messages and be able to transmit them to other recipients. This kind of communication can be performed at any place. However, pyramidal buildings have the power to concentrate human energies. In such buildings, people experience higher energies, easier fall in meditation and generally feel healthier. [Answer] Ok, here is a funny one: **communication by smell**. I don't know if that was ever tested, but in theory this form of communication could be especially useful under foggy conditions, for not-too-long distances, for the more subtle communication (let's say you don't want to let the neighbours hear the bells). Fog can smell. Usually gases and dust constantly break away from the ground and get away unnoticed by us. But when water vapour (=fog) condenses on fine dust particles and aerosols it builds up drops of water, dissolving some of these gases, which then end up in our nose. Not only could smelly gases be used, but fine, strong smelling powders of herbs could do the deed. Each substance indicating different messages. Edit: I have given this a little thought now and find the idea quite amusing. This method will rather suit coded messaging with low range (are there any statistics about how far smell can travel, assuming it is strong and the wind is in favour?). Sure, one can not use it at strong winds, but if we set this in a sheltered environment, eg a forest or svamp between tall mountains, it might be fairly functional. For the fun of it let's say a few people discover a conspiracy and in order to tell each other newest information without being discovered they release certain smells at certain times and in different combinations. Ammonia and lavender - *the king is replaced by a fraud*! [Answer] To prevent eavesdropping and concentrate your sound over long distances maybe your Victorian scientists could develop a version of [hypersonic sound](https://www.ted.com/talks/woody_norris_invents_amazing_things) -- which essentially makes sound act as a laser-- keeping it concentrated in a tight beam. [Answer] For slower, high-bandwidth communications, simply floating barges down a river loaded with pieces of paper that have been written on is hard to beat for cost/effectiveness. The societal conditions that require instant communication don't arise in preindustrial societies. [Answer] If you're trying to penetrate fog, best go with something *specifically designed to penetrate fog*: # Foghorns [](https://i.stack.imgur.com/aTjdr.jpg) (Image by the Cardiff Council Flat Holm Project, via TR001 at [Wikimedia Commons](https://commons.wikimedia.org/wiki/File:Foghorn_building_on_Flat_Holm_Island.jpg).) A [foghorn](https://en.wikipedia.org/wiki/Foghorn) uses high-pressure steam or compressed air to produce extremely loud, low-pitched notes; low-frequency sounds travel farther and penetrate bad weather *much* better than high-frequency sounds (the very name "foghorn" reflects their original use, which was to signal to ships in zero-zero visibility). Seeing as we're talking Victorian-era technology, steam power is certainly available in quantity, and the same is likely also true for highly-compressed air. Live steam could be tapped off directly from a high-pressure boiler (although running steam directly through the sound-generating bits might cause corrosion problems, depending on the materials used), and, if necessary, the steam pressure could be raised still further using a simple reciprocating or rotary compressor driven by steam (or water or animal) power; alternatively, the steam engine could drive an air compressor, providing a steady supply of high-pressure air for the foghorn (the use of air, rather than steam, would, besides reducing corrosion, have the additional benefit of producing a lower-frequency, more-penetrating sound, due to the greater density of air compared to steam). The sound could be rapidly switched on and off by turning a valve to either send the air or steam through the horn, or bypass the horn and vent directly to atmosphere; if necessary, the valve could itself be operated by steam power, controlled by a small hand-operated pilot valve. Unlike a bell or cannon blast, a foghorn signal can have an arbitrarily-long or -short duration, its sound characteristics do not change significantly over the length of the signal, and the signal's loudness can be increased without limit by increasing the pressure of the steam or air used to sound the foghorn (potentially even enough to *drown out thunderclaps*). This makes it easy to use a foghorn to send messages in (say) Morse code. The main disadvantage would be that, at very high power levels, [deafness](https://en.wikipedia.org/wiki/Noise-induced_hearing_loss) would be an occupational hazard for the operators; invest in hearing protection!1 --- 1: The hearing protection would be worn only while actively sounding a message (during which any incoming messages would be inaudible anyways), and taken off as soon as transmission was completed. ]

[Question] [ [Bubble wrap](https://en.wikipedia.org/wiki/Bubble_wrap) is a synthetic packing material featuring small bubbles that are designed to provide cushion to the protected object and pop in place of damaging the object under excessive stress. They also make a lovely crackling sound when popped. But this is a creation of man, and finding a layer of Bubbletastic® Extreme Guard© Bubble Paper™ across the floor or walls of a deep cavern would be... odd. My thinking is that an organism could use this natural feature to improve its ability to defend its lair or to hunt other creatures for food. **Is it possible for nature to create renewable, poppable bubbles (i.e., bubble wrap)?** *(Requested clarification)* Note: I am specifically looking for a mechanism by which an *environment* can possess this feature *independent* of any animal that may or may not be living there. --- *Vignette* Darian crept through the tunnel. The marks along the walls were high enough to suggest they were made by his quarry. The footprints in the silt were recent, and many. Drag marks as well. Hopefully it would be asleep after its meal and he could finish it off without it ever knowing he was there. A rush of air from ahead smelled of death and blood and... Yes! That smell! That unmistakable smell. He hurried ahead, almost forgetting to walk softly to prevent echoes alerting his quarry. A cavern opened at the end of the tunnel. In the dim light of his lantern he could barely see the other side. And, off to the right, the light revealed the mottled brown scales of the wyvern. Cracked bones were scattered about its reclined form. The rhythmic rise and fall of its sides indicated it was, indeed, asleep after its meal. Darian set his lantern down and drew his wyrmbane dagger before slowly, quietly, making his way toward the wyvern. When he was halfway there, however, the cavern floor unexpectedly gave way beneath his foot with a loud POP. The wyvern's breathing quickened and it raised its head to look at the terror-stricken Darian. Before he could rush back down the tunnel, the wyvern had claimed another snack and added a fine blade to its growing treasury. [Answer] I cannot believe that nobody has mentioned [puffball mushrooms](https://en.wikipedia.org/wiki/Puffball). [](https://i.stack.imgur.com/yErrU.jpg) They are plentiful where I am from. Basically, they blend in with the forest/natural floor, and have a hole that releases the internal spores when they are stepped on. (They can also release and crack open on their own). The older they get, the more brittle they get. Once they kind of "die" they are just waiting to release the spores. And the older ones make a distinctive sound when they are stepped on. Not a squish but a loud crackle-pop. It doesn't sound like bubble wrap. But it can be loud if they are old enough. If I were trying to make natural bubble wrap I would start with this design and reason for functioning. It's your world, so you can change them slightly to get that effect. You could make them smaller and have them cover the floor. The big drawback I see is this: if a creature is lairing somewhere and they use that route to come in and out, they will also deflate the modified puffballs. I can say that from my experience, puffballs are weird in that they exist in places with wet/dry cycles. That is, they proliferate in the wet, but they do best if there is a dry cycle after. I just can't see them doing as well in a constantly moist environment such as a cave. But I hope that this is enough of an inspiration to give you a start to creating something like this! [Answer] It is possible for nature to create the equivalent of bubble wrap. Some forms of seaweed have a vague resemblance in their [air bladders](https://www.pinterest.cl/pin/5066618309752635/): [](https://upload.wikimedia.org/wikipedia/commons/thumb/c/c9/Fucus_vesiculosus_closeup.jpg/640px-Fucus_vesiculosus_closeup.jpg) Given the correct evolutionary pressures it should be entirely feasible for an organism to develop a greater number of thinner walled air bladders so that it more closely resembled bubble wrap. The composition of the “skin” material would be probably be different in chemical composition but the physical properties could be similar. [Answer] # Mud bubbles In areas of high volcanic activity, it is common to find bubbling mudpits:  These are driven by underground heat that boils surface water in an impermeable depression in the ground, and eats away at the surrounding stone. Once the water is all gone, It leaves behind an expanse of dried mud filled with air pockets. From experience, walking on this dried out mud causes a cacophony of snaps and crackles as it settles under your feet, similar to walking on too-thin ice. It also reeks, because it lets out the trapped hydrogen sulfide. [Answer] **Fecal sacs.** [](https://i.stack.imgur.com/0DD0D.jpg) <https://en.wikipedia.org/wiki/Fecal_sac> > > A fecal sac (also spelled faecal sac) is a mucous membrane, generally > white or clear with a dark end,[1](https://i.stack.imgur.com/0DD0D.jpg) that surrounds the feces of some > species of nestling birds.[2] It allows parent birds to more easily > remove fecal material from the nest. > > > As with birds, fecal sacs evolved as a method to clean up after juveniles by keeping their excreta in a tidy membrane sac. This approach evolved into the bubble wrap type scenario requested in the OP. The animals litter their areas with these poo packs. The membranous wrap is the bubble. Natural decomposition of the feces produces the gas, inflating the bubble. On bursting these produce a characteristic sound and also smell; the products of anaerobic decomposition inside the sac smell bad. These decomposed and odoriferous materials usually get on the intruder to some degree, which helps the alerted animal to locate it. [Answer] ## Spores These bubbles are spores. The spores are filled with some kind of lighter-than-air gaseous mixture or compound (possibly hydrogen - don't bring an open flame near them!), designed to carry the spores high into the air and be carried by the wind, before descending onto some other location. Plant or fungus, doesn't matter, take your pick. The important thing is, it's a reasonably believable mechanism to make these bubbles a relatively common and entirely natural part of the environment. The spores you find on the ground or attached to walls are spores that are almost - but not quite - matured. They're almost ready to float off somewhere, but they just haven't detached yet from the parent. Make the pressure inside the spore sufficient enough to stretch the membrane a bit, and stepping on one will produce that tiny little *pop* you're looking for. Additionally, making it a fungus of some sort makes it believable in almost any location - particularly caves, basements, sewers, forest floors, or even just a particularly damp and shady wall or rock - exactly what you seem to be looking for! Alternatively, you could drop the hydrogen(?) part of it and use something more like the puffball mushroom in [Erin Thursby's answer](https://worldbuilding.stackexchange.com/a/163362/49819). Instead of floating away, the shroom would just build pressure in the bulb until it straight-up explodes, causing a loud pop, an effect which would also happen should someone step on one. [Answer] I am surprised nobody mentioned [**common snowberry** (symphoricarpos albus)](https://en.wikipedia.org/wiki/Symphoricarpos_albus). The berries give out pretty much exactly the same sound as bubble-wrap when stepped on a bit harder. Now of course it won't grow in a cave, but * The wyverns may simply like them and occasionally pull some branches in to use as a snack or “side dish” or even * pulling them in might be an adaptation to the human attacks; depending on how intelligent these wyverns are it may be either learned, or evolved over a couple of generations from the appetite for them as the wyverns who pulled in more sprouts tended to live longer. [](https://commons.wikimedia.org/wiki/File:Symphoricarpos_albus_003.JPG#/media/File:Symphoricarpos_albus_003.JPG) [Answer] Like Slarty, my first thought was wracks and other seaweeds or egg-pods with air bladders. With the changed criteria ("Note that I am looking for a way for these bubbles to be a feature of the natural environment (e.g., a cavern floor), rather than of an organism. – Frostfyre"), that doesn't work. We can't even use bubbling yeasts. In that case, there are a few mechanisms I can see. The easiest path seems like a gas bubbling through a liquid that hardens. This has been suggested already a few times (pumice, mud bubbles). Another mechanism is geode formation, where the forming substrate then erodes or is washed away, leaving the mineral spheres or domes of the geodes. Another option is a solid that gets a coating, then the solid melts, leaving only the coating. An example might be a stalactite dripping into a floor, leaving a small drip-sized pit. Seasons change, ice forms, the pit freezes and forms a dome of ice (because water expands as it freezes). Seasons change more and the thaw above washes minerals down, covering the dome with minerals; the beginning of a stalagmite. The ice melts from under that, leaving a hollow mineral dome. I have not seen this, and it would require a cave that changes temperature seasonally, which isn't usually a thing (underground temps are generally fairly constant). Another mechanism is for a liquid to harden at the top, then for what's below to go away (evaporate, etc). You see this in frozen puddles in winter: the puddle is gone and all that's left is the ice cover, that invites passing children to jump on it, and smash it like a pane of glass. Another mechanism is for the top layer to form flat, then the mud walls to rise up under it, like a honeycomb. Again, this happens with ice in the winter, in the right circumstances <https://www.featurepics.com/StockImage/20081207/frozen-puddle-stock-image-993984.jpg> Here you see both "glass pane" and mud honeycombs. **All** of these suggestions are "crunchy" rather than "poppy", however. To be poppy, you need the "mud" or "ice" or "bubbles" to be made of a more flexible material, which generally means longer-chain, biological molecules. For that, all I can think of is tar, which still depends on the existence of organisms, albeit millions of years in the past. But if your exclusion for organisms only applies to those in the present, then you could make tar bubbles, have pitch solidify, and so forth. [Edit: exclusion for organisms has been clarified to only apply to animals, not plants or fungi, so to me, bladderwrack seem the obvious candidate: Upvoted that answer.] [Answer] With some luck it would be possible to create a renewing popping sounding. Let's say you have a small pit in the ground, doesn't have to be large at all, filled with water, next something that has some rigidity falls over top the pit and forms a near perfect seal around the pit. The shape of the object over the pit is convex to allow an air bubble. When something steps on the object it flexes down and pushes the air out and forms a seal with the water, when the weight is release the object returns to its convex shape and the air breaking the seal the water underneath it to fill the gap once again creates a popping sound. [Answer] Inspired by MrSpudtastic's idea.. **FUNGAL PITFALLS** A fungus which predates animals by creating a pitfall. Essentially growing a large hollow cavity underground, displacing and consuming any material in its path. (note that a common characteristic of fungi is their ability to Animals then step on it, break through the thin upper surface of soil and mushroom and plummet as far as a couple meters to land on whatever non-consumable rocks the fungus left behind... They then die there, unable to escape the pit, or injured by the fall. Their remains feed the mushroom which then regrows the bubble. The problem is maintaining soil-coverage as camouflage. My thought is that it'd grow surface-stalks, filament thin or full mushroom-caps, these would act to bind the soil to keep coverage normally, and as necessary they could hydrostatically "wave" to draw more soil over the bubble. Their length before reaching the surface would be a factor in determining how near the surface the bubble is, as would be the weight of the material overhead. Properly calibrated, the bubble could withstand lighter animals walking on it. The surface stalks would also act as bait, many larger animals consume certain species of mushrooms for the protein. For that trademark Popping noise, the bubble is sealed and pressurised with a gas gathered from nitrates in the soil or possibly just C02 from its own respiration. This would have the advantage of suffocating the victim quickly since C02 is heavier than air. When the victim bursts it, the overpressure should produce a loud noise, either a loud pop or a distinct deflating *Phbbt* noise. [Answer] Scoria is Foamed Volcanic glass, similar to Pumice stone, but with larger bubbles. * <https://en.wikipedia.org/wiki/Scoria> Density varies a lot, according to the conditions when it was produced. Sometimes this forms very large bubbles and is easily crushed underfoot. [Answer] The mammals of nemo ramjet's speculative biology world "snaiad" have air pockets beneath their skin in place of fur, to keep them warm. This could be the function in your bubble wrap species: pockets of air that trap heat, keeping the organism warm. [Answer] Nature has already invented this: the [rafting snail](https://www.livescience.com/16476-bubble-rafting-snail-evolution.html) makes its own bubbles from mucus to stay afloat. The Janthinids use this bubble raft, and some species may even lay their eggs there, though it looks too exposed for predators. [Answer] Of course nature did create bubblewrap... it just had to create oil (from various sources, as yet unidentified) and trap it underground and evolve a creature capable of making machinery to make bubble wrap out of the oil. It reminds me of the SF story of an alien that crashed on a planet, breaking a part of it's ship... then manipulated the planetary life until it produced exactly the material it needed and brought it to the ship. The material being a short length of springy steel, previously used as a tie down to hold some piece of military hardware onto a pallet during WW2 [Answer] We humans create blisters. It’s not much of a stretch for them to evolve into something that can make a popping sound, or to grow without being triggered by injury. [Answer] A similar structure that occurs already in nature is honeycomb. [](https://i.stack.imgur.com/5pPYw.jpg) Honeycomb is made up of small individual cell structures arranged in a lattice, just like bubble-wrap. It does not strike me as unlikely that a colony insect might create a bubble-wrap like structure to house their larvae. The problem here is that bubble-wrap is filled with air. We would expect the insects to not make empty cells without a reason to do so. So the question is what properties of bubble-wrap might be useful to a colony insect? The one that comes to mind is *sound*. The very property that your sample story is concerned with. Since bubble-wrap makes a popping sound when it is stepped on, a colony insect living in a cave could build empty versions of their hive structure nearer to the entrance of a cave to alert the colony of intruders. (just as it alerts the dragon in your sample story, they might even have a symbiotic relationship with the dragon where the dragon deals with the intruders for them.) We could imagine this behavior developing pretty naturally. The bubble-wrap structure might just be a version of the wax cells specialized over millions of years of evolution. [Answer] Since you're talking about the inside of a cave, geological features would probably work best. You're going to end up with something that resembles and upside-down sheet of bubble wrap. That is: a reasonably flat surface, but with voids or air pockets just underneath. For caves created by volcanic activity, see the good [answer posted by @Ben](https://worldbuilding.stackexchange.com/a/163425/2690). Another option is to have the cavern floor made of slate, shale, or some other [fissile](https://en.wikipedia.org/wiki/Fissility_(geology)) stone. The stone naturally breaks apart into thin sheets. A heavy footstep on a weaker area could cause the topmost layer to crack or shatter. Step on an area where 2-3 layers lie on top of a void, and you could cause quite a racket. You could also have the floor be some sort of sedimentary rock that formed when this cavern was underwater. Crustaceans lived in the mud and left their shells behind when they outgrew them. When the cave dried out, the mud hardened and the now-brittle shells formed air pockets in the rock. If the rock-to-air-pocket ratio is right, you'll have something that looks like normal rock but would "pop" and collapse when too much weight was put on it. Some types of stone (like limestone) will dissolve in acid. You could build the cave out of a compressed conglomerate that contained large pockets of limestone. Over time the acidic groundwater dissolved away all the limestone but left the other stone around it intact, and now you have large voids that can collapse under weight. ]

