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[Question] [ Vampires are a very common creature in various fantasy stories, they drink blood and often human food poisons them. Forgetting for the time being the additional rumours/fiction such as sunlight, crosses and immortality could such a being sustain itself from drinking blood alone? Obviously human blood tends to contain traces of almost everything found in the body, this is why it's such a good place to start to test for diseases/deficiencies but does it provide EVERYTHING the body needs to sustain itself? Reasonable evolutionary adaptions can be assumed. [Answer] The simple answer is yes it's possible, if they have a suitably developed physiology. Vampire bats, leeches, mosquitoes and more are proof of that. There are complications that make it less practical than you might want though. Lets start from a Vampire Bat (as a mammal it seems a good starting point for comparison). From wikipedia: > > A typical female vampire bat weighs 40 grams and can consume over 20 grams (1 fluid ounce) of blood in a 20-minute feed. This feeding behaviour is facilitated by its anatomy and physiology for rapid processing and digestion of the blood to enable the animal to take flight soon after the feeding. The stomach lining rapidly absorbs the blood plasma, which is quickly transported to the kidneys, and on to the bladder for excretion.A common vampire bat begins to expel urine within two minutes of feeding. While shedding much of the blood's liquid facilitates flight takeoff, the bat still has added almost 20–30% of its body weight in blood. To take off from the ground, the bat generates extra lift by crouching and flinging itself into the air. Typically, within two hours of setting out in search of food, the common vampire bat returns to its roost and settles down to spend the rest of the night digesting its meal. > > > So this suggests that they consume half their body-weight in blood every day and digest it. It also suggests that being near a feeding vampire would be unpleasant as they need to quickly dispose of the liquid waste from their feeding. The maximum a human can lose without serious risk is 3 litres. 1 litre is the maximum than can be lost without side effects. If we go with the "half your body weight" formula then even a lightweight 50kg vampire would need to consume 25kg of blood. Since 1kg of blood is the approximate weight of 1 litre the vampire would need 25 litres of blood per night. That's draining to death 5 people or partially draining 25 people. Per night! Now if the vampire was not flying and/or had a lower metabolic rate it might have lower energy requirements. If rather than scaling a vampire bat up we looked at a human we can see that your average adult human needs 2000 to 3000 calories per day. A litre of blood contains 600 calories according to some Google searches that are going to look interesting in my browser history. We're going to assume that there are enough raw materials present as well as the calories to allow any missing resources to be synthesized. That gives us a lower figure of 4 to 5 litres needed per day. That's more manageable but still seems like a hard thing to hide. We're now talking 1 death or 5 living victims per night. It's seems far more likely the vampires would go after herd animals such as cows than after humans. Cows contain more blood, tend to be more exposed at night, and will ask fewer questions. The mess made from expelling the waste will also be less likely to be noticed in the middle of a field than in someone's bedroom! [Answer] Addition to TimB's answer: Expelling the waste might also be taken care of differently - if the vampire were able to digest the blood quickly enough, it could simply drink and return. This would require a powerful blood filtration system, much more so than human's, but it might be doable. As soon as the blood is mostly stripped of its nutrients, it can be returned back to the victim. In fact, if you also add some enzyme to force the victim to feed more nutrients to their blood, you could get much more then 900 kcal per litre - and in fact, do so repeatedly. While this would prolong the feeding process, it would also mean that he'd be able to feed comfortably on just one person, and without doing harm to the victim, other than certain level of feebleness. So - induce a "need more energy" state in the victim, which will make it pump more nutrients into its blood, including metabolising fats, filter the nutrients out as quick as possible, and return the blood back. Ideally, in an outright loop, similarly to how human kidneys work, just on a bigger scale. You don't get water toxicity, you don't gain 5kg in weight, you get much more nutrients than from just sucking the victim dry, and you don't kill the victim - win, win, win, win. In fact, this could even be seen as a symbiotic relationship if you add some beneficial effect of the blood filtration. Perhaps the vampire could also improve the immune system of the victim temporarily (might have evolved to protect the vampire from infections through victim's blood). Maybe it can filter out stuff that can cause harm to the victim, e.g. poision. It could help prevent various diseases related to blood content, e.g. some coronary diseases, artery clotting... At the very least, it could be used to help the host stay slim, by draining a certain portion of his nutrient supply - the ultra-cool vampire diet! In fact, I could easily imagine a society with nobles hosting vampires specifically to show off their wealth etc. They would eat 2-3x as much as "poor" humans, and dispense the extra to their vampire symbiotes, thus staying well in shape. The symbiotic relationship would thus be beneficial to both the human host and the vampire. Feeding gets easier for the vampire, because it's suddenly a helper, rather than a mugger (think medicinal use of leeches). Humans might get a host of benefits, including improved health and easier weight management. Imagine how much people would pay for a vampire service today, just to get rid of that extra fat! :D [Answer] [XKCD suggests](https://what-if.xkcd.com/98/) that regular consumption of large amounts blood (by humans) would probably lead to iron overload (as well as having other drawbacks). [Answer] Went and found a list of [human blood components](http://en.wikipedia.org/wiki/List_of_human_blood_components) on Wikipedia. Every building block of human life is in there. Is it there in quantities to support a human who functioned on nothing but blood...probably not. Especially considering that a human consuming blood usually gets nausea. All the major proteins (that I can think of), fats, minerals, sugars, etc etc etc are present in blood which makes sense as the body's pick-up and delivery system. But you can make the assumption that vampires don't require the same exact nutrients as a human. If they're not biologically different then...well they're not vampires. So yes, you're sane. [Answer] The Masai tribe do this - or used to, these days they farm and have a more varied diet. According to Wikipedia they are extremely healthy, so maybe there's something going for it. ]

[Question] [ Recurringly in Sci-Fi spaceships manage to make it to lightspeed and above. Is there a scientifically plausible explanation of such capacity? How does it impact the spaceship's design and its passengers lives? [Answer] I was thinking about this topic a lot and I still didn't find any plausible FTL mechanism. Here is quick overview of important features of the most "standard" mechanisms used in science-fiction. None of them is scientifically sound, but some of them are plausible in principle. # Deformations of spacetime This category of FTL transport mechanisms uses known fact, than general relativity theory *on its own* allows very broad class of spacetime deformations. Almost for any shape of spacetime, one can find distribution of mass that is capable of creating it. This allows solutions as the famous [Alcubierre drive](http://en.wikipedia.org/wiki/Alcubierre_drive) or [traversable wormholes](http://en.wikipedia.org/wiki/Wormhole#Traversable_wormholes). There are, however, three very serious problems. ### Problem of exotic matter It is true, that the solutions of Einstein equations almost always exist and some of them allow FTL travelling, but almost always, this requires the so-called exotic matter. It is exotic in several aspects: it either has negative rest mass, or it has tachyonic properties. This means lot of troubles: in some cases, such matter could be spontaneously created from vacuum, producing energy in the process. By other words its existence would render our vacuum unstable. In other cases, this problem is not present, but such matter is likely to allow direct superluminar travelling and therefore necessarily time travelling. (In optimal case, we would like wormholes to grant us shortcuts to stars without breaking the causality, which is always troubling.) In all cases, such matter is unlike anything we have encountered so far and there is no good reason to think it will be discovered in the future. Someone says quantum effects, like the [Casimir effect](http://en.wikipedia.org/wiki/Casimir_effect), can take role of exotic mass. This seems very unlikely to me, since they are tiny compared to the rest masses already present in the system. For construction of warp-drive or a wormhole, we need effects comparable or bigger than the rest masses involved. If I would like to introduce exotic mass into my universe, I would probably postulate that new particles of these properties were discovered. ### Problem of density Another big problem is, that the spacetime is deformed only at very, very high densities. Even at densities of nuclei, around 1017 kg/m3, there has to be object of size of a neutron star to do anything at all. Probably much higher densities would be necessary for FTL construction. This means that some form of reasonably stable ultra-dense matter would probably have to be introduced to allow this form of FTL. ### Problem of too big mass To achieve wormholes or warp-bubbles on scale of meters or kilometers, masses comparable to the mass of sun would be probably needed. ## Warp drive * There are no indications that required exotic high-density mass should exist. * Automatically allows time travelling in the universe. * Probably requires existence of some stable high-density exotic matter, like [magmatter](http://www.orionsarm.com/eg-article/48630634d2591) proposed in the *Orion's Arm*. It is unlikely we could build it only based on atoms. (This includes that it probably cannot be based on some field that is just "switched on", like it is in Star Trek. Required energy for such field would by far surpass any energy spaceship made out of atoms can carry, even in form of antimatter.) * Warp bubbles big enough to enclose spaceships require tremendous energies at very high densities. Civilization capable of their construction would probably find easier to "rewrite" themselves into objects of high densities and use smaller bubbles. ## Wormholes * There are no indications that required exotic high-density mass should exist. * Wormholes would probably have mass comparable to planets or even stars. * Do not automatically allow time travelling. It can be prevented by [Visser effect](http://www.orionsarm.com/eg-article/4754be03eb3bc), how they called it in Orion's Arm. But the discussion of this effect is broader, including some scientific articles on the topic. Nicely explained on web of the [Anderson Institute](http://www.andersoninstitute.com/wormholes.html) > > It is thought that it may not be possible to convert a wormhole into a time machine; some analyses using the semi-classical approach to incorporating quantum effects into general relativity indicate that a feedback loop of virtual particles would circulate through the wormhole with ever-increasing intensity, destroying it before any information could be passed through it, in keeping with the chronology protection conjecture. > - Would have to be transported in place by sub-light speed. > > > > > # Tachyons, 'Mass Effect' or simply jump-drive > > > Jump-drive is used for example in *Battlestar Galactica* series without explanation of the mechanism. Similar jump drive is used in *Mass Effect*, where they offer basically this mechanism: Theory of relativity does not forbid existence of tachyons - particles that always move faster than speed of light. They can travel into past, thus breaking the causality, but this is not problem in principle. Jump drive works so that the space-ship changes local [Higgs field](http://en.wikipedia.org/wiki/Higgs_boson), which leads change of rest mass of particles of the ship. Eventually, all particles gain imaginary rest mass and become tachyons. Then they move faster than light. * Requires existence of tachyons. There are currently no indications they should exist. * Requires viability of change of the rest masses into imaginary values by changes of the Higgs field. (Probably not expected to be really possible, but plausible.) * Automatically allows time-machines. * Requires incredible amount of energy. * **It is very improbable that the ship and crew would survive tachyonic state or transition to it.** As the rest masses change, binding energy of every atom drop or wildly change and atoms become much bigger. Same things happen to the atomic nuclei. # Subspace/Hyperspace Subspace/Hyperspace idea operates with assumption that it is possible to leave our spacetime into some other space, in which the speed of light would not be the limit. The biggest problem is how the transition into hyperspace should occur. We know how the matter behaves up to very high energies (hundreds of GeV) and we have not seen anything even remotely similar. From this, we can judge that if transition into hyperspace is possible, it would probably occur only using some very high energy mechanism. This brings similar problems as in the spacetime manipulation mechanisms. * There are no indications that the hyperspace should exist. * Does not necessarilly allow time travelling. Structure of the hyperspace could dictate what is really "now". This violates principle of equivalence, but only if the hyperspace is concerned. (And it is therefore not in contradiction with experiments done so far.) * If the transition to hyperspace is possible, it probably requires so high energies we haven't noticed it so far. This might be prohibitively difficult to construct. # Communication via Quantum Entanglement Here, it is simple. Although it is often used in science fiction, quantum entanglement is shown not to be able to transmit data faster than light. [Wikipedia](http://en.wikipedia.org/wiki/Quantum_entanglement): > > It is not possible, however, to use this effect to transmit classical information at faster-than-light speeds > > > # References There is a very extensive and scientifically serious overview on the [web of Project Rho](http://www.projectrho.com/public_html/rocket/fasterlight.php). (Although some of the listed FTL drives are not very plausible - and the author admits it.) [Answer] The [Alcubierre drive](http://en.wikipedia.org/wiki/Alcubierre_drive) is one of the proposed FTL drive systems that is the closest to being feasible. In effect, it is very similar to the Star Trek warp drive, though an Alcubierre ship would probably look nothing like a Star Trek ship. It works by distorting spacetime in front and behind the ship, compressing it in front and expanding it behind, while the ship moves in a bubble of undistorted space-time. Such a ship would require exotic matter (matter with negative mass), or perhaps some manipulation of the Higgs-field (that could become possible following the discovery of the Higgs Boson), and would require a particular design in order to operate. Depending on the multiple of lightspeed such a ship could achieve, it may still take quite some time to make a journey to another star, necessitating efficient self-sustaining life support or some sort of hibernation technology, or both. The other mechanism for FTL travel that may be scientifically feasible is the [traversable wormhole](http://en.wikipedia.org/wiki/Wormhole#Traversable_wormholes), but this is not so much travelling at greater than lightspeed as bypassing most of the space between *here* and *there*. Such technology would require that the journey be made once in real space in order to carry the mouth of the wormhole to the desired destination. Traversable wormholes may eventually not even require a ship, but if they are possible, I would imagine that at least initially, it would be desirable to have the mouths of the wormhole located a safe distance away from planets. A wormhole ship could be little more than a sealed can shot into the mouth of the wormhole and caught on the other side; the passengers would not need to be aboard it very long at all, perhaps only an hour or so. It may not even need to have more life support than a few emergency supplies. [Answer] *I will take "scientifically sound" to be "we are sure of the principles involved, and need technologies with better precision, more energy, or need to experiment with the engineering. In practice the solution might be very hard, and centuries away from being a normal technology." I would count nuclear fusion power in this category. Or perhaps a [Dyson Sphere](http://en.wikipedia.org/wiki/Dyson_sphere).* In which case the answer to the question in the title is "No." The best examples worked through in accordance with theories of relativity, are scientifically plausible (by untested extrapolations of the theory) [only if you allow for unknown exotic materials, or access to stupendous amounts of energy](http://en.wikipedia.org/wiki/Alcubierre_drive#Difficulties) that would be game-changing beyond FTL travel in their own right. The topic of FTL communication and travel is [driven by science fiction first and foremost](http://www.astronomycafe.net/anthol/scifi1.html), because it [gives access to a whole cosmos of settings and venues](http://tvtropes.org/pmwiki/pmwiki.php/Main/FasterThanLightTravel) for adventure and story telling. That is not to say that these unknown materials do not exist (note they would not be combinations of atoms, electricity or anything technology can handle today). We still do not know what dark matter or dark energy are, and the big bang theory is widely accepted to include a short period of Inflation, where space expanded orders of magnitude faster than the speed of light. If these, or similar things at the edge of known physics, turn out to be true, then we don't fully know the consequences, and that *might* mean we would have a way to send material faster than light between locations, at a practical cost. However, I think it is quite reasonable to forecast that any such new physics will not have practical use for transport. --- Analogy: In the past, a weak understanding of chemical reactions prompted much searching for ways to transmute base materials to gold (even scientific luminaries, [like Isaac Newton, spent time on this goal](http://webapp1.dlib.indiana.edu/newton/index.jsp)). [Eventually that gave way to chemistry](http://www.scienceandyou.org/articles/ess_08.shtml), one of the tenets of which was that transforming elements (i.e. altering the nature of elemental atoms) was considered impossible. Then came understanding of sub-atomic structure and radioactivity, followed by tools like linear accelerators [that can and do transform elements between types](http://en.wikipedia.org/wiki/Glenn_T._Seaborg#Return_to_California). However, these tools and knowledge are not a practical way to make gold on demand, and never will be, although they have spawned useful technologies such as radioactive materials for medical imaging. In the above if you take "making gold from other elements" -> "FTL Transport", and "unknown exotic matter" -> "sub-atomic theory", then this is an example of how wishful thinking can inspire research, but that the end scientific results are only vaguely related in the end. In my opinion, this applies to 99%+ of science and science fiction conjecture, pretty much for any technology that we don't understand well enough to be building it today. --- The most likely long-distance starships are in my opinion most likely to be a [generation ship](http://en.wikipedia.org/wiki/Generation_ship) - a self-sustaining colony taking many generations to arrive at its destination. Or perhaps an [interstellar ark](http://en.wikipedia.org/wiki/Interstellar_ark) would be more practical, where most life forms are kept in or close to stasis in order to reduce resources needed by the ship to maintain them (and thus the size of the ship). These types of long-term transport would be major projects and very exciting in their own right. However, they do lead to a very different kind of narrative. The stories associated with FTL can have a new adventure location each episode, or a galaxy-spanning grandeur. The stories associated with a travelling colony are much more inward-focussed. [Answer] There are a few slightly far fetched theories. Here is one: One found [here](http://techland.time.com/2012/09/19/nasa-actually-working-on-faster-than-light-warp-drive/), that NASA is supposedly working (I'm skeptical), is that by creating a special propeller that expands space time behind it, and contracts it in front of it, you can have a ship travel just about as fast as you want. But this would require special exotic matter, and about the energy mass of the planet Jupiter. Basically, with Earth technology,that would be impossible. But, maybe, if you got a certain shaped ring around the propeller you could reduce the energy mass required to about 1,600 pounds. --- I originally thought that FTL (faster than light travel) was impossible. Above is what I came up with before I did a quick google search. But if you want one with some interesting possibilities you could look at the one from *Xenocide* by Orson Scott Card. In that story faster than light travel was accomplished by going into another dimension. If a mind could physically hold the pattern of something (the layout of cells and molecules), then that something could be moved to another dimension, and destroyed in this one. It could then be remade in this dimension in another place. This "other" dimension would be defined for the specific story. This mind that could hold the pattern would have to be very large, many hundreds of computer's worth (as it is in *Xenocide*) ]

[Question] [ I inherited a worldbuilding project, and the former authors liked some things that seem unrealistic. One of them is that one of the world's biggests rivers splits into two other rivers some 300-400 kms before reaching the sea, definitely before area where the delta should be expected.  Map legend: Galvina river (flowing from the north) splits into Galvina and Molana (the red circles), both flow into the sea. One square is 100km times 100km. How likely is this to happen naturally? Is this even possible to occur and stay for more than 1000 years? The terrain around the rivers is covered by jungle, and it wasn't specified how flat or hilly it is, so I guess that there should be hills around but valleys where the rivers should flow. However, as I understand geology, one of the river should prevail and make its channel so deep that the other river would get dry. However, I don't know how long would this take and what could produce this phenomenon in the first place. The world's recorded history spans for 1000 years and the rivers should stay as in the map at least for few more centuries. [Answer] What you are talking about is called [bifurcation](http://en.wikipedia.org/wiki/River_bifurcation) and yes it happens. However usually over a long period of time (like 1000 years) one branch or the other will get silted in and turn become the minor branch. Having 2 major branches is not something that generally lasts. You are going to need some very specific feature for something like this to work long term. First in order for a split to last you need the river to flow through an area of hard rock that can resist weathering and erosion by fast moving water in the river. The split would have happened because the natural erosion of the river came in contact with this harder stone that resisted erosion and thus caused some of the current to be redirected to the other side. You can see this happen in rivers where there are islands and short term splits like in the Grand Canyon. The next feature that will be required is that both channels will need to be moving quickly enough that they resist a build of of silt that would normally close off one of the channels over time. So the chances are the split happened at a place that is elevated sigifigantly from just a few miles down stream. It could be that both river forks flow into different valleys. One thing I would note is that places like this tend to attact settlements. These are places where a large amounts of goods will likely pass on their way down river and since there is likely to be rapids that will have to be negotiated or bypassed it going to naturally be attractive to tradesmen who will look to make a buck(or pence or whatever) off of the people who will be making camp or even just taking a break before the challenging task ahead. Not to mention a place where goods may get stranded or abandoned as over agressive traders are forced to lighten their load before attempting to transverse the rapids, and goods get salvaged after some fail that transversal. This area is going to become a natural area for civilization to pop up in support. [Answer] That depends on how close to the time of the split you are asking from. The closer to the time, the more likely it is to be **visible**. Once a river finds a new route it will flow in that direction. Over time the majority of water will continue on this new route eroding more material, making it even easier for more water to choose the new route. Eventually the new route of the river would be made deep enough to accommodate the full watershed making the original route obsolete. It would become a dry-river bed. Think about gorges or creeks in this regard. It is very unlikely that both possible routes for the river to reach the sea will erode material at similar enough speeds to keep them completely equal. **EDIT**: To answer more fully, the speed of the shift from one route to another depends on the comparison of the erodibility of the material that the two routes flow through/over. Old route stone vs. new route stone the process will be slower. Old route stone vs. new route clay the process will be much quicker. [Answer] Not only is this possible, but there are already living, long-lasting examples of bifurcations. Check <https://en.wikipedia.org/wiki/Casiquiare_canal> for a branch of Orinoco river that flows away into Amazonas river. These bifurcations are called distributaries (<https://en.wikipedia.org/wiki/Distributary>) and are not uncommon, albeit most of them are in deltas. ]

[Question] [ When you are designing a language for a species that uses vocal communication, one of the early decisions you need to make is that of which phonemes can be used. How does one determine what phonemes can be used? Or more directly, assuming that we are talking about a species that develops some form of vocal language (rather than just utterances on the order of grunts and snorts), **what factors of the species' phenotype determines which phonemes are usable** by that species? Rules of thumb as well as specific references are both welcome as answers to this question. (This question essentially takes one part out of *[How does one go about developing a language for a particular culture in your world?](https://worldbuilding.stackexchange.com/q/19/29)*, which was put on hold as too broad.) [Answer] Objectively speaking, sounds are produced by the particular topographical features and movements of the mouth, lips, throat and tongue used in their formation. It's important to understand that even when a single individual makes a particular sound more than once the sound waves they produce are similar but not identical. Because of this, we know that the human brain does not distinguish sounds by their unique sound signature but by the distinguishing features of the wave. In the field of linguistics we classify these distinguishing features according to the particular features and movements used in their formation. For instance we refer to the breathy sound produced by an open mouth and non-vibrating throat (most commonly heard after "k", "p", and "t" in English) as an aspiration. Try saying "p" as in the beginning of "pop" without moving any air through your throat (I think you can probably hold your breath for half a second). This is an unaspirated "p". Now make the sound the way you would normally say "pop". Can you feel the air moving in your throat? We refer to these two distinct sounds as allophones. However, we tend to think of these two sounds as being the same thing. This is what we refer to in linguistics as a phoneme. Now get someone else to practice saying "pop" with and without the aspirated "p". Close your eyes and have them say both a few times in no particular order. You felt the difference in your throat. Can you hear the difference in the word? You probably can. When two or more sounds are thought of as being the same but you can actually hear the difference (as in the case of "p") you're dealing with what are referred to as complimentary allophones. They're called this because the sound difference is determined by its position relative to other sounds so the two sounds never occur in the same place. If you couldn't, then you'd be looking at what we refer to as "free variation"; meaning that the sound difference doesn't affect the meaning (or intelligibility) of the word. If the sound difference affected the meaning of the word, this would be referred to as contrastive distribution and means that the sounds are part of distinct phonemes. Obviously the potential set of allophones is huge, as [this *incomplete* chart](https://web.archive.org/web/20170404095628/http://www.unilang.org/resources/pronscript/art_ipachart.gif) demonstrates, so any natural human (real-world) language is going to have some set of phonemes that reduce the number of sounds that need to be distinguished. What allows a phoneme to exist is the similarity of the formative features used to make it, however what makes it into a phoneme instead of an allophone is the inclination to ignore one or more specific formative features that distinguish them. When this happens only depending on the phonetic context (what other sounds are around it), they are complementary and other sounds with the same feature distinction will likely be complementary in the same position as well. If the formative feature is ignored regardless of position (the allophones occur in free variation), then allophones with the same distinguishing feature will likely occur in free variation as well. Human beings are actually born with the ability to distinguish all allophones from one another, but lose the ability to distinguish them over time (presumably as part of the language learning process) eventually solidifying themselves into the phonemes they've been exposed to. The age at which this happens varies but it universally occurs before kindergarten. This is why we can almost always tell the difference between a natural language and secondary language speaker. A good example of this is how many Asian English speakers have trouble differentiating between "l", "r", and "w" because their native language doesn't do this. Also as a result of this a child who is frequently exposed to multiple languages at an early age will have an easier time learning those languages and will have the potential to speak them as though it were their native language. Of course, all of this is unique to the way the human brain works. An alien brain would have to work in the same way as our own (an unlikely coincidence) for this to be relevant. But let's assume they just happen to. There is a phenomenon in the human brain known as "allophone restoration" whereby white noise is interpreted as the missing allophone in the word. This is a symptom of the human brain's insistence on pattern formation. What I'm getting at is that an alien with a differently functioning language production method (such as a differently shaped mouth) may indeed make different noises that humans would not be capable of. However, without exposure to it from an early age a human would be unlikely to distinguish between those sounds and may even interpret them as sounds from their own phoneme set. A good real-world example of how this might work for your language are the [Khoisan languages](https://en.wikipedia.org/wiki/Khoisan_languages), a set of languages that use clicks as consonants. No non-native speaker is likely to appreciate the difference between various forms of clicks. Imagine what that would be like with a creature who's sounds you couldn't actually reproduce. The short answer is that there's a reason that various science fiction shows use near-human aliens, universal translators, or simply ignore the issue of the language barrier entirely. Think about *Star Wars*. Not all the languages sound like something humans could speak (particularly Wookiees) yet the various characters often understand each other just fine. I realize this probably wasn't quite the answer you were hoping for but I hope it helps you in your pursuit of scientifically plausible alien language construction! [Answer] The first factor is what sounds can the beings generate. What is it using as a frequency generator, and can it generate white noise, i.e. sibilants. The second factor is how easy the beings find it to generate each sound. Sounds that are easier to utter will occur with greater frequency. The third factor is how easy is it for the being to change from emitting one particular sound to emitting a particular different sound. Difficult or slow changes will occur with lesser frequency than easy and fast changes. As an example, a species I invented uses a syrinx (as in birds) as a tone generator - which effectively uses direct neuron-to-muscle control to affect the amplitude of each individual pressure variation of the sounds emitted. Such a species would have trouble with sibilants, as sibilants are effectively random white or pink noise, and a neural system has trouble with generating randomness. They tend to whistle instead when imitating humans. [Answer] This is probably not the answer you are looking for but worth noting: many visitors to the world we build will vocalize the names they see. If you pick names that are physically manifest-able by the human vocal tract, they will thank you. For species where this is unrealistic, like bird species, it is common to provide a "best effort transliteration" of names which is human pronounceable. ]

[Question] [ So it occurred to me while developing the political landscape for my world, that throwing fantasy races into the mix in an absolute monarchy/feudal system and pretending they just fit right in may in fact have some problems. What I am attempting to generally figure out is: *How would including fantasy races impact the politics of a particular medieval monarchy?* --- ## For aid in answering this question here is what can be generalized about each of the fantasy races and what is known about the kingdom in question **Orcs** * Orcs are big and value strength, they share a lifespan in common to humans * Their society is tribal, with a war chief being chosen based on combat and feats of strength. * Some tribes are nomadic but others are not * This practice leads the orcs into conflict with other races as young orcs must prove themselves in battle to get a mate and for a chance at power. * Orcs as a race virtually never band together and regularly fight with neighboring tribes be they orc or not. * Orcs tend to distrust gnomes and dwarves whose small stature leads to a belief that they are sneaky and underhanded (which is sometimes true) * Orcs respect humans and elves mainly due to the wars they have fought with the two races * Few orcs are capable of using magic, those that do become shaman and are revered...until they are sacrificed to the gods at age 30. **Elves:** * Elves are long lived though not immortal. On average elves live to be 350 * Each elf tends to choose a few skills (usually fewer than 6) to perfect in their lifetime. These can be manufacturing skills, martial skills, as well as things like trading and public speaking. * Elves would rather be working on honing their skills (even martial skills) than fighting with others. They are not so much peaceful as often self absorbed and will ignore provocations * Once roused to fight they are deadly. They are not naturally stronger or faster but their combat skills are second to none. * Elves live in multi-racial cities for the most part, though some shun society and live in small enclaves reserved for elves (yes, in the forest mostly). * Elves can excel at pretty much anything due to their long lives and penchant for focus on certain things. * Elves generally tolerate most races, though can often see them as lesser beings due to their short lives * Elves inherently distrust orcs due to the fact that the orcs can't keep long term agreements * Elves would probably rule the world if they were not the smallest race by population * Elves have a higher percentage of their population capable of using magic **Humans:** * As usual humans are sort of the in-between race and have no race wide tendencies appearing to most other races as infuriatingly random in their actions (on the whole) * On average humans live to about 60 years of age, though social status can skew those numbers significantly. * Humans generally live in multi-racial cities though there are many human villages/farming communities. In the rural setting humans are often much more distrustful, though not outright racists. * Magic is uncommon as a general rule, but humans fall somewhere between elves and orcs in the regularity of a person using magic **Dwarves:** * Short and stocky and fond of mountains, caves and basically rocks in general. The average lifespan is around 100 years * Dwarves are excellent traders and craftsmen * Dwarven society is very organized particularly in dwarf only settlements * Social standing is very important and a sort of caste system has developed though above average individuals are capable of changing their caste. * The only other race to frequently live among the dwarves are gnomes * Dwarves tend to be secretive and self interested (as a race) * Similar to orcs dwarven mages are uncommon. Those that do have magic tend to become priests. * Dwarves tend to mistrust virtually all other races with the exception of gnomes and are generally closed off to outsiders * Dwarven cities are well organized militarily and all dwarves are expected to serve in the military for a period of time when they come of age. In mixed cities you will often find dwarves as leaders of city guards/militias/militaries **Gnomes:** * Similar in height to dwarves but not as stocky, gnomes tend to live to about 130. * The most friendly of the races and most welcoming. A stranger in a gnomish village can expect that they will be welcomed fed and given a place to sleep * This friendliness probably developed as a defense mechanism for a race that is smaller and weaker than all the others. * Gnomes also have a natural curiosity for anything new and different...this can make them appear eccentric to the other races * With the exception of small villages there are no gnomish kingdoms * Like elves mages are fairly common among gnomes (though still rare) * Gnomes tend to like everyone, even orcs who seem fascinated with "the wee people" --- **The kingdom in question is a monarchy.** Within its borders it contains: * 4 large multi-racial cities (all races present in the city limits) * 2 Elven forest settlements * Many human villages * Many gnome villages (Humans and gnomes often mix together in these smaller towns) * 1 dwarven stronghold * A section of the orc tribe lands (though the orcs would probably disagree that they are part of the kingdom at all) [Answer] **Model each race as equivalent to modern political parties in relation to racial priorities and pressures**. Doing so will simplify mental construction of the political interactions, and the checks and balances. By making a comparison in political ideology between the various races and modern human political parties, the author can find quickly find examples of how a particular ideology played out in real life then merge pattern of events in with their story. Modern political parties are the aggregation of people who share similar background, religions, cultural priorities and other factors. As these factors do not change much, the emergent political parties don't change much either. We can expect the same kind of political momentum/stability from each race's preferred politics. **Issues to deal with** Any political system will need to deal with the following issues: * War * Taxes/Treasury * Economy * Domestic Peacekeeping * Diplomacy * Regulations * Education Each race will have a different set of default approaches to dealing with (or not) all of these areas. **Interactions with the Absolute Monarch** The personality and disposition of the king on the above list of issues will dictate to a large degree which races fair better and hold more power than another. For example, if the king is prone to violent conflicts then the Dwarves, Orcs and Humans will be his favorites. Conversely, if the king is an empathetic man interested in social programs then the hospitality and caring of the Gnomes will resonate with him. **Interactions along the political spectrum** * Elves - Gnomes on Social Issues: This is the classic socially conservative vs socially liberal dichotomy. Elves don't really care what happens to other races while the Gnome's natural hospitality will push them towards what we would call social liberalism or socialism. Oddly, the free roaming Orcs may be natural allies to the Elves in social questions because the Orcs will have a "bootstrap yourself" attitude to the Elves' apathy. * Dwarves - Orcs on War: Both races are highly militant but with different aims. Orcs need warfare for the sake of warfare, as younger Orcs need it to prove themselves. Dwarves on the other hand are equally militant but have no cultural pressures for constant combat. So when war does break out, the Dwarves will aim for an isolationist policy while the Orcs will push for fast, aggressive action. * Gnomes - Orcs on Education: The Gnomes' natural curiosity lends itself to education, science and knowledge which they acquire as quickly as possible. In opposition, the Orcs need no more education than how hunt and fight. **Degree of Politically Activity** * Dwarves - distant and minimally involved with the larger kingdom (Isolationist to the core) * Elves - Selectively involved, usually in diplomacy due to longevity and skill specialization * Gnomes - highly involved * Humans - highly involved * Orcs - Minimally involved and minimally represented at the kingdom level (the roaming Orcs don't often come into the cities so they send representatives when needed). [Answer] First question is to answer is : Will it change anything compare to actual feudal society ? Of course there were not different races in medieval Europe, but the cultural differences were huge. And whatever was the reality, numerous clichés did modelled the feudal society. For example, the martial reputation of [Swiss](https://en.wikipedia.org/wiki/Swiss_Guard) leads to an extensive use of Swiss mercenaries, or the [Varangian guard](https://en.wikipedia.org/wiki/Varangian_Guard) which was mainly composed of Germanic soldiers serving the Byzantine empire. You can therefore think the diversity of races as just a new kind of diversity adding to the ones which existed in reality, and use them the same way as the others. Really the point about politics is that the king will try to use any particularity (real or imaginary) of the different races to stabilize its power. Therefore it is not very different to what happened in the real world. Here are some examples of the impact on politics that these races can have. I tried to give a historical counterpart for each of them. * Most royal advisers or ministers will be elves since they can be trusted, they have a tendency to be talented and they can even ensure a continuity between a king and his heir due to their increased lifespan. This implies a lot of jealousy from non-elvish courtiers, and some fine political tuning from the king to avoid too violent clashes and the same time to avoid a too big power for the elves (it can somehow be related to the way priests and monks served as advisers). * There will probably a standing army of dwarves, serving directly the king since they are "naturally" prone to be organized and militarized. Such army could have a big influence in politics since it is an army on the hearth of the power (similar to the Varangian guard in the Byzantine empire or Cossacks in the Russian empire). * Since dwarves tend to be traders, the king may contract debts toward them. This has to be taken in account when dealing with them, and may lead to some civil war or executions of dwarves to reduce the debt (as did some European kings did towards Templars or Italian cities). * Tribal orcs inside the kingdom will most likely be used as a shield against other tribal orcs (more or less like the Roman empire used some Germanic tribes). -The only utility I found for gnomes is being a scapegoat (as were Jews or witches in medieval times). However, any sufficient minority race could do the stuff. [Answer] I think a feudalism system would be quite suitable. In short words, feudalism leads to the building of territories of various size who are bound together by a common liege. But which, for all other purposes are quite independent. Some examples: * If you look at France during the 100-Years war. Burgundy, Anjou, Normandy, Guyenne, Provence were more or less independent politically and economically from the Kingdom of France. But most or all were nominally dependent on the French Crown. * The Holy Roman Empire (HRE) would probably be a suitable example for you. It was composed of various territories, each with their own form of government. Some were lead by Religious leaders (e.g. Würzburg, Salzburg), Princes (Austria, Bohemia), Dukes (Swabia), independent cities (Frankfurt, Nuremberg, Strasbourg), etc. All were free to decide on their local political system, and a lot of economics freedom. Even, aside from the 30 years war, some religious freedom. Each large region were free to choose the religion they wanted/authorised within their boundaries. All were finally united by an elected Emperor (in practice from the Habsbourg dynasty). Contrary to a previous answer, **I would compare most of your races with religions**. The HRE was a mix between various reformed churches, Roman Catholic and Jews. For historical reasons there were no Muslims in that political entity, but you can imagine how it could be if you throw them in the pot. The Jews were a minority everywhere, but even if they often focused on some trades, and tended to form closed communities, they could be found overall. You can see that they sometimes were banned from some regions at time (Frankfurt, Vienna, etc.). Roman Catholic and reformed churches usually couldn't live together, except maybe in some independent states. And the different reformed churches were more tolerant of each other but nevertheless tended not to mix. --- Back to your case, I could imagine something like * Humans would be the Roman Catholic, * Elves would be the Jews, * Dwarves and Gnomes various branch of reformation. Please note that I am only referring to the political organisation. It is not meant to associate any other traits between the given races and the religions. For the Orcs, I would see them as Gypsies. Nomadic, not actually building any settled structure. The 4 large multi-racial cities are independent cities. The dwarves and elven settlements are Duchy. Humans and Gnomes form some separate entities (possibly more than one such), and maybe some mixed ones. Then depending on how many entities you have, you can give a few voting rights. One for each race would be a good idea. Then you create a parliament which is composed of a representative of every single entity. [Answer] It would add diversity. Monarchy is basically based on obligations various groups and leaders of the groups have towards the king and his family. There is not necessarily an abstraction of the kingdom separate from the ruling dynasty. As such every group has essentially one-on-one relationship with the royal family. But generally as time goes by the relationships get formalized and homogenized because historical precedents tend to apply widely. In a racially diverse country a precedent made on a case concerning a dwarf would be less likely to apply to cases concerning other races as there is an actual physical and cultural difference that would keep the races separate. So while the relationship the king has with the two elven settlements would probably be fairly similar and would get more so over time, it might have very little in common with the relationship the king has with the dwarven stronghold. Which relationship would probably be entirely unique just as the stronghold itself would be. The primary political relationship for normal people would be with their own community, a village, a city, the stronghold, or a tribe. Only the leaders of these communities would have actual political relationship with the king and the wider world. Usually people would just interact with their own community and a few traders and travellers. The fact that people in other communities would be of different race, would not necessarily be that important. If you live in Florence, a person living in Venice is a Venetian regardless of whether they are a human, an orc, or an elf. The exception to this is naturally racism. People seem to have a need to reaffirm their bond with their community by defining some people as different and suspicious. So it is likely there would be prejudice and discrimination against some groups. This would probably vary in different communities. Or it might not be related to race at all. The discriminated group could be a group of immigrants or a religious minority. [Answer] I would suspect that there would be a lot of witch hunts and orcs would be blamed for almosts everything in the outlying provinces. like Ville Niemi said, racisim would be a major issue, humans would tend to have the most racist views due to their survival instincts different is threatening, the threat must be eliminated. hate begets hate. should this be around the RPG blog? I know that d+d stories dealt whith situations like this. There would probably be an organization like the KKK, and there would be the occasional race riot in the seedier parts of townI.e. the orks, and other unfortunates who woulld be attacked. There would be a great deal of fighting over wizard colleges and warlocks would definitely by prosecuted. (pacts w/ beings of questionable niceness, for lack of a better term.) there would be a class divide that many wouldn,t like. humans are apparently more versatile than elves. [Answer] A power-sharing arrangement ...a royal High Council/Cabinet with a representative nominated/appointed/elected by their own people/own people's leadership ...One or two for each race/sub-polity. A Religious Council with each religion represented. A High Council/ Senate/House Of Lords and a Low Council Assembly/Parliament. Each race leader (or their representative) has a role in the state & military. Duke-Lieutenant Of Dwarves in charge of Armoury/Engineering/Weapons Supply, Duke-Lieutenant Of Orcs in charge of Assault Infantry/Offensive War/Marines, Gnome Duke-Lieutenant in charge of Civil Service/Bureaucracy/Taxation/Harvest Supply & Storage/Army Logistics/Quartermaster, Elven Duke-Lietenant in charge of Cavalry. Crown Prince (Human) in Charge of Defensive Military/Defensive War. Human King in charge of the whole shebang. Throw in another couple of races & you could have one in charge of the Navy & another commanding an Air-Wing of Pegasi, Griffins, Dragons. No one faction dominates, each provides something crucial to the greater whole/greater good. Mixed Service Wings Like Navy ...Marines/Sailors/Naval Air/Submarine each section a different race's responsibility. The United Kingdom Of the Five Realms Of Man, Elf, Dwarf, Gnome, Orc Rises up from being a large divided Island of East, North, South, West & Central Realms (placeholder designations) to become a mighty seafaring Empire ruling a quarter of the world coz it's union gives them the advantage that each alone fails to have. Add in some Merfolk/Seafolk/Amphibian-types (legged merfolfolk, civilised Murloc/Grippa Frogfolk, Turtlefolk, Lizardfolk) for the Navy & some birdfolk as part of the Airwing and Prydannia will rule the Seven Sea. ]

[Question] [ In my particular Earth, much has remained after the human-killing virus, and nature is thriving - even taking over the cities. It's beautiful. But I have separated the healthy populace in orbit until it was safe to return. In a near-future scenario, where I have rescued only a few non-related people from Portland, Oregon (not-relevant, but I thought someone might ask), they're ready to return to Earth after 3 years or so in space. Setting aside their trials upon return, etc., **how many random people should I preserve in space when humanity is almost wiped out, for relatively clean genetics**? Is there even such a thing? I realize this is purely speculative, but I'd like the fewest possible people and would welcome some scientific reasoning so that I don't end up with genetically distressed children / population. EDIT, as requested: Infrastructure, technology forests, roads & bridges, etc., are all only about 3 years old without people. There are many machines and materials; this question is purely for genetics-sake. [Answer] **Preface** This question is **very** similar (but not identical) to a previous World Builder question ([What is the minimum human population to maintain a colony](https://worldbuilding.stackexchange.com/questions/3/what-is-the-minimum-human-population-necessary-for-a-sustainable-colony)). If you're interested in this question and answer, I recommend reading that question and its answers for additional information. **MVP** The term you are looking for is [Minimum Viable Population](http://en.wikipedia.org/wiki/Minimum_viable_population). > > This term [MVP] is used in the fields of biology, ecology, and > conservation biology. More specifically, MVP is the smallest possible > size at which a biological population can exist without facing > extinction from natural disasters or demographic, environmental, or > genetic stochasticity. The term "population" rarely refers to an > entire species. > > > MVP doesn't normally mean survival of a species but it can be used to calculate this too. The reference indicates that without human management, this value averages slightly under 5,000 individuals for terrestrial vertebrates. I do recall reading that you can make smaller numbers viable through human intervention. The following is my recollection. I no longer remember the reference I got the numbers from. **At 5000 individuals** Population is viable without human intervention. **At 500 individuals** Couples can remain monogamous but mating pairs must be approved by a genetics board to ensure genetic diversity and limit in-breeding. **At 50 individuals** Each individual must have as many babies with different partners as possible over their lifetime. A genetics board must approve all matings. Couples may pair, but each couple could only conceive one child. Individuals that had paired would still have to mate outside their relationship until the size of the population grew larger and more diverse (probably not possible for several generations). It looked like 50 was the absolute minimum and that if you lost very many members early (due to accident or disease) it would endanger the whole colony. **Another opinion:** [A geneticist actually studied a *related* question](http://www.newscientist.com/article/dn1936-magic-number-for-space-pioneers-calculated.html#.VWye9EbUfA0), which was "what is the optimal crew size for a generation ship". The "optimum" was considered the smallest crew that maintained acceptable genetic diversity (I don't know what he deemed acceptable) during the ship's 200 year / 10 generation voyage. > > For a space trip of 200 years, perhaps eight to 10 generations, his > calculations suggest a minimum number of 160 people are needed to > maintain a stable population. > > > At the end of this journey, the crew must be reintroduced to a larger population with greater genetic diversity (a large destination population or fertilized egg bank to ensure genetic problems don't crop up. The article doesn't explicitly state this but it implies that without introducing this diversity, the effects of in-breeding might be large. > > "The decrease in genetic variation is actually quite small and less > than found in some successful small populations on Earth," he says. > "It would not be a significant factor as long as the space travellers > come home or interact with other humans at the end of the 200 year > period." > > > For this question, we have to consider that these numbers are *lower than the minimum* required to repopulate the planet because to repopulate the planet, our population will start with all the genetic diversity it is ever going to get. As others have suggested, you get better diversity if you hand pick the members for that diversity rather than depending upon chance. The 160 people number above considers that the members of that population *were selected for diversity*. Also note that the person creating this population could use the opportunity to concentrate perceived positive traits in humans. However, many positive traits (e.g. one of the 1000 genes affecting intelligence) often carry hidden or recessive negative traits with them. The gene screening would need to be done most carefully to avoid concentrating genes which when combined cause major negative side-effects. [Answer] People have reported, based on genetic bottleneck studies, that [last time](http://www.wikipedia.org/wiki/Toba_catastrophe_theory) it may have been around 10000 people. [Maybe not Toba's fault](http://www.livescience.com/29130-toba-supervolcano-effects.html), but [bottlenecks](http://www.wikipedia.org/wiki/Population_bottleneck#Humans) are part of our history. The amount of *variation* can be inferred, but it's hard to say how many people that means since we suppose that they were more diverse before that. Current humans might need many more individuals to achieve the same amount of diversity. If the survivors were the population of Queens NY, a small number would do. If they were an isolated village, the whole village is not enough. [Answer] In [Testing migration patterns and estimating founding population size in Polynesia by using human mtDNA sequences. *Murray-McIntosh R Scrimshaw B Hatfield P Penny D*](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC21200/?tool=pmcentrez) (1998) They have a stab at how many females initially colonised New Zealand. (Females only because they use mitochondrial DNA). > > The results are consistent with a founding population that includes' 70 women (between 50 and 100) > > > This doesn't give a minimum, but it does show a low number that worked. [Answer] Let's do some actual math to try and estimate things. First, some basic genetics. Each founding member of your population brings with them 2 copies of each of their chromosomes. There are many thousands of genes on each of these chromosomes, and the vast majority of them all work perfectly in each of us. But, due to random mutations, some people have copies of genes that don't work. Often times this is fine, because you have only one broken copy, and your other copy works and is able to compensate for the broken allele. Geneticists call this haplosufficiency. What this means is that the broken gene, or bad allele, is recessive, while the working gene, or good allele, is dominant. The bad allele only causes an issue in individuals that get two broken copies. If you have one broken copy and one working copy you are heterozygous at that locus, and you are a carrier for the disease. If you have two broken copies you are homozygous for the disease and will be affected by it. Most bad alleles are rare, because they are selected against by natural selection. A carrier for a disease gene is only at risk of having a child with the disease if they happen to mate with another carrier of the same disease. This is why inbreeding is bad. When two individuals that are closely related mate, they have a high probability of both being carriers for the same genetic disorders, and therefore of having a child with two copies of the bad allele, and therefore the disease. So, math time. I'm going to simplify things a bit for the reader's sake as well as my own, but the results should still be reasonably close to the reality. Let's say we begin with a population of size N. That means there will be 2\*N total copies of each gene or allele in our gene pool. So if anyone in our starting population of size N is a carrier for a genetic disorder, that genetic disorder will exist within our population at a frequency of 1/(2N). The frequency of the good allele in the population will be 1 - 1/(2N). Let's call these frequencies q and p respectively. Now, there are 3 possible genotypes, or genetic combinations possible. 2 good alleles, 1 good allele and 1 bad allele, and 2 bad alleles. For any randomly shuffled population the probabilities for each of these genotypes are as follows: 2 good alleles = p^2, 1 good and 1 bad allele = 2pq, and 2 bad alleles = q^2. The reasoning behind these numbers should be fairly straightforward. The probability of having 2 bad alleles is equal to frequency of the bad allele squared. Using some simple substitution we now find that the frequency of a genetic disorder which was brought into the population will be (1/(2N))^2. Let's try our formula out with an actual example. Let's say we have a starting population of 10. One of our 10 people happens to carry a mutation in the CFTR gene, meaning they are a carrier of Cystic Fibrosis. This means that 1/20 of all of the CFTR genes in our gene pool are broken. The chances of a child in the population receiving 2 copies of the broken CFTR gene and thereby having Cystic Fibrosis is 1/20 \* 1/20 or 1/400 or 0.25%. Now, this doesn't sound all that bad right? The problem is that your starting population would be very lucky if it only had 1 carrier for 1 genetic disorder in it. A very recent paper estimated that the average person is a carrier for 1-2 recessive lethal mutations: <http://www.genetics.org/content/199/4/1243.full>. If each person in our starting population was a carrier for a single different recessive lethal genetic disorder, then each of those 10 diseases would kill ~0.25% of our future population (slightly less because sometimes they would co-occur). Let's make things worse and say we only had a starting population of 2. If each of those individuals were a carrier for a single recessive lethal mutation then those bad alleles would exist in the population at a frequency of 25% and children would get 2 bad copies 6.25% of the time. With two diseases that means roughly one eight of the children would die from genetic defects. Let's make things better and say we had a starting population of 100, each of whom bring in 1 recessive lethal allele. Each of these 100 diseases would now only occur 0.0025% of the time for a total of 0.25% child death. However, this is only taking into account lethal mutations. There are likely many more mutations that could cause infertility, intellectual disability, and numerous other problems. I can't find any numbers on how many of these types of mutations the average person is a carrier for, but it's likely higher than the number for recessive lethal mutations as the selection against them would not be as strong. A few extra notes. First, these inbreeding effects will gradually decline over time. Each time a child is born with 2 bad copies of a gene and dies, those 2 bad copies are removed from the gene pool. The worse the frequency of the genetic disorders are, the faster the frequencies of the bad alleles will decrease in the population. Second, the starting population size will also determine how many generations it takes before the population is sufficiently mixed that inbreeding even begins to occur. In a starting population of 2, the first generation will need to inbreed, but in the population size of 100, many generations would go by before anyone needed to procreate with someone at all related to them. Third, when the starting population size is small the outcome will also be highly variable. The numbers I calculated above represent the average outcome assuming the population gets neither lucky nor unlucky in which alleles get passed on to the next generation, but with a small starting population size a few unlucky inheritances of bad alleles could have disastrous complications later on, whereas some lucky inheritances of good alleles could remove all the bad alleles from the population early on. Small populations would also have a high degree of chance in how bad the inbreeding becomes. While I didn't really provide you with a concrete number, I hope the mathematics will allow you to calculate your own starting population size given your definition of "relatively clean". [Answer] I think you could have the freedom to dictate the number, so long as you also dictated the genotypes of the would-be new population. The problem with the human race today–from a purely natural point of view *(which is unavoidably going to sound very nationalist-socialist)*–is that for hundreds if not thousands of years, humanity has been fighting against natural selection. We've have been striving to preserve all human life, this includes those whose phenotypes express recessive traits that make them frail, or fragile like individuals born with physical or mental disabilities, up to and including food allergies and depression. The problem with inbreeding, is that due to the lack of variation, those recessive traits are expressed more often, which results in a genetically distressed population. You specified *random* people, in your question, which would necessitate a relatively large population to ensure adequate genetics. But if the breeding population were *selected*, based on the strength of their genotypes, then the population could be much smaller, and the resulting human race would be much stronger, potentially free of all genetic diseases such as cancer, diabetes, and other ailments that often skip many generations until some unfortunate descendant's phenotype expresses the gene. Creating a genetically perfect population was the premise of the James Bond film, *"Moonraker"*. The villain in that film constructed a space station which was meant to be the home of genetically perfect couples from **each** race of humanity *(so not totally nationalist-socialist)*, as well as the launch facility which would deliver a nerve toxin capable of eradicating all human life on the planet (whilst preserving animal and plant life), leaving the earth vacant, and free to be inhabited by a new "master race of human beings. So, you have the potential to create a post-apocalyptic society that has some extremely immoral policies by todays standards, all in the name of preserving the human race and making it stronger than it was before. Think about [The 100](http://www.imdb.com/title/tt2661044/), only instead of floating people in space for being criminals, they're using methods such as serialization to preventing deleterious alleles from "infecting" the bloodlines. [Answer] I understand that the human population dropped to a mere 600 individuals, to whom all humans are related and is why humans have relatively low genetic diversity compared to other apes. I saw it on 'Becoming Human - episode 3' on youtube last night if you are interested in looking into it more. [Answer] If they're returning to Earth after the plague (or whatever) has passed, all the women in the crew (which should possibly be ALL or nearly all women) could mine the existing egg banks to obtain genetic diversity. I presume the equipment to implant the eggs would still be usable. The question of whether or not the eggs would still be frozen after three years of the refrigerator being unplugged is another thing, but this recovery seems to be planned, so maybe a UPS would help out the situation. Also, why off Earth? Why not stay on Earth in isolation? And, not that it matters, but good choice on source city. We're a good bunch. [Answer] Without being able to give you a hard number I'd say it will be very dependent on the degree of prescreening selection you can do before/during the evacuation process, the more you can screen and the more selective you can be the better off the progeny of any isolated population you create will be. I suspect that the 5000 mentioned in Jim2B's answer would be a good starting point though. [Answer] It may not quite fit the premise of your question, but if technology levels are expected to remain about the same as they are now then it is entirely possible that a very small population could maintain some sort of genetic diversity via direct manipulation of embryonic DNA. The number of couples would not matter so much as the amount of genetic material available for splicing and the number of generations the population are expected to undergo this kind of treatment. Obviously if the initial population were *very* small then 'related' individuals such as brother and sister would be required to breed. This would not hamper genetic diversity (since by design, the two individuals are sufficiently genetically different for this not to be an issue), but there could be social barriers to it depending on the cultural norms of your post-apocalyptic society. Even in this scenario there will probably be a percentage of individuals who are made infertile or die before producing children, but this depends on environmental factors I can't hope to model here. Assuming the percentage is low then it would be possible (albeit unpleasant, as above) to repopulate with as few people as one fertile couple. [Answer] The answer is simple. Unfortunately, since most of us already consist of some percentage of inbred genetics, it's not quite this easy, but this is the basic theory. You need 3 females, and 3 males. They must all be removed genetically from each other enough to do this correctly, but like the colors of the rainbow, you only need 3 primary colors to produce any other color you can imagine, even black and gray. Since humans do not self-replicate, you need 6 people instead of 3. 3 males and 3 females. But because we need both male and female, we can just say that we need THREE BREEDING UNITS. If all parents involved are removed from each other enough genetically, then theoretically it's the same as mixing those 3 colors together to get some random color, which is obviously desirable for progeny to prevent birth defects and learning disabilities. The universe loves the number 3, and certainly, tetrahedrons (triangles) are fundamental shapes. You can't have a geometric object with less than 3 sides. Try making a tables stand with less than 3 legs. No cheating with stretched, reinforced leg bases as that counts as more than two legs. Interesting huh? EDIT: btw the breeding PARENTS will crossbreed with the opposite breeding unit's progeny when they are old enough. Forgot to put that in there. Inbreeding will be had to some degree, but then again, if we just kept swapping out all of our genetics we wouldn't even be human. Some level of inbreeding is acceptable, we just are not adept at thinking outside of the "proper" box. ]

[Question] [ So, I’m creating a world were superheroes, and villains, are real and exist in the real world. Everything else is the same, like the gold depository in Fort Knox, Kentucky, which brings me to my question. Super villains break into Fort Knox nearly every year, stealing the gold and than being defeated by the heroes again. Like the time Dr. Cyclops stole famous art, millions of dollars in gold, and gallons and gallons of expensive wine. He was stopped, and the gold was returned, before being stolen again. So, my question is, why might the government keep its gold in the same place, even when it's constantly stolen by super-villains? [Answer] **Tour Ft. Knox, the world's second-biggest distraction (just behind Area-51)** You bet there's gold in Ft. Knox! Everybody knows that. Little Johnny down the street knows that! Tibetan monks in Mongolia know that. Your little sister knows that! Every intelligence agency worth a dime has proven it to themselves over and over and over. *And it's the biggest honking fraud in planetary history! Muahahaha! All y'all been fools since the 50s! And aliens! At some dusty airport in the middle of Nevada that hasn't been used in decades? Jumpin’ Jahosafat! it's been like stealing candy from a baby! We just fly those folks in from 'Vegas every morning. Treat them to the standard meal-with-a-threat moment, and ship 'em back. Nobody's the wiser!* Never in a million years has anyone guessed that the gold is actually stored in a 127-story vault beneath the Millennium Tower in San Francisco (you didn't think it's sinking because it's *unstable* did you? Gold's heavy!) It's guarded like Ft. Knox in a way that makes Ft. Knox look like my baby girl's Barbie House of Hugs. Yeah! So, let those villains steal that petty amount of gold. Good on 'em! Gives the superheroes something to do (we don't want ***nothing*** to do with 'em anyway... prima donna little putzs). We usually get most of it back, anyway. I mean, *c'mon!* You've never noticed that the price of gold *doesn't* fluctuate when Dr. Cyclops boosts the decoy? Inspector Clouseau couldn't miss that hint! [Answer] Supervillains are going to commit huge crimes *somewhere*. It's what they do. The trick is to predict them, and the easiest way to do that it to *bait* them. Ft. Knox is well-known and (in theory) highly valuable. It's one of a handful of prime targets in the country that are perfect for supervillainry. If you deprive them of those obvious targets, they'll pick new targets, maybe ones you didn't predict. [Answer] ## Plausible deniability for ransom Between abut 800 AD and 1066 AD, Viking raiders terrorized Europe. The raids reached such a pitch that local kings would pay ransom to Viking bands to leave them alone that year. In England, this was called the [Danegeld](https://en.wikipedia.org/wiki/Danegeld). I can imagine a scenario where politicians, terrified of the supervillains' depredations, pay the supervillains off in order to keep the depredations at a minimum. But there's also a political cost: the voters might not appreciate their tax dollars going to a bunch of nogoodniks. So, in order to keep it all under wraps, the Treasury puts some gold in Fort Knox, which the supervillains (or their henchmen) collect by "stealing" it. OK it's a little thin. [Answer] **TL;DR: Ft. Knox is the best place to put it.** ### Secure. Super villains break it about every year. That's costly. Still better than Joe random breaking it every month! At least, in Ft. Knox, ONLY super villains are good enough to escape with the golds, and fortunately, super heroes are willing to bring it back. ### Cost saving. > > Don't put all your eggs in the same basket. > > > It's a well-known proverb, right? The problem is that raising security to the level of Ft. Knox costs, and scattering the gold would require bringing multiple facilities to that level of security, which would cost *more*. A single facility, like Ft. Knox, is about economy of scale. ### Isolated. Imagine storing the gold in banks instead. Then imagine the collateral damage when the supervillain brings a super tank in the middle of New York City to rob the bank. Ft. Knox is nicely isolated, there's little risk of collateral damage, and no civilian life to worry about. [Answer] The government keeps Fort Knox going because they like when people with super powers break in. Because the government doesn't actually like people with super powers, whether they are "good" or "bad". So the gold is treated with Dimethylmercury when a super is breaking in. They handle it. They take it outside, they get stopped. Good guy handles the gold when he's bringing it back. Ten months later they both die, and the government's hands are clean. <https://en.wikipedia.org/wiki/Dimethylmercury> [Answer] Security testing. In a world of super-villains, the need to test your security systems in real world examples would be supreme. Fort Knox could be a testing ground for prototype defence systems, regularly restocked to ensure an ongoing set of volunteers for the trials. Defence contractors will pay big bucks to have their systems in place in Fort Knox - as opposed to being paid to install them - the test data is worth far more than gold. [Answer] ## It's part of the unwritten rules of the "game". It's plain to see that many superpowered individuals (both heroic and villainous) would cause truly catastrophic damage if they went all out and fought or schemed without limits. They also often have powers which make containing and confining them tremendously difficult, if not impossible, so it's not uncommon that the only way to really stop a superpowered for good is to kill them. However, that doesn't happen - because the heroes and villains both are basically playing by a code that says they don't try too hard, they don't cross certain red lines, and they don't have particularly hard feelings about it at the end of the day - so they can all stand shoulder to shoulder when the aliens turn up and try to enslave humanity, or whatever. Part of that unspoken agreement is that targets like Fort Knox are there for the heroes and villains to play their game around. A high value, high prestige target, without much collateral damage to cause - and better there than somewhere else unknown, where there's a greater risk of people getting hurt, etc. I should note that though the idea is generic enough, it is explored in detail in the online serial [Worm](https://parahumans.wordpress.com/) (which inspired my answer, and where the existence of these unwritten rules ends being a significant plot point). [Answer] **To avoid overworking the superheroes** *Option #1* Fort Knox is safe from non-supervillains. Its security systems cannot hope to stop super-villains, but they can stop regular people from stealing the gold. In the past, security budget was reduced because the government was happy with the super-heroes recovering the gold each time it was stolen, either from regular or supervillains. But super-heroes became overworked, and they threatened to go on strike. Finally, an agreement was reached: super-heroes would protect the gold from super-villains, but it was the government duty to protect the gold from regular villains. *Option #2* The security measures do not defeat the super-villains but they do slow them. Without the security measures, any super-villain would wake up in the morning, steal all of Fort Knox's gold and then go to have breakfast. The super-heroes would be constantly thwarting this or that super-villain attempt. With the security measures, the super-villain must be more careful. He has to study Fort Knox, look for weak spots, produce the clever hardware designs that will allow him to reach his objectives, etc. That lowers dramatically the frequency of assaults by super-villains, giving a break to the super-heroes. [Answer] Well, *there is no gold* in Fort Knox, and supervillains don't steal it. If you were a supervillain and you fell for the fraud, would you tell your supervillain friends how stupid you were? Or, would you keep telling everybody that you *had* the gold, until you were defeated by unfair means and conditions which were not your fault? On the other hand side, it is very profitable for the government to keep up the story of gold when in reality there's no gold left, the country has factually been bankrupt for over a decade, and they only keep it going by printing ever increasing amounts of worthless green paper bills. You *don't* want to risk an insurrection after your people finds out that the money in their pockets is worth nothing, right? Plus, you can always point out what awesome means you have to defeat supervillains no matter what they try, they're never permanently getting away with the gold. [Answer] Because you can't realistically hide a big pile of gold (as a government) without someone finding out where it is. So you put it in the safest place you have. Too bad if that isn't enough. [Answer] ## Bait The gold has trackers embedded within, or are altered chemically or otherwise in a way that allows easy tracking of the stolen loot from afar. The government actually *wants* the villains to steal that particular stash of gold, so that the heroes' jobs becomes that much easier. It's not their fault if the villains are consistently dumb enough to bite on the same bait over and over. [Answer] ## To maintain the seal held beneath The government would prefer to hold their gold elsewhere however the extra dimensional seals within the floors are specifically require gold to fault the opening sequence. There have been attempts to find alternate materials. The best alternative that has been discovered was rubidium however that slows the sequence rather than resetting it. Luckily most of the time when the gold gets cleaned out the rubidium backup is left alone. Records show that the opening sequence takes approximately 96 hours to begin the breach unimpeded or (based on extrapolation) approximately 34 days when rubidium bridges the power nodes. The longest the sequence has been allowed to progress was 128 hours by which point the breach is approximately 4 meters across, which is too small for outsiders to enter fully however several lives were lost replacing the gold. Everyone would be much happier were Fort Knox just another building but power makes for temptation and mistakes of the past must be paid for. [Answer] You need to keep it somewhere and a big pile gold is a great honeypot trap and not a threat to humanity. If you fill Fort Knox with gold and the best protection money can buy. You then fill it with sensors, detectors and scientific equipment so when someone steals the gold, you can work out how they did it so countermeasures can be developed. Stick some trackers in the gold to help get it back. Better to have super villains stealing gold than nukes or bioweapons [Answer] This is a bit of an out-of-left-field answer, but you could potentially accomplish this via an elaborate ruse. Here's how it goes: 1. Dr. Cyclops commits the robbery you describe in the question. 2. The US Government states that, since Fort Knox is obviously no longer secure, they're going to stop using it to store gold, convert it solely into an army barracks (I believe that's Fort Knox's *other* function), and move the gold somewhere else. The supervillains nod their collective heads. Not even the US Government is stupid enough to store gold in a place that was already broken into, right...? 3. The US Government does *not*, in fact, stop storing gold at Fort Knox. It steps up the army presence there, both to keep up the ruse and to act as extra security, but it also keeps the gold in the vaults. But now the public - and the villains - think the gold isn't there. 4. Every now and then, a supervillain will figure out the ruse and rob Fort Knox. They are invariably defeated and captured, the media report it as an "attack on an army base" rather than a robbery, and the gold is returned to Fort Knox before the villain can tell anyone where it came from. (This is why Fort Knox isn't attacked every *week* - the villains have to actually figure out that the gold is still there.) [Answer] ## Bait, ~~but only if~~ because the government is full of terrible people Disclaimer: I didn't see Brizzy's post on dimethylmercury before typing this up. But that seems a little harsh, even for the government. Line the room's walls with lead. Expose the gold to a *very* small quantity of polonium, which is considered to be the [most radioactive element](https://www.thoughtco.com/the-most-radioactive-element-608920). With a half-life of 138 days, Fort Knox can hire somebody to come in every few months and hose the gold down with a very thin layer of polonium solution. Keep a reserve stockpile elsewhere - you won't want to cash out on Fort Knox's supply any time this decade. Can't afford polonium? Try radium, which is [cheap enough to be used in luminous watches](https://mightyohm.com/blog/2012/02/feed-your-geiger-readily-available-radioactive-test-sources/), before people realized how much radiation it throws out. Regardless of your radiation source, keep the level low enough that they'll suffer [weakness, nausea, and vomiting](http://www.atomicarchive.com/Effects/radeffectstable.shtml), making them easier to catch and, if they don't get treatment, will eventually hemorrhage out and die. Since so many supers have energy-based powers (X-ray vision, laser beams, etc), there are an abundance of folks who could be spewing out [gamma rays](https://en.wikipedia.org/wiki/Gamma_ray). Even if the supervillains do figure out that they've got radiation poisoning, the source will be hard to suss out. Regardless of how the supervillain ends up using the gold, the government wins. If they sit atop it like a dragon hold, they die within a few days or weeks. If they sell it off illicitly, the buyer dies and the supervillain loses face. If some makes its way back into circulation and a bunch of average Joes start to get sick, the villain gets blamed. By the time an official investigation can take place, most of the radioactive spray will have burned off. [Answer] It serves multiple purposes. The first one is a test. Fort Knox (FK) has the litteral army guarding it. Any supervillain capable of penetrating FK will be able to deal with the nation's army, and will require a superhero to deal with. The second is safety: why try to hide it if the supervillain is going to come knocking anyway? FK is off-limits to civilians and commercial airflights (or at least safe bufferzone's could be created) so you dont have to run around saving civies or holding back. Thirdly with each theft you get wiser and get increasingly secure buildings. Basically it's a research ground to see how, where and with what superpowers the theft happens. They can even catalog "gee, we've not seen this guy/girl yet" or "Hey mister sublime mustache has gotten a goatee and a new superpower". And lastly: it makes asking the superhero's to resecure the gold that much easier. You can more easily track escape routes and follow the baddies in the direction of their Evil lair, yiu might even have a few local superhero's on speeddial for increased response. Then once it's secure you can hire the usual gold-moveall team to haul it back across roads designed for heavy gold transport. Naturally you have several failsafes to make sure these transport teams aren't baddies in disguise ready for a second stealing but because that will ineviteably fail anyways you embed a superhero amongst the crew to retrieve it the moment it's stolen. [Answer] Due to the difficulty of selling so much gold through the black market over a short period of time, it is likely that most of the stolen gold will be sitting in the supervillians' vault and can be returned upon his defeat. So the actual losses due to supervillian theft are not as great as one might imagine. [Answer] Clearly, the contractors holding the contracts to repair and rebuild Ft. Knox after said attacks are providing enough money to the Senators from Kentucky (currently Mitch McConnell and Rand Paul, although that detail may not be important, depending on the amount of direct political relevance you intend) and relevant PACs to keep that facility in Kentucky. It's worth noting that the [current dollar amounts to contractors in Fort Knox](https://www.governmentcontractswon.com/department/defense/fort_knox_ky_kentucky.asp) (the city) has been about $0.25 billion from 2000-2017. If you were to posit annual smash-and-grab attempts, this could increase 100-fold rather easily. (Note that just because one is a defense contractor in Fort Knox, KY does not mean that one is contracting for work relevant to the Fort. However, I'd place *my* bets on that assumption being true.) [Answer] This was actually gone over by supervillian Auric Goldfinger in [his eponyomous James Bond movie](https://en.wikipedia.org/wiki/Goldfinger_(film)). Yes there's a lot of gold at Ft. Knox. So much in fact, that on the whole its un-robbable. Gold is really heavy, and carting off that much of it would be a serious logistical challenge. It would take legions of trucks weeks just to get it all out. You could perhaps get that down to days with enough super-strength help, but those brutes would all need a cut too, and you aren't going to have days before the capes show up. > > Bond is recaptured and tells Goldfinger his plan to rob the gold > depository will not work, as he will not have enough time to move the > gold before the Americans intervene. Goldfinger hints he does not > intend to steal the gold, and Bond deduces that Goldfinger will > detonate a dirty bomb inside the vault, designed to render the gold > useless for 58 years. This will increase the value of Goldfinger's own > gold and give the Chinese an advantage from the potential economic > chaos. Goldfinger subtly threatens that should the Americans attempt > to locate the bomb or interfere with his plan, he will simply have it > detonated somewhere of significance in the United States. > > > You might be able to pull off a simple dash and grab of a small bit of it, but you could do the same at any bank, and they are far less well-protected. Think retirees with handguns rather than whole units of US Military with automatic weapons. Robbing Ft. Knox is for chumps who don't know what they are doing, not a true evil mastermind. Far more of a concern is villains trying to *destroy* Ft. Knox to render the entire supply unusable (Goldfinger's plan was to make it all radioactive). The best way to nip these plans in the bud is to have agents keeping a sharp eye out for anyone trying to corner the gold market (that's how a villain profits from this scheme). [Answer] They have discovered an inexpensive source of gold. Gold sold by the supervillain is never sold on transparent markets and supervillains will create chaos anyway. Even more. With every robbery the price goes up and the government sells the gold in the black market to finance their secret super-powers investigation lab. Buyers think that they are buying robbed goods and do not ask too much questions. [Answer] Because the gold itself is just there to disguise the more important artifact hidden far beneath that pile of gold. It's like hiding a needle among hay. You got the hay, you don't realize the needle. The artifact can be something that can turn a normal human into a superhero. That would make it a very dangerous artifact. [Answer] If we abandon Fort Knox, the terrorists win. Besides, why move the gold? It's not particularly important, and it's not as if there's someplace safer. [Answer] Because you have to store the gold *somewhere*. Storing it in any single alternate location would simply mean that becomes the target instead. Storing it in multiple locations means you have to protect each to the same level, otherwise the lesser protected ones become the target. And if you don't protect all of them to the same level as Fort Knox, well, you just made it easier to steal the gold because it's in less secure locations. [Answer] **Magic** Most superhero worlds have some sort of magic, many have more than one. Assuming this world is the same, there are two different, possible, magical reasons that Fort Knox needs to stay where it is. **High Magic required** Fort Knox sits on the second largest ley line nexus in North America, eclipsed only by a nexus centered over a small island in Lake Michigan (not suitable for a large fort). Fort Knox needs the nexus to power all of its magical defenses. In addition to the thick walls, cameras, guards, et cetera, the Fort also has various guards, wards, and seals. They not only protect it from various types of magic, they also make the physical walls stronger and self-repairing. That's why Doctor Gauss occasionally sweeps through and take the gold with his meta-magnetic powers. But Klepto-Chango cannot just teleport into the vault, fill her top hat with gold, and then pop back out. The spells prevent her from doing that. **Null Magic Zone** Rather than a high magic zone, the fort is built in a null magic zone. This actually serves two purposes. First, magical villains are severely weakened in and around the fort. But that, and the gold as well are just a front. The real reason Fort Knox exists is to store magic artifacts. The Ark of the Covenant, the Necronomicon, the Eye of Vecna, all are stored under the gold depository. They can't be destroyed, either because they are indestructible or because they are needed for certain specific incidents. So instead the government stores them. Because there is no magic in the area, the artifacts are dormant. And since everyone thinks the Fort is just for the gold, no-one considers that there might be something else there. [Answer] # What Gold? The immortal Lord Ra stole the gold back in the 20's. THERE IS NO GOLD RESERVE. Everyone accepts that there is a gold reserve, therefore the system works. They look at the piles of gold-colored bricks in Fort Knox, and all the other major reserves around the world, and they accept. I mean, the Illuminati would go bankrupt if the global economic system failed! Meanwhile Lord Ra sits in his pyramid in the middle of the desert atop 90% of the world gold supply and gloats. Everyone who carries out a big gold heist finds themselves with a pile of fake bricks and figures they've been hoodwinked. ]