[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. Most gases that are toxic to breathe also do nasty things to the skin when they're in the atmosphere at dangerous concentrations - and one is walking around without sealed protective clothing; sulfur and nitrogen oxides cause chemical burns when they mix with the water in perspiration, or on one's eyes, large amounts of ozone cause similar problems by different mechanisms. **So my question is what are the key gases to use and, probably more importantly, at what levels to create an atmosphere that is lethal if you get a breath or two but won't burn your skin off or poison you anyway when you walk out the door without your moon suit?** Priority is given to gas mixes that are made up of gases that occur in/are produced by a biosphere almost identical to Earth's, so Water Vapour, Oxygen, Ozone, Methane, Nitro-oxides, Organic Carbon compounds, Carbon-oxides, Sulfur compounds etc... The best answer is the atmosphere that is most similar to our existing composition while being deadly to breath but otherwise safe for one to wear their birthday suit, apart from a breathing mask supplying safe air. [Answer] Any atmosphere that contains gases that are inert to a human metabolism, but no Oxygen or not enough Oxygen. One would be an atmosphere containing 5% oxygen instead of the usual 20%, with the 15% made up of Nitrogen and Argon as here. At one atmosphere, it's equivalent to a depressurized airliner at cruising altitude. You don't notice anything wrong, but rapidly become first confused and then unconscious. You die after a few minutes from oxygen deprivation. There are creatures here on Earth that can breathe this. Geese and vultures can fly at aircraft cruising altitudes. Birds have a superior variant of haemoglobin in their blood. It's not directly lethal, though. You can be rescued after a minute or maybe two if there is someone else around with an oxygen mask. After this time you will have suffered irreversible brain damage. For near-instant lethality I'd suggest an alien biochemistry that puts [Phosgene](https://en.wikipedia.org/wiki/Phosgene) into the atmosphere. It's not entirely odourless (smells of mouldy hay) but it causes fatal lung damage that is not immediately apparent. Read the section on its use as a war gas. I think it's also cumulative in which case a small undetected leak would be fatal after minutes or hours. [Answer] **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. > > an atmosphere that is lethal if you get a breath or two but won't burn your skin off or poison you anyway when you walk out the door without your moon suit? > > > take our atmosphere and remove all the oxygen, replacing it with an inert gas like nitrogen. [Asphyxia](https://en.wikipedia.org/wiki/Asphyxia) will ensue after a couple of breathes. > > Asphyxia or asphyxiation is a condition of deficient supply of oxygen to the body that arises from abnormal breathing. An example of asphyxia is choking. Asphyxia causes generalized hypoxia, which affects primarily the tissues and organs. There are many circumstances that can induce asphyxia, all of which are characterized by an inability of an individual to acquire sufficient oxygen through breathing for an extended period of time. Asphyxia can cause coma or death. > > > This is the precise reason why, when using nitrogen to purge certain machinery, working in enclosed spaces can be lethal if proper precautions are not taken. Otherwise such an atmosphere is perfectly safe to walk in it naked. If you wonder what is the minimum oxygen concentration needed to sustain human life, you can refer to [this](https://sciencing.com/minimum-oxygen-concentration-human-breathing-15546.html) > > Serious side effects can occur if the oxygen levels drop outside the safe zone. When oxygen concentrations drop from 19.5 to 16 percent, and you engage in physical activity, your cells fail to receive the oxygen needed to function correctly. Mental functions become impaired and respiration intermittent at oxygen concentrations that drop from 10 to 14 percent; at these levels with any amount of physical activity, the body becomes exhausted. Humans won't survive with levels at 6 percent or lower. > > > [Answer] ### My suggestion: * **60% Xenon** * **20% Oxygen** * **15% Nitrogen** * **5% Carbon dioxide** ### Why Xenon? Xenon is a noble gas. It has very few common chemical reactions, and is frequently used in situations where *air* is too reactive to be safe. It's safe to touch and even safe to breathe. It's also a [very effective anesthetic](http://anesthesiology.pubs.asahq.org/article.aspx?articleid=1945725). Present-day doctors in Europe use it because it is remarkably side-effect free, if quite expensive. A few breaths of Xenon and you'll be out cold. ### Why Oxygen? 20% oxygen is around the level we have in our atmosphere. This way, fire still burns and iron still rusts in your world the same as on Earth. ### Why Nitrogen? You have enough carbon dioxide to grow plants, but they need N2 in the air to keep the nitrogen cycle running. 15% is too little for the nitrogen-fixing bacteria in the soil, but your crew could have genetically modified soil bacteria for farming. ### Why Carbon Dioxide? This is how you die. CO2 is very stable and inert, but at concentrations of around [40000 ppm](https://www.cdc.gov/niosh/idlh/124389.html) (4%), it becomes quite toxic. At these levels, it's so far above the lethality threshold that if you breathe this, you will die. ### How does it work? An astronaut is working on a new construction for the planetary base when her breathing mask undergoes a malfunction, disabling the low-air alarms. The astronaut continues working as her mask slowly runs out of air, and loses track of time. When the tank is almost empty, the broken alarm fails to remind her to refill, and without realizing, she begins to breathe the atmospheric air. After three or four breaths, she begins to feel unusually drowsy. As soon as she realizes what happened, she holds her breath, but the xenon has already taken effect. Two shaky steps towards base later and she collapses on the floor, unconscious. Her brain, fooled by the apparently welcoming air, resumes breathing, taking in 13 times more carbon dioxide than she can handle. Instead of carbon dioxide from her lungs breathing out into the air, CO2 diffuses from the atmosphere into her alveoli, flooding her bloodstream with carbonic acid. Her blood pH plummets out of control, and she dies of carbon dioxide poisoning in under a minute. ### Pros: * No damage to skin or clothing * Lethal after a few breaths * Behaves effectively the same as our atmosphere in most everyday situations * You can grow crops with minimal modifications. ### Cons: * You need to explain how the hell the atmosphere became 60% Xenon. A comet, maybe, or it orbits a star with lots of Xenon? **Edit**: To clear up the issue of where did all the xenon come from, here are a couple possible sources: * Presence in solar system: The planet orbits a star that burns hot enough to produce Xenon (our sun can't produce anything past iron), a nearby Xenon-rich star went supernova nearby a long time ago. This means that there's a lot of Xenon in the solar system to begin with, and its stability means that most of it will hang around. The planet either formed from a gas-and-debris cloud that contained xenon, which bubbled up to the surface during formation, or received it from xenon bubbles in porous ice and rock from asteroid and comet bombardments. This is where we got most of our atmospheric gases, because they exist in abundance in the space surrounding our planet. As long as there's xenon in the system, the planet will get a decent share of it. * Radioactive decay: Xenon is produced by nuclear decay from iodine-135 in our nuclear reactors (this actually causes problems because the gas blocks the nuclear chain reaction). The xenon produced by this is radioactively unstable, but there is another process that turns iodine-129 into xenon-129, which is very stable. The half-life of iodine-129 is 16 million years, so a planet rich in iodine-129 would steadily produce Xenon gas, bubbling up to the surface. This process could have already ended, resulting in a Xenon-rich atmosphere even after the decay has slowed to a crawl. Iodine-129 is a common product of nuclear fission, which occurs slowly in nature in underground uranium deposits. So a large amount of uranium, under immense geological pressure, slowly produces Iodine-129, which slowly decays into Xenon-129, which is stable and floats up to the atmosphere in geothermal vents, volcanoes, and hot springs. ### Sources: <https://climate.ncsu.edu/edu/Composition> <http://www.aragonvalley.com/en/effects-of-co2-in-humans/> <https://www.ncbi.nlm.nih.gov/pubmed/17552896> <http://anesthesiology.pubs.asahq.org/article.aspx?articleid=1945725> [Answer] Pure nitrogen is harmless -- except that it won't support life. A breath or two will do no harm, but you won't even notice you're suffocating, because the carbon dioxide will clear from your blood as if you were breathing air -- but you won't be gaining any oxygen. You'll fall over unconscious after three or four breaths, and you'll die in four minutes (give or take whatever level of exertion was going on before, and whether you knew what you were getting into and could hold your breath for a while). The same would be true of nitrogen/oxygen, if the oxygen mix is less than about half what it is at sea level on Earth -- except it'll take longer to fall over, and longer to die. Now, you wanted "lethal, but not corrosive" more or less. Hydrogen sulfide is biological in origin, more toxic than [prussic acid](https://en.wikipedia.org/wiki/Hydrogen_cyanide), and although it has a very noticeable odor, humans lose the ability to smell it well below lethal levels, [alarms are needed for concentrations as low as 5ppm](https://en.wikipedia.org/wiki/Hydrogen_sulfide#Safety). It claims a victim (or string of victims) on a fishing boat every so often, when refrigeration in the hold fails; a crew member is sent below to fix the system, doesn't come back, another goes to check on him, doesn't come back -- I've read about as many as eight people dying in this kind of scenario before anyone caught on. A concentration of 800 ppm is considered 50% lethal, and 1000 ppm (that's 1/10 of 1%) is instantly lethal -- one breath will kill. As little as 100 ppm (1/100 of 1%) is considered immediately dangerous -- in part because this is the level at which loss of sense of smell begins. These levels can be formed by decomposition in natural settings, as long as there is a depression to collect the heavier than air gas. Now, hydrogen sulfide will, eventually, form sulfuric acid, by oxidation and combination with water (vapor or liquid), but this is a slow process compared to its lethality. [Answer] **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. Carbon monoxide is a nice easy one. Colourless, odourless, non-corrosive, lethal at concentrations above 500 (or thereabouts) parts per million. It will oxidise over time to carbon dioxide in an oxygen atmosphere, so you’ll need some biological source to keep replenishing it. [Answer] Helium. It is very inert, and used by deep divers to replace nitrogen due to it being safer at high pressures. It can enter all your tissues without causing harm. The only side effect to breathing it is a funny voice. In an atmosphere made of pure helium, a human would die of asphyxia. That would be the only damage caused by such an environment. [Answer] Wait, nodoby mentionned *Avatar*? [Pandora](https://james-camerons-avatar.fandom.com/wiki/Pandora) is exactly what you describe: survivable but deadly if you breathe. > > Pandora's atmosphere is a mixture of **nitrogen, oxygen, carbon dioxide (>18%), xenon (>5.5%), methane, and hydrogen sulfide (>1%) and is about 20% denser than the atmosphere on Earth primarily due to the high percentage of Xenon**; a heavy, colourless, odourless, and generally unreactive noble gas. **The high concentration of carbon dioxide in the Pandoran atmosphere makes it extremely poisonous to humans**, rendering them unconscious in about 20 seconds and causing death in about 4 minutes when they venture out unprotected by specialized breathing masks. The hydrogen sulfide present is also quite poisonous; concentrations over 1000 ppm (0.1 %) can cause immediate collapse with subsequent loss of breathing, even after inhalation of a single breath. > > > [Answer] **[Oxygen](https://en.wikipedia.org/wiki/Oxygen_toxicity)** You cannot breath pure O2 for long, after a few hours it will start to destroy alveoli causing lungs permanent damage. It's also very toxic for your nervous system and can cause seizures and reach convulsions and unconsciousness. In fact, oxygen poisoning is a common cause of diving accidents due to the increased pressure in the diver body and from experience, I can tell you it feels like a serious hangover. A 90% O2 in 2 atm pressure is more than enough to do the trick. It can become a "public health" problem because young people from the colony can try it as an alcohol substitute because it can make you feel drunk. **Bonus:** Megafaun, insects in special can go very huge in an oxygen-rich environment. **Cons:** Fire, increasing oxygen will increase risk of fire because any fuel will burn most easily. Wood can burn like gasoline and even stuff normaly hard to get fire in earth will readily burn if theres enough oxydant. Be sure to make your planet lightning free. ]

[Question] [ Historically, there's about a 700-year gap between when crossbows start appearing in European texts around 950, and when bayonets do the same around 1670. And those bayonets are strictly associated with muskets, as sources note the change from plug bayonets to socket bayonets over the next 30 to 40 years. Modern crossbows usually have a cocking stirrup at the front instead of a blade. The lack of historical overlap and/or association hasn't stopped fantasy settings from putting bayonets on crossbows. Apparently there's a rule for it for D&D 3.5 in *Complete Scoundrel*, and several fantasy images popped up in my search. **But how effective would this actually be?** If a target armed with a sword managed to close the distance, how well would the archer be able to defend themselves with just a bayonet attached to a crossbow? --- <https://en.wikipedia.org/wiki/Complete_Scoundrel> [](https://i.stack.imgur.com/hFLKT.jpg) [](https://i.stack.imgur.com/XwTZ7.png) This one looks like a photo of a fantasy prop: [](https://i.stack.imgur.com/YgtVE.png) And this is a crossbow that's designed to be carried in a sword sheath. Not exactly the same thing, but close. <https://www.pinterest.com/pin/AQkXWXg76_rGUYO6uZ0XUicufGir8FDjQVMDlQf_MK4RJwKQ5H9fJ2c/> [Answer] Former Marine, I carried and was routinely trained with bayonets for years. Here's my input: Crossbow bayonets are not very effective. The bayonet was adapted due to the preceding pike and gun tactic. Half your guys had pikes, half had guns. The problem was that not only does this mean half your guys can't carry guns, but if the pikemen should falter or run you lose all of your musketeers to understandably angry enemy infantry venting their frustrations on their formerly unassailable adversaries. Muskets were very long, 6 to 7 feet, attaching a bayonet meant that instead of needing pikemen you can now have 100% of your men armed with guns, but still be capable of closing ranks and repelling cavalry with their bayonets. Bayonets combined pikemen and musketeers, and was so effective it essentially ended melee only infantry types within a short time of its implementation. The bayonet was useful against swordsmen due primarily to the large (by melee standards) amount of standoff distance it created when fixed to a musket. Crossbows are shorter by nature of requiring a heavy prod (proper terminology for the bow part of a crossbow) to be cocked without breaking. These prods provide an excellent handle for the swordsman to rip it out of your hands, and crossbows were only 1/3rd as long as muskets with bayonets attached, no such standoff distance is gained by attaching a bayonet. Not to mention that this prod is quite unwieldy and makes bayonet maneuvers difficult to impossible. The bayonet on a musket keeps the swordsman farther out of reach of a sword, and the musket itself adds another very important layer of uncertainty for the swordsman. The swordsman can't be certain that his target doesn't have a loaded weapon and is simply waiting to get him close enough that his death is guaranteed. A crossbow has a very obvious indicator that it is not loaded, as it will not have a bolt strung. So crossbow bayonets are not very useful weapons in my humble opinion. Hell, bayonets in general aren't very useful anymore either except as a tool for aggression training and physical conditioning. [Answer] It is interesting that the crossbow and the pike are in fact the complementary weapons of the "Infantry Revolution", both weapons allowing relatively untrained men (with the proper tactics) to *effectively* take to the field against highly trained knights and men at arms. Understanding why these are complementary weapons also explains why a bayonet was never mounted on a crossbow in real life. The mass of pikemen in a [square](https://infogalactic.com/info/Pike_square) presented a forest of blades which was difficult for mounted or dismounted fighters to penetrate. it is essentially defensive in nature, (pikes are set to repel charges and prevent dismounted men from penetrating the line), although highly trained men who are capable of moving together as a unit and aggressively led can use pikes offensively (as leaders from Alexander III to the Swiss confederacy well knew). [](https://i.stack.imgur.com/6k8Ru.jpg) *Modern re-enactors demonstrate a pike square* Crossbows allowed men with limited training to effectively shoot projectiles at armoured knights and men at arms, and in great numbers. Longbows and recurve bows as used by the English and Ottomans could be as effective as crossbows, but required far more training to use effectively than a crossbow, and in the case of recurve bows were also difficult and expensive to make due to the use of multiple materials, glues and careful setting and drying/curing times. Crossbows ultimately provided much more striking power as well, a spanned steel crossbow could have a [draw weight of 1200 lbs](https://todsworkshop.com/blogs/blog/crossbows-spanning-methods) / 600kg (far more than any unaided man could provide) and deliver a quarrel with lethal force even against an armoured opponent. [](https://i.stack.imgur.com/Znoxm.jpg) *Crossbowman in the late Middle Ages* So the crossbowman can shoot quarrels capable of dealing death and injury to even armoured knights, but has a slow rate of fire due to the need to span the bow. The pike square is essentially defensive, but provides the "stand off" distance to prevent knights and men at arms form closing with the troops. The ideal combination (and this was carried on even into the gunpowder age) was to mass blocks of pikemen and put the missile armed troops in between the blocks of pikes. [](https://i.stack.imgur.com/YZ4vt.jpg) *Although this is a diagram from the age of "shot and pike", substituting crossbows for the arquebuses gives you the idea* Crossbows by themselves are far too short to provide the "stand off distance" needed to protect yourself from a mounted man, and you would be well within the reach of anyone with a sword, pole arm or even a mace or war hammer to effectively defend yourself, unless you had extensive training (which of course defeats the entire notion of the Infantry Revolution in the first place). A crossbow on a stock long enough to effectively act as a "pike" when the bayonet was mounted would likely be too unwieldy to use effectively (the weight of the bow arms on the front of such a long stock would make it difficult to aim, and running forward to place the spanning mechanism on the bowstring would reduce the rate of fire even more). So short answer is "no", a bayonet would not be very effective on a crossbow. If if comes to blows, the bowman could start swinging the bow, or drop it and pull a long knife. Of course if it really does come to that, it means the pike square has collapsed and your side is pretty much done anyway..... [Answer] It might work.... but carrying a short sword or other stand-alone hand-to-hand melee weapon would probably work better. The cross bars/arms may make wielding your "pig sticker on a stick" harder. Any foot loop used for cocking it could be problematic, or at least reduce the effective length of the blade. Any windlass mechanism may be over sensitive to damage, or end up with strings/rope/cable swinging around causing a tripping hazard. Consider that the bayonet fixed to the end of a long barrel gun is really a way to let a soldier fire a shot or three, and then become a pike man or a spear man to keep other soldiers at a distance or to engage mounted enemies. Early firearms were fairly long - and VERY long rifles were popular throughout the age of bolt actions, the Mosin-Nagant (developed 1890/91) is 48 inches long and has a bayonet that extends that another 2 feet. I don't think a crossbow comes anywhere near to that over all length, which would reduce the efficiency of the bayonet. So... possible, if the engineering challenges are over come (windlass, etc. and foot loop). But probably unlikely due to unwieldiness, lack of length, etc. Edit after question was edited - Definitely plausible - after all someone who is being attacked will use anything at hand to defend themselves. How well it might work is still going to be dependent on a few things- 1 - How does the bayonet attach? If on a pivot point (like Mosin-Nagant, the SKS, etc) or carried in a sheath and locked into place when needed to be used? If carried in a sheath, depending on design it may serve quite well as a short sword/big knife. Draw and fix, or draw, drop crossbow, and engage in hand to hand? I still think that having it attached to the crossbow will be problematic due to the bow arms - plenty of basic training bayonet exercises on youtube, as well as historical stuff regarding early muzzle loaders (British redcoats, etc) - might be worth a watch to see how a mounted bayonet is used and then decide for yourself if the bow arms are an issue. [Answer] First, to reload a decently powerful crossbow, you need a stirrup to have enough strength. It might not be practical to attach a bayonet. Second, a bayonet is basically a dagger, and daggers do not do well against things like plate armor. Daggers only do well against armor in very close combat or to finish off someone by stabbing armor weakpoints or by having specialised daggers like Rondel daggers to stab through mail or other soft armor more easily. By attaching a dagger to a crossbow, you lose the agility and manoeuvrability a dagger has. Third, why attach a dagger to your crossbow if you can have a more handy backup sword? It's like attaching and underslung 9mm single shooter under a rifle when you can have a semi-auto pistol as backup. Fourth, it makes you crossbow more unwieldy. You have more weight on the front so less stable shot, your weapon is longer which might be a bad thing in close quarters, in corridors or tight spaces. Fifth, there are usually melee units to "take the aggro" for you as a crossbowman. Therefore, it is very rare when you have to use melee yourself, making the bayonet kind of a gimmick. Sixth, unlike with a backup sword, you can hardly parry any attack. You can still somehow block with your crossbow, but it would likely be damaged or unusable after a while. Seventh, you lack any reach to be intimidating. Muskets and rifles are pretty long (especially muskets). This makes them usable as spears, albeit kind of short ones, but they are still somewhat viable to keep an enemy at a certain distance. A crossbow being pretty short, you just cannot have enough reach to be intimidating. I think you would barely have the reach of a longsword, but without the agility or the parrying abilities. Eighth, your opponent can easily break your "guard". Many medieval techniques strike the opponent's weapon to set it aside, breaking the opponent's guard, and then strike at the now vulnerable opponent. Due to the nature of the crossbow, and opponent can do this both horizontally (as you would do against other weapons) and vertically (by striking on the bow itself and potentially disarming you or breaking your weapon). [Answer] On a close range combat, having a bayonet is for sure better, for self defense purposes, than having just your hands and maybe remembering some prayers. How much better of course depends on two parameters: * defenders' vs attackers' amount of training * tactical set up of the defense Effectively use any weapon, especially in medieval time, required years of intensive dedication. Train to use two different weapons such as crossbow and sword would have roughly doubled this time. Therefore I think on paper it could work, in reality it was too resource intensive, that's why it was not widely used. Also, a dead sword trained archer is a double loss for the defending army. [Answer] I would say that it is just as easy to just draw a sidearm (like a knife) in a pinch. For more info I would recommend this video by NUSensei: <https://youtu.be/jxHTZ1fVHMA> It is about sudden melee scenario's when using a normal bow and not a crossbow, but I think it still applies. [Answer] Probably not, the crossbow is so wide at the tip that it would be easy for your opponent to block it. If not totally, then enough to shift the blow off centre making it miss and or lose most of it's force. Not to mention the expensive mechanism is going to be at the front of the combat letting your attacker grab it and pull you or your weapon into their lines. Bayonets are really a two handed weapon, grips on rifles/crossows are designed for being pulled into your body not being pressed out like a sword. To use this the crossbowman would have to give up his pavis (if he had one). This might be more practical for the Chinese repeater crossbow as that is quite short range and you could be suddenly in a melee. But I would think that the blade should be on the back of the bow, maybe like an axe tucked under the firer's arm so the draw mechanism is not fouling the strikes. [Answer] Not very useful for a standard crossbow and a standard bayonet. However if designed as a unified weapon system it might have potential. The enormous draw weight of steel crossbows is a way of making the horizontal crossbow more compact without losing power, something a vertical longbow does using length. The whole cocking mechanism of a crossbow make a bayonet awkward. Have to think outside of the box. A butterfly knife type bayonet pivoting underneath the crossbow stock on a locking keyhole pivot post at the end of the stock. Out of the way until needed. A quick flip opens the blade for bayonet use and a twist disengages the blade and handle for independent short sword use. Cocking the bow itself would require a different approach. The bow would be held in a slide on the stock. Cocking is a two stage process. First pull the bow back to cock the string on the trigger. The Qin trigger lock is best since it automatically locks when the bowstring is pulled into it. Then set the front of the stock on the ground and step in the belly of the bow and push down with your body weight until the bow slider locks in a slot. I've thought of several slider-lock mechanisms that would be well within the ability of a medieval blacksmith. I'm really surprised that no crossbows except perhaps the Gastrophetes use body weight to cock it. Soldiers would weigh at least 150 lbs with armor. Why not use that weight? Far easier to train with than a traditional longbow. And using it as vertical crossbow allows far tighter masses of soldiers. So how effective would it be? Well it's better than nothing which is what both crossbowmen and archers had when it came to up close and personal. Some training in new tactics would be essential. And if the enemy tries to grab the bow pushing forward on the stock slides the bayonet blade straight into him. [Answer] If you look at the Italian crossbow guilds, their weapons are in between 4 to 5 feet as actual Medieval European designs weren’t as short as popularly depicted. The Chinese designed a different much shorter trigger with a smaller lever and in their armament inventories are often full with lots of crossbows and swordstaffs, making it the common combination of their forces, similar to Skandinavia depicted below. A bayonett doesn't have to be a dagger, but can quite well be a light short spear. This is a weapon type associated with mounted crossbowmen. So 4 feet bow with a 4 feet spear gives 8 feet of a half pike and with 10 feet you have a Morris pike used in naval warfare by the marines for millenia, although the way European crossbows were operated allows for a longer spear of 6-7 feet and a common naval pike of 11-12 feet. [](https://i.stack.imgur.com/Gjtyz.jpg) Dolnstein depicting a battle between Landsknecht pike from Germany against crossbow and swords taff native to Skandinavia. Unlike muskets, the crossbows aren't depicted firing volleys more than one rank deep. The swordstaff is an 8 feet long hewing spear. [This article on mounted crossbowmen](http://je-lay-emprins.blogspot.com/2013/02/mounted-crossbowmen-some-observations.html) shows their use in conjunction with lancers. The lance was a disposable weapon due to the likelihood of damage, so presumably units could switch and there are reports of light lancers with crossbows from the Balkan, North Africa and the Iberian peninsula, who previously used javelins instead of crossbows. Creating a weapon capable of switching is probably more expensive than creating both types of weapons separately and switching on demand to a streamlined efficient design. If you look through Liechtenauer's treatise on mounted combat, you find fights between crossbowmen and lanceurs, where the crossbow prod is used to deflect the lance and use the release of the bolt as a variable length spear. A crossbowman might have considered his weapon superior to a spear, leading to the situation depicted by Dolnstein, linked above. ]

[Question] [ **The Background** I have an early medieval/late dark ages society roughly equivalent to Anglo-Saxon Britain or Viking Scandinavia. Everything's fairly normal...apart from the fact that people who drown in the sea come back as draugr. This has always been a low-level nuisance throughout their history, but over the past decade or so (timescale flexible) they have started showing up in increasing numbers (perhaps a disastrous naval battle offered them an influx of bodies allowing them to gain a bit of a foothold). **Draugr** A draug in this instance is a semi-intelligent zombie-like creature that's generally vindictive and malicious. They're intelligent enough to use basic hand-weapons, rudimentary tactics and communication, but are generally pretty slow thinkers. Their motivations amount to not a great deal more than 'kill people, make more draugr', which they achieve by dragging bodies back into the sea whereupon they will emerge as more draugr after a short period of time. Killing one isn't a great deal more difficult than killing a regular person, and a reasonably trained person will usually prevail against a draug one-on-one as draugr are a little sluggish, but they don't stay dead for long. After about a week, they start getting back up again unless their bodies are burnt. **The Question** What measures might my not-anglo-saxons/vikings start taking to protect themselves from this new threat? For clarification: the draugr are the only magical element of this world. Everything else is mundane. Any other questions or clarifications please ask! **Edit:** Thanks for all the excellent answers. I'm not sure I pitched the intelligence level right, but I won't edit the original question as the answers provided answer it perfectly. So, as a corollary if it's not too broad, how might these precautions change if the draugr above were intelligent? If you split intelligence into capacity and thought-rate, they have the same capacity for intelligent thought as humans but a lower rate. Same ideas, just takes them longer to get there. If this is too broad, please let me know and I'll split it out into a separate question. **Quick clarification** Non-rotting undead. [Answer] **Fight draugr with dogr.** If you have weird dudes sneaking around the village looking for trouble, there is nothing better than a watchdog. They will be even better for draugr. Dogs will smell these guys coming a half mile away. They will bark like mad and alert the humans. They will do their best to hold off the draugr themselves, and for a dog their best is pretty good. Dog packs work as a team - one big dog might be a match for a single draugr but 5 dogs working together will make short work of it. Also if a human gets killed it gets turned into a draugr. If a dog gets killed it stays a dead dog. Dogs have been the wingmen of humans for thirty thousand years. They get along fine with us. They eat what we eat. They are cheap and you can get a big supply quick. If you have human enemies they will figure out the dog thing pretty quick and come up with antidog measures like poison or ranged weapons. Even a sabretooth tiger will figure out the dogs are there and steer clear. Not the draugr. They will never figure it out. Dogs are draugr kryptonite. There would be one dog whose special job is to bring back the head. [Answer] The dark ages were not without their threats, as such fortifications were not uncommon. These would seem to be pretty Draugr proof. So if there was a Draugr bloom, people could withdraw to the castle and let the archers handle it. Once no Draugr were standing a pire could be arranged to effectively deal with the bodies. It would be more of a threat in smaller settlements but a watch could be placed and people warned if a Draugr approached. If things got out of hand, move inland. The Draugr are connected to the sea dragging a body 10 or so miles is going to take a while and be obvious. So you could pick off Draugr more easily if you were further inland. You would have to also watch out for Draugr trials, and general superstition and hysteria. [Answer] ### Guard the places where new Draugr will appear If there is one location where the new Draugr will regularly appear you will want to have some guards trained in fast dispatching of Draugr to be stationed nearby. There should be multiple people and they should be far enough away to not be overwhelmed by half a dozen or so emerging at the same time, but I take it that they are not going out there en masse as a big army or your problem wouldn't be a continuous slowly rising threat. The same would be done with people who drown. If you know someone drowned in the river and you can't reach them without having to fear drowning yourself you would station people nearby to deal with maybe a handful off Draugr. Better safe than sorry, you don't want a single guard at the river and suddenly dealing with more Draugr than necessary. Other than that all dead would be burnt as a general rule of thumb. Again, better safe than sorry. Who knows, maybe they can get the recently deceased out of their grave after some time and put them in the ocean to revive them? People will have a lot of additional superstitions and prefer everyone to be burnt as a general precaution. As they are not the brightest and not the strongest they pose a little threat and there is not really any need to go against them on a large scale. Slowly decreasing their number will put them back into a reasonable number range sooner or later. If you pay the guards enough this will be a great job opportunity - guards that have to be trained and paid, outposts that have to be built, rations and weapons that have to be delivered, ... It's probably good for your economy. If their numbers are so high that they will pose a more serious threat you should think about securing common river passages better. Again, guards are a great thing to make sure that you at least know where someone died and will be coming back to life soon. Just don't take money for people to cross the bridges or they will find other ways and then you are back to the root problem. If there are a lot of these things you should make sure that no small villages will be overrun. The biggest problem with zombie-like hordes is if they start with small villages and are suddenly able to take big villages - because then large cities are not far anymore... Your higher ranked people should therefore reinforce the small villages, which will probably again be good for commerce. Basically you have the most harmless zombie apocalypse scenario I have ever encountered on this site - good job and have fun with your undead enhanced economy! --- ### If you want them *a lot* more dangerous than you have proposed - Only allow certain people near oceans/rivers and make drowning someone a *serious* crime First problem: undead rot. If you have rotting undead they don't have a lot of time to make more rotting undead, so they won't be able to formulate a bigger strategy. Especially because "kill people, make more Draugr" is currently their only motto. Change this to "Kill all the people and make them ever-lasting Draugr" to get a far more serious threat. Next problem: communication. You need to have a way for them to talk to each other. If you can give them telepathy of some kind to communicate with other Draugr via *magic* you would get perfect communication that can't be intercepted and can be used to change battle strategies extremely fast. Without that they are basically humans, so in theory written communication would still be possible. But paper and water don't go too well with one another and leaving message written in the sand of your beaches will be akin to crop circles - you can't get much more obvious. Problem number three: Intelligence. You need to *raise* their intelligence, cunning and patience to make them a more capable threat. A bunch of children that drowned in the nearby river will hardly be a threat for a castle. A bunch of enhanced war strategists that were fighting a naval battle might be better, but naval battle is still different from battles on the land and if they drown they probably weren't *that* good or they would have killed the other one or would have seen the storm coming. Of course there can be any number of additional reasons, but capable strategists are often not fighting on the frontlines so the dead from the frontlines won't be the best strategists that your capital can send to fight this threat. Four: Make them stronger and faster. You want them to drag people back into the ocean/river/... That requires strength. And it takes a long time during which you are incredibly vulnerable. To take a former example: a bunch of kids that drowned in the local river will hardly be able to drag the village's smith from the village center to the river. No additional Draugr and any searching party, no matter how inexperienced, will find their trail and pick them off while they are a basically non-moving target trying to drag something that is far too heavy for them. This gets easier with adult Draugr, but only so much - have you ever tried dragging a body across the ground for a few kilometers alone? (I hope not, but this should be very, very difficult for your Joe Average. So give your Joe Draugr more power so he's back to hunting faster.) Five: Your Draugr need to arrange raiding parties. But raising an army takes time and you need to communicate across distances and you need spies. If you have your Draugr be faster and more patient you could have Draugr spies, but currently any spy would easily be detected. Still, fishing villages would notice real quick that there is an army of undead in their waters. And if you kill every fisher that comes too close the village will know that there something is not right. This happens two or three times, they send someone to the capital, the capital sends someone to deal with the Draugr. A little war party should be enough - the Draugr have at most the drowned from the latest naval battle and a village of untrained Draugr at their disposal. Six: Drowning someone to murder them becomes a serious crime and is something you have to take care of because you suddenly have Draugr behind your walls. Imagine it works by simply drowning someone in a bucket of water - your Draugr, if he is really intelligent, could kill quite a few people without being detected and suddenly you have an attack from the insight. Combine this with telepathy and you can get some reasonable attacks - though you would need a human to be extremely careless or extremely hostile towards the city inside the walls for this to work. To counter this drowning someone would be a serious crime that will be punished by torture of you, your family, your pets, everyone you care about - you could unleash a zombie hell after all. Together with the supserstitions you would therefore have more laws to handle deaths and crimes in that direction. --- ### If you want to make them a threat Have all animals be susceptible to the Draugr curse - and all Draugr be capable of communication and comparable human-like intelligence. If it's not limited to humans and allows all Draugr, no matter the former species to communicate, things start to get interesting. People wonder why the hunting grounds are less dense when suddenly an army of wolves and boars rise from the tides to swallow whole villages in a sweeping attack with the humanoids carrying the prey off to make more infantry soldiers. It would still be a somewhat known threat as you say they have been around before, so people would know the signs and some may be prepared. But some would not be prepared and suddenly you have localized raids that start to grow into a mass scale attack. This would be horrifying zombie apocalypse - but it would need a lot of time and patience on the side of the Draugr where they are trying to covertly infiltrate the human regions and amass more soldiers for their army. This means a lot of time for people to figure out how to fight them and to prepare counter-attacks. If they are not vastly stronger it would be a normal battle and the best commander on each side might play the most important role in deciding humanities faith. [Answer] All current answers assume a military response. There is another solution. ## Talk to them. Contrary to popular belief, use of tools is *hard* mentally. Some species do, but it's rare to see invention happening. In apes, it tends to be a group thing, where some genius ape in the past has thought of the idea, and the others replicate it thereafter but can't translate it to new tool use. Crows are surprisingly good, but they still can't go beyond using bent sticks to retrieve something, and that's generally in response to human interaction which shows them how. The idea of using a tool as a weapon takes some serious mental agility. There's some fairly strong evidence that we're no more intelligent than the Cro-Magnons and Neanderthals who first started using tools to a significant extent - we just have a much bigger toolkit. This ties in with your concept of them being intelligent, just slower at processing. If they're intelligent though, they're capable of being reasoned with. A constant state of stalemate and attrition on both sides is not good for humans or draugr. Sooner or later a draugr leader will realise this, and there will be peace deals and formal allocation of territory. This doesn't mean that wars won't still break out - humans manage that perfectly well on their own, after all. But since it isn't possible for one side to fully wipe out the other, they will learn to live with each other. Terry Pratchett's trolls and dwarfs spring immediately to mind here. Since the draugr are intelligent, they presumably also have desires of their own, beyond simply "catch humans, make more draugr". Can they reproduce amongst themselves? Do they remember anything of their human lives? And how long do they live once they convert? If they remember their human lives, and they are long-lived (or eternal), it is entirely possible that the draugr may outcompete humans on technology. Once humans and draugr stop killing each other, draugr numbers will only ever go up, whereas humans are vulnerable to famine and disease. This will build a phenomenal "brains trust". Imagine if we still had Newton, Hook, Leibniz, Laplace, Boyle, Davey, Faraday and Einstein still around, working alongside Stephen Hawking. The results they'd get to would still be incredible, and science develops exponentially with bouncing ideas off your peers. Even if their processing speed is slower, their potential will greatly surpass humans. [Answer] **Enforce shore-watchers:** Since your draugrs come from the sea, it would be a good idea to reserve a share of the town guard / the army / the raiders to patrol the shores, killing and burning down any draugr they stumble upon. It's pretty easy to have a few armed man caring for major cities, but it might be difficult to protect far away, poor fishing villages. Governments (medieval governments, a that!) can usually ignore the loss of the occasional farmer, but as you state in your questions, an increasing number of causalities will affect the general wellbeing of your people. So, either your shore-watchers are raised from the area's populace, or their are trained kingdom-wide and then dispatched on the field. The latter assumes a more stable, centralized form of government. **It's your call**, whatever feels more coherent with your society will work. Of course, keep in mind that even a trained force won't be able to have the entire shoreline of your country in check, but it's a step in the right direction. A soldier is still better than a regular fisher armed with a pitchfork, even if your viking-like fishers will probably have axes or such. [Answer] The problem is that many or all good sites for settlements lie on a shore or along a river. Add to that that in the erly middle ages, transport by ship was far superior to any land based transport. An early medieval society battling Draugr would need to radically change it's relationship to open water bodies. If you feel my answer assumes to many or too powerful Draugr, tone down the responses - only some are follwed at some places etc. **Draugr attack methods:** * attack boats from below with grappling hooks, trying to capsize them * Sneak attack on villatges by the sea * Hiding in boats left on shore * sabotaging boats left on shore * March up rivers to attack towns further inland, along shores of rivers and lakes * Ambush in rivers at major fords, attack bridges to force the use of fording **Defenses and second order effects:** * Don't build enclosed harbors, instead have fortifications with a wall between the shore and the houses * Every night, drag boats into the walled settlements (this would apply to fishing villages and the likes) * When this is not possible, each new day for sailors and fishers will begin with a ritual check of their vessels for hidden Draugr (possibly with dogs) and sabotage traces * Naval architecture 1: I guess a boat shape that is well suited to drag across a beach twice a day would be flat bottomed and fairly light, which would be susceptible capsizing by attacks from below. So maybe the go-to boat for fishers will be a sort of light catamaran, as a good compromise of stability and lightness. * Naval architecture 2: Build boats so heavy and stable, with so much draft and such high boards, they can't be capsized by grappling hook attack from below. These will of course not be dragged on shore. Since a few patient Draugrs with drills could sink one on the high seas, I don't see much high sea travels. * rafting timber or other goods along rivers will be a thing for the reckless, as will be crossing rivers through fords * The uselessness of rivers for transport will force the societies to use more road based transport, at some distance from the cities. * Rivers will be even stronger borders than before [Answer] Consider what the volume of seawater necessary is to make draugr and whether the property is expended after a certain number of conversions. Is it due to a property within the sea itself? Another force, that can be reasoned with or dealt with at source? You'll need to account for the fact that it simply can't be *just* draugr that are magical - there would need to be some property or entity in the water that handles this exchange. An undersea portal, a monster, etc. Perhaps it's something that resides in all humans from birth from some long ago war (tying into above pact making and intellectual exchange between societies?). Could a malicious individual gather coffins of seawater, silently murder individuals, bind them, convert them, and raise a quiet batallion within city walls? Could a plague + a tainted water supply cause the same occurence? Is full submersion necessary? I'd develop the cause+effect further, at this point you should get some really interesting countermeasures (medieval desalination practices? rainwater gathering? waxing the skin in a religious pretense of protection, should one die? having some kind of dessicant on hand to take, similar to our cyanide?) Rivers and brackish water and previosuly thought-safe ponds that have connected to the sea through some intermediary become interesting pop-up issues. humans can only survive a day without water, let's remember. damned if you do and damned if you don't. [Answer] Draugr are basically stupid and aggressive people. You deal with them the way you would deal with the idiot of the village if he ever got drunk. Use standard weapons and armor, as if the draugr were a raiding party. [Answer] Heavy walls, spike/pit traps to slow them down and fire traps to destroy them. Greeks at the time of the Vikings had a few versions but they all amount to oil or tar in a pot thrown like a grenade. Bonus version, its tar with hay or cloth mixed in to form primative napalm. Combine with fire arrows.... if the threat is significant enough you see the culture over time shifting from a bunch of small scattered villages to focused towns around castles (heavy walls to go run behind). Ive only listened to one retelling of viking lore with draugr and that was in the Myths and Legends podcast, those draugr were everything the human was but stronger (tear through brick walls), a little dimmer, way more agressive, effectivly immortal and with the ability to curse people (guess being cursed is a quick way to getting magic). [Answer] While world in general would be mundane, it wouldn't mean that population would be completely "meta" and know that. Along with basic security measures - watch duties, watchdogs, signal light network, not leaving shore-side settlements open to ingress (especially during nighttime), they would employ little things like ritual "magic" wards, amulets, etc both on personal and social (settlement) level. E.g. some kind of effigies. Part of that would function just as "safety of mind", a morale support for folks, so they should be visual. Effectiveness and practices would depend on level of superstition in particular region. Also it's quite possible, that *some* of those methods might have an effect, especially use of some herb or substance to ward off walking dead (here I come from existing folklore). [Answer] Answering the revised 'intelligent draugr' question: **The same way you deal with humans** Dark Ages/Medieval communities frequently dealt with intelligent raiders coming from the sea and seemingly killing, looting and raping at random: the Vikings. The only difference between a draugr and a Viking in this scenario is the rate and means of reproduction (which is well-covered by other answers). Draugr may even (since they are intelligent) wait to form raiding parties rather than attacking individually. So, do what inhabitants of the British isles did: build fortifications, band together to raise armies for defense, or perhaps just hope it won't be you that gets raided. ]