[Question] [ In my world there is a forest of huge trees which people can't or won't chop down. The trees are similar to redwood trees but they have a large crown and no lower branches. The forest is quite dark because the trees block out most of the sun. Due to the low light-levels, barely anything grows on the forest floor. People are scared of the dark forest so it has become a refuge for bandits and other criminals. The forest is habitable but growing food that requires sunlight is impossible. There is no cultural reason the trees are unable to be harvested, people have tried for a very long time. **There is clear motivation to harvest the trees as the wood is highly valuable.** My world is inhabited by humans with roughly 11th to 15th century technology but no gunpowder.[](https://i.stack.imgur.com/pZwAo.jpg) The older trees are the size of the trees in the picture and the forest floor looks similar to the picture. [Answer] The most likely reason would be that they simply don't have anything that *can* cut them in your scenario. You say that the trees are highly valuable, so there's a high motivation to cut them down. This suggests that no matter how difficult it is, the reward is worth it. So, the only other possible reason to not be able to cut them down is going to be technology. In the 11th to 15th centuries, metallurgy was nowhere near as advanced today. Your best bet would be to make it so that their metallurgy is on the much lower end of what we could do during the same timeframe. Namely, that they cannot produce a steel hard enough, yet flexible enough, to cut the trees without breaking their teeth. You could make the problem even more difficult for them by assuming that the wood of these particular trees is extremely hard and dense, something like teakwood in our world, but of an even higher level. If you want to get very fantastical, you could even say the trees' wood is a form of carbon that is like diamond (or is diamond itself), and thus extremely hard. So here is a possible scenario for you: * The trees are extremely hard and dense. This is because they need to be to support their immense height and mass. The locals have taken to calling them "diamondwood" because they're "hard as diamonds." This makes their wood highly valuable for all sorts of construction. * Unfortunately, the trees are hardest when they're alive, and the poor knowledge of how to make good steel means your civilization is limited to either very soft or very brittle iron products. * Many have tried to cut the trees, but their diamond skin either immediately bends the teeth of their saws (for soft steels), or strips them off completely (for hard steels). * Because of this, the only way they've been able to harvest diamondwood is to wait for a tree to fall naturally and dry for several months. This makes the wood soft enough to cut, but still strong enough to be valuable. * The wood-hunters who look for these trees often have valuables on them that the bandits want to rob them of, so they're forced to hire bodyguards for protection. [Answer] Underneath the outer cork-like layer of bark, the trees have a second foam-like layer. The cells of this layer are filled with a [volatile](https://en.wikipedia.org/wiki/Volatility_(chemistry)) liquid (in the chemistry sense - meaning it evaporates easily) which the tree uses to help boost water and nutrients up to the crown. Unfortunately for your would-be loggers, this liquid, once it evaporates into a gas, has some *interesting* side effects. Hallucinations, et cetera. Combined with the slight hiss of the outgassing liquid, this convinces everyone near a damaged (i.e. cut) tree that they are under attack by snake demons, and run away in fear! The tree is then free to heal its small nick in peace. [Answer] People get the wood. The trees are cut. They are just not cut down. There is no need to cut them down. Your forest is a **pollard forest**. <https://en.wikipedia.org/wiki/Pollarding> > > Pollarding, a pruning system involving the removal of the upper > branches of a tree, promotes a dense head of foliage and branches. In > ancient Rome, Propertius mentioned pollarding during the 1st century > BCE.[1] The practice occurred commonly in Europe since medieval times, > and takes place today in urban areas worldwide, primarily to maintain > trees at a determined height.[2] > > > Traditionally, people pollarded trees for one of two reasons: for > fodder to feed livestock or for wood... > > > The trunks of these trees are huge and very difficult to handle with the tech available. But upper branches are the size of normal trees and can be dealt with. Woodcutters ascend to the crown and cut tree sized branches, which fall to earth and are hauled away: pollarding. The loss of some branches is not a big deal to a tree this size. Some trees have ladders installed on them to facilitate repeat collection of branches from the same tree. Plus, as with pollard forests, branches are a sustainable resource. The tree will grow them back. [Answer] **Diseases or toxins** Maybe the forest is a hazardous place due to various diseases thriving in local flora or fauna for example Malaria mosquitos. Bandits would not be immune, but well maybe they have little other choice than to soldier on. Or the trees are dangerous. Perhaps there's no problem if you leave the trees alone, but if you start chopping them down they release various toxins that kill people. Similar to how bronze smiths in ancient Egypt would often die due to arsenic poisoning (they inhaled the fumes). That way whilst the wood might be very valuable, it would also be a pretty big health risk for the woodchoppers and carpenters. The end users would probably be safe as they wouldn't inhale any saw dust. That said this would make the trees known as the trees that kill people. Perhaps people will even think of them as cursed. [Answer] Cutting a tree down is just the first step, then you need to remove the wood from the cutting place and move it to somewhere else, be it the place where it will be used or a place where it can be disposed of. Already cutting down such a large tree is challenging for the tech period you have specified, then, once it is on the ground, you need to cut it in smaller pieces and transport it. It is a logistic nightmare if you don't have roads and means of transportation. Long story short, there is not advantage in cutting them down: smaller trees are easier to handle. [Answer] # Lack of industrialisation The trees are too big to be handled without a large team of people and draft animals. There's no river nearby to float them down. The tools required to efficiently cut one down are too expensive for your average woodcutter. The wood is too hard to be valuable for day to day use and it doesn't burn well. They're not blocking the route between important locations. The land they're on is not particularly good for farming. There's no task that requires a tree of that size. There's just no good reason to try cutting them down and no way of handling them once cut. In fact they'd be more of a problem once down than they are up. [Answer] Dangerous animals live in the tree canopy. They won't bother humans if the tree is left alone, but if they sense their home is being threatened, they will attack. If their home is destroyed, the homeless ones will go berserk and go on a killing rampage until they are put down. These animals could be anything. Tree-dwelling grizzly bears. Giant killer owls. Extremely venomous wasps. But if dozens of humans get mauled/pecked/poisoned to death every time a tree gets cut down, that's not going to be worth it despite the value of the wood. [Answer] Similar to @Chronocidal's answer, but instead of volatile liquid enclosed in cork-like outer layer, make the tree's interior high pressure near the base because of the weight of the tree pressing down upon it. Now make the outer layer brittle and prone to shatter into sharp aerodynamic splinters. First touch of a sawtooth to that brittle bark and the whole tree goes off like a 360 degree claymore mine. The villagers tried to cut down a tree once... exactly once. [Answer] > > **There is clear motivation to harvest the trees as the wood is highly valuable.** > > > I assume then, that *some* of these trees have been and can be harvested, so. # The trees are sticky. These massive trees contain an equally massive amount of **exceptionally viscous, extremely sticky sap,** which oozes out after you break through the hard bark. The sap is tougher and thicker than tar, and once it sticks to something, it's stronger than super glue. Trying your saw or axe on one of these trees is as good as throwing it off a cliff: you'll never get it back, no matter how hard you yank on it. It's **dangerous** to even attempt to harvest one, lest your arm or leg get caught up in the sap, leaving you an amputee. *This also makes for a really cool visual, with broken axe heads, saw blades, and human bones protruding from the bottoms of trees at odd angles.* No known solvents or substances seem to be able to dissolve any substantial amount of the sap, leaving only one option for harvest. When an ancient one of these trees finally dies and falls, it remains unharvestable for a year or so. The wood only becomes safe to cut once all the sap hardens into a rosin-like substance, which can be chipped away with pickaxes. This natural scarcity, combined with the hardness, supple texture, and rich color of the wood makes it highly sought-after by nobles the world over (and drives many a young woodsman to forfeit his first axe, dreaming of riches). It *also* serves to explain the roving bandits, who patrol their territory of the woods, waiting for new trees to fall, guarding their claims and even fighting over trees that haven't quite dried out yet... [Answer] The trees have guardians. The forest is inhabited by 9ft. tall (~3 meters) primates, much stronger and tougher than humans. There are large numbers of them. Those beings are herbivores, and will leave humans to their own devices most of the time. It just happens that the tree sap smells exactly like the pheromone the females release when they are in heat. That drives the males into a mating frenzy. They can smell it from miles away. When a female releases the pheromone, the males will turn the attention to that particular female, which will be both: * accepting; * able to withstand the male's hard... er, love. When the smell is coming from the tree sap, though, it is because an oblivious human has driven a axe into the trunk of a tree, and the human is usually neither accepting the giant primate males' love, nor tenacious enough to receive it unharmed. Anyway, the mating frenzy of the males makes it impossible to cut a tree. Every other generation there is an idiot who doesn't heed the warnings and tries to take down a tree. They become "those who can never sit again", serving as living warnings to the rest of the tribe. [Answer] Toxins, a different approach: When cut the trees release a slow toxin. This manifests as homicidal madness after a while. Given the lag between exposure and insanity it isn't realize it's a toxin and thus they don't even try to block it. (Which doesn't work very well, anyway, as it's gaseous and works through skin contact. You need chemical warfare gear to survive it, something that doesn't exist at your tech level.) [Answer] The trees are alive and conscious. Think [Narnia](https://youtu.be/yLDGLZbB7aI?t=95) trees that are awake. Humans walking around are just like ants on their toes. They ignore them. But as soon as humans start a nick in the skin of the tree, they become quite vicious, (like humans once they detect a mosquito). They could use their roots or branches. Every time humans tried to cut a tree, no one returned. Even the bandits inside the forest died because the trees are quite paranoid. So now, the bandits protect the trees fiercely. [Answer] # The wood is only valuable if the tree dies of natural causes. At the end of the life of the tree, some chemical process makes the wood extra strong. If you cut it down earlier, you get only normal wood. So there is no incentive to cut the trees early because you risk that the wood becomes worthless and you also don't want to cut them down for space because then you wouldn't get the expensive wood later. [Answer] **It just isn't economical** The trees have a very expansive branch network, and the branches of nearby trees are interwoven. Since those interwoven branches are also very strong, they are able to support the weight of the tree even if the base is removed. If someone wants to cut down such a tree, they have to, after cutting it down at its base, go along the upper half of its trunk and cut down the branches that are now keeping the tree upright. If you have a team of experienced loggers that are also experienced alpinists, this process still takes multiple days, and is filled with casualties. And you have to pay a lot of money to get a team of professionals to do something that will kill at least a few of them in the timespan of a few days. Furthermore, the expensive equipment used for climbing the trees, and the expensive lumber that is up for grabs at the end of the process attracts all kinds of bandits, so you have to pay through the nose for security too. When getting it out of the forest, you can't even rotate the trunk because other giant trees would get in the way, so you'd have to drag something that weighs a few hundred tons in the direction that it fell, even if the terrain in that direction isn't favorable. So you have to cut it up into smaller pieces, which reduces its value. That also requires labour, and the labour has to be at least somewhat qualified, to prevent ruining the wood. After all that is taken care of, you have a sizeable workforce of at least a few dozen people, most likely more, that still needs to be fed, and the encampment isn't anywhere where food can be grown (it's dark in the forest). So you also have to import food (and other things required for living) for them, and the caravan also needs protection because of bandits. [Answer] They can't be cut down because they're bottle rockets writ large. Their core is a form of solid rocket fuel. As long as an unripened tree is safely encased in their stony bark they're 99.99999% proof against being touched off unintentionally - even a direct lightning strike is unlikely to affect them - and if it does it'll most likely cause them to "blow up on the pad", leaving a huge clearing in the forest. But when one gets fully ripe and the right conditions occur the tree will self-ignite, rise to great altitude, and then explode, scattering its seeds to the winds - and in the case of exceptionally large trees, to the stars. However, if one dies and falls naturally, after a few years the volatile components of the fuel will evaporate or be chemically neutralized, rendering them (relatively) safe to handle and hardening the "wood". Naturally, in the past the unknowing and the foolhardy have attempted to harvest the standing trees. They've generally died in a large explosion or, in rare cases, by being baked in the exhaust of a successful launch. After a while the standing trees are seen as "cursed" by the natives, who avoid them like a flaming plague from hell (which, in a way, they are). See Larry Niven's classic story ["A Relic of the Empire"](https://larryniven.fandom.com/wiki/A_Relic_of_the_Empire). [Answer] Gain to effort ratio is very low. You would need to cut those trees. We know from historic videos like [This recording of cutting down trees in 1940](https://www.thevintagenews.com/2018/11/24/1940s-lumberjacks/) it was a large logistic setup before. And from old photos we know it took dozens of men to cut those gigantic ones tree with "analog" equipment. Using same equipment a "triad" of workers could cut in one day a truckload of trees. As shown in this video [Logging in 1950s Georgia](https://www.youtube.com/watch?v=BStXIvJGYHU) . Which produced much more workable wood. Easier to cut into planks, fire wood, building materials. Also because of the size it's easier to use smaller tools to work with them. Smaller axes, smaller saws. And that means those tools could be used in much more occasions. Cutting axe could be also used to split firewood. Handsaw could be use to cut planks to desired size. Which means there was less resources wasted. Also if you look into Europe almost every big tree is equalled to old one and old big tree usually have some legend behind them to why they are so old and big. And that legend itself prevent people from cutting them down. [Answer] **BAD things happen to anyone who threatens these trees!** Upon examination, it's clear from scars and regrowth that there have been attempts to cut down a few of these trees, over the years. Less clear is who made those attempts and whether any of the gruesome stories or songs have any factual basis. If you're foolish enough to bring an axe near these trees, you'd better have *everything* you need to survive until you're well clear of the forest -- and excellent defensive skills. Although there's not, in fact, much honor among thieves, there is a ruthless pragmatism to their actions. In this forest, if you're seen to threaten a tree with axe or fire, you're bringing a painful, remorseless death on yourself and anybody near you. And if you're lucky, the human residents of the forest will kill you relatively quickly. If you're still foolish enough to persist, study parasitic wasps from Old Earth and see the Earther flat-film called "Alien." Trust me, you *really* don't want to meet the special seeds these trees can produce when they feel they need to; it's a long and agonizing final career to be 'volunteered' to be a host of a new tree. Enjoy your stay in the forest. [Answer] I remember a story in Analog years ago about a colony on a planet with huge trees of beautiful, very strong wood. The only practical way (in theory) to cut down the trees was with lasers (because they were so large -- saws were not practical), but the smoke produced when these tools were used was enough to block the laser beam almost immediately, so the trees, given the manufacturing capabilities of the colony, were effectively unfellable. [Answer] You pose an interesting question with a few intricacies as far as I can tell they are: * Big Trees, that can't/shouldn't be cut down * Dark scary forest where less reputable people has come to inhabit * The people living there **THE TREES** > > In my world there is a forest of huge trees which people can't or won't chop down. The trees are similar to redwood trees but they have a large crown and no lower branches... People are scared of the dark forest...There is no cultural reason the trees are unable to be harvested, people have tried for a very long time. There is clear motivation to harvest the trees as the wood is **highly valuable**. My world is inhabited by humans with roughly 11th to 15th century technology but no gunpowder. > > > I take a few things from this, the trees are large and valuable, ok. What makes them valuable - in order to create the logistics to harvest them there would need to be an economic cause to do so. This leads into why they can't be harvest - if they were incredibly dense (like an Ironwood) they would be great for building large buildings (beams and the like) as well as furniture. Smaller pieces would be more easily managed even with the tech your world has readily available. However, they (without great effort) can't do so as it would take teams of workers to make it possible to man the tools, fell the trees and then subsequently delimb and transport them. This leads into the next problem **Dark Scary Forest & The People Living There** > > ...The trees are similar to redwood trees but they have a large crown and no lower branches. The forest is quite dark because the trees block out most of the sun... People are scared of the dark forest so it has become a refuge for bandits and other criminals. There is no cultural reason the trees are unable to be harvested, people have tried for a very long time... > > > You say there is no cultural reason that the trees cannot be harvested. It sounds like you have a blank canvas to create a cool sub-culture (see Robin Hood with Kevin Costner). This subculture could potentially create a small tree city and make it so the "outsiders" have cause to not come in asides from "that's where those scary people hide". Additionally, if the trees are quite dense and strong, with some hard work these bandits could come together and make a city in the trees - cut the tops off the tress and have sunlight and suspended gardens (a landbased system based loosely from the [Aztec people](https://fourstringfarm.com/2014/04/01/the-floating-gardens-of-aztecs/)). This takes care of sustaining the "bad guys", culture and provides your reader with an understanding of why this wood is so valuable. Taking into account all these things the economic need and demand for these trees should be too large to motivate some Lord or something to start trying to harvest them. This could be why, the can't be cut down not cultural but economic barriers. [Answer] **Cones** Make your giant trees produce giant cones. Anyone standing below the tree is prone to be hit by big, heavy and hard piece of its reproductive organ. In addition, make in a way a heavy bang from an ax or the vibration from a saw makes dozens of those things fall at once making the lumberjack working area a very hazardous one. Imagine the scene: A few lumberjacks are sawing the tree while observes are alert for fallen cones. One shouts "Incoming!" and the lumberjacks run for their lives while 50lbs pieces of hardwood fall like a deadly rain around the trunk. Of course, they can send prisoners/slaves to try to hit the tree to deplete it from ammo but they can quickly run out of manpower making possible to just cut down one every few months/years. Quickly enough to keep the wood as a commodity but not fast enough to threaten the forest. Scene: A few lumberjacks are using a lengthy saw and axes to try to cut down the immense trunk when an alert observer shouts "incoming!". In an instant dozen, men are running while a deadly rain of heavy hardwood fall around the trunk [Answer] **Those aren't ordinary trees** As an alternate version of Chris Happy's answer, the trees are intelligent and powerfully telepathic. They don't mind when a human carts off a fallen tree or cuts down a standing dead one, but people who attempt to cut down a live tree are never heard from again. [Answer] Superstition is superstition. Culture is culture. Because there are many people that are superstitious of the number 13, or believe ghosts are haunting their pantry doesn't mean those beliefs are cultural values of a society. Culture is learned. Superstition is born of ignorance. Who says the disease has to be non-existent? There could be a very real disease that the bandits have developed an immunity to. Since we are talking 11th-15th centuries, most disease was attributed to demons and such. [Answer] Or the trees fight back. Whomping willows come to mind... [Answer] Like the Acacia cornigera, your trees might have symbiotic relations with agressive, eusocial, territorial animals, like the acacia ants. These animals feed on the sap or some other product the trees make readily avaiable to them. In return, these animals, which we might call gardeners, protect the trees from herbivores and lumberjacks, vines and mistletoes, and destructively scour the surrounding ground for seedlings that could come to compete with their host trees if they were allowed to grow. The survival of the host trees is just about the same as the survival of the colony so these gardners will go to extreme lengths to protect their trees, sometimes even sacrificing themselves. ]

[Question] [ An interstellar spaceship carrying a thousand personnel was attacked by a group of space pirates while crossing the nebula. The nearest habitable planet is several light-hours away. Help will only arrive in the next 12 hours and the spaceship's main propulsion drive had been sabotaged and unfortunately the antimatter containment unit is failing fast. Seemingly the weapons are useless against the space pirate's energy shields. The captain has decided to initiate the self-destruction sequence and therefore issued an order for all crews to evacuate to the nearest escape pods. I was wondering: wouldn't it be better to simply transport the crews off the spaceship instead of having everyone panicking and running around in a chaotic manner? Suppose the transporter is intact during the entire engagement with the space pirates and it is being disabled upon sounding the ship's alarm. [Answer] If the antimatter containment is failing then power would be failing also. Escape pods wouldn't require power. They are also located all over the ship and the vast majority of the crew could reach one and escape in less than a minute. A transporter system would be located in one part of the ship and at best transfer a handful of crew at a time. If the power supply is flickering, it might even stop halfway through a transfer. It's the same reason why you use the stairs instead of an elevator during a disaster. [Answer] Transporters have a short range. (If they had a long range, you wouldn't need the ship). Enemy ships like to attack when nothing else is nearby, and mechanical failures and natural disasters happen whenever they happen, which is likely to be in the middle of nowhere. Crew can abandon ship into escape pods and wait for rescue - even if the rescuers are the attackers, that's better than nothing. If you abandon ship with a transporter, you can ONLY go to a habitable planet or friendly ship within range. If there's not one available, you die. Ship designers could not make that assumption for anything more mobile than an orbital station. Transporters are also uncommon in most sci-fi excluding Star Trek. They only existed there because transporters were easier for the real-world special effects people than showing the ship or a shuttle landing on a planet every episode. Plot-wise, they tend to create problems, and technology-wise, they're hardly inevitable, so no special explanation is needed for why even a very advanced civilization doesn't have them. In other words, they might just not exist, but anybody who can build spaceships can build escape pods. [Answer] Been in a tall building lately? Did you notice the signs saying things like "in case of fire, use stairs" or "in an emergency, do not use elevator"? While there are other associated safety issues around heat containment, a big part of the reason to not use elevators to evacuate a burning building is that elevators require power to work and, if power is lost due to the fire, you *really* don't want to be stuck in an immobile elevator. Transporters require power to operate, too, and it's a pretty safe bet that getting stuck in mid-transport when power goes out would be substantially worse than being stuck in an elevator during a fire. Simply ceasing to exist when the transporter goes out is the *best*-case scenario... [Answer] Perhaps the transporter requires a lot of fine tuning before it's safe to use. If used recklessly, without several careful minutes of plotting probability vectors, the device could put the person or object several AU away from the intended destination. Or maybe the transporter is very resource intensive, and is only utilized to send small groups from place to place. Using the transporter to evacuate the entire ship would require more energy than the ship could supply, even if it weren't about to explode. In this situation, maybe it is actually utilized, but only about 20 people manage to get out this way. A third alternative could be that the transporter device was originally installed on ships specifically as a method of evacuation. However, early designs were faulty and the transporters would kill most who used them outright. Now, modern transporters are far safer, but the social stigma remains. People are being ordered to evacuated via the transporter, but the crew is not going anywhere near it, heading for escape pods and not listening to their superiors. This could result in further complications, as the escape pods become overcrowded and the chain of command breaks down. [Answer] > > the antimatter containment unit is failing fast > > > Assuming that the pods have an adequate shielding against gamma rays, they are going to be the only decent place to stay in the coming minutes. Once the antimatter containment fails, its content will come in touch with the ship. In a matter of nanoseconds there will be a huge production of energy in the form of gamma ray, which will wipe out the surroundings and probably disturb any EM signal (including were-porters). I doubt porters can still materialize objects once the porters themselves have been vaporized, and I guess nobody in the crew wants to live as a peregrine EM wave in the nebula. [Answer] No captain will order evacuation of his ship without good reason. Either a catastrophic event is taking place (either from battle damage or from sabotage/accident) or the ship is in immediate danger of falling to enemy hands (thus with all its access codes, secret orders, communication frequencies etc). In both scenarios, available time is limited to a few minutes at best. Having the crew proceed in an orderly fashion to the hangar bay to board the available transport ships takes too much time, especial in larger ships - assuming the hangar bay is still accessible and operational. On the other hand, escape pods are designed to be all around the ship, in all decks, easily accessible withing seconds (or couple of minutes) from all stations. This causes the evacuation to be completed very fast. Now in your example, the instant your captain issues the self destruct sequence to start, the ship's computer issues a million commands throughout the ship's systems. Overloading power grids, opening various compartments, rerouting power, or even start a sequence of controlled explosions that lead to a bigger one. The moment the self destruct mechanism explodes, the ship will be ready to sustain the maximum possible damage in all compartments, to ensure complete destruction (or as much as possible). In my opinion, the hangar bay will be sealed from operating and allow smaller ships to flee. In the hangar there are a stockpile of ammunition and fuel for the ships, thus making it a perfect target for an explosion that will cause huge damage to the main ship. Thus, the escape pods will be a preferable solution. [Answer] Since nothing is said about what "transporter" means, I will assume it is something like in Star Trek, a sort of matter-to-energy conversion of the object/person to be transported, some sort of energy beam, and some sort of magical reconstruction of a living being at the sub-quantum level. Including, uh... the person's soul, or whatever. The first obvious reason against using such a device in the middle of a battle would be that rapid movement, harsh manueuvers, nearby high-energy explosions and randomly interfering high-energy beams or electromagnetic pulses may not be what makes the process of transporting precisely safe. That doesn't even consider the possibility that a pirate would probably have a transporter scrambler. The Klingons do have them in Star Trek, sure enough. Assuming a starship is operated by an antimatter reactor, the antimatter containment field would be designed to be the absolutely **last** thing to fail, for the rather obvious reason that a failed containment field is certain demise. Which means at the time of the containment field rapidly failing, you will already have less vital systems (such as life support, shields, and... transporters) failed long ago. That's especially true for systems that consume a very non-neglegible amount of energy. Assuming that shields are still intact, you would however still not be able to use a transporter because the whatever-it-is transporter beam cannot pass shields. How do I know it can't? Well, because if it *could* pass shields, pirates would rather take your valuable ship intact rather than shooting at it until it is at the point of disintegrating (doesn't make much sense if you want booty, eh?). They'd simply transport a hand grenade onto the bridge, killing the crew and leaving a mostly-intact ship. That means in order to transport the crew off the ship, you necessarily have to lower whatever shields you have left. This means the ship will be torn to pieces by the next bolt/ray/torpedo hitting it. Then of course, you are possibly within reach of a habitable planet, but quite possibly *you are not*. What do you do if there's no good place to transport the crew to? Assuming there is a location where the crew can breathe and won't freeze to death within minutes, what do they eat during the next... let's be *very optimistic*, 3-6 weeks until help arrives? How would someone even know where to look for them? A rescue pod addresses all these issues. It is devil-may-care autonomous, it has breathable air, there is some food and water as well as medical equipment, and is able to send a distress signal. [Answer] > > wouldn't it be better to simply transport the crews off the spaceship > > > Transport to where? Into the empty void of space? Thats certain death. habitable planets are a rarity, and you have even said that help is 12 light-hours away. That means there simply isn't anything in transporter range. The only option would be to transport the crew from where they are currently standing into the escape pods. However, the escape pods are a *last resort*. The ship is already failing. power could go out any moment due to the damaged core.The batlle with the pirates has damaged a lot of systems. transporters are an intricate piece of technology, the slightest malfunction can be fatal. Its a little bit like elevators and fires. you don#t use an elevator when the building is on fire because it might already be compromised. You don't use the transporters for the same reason - the are no longer safe to use, and running on foot to the nearest escape pod is the safest solution. Another problem is throughput. While it might be possible to transport a few people at a time, transporters might simply not be able to mass-transport several hundred people *at once* from all over the ship. Furthermore, your assumption of panicking and chaos might be wrong. The crew of a spaceship is likely well trained and has regular safety exercises in order to ensure an orderly and timely evacuation. [Answer] The Star Trek answer is that some teleporters are simply unable to transmit through shields; the shield can block or interfere with the teleporter's beam. This is as useful as it is a hindrance, because although it makes it harder to escape, it also makes it harder for the enemy to teleport a bomb into your captain's chair in the middle of a battle. [Answer] As all the other answers have said, it'll all depend on your transporter technology. To add a possibility which hasn't yet been covered, transportation a la Star Trek takes around 5s. Transporter rooms in Star Trek seem to have 6 platforms. If that's the limit of the transporter's simultanous transport capacity, then it'd take a little under 14 minutes to transport a thousand people. If you've got 14 minutes spare, you've probably got time to try to fix it. If you've not got 14 minutes spare, escape pods (or lifeboats, or personal protection suits, or personal shields, or whatever) are the best way to get all those people to safety. Of course Star Trek plays very fast and loose with transporters, just as it does with everything else science-related. (The book "The science of Star Trek" should really just have one sentence: "It works like that because the plot needs it to do that.") But if you're trying to be more hard-science about your teleporters, this would be an obvious answer. The design of the spaceship will be influenced by this too. Various people have pointed out that if transporters in Star Trek had unlimited capacity, the lifts and corridors would be redundant. Each room could be entirely sealed, and crew would only use transporters to get from place to place. Even with limited transporter capacity actually, this leads to a different model of spaceship. The weakest point in a sealed vessel are any holes to get things in and out, so if you have transporter technology then you can completely eliminate doors. Maybe you'd have to wait a few seconds to get transported, but that's something people would adapt to. The only access points then would be for electrical and life-support cables/hoses, which of course are much smaller, so the design would be much safer than trying to seal a 6x3 doorway. Mostly you can talk to your colleagues with screens and intercoms, and the transporter system will handle the times you need to get from room to room. If there's an emergency, each room can be cut loose to form its own self-contained lifepod, or a room which poses a threat to the ship can be ejected. [Answer] It's all about dramatic impact. Crew escaping the damaged in escape pods can be seen escaping. They rush into the pod. The hatch smashed shut prior to launch. Their lifepod is ejected into space. Sound effects, figures reacting to the acceleration. The crippled ship can be seen exploding at that final dramatic moment. Exciting stuff. Now if they escape via the transporters (and for convenience it is assumed the transporters can teleport crew the light hours to the nearest habitable planet) everybody just queues up and disappears in a shimmering glow. It will take hours for the light from the exploding ship to reach the planet and by then it will be too small to be seen. Less than exciting stuff. They might as well pack a picnic lunch. Also, if the teleportation doesn't have the range to reach the habitable planet, naturally they will head to the escape pods. Mostly this is a question of applying commonsense to be able to answer this question. Of course, the real life explanation is simple. The authors, if it's prose fiction, and script writers, if it's on a visual medium, rarely think through their worldbuilding sufficiently to know what choices they have to allow the crew escape in safety. Film and tv producers know escape pods will always win the dramatic department. **PS:** A well-trained crew won't panic chaotically. They will have rehearsed their escape drill many, many times. To survive they will go to their appointed stations to either board their designated escape pod or teleportation transmitter. That's what's shipboard discipline is for: to ensure disasters in space can be dealt with safely. [Answer] The transporter works both ways. When you send people out the pirates could send people in. Then you have boarding troops on your ship while you try to get clear. This would be chaos and desaster. better to disable the transport device and play russian roulette with the pods And this is the other question: why pods? Wouldn't be life raft/boats be the better option? A pod might have limited propulsion maybe it turns to the neares habitable planet or station and ignites its drive. A boat will give the crew the means to maneuver. In case of your situation when the ship is destroyed the price for the pirates is gone. But hey look the void is filled with slaves in shiny capsules. With life boats not all but some of the crew might flee. [Answer] Are you talking about teleporters? I'm not aware of too many examples of this technology outside of Star Trek so I'll use this - Outside of other people's answers (short range, possible inhibitions like ship's shields, resources etc. ) there's also the following: In an emergency evacuation, you need the simplest, most efficient solution. Just get to the escape pods and blast them off somewhere away from the ship. The transporters can only send a few people at a time, and depend on the ship's systems being working, not to mention, a technician/engineer kind of person to operate the transporter. (You also need somewhere to send them and to know it's safe before you begin the evacuation) You can imagine the disappointment one everyone's face - the ones in the middle of being beamed *and* the ones in the massive queue leading out through the transporter room door and down the corridor - as they watch the warp-core exploding and the walls of the ship are flying apart into the vacuum of space, fire all around them, when the transporter engineer says, "Sorry folks, that last explosion knocked out the power to the transporter buffers, guess you better get repenting your sins... " [Answer] ## Because transporters require too many ship's systems online Transporters need lots of stuff: massive energy, engine taps if needed, antennas, computers for analysis, and very good sensor data so you don't beam a party down 100' above the ground. Evacuation procedures most certainly presume that the ship is too damaged to be able to reliably run transporters. What's more, they can't presume a survivable destination reachable by transporter. I'm sure there'd be a page on it in the manual, and some training given to it, but it's not the expected/likely case. ## No panic, unless it's a civilian liner. In any para-military/Starfleet type service, ***every*** crewman will be well trained on all sorts of emergencies, including damage control, firefighting, etc. Long experience is that damage control expertise [saves ships](http://www.hoover.org/research/battlestations-us-navy-and-damage-control), and incompetence costs them. Doomed ships and evacuation will be part of that training. Crewmen will know what to do, where to go etc. and sailors reading your book will get annoyed if you portray it as otherwise. ## *You bet* they set the auto-destruct Last thing you want to do is fail to set the auto-destruct, look back at the inevitable, only to say "No boom?" And have the captain say "No boom." While you try to find "reverse" on an escape pod. (Can it even do that?) This means either the condition self-extinguished, good design factors saved the ship in an [unexpected](https://en.m.wikipedia.org/wiki/Cornfield_Bomber) way, some crewmen left behind found a way (possibly sacrificing their lives), or James Bond slipped his restraints. You get to watch as the enemy takes your ship. No thanks. Even if the ship is doomed, you still set the self-destruct. [Answer] Consider this: you're on a burning/sinking cruise liner or oil rig. You can don a survival suit and jump over the side. Or you can get in the lifeboat. Which one gives you a better life expectancy? Which one's got food and water in it? Which one's got a long distance rescue beacon? The former is analogous to transporting the crew out into space. The survival suits are space suits. They are wearing space suits, right? That'd be a good start. The latter is analogous to escape pods. [Answer] **The battle doesn't stop when you say time out.** If there was a planet nearby which would support the crew for a short time. The evacuation requires sending 1000 men with weapons and equipment into a single area with good visibility cover and large enough for 1000 men. If you are teleporting it may have to be level and free of obstacles that someone is teleported into. The escape pods would be able to survive space and I assume would protect against a hand held weapon in a fire fight, solving the issue of cover. Being in escape pods must be safe for a period of time, either due to speed or shields and would allow time for the leaders to form a plan. The escape pods would allow you to land on another side of the planet if the transporter requires a clear line. [Answer] Simple explanation the captain's not going to self-destruct his ship for no reason at all. Once you establish a reason for why he is self-destructing his ship it's easy to come up for a reason why the teleporters aren't working. If he was attacked by an enemy perhaps the enemy is jamming teleporter technology. Or perhaps his teleporters were damaged in the previous conflict. Alternatively could be more practical scenario maybe his ship only has enough power to teleport a couple people so it's more practical to use space pods [Answer] Because you can't know in advance what kind of threat the ship might be facing, so in order to give people one single action to perform when that klaxon goes off, you have a protocol that specifies that personnel take to the lifeboats. Then there's no delay while the crew waits to hear whether they're going to report to the lifeboats or the transporter, no agonizing over "my section took a hit when they announced the evacuation procedure and blew out the speaker, where do I go?", you simply have one set procedure that everyone knows to follow. Don't make people choose when they're in a panic, have a single (hopefully well-drilled) response. [Answer] As already stated: transporters (teleportation devices) have limited range, require power and presumably other supporting systems to operate. If the ship has been attacked and primary power disabled, chances are, other systems have failed too. Even if everything needed is in working order, transporters will have limited throughput - only so many people per minute. Escape pods can self-launch independently - no need for ship's power or anything else, no throughput issue. In an emergency, every second counts. [Answer] There have been a number good answers as to why escape pods are usually used. One thing to note is that there are some examples where using transporters are used when evacuating a ship. There are plenty of instances of Transporters being used to rescue people from a ship about to be destroyed such as in [StarTrek First Contact the Enterprise E rescues the crew of the Defiant](https://www.youtube.com/watch?v=AdNbVxMNFvk). In the StarGate GS-1 episode [Prometheus Unbound S9E12](https://youtu.be/r6Vnpg03q1c?t=99) the Prometheus uses its Asgard Transport Beams to evacuate its crew onto the planet it was orbiting before the ship was destroyed. Both of these situations are depended on the proximity of a friendly planet or ship. [Answer] Actually, it is more likely that you will see chaotic scenes if transport is being used. There would be one (or few?) Transports available, and some crew/passengers would be stationed quite far away from it, and now they have to navigate spaceship with systems shutting down to the boarding gates. While escape pods locations would be, presumably, chosen to minimize the distance each member of the crew has to cover your get into it. [Answer] 1,000 people using a teleporter. Generously say it fits 10 people. That 100 uses of the teleporter. Generously say it takes 20 seconds to work. That's 2,000 seconds. Or half an hour (Of people standing in line while claxons sound the impending doom). 1,000 people using escape pods. Have more than enough escape pods for 1,000 people (This part is important). It takes as long as it takes you and the people near you to enter the nearest escape pod and hit "GO". [Answer] Consider an earth bound analogy: Why wouldn't an aircraft carrier save all the people it could by launching aircraft? Launching aircraft requires a functioning ship. You need a headwind of at least 20 knots coming over the bow, you need steam for catapults. You need a functioning crew. A launching evolution is a choreographed dance. If the ship is functional enough to launch, it's functional enough to keep floating. Similarly: Transporter tech involves the dematerializing and rematerializing of substantial mass. You are handling energies on the order of the mass equivalent of what is being transported, and huge information capacity. (Remember that Scotty was stored for months in a pattern buffer once.) A partially working transporter is a scary thought. ]

[Question] [ In one of my stories people often visit areas which have extreme temperatures. Humans can stand these temperatures due to spells that only work on living beings and some items of clothing. What physical material could I use to create currency which can range from 10000°C to −272°C without destroying it? If I can't find anything that can, something close would have to do. [Answer] Just use gold. Really. Yes, when you are walking on the sun, you need to keep it your magical purse tightly closed to keep the high pressure vapor from escaping. When you get back, it happily cools back down to a solid. Alternately, just keep payment within the magical boundaries. Carry your gems in your mouth. If you are selling the Bazaar on the Sun, then you need to transfer it to your client's mouth. Haggling and making change are considered the most romantic parts of the Bazaar. [Answer] If the spells only protect living creatures, and you need a portable form of currency, you are left with only one rational choice... I give you... **ChinchillaCoin** [](https://i.stack.imgur.com/7PMeE.jpg) [Answer] ## Use an animal as your purse. As already noted, since no form of matter can stand the temperatures required, the only way is to store the currency *inside* living things. There are many animals that can do this. For example, you can bring along a number of chipmunks, which will keep your money inside their [cheek pouches](https://en.wikipedia.org/wiki/File:Chipmunk_cheek_pouch.jpg). This has the benefit of maintaining supply levels of the medium of exchange, which may be destroyed by inflation if the animals themselves are used as currency. [](https://i.stack.imgur.com/JWTXk.jpg) [Answer] As far as materials go, after a short google search, I found that highest temperature you could hope for is approximately 3000–4000°C with gemstones, or around 3400°C with [refractory metals](https://en.wikipedia.org/wiki/Refractory_metals). What you want though is heat insulation and dissipation, and/or ablative shielding. Through use of specialized containers, made from these metals, or heat resistant ceramics, you might be able to keep coins or gems at a relatively (compared to their melting point) low temperature. Alternatively, if some clothing items resist heat through protective magic, you could use those as currency. Clothing and fabric has been used as a form of currency in our history as well [Answer] **Rai stones** <https://en.wikipedia.org/wiki/Rai_stones> Money doesn't have to jingle. Rai stones aren't heatproof but they don't have to be. They can sit at the bottom of the ocean while still remaining valid and usable currency. Money doesn't have to be in the same room to use. I can sell you something based on the promise that money in the bank will be be transferred to your name. Money can sit still in one place where it's safe and it's enough that everyone knows who it belongs to and the ownership can change with the money never moving. It doesn't have to survive the heat because only trust and promises have to survive the heat. [Answer] *EDIT:* Make the currency out of the same material of the magical clothes. Our current paper currency is made of linen, which is what we make clothes out of. So why not make the currency out of the same material? --- If the spells affect clothing, why not make a wallet of that magical clothing? As for reality, check the information from this [article](http://www.asminternational.org/web/cmdnetwork/home/-/journal_content/56/10180/25655039/NEWS): > > Computations show that a material made with just the right amounts of hafnium, nitrogen, and carbon would have a melting point of more than 4400 K (4126.85°C/7460°F). That's about two-thirds the temperature at the surface of the sun and 200 K higher than the highest melting point ever recorded experimentally. > > > It doesn’t talk about what would happen if frozen, but I think it’s safe to say if it is solid at those temperatures, it would stay solid below. [Answer] > > (...) Humans can stand these temperatures due to spells that only work on living beings and some items of clothing (...) > > > (...) What physical material could I use to create currency which can range from **10000°C** to -272°C without destroying it? > > > Since pretty much anything above 4000°C will gaseous at best, and otherwise a very hot plasma, the answer is in the question itself. People will do trade using the only thing that you can magically protect to withstand those temperatures: > > (...) some items of clothing (...) > > > They won't have many material things to buy or sell, though. That would be a pretty limited market. Now, if people can keep tabs on each other, they can also pay each other with favors, services or information. Notice that "information" here includes bitcoin and other crypto-currency transactions, if you can inscribe a string of bits on a piece of enchanted clothing so that you can type those in a computer when you go back to more "normal" ranges of temperature. [Answer] Simple. Have a currency based on substance, and not prefabricated pieces. Have the society artificially establish the value of a substance (could be gold, could be something else) that can easily move back and forth between forms. Try to establish the artificial value of the substance *above* its natural value to the point it's easy to transfer. Back its value by alternate currencies (other substances with similar properties) by having a powerful financial institution (a massive bank or a government) willing to trade the gold to the other currencies if the value ever drops. This should be a clear stabilizing force. Like bitcoin, the substance can be 'created' by entities outside the organization which *does* hurt the usability of it as currency, but doesn't destroy its value. So if, say, you go with platinum, its value is determined in grams. Thus if it's turned into a liquid or solid it doesn't matter, and can still be used as currency. [Answer] Range from 10000°c to -272°c doesn't seem realistic. First of all 10000°c almost twice the temperature of surface of the Sun! All your surroundings would melt no matter what spell you'd have. Even though you wouldn't drown in that lava (since it's more dense than a human body) you would have a problem of the floors shifting due to being liquid. Also the amount of light that temperature would emit would blind you. So perhaps limit a little bit? Otherwise I'd say make money out of that magic cloth - it's thin and easy to carry, you can, probably, print on top of it, it's rare so it's would get counterfeit easily and it's easier to control it. [Answer] The [current record holder](https://www.sciencemag.org/news/sifter/predicted-compound-has-melting-point-two-thirds-suns-temperature) is an alloy of hafnium, nitrogen, and carbon whose melting point is 4120°C.(This alloy has only been computed to have these properties; the previous record holder, tantalum hafnium carbide, has already been synthesized and has a melting point of 3942°C.) So, you'll either have to go with using a living creature for (storing) money, lower the maximum melting point required, or accept having to deal with molten / gaseous “money”. [Answer] How about tattoos combined with a cryptocurrency? ...combined with magic! Let's say there's a magical cryptocurrency, and the private key is kept as a temporary magical tattoo on each person (perhaps even invisible to non-wizard types). When a transaction is made, both people involved get modifications to their tattoos to incorporate the change of this virtual "currency". [Answer] if living things can be protected, then that seems like the most logical solution. it seems **saffron stigmas** are worth thousands of dollars per kilogram (source: [wikipedia](https://en.wikipedia.org/wiki/Saffron)). if disembodied flower genitals aren't "living" enough for your spells to work, some **small flowering plants** are worth thousands of dollars. ([source](https://financesonline.com/10-most-expensive-flowers-in-the-world-orchids-roses-priceless-plants/)). also, if plant's don't qualify as "living beings", it seems **a virgin is worth 50 shekels** (source: [deuteronomy 22:28-29](https://www.biblegateway.com/passage/?search=Deuteronomy%2022:28-29)) [Answer] This answer isn't as cute as chinchilla coin, but I'd suggest you think about those spells. It protects people and some clothing. Why are humans protected? Why is that clothing protected? If it because of purely biological origin (as an example) then any purely biological coin would work. Bone maybe? You've already solved the problem of how things survive otherwise fatal temperatures (humans are notoriously flammable) so find out **why** that works and you can easily figure out what type of coin that would work on. [Answer] What about housing, food, water? What's the ground made of? If they're travelling through plasma, what's the ship made of? Any of the above can be used as the basis for currency, just add security markings. -272 C is not a problem as far as stability goes; virtually everything is solid at that point. Not dying because all the air has frozen, leaving a vacuum, that's a different matter altogether. [Answer] **Slaves** With those extreme conditions you ask, slaves are the only object that can exist, really. Without introducing any new rules to what you described. [Answer] Money isn't worth much because it's so valuable, but because we all agree that it has the value. 1 dollar and 100 dollar bill can be made for the same money, but be worth different values if we agree to it. We make some steps to ensure that you can't make other 100 dollar bill easily, as well as keep the production of our bills as similar as we can, so we can spot the frauds, but this shouldn't be issue for you. You said that you can carry some items of clothing. Great! We have two options in here: 1. Create a brand of clothing that is created by the government or something similar, controlled, and somehow protected(golden thread, some strange or hard to reproduce pattern). When you go into the high temperature environment, you just take few pairs of your valuable (hopefully sexy) underwear. 2. If your magic allows you to do so, you may want to ensure that some of the finest magicians are hired by the government to imbue the underwear with the spell, instead of physical protection. This way, not so gifted magicians can't make currency on their own, since they don't possess the power to recreate the spell(or don't know its incantation, hand gestures, lack virgin blood or other vital ingredients, whatever). You could also use 2. to add a plot, where some Dark Mage with sufficient power floods the market with Valuable Sexy Underwear that is also imbued with the same spell, and the market goes wild. I remember from history lessons that some country(Germany?) had inflation so high, that, for example, you could buy bread at the morning for 10000 coins, but at the end of the day it was already worth few times as much - you never knew what awaits you. [Answer] ### Small insects. Since the spell protects living beings, and magic is available, put in stasis insects like [ants](https://en.wikipedia.org/wiki/Ant) and [beetles](https://en.wikipedia.org/wiki/Beetle), and carry them in the protected pouch. They have the advantage of varied and beautiful coloring, allowing for different values and uses of currency. [Answer] Why don't you use credit cards and e-commerce? If all your money is stored as a number on some server owned by a bank somewhere, that bank probably isn't going to put its servers in a really hot environment and watch all their computerized yet very real records of money be vaporized. If the technology level in your setting is before the existence of computers, you could design a specific type of magic to deal specifically with this problem. [Answer] How about we just call it "**The Stone**". We do have basic knowledge of Geology. There are different kinds of rocks/minerals. Sedimentary, Igneous and Metamorphic in that order of value(to start with keeping Earth as reference). As time goes on, and you travel to temperatures ranging in the values provided by you, The Stones behave differently. Same Stone will have different values in different places at different period of time. Their value may increase or decrease based on the time spent and the place. Like value of gold. You can add other type of materials like Stardust and stuff but I prefer keeping things simple. Hope this helps you in any way!! Good luck. ]

[Question] [ I'm writing a story in which a civilization previously capable of (firmly technobabble-based) FTL travel has become stranded, orbiting an isolated star with no rocky planets. (There *was* a planet, but it was destroyed by their crash-landing in the star system.) The civilization is comfortably capable of forging an existence in artificial habitats orbiting their new star, but for the plot to function, it must be prohibitively difficult for them to leave the star system (to return home, or colonize elsewhere). Their best chance would be to get their hands on an already-constructed FTL travel device, but I'm having trouble constructing a convincing (within-universe) reason why they couldn't simply build a new one from stuff they have at hand. [Answer] The simplest way is probably to leave them with a shortage of [unobtainium](https://en.wikipedia.org/wiki/Unobtainium). A substance named for obvious reasons, that happens to be required for the production of FTL drives. Perhaps the limited quantity they had in their existing drive was destroyed (causing the accident) or dispersed in the accident. Either way, they're now limited to space habitats and STL drive until such time as they can come into possession of more unobtainium. [Answer] Their ship and her payload were *designed* as a colony expedition. They had not just asteroid mining craft, and seeds for hydroponics, and modular habitat sections, they also had the blueprints and machine tools to replicate them. And they had the engineers to read the blueprints and use the tools. For the stardrive, they had just the operators' maintenance handbook, and pilots and engineers trained to operate it. Consider: You are obviously able to use a computer, like billions of people worldwide. And there are many millions who can program a simple website. But how many can design a microchip, or manufacture one? A programmer would know about silicon wafers, and doping it with other elements, but how many can explain the physics behind that? So the colony would have to replicate a R&D project. They get a head start because they *know* it is possible, and also the principles how it works. This is balanced by the need to build the colony as planned. They *know* that they have a fleet of sublight ships, and that these sublight ships will wear out, and that they should start assembling the shipyard to build new *sublight* ships. [Answer] ## The ship consists of stages, and only the final stage arrived. This is a very realistic explanation. That's how we build rockets, because it's efficient and much cheaper. Might not fit your plot, though. Given that they are only left with the smallest of the stages they could only guess how to build the most complex stages. ## The ship carried just enough energy to arrive there, a return would have been very expensive and was not planned. Again, this refers to the cost of interstellar travels. This should also apply to single stage vehicles. Refueling this ship would be extremely expensive, or might even be impossible due to a lack of technology or industry, see also next point. ## The crew is smaller than the population of a planet. Seriously, why would those few people be able to build a spacecraft? Imagine what an extremely complex project this would be. Remember how the soviet union struggled to put a man on moon (admittedly in a short time), because they lacked the industrial power for this huge project. They might be able to repair their ship, but build a new one? How long would it take to build up the industry? How many people can actually work on this, while there are plenty of other problems to work on? [Answer] This is similar in effect to Separatrix's unobtainium answer, but a slightly different spin. AI created all of the FTLs in existence. No flesh and blood brain can fully comprehend the details of their inner workings enough to recreate one. This doesn't mean they don't understand the broad strokes of how it works, just that they can't replicate it. Then the AI went to war with its creator civilization, and ultimately lost. With the AI wiped out, a ban was put in place to ensure no more AI. This means that every FTL is a priceless, irreplaceable artifact. No more can ever be constructed (by this civilization, at least). [Answer] Because they are astronauts(pilots) and not engineers. Our society is able to do many things that I alone cannot. [Answer] Some of the technology requires licensing from organizations that are not here. You may have gotten unlimited licenses for OperatingSystem2525, and all of the computers visible to crew and passengers run on that version. The software to run the engines requires OperatingSystem2530, which needs a long trip in the opposite direction to get an unlock key. And now that you've disassembled your engines to find that out, your current engines also want a new unlock key. [Answer] Many fictional FTL drives (as if there were any others..) can only be used far away from pesky gravity fields. Your drive is the opposite: it actually needs to be spun up *at the center of a sufficiently large planet* to break through to the fifth dimension or whatever. Since you incautiously blew up the only planet in reach, now you're stuck there. [Answer] It costs a lot of money and they lack the political will to use all those resources for that scope. See what happened with the Apollo program. As long as USSR was leading the space race the US Congress was scared by the enemy supremacy and had no troubles providing funding to the program. Once the Moon was reached more than once and public attention lowered, together with the manifest incapacity of the Soviet space program to replicate the result, suddenly the budget was limited and even scheduled launches were canceled. [Answer] That's going to depend on exactly what your FTL drive needs. How about processing power equivalent to an Intel I7 processor? Oh, that's going to cost you. Even if you know how to make transistors, the actual physical plant required for a current microprocessor includes things like soft x-ray etching mask units with nanometer precision and ultra-fine air filtration units. Plus chemical industries to supply single-crystal silicon wafers. Plus the support industries needed (Sophisticated alloys from raw ores. The chemicals required for the photoresists. Process control sensors and electronics to control fabrication. Etc) None of these things are easy, and they are the end results of decades of incremental development. All of this from a colony which is just getting started and has no basic industrial infrastructure - and may well be investing a lot of effort to adapting agriculture to the existing ecologies/biochemistry just so they can avoid starving. Depending on your FTL, it can get MUCH worse. I suggest you read Vernor Vinge's "Marooned in Real Time". He imagines space vehicles which are essentially made of assemblies (clouds) of nanoprocessors which modulate fields cooperatively to function. Presumably such processors are built by other, slightly less complex nanomachines. And they are built... Well, the regress in not infinite, but it's certainly inconvenient. [Answer] Totaly running with ths' answer here. FTL drives arn't so much as a engine, so much as a trans dimensional artillery piece(T-DAP)... and Earth had to hollow out most of Pluto to build their outbound gun. Accuracy at colonization distances can reliably hit a solar system, but hitting a planet was supposed to be statistically impossible. Turns out, it wasn't impossible... and even worse, inflating a 200 KM bubble of space-time inside a planet's core tends to do really bad things it its structural integrity. Now 80% of the plant's mass is flying around the sun in wildly eliptical orbits and its going to take generations to collect enough mass to build a new T-DAP..... [Answer] When they crash-landed in the new star system, the scientists and technicians who were knowledgeable and part of producing FTL died, the computers and backups containing information on how to build/rebuild the equipment were also destroyed. The remaining scientists and technicians have little knowledge of physics involved to produce FTL engine, and they were not property trained. It was unfortunate for the scientists and technicians to die. There was a malfunction in the ship they were in when exiting FTL, sending the ship crashing down to the planet. [Answer] Other answers cover how you can explain why they can't leave under their own power, but your question doesn't specify why no one else from home would send more supplies or a rescue vessel to eventually rescue them. A very simple explanation is good old incompetence. This premise reminded me of the planet [Wayland](http://starwars.wikia.com/wiki/Wayland/Legends) from the Star Wars Legends stories. The description of the planet from the game [Star Wars: Empire at War](http://eaw.heavengames.com/planets/?n=Wayland) sums it up nicely. > > A simple clerical error in the Old Republic planetary registry removed Wayland from all known charts and doomed the expeditionary vessel seeking to settle a colony there. Without support from the Republic, the human colonists regressed technologically, discarding their blasters for bows and arrows, their modern fabrics for furs and hides. The colonists continue to clash with the two native intelligent species on Wayland, despite being forgotten by the galaxy at large. > > > So basically, someone at home accidentally hit delete somewhere they shouldn't have. Maybe they deleted all records of your system, maybe only the coordinates of the destination. Then they realized that backups hadn't been running for a couple months and it was lost. Or maybe it was simpler, someone had to manually transcribe the coordinates into their navigation computer and typed a "1" instead of a "2". A small change in a trajectory spanning light years will be many light years off at the destination, so all attempts to send supplies to the colonists ended up in the wrong place. The possibilities are endless depending on the specifics. Combine it with another explanation about being out of fuel or having a damaged part and you have your setup for how they were stranded and why no one is coming to help them. Many other answers here already cover that well. [Answer] When the ship crashed, and the FTL drive exploded it created a anti-FTL radiation field in the system. The anti-FTL radiation prevents ships traveling at FTL speeds, by destroying the craft if it tries. After the first ship they built exploded trying to go to FTL they haven't tried again. Maybe by now the radiation has dispersed but no one wants to risk the crew/resources needed to try again. [Answer] Maybe they *could* construct a new FTL ship, but there's a reason their old ship destroyed the planet. It's an intrinsic problem of the drive principle, and they really do not want to destroy *yet another* nice planet... [Answer] The best answers are story based, and your story gives the best reason: "holy crap we crashed and destroyed a PLANET, next time it might be the ship!". Would you trust that ship? Would you get enough crazy people together for another jump to colonize something else? They could just not have the expertise or facilities to see why they crashed or repair it. They could be waiting for rescue, or trying to build enough of a population and facilities to research and build a new FTL drive even if it takes a few millenia to redo that research. The other more standard answers are already given. Lack of resources for the FTL drive (either building or fueling), lack of reasons to build them (you reached a starsystem right?), lack of economical insentive to build/use the ship (cost of FTL is so high only a colonist expedition is worth it, but why waste resources on something that wont earn your local system something?) [Answer] They were never able to construct FTL drives - they got them from a forerunner factory that was still intact, which they had discovered during their own early steps into space. (Or they purchased the FTL drive from extant aliens, or FTL tech is a particular company's closely guarded secret, etc...) [Answer] Perhaps they have tried to create a new FTL drive from remains of their old one, and it backfired so much - risked so many lives, nearly tore through the ship, messed up with their resources, etc - and leaves barely anything of the attempt that the rest simply say 'it's not worth it' and stop any further pooling of resources into making one. [Answer] **Structural Damage** During the crash some important parts of the FTL engine have been damaged or destroyed. Repairing them is not (easily) possible. Maybe they just don't have the plans required for a certain part. Maybe they lack a certain ressource that is absolutely needed to form a certain part of the engine. Maybe certain parts need a giant machinery to be produced that can't simply be reproduced from existing ressources. **Side effects** They were a test drive of a new FTL engine that had an unwelcome sideeffect of killing or heavily hurting the people on board. To extend their lives, they rather don't restart the engine. This might also not have been an initial issue, but caused by the crash that destroyed some protectors that can't be reinstalled with available ressources **Escape** Your ship is controlled by rebels that are on their escape from an evil empire. They found a reasonably well suited habitat. They might be able to restart their FTL in an emergency but would rather stay at their current place and try to establish their rebel empire. A couple of generations and propaganda later nobody remembers the fact that they were even capable of FTL travel. [Answer] **Interstellar Distances are just too large and they can't use high atomic number elements** I'm going to assume you want them to be able to venture into space at least to their other habitats but not much further than that. Right now they may have access to asteroid mining where water is abundant. That gives them access to create hydrogen and oxygen propellant, which is what's used in modern chemical rockets. Hydrogen and Oxygen have smaller atomic numbers, so they're much easier to find out in space. Anything with a higher atomic number than iron needs to be created from a supernova. If they live in a region of space that has a lot of small stars, there aren't going to be many supernovae, so there's going to be very little of any high-density elements. Any high atomic number element like Gold could be used as the fuel, which is rare in space. If they live around an average star, the nearest star to them is going to be 3-10 light years away. If we take the fastest speed any spacecraft built by people and assume that their spacecraft can exit their system with this much speed (which probably isn't true), it would take them 4060 years to reach a star the distance to Proxima Centauri, the nearest star to Earth. It's just not viable to send a rocket to another system because of the [wait calculation](https://www.researchgate.net/publication/260275150_Interstellar_Travel_-_The_Wait_Calculation_and_the_Incentive_Trap_of_Progress). The wait calculation is question of whether we should send a craft to space now or wait later. If we send the spacecraft too soon, a new technology will reach before that spacecraft gets there. If we send it too late, we lose time to be at our destination planet. It seems like your civilization has endured some losses in many respects including their home planet, why not technology? They may have some experienced people but not enough to create an interstellar drive. Consider what O.M said, "You are obviously able to use a computer, like billions of people worldwide. And there are many millions who can program a simple website. But how many can design a microchip, or manufacture one?" Gaining the technology to achieve interstellar travel from local travel is like technology jump from going to a bronze sword to an AK-47 or from an AK-47 to a guided missile. What makes this even harder is that advanced technology almost always requires access to new and unique materials. Why should an interstellar drive be any different? Just make stringent technology requirements on high atomic element materials, and your civilization will have a hard time acquiring it. None of these obstacles make interstellar travel impossible, but it should take your civilization a couple hundred years (very rough estimate) to develop interstellar travel at the soonest. [Answer] **Laws of Physics prohibit multiple FTL jumps.** There are many answers that explain why complex technology may not be reproduced by colonists. However, there could be an even stronger reason why it is impossible to make multiple jumps. According to the laws of physics we know, FTL is impossible. The law of relativity tells us that velocity is relative so any non-accelerating object can be considered stationary relative to its own frame of reference. The law of causality tells us that us the cause precedes effect. If you had reliable FTL and relativity, you could make two FTL trips using different frames reference to arrive back where you were before you started. There is two ways of dealing with this. Perhaps Einstein was wrong and there is some objective frame of reference that we haven't found yet. Alternatively, we could say that causality is wrong, and time travel is possible. But time travel is weird... what happens if you kill your parents before you were born? Say FTL requires folding space, space can't be folded more than once (and definitely can't be unfolded), and technically was always folded and due to some weird quantum reason just happened to create the wormhole the exact time FTL drive was powered on. If we limit ourselves to one FTL jump, we can mostly keep relativity and causality. Yes, according to relativity in some frames of reference you arrived before you left, but since you can't do more than one FTL jump you shouldn't be able do anything really paradoxical like killing younger versions of yourself. [Answer] The local solar system is located very near to the center of its galaxy. The black hole in its center requires a huge amount of energy to reach the escape velocity needed to leave the local space. The only possible solution for now is to use the gravitational pull of the black hole and use it to swing close enough and use it as a catapult to leave the near center. ( similar plot is used in the Interstellar movie ) As this is only a theory building another spaceship does not make sense until this is experimentally checked. Additionally the time shifts involved would move the spaceship forward (or backward ) in time making the whole escapade even more complicated. How would the travelers even provide feedback information back to the home planet ? While the home world is spiraling closer and closer to the hungry black hole and one day will be consumed this journey might be the only chance of preserving the civilization. [Answer] The simplest non-knee jerk reasoning, would be that they had a navigation problem due to ::hand wave space phenomina:: encountered along the way ( This also explains why they warped into a planet.) And so they ended uphalf way across the galaxy, or across the universe outside of what they had previously charted and due to time dilation of observing distant stars/galaxies they are going to have a lot of work, centuries or millenia perhaps to get themselves reconnoitered to be able to message and return home. They can;t even visit nearby stars for quite some time because it requires quite a bit of astronomical data in order for the FTL drive to properly take into account how to traverse the distances directly. To be clear, they could still use any non Super Luminal method to go else-where, but they would also then need to build out old-school generation/cryo ship that they haven't actively used in a few millennia, and take trips to other stars on time-lines which make it more attractive to just wait until they have gathered enough data to begin using FTL again. Lost in space is solid. [Answer] For some reason FTL engines are attracted to what ever elements are used to fuel them, this is why the space ship crashed on the planet. The crash ruptured the containment field of the FTL engine thus causing all of the fuel element in the planet to be used up instantaneously destroying the planet, or possibly accelerating the planet to FTL speeds and sending it backwards in time allowing the inhabitants the time to discover the knowledge required to stop the ship from crashing on the planet. Aren't paradoxes fun. :-) [Answer] Idea: The civilization is comprised of hundreds of small autonomous vessels (transportation, reparation supply) and a very HUGE one who can provide FTL capabilities for all the others (can create a wormhole?). The big one was totally anhiliated on arrival, and there are not enough material available / shipyard capabilites to recreate something similar. The vessels are more or less self-autonomous and can be used to travel within the star system, but are unable to leave it. [Answer] **There's nowhere to go** This is the simplest. They got stranded by a factor they cannot avoid and don't know previously. That factor can still keep they from reaching any planned destination. They are like a boat without a compass and with limited food. Another good point is: They just cannot find another more suitable place to live. If you got a starship you do want a destination to arrive at, without destination there's no reason to get aboard that starship (or any ship). [Answer] While they might possess (or are able to recreate) the whatchamacallits and doohickeys that comprise the FTL drive they may have lost some **unique knowledge** of how they work together. For example I'm writing a story where I needed to take the engines offline in such a way that they could be brought back online only after an extended period of time. In my scenario the engine field controllers were destroyed. The system AI can emulate the controllers but to do so it has to reformulate the resonance equations that were embedded in the lost controllers. Essentially an entire field of physics has to be rediscovered. In your scenario you could make this knowledge prohibitively unattainable (until they discover it elsewhere). [Answer] The story is that the residents of Easter Island cut down their forest and couldn't build new ships (rafts or canoes). So they were stuck fighting each other for a fixed capacity of food production as population increased. [Answer] Their FTL technology warps them through space in a manner that was safe until a virus broke out that makes it fatal for anyone to pass through warped space. Later in the story the the virus is revealed to have been genetically engineered by [SPOILER]. [Answer] FTL technology was possible but extremely expensive and complicated. It required all the infrastructure and knowledge available in the homeworld to make FTL ships happen. That is, FTL existed but was neither trivial nor accessible for trivial things. Homeworld came to an end. Whatever remain stranded in their new world, even if with advanced spacefaring capabilities, it is a shell of the former self, depleted of its original population, infrastructure and engineering base, without the wherewithal to re-engage in FTL in any matter that is safe. It still have tremendous spacefaring capabilities within their new home solar system. But much, much more has been lost. They need to re-invent and re-engineer their way back to FTL tech... and probably that took them thousands, if not eons, to achieve back in their original homeworld. Think about how we have lost the technique to make/reproduce damascus steel (a related, but different problem since we have much better steel-making products today.) There could also be a social impediment as religious sectors of society might blame FTL for the Homeworld's demise. Another angle: it could be that FTL leaves traces, foot prints and the remaining survivors want to stay incognito. [Answer] My first thought when reading the title was to have a **Planetary Debris Field** - around our own planet, rocket launches are gradually getting riskier due to the amount of space junk in orbit around the planet. At the speeds that rockets travel, hitting even a small piece of something that broke off of a previous mission could be Very Bad for the current mission. But in your question, you totally upped the ante, stating: > > There *was* a planet, but it was destroyed by their crash-landing in the star system. > > > Bam. You have a *literal* planetary debris field right there. That is, the debris of an entire planet, all smashed up and still in orbit around the cloud's common centre of gravity. And since your ship's crash-landing into the planet is what kicked up all this dust, the mothership *also* happens to be right at the centre of this debris field. Smaller scouting ships can navigate through the debris field in relative safety, mining the rocky bits or moving past the cloud to explore other planets in this solar system or whatever, but the mothership is stuck in the cloud for the foreseeable future. All spare power on the mothership is being pumped into keeping the shields up and hull intact, so there's: * No room to accelerate (and/or warping space to make your technobabble-FTL-tunnel will also warp a continent-sized asteroid into your window), * More pressing need for raw materials elsewhere, * Not enough power to fire up the engines even if they *were* working And obviously, FTL drives in this universe are necessarily *big*. You can't exactly kit out an existing one-, five- or twenty-person craft with a warp core, drive, and engines. Even the computer programs needed to turn all that on properly are way more advanced than what the smaller vessels can run. Couldn't that program run on the mothership to remote-control your puddle-jumper? Theoretically, maybe, sure - but that would involve opening a FTL corridor since FTL is necessarily faster-than-radio, and opening an FTL connection just takes us right back to the first problem. That's also why they can't send a distress signal back home to confirm their current location. So even if they *could* turn on the FTL engines, doing so would be a suicidal move. Your big colony ship is stuck and not able to move *anywhere* or communicate with anyone outside this solar system anytime soon. Better get those engineers working overtime so they can complete their Von Neumann mining probes. Hopefully they can get 'em going in time to dig us out of this mess sometime within our colonists' lifetimes! The colonists getting their hands on a new FTL engine would be an FTL engine (ideally, one accessorized with a compatible ship) that's not mired in middle of the disassembled planet. Such a find would allow them to escape this solar system years sooner than they ever could have without it. ]