[Question] [ I have a character who can teleport to essentially anywhere he can think of, assuming he either has been there before, or is given exact coordinates. The problem is, I can only think of two ways to complete this: 1. He disassembles his molecules at the same time as he is rearranging them at the target location to copy him. (Yes, he does have complete control over molecules; he basically has matter manipulation powers on an extremely powerful scale- he can rearrange them, fuse them, give them energy, etc, even down to the scale of single molecules. This is done semi-subconsciously, but he can control it when need be.) 2. He transports his molecules at the speed of light to wherever he needs to be. I have problems with both of these. For (1), doesn't disassembling his molecules and making a perfect copy of them elsewhere mean he's cloning himself and then killing one of himself? That's not nice, and I don't want to use that, unless we can find a way around that. (A way around that is not constituted by changing physics so that he isn't killed.) For (2), that means he can only travel at the speed of light. He is going to travel extreme distances (several light-years at most), so that should mean he takes several years to get there, including through deep space where he doesn't have any molecules to give him air or something. Faster-than-light travel is not possible for him (though such technology exists) because he has limitations. Also, this isn't really teleportation. It's just superspeed. How do I create a plausible way to teleport (based on either 1 or 2)? I can't just say "Yeah, he knows how to do this despite being one of only six beings in the known universe who have these powers and therefore never has received training in this." Also, my character needs to learn to master this technique. What is the best way to do this without killing himself? It's not plausible that he gets it on his first try. (Seriously, you try rearranging your own molecules and surviving.) Edit: I should have made this clear based on the responses: the **only power** he has is molecular manipulation. He can use this to various effects: for example, he can emulate thermal powers by giving or taking energy from molecules, he can emulate electric powers by moving electrons, he can even emulate biological powers- that is, he can change the biology of an organism so that they have changed strength, speed, metabolism, reaction time, etc. (I know this last one probably shouldn't really work in real life. But then again, molecular manipulation probably shouldn't really work in real life, either.) But I still like the wormhole/spacetime manipulation solution, and I also like the quantum entanglement solution. Thanks, everyone! Edit #2: I just realized that my light-speed transportation system doesn't pose any problems for him (courtesy of everyone who reminded me that my use of Lorentz relativity is wrong, oops.) But the problem still stands for everyone else who's gonna be waiting forever for him to come back. [Answer] Wormholes! or more accurately, an Einstein-Rosen Bridge. Basically the teleportation mechanism is to connect two points in space-time. One end is your current location, and the other is the desired location. The endpoint sizes are set to the exact size of the character to eliminate potential hitch-hikers. Mastering the technique would involve determining the size and placement of the wormholes, and how to correctly match their inertial reference frames with the source and target locations. It would be unfortunate to "exit" the wormhole with a high relative velocity. Another danger would be having your source wormhole size incorrect, and pulling in extra matter, such as a section of the floor you are standing on, or your pile of dirty socks from the bedroom floor. [Answer] What if consciousness is something apart from this bodily realm? It's an entity that cannot be dismantled and reassembled at will, nor does it have any matter or occupies any space? There would be no fear of disassembling his entire body so long he knows that, in essence, he is not this meaty mess of chemical reactions that we call body. [Answer] Direct Parameter manipulation. Consider that every elementary particle (proton, neutron, electron, etc) can be accurately defined by a set of parameters that determine it's location, and velocity. Each particle has an x, y, z, dx, dy, dz, etc. Your character has the ability to select all of the particles that make up his body, and directly change any of these 6 parameters. If he changes the z parameter of every molecule in his body by +6 inches, then he has teleported 6 inches upwards. [Answer] I've thought about this very question and for years I was adamant that deconstructing yourself and then reconstructing elsewhere meant you were killing yourself and then creating a clone. Recently, I realised that this DOESN'T MATTER. Our definition of 'death' is insufficient to describe the universe where this power is possible. You are disassembling yourself and then reanimating your constituent particles. The point at which 'death' occurs isn't strictly relevant, even if this doesn't happen instantaneously (which I assume it does). There will be a gradual change from animated and thoughtful, some momentary confusion and then you'll 'come to' somewhere else. If you've ever had a dreamless sleep in a moving vehicle, this is the same thing as far as you're concerned. You don't have memories of the travel and you're basically the same person as when you started (but crucially *not* the same - we change at every level, every second of every day). It's hard to divest ourselves of the idea that we won't be the same, but we forget just how often we undergo consciousness dissolution via sleeping, drugs, anaesthetics etc. Imagine someone in a coma for 5 years. No brain activity, no physical movement. They've travelled millions of miles around the sun, the galactic core etc. Their entire body (give or take a few bits) has been replaced and yet they are still the same person when they awake. They might feel a bit odd, but they are still 'them' and they'll accept it eventually. Death, *actual* death, is the slow atrophy of brain function resulting in irretrievable destruction of the mind and no way to bring it back. Even if we could (with some Star Trek tech, rebuild the broken neural connections etc.) then that would be largely the same as teleportation. i.e. molecular reconstruction, specifically the re-building of the individual from the 'buffers' (cached physical image). I imagine people teleporting in the future will feel nervous in the same way as people about to undergo general anaesthetic. They fear that 'they' won't map to the new state, but they'll do it anyway and the person who's left at the end will accept their situation just like patients do today. We're basically the cognitive inertia represented by our memories, and while (as one comment suggested) it's possible to hijack our pattern in transit and reproduce it at will, there is only one set of particles making the trip and the others are simulacrums. They won't know that, though... So be nice. Update: (thanks to Rozenn and Forest's comments). Some parts of our bodies do NOT undergo change over time, and could in fact be traced to before our birth, right until we die of old age. However, the broader point still applies, it's just not true to say that 100% of our bodies undergo complete replacement/renewal. It's likely around 99.9%, but that doesn't seem to relate to anything that could be called 'individual', as the molecules that *have* persisted aren't protected in any way, they just got lucky and could go at any moment. [Answer] ## [Quantum Tunnelling](https://en.wikipedia.org/wiki/Quantum_tunnelling) With the quantum tunnelling effect, you could tunnel through a barrier that it classically cannot surmount. This effect could be explained using the [Heisenberg uncertainty principle](https://en.wikipedia.org/wiki/Heisenberg_uncertainty_principle). Here I will do a basic explanation: [](https://i.stack.imgur.com/ycjkB.png) We have a green ball, two valleys (one below the another) and a mountain. We push a little the green ball, it moves and falls in the first valley turning some of its potential energy into kinetic energy (light green line), then, the ball tries to climb the mountain using all its kinetic energy (yellow line), but sadly there isn't enough to climb the "barrier", and finally it falls in the metastable valley (red line and ball), a zone with some energy (not rest state) but not enough to climb the wall. But if we think about energy, the ball can be in any place below the brown line because it doesn't need more kinetic energy to archive it, even more, reaching that states can turn potential energy into kinetic energy. So, if we close the eyes, the uncertain principle said that this ball can be anywhere below the line, even inside the mountain! Using this principle and not looking elsewhere, the ball can do some tricky physics and move through the quantum tunnel in order to archive the real stable valley, where it doesn't have more potential energy. Your character can use this quantum tunnel in order to move instantly into zones below its brown line, which would be something like its chemical energy (stamina?) or maybe potential energy (can't teleport outside gravity wells), I don't know, that is your problem, not mine ;). Other ways could be: ## [Warp Drive](https://en.wikipedia.org/wiki/Warp_drive) ([Alcubierre drive](https://en.wikipedia.org/wiki/Alcubierre_drive)) There is a way to move faster than light without becoming pure energy, disintegrate or move through quantum and weird tunnels. In soft sci-fi it's called warp drive, but in hard science it's usually referred to it as [Alcubierre drive](https://en.wikipedia.org/wiki/Alcubierre_drive). [](https://i.stack.imgur.com/Uzszq.png) It collapses (make smaller) space towards it and expanses (make larger) space behind it in order to move less distance to archive further destinations. And extremely collapse and expansion of space towards and behind the teleporter respectively in a fast way could be experienced as a "teleportation". The most realistic way to archive this could be manipulating gravity wells but it doesn't matter much. ## [Wormholes](https://en.wikipedia.org/wiki/Wormhole#Traversable_wormholes) A wormhole connects two points in space-time themselves making something that could be described as a "bridge" between the points. By this way, you could travel almost instantly shortening the distance between you and your destiny. Also, you don't need to disassemble into molecules. ## [Lightspeed](https://physics.stackexchange.com/questions/29082/would-time-freeze-if-you-could-travel-at-the-speed-of-light) If you become energy and travel at speed light, then become matter and reassemble philosophically speaking is a bit difficult to tell you if you are still alive, but at least it would be instantly for you. A particle travelling to lightspeed will not experience the pass of time. [Answer] ## [Quantum Entanglement](https://en.wikipedia.org/wiki/Quantum_entanglement) This is method 1, but with a twist that should make it a lot easier to believe that he is not creating a clone and killing himself. You assemble the exact copy of yourself somewhere else, except that for each particle you quantum entangle it with it's corresponding particle in your body and give it the opposite spin. Thus, when the clone is complete, it's certainly not you yet because everything is spinning backwards! Now all you have to do is suddenly reverse the spin of all of the original body's particles. The entanglement will immediately reverse the clone so that it becomes "you", while the original is not instantly not you. The reason that this adds a layer of ethical security is that it's not possible for the two versions of person to actually exist at the same time. It's less creating a clone and killing the original, and more just transferring consciousness. Just practice by teleporting other things. ## Possible tweaks If you're not convinced that a body with every particle spin reversed isn't you, choose another characteristic. Charge, velocity, etc. If you're uncomfortable with two bodies even existing at all, choose a type of entanglement that will result in different molecules at the other side. With careful coordination and selection maybe you can make the new body be just a gas cloud until you flip the switch. **Disclaimer:** This is not really how quantum entaglement works in practice, but given your character has the ability to manipulate fine matter at a distance, I don't think it's too egregious a stretch. [Answer] Another try on space manipulation: Instead of creating a wormhole as suggested by [this answer](https://worldbuilding.stackexchange.com/a/118484/52691) by Nate White, your hero could encapsulate himself into an area of space-time that's moving with superluminar speed to the desired location. We know that space-time can move at those speeds, and you would not kill your hero, so this would be a viable alternative. Furthermore, his molecule-manipulation can be explained by manipulating space-time itself, so this could be a nice little workaround. [Answer] Travel at speed of light is instantaneous *for the traveler*, so he'll be "there" in an instant even when it's 10 light years, but when he travels back he'll find that 20 years have passed. (Note that this kind of travel is already enough to construct signal-your-own-past paradoxes - not for the traveler himself but for people who are moving at relativistic speeds in relation to him.) Whether disassembling a person and reassembling it elsewhere is an instance of death or not, now that's a deep philosophical question. You can make your traveller unsure about it (which may be an interesting narrative sideline or not for your story), or you can answer it as "yes he dies every time and resents it but is forced to accept it", or you can answer it as "no, the generally accepted consensus is that the person is still the same in all relevant matters". Or you can simply ignore the question in the story, and leave it to your fans to ponder the question; you'd be in good company doing so, many great writers have. [Answer] The simplest answer I can think of from the perspective of this hero is that what they actually do is deconstruct and reconstruct *the entire physical universe* around themselves subconsciously. They don’t die by any reasonable measure,it seems like they’ve moved instantaneously, everyone around them seems to be exactly the same (just in a different place). I mean, they only half-killed everyone in the known universe, right? [Answer] **4th dimension.** Grab your kata and ana while I take you on a trippy dimensional trip. Imagine you are a one dimensional creature: a point. Your world is a line. You can move back and forth along it. Your point dog is behind you. Now imagine that your one dimensional line world can fold back in two dimensions. You are still a point moving along a line from your perspective. You cannot tell it bends, because what is "bends"? But in the second dimension, you are now immediately adjacent to the point containing your old dog point, who is one point behind you along your line. But adjacent is not the right word. Consider the line, now in a two dimensional square. How many one dimensional lines can fit in a two dimensional square? Infinitely many. The point you occupy has no depth. Your point might be in the same two dimensional space as that of your dog, whose point also has no depth. Every point along the 1d line could be folded back so that every point overlaps every other point in 2d. The points take up no 2d space; they will fit. Consider now that you are a 2d flatlander: a square. A cube can hold infinite squares. If the 2d square flatland world is folded through the third dimension, you could fold back to be right on top of your dog. In fact, since 2d space has no third dimension, you could overlap the space your dog is in. There is nothing between you. If you could move through 3d, you could reach into his space and give him a treat. Like the line, you can fold your 2d world up so everyplace is overlapping everyplace else. Now consider a three dimensional universe cube from the standpoint of 4 dimensional tesseract (4d cube). Like lines in a square or squares in a cube, an infinite number of cubes can fit in a tesseract. The cube can be folded in 4d an infinite number of ways. This will not be apparent to 3d residents of the cube. In 4d, a three dimensional space might overlap with another 3 dimensional space. In 4d, *every* 3d space might overlap with every other three dimensional space, just as all the points in the lineworld might overlap in 2d space. Here is the trippiest part of the trip: back to the lineworld. In one 2d space it is straight. In one 2d space it might be like a paperclip. In one 2d space it is folded back on itself so that every point is superimposed on every other. Which is it? Well, how many 2d spaces are there? How many are in your 3d cube? Infinite. The line world occupies them all. For any given configuration of your folded line world, there exists an infinite number of 2d spaces in which the world has your configuration. So too with our third dimension. For any given folding pattern in 4d, there exists infinite 4d spaces in which our universe is folded that way. Because there are infinite 4d spaces in a 5d space, and infinite - well, turtles all the way down, you know. Your characters mastery of molecules can understand their position relative to each other in the 3d world he inhabits, and also, to the degree his mind can encompass, their position in some of the infinite 4d spaces his 3d world is folded into. Really only the subset of 4d spaces where all cubes of his 3d space overlap is of any use (that I can think of), and of the infinite number of them maybe he wrangles only a couple. The awareness of such spaces and the ability to manipulate them means he can move through 4d space to any other 3d space, and really not move at all. His dog is right next to him even though he is a continent away, and he can reach through 4d with a steak scrap. [Answer] **Teleport one chunk of the persons brain at a time instead of the entire brain at once** Have another body for the traveler set up at the destination and remove a small chunk of the travelers brain and put a copy of that chunk into the other body and have communication between that chunk and the part of the travelers brain back in the original location. Then repeat the process until every chunk of the travelers brain has been copied into the body at the destination. This way the travelers experience is continuous as at every point during the teleportation the travelers consciousness is composed of both parts in the original brain and parts in the new brain. [Answer] Remember about no-cloning principle in quantum mechanics! Consider the state of his psyche/qualia/consciousness/whatever as a quantum state too. His body is only a set of matter particles. Only proper configuration makes his body himself. So he is not cloning and killing himself but also transfers his mind state to a new body. Because he is unable to really copy the state, he is unable to suffer the death neither (by his clone at least). What remains in departure place after teleportation is only some set of particles in disorder. The real problem here is the speed of light. Quantum teleportation requires some classical information channel. You even have to transfer the information about his body ingredients before transferring quantum state. But it is all your universe, so you are free to invent some mysterious law of physics to overcome it: tachions, wormholes, magic, etc... **Edit** What is the problem about travelling with the speed faster than light by any object? Obviously we can find an inertial system where given object travels through time. So this is my point now! Give you character an ability to travel through time! [Answer] Most answers focus on the solution for teleportation, and I think the wormholes solution fits well for your requirements. This part is well covered by other answers so I will not go into it deeper. My answer focuses on the training part. This was too long to fit in a comment, so I turned it into an answer. Creating the wormhole entry and exit points could probably be done with molecules manipulation, the construct requires extreme energy input, which he could probably generate with his powers. He could first learn to create a small construct in such a way that it covers a small distance like let's say enough to push a bug through and see it pop out 2 meters away. He could wreck his surroundings while doing so, being inexperienced. With practice he would learn to generate entry and exit portals so that they match his body shape with molecular precision (so he gets to spend less energy), also he would control the side effects on the surroundings better. You could even pop in some humor like him teleporting himself and getting on the other side naked, or him teleporting other people with the same effect. Then mastering the technique to include clothes. Edit: you might want to read A.E. van Vogt's **Non-A World** (a three book series). It's about a guy who can teleport himself, or others (or the tail of a flying plane to destroy the said plane). [Answer] I would say that approach #1 does not necessarily kill the man; only if it happens too quickly. I remember a story about a ship that travelled the world. It would rot away, erode, become damaged... but the crew would repair it. Eventually the ship lost each original part, yet completed its voyage. Your body is as this ship; new parts as the old degrade. So if he really moves his molecules one at a time, instead of instantaneous transmission, I could argue he never dies. [Answer] I recommend "A Fire Upon the Deep". Let's say a pack animal was able to communicate fast enough that it was able to act and think as one mind. If a "mind" is five animals what would happen if the mind was transport elsewhere one animal at a time? Would the mind die and a new mind form afterwards? I don't think so. In your case the character could break his mind into five parts and only one part is disassembled and transported at a time. As far as distance goes what if each part only goes 1 light second (186282 miles) at a time and the parts leap frog each other? The speed of travel will be the speed of light plus however long it takes to disassemble and reassemble a part. He will think slowly during this time and will only be 4/5th as smart as normal but I'm sure he's a bright guy right? [Answer] Other answers have provided potential scientific techniques to move yourself instantaneously to simulate teleportation (whether or not it would still count as teleportation or merely faster-than-light travel, I don't know). I will argue that this is not philosophically necessary in the first place. ## You've already been reconstructed You may not realize it, but this process has already happened to you countless times. Every second of every day, molecular turnover is occurring in your cells. Molecules that make up the neurons in your brain that hold your dearest childhood memories are not the same molecules that you had when those memories were formed, and yet you didn't die as a child. Because of this fact, the effect of teleportation will be no different from natural turnover in your body. Unless you argue that a more rapid turnover somehow kills you but a gradual one does not, or that you are already dead from molecular turnover, you are stuck with only one conclusion: teleportation is survivable! ## Death is not death if you survive Death is defined as the *irreversible cessation of all vital biological functions*. If your teleportation is actually duplication and not merely near-instantaneous movement, you have not died. This is because our consciousness comes from the arrangement of neurons in our brain, not from the matter that makes up these neurons. As long as this arrangement is preserved (and you do not materialize as a homogeneous blob of organic matter), your consciousness and sense of self will be preserved. The simple fact is that our mind is an emergent product of a processing medium, in our case, our brain. As long as the medium is functionally the same, you will have the same individual. ## The Ship of Theseus This is a thought experiment involving a physical ship kept in a museum on display. Over time, one part breaks and is replaced, yet it is still the original. Over time though, *every* part will have been replaced. At what point is it no longer original? This thought experiment assumes that the replacements are identical. In the real world of course, replacements will be made of different materials and will have different properties, but in a thought experiment where the replacements are the same, you can never say, at any specific point, that the ship is no longer original. The same applies to your own body, whether this restoration occurs over years as the result of natural biological maintenance, or instantaneously as the result of teleportation. [Answer] I think you need to rethink your perception of speed of light and light years. A 'light year' is a measurement of distance. 'Speed of light' is a perception of speed over distance and a constant in our universe. But when an object travels at the speed of light, time effectively stops still from your reference point. So assuming your character can travel at the speed of light why would he need to create an extravagant method of teleporting himself to save time travelling several light years, there would be no notion of time passing while travelling at the speed of light. Accrual of time would only happen at sublight speeds, so there would be no need to teleport, if the reasoning is to save time. This answer from physics exchange might help understand a bit more. <https://physics.stackexchange.com/questions/29082/would-time-freeze-if-you-could-travel-at-the-speed-of-light> [Answer] **Quantum Teleportation via Entanglement** Teleportation without dying: First: "Create" a bunch of particles, each entangled with the particles in the living body that needs to be moved. Next: Move them somewhere else Finally: Reassemble and "observe" them. Quantum entanglement is an instantaneous non local effect. It doesn't matter how far apart the "clone" is, as the clone is observed in the new location the quantum states of each of the other particles will now be here - while the remote state becomes decoherent. Each component of the living being simply changes which of the particles it is on, allowing for an instantaneous transfer of the entire creatures quantum state including consciousness to simply toggle. You need quite a bit of energy obviously as during the process you need 2x the mass of the body being transported, and a place to dump the energy afterwards as the now decoherent set of particles that *were* where the body was are now just free mess of gluons, up/down quarks and electrons. [Answer] This is a fun problem to approach from a theoretical standpoint. And really to reach a satisfying conclusion we need to discuss what constitutes consciousness in general. Basically what approach this character would come up with for the famous ship of Theseus problem. To avoid rambling on for paragraphs upon paragraphs I would say that an acceptable philosophy to take is that consciousness and the 'self' exist only so long as there is a continuity of experiences. So the new ship is the ship of Theseus because the ship is defined not just by its parts but the continuous state of *being* the ship. In order to rectify the 'dying' situation, have the teleport happen more slowly. His body slowly dissolving and being rebuilt in real time at the other end. This way he is experiencing both places at the same time as his body slowly fades molecule by molecule to the new spot and his experience and consciousness is continuous. Admittedly that's more of my personal philosophy on teleportation as defined by most scifis. But I hope it gives some helpful things to think on. [Answer] It could be that his ability to manipulate matter also allows him to change properties outside of our 3+1 spacetime dimensions. If he's able to shift himself outside of our normal space dimensions, and then shift back, he could shift back to another location far away from where he started. You can avoid the time travel issue by saying that while space might not apply in other dimensions, time is always moving forward at one tick per tick, and so you can't travel away and back and end up before you left. Some amount of time will have passed, even if it's only fractions of a second (based on time dilation and all the other messy things.) ]

[Question] [ Heat is energy. Temperature is an indication of the level of heat in a substance. But the normal way to *measure* temperature is to observe how the substance interacts with its surroundings - most commonly, by giving off heat to a cooler body, or receiving heat from a warmer one. (A classic thermometer reaches thermal equilibrium with the target, so it depends on such heat transfer.) Is it possible for a crystal to be so tightly formed that its molecules * have very little heat, * do not receive heat from their surroundings? Such a crystal would feel warm, despite potentially having a true temperature of a few Kelvin (or less). This substance would then make a superb insulator, just like a true vacuum but without the problem of pressure. Willing to accept answers that require a small amount of magic, but I want it to be at least plausible. Would be perfectly happy if this is possible and stable without magic, even if it requires magic to create such a crystal. [EDIT: It appears my use of "temperature" above is strictly incorrect. By "true temperature" I really mean something along the lines of "Joules of heat per kilogram of mass". I'm looking for a way for a substance to have very little heat, yet interact so little with its environment that it is nearly impossible to measure this as a low temperature.] [Answer] Temperature is an empirical, macroscopic concept and is not in general equivalent to energy. It breaks down at some point (energy does not), for example at the point you are asking for. But let's try to make sense of this: 1. Temperature is proportional to the (square mean absolute value of) relative motion of atoms. You might get in trouble choosing your reference point (relative to *what*?), we'll need to keep that in mind. 2. So with your substance, when you touch it or apply forces to it, those forces aren't allowed to change this. 3. So they can't interact with a single atom, they need to somehow know to act on the whole structure. They could act on a single atom in very specific implausible ways so as only to change the directions of the atoms motion. Let's ignore this. 4. But you always have forces which would only act on some atoms and not others (check: real life). 5. So you need a force applied to just a single atom to propagate to the whole structure (with structure being everything that shares the same reference point, say the center of mass of some blob of material). 6. If the structure is a gas or a fluid, you are now fu... I mean, you start waving your hands furiously. But the concept of a solid body is exactly that force applied to part of it propagate to the rest. Right? Right? Nope. That's one of those macroscopic things again. In real life the force spreads at the speed of light like a wave, ripples around in crazy unpredictable ways, thus does all sorts of things to the motion of individual atoms and ... heats the solid body up. Basically just like in a fluid or gas, but on a microscopic scale instead of a macroscopic one. Your intuition with the crystal seems to go in that direction, crystals do pretty well at being solid - just, well, you can still heat them up just fine. You couldn't if they were an idealized solid. 7. So: Hands. Forget about science. Maybe your substance is made up from [Platonic Solids](https://en.wikipedia.org/wiki/Timaeus_(dialogue)#The_Elements "Platonic solids") aligned exactly face to face and fused together with super glue to create a Macroscopic Platonic Solid™. Footnotes: * My argumentation is very simplified. Each simplification is an opportunity to start waving your hands, you don't need to wait till the end. * In the first step I'm saying "atoms". In reality there are smaller particles. I know little about quantum physics and can't tell you how this could be exploited (other than just yelling "Quantum Physics" and leaving it at that). * If you want to start your magic at 3, you could manipulate all forces acting on the substance and between the atoms of the substance so as to fix the energy of the individual atoms and just change the direction of their microscopic movements. You could probably do this by stretching space itself by tiny amounts in incredibly many places and adapting this in real time. * At step 5, you could exploit that caveat with the reference points and allow some internal motion. Say some kind of super super fluid (real super fluid doesn't work), where instead of heating up in the classical sense, internal cyclic currents (whirlpools or something) form so that you have macroscopic kinetic energy instead of microscopic one. Or just put two hollow rigid spheres inside each other and any energy received goes towards rotation of the inner sphere. * The problem with idealized solid bodies isn't just that they are imaginary, they would also allow information to travel instantly within them, bypassing the usual limit of the speed of light (thanks for reminding me @rosuav). I can't think of a paradox right now, it's not as bad as time travel, but I'm sure you could come up with *something* strange. I'm like 30% sure it won't blow up your world, should be fine. :) [Answer] Hmm ... does your material have to be a crystal? If not, try an *aerogel*. From wiki (<https://en.wikipedia.org/wiki/Aerogel>): > > Aerogel is a synthetic porous ultralight material derived from a gel, in which the liquid component of the gel has been replaced with a gas. The result is a solid with extremely low density and low thermal conductivity. Nicknames include frozen smoke, solid smoke, solid air, solid cloud, blue smoke owing to its translucent nature and the way light scatters in the material. > > > It's supposed to be an extreme thermal insulator. And they're not kidding: [](https://i.stack.imgur.com/8d5vV.jpg) Seriously, they're not kidding: [](https://i.stack.imgur.com/bhVon.png) Did I mention they're taking this pretty frikkin seriously? [](https://i.stack.imgur.com/k79id.jpg) You won't get the structural benefits of crystal, but if you get a big roll of this aerogel stuff, you can coat whatever you want in it! > > Update: Flower is from en.wikipedia.org. Crayons are from stardust.jpl.nasa.gov. The brave, brave Lady is from thermablok.com. > > > [Answer] The best you can have is that the material is so highly insulating that touching it won't give the true feeling of its temperature, and only the thin layer in contact will be thermalized with the touching object. Something similar happens for example with the ceramic tiles used in the thermal shield of the Space Shuttle: few seconds after being taken out of an oven at about 1000 C, they can be touched bare hand without harm. Still, this doesn't mean that the material won't exchange heat. Thermodynamic is not a beast you can easily lure. [Answer] If you want to stick with science, then first you need to correct a misconception or two. You seem to be thinking of heat or temperature as an intrinsic property of a material, but it's not. Whatever the apparent temperature you measure by e.g. touch, then that's the temperature. A material *can* have temperature gradients in it : one part hotter or colder than the rest, for example. But it can't appear to be one temperature and actually be another. What a material can have is low thermal conductivity. That means it can act as a buffer to the flow of heat. Heat will only transfer slowly within the material. But it *will* eventually transfer. An example would be the tiles used on the space shuttle. It's not quite as simple as a low thermal conductivity, but these tiles were designed to "soak up" heat and release it slowly. The aerogels mentioned in another answer ( by @akaioi ) are another example of a material designed to have low thermal conductivity. But it's low, and heat does flow. Also note that the thermal conductivity is temperature dependent. As the material heats up, it's thermal conductivity can increase (and of course it can suffer other structural issues). > > Is it possible for a crystal to be so tightly formed that its molecules > > > * have very little heat, > * do not receive heat from their surroundings? > > > No. A material has as much heat as was put in, so to speak. You can heat it up and it gets hotter. Low thermal conductivity will slow the spread of heat through the material, but not stop it. It's impossible for an object that is cooler that it's surroundings not to receive heat from it's surroundings. Likewise if the object is hotter than it's surroundings it will transfer heat to them - typically by radiating thermal photons. So if you want this, you have to "handwavium" the thing. :-) [Answer] Assuming you could make such a substance in the first place it would be stable by definition as it is completely inert. The problem I see is that this substance will share some properties with a [Bose-Einstein Condensate](https://en.wikipedia.org/wiki/Bose%E2%80%93Einstein_condensate) mainly the fact that being so inert and so cold the constituent atoms are not moving and their position takes on a quantum smear which in turn makes the structure less stable and certain and increases its activity, at least that's what happens to the model in my head. The point is you get into some very tricky quantum physics territory where very small effects, one's you don't notice at higher temperatures, become very big issues when you get down close to [Absolute Zero](https://en.wikipedia.org/wiki/Absolute_zero), which is by definition the temperature of a thermally inert substance. That's my take on it anyway, hopefully it's of some use to you. [Answer] **Whitebody.** A [blackbody](https://en.wikipedia.org/wiki/Black_body) is a hypothetical object which absorbs all radiation and does not reflect or transmit any. A white body is the opposite: it reflects all radiation and absorbs / transmits none. The white body will not be heated by radiation. Convection and conduction (really the same method of heat transfer - by intermolecular impact - for gases and solids respectively) could still heat such an object. If one magically enhances the reflection ability such that molecules of, say, my hand impacting the white body are reflected with all of their original energy, they will not give up any energy to the white body and so will not heat it. This white body might emit radiation, and so the interior would cool to absolute zero. Because it is not heated by exterior forces this would not be detectable from the outside. The white body would not, I think, be white but rather look like a mirrored surface. If that surface were cracked the exposed inside would immediately freeze solid the gas that flowed into it. [Answer] **No…but** Heat energy is contained within a solid as vibration of the materials chemical bonds. All chemical bonds can be induced to bend, rotate or compress by the application of some frequency of infra-red radiation. So there is no chemical substance that is immune from absorption of heat energy at some frequency. If chemical bonds could be “tightened” by increasing the attractive forces between atoms to a degree much greater than is possible in nature, then adsorption of energy would only occur at frequencies much higher than infra-red. Such a material would be more like nuclear matter composed entirely of neutrons as found in a neutron stars. The strong nuclear force bonds between neutrons would be so strong that they would not be susceptible to any vibrational motion induced by feeble infrared energy levels. It would need x-ray energy or even gamma ray energy to induce vibration within the neutron to neutron strong nuclear force bonds. [Answer] Going right off-piste here, but since we're 'world building'... could your material be quantum entangled with an equal bit (or 'opposite' bit) of material somewhere else? I mean, the bit in your hand is 'spookily' connected to another bit which happens to be in the freezer, or out in space, or orbiting the sun or whatever. The bit out in space either absorbs energy and passes it along to the bit in your hand, or else expels energy by taking it from your hand. Trying to tie this up with my pidgin-physics... the temperature of something sort of defines the amount the atoms that make it vibrate. The higher the temperature, the more they vibrate. How about each atom in the material in your hand makes it's opposite number in the bit of material out in space vibrate instead? Such a material would have a weird heating or cooling capability, which isn't exactly 'thermally inert' as I'd understand that to mean (I'm thinking more of an insulator there), but it would be able to (seemingly) absorb vast amount of energy without getting hot (and likewise could transfer a great amount of heat to its surroundings without getting cold. [Answer] **Absolutely!** What you seem to be looking for is a material that meets 2 criteria: > > have very little heat > > > I take this to mean it has a very low [specific heat](https://en.wikipedia.org/wiki/Heat_capacity). Basically, specific heat, or heat capacity, is the energy required to raise the temperature of a mass. An object with a low specific heat takes very little energy to raise the temperature. Similarly, it is very poor at storing thermal energy because its capacity is so low. The difference in heat energy between when it is hot and cold is very low. > > By "true temperature" I really mean something along the lines of "Joules of heat per kilogram of mass". > > > This matches the units used to measure specific heat, which is energy/(mass \* temperature). One of the SI conventions used is Joules/(Grams \* Degrees Celsius). > > do not receive heat from their surroundings? > > > This just means that what you are looking for is also a great thermal insulator, meaning that it resists the transfer of thermal energy. The temperature of an insulator will eventually change, but it happens very slowly. This means that, to the touch, it is often difficult to determine the temperature of a good insulator. You can test this by putting some wood and some metal in the fridge for a while and then touching it. The wood may feel slightly cool but the metal will feel far colder, even though they are the same temperature. If your material has both of these properties, it will always *feel* like the temperature of whatever is touching it, but in reality be colder or warmer if it is still cooling or warming. Additionally, it will hold very little thermal energy. An idea how a thermometer might misread its temperature: Perhaps the surface is actually very conductive under pressure, so that a thin skin wherever it is touched by a thermometer will quickly absorb the very small amount of energy necessary to raise it's temperature (or vice versa), causing a temperature gradient and a misread by the thermometer. Or maybe the surface oxidizes which causes it to lose its insulative properties, but maintain its low specific heat. [Answer] What you're looking for exists in engineering in some context. It's called a heat sink. It's generally something really big with a pretty high specific heat that doesn't change temperature based on the amount of energy you put into it. For example think about using a stove top to heat the ocean. The heat generated by your stove top isn't going to change the average temperature of the ocean at all. What you want is something that never has a heat to begin with. That's going to require a ton of energy to maintain. You'll essentially have to use other forces to stop random movement due to heat energy in your material. I think MIT did something like this to reach pretty much absolute zero. I believe they used magnets to do so. A few other people have done something similar. This also might not have been MIT. The cooling method they used is useful. The material isn't really. Or, since this is writing, you could just claim some BS that won't easily be proven wrong with a google search. The particular BS that comes to my mind is that "the broke time symmetry". Believe it or not, that's not complete hogwash. That is in fact something that you can in fact break. Who knew?(physicists did after the fact) I'd expect most people to stop looking into your assertions after discovering that broken time symmetry is real. If you're willing to get super loose with it and you still want a somewhat sciencey explanation as to why your material never has any heat, then just go with transferring all the energy to a different dimension or to something else. If you could suspend disbelief for the ability to do that, then it should work out. That is essentially magic though. Quantum entanglement doesn't work well enough to make something thermally inert to my knowledge. [Answer] Use a [topological insulator](https://en.wikipedia.org/wiki/Topological_insulator). Note that in a metal electons cary heat as a fluid. If that moves along the surface only, heat cannot be transferred inward or outward. It’s impossible to be perfect though. You’ll still have radiation, e.g. IR at normal temperature. So add another layer of stuff to reflect it perfectly. I think this is also impossible without consuming power, but you might get so close that the loss is insignifact. [Answer] In any system an equilibrium don't all the atoms have statistically equal energy? That's why the average velocity of a helium atom is much higher than that of an argon atom (and why we fill windows with argon) One of the reasons that metals are good heat conductors: You have a general electron cloud of valance electrons. Get one moving faster, and it sheds energy bouncing off it's nearby slowpokes. Materials that don't have clouds of electrons interacting (insulators) you add energy to an electron it has to shove the nucleus around, and then it bumps.... Suppose that you have a fantastically rigid substance so that the matrix of atoms is locked in place. Would not this material now act as a single 'atom' Hence it's amount of energy would be the same as as that of any ordinary atom. Essentially zero. To do this the positions would have to be held with nuclear forces, not merely electrostatic forces. At this point my physics starts to wander... ]

[Question] [ In any modern story nowadays, shapeshifters always have an original form; [Andalites](http://aliens.wikia.com/wiki/Andalite) from [Animorphs](https://en.wikipedia.org/wiki/Animorphs) or [Mystique](https://en.wikipedia.org/wiki/Mystique_(comics)) from [X-men](https://en.wikipedia.org/wiki/X-Men) to name a few. It raises the question of why something that can change forms would even bother with an original form. Ignoring the unrealism of a creature evolving the ability to shapeshift, why would a shapeshifter bother having an original form? [Answer] A shapeshifter doesn't "choose" an **original** form. A shapeshifter's "original" is whatever form it started as - that's what "original" means. That form is whatever it was in before it gained/learned/discovered its ability to shapeshift. In cases where maintaining a shape requires concentration and effort (Odo in *Star Trek: Deep Space Nine*), has a maximum time limit, or is triggered by an outside influence or external catalyst (classic werewolves), a shapeshifer may have a **default** form that they revert to when resting (Odo turns to a liquid) or in absence of the catalyst (werewolves become human). Shapeshifters without such a restriction (Mystique from X-Men) or with a default form not conducive to interaction (Odo, again) may have a **preferred** form. [As Cort explains](https://worldbuilding.stackexchange.com/a/41053/8862), having such a form helps such an entity reinforce its sense of self. Sentient beings in most stories want to have some way to be relateable to other sentient beings; a preferred form helps you maintain those relationships, too. [Answer] In many stories, shapeshifters have a lot of difficult with their sense of self. In a world where a physical shape is often associated with an identity, they would continually be bombarded with interactions from everyone based on their physical appearance. Retaining an original form would be one way to make sure you *have* an identity that you don't lose over the years. It's something solid and stable. (except for those rare circumstances where one shapeshifter emulates another, but its rare to find stories where they try to rob another shapeshifter's identity). [Answer] Reasons for why a shapeshifter would return to its original form: 1. A shapeshifter cannot remain in a new form forever and must return to its original form in order to survive. 2. Staying in another form requires a large amount of energy or concentration. 3. A shapeshifter must stay in his original form in order to have access to the benefits of his identity, such as his bank account for example. 4. A shapeshifter chooses to stay in its original form when it's around its childhood friends, to prevent confusion. 5. The shapeshifter feels sentimental about its original body the way we feel sentimental about our childhood home or our favorite movie. [Answer] As a metaphor, I will use online screen names. A person can potentially have as many screen names as they like, with a different one on every site, and potentially several for the same site (discouraged as this might be). So why is it that most people like to use the same screen name in multiple places? People like to have an identity, something that others will recognize immediately. While there are exceptions, it is human nature to want a symbol to identify themselves, taking on other forms mainly for practical purposes. Unless a shapeshifter is particularly antisocial, it stands to reason that they might feel the same way. This is also why a shapeshifter who does enjoy mixing it up somewhat might have a common 'mark' possessed by all their forms (for example, all of their forms have the same color skin or fur) so that they can be immediately recognized. An antisocial shapeshifter will probably be different; in their case their shapeshifting may be an acquired power and they must expend energy to sustain an altered form. Shapeshifting *species* are prone to defaulting to an amorphous 'blob' form when resting because this shape takes the least amount of energy to maintain. Alternatively, they may have a form that they have more experience with and will generally stick to that one when another isn't more practical, simply because the familiar is comfortable. Antisocial shapeshifters with capricious personalities and without physical limitations are the least likely to have an 'original' form. Bartimaeus from the Bartimaeus trilogy is a good example, although even he has a common thread between his many forms (he prefers to take the shape of desert animals when possible). [Answer] Supposing you had a shapeshifter for which any form would be equally fitting (ie. we are talking about *preferred* forms, not *original* ones), and living in a non-shapeshifter society, I see several reasons for them to have such identities: * Keeping the *face* people is used to. This is specially important when dealing with people unaware of your shapeshifting abilities, but it is still appropriate in general that people is able to associate your body with your identity. * Bureaucracy. Generating a background takes time and effort. Even though as a shapshifter you can change your appearance as much as you wish, you will probably have only a few identities with a driving license. Similarly for other tasks, such as opening a bank account or renting a house. You may be good at creating fake documents, but some will still require a more careful creation. And they won't be as as shape. * Related to the previous reasons, some identities will require a more detailed crafting: name, job, marital status, studies… Some identities will need the shapeshifter to remember lots of information not to contradict himself. Thus these can be considered as "permanent" identities even if only presented to a few people. * Sentimental reasons: [Martian Manhunter](https://en.wikipedia.org/wiki/Martian_Manhunter#Post_Zero_Hour_.28mid-1990s.E2.80.93mid-2000s.29) adopted the identities of dead people (often killed) as a tribute to them. [Answer] > > Ignoring the unrealism of a creature evolving the ability to shapeshift, > > > Chameleons can change their skin color. Not shapeshifting, but a first step to that direction. As a sidenote : they have a default/resting/original color that is different for each chameleon species but mostly green or brown. > > why would a shapeshifter bother having an original form? > > > Assuming that the shapeshifter species developed this ability during their evolution, the "original form" is something they inherited from their ancestors. [Answer] I think it depends on how the actual shapeshifting works. In engineering there are three type of deformation: Elastic Deformation, Plastic Deformation, and Fracture. I won't consider fracture. In elastic deformation you apply force to an object to get it into a shape. Once the force is gone it will revert to its' original shape. Think about an elastic band. If your shapeshifter is an elastic deformer, then reverting to a natural form is what happens when you stop using the force keeping you in a particular form. Keeping up the shapeshift costs energy so to stop draining that they will revert. That's why they prefer their original form. In plastic deformation you apply force to an object to permanently change its' shape. Think about: clay. If your shapeshifter is a plastic deformer, it probably won't revert to a natural state. Because keeping up the current form doesn't cost extra energy but the act of shapeshifting can cost a lot of energy. That's why they don't prefer an original form. [Answer] Speaking as a shapeshifter irl ( ͡° ͜ʖ ͡°) It is because we can't stay in the same form for too long. you can change your main form, but it is very hard as doing this would take a lot of energy, eating a lot of junk food for 5 weeks strait should do the trick tho [Answer] Rejection of their powers. If they don't like or want to have powers, they could just stay in their original form and pretend that the powers don't exist. ]