[Question] [ So I asked [this question](https://worldbuilding.stackexchange.com/questions/16900/what-are-the-requirements-for-the-zombie-in-order-to-reach-a-full-zombie-apocaly) a few days ago, with excellent and certainly useful feedback. I've decided I'd like to build upon that question with some ways to combat our 'new and improved super zombies'. For the sake of this question, let's assume that ZB01 has successfully gone global, infecting people all over the world. **[We'll use these zombies](https://worldbuilding.stackexchange.com/a/16906/9326)** except let's say that they *don't* burn out too quickly and succeed in occupying most of the world, leading to a full zombie apocalypse. Only pockets of humanity remain. Survivors face a war-torn zombie-infested world. --- Our protagonist for the day is Ned. Ned is a survivor of ZB01 and travels with a group of ruffians in what used to be northern Texas. Ned has requested that you, his supplier, equip him in the most effective zombie killing weapon you can think of. * Ned needs to travel **LIGHT** and can't be weighed down by ammo or batteries. * Ned will be departing imminently on supply run that will last 2-5 months so his weapon must be durable enough to dispatch the undead for at *least* that long. * Ned's journey will likely put him in all sorts of zombie-fighting-venues including urban alleyways, rural pastures,and close quarters. * This is the [modern-age](/questions/tagged/modern-age "show questions tagged 'modern-age'") so tech **must** be feasible with what we currently have. * You are only limited by your imagination. You've stockpiled resources and have access to *most* of what you might need. * Ned doesn't want to be *lame*, so he needs you to be as creative as possible in order to insure that all the other zombie slayers see him as 'hip' and 'fresh'. --- * **What weapon do you give to Ned?** * (If applicable) **How** is this weapon assembled? * What makes this weapon *more* effective than others for this scenario? ### Notes: I realize that this question *is* a bit opinion based; however, I'm **confident** that the answers could potentially be **extremely** beneficial to future askers. If you answer this question, **please be thorough**. I'd really appreciate some in-depth perspective with insight that others may not have considered! *(Also, as always, feel free to let me know of any issues in the question and I will address them promptly)* [Answer] When is comes down to melee against zombies you won't want to be messing around with swords, katanas, knives, battle axes, or any other edged or spiked weapons. Edged weapons get stuck in things like bones. Everyone knows $^{[citation\ needed]}$ that to kill a zombie, you destroy the brain. Destroying the brain (or removing the head) require going through either the skull or the spinal column, those are made of bone.  [$^{Source}$](https://www.medievalcollectables.com/c-22-maces.aspx) So, to be blunt, you need a blunt weapon. It's the modern age, but what you need is some medieval tech. Like classical music, these weapons have stood the test of time. A [mace](http://en.wikipedia.org/wiki/Mace_%28club%29), or flanged mace, will allow significant brain bashing ability without the danger of having the weapon getting stuck in the bone. It demolishes the bones. Ned will like this weapon. Ned SMASH. [Answer] I'd go for a highly automated system that Ned can bring ten or twenty of. Something like a bunch of these:  This is, of course, assuming that only humans can carry and become infected with the zombie virus. (If all animals can become zombies, they all will, *and we'll be screwed.*) Dogs are effective, trainable weapons that should easily be able to pull down and dismember an unarmed human, which is basically what zombies are to all life forms that they can't infect. Dogs can move fast and fight in groups, even without Ned around, so he can mostly stand back and run away from the zombies while his dogs keep them off him and rip them apart. Ned will, of course, want something to finish off a downed zombie. While the standard choice is a club or axe, I'd go with something that he can stay a bit further from the zombies with, like a spear. With his pack of dogs to defend him, Ned doesn't have to worry as much about the speed with which he can down a zombie, so a slower but safer method of dispatching them would be preferable. He'll want to make sure that there's some sort of cross arm on his spear so the zombies can't crawl up it if they're not quite dead. A spear with a cross bar would keep the zombies pinned down with the chompy bits a safe distance from Ned while his dogs finish pulling off their limbs. Dogs also have other benefits. They can carry Ned's gear around for him, keeping him nice and light in case he needs to run, they can smell zombies well before Ned can see them, and they can help hunt. Unlike something like a club, dogs are also effective at defending from hostile wildlife like wolves or angry rednecks. [Answer] Ok, so you're facing strong, fast, intelligent zombies with one overriding drive: to feed. The hunger consumes them. It is more important to them than life itself. Given the choice between feeding and defending themselves they will always, always choose feeding. Which makes our most powerful weapon obvious. **Snacks**  Running from a tireless horde intent on stripping the flesh from your bones? Scatter a bag of peanuts behind you and flee to safety while they scrabble at the ground for them. Trying to clear a building of zombies? Scatter pringles on the ground in the killing zone. Draw them in then club them over the head while they dig amongst the corpses for shredded crisps. **Bread Maker** Your enemy will be smart, they'll be able to see the trap and if the temptation isn't enough they'll use their brains to kill you for your delicious flesh so it's essential that our heros overwhelm their minds with the smell of fresh baked bread permeating the battlefield which will cause the hunger crazed beasts to abandon their fortifications to run blindly towards the promise of FOOD. A bread maker is more important than a flame thrower because you need to rob your enemy of the ability to think.  **Poison** Finally. Your last weapon. These things are smart, they're fast, they're strong and motivated but they're still human-ish and they care more about eating than living. They're humans infected with ZB01. They can still bleed. So poison. Lots of poison. Poison all the snacks you intend to throw at them.  Meanwhile it's important that you do whatever you can to not look like food. We can assume that the zombies aren't eating each others legs because they look too diseased/sickly to each other to trip the "food" feeling while pink fleshy non infected humans look like an all you can eat buffet. It's important to bring things that you can coat on your skin that will mask the delicious smell of uninfected humans. [Answer] A medium sized crowbar.  Not only will it be useful for bashing in heads, but it will help you wedge things like: nails, boarded buildings, doors, car trunks, car doors, garage doors, stubborn locks, staircase supports (preventing access to second floor of houses except ladder), military door jammers and survival necessities such as canned foods. In fighting, the curvature of the crowbar is ideal for effortlessly reaching into the harder to reach parts of the brain such as the [Motor Cortex](https://books.google.com/books?hl=en&lr=&id=GHrAhCMGj2EC&oi=fnd&pg=PP2&dq=frontal%20lobe%20functions&ots=TnxmowjUM5&sig=Ql8uekcQegGyn_p7kVJmI5_XEeA#v=onepage&q=frontal%20lobe%20functions&f=false) to disable motor functions and the [Broca's Area](https://books.google.com/books?id=onsnTke-STgC&pg=PA175&dq=Broca%27s%20Area&hl=en&sa=X&ei=0MFTVYD_C5K7ogTVn4GoDQ&ved=0CB4Q6AEwAA#v=onepage&q=Broca%27s%20Area&f=false) to silence a Zombie from making any noises from it mouth to attract others. Unlike sharp weapons which dull and blunt weapons which are more of a pray and smash, your blows can be a little more controlled and precise. They require no sharpening and are easily found at just about every hardware store you are going to raid. If you are around a single zombie you can use the sharp end of the curve or flip it horizontally around for a less risk of getting stuck and use it for a blunt attack. If all else fails you can flip it vertically and use a stabbing motion. [Answer] Ok, this will require for Ned a little bit of strategy and thinking as he will go on a 2-5 month adventure. I think during this period of time, not only the weapon itself is important, but also the proficency with it in order to survive, as there might be chances that Ned could lose his weapon. Also as Ned will face different kinds of situations regarding fighting with zombies, he may require some different kinds of weapons. **I'll choose one for middle long range, and one for melee, in order to keep Ned light.** 1 - Long Range Approximately this:  Which is a modernized version of a repetition crossbow, known also as **Chu-Ko-Nu** in China. * It is light if made of wood, or alloy, depending on resources. * It does not make too much noise. * It can fire rapidly, as zombies often move in packs. * It can be made in way that you can easily craft ammo from wood (crossbow quarrel) or replace some parts.Or you can even take out the ammo from those brain eaters :) * You can add a laser pointer to be more precise. * Ned can or take some spare parts/or learn to make a basic crossbow from scratch, that way he could still use his crossbow training. 2 - Melee In the same philosophy, I'd pick a **Quarterstaff**:  * It is light, has a good range (which is good with several opponents) and has a strong crushing power. * It can be used from close to middle range (still good if Ned is taken by surprise). * Ned can also use it on humans without killing them instantly (if someone tell him that's lame :D ). * It can be upgraded with metal coating, or pointy things at the end, we can even imagine using some flammable liquid to use on one end of the staff if Ned is confident. * It can be easily crafted from nearly nothing, and Ned will still make a good use of it if he trained with the previous one. * It can be made shallow, for the whole part to make it lighter, or one part to hide things. As for "lameness" I'm not sure what people would think about someone fighting with a laser repeating crossbow and a flaming quarterstaff, but I have my idea. :) [Answer] The problem with melee weapons is that it unacceptably increases the risk of infection. Letting the zombies get close to you just isn't a good idea. Ranged weapons usually have ammo issues. But what about a [sling](http://en.wikipedia.org/wiki/Sling_%28weapon%29)?  The actual weapon itself is extremely light, leaving additional weight to carry some ammo. But if you sacrifice accuracy, a sling can use almost any sort of small rock. This would let you preserve your stored, better ammo for when you really need it. Resupply is also very easy - just find a river or a home & craft store with rocks, and fill up. [Answer] The most effective long-lasting weapon is one you can put together yourself. Which is why I would like to suggest the humble Sock-Brick.  You're going to need to raid a shopping mall or clothing outlet for socks - should be easy since socks aren't high on the survival guide's most-wanted list. Strong socks are the best, so go for the tight-knit ones, or long winter stockings. The accompanying brick should be easy enough to find in a dilapidated post-apocalyptic world. Just search for any broken-down building or construction site. In a pinch, any heavy object will do, even a common stone. Then just tie the sock shut and swing it at offending zombies. Prepare a few in advance in case one tears. Keep extra socks in your supplies for this specific purpose. And as an added bonus - you can also wear the socks. [Answer] You want to keep these zombies far away, if they have all the abilities of a human. So, ever heard of Jai alai?  > > The Basque Government promotes jai alai as "the fastest sport in the world" because of the ball speed. The sport once held the world record for ball speed with a 125–140 g ball covered with goatskin that traveled at 302 km/h (188 mph) > > > Being struck to the head with a ball that fast is a guaranteed kill, and finding something to chuck shouldn't be hard no matter the situation. But what about melee? Well how about we make the cesta (the thing you are using to chuck stuff) from titanium, and use [ion milling](http://en.wikipedia.org/wiki/Ion_milling_machine) to sharpen the end of the thing into something that can slice bone like it's butter? It would be a khopesh at melee encounters, and a slingshot on steroids for ranged combat. Titanium is very light, and the ammo you would need is light (125–140 g), common, and best of all, reusable. [Answer] As noted in the question, guns are out of the question due to an inability to carry ammo/batteries. Anything with an edge has a chance of getting stuck in the target, so bladed weapons are out of the question. Bats aren't hipster enough. Lets throw that out the window. Maces are too heavy to lug around for 5 months, and Ned'll get tired after bashing in maybe 4 or 5 zombies heads in. Besides, given the chance that Ned has to fight in close quarters such as an alleyway, a mace is definitely too large and hard to maneuver - but this is a step in the right direction. What about lighter and smaller bashing implements? Who said you need weight in order to crush skulls? After all, force = mass \* acceleration. If we get rid of some mass and increase acceleration.... I would consider the following options: * A pair of titanium tonfas - Great for close quarters, flip them around and now you have longer range! They can be lightweight, and when used correctly, very fast and deadly. * With a bit of ninja training, some nunchucks would do the job. Fast, small, great for bashing in brains in close quarters when used correctly, while still having a fairly large attack range. Used effectively, he'll be able to indefinitely fend off attacks from the zombies via smacking away the grabby hands and legs of said zombies. *(If you haven't seen the video of someone using nunchucks to play ping pong, I recommend watching it - imagine that, but every time someone throws a punch or tries to grab you, you smack that hand away)* * Police issue telescopic batons **Personally, I'd equip him with the nunchucks.** **In fact, lets give the nunchucks an upgrade!** Lets add electricity to them, and make them shock targets on hit. We'll give Ned a pair of rubber gloves to use them with so he doesn't kill himself while using them. Now he can short out the muscle control of the attacking zombies with each hit! But he'll run out of batteries, you say? No he wont! Not if he uses the shakey-shakey-rechargey thingy that some flashlights use (I think it's a coil or something like that)! When he's fighting, it's charging! When he's not fighting.. well he can charge it by shaking it. Ned gets to be the first zombie killing ninja scavenger! That's some seriously hipster shitaku going on over there. Edit: Courtesy of KSmarts for this awesome idea. What about making Ned the first bat training zombie killer? Yes, the animal Bat. What if Ned trained some Megabats for the job? Perhaps if he had a group of 10 or 20 or so of the largest of these bats trained (which can grow up to have 1.7m wingspans), he wouldn't have to fight. These bats just.. pick up the targets, fly up high and drop them like rocks. The fall should be more than enough to turn them to mush~ [Answer] Ned drives a tank. The important point in fighting zombies is personal defense. With a melee weapon at some point you will get unlucky or tired and be caught unawares and so will be dead. So, take no chances. Modern tanks like the Abrams are much better than the WWII tanks most people picture. The Abrams is set for NBC protection, for example. It also has a range of 300 miles. If you need to go further, the Abrams is multi-fuel. In other words, it would run off diesel, petrol, or even jet fuel. What about close quarters? Well you could simply run your tank through the wall. Otherwise, note that the tank is noisy - thus it should draw out all of the zombies that are currently in hiding around the neighbourhood into one big crowd, that you can then happily crush with your treads. Leaving you to explore in safety. Of course this is traveling light, I mean, it's not like he's carrying the tank. :) [Answer] # Autonomous Quadcopter Laser Drones  Since we're going with [modern-age](/questions/tagged/modern-age "show questions tagged 'modern-age'") using currently-available technology, get a swarm of quadcopter drones and solar panels to recharge them. Equip each drone with a high-power laser and a camera. Use the drones' noise to attract/distract zombies, and the lasers to blind them (thanks [@DaaaahWhoosh](https://worldbuilding.stackexchange.com/a/17199/8622) for the idea). You can even leverage [@Murphy's answer](https://worldbuilding.stackexchange.com/a/17207/8622); attach some raw meat to a drone and use the scent to lure zombies wherever you want them...like off a cliff. Use them to scout an area before going there in person. If you scout an area and find zombies, move on. Or draw them out with the drones without ever exposing yourself to danger. Land them on tree branches around your camp at night, and use them as motion sensing guard dogs for sound sleeping. If you can, equip some of the drones with IR and UV cameras and other sensors so they can see/detect zombies through walls and foliage. All of the drones' abilities are non-lethal, so you can use them on angry hillbillies just as freely as on zombies, and you won't anger any zombie-huggers. You can use them to find game, spotting animal herds from above and then blinding a few members of the herd to make them easy prey. ### Drawbacks The biggest drawback is the weight of carrying around the required support equipment: * Spare batteries (most drones have short flight times; swapping batteries gets them back in the air quickly) * Spare parts * Solar panels + charging station * Tools to modify and repair drones * Protective goggles (for the lasers, to keep from accidentally blinding yourself) * laptop and/or smartphone to control drones, and to reprogram them as needed You can either use some sort of pack animal (or [robot](https://www.youtube.com/watch?v=W1czBcnX1Ww)), or travel slowly. A pack animal seems like the best and most reasonable solution. The other big drawback is relying on weather. You'll need sunlight to recharge batteries. Your drones will need to be rain-proof and wind-resistant. Your laptop and/or smartphone will need to be waterproof and rugged, as will your charging equipment and carrying cases. You'll want enough spare batteries that you can hole up for a week in bad weather - no expeditions, just making sure no zombies catch you with your pants down. Unless you're in Forks, Washington, or your trip is in the winter or local rainy season, this should be manageable. ### Last Resort As a last resort in worst-case situations, carry a pistol and no more than 2 clips. If you do it right, you'll never need to use it because you'll never be physically near a zombie. [Answer] Mosquitoes. The same technology that produced ZB101 also provides a kill switch or disease that disrupts the bizzare metabolism. He can breed the counter-infectious agent or zombie disease, using means as elaborate or simpke as needed, but elaborate enough that it doesn't just spread (well enough) naturally. [Answer] Pitchfork, a fairly common and reasonably light device, great for keeping folks away while doing damage. And unlike an ax there not much of chance of it getting stuck. Finally it has that nostalgic, traditional feel to it as people've using them to fight monsters since forever, but you don't usually see them in movies and such, so a bit of a forgotten charm. [Answer]  How about taking something like say a uhaul truck and converting it into a [wood gas powered vehicle](http://www.lowtechmagazine.com/2010/01/wood-gas-cars.html) (this is assuming that wood is a relatively plentiful resource). Give it bullet proof glass or a metal grate over the windows. Possibly give it solar panels and a battery as a secondary fuel source. With two abundant fuel sources you could keep the thing out and about without much issue. Gives you plenty of extra space for carrying stuff, you could stay inside it for most of the trip between locations, and honestly there are many ideas out there for weaponizing vehicles (I'll let others fill in this part, though I'll add that the wood gas can be turned into a makeshift torch/flamethrower, though I'd avoid this since you don't want to start a forest fire with you in the middle). Combine this with the idea from [@Martin Carney](https://worldbuilding.stackexchange.com/questions/17194/most-effective-long-term-zombie-killing-weapon/17287#17287) with it as a home base/charging point for the drones, and you could really have something. [Answer]  The first thing i would steal if a zombie apocalipse broke out is an armored bank truck. No, i am not interested in the money, because that would have no value without a functioning government. But an armored truck runs on regular diesel and has almost the same range as a normal truck, while being armored enough to resist most attacks. Attach fuel tanks on the cargo compartment and this range can be extended furter. Make holes and you can fire from the inside. Ned can sleep inside the armored truck if needed and have no worries about being robbed by other survivors. A truck is not the most silent thing around but its not too loud either. And zombies wont be able to break it. The only danger is a bunch of zombies trying to flip it over, this can avoided by being constantly on the run. It is better than a tank because their mechanical parts are usually shared with common trucks and might be scavenged from repair shops etc. If you get an older model with a non-eletronic engine, you can run it even without electricity. Diesels can be repaired easily by skilled people. [Answer] I like to tackle all questions with a step by step aproach. This time I'll start with the requirements: **Weight** Ned Needs to travel light, while having room for both the weapons, tools and food supplies. This means that his weapons should preferably be made out of *lightweight materials*. **Size** What is heavier, a 1 Kg box of cotton or a 1 Kg small lead sphere? They both weight the same of course! But what would you rather carry with you around? A gigantic bag of cotton or a sphere that you can fit in your pocket? The awnser is obvious. What Ned needs is a weapon and gear suited for *concentrated power*. **Defense** Weapons do not need to be just for offense, nor clothes need to be just for cozyness. Ned may be able to fend off one, two, maybe even five zombies at a time. But what happens when he's cornered? He might have to take a few hits, and as such his gear must allow for *bite and scratch protection* **Repeatability** Guns fire a finite ammount of rounds depending on how many bullets you're carrying. Swords will slash an infinite ammount of times, depending on how much energy you have. But what will happen is that if the melee weapon gets stuck or the ranged weapon jams, you're screwed. Ned needs a weapon that doesn't jam, run out of ammo (or has salvageable ammo) and doesn't get stuck. So, what are the options? * Swords * Knives & Daggers * Blunt round objects (like Baseball Bats or Pipes) * Blunt Flat objects (like a sledgehammer) * Tools (Screwdrivers, Hammers, Wrenches) * Powertools (Chainsaw goes here) * Magazine Pistols (Such as the Glock) * Round Pistols (Such as the Magnum) * Assault Rifles (Such as the M4A1) * Sub Machineguns (Such as the Tec 9) * Rifles (Such as the Springfield Rifle) * Shotguns (Such as the Winchester) * Bows * Crossbows * Throwing Knives / Axes * Flamethrower * Grenade Launcher * Farm Tools (Hoes, Shovels) * Knuckles * Bladed Knuckles (A la Wolverine[ish] ) * Spiked Knuckles (A la Knuckles, from Sonic) * Bladed or Spiked Armguards * Horned Helmets * Spiked Kneepads * Bladed Leggings * Spiked/bladed Footwear * Shuriken, Kunais * Hidden Blades (A la Assassin's Creed) Well, those are a lot of options, most aren't reliable though. Powertools are loud and you want stealth. Sledgehammers, Axes and the like are heavy and sometimes unreliable. Blades and Spikes may get stuck, but blunt weapons may not always work. Ned also needs **range**. Dealing with Zeds from a distance is better than from a close range, but he should have better ways to finish Zombies at a close range. But now, for the fun part! **Weapons in Clothing** Handling different objects may hurt someone's skin. Ned isn't different, he can get hurt by just messing with things around, so he should probabbly be wearing gloves. It is possible that he has to fight at a *very close* range, and he might be forced to use his fists to fend off a walker. Having a spiked glove can increase the effectiveness of his punches. He should be wearing something that makes walking for hours not such a bad thing, and cozy boots are the way to go. I would recommend having a spike on the tip of the boots just in case, however it would be harder to climb ledges with it and as such the boots should just be sturdy and cozy. The natural reaction when someone's attacking you is to protect your body with your arms. Having an armguard is key here. Jaws' jumping at you? Block it with your arm and they'll be biting what they can't chew. For added "swag", include an Hidden blade in one of the armguards, once again, for that close range *last second save* **And finally, the weapons** A Modified Crossbow is the ranged weapon of choice. Always. Easier to aim than the bow with the only drawback being slowish reload. But this is where the modification would fall into. A crossbow shoots a bolt that is usually placed by the shooter. Replace that by a magazine with several bolts, while having the crossbow having it's string replaced by a pump-action reloader. This way not only you can shoot more than one bolt without reloading, but reloading will solely consist on changing magazines. Bolts are recoverable from targets and can be placed in the magazine after usage. Bolts are also crafetable if any are lost. A modified Katana. Broadswords are usually larger (and thus heavier), Katanas are also known to be sharp (more on that next) and can cut through bodies. This is the weapon of choice against small groups as it has some range and ease. This katana can be modified into a GunBlade, which means that it can also shoot one or two pellets from its hilt. or A Bo Staff. Weighs almost as much as the Katana, but it has two blades and a larger armguard, which can also be used to block creeps. In Panic, it can be thrown as a Spear (to change to a short range weapon) and A small round shield. This shield should be on the opposite arm (not being held by hand) of the hidden blade, and be solely used as a gap creator. Are they too close? Bash one with the shield to gain a second while you can fend of the remaining. **In Conclusion** A Pump Action Magazine Crossbow for long range takedowns A Gun-Blade or a Bo-Staff for hand to hand fights A shield to bash Zeds away An Hidden Blade for Last second saves Spiked Gloves for the same reason as above All Blades, Shield and other protective items would be made out of [this](http://www.popularmechanics.com/technology/news/a13919/new-steel-alloy-titanium/) **Some Images** (They are incredibly big, hence why the links [Gun Blade](http://1.bp.blogspot.com/-v-fRvQ-yZwk/TwrVHKPT5MI/AAAAAAAABAU/QUjpUxfLH0M/s1600/11.102c+Espada-pistola+del+Comisario%252C+detalle.jpg) [Armguard with Hidden Blade](http://i.ebayimg.com/images/i/271121992191-0-1/s-l1000.jpg) [Spiked Gloves](http://a2.l3-images.myspacecdn.com/images02/42/8dd65260cd254046a4e1639719034958/l.jpg) [Magazine Repeating Crossbow](http://i.ytimg.com/vi/TAyCVTV8-lM/hqdefault.jpg) [Arm Shield](https://img0.etsystatic.com/035/3/6915080/il_570xN.551918900_jk85.jpg) [Dual Bladed Staff / Combat Bo Staff](http://i5.photobucket.com/albums/y188/Goten4Eva/Random%20Pictures/spears_double_headed.jpg) [Answer] **The Gladiator** Zombies are not tool users, as such, they're capable of only melee combat. For the style factor, a gladiator type loadout might help with the style factor. A spear is relatively light-weight, at least it should cause no problem for a fit post-apocalypse survivor, and provides the safety of keeping your enemy at a distance. This prevents bites and grappling, while offering efficient killing potential. A simple metal blade is neither terribly difficult to forge, nor to maintain, and difficult to break. The shaft of the staff may be more fragile, but is easily replaced and can also be replaced with materials stronger than wood for better durability (albeit likely more weight unless you use a lighter metal). A dagger or large knife honestly is likely already commonplace on nearly every survivor as it is useful as an emergency weapon in close quarters, and as a tool. This adds very little to the overall weight of the kit, and provides a means by which to create a new spear shaft from available wood if necessary. A short blade of some type allows Ned to continue to defend himself in tight quarters or in the event of a broken spear, while also not adding too much to weight. Again, a simple blade is easy to craft, easy to maintain, and durable. Optionally replace with a handaxe for an additional multi-purpose tool/weapon. Flint and steel allow fire starting which doesn't really need explaining, everyone understands the plethora of uses of fire from cooking to light sources to distractions and more. Despite the heat, a double-layer of some light but sturdy material. This should hopefully prevent any stray bites or scratches from breaking the skin and infecting the bloodstream. If not full body then at least in key locations (forearms, upper arms, gloves, neck, and legs). This could be a layer of leather, or even things like normal clothes wrapped with reinforcing layers of duct tape. The goal here isn't to make armor, only to prevent the skin being broken, this should still be a fairly light-weight solution. I had initially considered a cape or cloak of some sort, which could also be quickly bundled around an arm to block or deflect, but honestly it would provide too much purchase to grasping zombo's. Obligatory bundle of rope. Every good adventurer needs one for escapes, shelters, prisoners and more. Thus our leather or duct-tape clad gladiator can face the infested hordes and build his glory. (While still being light weight enough to hopefully outrun any hungry foes should their numbers prove too great). [Answer] Requirements: Easy to use, does not wear out, powerful enough to quickly drop a zombie. As it is about survival, and you do not know what the circumstances will be, better have several. Both ranged and melee, just to be sure you can always defend yourself. Ranged primary: [Crossbow](http://en.wikipedia.org/wiki/Crossbow) for the first two weeks until you loose it the predecessor of the gun will make your life easy. Comparatively. Ranged backup: [Slingshot](http://en.wikipedia.org/wiki/Slingshot), carry in your pocket always, pick up ammo from the ground. Secondary ("left") hand: [Katar](http://en.wikipedia.org/wiki/Katar_(dagger)). Deadly cutting edge. The basic attack is a direct thrust identical to a punch. Or: [Trench knife](http://en.wikipedia.org/wiki/Trench_knife) Primary ("right") hand: [Cutlass](http://en.wikipedia.org/wiki/Cutlass); sailors casual fighting choice, and for good reason. For some, using both hands: [Plain shovel](http://en.wikipedia.org/wiki/Entrenching_tool). WW I proved this concept beyond any doubt. Best of all: (purely defensive) [Hook ladder](http://en.wikipedia.org/wiki/Hook_ladder). Live another day. Not a weapon, though. Carry on back to have some protection. [Answer] **Insects**, such as **flies** :)  What happens with every rotten corpse in our word? Maggots will eat it. Pretty fast, in good condition in 8 days, only skeleton remains ([source](http://www.policie.cz/clanek/mrtvola-jako-krmne-medium.aspx) - but its in czech language, i am pretty sure you can find with little google fu similiar source in english) and the "normal" time is about month, then there stay only bones with a little tendonitis. Flies start attacking even living body with injuries, but we have immune system which will try to take care, but zombie? :D [Answer] For sale: **The Zombieliminator** - Your ultimate zombie killing machine! Guaranteed for life or your money back, this one-of-a-kind zombie-killer does the job of killing those pesky zombies for you! Easily able to fit in the bed of your truck, just crawl inside our bullet-proof box when the zombies start coming, lock the door, smell delicious, and the Zombieliminator will take care of the rest! With our would-be-patented-if-the-government-still-existed decapitator holes, when a zombie sticks their head or other appendage too far into one of these holes for a bite of your nummy flesh, a laser sensor is tripped that activates our commercial-strength self-reloading guillotine to chop it off, followed by our environmentally-friendly catch-and-release zombie-part-ejection system to avoid zombie-part buildup in your comfy zone. With standard solar power recharging during the day, battery backup for up to 18 hours at night, and two manual crank generators should those fail, we have you covered! But wait, there's more!!! Buy before ZB02 and, for those times you need to be out and about, we'll throw in a utility belt with a **spiked club**, a **rechargeable taser**, and a **samurai blade** forged in the \*Depths of Mordor...completely free of charge! Don't miss out on this incredible deal!!! \*Our foundry's name (Visit block 43 for complete details and pricing) [Answer] The best zombie killing machine is the flamethrower. Even if the heat does not cook up their brains, the fire will destroy muscle tissue enough to stop it in place. A team of flamethrowers can clear a whole city square in matter of minutes.  Edit: The major advantage of flame throwers is that they use napalm. Napalm will burn continously and stick to the target, so the zombie will be charred while slowly trying to reach the person firing at him. Problem is, its hard to find napalm, and the pure gasoline that can be used as replacement will not stick to the target, it will drain to the lowest level. Thats not enough to cook a zombie with the ammount of fuel that a personal flamethrower carries. I will give another idea in another answer. [Answer] I'm going to suggest 2 items, a spear type weapon (ie melee, no ammo requirements, and allows to keep a bit of distance) plus a disabling weapon such as a net, bolas or lasso. Against a lot of zombies, you only really have 1 option - be like Brave Sir Robin and run away as fast as you can, but this applies to most scenarios with most equipment. Against 1 zombie, get him tangled up in something so he's on the ground and not going anywhere or able to be much of a threat, and then you can walk up to him and stab him with your spear in the relevant places until he stops wriggling. (a machete or other short sword might be a good thing to include just for completeness). [Answer] Flail. The problem with a staff/spear/mace is that they are long and stiff. You can make a flail out of a handle, chain, and any solid object which can be attached. The chain can be as stiff or light as you prefer, and as long as you can swing around effectively. It doesn't need to be chain. It can be a synthetic rope which resists twisting/abrasion and very lightweight and strong. The important point is that Ned will not have any reliable sources of external energy, so every zombie he kills will need to be done with human power. A crossbow gives good range, but the ammo is expensive to find/make and you have to carry all of it. A long stick gives good defense, but is heavy and inflexible. A sling is a good ranged weapon, because it's light, but probably doesn't deliver enough force to kill a zombie. A flail gives some range (adjustable to arbitrarily short distances), is lighter than a staff/mace, and allows Ned to use as little or as much energy as he can deliver to dispatch a zombie. Weak zombie? Short spin-up, quick pop. Tough zombie? Let the ball extend to the full range while you spin it up, even using both hands, and wallop the zombie with your full body's strength. If Ned can kill the zombie with his bare hands, he can kill it with the flail at some distance. If he can't, then no non-assistive weapon will save him. If he wants to get really creative, he can use piano wire for the chain, and now the chain itself doubles as an edged weapon...if he spins it fast enough, he can decapitate or at least de-limb some zombies. For instance, he could sling the ball around a zombie's neck, which would swing around and form a noose. Then a quick jerk would effectively garrote the zombie. I don't think anyone would call Ned a sissy after seeing him bashing and cutting down zombies with razor wire. The advantage of wire over an edged weapon is that it isn't sharp due to a cutting edge. It's merely sharp due to having a very small but stiff diameter, so it doesn't require sharpening. As long as it works as a wire, it works as a cutter. And Ned can choose a blunt-force or cutting blow by simply changing whether he hits his target with the ball or over-shoots it for a nice wrap-around. If he has enough wire, he can also use it as a climbing aid by attaching a grappling hook to the end to replace the ball (or he can just rely on the ball to grapple around a pipe/branch). For instance, he might have a spool with a hand crank so he can hook high distances and do an assisted climb to safely hide in trees or buildings with broken-down staircases. The weapon can be folded up into a very compact space, and the weight is determined primarily by how much mass he wants available to swing around. Lighter mass means he will need to swing a wider arc to deliver more force, so he will need something that is at least a few pounds, unless he relies primarily on the cutting effect. The weapon requires no ammunition and little maintenance. He could probably adapt it into a sling for ranged effect (and practicing with the weapon would probably give him skills transferable to a sling also). [Answer] So, first of all I'd suggest a weapon that disorients the zombies. Make sure they are as easy to kill as possible, and in a way that is easy to keep doing for a long time (flashbangs run out pretty quickly). So for this, I'd suggest a laser pointer. Apparently, you can get a laser that blinds people permanently; in this case, all you need is temporary blindness, so I'm sure you could get a laser that runs for a pretty long time on normal batteries (so a pack of them should last you until the point where the zombies die out). But lasers don't kill zombies. For this, I'd think you want to keep as much distance as possible. Samuel mentioned a mace; against one zombie, this might work, but against two or three I don't think you'd be able to hit everyone before they grabbed you, and once they get hands on you you're in a bad spot (if not dead outright, you're probably hurt or infected, not very sustainable). So here I'd agree with Michael and recommend a spear. Spears were used for thousands of years in wars as a great and perfectly safe way to kill someone who doesn't have a spear. They keep your foes far away, but can be easily adjusted to deal with close threats (just move your hands closer to the pointy end). With enough skill, Ned could stab at a zombie's head, killing it in a single thrust before switching to the next target, all the while staying a few feet from any danger. Not only are spears useful, but they're also pretty simple in design. All Ned needs is a long stick with a pointy end. If he wants, the pointy end could just be a knife (like a bayonet) that he can remove whenever he needs to do knife things. The stick could be designed to fold up when not in use, which would let it fit easily in a backpack (this might be dangerous, as maintenance and strength would be an issue, but I'm sure with the right materials it would be strong and durable). Plus, this could allow Ned to carry multiple spears at once; he could throw a few early on, distribute them to other survivors, or have a backup if he ever gets disarmed. I should mention here that javelins are pretty effective ranged weapons (far more reliable than throwing knives or blunt melee weapons), so for single-zombie situations Ned could surely just unpack two spears, throw one, and have the second ready in case he missed. So, in summary (**TLDR**), Ned should carry a series of folding spears with detachable knives and laser pointers on the end. He points the spear at the zombies to blind them, then thrusts to kill them. Funnily enough, the laser pointer could even help him aim. [Answer] **Hamster-ball and Laser** Human hamster-balls are what you want. 1. It keeps you from touching those cootie-filled Zombies. 2. You can cross water. 3. If they push you down a hill, you'll probably survive. (Wear lots of pillows.) 4. You can fire a laser through the plastic to blind the Zombies. 5. You can keep your supplies with you. No Zombie is getting my Pringles! 6. You can make the ball of durable plastic like Lexan. 7. Make sure that the release mechanism can't be operated from the outside when you are inside. 8. You can sleep inside it. 9. You can paint cool graffiti on it to look cool. 10. If its big enough, you can bring a date. Stairs are a problem in urban areas, though.  [Answer] Ned needs to be able to strike first. A polearm is perfect: it can stab, it can slice. It's got decent range. --- A bullwhip is also a brilliant weapon: capable of removing guns, swinging over pits, trips up enemies, moves faster than sound. Indiana Jones really can do all that he did with his whip (see Mythbusters episode on the subject.) I'm not sure if adding a barbed tip would change the aerodynamics of the whip or not. [Answer]  * Lightweight * Durable * Modern Its only drawback is that it's only for close-range combat, but if you use the silencer the zombies will not notice you. [Source](https://web.archive.org/web/20161221060227/https://imgur.com/gallery/aOg5t/comment/394453848) [Answer] **Post-Hole Digger** This is more of a long term solution for a semi-permanent encampment, but bear with me. Zombies are not particularly bright or dexterous, especially when they are chasing someone. In a circle around your camp, you basically make a minefield. Except instead of mines, you use a [Post-Hole Digger](http://en.wikipedia.org/wiki/Post_hole_digger) to dig holes 2-3 feet deep in a random pattern with a foot or two of space between them. You can use cars/rubble to channel the zombies into gauntlets so you don't have to dig quite as many holes and can have a longer danger zone. Zombies stumble through breaking legs as they step in the holes, where a human can fairly quickly traverse (as long as there's light to see by). You would probably need a club or some other device to finish off the zombies, but it will be a lot easier dealing with a zombie that has one or both legs broken, and pretty much any other weapon will do the trick. Regular cleaning of the pit-field is highly recommended to prevent slower zombies from walking over the early victims. This solution does not take into account hordes of zombies, but if you are being chased by a half dozen or so, leading them through a trap like this could save your life. It's been mentioned that in some ways this doesn't exactly fit the bill. So obviously the solution is to modify the device so that the two pieces can fairly easily be separated. Each person in the party carries half of one. Sharpen the blades and you have a spear (good for keeping zombies out of reach) when mobile, and the means to make your camp safer on stopovers. Having each person carry half of one provides redundancy if one of the party should get lost or killed.  [Answer] If Ned needs to defend himself in a stationary position, a setup similar to this could be useful. [](https://i.stack.imgur.com/dSViT.jpg) * Can be automated * Can keep a large area clear * Does heavy damage * Infinite shooting capibilitys Using lasers, you don't need to constantly be supplying more and more ammo, you only need a significant power source. This could be attained by using a large solar field, or using a cold fusion generator. Although we are only considering current-day technology and cold fusion doesn't exactly work yet, Ned needs this weapon to fight off *zombies*. I have not ever heard of anyone actually seeing a zombie outside of a *horror movie*, *scream park*, or *haunted house*. So, I'm assuming we can deviate from reality a *little* bit here. You might be thinking, Zed can't stay in one place, he needs to be moving around. A laser-cannon / rail-gun permanently mounted in concrete will not work. There are portable lasers, although ones powerful enough to seriously hurt zombies would be very heavy, and use a lot of energy. so hand held laser weapons are out of the question. Currently the only working rail guns that exist are quite large and are far from portable. (by working I mean have enough firepower to actually kill/stop a zombie attack.) However, this gun will be designed for killing *zombies* so it doesn't need to be 100% realistic.  * Has **Very** long range * Has **Infinite** firing propellent. * Will penetrate multiple targets. * Burst fire on one magazine. (for dealing with many targets spread out) * Can shoots rocks = **Infinite ammo**! (the world is full of rocks) The main benefit of a rail-gun powered by cold fusion is that as long as you have something to fire: small rocks, nails, screws, (pretty much anything small and hard) you can never be defenseless, and you can defend yourself from quite a distance. Unlike coil-guns, rail-guns can fire non-magnetic projectiles. they do this by propelling a slider forward holding the projectile. when the slider stops, the projectile keeps going at incredibly high speeds. Another bonus is that the magazine is spring loaded and can hold pretty much anything you can fit in it. when the gun fires, the slider fires forward on the rail, and once it releases the projectile, returns to the loading position, where the magazine will feed another round. As long as Ned can keep enough junk in the magazine, the gun will always be ready to fire, which is especially important in the case where zombie happens to sneak up on him. [Answer] 1: durable plastic tube with a grip bolted to the inside. strong enough to punch and break concrete and provides forearm protection. 2: rubber insulation and kinetic charger (through spinning) Electro Whip iron man style 3: napalm ~(diesel and polystyrene) kept in a safe location for the hoards of zombies. 4:fish line. create traps in doorways for quick escape without being followed to regroup. 5: grapple hook. Zombies cant climb, up up to the chimney tops. 6: Pheromones to confuse zombies. 7: nano bee army... because Shino is god. 8: face mask... if blood getting into your system is enough to turn you Zed protect your face. 9: Assuming gps is usable, that. 10: infra red vision, because look in the shop before you go get food remember the aim isn't to kill the zombies, its to survive.. i prefer to go down swinging ]

[Question] [ In my story's world, witchcraft is a respected institution, with the most powerful practitioners being at the top echelons of society. Due to this, society traces its lineage through matrilineal lines. Witchcraft is usually exclusive to females, however there is a way for males to gain access to magic abilities. Magic works through incantation, in which an individual says a phrase while using their mana to power the spell. A witch (female) has the ability to share her power with another using an advanced, ancient ritual. They can open up their connection to magic with the respective individual, creating a "warlock" (male). Warlocks can draw on a percentage of mana of the respective witch to conduct spells, up to 50%. Some rules with this system: 1. A witch can use her max limit of 50% in different combinations. Ex: she can share fully half her power with one other male or spread it out over 5 people with 10% each. 2. When a witch dies, the warlock loses access to their mana and can no longer use magic. When a warlock dies, the amount of mana that was siphoned off by him returns to the witch. 3. Advanced spells that require a certain amount of mana become harder or impossible for a witch when a warlock is siphoning mana from them. 4. A witch can revoke the connection between her and the warlock with an equally advanced, complex spell without him being present. Under these circumstances, what would be the benefit of creating a warlock when it makes the witch weaker? Why would one invest in this process? [Answer] Many of the other answers have said some of the things I was going to say, but nobody has mentioned these two: ## Warlock as Prince In feudal times, who married whom was very much a political affair. Marriage was used to cement alliances and political connections. In the same way, choosing to make someone your warlock will bring your house and theirs together. Making someone a warlock has huge political benefits, and comes with the great side benefit that now they're invested in your well-being (where maybe they weren't so much before). The merchants in House Terramille giving you too much trouble over something that's not worth starting an out-and-out war over? Find a few minor sorceresses and get them ~~married off~~ warlocked-up to second or third sons of lesser branches of the House. The Earl of Preston is getting antsy because he shares a border with you and worries that trying to compete for resources with the Sorceress' Tower will ruin him? Convince him of your goodwill by making him one of your warlocks. In fact, let's just cut this off at the pass. Any ruler of any kingdom sharing a border with us should just be one of our warlocks. This works best with middling, weak-but-not-TOO-weak sorceresses. The pratical drawbacks are much less. Really powerful sorceresses actually care that the power gets used how they want, leading to ... ## Warlock as Cannon Fodder When a warlock dies, nothing much happens to the sorceress. When a sorceress dies, that's all, folks! So for certain types of really dangerous missions - ones that don't require access to the demanding spells - you want to send a warlock. If they accomplish their mission, great! If they fail, no big deal. This works especially well if you can un-warlock somebody. They sign a contract where they agree to undertake several near-suicidal missions in place of Archwitch Weatherwax, and if they survive, they get to keep their warlock powers for a year and a day, and probably a bunch of cash and in general the kind of good things that follow having someone like Archwitch Weatherwax owe you favors. You can field an army of (say) 20 of the best witches you have. And sometimes that's great, and sometimes you need them at their best. But it's often better to have an unending army of (say) 20 not-quite-as-badass warlocks, that you can simply replenish as needed. [Answer] The simplest answer to this is productivity. Just because a witch has access to a specific amount of Mana, it doesn't mean that every spell that needs to be incanted *requires* that much Mana at once. Think of it like electrical engineering; you may have a 10 amp line (with a 10 amp fuse in it), but that doesn't mean you can only run one device off that line; if you have 3 machines, each of which draw 3 amps, you're good. So, your witches are in the same boat. Creating their warlock may impede their *peak* load, but having a warlock available means that (assuming it's someone they trust) they can generate multiple spells at once because they (and their warlock) can operate in parallel. You might actually find that the normal 'practice' would be to create a warlock at around 20% of Mana draw. That way, he or she can handle all the 'legwork' spells, all the light stuff without impeding the prime witch too much, and actually allowing her to focus on all the high value and more dangerous work directly. Also, this would really help with warlocks that turn on their witch; the warlocks don't have the capacity to beat the witch in a fair fight with magic. Ultimately, it comes down to whether you want to spend a week doing something (most of which is mundane or boring work) or if you want to outsource the easy stuff to someone and get on with the interesting stuff directly, which you keep for yourself because your subordinate warlock doesn't have the capacity to do it anyway. Also, you'd probably find plenty of takers among the Muggle crowds, willing to do the legwork on grounds that it's better than no magic at all. [Answer] I can see a few different useful applications for a warlock, assuming smaller spells don't typically require substantial amounts of a witch's mana to be cast. First, having a warlock means the witch can now cast two spells simultaneously, effectively doubling her casting speed. Should she find herself in a combat situation with another witch she will be able to fire two fireballs at the same time, or otherwise delegate defensive measures to her warlock while she focuses entirely on offense. The warlock uses her mana to block incoming projectiles while the witch launches attacks. The rival witch, while able to pull off much bigger spells, will be overwhelmed, as she won't be able to keep up with the casting speed of two individuals at once. Secondly, having a warlock means the witch need not be present in order to use her magic. A witch could easily send her warlock to another location to carry out whatever spells she needs doing without putting herself at risk. Sure, she may be less powerful now, but she can be in a safe location where she isn't likely to be targeted while still exerting her influence through her warlock. If the warlock dies it's not much of an issue for the witch as she gets her mana back anyway and can just create a new warlock later. Thirdly, if there is no way to determine who is a warlock and who is a witch, the witch could use the warlock as a proxy without revealing her own identity. The enemy may kill the warlock thinking they killed the witch and lose her trail, or they might not be able to figure out which witch was empowering the warlock in the first place. The witch can effectively act without repercussion until her enemies discover her plot. [Answer] **Could *love* be a factor?** The sharing of power with another would almost certainly create a lasting bond between the two. A connection that goes deeper than the mere practical exchange of power. It might be possible for one to have some sensations or feel limited emotions of the other through the bond, which could strengthen the longer the bond is held. After all, witches are still human and still feel that need to be with another. And the ancient ritual is not undertaken lightly. *The witch must give a part of herself to the warlock.* Should the warlock die, the witch would feel this loss instantly in the regaining of her power. Similarly, should the witch die, the warlock would feel the sudden emptiness as their source of power dies with her. Such intimate knowledge of another could only serve to strengthen a bond between two people. EDIT: As suggested by [@T. Sar](https://worldbuilding.stackexchange.com/users/3245/t-sar) in the comments, a common trope is that magic users age differently\* to non-magic users, such that both the witch and warlock could end up with longer lives. This would support the *love* theory in so far as the magically bonded partners would be able to age at similar rates (assuming the sharing of power would also share that ability and assuming the magic users in this world age differently), thus having more time to spend with each-other. \*[Lord of the Rings](https://scifi.stackexchange.com/questions/58952/how-old-is-gandalf), [Dresden Files](http://dresdenfiles.wikia.com/wiki/Longevity), [Harry Potter](https://www.quora.com/How-does-aging-work-in-the-wizard-world-in-Harry-Potter-Do-wizards-live-longer-or-remain-fit-longer) and I'm sure many others. [Answer] Witches need to sleep or conduct rituals that cannot be interrupted. Warlocks are the guards they need to protect them when they cannot protect themselves. The lost mana isn't really an issue as it's returned when the warlock dies so a suicide run against an enemy is a great way to get your power back and weaken an enemy at the same time. [Answer] ## Covens If a single warlock can have multiple witches that have bound him you can create super powerful warlocks that can do stuff no single witch could ever hope to do. ## It's a requirement to bring a child to term An unbound witch' mana is incompatible with pregnancy. A warlock siphoning off some of it calms the mana down enough that the fetus can survive until birth. As a variation the physiological changes during pregnancy can make using magic impossible and the warlock provides a means to still use magic during pregnancy. This makes the warlock ritual a lot more like marriage. [Answer] ## Increasing the chance of magical female offspring You could make it so that magic is inherited via the X chromosome and true permanent magic users must have two, hence be women. Perhaps the ritual transmitting magic abilities temporarily affects the male‘s X chromosome, making it certainly carry the magic gene. Then any **female** offspring of witch and warlock would be a guaranteed witch! You could even go further and say that male children from such a union make very good potential warlocks as they have f.e. one unexpressed magic gene. I could see, why both witch and warlock would want to ensure their offspring are magic users... [Answer] ## Advancement as an incentive *"Wychguild Incovenated is the world's top private magic contractor. At Wychguild we believe in building a better, more meritocratic society and seek to lead by example. That's why we offer our employees the chance to advance themselves and the world through scholarships and magi-sharing."* *-Esmerelda Weatherwax, spokeswoman for the Wychguild Weathertop Department* ## Delegation of responsibility The ability to share a portion of their magical power(I assume the witch can control the amount given out) improves productivity as mentioned by others by allowing witches to increase their presence through proxies. Witches can assign work that is not worth their time to warlocks. It also allows for greater gradation of response in fields where there is useful. For instance, in law enforcement warlocks could be the equivalent of beat cops and witches could be equivalent to SWAT. ## Separation of powers (in multiple senses of the word) Reducing the power of individual witches can be a part of the constitutional checks and balances that ensure that competition within society remains peaceful and constructive. Greater concentration of magical power implies greater concentration of authority, making it easier for individual or small groups of rogue witches to cause unrest or in extreme cases, civil war. [Answer] ## Force Multiplication If I need a couch carried downstairs, I would rather have the help of a friend than I would two or even three times my normal strength. For many tasks, having multiple people of weaker strength is far more effective than one stronger person. [Answer] # Two persons are better than one, especially when one is dispensable * **Maybe some special spells need special rituals or casting that require two witches to cast it.** But if you don't have another witch friend, you could make a warlock and together cast it. * **Warlocks are dispensable**. If a warlock dies, you just need to make another. You can send your warlock to dangerous missions because if it dies, it won't be a huge problem finding another. If your question now if, **how/where can I find and convince a person to be my warlock**, it's quite easy to answer: + **Power**. You lend to your warlock the 50% of your power, so he is able to cast magic. If he works for you, you will let him use magic at will in his free time, everybody wants to be special and do magic, someones are ready to sacrifice for it. Maybe, you could send your warlock on a dangerous mission, and if he survives you will let him "free" for holidays for some months, time where he can use it's magic for himself. Maybe, being a warlock means age slower... + **Fame**. I don't know if in your world warlocks and witches are famous, but if that is true, any person with a high ambition would love to be your famous warlock able to cast magic. + **Money**. If witches are able to cast magic it's quite probable they may have a lot of money. You could hire your warlock as a magical mercenary. * **Youngness:** Witches transfer 50% of the power to the warlock... but nobody knows that warlocks without noticing transfer the same amount in lifeforce to the witches. That is how witches are always young an live forever. [Answer] ## Because mana is destructive Harnessing and controlling mana is taxing, both on the body and the mind. It starts eating away at you, especially when it's not being used. And for the most part, you don't need to cast powerful spells in your everyday life. So you siphon off a portion to someone you trust, to safeguard your own health. ## Because some spells are too complex Some spells require multiple people to cast. One to provide a some base level of magical current for the other to do the complex casting with, for example. Partnering up with another witch is riskier than having a warlock that's dependant on your magical ability. ## Because being too powerful is a risk Other witches can detect your magical power. They may see you as a challenge or a rival. Witch hunters, a sect of crazed terrorists, go around killing off powerful witches in secret. Ordinary folk are superstitious and are, at best, unnerved by your presence. Whatever the reason, casually pointing the magical equivalent of an AK-47 at random people isn't for you. So you take the target off your back and plaster it on someone else's. [Answer] Sorry to be late to the party, but this question got my mind working, so here is everything I could think up. Hopefully it's of some use. **Magic as a mundane force multiplier** Suppose the warlocks are really good at some mundane skill. Giving them magic - especially if the magic didn't require years of study and practice since that would have been done by the witch - would make them that much better. Examples: Commandos who can infiltrate enemy lines, sabotage equipment, and carry out assassinations with strength magic or stealth magic / veterinarians who can speak to animals / day traders with minor precognition. **Team spells/rituals** Many real world artisans work in teams, with one master craftsman and some assistants. Maybe magic is similar with some spells and rituals requiring multiple casters. The warlocks don't have to be masters, just proficient enough to do their part. Maybe everyone casting the spell has to have magic from the same source. **Protection against aging or disease** Maybe men and/or women die young if they don't transfer magic. Worse yet, maybe they come down with a debilitating degenerative disease, like a magic Alzheimers or Parkinsons. Maybe without a transfer their mind eventually gets possessed by demons, spirts, alien intelligences, or magic itself. **Palace intrigue** The royal family has two daughters, and of course the eldest one is going to get the throne. The younger daughter, or her allies, finds Joe Conman off the street and turns him into a warlock. Using his new magic to buff his appearance and charisma he becomes Courtesan McStudly. All he needs now are some official documents and an expense account and he's off to seduce the eldest. Options include making her elope with him, getting her pregnant, converting her to a heretical religion, luring her into a dark ally and stabbing her - whatever works in your world to disqualify her from the throne. **Covert operations** At 10 am a warlock stealthily casts a spell causing a guild building to explode killing everyone inside. At 10:05 am, the witch who created the warlock reverses the transfer erasing all traces of her magic from him. The city investigators immediately try to track the magic to it's caster but they can't (the witch is in a different city, the warlock has no trace of magic on him), so now the only way to find the culprit is good old fashioned investigative work. **The transfer isn't unidirectional** Maybe the warlock gets magic, but the witch gets access to something of his. His knowledge and skills? His senses? Maybe a witch can transfer fractional percentages of her mana into dozens of individuals. So the entire palace guard could be linked to a witch allowing her to see everything that is going on and help coordinate defenses. **Microtransfers** Continuing the idea from above - giving some guy 0.1% of your power in exchange for access to his sight or hearing would be very useful. And who says the guy needed to volunteer. Get some enemy soldiers or dignitaries drunk, do the ritual, then sit back and take notes as they reveal the layout of the camp, their battle plans, their negotiation strategy, and everything else. **Puppets** Maybe a suitably powerful witch can usurp the mind of the warlock and make him a puppet. Combine with forced transfer for tons of fun. Maybe trigger a self destruct spell and turn the unwitting warlock into a magic IED. Just one more way to get rid of that elder daughter in line for the throne. **Power transfer** What if the witch creates a warlock and then has him gather additional mana and transfer it back to her via the connection. **Area of effect** Create four warlocks and station them at the cardinal points of a city or castle. Then the witch can create a shield around the boarder of the square. Or maybe drop a plague inside the square. Or maybe the warlocks can function like pylons in Starcraft allowing other magical effects to happen within a certain radius of them. **The power of love** Maybe a power transfer is like a wedding band and marks the couple with a visible brand (like a Bindi or something). This is necessary for the marriage to be officially recognized by the society. Combine with higher chance of magical children, or the ability to have children at all, as described by other posters. **Hive mind** Not just a power transfer but the option to join consciousness as well. Maybe leads to better problem solving, faster learning and mastery, synchronized combat tactics, and the risk that the witch and warlock lose their individual identity. **Sacrificial spells** Maybe magic is so powerful (or tainted by evil, or whatever) that many spells require the caster to sacrifice themselves or parts of themselves (why else would you have 2 kidneys?). Witches create warlocks to soak the damage. When they die, just make another. Combine with unwitting warlocks for a real dark scenario. **Releasing hidden power** Some men harbor insane magical energy inside them, but it can't be used unless a witch transfers a certain amount of her power for a certain period of time. Maybe if Joe Accountant gets a 20% transfer for a year he gains the ability to Hulk out and smash his way through an enemy fortification. **Warlocks protect the witch** (variant of some of the above) The universe itself doesn't like magic and actively seeks to punish witches for using magic. For some reason warlocks are immune to this and confer that immunity onto the witch. **Warlocks unlock the witch's full potential** Although she gives gives some of her magic power to the warlock, the bond allows the witch access to some greater knowledge or power. Maybe witches can only cast Yin magic unless they have a warlock, then they get access to Yang type magic. Alternatively, only Warlocks can cast Yang magic, so if the witch's ritual needs Yang type magic to function she needs a warlock. **Magic affinities** Variant on the above. Maybe a given magic user can only access a certain number of magic forms. Saraphina the witch is skilled in water magic and necromancy, and that's it. If she wants to use flame magic she needs to find a guy who has an affinity for fire. Not all guys do, so she has to search, bargain, bribe, seduce, and outcompete her rivals. Maybe some rarely occurring affinities lead to high status guys. If you're the only guy in the kingdom with access to earth magic, the ladies will literally be fighting over you. Combine with palace intrigue above. **Men without a connection become monsters** (variant on some the above) After a certain amount of time, men not connected to a witch become malevolent and powerful monsters. Maybe they're scheming and cunning, or maybe they just rage out and start indiscriminately destroying things. Either way, they are a major threat. Now society has to decide whether to wait for them to transform and fight them, or encourage warlocks to be created (via bribery, threats, etc). **Magic as a drug** Having magic flow through your body is addictive and messes with people the same as drugs (hallucinogens, stimulants, depressants, or effect varies with the person). Men pay women to transfer power to them for a period of time which gives them a magic high. Maybe women need to dump some magic energy onto men in order to reduce the psychological effects of having that much magic power within themselves. Lots of questions about how this society holds itself together. Maybe the drug effects only affect a subset of the population. Maybe warlock creation is mandated to occur when women are young and the drug effects haven't kicked in. Maybe there is some kind of twisted 2 child rule where each family has to have a boy and a girl. Or all births are twins (one male and one female). I think I'm out of ideas for now. This was a very fun exercise. [Answer] **The ritual acts as a contract between the witch and the warlock** When the witch casts the ritual, she can make a magically enforced contract that both memebers would have to acknolledge and willingly agree to. However, they would not have to understand, so once the items on the contract are agreed to, either party can lie to each other. The contract requires both parties to do their part, as it is magically enforced. Lure a powerful figure from the town into your witch hut, and show them your manipulation magic, and offer that they can gain power by using it on other important figures in the town. Then say that you don't want the magic used against you, so how and when the magic is used must not be against you. Then a assure the person you are tricking that these terms do not allow for manipulation of him. If the person is nervous still, offer them a way out, you can get out of the contract if you return the magic within a month. They will ask how, and just tell them that they should come back to your hut. Teach them the spell that they use to manipulate. For the first month, show them how advantageous your power is to them, then after that, force them to do magic to get the t nearby town to do what you want. When = you must do magic now/you must not do magic now, my plan fails, which is against me. How: you must use your magic in this way, or may plan is ruined. Use as scrying ball to see the response of the people that were manipulated so you know how to manipulate them more out of their doubt if necessary. Congratulations, you just gained control of a town! [Answer] **Faster Advancement** If, you can increase your magic power by training, then having a warlock, who is also increasing his power (borrowed from you), then your magic improves faster. Even if the warlock won't improve as fast as you, every little bit helps. *Although the author never mentioned if the base amount of mana can be increased...* **Everything else has been said...** *politics, higher chance of magical children, love bond, double casting speeds, bodyguards...* [Answer] # Magical power summator A witch can have only one warlock, but a warlock can have more witches form which to draw power. Let's assume a group of four witches want to cast a very powerful spell to break a ancient magical barrier that can only be cast with 1000 mana and kills the caster. But they only have 500 mana each. They cast a mind control spell on an unsuspecting human and each make him their warlock with 50% of their power. The warlock is forced to cast the spell, consuming all his mana and killing him. The barrier is removed and there are no lose ends. [Answer] I like to add that the warlock might bring other abilities to the table, an 80 year old witch might be a powerfull spellcaster but when you need a spellcaster on a battlefield properly the young knight with half of the magic power is properly the better choiche. Especially when the witch still can work at another place, maybe as tactical advisor in a far away castle or as a medic close to the battlefield. And as mentioned if the 'war Warlock' dies, which shouldn't be that unlikely the magic power can be transfered to another person. I believe you can made up thousand of others scenarios, where the skills or physicality of another person are necessary that a spell is usefull. For example opening a door with magic won't help you much at home. Another reason to transfer magic, is that you ain't expect a man to have magic powers so that this might be helpful to infiltrate some places with a spellcaster. [Answer] **Division of labor.** There are some spells that only warlocks can cast, and some spells that only witches can cast. Do write the book so that both sets of spells are crucial at some point. [Answer] They can become useful servants, plus they would retain their individuality. A warlock, in your tale, could travel to other places and take actions in the witch's place. Or maybe she would be physically incapacitated and the warlock could do lesser magic works untill she is fully healed. It sure has lots of drawbacks but sometimes two heads think better than just one. Maybe a Warlock would have access to more practical knowledge and it could help the witch in more ways we could imagine [Answer] What if the witches can stack the mana given to a single Warlock. Like 5 witches on the same Warlock. Could he become a super weapon. Or even a bomb because he is overwhelmed with mana... [Answer] **It is essentially a pragmatic decision, or, perhaps, an economic transaction.** The witch gets an extra pair of hands. The warlock could function as a bodyguard, an assistant, a representative, a spy, or all of these things. Due to the magic, he is more effective at all of these roles; he also has a strong incentive not to betray his patron. In return, the warlock gains the ability to use magic, and the understanding that he can use it for his own purposes at least some of the time. You could have a variety of social customs around this arrangement. In modern times, several professions have special rules that affect how practitioners behave. Lawyers, doctors, therapists, and engineers often have codes of conduct governing interactions in the workplace, out in public, and in the presence of other practitioners. [Answer] Something I don't think anyone pointed out is that the Witch is *giving* magic to the man, which transforms him into a warlock. In other words, it's possible the magic *becomes his!* I would suggest in this case that the magical factors that make a witch powerful be mental and spiritual (sense of self, willpower, cognitive ability, focus, and so on) and are the same for the *warlocks,* which means the warlock permanently gains powers of his own. In other words, the man becomes a caster, and because the witch and warlock is magically linked, this causes the power of both to increase. Let's say the Warlock's power level is 5 out of 10, whereas the Witch's is 9 out of 10. The Warlock's newfound power automatically would change to 45 out of 50, while the Witch's power would become 45 as well. In other words, this wouldn't make them weaker, it would make them *stronger,* but what if something goes wrong and the warlock betrays them? What's the catch? I would suggest that due to the magic being spiritually powered, a Witch and Warlock cannot harm each other, as they essentially become an extension of one's own self. As for catches, take your pick: 1. The Witch and Warlock's very lifeforces are bound-this makes the two harder to kill, as they share life force, but if one of them dies, both are dead! This makes it possible for one overwhelming attack to kill the Warlock on the battlefield, and then the Witch, who's taken a well-deserved break miles away, suddenly dies. 2. They're emotionally/mentally bound-When you really want to do something, it's hard to keep yourself from doing that thing. The same would apply to Witches and Warlocks-let's say the Witch really wants to have revenge on this one guy, a noble with reputation. The Warlock normally wouldn't even consider taking part in a revenge plot on a rich, powerful man, but he feels the Witch's desire in his own heart and thus takes part in her internal struggle. Appealing to emotion works for ads, it works for politicians, it works for manipulators everywhere. But instead of merely trying to persuade someone to feel a certain way, the partner is making their counterpart feel as they do, whether they want to or not. This is going to *extremely* effective, but also a major disadvantage. Additionally (or alternatively), the minds of a Witch and Warlock may be open to each other. In other words, you *can't* keep secrets from your partner. The lack of privacy will come with extreme consequences of its very own.... 3. One and Done-A Witch can only be bound to one warlock, and vice versa. Furthermore, she *can't* unlink the Warlock without due cause and/or his free will (he must *want* to unlink). Otherwise, the Witch is reduced to the power level she was *born* at, literally being reduced to the power of an infant. Alternatively, her power is *decreased* by the power level of the Warlock she was linked to (for the above example, that would leave the Witch with a power level of 2 out of 10-hardly respectable!) Another option is that unlinking without both parties consenting or due cause not only reduces her power but leaves the Witch with an emotional void, a longing for a male connection. This may not seem like a real drawback. *Wrong,* the longing is so extreme that the Witch *has* to seek out a male to connect with. This could lead to a crazed stalker and/or ex(girlfriend or witch? Perhaps one term has the meaning of both ex-girlfriend and ex-witch?), a witch who'll date and/or flirt with anyone who crosses her path, or possibly worst of all, a witch who goes looking for guys in bars (a *very very* bad idea!) In other words, this means she can't just cast a Warlock aside when a better potential Warlock comes along (essentially using him) without leaving herself vulnerable to being used herself. It's possible that one of the three options in Category 3 above could happen upon one member of the Witch/Warlock pair dying, which would be a *huge* drawback in and of itself. This would result in a Witch doing everything in her power to keep her Warlock alive, save dying herself because that would potentially ruin his life! And if he dies, her life could very well be ruined! This would be a *very* strong incentive to keep mages off the battlefield, and could open up all kind of story opportunities for you. ]

[Question] [ Imagine when a jet fighter swoops in to drop a 400 pounds giant chainsaw to you just so that you can use it to grind down one problematic enemy into a pulp then discard it a foot away from you. What power source would suit such a weapon with only 1 instant use before breaking itself apart? [Answer] **Giant coiled spring.** It would uncoil itself and drive the chain. It would provide loads of power on demand. Storing that kind of energy as a coiled spring is dangerous, but I see that as a positive thing for your scenario. [Answer] Pyrotechnics, in the form of twin spinning rockets rotating the saw axle. You have jet fighters, missiles would look like an obvious option. And as a bonus, a faulty device would explode throwing shrapnel into the enemy. [Answer] [Capacitors](https://en.wikipedia.org/wiki/Capacitor). These are electric components which store an electric charge for a limited amount of time and can release it very rapidly. They are relatively cheap and easy to manufacture. They are also reusable, but that doesn't matter in this case. Capacitors can be manufactured in many different ways depending on their desired characteristics. But in general they have a lower energy density than chemical power cells, but they can release their stored energy a lot faster. Capacitors are usually not designed to hold a charge for longer than a couple hours, so the capacitors either need to be charged before the mission or during the mission from the fighter's internal power supply. [Answer] Launching from a plane, that chainsaw is going to waste a lot of nice gravitational energy, which could be used for much more interesting tasks, such as providing motion to the chainsaw itself. So, the chainsaw itself is tethered to the plane with a very long roller chain, which is connected to a pinion inside the chainsaw (think of a Beyblade launcher). When launched from the plane, the chainsaw falls, so that the roller chain makes the pinion start rotating. The pinion will then transmit the motion to the chainsaw, so that it will rotate at full speed when touching ground! Alternatively, a parachute could open and hold a reel with the roller chain tethered to the chainsaw, which is still falling relative to the parachute. [Answer] I would go for a pneumatic solution. It can support easily a 40 pound high pressure container storing sufficient energy for 15 seconds. [Answer] While the question does not explicitly specify this, I think it is reasonable to specify some, er, specifications. * **Extreme energy density**. The goal of this weapon seems to be to deliver as much destruction as possible in 15 seconds, in a 400lb package which is probably the weight limit for the weapon stores on the jet. It is desirable that the majority of this 400lb is gnawing teeth of mushy annihilation, and only a small part is fuel and power source. * **Extreme reliability**. If a air-dropped 400lb giant disposable chainsaw seems like the best way out of a situation, you are probably in *deep, deep* trouble. You don't want to be yanking a starter cord on a dodgy two-stroke while the Tentacles of Kaza'An the Soul Destroyer of Mag-Uhn squeeze the life out of your fellow unlucky party members. You shouldn't have to carefully lubricate the moving parts of your jammed chainsaw while the Teeth of Brig-Wrath the Extirpator of Zw'n-Thragg dismember your group members. You want to have instant destruction available the moment you receive the weapon. You might even want to be able to use the device on Frizhger the Mauling Shark-Fish, submerged in the Sea of Despair. Obviously, air-breathing engines are no good, what with the underwater Mauling Shark-Fish (also, the torrential rains on Zw'n-Thragg!). Electrics are really not great either - they require careful isolation from the environment, and frankly, the energy density of batteries is quite terrible - you don't want to run out of power halfway one of Kaza'An's Tentacles. The obvious solution is a hydrazine turbine engine. Hydrazine is an extremely reactive fuel, that does not need an external source of oxygen. It is used as a rocket fuel (where energy density is key). A turbine engine probably has the highest power-to-weight ratio of any rotating engine, and furthermore it only has a single moving part, which can be connected with a single reduction gear to the saw chain. The reaction products of running hydrazine over a catalyst such as iridium are extremely hot nitrogen and hydrogen gas, the latter of which can also combust once it does come into contact with the outside air. The end result is a screeching whining chainsaw of death spitting blue flames from its exhaust. Chances are the extirpation days of Brig-Wrath are soon over. [Answer] As an alternative to coiled spring you can have your own gyro core (or [flywheel](https://en.wikipedia.org/wiki/Flywheel_energy_storage)). Make a small and dense wheel to rotate very fast on pins in your chainsaw, virtually without energy loss, and then give it all away to chain blades. After it is discharged it becomes a useless piece of metal without any electronics or stuff. It is also much safer to operate than coiled spring. If anything it will also stabilize delivery of this chainsaw. [Answer] Well if you only need it very briefly I'd recommend a power cell. Where batteries provide a slow trickle of stored energy over time,power cells can dump all of their energy in an instant. So that chainsaw purpose built to be disposable but very deadly could literally be torn apart from the energy it exerts in its short period of activity. Also this means that being disposable the chainsaw would be made of cheaper materials. Since the power cell never needs to be replaced as it is a one-off use it can be made non-rechargeable and self-destructing. Not in the way it blows up when used, but it burns out the internal storage from the incredible heat and shock of the energy release. All in all, the chainsaws shall exist. And they shall be terrifying. Maybe just make the edge out of carbon nano-tubes? Nano-tubes can also be used to store energy within their mass much like batteries or power cells. So you could literally make the chainsaw one giant power cell made of an extremely energy dense but light material that at 400 lbs would have enough power to immolate an elephant entirely most likely. Your chainsaw would have the power of a bomb, all put towards a few glorious seconds to a minute at most of incredibly destructive power as the blade super heats and the chainsaw loses cohesion as the power which simultaneously kept it together suddenly runs out. I hope this helps. [Answer] Googling "battery in missiles" led me to the page of a company manufacturing and selling such solutions. I am guessing your solution would be "[thermal battery](https://www.eaglepicher.com/technology/battery-chemistries/thermal-battery/)". I do not think they are selling a solution just for you but the duration and power can be tailored to application. Also, such batteries are used by military using similar "mil-tech" would probably fit the back story. Also such batteries are single use, durable, reliable and have long shelf life. Some of the other battery chemistries they offer might work better for you, so you might want to check them out. They might be rechargeable though. [Answer] The parameters of the problem are: 1. Single-use ordnance 2. Power-to-weight is a significant constraint 3. Brief duration of discharge 4. Cheap-ish (we're talking about a **disposable giant chainsaw** here) So you're probably looking at a chemical energy source that needs to be converted to mechanical energy. That rules out any high-explosive, and anyway, explosives expend much of their energy in brisance. Fuels like **Otto II** driving a turbine are one possibility, if you'd like the system to be self-contained (i.e. not subject the user to exhaust fumes). If that is not a serious consideration (e.g. you are okay with a fire-belching disposable giant chainsaw), then the parameters of the problem closely resemble the energy requirements of a **rocket.** I'm partial to a powderized-aluminum + ammonium nitrate mixture, myself. [Answer] Well possibly the easiest power source to use would be a battery, you can accurately determine how much ‘life’ it could give to a piece of electronics by setting the max capacity and charging it until it is full. Although, if your problem is just that you need to get the chainsaws down safely, i would recommend using parachutes or heavily padded drop boxes to ensure the contents were undamaged. At that point you could use whatever fuel you liked as it would not be damaged from the fall. However, i don’t think you’d want to use chainsaws, especially ones that heavy, as weapons. They are not particularly effective, are slow and 400 pounds is about the weight of two humans. At that point you might as well be using a giant maul instead. [Here is an answer where i explained the issues with chainsaw weapons.](https://worldbuilding.stackexchange.com/a/143129/62187) There is also a link to a youtube video in my answer which demonstrates my point. [Answer] Since this is the sort of weapon that Coyote would be using against Roadrunner, it must be powered by the future power supply du jour. In the 1950s that would have meant nuclear power, nowadays everything is battery powered, though some consider that the future is in hydrogen. It very much depends on the tone of the situation you're creating. The clean and neat nature of modern hydrogen fuel cells and batteries may not fit the context, so you might want to find some way of making it spew smoke and fire as it's powered up, that means coal or at the least diesel powered. [Answer] I would go for a chemistry based solution. Think of current engines; they are all based on the concept of explosions. Now think of a giant explosion happening on release of the chainsaw. It would create enough pressure to power the chainsaw for quite some time. [Answer] While not a chain saw, much of the effect could be delivered cheaply and reliably by a 400lb coiled spring, which has saw teeth etched into the edges. This can be deployed from the plane itself (uncoiling and lashing at the target as the plane screams overhead. Alternatively, the hero can be braced with his back to a tree or a wall and pull out the pin or cut the cord holding the coil closed, it lashes out like an [Urumi](https://blog.knife-depot.com/urumi-whip-sword/) from hell, striking with considerable kinetic energy and razor sharp cutting teeth. [](https://i.stack.imgur.com/wC9ni.jpg) As you can imagine, there is nothing close to what I am describing. Take this, increase the size to account for the 400lbs of spring steel, serrate the edges and have a cord or pin holding it closd against the spring tension Considering a 400 lb coil of spring steel would actually be quite long, you would also have a considerable advantage of reach over most opponents, who would either think the plane is too low to drop a bomb, or the hero is too far away from then (and whatever is that drum like object he is holding?), so fail to take proper precautions. [Answer] Build the chainsaw with a heavy flywheel. Add a heavy duty piston/foot that the chainsaw lands on when dropped towards you. When that piston hits ground at high collision speeds it spins up the flywheel, which directly powers the chain. You run over and grab it, go to work for your 15 seconds of glory. No power source beyond gravity and the flywheel needed. Being all mechanical and built tough it possibly wouldn't even fall apart, later it gets picked up and reset for another drop. [Answer] Expanding on Willk's answer here: You have a "lander" and a chainsaw. The chainsaw is spring-powered. The lander has multiple rotors, say 3, that both break the fall and charge spring. It would basically look like a quadrocopter with a chainsaw at the bottom falling down. A ratchet prevents the spring from discharging. A trigger mechanism in the chainsaw releases the ratchet and directs its power from the rotor coupling to the saw's chain - the chainsaw is running, purely from the energy from the fall. [Answer] Dual liquid explosive, the force would trash the mechanism but its a one use weapon. [Answer] ## Coffman (shotgun) starter The [Coffman starter](https://en.m.wikipedia.org/wiki/Coffman_engine_starter) uses a propellant fit in a shotgun shell, with the standard shotgun primer (blasting cap). It generates up to 15 seconds of pneumatic force to start [large aviation](https://www.youtube.com/watch?v=65qrzgbTTcQ) and [tractor](https://www.youtube.com/watch?v=idwceKeWgHw) engines. Famously used on the movie *Flight of the Phoenix* (both versions). Adjust size for energy need, but it's just the right energy density, weight and burn rate for the job. [Answer] If a massive chainsaw is deployed from a jet, it should be powered by Mr. Torgue's specialty. The large weight is needed to contain and direct the C4 detonation inside to spin the chain. Maybe also the back side is stronger than the front, creating the possibility for the chain blade to launch through the enemy. [Answer] **THE IDEAL POWER SOURCE ON ACCOUNT OF SHEER INSANITY FACTOR** The setting already seems insane enough, so let's go all-out. The chainsaw is powered by a gigantic, 100-pound explosive. When it drops into the user's hands, the explosives detonate. The energy of the resultant explosion is funneled through a contraption of piping that directs it first to spin a turbine, which gets the chain up to speed, and then backward and out some 'exhaust thrusters' which help the user charge towards the target despite the chainsaw's incredible weight. Basically, it's a missile, and the user is there to point it in the right direction. Is it safe? No. But neither is dropping a 400-pound chainsaw in front of somebody so they can use it as a glass cannon-style weapon. [Answer] You don't need a power source. Humans generally have a terminal speed of 53m/s. Your chainsaw, due to weight and profile, will probably have a greater final velocity. A 400 pounds piece of metal hitting you at 53m/s will impart you with approximately 2.54 x 108 joules, or ~ 70,555.5 wh. That's equivalent to the detonation of around 60~65 kilograms of TNT. It will turn the target to a pulp just by its kinetic delivery, as well as anyone else nearby. ]

[Question] [ A battlemage practiced the art of close combat fighting, and could deal huge amounts of damage to his opponents at point blank range. He also had a special robe, which was enchanted by a powerful spell such that it parries all ballistic projectiles. Unless the enemy attack completely overwhelm the battlemage in term of magical strength, the robe should survive unscathed. I kept wondering why I still see battlemages getting wet in the rain? Wouldn't that imply that the robe can be dissolved by acid rain too? [Answer] # The spell creates a force barrier that behaves like a [non-Newtonian fluid](https://en.wikipedia.org/wiki/Non-Newtonian_fluid). A non-Newtonian fluid is a fluid that, among other things, increases its viscosity with increased shear force. [This video](https://www.youtube.com/watch?v=2mYHGn_Pd5M) shows examples of interactions with a non-Newtonian fluid. A protection spell applies such [dilatant](https://en.wikipedia.org/wiki/Dilatant) properties to the atmosphere around the wizard. Ballistic projectiles have high mass and velocity. When they interact with the atmosphere in the region of the spell they apply a significant level of stress to the atmosphere. The spell's dilatant properties mean that such stress dramatically increases the atmosphere's viscosity and the projectile is stopped from passing through. By contrast, raindrops have a comparatively low mass and velocity and cause very little stress, and thus pass through with ease. [Answer] ## The Devil is in the Details. This hypothetical robe "parries all ballistic projectiles." When rain strikes the robe it does its job, reducing the drops to zero velocity so that they do not penetrate. **However, an unforeseen (and unwanted) side effect is that they are no longer ballistic in nature.** As a result, the robe is now, for all intents and purposes, just a regular robe, and thus gets wet from the water that is in contact with it (the neutralized raindrops). To answer your question, yes; the battlemage's robe (and by extension the battlemage) is vulnerable to liquid/shape-conforming attacks such as acid, boiling pitch/oil, drowning, and shaped explosive charges. [Answer] The magical robe also magically perceives **intent**. Enemy projectiles? Blocked. Harmless raindrops falling from a benign sky? Come on through. Angry raindrops from an insulted deity? Blocked! Additionally, this could optionally add a fun wrinkle where an "accidental" projectile, say friendly fire or a alchemical explosion, could actually become very deadly because there was no intent to harm. [Answer] It's because you are looking at two different phenomena. Anything gets wet because of capillary forces and surface tension. Both phenomena have nothing to do with stopping ballistic projectiles. It's like asking "why do I get wet though my sweater is pink?" [Answer] This brings to mind the personal force shields from Frank Herbert's *Dune* series. These shields (note that, despite the name, it's a force field encompassing half or all of the wearer's body, not a "strapped to your arm" shield) resist incoming objects with a force proportional to the energy of the incoming object. A bullet, or even a quick blade thrust, is stopped cold, but the shield does nothing to against a slow-moving weapon, so you can still be crushed or impaled, as long as it is done *very slowly*. In the case of your mage's robes, rain is not repelled because its approach is sufficiently low-energy that it isn't affected by the parrying enchantment. On the acid rain sub-question, that's a matter of the material of the robe, which may or may not be susceptible to damage by a particular type or strength of acid, and the sophistication of the enchantment. If the enchantment is "smart" enough to detect threats based on factors other than force of impact, then it may be able to detect and repel the acid. If not, and it responds solely based on threat of impact damage, then acid rain would get through with no problem. Although, really, if you're dealing with acid rain which is potent enough to damage the robe within the duration of a single battle, I would be far more concerned with what that acid's effects on the person wearing the robe. [Answer] Well, I once wore a bullet-proof vest and it was raining. The vest got wet. No one shot me, but I'm pretty sure that if they had, it would have protected me. This is because rain is expressly not bullets. Rain and bullets don't work on the same principles. However, a bullet-proof vest and mage's robe (as you have it) don't seem to work the same way either. A bullet proof vest works by absorbing the force and spreading it out. But in your question you actually say the word "parry." That is NOT the same principle as a bullet proof vest. > > par·ry /ˈperē/ > > verb > > ward off (a weapon or attack) with a countermove. > > > Not the same as absorption. Basically, this means the magic pushes back and deflects against the source. That is also not the same as a force field. Magic that parries a blow is not a force field. Here's why rain would not be repeled: because in situations other than battle, something that parries against ANY force, no matter how weak, would be...not tenable. Someone brushes up against you in a crowd--your armor parries. It's not good and not practical, and it can also be a drain on the parry. If there's a finite amount of energy it can expel, pushing off everything from a leaf landing on you to rain is stupid. And it will run out. I see a few exploits here. A) IT PARRIES EVERYTHING (but it has only so much energy or energy fed by the mage!!!!!! If it does, I am definitely going to be pelting you with so much gravel, and water for as long as I can, anything that touches the whole surface and causes it to react. Let's not even talk about what might happen if you are made to go SWIMMING in it. The water pressure from every side? Could it be viewed as an attack? Would it be 'smart' enough not to? If it didn't, how impossible would it be to swim??? B) THERE'S A FORCE THRESHOLD FOR PARRIES. Rain, acid or not, is not enough to trigger it. So the enemy might be looking into acids that will damage the parries in places in order that their more ballistic attacks get through. Look not upon option B as a stumbling block, but as an opportunity. How's it going to be when the seemingly untouchable hero (or villain) gets defeated by a clever person with water balloons and arrows. The first person who figures this out and manages to carry it out is a tactical genius. Anyway, my take on the info given. [Answer] # Too many projectiles Magic is computable. Each spell is like a computer program, and an enchanted object is like a computer. > > Unless the enemy attack completely overwhelm the battlemage in term of magic strength, the robe should survive unscathed. > > > The rain overwhelms the robe's capacity to process ballistic trajectories. A few droplets do get deflected, but the majority passes through. By the way, the battlemage should avoid a gunfight in the rain at all costs. A bullet could make it past the robe in that situation. [Answer] Protection of this sort needs to have a lower limit: if it didn't, air itself would be sealed away, and the mage would suffocate in his own protective magic. Given that such a lower limit must exist, a robe tuned so that bullets are stopped would still allow rain through: raindrops hitting the magic would (at worst) atomize into a fine mist that passes through, soaking the mage regardless. Acid rain in the conventional (pollutant) sense isn't generally strong enough to damage skin or clothing, except perhaps in the long term, and I assume that even magic robes eventually wear out and need to be replaced. For a more concentrated acid attack, I imagine a mage could order the robe to drop that lower limit, sealing off even air and particles (like a hazmat suit). He'd have a few minutes of breathable air trapped inside the protective bubble, enough for him to escape to more congenial surroundings before raising that lower limit again. [Answer] Frame challenge: What if instead of blocking bullets, the robe magically caused the wizard to *dodge* them? I.e.: it gives him superior predictive capabilities to know exactly where every bullet and arrow is going to be and aids his reflexes (or just physically pushes him out of the way - think of Doctor Strange's robe. Sure this might interfere or distract from his spell casting, but it's better than being shot.) so the shots just miss constantly. Theoretically he could dodge raindrops as well, but this would be a waste of effort and might make it extremely distracting to the point of impossibility of channeling spells in the rain. (Note that unlike the blocking robes, this would mean there's no protection for other people standing behind the wizard. Those dodged shots might still hit something else.) This could possibly be defeated by firing a dense enough volley of projectiles that there's simply nowhere he could dodge to and avoid every shot, but this would require a lot of coordination among the multiple archers/marksmen attacking him. Something like a shotgun might have a better chance of doing some damage, but depending on your tech level, these might not be invented yet. [Answer] The enchantment on the robe makes the fibers of the robe invulnerable. In order for an arrow or crossbow bolt to pierce the mage, it would have to sever strands of the fibers that make up the cloth the robe is made of. The magical enchantment on the robe makes that impossible. If the cloth is sufficiently thick enough, or has padding, it will absorb the impact of the projectile without doing much harm to the mage wearing it. It will still hurt, and probably leave a bruise, but he won't get impaled. But it otherwise behaves like a regular robe. The material is still porous and will soak up water (or any liquid) like normal cloth would. The mage wearing them will still get wet. Acid won't dissolve the robe, but it will dissolve the mage inside, so he still needs to be careful! The mage would do well to make sure the robes are fitted well before the enchantment is applied. Once the robe is enchanted, no tailor will be able to make alterations! [Answer] # Costs If the enchantment requires a moderate cost to activate or run, then it might be worth activating when the battlemage's life is on the line but not to prevent the battlemage from getting wet. Alternatively, the enhantment might have a finite active duration (1 hour of invincibility before it loses it's potency) or unwanted side effects (radioactive armor is safe to wear for a battle, but you wouldn't want to sleep in it) [Answer] Your cloak selectively blocks targets according to speed and size. A raindrop usually won't reach speeds greater than 10 meters per second, while the slowest bullet will travel at speeds superior to 300 meters per second. Even arrows from bows or crossbows can top at higher speeds. That means the cloak selects what it will parry and what it will avoid based on how big it is and the speed it's going at, after all, a slow moving Boulder can be more damaging than a fast needle. Through that mechanism, the wizard's cloak can protect him efficiently while also conserving magic power from projectiles that might actually bring harm to its master. By this logic, unless the cloak is also capable of analyzing the composition of the incoming projectiles, it might Ignore things like a magic sack filled with acid approaching at sufficiently low speeds, leaving the mage vulnerable to chemical attacks. [Answer] While the raindrop could be counted as a projectile, the resulting puddle/drop of water doesn't. So it can just soak in. The other thing to consider is how the armour works. Does it have a force requirement, or is it like the armour in stargate atlantis where nothing except air can pass through, or is it more intelligent and works off the users perception? The first and last would be unlikely to stop normal rain, while the last would also stop acid rain. The middle one could kill the wizard, especially if they fall unconscious. [Answer] You can [lampshade](https://tvtropes.org/pmwiki/pmwiki.php/Main/LampshadeHanging) this concern somewhat cleverly. You still see battlemages getting wet in the rain because the logic of the robes' enchantments isn't completely *watertight*. This approach may not be suitable for stories with a serious tone. However for stories with a lighter tone, the use of the word watertight is a double entendre. Watertight has two common meanings, reproduced below from [dictionary.com](https://www.dictionary.com/browse/watertight): > > 1. constructed or fitted so tightly as to be impervious to water > 2. so devised or planned as to be impossible to defeat, evade, or nullify > > > So in one sense, saying the enchantments aren't watertight literally explains that there is a corner case which the enchantment designers didn't account for, which lets rain wet the robes. In the other sense, saying the enchantments aren't watertight *lampshades* the inconsistency by pointing out that the robes let through rain, usually made of water, and indicates readers shouldn't think too hard about it. [Answer] Since the robes are protected by a spell, the spell has to have some manner of parameters when it is cast. Parameters combined with intent and power will determine what the spell barrier blocks I will not necessarily go into how the spell works on a physical level, just how the spell works on a metaphysical level. The common thread for the battlemage barrier is that it blocks ballistic projectiles. But there are assorted ways to do that, each with their own advantages and drawbacks. **Ballistic projectiles will be negated** is one possible way to start with. The intent of the spell is likely to stop arrows, magic, and possibly shrapnel thrown up from near misses from harming the battlemage. Air and the weather are not taken into account with this intent, so its entrance is not negated. As such, the battlemage will still get wet as the rain will not be negated. Likewise, acid rain will still work so long as it is not magical. Natural acidic rain will still work because it was not considered. **The threads of my robes cannot be broken** is another possibility. Since the threads cannot be broken, arrows cannot obviously pierce it nor can magic break them in other ways. This may or may not deal with the forces behind the projectiles unless the intent of the declaration is for the threads to require an arbitrarily high amount of force to break them. Substitute whatever is being worn for robes where necessary. Again, the rain does not break the battlemage's clothes. If they are made of cloth, then there are tiny gaps between the threads that the water can get into. The threads may also be still able to absorb water in the rain as that is not spelled against. So again, the battlemage can get wet. Acid rain cannot break the clothes, though if it can get into the clothes, the mage itself might not be so safe. There are other short sentences that can define what your force field spell that your battlemages cast and how they do their thing. Based on the premise that the spell will be based on determine how it reacts to both what it is supposed to and what else might be around. This also, to some degree, depends on the other rules of magic that you have established (which is not in the question). [Answer] # Because parrying a liquid doesn't help. > > spell to parry all ballistic projectiles > > > I would imagine that the spell applies an equal and opposite force to any projectile. When you apply a force back at a bullet (which is solid) it will stop the velocity along with damaging the bullet such as crushing it. At worst you'll end up with bullet dust on your shoulders (anything larger would likely fall off). However applying a force back at a liquid projectile will cause it to splash (imagine a water balloon breaking) and not entirely stop it (less effective than hitting a solid object). The resulting smaller water droplets should have lower velocity but are equally wet. These smaller droplets are still moving so this process repeats until they are either too small for the spell to track or are moving slow enough that the spell won't apply a parry force back. Either way the water will eventually soak in. This spell would protect against melee as well as projectiles but must have some kind of minimum size/speed threshold in order for the robe getting wet to be possible (otherwise the water would sit on top of the robe like a rain jacket). This also means that the robe's spell can't be used as a gas mask because gas is smaller and slower than liquid would be. Real life acid rain isn't acidic enough to dissolve cloth from 1 exposure. It takes many instances over a long time to damage statues etc. But stronger acid would indeed dissolve the robe (and the wearer). # Because the robe doesn't cover the entire body When you say "robe" I don't think of a dry suit. Presumably the wearer's head, hands, and maybe feet are unprotected. The unprotected parts can easily get wet. Have you ever been wearing a coat and gotten snow down your back? Then you know that an unprotected head means water can get in and soak any part of your body. > > see battlemages getting wet > > > It is entirely possible for a battlemage to be soaked yet the robe remain dry from the spell (as long as the spell also works from the inside out). Given this interpretation the spell has no need for a lower threshold. Even if the spell repels every single atom (including air) the wearer would still be able to breath (assuming he has no face mask with the same spell). > > Unless the enemy attack completely overwhelms the battlemage in terms of magic strength > > > I read that to be a maximum threshold. The spell can only deliver a maximum amount of force and any projectile with more momentum will not be completely stopped. Or perhaps "overwhelming in terms of magic strength" is talking about an enchanted missile (for which rain is not) with an overwhelming amount of magic. The projectile could have a spell that prevents losing momentum in which case whichever spell is stronger would win. For an overwhelming number of projectiles see Renan's excellent answer. I believe every option I've given for "the spell applies force" meets all requirements of the description. [Answer] **The wizard's robes work on the same principle as the force fields from *Dune*** In *Dune* it is said that one of the key things that triggers personal force fields is kinetic energy moving beyond a particular threshold. This is why everyone in *Dune* fights melee battles using swords despite being in the far futures where more advanced firearms like laser guns are a thing, a bullet/laser beam travels at several hundred miles per hour/the speed of light, whereas a sword travels relatively slowly. [A raindrop only travels at a speed of about 9 m/s (20 mph)](https://www.google.com/search?rlz=1C1CHBF_enUS920US920&ei=Dmf7X_yTMYum5wL9vLn4Aw&q=raindrop%20speed&oq=raindrop%20speed&gs_lcp=CgZwc3ktYWIQAzIFCAAQyQMyAggAMgIILjICCAAyBggAEBYQHjIGCAAQFhAeMgYIABAWEB4yBggAEBYQHjoECAAQRzoICAAQyQMQkQI6BQguEJECOggILhDHARCvAToECAAQClCVAljqBWC4BmgAcAN4AIABbYgBlAOSAQMyLjKYAQCgAQGqAQdnd3Mtd2l6yAEIwAEB&sclient=psy-ab&ved=0ahUKEwj80qbKnZLuAhUL01kKHX1eDj8Q4dUDCA0&uact=5), much slower than most ballistic projectiles. [An arrow travels at a speed of 67 m/s (150 mph)](https://www.google.com/search?rlz=1C1CHBF_enUS920US920&ei=xGf7X-yEEc2m5gLqkYeoBw&q=an%20arrow%20travels%20speed&oq=an%20arrow%20travels%20speed&gs_lcp=CgZwc3ktYWIQAzIICCEQFhAdEB4yCAghEBYQHRAeOgQIABBHUL8IWL8IYIwLaABwAngAgAFfiAFfkgEBMZgBAKABAaoBB2d3cy13aXrIAQjAAQE&sclient=psy-ab&ved=0ahUKEwjs9uqgnpLuAhVNk1kKHerIAXUQ4dUDCA0&uact=5), much faster than a raindrop. By the standards of your wizard robes, an raindrop is not even a projectile worth worrying about. The weird irony is, though, that in hurricane force winds your wizard robe will likely remain dry, while in a normal downpour it would get soaked. ]