[Question] [ The story I'm writing is about an intragalactic war and is told from several perspectives including the CO of a small warship. Because space is massive, I have run into an issue with presenting distances and speed in a way that makes sense to the reader. I decided not to use km/s or km/h as that would result in numbers with little frame of reference of speed or are so astronomically large that they lose meaning. I have toyed with the idea of using "light seconds per hour," or something similar/smaller. Are there any better-suited units of measure I could use? Necessary changes to them to make them more useful within a solar system vs deep space? Any way to abbreviate it similarly to "knots" for nautical miles? [Answer] **Frame challenge: Discuss time, not speed or distance** Let's look at the issue here. In space, "speed" is meaningless and the more technically correct "velocity" is always relative to a particular frame of reference. What the captain of a ship needs to know is *when* things will or can happen. "The dreadnought will have us in range in 30 seconds." "The missiles will impact in five minutes and point defence will only be able to engage them effectively in the last minute before impact. We can buy ourselves another thirty seconds if we start accelerating away from them right now." "It will take us nine days to reach orbit around Frogstar B, or twenty-two days if we want to keep half our fuel in reserve." "It will take eighteen minutes for our transmission to reach the Mars colony and the same for their return signal to reach us." (If lightspeed is a limit in your universe then savvy readers will be able to infer the distance, but the effect can be understood regardless of education level.) The computers and the human(?) subordinates using the computers on the warship can be working out distance, velocity and acceleration values in the background - you may want to work them out too as a writer if you are wanting this to be hard(ish) sci fi, - but the reader and the captain just need to know how long things will take - is there time for a breath, a meal or a nap before something is going to happen. The only time distance matters is at more understandable human scales - "Captain, the breach in the hull is 150 metres aft, it will take damage control ten minutes moving through the corridors in zero-G to get a patch in position." [Answer] **Percentage of the Speed of Light (c)** I think this is the one I see used most often. How fast are we going? ".02 c" or "2% light-speed" or "2% c". It's a nice relative frame of reference to use and handles high speeds well. You could pull a Battlestar Galactica and [invent your own words](https://en.battlestarwikiclone.org/wiki/Category:Units_of_Measure) (but I always thought that was a bit silly). Then again, [Star Trek does it](https://www.startrek.nl/database/miscellaneous/warp-speeds-chart). How fast ya going? Warp 3. How fast is that? See the chart. [Answer] Let's start with a basic truism: you always want values that will normally be described in two-digit numbers. That's just how humans think. It's ok to go outside of those ranges, but anything three digits are more should be "big" and single digits or less should be "small." Start by picking the time period that your numbers are meaningful over. Hours, days, weeks, months, years. You'll notice that a car that can go 100mph really averages 60mph, but still doesn't actually travel 1440 miles per day. We have to stop and rest, refuel, get our bearings, slow down for traffic etc., so the number winds up being more like 500-900. This is the difference between burst, instantaneous, and sustained speed, and these numbers aren't generally translatable. Once you have a time period, then you can identify your distance. Light-years is pretty standard outside of a star system, and astronomical units (AU) is typical within a star system. Parsecs is kinda dumb for measuring travel because it's based on Earth-based observations. Also, it translates to 3.26156 light-years, which isn't terribly useful. If these numbers aren't convenient for you, pick something that relates to your FTL technology. This gets into technobabble, but can improve your immersion. For instance, you might call something "Warp 2" if that speed causes relativistic distortion that makes stars look half as wide outside your port holes, or whatever. **update**: Here's [a good discussion](https://www.sffchronicles.com/threads/566209/) I found on the topic on SFFChronicles discussion board. The gist of the discussion is that (a) yes, all units of measure are human, but (b) if you story is translating their language, you might as well translate their units of measure while you're at it. Unless it's something you're using to highlight alien-ness, you'll only confuse your readers. **Update 2:** Nosajimiki quite rightly pointed out that having aliens with no reference to human culture talk in miles, or even kilometers, can be quite immersion breaking. Here are four ways I can think of to deal with this problem, in order of my preference. 1. Rewrite your text to describe the distances in terms of what it means. "It'll take days to get there" instead of "It's thirty light-years away" 2. Use units that sound like their human equivalents, like "kliks". 3. Have a foil around to explain the measure to. 4. Provide copious context so that the reader has something to relate to. This one still probably won't work unless your measure is similar to something in the reader's experience. I would like to further point out that being vague can often to be a writer's advantage. You can go crazy trying to chart out all of the precise times and distances and velocities so that you avoid continuity issues. Better to just not specify in the first place. [Answer] ### 20,000 Leagues Across Space I wouldn't bother with any real, identifiable standard of measurement. Basically, people think in miles (or kilometres). They're big, but human scaled big. I'd recommend just bumping that up a couple orders of magnitude, very much like what we do with velocity. MPH for lower speeds, like cars and trains; Mach for super/hyper sonic speeds; Warp for transluminal speeds. Since light is so painfully slow, on a galactic scale, you'll certainly want to come up with a similar scheme for the next order of magnitude or two. I'd just pick some cool sounding, relevant terms like leagues, knots, clicks, chains, blasts, etc. These would all be understood in context to actually be the supersized units of measure better suited to galactic space travel. A league could, for example, be 1/100 or 1/1000 of the galactic diameter and a knot could be a tenth or hundredth of that. Smaller units like chains and blasts could be more relevant to solar system astrogation; whilst clicks or ticks could be used on a planetary scale. [Answer] ## Increase the numerical prefix used in front of -meters to whatever is the most useful for the speed of your ships. * 1 kilometer = 1000 meters * 1 megameter = 1000 kilometers * 1 gigameter = 1000 megameters * 1 terameters = 1000 gigameters * And so on if necessary (here is a [numerical prefixes chart](https://d32ogoqmya1dw8.cloudfront.net/files/mathyouneed/metric_prefixes.v2.pdf)) With this system, you can express speeds in a way that is familiar to your readers while staying relevant to what your ships are capable of. For instance, as 1 light-second = 299 792.458 kilometers, the speed of a ship that can travel this distance in an hour could be written as slightly less than 300 megameters per hour. 3600 times that is equal to a little over 1 terameter, so the speed of light is roughly 1 terameter per hour with this system. As you can see, its enough to cover all speeds below this supposedly unreachable limit ; if you decide to go the *Elite Dangerous* way and make it not only reachable but breakable, you can start using the speed of light itself as a unit (1c, 5c, 25c…) but then again, you could simply keep using terameters at this point. I'm unsure about abreviation conventions, but I imagine you could shorten those with Mm/h, Gm/h and Tm/h (or Mm/s, Gm/s and Tm/s if those apply) (Edited a *lot* of times because of calculus mistakes. Math is hard and my head is empty.) [Answer] "The distance between the home planet and the first habital Star - called 'kerf' represented a distance of some 3 earth Light Years. This distance was used as the basis of Interstallar travel. A Kilo-Kerf being 1,000 times this distance. The related unit of Kerfacs was the number of Kerfs travelled in a standard home planet day. A commercial grade space freighter in good order could be expected to do 6-7 Kerfacs. Whereas the elite Military vessels were rumoured to be able to break 100 Kerfacs in emergency situations" [Answer] > > I decided not to use km/s or km/h as that would result in numbers with little frame of reference of speed > > > *Give* them a reference. Realistically, Earthly references aren't that useful in space. Trying to relate a car ride to interplanetary (never mind intragalactic) distances will result in those large numbers you're trying to avoid. Describe the impact and relevance to the situation. 10 km/s, for example, is slightly too low to escape Earth's gravity from near its surface. It's also practically a dead stop for something capable of traversing light seconds in hours, and it's fast enough that each kilogram has kinetic energy equivalent to 12 kg of TNT, so you really don't want to hit something at such speeds. [Answer] I'm not sure if this actually constitutes a helpful answer, rather it's two excerpts that seems rather useful. > > "Well, have you any conception of the sort of thing you're setting yourself to?" The Space Viking snapped his lighter and puffed. "You know, of course, how big the Old Federation is. You know the figures, that is, but do they mean anything to you? I know they don't to a good many spacemen, even. We talk glibly about ten to the hundredth power, but emotionally we still count, 'One, Two, Three, Many.' A ship in hyperspace logs about a light-year an hour. You can go from here to Excalibur in thirty hours. But you could send a radio message announcing the birth of a son, and he'd be a father before it was received. The Old Federation, where you're going to hunt Dunnan, occupies a space-volume of two hundred billion cubic light-years. And you're hunting for one ship and one man in that. How are you going to do it, Lord Trask?" > > > -- Page ~26 of The Space Viking by H. Beam-Piper A second, which I'm going to have to somewhat abridge (a travesty), comes from Gray Lensman by E.E. Doc Smith: > > "I never could see how you deep-space men can really understand what you're doing—either the frightful speeds at which you travel, the distance you cover, or the way your communicators work. In fact, a professor told us that no human mind can understand figures of those magnitudes at all. But you must understand them, I should think ... oh, perhaps—" > > > "Or maybe the guy isn't human?" Kinnison laughed deeply, infectiously. "No, your professor was right. We can't understand the figures, but we don't have to—all we have to do is to work with them. [...] > > > "I can explain it best, perhaps, by analogy. You can't visualize, mentally, the size of North America, either, yet that fact does not bother you in the least while you are driving around on it in an automobile. What do you drive? > > > "We'll have to pretend that you drive a Crownover sedan, or some other big, slow jalopy, so that you will tour at about sixty and have an absolute top of ninety. Also, you have a radio. On the broadcast bands you can hear a program from three or four thousand miles away; or, on short wave, from anywhere on Tellus— > > > "Well, change 'miles' to 'parsecs' and you've got the picture of deep-space speeds and operations," Kinnison informed her. "Our speed varies, of course, with the density of matter in space; but on the average we tour at about sixty parsecs an hour, and full blast is about ninety. [...] > > > "Ultra-waves are faster than ordinary radio waves, which of course travel through the ether with the velocity of light, in just about the same ratio as that of the speed of our ships to the speed of slow automobiles—that is, the ratio of a parsec to a mile. Roughly nineteen billion to one." > > > "Nineteen billion!" she exclaimed. "And you just said that nobody could understand even a million!" > > > "That's the point exactly," he went on, undisturbed. "You don't have to understand or to visualize it. All you have to do is to remember that deep-space vessels and communicators can cover distance in parsecs at practically the same rate that Tellurian automobiles can cover miles. So, when some space-flea talks to you about parsecs, just think of miles in terms of an automobile and a radio and you won't be far off." > > > These two do a better job of conveying the matter than I could. Fundamentally, humans can't process the stupid numbers, they just pick a unit and/or multiple that results in reasonable quantities and forget the rest. In practical terms, both these works resort to light-years per time unit (can be shortened to lights) for general speed and switch to light-seconds for shorter distances. Without looking it up I think it's something like 8 light seconds to the Moon and interplanetary distances are all measurable in light minutes. [Answer] Earth human characters should probably give distances in light years. A light year is the distance traveled by light in a Julian calendar year 365.25 Earth days or 31,557,600 seconds long. Long distances could be given in kilo light years or mega light years, thousands or millions of light years. Speeds can be expressed as so many light years, per year, day, hour, or other time unit. 5 light years per hour is 120 light years per day, for example. Or speed can be given in multiples of c, the speed of light, as in 1,000 c or 1,000 light speeds, for example. Those units are for interstellar navigation, and for strategic considerations. Combat might happen at much shorter distances and at speeds much slower than light, as it does in some space opera type war stories, in which case different units would be used for tactics. But since I don't know the space war tactics in your story, or what units would be useful in those tactics, I am considering the units used to describe how far away a destination star might be and how long the voyage there might take. If you are writing about an intragalactic war, which is a war between different governments in the same galaxy, usually called an interstellar war, you probably need to have spaceships which travel faster than light, or at least arrive at the destination in much less time than light would take to travel the distance. Part One: Average Speeds. In our region of the galaxy, which may be the setting of your story, especially if the story involves Earth humans who only had faster than light (FTL) interstellar travel for a few decades or centuries, the average separation between stars is about 5 light years. Distances to stars are usually given in parsecs, preferred by astronomers, and in light years, preferred by science fiction writers because they make, time, distance, and speed calculations easier. So if your characters travel between two stars, the distance will probably be at about 5 light years if those two are the closest neighbors, and of course if those two stars are not the closest neighbors to each other the distance can be many times as great. Suppose that the spaceship travels between two stars five light years apart. If the voyage takes one Earth year, the average speed will be a 5 times c, the speed of light. If the voyage takes one Earth day the ship will travel 5 x 365.25 light days, or 1,826.25 light days, in one Earth day, or at an average speed of 1,826.25 c. If a spaceship travels 100 light years in 1 Earth year, it travels at an average speed of about 100 c. If a space travels 100 lightyears in 1 Earth day, it travels 100 X 365.25 light days or 36,525 light days, in one Earth day, or at an average speed of 36,525 times c. Part two: Accelerating to a Steady Speed, and then Decelerating at the End of the Voyage. Note in my examples I talk about average speeds. Suppose that it takes one week, or seven Earth days to accelerate to the ships travel speed, and that travel speed is 1,000 c. Halfway during acceleration, the ship will be travelling at 500 c, and 500 c will be the average speed of the ship during acceleration. So during the acceleration phase the ship will travel a distance of 7 X 500 light days, or 3,500 light days, or 9.582477755 light years. With these assumptions the acceleration and deceleration phases of an interstellar voyage will total 14 Earth days and a distance of 19.16495551 light years will be travelled in those two phases of the journey. So if a space travels 100 light years it will travel 80.83504449 light years at 1,000 c, for a total of 0.0808 years or 29.5122 days, plus 14 more days for acceleration and deceleration, making the total voyage last for 43.5122 days. Part Three: Accelerating for Half the Voyage and Decelerating for Half the Voyage. What if a spaceship constantly accelerates for the first half of the voyage, and then constantly decelerates for the rest of the voyage. Suppose it travels 100 LY in one earth year. So its average speed is 100 c, reached after 0.25 Earth year of acceleration. Supposed that a ship with that acceleration rate travels 1,000 light years. It will reach a speed of 200 C after half a year, and 400 C after 1 year. If the ship then decelerates for one year. it will travel for 2 years at an average speed of 200 C and thus travel 400 light years. So suppose that it accelerates for two years and decelerates for too years. Thus it will travel four years at an average speed of 400 c, and a total distance of 1,600 light years. Suppose that it accelerates for 1.5 years and decelerates for 1.5 years. It will travel for 3 years at an average rate of 300 c and travel 900 light years. Suppose that it accelerates for 1.75 years and decelerates for 1.75. It will travel for 3.5 years at an average speed of 350 c, travelling 1,225 light years. If it accelerates for 1.6 years and decelerates for 1.6 years it will travel for 3.2 years at an average speed of 320 c. for a total distance of 1,024 light years, which is close enough for now. Suppose that this spaceship accelerates for 10 years and then decelerates for 10 years. It will travel for 20 years at an average speed of 2,000 c, and thus travel 40,000 light years. Suppose that this spaceship accelerates for 20 years and then decelerates for 20 years. It will travel for 40 years at an average speed of 4,000 c, and thus travel 160,000 light years. Part Four: Constant Speed. Suppose that space ships don't accelerate to reach FTL speeds. Instead they instantly reach their travel speeds and instantly stop at the end of the voyage. In our region of the galaxy a star might be only 2 or 3 light years from its nearest neighbor, or as many as seven or 8 light years, but the average distance between a star and its nearest neighbor is about 5 light years. So in your story a voyage between two stars should be at least about 5 light years long, even if one of those stars is the closest neighbor to the other. The stars in our galaxy are thinly scattered in a sphere about 100,000 light years in diameter, but the vast majority of stars are concentrated in the galactic bulge area a few thousand light years in diameter, and the galactic disc extending our from the bulge, which is approximately 1,000 light years "thick" from "top" to "bottom" and approximately 100,000 light years in diameter. So a starship travelling through the thickness of the galactic disc in our region of the galaxy would pass close by about 200 stars or so, while a starship travelling through the diameter of the galactic disc would pass close to about 20,000 stars. That assumes that the stars are equally spaced in all regions of the galaxy, even though they are closer together at the core of the galaxy and farther apart in the outer parts of the galactic disc. Unless your characters happen to make a voyage from one star to its closest neighbor that happens to be unusually close to it, the shortest interstellar voyage they can make in this region of the galaxy is about 5 light years. Since the galactic disc is about 100,000 light years in diameter, the longest straight line interstellar voyage your characters can make within the galactic disc is about 100,000 lightyears long, or about 20,000 times as long as the shortest interstellar voyage they can make in this region of the galaxy. Since the Earth is about 26,000 light years the center of the galaxy, the farthest your characters can get from Earth within the galactic disc is about 76,000 light years or about 15,200 times as far as the shortest interstellar voyage. Thus if your space ship travels at a steady speed of 10 times the speed of light, or 10 c, it will take 0.5 years to travel from one star to its nearest neighbor, and about 7,600 years to go from Earth to the far edge of the galactic disc, and about 10,000 years to travel across the diameter of the galactic disc. If your space ship travels at a steady speed of 1,000 c, it will take 0.005 years or 1.82625 days to travel from one star to its nearest neighbor, and about 7,600 years to go from Earth to the far edge of the galactic disc, and about 10 years to travel across the diameter of the galactic disc. If your space ship travels at a steady speed of 100,000 c, it will take 0.00005 years or 0.0182625 days, or 0.4383 hours, or 26.298 minutes to travel from one star to its nearest neighbor, and about 0.76 years to go from Earth to the far edge of the galactic disc, and about 1 year to travel across the diameter of the galactic disc. Part Five: The Scale of Your Story. The Milky Way Galaxy contains about one to four hundred billion stars (100,000,000,000 to 400,000,000,000 stars) so any government of even one percent of all the stars in the galaxy would be an incredibly complex government. Thus you might want to make your interstellar war fought between between governments ruling tens, hundreds, or thousands of stars, so their governments might be no more complex than that of the USA, or the Holy Roman Empire, or the United Nations, instead of incredibly complex galactic scale governments. Thus you might want to make the governments fighting your space war rule only tiny fractions of the galaxy, and make the greatest distances traveled in your story only a few tens, or hundreds, or thousands of light years. One effect of that would be to reduce the difference between the shortest and the longest interstellar voyages in your story, and thus reduce the difference in travel times. Part Six: Faster than Light (FTL) Space Radio? Will your story have a FTL space radio form of communication, or will space ships be the fastest methods of communication? If there is a space radio type of communication, you will have to decide how fast it is. Do you want to have characters sometimes have conversations with people in other stars systems with no detectable lag in the conversation? Conversations with astronauts at the distance of the Moon had a noticeable time lag due to the three second round trip time for radio waves. Thus I guess that the round trip travel time of hypothetical interstellar FYL radio can be no more than about 2 seconds to avoid noticeable time lag in conversations. A light year is defined as the distance light travels in a Julian calendar year of exactly 365.25 Earth days. Thus a round trip conversation between two star systems exactly 5 light years apart would have a round trip distance of 10 light years or 3,652.5 light days, or 87,660 light hours, or 