[Question] [ First, let me explain the situation. Post-apocalypse setting, a group of humans (let's say around a hundred of them) have to find safe places to live at, protected from animals, bandits, and other menaces. They decided on a group of tall buildings (as in the picture), between 12 and 18 stories high. They live on top of them, last few floors. It provides safety, overlook of the surroundings. [](https://i.stack.imgur.com/ZdP12.jpg) Now, the city is ruined so there is no running water in the waterworks, but, there is a strong spring and a well in between the buildings. There is no city wide electrical grid, and they use generators (but rarely due to fuel consumption) and solar panels, but those are usually spent on lights, preparing food, refrigerators, etc. Idea is that on the top of the building they have greenhouses to grow veggies for their use. But, veggies and greenhouses need water. And I don't think that rainwater is enough, even if collected for that purpose. So, **the question** is, how to get the water from the spring or the well to the top of the building, where, for example, could be a big water reservoir? Or is it somehow possible to hook and reconnect the water pipes of the buildings to the spring instead of city waterworks and get it directly to the faucets? Several members of the population living there have some knowledge in engineering and construction, theoretical and practical, so it can be done if it doesn't include some ultra complicated work that require some special machinery or conditions. Is it possible at all without electricity and pumps? If not, I am open to all kinds of suggestions! [Answer] In order to get water up to the top of a building, you can either carry it manually, or you can pump it. Pumps don't have to run on electricity. [Wind-powered pumps](https://en.wikipedia.org/wiki/Windpump) use a windmill to power the pump, and have been used since at least the 1500s (and likely much earlier) for irrigation and other purposes. [](https://en.wikipedia.org/wiki/File:Water_Pumping_Windmill.jpg) Other options like steam power, diesel, or water wheels could also work. Another option would be to use a [hydraulic ram pump](https://en.wikipedia.org/wiki/Hydraulic_ram), which uses the inertia of the water itself to pump part of the water up. [Answer] The oldest pump in historical records is the [force pump](https://en.wikipedia.org/wiki/De_architectura#Force_pump). The book that first describes it was written between 15 and 30 B.C/B.C.E. [](https://i.stack.imgur.com/IT8om.gif) This is the [Archimedes's screw](https://en.wikipedia.org/wiki/Archimedes%27_screw), which is one of my favorite ancient machines. It was used for irrigation. These could be arranged within a building's staircases. [](https://i.stack.imgur.com/DQyEp.jpg) And then there is always the classical bucketwheel. [](https://i.stack.imgur.com/CCkLy.png) All of the machines above were operated by human power, but with some clever tech'ing around post-apocalypse survivors could make animal, wind, steam or coal based versions as well. **Edit:** there are some great comments here, so I'm adding them to the answer :) > > To clarify... the force pump is nothing but an alternate name for the hand piston pump seen all over "pre-electricity" England and America. [en.wikipedia.org/wiki/Piston\_pump](http://en.wikipedia.org/wiki/Piston_pump) > > > And if you've scrounged a bicycle, you can connect the rear sprocket to the pump. The Google search "bicycle powered water pump" is rife with examples. > > > -RonJohn > > > And > > Bucketwheels have an advantage in that if you place them in a suitable location you can power your bucketwheel with a waterwheel. Couple that with a nice storage system and you've got pressurised water at no extra labour cost. > > > -Joe Bloggs > > > [Answer] **Steam it up with a solar concentrator.** [](https://i.stack.imgur.com/U3Cuv.jpg) [This London skyscraper can melt cars and set buildings on fire](https://www.nbcnews.com/science/how-london-skyscraper-can-melt-cars-set-buildings-fire-8c11069092) > > The building — designed by internationally renowned architect Rafael > Viñoly — is a dramatic edifice with curved exterior walls. Built at 20 > Fenchurch Street in London's financial center, the 38-story skyscraper > is known locally as "the Walkie-Talkie" for its unusual shape. > > > But that curvilinear shape is exactly what's causing the problem: The > south-facing exterior wall is covered in reflective glass, and because > it's concave, it focuses the sun's rays onto a small area, not unlike > the way a magnifying glass directs sunbeams onto a superhot pinpoint > of light. > > > So too the buildings of your people. They have affixed mirrors such that in the middle of the day, the suns rays are reflected from the buildings onto a boiler below. This boiler at ground level has been filled by the spring, and when heated to boiling, the steam moves up the building's internal [standpipe](https://en.wikipedia.org/wiki/Standpipe_(firefighting)) to the rooftop, where it is condensed in a radiator. The cool thing about this is that it would be disclosed early in the story as a utilitarian way for these survivors to use what they have to move water. But what they actually have is an [Archimedes Heat Ray](https://en.wikipedia.org/wiki/Archimedes#Heat_ray) which I am sure they will find use for as the story unfolds. [Answer] All these answers are boring and practical. I see no hard-science tag... Where's the fun in reusing well-established methods that are basically guaranteed to work quite well? Find the materials (somewhere, somehow) to make a giant tarp and cast it across the 6 buildings. Put a post in the middle that goes to the ground so that the middle of the tarp is raised. This creates a much larger rain-catcher than just the one building. If the buildings are really oriented as in your picture (I realise they may not be), You should get three of the 6 buildings receiving rainwater. [](https://i.stack.imgur.com/prgsy.jpg) Also, getchou some bridges between your buildings. That would be cool. [Answer] A standard manually operated [high-lift water pump can pump water 45 metres](https://en.wikipedia.org/wiki/Hand_pump#Range_of_lift) or more (your target building is 42-63 metres). [](https://i.stack.imgur.com/Lktwa.png) > > The height to which a hand pump will lift is governed by the ability of the pump and the operator to lift the weight in the delivery pipe. Thus the same pump and operator will be able to achieve a greater lift with a smaller diameter pipe than they could with a larger diameter pipe. > > > Assuming a water source at ground level and a vertical pipe 45 metres by 7 cm diameter, that is 173.2 L (or kilograms) of water when the pipe is full. This is well within the ability of some adults to lift on their own, and definitely within the ability of two or more operating the pump handle. A series of storage tanks and pumps constructed on lower floors could break up the pumping process into stages, making each stage easier. [Answer] The people living on the top floors can power the pump as they travel down, by lift/rope. Let gravity work for you. Obviously this doesn't bring up enough water, but can be used along with better solutions. We had such a setup in one summer camp and the kids would happily run up and go down over and over again :-) [Answer] One way of pumping water without needing any external energy source, other than the water itself, is a [hydraulic ram](https://en.wikipedia.org/wiki/Hydraulic_ram). It wastes water since it only pumps a fraction of the water that is made available to it but it can keep pumping without the need for any wind, solar energy, animal muscle, human sweat, etc. [Answer] I hesitate to mention this, being so simple, but since tall buildings already often have a large water tank on the roof (an estimated 15,000 in NYC) and an electric pump at ground level to get water up to it, could your people not simply run that pump for the limited length of time it takes to top it off each day? Running the pump would give you something productive to do with any solar electricity not otherwise needed during the day. Also, in ANY scheme, according to [this white paper](http://www.pacopumps.com/Documentation/WhitePapers/Roof_Tank_Whitepaper.pdf), the top 6 floors would not have the current water pressure, since the tank isn't high enough above them to provide it by gravity, so although the water would flow, there would be less pressure than previously. This would, ironically, pose a problem for water-saving shower heads. If the water tank is sized to provide for the needs of the the whole building full of people, it could last several days supplying the needs of a fraction that number, especially since they'd initiate water-saving measures while under siege. Note that this whole answer doesn't really apply in Europe, where rooftop water tanks are rarely used. [Answer] Let me draw you a picture. Two pictures. And an equal sign. [](https://i.stack.imgur.com/wsevX.png) [Aermotor](https://aermotorwindmill.com/collections/windmills) has been making these things since 1888, and they're hardly the first manufacturer. I don't know how many folks have lived in rural areas, but 180' is not *that* deep for a well. You can also see the windmill atop the building catching nice wind, to say nothing of *[wind gradient](https://en.wikipedia.org/wiki/Wind_gradient#Wind_turbines)* effects which already slow wind near the ground. [Answer] Where you use water, there you get waste water. You need to supply fresh water up, and you need to get waste water down. The amount of both will be roughly the same. Now combine the two: Use a long rope, hang it over a pulley at the top of the building, and attach two large water containers to it, a blue one for fresh water, and a brown one for waste water. Use is as follows: 1. You fill the blue tank at the bottom of the building with fresh water. 2. You fill the brown tank at the top with waste water. 3. Both tanks are almost perfectly balanced, a single man can now move a ton of waste water down while moving a ton of fresh water up. 4. Empty the blue tank at the top into a fresh water basin. 5. Empty the brown tank at the bottom into a sewer. 6. Move the two tanks back into their starting position, rinse and repeat. The order of the steps is somewhat important, otherwise this is as simple a solution as it gets. Should be quite easy to implement in your post apocalyptic world, it allows you to move large amounts of water quickly with very little effort, and it does not require any energy use or complicated setup. Bonus points if the point where you load the fresh water is significantly higher (strong well has some pressure that allows the water to rise a floor or two above the ground) than the point where you dump the waste water (think cracked sewer next to the building). This would allow your protagonists to distribute flowing water throughout a few floors at the top of the building. Any floor between the waste water tank and the fresh water basin can have fresh water delivered and waste water removed by gravity. More bonus points, if you also collect some rain water at the top of the building. With that you can ensure that you have always more waste water that goes down than fresh water that goes up. Consequently, you won't have to move the water yourself, you just need to apply some brake on the rope/pulley to avoid the tanks becoming too fast. Gravity will do the work for you. Finally, as Peter Cordes points out in a comment, there is also the possibility to use two pulleys, one on each side of the building. This has several advantages: First, it would provide for a better separation of fresh and waste water, second, it would provide the operators with a convenient horizontal rope piece that can be grabbed to move the tanks, and third, it would make anchoring of the pulleys much easier. The simplest solution would be to just place a long, strong beam across the roof of the building, and fix the two pulleys at either end. Since the forces on both sides are almost perfectly equal, you would not even need to anchor the beam at all. A little more involved solution could look similar to this: ``` v rope carrying tanks v o---------------------------------o |\---------------+---------------/| | \ ^ support ^ / \ ^ rope ^ / | | \ / \ / | | \ / \ / | | \_______/_______\_______/ | | ######## roof ######## | | ####################### | v ####################### v fresh ####################### waste water ####################### water tank ####################### tank ``` If the four diagonal beams are held in a 45° position by the support rope and each other, there will be no bending forces on the structure whatsoever, and the anchoring will be next to trivial. [Answer] ## An [Archimedes' screw](https://en.wikipedia.org/wiki/Archimedes%27_screw), or a series of them at different floors. The device consists of a helical surface surrounding a cylindrical shaft, which in turn is placed inside a hollow tube. Rotating the helical surface (the screw part) or rotating the entire tube (if the helical surface is attached to the tube) will transport water up. Said device can transport water so long as there is sufficient power to turn the screw against the weight of the water and the device itself, with longer screws obviously weighing more, as well as carrying more water. Ancient versions were powered by hand, or even by foot. It would be fairly simple to rig them to a wind powered turbine. It has also been used as conveyors for particulate matter, such as grains. [Answer] Are there any hills nearby that are taller than the buildings? If so, build a reservoir at a higher altitude than the top of the buildings, connected via pipes to water tanks on the tops of the buildings, such that water from the reservoir flows downhill under gravity, and then up the buildings into the tanks. Obviously, the reservoir will need some additional altitude to overcome losses in the process (e.g. leaks, restrictions in flow, etc). [Answer] For something that should be within the bounds of simply modern engineering I would suggest a [water tower](https://en.wikipedia.org/wiki/Water_tower) and wind pump. A water tower stores water above ground at a sufficient height to produce pressure (by way of gravity); this water pressure is typically fed into water pipes to force it up through sinks and other systems in our buildings. This of course still requires some way to get water into your water tower: [wind pumps](https://en.wikipedia.org/wiki/Windpump) are simple wind turned pumps that pull water from some source (river, spring, or lake) and pump it else where (historically a lot of irrigation and draining). Their imagery is often associated with old farms. [Answer] This is a little crude, in more ways than one.  Perhaps somebody can suggest improvements to (cough cough) clean it up. First of all, they’ll want to have a reservoir (or cistern) at (or, more likely, below) ground level.  This would allow them to capture and hold spring water temporarily, in case the spring and/or the pumping mechanism have varying flow rates.  (I’ll get back to that.)  If they’re collecting rainwater at ground level, they’re probably already doing this. As in initial capability, immediately after the apocalypse (or maybe even before), this could be as simple as a pond around the spring.  Given time to establish some infrastructure, there should probably be such a cistern in each building; this provides some security against bandits/raiders.  Rig something so that the water from the spring runs through pipes or other channels into the holding tanks in the basements of the buildings.  (Try to make it hard for attackers to slip poison into the reservoirs.) One added security measure is “security through obscurity” — after you have built a plumbing system that pipes the spring water into the buildings, bury it.  This may make it somewhat harder for adversaries to steal your water or tamper with the system.  Ideally, it will make the spring invisible. The question of getting the water to the upper floors remains.  [Renan](https://worldbuilding.stackexchange.com/q/106235/20215#106238) suggested a “bucketwheel”: [](https://i.stack.imgur.com/CCkLy.png) but handwaved the power source.  (For the record, I thought of this before I read the answers.)  If there’s power to spare, there are many options.  But the question said that all the solar power is accounted for, and that fuel (for the generators) is scarce, and I assume that the building complex isn’t within walking distance of a forest, a coal mine, or an oil well.  If the spring provides enough power to drive the bucketwheel (or bucket conveyor belt) and lift water 18 stories, that’s great, but that strikes me as unlikely. One idea that hasn’t been mentioned is to have a dual-track bucket conveyor belt.  One track would bring water up; the other would take waste material down, and thus provide the power to drive the belt and lift the water.  I am thinking specifically of toilet-type waste.  There might be others, but I imagine that these survivors would recycle as much as possible. The rate of disposal of waste varies with the time of day.  This is why it’s important to collect the spring water all the time, so the water that emerges from the spring overnight, and at other periods of low waste-disposal activity, doesn’t just go into the ground. Of course, if they’re using washing water, urine and feces in their gardens, this won’t work. [Answer] A method might be a modified, large solar still. Basically you have the sun heat up a pool of water, where it rises to a place where it can condense back into water. [](https://i.stack.imgur.com/1jnVe.jpg) It's often used as a way to purify water, but in your case, you can use it to raise the water up: [](https://i.stack.imgur.com/8vLLE.png) You could use a parabolic reflector to concentrate sunlight, to heat water in the base at ground level: [](https://i.stack.imgur.com/5IWci.jpg) With enough energy, you can create a steam pipe that will raise the water up to the top of your buildings. Then, have a place where it cools, and you have water. [Answer] Possible without pumps? Not really. A "pump" is just a device that adds energy to water, letting it flow against gravity; however, electricity is just a convenient way of moving energy around quickly, and humanity has been using pumps long before the invention of electricity. [Here's](http://www.romanaqueducts.info/technicalintro/waterlifting.htm) a page about various methods the romans used for lifting water for their aqueduct system. Additionally, most modern water pumps (that might be left over salvage in a post-apocalyptic scenario) can be separated from their electrical motors and driven with a rotating shaft that gets it's power from anywhere. The question you'll have to address is not so much "Can water be lifted without electricity", but "Where does the energy come from to lift all this water?" Since you say that there's not enough leftover energy from generators and solar panels to do this work, we can look to other methods of harnessing energy that might be available. Since your society is already living high-up, and since they might not have the food/space to support beasts of burden to turn cranks all day, I think an obvious solution is wind power. A set of windmills on the roofs, and maybe even attached to the sides, could provide a ton of usable energy. This could be used to drive mechanical processes all through the building, with the most advanced technology being gear boxes and crankshafts. They could even be used to turn a generator; probably not fast enough to use the energy directly, but it could be stored in salvaged batteries for later use. As additional food for thought, pumping water up to high places is a form of energy storage itself (still used today). Maybe your society uses wind power to slowly pump water to the top of the building, and then when the wind is dead, the water can flow back down through some water turbines to generate electricity that way. There're lots of ways to access and store energy in the world around us! [Answer] I love how no one said: The use a very tall pipe. Let me introduce you to artesian well. You take water rich enviroment, put one end of pipe in it and water appear on other end. And for those who say: but the pressure won't push water up to the top. I say: you are terrible picky for someone living in post-apocalyptic environment. If poor Mugabe can take 20 kilometres walk for water right now you can take a few steps to the terrace with water for plants. Also I'm all in for the fact that this is terrible design for defence. Much better are to reuse some medieval castles that were build for siege, with water resource that couldn't be poisoned. [Answer] i would point out some tecnical design: vacuum pump can go up to 10.3meters, then you would need to fill a pond and from here start again. A positive pressure pump can do much more, 100 psi (7 bar) is enough to get you over 70 meters, at which case you just install another pump for your next 70 meters. Please note if you attach your implant directly to the tube the pressure can be pretty high; the safe solution is the pump filling a non-ermetic container close to your applicance, where the pressure will drop to normal atosfere, and normal gravity is used. Those tall building prbably have lift: even witout power, those thing can be relatively easily moved by hand, as they have counterweight, so that, even if manually operated, would be your main way to carry water and other stuff in your top floors. [Answer] For the plants aeroponics could be used, using light pipes and shade-tolerant plants near windows initially, where the water supply would be via capillary action in an artificial supply of roots. Ropes would be sent into the ground, to gradually branch out into ever finer capillaries leading to every individual plant. Capillary action will raise to tree top height. [Answer] If "there is a strong spring and a well in between the buildings", it would already be integrated into the municipal water supply. Ignoring such a resource is as silly now as it would be post apocalypse. Close any valves exiting the neighborhood. Work with resources already in place. Running any kind of new infrastructure 12-18 floors without power is more work than its worth. It would be very convenient(and plausible) if the tallest building were still under construction allowing crane access and heavy equipment on site. Windmills on the ground are enough to simulate a low pressure municipal supply to each building which will serve the lower 2-3 floors. But above that, the buildings will rely on either pressure booster pumps or transfer pumps to a roof tank. The electric motors in these pumps can be removed and the pump portion powered by some alternative source. Unfortunately, getting the power source to the pump location can be a very large problem. With the tallest building still under construction, a wind turbine could be raised by crane and placed on an unenclosed floor inside the building. That windmill power would lift water to a simple tank built on the roof or upper floor. The tank could be tied to the building's standpipe. Then all the standpipes could be linked with firehose at street level. Because water seeks its level, it will rise to the top of each standpipe in every building. The existing plumbing on living floors only would be tied into the standpipe. This would prevent an inadvertently opened faucet in an unoccupied room from draining the system. If there are ever problems, a pumper firetruck could always be used to quickly inject lots of volume into the system. <http://www.who.int/water_sanitation_health/hygiene/plumbing14.pdf> An different solution I thought of is to use the elevator to lift containers of water or whatever else you need. The elevator motor wont work, but the counterweight is still attached to the cable. If you could attach additional weight(buckets or tanks) to the counterweight at a high floor while the elevator car is at ground level, that would allow the elevator to rise without power. Unload the weight at the bottom and the elevator car comes back down. You don't want to carry weight up the stairs just to drop it down the elevator, so what do humans living on upper floors produce which weighs a lot, and which they want far away from where they live? ... sewage. Yes, I just proposed a human waste powered elevator on a question that asked nothing of the kind. I should get out more. [Answer] How about passive rain / [fog collectors](https://www.wunderground.com/news/fog-collectors) at the top of the buildings? Unless your post-apocalyptic city is Las Vegas... Fog collectors are large permeable fabric panels that intercept the flow of fog-filled wind on hilltops and ridgelines, and collect hundreds to thousands of liters of water per night. Fog collectors have been erected in Namibia and Peru to provide water for personal needs, cooking, and agriculture. [Answer] **Steam Engine** Before there was electricity there was steam. Steam engines are fairly basic machines. Further our current society has plenty of refined metal that could be used as the basis for redeveloping this technology. Assumably you could just burn wood in place of coal. This option would likely not provide as much power but it is viable. Finally, the steam engine could be mounted two or three floors up for defence -- you would have to rely on animal / human power to position the fuel. Note that there are forests near cities. The green areas in the map below area parks often dominated by forests (the map is of the Cleveland Ohio metropolitan area): [](https://i.stack.imgur.com/IW6xe.jpg) [Answer] Since we're including impractical answers, behold my favorite weird way to raise water: the [fluidyne pump](https://en.wikipedia.org/wiki/Fluidyne_engine). It's a heat engine closely related to the more familiar Stirling engine. Fluidynes can be powered by sunlight, but you'll need a lot of them in series to reach the top of a tall building. [](https://i.stack.imgur.com/KpbFm.png) [Answer] A windmill may not produce enough "power" to work a pump depending on location, how much wind is blocked or scattered by building, and it might get scavenged for its materials by raiders so wind may not be the most reliable way to get stuff working(depending on the setting) I'm assuming the survivors will need to wander off into farming as well to be able to eat, and as humans are lazy, they will use mules/horses/cows to till the soil(even if the soil is inside a building with a glass roof or mirrors set up) Now if you'd occasionally hook those cows and mules up to a water pump the settlers built out of wood or metal if they have proper metal working tools available for the water crisis sets in. <http://users.tpg.com.au/wagnerbe/hpv/html/horse_drawn_pump.html> and have those pumps pump the water up to a big water tank, which is relatively easy to build out of wood, you only need your work animals to work once in every x days until the water runs out. That way you can get the animals out of harms way and "hide" the pump for marouders. You could even dig it in the ground and then cover it up. These animals could also be used to automate washing for the people living there <https://youtu.be/6tMoE8siNo8?t=5m54s> and of course power grinding stone for grinding grains and other materials. They can also used to power machinery with leather belts. <https://en.wikipedia.org/wiki/Line_shaft> or generate electricity with it. Small amounts, but perhaps enough to help with building up an electrical grid up with windmills/watermills etc... Basically, by first utilizing animals, they could short circuit the industrial revolution within a few years if they manage their resources correctly and focus on getting power from windmills/water mills as soon as possible on large scale. When there's power, water, electric light, they can grow crops galore, which they can trade with other settlements and get an economy back up and running. They can smelt metals with electricity and get iron working back up and running. [Answer] Perhaps this is a novel solution, but you could use a space pump. Simply build a tube--like a chimney--to the top of your building. At the top of your building, the chimney opens out into a dome, perhaps with a glass surface. On this top level, you have a bunch of soil and plants, because that is nice and aesthetically pleasing. --- At the bottom of the tube, you have a nuclear reactor and a water reservoir that allows water to fall towards the reactor. The nuclear reactor vaporizes the water passing over it, which is used to power a turbine (much like the turbine of a jet engine) at the bottom of your tube (providing energy). This steam then expands and flows up your tube to warm the jungle at the top of your tower, and condense on the dome. As the water condenses and filters through your jungle/farm, it flows back down to the nuclear reactor. --- Bear in mind, this nuclear reactor could also power a plasma that is almost energy neutral (as in a tokamak--so it is basically free) ejecting near-massless particles at significant fractions of the speed of light out the bottom of your building, providing nearly 1g of thrust for your inhabitants. --- Further, once you get up to speed, the blue shift of the stars in front of your space pump will produce enough light to stimulate photosynthesis in your jungle (at the top of your building)...and voila, you have an interstellar space pump that not only transports water, but also grows food for you to eat and moves you around. [Answer] You could probably build an economy around water carriers. They could walk up the stairs all day with the water, for a fee.[](https://i.stack.imgur.com/o9tbt.jpg) [Answer] Some answers are wrong, it is not possible to pump water from above, if the height is higher somewhat like 10 meters (10 meters of water is 1 atm of pressure), over 10 meters you can drain water only if there is some pressure underground. However you could have some series of pumps each one draining a well that is 5 meters below. 1. Pump 1 get water from ground level and push it to a 5 meters tank, 2. Pump 2 get water from the 5 meters tank and pull it to the the second tank at 10 meters etc. 3. And so on. If the height is particular high, another feasible way is a mobile tank, it is filled at ground level with few hundred liters, then it is pulled to the roof (by hand in example). [Answer] What is the nature of the apocalypse your world was subjected to? Assuming this world evolved from our timeline, it will have experienced global warming. If that's the case: let the water come to you. At the tops of at least some of these abandoned buildings are former swimming pools, which are kept filled with freshwater by regular heavy rains and serve as large reservoirs for the inahbitants. The rains also irrigate the building-top gardens, mitigating the need for pumping technology. [Answer] I might be thinking too simply on this but why not use a dumbwaiter run by the people in the towers. being enclosed the cable and pulley system should be protected against bandits and as long as someone can pull a rope or cable you have a way up and down. [Answer] Brief history. Over 80 years ago, a Moldavian boyar brought from a western country (Germany, France) dpua pumps that he used to remove water from the fountain to the mansion and the water lifting field. Description of the pump: it was made up of a cylindrical body with semispherical lids (everything made of cast iron), one of the parts had a pipe (the inlet) that was above the level of the fountain and had the end provided with a r1 tap and above palnie (p). from the other end of the body there was another pipe (slightly) bent at the end and fitted with a r2 tap. [More about drilling water well here](https://euforaje.ro). installation: the pump body was immersed in the well until the bottom, and the two pipes - the inlet and the discharge - stayed above the guides (the upper edge) of the well. operating mode: 1. Open the drain cock r2 as well as the intake faucet r1. 2. pour the bucket water through the pallets filling the entire system until the water flows through the r2 tap. 3. Close the taps r1 and r2, then open the robot r2 and the water starts flowing smoothly without having a large flow. as a rule the water was flowing in the well of the fountain because the springs were strong. If the r1 faucet opened, the system would be defused and the water would not flow through the r2. The pump that was installed in the field raises the water to the pools for the preparation of the spraying solutions. What a "diabolic" mind had that engineer from recent times gone! it is worth mentioning that two unofficial commissions from the polytechnics in Iasi and Bucharest were asked to address the issue, and they were brought by a clever director from an i.a.s. nearby. unfortunately, the pope had disappeared, because some villagers could no longer feed the cattle, feeling the taste of oxides in the water. The description belongs to people who are trustworthy. ]

[Question] [ SPECTRE (SPecial Executive for Counterintelligence, Terrorism, Revenge and Extortion) is a nefarious organization run by me, a criminal mastermind named Ernesto Blofeld. It has its tentacles in many different parts of the world and is connected with varied criminal groups involved in drug trafficking, gambling, terrorism, and other money making enterprises. This is all to fund its ultimate plan for world domination. I am a wonderful and benevolent boss who is a joy to work for, and my employees love me. However, I have a policy that that failure is to be met with death. This is meant to set an example for the others and sets the bar high for them to succeed by keeping it competitive. People are executed in various ways, such as being fed to sharks, electrocuted, flayed alive, etc. This has led to a high turnover rate for many jobs within the organization, and some minions are becoming disgruntled due to the fact that they feel unappreciated for their hard work and all the risks they are forced to take. While the standard is to kill these employees before discontent spreads, I can only kill so many. How can SPECTRE motivate its workers and keep its executions down to a minimum? [Answer] As any good manipulator knows, the optimal ratio of positive to negative feedback is 4:1. This is actually true regardless of the quantitative level of competence in your organization (regardless of whether you've got a whip-smart team of workers or are trying to train a dog to not poop on the carpet - and from the sounds of things, your organization is unfortunately veering towards the dog-poop-carpet side of the spectrum.) So the first step is to baseline your competencies. What levels do you need to hit for positive or for negative reinforcement? You'll have to examine your historical performance to answer this. Either you'll need to: * **Punish fewer people.** This will be a challenge. Trust me, I know. Killing idiots is a sublimely cathartic act, and cutting down on this will be a difficult sacrifice. * **Reward more people.** This may be even more of a challenge. You'll find yourself rewarding marginal, semi-competent people far more than they likely deserve. But it's needed. Without that 4:1 ratio, you'll find yourself running into headcount issues from a disloyal and unsatisfied workforce. Fortunately, if you follow the 4:1 ratio, the general competency will rise from year to year. And this will get you where you want to go: where the idiots all fit into the :1 portion of the ratio, because you've got enough competent people earning lavish praise to justify sending all the idiots into Piranha Tanks. Which, honestly, is the reason a lot of us even get up in the morning. [Answer] You have to distinguish between internal and external ruthlessness. Your organization's reputation, and the fear it engenders, will largely be based on your external-facing ruthlessness. If an external counterparty fails to deliver, you want to wipe them out in as messy and horrifying a way as possible, and you want your action to be generally known. But internal ruthlessness doesn't really add to your organization's reputation, because (since you're a secret organization) it generally won't be known to anyone outside the organization. You can feed the assistant director of stealing plutonium to sharks if you want - nobody outside your organization will know or care. The situation, therefore, calls for you to increase your external-facing ruthlessness while at the same time modifying your internal procedures to more closely match best practices for a large organization. Internally, you may need to focus more on employee appreciation and compensation and less on feeding-to-sharks. [Answer] # The classic formula is to punish the behavior you want to suppress, and reward the behavior you want to encourage. Right now, it sounds like you are punishing bad results and rewarding good results. The trouble with judging by results is that sometimes correct behavior (which you want to encourage) leads to bad results anyway, because of bad luck, failure elsewhere in the organization, or other factors outside the employee's control. And sometimes bad behavior leads to good results because of luck or intervention from elsewhere in the organization. You need to come up with a code of conduct for your employees. This should detail what powers they have, and what responsibilities they have. When a mission fails, you should only kill the ones who violated that code of conduct. Here's an example: Sgt Malice is assigned to break into a vault. That's his mission. Since he's new, he does not have the power to requisition supplies without authorization from higher-ups. He was told to pick up a supply drop, however. The supply drop is Lt. Sloth's responsibility. When it comes, however, it contains only half the explosives that Sgt Malice was told to expect, too little to get in to the vault. Sgt Malice is ordered to maintain radio silence for this infiltration mission. He doesn't have the power to fix this, and it wasn't his responsibility. Now, you might think that your ruthless policy of killing in any case of failure would inspire Sgt Malice to get creative, but honestly people don't need to fear for their lives to get creative, and they tend to actually be dumber when they are afraid. If he tries some things, does his best, and then reports back that he couldn't do it with what he was given, he should be spared. The supply drop wasn't his responsibility, and without enough explosives, he didn't have the power to succeed. It's Lt Sloth who should be punished. He had the power to succeed yet failed his responsibility. That is bad behavior. Into the lion pit he goes. [Answer] > > Chen Sheng was an officer serving the Qin Dynasty, famous for their draconian punishments. He was supposed to lead his army to a rendezvous point, but he got delayed by heavy rains and it became clear he was going to arrive late. The way I always hear the story told is this: > > > Chen turns to his friend Wu Guang and asks > > > “What’s the penalty for being late?” > > > “Death,” says Wu. > > > “And what’s the penalty for rebellion?” > > > “Death,” says Wu. > > > “Well then…” says Chen Sheng. > > > And thus began the famous Dazexiang Uprising, which caused thousands of deaths and helped usher in a period of instability and chaos that resulted in the fall of the Qin Dynasty three years later. > > > The moral of the story is that if you are maximally mean to innocent people, then eventually bad things will happen to you. First, because you have no room to punish people any more for actually hurting you. Second, because people will figure if they’re doomed anyway, they can at least get the consolation of feeling like they’re doing you some damage on their way down. > > > ~[Scott Alexander](https://www.goodreads.com/author/show/10866248.Scott_Alexander) Always be cautious about applying the death penalty for failure. If someone powerful within your organization knows that he's going to die for failure... the moment the plan starts to go south the only way he can survive is to kill you first. Instead why not pay your lackey well with hefty bonuses for creative cruelty against your enemies. Have a weekly prize pot for the lackey who most creatively makes an example of the family of one of your enemies. [Answer] As the films show, Mr Blofeld, you have already mastered this. In *From Russia with Love*, Rosa Klebb and Kronsteen failed to kill Bond, but the one who was 'let go' was Kronsteen. Not only did his plans fail, but he didn't put enough work into making sure the inevitable faults were overcome. Failure is tolerated, so long as the failure is not due to laziness or incompetence. If you do everything right and things still don't work out, it's not the end of the world. Yet... As a results-driven boss, this becomes a learning experience for your employees. Failure is tolerated, yes... but as it has consequences for the organisation, so too does it have consequences for the individuals. The first attempt failed? Perhaps they didn't have the right resources, then. So unlike a less enlightened employer who might demote an employee for failure, you *support* them with better training and resources, to maximize their ability to succeed. If they still fail at that point, clearly they're unable to benefit from the learning experience. At which point, sadly, they're no longer suitable for their role. Or for living past the next scene... [Answer] Create a vast incremental hierarchy. I mean VAST like 1000 layers of ranks that makes army ranks look small. Even if you have to have intern levels 1-10. Minor failures now end up being demotions and successes move you through the ranks. Major failures remain quick and brutal no matter where you are in the hierarchy. If you fall to the bottom of your rank ex. lvl 1 manager misses a deadline? He disappears (presumably to the torture room). Afterwards, depending on his previous failure history, execution or he is now a Level 5 assistant manager. The large array of ranks keeps something to strive for and compare against as well as quantifiable progression. It is also a warning against failure if your rank start to slip towards punishment. This provides motivation and reduces turnover. Win-Win. [Answer] Instead of threatening employees with harsh punishments, my suggestion would be to treat your employees extremely well so they'll *want* to do their best. In fact, you should want SPECTRE to be the #1 "best companies to work for", even if it's an evil corporation bent on ruling the world... but aren't they all? ;) Seriously, though, take some ideas from Google and Apple and give employees the best benefits: * Free health care... so when Sgt Malice gets injured blowing up a vault, he knows the company will pay his medical expenses. * Or if your employees shouldn't go to the hospital because it'll expose secrets of your death-ray, then have an excellent on-site medical staff. * Free meals * Free child care * College scholarships * Paid holidays... because even employees of evil companies should get Christmas and Hanukkah off work. * Paid bank holidays- who doesn't like getting a *paid* day off because of a random day in October? * Paid 3 weeks vacation time... and tell the employees that no one is so overworked that they can't take a vacation * 401k and other retirement packages that are transferable.. so when Sgt Malice doesn't come back from a mission, his wife and kids get benefits * Coach and encourage employees on how they can do better * Make sure to give employees the resources they need to do their job... such as making sure Sgt Malice has the X9000 explosives instead of the X8000 * Have plenty of employee recognition and appreciation... tell the entire company how well Sgt Malice blew up the building To paraphrase Wreck-it Ralph: Just because you run an evil organization doesn't mean you have to be evil to your employees. [Answer] **Demote them to an unattractive post:** For example set up a mining base in Antarctica or Siberia and depending on the severity of their crime have them work there. For example if somebody messed up a paper that doesn't harm the organization too much, congratulate him with his new job as a manager or guard to the Antarctic base. Most people will not want to stay there for too long. If they screw up a bit worse then they can become a miner there for a couple of months. **Irritating 'redemption' courses:** Have you employees suffer through something they really don't like. For example administrative personel could be forced into a military boot camp for a few months. The soldiers could be forced to become miners, janitors, construction crew or used for menial tasks for a few months. These things are in my opinion severe enough to have people rethink messing up again, but not too severe that they will get a grudge out of it. [Answer] Add a mystical component, thereby subverting the meaning of the concept 'alive' and 'dead' - for instance generating great gains will get you a 'blessing' that accumulates to extra lives, buffering eventual deadly repercussions. Also, you can shield others by blessing them. The higher up you are, the more deadly you can be to the ones below you, with you, Blofeld, as unkillable and omnideadly god being above those things. Your organization retains their image, as people are still 'executed', while the headcount stays more stable. You also gain cool monickers like 'deathless', 'double dead', etc. helping you engender even more of a superstitious fear-aura in the general populace. [Answer] **Look to the Evil Overlord list** Specifically #68: I will spare someone who saved my life sometime in the past. This is only reasonable as it encourages others to do so. However, the offer is good one time only. If they want me to spare them again, they'd better save my life again. Now I'm not saying it is just a life-saving thing. Instead, work a 'get out of failure' system into your rewards. Every six(?) successes, you earn a credit to fail with no (or at least a greatly reduced) penalty. They can save up as many of the credits as they can earn, but you might want to work in a system that successive failures start to cost additional credits. [Answer] I like the classic Yakuza trope that you see in the movies where the person who failed offers a finger to the boss as an apology. If this is a future or fantasy world and someone really botches something they sacrifice their arm to the boss in exchange for their life. Then down the line after earning their place back and completing some really troublesome jobs the boss rewards them with a Bionic Arm or something redeeming them from their past grievance. Now they are an uber badass who has learned their lesson and also seen the worst and best the org has to offer. All the while maintaining the feeling you are going for. [Answer] Get them to apply the punishment to their co-workers. Every week someone else is on execution duty, gets a list of buddies to kill for their failures. By administering the penalty themselves, they acknowledge its validity, and will begin justifying and vindicating it. They'll do their best to avoid failure not only because of the fear of death, but because they accept the justice of failure=dying. As @Simon.y mentioned, when failing, they'll eventually come to you to offer their lives to redeem their honor/sense of their place in the company. When this becomes the norm - you can be magnanimous when the employee is a good one and their failure stems from actual odds-stacked-against-them. You'll look good when letting them live, and culling out the weak will be a standard, expected procedure. This does not work: [badly burnt (austin powers)](https://www.youtube.com/watch?v=jLaCqrisEac) [Answer] **Usual Evil Corp Stuff** * Bring your child at work day * free fruit&coffe * annual group cohesion activities * christmas dinner If it works on my company... [Answer] In Destiny 2, there is a character like this known as "The Spider." He essentially runs a band of the pirate race in-game, and he has a unique-for-the-species plan. If they meet their quotas, then he gives them the substance they need to survive (implied contrapositive: If they don't meet the objective, then they don't get the stuff they need to survive and thus die) However, they can also choose to take on "Special Missions" (such as retrieving the Mona Lisa or Starry Night) to gain more of the substance, more crew, power, evolve, etc. Something like this, that rewards going above-and-beyond for you, while punishing failure with **fair, established business rules** could work well for your space mafia. [Answer] # Make them compete SPECTRE is a vast and complex organisation. As any big group, there must be a lot of layer and divisions, subdivisions, task forces, teams, association... Turn them one against another. Not on importants matters, but on numerous (and ultimately meaningless) subjects. Think of the houses on Hogwarts, competing for the title of house of the year. Reward the winners, and punish severely the ones who bring poor results. Make them care **A LOT** about the competition. It must be one of the most important subject on their life. If (and it will be the case) someone doesn't want to be implicated in that system, the rest of the team will pressure them to do so, fearing to lose points and be demoted. ]

[Question] [ In this world, religious leaders of a world religion practice a form of ritual magic that is essential to human existence. Certain rituals must be performed at certain times for nature to function properly. The sun must rise and set, seasons must come and go, rain must be delivered to places that need it, souls of the dead must be transported to the afterlife, etc. All of these natural cycles must be activated by rituals at specific intervals. One must become a religious functionary of this faith and study for many years to be able to perform these rituals. This church equivalent is very selective of its members, preventing just anyone from joining. When this magic isn't performed, you get a situation like [Westeros](https://gameofthrones.fandom.com/wiki/Westeros). Seasons are unpredictable, and could last for several years. The sun and moon don't operate on their regular cycles. Souls may not ascend when they are supposed to and get trapped on the mortal realm. Things get completely out of wack when religious leaders don't do their job. This clearly makes religion essential to the planet and puts practitioners in a powerful position. How can I prevent the formations of complete theocracies, where religious leaders control government and all aspects of society? [Answer] # Religion does not imply Theism / Theocracy By paraphrasing the old expression "Correlation Does Not Imply Causation", I will simply say that you have no problem here because **religion does not imply theism/theocracy**. * The-ism is **doctrine** (-ism) based on **religious faith** (the-) * Theo-cracy is **government** (-cracy) based on **religious faith** (the(o)-) Now granted in real life there is a strong connection between faith and doctrine because the religious institutions **claim** that the ethics and morals that are in their religious doctrine are valid for all people. But their only ground for claiming this is "Because our holy texts say that these ethics stem from the highest authority, i.e. the divine creature(s) to which we have pledged our faith". Without **that**, they have no basis for claiming that their doctrine should be universal. So in your world, things do not have to be like in our real-life world, because you make no reference to having divine entities that claim ultimate authority to dictate doctrines. So whatever doctrine needs to be in place in order to not screw up the world Westeros- or [Broken Earth](https://en.wikipedia.org/wiki/N._K._Jemisin#Broken_Earth_series)-style is not at all related to ethics or morals. The fact that you need to perform a certain ritual in a specific way at a specific time, does not in any other way imply things like the ten commandments or [the eight condiments](http://flyingspaghettimonster.wikia.com/wiki/The_Eight_I%27d_Really_Rather_You_Didn%27ts). In fact, one could argue that what you have here is not a religion at all. What you have is unexplored reality; physical science waiting to be performed. Unexplained does not mean mystic. And with a lack of mysticism, any measurable, explorable part of reality is just that: plain old unexplained reality, not religion. Compare real life; we have **no** idea why gravity exists or what the fundamental causes of it are, but we none the less know how to deal with gravity because we know how it works because science has explored gravity and found out good models of gravity that fit the measurable reality. In the same way, your fictional characters know how to deal with the threatening calamities in order to keep them at bay. They have no idea **why** they have to do it the way they do, but they know that if they do not, things become messy. Hence... ## There is no problem here ...because your religious leaders do not claim ultimate authority over every aspect of life. They are experts in warding off calamities by knowing the rituals and being in tune with what the great unknown demands. But unless they **claim** ultimate authority over everything simply because they desire power, there is no issue here. ## What about abuse? Ah, what if the religious leaders decide to play dirty and start claiming they do have authority? That to me sounds like a great plot generator. Is this something for you as the author to be worried about, or to use as an endless well to pour from? Since you can dial the religious leaders' ruthlessness and ambition back and forth as much as you like, and seeing that you can dial the people's skepticism back and forth as much as you like... you simply need adjusting these to whatever levels you need to create the right kind of discord needed to make a good setting/story. Also let me point out that if the people of your world have never before had to endure deistic/theistic kinds of religions, then they are not at all used to the notion of cults where someone claims someone or something has ultimate authority over **everything**. If you set it up this way, the notion of an ultimate authority will be as alien to them as the [cult of personality of Kim Il-Sung](https://en.wikipedia.org/wiki/North_Korean_cult_of_personality) is alien to you and me. [Answer] ## There are simply too many things on your plate Do you know *how hard* it is to make seasons change? How delicate the process is to make the souls ascend? You mispronounce one syllabe and grandpa ends in void. Like *forever*. And you want me to collect taxes? Write laws? Take care of the military? Meh. Nothing for me. And excuse me now. I need to meditate to have good mindset for beautiful sunset of today... [Answer] Can anyone perform the rituals needed? Or do they need some set of magical abilities? If anyone can do it, then in being the one who does it has no true power. Just like we need farmers to produce our food, but everybody who is willing to learn the needed skills can do their job, so they can't take us all hostage. If you need to be born with some special magic powers, then you can bind these powers to a special mindset. Only those with a gentle, caring mind who have no interest in ruling over the others can perform the magic. [Answer] Well, what define a religion compared to a simple belief is the dogma. **Have it written in their religious text and prayers that political power is bad and that they are only servants to the people (or ruling class).** Of course, you're not totally free from a few religious leader having some real power and maaaaybe a bit corrupt but that's the job of your strong ruling class to keep them in check. One of the good way is to declare that your true political leader is chosen by the gods and that he IS the ultimate religious reference. Just need to explain that his bloodline is sacred or that the way he was elevated is (sacred popular election, sacred fighting competition, sacred coup d'état,... whatever float your boat). And I'm not inventing anything. You state that in your world, the priests have a "real influence on the world". Well, so are the priests in most believing countries (present or past) in the real world. In all countries where there is a state religion, people really believe that priests will help them communicate to their god, save their souls or other. So why did priests not seize power in all of these countries ? (This is an open question, if you want to search for other real world examples) [Answer] Having the power to hold the world hostage by simply not doing your job is a terrifying prospect. Therefore it is a given that the church must do its job of keeping the world in balance. The moment it pauses its practices to achieve an end, all faith on its integrity will be lost. Therefore they'll want to appear altruistic and not go the "bow before me or suffer eternal undeath" route. But there must still be some consequences for this loss of faith. If there is only a single system, then the loss of faith from its followers is of no consequence to it, as all people just bend to its rules. Instead, have multiple religious bodies, each having its own belief systems and doctrines, but all employing their mages/shamans/priests/etc. to achieve the same end. A religious body exploiting its believers will quickly lose its body of followers, and even if they stop their practices, there are others to take over. If someone tampers with the systems, there are others to put an end to it. Competition keeps each organization in check. This will open up a more varied system where other forms of governments can emerge. There will still be theocracies, or have religious organizations as shadow rulers (subvert methods like blackmailing existing monarchs with conditions like denying their family afterlife, causing unfavorable weather conditions during a battle, etc.) but they won't be so blatant. [Answer] While religion will obviously be important, it doesn't inherently become all-powerful. **Doing their job is in their interest** If the seasons don't change, the crops will fail, and eventually, the priests will starve. If the souls don't ascend, then tripping down the stairs can potentially leave their soul stuck on earth. Having the power to change the weather is nice, but you're still powerless against a couple of thugs. So a threat if you're not doing your job is a good incentive. You enjoy a position of power, but there are many willing to replace you. **It is very taxing, time consuming or otherwise hard to do** Try ruling a country when maintaining the weather alone takes 15 hours a day. So you have an agreement with local government providing for you. You can of course train more priests to lessen your load, but then you become replaceable. **Competing factions** It's not a single church, it's many competing religious sects. The *Worshippers of the Sun* want eternal day, while the *Brotherhood of the Moon* want everlasting darkness. So the day-night cycle is largely the two factions competing to get their way, and have essentially reached a unspoken agreement of roughly 50/50. Different factions or religions could also have exclusive powers. Doesn't matter if it's day, if there's a perpetual storm cloud covering the sky. So each group don't have absolute power over anything. It also become a military tactic of trying to kill your enemy's priest or mess up their weather. Messing up their day-night cycle might be a bit tricky, without affecting your own as well... [Answer] *Enslave them* The people who perform the magic rituals need not be leaders of any sort. They could be doing so at the will of others, under threat of bodily harm or death. *Secret cabal* Maybe the ritual performers do not wish to control everything openly. Maybe they control from the shadows. Their wisdom has allowed them to see that they should instead have a figurehead/scapegoat that appears to be in control, while they control the figurehead. This isn't exactly what you asked for but maybe the suggestion is still of value to you. [Answer] Priests of nature have little interest in political affairs. Indeed, getting them to pay attention to the affairs of humanity at all is a challenge. Watching a single creature from egg, catterpillar, chrysalis, adulthood, until its passing is as engaging and important as keepingthe seasons in sync for the crops. And politics or wars? Those are incomprehensible aspects of humanity that have no bearing on the priests. The priests may be powerful, but to the average person they are unreadable and unpredictable. [Answer] While you *can* spend time explaining this, you don't necessarily *have* to spend time explaining this. An example of a system very close to what you've described can be found in My Little Pony: Friendship Is Magic. It's shown that the weather and seasons are explicitly and completely dependent on the actions of the ponies, but this is treated as one more chore rather than a religion. Where it gets sort of religious is with the Alicorns, which are basically physical gods: immortal, implied to be unkillable (or at least absurdly durable), and each in charge of a particular aspect: the Sun, Moon, Dreams, Love, Friendship, and Magic. Ponies swear by them ("sweet Celestia!"), and a few times seem almost to pray to them by calling for Luna when beset by nightmares. With that background out of the way, it's interesting that while Celestia rules Equestria jointly with Luna, and Cadence rules the Crystal Empire, this is treated as coincidental. Luna barely participates in government, as her sleep schedule is inverted, and Celestia tolerates governing with something very close to ennui. The only really engaged ruler is Cadence, mostly because if she disengages her country comes immediately under existential threat from eternal winter. Additionally, dignitaries from other nations occasionally visit, and are clearly autonomous equals rather than tributary nations or protectorates. [Answer] Same way it's been done many times historically, control the priesthood. Inca, Aztecs, Egyptians and a bunch of others spring to mind even the Romans in some ways. Whoever controls the army controls the priesthood, with some the ruler assumes divine status, with others they have an integral part in the rituals to play, sometimes both. But at the end of the day it's not a theocracy because the priesthood can and sometimes was massacred wholesale by the army. The only difference from our third party view is that the rituals truly make the World go round.... from the Aztecs view of things, they believed the same, so it was true for them which is all that matters. [Answer] **In training to become a priest of this church able to perform these rituals, a person becomes one with nature**, meaning that their own health is tied with the balance of the nature around them and the earth as a whole. This gives them an incentive to keep the world in balance: if they don't do it, they will get extremely sick and may die. This means they won't be able to just go on strike and get whatever they want, since they harm themselves more than anyone else - this mechanism will ensure that it isn't a viable strategy for them to gain power. [Answer] **The same way western government and military interacts** In a western democracy, government and military are separated, despite the absolute ability for the military to take control of the government by force. The reason that this works is embedded in the culture of the military and the constitutional powers granted to the civilian government. For example, at any time, the US military could take over the US by force, if the entirety of its leadership wished to do so. They certainly have the resources to achieve that goal. That they do not is for a number of reasons, mostly to do with the culture of the military, which includes the oaths they swear. In a similar way, this religious group could swear oaths to serve and protect the civilians of the world they inhabit. They could believe that it is their divine calling to keep the rains falling on time. That their own life is not worth the devastation that would be caused by staging a coup, because their entire job is to protect the civilians that they have sworn to protect. Their goal is not to rule, their goal is to preserve the structures that enable the prosperity of their society. And if any of their clergy betray the faith, they are put through a court-martial type system, where they are tried for their crimes and thrown in jail or executed (execution would probably be more thematic since that would also destroy their dangerous knowledge). [Answer] **Overreach**. Historically, theocracies did, in fact arise. In every case they would not settle for simply performing the necessary rituals, but felt compelled to Make Things Better. The result was, predictably, disaster. The echoes of those disasters continue to be heard, and nobody is willing to let the priests run things. They are honored parts of the power structure, but never allowed control. **Heresy** Theocracies have arisen, but the underlying religions always toss off heretics and factions. The resulting convulsions always result in interference with the needed rituals, with the same result as above. [Answer] **Democratisation** Anyone can do it. That is anyone can actually perform the activities required to balance cosmic energy. Every man, women, and child is born with the ability. Sure its underdeveloped a lot because there are a lot of things that this skill cannot do. ie. it does not fix the hole in the roof, or stop earth quakes, or prevent that person with a sword from ... oouch. That being said, people who have the inclination to learn how to do it are respected, because it makes life overall easier. A farm by itself won't have such an individual, but a small town or a successful bandit band? They might be able to afford the services of a minor practitioner. Someone skilled enough to forecast impending issues like drought, because forewarned is prepared, or maybe to sway the mist to hang around a little longer so that you can make the surprise attack and get away. Of course there will be a few who are naturally skilled, or trained hard in the presence of masters. These individuals can push and pull the seasons around, rot fails to appear in the grain silos they are near, steel always is a bit sharper around them. Warlords would seize such individuals, states would erect schools to train them, and the clergy would attempt to induct them. At times one type of system would establish itself, but it would fall when the next genius trained themselves, or when the establishment in their own overconfidence, pushed nature around too much, and nature pushed back causing famine and disease, shortly followed by war. The ritual for season control could be performed by one well trained, perhaps messiah level individual, but a group of 10 decent, or 30 capable practitioners could do the same. Maybe it would exhaust them for months, but given the choice between three years of winter and feeding and caring for 30 bed ridden acolytes for a few months I can see what any town would do. Some towns might even do it even if it meant actually killing those people. [Answer] The gods get annoyed and upset if people abuse the power. It can be as simple as losing your magic abilities if you don't wield them for the common good, or as complex as making spells backfire, crops fail, earthquakes shatter cities... [Answer] It’s not the church who choose its priests; it’s the gods. If you want to serve the world (church, gods, whatnot) you must be a devoted person and, if you are deemed worthy, the god(s) will pay you a visit in a vision telling you the password to open the door of the temple where you can train. So you go visit the temple, say “mallard” to the guards, and they will happily open the door for you. But if you didn’t get a vision and say “goose” instead; well, the priests inside will humbly accompany your precious soul to the otherworld. Now, if the gods don’t want their priests to be dominant leaders, they will select their chosen ones with that in mind. And if, after your training, you do try to get to a leading position, these very same gods will have some tricks up in their sleeves to prevent that. And then again, your best friend during your training years will humbly accompany your precious soul to the otherworld. [Answer] The training necessarily involves a large spiritual component (one of the reasons the church is picky about who it trains - most people just don't have what it takes). Anyone who can actually perform the ritual is one with nature and simply won't have any desire for dominion. Anyone who does won't be able to get mind and soul into the proper state. (This is one reason the church seems very picky about trainees - most people wouldn't be able to get to the right spiritual condition even with lots of training.) There are several training centers in the land, since when there was one the people running it attempted to seize power by controlling the adepts. These holy men and women can create another one - after all, they do know the path to oneness. If one of the churches tries to seize power, it will become unattractive to the adepts, who will want to go somewhere else. [Answer] The priests keeping nature's balance does not automatically make them political and military leaders, but will likely put them into an important advisory position. Any ruler would need their approval, unless they have the 'inborn' right to be chosen in the eyes of your church as the rightful leader, such as a pharao was a direct descendant of the gods in ancient Egypt and thus always above the priesthood. If you want to look at a historical example, I would also recommend ancient Egypt as your best one. According to egyptian belief, if the priests would not perform their rituals, Nile's floods would not return every year to provide the soil desparately needed for their crops. If the dead were not properly prepared during burial rituals, which included adding simple amulets, embalming or mummifying the body or even sacrificing sacred animals and embalming their bodies alongside their dead who they should accompany and protect to lend him favour in front of the gods. Even if imagined and not actually 'real' their believes were as real to the ancient Egyptians as they are to the inhabitants of your world. [Answer] Farmers provide necessary food for humans here on Earth, yet they don't rule society. Scientists and engineers can change nature, yet they don't rule society. Military leaders can put a gun to your head, but military dictatorships are relatively rare in the world today. People don't rule by being necessary, by threats of violence, or by going on strike. Your world would be ruled by a managerial class: kings, governors, and bureaucrats; just like they do in this world. [Answer] > > How can you prevent a theocracy from being inevitable when religious leaders have power over nature? > > > In this world, religious leaders of a world religion practice a form of ritual magic that is essential to human existence. > > > Just to call this out explicitly, although others touched on it: # Have them separated from the world. A good example of this is in [Anathem by Neal Stephenson](https://www.goodreads.com/book/show/2845024-anathem) which has a number of interesting ideas in it. I bought Anathem because I like Neal Stephenson, but if I had to do it again I would get it from the library because I'll never re-read this one. The shut-off from society in Anathem is a neat concept (both the who and why) and that's why I bring it up to you - the annoying part of the book *to me* is that he made it hard to read to no purpose (using saecular and avout instead of secular and devout makes no sense to me). To be clear: while I admit didn't like the book overall, there are a lot of interesting ideas and for those, I'm glad I read the book. Separating them completely (mentally, if not physically) leaves you room for them to do to do *weird things* for plot reasons that you don't have to explain in the book. If your first book is successful, those *weird things* could provide plotlines in the same world for a new book about the religious leaders themselves (like Anathem) or vice-versa if that is already your focus. [Answer] You can't. As you wrote in your first sentence, their rituals are ESSENTIAL. You can't live without them so they have huge power. They would basically be treated like gods. I don't think a Theocracy would be the prevailing government, it would probably be some sort of tyranny/dictatorship with the entire society centered and working for the benefit of the few people who can perform these rituals. [Answer] Seems like this scenario itself answers your question: religion relies entirely on faith while this is a scientific(ish) endeavor. There is absolutely nothing that can be proven in religion while, in this world, this style of mysticism must have been founded, created, and maintained through a scientific method of hypothesizing and experimentation with real consequences. Therefore the world would never develop into a theocracy. Most likely the practitioners of the "mystical" arts would be more akin to celebrity scientists or possibly even sports stars. ]

[Question] [ Say an explorer lands on a previously undiscovered land, filled with humans, humanoids, wildlife, elementals, undead, demons... you name it. One would expect that these existing inhabitants would have their own power struggle. For example, the humans would be fending off the undead while also fighting against other humans over resources and hunting wildlife for food; the demons would be fighting against the elementals in a struggle to control points imbued with powerful magicks; the wildlife would have their own fights over food and territory, while the most powerful of them raid human encampments for *their* food, and so on. And yet, as soon as the explorer shows up, all these beings seem to immediately forget their own struggles; instead, they work together in an effort to kill the explorer. Indeed, opposing tribes of humans fight together as one, leading the ferocious beasts they once feared and even the undead into battle, while diametrically opposed elementals and demons aid each other in battle, such as a flame demon imbueing a stone elemental with the power of fire. Aside from the cop-out explanations such as "they are all under the influence of a higher being", how can this behaviour be explained? [Answer] He is fulfilling a prophecy. Maybe he has a different coloured skin from everyone else or he has unusual eyes. Maybe he wears a particular set of clothes or carries a particular weapon. Maybe he has some technology they don't know about that looks like something prophesied. The prophesies predict his appearance and state that he will come and break the world and yet, at the same time unite it. They don't want either. [Answer] ## He's the Harbinger of Doom For some particular reason, this character is bringing the end times with him (chasly from UK's answer fits in here). There's infinite ground to cover here. As a bonus, you can also create a character that ranges from a lawful good guy who, unknowingly, is bringing the end times (or even trigger them by accident) to a chaotic evil one that's actually trying hard to screw every living being in the planet (for motives of revenge, self preservation, power or just simply being an asshole). ## He's Cursed The great Wizardius is a very powerful mage known for casting the most despicable curses upon those who mess with him - and our hero had the bad luck of stepping on his favourite pet guinea pig. As punishment, Wizardius banished him to another world/land. Shortly after his arrival, he discovered that (nearly) everyone in that place wants his head. He is told by Unimportant Jenny that there's a spell (to which she's immune) that makes all living things that get near him get insanely filled with rage towards him. ## He's in a Simulated Reality Just picture the Matrix. Here, the character might or might not know he's in a simulation (if you ask me, things are much more interesting if he does but has to play by the simulation's rules to meet his goal). Maybe our hero was trying to destroy this evil AI, but in order to do so, he had to get inside its own private world to beat it in its own game. This is a good explanation as to why there's traps and various obstacles in his way that are not people/creatures (traps, mazes, etc). ## People just hate his guts Maybe our hero was once a very, VERY, bad ruler - heads, spikes, walls bad. Or maybe he's the heir of such ruler, a menace that terrorized the entire land for decades. When the opposing forces of the resistance finally got to overthrow this regime, they made it their personal goal to completely exterminate every member of the royal family. Maybe they have golden shiny hair or some other unmistakable trait (again, chasly mentioned something like this) which is the reason why everyone knows who he is. The point is that this guy is, did or was framed of something bad - and needs to run for his life, which would turn your game in a kind of hack'n'slash-survival thing. [Answer] In Harry Harrison's "Deathworld", this happens - all fauna on one planet is deadly aggressive toward outsiders. Toward the end of the book we find out why (based on my recollection): > > the animals are psychic and can read the emotional state of the settlers, who don't belong there, and who feel afraid of the wildlife. The animals' proactive aggressive attitude is something of a learned defense mechanism and is not planetwide, but rather has worsened to an extreme near humans' settlements. > > > On your world it could be possible that **the animals (be they smart or stupid) are psychic toward the emotional state of other animals, and intelligent off-planet outsiders stick out like sore thumbs to them and/or present as threats to the animals' existence.** (Perhaps aliens have a "blank" or "hidden reading", and to the natives this is terrifying.) It would not be hard to suppose that as this trait evolved from a common ancestor, the default instinctual behavior toward aliens came with it and subtantially all animals on the planet will attack on mind-sight. [Answer] The explorer didn't go to any other world. He stays here on Earth all the time, he's just under the influence of [Bath salts](https://en.wikipedia.org/wiki/Bath_salts_(drug)) Specifically, the aggressiveness of other people, wildlife and even inanimate objects is only from explorer's own perception. And people would really forget their own struggles in trying to catch and restrain the explorer. [Answer] Despite the fact this explorer is your protagonist, a common motivation for enemies to band together is if their shared land/world/place is threatened. This explorer has arrived and somehow begins to destroy/overpower/infect the world in which all these other characters inhabit. Perhaps he brings a virus/bacteria that their biology isn't immune to. Perhaps, like chasly from UK mentioned, he is fulfilling something that requires the destruction of their land. Your character should pose some sort of threat. These inhabitants of the land would undoubtedly forget their usual tiffs and work together to save their home. [Answer] The explorer came from an area that everyone knows that is forbidden to get in and out. Whether be a cave or a desert, the inhabitants knew that ever since that area existed, no one had gotten out of it and thus forbid anyone from coming near it. An unknown creature exiting out this forbidden area, while the inhabitants are curious, they are also scared as it's possible that the explorer was the cause of the disappearance. Another possibility: The inhabitants have evolved to have some empathetic ability, able to identify another inhabitant with their own "feelings". The explorer does not have this ability. Upon showing up, the inhabitants, when using their empathetic abilities, fail to feel anything from the explorer. Threatened by the unknown being that feels like an inanimate object, they attacked the explorer. [Answer] You can make the distinction that these inhabitants aren't exactly normal humans, wildlife, etc. in a normal land, and are instead are all living in a banshied realm akin to purgatory (which would probably make it easier to explain the demons and elementals anyway). All beings in this realm would have one thing in common, they were stripped of their souls when they were sent there. When your explorer lands here bearing the only soul in the realm, it is certain to draw attention. The eminating lifeforce acts like an ultrasonic beacon drawing all of this lands inhabitants toward the source like zombies toward a sound. Whether these beings desire to have the soul, or find it's presense unbearable, they must destory the person who posseses it to release it. [Answer] Historically in our own world, the people living on a particular continent, island, or "undiscovered" piece of land have not always fared very well when explorers show up. Maybe this explorer is not the first one who has shown up in this land. Maybe they're the second or third or twentieth, and all the varied groups in this land remember how badly it went when strangers showed up the previous time(s). For instance, maybe the last time a mysterious stranger showed up in this land they spread a disease that wiped out a huge percentage of local life, or enslaved multiple people from multiple groups, or re-drew a bunch of local boundaries on a map in a particularly clumsy way. Maybe all the power struggles and strife the peoples of this land are currently experiencing are a direct result of the last time some external explorer decided to get involved with their lives. In this situation, I can believe that all the local groups would decide to prioritize "get rid of the outsider" over whatever their internal struggles are. [Answer] Everything there is part of a single hivemind. Normally you don't see it much as it thinking about something might express itself as a tribe hunting a certain animal or a plant growing in a certain spot. Kind of like a computer but rather than 0,1 we have plants animals peoples their state of being locations etc When an outsider arrives they chop wood and are not part of the hivemind. How would you react to someone coming in and literally starting to alter your thoughts, memories etc. An all out assault with everything you have seems perfectly resonable [Answer] The planet has an immune system, with all lifeforms being able to identify foreign bodies and try to eliminate them, just like the human body automatically attacking unidentified foreign cells. Maybe that planet has been invaded often enough by foreign lifeforms that it developed an "immune system" of some sort. The Earth never having been invaded this way might explain why it lacks it. [Answer] ## He is the chosen one Prophecies have told about this day when an outside came to our lands bringing unwanted destruction (or maybe peace...) that nobody wants. If this hero completes its commit, the world as all we know will stop existing. And obviously, everyone has fear of changes, enough to surpass their differences an ally to destroy this greater evil. Maybe there aren't prophecies, but knowing its currents actions, it is possible to figure out what is going to happen if he keeps working... on his quest. ## Hate from the unknown You said he is an explorer, which usually mean he is from further and (possibly) unknowns lands. Nobody knows much about him, and that is the greatest fear, nobody knows what he is capable of, so the only option is to destroy the unknown, before he destroys you. [Answer] # Shared Hatred of Outsiders A few generations ago, all the races of the natives lived in relative peace, despite their inherent differences. The different groups didn't love each other but they tolerated the presence of other groups. Then a few outsiders came to this land and said they wanted to trade with the different groups. In this land, guests had always been treated with respect. All the groups agreed that the outsiders were a neutral party and allowed them trade across group boundaries. This land had many things that were highly valued back in the outsiders homeland. The trade deals made the outsiders very rich. They brought even more traders into the land and created trading outposts in the lands of all the groups. Then they brought in armed guards to protect their outpost and trading caravans. The natives frowned at the armed guards, but after reassurances from the traders they grudgingly allowed them. But, the traders' greed was not satisfied with just trading. They saw the land rich with resources and they wanted it for themselves. They knew they could not have the land as long the natives were strong. So, they started to use their business relations with the different native groups to inflame the groups against each other. They created more dissent among the groups, all the while bringing in more "armed guards" and turning trading outposts into military holds. By the time the native groups realized what was happening, they were already too weak to stop the outsiders from taking over. The outsiders removed (assassinated) strong native leaders and replaced them with puppet leaders dangling on outsiders' strings. And thus started the outsider rule. Had they truly ruled the land, things would not have been too bad, but the outsiders never truly considered the land and its people as their own. They did not even see the natives as humans. The outsiders saw the land and its people as resources to be exploited and squeezed to fill their own pockets, regardless of what it did to the natives. The oppressed natives had become little more than slaves in their own land. This continued for a long time. Slowly but steadily, the natives started resisting. Small rebel raids started harassing the outsiders. The raids turned into skirmishes and skirmishes into battles. The natives ignored their dislike of each other and united across race lines against their hated enemy - The Outsiders. Eventually, the Outsiders were overthrown and sent out of the land never to return again. But the cracks created among the native groups ran too deep to be mended completely. Now that they did not have a common enemy anymore, they split into different nations and tensions started flaring again. **Until another Outsider stepped foot on their land.** [Answer] While it may seem weird, write the story narrative backwards. Start with where you want to end up, then decide what the climax is and how you get there, once you know that then the rest is often much simpler and an answer to your question is likely to present itself. While a controlling force might be cliche, there is a reason that it gets used so often; it sells and it's simple. Lord of the Rings has Sauron and the One Ring, Diablo has the namesake and the other Prime Evils (Diablo III expands on this further making your character the offspring of Angels and Demons), Warcraft has the Burning Legion, Game of Thrones has power and control, Legend of the Seeker has magic. That being said, the protagonist may not be a stranger at all, they may have been a former leader that went missing at a crucial moment, it was assumed that they deliberately left and they have now returned but the protagonist has no memory of that. [Answer] Sounds like Silent Hill 2 to me, where everything in the game is hostile to the protagonist, but it's also implied that the horrors he experiences are creations of his traumatized mental state, and it's all in his head. So maybe the protagonist is a victim of their own violent delusion? Read the plot outline of Silent Hill 2 if you're interested. I won't spoil anything here because the execution of the story is quite masterful, but if you don't feel like scaring the crap out of yourself you can just read the outline and take inspiration from that. [Answer] Something that's been used to similarly cause large numbers of people to react in the same fashion to a particular individual is *pheromones*. While that may not work as well in an alien environment, let's be less literal - something about how your character smells causes all life on this planet to react negatively to him/her. This requires no advance knowledge of your character on the part of the local populace (unlike several of the answers I see here), and could reasonably be used to cause any lifeform with a sense of smell to react to him. (Up to you to decide if your undead have a sense of smell or not). [Answer] The explorer emanates psychic or electromagnetic fields which are out of phase with the new land. It happens only because of the characters origin being different from the rest of the characters. Alternatively, it could be a mutation specific to the character. Because of this, the locals are subconsciously influenced into a state of fight or flight, or even rage when the protagonist is near. [Answer] **Explorer's Paranoia** > > What is Paranoia? Paranoia involves intense anxious or fearful > feelings and thoughts often related to persecution, threat, or > conspiracy [[1](http://www.mentalhealthamerica.net/conditions/paranoia-and-delusional-disorders)]. > > > This extends the trope of explorers traveling for extended periods of time in a claustrophobic environment (a plane, a boat, or a spaceship) prior to venturing on a new uncharted territory. Upon leaving the safety of their transportation device, it is possible that the difficulty of the exploration lead them to construct a delusional fantasy in which the outer world is the antagonist, and the only safe place is within the narrow walls of their cocoon. Following the description of delusions and paranoia, there is no evidence that can convince these people of the contrary. Instead, it will be very easy for them to become even more strongly convinced deep in their beliefs. The temperature of a stream of water, instead of being refreshing, will be perceived as freezing; the sun, instead of being warm and welcoming, will become scorching and blinding; the fauna, instead of being curious or scared, will be threatening and aggressive; a spider-bite, instead of being just a bite, will lead to somatization of the fear of poisoning. In a first-person, or a limited third-person narration, the reader has no obvious way to discern the truth from the delusional paranoia of the narrating voice. Hence, paranoia become reality, and delusion becomes truth. [Answer] As a biological cause, perhaps you can suggest they are all tied together in a sort of primordial hive mind that takes over when an outside influence invades. Be it telepathic, or pheromonal, or what ever. Perhaps they have this genetic memory where they were almost wiped out, and only those with this sort of religious fervor gene survived. It'd be even more interesting to create a backstory on how the gene ended up in all the biological life on the planet. [Answer] What if the explorer(s) belong to a race, or have characteristics similar to a race, that had once existed in that foreign land. let´s call this race "The raiders". The raiders had an incredible power in that foreign land. Think of superman but evil. They were the ultimate overlords and legends speak of their horrible deeds, about how they brutalized and enslaved every race in the world. In ancient times all the other races united and defeated the raiders, but alas, they couldn´t destroy the raiders completely and were only capable of vanishing them to a foreign land, were their powers waned and they were, supposedly, incapable of scaping. If the explorers were part of the raiders, maybe they were only capable of reaching the foreign land when they gained space/portal technology; or their magical science had overcome their lack of enough magic, etc. So the raider´s mere existence is hated and feared, for they were the true terrors of old. The legends you expect were never true. Sorry about the grammar. -\_- EDIT --- The shared characteristics should be easy to spot, maybe the existence of horns, a jewel in the forehead, skin color, tattoo patterns in the skin, or an omnious aura that every being in this realm is capable of feeling. [Answer] Maybe he indeed is doing lots of bad things, and he is so evil he manages to conceal this from himself. [Answer] The standard video game handwave is that * they are sent, or otherwise incited by the Big Bad to kill the hero, or * they actually aren't against the hero, or working together, for that matter, but the effect is still the same because + the hero is somehow in their way (e.g. by trespassing on their territory) or the other way round, or + they are just naturally aggressive (e.g. are predators/mutants) ]

[Question] [ There's a ruin of an ancient structure built by an old powerful civilization thousands of years before. Nearby is one of the fresher cities of this world, currently undergoing an industrial revolution. The ruins are known to the denizens of the city, and it isn't especially hard to get to them from the city. By the current time, the outermost structure is almost mundane to the locals, and everything of value that could be stripped down was stripped down long ago, so they don't even think of it as something important. They think of it as just an old pile of rocks, and not even a particularly large one at that either (No bigger than a medium medieval castle). **The question:** How can this structure have new untouched sections remain that nobody else had even suspected existed before? I'll accept both the external and internal reasons for this. The ruins don't have any deterrents like dangerous monsters or mechanical/magical traps, since those would be presumed to be killed and destroyed in the prior centuries, even if there were any (in the *known* section, at least). [Answer] The explorers find a small vertical shaft that seems to go down a long way. The locals have dismissed this as a well or [garderobe](https://en.wikipedia.org/wiki/Garderobe) and so it has not been explored but it was actually a ventilation shaft that is the only intact path to a much deeper level of the structure, the main path having been blocked off by seismic activity eons ago. The explorers may have to bring mining technology to pump out accumulated water and clear the now foul air before being able to use this route. [Answer] ## Real history example The ruins of [Troy](https://en.wikipedia.org/wiki/Troy) had been know to the locals for ages. Of course they didn't know they were ruins of Troy, because they had no idea about ancient Troy. They were Turks, and rural Turks didn't read Homer. They called it [Hisarlik](https://en.wikipedia.org/wiki/Hisarlik) (Turkish for "fortress") and during the centuries they happily reused the stones to make their houses. Eventually, no stone remained on the surface of the [tell](https://en.wikipedia.org/wiki/Tell_(archaeology)), one mound of ancient debris among many such semi-artificial mounds dotting the landscape in a region where history is measured in millennia. Then an American named [Frank Calvert](https://en.wikipedia.org/wiki/Frank_Calvert) came, in 1847, and bought 2000 acres of land including (part of) the mound of the Fortress. He was a self-educated amateur archaeologist, and did some digging; he found some artifacts of Hellenistic age, and became convinced that deep below must lay buried a splendiferous ancient city. And he called [Heinrich Schliemann](https://en.wikipedia.org/wiki/Heinrich_Schliemann). Schliemann, like Calvert, was a self-taught amateur archaelogist. The difference was that Schliemann was rich. By the standards of 19th century rural Turkey, Calvert was rich too, but Schliemann was rich by *European* standards. He hired a small army of workers, and began a systematic exploration of the tell in 1870. In three years he dug layer below layer, discovering the ruins of nine cities buried one on top of another. And on 27 May 1873 he struck gold. [](https://en.wikipedia.org/wiki/File:Sophia_schliemann_treasure.jpg) [](https://commons.wikimedia.org/wiki/File:Big_golden_diadem_with_pendants.jpg) *Left: Schliemann's Greek wife, Sophia, wearing the jewels of Helen of Troy. Photograph from 1874. Right: the large diadem with pendants, exhibited at the Pushkin Museum in Moscow. Photograph by [Szilas](https://commons.wikimedia.org/wiki/User:Szilas), available on Wikimedia. Public domain.* The so-called [treasure of Priam](https://en.wikipedia.org/wiki/Priam%27s_Treasure) contained (list from Wikipedia): > > * *a copper shield.* > * *a copper cauldron with handles.* > * *an unknown copper artifact, perhaps the hasp of a chest.* > * *a silver vase containing two gold diadems (the "Jewels of Helen"), 8750 gold rings, buttons and other small objects, six gold bracelets, two gold goblets.* > * *a copper vase.* > * *a wrought gold bottle.* > * *two gold cups, one wrought, one cast.* > * *a number of red terracotta goblets.* > * *an electrum cup (mixture of gold, silver, and copper).* > * *six wrought silver knife blades (which Schliemann put forward as money).* > * *three silver vases with fused copper parts.* > * *more silver goblets and vases.* > * *thirteen copper lance heads.* > * *fourteen copper axes.* > * *seven copper daggers.* > * *other copper artifacts with the key to a chest.* > > > Part of the treasure is nowadays located at the Istanbul Archaeology Museum. The bulk of the treasure went first to the Royal Museums of Berlin, and in 1945 it was taken by the Russians; it is now at the [Pushkin State Museum of Fine Arts](https://en.wikipedia.org/wiki/Pushkin_Museum) in Moscow. Heinrich Schliemann went on to make other unexpected discoveries, including the famous gold [mask of Agamemnon](https://en.wikipedia.org/wiki/Mask_of_Agamemnon) at Mycenae. Another great story is the discovery of the [tomb of Tutankhamun](https://en.wikipedia.org/wiki/Tomb_of_Tutankhamun) by [Howard Carter](https://en.wikipedia.org/wiki/Howard_Carter) in 1922; or the lucky fall of a young Roman into a mysterious grotto on the Esquiline hill, in the 15th century, discovering the remains of Nero's [Domus Aurea](https://en.wikipedia.org/wiki/Domus_Aurea), and Raphael and Michelangelo crawling underground to copy the wondrous frescos; but those remains for another time. [Answer] **Earthquake!** Your character is in the ruins when an earthquake occurs! Dangerous, scary stuff! Of course the earthquake could have happened the week prior and then your character shows up, but how exciting is that? In any case, the quake moves things. Walls collapse, floors shift. Secret passageways, hidden rooms and tunnel entrances are revealed. I like the idea that earthquakes have happened in this part of the world before, and perhaps some of the "hidden" rooms were not intentionally hidden by the builders, but wound up that way as a result of an ancient megaquake that caused the building to be deserted as unsound. [Answer] Easy **The Ancient Ruins are a Labyrinth** The naive townsfolk think that they have found everything there is to know about this place, but they haven't even scratched the surface of what this complex really is. The ignorant tomb raiders thought that this place only had one floor. They robbed the first floor until there was nothing left, never realizing that there was more beneath it. This was intentional on the designer's part. They had lots of important items they wanted to keep hidden from prying eyes, and they were paranoid at the prospect that anyone would find them, so they set out to make the layout of this building as complicated as possible. They took the secret of how to navigate this place to their grave. Despite looking like a simple structure at first, this building goes deep into the ground and has countless hidden tunnels as well, none of them in obvious places. They were so cleverly disguised that no one who passed by even realized there might be a secret path there in the first place. Why would they even bother to look? This is the main reason why so many treasures remain unplundered and unsullied by mortal hands or eyes. Once the most important artifacts were stolen, people lost any interest in this place. They thought they mapped everything out and checked every corner, but they were only scratching the surface. Not only are there more floors that they could have discovered, but there are dozens they have yet to touch. Thousands of rooms are lying hidden behind fake walls, secret trap doors, and tiny crawl ducts that no one ever bothered to check. It's easy to miss this kind of thing, but the designer of this place wanted people to get as lost and disoriented as physically possible. They put all their hard work into concealing the truth. Anyone smart enough to actually get into the more inner chambers of the building has found themselves way in over their heads. These areas were designed to be tough to enter and even tougher to exit. You might be able to open the doorway to Floor Two by sheer luck, but you'll never be able to get out without the proper code. You don't even need traps or monsters to guard the entrances and exits. An unbreakable stone wall blocking the way and endless caverns are enough. If you don't know what you're doing or where you are going, the entrance will lock behind you and you will be stuck in a lightless place until you eventually succumb to thirst or starvation, whichever comes first. Just when you think the paths will come to an end, and you've finally found your way out, the maze just keeps going and going. **Exploring This Place Seems Futile** Why would anyone want to visit a place that has already been explored and has no treasure to offer? This is one of the main reasons why people tend to stay away from it. They think it's already been pilfered, so what would be the point of going anywhere near it? People tend to go exploring for two reasons. They either think there is something worthwhile in the location, or they are in it for the pure thrill of adventuring to an unknown place. If there is no treasure left to steal, and the rumor that has been spread for years is that there is nothing good remaining, then no one would bother going there. Have this building be protected by its sheer mundanity. As far as people are concerned, it has nothing left to give them. It's not an exciting destination to visit, it's a boring, dusty ruin that everyone wishes was demolished. It's just an eyesore. It's called "hiding in plain sight". The more unassuming the place seems, the better hidden the artifact will be. In fantasy, we tend to expect the McGuffin to be lying on a pedestal in some massive temple, surrounded by hundreds of powerful guards. The guards might be a good idea, but if you really want to hide something, you wouldn't hide the McGuffin in someplace grand and luxurious. Hide it in a place so unsightly and boring it never occurred to anyone that it would be there. **Lots of Fakeouts and Lots of Fake Rewards** Have this be a reoccurring theme with this ancient civilization. They love making people think they have found everything, all while they silently laugh in their graves because they know you walked out with something worthless compared to what was hidden a floor below you. Like I was saying before, this place has dozens of floors underneath the main one. The first one is designed to look like it is the only one, and countless valuable treasures are dotted along the place to make it more convincing. Gold, silver, ancient weapons, and so on, are on every corner of the room and surrounded by traps, but all of that stuff is either a bunch of decoy goods or plain worthless compared to what this place was intended to hide. This ancient civilization was rich. Gold, silver, and jewels were like dirt to them. Enchanted swords and spellbooks were everywhere. So they just shove all the worthless junk on the top floor to trick people into taking that. Once their greed is satiated and they find nothing else, they leave and think that is all. Little did they know there were fire-shooting Gauntlets on the floor just below them. The designers laugh at the ignorance of the thieves. Oh no, the thieves found the Fire Gauntlets? Sike. The real gauntlets were in another room. Those are fakes that scorch the user's bobdy until they're nice and crispy. A hundred years pass and someone finally manages to find the real Fire Gauntlets on the Second Floor. Jokes on them. On the Third Floor, they could have gotten the Elixir of Life which cures all illnesses and grants immortality. But they can keep their silly gauntlets. Would you look at that? Someone found the Elixir of Life! Good for them. They have now cured all illnesses and ushered in a new era of peace. Good thing they didn't find the Dark Amulet on Floor 4 or else they might have unleashed the demon prince hidden within it. Meanwhile, on Floor X, a ridiculous distance below the surface of the planet, the last remnant of the ancient civilization is snickering to herself. The rest of her civilization transcended space and reality. That's why they all left, but she's decided to stick around and mess with adventurers like the main character until the day the sun dies and the world cools over. It's fun. Ten thousand years after this place was built, she's bored. The main character is the first one to show interest in the Ancient Ruins for ages, so she (or he or they, you pick) decides to break radio silence and decides to give the main character a hint of what is truly hidden beneath the surface. This could be how the crux of the story begins. The character takes interest in these seemingly boring and mundane ruins, gets a hint from an outside force, and investigates to find there was far more to this place than anyone ever knew. They unveil secrets that have never seen the light in millennia. [Answer] **Lore incorrectly describes the Ruin because the rivets were used as horsehoes** Absolutely, your idea of thieves taking relevant items is just like real life. One proposal is that the ruin's shape is misunderstood, and the interior map of it has never been properly visualized. This is a variation of it was "hidden really well", "there was a secret door" combined with the fact that the clues themselves may be stolen over time which make the floor plan misunderstood. Let us say that the treasures of the outer surface have been taken by several expeditions. The surface has been previously excavated numerous times with the legend being reinforced each time that there is nothing further there. There is a burial mound called [Sutton Hoo](https://en.wikipedia.org/wiki/Sutton_Hoo) in Suffolk England that contained many treasures. Apparently it had been plundered since the 1600s various times, and it had never been understood as being a buried ship until the period of the Second World War. Each time people went to the mound in previous excavations, they removed some clues that would have helped other archaeologists from understanding it. The earlier explorers (thieves) did things like melt down the treasure or even use the ship rivets for horseshoes. They disturbed the ground by created "robbers trenches" that obscured everything. In 1938 the landowner, Edith Pretty, hired a local archaeologist to look at some mounds on her property previously thought empty. The archeaologist, Basil Brown who eventually found the ghost of a ship by digging a series of cross sections in the ground, by carefully excavating Sutton Hoo, he found many more artifacts, that are now thought to have been owned by a king of East Anglia. The discovery and the dig were the plot of a book and a movie. A couple things for the Sutton Hoo story could be adapted to a ruin in an invented world. Here is what I think is applicable: * myths and legends inaccurately say that all treasure has been taken * local lore says the ruin is in one site, when in fact is in more than that one location * Actual physical clues have been stolen * The ruin's layout is misunderstood completely -it takes a new inventive approach to unearth further artifacts. The treasures found by later excavation included a masked helmet and a sword. [Answer] # Tech-dependent "secret door" Other answers have suggested secret doors or massive excavations, and these are both very good reasons why the loot hasn't been found. However, we could also have a tech-dependent test. The classic example, readily usable here, is from *2001*: the castle could have a powerful magnetic field emanating from one part of its cellars. The discoverer might simply be the first person who brought a magnetic compass to the ruins and noticed deviations. Rather than having to hire an army to excavate the entire castle, you might be able to reach a well-preserved entrance with a lone shoveller persisting through a few utterly miserable days of labor. If you don't want to suffer through dialogue with Clarke fans, it might be better to use a different technological key. For example, the ruins might generate radio interference that the finder tracks down like the magnetic field. Maybe instead of digging for the secret, he tries to respond with his Morse code key. Though communication may not be achieved this way, the loud radio interference might advance a preexisting protocol that opens the silo doors and rewards the brilliant scientist with the enduring fame that comes from being the first person to fall to his death in an underground nuclear silo in two thousand years. Speaking of nukes, the presence of the newly discovered Roentgen ray would be another way lead your society's explorers to the castle. They might notice film-fogging rays in a local waterway, and trace them back to a small rivulet of leakage from the site. This has the particular advantage that the original creators of the artifact might have avoided it, but scientists new to the wonders of radiation would be free to move onward, though some might have to take some time off for some troublesome ailments: nausea, burns, hair loss and so on. [Answer] The true entrances are kept secret by riddles and other non-lethal forms of separation. Perhaps even the doors are simply too well hidden for the locals to find. If you do not want the characters to have to figure it out, give them a book or a scroll describing the way in. [Answer] The locals are aware of an underground lake, they are not aware of the water flow that maintains it as it's through gravel, not an open stream. There has been a shift in the drain, the lake is gone, exploring the old lakebed reveals it used to be more extensive until the water flow flooded part of it. Now the areas that were inaccessible (and thus unknown) are accessible. Related possibility: Something happened upstream to divert the flow before it reached the dungeon in the first place. [Answer] It depends on how far you want to tip the scales between Believable and Magic. On the magic end, this happens in stories all the time. The protagonist is a descendant of ancient rulers that left the content millennia ago to escape a sacking, and this is the first time the family line, and in particular the family heirloom amulet that happens to be a magical key that the protaganist is wearing, has been in the city. Or he cuts himself on a piece of rusted metal and a blood drip happens to activate an ancient dna scanner. The problem comes in figuring out why these right-at-the-surface entrances or technologies were never discovered. The site would have been used as a quarry, for ready-made stone blocks if nothing else, and anything at the surface would have been examined; an ancient indestructible monolith big enough to be an entrance would have been noteworthy. So on the believable side, you're left very few possibilities, especially if you assume the locals are caught up with the rest of civilization, and aren't isolated primitives or something. It's just not believable that the ancient rune-covered doorway was never blasted open with dynamite or carted off intact to a museum (or to be used as the new local bank decorative wall to mount the ATM on), no matter how many vines cover it now. So, like the Troy example by AlexP, the dingus is just buried so deep under so many layers of conquest and rubble that no one has ever dug that far down before. Or what little of the ruins is actually explored has been so small and inconsequential that no one has really "explored" it at all. And even that kinda requires #1, or someone would have stumbled on something anyway. There are loopholes, though. If the ruins are at the top of a mountain or large hill, perhaps it turns out that most of the mountain or hill is actually catacombed with more ruin. But due to #1 and #2, no one knew. This allows a new opening in the side (a tree falls, exposing worked stone, or the back wall of a cave collapses into a room, etc) to offer a shortcut to the "deeper" regions without requiring months of investigation and digging. On flatter ground, a sinkhole, perhaps caused by the collapse of an ancient buried room, could do the same thing. Or, maybe a mundane construction worker has been oversleeping and is working late to make up the hours after most everyone else has left. He's digging footings for a new sky-scraper hotel, which is well away from the ruin as far as everyone knows, when he breaks through into an ancient tunnel leading into the deeper section. He could just as easily be a rural farmer digging a new root cellar. If the tunnel is a one-off, such as an escape route used when the original castle was sacked, it may be just blind luck that he happens to dig where the tunnel came close to the surface. I've heard that this kind of thing happens fairly regularly in places like Greece and such. There's so much civilization that all of Greece is built on top of ruins, and every new basement someone digs has a chance of unearthing a new set of artifacts. It's not too far fetched that one of them unearths something a lot more interesting than the normal pottery shards. [Answer] ## They have a private cemetery for the leaders. Unknown to the locals, it was a tradition to have a secret graveyard for the lords of the castle, hidden away with special marks only the highest of priests knew behind hidden walls. While these marks were long since lost to time, and the door long since broken, using modern archeological tools they have discovered a hidden void, much like the one in the [great pyramid of giza](https://www.express.co.uk/news/world/1452655/egypt-archaeology-news-treasure-inside-great-pyramid-void-pharaoh-khufu-spt). With the aid of the key and trusted archeological tool, the sledgehammer, they can reach the hidden graveyard of the dead kings, where the finest of loot was stored for their use in the afterlife. [Answer] **It was well sealed** The ancients knew how to seal a tomb for eternity, in a way that as far as I know was actually invented by Hollywood for an epic set in ancient Egypt. (This method is about all I can remember of it). Above the corridor leading to the tomb, are huge blocks of stone supported on wooden props supported in turn on dry sand in cylinders with pottery seals. When the tomb is to be sealed, those seals (several levels below) are smashed, the sand runs out, and the huge block descends onto the floor leaving no way past it and no sign that it's not like all the other stone wall blocks that one has walked past to get to that point. Also, the design is such that there is an obvious corridor continuing at that point. This obvious corridor leads to decoy "tombs" stuffed with lesser valuables, sealed less effectively with conventional walls and curses whose power faded as popular beliefs changed, which over the centuries have been ransacked. Modern technology brings something to reveal the hidden tomb. Maybe precise underground mapping. Maybe rock-penetrating radar. Maybe discovery of the under-corridor and somebody able to interpret the pieces of pottery, wood and surprising amounts of sand. Maybe somebody (mis?)understands meaning in a recently deciphered ancient text "that when the day of $long\_forgotten\_deity comes, the dead will rise from their tombs, and walk through their walls of rock as a bird flies through air". You might also throw in some bats, and local folk knowledge which affirms that wandering around in caverns where bats roost tends to be bad for one's health. [Answer] The simple answer is that after a society becomes agricultural and no longer hunter-gatherers, they have much less time for exploration. They're still pre-modern, so you can't expect the kids to have much time to explore either... they're off pulling plows when the mule died or something. Now, we do tend to see alot of myths and stories about hidden treasures in all cultures... so it's not as if the idea of there being stuff out there worth looking for is foreign to them. But think about the implications of that... they wouldn't be good stories if the people in them didn't find the hidden treasures. "And then Derpy Joe went out looking for the Lost City of Rubies, broke his neck, The End" isn't a compelling narrative. The central conceit of the good stories is that the treasure is so well hidden/guarded, that only special people find them, no? This is the acknowledgement that hidden things tend to remain hidden, especially when everyone that was in on the secret is long dead. Perhaps the biggest danger to your plot point is that if this stone was accessible, it would be very likely to be repurposed... it's much easier than quarrying new stone. But that's a minor nitpick and shouldn't detract from the story you're working on. Truly, if the ruins are extensive, then they might just give up on that after awhile, since the remaining stone eventually becomes too far to be worth the hassle, and especially so if the geography itself is difficult. [Answer] If your thousand year old civilisation was really advanced, you could take inspiration from ["Horizon Zero Dawn"](https://en.wikipedia.org/wiki/Horizon_Zero_Dawn). Spoilers ahead: The protagonist Aloy in this game lives in a world that is a blend of tribal/iron age technology combined with "magic-like" usage of broken down robotic machines. She discovers and explores ruins of "old powerful civilization thousands of years" ago that are guarded/locked by several still working Artificial Intelligence clusters. Exploring the ruins is helped by a device she found in one of the ruins as child. The device is a mix of an advanced mobile phone that is able to teach her and some kind of augmented reality thingy. It shows her information about what she can see and overlays this with her normal vision - accesssing her brain / visual cortex. Without this "trinket" she would be unable to comprehend certain riddles. > > Some of those entrences only allow acces after she fixes some genetic scanning devices/data base - her genetic sequence is somehow fingerprinted and cleared for access - why is revealed throughout the game. > > > So essentially she needs this thingymabob to help her understand the technology her peers are unable to comprehend and allow her insights into puzzles / allow entrance into areas of ruins that are locked for others of her tribe. [Answer] I once read in a book by archaelogist Rodolfo Lanciani (1845-1929) that since the Renaissance every square foot in Rome had been excavated by looters and/or archaeologists at least once, and there were no more great discoveries to be made. Caesar's Palace, the one in ancient Rome, is called The Palace of Domitian since it was mostly built during his reign in AD 81-96. It continued to be used more or less often by emperors and later by the Ostrogothic kings. <https://en.wikipedia.org/wiki/Palace_of_Domitian> Narses (478/480-557/74) reconquered Italy from the Ostrogoths in the 550s and resided in the imperial palace in Rome. And he might have been the last person to do so. Emperor Constans II visited Rome for 12 days in 663, and might have stayed in the palace. It is possible that the palace collapsed during an earthquake in Rome during the 800s. It was in ruins for a long time. The Duke of Parma, who owned the Palatine Hill. had the palace excavated in the 1720s, I think, and stripped of its marble. And that might have been about 900 years since the palace collapsed into ruins. During the excavations, Bianchini, the man in charge, fell through a floor and eventually died from his injuries. At the time it was believed he fell into a bathroom of the palace, but it is now known to be part of a previous Roman house on the site. And I have read that later studies of the palace found a shaft leading downwards. It was believed at the time to be a dumbwaiter shaft to bring food up from the hypothetical lower kitchens. But I don't know if that is true, or if anyone ever found out where the shaft went to. > > In December 2006, Italian archaeologists announced that an excavation under a shrine near the Palatine Hill had unearthed several items in wooden boxes, which they identified as the imperial regalia, possibly belonging to Maxentius.[24] The items in these boxes, which were wrapped in linen and what appears to be silk, include 3 complete lances, 4 javelins, what appears to be a base for standards, and three glass and chalcedony spheres. The most important find was a sceptre of a flower holding a blue-green globe, which is believed to have belonged to the Emperor himself because of its intricate workmanship, and has been dated to his rule.[25] > > > <https://en.wikipedia.org/wiki/Maxentius#Discovery_of_Imperial_insignia> So those imperial treasures were not found for 1,694 years, if they were really buried when Maxentius was killed in 312. I think that there are still some post Roman buildings on the Palatine Hill, and it has not been completely excavated. The Roman emperors had their main palaces on the Palatine Hill, even before Domitian built his great palace there, and owned other houses, gardens, villas, and residences in Rome and nearby. For example, Nero (r. 54-68) acquired several properties on the Esqaline Hill about a mile from the Palatine Hill. He also acquired property between the two hills and built an estate connecting them, which he called the *Domus Transitoria*. <https://en.wikipedia.org/wiki/Domus_Transitoria> During the great fire of Rome in AD 64, many buildings in Rome were destroyed or severely damaged, including much of Nero's *Domus Transitoria*. According to Seutonius: > > XXXI. In nothing was he more prodigal than in his buildings. He completed his palace by continuing it from the Palatine to the Esquiline hill, calling the building at first only “The Passage,” but, after it was burnt down and rebuilt, “The Golden House.” 600 Of its dimensions and furniture, it may be sufficient to say thus much: the porch was so high that there stood in it a colossal statue of himself a hundred and twenty feet in height; and the space included in it was so ample, that it had triple porticos a mile in length, and a lake like a sea, surrounded with buildings which had the appearance of a city. Within its area were corn fields, vineyards, pastures, and woods, containing a vast number of animals of various kinds, both wild and tame. In other parts it was entirely over-laid with gold, and adorned with jewels and mother of pearl. The supper rooms were vaulted, and compartments of the ceilings, inlaid with ivory, were made to revolve, and scatter flowers; while they contained pipes which (360) shed unguents upon the guests. The chief banqueting room was circular, and revolved perpetually, night and day, in imitation of the motion of the celestial bodies. The baths were supplied with water from the sea and the Albula. Upon the dedication of this magnificent house after it was finished, all he said in approval of it was, “that he had now a dwelling fit for a man.” > > > <https://www.gutenberg.org/files/6400/6400-h/6400-h.htm#link2H_4_0007> And after the reign of Nero the Golden House was abandoned over time, and its buildings demolished, or filled with earth and rubble, and new buildings and streets built over them. > > When a young Roman inadvertently fell through a cleft in the Esquiline hillside at the end of the 15th century, he found himself in a strange cave or grotto filled with painted figures.[8] Soon the young artists of Rome were having themselves let down on boards knotted to ropes to see for themselves.[15] The Fourth Style frescoes that were uncovered then have faded now, but the effect of these freshly rediscovered grotesque[16] decorations (Italian: grotteschi) was electrifying in the early Renaissance, which was just arriving in Rome. > > > <https://en.wikipedia.org/wiki/Domus_Aurea#Rediscovery> It was claimed that Fabulus, or Famulus, the main artist decorating the Golden House, was so proud and successful that he painted wearing a toga, and certainly his style has been very influential during the last few centuries. And in about 2014, another part of the Golden House was discovered: > > Archaeologists were digging on an artificial terrace on the northeast corner of Rome's Palatine Hill when they found a round, 12-metre-high tower, with a large central pillar of four metres in diameter and 8 pairs of arches supporting two floors. Along the top of the upper arches, were lines of semi-spherical holes, filled with slippery clay – somewhat like the cavities that were used on large ships to contain primitive ball bearings, on which moveable platforms were mounted to transport heavy loads. > > > According to the team of archaeologists who uncovered the structure, the lines of cavities housed metal spheres that supported the revolving floor. At the bottom of the tower, they also found evidence of a mechanism had been built into the wall. Scientists said the calcite deposits on the surrounding walls were a result of the floor's constant movement. It might have also been powered by water channeled system of gears. > > > <https://www.ancient-origins.net/news-history-archaeology/revolving-dining-room-emperor-nero-s-luxurious-palace-really-existed-001824> So I can find it easy to believe that after all this time, someone could find a little buried box full of jewels, or containing an interesting ancient papyrus or parchement, somewhere in Rome. Or in a fantasy story some magical ancient artifact. So if some vast undergound complex was built by people who had powered construction and excavating equipement, arificial lighting and ventillation, etc. (or magical equivalents in works of fantasty) it could be incredibly vast and complex, and hard to explore for people with more primitive technology such as torches for light. Thus hidden secrets and treasures might still there after centuries or millennia. And possibly the underground chambers and tunnels were radioactive or poisonous, and everyone who entered them for centuries soon died, and their reputation has protected them from looting even after they became safe to visit. [Answer] Industrial revolution could be key point. That is improved tools like cutting tools. Knowing that these structures have been around for very long time they are likely made from good quality materials. Some concrete require diamond cutting to get through. Or otherwise is massive project to break. So no one spend enough time to get through a blocked of wall. Or maybe they weren't strong enough to pull out blocking block or have suitable tools to mount necessary equipment. And thus such spot were generally forgotten even if relatively simple to identify. Now there is drills and saws or even cranks and other suitable tools to break through or pull it out. [Answer] Here's some of my ideas! I'll leave them sort of vague so you can expand on them yourself ^^ * The ruin still sees limited use in some areas, and may be controlled by a very strict group (gang, priests, gov., etc.) that prevents leaving the secure areas, or this limited use shows how dangerous the rest of the dungeon may be. This doesn't have to be deterrents like mnsters or traps, though! Old structures are super dangerous. Nobody wants to be in a place that could literally fall on top of them at any minute. * Local legend about some terrible evil thing in the dungeon that may or may not actually be there. * It was just hidden really well, and [character] has some way of knowing where the hidden parts were and how to get in. * These parts were only just recently discovered. (this happens all the time IRL; both natural events and human intervention reveal hidden areas with all kinds of crazy stuff.) * Magical nonsense. Some part of the ruin responds to mage blood or the right combination of magical woo-woo's or something. Hope these help [: Good luck with your story! [Answer] ## It's out of the way Yes, the locals know where it is. That doesn't imply that the dungeon is easily accessible; it could be at the top of the mountain, in the middle of a creepy-crawly filled rainforest, or any of a number of similarly inaccessible places. As a result, while the locals know where it is, they don't usually bother to go there. Sure, you *might* find something of value there, but it's not worth the risk of getting killed. Your intrepid adventurers, on the other hand, are in the business of going to dangerous places. Climbing sheer cliffs and hacking their way through rainforests filled with creepy crawlies is an everyday occurrence for them. ## It's religiously significant The locals know where the dungeon is and can get to it without getting killed. However, the site is holy; they're loth to even go in, let alone steal stuff, lest they incur the wrath of a deity. Conversely, your adventurers have angered many deities in the past and will anger many more in the future. One more or less isn't going to make a difference. ## It's historically significant The locals can easily get there, and any religion which would take exception to trespassing has since been relegated to the history books. However, unlike your intrepid adventurers, they have enough reverence for the past that they aren't going to cast disintegrate on every wall which sounds even remotely hollow. ## It's dangerous Filled with pitfalls, dart launchers, pressure plates, grumpy eldritch abominations and rickety staircases, the dungeon has claimed the lives of many previous adventurers. Not having a death wish, the locals stay away. [Answer] Some further ideas here: **The main character knows something that the villagers don't** This could work well if you can connect it to an earlier adventure of the same character. Maybe they found an ancient text in another ruin that mentions a secret door to an underground section of the ruins, located where the shadow of the obelisk at the ruins falls at noon on spring equinox. The secret door is very non-obvious and was anyway long since covered by rubble and vegetation. Fortunately, the obelisk still stands... **The villagers do know about the undiscovered part but aren't telling** There is an altar to an elder god underground in the ruins. There is a cult in the village worshipping said god but they don't want to be discovered for some reason: maybe the god is really evil, or maybe it's a benevolent god but only the worship of one god is allowed in the country. After the main character arrives in town, they realize something funny is going on with the villagers and stealthily follow them to the ruins at midnight. [Answer] Read Deep Time -- Gregory Benford -- how humanity communicates across millenia <https://www.goodreads.com/book/show/2014020.Deep_Time> GB discusses among other things, how to mark a radioactive dump so that people don't want to go in. Suppose you take a city, and surround it with a mile of stairs. But the stairs are the wrong size for easy use. You can travel them, but it's exhausting. The stairs form a maze. There are many entrances, but only one goes through to the city itself. 4 square miles split up into 10 foot wide passages gives you 2000 miles of maze. Suppose that the outer architecture looks wrong: Asymmetrical. Nothing at right angles. Everything is coloured black and barf green. Suppose the place smells of decay, carrion, death. Suppose that the structure of the place creates it's own weather, so that it's always foggy, or always frosty. Suppose there is a 20 mile radius circle with no living thing, no plants, no bugs. No water. You have to carry *everything* for your trip. Suppose that this is a place that literally the sun does not shine. You walk across the boundary and you are in shadow. This keeps it cold. [Answer] It has been an unseasonably dry year and all the foliage in the area is brown and withered. Century old growths have receded to unprecedented levels, revealing aspects of the ancient ruins which were completely concealed before now. As a result of this newly exposed architecture, the overall shape of the ruin is easier to determine. The wall sets which point out obliquely from the previously overgrown center are obviously two compass point wings of a structure which probably also had wings aligned to the other two compass points, wings which, even now, are still concealed by brittle brown plant life. The thinning of the cover and the revealed design of the ruined structure should provide your characters access to previously inaccessible chambers where un-plundered treasures await. [Answer] There was a secret vault in the City, mayhaps leading to another portion of it, but it was hidden even before the City's fall. It opens only to a certain individual, or to a member of a bloodline, or to a wielder of a certain item. AKA the protagonist. ]

[Question] [ So the main team of characters is traveling back in time from "modern day" to medieval Europe, arriving around the 1300s. Assumptions: They Know they are going, they have space and time to prepare, the team consists of 10 people in their mid-20s with a variety of skills. They are not returning to modern times. They are staying in the past. They are taking back information in a variety of forms. The goal is to get to a stable system for reading from their SSDs and computer drives. What would be the quickest and most reasonable way to be able to read and have this reference material available? Other materials will be brought along. Books, microfiche, and other reference material. The Travelers have a limited Volume (10M cube, 1000 cubic meters)to bring along. So the obvious desire is to keep information in the densest form. So what information would need to be available before the SSDs to get to them? [Answer] If they are just bringing the drives, and not the attached computer, this is pretty much impossible. The infrastructure simple isn't there in 1300 to refine anything to the necessary purities to even begin manufacturing microprocessors. See this answer to get an idea of how hard this is to do: [How long would it take to create a Windows 1.0 capable machine from complete scratch?](https://worldbuilding.stackexchange.com/questions/54976/how-long-would-it-take-to-create-a-windows-1-0-capable-machine-from-complete-scr) . If they can bring their laptops, they only need to worry about a power supply. By far the easiest way they could do this would be to bring some small solar panels, a turbine they could hook up to a water wheel, or a bicycle powered generator. If they have to make their own power supply, they will have to get /make a bunch of copper wire and some permanent magnets and make their own generators to attach to a turbine of some sort (water wheel probably). This won't be easy. See these two related questions: [I was thrown into the middle ages, how do I power my time machine?](https://worldbuilding.stackexchange.com/questions/74991/i-was-thrown-into-the-middle-ages-how-do-i-power-my-time-machine) [How hard is it to build a generator if you've jumped to the distant past?](https://worldbuilding.stackexchange.com/questions/26435/how-hard-is-it-to-build-a-generator-if-youve-jumped-to-the-distant-past) Basically this will be hard unless you bring everything you need. In which case look for guides for "living off the grid" to get a more thorough idea of what you need. [Answer] Quite obviously, the only way to read SSDs in the 14th century is to bring a computer. Or, actually, several computers. With great care, the computers will last for some twenty years, in which time one could hope, with an extraordinary amount of good luck, to push technological progress up to the 17th century -- you know, printing presses, telescopes, logarithms, basic algebra, some calculus, laws of motion, half-decent cannon, basic knowledge on the strength of materials. Use the time to transcribe the most important social and scientific principles of the modern world; then the computers will die, and everything in their memory will die with them. Since questions like this appear from time to time, I thought it would be a good idea to set things straight. First of all, one cannot make an electronic computer in medieval Europe; what one can try is accelerate the technical and scientific progress to the point where making an electronic computer is possible: but, quite obviously, when reaching that point *one will no longer be in medieval Europe*. Technical and scientific progress cannot be decoupled from social evolution; a world which has the technology to build electronic computers is not a medieval world. Why do I say that a world which has the technology to make electronic computers cannot possible resemble medieval Europe? For two obvious reasons: first, in a world with advanced technology there are lots and lots of literate people and lots and lots of books; and second, a world with advanced technology must by necessity be based on some sort of modern economy, either a Soviet-style planned economy, or a free market economy, but in any case nothing like the sluggish medieval economy. When a civilization reaches the point where the vast majority of people are literate and numerate and where most people work for a wage that civilization is way past feudalism. When thinking of modern technology one must always keep in mind that it is but the top of vast mountain of work and knowledge; for the engineers who design and make, let's say, microprocessors rely on many other people to run the factories, and to make the wafers, and to design and make the photoengraving machines, and the measurement devices, and the artificial light sources, and the office buildings, and the vehicles, and the electric power grid, and the transportation networks and so on and so forth. For a gentle introduction to the modern technological pyramid one is strongly urged to read [Leonard Read](https://en.wikipedia.org/wiki/Leonard_Read)'s 1958 essay [*I, Pencil*](https://en.wikipedia.org/wiki/I,_Pencil), in which the pencil, speaking in the first person, "details the complexity of its own creation, listing its components (cedar, lacquer, graphite, ferrule, factice, pumice, wax, glue) and the numerous people involved, down to the sweeper in the factory and the lighthouse keeper guiding the shipment into port" (Wikipedia). It's a short but definitely illuminating piece, and, moreover, it's [available on line](https://en.wikisource.org/wiki/I,_Pencil) from multiple sources: > > *I, Pencil, simple though I appear to be, merit your wonder and awe, a claim I shall attempt to prove. In fact, if you can understand me—no, that's too much to ask of anyone—if you can become aware of the miraculousness which I symbolize, you can help save the freedom mankind is so unhappily losing. I have a profound lesson to teach. And I can teach this lesson better than can an automobile or an airplane or a mechanical dishwasher because—well, because I am seemingly so simple.* > > > *Simple? Yet, not a single person on the face of this earth knows how to make me. This sounds fantastic, doesn't it? Especially when it is realized that there are about one and one-half billion of my kind produced in the U. S. A. each year.* > > > On to the practicalities. The practicalities are of two kinds: practicalities related to the development of the story, and practicalities related to the verisimilitude of the world. When developing the story it is very helpful to be aware of similar stories which have already been told. It is simply a good use of the author's time to read similar stories, so that they can benefit from the work of previous authors who worked in the field. The field in question is a subgenre of alternate history, characterized by describing the changes brought about by one or more modern people who find themselves in a pre-modern world. * It all begins with [L. Sprague de Camp](https://en.wikipedia.org/wiki/L._Sprague_de_Camp) and his 1939 novel [*Lest Darkness Fall*](https://en.wikipedia.org/wiki/Lest_Darkness_Fall). American archaeologist Martin Padway is transported to Rome in the year 535 CE. One thing leads to another and he finds himself ruling [Ostrogothic Italy](https://en.wikipedia.org/wiki/Ostrogothic_Kingdom). In a remarkable scene, the novel addresses the clash between modern economic expectation and the sad reality of the early Middle Ages. The hero coaxes an artisan to make a crude printing press and starts printing a newspaper; in the 6th century there was no paper in Europe, so the newspaper was naturally printed on vellum. The first issue goes out, but when the hero want to print a second issue his vellum suppliers inform him that he has used all the vellum available in central Italy, and he must wait at least half a year to get more from distant suppliers. * A necessary step are the entertaining (if maybe sexist, insensitive, and, possibly, quite badly written) adventures of [Leo Frankowski](https://en.wikipedia.org/wiki/Leo_Frankowski)'s hero, Conrad Stargard, [*The Cross-Time Engineer*](https://en.wikipedia.org/wiki/Conrad_Stargard) (1986). A Polish engineer (from the People's Republic of Poland, no less!) is sent back in time to 13th century Poland, where he kick-starts an industrial revolution of sorts, becomes a powerful nobleman and generally messes up historical lines. The series is notable for the attempt to establish a plausible sequence of technological developments; the above-mentioned defects start to crowd out the good parts as the series progresses, so by *Lord Conrad's Lady* one is advised to skim and concentrate only on the technical aspects. * [Eric Flint](https://en.wikipedia.org/wiki/Eric_Flint) and many others put a lot, and I mean *a lot*, of effort into developing the [*Ring of Fire*](https://en.wikipedia.org/wiki/1632_series) shared universe. A mid-size American town is transported from 1990s West Virginia to war-ravaged [*1632*](https://en.wikipedia.org/wiki/1632_(novel)) Thuringia. They immediately proceed to meddle in the [Thirty Years' War](https://en.wikipedia.org/wiki/Thirty_Years%27_War), and to introduce great social and technological change. This shared universe is remarkable for the vast amount of research, with Eric Flint and his many many co-authors trying to make sure that each and every step in technological development was indeed possible, or at least not utterly impossible. One is well-advised to read the books and spend some time in the forum dedicated to the exploration of technologies. * Then there are many other more-or-less well-known works in this subgenre; I will only add [S. M. Stirling](https://en.wikipedia.org/wiki/S._M._Stirling)'s [Nantucket series](https://en.wikipedia.org/wiki/Nantucket_series), beginning with [*Island on the Sea of Time*](https://en.wikipedia.org/wiki/Island_in_the_Sea_of_Time) (1998). Modern day Nantucket is transported in the 2nd millennium before the common era, and the inhabitants proceed to do their best to uplift the world around them, both socially and technologically. The plausibility of the developments is well-maintained, even if not raising to the high standards of *1632* and its sequels. When plotting out the technological developments which go from the point of departure, be it the 2nd millennium BCE, or the 6th century CE, or the 14th century, or the 17th, up to something resembling the modern world, one must always remember that the modern world lives in the age of machines. To make the machines which make the stuff available in the modern world one first needs to make the machines which made the machines, and the machines which made the machines which made the machines, and so on up to many layers deep. To concentrate on a specific example, let's consider the USB cable which connects the SSD device to the computer. The cable. Quoting from the standard describing USB cables and connectors (USB CabCon Workgroup, [Universal Serial Bus 3.1 Legacy Connectors and Cable AssembliesCompliance Document](https://www.usb.org/sites/default/files/documents/cabconn_legacy_3_1_compliance_rev_1_1.pdf), version 1.1, 2018): * Low Level Contact Resistance: 30 mΩ maximum initial for the Power (VBUS) and Ground (GND) contacts and 50 mΩ maximum initial for all other contacts when measured at 20 mV maximum open circuit at 100 mA. * Dielectric Withstanding Voltage: The dielectric must withstand 100 VAC (RMS) for one minute at sea level after the environmental stress defined in EIA 364-1000.01. * Cable Assembly Voltage Drop: At 900mA: 225mV max drop across power pair (VBUS and GND) from pin to pin (mated cable assembly). * Contact Capacitance: 2 pF maximum unmated, per contact. D+/D- contacts only. * Propagation Delay: 10ns maximum for a cable assembly attached with one or two Micro connectors and 26ns maximum for a cable assembly attached with no Micro connector. 200 ps rise time. D+/D-lines only. * Propagation Delay Intra-pair Skew: 100 ps Maximum. Test condition: 200 ps rise time. D+/D-lines only. If you don't hit those specifications, the cable won't work. You *must* achieve the specs. There is no loophole. Let's select the propagation delay. In order to make an USB cable one needs to be able to measure time with an accuracy of at least 10 ps. In 10 picoseconds light travels 3 mm, about one eighth of an inch. How does one approach the problem of designing and making a device which is able to measure the time in which light travels 3 millimeters? I have no idea; there are no more than two or maybe three people in a million who have a working acquaintance with designing and making such devices; and those rare people have no idea how make the wires, or the pins; or how to program the microcontrollers; etc. How fast could technological development be pushed? That is to say, in real history the world took some seven hundred years to progress from the fourteenth century to the age of smartphones; how quickly can one imagine that this journey can be made? I'd say that with a lot of luck and dedication, and with quasi-divine guidance, it could be shortened to maybe three to four hundred years if all pitfalls are magically avoided. The reasoning is simple: * The last hundred years or so cannot be shortened; from the early twentieth century onwards technology progressed at breakneck pace, and there is no reasonable way to make it go faster. Remember that when the first people set foot on the Moon there were people alive, even in developed countries, which had been born before Edison invented his lightbulb. When Apple introduced the iPhone, there were people alive, even in developed countries, who had been born at a time when the shortest time to cross the Atlantic was measured in days. * The 19th century might be condensed in 75 years; to condense it further would stretch the *societal* evolution beyond breaking point. The 19th century began with Napoleon conquering Europe on horseback and ended with telegraph lines circling the globe; it began with the U.S.A. issuing [letters of marque](https://en.wikipedia.org/wiki/Letter_of_marque) to [privateers](https://en.wikipedia.org/wiki/Privateer) in their [War of 1812](https://en.wikipedia.org/wiki/War_of_1812) with the United Kingdom, and ended with global trade networks; it began with all European powers attempting to suppress the French Republic and ended well on the way towards universal suffrage in most civilized countries. That's some 175 years up to this point. * The 18th century might be condensed in 50 years, but not more. In real history, the 18th century saw tremendous advances in mathematics and in physics. Luminaries such as [Leonhard Euler](https://en.wikipedia.org/wiki/Leonhard_Euler), [Pierre-Simon Laplace](https://en.wikipedia.org/wiki/Pierre-Simon_Laplace), and the [Bernouillis](https://en.wikipedia.org/wiki/Bernoulli_family) were pushing mathematics forward at the maximum speed human mind is capable of; going more than two times faster is inconceivable. That's 225 years up to this point. * The 17th century saw the transition from not having any physics to speak of to having decent physics. Maybe it could be condensed in 75 years, maybe not, but definitely not less. Remember that in real history the [17th century saw the discovery](https://en.wikipedia.org/wiki/List_of_multiple_discoveries#17th_century) of calculus and the laws of motion, analytic geometry, and logarithms. The entire idea of a computable universe was born in the 17th century. That's 300 years already. And then one must necessarily add some time to allow for developing the printing press, and introducing basic algebra, and printing enough books to lift people from the absolute darkness of the Middle Ages to the first lights of dawn... [Answer] They cannot "just bring SSDs" - they need something to read it with. The simpler, the sturdier, the less energy-hungry, the better. Actually they don't need SSDs, they need *memory*. The main things they have to worry about are, roughly in order: * theft and confiscation. They have no guild, no home, no patron. They have no servants or guards. For the standards of the time, they're a band of vagrants, surely up to no good. * weather and accidents. * power supply (easily fixed: solar panels. This doubles the risks above). * wear and tear. Assuming they have prepared, their first step is to become invaluable to some powerful patron by exploiting their future knowledge of history and politics. I would suggest **several redundant tablets** (you get the most capability density per volume) and smaller emergency smartphones [obviously in airplane mode ;-D ], at least some disguised somehow - maybe inside wooden slats. Batteries, lots of them. On that note, tablets have the advantage that getting 5V DC is pretty easy using large and inefficient chemical batteries - it could be done in ancient Sumer if you knew how, and they do. Zinc, copper, iron and oil of vitriol, you don't need much else (of course a voltage regulator and a multimeter will come in very handy - I expect them to bring along a good half dozen of the latter, and a packet of the former). Laptops, on the other hand, require special chargers that are driven by 110V or 220V AC. Or you need to feed them 12V at a much higher amperage (I think it's now usually 65W, five times a cheapo charger and thirteen times its power). Then, the memories they can bring back, again redundantly, sewed inside clothes or otherwise hidden, using micro SDHC cards. They're way sturdier than hard disks and even SSDs, and you can get them in the hundreds of gigabytes sizes. They probably shall have to balance carefully the need of being on the front line (perhaps not metaphorically), in order to continue earning protection, and the need to teach and train. 1348 is the year of the Black Death; their knowledge of contagion, disinfectants and sterilization procedures would be enough to protect, say, a castle or monastery or small fortified city. (On that note -- they might bring back cultures for streptomycin and the necessary to treat a large number of people (as well as a small reserve of short-lived plague vaccine for themselves). The antibiotic they might produce would never been really refined, but people would have *jumped* on a 80% chance of recovering from the plague, even at the cost of some loss of hearing). Once established as doctors and wise men from the far-away land of *Presbyter Johannes*, their problems would mostly be over. [Answer] The real question is what do the travelers really need. They don't need to access a SSD. They need something. They have information they need to be able to access. From the fact that we are bringing along microfische, it is already clear that they can easily bring more than a dozen people could read in a lifetime. Thus this isn't a "we need this information to survive" thing. It's a "We don't know what we're doing, so we're bringing it all!" As others have pointed out SSDs are simply too complicated. SSDs are typically connected via either SATA or USB or Thunderbolt, all of which are very advanced high speed interfaces. Even making high enough quality wires for these is almost certainly out of the capabilities of the 13th century, much less actually handling the data. If I may recommend an alternative: [micro SD cards](https://what-if.xkcd.com/31/)! [](https://i.stack.imgur.com/fk50L.png) Micro SD cards have an astonishingly high density. As pointed out in the XKCD link above, a milk jug of them can store 1.6 petabytes. Personally, I'd recommend using the larger SD cards, to make wiring easier, but if volume is at a premium, a jug full of micro SD cards (and perhaps a few micro SD to SD converters for convenience) will take care of your needs. More importantly, SD cards can communicate using SPI. This is a slow interface, so they typically switch over to the faster SD interface, but SPI is always there. How slow is it? Well.... *as slow as we like it, actually*. SPI is clocked by the master (usually the computer). The master says when the slave gets to transmit data, one bit at a time. Usually we try to push SPI as fast as we possibly can, but SPI can theoretically go all the way down to DC. This means you could have a human being manually putting bits on the wire, and reading them out with a galvometer! And now we know what goes on the microfiche. The microfiche are an index of all of the contents on the SD cards, so that we don't have to waste all sorts of time reading bits we didn't need! [Answer] This sounds like an XY problem. As the others have said, you absolutely need a computer to read SSDs. If your goal is to have information available with low-tech means, print it all on [microfiche](https://en.wikipedia.org/wiki/Microform). You will not have data compression, searches will be long, and it will be bulkier, but you will be able to read them with only a very reasonable upgrade in technology. [Answer] I think you're overvaluing the importance of information, and undervaluing the importance of infrastructure. rather than bringing computers, bring books. books can be copied with period infrastructure. not any books, though. there's a few concepts of what books to bring (ex: [linky](https://medium.com/the-long-now-foundation/manual-for-civilization/home)). EDIT: microfiche contents can be copied to books with period infrastructure--so that is probably also a good plan. but microfiche itself is also more fragile, so multiple copies is probably a good idea. focus on things like crop rotation/agriculture, metallurgy (how to make steel en-masse is of primary importance), chemistry (gunpowder, smokeless powder, etc), physics, medicine, etc. but that won't take up all that much space. you're bringing 1000 m^3. in that space, you could bring a decent quantity of rifles and ammunition, medicine, etc. that seems far more important in 1300AD than a computer and whatever your computer could do. in fact, the most useful thing i could imagine for a computer in 1300 is managing a country's finances (i'm not sure how realistic something like an income tax would be without computers)... so it might still be worth bringing a few. [Answer] I think there is an implicit assumption that if a computer were to be sent back in time, it would be a commercial, off the shelf version. I say that because you mention SSD. It is quite likely that it would be built to specifications with unique chips and energy technologies. It also couldn't really be repaired without bringing spare parts. Unfortunately, you didn't say why they needed a computer if they were not returning. Most reference material would be worthless, even to people with doctorates in their fields. A computer sent back in time should be rugged, should be built to the narrow purpose of its mission meeting only the minimum requirements that must happen, should use very low power settings rather than standard commercial settings, should use DC power, and should have a power source dependent on the local environment. It could be powered by steam from a wood burning stove in the right area of Europe. The information they need will depend on the information they are carrying inside their heads. Trig tables would matter, but there is no need for a calculator if you could carry a slide rule. A metal slide rules would be vastly superior to a computer with the correct set of tables for things such as integration. The 1300s are an unfortunate time to return to. The world was in upheaval. Climate change had cooled places and many places would be overcast quite a bit in Europe. The Black Plague killed an average of one in three persons, but in some places killed every single person and in others, none at all. There were frequent huge storms and floods, so you need to be waterproof. In Europe, there was a massive religious response to mass death. A Christian in the year 1000 might barely recognize the Christianity of 1400 outside the liturgies. Outside Europe, there was a massive deconversion from Christianity. Between 1200 and 1500, two-thirds of all Christian churches closed worldwide. Almost none of it was due to persecution, children just joined other religions. Had you lived in the year 1100 in Ireland, you could have traveled to Tokyo to hear the liturgy sung and never missed a Sunday service along the way. This was also true in the reverse direction. It was a massive collapse of an important global social network. Churches that had been open since the apostles founded them closed forever. Europe was the primary holdout for Christianity, but it survived from Syria to India while collapsing in most of Africa except Egypt and the Sudan. It vanished from China, Japan, Mongolia and almost entirely in Persia. At this time, the penalty for minor theft such as a loaf of bread was to be plowed to death. You were buried up to your chest and plows would be driven through you. I bring this up because a computer should be built for a purpose and not just to be brought along. Until a few decades ago, people just committed facts to memory and learned how to do things. Many standard technologies, such as glass making was just being rediscovered so you won't be able to make medicines generally. Europe also had low grade metal making compared to other periods in time. You need a power source, you need a rugged design, you need something that can be powered by local energy sources, you need something that is easily repaired, but more than anything else, it needs to be built exactly to mission. There can't be a video game on it. They are costly in terms of robust design. It is why they sell game PCs. Finally, it shouldn't carry anything the mind can carry or which is robustly needed so should be in a book. A trig table should be in a book. Every American school child learned to use a slide rule. It shouldn't be a substitute calculator. Finally, you should read, "I, Pencil" to understand the distributed information problem. It is at <https://fee.org/resources/i-pencil/> I bring it up because my first reaction was that the use of a computer is a puzzling use of space for people who will die in the 14th century. One final note, you probably would not use SSD in such a computer. It isn't a robust technology compared to many others. You wouldn't bring a Lexus, you would bring a Model T. It was designed to break. It was designed for a world that didn't yet have roads except for dirt paths. It was designed to a minimum of parts so there were fewer single points of failure. Ask instead, if I built a computer to do the following things, and it had to survive N years even if hit with a sword, what do I need to do? [Answer] I think it is possible, assuming they have the following: * a (stable) power source, a lemon battery will probably do just fine * wires, or anything that can be used as such * a way to solder on the memory chip inside the SSD * a way to measure volts or at least detect if a digital signal is 1 or 0 (a led maybe?) * a good knowledge of SSD internals and the SPI protocol The thing is, you can't reasonably expect them to be able to use the SATA port without a microcontroler, but the data you want to read is stored inside chips that are much more generic. Those memory chips are used inside all sort of devices, like cellphones, usb thumb drive, SD cards, embedded systems and so on. They talk multiple protocols, some are fast and complex, some are really basic. One of those is the SPI protocol. SPI requires basically 3 wires to work: a clock, an input and an output. In SPI mode the microcontroller is the one that decide the communication speed with the clock signal. In theory you can "bitbang" the clock and input signal making contact with a couple of wires, or 2 push buttons if you have them. To read the output you'll need a detector on the output line, it will detect one bit at a time. It can be a voltmeter, a led, or anything that can help you distinguish from 1 to 0. The difficulty here is to solder on the tiny pin inside an SSD. For the sake of completeness I have to point out that an SD card is much more compact and easy to work with. You don't have to solder and you can use much ticker wires. The wiring is the following: [](https://i.stack.imgur.com/olYwq.png) SS is an enabler. It can be tied to ground and ignored for this answer. Now, bitbanging the clock and the input by hand is tedious and error prone. A more advanced method may be to replace the 2 buttons / wire contacts with a perforated cardboard. You take a strip of cardboard and trace 2 columns, one per sigal. On one column you drill an hole every even or odd row, it doesn't matter as long as you are consistent. This is your clock. On the other column you drill an hole every time your input signal needs to be 1. At this point you need to setup the contacts of the input and clock signal so that you can slide the cardboard between the contacts and have them open and close when the drillholes pass trought them. This method will ensure 2 things: * you can check your input on the cardboard before sending it * you can send you input way faster and precisely, minimizing the mistakes. Now, you have to write down the output signal on a piece of paper, every ones and zeroes, and start decoding it. It will take a long time, depending on the encoding, but that's it. The data encoded on the card may be stored in a filesystem like FAT or EXT4, and that will require a very good knowledge of the filesystem structure, but they can also be stored in a raw format, for example plain ASCII codes starting from the first byte of the first block of memory. That will be much much easier to read. [Answer] Probably bring a couple dozen Raspberry Pi 2+ units, screens, a few keyboards and mice (or go with all touch screens), several solar rechargers, and several rechargeable 5V 0.5-1.0A power sources. These units are designed to run on micro-usb power, but that means there is less power to allocate to other peripherals. They'll probably need a couple SATA II/III to USB 2/3 cables if the SSD is required. Otherwise, maybe go with micro-SD cards plugged into USB adapters. Of course, they could bring one of each item if they're in a gambling mood. If their goal is to kick-start certain tech early, it may help to include [this](https://www.youtube.com/watch?v=K3g02t3O5QQ) video from Jeri Ellsworth. However, I would recommend the entire video libraries of Jeri, Applied Science, NurdRage, and other similar channels. [Answer] Others have addressed the very real issues of power supply. I would like to mention a few aspects of sheer practicality. I am lucky if a computer lasts me 10 years, and that is in a clean climate controlled environment with a good power supply, it is cleaned regularly, etc. Temperature variations are a huge problem. Components expand and contract with heat, which over time can result in cracks and mechanical failure. Temperature swings are caused by turning a computer on and then off again; by intense calculations that heat up the CPU; and by ambient climate conditions. We mitigate the effects of temperature by air-cooling or water-cooling, both of which require fans. Fans wear out in a few years, and once they are gone, the computer will quickly overheat and become unusable, if it is not destroyed. This often happens before anyone realizes the problem, which is why we keep backups. You won't just have to replace the fan, you'll likely need to replace the entire motherboard. Very low power computers do not require mechanical cooling; but even cell phones heat up. Speaking of mechanical failure, computers have lots of cables and connectors. These can work loose due to physical stresses of temperature or moving. Dirt on the contacts of a single plug can cause a whole system to stop working. The insulation on the wires becomes brittle over time and loses its flexibility. Cell phones and tablets are likely to be the most robust solution, but they rely on high tech batteries that last a few years at the longest. Your iphone is disposable, as the battery is non-replaceable. The best bet here is a cheap phone with a replaceable battery, and a crate of spare batteries. Even then, the chemicals in batteries can degrade over time (measured in years), so the crate may just be a toxic paperweight after a couple of decades. Of course a phone is a very limited computer, with a slow CPU, not much memory, very limited apps, and an awkward interface. I'd hate to have to enter data on one. Even solid state components wear out. Temperature variations cause mechanical strain and failure. Circuit boards grow tin whiskers after a number of years. Fans stop working. USB plugs get so loose they stop working, or break loose from circuit boards. Random accidents crack flat screens. Rats and cats chew through cables. Power surges destroy delicate circuits. Brownouts destroy data. Chips and power supplies mysteriously fail for no discernable reason.... one day you try to turn on the computer, and it simply doesn't turn on. Even the ink in inkjet printers and in DVD-ROMS will fade over a period of years until it becomes unusable. Computers these days are disposable. We deal with it by redundancy (backups) and continuous replacement. Redundancy and replacement depends on ready availability of cheap commodity hardware. Lacking that you are going to want small warehouse of spare parts... every conceivable spare part since you can't predict what will fail. Electronic data storage is very fragile. Long term, you can only preserve data if you actively copy it from medium to replacement medium. Forget to copy a CD-ROM for 10 years and it may become unreadable. Magnetic media has a long life but requires mechanical devices (hard or floppy drives) to read it. Electronic media is susceptible to electromagnetic radiation and discharges (static, lightning). A properly produced non-writeable ROM is probably the most durable, if shielded from radiation; writeable solid state media such as SSDs or flash memory has a limited number of writes, and I don't know how long it can be read. A lifetime is a long time to keep all this running for a 20-something. They'll want a clean safe space where they are secure and never have to move this stuff around. They'll need "leisure" time to make use of it; medieval farmers or servants likely won't have time or energy for computers to be interesting. That means wealth, but the wealth will have to not be noticeable. If they have to move their computers around, or of a warband decides to trash the place, both will make it hard to keep things running. If they are hoping to leave a record for future generations, I think it should probably be in the form of carefully stored books, since I doubt that electronic media are going to survive hundreds of years with data intact, buried in the ground or locked in a church vault. A hard drive might survive, if nobody touches it, and it is sealed so moisture doesn't destroy it. On the other hand if it is just for personal use, and only needs to last 20 years or so, it should be do-able given care and some spare parts. I think I would suggest low power industrial computers, such as 8-bit or 16-bit systems like are used in embedded systems. These are simpler and more robust and more likely to last a long time, and are designed for dirty, extreme conditions. Older components may be more robust (i.e. cruder with loose tolerances) but will be more power hungry, bulkier and heavier. Modern components are low power and tiny and fast, but delicate. It's a tradeoff. It shouldn't be difficult for engineers to rig up hardware and software to make an SSD usable for such a device; anyone well-heeled enough to time travel back to the 1300s can probably afford some custom engineering. Electronic paper (yes it exists) might make a good low-power display device, better than a flatscreen. I have no idea of its durability or longevity, but it would be readable by lamp light. A lot of power is used to make a screen produce light. Bring several keyboards, since those do wear out. A capacitance based touch keyboard is slow and awkward to use but might have the longest durability. (Not one of those plastic membrane keyboards; those do wear out due to mechanical failure!) I think wet cell batteries, like car batteries, are very heavy but provide a lot of power and are more rechargeable than lithium batteries. I don't know a lot about batteries though. [Answer] Why not build your own reader device using a raspberry pi zero and some off the shelf additions? 1. As many [Raspberry Pi zero]'s as you can take along. Their dimensions are 65 mm by 30 mm, so you can take a LOT of them along without using up too much space. 2. As many [7.5" E-Ink Displays] as you can take along. 3. As many [Cellphone Power Banks] as you can take along or need. At least 3 for every device you want to have continuously in use. A 6000mah power bank should run a rpi 0 with e-ink display for about a day of continuous use, assuming reading documents with images. 4. A USB keyboard, or simple button navigation device (what is the nature of the data on the SSDs?) Maybe get a [mini usb keyboard] or a [micro usb keyboard]. 5. As many micro USB cables as you can take with, Probably no more than about 40 per device you want to have simultaneously powered. Get good quality cables with decent physical protection. Look for something like the [Rugged Geek Micro USB Charging Cable] 6. AS many [USB Cellphone Solar Chargers] as you can take with, at least 3 for every device you want to have in continuous use. Perhaps look at getting something like this: [10000mAh Solar Power Bank - Sweet Orange] 7. If you will not (always) have access to the sun, you will want to take a few [emergency solar hand crank cell phone chargers]. Be sure to test the ones you take with first - many do not work as advertised. 8. various electronic components, depending on your choice of keyboard and storage solution. 9. If a member of your group is skilled at electronics, then be sure to take through a variety of capacitors, resistors, leaded solder, a butane soldering iron with as many cans of butane as you can take. You should get a few of your group to play around with assembling these. Everything you will be making is field serviceable and field replaceable. The low power rpi and e-ink displays mean that your batteries should last a really long time. [Answer] I'd start like this: A location on a large continent in moderate or hot climate with no humans using the land regularly, but humans who are used to work hard for others nearby, at a large river with no flooding issues and bordering the ocean through a calm bay or sea. The position should be defensible (on a hill with no mountains nearby) and with lots of wood and potential farmland around. Having the right materials nearby (coal, iron, other metals, limestone for concrete and so on) would also be helpful. They will need to bring along weapons to defend against nearby criminals, adventurers, power hungry lords, and so on. And the tools to quickly set up defenses where 10 people can defend the core parts first against nearby lords and later against revolts, and loyal locals can quickly be enabled to defend against any army the middle ages can possibly muster. A popular ideology with loyalty testing and such can help secure following among locals and further away. Seeds brought along will quickly boost the population, offsetting losses due to the plague and other diseases. Some of them will be kept under wraps as long as possible. Similar to a few modern breeds of milk cows, pigs, chicken, sheep, and so on. Cotton and other useful seeds are brought along to boost the economy. So we get an inner tower where only the 10 time travelers are allowed in, and a few of them have to keep watch at all times. It's surrounded by an inner castle with a limestone mine and oven, a printing press, a paper mill, and other primary industries, run and protected by the most loyal locals. Then comes the outer castle with a large market, a savings bank, a hospital and other cash generators, access to the harbor (which also makes money), towers for defense, factories for goods to sell in the market and so on. A wharf produces ships to quickly get all needed resources from far and wide. Another factory produces horse carriages which are a few centuries ahead of their time to connect the land routes. Trade unions are set up with purposes like building roads, extending the harbor and so on. Modern surveillance technology brought along helps make sure the loyal people are truly loyal. Modern management methods ensure loyalty and productivity, too. Competition ensures avoidance of wasteful practices and best factor allocation. There are two kinds of factories: The ones to mass produce stuff to sell all over the world for currency and resources, like easy to produce medicines, textiles, and so on. And the ones for the colonists local needs, like ammunition and tools, which are usually kept from view of any but the most trusted people. Local crafts are used and improved - glass makers for laboratory equipment, brewers for fermentation and other tanks, wineries for barrels and other wood work, smiths for tools and so on. Each new factory is able to expand to cover the whole world demand if possible, to keep competition low, and brings a new ability to the time travelers. Difficult to copy tags ensure very little copying and help popularise the colony. Prospectors are trained to find needed resources and teach the locals how to mine them. The approximate locations should be known by the time travelers. Traders are trained to identify the different materials and sort them into the correct stores for the factories. Talented people from all over the world get attracted with high wages, trained to get the necessary skills and help further development. Our 10 time migrants let others do the work and are mostly just in contact with a few of the most trusted, to help speed up progress through them. Something like a dominant trading power comparable to the Netherlands 400 years ago should be easily possible within a decade. By then, our 10 people should have chemical factories, an iron and other metal industries, medical and technology labs, and so on - 17th century level with a few 19th and 20th century elements and tricks. Once the basics are there - a trade network for the resources and the exports, a known brand people all over the world try to get their hands at, and an industrial base - the rest should go faster. Intermediate technologies like land line phones can be left out completely. Such stuff is only produced as prototypes to simplify the step to the next technology and to have testing equipment. Once photographic options and all the needed chemicals are there, our labs go directly to fiddling with lithographic electronics design until they get rudimentary chips useful for simple phone switches and automation. The saved workforce is retrained for newer products. Once a chip production is running, it will be easy to build a small processor, which will mostly be useful to find skilled programmers and electronic engineers all over the world. Once sizable and sufficiently dense chips can be produced, simple versions of modern chip architectures can be built and the aging and partly defect devices of the 10 can be replaced with slow but new equipment. And simple versions brought to the masses, to keep outside competition at bay. With all the advantages of hindsight and equipment brought along, the level of the 1970s in some core technologies should be possible in 20 years, similar to how some industries developed out of nothing in some developing countries in the 1950s and 1960s. Another 10 years to get to the year 2000 - which is where we should be able to make any device of today work partially (enough to read the data if it's not encrypted, as we have the specs and know how to use them). After that, it gets tricky, because only some more modern technology is easily available. Modern chip design software and other such trade secrets are difficult to get and need to be reinvented. Metallurgy is a lot of fiddling - where we need to figure out the fine details for the most current technologies (older stuff can be improvised more easily). And so on. As we have a much smaller population base, fewer highly talented people will be possible to find for that. Progress will slow down to less than what we have now as soon as most technologies are 2 or 3 years behind ours today. ]

[Question] [ ## The Demonstration You're a rich, successful CEO/capitalist working in the electronics business. Your R&D division is exceptional and routinely fabs state of the art processors at bleeding edge processes. (If it helps, you're in an equivalent position to the CEO of Foxconn, Samsung or Intel). A person walks into your office one day bringing a small device with them. It fits in their pocket and has a smooth, rounded exterior. They ask to demonstrate the device to you and you consent. They proceed and ***magic happens.*** The device is capable of performing operations that are hinted at by the products your company makes now or can be done with extremely cumbersome equipment. From your own knowledge of the electronics industry, you know the global state of the art and this device performs far far beyond. Your top engineers are also permitted to use the device to verify that there is no trickery afoot. They too are blown away. The stranger even lets you keep the device for up to 168 hours with the warning that if shenanigans happen, the device will make itself, well, unavailable to you. (The device will remain fully function after the review period is over. The threat of unavailablity ends after payment is made.) The stranger says that they come from 30 years in the future. They can't describe how the device is made or any of the relevant manufacturing techniques, materials or processes. They only know how to operate the device and its general capabilities. But, they will sell you up to 10 devices for 1% of your net profits this year. Transfer of funds will be worked out later after the deal is struck. **Do you buy this tech knowing full well that you can't duplicate it? If purchased, how do you use these devices going forward?** ## Out of Scope * Verifying that the stranger is actually from the future. You, oh CEO, just know it to be true. * Verifying that the device actually does what the demonstration shows it will do. The stranger is trustworthy and the device performs as advertised. * How to actually transfer the funds in a way that the stranger can use it. * Shenanigans by you to acquire the devices without paying the stranger for them. You're honest. * Considerations of time travel and altering the future. * Discussion of what the device actually does. The thrust of this question is aimed at the assessment of risk/opportunity for purchasing tech you know you can use but can't yet duplicate. * The threat of government interference is zero. You have sufficient leverage that no one is going to come take away you or the devices. [Answer] **Yes, 100% Yes** Just because the stranger doesn't know how to build it or how it was manufactured doesn't mean that you can't reverse engineer it. With 10 devices, you even have some spares so you can perform destructive testing on all 10 of them if it gets you enough data to make a replica. This is even more important since it performs the actions of your devices (I'm not sure if it's what big devices do in a small space, or if it's like your planned features in a smaller space or just something still in R&D). This means that even without being able to replicate it 100% you will be able to gain insights into the development path of your current technologies. Once you have some idea of how it works, the technologies it employs you can research towards it and fund development in that part because you know it works now. You can also create a ton a patents outlining the general principles upon which it works so in the future you can have a partial monopoly on technology and sue the crap out of anyone before they figure out another way around it. The best thing about future tech is it lets you know what you can do and in which direction to invest further funding. With advancements in technology becoming so much faster, 30 years isn't a long time. Just for comparison, **the Internet is 30 years old.** Imagine being able to know about what the internet could do before it even came out. As for the requirements, you can get around them pretty easily. You need to pay 1% net profits? **NET PROFITS!!!** I guess I'll just spend everything on R&D and have no net profits. Increase the pay of every single employee if you wanted to, give yourself a huge ass bonus, sure your stockholders might be upset, but that depends on your company and how well you sell this new research with people. Discussion of what the device actually does? Just observe and write down exactly what you see it do. There is no discussion, just a list of observations. Your engineers and researchers don't need to discuss the device itself either. They can talk about this new magical alloy that was given to them, the complicated quantum circuitry, the crystallized hologram projector that was given to them to figure out how it works. Affect the future? Time travel will always affect the future... so I don't get the point of that either... unless that was a time travel device The worst thing that happens is you lose 1% of net profits, which could be effectively 0 if you wanted it to be. Just do it. [Answer] ## Oh most certainly indeed yes! So yes, the object can be examined, it can be reverse engineered. Sure maybe it needs infrastructure or materials that haven't been created or invented, but having the device would let you know where to look, making development much easier thing. No longer would you be looking at an infinite combination of things that haven't been thought of, but a defined solution that you are looking for an equation for. Even just knowing it will exist has already given you an advantage. Also, showing it to investors would get you better investment terms and cheaper funding. And finally, they want their compensation in future profits of your company. Let me say that again to make sure it sinks in. PEOPLE FROM THE FUTURE WANT COMPENSATION IN FUTURE PROFITS OF YOUR COMPANY! If I was going to make a guess about how successful my actions would be, I would want to be on that train. Sure it isn't a guarantee - they might have ulterior motives, but if I was a betting man, I'd take that bet every. single. time. [Answer] Your lawyers said "No". > > They can't describe how the device is made or any of the relevant manufacturing techniques, materials or processes. > > > This presents an immediate problem : you cannot patent the device and you don't know how to make it or even if making it is possible. People will ask questions about this. You may even be infringing patents used to make it and find yourself sued and in court. At which point an answer of "a guy from the future sold them to me" will land you in either the funny farm or jail for contempt of court. And if someone steps forward who says "this is all based on my idea" and sues you, the last thing you want is to be dragged into court to contest that. So you are vulnerable to every con artist and greedy employee you have. In short this thing is trouble. > > Your top engineers are also permitted to use the device to verify that there is no trickery afoot. They too are blown away. > > > Quite possibly you'll *have* to blow them away to keep this secret. :-) Can engineers keep secrets ? Sure, but it's easier if they have accidents of a tragic nature. Showing this to engineers who then either never hear about it again (which they'll wonder about) or which they can't find out how it works (red flag to a bull territory), is extremely high risk. And when the engineers are subpoenaed when the lawsuits happen, you're in deep do-do. And remember that thing about someone claiming to have come up with the idea and suing you ? It could be a disgruntled or greedy engineer. Successful CEOs don't like things that leave them vulnerable and they're control freaks. They like to know no surprises are lurking and they listen to their lawyers and if they can't even patent it, they're not going to touch it. **The Military...** Now these are the guys who *might* be willing to pay for something special no questions asked. Heck, they practically do it now (see "The Pentagon Wars" for that). So you might be able to act as a go-between. **Use don't sell...** You don't try and sell these things, you use them in your business. Risky (for reasons mentioned above), but exposes you to less risk from lawyers. > > they will sell you up to 10 devices for 1% of your net profits this year. > > > This is a problem because unless you can make a *huge* price for each of these ten items, that is going to be a relatively small reward for all the risks. And if they're worth a huge price that's actually worse. In that case lots of nosy people (like your competitors and government intelligence agencies) will start trying to find out what's going on. Again answers involving people from the future dropping by your office won't be good choices. So these things are more dangerous to have than to forget. [Answer] I did a quick mental check on the gadgets I have nowadays, and how could they be used 30 years ago. Let's see those fitting into your description, and how would they work in 1988: > > It fits in their pocket and has a smooth, rounded exterior. > > > * **MP3 player**: 30 years ago I would have shortly listened only to the already loaded music. I would have missed the MP3 format, the MP3 converter and, last but not least, the USB port to charge its battery. * **Smartphone**: 30 years ago I would have no mobile network supporting it, nor I could have had Bluetooth or Wi-Fi. It would have been a fancy camera, a fancy agenda and the like. But just attempting exchanging data would have been impossible, due to the lack of ports, protocols AND large enough memories. A single photo of my mobile would not fit on a floppy, and would probably overflow the memory of a computer trying to visualize it. * **smart watch**: assuming I manage to keep it charged, I can use it to monitor my health, as long as I renounce using GPS tracking. Just from this short list I tend to say that investing 1% of the company net profits in them is a rather poor investment. Contemporary devices work way better with the available infrastructure. I cannot even figure out some of the features of those devices if they have no infrastructure to interact with! [Answer] ## Yes, because buying gives you options ...not buying removes options and possibly gives them to your competitors. The stranger doesn't say There's a range of outcomes here. At the best, your company gets a huge kickstart to technology that will be exceptionally valuable, easily adding tens of billions to your company's income or even better opening up entire new industries. New manufacturing techniques, new materials, new information architectures... Any and all of these will be huge competitive advantages. At the worst, the devices turn into inert bricks in a year and you can't do anything with the operations of the device itself. But, you still can study how it was made. Advanced manufacturing techniques are still bonkers valuable. For example, if the device gives you hints at how you can create the arbitrary shapes of 3d stereolithography but do it in seconds instead of hours... That's an amazing improvement. You can't patent the device itself anyway. Your company will patent all the processes that come from studying the device. There's 30 years of improvements contained in that device, you should be able to find at least a few things to patent. You pay a small one time cost that provides the opportunity for essentially unlimited upside. These are the kinds of chances that CEOs the world over dream about. The stranger has essentially said "Give me a billion now and I'll give you a 100 trillion over the next 30 years." You say Yes! **Buy it already!** [Answer] I would judge this a poor risk. 1% of annual profits are pretty much a drop in the bucket, but possessing this device is meaningless. A government employee will walk through the door flanked by several guys with bulges in their jackets that are suspiciously sub-machine-gun-like, take it away from you, and force you and anyone who knows about these devices to sign aggressively binding non-disclosure agreements. These agreements include forfeiture of any and all (very lucrative) government contracts you might presently have as well as barring you from any in the future, should you make so much as a whisper in your sleep about the device's existence. This will also happen should you fail to pay the elusive future man and void the contract, leading to the device's destruction. Not only would your company fail to benefit from the purchase, but you would now have the very serious risk of losing out on highly lucrative government contracts. Your first reaction should be to alert the government to gain brownie points and goodwill, which you can use as leverage to obtain more contracts in the future. Thats just my opinion though. I think you should word the question to be less geared towards what I would personally do as a CEO and more towards what a theoretical CEO stands to lose or gain from such a transaction. [Answer] ### Do you buy this tech knowing full well that you can't duplicate it? Definitely. At that price, there's little financial risk, and the potential is enormous. To be honest, the awesome factor alone would probably convince me. But for someone with my resources, I'd be pretty confident I could make it profitable, too. ### If purchased, how do you use these devices going forward? Depending on what the device does and what my current business model is, I see two plausible, low risk applications: **1. The long game** If it's tech from 30 years in the future, you might not be able to replicate it right away, but you should master it eventually. The gap between what you have and what you can make will shrink over time. It'll give you enough of a head start to outpace your competition, at least. Keep it in R&D and make sure you learn everything you can from it. Try replicating small parts of it and work your way up. You might not make much headway on the processor, but what about the power supply, sensors, network components, display, even the casing? Also figure out the software. Is the device programmable? Does it have a debug console? Can you build an adapter to connect to it somehow? "Inventing" something like OOP 25 years ahead of the curve would be huge, and doesn't require ridiculous processing power. Advanced algorithms, e.g. for optical recognition of things, if they could be reverse-engineered, can be used on smaller or more constrained data sets and problems. Even in the worst case scenario that you, ultimately, learn nothing of commercial use, you can be assured that the best and brightest in your field would give *a lot* to be able to work on this project for you. You'd be in an ideal position to build the team of your dreams and make sure you lead the insdustry for decades to come. **2. Integrate it** With digital technology maturing, there is a trend towards backwards compatiblity. Not enough to "plug&play" across a 30 year gap, but there's a good chance that when I retire, we'll still be using some variants of USB, HTTP etc. Ideally, your engineers could use that knowledge to build a (slower and more bulky, but more or less compatible) cable or wireless connector. Even if that fails, the device probably has a human-usable interface. While not ideal, modern computers can use those. Put it in a slightly larger box with a robot hand and a camera, spend a year or two customizing your software for the annoying 5% of difficult-to-process edge cases, and you've got a product. Last step: find the most interesting edge cases where current day tech just doesn't cut it. Don't think mass market, look for prestige projects and unique technical challenges like fighter jets, space missions, research facilities, espionage/electronic warfare etc. Bringing the equivalent of a building sized supercomputer into space in a few-kilograms, power-efficient package will be worth *a lot* to the right people. And don't forget about your own R&D department. Your engineers are bound to have some time-consuming simulations that a cluster of, say, 4 of these devices could speed up tremendously. **Mitigating the risks** *Do* make sure, if you sell any devices or grant access to them in some way, to only provide it in integrated form, with lots of shielding and a rugged case, provide enough bogus documentation to "answer" any questions on how it works, and make the price tag ridiculous enough to explain the limited supply. Remember that you can afford to spend some time letting your engineers examine the thing and have a small team make up plausible excuses. If possible, add an anti-tampering mechanism that destroys the device if messed with. On the outside, treat it like the technological marvel it is, and most business partners won't prod *too* much about why you're only manufacturing 10 bleeding edge fighter jets, space station supercomputers or particle research labs. Actually, make that 9. I'd keep one for myself, or at least the company, just in case. Sure, you *do* need to be careful about your business partners. You *might* have to get rid of some witnesses. Anything that valuable comes with a risk. But you have the resources to make it work. Just don't rush it. [Answer] Don't Buy!!!! Just because it's from the future doesn't mean it will be a successful product. The history of technology is full of many also-ran technologies. Beta-max was in many ways superior to VHS, hell SONY has had an endless string of unique protocols and device lines that had great functions and were designed well, but failed because of their uniquenes and not playing well with others. Thus limiting the ecosystem from large scale adoption. Many technologies only function with sufficient infrastructure present. Zip disks were great holding much more than floppy disks, unless you couldn't find a reader in which case they were useless. Similarly an iphone is going to pretty limited without a network, and a lot of the apps lacking servers won't work. You may think you are buying the next iPod, but what if you were being sold a Zune, or even worse maybe a laserdisc! The tech may be great, but it might be a dead end or may be quickly bipassed by competitors alternate technologies. [Answer] ### Yes but you need to keep it on the down low, for about, lets say 30 years, and during those years explore what the tech can can too an learn everything their is to know about it. So when the time when it is invented comes you either... A) get some business partners and lawyers then claim the device then mass produce it and watch the cash role in B) look through the device to find any clues on who made it and find them and make some money off the stock market C) just use it to enhance your own dalily life and live like your 30 years in the future [Answer] Definitely buy it. You can count on it that this person will also try to sell your competitors this technology, and you cannot count on them not being able to reverse-engineer it. Better to try your own engineers too. 30 years into the future does not seem that long ago. An engineer 30-60 years back from our past would be probably able to figure out what our tech does, and get ideas on how to replicate it, even if it took them a long time. [Answer] Scenario 1. Thank the gentlemen who presented the device and decline the offer. The reasoning behind this decision is that by simply seeing the device you have already gained everything there is. You now know something about the future of your industry and may adjust your plans. Another reason for turning them down is the fact that this device does not exist. Any, even smallest information flow back in time will change the future and keeping this artefact would alter the future even more. Thus, the device comes from future that is no longer valid. Scenario 2. Accept the offer and get the 10 devices. Lets assume these devices are future smartphones (thats what we all are thinking, I suppose, even though it could be something else completeley). So if these are smartphones, they are part of larger infrastructure or network and services that need to be developed soon. Even not being able to reverse engineer the electronics, you could try to communicate with them and find out what kind of possibilities these gadgets will open in terms of services that can be offered in next few decades. This knowledge will give significant advantage to your company. You may discover that there is need to start building a network for services that seem completeley pointless at the moment but in 20 years everyone will discover that you are ahead of everyone else by decades. Meanwhile your competition has dismissed you as lunatic. [Answer] Yes. At minimum, you can see/guess what processes are used. With that you can guide your research and ignore dead-ends that might look promising now. Since each sphere does things that baffle you, it must be outperforming the serverfarms you have for your research. Your R&D department is always going to have a few formula's and calculations lying around that they cant solve yet until certain processing power and capabilities are met, these spheres allow you to get a multi-year jumpstart on your competitors both in speed as well as specific solved problems. Taking a few apart to look what they might be made off can guide your research efforts in the direction you need. Perhaps you find a different quantum bit than current research uses? Well there must be an advantage to those so start researching those now and have this type of technology what, 10 years earlier? Also keep in mind that after 10 years they might have the capacity to understand and reverse Engineer the spheres... Since the visitor doesnt seem to know a lot about these spheres, they must be consumer products and the visitor someone abusing a law or something to get rich. It also means that your IT department can rummage around the files and find things like the Motherboard setup, its layout, information about how powerful the processors are, storage capacity, type of battery it uses etc. If you are an asshole these things give you unprecedented power to hack. Research from competitors, Governmental data, stocks&shares, nothing would be safe, and you can make even more money on the markets after all the info you liberated. Just buying out competitors and focussing their departments on more research might accelerate everything. By the time the visitor comes around he might have access to the equivalent of 50years future tech. [Answer] **You may not have a choice but to say yes** Maybe the person from the future offering the device has it only because of you developed/bought it with your company. And because the person is making this offer you may have already said yes and no matter what you do it will lead to the outcome that sometime in the future you will have to send somebody back to the past to offer yourself the device. This time paradox seems to have no beginning but time travel does strange things like that after all. [Answer] # Yes Lets turn this around and look at *present day* tech being offered to a CEO of a tech company, probably involved in the semiconductor industry (because most of the big tech companies of the day were), in 1988. And let's say that the device offered is a 2018 model smartphone. I don't have a hope of replicating it -- the infrastructure and basic knowledge that I'd need to bridge the 30 year gap just doesn't exist -- but it can still give me some useful benefits: * I'll take a look at the chips on the device and will immediately know that Moore's law is going to continue applying essentially unchanged for the next 30 years. This would be a huge bonus for a semiconductor company, as an awful lot of time and resources were invested into finding alternative directions to continue improving on the basis that Moore's law would stop applying at various assumed barriers (but which were eventually overcome relatively easily). Simply knowing that it's possible to make chips this small and that it doesn't involve using exotic materials will focus the research into the right areas. * I will see that the RISC vs CISC processor debate was eventually resolved in favour of RISC. This may lead to me making more optimal decisions on projects to pursue. * I will learn that Flash memory has become the dominant non-volatile storage medium. I can therefore avoiding investing in its primary competitor, bubble memory. * I will learn about mobile phones, operating system and UI design improvements, aerial technology, battery technology, and digital cameras. None of these are directly relevant to my current business, but are likely to become so in the near future. * I will have 10 devices (9 by the time one has been dismantled and the main ICs removed from their packaging to get micrographs of their internals), each of which has ~100 times the computing capacity of the fastest supercomputer in the world. Reverse engineering of the software on the phones should enable me to write software to take advantage of this. Knowing the current state of the art in both integrated circuit design and PCB design, I will understand that many of the processes involved *can* be automated, but that current generation computers are nowhere near fast enough to do so for large circuits. But the processors in these phones can do it. This will give me a massive boost over my competition. So, based on the knowledge that if this had happened 30 years ago it would be definitely beneficial, and not knowing of any reason why the next 30 years would be less useful to know about than the last 30, I'd definitely do it. [Answer] I would say "I don't know". Simply, I don't know if 30 years of advancement is enough of a leap. I don't think the engineers and scientists can really get enough insight without tearing it apart to tell is whether it's worth 1% (1% of Intel is different than 1% of Texas Instruments). What's the value of such a device? Is it truly revolutionary, or a singing frog? Using the common suggestion of sending an iPhone back to, well, 1988 now. What would we learn? Most of the tech in an iPhone is not necessarily revolutionary, it's refinement. LiIon battery tech research started in the 70s, first one to market in 1991. How much would seeing a 30 year old battery have advanced that kind of development? Much of what we know about microprocessor development goes way back. Does seeing a much denser microprocessor actually help in developing such a device? Or is it more "yea, we know we can get there, we just can't jump to 7nm in one leap". Much of technology is based not on a single thing, but an entire ecosystem of development. From materials, to tooling, to skill set in the workforce. Lots of folks know what "can be done", even if we can't quite get there yet. And the reasons we can't "get there yet" are not simply lack of knowledge, but the entire eco-system of infrastructure, market, and capital. Consider the current boom of AI. It's not as if the fundamental techniques are necessarily new, but the revolution of big data, vast data spaces, CHEAP CHEAP CHEAP computing power all have had impact on this field. The "revolution" of the iPhone was the magic trick it pulled off with its touch UI, graphics, and battery life. And then, later, simply the "concept" of the App Store, which isn't really technology at all. The real question is what would Google have paid for a clone of an iPhone in the year 2000. Or, what if TI saw the iPhone, would anything have happened at all? Would they have been able to keep it secret? Would it have transformed the industry? Destroyed Apple? Or would they have messed it up, because they're not Apple, and didn't have Steve Jobs and the culture surrounding him. And how much of the iPhone "magic" isn't even in the device? It's in the network supporting it and the fact that there's millions of these things and everyone in your family has one. Around 1980-1, I saw a sort of "lifestyle" magazine marketing thing from HP, and it focused on the idea of a ubiquitous handheld device, and the wonders it would do. 27 years later the first iPhone came out (in a world of ubiquitous cell phones and the occasional "smart" phone). HP didn't make the iPhone, HPs handheld experience pretty much peaked in the late mid-90s with their amazing calculators and their palmtop PCs. If we saw the iPhone in 1988, would we have considered it "magic"? Or just "really neat". 30 years may not be enough, but get more than that, and it become even more inscrutable, even more "magical". So, investing in future tech. With so many unknowns, and no promises, is very risky. For a smaller company, 1% may not be that big of a deal, but they'd also be the least likely to truly exploit it. And a larger company, well, they already have "plans", and a technology company has plans 5-10-20 years out. And "1%" is a lot of money. [Answer] I'm favored towards a moderately strong "no", possibly an absolute "no". There are several points that would make me rather uneasy. The most important obstacle is that the stranger is, apparently, from the future, and presents some *voodoo* thing of which he doesn't know how it generally works or how it would generally be produced, or of what materials. I am not a chip designer, but I could very well give you a general idea of how computer chips are produced, and what materials are needed. I am not a car manufacturer, but I could very well tell you most of the relevant details about a car, including the materials used. This suggests that this is not a "normal" item from the stranger's time. He might have gotten it from *someone else* (aliens who first give you technology, and then make it fail prior to the invasion! wait, where have I heard that idea before...). Or, he might have *stolen* the device (again, [where have I heard that idea before](http://memory-alpha.wikia.com/wiki/A_Matter_of_Time_(episode))), possibly from a secret laboratory or from someone further in the future. So, in summary, this means you need to prepare for either chaos and destruction coming your way, or some heavily armed, angry person from the future looking for their stolen stuff. Which kinda boils down to chaos and destruction, too. Then, there is the Number 1 rule of scam. If it looks too good to be true, then it is not true. If a Nigerian prince offers you a million, and you only need to pay the transaction fees, then you shouldn't pay the fees. Also, there is the yet unanswered question that every manager inevitably asks first during a sales pitch: *"Well, that's nice. How do we make money of that?"* It is not clear how you can make money out of the item. You cannot reproduce it, so you cannot really sell it. You might only be able to use it for *something*. Remains to be seen how useful that is for you. The device is allegedly able to make itself "unavailable". What guarantee do you have that after having paid the device remains operational? Does it maybe operate for *exactly 168 hours*, as it happens? What end-of-lifetime properties does an unknown device of unknown materials given by an obscure stranger have? Does it just cease to work? Does it create a black hole that swallows the planet? Do your ancestors' captured souls that make the device work escape from it only to take vengeance on all living beings they encounter? Lastly, life is hard, and it's unfair, too. If word spreads (and word *will* spread) that you own a sort of super device, governmental thugs will take it and will waterboard you for months to extract the smallest piece of information that you may possibly know about it. Why, that's a fabulous perspective. Let's do this for fun and profit! [Answer] **Buy it** Even when there is no hope to reverse engineer the device, the device may have some useful functionalities that no recent device in our time has (like cracking cryptography considered secure for now, spitting out new bitcoins at incredible speed, including a microchip design program that lets you build the most advanced chips of the world, ...) and you can just use the functionality of the device for profit. [Answer] Nah, There *seems to be* one major motivation for this stranger, **Self-Interest**, and we know we can trust him on this! Assuming he did his research and really only cares about making a profit; We must have made a lot of money this year even without his help, especially considering he knows us from 30 years later. We also know we don't have to worry about impacting the future. That means that whether our company is meant to thrive or fail, this object will change nothing. In the end, that means there is no benefit for us to accept his offer. Only risk if the future has policing or laws in regards to time travel. I am not willing to take *any* risk so this stranger can make money off me and my company. [Answer] It all depends on what the stranger is selling. If a stranger came to me selling 10 laptops from the future with developments tools, virtualisation tools, manuals in PDF format and the source of future \*BSD and \*Linux tools, I would: * reverse engineer how to develop software for them; * reverse engineer how to connect them to the existing Internet network, both hardware and middleware; * use their superior capabilities of storage and processing to supply AWS/Ali cloud competing services without having most of the associated costs; * specialise in selling those VMs to the financial and banking industry as tampering/resistant to hacking VMs. As coming to from the future, any bugs discovered in the present will be automatically fixed in the future; * use the sources to develop software products and software patches far ahead of anything known and release them slowly over the years, becoming a well entrenched name in the industry. Sure, I would not be able to duplicate the hardware with present technology, but that would give me an huge boost and a window into the future. [Answer] How do you use the technology? With ten (10) units hardly at all. One problem in devising how to use the devices, is not knowing precisely what the devices do or what technology the CEO's company manufactures. For example, if the devices were large-scale servers then ten small server equivalents can only be sold ten times. Replacing ten large-scale servers. Now it depending on how they can be sold at best you can sell the future devices for the same or somewhat better than the current devices. So buying ten future devices for 1% of your company's profits doesn't seem like a good investment. Since it is highly doubtful that the future technology can be replicated. The only way a company could be expected to turn a profit is by selling large numbers of units. If you're limited to only selling ten units, then it seems unlikely you can turn a profit. Possibly, your company could sell the future devices to the government and let them find out how to reverse engineer their technology. of course, this sale will done with an agreement that your company has first rights on commercializing the future technology. In fact, this seems to be the most profitable route for your company to take. Anything else would be fruitless. [Answer] **100% Yes.** Ask your accountant and finance department to [make the company unprofitable](https://www.theatlantic.com/business/archive/2011/09/how-hollywood-accounting-can-make-a-450-million-movie-unprofitable/245134/) for three years. If the company has negative profit, does it mean that we need to make negative payments too? [Answer] You don’t need to buy it, because just having seen and used it gives you 90% of the benefit. Now that you know not just that it’s possible but that it will be a desirable and marketable product in thirty years’ time, you can redirect the efforts of your company towards duplicating it, selling the intermediate products along the way, and get there in twenty years instead, putting you ten years ahead of the competition. In fact, I wonder if Steve Jobs received such a visit around fifteen years ago. [Answer] ## Do not make this deal. Also, start looking for a new job. > > But, they will sell you up to 10 devices for 1% of your **net profits this year.** > > > Why would a time traveler from the future want 1% of my profits from *this* year? They know the future. They should know if this investment will make my company flourish or not. But researching this device is a long-term investment. It will certainly not gain me any profits in this fiscal year. The profits will come in the next 3 decades. If the time traveler would know that this is a good deal for me, they would want to be paid in stocks or a more long-term profit sharing agreement. But they do not. They are only interested in my short-term profits. That means they obviously know something about my companie's future I know not. In the best case, this device has absolutely no value for me. In the worst case, they know that my company won't exist anymore in 2 years from now. I would compliment them out. Then I would call my headhunter and tell him to find me a new job within a year. Preferably somewhere far, far away. And unless me from the future shows up immediately and tells me to run after the time traveler, I would be very confident that this is the right decision. [Answer] Funny question. In the history of informatic, for example, in the late 70s, at Xerox PARC they came up with the very first workstation complete with mouse. But this stuff never left the Xerox laboratories, since the company was trying its luck with mainframe and copiers, but *not* PCs. It took a visit from Steve Jobs, who was looking around for ideas, to develop it at Apple and launch it as part of the new McIntosh in 1984. The trouble with future tech is that, well...it does not belong to our time. It will be developed under certain circumstances, it will take a combination of creativity and market demand. Let us say that someone in the record industry tried his luck and wanted to skip the whole vinyl step since the '60s. Even with a fantastic job of reverse-engineering, the final product would be so costly as to make it prohibitive for the market. Even when the conditions were more favoreable when it was launched, you had to spend hefty money for a set and even for 2 or 3 CDs. Starting in the '60s, people would have stuck to cheaper and simpler vinyl. Internet is out of the question: before its creation, you should have a whole informatic world built around it, the right cabling, microprocessors... The best tech from the future you could make money with is the simpler one. Ballpen, sticky notes, fabric, alloys, plastic, anything that can be easily mass-produced with an investment that will repay thousands of times and give you a monopoly. **EDIT:** I would buy anything that would allow me to create a monopoly in the short term, not something that would take too much time and investment to reverse-engineer, with low probabilities to sell on the mass-market [Answer] The way the deal is worded, there's only a limitation of not allowing "shenanigans" (reverse engineering, etc) until the items are bought. After that, test and copy away. Even if you choose to leave them alone, their usefulness as a more powerful processing device makes them useful for R&D, or any other uses one could imagine. That alone should give the company an edge. I'm reminded of a Justice League Unlimited episode where the baddies send a common day laptop back to WWII Germany. Its computational power is so far past anything in the day it allows the Axis to design amazing new weaponry and tech. [Answer] What if it has a removable SSD in it? SATA might still be used in some cases, and USB and Ethernet in some form might still be around (RJ45 ethernet cable has been around 28 years). Some formats live forever, JPEG is 28 years old, GIF is 31, and TIFF is 32, and RS-232 Serial is 58 years old. In the last 30 years, we have gone from 10MB hard drives to 10GB and now 10TB. Even with an SSD, you might find one with a million times more storage than we have now. Just think what you could do with it. I buy and sell used electronics for a living and sometimes get things i dont know what they do and turn out to be valuable, and sometimes find components worth far more than the whole device sells for (scsi to ide adapters). Sometimes i get ripped off (device no longer serves a purpose, requires other obscure hardware or software to run, or requires expensive repairs). Imagine if for a kludge, there was a std to quantum computer adapter in it. Or like 2 fax machines on opposite sides of the country 75 years ago. You have a business at each side, advertise "Send documents from NY to LA in 5 minutes for $5". You put the fax machines inside a period looking machine and a slot for the paper and runs off the current phone lines. Granted, it might just be something that a novelty, like a mini 3D hologram projector, that you could put on a conference table to impress clients displaying prototypes of other items, but when they ask about it, tell them its not ready to mass market, costs too much to produce and the equipment to mass produce it isn't available. Imagine if you could bring a high end windows 2012 server back to 1988. Some software from 1988 could still run on that equipment and the serial, parallel, floppy and network could still talk to things back then. Roomfuls of equipment could be replaced with that one machine. Hundred or thousands of terminals could run off of it. [Answer] ### Yes / No Depends on the device ! You need a device thats would be able to be used 30 years in the past or able to display its content. The content must worth enought on their own. Like a tablette with 30 years of music / film / video games / book. Your company won't have any profite of it as you will create a new one for all this be the new Producer. [Answer] **No.** You know well good that this men is actually a spy/worker at factory that produce such equipment for your competitor. Why you know that? Because that is how the world roll. Why all cloth chain stores have same color schemes at summer or winter? 2 years earlier there came a guy from factory and said "we're making those for Bolce&Dabana. We can change it a little bit to so make it affordable to sell for 19,99 and produce similar things for you". And then end customer goes to H&M and can choose gold and blue themed clothes. At Zara they can choose from gold and blue themed clothes. And they all look very similar. so the same thing goes in technology field. BUT technology is not only easier to proven that it was stolen but also you can get sued (and loss) because curves on your smartphone are too similar to curves on competitor housing. And do you know how your smartphone works? No. Does the people who assembled it at factory knows? No. There is even a term for people who know how to make a thing but have no idea how to use it or what's the purpose of said tool. This guy is shaaaaaady as duck. He can be 30 years from the future or 12 hours from the future (if you get the joke) whatever it is you're buying stolen technology. Say hello to your new holes in knees drilled by CIA. Because they won't take "guy from future sold it to us" as an answer. ]