5,259,600 light minutes, or 315,576,000 light seconds. So if the round trip travel time has to be two seconds or less to avoid noticeable time lag, the speed of interstellar FTL radio has to be at least 157,788,000 c. At that speed communication over 76,000 lightyears will take no more than 0.000481658 years, or 0.175925925 days, or 4.22222 hours, and communication over 100,000 light years will take no more than 0.0063376 years, or 0.231481481 days, or 5.55555 hours. And maybe a writer will want round trip communications between two stars to take one Earth year for story reasons. In that case the speed of FTL radio will be 152,000 c if the two stars are 76,000 lightyears apart and 200,000 c if the stars are 100,000 light years apart. At those speeds two way communication over 5 light years will take 0.000065789 years, or 0.024029605 days, or 0.576710526 hours, or 0.00005 years, or 0.0182625 days, or 0.4383 hours. Of course if the two stars that two communication between takes one Earth are not 76,000 or 100,000 light years apart, but much closer, the speed of FTL radio will be much slower, and communications over about 5 light years, the average distance between a star and its nearest neighbor, will take longer. If your space war happens within a relatively small section of the galaxy, the difference between the longest and shortest communication times will be much smaller, but still significant. And of course, a writer might decide that the speed of FTL interstellar radio is not constant, but can vary according to scientific factors that the main characters might not understand, not being FTL radio operators, and thus have more leeway in how long interstellar messages might take. Part Seven: Jumping Between Stars. And another possibility is that a space ship might make a jump through hyperspace or subspace and disappear from one star system and and reappear in another star system without travelling the distance between the two star systems. In such a system of interstellar travel every voyage should take exactly the same travel time, which a writer might or might not desire. If the writer wants starships to teleport between stars they can make interstellar voyages take longer or shorter times by limiting the distances of jumps between stars. If it takes time to recharge the jump engines between jumps, or time to calculate how to jump to the desired destination, the number of jumps the starship has to make to reach the destination will determine the travel time. Or maybe a starship can travel any distance in a single jump, but various scientific factors change how much time it takes to charge the jump engines, or how long it takes to calculate the jump factors before a jump. Depending on the roles of the main characters, they may understand those factors or be completely ignorant of them. [Answer] I agree that in many cases the amount of time until an event can be more important than the velocity, but velocity is easily standardized to the speed of light (a fundamental constant so far as we know). If you're telling stories about humans from Earth or descended from Earth, then this is less of a consideration. You can just say that when humans began exploring the stars they continued using seconds, hours, and years that were in use on Earth. If it's a story about a different civilization, you can use the speed of light to bring it into the reader's frame of reference. For example, if a ship is capable of 100,000 $c$ and it crosses the Milky Way in 20 kreptons, then we know 20 kreptons are about equivalent to our year. Well, assuming they're using a base-10 number system; the numbers could be adjust to other systems, but you'll probably just lose your readers. I think there are two main options: invent your own units (e.g. warp factor or impulse speed in Star Trek) or to compare to the speed of light. ## Invent Your Own Units Personally, I'm not a fan of the first one. While it's clear that warp 9 is faster than warp 8 (and warp 10 just turns you into a lizard-thing), I don't think it's good for much beyond that. In particular, ST warp is on some kind of weird exponential scale so warp 1 is basically the speed of light and warp 9 is somewhere around 2000 $c$. Since warp 10 is infinite velocity, they have to start tacking on more and more decimals to represent faster speeds like warp 9.975. I think the only benefit to this system is when you have a sprawling franchise and you just want to be able to say "warp drives run at the speed of plot.". When the USS Voyager got transported 70,000 light years across the galaxy and it would take them 70 years to get home, I pretty much equated that to averaging about 1000x the speed of light and that became my reference for the cruising speed of an ST ship that has to stop regularly to find supplies. ## "Lights" for FTL; "PSL" for Sublight In the Culture books by Iain M. Banks (and I'm sure there are plenty of other sci-fi sources that use a similar system), he uses "lights" as a measure of velocity. A ship travelling 144,000 times the speed of light would be said to have a velocity of 144 kilolights. Similarly, distances tended to be measured in light-seconds, light-minutes, light-weeks, etc. He established early on in the narration that a second and metre were so similar to Earth ones that it's not going to matter if a day in the Culture is 15% longer than an Earth day. If your ships are travelling at relativistic velocities, but not superluminal velocities, then you could go with a fraction of *c*. Gene Roddenberry's Andromeda called it PSL, so 25 PSL was 25% of the speed of light. Though "point-two-five $c$ probably works just as well. For interstellar travel, I think that "lights" is the way to go. I think that most people think of interstellar distances (if they think about them at all) in light-years; Proxima Centauri is about 4 ly away; the Milky Way is a bit over 100,000 ly in diameter; etc.) so it makes it easy for readers to calculate times in their head (if they care to do so). If a ship is capable of 24 gigalights (that sucker is moving) then I know this is a really advanced civilization that can travel the entire Universe as it pleases. For velocities less than *c*, it's a bit trickier. While I know that the moon is about 1.25 light-seconds away, and the sun is about 8 light-minutes, I don't know the distances for other objects in our solar system in those units. I think km or astronomical units (AU) is a more common metric for those distances. ## Distances If any of your civilizations are Earth-based (or primarily descended from Earth), I think it makes sense to stick with light-years, light-weeks, light-seconds, etc. If it's a different civilization, you can use the trick of using a fundamental constant $c$ along with a known reference distance (like the diameter of the Milky Way) to give an impression of how times and distances work for that civilization. You can also pop on SI prefixes to keep the numbers from getting too big (kly for kilolight-years). Personally, I would recommend finding a way to establish that the alien versions of distance and time all work out to roughly similar to Earth ones to keep it easier for readers. ## Light-seconds-per-hour The units here make me uncomfortable. It's taking a velocity (something we could turn into m/s), multiplying by 1 second, and then dividing by 3600 seconds. $c \cdot \frac{1 \textrm{ s}}{3600 \textrm{ s}} = \frac{c}{3600}$ So ultimately, we're just using a scaled down version of the speed of light. Then 3600 light-seconds-per-hour is just the speed of light. If you need numbers much smaller than $c$, maybe this is workable, but 1 light-second-per-hour is only about 83 km/s which seems easier to deal with. [Answer] You don't actually need a new measure unit. There are mainly two methods to save you from using units other than km/s or km/h. I list them as the titles below. ## New Technology to Achieve Low Speed All you need is a new technology which can finish the travel in a short time even with a slow (compared to light) speed, so that you can continued to use a not-that-big number with km/h. You can try the [Einstein-Rosen bridge](https://en.wikipedia.org/wiki/Wormhole), aka the wormhole, which connects two distant places (in an astronomical sense) so you can travel across billions of miles by something equivalent to a few miles. This is what many sci-fictions do. It can save you from bothering about a world of problems arising from the high speed of the space craft and the general relativity, say, the accordant time and people's behaviours, if you're rigorous enough about your works. ## New Unit to Achieve Small number (Warning: The numbers mentioned here are way too large for the current observable universe even if you use *nanometer*, but since it's a fiction, maybe you have an even larger universe in your story.) Maybe you prefer [a single word that represent a large number](https://en.wikipedia.org/wiki/Large_numbers), then try **googol** (= $10^{100}$, which is a '1' follows by 100 '0'), which [inspired the name](https://www.merriam-webster.com/dictionary/googol#:%7E:text=The%20search%20engine%E2%80%99s%20name%20was%20inspired%20by%20the%20number) of the famous search engine *google*. (see [this](https://www.indiatoday.in/technology/news/story/on-google-s-22nd-birthday-learn-how-the-name-came-from-word-googol-1726205-2020-09-28)) If that's not large enough for you, there are (from really large to even larger): 1. centillion = $10^{303}$ or $10^{600}$, depending on number naming system. 2. millinillion = $10^{3003}$ or $10^{6000}$, depending on number naming system. 3. googolplex = $10^{{10}^{100}}$ = $10^{googol}$, obviously a larger version of googol, as the name suggests. 4. [Graham's number](https://en.wikipedia.org/wiki/Graham%27s_number), it's so large that even if you have a storage disk as large as the observable universe, you still can't storage the number digit by digit. This is also quite famous among hardcore sci-fans, since the famous popular science writer [Martin Gardner](https://en.wikipedia.org/wiki/Martin_Gardner) had once introduced it to the general public back in 1977. [Answer] For space-based distances and speeds, you could use **"astro-units"** or **"AU"** for astronomical units (**1 AU = approximately 93 million miles**). You can then measure velocity in terms of **AU per hour (AU/h)** or **AU per day (AU/d)**. To make it more useful within a solar system, you could also use **"planetary units"** (**1 PU = the average distance from the planet to its star**). For **velocity**, you could use "**planetary units per hour**" (**PU/h**) or "**planetary units per day**" (**PU/d**). For more practical comparisons to speeds we're familiar with, you could use terms like "sub-light speed" or "super-light speed" for speeds much slower or faster than light respectively. As for an abbreviation, you could use "PUs" or "AUh" for Planetary Units or Astronomical Units per hour, similar to the abbreviation "knots" for nautical miles. ]

[Question] [ The year is 2020, 98% of the world population are normal people with normal skills, two percent (2%) are people who have the ability to become invisible at will. The majority of the invisible people live in peace with us, following the law. But part of this 2% are criminals, and we must find a way to prevent them committing crimes. * Robbery * Murder * Etc... One more ability the invisible people have is that, everything that their skins are touching also become invisible (That includes clothes, other people, objects). Floor and Walls are not affected. Body heat and so on occurs the same way as normal people body. **How to prevent invisible people from committing crimes?** *Our technology is the same as we have in today's world.* [Answer] Spencer Muise already mentioned that they could be invisible to our visible spectrum, but could be still visible as a source of heat or another kind of radiation (maybe the process of becoming invisible itself leaves some kind of electromagnetic signature). Another thing that would work is, quite simply, **pressure plates**. Invisibility can't hide the fact that people have a weight, so, covering the floor of some sensible building (e.g. a bank, or a jewelry store) with pressure plates, or other weight-detecting technology, would serve as an alarm against robbery. This could be quite expensive and require some major restructure on some buildings, but it would probably be a good option. If you think about it, a lot of **conventional measures** of security would still work. If you have a bank with a safe that opens only at certain hours (to allow employees to make deposits) you could try to enforce some kind of policy to prevent invisible people from getting in and out. After all, locked doors still work well against invisible robbers. Each sensible building could have "private quarters" where only allowed people, based on facial recognition, can enter, along with a mantrap ( [Mantrap](https://en.wikipedia.org/wiki/Mantrap_(access_control)) ): a door that doesn't let more than one person in at a time. An invisible robber could still try to sneak behind a regular employee, but would risk the door closing on himself (pain and detection involved). Also, I suppose invisible people still emit and produce **sounds**, so that's another range of sensor that could be used at their disadvantage. Moreover, even in the case that their body **heat** cannot be detected, they still need to breathe. The air in an empty room is usually colder than air with a person breathing it - on certain occasions and/or weather conditions, this could serve as an alarm. You noticed I've only talked about robbery thus far because robbery - at least if we are talking about "big, stylish robberies" are actually easier to avoid than petty crimes or murder. As Ash pointed out, you can't "prevent" crime, you can either dissuade it and prosecute it. An invisible assailant could rob whatever he pleases in an open street, taking it by force by the hand of unsuspecting strangers. Still, in a world where invisible criminals are a thing, the other 98% of the people would probably like to have stronger security measures - or maybe they would stop carrying wallets, at least. I'd have other ideas, but I'll leave you those two cents. [Answer] You don't, you can't, same as you can't prevent normal people from committing crime, if you're asking how do we detect and prosecute crimes committed by invisible people that's a whole different thing but the answer is the same, the same way you do with normal people; just with a couple less tools. Invisibility precludes primary witnesses both human and machine but in no way removes DNA, trace, footprints etc... it also doesn't stop people noticing things are missing or people are dead. [Answer] Luckily for us, we have created machines that exploit all of the non-visible aspects of objects. There are several interesting ways to deter invisible people from committing crimes. **Infrared** Infrared cameras allow us normal humans to see the effects of hot objects in any circumstance. Your invisibles may give off heat, thus this is an effective method. Using advanced algorithms in target finding systems, it would even be possible to have a machine or weapon with two cameras, one visible light and one infrared, that compares the two images. If an object is present in just the visible light camera view but no in the infrared, then the machine/weapon may engage with that object to whatever effect you desire. Make sure the police are equipped with infrared goggles and the like. Even normal people will likely start wearing infrared countermeasures simply to make sure they're aware of what's around them. **Seismic** Humans may no be really heavy, but they still have mass. Each time a human, visible or not, takes a step, he will impart force to the ground. Using that, we can take advantage of seismic sensors in areas that shouldn't have foot traffic. If those sensors detect motion, they set off an alarm and alert other people an invisible person is there. **Physical deterrents** Even an invisible human can't jump really far or fly. If you put something high enough or far enough away that a normal human can't reach it, you've succeeded in making sure invisibles can't get to it either. [Answer] As Always, nothing is safe from a skilled thief who really really wants it. Not in the real world, not in this fantasy world. The best we can hope for is to make it really hard to steal (which means someone has to be really motivated) and recovery after it's been stolen. I'm also assuming heist movie level theft here because that usually makes for more interesting reading :) OK, now that we have that little caveat out of the way, there are tons of ways to rig security around things that do not rely on sight. Humans have a bias toward that sense because that is how we evolved, but we have other senses. Smell: Most animals, as far as I know, produce pheromones. These can be detected. For a high tech alarm system use a clean room type system to make sure the chamber for whatever valuable [Dingus](https://en.wikipedia.org/wiki/The_Maltese_Falcon_(1941_film)) you happen to be trying to protect is free of any lingering pheromones. Once closed, the chamber is sealed off and sensors enabled to detect anything scent related, triggering an alarm. Bonus points if you can use the same system to evacuate the chamber with the would-be thief inside, suffocating them. Hearing: I'm putting all sorts of vibration testing in this category along with various uses of ultrasensitive microphones. Here is a more specific idea. Echolocation type pings akin to sonar. Anything changes in the soundscape of a room, like maybe a person moving about, triggers an alarm. Your evil mastermind bonus to this one is again, the room seals, and our would-be thief is bombarded with super high decibel noise that would deafen them, or just the "Brown Note" (yes I know the [brown note was busted on mythbusters](http://www.discovery.com/tv-shows/mythbusters/mythbusters-database/brown-note/), but I'm having fun here so hush) Touch: this is where the whole range of pressure sensors go. Everything from the Indiana Jones Idol pedestal to The floor that Tom Cruise sweat on in Mission Impossible. Pressure sensors are pretty common, so this should be easy to do in a ton of creative ways. Taste: This one kind of goes with Smell, since it is all about chemical detection. I really don't know what do do with this, unless you make the person trying to access your treasure chamber, I dunno, eat scotch bonnet peppers and then the High tech tongue analyzes the sweat as an identity key. Pretty farfetched though. The long and the short is that there are a lot of modern-day tech things we can do that do not rely on Visible light to aid in our security efforts. In fact, we could even use the idea of checking in with our other senses to set the story and just about any tech level or time frame, from the bronze age to modern day. Smell: Dogs. They bark when something doesn't smell right. Hearing: Dogs again. Their sense of hearing is a lot sharper than ours. Taste: Dogs yet again, Hungry, angry dogs will eat intruders. Touch: No dogs here, but things like bead curtains in doorways make it hard to pass through silently. Put spiky bits along the tops of high walls, generally, make it hurt to get to whatever you are protecting. Finally, since I just watched Ghost in the Shell, How about shallow water? Even someone who is invisible will make ripples in the water as they move or even just stand there. Those ripples will be visible. Disturbed water will make noise. So your invisible people have just a small edge over normal thieves. Testimony based on what someone saw will become circumstantial, so securing convictions will require an advance on other forensic tools. They will be harder to trace in the immediate time after a crime unless you have a dog who can give chase based on scent. So yes, advantage, but not as much as you think [Answer] If we are thinking at OUR world, i.e. not an idealized world where everybody is smart and scientifically minded, I would bet that the first type of response would be simply some sort of law forcing the Invisibles to make their presence known to everybody all the time when in the public space. Imagine the following scenario: * average Joes already generally uncomfortable with the idea of invisible people around ("how do we know what they are doing?") * first random act of crime from one of the Invisibles: huge media campaign, public outrage ("See, I told you they are all thieves/rapers/etc?") * public hysteria follows. Politicians pressed for quick answers pass laws to force the Invisibles to make their presence known. From now on the simple act of being somewhere and invisible without declaring it can be prosecuted. Some populist-type politicians propose that you have to wear a tracker all the time which beeps automatically to make people aware of your presence. Like people with leprosy in the ancient times who had to ring a bell when passing on the street * most of honest Invisibles outraged with support of NGOs but nobody cares as they are only 2% until... [Answer] To propose some different security mechanisms: If doors are affected you can easily detect an invisible person indirectly by detecting if a door (or any other suitable object) becomes invisible in all relevant spectra. Point a laser at the door and ring an alarm if it hits the receiver on the other side of the door (basically the opposite of a standard photoelectric sensor). Bonus if you place the emitter on the inner side of the door so the laser-beam cannot be seen from the outside. Another possible method is ultrasound. As sound waves are a physical phenomenon related to air and not an optical method you can use it to *see* even persons who are transparent to any electromagnetic wave. The range is a bit limited, but to cover a whole room should be easy. They can't look through anything though. Even a very thin glass-pane is opaque to ultrasound. Positive is that we already mass-produce ultrasound-detectors, e.g. for use by roboters. And, as already mentioned, mechanical sensors like tripwires, pressure plates and so on. --- This is of course only useful to protect properties. Nobody can prevent an invisible person to simply snatch a bag that is standing around. But then again you can't stop a normal person as well. Good thieves know when no one is paying attention and will not be seen (the bad ones are seen once and then land in jail). To protect small things I can imagine that trackers will become very popular. You also have to imagine how difficult it is for an invisible chased person to escape. Nobody will evade them, and followers can easily track the trail of vanishing and reappearing persons as the invisible person accidentally touches persons and objects. Invisible Assassins though... They can get much closer, can carry equipment in supervised areas... Luckily we don't have that, right? *Right?* --- Police will probably tend to use nets and other area-based attacks to engage invisible offenders. I imagine tactical equipment like shields to be equipped with an "ultrasound-camera" to get an idea of the position, combined with pepper spray or other sprays. Laws will probably be adjusted to make it illegal to become invisible in public space or at least in the presence of police officers. Resisting this will allow excessive use of material not usually deployed against civilians. --- **TL;DR:** Invisible persons probably have an edge when committing crimes, but in a lot of situations this can be offset by technology. There are areas where invisible criminals definitely have an unfair advantage, but their visible counterparts are apparently as efficient with a bit more preparation. You can't stop them, but you can adapt. [Answer] I can imagine a political/social upheaval that would *require* everyone to have an RFID chip implanted at birth (i.e. before you learn to turn invisible). Readers at all or important portals would identify who has just entered. If there is a discrepancy (RFID reports someone, but cameras or other detectors do not) it would set off an alarm. If you have the chip removed or disabled, you would be subject to prosecution, unless you can prove it happened by accident or defect. Your requirement that floors and walls aren't affected would need a reasonable explanation. What is the difference between a wall and another person? Density? total mass? What about the other person's clothes, i.e how far does the touching effect spread? If the invisible touches a person who touches another etc, at what point does the effect fail? On the other hand, if walls would be affected, imagine the possibilities for peeping! EDIT: I meant to include this link: <http://www.dailymail.co.uk/sciencetech/article-4203148/Company-offers-RFID-microchip-implants-replace-ID-cards.html> There are companies now using RFID to replace other authentication methods (passwords, swipe cards, etc.) [Answer] When you have [mutants](https://en.wikipedia.org/wiki/Magneto_(comics)) [committing](https://en.wikipedia.org/wiki/Mystique_(comics)) [crime](https://en.wikipedia.org/wiki/Sabretooth_(comics)), then you may also have [other mutants trying to prevent those crimes](https://en.wikipedia.org/wiki/X-Men). Give your Invisibles the ability to sense other Invisibles better than normal people. Most Invisibles will not be criminals, and there will also be those Invisibles who are ready to take a stand against the evil and corrupted of their own clan. The sensory ability need not to be perfect vision. Here are some ideas: 1. Invisibles can always tell when another Invisible is in the vicinity. 