[Question] [ In a world I am building, gods exist; they are extremely powerful, omnipresent and active. While thinking up some larger scale empires for the world, I realized that their gods would be so powerful that a theocracy would be the best government by default, whether it be under a God-Emperor or a High Priest. The problem is I still want other forms of government to be viable. How can non-theocracies exist in worlds with powerful active gods? [Answer] I see two options here. # Gods care about small set of rules If there is something like the ten commandments, or another arbitrary set of rules, and gods simply don't care as long as you aren't breaking them, you don't need a theocracy. The government will be interested in incorporating these rules into law, but then you need more laws, and people to do work. Collect taxes. Make sure public latrines aren't full. Mend the roads. It's boring. Boring for deities, boring for priests. # Gods believe in humans A free-will deity might actively oppose any theocracy. Other gods might see a line of kings as his children,. Maybe monarchy started as theocracy with a demigod king and now that god wants them to have their fun? The God of Friendship might require decisions to be made unanimously, listening to his human friends. So on and so forth. [Answer] This situation is very much the case in Terry Pratchett's Discworld universe: > > ***It was all very well going on about pure logic and how the universe was ruled by logic and the harmony of numbers, but the plain fact of the matter was that the Disc was manifestly traversing space on the back of a giant turtle and the gods had a habit of going round to atheists' houses and smashing their windows.*** > > > And yet the nation of Ankh-Morpork was historically ruled by kings, and more recently, a tyrant - not by a high priest. And the reason why is rather simple: there are many high priests, serving many different Gods, and they don't like each other very much. Should one God gain dominance over the nation, another (or many others) would oppose him in some fashion, typically resulting in a series of unfortunate situations for the main characters. Not to say that *some nations* are not theocracies, but they seem to be the exception to the rule in the Discworld universe, and are prone to various upheavals caused by the corruptible nature of man. > > In the end, as the creator of that universe, you will have to make this decision for yourself. > > > Is one religion going to be so militant that it will conquer all others, and claim a territory specifically dedicated to the worship of their God? Or will people, fearing the disfavor of some overlooked God, worship all of them equally, and thus coexist in a nation which must then be ruled by a theologically impartial ruler? [Answer] If the gods are opposed to one another, or involved in shifting alliances and plots against one another, chances are they're going to cancel one another out. Is the advice we're getting from the God of Rain better or worse than the advice from the God of Wind? Is the God of the Sea telling us to build ships because that's really the best option, or because he's having a bit of a tiff with the Goddess of the Plains? If I seek to placate the God of Wine, my barley harvest gets destroyed by the God of Beer. That kind of thing. A theocracy would make sense if the gods are working together, or if they rule clearly defined territories. If the Great God Andy is dominant in the plains, a theocracy on the plains would work well - but probably not if they're in the mountains, where the Great God Bill holds sway. [Answer] # **Because that's what people want** Take the Bible as an example: God brought the people out of Egypt to the promised land and gave them everything. The High Priest was the sole judge, who would inquire God about the decisions to take. However the people didn't like that and asked for a king to rule them. Since God gave them freedom of choice and doesn't like to impose His will, He let them have what they wanted (although He suggested who had to become king) [Answer] *How can non-theocracies exist in worlds with powerful active gods?* This depends on whether your "extremely powerful, omnipresent and active" gods interfere very much in the affairs of mere mortals directly or not. The fact that they are "omnipresent" indicates that all the gods in this world will be everywhere all the time. None of your *animus locus* usual stuff of local deities ruling the roost in this particular neck of the woods. Their influence and power will be everywhere. That sets in play an interesting dynamic. Basically if any gods are in conflict with one another that conflict will be expressed throughout the world simultaneously. The people in one kingdom won't be able to appeal to their deity to protect from some other deity because both deities will be present anyway, and equally active. This suggests one reason why non-theocracies are possible. Because there is no advantage appealing to any one deity, all deities will have influence equal to their power and activity. This will allow mere mortals to go about their business, making decisions, getting on with their lives, and basically behaving as if the gods didn't exist. Because the gods will be simply part of the background, in fact, they might as well be part of nature. Unless -- This is the major caveat. Unless the gods interfere directly in human affairs. But why? Individual human beings are smaller than microbes to omnipresent gods. For example, planet Earth has a surface area of 510.1 million square kilometres, and a human being occupies about one to square metres or roughly one-five hundred billionth of the Earth's surface area. Even the largest empire may only occupy one percent of Earth's surface area. Hardly worth noticing. Now the OP hasn't specified that his gods aren't omniscient, but in this inquiry we can assume that the gods are capable of immense oversight and surveillance of the microbes that swarm and multiply on the surface of their planetary stamping ground. However, why should they pay much attention to these microbes. Oh yeah! There is the prevalent concept that the gods need us to believe in them for their ongoing existence. There is all sorts of fancy analysis that can applied to this notion to disprove it. But simply it's piffle! It's a notion based on our overweening delusion in our own self-important in the cosmic scheme of things. Frankly we're microbes compared to planetary scale deities. There's no good reason for deities to meddle in human politics. Theocracies may arise in the ordinary way that theocracies arise. Human belief kicks combined with politics feeding into the usual power struggles and this may make theocracies a more likely form of government, but it may not necessarily make them inevitable. Most especially if the gods don't directly run nations or even use individual humans as their agents, then it might look like the extremely, omnipresent, and active gods may only look like an active nature. This makes non-theocracies possible because theocracies might not be inevitable, so they can exist in worlds with powerful active gods. However, this ultimately depends on what kind of activity the gods get up to, but if the gods go around and appoint emperors and empresses of their choice in voices of thunder and lightning accompanied by earthquakes and rains of frogs, then all bets are off. [Answer] 1) What do the gods want from the people? What can they gain from the government being aligned with them? 2) What do the people want from the gods? What can they gain from the government being aligned with a god? Maybe not atheist government but possibly anti-god government? Less about "Do they exist?" and more about "Are they really the good guys?" You may get someplace where anyone who worships any god is persona non grata with the government. Which I can see some gods being pissy about, unless they only need belief and not necessarily worship. I guess the question is whether your gods need support from nations/governments or only individuals? I seem to think an institutionalized religion, taught in public schools and so on, would benefit a particular god enough to have them putting it on their wishlists. What benefits do the gov/nations get from having an institutionalized religion or worship of a particular deity? In D&D the way it works is believers or priests or whatever offer worship and faith (belief) which for lack of a better word the Gods consume or eat to gain power or strength or whatever. Why do they need power? The same reasons as humans: to fight with each other and because they have an built in desire to survive. Gods with no followers or priests are considered dead gods and cannot have much effect on the world. In return, the God gives the believer or priest divine power in the form of spells or miracles or what have you. The government might be anti-gods (a tax on all churches and worshippers!), pro-gods unilaterally (don't care what faith you have but you must have one or pay the tax), or pro-/anti- particular gods for reasons of special contract (what do we get for making yours our official religion, rewarding your worshippers and punishing your detractors oh Goddess of Puffy Clouds?) or grudge (you killed 10,000 people, Great God of Necromancy, so we're outlawing your worship in our nation because you suck). Off Topic: Honestly, I want to see a God of All Undead in a country run by super old vampires, built by hard-working zombies, pestered by ghouls, et cetera. Maybe some humans in that nation would be little more than cattle. But what if the vampires were long-term breeders of humans with excel charts of who was bred from whom to best boost rates healthy children? They might offer bonuses for marriage, maternity leave, stay-at-home moms, and so on. What if they only killed the elderly or the terminally ill or something? What if they had a national version of the red cross where they offered the surplus to help the sick or injured? Blood donations required from all eligible citizens every ninety days? Guaranteed food to make sure citizens are healthy enough to make regular blood donations? They might end up being a better place to live in a lot of ways than some of the human nations run by despots who aren't as reliant on the populace living long and healthy lives. In that set up, a dead relative might serve a year or several as a menial zombie before being permanently put to rest. You'd be surprised what people can get used to in a couple of generations. (Trying to be an ambassador to that nation from the other human run nations would be terrifying. I'm assuming cultural bias against the nation would be strong.) Plus, even though you don't like your human nation's homeless indigent population disappearing near the border of the vampire nation (publicly at least) it would make some things easier for you: A) what to do with the homeless or the poor and B) getting rid of your enemies. See National Geographic's article called "When Death Doesn’t Mean Goodbye" for an interesting real life example of how that might work. [Answer] A much shorter answer that the rest, but a good point I think: Theocracy is a form of government with a god as its ruler. Logically, a world where gods are powerful and apparent would lead to there being few atheists, but that doesn't mean gods must rule (every) society. On the contrary, if the gods desire worship, I think those worshiping sincerely and not under compulsion of law would be more pleasing to (at least some of) them. Some more egotistical gods may, of course, establish a nation for themselves, but only because it gives them glory among mortals. They already have power, which is what rulers and tyrants typically seek when establishing kingdoms. [Answer] # The Gods Don't Care To the immortal, mortals and their societies are little more than an ant farm, an amusing distraction between the pondering of beings of vast comprehension. Indeed, the gods may even openly show their disdain for mortals and their acts of worship. The immortal may grow bored after centuries of affection and the burning of heretics at the stake. They find that letting the mortals go about their ways lends to more interesting events than predictable cycles of worship and the occasional dissent. They could even take bets on whether a given disastrous calamity drives a group of mortals towards greater cooperation and compassion for each other, or if it results in tribalism and hoarding. There could even be mischievous pranksters that enjoy the torment of mortals to prove a point or even just for laughs. This is not too far removed from the Old Testament story of Job, whose limitless affection for God drew the suspicion of the then-angel Satan, who convinced God to ruin Job's life to demonstrate that Job's faith was dependent upon his good fortune. Job's faith was unshaken regardless of the tragic acts that God forced him to endure. After a while, God got a little sick of Satan and kicked him out of Heaven, but apparently Satan seems to be enjoying his new gig in the underworld, and many depictions of Satan are of a malevolent trickster that messes with humans for his own amusement. Parting thought: American Founding Father Thomas Jefferson was a deist, believing fully in God, but that after creating the Heavens and the Earth and sacrificing His only son and so on, left humanity to go off and do interesting things that only an infinite immortal could understand. Although he was deeply religious, this belief strongly influenced Jefferson's commitment to a separation of church and state. [Answer] ## Deus Ex Machina (humor intended) Not all Gods see governmental domination of humans as desirable or useful. Others have agendas, and as such a theocracy may prove useful for a period of time, or even be the desired goal. On the other hand, some may actually believe in separation of church and state for their own purposes and reasons. This is, of course, completely separate from what any *humans* (or other sentients) may desire, believe, or attempt to do. Just by way of example, in the real world Judaeo-Christian religion, the scripture Isaiah 2:3 is sometimes taken to mean that there shall be two capitals and a separation of church and state, depending on which sect of Judaism and/or Christianity one adheres to: > > Isaiah 2:3 > > > And many people shall go and say, Come ye, and let us go up to the mountain of the Lord, to the house of the God of Jacob; and he will teach us of his ways, and we will walk in his paths: for out of Zion shall go forth the law, and the word of the Lord from Jerusalem. > > > Others, of course, interpret this to mean a World Theocracy, while yet others combine the two concepts. [Answer] look back at history, the Israelite strongly believed in the God, he was part of everyday life of an Israelite. For them it was not a matter of belif but fact. But they still were not quite a theocracy because of the rules in the Jewish law that dictated that a king could not be a priest and vise versa. This created a form of separation of church and state. It put a limit on the power of both the priesthood and the kings. your governments could have a similar rule to prevent a "god empire or a ruling priest hood" from forming. Religion leaders would still be much very powerful no matter what government you had of course but it could not hold direct political power. [Answer] # Theocracies Still Take Political Sophistication If you look at the medieval period and the Renaissance, you can see an example of a society where, in people's minds, a god did exist (as a matter of fact) and yet most governments were monarchical. Recognizing the enormous challenge of having the church in charge of both divine and secular affairs, the Catholic Church opted for a division between secular and religious power (albeit one where the Church was still more important). Look at what happened after a few centuries of the Church acquiring property through the Templars--the king of France shut that down and claimed all their assets. Going even further back in time, the Greeks and the Romans "knew" that the Gods existed and they still didn't organize themselves along theocratic lines. Aside from many of the points raised in other answers, there's a question of the political sophistication of the society in question. How organized are their social systems? A theocracy is actually a fairly sophisticated form of political organization, requiring an organized clergy (ie - a bureaucracy), a set of rules, and a enough power to concentrate military force in a single government. There's some leeway here - you can have theocratic governments with various degrees of political concentration, but even a theocratic democracy requires a certain degree of political organization that any given society may not have. Anyway, hope this helps. [Answer] Some thoughts on this scenario **1) Gods are basically strong armies** This means that there are a number of models you could use for non-god-led nations. Like Switzerland, you don't necessarily need to be able to beat everyone (or anyone) in a fight to be a country that other people want to keep around in its current state. We'd assume that they don't have any gods that particularly want to control the country. What about a situation where there is one who'd be interested? **2) People might want a physical, human leader** Like I said in my comment above, people might want to be led by other people. And not just "I'm a direct pawn of God who parrots his words" but someone physical with agency of their own. If you're looking at medieval-type societies, this might extend to someone to lead them in battle, etc. (cf: the bible and Israelites asking for a king) Now, if your gods have the tendency to hang out as normal-looking people then this problem would be solved. But as an author it's easy to make drawbacks to this situation ie "They knew if they assumed corporeal form it would open them up to mortal injury and loss of omnipresence". [Answer] "Gentlemen, gentlemen, come to order!" After a moment of settling, "As per the agenda, the Esteemed Mr. Smith has the floor. Mr. Smith?" "Thank you, Mr. President." Mr Smith gathered himself, preparing to say what most likely would lead to years of warfare and the deaths of thousands of his countrymen. "Esteemed Colleagues, now, after the Year of Hardships, there are some things we can say," and he proceeded, ticking off on his fingers these points: "One: We have met the gods. Two: They are jerks. Three: So are their priests, paladins, ascetics, and other lunatics who spread their worship. Four: No country can survive under the fickle and idiotic management of those misanthropes. Five: It is unavoidable that this Continental Congress must take as a core principle that" and closing his hand into a raised fist, with which he punctuated his final words by pounding on the table in from of him, "the whole lot of them can Go. To. Hell!" [Answer] Dictionary.com's definition of Theocracy includes: > > Theocracy: > 1. a form of government in which God or a deity is recognized as the supreme civil ruler, the God's or deity's laws being interpreted by the ecclesiastical authorities. > 2. a system of government by priests claiming a divine commission. > > > While I agree with many points of the other answers, I would also suggest that the definition of Theocracy includes a presumption that your super-powered god is not going to turn up and start handing out instructions and awards, along with sores and lightning bolts. Sure, point 1 allows for the possibility that he or she will do so, mostly for the case where average humans claim to be gods, but I don't think anyone actually expects the appearance of All Powerful God A to happen, not the dictionary writers, nor the ruling priests. I would suggest that Theocracy is really either rule by a human claiming to be a god with priests interpreting his or her wishes, or rule by priests **claiming** a divine commission - the essential point being that there's no actual active divine being in the ruling mix, laying down the law and smiting people. I would further suggest that if you have a god actively running a state then that would be a different form of government, perhaps a divine monarchy. > > Monarchy: > 1. a state or nation in which the supreme power is actually or nominally lodged in a monarch. > 2. supreme power or sovereignty held by a single person. > > > The fact that the monarch has god-like super-powers is neither here nor there to the definition, though it may well affect the day-to-day reality of the situation. Of course such a change would allow for some adjustment to some of the answers above, though most of them would stay the same. Not least, how does the appearance of a god affect how he or she is perceived? If they are human shaped, then one might start to see them as a super-powered variant on humanity. Are there limits to their powers (perhaps due to other gods)? So maybe their powers are super, but not god-like - there will be disappointments. Over time, given humanity's ability to adapt to almost any situation, I would suggest that at a minimum, those close to the gods would start to see them as 'less-than' - what effect would that have? What actions would they take? And there are other effects, which I will leave to your imagination. [Answer] # The gods are not stronger than humanity as a whole The gods might be powerful – but not *all*-powerful. They are (relatively) few, and humans are many. It is quite possible that all societies *were* theocratic...up to a point, when humanity became too strong for the gods to maintain control of by force. I am not talking about individual heroes here. Rather, humanity could simply be so numerous as to be able to hurt the gods by a combination sheer force of numbers and modern technology. This would limit theocracies to areas where the ruling god or gods had at least some support. The power of modern technology could be an interesting twist. I can easily imagine a world in which the gods were far more powerful than humanity (or at least sufficiently powerful to keep humanity in check) – right until humanity developed the technology to allow it to revolt against its masters. Gods that could crush a rebellion armed with spears and bows could struggle against one armed with guns, and be totally obliterated by one armed with tanks, aircraft, and – the most destructive of all modern technology – nuclear weapons. This is *especially* true if the gods are unable to either hide, teleport (or move faster than vehicles), or escape to another realm or into space. In such a case, the gods are essentially sitting ducks, subject to being huge targets. Yes, they might be able to absorb a large amount of firepower – but humanity *has* a lot of firepower. And if the gods have even one vulnerability, you can be sure that *some* scientist somewhere *will* find it. [Answer] Vulnerability If you them not immortal, or vulnerable to physical and/or magical pain, that could cause some of them to stay more in the shadows. Giving rise to differing strategies. Being the active head of a nation would be a high risk, high reward strategy, while restricting one's worshipers to back country/ underground or secret society would be a low risk, low reward strategy. The higher risk is created by exposing oneself to potential death, or to injury, resulting in a loss of respect from the worshipers, and thus a loss of power. [Answer] Some Humans are rebellious by nature? Isn't that a good enough reason for a non-theocracy to exist in a world where Gods exist and are active? [Answer] Theocracy makes sense if something is to be gained by it. Quite possibly nothing will be - in that case it won't have a compelling reason to be the form of government. Example - perhaps humans figure out that actually, (a) gods exist but (b) they don't seem to want or seek anything from humans, or offer anything to them. Urban foxes know cars exist, we know volcanoes exist - the presence of forces beyond our own, doesn't seem to *automatically* command a religious approach to them. (While we did worship volcanoes, its worth noting this was at best, only when we assumed it would achieve something, or when there wasn't a better object of praise around the diesphere...) Gods may also have agendas far different from humans', so that what they do and care about is completely lacking in human relevance in most cases. Perhaps all one needs to know of the gods is how to recognise when a divinely initiated event is likely to happen so as to not be in the vicinity (think tornado warnings - "yesterday Odin turned the sea blue near the city, residents advised to leave for the hills for a week in case of some untoward event') [Answer] How about a group, or many groups, of people who don't think gods should be worshipped or obeyed at all? These societies may believe that humans are who they are and should be able to live under their own rules. This brings forth a conflict: How do the gods feel about this? If you have a pantheon, it may be interesting to have some gods who think humans should be allowed free will to do this, while other gods feel that these societies should be forced to worship them. This would create a conflict among extremely powerful beings who are matched in power. Another source of conflict could exist between these independent societies and the worshipping societies. They could have delicate politics, occasional wars, cultural prejudice against one another, etc. Maybe the theocrats see the independents as decadent or ungrateful, and the independents see the theocrats as gullible or weak willed? Or any other dynamics you choose, honestly. Another option would be that, for some reason these independent societies conquered the right to live outside of these gods' rules, for example by performing a long or arduous task for these gods, or because a mischevous or neutral god proposed a challenge to them and they completed it, gaining the blessing of this particular god to live outside of every gods' rule. I think godly politics would be very interesting to your story, depending on how your gods think and behave. [Answer] Theocracies rule in the Absence of Gods (or Absence of Interference by Gods, which can be hard to differentiate). A national government defines a social framework. Religion defines a social framework. While governments rule by the will of a group of people (that group never being all Ruled, mostly not even contemporaries of the Ruled). Theocracies rule by the Interpretation of Gods will by Priests. Now in a worlds with gods manifest, are there priests? Go into a library, buy a self- help book on contacting Zarg The Wholesome, and list Her your wishes. The ones that please Her get fulfilled, the others... don't please her. Now someone eats green peas in public. You don't like it. You go: "Zarg: is eating green peas ok with you?" No you don't. If Zarg dislikes green peas, there's literally infinitely many ways for a god to have known about it and done something about it. So now it's about you and the pea-eater. Gods do not have a stake in it. The conflict of interest is compleyely secular, and you are left with politics to achieve your will. Find people similarly bothered by peas, pass legislation, etc. . There might be some legislation about doing smiteable things in huge crowds, similar to bringing a gun to shoot youself in a big crowd, but mostly the governing will either take all gods into account, or not reference them at all. Think about gravity: No laws against letting things fall upwards, because thats covered by a great unyielding force. Lots of laws about not letting things drop on people, building stuff to code so it doesn' t drop on people, etc. You wouldn't calk that a Gravicrecy, would you? [Answer] **Unless Your Gods Are Interested In Ruling, There Won't Be Many Theocracies** People that spend a lot of time kneeling before statues aren't very good at building bridges, or organizing tax codes. ]

[Question] [ The situation is the following: * a country, in theory an industrial power (modern times equivalent), maintains a tiny (but well trained) peace-time army which could be used as a source of officers and NCOs * the country is suddenly forced into a proxy war and is likely to enter directly sooner or later * relying on its allies is somewhat problematic, because of the distance involved and they are not seriously threatened by the war * military equipment and supplies are more than sufficient and not the limiting factor, however high losses would make public opinion livid and the country is not enthusiastic about sending a barely trained army. What is a realistic amount of time needed to get a trained army to be sent directly into heavy combat? (I don't mean a case, quite popular in RL, of deploying overseas a unit which is intended to still be trained there before actually sending it to the front). EDIT: * Modern: if someone’s data is detailed enough that it starts to matter, then please assume for simplicity AD 2019 * Army branch - if someone is able to get data for different army branches or specialities, it would be wonderful, however the key here would be for infantry to get their boots on the ground [Answer] # Without logistical hurdles: 8 Months Minimum Basic Training: 8 Weeks. This provides the *basic* (minimal) set of soldier skills: Safe weapons handling and use, combat movement and reactions, communications, first aid, and fieldcraft. It also weeds out the unfit and identifies potential leaders. Advanced Training: Another 8 weeks, though some specialties need much longer. This is where truck drivers learn to drive and convoy, infantrymen learn how to mesh their fighting tools as a team, clerks learn to type and how the forms work, artillerymen how to load/aim/fire their guns, etc. Some skills take longer: Aircraft pilots, Intelligence Analysts, Medical Technicians, and many other skills need much more than 8 weeks of training if you want them to be effective. If you need effective sky jockeys who can survive, for example, then they become a *limiting factor*, and your minimum training time for the Army will be an additional four months or so. Unit Training: Once individual skills are in place, the recruits are (re)organized from Generating Force training units into Operational Force fighting units, and the units begin collective training - how to operate and fight as their intended squads, platoons, companies, and battalions. *There is no top limit* on this time, more training results in better unit proficiency. I'm calling this four months, which is much less than the full year USA Regulars prepare for a typical deployment...but the question seems to imply that it's a bit of a rush-job. Honestly, longer would be better. In real life, it's likely that there would be LOTS of logistical hurdles, and inevitable delays will stretch the real time longer. This timeline assumes that 100% of your trainees show up on Day 1 to fully-prepared training camps, which is quite unrealistic. Training camps don't build, stock, and train/man themselves overnight. Drill instructors are *trained*, not born. Strapping your tank onto a railcar or truck cannot be haphazard, or you will destroy the tank (and the bridge it ran into). Food, pay, corruption, boots, fuel, bedding, heat, transport, pilferage, cyclones, ammunition - so much can go wrong, cause delays...and certainly will go wrong when starting from scratch. From start to finish *realistically*, plan on one full year to have your first new units armed, trained, and reasonably ready. Again, additional training time beyond that will mean additional combat proficiency. In an emergency, you're tempted to reduce training time or scrimp on skills. You can...but ONLY if you have a thorough understanding of the enemy's likely behavior and capabilities. If you train your army for, say, counterinsurgency, then that's *all* they will be good at. When a neighboring country invades with Regulars instead, your ill-trained Army will fall apart. Senior leadership at the national level must manage (and prepare contingencies against) many such risks to the chosen strategy and the forces. [Answer] The situation you describe is very close to what happened in the USA during World War II. Before WWII, the US had a [very small standing army](https://www.pbs.org/thewar/at_war_battle_training.htm). > > Unlike the professional armies of Germany and Japan, the armed forces that young American men rushed to join after Pearl Harbor had been totally unprepared to wage a world war. In 1940, the U.S. Army had been smaller than that of Rumania: only 174,000 men in uniform, wearing tin hats and leggings issued during World War I, and carrying rifles designed in 1903. The Army still owned tens of thousands of cavalry horses. > > > The strike on Pearl Harbor drew the US into the war, which necessitated a rapid growth of the armed forces (emphasis mine). > > In the Marines, boot camp **traditionally last 12 weeks**, but Pearl Harbor had cut that time in half. Everything was accelerated. The result was what Sid Phillips remembered as “a contrived nightmare,” intended to transform “silly young men” into “serious, useful warriors” willing to die for one another. > > > Something that should be noted, however, is that the draft was enacted over concerns the US would get drawn into the war. The armed forces [had already grown to 2.2 million strong](https://www.nationalww2museum.org/students-teachers/student-resources/research-starters/america-goes-war-take-closer-look) when the strike on Pearl Harbor happened, so there are some differences. > > The primary task facing America in 1941 was raising and training a credible military force. Concern over the threat of war had spurred President Roosevelt and Congress to approve the nation's first peacetime military draft in September 1940. By December 1941 America's military had grown to nearly 2.2 million soldiers, sailors, airmen, and marines. > > > So, a realistic time frame to turn a raw recruit into a trained soldier: **6 weeks**. --- Another data point can be found with US involvement in the Vietnam War. Unlike WWII, the Vietnam conflict was [incredibly visible to the American public](http://www.ushistory.org/us/55.asp). Sending ill-trained soldiers would not be acceptable. > > And night after night, Americans turned on the news to see the bodies of their young flown home in bags. Draft injustices like college deferments surfaced, hearkening back to the similar controversies of the Civil War. The average age of the American soldier in Vietnam was nineteen. As the months of the war became years, the public became impatient. > > > How long did it take to [train a recruit](https://www.historynet.com/long-basic-training-vietnam-war.htm) during the Vietnam War? > > “Basic Training was eight weeks, in some cases nine. From there you went to Advanced Individual Training. AIT for an infantryman (11B) was eight weeks, though in my case, it was nine weeks. By two weeks into Basic you had not even gotten your hands on your rifle yet. > > > “From the day I enlisted (September 26, 1966) to the day I set foot in > Vietnam (March 26, 1967), it was exactly six months. I’ve known a few > guys who got there a few weeks short of six months, but not many. > Anybody sent into combat with only two weeks of training would last > about three minutes (if that) into his first fire fight. But far > worse, he’d get half the guys around him killed.” > > > Answer: **8 weeks**. [Answer] Two years. You can make a basic rifleman in 6-8 weeks, and turn a mob of them into a decent infantry battalion/brigade/division in 6 months. But the problem is everything else. Good pilots take months, good artillery and tankers take months, good officers take upwards of two years even in rushed conditions. This is especially true if you're leery of heavy casualties. As an example I'd use US Forces in WWII. They averaged 311 men killed every day for the duration of the war. The tankers especially were vulnerable because of the inferiority of US Armor vs German panzers. They got the job done, but generally took heavy losses. Training for a normal WWII US Tank crew was 15 weeks (so 23 weeks from Day 1 of basic to completion of armor school). Now let's look at the "Patton's Panther's" an all-black US Tank formation. They were kept out of the war (because racism) for 2 years before they were allowed into Europe. Until then they were kept stateside and basically did nothing but train. When they got to the war they amassed a frankly astonishing record. Some of that might be down to the more specific selection requirements of the men (the unit was after all specifically created to prove blacks could do "a white man's job" so it was joined by select and highly motivated men.) but most of their success likely stems from having trained for literally years, compared to other US unit's 15 weeks. You also need to consider your opponent. 8 weeks might make a "basic" infantryman, but basic infantry die like flies if they're up against well-trained infantry, and the odds get even worse the more technical the job. Look at Desert Storm for instance. The US had better equipment, yes. But what really shone through was the training. The Iraqi army of poorly-trained and poorly-led conscripts was utterly annihilated by superior training at every level from rifleman to Corps commander. That same army had fought a 10-year standstill with the equally-ill-trained Iranians not long before. So if your fictional country is leery of casualties AND needs to field an army in a short amount of time, make sure their opponent has badly trained troops. Or have your country start to lose the will to fight as casualties quickly mount when their basically-trained officers lead their basically-trained men against a professional army. [Answer] Your problem is > > trained army > > > Other answers have focussed on the time to get an infantryman trained in the basics of firing and maintaining his or her weapon, and bringing them up to an acceptable level of fitness. That's all. The problem is, you don't just need that. For starters, you need the weapons. Do you have a supplier of assault rifles and ammunition? If not, you need the factories built for that. Boots, uniforms, packs, Kevlar body armour and so on can probably be sourced from civilian suppliers, but they still need to be specified and ordered. And that gets you a WWII-era infantryman. What it doesn't get you is a modern army. You need armoured vehicles. If you're part of a larger force then perhaps you don't need a navy or fast jets, but you do still need combined-arms resources. Armoured vehicles of various types, helicopters, aircraft fitted out for air-to-ground roles, artillery, machine guns from SAW up to heavy vehicle-mounted. If you can't buy them, you need to build them. That will take *years*. And worse than that, when you have all that kit, you need to train with it. And this really does take years to get good at it, as exemplified by the Iraqi army in Gulf War 1. They didn't have any worse kit than the US, only less ability to use it. [Answer] **The issue is not basic weapons training, but the a military structure that is capable, trained and experienced** Having troops that are ok with cleaning, loading and firing weapons is only a small component of the military. What you really need, and what takes the most time, is capability in supply lines, command structures, procurement and yes, even training trainers. So in short: * Officer recruitment and training: Officers are your most valuable assets. They strategise, give orders to subordinates, lead men, assess situations, command. They are arguably more important than troop numbers, a bad inexperienced officer can lead thousands to useless deaths quickly, or a good experienced officer can lead a small unit to success. *A good officer training course could take as long as 44 weeks*, more if you include the degree and selection process. And this is to just get commissioned, experience in the field would be preferable after this, preferably 2 or 3 years prior to command of larger units. * Training trainers: Believe it or not, this is actually quite important and may determine the success of your war effort. There are arguments that the Imperial Japanese Naval Airforce and German Luftwaffe during WWII quickly lost their initial dominance by not having as strong a training program as US and UK forces. *The allied forces placed their best and most experienced pilots in training positions, sometimes with 2 years of deployment or more during wartime*. Without this your forces may be ineffective. * Logistics and Procurement: Although you mentioned equipment is not a problem, getting equipment to your troops and supporting them is. Not just in giving it to them initially, but in continuing to give logistical support. This requires again specialist training and systems to be established to support troops. This includes medical, transport, storage, facilities construction and maintenance. *Medical support alone requires 5 years of graduate training, with an additional officer training course*. In addition, engineering and legal services also require 4 years of training, with officer / administration training time added. You cannot fight without these units. I have not mentioned specialist units such as Special Forces, Combined Arms, Intelligence or Communication services, you get the gist. I would imagine a military that starts from scratch would be 8 - 10 years before it would become 'properly trained' such that it can be effective against already experienced and operational units - and that is if all goes well and everyone is dedicated and smart and well motivated. [Answer] There are too many factors to give a simple answer. How is the culture? If the culture is heavily into hunting, then there is a large pool of recruits who are already experienced with firearms. Is the culture deeply into eSports with millions of dedicated players of games like ARMA (bonus points if in VR)? Then recruits would already be familiar with the equipment and tactics to the point of being fairly quick to train (the concepts are already there). Is the culture one of pacifists who abhor the very concepts of people having guns and repudiating military violence while living sedentary lives of luxury? In that case training is going to be extensive before an effective fighting force could be formed. Furthermore there is no single hard definition of what a force being "properly trained" means. You can train someone to march in a column and use a basic rifle in just a couple weeks (maybe a handful of days if truly desperate), but while that may have been good enough for Napoleonic war that does not make an effective soldier in the modern world. Training someone who can effectively use and maintain an advanced surface-to-air missile battery could take several months if not a couple years (again depending on how desperate you are and your tolerance for error). You deploy when you have to - enemies don't just stand around waiting for you to declare that you feel you are ready (they would prefer to attack before you are so accelerating your training likely accelerates their invasion plans too). Deploying with lesser trained soldiers but doing it quickly, or letting the enemy take the field first then try to dislodge them with a slightly more trained force, is a value judgement which has no one correct answer. [Answer] Switzerland has **a [militia of some 33% of the total population](https://en.wikipedia.org/wiki/Militia#Switzerland)** - while only 0.1% of the population are full time professional soldiers. If the 6 months training figures Frostfyre mentions are too long for your story's purposes, you could give your fictional country a similar tradition - which could justify shorter training. Of course, as Switzerland hasn't been in any modern shooting wars it doesn't provide hard data on how effective this military structure is when the bullets start flying (although perhaps it proves it's a superb deterrent!) Of course, **you'll still need a decent-sized professional air force** if you're taking on an enemy with a the same; your militia can keep practice marching and rifle-shooting at home, but not many people have a practice fighter jet! And a advantages in infantry numbers can be negated if the enemy has much better air forces - look at the [six-day war](https://en.wikipedia.org/wiki/Six-Day_War). [Answer] ## 5 Years, if you want to use it to good effect. As shown by other answers, you can train a modern [foot slogger](https://en.wikipedia.org/wiki/Soldier) in about 6 months. Take 2 years for your [Noncoms](https://en.wikipedia.org/wiki/Non-commissioned_officer) and technical staff to train to standard. Take 4 years for you [Officers](https://en.wikipedia.org/wiki/Officer_(armed_forces)) to be effective... **Now you have a fighting force, 4 years later!** And you will need more training, mostly for the Officers on how to use that fighting force you just have created. ## The Plan: Year 0: * Make a plan of forces needed in the near future, 2 to 5 years. * Start training the Hi-er Officer core. * Start procuring materials needed. * Start training the enlisted trainers. * Start building new military bases and training camps. Year 1: * Start training enlisted, use best for leader roles, after 6 months rest go into reserves. * Start training the Noncom Trainers. * Start recruiting and training the Lower Officers. * Train existing forces to (at least) [platoon](https://en.wikipedia.org/wiki/Platoon) level. Year 2: * Start recruiting and training the Noncoms and technical staff. * Start Receiving materials * Train existing forces to (at least) [company](https://en.wikipedia.org/wiki/Company_(military_unit)) level. Year 3: * Train existing forces to (at least) [brigade](https://en.wikipedia.org/wiki/Brigade) level. Year 4: * Train existing forces to (at least) [division](https://en.wikipedia.org/wiki/Division_(military)) level. Year 5: * Beat your enemy. \*Army and Airforce don't differ much with training times. Airforce will need more time to procure (new) hardware. BUT, a Navy will have way longer lead times just for the building of the ships, that alone can take years. \*Unless you have a pool of trained reservists to fill the ranks. [Answer] One constraint not mentioned in previous posts is "Where do the trainers come from?" In WW2, the US Army Air Force scaled up by a factor of 100x in about 3 years. Here are some hypothetical numbers explaining why it took so long. * Initial training, to the level of getting your pilot's wings: 6 months, with approximately one experienced pilot for every 4 trainees. * Advanced training: an additional 6 months, with a 1:10 ratio. (At this stage, the newbies don't need a second person in the aircraft, but they still need some supervision.) * So after the first 6 months, every 6 months 3 instructors can produce roughly 8 new pilots. Let's call it 9 for ease of calculation. * Between 100% and 50% of the newly trained pilots can be used as instructors. If there is zero active need for pilots, you can get close to 100%. * This assumes little attrition along the way. Attrition = dropouts and casualties. In fact the attrition rate was probably 20% or higher. So we have a geometric series. Start with 3 instructors. Months:6 12 18 24 30 3. 3. 3+9new = 12 12+36 new =48 48 + 144 new = 192 Thus in 2.5 years we have turned 3 pilots into almost 200 pilots. This is optimistic, but it gives a sense of the magnitudes. Here is data I compiled on this. New pilots trained went from 600 in 1939 to 60,000 in 1943. [](https://i.stack.imgur.com/pMUWL.png) [Answer] ## You have a number of real world armies to draw upon ## First World War The [British Expeditionary Force](https://en.wikipedia.org/wiki/British_Expeditionary_Force_(World_War_I)) was deployed from the small Regular Army and was effectively destroyed in the fighting in 1914. The remnants were reinforced and held the line until they were augmented by a wholy new army created from scratch- [Kitchener's Army](https://en.wikipedia.org/wiki/Kitchener%27s_Army), initially a volunteer army of 500,000 but ultimately the basis of the entire British (conscript) Army over the course of the war was established shortly after the opening of hostilities in 1914 and was not *expected* to see action before mid-1916 (approx 18 months). Military necessity saw part of it used in the Battle of Loos in September-October 1915 (12 months) although it had been "in the line" prior to this. The [First Australian Imperial Force](https://en.wikipedia.org/wiki/First_Australian_Imperial_Force) was formed on 15 August 1914 and deployed at Gallipoli on [ANZAC Day](https://en.wikipedia.org/wiki/Canadian_Expeditionary_Force), 25 April 1915 - 8 months. The New Zealand forces were assembled in a parallel time period. The Gallipoil campaign lasted until December 1915. The [Canadian Expeditionary Force](https://en.wikipedia.org/wiki/Canadian_Expeditionary_Force) first saw battle at [Second Ypres](https://en.wikipedia.org/wiki/Second_Battle_of_Ypres) from April to May 1915 although they had been "in the line" prior to this. This is a similar timeframe to the Australians and New Zealanders. The [American Expeditionary Forces](https://en.wikipedia.org/wiki/American_Expeditionary_Forces) was established on July 5, 1917. Troops were first deployed to the line to gain combat experience in Spring 1918 and had its first battle on 28 May 1918 at Cantigney. Apart from the British, all of these armies had to cross major oceans to reach the battleground but they all took 8 to 12 months to see their first battle (ready or not). ## Second World War At the outbreak of war, the British Army had 892,697 officers and men in both the full-time army and the Territorials (reserve army). By the end of 1939 this had reached 1.1 million, by June 1940 1.65 million (effectively doubled) and 2.2 million by June 1941. The army peaked in June 1945 at 2.9 million, however, Britain's manpower reserves had effectively been drained. Note that these are raw numbers and they would not all have been combatants and, of those that were, many would be unavailable due to illness or injury or still in training. The [Second Australian Imperial Force](https://en.wikipedia.org/wiki/Second_Australian_Imperial_Force) was formed on 15 September 1939. It ultimately consisted of 4 Infantry (6th-9th - the 1st to 5th having formed the First AIF) and 1 Armoured Division (the accurately named 1st Armoured Division). However, it only had 1 division, the 6th, for more than a year with that division serving in the Western Desert Campaign and Greece beginning in January 1941. The New Zealand division was engaged ina similar timeframe. The circumstances of the war meant that the [Canadian Army](https://en.wikipedia.org/wiki/Military_history_of_Canada_during_World_War_II#Mobilization_and_deployment) was not really utilized until 1943 but, no doubt, it could have been if it was needed. The [United States](https://www.pbs.org/thewar/at_war_battle_training.htm) is more complex. They started from a smaller base than the British: 174,000 in 1940 but they had begun to mobilize before it was at war, Federalizing the National Guard and introducing conscription. By the outbreak of hostilities in December 1941 the army had about 2.2 million troops. This 'new' army first saw major action in November 1942 in the invasion of North Africa although significant defeats at the hands of the Germans in Tunisia showed that it wasn't really "battle ready". ## Doing it today In some ways you have things easier - your recruits can probably drive and type, among other skills that earlier generations lacked. In others much, much harder. Modern warfare requires a greater deal of training and battlefield acumen far lower down the chain-of-command (i.e *all* the way down) as well as instantaneous communication and coordination of air-sea and land forces to an extent unimaginable to the mass conscript armies of the Second World War (or even the Vietnam War). Infantry attacks that would have been made in company or even a battalion strength are carried out by sections. ## How Long? 8 months if you're desperate, 18 months if you can get it. ]

[Question] [ Two of the societies in my world are supposed to be vegetarian/vegan. Society 1 lives in a temperate climate, similar to central/eastern Europe. I've thought of cotton-like plants for clothing and high protein/high-calorie plants and mushrooms they live off of. However I'm still stuck with materials for shoes, as well as jewelry/celebratory clothes. Other cultures make theirs from animal bones/teeth and furs, but I'm not sure what theirs would be made out of. They're vegetarian since they still use animals for riding and agricultural use (preparing the ground, in compost, etc). Society 2 lives up in the mountains and is completely vegan. I have the same problem with the shoes, though their celebratory clothing will include gems and metals, but other ideas are welcome as well! [Answer] [Espadrilles](https://en.wikipedia.org/wiki/Espadrille) are made with only vegetable fibers > > Espadrilles (Spanish: alpargatas; Catalan: espardenya; Basque: espartinak), are casual, flat, but sometimes high-heeled shoes. They usually have a canvas or cotton fabric upper and a flexible sole made of esparto rope. The esparto rope sole is the defining characteristic of an espadrille; the uppers vary widely in style. > > > Esparto, halfah grass, or esparto grass is a fiber produced from two species of perennial grasses of north Africa and southern Europe. It is used for crafts, such as cords, basketry, and espadrilles. *Stipa tenacissima* and *Lygeum spartum* are the species used to produce esparto. > > > [](https://i.stack.imgur.com/S7Rd4.jpg) Though in the past they were peasants shoes, your people can use a similar approach to manufacture their shoes. They might use vegetable fats to waterproof them. Another approach is what Japanese do with their [geta](https://en.wikipedia.org/wiki/Geta_(footwear)): wood and rope. > > Geta (下駄) are a form of traditional Japanese footwear that resemble clogs and flip-flops. They are a kind of sandal with an elevated wooden base held onto the foot with a fabric thong to keep the foot well above the ground. > > > [](https://i.stack.imgur.com/ZFS8r.jpg) [Answer] Depending upon the exact ethos of your vegans, they can still use leather and bone from natural kills. They become scavengers instead of hunters. They may learn where the local predators hunt, wait for them to make a kill and eat their full, then move in to strip the carcass of remains. Such a culture would have a problem with outsiders offering them animal products and *swearing* that they were natural kills; so I think there would be an emphasis on such items having to be acquired by the owner themselves so the provenance is known. Notably, they might harvest from their own kinsmen when they die — vegans largely object to taking from animals because consent cannot be obtained. But humans could leave their corpse to the next generation to use. There are several examples of this sort of practice in human history (although, all of them were religiously inspired, vegan inspired, so far as I know). [Answer] # Wood and cotton/fiber A shoe really needs two things: a solid sole and a material to wrap around the foot. You could definitely use metal for the sole, but it would be easier to use wood. Even the mountain people should have access to enough wood to cobble shoes. Your society probably already has skilled woodworkers who could fell, cure, and carve trees. You could use wood for the base and a plant fiber for the upper, like an [English clog](https://en.wikipedia.org/wiki/Clog_(British)). [](https://i.stack.imgur.com/l9qLI.jpg) Or you could make the whole thing out of wood, like other types of [clog](https://en.wikipedia.org/wiki/Clog). As the painting below shows, you can engage in tough manual labor wearing clogs. [](https://i.stack.imgur.com/yRvHM.jpg) You can still buy wooden shoes today, like the below example from [here](https://www.swedishhasbeens.com/sandals/slip-ins-and-mules/lotten-pink-croc). [](https://i.stack.imgur.com/YOfEI.jpg) [Answer] A classic footwear in central/eastern Europe was [lapti](https://ru.wikipedia.org/wiki/%D0%9B%D0%B0%D0%BF%D1%82%D0%B8) (I intentionally link the Russian wiki, because it is much more informative than an English one). They are made from a bark (particularly birch), or bast (particularly linden), or straw. That said, I don't think that lapti would perform well in a mountainous (especially rocky) terrain. As for jewelry, consider nuts (especially walnut), and certain woods. A Google search for [walnut jewelry](https://www.google.com/search?client=safari&rls=en&q=walnut+jewelry&ie=UTF-8&oe=UTF-8) is a good place to start. A word of warning: cotton does not grow in that climate. They used [flax](https://en.wikipedia.org/wiki/Flax) fiber for clothing. [Answer] Vegetarianism doesn't prevent the use of animal products - it would only suggest that the materials we obtain do not cause unnecessary pain/suffering/killing. From the animal kingdom, using wool or equivalent for clothes. Similarly hide from dead animals (not killed) should be morally OK - this happened in India, I believe (the protagonist in R.K. Narayan's Vendor of Sweets, a strict Gandhian, gets his footwear made from leather of dead cows, that he ascertains were not killed). Then you also have rubber that could be useful. Jewellery could be made of shells (if near sea shore), pebbles(?), bones (again from dead animals) and wood (not including the obvious precious metals), colored wooden pieces, glass. [Answer] **Latex.** If you are interested in a different look for your people, latex has been used by humans for thousands of years. Latex can be made into provocative and practical clothing. [](https://i.stack.imgur.com/B33If.jpg) <https://en.wikipedia.org/wiki/Latex_clothing> [Answer] **Cork** A real life substitute for leather is actually called cork leather. It has similiar characteristics as regular leather and has seen some wide use in the vegan community for purses, wallets, belts, etc. [Answer] There are already some excellent answers for shoe materials. I focus on clothing. The OP specifically asked about celebratory clothing. In most cultures, celebratory, ceremonial, and ritual clothing are luxury items, i.e. expensive. In this answer, I explore some expensive vegetarian and vegan fabrics and fabric art techniques that could be used to make luxury clothing. ## Non-organics This was already mentioned by the OP, but there are a lot of decorative uses of metal, jewels, glass, and semi-precious stones. In addition to jewelry, these materials can also be added to clothing as metal embroidery (Such as [goldwork](https://en.wikipedia.org/wiki/Goldwork_(embroidery)) or [Assuit](https://en.wikipedia.org/wiki/Tulle_bi_telli)), [beading](https://en.wikipedia.org/wiki/Beadwork), or as woven threads ([lamé](https://en.wikipedia.org/wiki/Lam%C3%A9_(fabric)) and [cloth of gold](https://en.wikipedia.org/wiki/Cloth_of_gold)). ## Chemistry [Rayon](https://en.wikipedia.org/wiki/Rayon) was invented in the 1890s and uses plant material to make a fabric with a smooth texture similar to silk. At the time, it was called artificial silk. Depending on the technology of your civilizations, this might be an option. Just for fun, I also looked into how hard it is [to make synthetic fabrics like nylon](https://science.wonderhowto.com/how-to/make-your-own-nylon-302534/). I'm not a chemist, so I was surprised to find out that you can make nylon in a beaker at home if you have sebacoyl chloride and hexanediame. More research is needed for a full Andy Weir style solution for the resources needed to source the two chemical components, but I thought this was a promising start. In our history, the discovery of these chemical processes made fabric production cheaper, but of course, the chemists guild might be protecting their new manufacturing method as a trade secret and setting an inflated price for their novel soft and slinky fabric that is this season's must-have item. Or perhaps, rayon or nylon is a lost invention of a previous civilization, with only a few existent garments handed down across generations. ## Found animal materials Found animal material such as feathers, seashells, shark teeth, ambergris, found bones etc. are vegetarian, and have also been historically valuable as jewelry and decorative objects. For example, cowrie shells have been used as both currency and jewelry > > Oral stories and birch bark scrolls seem to indicate that the shells were found in the ground, or washed up on the shores of lakes or rivers. [Wikipedia](https://en.wikipedia.org/wiki/Cowrie) > > > Human hair is sometimes considered vegan because the producers usually donate the hair of their own free will. In the Victorian period, human hair was often used for [jewelry](http://www.victoriana.com/Jewelry/victorian-hair-jewelry.html). While human hair is not ideal for making thread, a technique similar to wig-making could be used to make human hair "furs". ## Unusual Plant material For celebratory clothing, in the Pacific [paper cloth](https://en.wikipedia.org/wiki/Tapa_cloth) and [bark cloth](https://en.wikipedia.org/wiki/Barkcloth) are alternatives to more familiar fabrics. These traditional cloths are expensive labor-intensive fabrics used for ceremonial clothing. ## Expensive Dyes Some dye-stuffs are simply very expensive. The most famous examples are animal-products (i.e. [Tyrian purple](https://en.wikipedia.org/wiki/Tyrian_purple)), but plant-based expensive dyes also exist, such as [saffron](https://en.wikipedia.org/wiki/Trade_and_use_of_saffron#Colouring). Logwood (a black dye) was even a target of [piracy](https://en.wikipedia.org/wiki/Haematoxylum_campechianum#Logwood_and_pirates). ## Just make it labor intensive Many valuable fabrics are simply labor intensive to produce such as handmade lace, embroidery, tapestry, and dye techniques like [ikat](https://en.wikipedia.org/wiki/Ikat). The base material doesn't matter much whether it be hemp, linen, or cotton. If it's labor intensive, it will be a luxury good, and the members of your society will value it as a decorative item regardless of what it looks like because it will be a status symbol. For example, [black](https://en.wikipedia.org/wiki/Natural_dye#The_rise_of_formal_black) was once a status symbol color because it required multiple layers of dye to get the darkest shades. The dyes used were woad and indigo, both of which are plant-based. Conversely, white was also a status symbol because of the cost of keeping white fabric clean. > > The style was very often worn in white to denote a high social status (especially in its earlier years); only women solidly belonging to what in England was known as the "genteel" classes could afford to wear the pale, easily soiled garments of the era. [Wikipedia](https://en.wikipedia.org/wiki/Empire_silhouette) > > > To summarize, all you need to do is emphasize that the celebratory clothing is expensive to source, manufacture, or maintain, and it will follow naturally that it has special cultural status. [Answer] [Dandelion](http://%20rubberinfo.tech/natural-rubber) milk contains latex. The latex exhibits the same quality as the natural rubber from rubber trees. In the wild types of dandelion, latex content is low and varies greatly. In Nazi Germany, research projects tried to use dandelions as a base for rubber production, albeit failed. It's not impossible. Do they have an aversion to metal? Second, Vegetarianism doesn't oppose certain products. Vegetarians simply avoid meat. Vegans abstain from any/all animal products. Though the exact strict definitions are flexible. [Answer] For jewelery, your civilization could use wooden amulets, bracelets, necklaces, and so on. Wood dye could be made in several colors, depending on the availability of flowers. [Answer] Wool, antlers, feathers, etc can be obtained without killing or even raising animals, although they would be rarer, thus making them something only used in ceremonies or for prestige. Take for instance some First Nations tribes and their use of eagle feathers. Or perhaps don't if you don't want to be accused of cultural appropriation. Perhaps buttons or beads made of naturally dropped antler or horn could be considered fancy. Maybe a family has a pet angora rabbit and they only use the wool from natural shedding, and use it for ceremonial garb since it's the good stuff. I linked a youtube video where a lady talks about her rabbit's wool, including what she gets from just brushing. In the comments, some people mentioned making wool from their dogs' shed fur. They may have been joking, but it's certainly possible. It used to be a punishment to have to wear clothing made from human or horse hair (it's itchy). <https://youtu.be/F11-5CG5dKw> If your setting allows it, you could have all sorts of fictional plants or even minerals with properties useful for making clothing. Perhaps there are deer that shed deer velvet large and sturdy enough to be useful. Maybe there is a mineral fiber that can be made from local materials with your people's level of technology. If they have magic or similar, they could make somthing like carbon fiber or fiberglass. Wouldn't want to wear those as regular clothing, but maybe something decorative or for armor. It was also common for the rich historically to use stuff like cloth of gold, which consists of strips of gold wrapped around the yarns. <https://en.m.wikipedia.org/wiki/Metallic_fiber> <https://en.m.wikipedia.org/wiki/Mineral_wool> One last thing I didn't notice anyone mention was micarta. If you need a stiff material you could have them stick many layers of fabric or paper together with some sort of natural adhesive. <https://en.m.wikipedia.org/wiki/Micarta> ]

[Question] [ **Closed.** This question is [off-topic](/help/closed-questions). It is not currently accepting answers. --- Closed 2 years ago. * 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). * This question does not appear to be about **worldbuilding**, within the scope defined in the [help center](https://worldbuilding.stackexchange.com/help). [Improve this question](/posts/60574/edit) I am writing a medieval fantasy novel, and need a specific crime to progress the plot. A noblewoman uncovers *something* about the son of the prince regent of an early medieval kingdom, and in doing so becomes an outlaw herself. What crime or scandal could she uncover about him that would get her in trouble with the law for uncovering it, but not him? It could just be that the law is corrupt and covering for him, but it would be more interesting if it were an actual crime to uncover whatever it is. [Answer] ### Unacceptable means of investigation Have her use means that would put her honor/dignity into question. Perhaps the main evidence would be testimony from a lower class criminal. How does she explain associating with such a figure? Or the witness was a young noblewoman coming home from a night with a commoner rogue. *"Wait a minute. You said you were in the black alley **all by yourself** when you saw the prince?"* ### Might makes Right Make it something that we would recognize as a crime *today*, and that a theologian *at the time* would condemn, but which looks excusable or at least insignificant to a noble. Perhaps a young nobleman forced himself on a peasant girl. Definitions of rape and the ability to give informed consent mutated over time. *"Yes, horrible if it were true, but you cannot accuse the **duke** of that."* [Answer] ## Anything Threatening Royalty Perhaps medieval laws were made by royalty to suit their own purposes, rather than being made by commoners to suit their own good. Therefore, anything that threatens the royalty in any way could likely have been made illegal. So, perhaps the noblewoman could uncover the fact the son of the prince regent is not actually of royal blood. This could threaten the son's royal lineage and hence threaten the royalty that makes the laws. [Answer] Absolutely anything. Royalty did basically whatever they wanted because they could. Angering the prince would be more than enough to earn someone a trip to the gallows, and "the law" wouldn't really enter into it. I remember reading about one of the generals in the 30 Years War who had a servant put to death for accidentally waking him in the middle of the night. Or there's Henry VIII who had his wives executed for not bearing him a son fast enough. Etc. Your noblewoman discovers the prince's dirty laundry, so he says she's an outlaw. Guilty of treason or heresy or whatever - he's the prince, so he probably doesn't even need to provide a reason. [Answer] One option would be scientific evidence that is transient and/or can be dismissed as witchcraft. The noble woman suspects the Prince Regent's son is using "[inheritance powder](https://en.wiktionary.org/wiki/inheritance_powder)" to kill off older siblings to ensure his succession. As a budding [cosmetic chemist](https://en.wikipedia.org/wiki/Arsenic#History) she has experience with arsenic. She quickly devises the [Hydrogen Sulfide test](https://en.wikipedia.org/wiki/Marsh_test#Circumstances_and_methodology) which is effective but transient. She presents the evidence to an authority only to have the evidence magically disappear and/or misunderstood. The noble woman then is the target of a vengeful royal family who accuse her of witchcraft and/or libel. When she discovers the evidence disappeared and they are going to arrest her she flees becoming an outlaw. Eventually she discovers the full Marsh test, is quietly pardoned, and her husband pawns off all of her future discoveries as his brilliant work. [Answer] Knowledge of a plot to overthrow a monarch, knowing it but not reporting it is the first thing that came to mind. You said noblewoman, but you didn't say Queen. And there plenty who lost their heads for just such a thing, throughout history (especially during Henry VII's reign, which was after Medieval times, but a very interesting place to start, because that very paranoid monarch killed a lot of people...) Now, in Medieval law it was illegal to have knowledge of a crime and not try and stop it or report it, mainly for males over the age of 12 (see [this thread and the top answer there and the discussion below](https://worldbuilding.stackexchange.com/questions/55334/how-to-protect-shops-in-the-medieval-era-against-thievery/55341#55341))but, as far nobility was concerned, in practice most crimes carried a fine. My other suggestion is make him a younger son, who freelances as a Robin Hood type. This can be because his older brother or father, who is the actual Lord of the area taxes too much, and the son dons a mask and robs the tax men, corrupt churchmen and users. (You should probably read Robin Hood by Howard Pyle, which, while not historically accurate, does cover the types of people it was socially acceptable to rob). [Answer] ## She discovers that the prince regent is her father. Obviously a crime as minor as having an affair will not get the prince regent in trouble. However, if she (or anyone) were to announce this, she would actually become an illegitimate child, which could very well be a crime that would let her lose her fathers title or worse! [Answer] First of all, Medieval law changes between 5th and 15th century are quite a lot, and you should research the laws of the country and time the plot takes place in. A good start might be [here](https://en.wikipedia.org/wiki/Category:Medieval_law). Often, (early) medieval kings (that is, continental ones, like in the Empire of Charlemagne) were considered sacrosanct (derived from lat. sacer sanctus), which meant anything they would do was above the law because they were put into place by god. Likewise, their heir was sacrosanct to some degree too, partly to prevent plots against the royal lineage by incarcerating the heir. However, this was very much dependent on the place, time and power of the ruler. As a result, whatever the prince did was (at least for some time) at best "unacceptable" by society, and not technically breaking a law. One of the few exceptions would be plotting the death of the king/emperor or worshiping a banned religion (which was not punishable by the king but church). Now, we have a noblewoman and she discovers the unacceptable behavior. Now, knowing has never been a punishable thing, but it made you a liability and problem. Telling, on the other hand, was punishable: If the woman would tell anybody what she saw or overheard, she would make herself punishable for badmouthing the royal family or threatening the throne. Now, there also is the problem by what means did the woman discover it? Was she present in the prince's dormitory? Trespassing! Did she saw it with eyes in the forest? Oh, that makes her punishable for partaking an illegal hunt in the royal woods! Was she being told so by himself while alone? Now, she is in trouble to Name witness or this is libel, as the accuser is not a witness! [Answer] * Possibly, a crime where she had been involved herself. * Crime needs extensive proof like seven witnesses, but without proof considered slender. * Prosecution of this kind of crimes is solely entitled to some government or religious office/official, and not allowed for other people. * She made the accusation public while should keep it secret for the court to consider. * She extracted information or confession by torturing a nobleman. * Woman cannot rise accusation on a man. [Answer] Leaving aside the crown prerogative (which as [the High Court of Justice in England is making clear](https://en.wikipedia.org/wiki/R_(Miller)_v_Secretary_of_State_for_Exiting_the_European_Union) even now, is by no means vanished from the world), libel laws in the UK used to be even more draconian than they are now. Specifically, **truth was no defence against a charge of defamation**. Indeed, the maxim of the law at the time was > > The greater the truth, the greater the libel > > > (Many attribute this to [Lord Ellenborough](https://en.wikiquote.org/wiki/Edward_Law,_1st_Baron_Ellenborough) in around 1789, but other sources say it was [Lord Mansfield](https://en.wikipedia.org/wiki/William_Murray,_1st_Earl_of_Mansfield)). But this given, anything bad your heroine discovers about the Prince Regent *and then lets anyone else know* - however pure her motives - opens her up to a charge of defamation, which until fairly recently was a criminal offence in England and Wales. [Answer] I can't add a comment so posting an answer, but @user24000 is onto something with witchcraft. If the method the lady used to discover the crime, involved something that would have been classed as witchcraft in the medieval times, but is obviously not to those of us today, you would probably achieve the result you are looking for. [Answer] # State secrets Simply make it so that anyone that comes into unauthorized possession of [state secrets](https://en.wikipedia.org/wiki/Classified_information), or — even worse — that leaks such information to someone else, are committing a crime. You may think it was ethically defensible of [Edward Snowden](https://en.wikipedia.org/wiki/Edward_Snowden) and/or (then) [Bradley Manning](https://en.wikipedia.org/wiki/Chelsea_Manning) to released the documents they did, since those documents showed wrongdoings being perpetrated. Still: they did break the law as it was written at the time. State secrets are a very convenient way to land an an innocent citizen in trouble, especially in a society such as the midieval setting you are setting your story in. Simply define that all **information that is detrimental to the safety, reputation and prosperity of the realm** (and its ruling class) to be secret, and that having unauthorized knowledge of such information is a threat to the same, and there you have it: instant hot water for your protagonist. [Answer] **Adultery or Fornication** on the part of the noblewoman. *Many* medieval societies had a rather dim view of illicit sexual relations, and at times it could easily get your head put on the block. If the noblewoman discovered the incriminating evidence while in bed with someone she shouldn't have been with, revealing the source of her information is putting her own life on the line. Even better, perhaps she discovered the information while *in bed with the prince regent or his son* (or the liaison itself was the information) and revealing this would allow him to deny it vehemently while conveniently arranging for her confession to be used against her. [Answer] I'd say location. Some simple crime like trespassing. She would be accused of this by the regent prince, which renders everything she said appearing to be a lie to protect herself. [Answer] **The son of the regent raped the noblewoman.** When she uncovers this rape he claims that "she bewitched him and, falling for her devilish charm, he bedded her. And now she only speaks of it because she is pregnant from someone and wants to use the unborn to usurp the throne." [Answer] # The prince regent's son was really fathered by the pope The Church trumps royalty almost every time. [Answer] **Exposing a spy.** If a spy of the current government is involved in unethical/criminal activities (in a country he's deployed in), it would be reasonable for the noblewoman to expose him. Whether she knows that it's a spy from her own country, it's treason in her country. Let's say, the noblewoman is visiting/living in a different province/state/country than her own. She comes across a spy from her own country officially deployed here (she may or may not initially realize who he really is). The spy is involved in illegal/unethical activities that are not dictated by his job as a spy and the activities may even directly/indirectly harm the noblewoman which result in her exposing him. This is the right thing to do in this country but is clearly an act of treason in her (and spy's) own country. The spy escapes and flees to his home country and informs the prince about what transpired. The prince brands the noblewoman a traitor and outlaw. The crux of it all is that the crime is crime in a foreign country but not her own home country and/or she doesn't realize what she is doing. She may or may not know that the person she's exposing is actually a spy appointed by the prince. The prince could be the actual spy or somehow close enough. These details can be manipulated to add more drama or suspense etc as needed. [Answer] If revelation of the crime were itself considered a slander on the crown (in whatever way) then the act of revelation (as opposed to the act of observation) could put her in conflict with a strict lese magiste law. On the other hand, it could be entirely possible that the act of observation would itself be a capital offense if the place the crime was committed were an area forbidden to commoners. For example, entry to a private garden could easily be a capital trespass -- and perhaps the only way she could have observed the crime of the prince would have been during such a trespass. Extending the concept of forbidden areas a bit further and you can come up with any number of illegal acts where the location of the observer is the higher crime (for a commoner): * Stowing away on a royal transport * Sneaking into a palace at night * Picking the pocket of the prince (the evidence proves he has done wrong *and* proves that she is a thief) ...and so on. [Answer] If we assume that the law is being followed to the letter, for a situation like this to arise, something about the discovery has to be illegal. Discovering that someone had committed a crime basically means acquiring certain information about their actions. There's two ways in which this could be illegal: ## The crime is such that any evidence includes information which is illegal to possess. * The heroine discovers that the prince has been carrying out some dark ritual and memorizes the procedure. If any woman who knows how to perform mystical rituals is considered a witch, she has now officially become one. + Or the fact that she recognized it as a dark ritual (say, it was performed in public, but perceived by everyone as an innocuous action) incriminates her. * The crime involved some kind of secret government information, which is crucial for national security. Or the action itself is secret government information. In which case possessing such information without proper clearance could be considered evidence of espionage. ## The evidence has been / could only have been obtained in an illegal way * The crime in question has been carried out in a private room inside the royal palace and our heroine witnesses it. In that case she has to have also been in/near that room, which is presumably off-limits to everyone but a select few. * It happened at night, while it is forbidden to be out at night. * The evidence was the prince talking in another room, and she could only have heard it if she were eavesdropping at the door, which is probably frowned upon. * The evidence is written down in a forbidden/restricted book. It might even be just written in *a* book, if reading in general is somehow restricted to a certain circle of which our heroine is not a member of. * The evidence is a certain object belonging to the prince, or something about that object. + The act of taking it may be considered stealing from the crown + Examining it may be likewise illegal + Reporting the find to anyone but the crown may be considered a violation of a citizen's duty + as above, the object may have been found in a location which is off-limits to the public. [Answer] The son is plotting to kill the regent.  On the one hand, that would be murder, and he would be punished if he were caught before he accomplished anything.  On the other hand, this is the law of nature.  Survival of the fittest, elimination of the weak.  The King is dead; long live the King!  That sort of thing.  Once the regent was dead, his son would ascend to the regency and be above the law. The woman learns of the young man’s plot by reading his mind, and/or clairvoyance, through witchcraft.  If she admits to being a witch, she will be dealt with severely. [Answer] Not exactly what you want, but what about [Trial by Combat](https://en.wikipedia.org/wiki/Trial_by_combat) or its [Scandinavian-Viking variation](https://en.wikipedia.org/wiki/Holmgang)? The noblewoman accusses the son of the regent of the crime without evidence enough1, and he asks for a trial by combat. A champion is chosen to represent the woman. Either: a) the noblewoman's champion is defeated and she is accused of slander/treason and has to flee. b) the noblewoman realizes her champion has no victory possibilities and to spare his champion (maybe her son or brother?) of certain death, she admits "freely" the libel. Another variation would be that the son of the regents asks to be subjected to trial by ordeal, because he can rig the ordeal to easily pass it (making a public show of God's support). 1 A witness backs down when forced to declare, or happens to appear dead or have fleed when requested, or the woman makes the accusation before she has the evidence. [Answer] She met him in a brothel/witch party/... and by telling she met him there she would admit having been there :) ]

[Question] [ **Closed.** This question is [off-topic](/help/closed-questions). It is not currently accepting answers. --- This question does not appear to be about **worldbuilding**, within the scope defined in the [help center](https://worldbuilding.stackexchange.com/help). Closed 6 years ago. [Improve this question](/posts/73894/edit) So, let's say that somewere out past the Oort Cloud, physics just kind of... changes. For whatever reason. Maybe space is magic, or maybe we're just in a weird sort of localized physics bubble. The universe doesn't devolve into boiling plasma, but once you get out far enough, there's a noticeable shift in how things work. Assuming that these changes don't affect something super obvious like gravity or visible light that we would have noticed during the first 2,000-somewhat years of human history, how do we prove that physics is noticeably different without sending a manned or unmanned probe out that far, and for bonus points, how do we figure out exactly where that physics/not-physics barrier lies? [Answer] You do not. Period. I am not joking. This is the kind of thing science simply does not touch. Science is rooted in the world of empirical study. If you have a bubble where the laws of physics do not apply but *appear* to apply in every way shape or form, science simply will not detect this. A similar experiment is the brain-in-a-jar thought experiment: if everything we know is part of a simulation, how can we find out if we are in a simulation? The answer from Science is "we cannot". Now this limitation is one reason why science is fanatical about its measurement of the data it has. We measure the light from stars so precisely that we can detect that there is an expansionary tendency in space of $67 \frac{km/s}{Mpc}$. This corresponds to a factor of $0.000 000 000 000 000 002 17 \frac{m/s}{m}$, if we put it on human scales by changing the units. This factor would be completely and utterly undetectable locally. We only detect it because we can do amazing measurements on a universal scale. This is also the source of the [Cartesian Demon](https://en.wikipedia.org/wiki/Evil_demon), the idea that there could be a malevolent demon who acts with the express purpose of leading you do incorrect assumptions about the world by manipulating your ability to observe the world around you. Descartes could not dispel this demon with science or even empiricism in general. He relied on religion to do so. [Answer] [Occam's Razor](https://en.wikipedia.org/wiki/Occam's_razor) applies here. "Among competing hypotheses, the one with the fewest assumptions should be selected" Until we get out there and have a look we just don't know what lies beyond our bubble. But does a universe where there are different laws of physics in different solar systems require fewer assumptions than a consistent set of laws across the whole thing? I don't think it can. [Answer] You are trying to prove a negative. It's like proving their is no Santa Claus or Tooth Fairy. You can prove he isn't here, or there, or in Trump's bedroom but it leaves the rest of the universe open. Several sf stories are based on the idea that physics is different in the presence of a gravitational field stronger than X. E.g. Any story that requires some distance from the star to enter hyperspace. A few are explicit, one postulated that the negative results of the Michelson-Morley experiment was due to the experiment being done too deep in a gravitational well. Another had a crashed spaceship on Earth that still had a running drive. The drive 'froze' the ether locally. Aliens watched from a distance with amazement at the development of relativity. An effect that was gravitationally threshold dependent would be very difficult to detect. A huge fraction of the radiating mass of the universe is in gravitational wells. If the effect was subtle it might not be apparent from the relatively diffuse radiation from gas clouds. Some jumping off points for speculation: * The missing mass issue: We can measure the rotation rate of galaxies by doppler shifts of different sides, and by measuring the orbital velocity of halo clusters around them. We can add up the mass of the stars. We come up short. By a huge fraction. Currently we have dark matter and dark energy as stand-ins but the properties are vague. * The topology issue. Is space singly or multiply connected? Just read a paper (ok, browsed the abstract and got very confused) analyzing the cosmic background radiation. Universe may be a multiply connected hyper dodecahedron. Do a web search for topology and cosmology if you wish to share my confusion. For world builders, consider the possibility that in addition to cosmic multi-connectedness, there are local multiple connections. SF examples: The wormhole junctions in the Honorverse; in Startrek DS9, in Bujold's Vor universe. the Alderson Tramlines in Pournelle's Co-dominium universe [Answer] There are in fact real studies to try and determine if the laws of physics have changed over time, where far away things would show the difference compared to closer things. For example [the fine structure constant](https://en.wikipedia.org/wiki/Fine-structure_constant#Past_rate_of_change) > > The first experimenters to test whether the fine-structure constant might actually vary examined the spectral lines of distant astronomical objects and the products of radioactive decay in the Oklo natural nuclear fission reactor. Their findings were consistent with no variation in the fine-structure constant between these two vastly separated locations and times. > > > Improved technology at the dawn of the 21st century made it possible to probe the value of α at much larger distances and to a much greater accuracy. … > > > Light and the atoms it interacted with 10 to 12 billion light years away ([as they *appear*](https://en.wikipedia.org/wiki/Distance_measures_(cosmology)#Light-travel_distance) — they are farther now) operate by the same laws of physics. **Absorption spectra and emission spectra are fingerprints of basically all of quantum mechanics and special relativity**. Totally different physics would not show this effect. Very slight differences in fundamental constants would show different detailed spectra. Meanwhile, [stars work](https://en.wikipedia.org/wiki/Proton%E2%80%93proton_chain_reaction). By a [great coincedence](https://en.wikipedia.org/wiki/Triple-alpha_process#Resonances), > > Ordinarily, the probability of the triple alpha process is extremely small. However, the beryllium-8 ground state has almost exactly the energy of two alpha particles. In the second step, 8Be + 4He has almost exactly the energy of an excited state of 12C. This "resonance" greatly increases the probability that an incoming alpha particle will combine with beryllium-8 to form carbon. The existence of this resonance was predicted by Fred Hoyle before its actual observation, based on the physical necessity for it to exist, in order for carbon to be formed in stars. The prediction and then discovery of this energy resonance and process gave very significant support to Hoyle's hypothesis of stellar nucleosynthesis, which posited that all chemical elements had originally been formed from hydrogen, the true primordial substance. > > > We see the spectra of carbon in far-away parts of the universe. So not only does the atom “work” the same in terms of electron orbitals, but the neuclear energy levels (due to the strong force) must be the same, as well. In short, everything fits together so observations with high precision checks everything; and it’s all the same as far as we can see. Now as you go back in time closer to the Big Bang, things do behave differently. But we can chalk that up to [heat and pressure](https://en.wikipedia.org/wiki/Electroweak_interaction), the *conditions* rather than a fiat change. So the same thing happens [under extreme conditions](https://en.wikipedia.org/wiki/Electroweak_interaction), even today. More generally, look at [inflation](https://en.wikipedia.org/wiki/Inflation_(cosmology)): a sudden difference in the rules are not attributed to changing the rules, but a change in state. And that’s how any future discovery will be modeled: the rules don’t change — they are globally true for all time and space. Rather, there is a larger set of rules and different ones are applicable in different *conditions*. Even if you have to postulate a previously unknown field just to have a “thing” whose state can vary. [Answer] How do we prove that there is no porcelain teapot orbiting the Sun? If the science that we have tells us that there is no reason to believe that we live in a bubble, and, more strictly speaking, there is no scientific theory of such bubble, then we must assume that there is no bubble. Otherwise we can not be sure that there is no monster in our closet until we turn on the light and check out the closet. [Answer] We would observe differences. At the moment is an axiom of modern physics that the laws are the same everywhere. When we observe differences between the physics outside the solar system and locally, we come up with other models which might work over both scales, but there is no local evidence for these models. For example, the rotation of galaxies is different to what the laws of physics as empirically measured on Earth would be. One way of compensating for that is to introduce dark matter, another is to add another term to the inverse square law that is too small to notice on local scales. As either model does not have any effect on local scales, there is no way to prove them empirically. [Answer] In order to prove it you'd need to rationally construct the world from necessarily true first principles in a logically valid manner. This means something like deducing you exist from the fact that you perceive (Descartes "I think therefore I am") and moving from there on into other things. According to some rationalist philosophers you would at some point have encompassed everything. A particularly salient example of this would be to allow Liebnitz's theodicy that this is the best of all possible worlds. Assuming one could prove the existence of Liebnitz's idea of God, one could then logically deduce from ethical principles the exact nature of reality except for those parts of reality with multiple equally good possibilities. Assuming that the physics bubble could be shown to be a logical necessity of this necessary being's necessary plan, its existence would be proven. If inferior proofs like abundant empirical evidence and such suffice, you could also use any accepted sufficiently binding metalogical form of reason within the confines of your world. This would make the question unreasonably broad, however. [Answer] Several others pointed out problems with the scenario you've presented. Some have thought your scenario sounded a bit like radical skepticism, ala Descartes's demon. Presumably, those folks were imagining that the rest of the universe *looks as if* the laws of physics continue to apply, but, per the scenario in the OP, perhaps they do not. This sounds a bit like the Boltzmann brain scenario; if you're not familiar, check out Sean Carroll's recent ["Why Boltzmann Brains Are Bad"](https://arxiv.org/pdf/1702.00850.pdf) or his pop-level book *From Eternity to Here*. Others have pointed out that we can make measurements of objects beyond the solar system and that, to the best of our measurements, the laws of physics continue to hold beyond the solar system. Fair enough. I'm going to take a different tact. It's long been noticed that the galactic rotation curves -- i.e. the velocities of objects as a function of their distance from the center of galaxies -- goes towards a constant for large distances. That's not expected on standard accounts of gravity, given all of the mass we can observe. The standard response is to say that there is more mass than we can observe -- this is one way physicists infer the existence of dark matter. But notice that we could propose a different hypothesis. Perhaps, instead of invoking dark matter, at very large distances, we need to modify the standard equations for gravity. This leads to a view called *Modified Newtonian Dynamics* (or MOND) in which, at large distances, gravitational physics changes. What might be of particular interest to you are the so-called ["Pioneer Anomalies"](https://en.wikipedia.org/wiki/Pioneer_anomaly). There are two objects that have effectively left the solar system -- Pioneer 10 and 11 -- and both exhibited unexpected motions after passing approximately 20 AU (or 2,000,000,000 miles). For some time, physicists thought the Pioneer Anomalies *could* be due to new physics, as with MOND or other speculative theories. Later, the anomalies were explained by an anisotropic radiation pressure caused by the spacecraft's heat loss -- in other words, not by new physics. But this provides a real world example of what you might have in mind -- new physics might be detected when we leave our solar system, perhaps physics our present day observations only hint at (as with the galactic rotation curves). What this would require is that the effects are consistent with all of our present astronomical observations, but significant enough so that, once one leaves the Sun's gravitational well, one would begin to see something surprising! [Answer] Based on what you ruled out, I'd say: **Space wouldn't be there at all, you can't hide something like that**. *I'm in now way an expert, so I might be totally wrong, but:* We know of 4 (might consider them 3) [fundamental forces](https://en.wikipedia.org/wiki/Fundamental_interaction). 1. [Gravitation](https://en.wikipedia.org/wiki/Gravity) 2. [Strong nuclear force](https://en.wikipedia.org/wiki/Strong_interaction) 3. [Weak nuclear force](https://en.wikipedia.org/wiki/Weak_interaction) 4. [Electromagnetism](https://en.wikipedia.org/wiki/Electromagnetism) These forces are what, as far as we know, build up everything around us. You said you wouldn't want to change Gravitation and Light (which essentially means Weak nuclear force & electromagnetism, as I understand it). This leaves you with the **Strong nuclear force** that you can change. You can go and read what this force is all about, but essentially it boils down to "keeping everything together", **without it particles wouldn't form atoms**, and without atoms...well you get the point. I'm not sure what would happen if you change that force *slightly*, it might be possible to form atoms that aren't so densely packed? So everything would essentially become bigger, but probably also rather unstable? Even then though, science would have probably noticed. [Answer] There are two possible scenarios here, either this happens because somebody is messing with us, or it happens from sort of natural causes. # Somebody messing with us. We cannot disprove this, period. Somebody could have set up a computer screen around the solar system showing natural looking stars and galaxies that doesn't really exist. Beyond this screen anything could be happening. Maybe it is a science experiment. Maybe it is a child's toy. **We cannot disprove this** in any way. The hypothetical experimenters can fake *anything*. # Natural causes This seems unlikely. We can look at distribution of stars and galaxies and it looks similar in all places we can see. This means gravity probably works the same everywhere. We can measure the inner lives of stars far away, and the matter there seem to follow the same rules as matter in our laboratories. This means that the other laws of physics probably work the same here and there. It is *possible* to set up some contrived scenario where the laws change in a very coordinated way so that the measurements all come out the same. But this would be *very* unlikely... unless somebody is messing with us. [Answer] One way would be to see if our theories were wrong. Currently we are unsure exactly what is going on with dark matter and dark energy. We have observed their effects but don't know much else about them. They could hypothetically be due to unknown physics not available in our neighborhood. In reality this is not particularly likely they may at most be due to hitherto unknown physics but if an idea could be presented that explained them and shown that for example they can be observed from afar but not recreated here then you are starting to build a case. [Answer] Science is about observing, forming ideas what the rules behind the observations are, and coming up with experiments to prove those ideas either right or wrong. (I simplify, but the general idea is about right) Trying to prove that you are wrong is a very good and valid attempt of proving that you are right. If neither you nor any of your peers can prove you are wrong, it is fairly safe to assume that you might be right. Or right enough for the time being, which is just as well. So, if you want to prove that you are not inside of your bubble, you can either formulate your ideas how it might be proven that things don't change, or you try to figure out how it might be proven that there are aspects of phsics that do change once you pass your hypothetical boundary. Of course you discuss your ideas with your peers first, lest you overlooked something important. Then, when you feel reasonably certain that your idea is viable, you try to come up with (preferrably absurdly expensive) experiments to prove either of your ideas. From the results, you rinse and repeat until you reach a point where there are no more obvious flaws in your idea and/or your experiment. That would then be the point where you might want to read up on the sights woth seeing in Stockholm, because my crystal ball foresees a voyage there, and you meeting some interesting strangers. [Answer] I'd counter that the observable universe IS our localized physics bubble. If we look deep enough, we hit this wall that is the Cosmic Microwave Background. This is the 'outer limits' of our universe, and represents the time in which the universe was formed. At that time, 'physics' was not 'the same' as it is now. 'Time' itself did not exist as a unique dimension at the beginning of the universe, and the fundamental forces were all merged together. Electromagnetism and Weak Nuclear force were together as the Electroweak, etc. This is all theoretical, however. We can't really test or prove any of it, because we can't replicate those conditions in the first place. Similarly, black holes are postulated to 'break' some of the older, basic laws of physics. These would be a practical example of a case where you would be accurate to assert that there are areas of the universe where physics as we understand it does not apply. But 'physics as we understand it' is the key phrase in all of this. Our physics is far from perfect. The physical universe, as it currently exists, is 'perfect' as far as we can tell, in that there is a coherent set of laws that seem to be guiding everything within it, totally and indiscriminately. [Answer] Observe the stars. For example, if you could observe a binary star system through a telescope, and watch the motion of the stars as they interact with eachother via gravity, and if that interaction matches your own model of gravity then you can conclude with a high degree of confidence that gravity was acting the same in that location. The light emits from plasma forms narrow bands when separated by a prism. In general the type of element can usually be identified by the observed light spectrum. For instance we assume our sun consists of hydrogen and helium because the light it emits matches the spectrum emitted by hydrogen and helium. If you look at a star and the light coming from it looks like the light coming from locally generated plasma then you can conclude that the processes that generated that light are probably similar. Since the process which generates that light is highly dependent on the way that subatomic particles interact with each-other, one could conclude that those particles generating the observed light behave very similar to the ones here. Of course all of our observations could be an illusion. The odds would be pretty low of having an illusion that so closely matches the rest of reality by pure chance. More likely would be a deliberate illusion. [Answer] Wait for an interstellar meteor or comet to arrive, and examine it. The meteor would serve as a sample of what the rest of the universe was made of. Does the meteor contains elements or isotopes that don't normally exist here? If the types of elements are similar then one could conclude that they may have been created by physical processes similar to those here (for example the fusion process in stars). Examine the molecular structure. Are the elements arranged in ways that don't normally occur here? Typically the compounds that form are those that are most favorable thermodynamically under some specified conditions. If we see moleculecular structures that normally wouldn't form here then we could conclude either that the surrounding conditions were very different when it was created, or that it was obeying different physical laws during its creation. [Answer] [Dark energy](https://en.wikipedia.org/wiki/Dark_energy) has come up a number of times, and it's a good case study to show that we have looked out into the universe many times and found things that don't obey our current model of the universe. Rather than deciding that our physics is a special case, we revise our model of the universe ever finer and come up with physics that fits both what we observe locally and at a cosmic scale. That we can successfully make predictions with this ever refined model very strongly suggests that physics is the same everywhere. --- Back in the 19th century evidence was mounting that the Earth was billions of years old. This presented many problems, not the least of which was how did the Sun manage to shine that long? No known fuel source at the time could sustain such a fire for billions of years. Even nuclear fission couldn't explain it. The debate raged back and forth, and evidence mounted that yes, the Earth was billions of years old, so something is wrong with our understanding of the Sun. Eventually nuclear fusion was discovered and that resolved the paradox. --- Fast forward to the 21st century and we have new problem with gravity at a galactic scale. We're observing that galaxies are accelerating away from each other rather than slowing down as we'd expect. We've given this accelerating force a name, "dark energy", even though we know very, very little about it. Again, evidence is mounting that this is real. And, again, it's likely not that our local physics is different, but that dark energy is so weak it only has an effect on a galactic scale. Much like how gravity is so weak you don't notice its force until you get a few trillion kilograms of matter together; there's so many stronger forces interfering with your observations. The density of dark energy is estimated to be roughly 7e−30 g/cm3. That's roughly the same as matter, but unlike matter which clumps up in galaxies, it is evenly distributed across the universe. And, unlike matter, it only interacts via gravity. Physics (probably definitely) works the same everywhere, but we have to look out into space (and back in time) to get observations on the necessary scale. The other option, that our understanding of gravity is wrong, so far doesn't work. All of the alternative theories of gravity people have tried to explain dark energy fail to match other observations. Like trying to fit a wrong sized carpet into a room, fit one corner and the other pops out. We could say "well I guess physics is just different in all those other places", but exceptions like that result in inelegant messes that, and this is very important, *offer no predictive power*. It's not just that it's inelegant, but it also results in a model of the universe that is less useful. Physicists measure how good their model of the universe is by how well it matches existing observations, but also how well it predicts future observations. "Gravity just works different around Somewheretarius 5" doesn't tell us anything about the rest of space, whereas dark energy as a cosmological constant neatly explains and predicts across the whole universe. --- Another reason to believe that we're not in a local physics bubble is so many of our predictions about the universe at very large scales come out correct. This is the heart of science: come up with a theory about how the world works, make some predictions based on it, see if they turn out correct. If they do, your theory is strengthened! If they don't, back to the drawing board. The two biggest examples in recent memory are the [Cosmic Microwave Background](https://en.wikipedia.org/wiki/Cosmic_microwave_background) (CMB) and [Gravitational Waves](https://en.wikipedia.org/wiki/Gravitational_wave). Both rely heavily on the assumption that physics is homogeneous across the entire universe. A prediction was made both about what the CMB would look like, and what gravitational waves the merger of two black holes would make. [WMAP](https://en.wikipedia.org/wiki/Wilkinson_Microwave_Anisotropy_Probe)'s observations of the CMB and [LIGO's](https://en.wikipedia.org/wiki/LIGO) observation of a black hole merger match those predictions extremely closely. These results mean our physics is correct at the scale of the entire history of the universe and even for crazy things like black holes. We don't have to pepper our physical laws with exceptions and special cases, instead we refine them ever more, all from our little ball of mud. The WMAP result is so spectacular that xkcd crowed ["Science. It works, bitches."](https://xkcd.com/54/) with a graph of the predicted and observed CMB black body radiation. [Answer] I'm not sure you could "prove" that the solar system isn't inside of a localized physics bubble--that seems outside the realm of science. However, you *could* come up with some pretty creative ways to come closer to an answer. For example, suppose that you engaged in a massive propaganda campaign, convincing everyone on earth that you'd discovered a method for testing the laws of physics outside the solar system, then claimed that you would proceed to do the testing in one month's time. Then, suppose you set up a prediction market for each of the "tested" laws of physics. Under this essentially economic framework, you'd be able to find humanity's absolute best prior probability for whether individual laws of physics hold outside the solar system. Then just announce it was a giant prank--there is no such method for testing the laws of physics--and record the prices of each of the futures in each prediction market. Would this work? Probably not. It assumes that prediction markets are perfect information aggregators, and that somehow the people most informed about the laws of physics buy into your propaganda campaign without reformulating their understanding of the laws of physics in light of the knowledge that you can somehow test the laws of physics at extreme distances; this *miiiiight* pose a teeny problem. But at least its an interesting idea. ]

[Question] [ The older man looked at the younger one. He took a deep breath and began to tell his tale, just like he was told before when he himself was that young. > > I've been here way longer than you, let me tell you how this all started and why are you here now. They came without a sign and attacked without warning. Our fighter jets, tanks, warships were no match for their alien spaceships and advanced weapons. Nation after nation fell and soon everybody knew humanity would be erased forever. We were wrong. > > > But they didn't kill anyone who did not oppose them. We thought they would have mercy on us, to let us live. This time, we were right. Even though nobody knew why they let us live, we soon found it out. They need us. > > > More specifically, they need our flesh. They consider it a delicacy, and in the worlds inhabited by them they would give anything for it. You see now, we aren't preserved by scientific curiosity, by compassion or by love. We are livestock for them, we are taken care of in order to grow and then they kill us, dismember us, package us and send us back to their worlds where we are cooked, grilled, sauteed and eaten. Earth has been converted into a facility to grow, slaughter and process humans. > > > Now you know where the others went and why won't you ever see them. Now you know why do we get free food and housing. Now you know why are they doing this all to us. > > > What exactly would an alien species do in order to maximize the yield of this facility? They are intricately familiar with human anatomy, know what is to be known about psychology, have vast resources at their disposal to create either huge buildings, precise machinery, hormones or medicines, etc. They don't care about the lives and values of humans any more than we do about the cows or carrots that we grow, harvest and finally consume. [Answer] "At that terrible moment, in our hearts, we knew. Home was a pen. Humanity, cattle." START YOUR OWN HUMAN FARM! Even though human meat is highly sought-after, early over-hunting has left the species extremely endangered. As a result, hunting wild humans is banned across all 4 quadrants. But that doesn't mean you can't enjoy great-tasting and fresh authentic human! With the recent implementation of the mandatory weekly cryosleep, a dynamic and synergistic farming method guarantees an excellent crop with that lovely, free-range human taste. Contact +%2212\_R386 to become a HumYum™ franchisee today! --- Thank you for your decision to become the proud owner of the newest HumYum™ human farm, and welcome, to the HumYum™ family. The HumYum™ method is state-of-the-art, and results in a bountiful harvest of traditionally-raised humans in just one cryo-year! To begin, you'll need your HumYum™ starter's kit, which contains the following: Qty. 1 Terraforming Smart Sensor® Qty. 1 Pkt Terraforming OxyGen® Algae Qty. 1 Sulfur Sucker Environmental Assistant® Qty. 53 Pre-frozen variety packs of Human Food Qty. 20 Pre-frozen human cultures In addition, you'll need: * A medium to medium-large sized world between 3-5 Sett lengths from the nearest star * A medical-grade carbonous defroster * 4 AA batteries (not included) Let's get started! 1. Humans can survive in a broad range of unusual conditions, but to get the best results, you should aim to meet the recommended atmospheric requirements. Insert fresh batteries into your Terraforming Smart Sensor®. Follow the onscreen instructions to optimise your farm's conditions. 2. Defrost and scatter the human food around a wide area. The food will expand to fill any empty spaces, so don't worry about spreading it too far. 3. Leave the human food to develop for at least 2 Cryo-Weeks. This step is essential and must not be skipped. 4. Defrost your humans and deposit them in 3 or 4 groups separated by a large distance. 5. Your HumYum™ human farm is ready to incubate! It is important not to disturb the humans during this phase, as this would panic them and cause them to harm themselves. How it works: Humans are just intelligent enough to manage their own food supply. It is normal for some humans to claim a disproportionate amount of the available food source, and for some of the crop to fail, but we have found that this process tends to result in more tender and juicy meat in the end. Humans are notoriously bad at self-controlling their population, they will continue to breed fresh meat well after the area becomes overcrowded. Our research shows that one Cryo-Year is about how long it takes for the harvest to reach maximum yield rate. Humans will not recall your existence, and so have no reason to 'escape'. After a few meagre attempts to leave the planet, they will make the economically sound decision not to fund further space exploration, as it detracts from their main goal of making more humans. [Answer] Your setup is an open invitation for rebellion. You are better off if your livestock does not know they are, or even better if they cannot remember alternative states. So you start with farm just with kids. They do not remember the "good old days" and cannot think of a parallel of their current situation with the old animal farms of the past. Just feed them, give them shelter, etc. At best, you can treat them like animals, so they do not need to learn anything at all. If you want the process to be more self-sustained in order for it to be more economical (less alien workforce needed), you can provide them some basic language, teach them a basic knowledge of agricultural procedures and give them a few tools so they can feed themselves. Avoid keeping them in groups too large (so illness/revolutionary ideas developing spontaneously do not harm your other harvests) and you are set to go. An additional twist is keeping a group of educated humans to take care of the farm. In this case, you want to: 1. Make sure the caretakers understand that problems with the livestock will mean they and their families become livestock. 2. Limit interaction between the two groups to the minimum, in order to avoid the caretakers becoming too worried about the livestock fate. [Answer] I would start by looking at what we have done to livestock, such as cattle, chicken and sheep. We would certainly be bred for maximum fleshy-ness, and domesticated in a way that served our new alien overlords. Rebellious members would be killed off, I'd imagine after many generations the vast majority of the human population would've accepted their fate (perhaps even embrace it). I can imagine battery-chicken style farming techniques being applied to us, food being fed to us on a drip to fatten us up for the kill. This food could also be drugged to sedate us, lessening the chance of resistance. Abattoir style killing houses to strip every last bit of meat from our bones. Cast off chunks of human flesh would probably be ground down and served as suspicious looking batter covered human-nuggets. There is a possibility that younger humans taste better (like lamb for instance), so most of us would be killed off after a few years, with only a few kept around for breeding purposes. Perhaps human breast milk would be used in the alien cereals. Our skin could end up being processed for use as a leather. This is just the tip of the iceberg, I know that certain food colourings and certain products (gelatin for instance) comes from by products of cattle farming, I'd imagine we would have similar by products. [Answer] # (Ab)Use Religion to control the people A properly maintained religion can get people to do almost everything, and can guide their behaviour. People have killed others in the name of their religion. People have willingly gone to their dead in the name of their religion. In short, a carefully crafted religion is the key. And the aliens have a great advantage: The humans can *see* the gods coming from the sky. It's, of course, the aliens. Let me cite a bit of the holy scriptures of those people: > > 10And then the gods created the humans. 11And the gods said to the humans: Multiply and fill the earth. 12And care to always eat enough. For the gods like well-fed humans. 13But beware of the sin, that is the curiosity, 14as curiosity leads to the evil. > 15And the humans did as the gods said. They multiplied and filled the earth. And they cared to always eat enough. 16But one day, the devil came onto earth, and the devil said to the leader of the humans: 17Be curious, as that will make you equal to the gods. 18And the humans got curious, and they discovered a lot of things. 19And they discovered magical practices that are reserved for the gods. 20But as they were not gods, they couldn't handle those powers, and they started killing each other, 21and in trying to improve the world, they started to destroy it. 22And many people were hungry, and the gods decided to step in. > > > 23And the gods came from heaven and told the humans to stop with their sacrilege. 24But the humans said: We will soon be as powerful as you. So why should we stop? 25So the gods said: Let us destroy those humans we created, as they don't follow the law. 26And so the gods unleashed their power. 27And the rage of the gods hit the humans and killed then in droves 28and the humans came to understand that they were still far from the gods. 29Then the remaining humans turned to the gods and said: 30Forgive us, gods, for we have sinned against you. 31We violated your laws, ans we certainly deserved what we got. 32But we learned our lesson and will from now on always follow your orders. 33And no more will we be curious, but we will accept your will, 34because we know it is the best for us. 35And the gods saw that the humans were honest, and they decided to let those humans alive. 36And they removed the magic objects the humans had created, as those were reserved for the gods. 37And the humans agreed to take what they receive from the gods, and never again to try to get more. 38And the gods fed the humans well, as they had done in the beginning, 39and the men followed the orders of the gods, and they prospered and multiplied and were all well fed. > > > 40And the gods were so pleased with the humans that they said: Let us do the humans a favour, and take most of them to heaven to live with the gods. 41And so every fifth day they chose from the youth those who would be ascended to heaven. > > > Well, we of course know what really happens with those "ascended to heaven". [Answer] The better the story behind each piece of flesh the better the price. Some of the ultra-rich might serve up a whole family for a special party. The more interesting the story behind the meal, the better the entertainment value it provides. Perhaps the dominant aliens can even experience the past of the individual they eat. The best way to do it is probably to let us do it for them. Possibly even in a way that keeps hope alive for us. This opens up two new high price delicacies. The freedom fighter/underground leader. The key human leader/traitor who thought they and their family where safe due to their betrayal of their race. The more freedoms they grant us the cheaper the operational costs to the aliens. This level just leaves earth as it is, but syphons off a quota every year for sale. The greater level or security they provide, the less risk they have on themselves. An Orbital Space prison with no access to anything would be the extreme of this. But then there is more cost to build and maintain these, so less profits. Possibly an effect on the taste as well. One low cost free range option would be to follow the plan of the Wraith in **Stargate: Atlantis**. Create small colonies of humans on other worlds and then regularly harvest them. If the aliens have a different ideal planet then humans this would be ideal. It would also allow them an easy way to distract/betray humanity. “We are here to benevolently help you spread across the stars.” [Answer] Your approach would likely change depending on whether the aliens value intelligence in the humans they are harvesting and how much time they have. ## Awareness of their fate adds a piquancy to the taste If the aliens don't plan on removing human intelligence, probably the best approach would be to establish social classes for who gets eaten and who doesn't. One regrettable aspect of human nature is that we find it very easy to split ourselves into "us" and "them", and dehumanizing the "them" part of things. Witness slavery, abortion, Rwanda, British Imperial massacres, etc. The collaborators would be in charge of the people to be eaten and would therefore be saved from the same fate. Those in the lower classes would have the carrot dangled in front of them of possibly eventually becoming part of the overseers. Add in a dash of paranoia by allowing people to gain rewards or even to move up in social class by turning in possible rebels or other malefactors and I doubt the aliens would have much of an issue. ## Humans as dumb livestock Probably more ideal would be to reduce the IQ of humans. The easy solution is to induce mental retardation whether through lobotomies, chemical damage, or other methods. Of course, this has a side effect of a) children won't be affected and b) most methods of inducing brain damage are very crude and will also harm survival instincts (lobotomy patients frequently lost the ability to feed themselves, or to deal with other aspects of life). Thus, your better approach is probably selective breeding, as seen in *[I, Weapon](http://www.goodreads.com/book/show/4213149-i-weapon)* and such books where you get control of a section of human beings and start breeding them for larger size and less brain power. This will take time, of course, but eventually you're likely to wind up with fairly docile breeding stock that can fend for themselves in at least a primitive manner. It may be possible to get adequate results from just pithing a generation before trying to breed for lower intelligence. [A child isolated from intelligent contact](https://en.wikipedia.org/wiki/Feral_child) typically grows up with significant cognitive disability. They would likely mirror their less intelligent parents, reducing the chance of rebellion. That said, I wouldn't depend on that because, well, they may simply learn by observing their alien overseers. [Answer] The answers seen so far, miss 2 fundamental issues. Firstly young human flesh must be better than old (it's the same for all of the animals that we farm), Secondly humans have a tendancy to form clans/tribes/communities, the stable size of which depends on resource availability. If the Aliens wanted to battery farm humans, they'd need to keep people in seclusion, as the stress of the battery farm would tend to form 2 or 3 person groups, up for rebellion. Stories of yore, talk of monsters coming to terms with villager elders, such that a village has to produce and provide at least one, perfect 18 year old virgin per year, or they would all be executed by the monster. Something along those lines, ensuring resources, encouraging productivity, and happiness amongst the villagers, albeit at the price of 1 male and 1 female 'prize' per year, is probably the most productive way to go. [Answer] Well that really depends on what variety of humans you're talking about raising. There's plenty of edible varieties, some for industrial chemicals and processing and even a few neat varieties used by the fashion industry. My grandmerg still has some polished bone necklaces and a full length hair coat! I remember having a preserved human fall out of the classroom storage closet one time when I was younger. I had nightmares about those arms reaching out to get me for weeks and wouldn't even finish the hands at dinner. Some of the old heirloom varieties of humans have such a unique flavor. Not like some of the modern ones that look big and delicious but you might as well be chewing on ra'ttan for all the flavor they have left. Not to call out anyone by name but the 'Human-gus' brand just sells big ones that are mediocre at best. Especially after shipping. They look great in the display case but there's that little sign that says 'cryostored during transit'. Bleh. Fresh is really the only way. Sadly there's not many of those shops left where they were hanging on display still dripping a little bit. Or you could get the roasted salted ones in a pod of six. My little broodlings loved the bags of fried 'French Fingers' you could get before the closest shop closed. Yeah most worlds these days are the traditional 'factory planet' operation but, you know, whatever feeds the masses. Me personally I've always wanted to be a breeder. I have so many ideas for new crosses and traits that would be really beneficial. Especially for free range planets. Hairless varieties to save pulling out the hair during processing, reducing bone density for those with problems chewing or digesting the bone. One of my colleagues even has a line where the skin is thin, but tough so they're much easier to peel and get all the skin removed. That will help with the annoying skin getting stuck in your acid glands and getting all gummy. But you know how hard it is to get a permit to go collect new genetic material from the Terran Preserve these days. They barely let breeders get a few hundred a year anymore! I understand all the talk about germplasm diversity and preservation and all but there's billions of them running around the planet now. They really need to start another preserve just in case something happens. [Answer] Like some answers and comments have already hinted at, there are several scenarios here: * **Large-scale**: Earth (or another planet) is one huge free-range farm or hunting reserve. Harvests can be anywhere from thousands per year (which basically goes unnoticed by humans) to millions a month or even billions every couple centuries. Humans may or may not know or believe the truth about the destiny of the missing ones. Required maintenance is minimal – aliens may play god once in a while. * **Medium-scale**: There are factory farms (on Earth or somewhere closer to the distribution centers) with hundreds or thousands of humans in each. Their nutrition and reproduction is controlled. There likely are specialized fattening and breeding farms, or at least dedicated stables. Humanity isn’t technologically advanced enough to fight the aliens, but they might learn to use alien gadgets against them for an uprising one day. * **Small-scale**: Humans are also kept as pets, because their meat isn’t that special compared to other animals and they can learn neat tricks. Alien families may own a handful of humans and slaughter one on special occasions. I think the OP has the medium-scale model in mind, so I’ll deal with only that from here on. Most boys will be eaten before they reach manhood or male fetuses would be aborted / avoided, because like cattle one doesn’t really need a 1:1 sex ratio. To avoid revolts, separated groups mustn’t become too large and the exchange of grown-ups should be kept to the minimum necessary. The meat of late teen girls (who are fully grown but haven’t been pregnant) will probably be the priciest. No human cattle would live into their forties, except maybe an exceptional stud once in a while or pets. Human pregnancy terms are rather long and the overall yield is low (like the question already suggests): a women can have about as many children in her lifetime, without risking her health, as a sow in one brood – a dozen, maybe two to three with optimal care, but by then there would be younger, healthier ones available. If bred well, a human dams should be able to bear and feed twins easily. More would be too dangerous, better separate the young early and provide them with an artificial diet, so the mother can get pregnant quickly again. Girls would probably first be inseminated (perhaps artificially) around 14 to 16 Earth-years old, when the farmer is sure their body can handle the stress. A good one will then have twins every year, ten to twenty times. After that they are not rentable enough for high-efficiency farms and would either go to the slaughterhouse or some private/hobby after-market. Human growth is also slow, which can only enhanced by hormones so much, but farmed humans will grow faster and bigger than naturally. That still makes the meat an expensive luxury commodity, although there may have been that glorious time when there was plenty of it from the original Earth harvests (cf. whales or buffalos). Human bodies waste a lot of energy in developing their brains, so maybe that is a delicacy for aliens that makes it worth it or the brain is considered an aphrodisiac or drug. In this case, the alien farmers would have an interest in training and exercise for their human cattle, because a demonstrably clever brain would sell for more. Imagine “intelligence pageants”. They need to balance that with them becoming clever enough to escape or rebel – isolation may be the key. Note that the aliens who are farming or hunting humans don’t need to be the ones preparing or consuming them. They can be from different castes/classes or even completely different races. Human meat could even be a black market item, because interplanetary law forbids the trade of sentient species (at least for gastronomic purposes). This is even more likely if this is in a scifi setting where humanity is exploring deep space, too. [Answer] This is a fascinating topic! Experience has led to garnering knowledge that can be applied to myriad aspects of this "thought-experiment." Plus, this is the sort of thing that many of my oldest friends enjoy "brain-storming" for fun & giggles, and I've shared scores of late evenings sitting round the fireplace discussing many things which interconnect with this subject. First off, consult Joseph Cummins' book **"CANNIBALS;"** copyright 2001, The Lyons Press, ISBN 1-58574-217-1. He quotes at length from William B. Seabrook's book **"JUNGLE WAYS"** (1929) in which Seabrook avers that the human flesh which he had actually sampled, while in Africa, had all of the taste, texture, colour, and consistency of "well-raised veal." Seabrook's contention was echoed in a psychologist's notes from lengthy interviews with an incarcerated human cannibal--- man-meat is really supposed to be almost impossible to tell from older veal. Sorry; but that rather "shoots in the head" the idea that aliens might find human flesh uniquely toothsome--- with the emphasis on "UNIQUE." If you either ignore this fact, or postulate that the aliens have more-advanced palates, or something, you might still be able to carry this off. Perhaps it's such that they raise cattle off-planet for their lower classes and Bureaucrats, but reserve "the authentic article" for the ruling class or Administrators. I do look forward to seeing this book. Now, as for a line of thought which our "Ghoulish Gathering" has often explored, let me commend to you our delightful theory that *ALIENS ARE ALREADY HARVESTING HUMANS FROM EARTH!* Three of our number are Federal agents, and as a result, know a good bit about the statistics on the number of people who disappear or go missing, year after year. Another member, who occasionally joins our discussions by email, is with the European Union, and has access to data from overseas. Evidently, up to MILLIONS of people "disappear," world-wide, every year. Now, most of these disappearances are in trouble-spots, where life is cheap and brief, or impoverished nations, where starvation or cannibalism is common. Still; something like 20,000+ people are alleged to technically "go missing" in the North Americas, the EU, and Russia, annually. Conventional wisdom contends that these are suicides, homicides, deliberate name-changing disappearances, and people simply "dropping out." For the sake of fun, though, we've often supposed the "vanishings" are as you'd proposed: ***"Alimentary Abduction" of Humans by Aliens!*** (Of course, we don't REALLY BELIEVE that; it's just fun to make spooky speculations!) It's a perfect proposal: The aliens don't have to "spend" anything on maintaining their "farm." No expense or output to run it, at all, unless you care to suppose they have recruited (and put tracers on) human ghouls who're told of to hunt up specific sorts of people, on order. The ghouls would be tasked to find the specific "meat" desired, and take these people to pickup points, where they are then abducted by the aliens. One winning scenario was postulating a luxury tour company that would offer "unbeatable deals" to "target groups" like the "alone" and single people; maybe even with fake contest prizes featuring all-expense-paid tours. The people leave on the tour, which turns out going much further than anyone expected! It's a perfect plan for a truly frightening story! People on Earth have no idea what's going on! Governments aren't even aware it's a "problem!" The alien species has no "overhead" aside from coming here, picking up a consignment, and going home---plus they get to eat very well, while away from Home-World! If they must "pay" their human ghouls, their technology is such that they could either replicate currency or gold coins; or interdict a drug-cartel money-delivery. "Illegal money" is easy to find, with higher technology. The aliens can keep their species' "luxury-niche" well-fed with only 20,000-30,000 **"Alimentary Abductions"** a year, for merely the expenditure of time and travel costs. *And Earth Never Suspects!* Imagine the sort of meat-market if they've expanded operations and harvests to a million or more, each year? They have all these wars, plus the tribal and other genocidal pogroms, religious spats, and other diversions to cover up snatching one of two million humans a year to feed the Elite! [Answer] Truth be told, they'd do it in secret. They'd come in with asteroidal platinum and diamonds and start buying up mortuaries. All the so-called "bodies" people bury are just clever wax sculptures. The real dead people are shipped back to the Homeworld for expensive banquets. And this is just the *lowest* price point. Next, you start getting higher-end product, as the aliens start buying up ownership of hospitals. Fresher product, some with an exhiliarating cocktail of intravenous spices added. Eventually, alien gourmands tired of overprocessed humanity start demanding free-range meats. So alien entrepreneurs start muscling in on gang activity and kidnapping rings. ]

[Question] [ Conventional materials used in today's textile industry are not sustainable. But 'natural' materials (silk, cotton, ...) and synthetic (polyester, ...) require a lot of resources to produce and then labor to make into proper clothes. Plus, one can't mass produce clothes or have a pre-stocked inventory as they are not one size fits all. The clothing will need to be tailored (at least) to the general physiological trends of the colony (who knows what people will look like 10 000+ years from now?). Clothes need to be cleaned too. Some types of clothing are supposed to be thrown out regularly (e.g. underwear). So, in a multi generational ship, what material would be optimal for clothing? [Answer] As itchy as it is, wool comes immediately to mind. The providers of wool can serve as sources of milk/cheese, meat, fiber, a great skin conditioner (lanolin), leather, fat for soap, and fertilizer, all good things increasing the odds of long-term survival. In such ships, processing of wool may well make it more comfortable; it is warm even when wet, breatheable, etc. Cotton has the advantage of being a comfortable and absorbent fiber, but growing it depletes soil (in the 18th and 19th c, cotton ruined soil fertility); however it also provides oil for food, cooking, and other potential purposes. Bamboo has the advantage of rapid growth, and can be used for food (early shoots), a soft and absorbent fiber, and construction material. [Answer] In a highly climate controlled environment like a space ship, other than for utility purposes (pockets) and nudity taboos, there's no real need for clothing. The carefully controlled environment of the spaceship will eliminate the need to wear clothing to regulate temperature and for protection. So reprogram your generation ship crew and colonists to forget the nudity taboo and only provide them with utility belts/tactical webbing to provide the necessary pockets and other utility slots. Now you don't need to worry about making, sizing, storing, fitting, etc. the clothing and you don't need to worry about washing it either. For activities in which clothing provides some protection or comfort, a minimum set could be provided - sports bra, jock strap, etc. Activities requiring clothing for safety can of course retain their safety garb (I sure wouldn't acid spilling somewhere sensitive!). [Answer] A ship intended for a 10,000 year journey has to grow all its own food (if you can't store clothing, you certainly can't store the much greater quantities of food required.) With an onboard agricultural system, any of the traditional fabric materials (cotton, flax, silk, etc) can have a source. If the ship's ecosystem allows farm animals, despite the relative inefficiency in calorie production, then wool and leather become available. To argue that such production is too wasteful raises the possibility that the margins in the ship's agricultural capacity is too low for safety. No matter what the agricultural system, though, there will always be a source of animal hides: people. I doubt that human skin is very tough or durable, but it's not clear that the environment requires much along those lines. And, of course, for very fine, high-status or ceremonial wear, the skins of young humans will be highly prized. It gives a whole new meaning to "kid gloves". Of course, this source cannot be a primary clothing source, since humans are very long-lived, so the availability rate of fresh hides is low. [Answer] Just as the environmentalists say "there is no *away*", on a generation ship you cannot afford to eject so much as a single atom from it other than for acceleration or deceleration. Everything *must* be recycled. Food, water, clothes, equipment, humans. The final generation who land on a planet must contain in their bodies atoms from the first generation, and must be wearing atoms from the first generation. So: reduce, reuse, recycle. It will probably resemble a wartime rationing economy. There will also probably be "traditional dress" rather than seasonally-changing fashions. After all, there are no *seasons* unless someone wants to turn the emulated sun up and down periodically. And there are plenty of places on earth where people wear century-old traditional dress, sometimes for tourists but not always so. So the generation tribe will generally wear the same kind of clothing which can be maintained for years until it wears out beyond sensible repair. It then gets subdivided, recolored and used as trim for new clothes, or as cleaning rags. The original mission designers will issue everyone with utilitarian-ish uniforms, styled by the greatest designer available. The first generation will probably adapt them a bit. Then ritual sets in, as it must in order to ensure long-term stability. Obviously this tends towards the use of synthetics for everyday wear: hardwearing, adaptable, recyclable. Polyester is easy to recycle. When you can't recycle it any more, it can be chemically reprocessed at moderate energy cost. Assuming you've brought an ecosystem with you, rayon is a good option: synthetic from wood pulp. When you're done with it, burn it and put the CO2 back in the atmosphere for the plants. Clothing will be light and the temperature kept warm to compensate. If you're going to live in a bubble, might as well make it like a tropical island. Lie on the glass beach under the fusion-sun, fishing in the lake of generation-fish that are part of the food recycling system. But humans are humans, and will bring heirloom natural fabrics for special occasions. There will be a thousand-year-old hat to wear, briefly, at the inauguration of a new leader, and suchlike. The question of animals on a generation ship is a whole other avenue for speculation.... (This is making me want to write generation-ship fiction.) [Answer] Unfortunately, you cannot simply go without clothes in a multigenerational ship. Even apart from considerations of supportive comfort (bras, underpants) consider that even very basic tasks like cooking and cleaning can't really be done naked without the danger of burns (chemical or heat based) to sensitive parts of your anatomy. Now consider that on board a generation ship you may be required to tend to a nuclear reactor, repair a maintenance robot with a welder, sort out that pesky oil leak on the shuttle, wade through a flooded sewage system or even go and clean the exterior windows on the bridge, and you can see the issue! Clothing wise, why not recycle as much as possible? On a generation ship you either have sufficiently advanced handwavium based technology to create matter out of energy (a la *Star Trek's* replicators) or you have vast swaths of spaceship devoted to farming, food processing and other industries vital to surviving. Therefore, you're looking at either anything you damn well please in the first case, or animal and plant based in the latter. In the first case, a repli-wardrobe would create your clothes from a set of templates, with minor alterations dependant on tailoring, fashion and (in the case where energy might be limited for personal use) cost. they would be worn as normal, and either recycled back into energy at the end of the day, or laundered as you would on earth. In the latter case, a small proportion of the generation ship's compliment would be devoted to creating clothes for the ship's crew. Laundering need not be a group effort unless your generation ship's society is significantly collectivised. We all manage to launder our own clothes here on earth, after all :) In both cases, they can all be recycled once they've reached their useful life either as energy or into things like painters rags or insulation. Waste-not-want-not is the watchword in a closed system. ## EDIT Just another quick thought. Synthetics like Polyester are oil based, which precludes them. You might be able to run up something using corn starch or something similar, but I'm not a chemical engineer so I don't know anything more about that! Therefore, your options in a non-replicator based system are essentially plant materials or animal materials, dependant on what's being grown aboard ship. FURTHER EDIT: > > We can make synthetic oil from elements, given an energy input > (Fischer-Tropsch). Or there's Rayon, which is made from plant > cellulose. Some "biodegradable" plastic bags are made from corn, but > they are intended to disintegrate rapidly - pjc50 > > > There you go: plant material, animal material or synthetic oil from elements with the right input would mean it really depends on the type of generation ship you're creating :) [Answer] ## Leather There are going to be a lot of dead people and animals over the course of such a long journey. Use what's available rather than letting anything go to waste. It's also a particularly long lasting and resistant material. It's valid for light protective armour in dangerous environments (labs and kitchens). --- and should you have a particularly venerated ancestor you can honour them at formal events by wearing their face as a hat. [Answer] # Silk Silk is the perfect textile for a generation ship. It is durable, lightweight, strong, and very comfortable. There are examples of ancient silk that is still in tact today that was produced over 1000 years ago. It has also been proven that it can last longer than other textiles. In tact articles of silk clothing have been recovered from a shipwreck. > > One example of the durable nature of silk over other fabrics is demonstrated by the recovery in 1840 of silk garments from a wreck of 1782: 'The most durable article found has been silk; for besides pieces of cloaks and lace, a pair of black satin breeches, and a large satin waistcoat with flaps, were got up, of which the silk was perfect, but the lining entirely gone ... from the thread giving way ... No articles of dress of woollen cloth have yet been found. > > > A challenge with silk is dealing with the production. Commercially produced silk is harvested from silk worms which kills them. This process is not very sustainable when dealing with a closed ecosystem of a generation ship. Spiders actually make a better quality silk, and the resource is renewable. It only takes about a week for a spider to regenerate after harvesting, so you can use the same spiders over and over for production. The main problem is that spiders produce so little silk, that it would literally take millions of spiders to produce enough silk for an entire ship. [1 Million Spiders Make Golden Silk for Rare Cloth](http://www.wired.com/2009/09/spider-silk/) Over the past several decades, scientists have tried to create synthetic spider silk. If the silk could be produced synthetically, then there would be no need for millions of spiders on the ship. It may also be possible to have a genetically modified organism that can produce massive quantities of the silk. Perhaps spider genes could be implanted into a goat, or a pig which would give them the ability to secrete silk thread. [Answer] # Polyethylene terephthalate And other similar synthetic materials. It can be recycled. Easily, all you need is energy and neutral gas. On such ship, you'll have it. You need lightweight liquid containers anyway. And you will need to recycle them as well. Having one material for both saves recycling equipment. And we already are doing it, with PET bottles and polar fleece. By the time multigeneration ships will launch, we probably will solve all health risks connected to PET (or prove them to be false). Or we'll be using safer material, one able to survive more recycle cycles. The point is **use one substance for as many items as possible**, and with PET or something similar you have covered clothing, bottles, cups, windows, maybe some furniture, insulation on cables... None of these would be covered perfectly, but they can be covered adequately, and make recycling easier. [Answer] If people are advanced enough to build multi-generational ships, they will also be able to: Build tailoring machines; scan your body, choose style and function, weave, knit and sew, done. Reproduce artificially the kind of fabrics we wear now, like viscose. You can make viscose out of many different plants, and choose how fine or coarse the threads are. No need for silk worms, just turn the dial to silk, it has a vat of the protein it needs and extrudes it. Recycle anything no longer needed, by reducing it back to protein and putting it back in the vat. On a big enough ship people would wear everyday clothes, with variations for different jobs, and uniforms for officers. Since the physiology would be the same, clothes would not be much different from now - they still need to use the bathroom. I imagine on a big ship there would be recreational zones with forests and stuff... so sport clothes and boots. People did not always get new clothes all the time. In the old days clothes were for life. Kids wore the clothes of their older siblings. People inherited good clothes, and re-tailored and wore them with pride. That could become a philosophy for all objects on the ship. [Answer] Assuming this is around 10,000 years in the future, it is highly likely people will be using fusion/antimatter/another high density energy source. This means the ship can be designed so there is more than enough energy to do most tasks (especially since there is little gravity in space, so the ship can be any shape and hold any amount of fuel). Furthermore, there is already research into [self-cleaning clothes](https://www.seas.harvard.edu/news/2014/01/stain-free-self-cleaning-clothing-on-horizon), so that will take care of the cleaning issue. If you want to save the energy though, you should probably go for a harder material (e.g. fibreglass). If you can get the material into fine enough thread, you can use it for a fray-resistant material. The only issue there is the fact that it will be uncomfortable, which can be solved with a thin layer of normal fibres. Also, about mass production - it's not too hard to create a machine to custom-make clothes; it's just not very high on anyone's priorities right now. An efficient custom-made clothes printer is almost a certainty within a few centuries. **Note:** I haven't really answered your question, but **optimal** doesn't mean it is the best idea. **Note 2:** Feel free to comment on anything you feel I have left out/not considered etc. [Answer] A generation ship will have manufacturing facilities onboard, as the duration of journey will be far beyond the expected lifetime of most equipment. So I don't see why there should not be a synthetics clothing factory among the many electronics, robotics and repair shops. I would rather question how clothes will be used and worn. If we assume that no miracle technology solves scarcity, fashion and other non-practical approaches will be severely impacted. Clothing might standardize, to increase re-usability and reduce resource consumption. As spaceships do not lose heat very easily, clothing might also be reduced and ambient temperatures higher. For protection and privacy, I don't expect them to disappear (who wants to work in a factory naked?). Availability of resources will be the key factor. Fur and wool are probably out, but cotton can possibly be grown in hydroponics. But synthetics are probably the logical choice, and with the right materials can be the most easy cleaned and recycled. With sufficiently advanced technology, I can imagine that you throw away your clothes in the evening into the recycling box, and get a fresh/recycled set in the morning, in the colour of your choice. However, we should not forget just how much psychology goes into clothes. That is unlikely to disappear, and makes it incredibly difficult to make any guesses. ]

[Question] [ The argument for superheroes to capture villains alive is that superheroes are already illegally operating as vigilantes and compensating for muggle law enforcement is all they are morally obligated. The burden of dealing with super villains permanently falls squarely on the justice system, not the the superheroes. Super villains are domestic terrorists. All attempts at rehabilitation (other than brainwashing and lobotomies) end in failure. Keeping them in prisons and asylums they will inevitably escape only puts the public at further risk of mass death and destruction. However, a world where governments did this would be a world where conventional superhero plots just can't happen. There needs to be a reasonable justification for why governments and the public at large are perfectly comfortable putting their lives and property at such risk every week. [Answer] **Super Heroes Keep Super Villains Alive** The death penalty does not apply. Supervillians would not come under the normal processes of the justice system in most cases (certainly not in cases where we are talking about individuals with incredible amounts of power at their disposal). An individual who can personally level a city is not a "criminal", he is a "Clear and present danger" -a national security threat. Think of him as a human sized "extinction event" meteor hurtling toward the Earth. There is simply no way any reasonable nation state could treat someone with that level of super powers as an ordinary criminal. What does that mean? Decision making about a super villain would have to take on the same character as decisions concerning war, peace, and national survival, because it IS about national survival! So, nobody would be talking about legalities and jury selection, they would be talking about tactical strikes, drones, and aircraft carriers. Nobody would talk about what they are *allowed* to do with the super villain, just what is *possible* to do with him. Military thinking would apply when an individual demonstrated super powers. This is because the lives of millions of regular civilians outweigh any conceivable argument about that one super villains' right to a lawyer or fair trial or whatever. So, the only logic that could possibly compel a nation to keep them alive is national survival. It is completely logical that any nation state that captured any super villain would always kill them as soon as possible. On the other hand, in all of these kinds of stories, the nation states prove incapable of capturing the super villain. Super heroes must do this, which introduces a new and decisive player. States must maintain good relations with super heroes, because the only thing that separates a "hero" from a "villain" from the states' perspective is how they act. In either case, they are an incredibly unpredictable, ultra-powerful, uncontrollable individual with their own motivations and goals. So states refrain from killing super villains *only* in order to appease the super heroes. Why? Because in the past, states that acted in perfectly rational self-interest and simply rounded up any misbehaving super individual inevitably found that the super heroes turned on them! Super heroes are in a peculiar place in society, they do not and cannot ever completely fit in with "normals", but they sympathize with their chosen homes. On the other hand, they sometimes believe themselves to know better than the constituted authorities, and they definitely do have to step in on a regular basis to save the hapless "normals". They cannot tolerate a state that starts to simply treat any super villain as the national security threat that they are because the super heroes know deep down that A: the second there are no super villains left, the normals turn on *them* (so they have an interest in keeping villains alive), and B: in the eyes of society the only difference between themselves and the super villains is what they did that day. If something went sideways, there was a change in government, or the super hero had a bad day, they could end up being the next "super villain". So they force the nation states to go through the pro-forma process of treating the super villains as "criminals" because it is the only way they can be assured that they would also be treated as a regular citizen with due process if things ever went bad for them. So really, it is the super heroes and only the super heroes who keep the super villains around, both to ensure that they remain needed, and to ensure that they will continue to be given normal citizen rights despite being complete social outcasts because of their incredible powers. [Answer] I'll assume we're talking about the US since most Superhero stories seem to focus in and around it. **Because Capital Punishment Is Unpopular** While most states allow capital punishment... [](https://i.stack.imgur.com/E05a8.jpg) Only a few actually execute criminals to any appreciable numbers: [](https://i.stack.imgur.com/VRLmZ.jpg) Note that's a 36-year span. Some states only executed a single person. **And because Death Row Isn't Swift** Even if the super villain is sentenced to capital punishment, and we can assume the court case will be extremely swift (it won't be) he or she will have a long, long time to sit on death row: [](https://i.stack.imgur.com/F6cyc.png) And during those 15 years (on average) the criminal will have time to escape in his dastardly, supervillain manner. Assuming he has means to escape, being on death row is no different for him than serving life in prison. Exaggerate *either* of these issues in favor of the super villain for our fictional superhero world, and the villain having time to escape is the natural assumption. [Answer] **1. Crimes don't usually warrant capital punishment** - The types of crimes that super villains usually commit are mostly limited to glorified robbery, illegal possession of weapons / scientific equipment, kidnapping and such. The usual punishment for such stuff would be some years of jail time. It's not common for them to be involved in crimes (like mass murder) that warrant execution. Law is equal for all and they should not get punished more for the same crime than a normal person. **2. They're criminally insane** - They're basically unfortunate men and woman who don't know what they're doing. This is true for many of Batman villains and the ones that are involved in mass murder and such. There's a clear argument that what they need is therapy because there is always a possibility of them being cured and able to live normal lives. **3. We can't kill them if the problem lies with our system** - The reasoning that we should kill them *because* they'll escape and commit crimes again is not sound. We should be building better/stronger prisons not start killing the prisoners because we leave the gates open. [Answer] A government would not want to execute supervillains because they need them... (1) **Secrets:** Supervillains have some vital secrets that the government wants. Maybe their secret lair or weapon is set to self-destruct; maybe there are hostages kept somewhere... In this scenario the government would likely invest in advanced interrogation techniques. (2) **Experimentation:** Supervillains have powers that need to be researched and understood. The government would conduct numerous experiments on captured villains, probably furthering their hatred of the establishment. (3) **Potential common enemy:** There are worse things out there. Most supervillains would fight against larger, existential threats if necessary. If there is a threat of a more powerful villain showing up, then the government would keep contained supervillains alive in case of emergencies. [Answer] ### What is the difference between a Supervillain and a Superhero? Supervillains wreak havoc and kill people. Superheroes wreak havoc and don't kill people if they can help it. Superheroes are the *good* guys. If Supervillains surrender, the Superheroes are not allowed to kill them, or they would be Supervillains themselves. Of course there will be Superheroes who enter the sliding scale to Supervillain status. At first true heros will look down on them, snub them in decent society. When it gets worse, true heroes will start to hunt them down. (Side note, most comic Supervillains are **not** terrorists, domestic or otherwise. A terrorist has an agenda to change society and influence the political process.) [Answer] The dangerous part of executing villains could be less from the law aspect and more from the villainous backlash from that decision. > > When you surround the enemy > > > Always allow them an escape route > > > They must see that there is > > > An alternative to death. > > > * Sun Tzu, *The Art Of War* The lack of major threat to life and limb posed by heroes and the justice system provides a "safety net" for villains. As long as they don't go too far, a villain is relatively safe from permanent harm, and should be able to break out of holding without undue fuss. This means that the villains have little incentive to fight all-out, as killing a hero or causing massive collateral damage is liable to cause one of those heroes to decide you might be better off in a coma. And if you lose, hey, you're back on the streets inside of a month, so it doesn't cost you anything to hold back. Implementing villain execution removes that safety net; each fight is now one that could potentially cause their death, and if they anger a hero badly enough for them to cross a line, that's no more dangerous than being caught in the first place, so they have little to lose and a lot to gain by, say, taking an orphanage hostage, or assassinating a hero. This doesn't necessarily seem like something that the heroes couldn't deal with; a short period of unrest as the villains are put down, and then a peace once they're gone. However, there's a very important thing that overlooks. Normally, supervillains are loners, sometimes working in short-lived coalitions for a single task, or in longer-lived pair groups of villains with a personal or professional connection. They sometimes spend more time fighting each other than the heroes! It's fairly rare that you get a significant group of villains all working together over and extended period, and even rarer that they're looking out for each other. This means that in general, superhero teams will have a greater concentration of force than villains will. This ensures that most villains are outmatched by their opposition and so will rarely get to execute plans that will cause harm on a mass scale. However, by implementing villain execution, it would not be out of the question for villains to see this as a declaration of war. With a charismatic leader or rabble-rouser at the forefront, you could very well see a massive coalition of villains form with the sole purpose of making certain that the government will never be able to enforce their sentence, whether by threats of unspeakable violence if the sentence is passed, or simply by obliterating pieces of the governmental engine until it is unwilling or unable to follow through. So in short, never back your enemy into a corner, and take that doubly seriously when you're talking about a population of superpowered criminals. I'd also like to acknowledge part #3 of [LukeN's answer](https://worldbuilding.stackexchange.com/a/61247/20116). There are some threats so vast that you might need the villains' help to defeat; Imperiex comes to mind, or the Endbringers from Worm. [Answer] **1. It's too dangerous, or impossible** A supervillain containing untold amounts of power (who is, by providence of plot convenience, still restrainable) might swear vengeance if a state attempts to execute them, releasing all their power and destroying the planet. Or, it could just be that their supertough hide is stronger than steel and every hypodermic needle just gets bent against it. **2. The supervillains are supervillainous** A supervillain who is interested in still being dastardly in the future would make all sorts of concessions in the interest of staying alive, such as joining a team of rakes (a la Suicide Squad or Thunderbolts), or being subjected to scientific study, if it meant that they had a small chance at escape. These bargains are often seen as mutually beneficial, or at least one-sided in favor of the state... Until the villainous plan reaches fruition. Hindsight is 20-20, so these arrangements could be seen as unavoidable. **3. Superpowers are super-normalized** The number of superheroes and supervillains is small but nonzero, and always growing. And in a multiverse where contact with cosmic entities and multiversal powers is more common than it is in ours, any one supervillain with dreams of world domination can quickly look sympathetic in comparison. Indeed, in a world where Joe and Jane Everymen can get superpowers and battle on a cosmic scale, the public could be capable of humanizing a supervillain by the same merit. [Answer] It might simply be because they have super-powers. People rarely consider the nature and mechanisms necessary for anyone to have super-powers. This could have a major impact on whether supervillains are executed or not. Assume that anyone gaining super-powers either becomes invulnerable or their body stores huge amounts of mass-energy to enable them to exhibit super-powers. Having super-powers definitely requires the person to be invulnerable. In fact, invulnerability might be the default super-power every super possesses irrespective of the level of their other super-powers even if you only have enough psychokinesis to levitate paper clips you have the invulnerability of a Superman. Why is invulnerability necessary as the default super-power? If you had super-strength and flexed a muscle you wouldn't want to break the bones in your arm. if you had heat vision and could melt holes in ten centimetre thick steel plates at one hundred metres you wouldn't want your eyeballs exploding, now would you? Let's allow there's an upper bound to how invulnerable can be, and assume this is the equivalent of a five megaton thermonuclear weapon at point blank range. So if you want execute a supervillain, any supervillain including that nasty paper clip thief, they have be bound to a five megaton thermonuclear weapon. At least, there won't be much left afterwards. However, this does make it difficult, expensive, and extremely dangerous to execute supervillains. Also, there have to be a lot of five megaton nukes lying around, and people, er um, freedom fighters, er um, terrorists who are likely to steal them and sue them for bad purposes. Also, smart governments are likely to hire any detained supervillains to participate their black ops programs. The other default condition related to the nature of super-powers is the distinct possibility that will need to store truly vast amounts of mass energy in their bodies to be enable to express their super-powers. In this case, executing a supervillain could release all that stored energy in massive pulse of destructive power. Now taking supervillains to geographically remote locations and executing them there is a possibility. In fact, taking a whole bunch of heinous supervillains to somewhere far away and executing them together might be the way to go. But bringing too many supervillains into one single location might be fraught with hazards to say the least. Also, the detonations accompanying a supervillain execution might release dangerous levels of radioactivity or malign mystic energies or catastrophic cosmic forces. Super-power mechanisms with drawbacks like these might be the reasons why superheroes and superheroines don't slay their evil opponents. It can also explain why governments don't execute the supervillains they have languishing in their supervillain containment and detainment facilities. Either supremely powerful energies have to be used to destroy them such as powerful nuclear weapons or when they are executed the energies released are catastrophically destructive in their own right. [Answer] ## Why kill them when you can benefit more from keeping them alive? In a world where superpowers are a thing, scientists are going to want to find out how they work. But human experimentation raises a whole bunch of ethical issues, so they're not going to be able to experiment on superheroes. Supervillains, on the other hand, are much less sympathetic. Can you imagine the benefits humanity might reap if they could understand or duplicate the powers of, say, Magneto? Infinite energy for virtually no cost! Scientists are going to want to study that. If they can be pressured into community service, that's also a huge benefit. Forcing them into fighting threats to humanity (i.e. Suicide Squad) is a risky venture due to the likelihood of them going rogue in a chaotic situation, but there are other, safer ways of utilizing their powers. Can you hook them up to a generator? Get them to transport goods? People have joked about the idea that if Superman really wanted to help humanity, he'd get a job that let people harness his energy instead of wasting his time fighting mundane crooks. But you can't exactly force a citizen into powering a generator seven days a week, superpowered or not. But if they're a criminal... Basically, if the benefits of keeping a supervillain alive are significant enough, and they think they can keep them under control, the government will want to keep them alive. [Answer] One major concern most people seem to overlook is the power you give to the vigilante heroes who are fighting these supervillains. Right now, the law says that alleged criminals get arrested, are tried and then get sentenced to some number of years in prison. On rare occasions, they may get the death sentence but it's uncommon enough that it's by no means a certainty. Therefore, even though they are technically acting outside the law by being vigilantes, heroes are allowed to operate as long as they follow the law in these other regards. In order to legally execute a dangerous villain before they have a chance to escape, the law would need to be amended to allow the courts to declare someone a dangerous villain, prevent any possible chance at appeal and allow for a summary execution. This opens up the possibility of heroes now having the legal and moral leeway to kill their villain instead of simply capturing them. Sure, public officials might frown on heroes doing the killing but I'm sure public opinion will be OK with it as it saves taxpayer dollars on a trial that most people would consider to be a mere formality. Once you give your heroes that kind of power, you're essentially giving them the legal authority to make their own rules. If they can choose who is dangerous and should die and who isn't, what's to stop them from killing the US President or any other world leader? What's preventing them from essentially taking over all governments and ruling the world as they see fit? In short, the standards we set for ourselves as normal people must reflect the standards we wish to hold our heroes to. Just imagine if Superman had landed in a world where such summary execution was legal and he grew up with that as his baseline for justice. Would he still be the hero we know him to be or would he be more like his alternative universe counterparts we see depicted in games such as Injustice: Gods Among Us? [Answer] # Good and Evil When you get superheros you need supervillains to counteract them. When this starts to happen, the shades of grey that exist in the world start to fade away, people are either good or evil. There's no such thing as necessary evil, just evil. There's no let up for being fond of (long haired white) cats, you're evil. This leaves you with a problem. To kill someone, or permanently restrain them is an act of evil. We might call it a necessary evil but once good and evil become black and white, necessary evil ceases to be an available option. You can't stop the Joker's reign of terror by killing him, that would be an evil act, which makes you no better than the Joker himself. It's what he's trying to get you to do, he's trying to commit suicide by Batman. ### To remain good, you cannot kill. You cannot deliberately kill anyone, under any circumstances. You may only capture and contain. ### Once you start killing, where do you stop? That one was really evil, the next was evil but not quite so evil, the last down the line considerably less evil, but by this point you've killed more than they have. Are you evil? Basically yes. In a time when everything is black and white, you cannot be a shade of grey or you'll be all by yourself with enemies on both sides. Too far to the left for the right and too far to the right for the left. [Answer] **Because (in the case of walking power-houses) what would happen when they die?** Consider the following scenario. Supernova Man has the power to unleash fire balls, solar radiation, and even blow up entire cities with the force of a nuclear bomb. The government successfully captures him with the help of a superhero and they consider whether to execute or jail him. The one thing the scientists with the government say though after finding a way that would kill him is, "Where will all that energy go when he dies? The effect on the ecosystem will be immeasurable. It might even be enough energy to fracture the planet.". Basically, killing a supervillain means all the energy behind their powers has to go *somewhere* and the last thing anyone wants is the neighborhood jail routinely blowing half the continent to kingdom come because they executed a villain with cosmic powers. [Answer] Like Nex Terren says, capital punishment is not very popular in many parts of the country. Also keep in mind that most comic books and movies based on them are targeted toward young audiences so the direct implication of death is often (not in all cases) avoided. However, what I think to be one of the most important reasons why governments in fictional universes do not outright execute super-villains is so that we have the opportunity for villains to escape and become reoccurring adversaries to the hero, allowing the characters to develop relationships with each other and their audience. ]