2. Or, Invisibles can see other Invisibles as mists/point-light-sources/ghostly figures. 3. Or, upon becoming invisible, their vision alters to infrared and microwave bands, making them able to see the body heat of Invisibles. This will make it disadvantageous for someone to become invisible, because the world would have lot less color and resolution in those high-wavelength bands. [Answer] This is kind of a different angle but what if the powers were endowed by some sort of deity with the caveat that if the power is ever used for ill then the one that committed the crime loses their power. This could be communicated with some sort of mark that would be obviously visible to everyone thus would be viewed as social outcasts or at least a lower level of society. [Answer] You can use paintings, to make them visible, or water spraying [Answer] What about the reverse? If ordinary sensors can see only visible people, put them on your automatic doors, so that they'll only open if they SEE visible people. A fingerprint reader wouldn't need a database of fingerprints. If it can see your finger, you're in. [Answer] One thing that I don't see mentionded but feel compelled: Humans are actually quite capable of echolocation, and even though the most proficient are blind, it is quite capable of being learned by sighted individuals too. In fact, studies have shown that there is no difference in recognizing distance or general shape of an item in three dimensional space and at least one individual was proficient enough by childhood (and self taught methods) that he was able to operate a bicycle and and convince his parents he still had his sight. It might become a form of self defense. It would allow individuals so trained to identify and attack an invisible agent with something of an equal playing field. Again, the only reason most humans do not use it is because we rely on sight. And all that stuff, yeah, that's gonna help... but when the chips are down and someone who you can't see wants you dead, it's a nice fall back technique. [Answer] **Subcutan electromagnetic receiver/sender, probably combined with remote controlled taser** Because the invisibility gives perpetrators too much of an advantage, each person able to turn invisible gets a receiver/sender under their skin which gives away their position and tracks their movement. The receiver can use a multitude of frequencies (GPS, Wifi & special radio towers triangulation) and if all fails, use inertial navigation to get a raw approximation where the person was. The protection is multi-fold. First the tracking allows to retrace the steps which the person has made. If (see later) the tracking fails, the failed tracking is automatically assumed to be a proof because the person is the only one which lacks tracking (so that in the own interest the person handles the tracking device with care). If two or several smartasses lack tracking at the same time, everyone of them is considered guilty. Second some areas are geo-fenced or, if people are afraid that an invisible enemy entered their area, activate the EM defense. In both cases invisible people will be internally tasered by the chip if they enter the area or are inside the area. **Traps triggered by invisibility**. Use their ability against them. A laser is inside the door/door handle/wand/floor and is reflected by the opaque material. Once a invisible person touches the material and turns the material invisible, the laser is not reflected anymore and can trigger a multitude of nasty traps: Gas grenades, trap doors etc. [Answer] There are [devices](http://www.flir.com/flirone/ios-android/) in today's world that you can attach to your mobile phone to take thermal images. Such things would for sure expose invisible people as you described above, and I'd assume that such technology would sell at a much higher rate in your world. With a given demand people would be willing to write certain apps that are specialized to detect such people, using thermal imaging or other devices. In addition invisible people still fill the room they are standing in, so they'd be pushing things away and can be touched and felt. This turns even simple house-hold items into detection-devices against invisible burglars. Shop owners would probably add a kind of curtain to their front door tied to a bell to be alerted if someone invisible stalks into the room. Window displays could be covered with transparent hardcover that you'd need to pull up to take the product. Guard dogs would still be able to smell invisible people and could become a more common sight. Banks or similar institutions with enough money available would have a hallway filled up with solid fog, that would make anyone invisible trying to walk through it immediately visible. More advanced research would try to find materials that are sticky but don't become invisible, and then cover areas with that "anti-invisible paint". Or in reverse someone could invent something like a laser-pointer that emits light, that is refractioned by the invisibility effect, and turn them into a shining disco ball. [Answer] I've read quickly the other posts and I've seen a lot of good ideas, so here's mine. Depending on the degree of dystopia your world is set, you could have some kind of authority that forces people who can turn invisible to wear an ankle monitor, just like the ones used in the USA. In addition to the GPS tracking, you could imagine that those monitors detect if the wearer turns invisible (laser trigger, if he is visible the laser is stopped by the ankle, if he's invisible the laser goes right through it and triggers the device, even if the device itself is invisible). Once triggered, it could either alert the police or emit a loud beeping sound or whatever. That device could prevent petty crimes, but also is difficult to manage : how do you know a person has that ability in the first place? What if they are not detected, and hide that power? [Answer] I guess the most important part of this is the mechanism by which they become invisible. Can they be seen in other spectrums? If so, cameras may still be able to pick them up. Or if they still emit heat, then something like [FLIR](https://en.wikipedia.org/wiki/Forward_looking_infrared) could be used to track them. [Answer] Microphones and signal processing to detect the location of heartbeats. Computer-generates an image of the room with everyone in it that the guards can compare to what their eyes see. Room contains light fog. Hole in the fog means an invisible person. [Answer] Manufacture and sell 'infrared contact lenses'. This technology is under development is entirely possible. The contact lenses will allow the other 98% of the population to see the invisible people. [Source](http://spectrum.ieee.org/nanoclast/semiconductors/optoelectronics/graphene-gives-you-infrared-vision-in-a-contact-lens) [Answer] Let's say you have a vault with valuables which needs to be protected. Litter the hallway leading up to it with microphones, pressure plates, air current sensors, whatever you can imagine that would detect a human (or anything out of ordinary) without relying on the visible spectrum. Then, you might not even care if anyone walking the path might get soaked or dusted. Perhaps because he would normally be in a bunny suit - it could be a vault containing hazardous materials. A biolab for example. So, once "something" is detected but the cameras don't show a picture, flood the hallway with dust or an aerosol. Then you'd surely see the silhouette of the trespasser. For added measure, make the aerosol flammable. A fuel/air mixture for example. But even simple flour or iron shavings floating through the air coud suffice. Then, if you *really* wish to keep said trespasser away from your vault, provide a spark. [Answer] ## Simple, you have infrared cameras placed in public spaces. Due to the fact that you mentioned that body heat occurs like it does in normal people the cameras will be able to see them. [Answer] I think the best way is to find the physiology of invisible people and what makes them invisible,taking in mind all the parameters that people have said, I assume for example that there is science in this world.If so, the only that you have to do is have some tracking mechanism. If someone does a crime, there are always somehow hints of the actions.Police when finds a murdered man, at first the murderer is like an invisible man, they don't have apparent hints of who is he.They track down the hints.I think the same could be with the invisible men.I don't think the point is to have physical devices.Like surveillance systems of any kind. If the invisible men just appeared, and there is no history, thus research on them, the questions are more, they just made invisible? They born that way? It is like a mutation? [Answer] Someone already mentioned part of my answer: use GPS like an Ankle Monitor (and additional equipment if necessary like implants) on any invisible capable person. The second part is simpler: make any invisible capable person guilty-until-proven-innocent for any potential invisible-crimes commited nearby them (with the caveat that a normal investigation is run to find any other likely culprits that might have done it and exhonerate the invisible-capable people). This means that invisible persons are commited to either proving their own innocence or the guilt of someone else. The first one is relatively easy: make sure you are seen/detected, and that your GPS is never too close to a crime (unless its to try and stop it and you can prove that). Its likely that many of these people would have to start wearing bodycams constantly, filming themselves in the mirror before they leave just so they could prove what happened during their day (and a camera showing where they were at night). Its the cost of invisibility but easily reduces the chance invisibles commit crimes. Add some other things that can weigh in during investigations to exhonerate them, such as psychological evaluations and background checks and you have a system that should work pretty well I think at preventing most invisible-related crime. ]

[Question] [ We have a lot of weird questions come up [in chat](http://chat.stackexchange.com/rooms/17213/worldbuilders-general-chat) and fun comments about how we destroy worlds over a lunch break. Here is one that though I might share. You are a power that can affect cosmic bodies and phenomena. You have been offended mightily by some questions on SE and wish to blow up their servers. **How would you take out the SE Servers while causing minimal casualties and disruption to humanity?** * Humanity must be impacted as little as possible by the strikes (other than the great loss of SE). * You may assume that the servers are only located in the [office locations for SE](http://stackexchange.com/work-here). * You may assume no backups * You cannot approach earth any closer than the moon does. Nor can your influence cross that barrier. * Current science must be aware of any principles you use. * You can affect anything you like, but you can't 'undo' a change. [Answer] Except "Gamma ray sniper shot" stated in the comment, I have another idea: **Hacking from the moon** It would be easier to do hacking from the orbit (send one of my alien - probe and hack into global satellite system, to connect to SE servers) but this would be still feasible. In other words there is my how-to list: 1. Connect from the Moon to the Internet (prices for dial-up may vary alien race to race). You could hack yourself into NASA communication system, or the China one 2. Use the internet connection to reach SE servers 3. *Optional:* Post question to [Programming golf and puzzle](https://codegolf.stackexchange.com/questions/40715/break-stack-exchange): "Hack me Stack Exchange in your favourite programming language. Shortest answer in bytes wins" 4. *Other option:* Use your superior mother-ship computer ([backwards compatible to old computers](http://www.imdb.com/title/tt0116629/)) to get you solution 5. Upload solution got either from point 3 or point 4 to StackExchange servers 6. Result:  [Answer] ``` Population of Denver, CO, USA, Terra (2013) ~ 649,495 Population of London, UK, Terra (2013) ~ 8,308,000 Population of New York, NY, USA, Terra (2013) ~ 8,406,000 ... Assuming 50% casualty rate using conventional nuclear strike on chosen targets Estimated casualties ~ 8,681,748 Population of Terra (2013) ~ 7,125,000,000 ... Casualties Estimated at 0.12% Casualty rate within acceptable bounds. Begin orbital bombardment? Y/n > ``` [Answer] Simple. Arrange the stars into a message saying, "Hi humanity, I am an extremely powerful alien. For more information, please go to stackexchange.com" and then sit back and await the slashdotting. [Putting a message on the moon](https://worldbuilding.stackexchange.com/q/877/29) (or a giant orbital sign) would also work and might better fit into the "understandable by modern science" requirement. [Answer] Fire *something* very small, which generates a very strong magnetic field, through the roof of the data centre. It could be a miniature electromagnet or something more exotic. Data eliminated, zero human casualties, and none of the uncertainties of hacking. [Answer] My suggestion is to create a small black hole (small enough that it will dissipate given time). Drop it through the earth at the precise angle required to take out the three data centers on it's route through.  Here you can see the black hole striking the London data center, orbiting through the center of the earth then coming up through the New York data center before finally coming back down and striking the Denver one and then dissipating. [Answer] Bribe or threaten Jon Skeet to delete all his posts. That would destroy half of SE right there, and then everyone else would abandon it. [Answer] 1. Secure [$850 quadrillion](https://en.wikipedia.org/wiki/Death_Star#White_House_petition), preferably in cash. 2. Figure out a way to get around [one](https://en.wikipedia.org/wiki/Outer_Space_Treaty) or [two](https://en.wikipedia.org/wiki/Strategic_Arms_Limitation_Talks#SALT_II) famous and fairly successful treaties. 3. Build a [Death Star](https://en.wikipedia.org/wiki/Death_Star). 4. Modify the Death Star so it won't [blow up the entire planet](https://en.wikipedia.org/wiki/Alderaan), but instead will concentrate a fair amount of energy into a single spot. 5. Wait for each office location to come into your scope (while somehow making sure that your orbital period accommodates this). 6. Fire at will. [Answer] I would take away the need for SE entirely by making Google return the perfect answer for any question that you would ever ask on SE. The question: how would you make Google omniscient? by making it link to your personal knowledge. How do you do that? *accidentally* let one of your older uplink nodes land on the Google Campus, older meaning it's similar in capacity to Earth systems. [Answer] * Find one (1) naturally-generated, stable [Einstein–Rosen bridge](http://en.wikipedia.org/wiki/Wormhole) - also known as wormhole (`WH1`) with a naturally time-shifted endpoint (`TSE1E`). We're going to use this wormhole to travel to the past and back. * Implement one (1) artificial, stable wormhole. Let's call it `WH2`. * Bring one of `WH2`'s endpoints to orbit very close to the Sun, while leaving the other around Earth. Relativity kicks in, and time slows down for the sun-bound endpoint. Let's call it Time-Shifted WH2's Endpoint (`TSW2E`). We'll use this ERB to travel to the future and back. * Stay together with `TSE2E` while it travels around the Sun. Choose the heat/radiation shielding of your liking. * Time dilation will bring you to the future in a matter of hours. Go back to Earth. locate discarded StackExchange servers. Take note of their serial numbers. Determine the precise moment they were created, and which BIOS they were using. * Go back to Sun's orbit. Enter `TSE2E`. You'll travel to the past - the current time - but you need to move further earlier. Enter `TSE1E`. You'll travel back a few years if you're lucky, or a few billion years if you're not; you may need to implement [Cryonics](http://en.wikipedia.org/wiki/Cryonics). Details are outside the scope of this question. * Start working for the company that made the servers. Work your way up to BIOS programmer. Keep in mind that time is of essence. * Months before the servers are assembled, insert a piece of malicious code that will detect the kind of software running on it. As soon as it notices Stack Exchange's production code signature, a timer starts ticking. Make it go off in a most catastrophic way - a 404 (or a [418](http://en.wikipedia.org/wiki/Hyper_Text_Coffee_Pot_Control_Protocol), if you're feeling specially ebil.) Switching servers will do no good - all servers will have the same piece of code running on their BIOS. * Watch despair and chaos as it ensues. Enter `TSE1E` as many times as you want for infinite replays. [Answer] Land a large nuke outside the server building. It's got a sign on it: 30:00 minutes until detonation, wipe the Stack Exchange servers to prevent this. The timer is counting down. [Answer] Just reorient a couple asteroids such that they impact the appropriate locations. Sure, there will be collateral damage, but sometimes you have to break a few eggs to make an omelet. [Answer] **Economics** If enough money was on the table, you could buy the Stack Exchange Inc, and simply shutdown or wipe the servers. **Mind Control** Hack into one of the communications satellites, and use hypnotic messages to control the Stack Exchange server admins. Get them to wipe the data, the backups, kill the servers with axes, etc. [Answer] Build or conjure up a giant lens, place it between the sun and the Earth, and use the resulting beam to etch the servers off the face of the planet. It's low-tech enough that humans are unlikely to blame it on a super-advanced alien weapon, and the sheer scale of it is ridiculous enough that it really drives home the notion that there's something very big and very powerful that's angry with you. Collateral damage can be minimized since you can adjust the beam size by tweaking the lens. Not recommended for cosmic beings with shaky hands. For bonus points and a more impressive visual effect, add a couple of giant mirrors into the mix and hit them while they're on the night side of the planet. [Answer] Create autonomous robots and have them do it. There are myriad ways in which this could successfully play out. For example, you could pack the robots into a small asteroid and have it hit the Atlantic ocean to disguise the approach. They then could use earth's GPS system to let them home in on the offices, drill in, and then set themselves on fire. Making them look superficially like toys (e.g. remote controlled cars) would help avoid detection, plus they should move primarily at night. The main point is that when something complicated needs to be done remotely, robots give you much more flexibility than do simple application of physical laws. [Answer] Send a message from several locations from the Heliopause which sources (let say millions at least) evenly distributed on the virtual sphere of the Heliopause on the form of every encoding scheme known to human (mors, binary, etc) in the every human-language, with the strongest possible non-lethal electromagnetic radiation from all the electromagnetic spectrum which can be seen or read by the humans saying: XOR EVERY BIT WITH ITSELF WHICH BELONGS TO S.E. (Stack Exchange) OR ELSE... ]

[Question] [ From what I know about the Heisenberg Uncertainty Principle, one of its consequences is that when you learn a great deal about the position of a particle, you greatly increase the uncertainty of the particle's momentum. This got me thinking about a super-accurate scanner that will measure the positions of all the particles in an object (for example a building) to an extremely high degree of certainty. This would cause the momentum of all of these particles to become extremely uncertain. I am not sure where the energy would come from for this, but if the numbers are extreme enough, most of the particles should have extremely high momentums in random directions, causing the object to be obliterated. Is my understating of the uncertainty principle horribly flawed, or does this have enough reasonableness for a science-fiction super villain weapon? [Answer] > > I am not sure where the energy would come from for this > > > It would come from the scanner itself. In order to make extremely-high-precision scans, the scanner itself has to direct considerable energy at the target of the scan. The more precision you want, the more energy you need to pump into it. Much of that energy is absorbed by the target, which is what would cause the particles to fly apart when scanned. It should be obvious that, in the real world, it would be much easier to build a device (let's call it a "disintegration ray") which just hits the target with all that energy and scatters its constituent particles to the wind without bothering to also determine and record the original positions of the particles. Building a machine gun is easier than building a machine gun which also tracks where its bullets end up and uses that to determine what the target originally looked like. So I'd call it *possible*, but extremely *impractical* in real-world terms. As a supervillain super-weapon, however, I really like it. The concept makes me smile and it's based on technobabble that sounds reasonable if you don't think too hard about it. And aren't those really the most important factors when designing a doomsday weapon? [Answer] This "weapon" has already been built. It's called the [European X-Ray Free Electron Laser (XFEL)](https://en.wikipedia.org/wiki/European_XFEL), and it's used for super-accurate imaging of molecules. Point is, whenever the XFEL hits a target molecule, all the electrons are simply blasted away from the molecule, and the more inert rest of atomic nuclei dissolves in a Coulomb-explosion. The scattered X-Rays are used to reconstruct the 3D positions of all the atoms in the instant that the molecule was hit. This blasting away of the electrons is not by accident: The shorter the wavelength of the photons, the smaller features you can detect, because the *change of the photon's momentum is greater*. Of course, that change in momentum comes from somewhere, and it's the electron cloud that gets the kick in the opposite direction. So, the quality of the localization is directly related to the uncertainty of momentum after the measurement. [Answer] No, your conclusions are wrong. Heisenberg uncertainty principles states that the uncertainty in the measurement of two conjugate variables, in this case position and momentum, is always higher than a certain value $$\Delta x \cdot \Delta P\_x > h/4 \pi$$ Mind that the uncertainty is on the measurement, not on the actual value (whatever "actual" might mean under the assumption of quantum physics). Particles in macroscopic objects already move randomly in all direction due to thermal agitation, and that does not destroy the object. When you increase the agitation you are just increasing the object temperature, maybe melting it or evaporating it. But it has nothing to do with Heisenberg principle. Also, citing [this other answer](https://physics.stackexchange.com/a/189816): > > $h/4 \pi = 1.054571726(47)×10^{−34} Js$ > > > All it needs is some algebra to see that a kilogram ball moving at a micron per second and measurement accuracies of the order of a micron will still fulfill the HUP constraint as $h/4 \pi$ is a very small number. For classical dimensions $h/4 \pi$ is essentially zero and the HUP always holds. > > > When one goes to dimensions of less than nanometers and masses of the order of molecules then one is in the quantum mechanical regime and can start talking of uncertainties . > > > [Answer] You're misunderstanding the Heisenberg Uncertainty Principle, or rather what "measure" means. In order to measure something, we have to interact with it - on the nanoscale this commonly involves bouncing electrons off of the item we're imaging. > > A scanning electron microscope (SEM) is a type of electron microscope that produces images of a sample by scanning the surface with a focused beam of electrons. > - [Wikipedia](http://A%20scanning%20electron%20microscope%20(SEM)%20is%20a%20type%20of%20electron%20microscope%20that%20produces%20images%20of%20a%20sample%20by%20scanning%20the%20surface%20with%20a%20focused%20beam%20of%20electrons.) > > > Imagine "imaging" a pool table by analyzing the path the cue ball takes. It'd be trivial to figure out where a ball is - or more accurately was - at the moment of impact. The cost of this is that you've transferred some of the energy of your scanning cue ball into whatever ball you've measured, altering its momentum - you can no longer be certain the ball is at a standstill. The system you're proposing is one that increases uncertainty by deposing large amounts of energy into a target object. In other words, basically every projectile, energy, or nuclear weapon system known to man. The only difference is the word "measure." Attaching a telescope to your death-ray arguably fits the bill. Rather amusing way to bypass a treaty, don't you think? It's not a planet killing Nicoll-Dyson beam, it's a Planetary Spectral Analyzer. ]