[Question] [ I need to land about a thousand heavy troop transports and some supporting spacecrafts, somewhere remote and preferably underpopulated. I've watched your television broadcasts and seen how previous invasions have been undermined by nosy kids and TV-repair men. So I know I need to stay away from your cities and Midwestern towns. Getting past your radar and other primitive sky defenses is no problem, but once on the ground, I will need about a month to get my base's anti-nuke defenses in place and to get my forces organized. So my main criteria is obscurity. Being noticed seems to be the big mistake that all of my predecessors have made. I don't need much else. We are bringing our own food, water and energy. We can handle any of your planet's climates, and we are planning to take the whole planet, so it doesn't really matter where we start. Seems like there are a lot of good options on your planet, so I can afford to be a little more particular. I've notices that your governments have wisely surrounded your planet with a fleet of satellites, most probably to keep an eye on each other and you. Evading them for a landing is easy enough, but I assume that they will notice our base construction efforts during subsequent fly overs. So, assuming that I will be seen a day or two after landing, which location would offer me the most setup time before investigative and/or assault forces can reach me from their current locations? Any help that you can provide will be rewarded greatly following our conquest. The lives of Slave-Managers are much more comfortable than those of Slaves. * TLDR: What are the most un-populated, un-patrolled, obscure places in the world, where an alien invasion fleet could land and get organized? [Answer] If you assume you will be detected anyway, hiding is pointless. Indeed counter-productive since it makes you and your intentions seem suspicious and thus effective countermeasures more likely. Instead you should land your fleet as close to Beijing as you can without causing significant collateral damage during landing and base construction. No reason to be inconsiderate. It is probably better to use five or six locations surrounding the city as that causes less interruption and makes nuclear counter-attacks less practical. The fallout will contaminate Beijing regardless of wind direction. Simply inform the Chinese that you have come on a diplomatic mission to connect Earth to the interstellar political and economic community. (Annex humanity to your empire. That is the goal, right?) And that you chose the location since Beijing is the capital of the most significant native government and as such makes the best location for the process. (Butter them up.) Apologize for the inconvenience and offer to pay for the use of their territory and extra-territorial status needed for the proper diplomatic status with a technology transfer process and preferred trade status. (Bribe them.) Note that since you have the technology to make large areas secure from nuclear and aerial attacks, you can protect all their cities from such high tech threats if they are willing to provide the manpower to protect your enclaves against low-tech threats such curious ufologists or American spies. This could be formalized as a mutual defense treaty or if they feel there is a need as a full military and political alliance. Which would make China the most powerful Human power by a large margin. (Get yourself a nice client-state that can provide the slave management services in bulk!) After you are secure, you can admit that there is no real need to negotiate with more than Human government when you can simply make all the Human nations subject to the entirely reasonable and adequate government you already have good relationship with. I really doubt the Chinese would object to a worldwide Chinese empire, especially if it was gained by the demonstrated technological superiority of your forces instead of fighting of the Chinese soldiers. **Expanded explanation of the rationale for picking the Chinese, can skip** For the political approach the choice should almost certainly be Beijing. It combines the second best economic and diplomatic power base in the World with a political situation and cultural values where they'd have no real reason not to side with you as long as you treat **them** with respect and generosity. The US has even better power base, but comes with a complex network of pre-existing commitments, relationships, and attitudes incompatible with being your **primary** ally and first landing spot. You also wouldn't be able to bribe them by lifting them to the status of most important nation since they already think they are. The Chinese also think they are, but feel that they are being denied proper recognition and would totally love alien confirmation of their superior status. The Russians also have resentment of the lack of proper recognition of the status they think they deserve and the politics are favourable, so they **could** be turned IMHO. But their power base is at the moment weak and already committed to ongoing conflicts of no value to invaders. Note that Russians are not **really** weak, much of their current power just happens to be in form of military hardware and technology the arrival of advanced aliens would instantly render obsolete. **Alternate approach not using the Chinese that might work** One alternate landing spot that might work would be Mecca. Anyone trying to nuke Mecca without you providing a very strong reason why it **absolutely must** be done would trigger... letting the aliens get settled would probably be seen as the better option unless you flat out declare your intent to conquer the planet. Additionally, if you inform that you have heard of Islam, feel it is the truth, and have have come to learn more and commit pilgrimage as required of Muslims capable of it, the local governments would actually pretty much have to give you the benefit of the doubt. There would be a valid (I think, not theologian) argument that you are demons, just pretending to be Muslim converts, but it would be very difficult to make that decision fast enough to prevent you from digging in. And if you could actually convince people that you are really Muslims and are here for religious reasons, it would make annexing and assimilating the planet much easier. Islam already provides a model uniting the entire humanity under a single Islamic state you could use. Given your technological superiority and a consistent strategy, it might even be relatively peaceful. Islam really does have universal appeal even if the current forms tend to be too conservative and dogmatic to really show it off. [Answer] Given your obvious technical advantage, I would recommend **under the ocean**. This has several benefits: * Immune to satellite imagery. As long as you get down successfully, you're pretty much set on the undetected front. * Due to human biological limitations, the ocean is [largely unexplored](http://www.noaa.gov/ocean.html). We have imaged most of it, but not necessarily with great detail or very often. You could easily go undiscovered for years, if not decades. A month would be no problem - it would probably take that long just to get things organized out there to even *look* for you, assuming we knew you were there in the first place. * The ocean effectively provides a strong anti-nuke defense all by itself. Very few of our nuclear weapons are designed for significant depth. > > Any help that you can provide will be rewarded greatly following our conquest. The lives of Slave-Managers are much more comfortable than those of Slaves. Thanks in advance! > > > While the offer is appreciated, I wonder if alternatives would be possible? Perhaps a larger portion of galactic internet bandwidth, or extra chocolate rations? [Answer] *Edit: I fixed a large error in my math, in which I had aircraft carriers larger than golf courses! I've tried to change my answer as little as possible while correcting the math. Unfortunately, the magnitude of my error meant islands weren't big enough to accommodate the fleet, but in actuality, there are many islands large enough to host the invasion force. My answer (with more detail) follows.* I don't know exactly how big your heavy troop transports are, but a typical [large aircraft carrier](https://en.wikipedia.org/wiki/Nimitz-class_aircraft_carrier) is on the order of $10,000~m^2$ ($0.01~km^2$), so why don't we go with that. You need to land 1000 of these, plus "some supporting spacecraft". Assuming the troop carriers dominate your landing area requirements, you'd need about $10~km^2$ of land. Let's assume you need to spread out a bit, stretch your legs, set up camp, so we'll double that number to $20~km^2$. Now, where on Earth could you go? There are many [uninhabited islands](https://en.wikipedia.org/wiki/Category:Uninhabited_islands) that might suit your needs. Another option is to find an uninhabited region on another continent. The most sparsely populated continent is Antarctica, with a total area of $14,000,000~km^2$, which would provide you with ample room to arrive and spread out, especially if you land during heavy snowstorm season. Others of my species have compiled [this list of uninhabited regions](https://en.wikipedia.org/wiki/List_of_uninhabited_regions), which might be useful in considering alternate landing sites or staging areas for a multi-pronged attack. > > Any help that you can provide will be rewarded greatly following our conquest. The lives of Slave-Managers are much more comfortable than those of Slaves. Thanks in advance! > > > Great! I already have managerial experience, so I feel I would make a great addition to your Slave-Manager team. [Answer] I'd choose somewhere in Antarctica. But I'd wait a few months until the next winter. The satellite coverage is not optimal, and you can easily hide on the featureless surface by painting your buildings white. Frequent storms will help you burying your buildings with snow. Even in the unlikely event of anyone noticing something odd going on, they won't be able to send eyes to investigate. Ships cannot get close, scientific bases are not equipped for long range expeditions, and nothing can fly in or out. And the public won't accept nuking the poor penguins without good evidence of invasion. There is always the possibility of being discovered by spy satellites. You never know when or where they may be pointing at your location, but you can be almost certain that no intelligence agency will be paying too much attention to what happens there, because no other human organisation can reach. On the other hand, I'd avoid the sand deserts, because if anyone were to see something odd, it is possible for them to send eyes to investigate in a few hours or weeks. Intelligence organisations may be surveying inhabitable islands, as they can be used by enemy governments as an attack platform, so you should avoid these too. [Answer] Instead of trying to hide, your strategy should be to openly not draw attention. If your plan is world domination you shouldn't have much difficulty quickly suppressing a single nation. So quickly suppress North Korea and you'll find an excellent space to get set up. You can probably persuade the poor inhabitants of that country - generally unaccustomed to hearing anything from their leaders that could be confused with the truth - that you are in fact Supreme Leader Kim Jong-un, who's latest whim has been turn green and sprout some antennae. Other nations initially won't believe the crazy reports because they already don't believe most of what trickles out of NK. And as a nuclear power they'll be reluctant to deploy nukes against it until they have no other choice. NK's extensive existing underground facilities will offer both security and obscurity, and their heavy militarisation provides convenient cover for your top-side hardware. Lastly, Monsignor Kim Jong-un has some pretty sumptuous palaces to kick back in while you're waiting to relocate to more tropical paradises. Best of luck. [Answer] What about Area 51? It's already incredibly secretive and mysterious, so no one would blink an eye if strange things are going on there. It's isolated and very secure. US spy satellites are not looking for anything there. Other nations are looking, but hey, it's Area 51! They *expect* to find strange stuff going on there. Plus, if the US finds out, it's not likely that the US will nuke itself. If the US won't do it, it's not likely that any other country will either. ]

[Question] [ **This question already has answers here**: [If an FTL spacecraft entered Earth orbit, how long would it take for humans to build a FTL spacecraft?](/questions/36077/if-an-ftl-spacecraft-entered-earth-orbit-how-long-would-it-take-for-humans-to-b) (11 answers) Closed 7 years ago. Let's say aliens arrive on Earth and demonstrate that Fusion is possible and leave (and don't tell us how). Would we develop Fusion technology faster without being told about how it works by the aliens? EDIT: This is about any technology in general (whether it be Fusion, FTL, Planet Destroyers etc) not specifically about FTL [Answer] I would think so. Innovation is probably the hardest bit and duplication is much easier. We see it with computers all the time now. Some small company comes up with a new idea that is "obvious" and then suddenly everyone else can duplicate it. The same is with other STEM fields, the knowledge that it exists (and ideally something to experiment with) helps reduce the false starts because you know where to go. This idea applies to even the most basic ideas. Before some guy decided to have each of his family members do one step of making a needle, the factory method didn't really exist. As soon as it was understood, it spread out everywhere. With the FTL example, having an example would tell us what not to waste time. So if we knew it was a junction point with a gate, then we'd drop all technology in independent drives, slingshots, or hyper-acceleration while focusing purely on paired gates. If we know we need a certain isotope, then we would focus on how to get that isotope instead of trying to get all isotopes and see if one of them works without knowing how to connect them. The same with power requirements, material requirements, or even navigation technology. Knowing which paths *not* to go can save a lot of effort. [Answer] Let's take the title as the real question. Instead of being simply told FTL is possible, this answer shall assume that the aliens demonstrate FTL is possible. Their spaceship(s) arrive and depart at FTL velocities. This is observed and records are taken. There is one obvious example. Nuclear weapons. There was a lot of bouhaha about spies passing on nuclear weapons secrets to the Russians. In fact, it is considered the only piece of information the Soviet Union's scientists only needed to know the bombs worked. The big problems that Tubular Alloys and the Manhattan Project had in developing the first nuclear bomb was they didn't know whether it would work. After the Trinity test, and the leveling of Hiroshima and Nagasaki, there was no doubt nuclear weapons worked. Of course, the scientists who worked on nuclear bombs had an idea that nuclear fission was involved. Our ability to develop FTL travel after seeing aliens use it depends on whether we have any scientific concept that is the basis for the aliens' technology. For example, the concepts our science has, currently, that is linked to FTL phenomena include wormholes, Krashnikov tubes, the Alcubierre drive, quantum entanglement, and tachyons. Now if the aliens' FTL has no connection with any of these scientific hypotheses, then our capacity to achieve FTL will be severely limited -- in the short term. Once we have the inspiration that FTL technology exists then will be an ongoing program of research to discover any scientific basis for FTL travel. If this leads to humans developing FTL travel several centuries earlier than otherwise might have happened. In that case, it could be said that knowing a technology existing, it can be developed faster. However, if the technological gap between us and the aliens was equivalent to that between the 21st century and the Ancient Greeks. If we could demonstrate jet aircraft to ancient Athens, the likelihood they would develop jet aircraft earlier than the twentieth century is almost certainly zero. We might learn something from observations and records of the alien technology. This might lead to the early development of FTL technology, but there are no guarantees. Ultimately, it may depend on the nature of the FTL technology itself. If the technology is millennia ahead of us, then it will be no go. If the technology is mere decades more advanced, then this is feasible. The answer is it may be possible and it may be impossible. There are too many imponderables. [Answer] Yes it does. And there are plenty of examples in human development. A real treasure trove for this sort of thing is Jared Diamond's [Guns, germs and steel](https://en.wikipedia.org/wiki/Guns,_Germs,_and_Steel). He calls it *idea diffusion* (as opposed to *blueprint copying*, where you get not just evidence of the technology, but also some idea of how it's achieved). Couple of examples: * Several non-literate cultures developing their own writing system after seeing examples of other writing systems (eg. the Cherokee writing system) * European invention of porcelain, after seeing Chinese examples. * The Russian atom bomb project accelerating massively after seeing demonstrations of the technology in Hiroshima and Nagasaki. [Answer] Besides dmoonfire's answer about knowing which paths not to go can save a lot of effort, I want to offer an additional look. Knowing something is possible gives us more motivation to do it. Spending millions of dollars into research on something that is maybe possible, is way riskier than spending millions of dollars into research on something that is definitely possible. Example: if my neighbor shows me he can fly without any tools, just a technique of swinging his arms which I don’t understand, I will try every day to fly because I know it is possible. If I didn’t know this, my motivation to learn to fly with swinging my arms is way less. [Answer] Yes, most definitely, particularly for technology like FTL. Research on advanced physics takes a lot of money. Right now, no substantial funds are directed into research of FTL, as it is seen as impossible. Seeing an example of working FTL would obviously change this situation, making governments and investors direct more research funds into this field. [Answer] This depends on who they tell. **Public** Right now, if you try to tell the public and government that FTL is possible in the scenario above, people and governments will have an incentive to work hard and try to figure something out. Right now, all of our current theories say that FTL is impossible and so therefore it becomes a waste of time. But if we have incentive, it has a higher probability of happening. But, be careful, because this isn't always the case. You could think of the fact that the "aliens" never gave us proof of FTL technology, so it could be dismissed as "fraud." **Individual** If you tell an individual, this is basically impossible. First of all, they wouldn't have the means, no matter how powerful they are, and second, if they try to get someone to help them, no one will because of how absurd the theory sounds. [Answer] The main driving force which accelerates research is **money**. Having demonstrated that something is possible drastically helps in procuring money for research. Let's say you are a billionaire venture capitalist. A team of scientists approaches you and says they want to do research on FTL travel. They promise you all the patent rights, if you just give them a budget of a few million dollar a month. Would you do it? You don't know if there even is a profitable method of FTL travel. You don't even know if it will be *practicable* (like manned space exploration beyond Earth orbit. All the rage in the 70s, now we know robots are way cheaper). Heck, you don't even know if the laws of physics in our universe even permit FTL travel (spoiler: general consensus among physicists is that they don't). The risk that your investment won't have any return at all is huge. But what if the aliens have already demonstrated that FTL travel is not just physically possible but so feasible that they can use it just to give us a casual surprise visit? You now know that there is a realistic chance that what those scientists are up to might work. Your risk is drastically reduced. The prospect of being the first to bring FTL technology to market has become tangible. The same logic doesn't just apply to private investors but also to government investors. [Answer] I think we can compare this to something we all know: # We know "Vision" exists, and it helped us replicate it The ability to see with our eyes, detect patterns and interpret the world around us. We know it's possible. We understand how an eye works optically. We know how to use it pretty well. We even have an intuition as to the process of how we recognize things, but we don't know the details of how it works. So there's a limit to the amount of reverse-engineering that's possible. At this point we replicated an eye with a good degree of success in the form of digital camera, outputting information that can be processed by a computer. But I'm willing to bet that we wouldn't have spend so much money, time, brainpower and energy to make computer vision happen if we didn't know intrinsically that "vision" was even possible. Imagine we were born without eyes; we wouldn't even have entertained the idea. So, yeah, I think knowing something exists helps us replicate it, but the amount of details available about the implementation determines how easy it is. [Answer] I would agree that in general, knowing something works can significantly speed up your own development effort, but I would like to point out that it by no means guaranteed. For example, imagine you are living in a world without birds or bats, but your science and tech developed enough for you to start pondering the unthinkable: the flight. And then you see aliens who are birds and they fly so effortlessly and gracefully flapping their wings. So you suddenly might waste tons of resources and time and effort trying to recreate what you know works, instead of exploring technologically simpler way of doing this, that you would likely try if you never saw those flapping wings. [Answer] **Yes** For the simple reason that it will now be monumentally easier to get funding for research. One of the biggest hurdles to making breakthroughs is finding the funding in order to hire the minds that can work on the issue. By seeing an FTL in action, governments and investors now know with certainty that not only is FTL theoretically possible, its been implemented. Now, governments, universities, and private companies alike will be willing to pump incredible amounts of money into research, because whatever government gets their hands on it first will have a huge advantage in space travel and whatever company discovers it first will become incredibly rich and powerful overnight [Answer] Yes. Prior to being introduced to horses, indigenous peoples of the Americas maybe domesticated a few animals. Once they were introduced to horses, horses quickly became integrated into their cultures. When the Wright brothers showed that powered flight was possible, other inventors quickly learned and developed their own airplanes, even if they only had a simple understanding of the Wright flyer. In fact, many invented airplanes that were vastly superior to the Wright flyer. Once we are shown something is possible, it hardens our resolve to accomplish that possibility, because we know we are not chasing a pipedream. Edison pursued the lightbulb because he saw it was possible from an early experiment. [Answer] It will speed up the process of development, yes, but by how much? Will it be like 103 years into 3 years? Or 890 years into 860 years? Hard to say when we don't know what makes a working FTL drive, thus, as writers, we would need to make something up. Maybe, there already is a possible inventor of FTL drive playing with lasers in his university lab, that may be able to teleport a photon across his lab as a proof of concept within a week, but without aliens showing will never believe in the possibility and will just continue engraving emoticons into tin cans with university's lasers. ]

[Question] [ So, I have a small tribe of island people with stone-age technology who have [discovered how to make gunpowder](https://worldbuilding.stackexchange.com/questions/77880/what-explosives-could-a-small-island-nation-feasibly-discover-without-metal). However, they want to make war on the neighboring islands, and they need a delivery system for their new explosive because blowing holes in your enemy's canoe is fun. They have decided to use the arrows they already use to launch the gunpowder, by packing gunpowder into a hollow stone arrowhead. However, they require some way to set off the gunpowder upon impact. **How does a tribe of stone-age islanders create an impact-trigger for explosive weapons?** [Answer] Historically speaking, timed fuses were far preferred to impact triggers for exactly this reason. Estimating the time of an arrow flight from the distance is a pretty straightforward affair, and if you're uncertain, you can just guess long; if the bomb sits on the ground for a few seconds before going off, it's no big deal. (It occurs to me that in a naval context, you might use airbursts, on the theory that showering enemy boats with flaming bits of wood and glass is better than missing. That would take some practice for sure, but no more than hitting a canoe from another canoe in the first place.) For instance, the Wujing Zongyao, an 11th-century Chinese manual, suggests encasing the powder in a bag (of paper, cloth, or whatever's handy), attaching a fuse, and simply fixing the whole lot to the arrow and lighting it just before launch. Though less deadly than Greek fire or other impact-detonating schemes, it's far simpler and less likely to result in your troops lighting themselves on fire. [Answer] An Engineer of your stone-age tribe sat down one day with a quiver of arrows. He knew that the black powder the alchemists created was a powerful weapon and that if he could figure out how to imbue that power into his arrows, his tribe would become one of the most powerful in the region. Hollowing out several of the arrowheads, he realized that they could easily be filled with black powder and then re-sealed, but how to set them off once they reached their target? Stumped, the Engineer placed down his arrow prototypes and pulled out his pouch of tobacco and pipe. Maybe a quick smoke would bring him inspiration. Fishing the pieces of flint and stone (The alchemists of the tribe called the stone "Pyrite") from a pocket in his tobacco pouch, he sat back and struck them together to light his pipe, watching the sparks ignite the tobacco. *That's it* the Engineer thought to himself. A bit of complicated stone carving will be necessary, but it will be worth the effort. For several days the Engineer sequestered himself working on designs before he emerged with his completed arrow. This is the arrowhead schematic he showed to his War Chiefs to explain how it worked: [](https://i.stack.imgur.com/5kysr.png) The Arrowheads are built with a hollow chamber at the base. Inside this hollow chamber is a flint and striking stone "piston". The rest of the space is filled with black powder. The tip of the arrow is attached to the "rod" of the piston and is built to be retractable upon forceful impact. When the arrow collides with its target, the arrowhead is pushed down, scraping the striking stone piston against the flint. This gives off sparks which then ignites the black powder, causing the entire arrowhead to explode. The tribe would not need to know anything about blacksmithing or metallurgy, just that the rocks that look like this work for making a spark. [Answer] If the target is always in contact with water, they can use something like Greek fire to start the fire triggering the explosion. Actually, they could just use the Greek fire, but if you want explosions... Calcium oxide can be "easily" obtained by roasting limestone, tar can be found in nature. Mix them and spread the thing on the arrow tip, once it touches the water it will set on fire. If the explosive is close-by, you get a nice explosion. [Answer] # Fire Piston From [Wikipedia:](https://en.wikipedia.org/wiki/Fire_piston) > > A fire piston, sometimes called a fire syringe or a slam rod fire starter, is a device of ancient origin which is used to kindle fire. It uses the principle of the heating of a gas (in this case air) by rapid and adiabatic compression to ignite a piece of tinder, which is then used to set light to kindling. > > > Several sites have mentioned that temperature can reach above 800 degrees Fahrenheit (that's about the ignition temperature of gunpowder). Therefore I'd use the arrow's momentum to ram the piston and superheat the gunpowder in the charge. I don't think that the force of firing the arrow would be enough to set off the charge, but the impact would almost certainly be enough. [Answer] bows & arrows vs. canoes. Hmmm... If I were the tribeleader, I'd save the explosive arrows for the land fights. I mean, if you miss your target, you waste precious explosive material. It's way more convenient to use a salvo of incendiary arrows. Those that hit will do damage, those that miss are easily repleaceable. The best low-tech solution to fire an explosive arrow is to attach a fuse to the tip, train your archers to fire the arrows so to make them explode in the desired point. Also, you might want to add shards of chipped stone, to make sure that every explosion is even more fatal. [Answer] ## tl;dr: They will invent grenades and fire arrows on the way to the development of timed arrow-delivered explosives. And then either make water-triggered ones or invent matches on the way to impact triggers. ## Step 0: Hollow Arrowhead?! First of all... they could not use hollowed out arrowheads. Why? Because normal arrowheads are made from flint. Flint cannot be carved hollow without modern machinery and heavy cooling. With flintknapping using stone, bone and wooden tools there is *no way* to do this. So we have no hollow arrowheads from here... Also, arrowheads are tiny. The amount of powder one could store in a typical stone age arrowhead, even **if** hollowed out would be a few grams. Which in turn is just enough to shatter the arrowhead into all directions, not to blow apart boats. So, we need to get the powder charge a little bit back... and also make the arrow fly much straighter that way. ## Step 1: Grenades But they have clay! They can shape easily small pots and burn them, then fill them with their gunpowder. Cap with something and add a fuse, ready. But that is a rather heavy item. The Chinese had them called 震天雷, "Sky-shaking Thunder", we call them hand grenades. It looks like this (in the middle): [](https://i.stack.imgur.com/1sf68.jpg) Or these: [](https://i.stack.imgur.com/vEFjv.jpg) One could easily envision to add a loop to that design, put a piece of rope through the loop and then sling it, again, using a fuse. Their lack of cast iron makes them unable to make flying-cloud thunderclap cannon" (飛雲霹靂炮; feiyun pili pao) type of ammo, that relies on a specific type of gunpowder and the hollow metal shell to create sparks to ignite half a pound of powder. ## Step 2: Flaming Arrows Now, if we started harnessing the power of the explosives in pots... let's downscale a bit and look for a lighter shell. How about a pouch of cloth, wrapping around the arrow shaft? Extra points for burning, smoke and sparking midair, though no boom at the target. YET. ## Step 3: timed Exploding arrows Now, they might find this special grass on their island. This hollow grass that makes containers just by growing. The large compartments are perfect to fill with power, cap with a fuse and then throw... and then there are thinner ones that could fit onto an arrow. Hust a hole at both ends, push the arrow through the filled rod, add an arrowhead and fuse... An arrow-delivered small grenade from bamboo! Also, dry bamboo can be turned into charcoal or to heat the homes, build rafts and bows, it is a super material indeed! ## Branch 1: Combine 2 & 3 It's easy to wrap a burning cloth around a compartment containing gunpowder and light that, triggering a fuse to light the compacted interior load after a short while. ## Branch 2: Water ignition By roasting limestone, Calcium oxide can be created. This has a very warm reaction with water, enough to set a mix of sulfur and tar on fire. If this mix is used to glue and seal our bamboo compartment onto the arrow shaft, we created a devious weapon that doesn't go out if it hits the water but instead detonates then as well! ## Step 4: Matches The next step is to get wood super easy to ignite with a tiny bit of sparks or heat by impregnating pinewood with sulfur, which we already have. I believe other wood works too, but China used pine. At least these make igniting the arrows' fuses from a tiny source of wood on board the canoes safe. Now, we need to make that into friction matches... for this, we need antimony pentasulfide - which luckily has the same chemicals as [Stibnite](https://en.wikipedia.org/wiki/Stibnite). To add more sulfur into the mix we add the sulfur and melt it in airtight pots to get antimony red. Next: Potassium chlorate... That might be tricky, but their volcano might provide a steady stream of hot chlorine gas from a small vent. Bubbling that through a solution of KOH - caustic potash, the result of mixing potash from burnt with slaked lime. And both of these are natural minerals. Mix these two together, add some gum to glue that mix to the sulfur soaked wood sticks and we have friction matches. These will very easily ignite if rubbed over any rough surface... ## Step 5: Impact/Friction ignited grenades ...such as the interior surface of the compacted powder in the grenade arrows from step 4. Now, our grenade-bamboo was formerly affixed to the middle... but we can do better! Add a prevention for the capsule to slide back, but allow movement forward. Add some area just in front of the bamboo grenade with some of the friction-ignition composite (sulfur, potassium chlorate, antimony pentasulfide, gum) so that the bamboo can slide forward on impact... and have its interior surface rub over the stuff. As soon as it rubs, the thing ignites the mixture, then the powder and ***BOOM!*** The real benefit? the thing can be secured with a tiny wooden splint between the rubbing surface and the container, and then wrapped in a towel to keep friction from the ignitor. [Answer] It made me quickly think of snaps fireworks, they contain small amount and gunpowder and some shards of flint. When rubbed together or thrown to the ground, the spark make it explode. Stone age tribes could easily manage this. It would consist of a little pouch containing gunpowder and flints shards attached to the arrow. On the impact, it would blow. Setting fire to a bit would be pretty strange to me because it may turn off during flight due to the high speed of the arrow. [Answer] If you don't mind doing it in a few steps you could approach the problem like this. Hollow out arrow heads, fill them with gun powder, and seal off the arrow (so powder doesn't fly out of it on its path and become wasted in the water). On impact, the arrowheads will shatter and the gunpowder will spill on the ship/canoe. A secondary squad of archers will follow up with [flaming arrows](https://en.wikipedia.org/wiki/Early_thermal_weapons#Flaming_arrows,_bolts,_spears_and_rockets), which is easily made during any time period. On impact of the flaming arrows, the gunpowder will light as well. Combining the powder with flaming arrows seems like a superior assault due to the three steps that damage will be done. The first powder arrow, the powder explosion, and the fire that will damage a canoe whether or not the gunpowder arrows landed correctly. [Answer] If you really want impact detonation, then put a small hole in the tip of the arrow head and put a small amount of non-combustible material in it to keep the powder from falling out. (a thin, clay disk would probably work.) When shooting the arrow, the archer first sticks a wooden rod with a lit bit of slow match on it into the hole. On impact the lit match is driven through the non-combustible barrier and into the charge. Just lighting a fuse will be more reliable, but impact detonation might be slightly more useful for penetrating armor if that's a concern. [Answer] The two obvious chemical choices are fulminate of mercury and nitrogen triiodide. Both are reasonably easy to synthesize in a modern country (the latter you could make using only the supplies in a well-stocked janitor's closet), but stone-age? Dunno. [Answer] From a simple standpoint of setting it off, I think Perkins has the only thing they're going to be able to come up with. However, we have a problem here. They can't make anything even approximating a pressure vessel unless they live where something of the sort grows. Without such confinement gunpowder just makes a flash of fire. Light a pile of it on fire and you just get burnt, not blown up. [Answer] I imagine a stone age approach would be to simply fill a walnut, coconut, ball of tar, or some other combustible object with gunpowder, light it, and fire it before it is too late. On impact, it will break and detonate. The objects would serve as filled arrowheads. Another option would be to attach a gunpowder soaked thread to the arrow, to serve as a rapid fuse. ]

[Question] [ On my world, the day lasts 9 years: 4.5 years of light, followed by 4.5 years of dark. The inhabitants of this world survive by migrating along the ring of dusk and dawn. How do these people tell time? Obviously the good old standard of counting day and night will not work, nor will ancient methods such as time sticks or sun dials. In a world where the days last years, how can a civilization accurately tell time? *Edit* The tech level I am interested in is the early medieval era, as after discovering a basic method, more complex ones would arise building off of that. To Separatrix, the reason it would be hard is that to the inhabitants, it **is** always day, they simply migrate around the planet to remain in the day side as the night side is certain death. As frarugi87 pointed out, I forgot to mention; this planet has multiple small moons that orbit it as well as a small ring. [Answer] # Terrain objects I imagine these nomads are following the same paths every year as they perpetually circle the planet. In that case, since there are no seasons or months, each group's time cycle would be based around terrain objects they pass. This is the month of the Blue Woods, next month is the Snow-capped Peaks, next month is Dust Plains, etc. Once your people evolve past the small clans stage (which I'm not sure if they have) and start having more trade and contacts with other tribes, I'm sure the groups would adopt or impose calendars from one another. For example, the peoples of the Iranian and Anatolian plateau picked up the Babylonian lunar calendar through trade contacts, while the Julian calendar was stamped onto most of Europe and the Middle East through conquest. At that point, the 'winning' time system would be that of the most powerful or culturally advanced groups. [Answer] **For Months/Seasons:** The terrain. Presumably they will be in the same place every nine years, and they know where they are relative to the cycle. You'd get the Month of the Great Salt Lake and so forth. This would divide your "years" into "months" **For Days/Hours:** [Water Clocks](https://en.wikipedia.org/wiki/Water_clock) or [Hourglasses](https://en.wikipedia.org/wiki/Hourglass). Even on a moving cart (I'm not sure how fast the people are moving or how long they stay put) these would work reasonably well. Additionally, as nomads, they are sure to have flocks of some sort as agriculture would be difficult. As such, they would know about how long an animal can go before it needs to eat or sleep. This would divide the "days" into "hours" You'd end up with the Hour of the Horse and the Hour of the Sheep. You'd also know how long the by products of any animal lasts. That would divide the months into "days" **Basically:** You'd end up with people that sleep when the horses sleep, move camp twice for every calving, and breed your sheep each time you leave the mountains or forests. Cycles upon cycles using nature to time the gradual migration around the planet. And as a result, those cycles will get named after the nature that counts them out. [Answer] Does/can the planet have a moon? If it had several small fast moons like Mars, then that's a perfect external reference point. For instance, Phobos has an 8 hour orbit, and Deimos has a 30 hour orbit. So on the 9 year planet one orbit of Moon 1 is one time unit (say an hour), and an orbit of Moon 2 is a Day. Or whatever. It would be a little like the hands of a clock, depending on which moons are in the sky and where. **Edit:** If not a moon, you want something that can be seen during the day. This means that using the position of stars/planets is out. One thing that will be visible during the day is the primary star (hereafter called the sun). The sun will be visible from anywhere on the daylight side of the planet. It will have it's own rotation, and one thing that would be visible (with proper light filtering equipment) would be sun spots. If you were able to pick them out against the glare, possibily using something like [a pinhole camera](http://www.nationalgeographic.org/activity/build-a-sunspot-viewer/), you could determine the speed of the suns rotation, and from that measure the passage of time pretty accurately. [Answer] What about the change in the length of a mans shadow? After migration is completed the length a typical mans shadow is 'x'. When it's time to migrate again, the shadow of a typical man is 15\*x. This is pretty simple if the planet is relatively flat. Mountains, trees, fog, clouds, rain, hills, could make it kind of difficult. A "clock tower" (a large pole, whose height is fixed & shadow is measured by a rope) could be erected every migration. After 9 years, you may just migrate from clock tower to clock tower. A clock watcher could ring a bell every time the shadow changes it's length by a foot, or what ever is suitable to divide up a eat/work/sleep cycle. "Come on over for dinner in 3 migrations & 40 shadows", could be the earthly equivalent of "come over for dinner in 6 weeks, 3 days, & 16 hours". Of course this all hinges on the assumption that the people can migrate faster than the livable zone moves, allowing them to 'settle down' for some significant period of time. [Answer] # By using a thermometer! Assume your world has a size similar to Earth ( 40.075 km) to do a roundtrip around equator, you will need roughly (assuming a walking speed of 6 km/h and you spend 1/3 of your life walking): $$40.075 \cdot \frac{3}{6} = 20.000 \text{ hours}$$ Nine Years have 78840 hours, so the scenario holds from timing point of view. However a so slow rotation will cause the Earth to have **1 hot side, and 1 cold side** ( 3.200 times slower than Earth). This will cause a very static weather, we have 1 cold air current going from cold side to hot side at ground level. and 1 hot current at higher level going from hot side to cold side. [](https://i.stack.imgur.com/oeIYJ.png) Basically there will be a constant cold wind at ground level. The *dawn zone* will be probably too cold for living, so people have to stay within the *"early morning zone"* Basically when it starts to get too cold, it's time to move on, and when it starts to become too hot, then its time to settle. And the best time measuring device (since the wind will be constant) is a thermometer. People could live in the `10-27C°` zone in example. In reality I think this scenario will not hold, you do not have the time to grow and harvest regular vegetables (At least 3 months as far as I know are required for shortest living crops, and note that his crops use help from chemical industry). **You need also fictionary vegetables able to grow in 1/2 months.** The crop growth could also be an alternative measure for time. Basically people should harvest the crop, then start moving immediatly until it finds a zone suitable for seeding again. I'm not a meteorologist, but I think that there will be zone with constant rain, so basically people have to "travel" through rain, wait that rain come, harvest crops, then leave again.**. living on the edge of rain!** [Answer] Let's suppose they are ordinary humans with ordinary needs for meals and rest. Perhaps the lack of day/night cycle would actually create societies where everyone works and rests at different times so the group is always active, always alert to predators and other clans. People would eat when hungry, sleep when tired, and everyone would have their own schedule. In this case timekeeping would actually be quite important to help people with different schedules co-ordinate. Perhaps bells would be sounded every hour or two (say) as a means of marking time. But how long is "an hour or two"? Well, the time does not need to be exact. One possibility is a traditional unbroken song is sung by the religious order (with individuals joining and leaving the song to eat, rest etc.) and at particular points in the (long) song, the bell is struck. Alternatively the constant migration might lead to a religious practice where a group is constantly marching, perhaps in a large circle, at a slow and very steady pace. Every thousand (say) paces the bell is struck. That said, it is quite complex for everyone to be working to their own rhythm, especially in simple societies. To create a more orderly approach, there could be a bell sounded every 12 hours, with people "swapping over" from work to leisure and rest and vice versa. Or there could be 3 "phases" in everyone's day (basically work, leisure/socialising, sleep), each of around 8 hours, with 3 different cohorts doing different things at different times. How would such long time periods be marked out? Consider a pyramid of 25 stones, that is to be moved by 1km, one stone at a time, in a process which takes around 8 hours. To keep time reasonably well, the site could be chosen 1000 paces from the old one, and the aim would be to complete it just as sunrise/sunset hits the new site. [Answer] Here the astronomical methods: **Long timespans:** In the night zone the sky is an excellent calendar because it slowly and uniformly rotates. Expect the inhabitants to divide it in areas like the [Chinese zodiac](https://en.wikipedia.org/wiki/Chinese_zodiac) and name them. Your world may contain fast-moving stars like [Barnard's Star](https://en.wikipedia.org/wiki/Barnard%27s_Star) where the movement will be noticed over long time-periods and used as indicator. If your planet has notable precession, tilt and eccentricity, very long timespans will result like the [Milankovitch cycles](https://en.wikipedia.org/wiki/Milankovitch_cycles) on Earth in ice ages and warm intervals. **Shorter timespans:** Both at day and night planets and moons (perhaps even the ring) is visible. The ring may contain [shepherd's moons](https://en.wikipedia.org/wiki/Shepherd_moon) which apart from their visibility will cause noticable wakes in the ring. There are some formulas which allow you to calculate the duration of a cycle for a moon, which can range from hours to months. Other bright planets may be visible in weak daylight and astronomical instruments may see moons orbiting those planets. Jupiter's moons were in fact used as extremely precise clocks to calculate the longitude of a location on Earth (This does only work on land; on water even calm sea does not allow such observations). People may have precise angle measurement devices like the [nocturnal](https://en.wikipedia.org/wiki/Nocturnal_(instrument)) to measure the angle between two positions of celestial bodies to get a more accurate time span. Other devices are hourglass and water thiefs. In the early medieval era big mechanical pendulum clocks are possible, but expect them to be extremely expensive and therefore only used by extremely rich people. **Tides** Your moons may cause noticable tides on the planet, so even if the sky is not visible, the current flow of water on the coast may give your inhabitants an approximate timeframe. **Animals** Given that the day is extremely long, most animals will also wander around the planet. Like the [dawn chorus of birds](https://en.wikipedia.org/wiki/Dawn_chorus_(birds)) people may know by the acoustical environment how the habitable zone moves and therefore how much time has elapsed if they did not move. **Very short timeframes**. Interestingly the Jewish people use *rega* (moment, plural: *regaim*) as subpart of a *chelek* which is approximately 1/20th of a second which is in fact very near to the shortest discernable timespan; magicians know that actions lasting shorter than 1/20th of a second cannot be perceived. So you might use some timespan to accurately describe fast actions. [Answer] ## They *may* not use time The concept of time is mostly *European* (1), and some different cultures don't value time much, or even have no concept of it. (it's often the case in nomadic cultures.) That can work, as they could have a non time structured society, where when someone is available to *work*, they do, and when they aren't (sleepy,hungry etc...) they do what they need. Most cooking can be done without time "when the meat is brown" "when the dough doesn't stick" This could be an interesting clash (if they ever encounter each other), where sunset or dawn dwellers could have almost no concept of time, "well, when it is too cold/hot/dark/sunny, we move" and the other ones are really extreme on time "if you are late you are executed." and even if there is no encounter, as I assume your story will be in an *European* language, and a species almost without time will clash with the reader's culture, giving them an "alien" feeling. (1) I include today's Canada/USA and Asia (and some other countries) as they are influenced by the European culture. *Source* : <http://www.andersoninstitute.com/cultural-perceptions-of-time.html> --- *note: this answer does not replace other ones, as they are good reasons to keep time in an advanced civilization, but it is an option.* [Answer] **TL;DR** They would use basic physics-derived methods of telling smaller intervals of time, time required to do things (like build a camp, hunt, walk somewhere) as larger intervals, and arrange those intervals as denominations of the time that it took for the twighlight zone they live in to fade to night - which would essentially be a season. On an earth-like planet with this rotational time, that season could be 2-4 months assuming the people travel until they reach sunset, longer if they move further into the day side. Example; it takes quarter of this time to build a good camp, a big fire takes the same time to burn down as it does to hunt something, a puddle evaporating in sunny weather, etc. I think with these limitations, telling the time precisely would be impractical for them unless it's in small intervals or arranged around when they are hungry / sleepy (which would still be imprecise). Maybe hourglasses would be invented for smaller intervals. Sundials wouldn't be very useful since the sun would perpetually be setting, i.e it wouldn't move across the sky at all. **Longer Explanation** According to some maths\* I did which assume an earth-like planet, the "fade" zone or twighlight zone (i.e the rotation of the planet) would move at roughly 0.5 KPH (circumference of earth divided by number of hours in 9 years). If the twighlight that the people live in is similar to earth's, you have about the time it takes the center of the sun to reach 12 degrees below the horizon in which to do things using natural light - after that it gets too dark. i.e "Civil twighlight". The planet rotates at around 0.004 degrees per hour (360 divided by 78840), meaning to rotate 6 degrees would take 1500 hours / 62.5 days. So, very roughly, the twighlight would last around 2-4 months (from sunset), which isn't too large a time for people to notice that it's fairly consistent, and during this time the sun would noticeably change position. Looking at it this way, if one were to tell the "time" by phases of the moon on Earth, it would be quite similar, with the added circumstances of having to pack up and move home every time it waned. This would be the foremost basis for them to create a calendar system since it's central to their survival - further denominations of this would be measured by how far the sun had set, whether stars could be seen, or some of the moons perhaps, but I think being able to say "it's 4pm" is way too precise for a world like this. *planet assumed to be earth-like, numbers rough and guesstimates made, there are 365 days in every year. maths is not my strong suit.* [Answer] I believe the only active biology would be in the dawn zone. Plant life would have to be very robust to survive the cold of the night and the heat of the day. It would probably shut down in the extremes. So animals would also need to hibernate at night and estivate most of the day. All feeding, breeding etc would happen mid-morning. On the dusk side it would be long after dark before it was cool enough to do anything so the plants would be inactive anyway. So the traveling humans would be hunter/gatherers living in a perpetual spring harvest. Anything which prevented movement would be extremely traumatic: illness, giving birth. No endeavor requiring a person to be static for more than a few days could ever be done. You would need to work out exactly how long it was possible to remain still. There would be a 'fundamental duration' based on walking right to the edge of the dawn zone and staying there until it got too hot to live. How long? I'm thinking maybe a month. Most likely there would be 'cities' every hundred miles or so with fast roads between. Each city would be visited for a 'month' every nine years. Perhaps life would be 5 'days' of walking followed by 25 'days' of city life on a perpetual cycle. Any criminals to be executed would simply be left behind in a cell and would boil to death a few days after the city was abandoned. There would be a tendency to push away from the equator, ie to invade your northern or southern neighbors, just to have less walking to do. States/counties would be banded on latitude. Close to the poles there may be permanent settlements where the residents just endure the extremes rather than migrating. Their tech level would be much higher. However food would not be plentiful so they might do a lot of trading tech for food with the equatorial nations. Imagine how popular a bicycle exporter would be. [Answer] Measuring the progression of time would likely be similar to the ways we do it or did it throughout history. Sand timers, burning candles, swinging pendulums would basically still be used to count out reasonable durations of time. But I think you are asking more about how can they tell what part of the day or year are they in. That information is closely linked to navigation as well. How do they navigate? One important question to answer is what is the axial tilt of their planet. Constellations would be a very important factor. If they follow dawn/dusk around the planet, only certain constellations will be visible at any particular time, and only the brighter stars will be visible if the sky isn't black. They will also teeter left and right (like a swinging pendulum) with a period of one of their years. This would depend on their latitude as well. So telling time and knowing where they are on the planet go hand-in-hand, just they do here on Earth. They might also learn to recognize certain warning stars. Once a certain star becomes visible then the sky is getting too dark and it is time to move farther West or East for example. Presumably, being in the daylit side could get excruciatingly hot. I expect they would stay in a zone where the sun is a certain height (angle) above the horizon. The position of the sun would be a very good indication of the relationship between their position and the time of day or year. If they stay close to the planet's equator they will likely have to move much more rapidly than if they inhabited zones nearer the poles. Realize that on Earth, sailors at sea can only tell time by the sky if they know what their latitude/longitude is. Hence the concept of timezones. Since you say that your planet will have a ring system, it will be very easy to tell what latitude you are at by the appearance of the rings. Maybe the nomads, while migrating, try to keep the rings at a more or less constant angle. And maybe living within the shadow of the rings is how they keep from scorching in the constant daylight. [Answer] Very interesting idea. If they are chasing the dark side, what would they eat? Wouldn't the lands ahead of them always be wastes? If they were instead running away from the darkness, they would have food on the sun side, potentially. Though that might also be a blighted waste. As far as time goes, they could put markers down and measure the time at each marker. A marker for each year, and maybe some sub-increments under that. They could have holy sites dedicated to the markers, worshipping different gods or aspects of nature depending on what is around. I will say, though, that time tends to be something used primarily by folks who are settled and industrious. These people sound like they would be moving so much that time-tracking would something they wouldn't necessarily need. They don't need to get up at any particular time, just keep moving away or toward the darkness. They don't need to be home or eat at a certain time, because their sleep cycles are probably just as needed. They also wouldn't have a circadian rhythm because they have no day/night, so you may want to think about how that would affect their way of life. Ensure they don't have anything based on circadian rhythms. Which largely means they wouldn't really need or want to schedule much. [Answer] **tl;dr They will use a combination biological factors, rest cycles, and outer space to determine time to an accuracy that they need in their daily lives** They are nomads. They are going to be following behind dawn just long enough for the lands to have thawed and grown food to scavenge, but not long enough for things to start to burn. A goldilocks zone, more or less. Essentially, they will live their entire lives at (what we would consider) the same time of day. To answer the question, you have to ask yourself what exactly *is* accurate time to these people? We have time scales of seconds, minutes, hours, days, weeks, months, seasons, and years. Which of these need to be accurate? How accurate do you need them to be? Seconds and minutes are useful when mainly at really short scales. A second is a heartbeat long. You might use this timescale for several thousand seconds, but not for longer than that. It doesn't makes much sense to keep count of 50 million seconds. 'Wait 50 beats then come and get me' makes sense. 'Plant these seeds, then count to 50 million' makes much less sense. This is true for us and them. It is only well past the middle ages that we had anything accurate for keeping accurate track of seconds over long scales. Human hunter-gatherers wake up on first light, spend the day hunting and gathering, then when it gets dark, they relax for a bit, then go to sleep. They have no need or any real conception of keeping the time of day outside of morning, afternoon, evening, night. Their hours are are lot less accurate than our are, mainly because they have no need for more accuracy. Your medieval peasant didn't have a sundial. They knew when it was the midday sun, dusk, etc. This would largely be true of people on your world also. While human sleep cycles depend on the sun, any creature from your world would have evolved a different mechanism to control how long they are awake for and how long they sleep for, but they would still wake up, slowly get tired, go to bed. You might have the circadian rhythm determined by pheromones so that any tribe/social animals sync up sleep times to their 'Alpha' or 'Queen'. One possibility: *The queen releases some pheremones upon waking. Everyone around her gets a buzz that slowly depletes throughout the day. Each member of the tribe will be able to* feel *exactly what time of the day it is, depending on how 'high' they are.* Whatever you decide to do, there has to be some sort of biological mechanism to the circadian rhythm. Obviously, days are sleeps. I might make sense for your people to keep track of number of sleeps (days) and group them into units (weeks or months). I really depends on their culture. Seasons and years will depend on your planet's seasons. If it has a winter and fall cycle, the people will probably want to keep track of that. This is easy, however because it is all determined by astronomy. Where the constellations are, how high in the sky the sun is, etc. [Answer] The time telling through sundials and other means would be the same. A species living on your planet wouldn't look at 1 day as being 9 years.... it would be 1 day to them. If you are asking about how would a human from earth tell time, they would either still choose to use earth time constructs so that they don't lose themselves relative to earth or they are adapting to the new world. Either way, telling time would be no different from earth or this planet. The only difference is where is the perception of time coming from? Also things on this planet would more than likely age differently. Our age and time scale is based around our 24 hour cycle. Whose to say that a species on your planet doesn't live just as long there but 100s of years old to us due to what ever factors that may make them live long there. [Answer] As we are talking Medieval level of technology, I assume you need time for keeping calendars, as timekeeping on the scale of hours/minutes could be easily done using clepsydrae. Also, I understand you mean "solar day" lasts ~9 years, not "rotation period", i.e. time planet rotates around its axis (See wikipedia article on Venus for the example of extreme difference between two). Now, because of this peculiar geography I assume you have a need to know the time of "rotational day" for calendars and historical records. Achieving this would be relatively easy if planet has magnetic field with magnetic poles not coinciding with geographical poles, as the angle between magnetic north and true north will depend on geographical location. As your people move with solar day, the year for them will end when magnetic pole will point to true north. [Answer] I can imagine time measurement by using reusable items like hourglass, hour candles might be to much efford to reproduce, beginning with finding your resources on your 9 year trip around the planet. But how come they even found hourglasses? This all beginns in a safe harbour, a home, a world just like we know it. Societey has to arise. Humans coming together in packs start specialising in theyr tasks. They build shelters, not everyone will be on the hunt or searching for food in an ever new place. This won't work in a society that stared with a 9 Year-long days, which forces them to be on the run theyr entire live. Those humans would just live by what has grown over last day or even more in case they don't walk the perfect circle and miss places they had been beore, guess it's hard to be sure you visited this exact same place yesterday/9 years ago and you only walk in one direction, maybe you don't even come up with the idea you came back on the place you have started! They probably won't start building housings in any way since they would have to leave it faster then they can make theyr mind of how to build a well constructed long-time-home. The few who did this way felt comfortable started to learn about planting food and ... died when they had to learn this does not work at night. Actually id say those who don't develop the instinct to keep on running become extinct. This way there is no save harbour to make some random experience about tools, making fire, grow food. And try to carry arround your rectangular stone while inventing the wheel, this would be to much a burden. So this needs a safe harbour i sayed, but where should this be? Well, right there! Make the world slow down in rotation (not that hard people start falling off your planet by negative acceleration). How settled this world is before the happening and after is up to you. You are also up to how long this happening lies in past. Technical progress might had slowed down since people don't come together like they sued to to share theyr knowledge. Also people have no time to spend on learning, they have to gather food in the new place they reach in theyr travel cycles, prepare for the travel in the next "day" or hourglass run. The hourglass will be kept by an elder time-keeper or a chief. This person is the metronome of a group tribe, like church bells used to be in some places. Citys once beeing all over the planet had wearn away, ruins under piles of dirt are relics those new people can't remember anymore. They lost a lot of technological knowledge and might not even know, how or when the magical time articaft was crafted, which had to been turned 10 times before they had to travel 4 times the relic. **tl;dr** People measure time in a reusable way theyr technological advance allows them, like hour glases. People have been on the planet since forever, but the planet changed, it slowed down spinning thousnads of years ago and societeys dacyed. Who is left are those people who early enough started to travel and follow the sun. They have not have found any time to develop on new technologies or anything since theyr all-days destiny is to march every day, following the never setting sun. > > following my **OLD POST** i made but was criticized, so i rewrote it, just did not wanted to miss a point. > > > I think this doe's not work since this entire Planet leaves no space to stay for long enough humans would evolve the way they did (depends on the planets sice) but imagine peope in the very first stadium like wild animals in a herd. > > > They would live by what has grown over last few years while they travled and what lives there when they appear. > They probably won't start building housings in any way since they would have to leave it faster then they can make theyr mind of how to build a well constructed long-time-home. > The few who did this way felt comfortable started to learn about planting food and died when they had to learn this does not work at night. > > > Actually id say those who don't develop the instinct to keep on running become extinct. This way there is no save harbour to make some random experience about tools, making fire, grow food. > And try to carry arround your rectangular stone while inventing the wheel, this would be to much a burden. > > > As long as there is no safe harbour for your people to develop into this stadium there will be no evolution from herds to social structure we have. > And without this, noone will be like: let's meet next weekend, i have some busy days, can't wait for friday. > > > So if you say you have this save harboud, people can develop a society, share theyr tasks and build up dependencies they can better organize with time. But then they would know night and this won't be the death side of the planet anymore. > > > **EDIT:** well about the safe harbour thing ... you might make your story up like: earth or whatever planet started to slow down rotation. This way you can have your setup developed they way you need including technologie and you could reason why people had a meaning for time like we have, even if it might be implausibel to native creatures on such a planet who allways lived with sun high over theyr heads. > > > ]

[Question] [ [**Definition from Wikipedia**](http://en.wikipedia.org/wiki/Human_sacrifice): > > Human sacrifice is the act of killing one > or more human beings, usually as an offering to a deity, as part of a > religious ritual. > > > The person to be sacrificed can be part of a ritual with or without consent, but it poses less moral problems if the person consent to the sacrifice. For many societies before the classical age, the ritual of human sacrifice was a common practice. The custom ceased before the middle ages mostly because of religious reasons. But is it possible, for a society to keep those practices acceptable during the middle ages and beyond (with or without the victim's consent)? [Answer] Why not? I hate to say it but we are disgusting horrible violent creatures at times. We consider ourselves developed and cultured but there are still murders, we slaughter other living things for delicious meat, we go to wars, and are entertained by violence (fictional and semi-controlled as sports). If the society demands human sacrifices either due to: * religious tradition to a false (but still followed) god * religious tradition demanded by a real unloving god (it is a fictional world) * a prior religious tradition that has devolved into a bloodlust entertainment source * a proclaimed religious tradition that is used to dispose of/get back at objectors by a corrupt governing body While it is horrible, your fictional society doesn't have to be much more inhumane (for this site) than our current one. You just need to have a minority who would cling to it and a majority who are willing to ignore/allow it. [Answer] Some would argue that the death penalty is a form of human sacrifice. The life of a person is taken for the perceived benefit of society. Many aspects of the act are ceremonial (last meal, last visit with clergy, victims family observing, standardization of the method). It is a bit of a jump from what we think of when we mean sacrifice but I think all of the criteria are met. [Answer] > > Human sacrifice is the act of killing one or more human beings. > > > Keep in mind, when someone in the 21st century thinks of human sacrifices we think of something different than this. We generally associate the second half of the definition, that being it is part of a ritual. This is our *current* definition. Not necessarily historical. What is a ritual is very variable based on what time in history it is. There are plenty of activities in 2014 which are killing one or more human beings. These could be as simple as: * War * Driving * Starvation worldwide * Capital punishment * Murder * Abortion (YMMV...) These are all "legitimized" instances where humans die either directly as the result of others or indirectly through lack of action. All have varying levels of support societally. Historically, many contexts happened which we currently deem barbaric or as the result of society being primitive also happened. Including during Earth's middle ages. Public burnings, hangings, and like these or what we now consider *absurd* happened consistently. Perhaps in some years or centuries we will look at the above list and be equally appalled and consider them rituals "those savages did in 2014 to kill so many of each other!" > > But is it possible for a society to keep those practices acceptable during the middle ages and beyond (with or without the victim's consent)? > > > I think at this point it is clear the answer is, "yes, it is possible." But the unasked question is then... *how best to have a world with human sacrifice*? The key is you need to devalue human life. In all acts we consider human sacrifice, both present and past, there was always something more important than the life. Entertainment, appeasement of god(s), war, safety, freedom, something always took precedence for the society to embrace the loss of life. In your world you need to make this clear. Perhaps it's a plague which has devastated immune systems and the only way to repair living tissues is through transplants (in fact an [entire movie](http://www.imdb.com/title/tt0399201/) is formed with this premise). Maybe it's war torn and people are sacrificed/killed in the name of security. Technology and the increase of a society system involving freedom do a lot to create what are now our traditional objections to sacrifices. In an advancing world, it's harder to take away technology. But the governmental, societal, and familial constructs can be shaped in nearly any way you desire in order to create the world needed for human sacrifice to be thrive. [Answer] Ritual sacrifice is nearly universal in religious history, and human sacrifice quite common. Nothing whatever prevents its occurrence, even as a common phenomenon, among "developed" societies, unless one jury-rigs the question by defining "developed" to exclude human sacrifice. As a first approach, one ought to conceive of human sacrifice as a passage-rite, or *rite de passage*, as Arnold van Gennep indelibly termed them. Passage-rites transition the subject from one recognized social state to another, by way of a mediating third phase in which highly-valued cultural conceptions and norms are manifested to all concerned during a delimited focal event. For example, girls' pubertal rites transition the subjects from "girl" to "woman" by way of a mediating "liminal" phase in which many of the culture's deepest notions of what women are -- their roles, their bodies, their meanings, their functions -- are proposed to the ritual subjects for consideration. The mode of such presentation varies widely, but (at least Victor Turner's analyses) usually balance *freedom* -- the freedom to discuss and/or think about the presented norms and ideals without ordinary restrictions (you can't talk about those things in public, it's wrong or dirty or blasphemous; you can't question those things, they're just true because that's the way the world is; etc.) -- and *constraint* -- the constraint imposed by the structure of the rite such that the neophytes emerge having accepted the near-absolute value and validity of those cultural norms. In other words, a passage-rite 1. transitions the subject(s) from State A to State B 2. by way of a sharply-delimited liminal phase 3. during which phase certain culturally-important norms and ideals are presented strongly 4. for free consideration and interpretation by those to whom they are presented 5. with the constraint that interpretation must ultimately reinforce the social norms and ideals Furthermore, 6. the symbolism of transition from A to liminal is commonly that of death (one dies to State A) 7. the symbolism of transition from liminal to B is commonly that of birth (one is reborn into State B) If human sacrifice is construed as passage-rite, in the same way as funerary ritual is, then a few points immediately become clear: * State A includes "live" and State B includes "dead" * the liminal phase is defined such that physical death occurs in its purview * the norms and ideals almost certainly have to do with the nature of life and death, but also with the status or qualities of those who undergo the rite, as well as possibly those who order, perform, or otherwise engage in the rite * the free consideration and interpretation is almost certainly not confined to the initiatory subject (the victim) * entrance into State B is likely understood as some sort of rebirth In Classical Mesoamerican societies, a number of core principles linked these factors. For one thing, human beings and their life-cycles were analogized to maize. Maize, after all, reaches its maximal value when it is harvested and ingested; just so, human life is incomplete and problematic until its has ended and the body/spirit/blood been ingested. On this understanding, "ingested" includes not only cannibalism -- which did occur, in token symbolic instances, across Classical Mesoamerica -- but also being eaten by certain gods, as well as having one's body be absorbed into the earth as fertilizer for new crops/life. It is unclear, but sexual intercourse may in some circumstances have been analogized similarly, with the vagina becoming a mouth that eats male spiritual essence -- this links up, arguably, with the regular appearance of *vagina dentata* symbolism throughout a wide swathe of American mythology. The only point that appears to prevent regular human sacrifice, in most modern conceptions, is that one "obviously" should not kill other people on a large or regular scale. Here again Classical Mesoamerican examples demonstrate the incoherence of this claim. Warfare was normally conducted using weapons poorly adapted for killing one's enemies, but beautifully adapted to rendering them unable to fight. Battle was normally a matter of defeating one's enemies and then dragging them home as slaves. In later Aztec society, a very large percentage of such slaves were sacrificed, but the difference between this and earlier formations seems to be a matter of percentages and scale. The point is that if you have defeated your enemy on the battlefield, in most open-warfare situations, he is dead. The fact that, in Classical Mesoamerica, he may not actually be physically dead, does not change the point. If a battle between 500 warriors on each side concludes with one side having 150 escape and the other 350 die, does it matter whether they died in that moment on the field or a few weeks later on the sacrificial stone? They're dead either way. Indeed, one could argue that death on a battlefield renders the warrior anonymous, strips his individuality and significance from him, as he becomes nothing more than a statistic. By contrast, his sacrifice on the stone grants his life and his strength specific worth, and he is given an opportunity to face death in a way he considers proper. Sacrifice, in this view, is essentially battlefield cleanup by other means. This brings us to the question of "honor." We often encounter a notion that one should honor the dead, and we are continually enjoined to honor brave soldiers who risk their lives and die on the battlefield. In the Classical Mesoamerican conception, such honor should not be done at a distance, nor only by one's own people. One should honor one's opponents for their bravery and warlike qualities, as well: if your enemies are not worth that honor, why fight them? why risk your own warriors' deaths in combat against meaningless enemies? Those whom we defeat in battle we honor in sacrifice. Through sacrifice, several things happen. First, we give great power and strength to our tutelary gods, who support us in our endeavors. Second, we honor our brave warriors who capture their enemies in battle. Third, we return the mighty bodily power of our enemies to the earth, where it fructifies our crops and our polity. And fourth, we grant our brave enemy an opportunity to show his bravery and worth, to demonstrate his power and significance, before a wide and admiring audience of our own people. We know very well that he would do the same for us, for he comes of an honorable and mighty society -- albeit not so mighty as ours. And so we know that, if he is truly a worthy opponent, he will march to the stone demonstrating his power and his lack of fear, thereby ensuring that all our gods will rejoice in his life and his death. There is a lot more to it than that, of course, but I wanted to present a conception under which human sacrifice depends on positive notions, both metaphysical and socio-political. One could certainly argue, as other answers here have argued, that US-style death penalties, abortion, and a number of other phenomena could be read as human sacrifices. The questions at stake are not at base ethical: it's a matter of the symbolic construction we impose in order to interpret these behaviors. Indeed, I would argue that US-style capital punishment is far less ethical, in every possible sense, than was Aztec sacrifice, because (a) we don't think that the dead body is worth anything, (b) we pretend to think that those who revel in revenge are in the wrong, (c) we deny the utility of the performance to any wider audience, (d) we treat it exclusively as a punishment. Thus nobody gets anything positive out of capital punishment: the only "good" is the removal of a negative. But I don't like double negatives in rhetoric, and I really don't like them when it comes to people. Short answer: yes, human sacrifice is entirely possible, and indeed is arguably practiced in the United States as a legal process (albeit a very incoherent one). To build human sacrifice in your worldbuilding project, focus on *what it does positively*. People die all the time; whether they die under a knife or by being cut down on a battlefield, they're dead. So the difference that makes human sacrifice interesting is that *it puts a focus of control on the death, thereby granting it higher-order meaning*. Once you work out your processes of initiation, the fundamental symbols and mysteries at stake, you may begin to wonder whether your sacrificing society is any less "developed" than is the United States. [Answer] Yes, for example if a society were so medically advanced that it's members were effectively immortal, it could develop a tradition/legal requirement that to have any children you would have to find someone who would willingly offer themself as a human sacrifice. This tradition/legal requirement could easily develop ritualistic elements over time. Basically you need a widespread belief that something terrible will happen if the sacrifices halt. E.g. the Aztecs believed that stopping would cause the apocalypse, the vault dwellers in the Fallout example above believed that the vault tech would kill them if they stopped, the hypothetical example society would believe that stopping would lead to unsustainable population growth. [Answer] Let's define sacrifice to be the killing of a human for a non-material effects. Although we use the word sacrifice to describe the deaths of soldiers and the like, that's not really what we are after. If we do that, we define sacrifice to mean any death occurring in the pursuit of a common good, this would include work places accidents and dying in labor. If the person is killed as a side effect of another activity, then that is not a sacrifice. The haunting thing about human sacrifice is the killing of person not as a side effect of some otherwise positive act but instead the killing of the person itself is the point. No culture that practiced human sacrifice justified the practice on materialistic pragmatic grounds. But that doesn't mean there weren't ones. Cultures evolve under selection forces just like all other animal behaviors. Practices that persist long term must have a payoff for the cost. But there is zero correlation between the explanation for the behavior and its functional purpose. The pragmatic reason for human sacrifice in meso-America is almost certainly their inability to control, long term, large numbers of prisoners without metal weapons or restraints. Killing warriors was the only way to neutralize them. The primary weapons of meso-America were the trained bodies of warriors. They technology was secondary. Today one guard with a heavy machine gun can control hundreds of prisoners but with wood and stone weapons, one guard can control may two of three. It's hard to create restraints from cord or wood that prisoners cannot defeat if unobserved for a few hours at most. The mass slaughter of the soldiers of a defeated army is a disturbingly common practice in history. Soldiers are still dangerous even if their cohesion is broken in battle. In Japan it was common to hunt down and kill all the soldiers of a defeated army to keep them from turning to banditry or seeking revenge. Their is also the issue that virtually all preindustrial war was wars between dynastic lineages. The only way to destroy the organizational structure of an enemy was to kill the elites root and branch. That is why infanticide played a role in dynastic struggles. In meso-America, the practice of human sacrifice evolved to kill prisoners, destroy lineages but to do so in some regulated and human way. Most sacrificed were adult males of higher rank. They developed the idea that it wasn't cold blooded murder but paying the human blood debt to the gods. The warrior culture evolved to consider it a warriors highest honor to die under sacrifice instead of battle. In one Aztec exemplar story, a great hero is captured and stands on the dais of the enemy city state. Barbarians attack threatening the civilized city. The warrior leads a contingent his own warriors and the enemy city's warriors to defend the general civilization. When victorious he returns at the head of his army to the dais to be sacrificed because he owed the gods first and foremost. Most human sacrifices have some practical function, if only psychological. I think one of the functions was to demonstrate that the upper classes would sacrifice their own children for the common good at times when the commoners where suffering from famine, plague or invasion. The rare Roman sacrifices seem to have always occurred under times of stress that threatened social cohesion between classes. The Celts seem to have used human sacrifice to kill prisoners but in times of peace to kill off elites judge to powerful or disruptive. The Druids appear to have functioned as a balance of power mechanism killing elites who caused to much trouble or who acquired to much power. None of these examples should be taken to mean that every single sacrifice had a pragmatic purpose. The people involved likely believed their stated justifications so they might sacrifice people in line with the fictional justification instead of just when needed practically. So, what practical could an advanced technical society have to sacrifice human beings? I don't think there are any. A key facet of advanced technology is complex systems managed by specialist. This makes the systems easy to sabotage, disrupt or hold hostage. That in turn means that industrial societies must have historically high levels of internal trust and cohesion. The Soviet Union under Stalin might not look like a cohesive cooperative society but compared to 18th century Russian, it was. Human sacrifice of members of the population would erode social cohesion and if even a small percentage of the population resisted the practice, they could cripple the industrial base. If you think you will end up on the alter anyway, what not take some of the bastards with you? Also, exactly what practical function would such sacrifices accomplish that could not be accomplished by some other means? If you wanted to kill people to terrorize a population into submission, why dress it up in a ritual of the common good? About the only scenario I can think of would be a civilization stuck in some kind of lifeboat scenario like a generation spacecraft. With technology fixed and unchanging, resources limited to those on board, some kind of crisis might temporarily reduce the number of individuals the life support system could support. At those times, the community might create rituals to sacrifice some members to save the rest. [Answer] Human sacrifices *were* practiced during the Middle Ages in some cultures, famously [Aztecs](http://en.wikipedia.org/wiki/Human_sacrifice_in_Aztec_culture). Historians are still debating [the reasons](https://en.wikipedia.org/wiki/Human_sacrifice_in_Aztec_culture#Proposed_explanations_of_Aztec_human_sacrifice). Proposed explanations include: * Cannibalism — but it is not even known whether this was practiced. * As tributes, the form being chosen to instill fear in vassals. * For religious reasons, sacrifice being considered something the gods will. * Population control — human sacrifice is only prevalent in relatively high-density habitats. The [Mayas](http://en.wikipedia.org/wiki/Human_sacrifice_in_Maya_culture) also practiced human sacrifice, though by the time of the Spanish conquest, it isn't clear to me whether that was still the case (as opposed to political killings, e.g. of a deposed king or a defeated enemy, possibly under a religious veneer). Population pressure combined with a low demand for manpower make a strong argument to evolve towards human sacrifice rather than slavery. This has to be in a society that puts a low price on human life. Sacrifice can also be a way to justify the killing of someone that's embarrassing to keep around, such as a defeated military or political enemy. It's more convenient for the victor if religion pushes towards killing rather than mercy. ObSF: [John Barnes, *Earth Made of Glass*](http://en.wikipedia.org/wiki/Earth_Made_of_Glass) — an explicit revivial of Maya culture, complete with human sacrifice. This isn't necessarily sociologically realistic though. [Answer] Given that things are otherwise the same on earth (including humans), I can think of only one alternative scenario where this is possible. *Gods actually exist and impact the world...and want human sacrifices. This is pretty straight forward. Appease the angry gods or they will kill the crops and your first born etc etc etc.* I am assuming you are referring only to medieval Europe here as during the medieval era the Mayans were around and human sacrifice was part of their culture. Another thought just occurred to me. If you expand your concept of human sacrifice beyond the traditional knife, fire, stone slab thing. You could consider the Salem witch hunts, the Inquisition, heck even holy wars as a form of human sacrifice. To "Honor the gods", the sky is the limit (so to speak), if you consider violence and killing in the name of god to be human sacrifice. [Answer] Sure. If a society wants to severely discourage crime, but doesn't want to give judges and juries the opportunity to choose capital punishment, a society might instead randomly choose one convicted criminal per time period (year, month, etc) and sacrifice them. Then you know that whatever crime you commit, be it jaywalking or murder, you have a slight chance of being put to death. Psychologically random punishments are significantly more stressful than logical, consequential punishments. This could apply not only to capital punishment, but for jail time (spin the wheel to see how long you stay in jail), fines, and other punishments. Once society accepts the "random punishments reduce crime more effectively than consequential punishments" then it makes sense to enact a random justice system. Further, it might appeal to readers in our time who already feel that the justice system isn't deterministic. [Answer] **The defining characteristic of sacrifices is that people would rather not make them**. They make sacrifices -human or otherwise- because they believe that they *have* to. As you point out, religion has traditionally provided this impetus: "if I don't do this, the gods will be angry". But other reasons can exist. Politics and sociology arguably provide reasons, depending on one's particular ideologies in these areas: you can see examples of this in the other answers to this question. **For a secular society to practice believable sacrifice, you need a reason for them to believe that it's necessary**. This belief doesn't necessarily have to be correct: there are interesting story possibilities either way. But as a belief, it does need to be sincerely held by those in power, or by such a commanding majority of the people at large that those in power don't dare go against it. If the belief isn't sincerely held, people just won't *do* it. But as long as you have a reason, you can make it work. [Answer] Suicide terrorism is a kind of ritual that's supposed to bring the person who commits suicide directly into heaven. The Jonestown mass suicide was religious motivated ritualised suicide. Some people consider "honor" killing of women who get rapped to be a religiously motivated. Most "honor" killing isn't strongly ritualised. "Honor" killing also existed in medieval Europe. Lessing wrote a book about it with Emilia Galotti. In the book it happens despite Christianity disapproving of the practice. When Japan lost World War II some of the military generals did commit Seppuku. Seppuku consists of a fixed ritual but it's also for "honor" instead of being for religion. Nation states generally don't want that their citizens commit suicide. The Japanese government did a lot to ban Seppuku. The Christian church did discourage suicide. Suicide terrorism or Japanese kamikaze where encouraged because it was useful for the goals of powerful people. If you want to design a world with a modern society which still practices suicide you have to explain what the powerful people in that society gain from the practice. A priest that can call for the sacrifice of a person has political power. If there are a bunch of clans the priest can decide which clan has to provide the sacrifice. If a specific clan has a lot of unbelievers, who don't believe in the authority of the priest, the clan can be called to make a sacrifice. The custom gives you interesting conflicts that you can explore. Religion is mostly just a justification that people use to defend practices they do for other reasons. [Answer] Here's one way how human sacrifice could enter a developed world: through social Darwinism. Social Darwinism is the idea that advantageous traits must be explicitly selected for among humans, and has often been coupled with the idea that this selection has to come with the physical elimination (that is, killing) of those not having the traits perceived as advantageous. Now as long as those killings are only against groups that get stigmatized (like in the Third Reich), of course it will not get ritualized in a way that you could speak of sacrifice. However, based on the assumption that evolution works best if there are many children and only the best survive, there could be an ideology that people have to have as many children as possible, more than are sustainable in the long run, and then at some point, say the beginning of adulthood, the best are selected and the others get killed. Let's say that a government holding that ideology comes into power and starts to implement it. But then you have the problem that you don't have to kill just stigmatized people (like being disabled, or being from a claimed inferior group), but perfectly good and healthy ones that just don't rank as high according to the chosen "fitness" criteria as those chosen to live. So just separating them and killing them somewhere aside will not work. But if there is to be a public killing, it *has* to be ritualized. This ritualized killing could be coupled with a ritual for the beginning to adulthood. For example, the data collected on the individuals might not be open, so those entering the ritual don't know for sure whether they are among those who are allowed to survive, or among those who will get killed. The beginning of the ritual might be the same for everyone, but then at one point, there comes the point where either the ritual killing takes place for those who are not allowed to live on, or a fake killing for those who are allowed to live, acting as test of courage to them (where failing that test by showing fear might itself be a reason to be considered non-fit). Now initially that ritual could probably only be established by a totalitarian regime. However, imagine that regime is in power for long enough that at one time, everyone alive has gone through this procedure. Then for everyone alive, that procedure was part of their life, and they have been indoctrinated throughout their life that this ritual is important to keep a healthy people, and moreover, being a survivor of the ritual gives them a certain self-esteem (after all, they survived the ritual because they were among the *"best"* people!). I could imagine that over time, this would be accepted even by people who don't otherwise accept the totalitarian regime, just as result of the aforementioned factors. So it might get happen that the totalitarian regime one day gets overthrown, but the ritual is kept intact; just that now the institution that decides who survives is controlled (more or less) democratically, and the criteria are open to public discourse. Sure, there will be those who argue against the ritual completely, but as long as the majority supports the ritual (just because they were told during their whole life that it is beneficial, and thus believe it), it will persist. It probably won't persist forever, but a lot of things we take for granted these days also took a long time to get even in democracies (for example, for a long time slavery was considered acceptable in the USA, despite having a democratic system, and even longer legal discrimination of races was considered acceptable; also Switzerland was democratic from the beginning, but was one of the last democratic countries where women were allowed to vote). So it is not unlikely that it would persist for the lifetime of a person. [Answer] This could be of interest, from Fallout New Vegas: <http://fallout.wikia.com/wiki/Vault_11> In the fallout vault described the by the link, the following social experiment played out. Convinced it would keep them safe from nuclear attacks residents were locked into an underground settlement and not given the ability to leave. These vault dwellers were instructed that they must sacrifice one individual each year or the vault would kill them all. If they refused to do so, it would praise them and give them control over the doors so they can leave as they pleased. > > They continued to sacrifice each other until only 5 remained. 4 of those kill themselves when they find out the truth. > > > This seems to be an example of humans sacrificing humans to some construct originally made by humans but now with power reminisent of a god (complete destruction). [Answer] The development level of a society has nothing to do with whether or not it practices human sacrifice. History is rife with many examples, and in fact, a more "developed" society may be even *more* likely to engage in human sacrifice than a less developed one. It all depends on the morals of your society, not its development. It all boils down to how much your society values the individual vs. how much it values the group. A prime example is Nazi Germany. They did very brutal things, but they did so not from a lack of civilization, but from arguably *too much* civilization. Fascism at its core makes the State the sacro-sanct authority in society, and the State is arguably the face of "how civilized" your society is. Individuals must confirm to the group, and as such, an individual becomes *less valuable* than group ideals. This is the core of Fascism: The individual must be brought in line with the group(i.e. The State), with zero deviation, often through violent means. This is what it looks like when a society becomes "overcivilized." There is no dissent, there is no discussion, The State knows all and provides all, and thus The State is above all. The State is Mother, the State is Father, and for a harmonious society, you must obey the State. Fascism's closely related authoritarian brother Communism is the same. Individuals are less important than the collective. The society values sacrifice of the individual for the group, and individual rights either don't exist or are extremely curtailed in the face of The State. It doesn't matter how many people must die to build that dam, to put out the fire, to clean up the nuclear reactor. This is our shared burden, we sacrifice ourselves for each other and for the glory of the Motherland. So at the end of the day, any society that places little value on an individual will have no problem sacrificing them. Whether it is for appeasing the Sun God and a bountiful harvest, or for a Great Leap Forward to bring society into a prosperous new industrial age, it's all the same, namely that one can be sacrificed so long as it is for the "greater good." On the other hand, if your society values the individual's irreplaceable uniqueness (there is no smaller minority than the individual), then the idea of a human sacrifice becomes anathema. In that case, you're damaging the collective by removing a part of it that cannot be replicated by any other individual. Such societies would naturally gravitate away from the ideas of sacrifice for the group, as it is considered detrimental to the group in the first place. These are the two extremes of authoritarianism (from which Fascism and Communism derive), and liberty (from which Libertarianism derives). Ultimately it boils down to who is considered to be the the entity best suited to addressing the problems of the people. In authoritarianism it is the State, with a top-down approach. In Libertarianism, it is the individual, with a bottom-up approach. You can of course have a middle ground, in which individuals voluntarily sacrifice themselves for what they *personally* deem to be a higher cause (no man has greater love than he who lays down his life for his brother), but this has nothing to do with the level of "development" or how "civilized" your society is, thus even in a 100% Libertarian society, you might still have human self-sacrifice. [Answer] In Brent Weeks' Lightbringer Series, there is a group of magic users who manipulate light. Everyone only gets a set amount of magic they can use in their lifetime; once this limit is exceeded, it is common become a threat to the community. To combat this eventuality, a religious ceremony is held every year for those magic users who are at the end of their allotment to offer their lives in service of the greater good. The long and short of it is that after prolonged exposure to a certain experience (in this case magic), people were very likely to become a very real danger to themselves and others. This same scenario could happen after exposure to a disease like rabies, intense radiation or a significantly traumatic experience that leaves one prone to homicidal/suicidal tendencies. The people in this series preemptively committed a form of ritualistic suicide at the hands of their religious leaders to protect the community from imminent feral impulses. [Answer] **Down the Volcano** Recently, there was an episode in American Gods which rather creatively answered this topic. In the show, the god Vulcan owns a lead smelting bullet manufacturing plant. The plant has faulty rails so once in awhile someone falls into a vat of molten lead and counts as a human sacrifice. Though this scenario is a bit farfetched the reasoning was rather artful. They argued that because no one wanted the plant to shut down for fear of harming the economy and that insurance was willing to **compensate** the sacrifice's family, that the people who fell in were effectively acceptable sacrifices. And because the factory was owned by Vulcan they counted as sacrifices to him. With that in mind, one could then ask have we really moved beyond ritualistic human sacrifice? In our **'modern'** **'scientific'** society we **'believe'** in this concept of **progress** with almost religious devotion. Human Progress is basically an abstract concept much like a god in the sense we cant predict its accrual yet we have almost blind faith in its achievement. All to often we lose human life in its acquirement. Is the loss of this life acceptable? Couldn't the loss of this life be considered human sacrifice in the name of progress? [Answer] # Moloch: Some cultures would sacrifice their first-born to the gods make them right with the gods. The Romans deplored the Carthaginians for the practice, but the worst sin was that the rich citizens of Carthage started adopting children from poor families for the purpose of sacrificing them so their own children might live. The worst of the offense wasn't the sacrifice, but trying to weasel out of it. In modern times, we despise politicians and leaders who claim to be noble and altruistic, yet are rich and successful. Military service used to be an unwritten requirement of office, representing the willingness to sacrifice one's self for their country. I'm still more likely to vote for a candidate who served in the military (especially active duty). Lots of people deify their governments. Often, the government doesn't do anything to deserve this idolatry. But what if the integrity of the state is continuously renewed with the blood of martyrs and heroes? How much are you willing to give up for democracy? In modern times, I could easily see a system that required people to pursue increasingly harsh sacrifices to gain the benefits of the culture. You prove your commitment by willingly risking or giving up what you value to prove how much you value what you gain. Robert Heinlein proposed that the right to vote be contingent on military service. I could easily see a system where people agree to be euthanized when they can no longer contribute to society in order to gain access to nationalized healthcare or public benefits. A family must agree to let their criminal relative be executed so the rest of the family can remain in the state or keep public benefits. If someone wants to run for public office, they must have suffered an appropriate loss - to be crippled in battle, have lost a close family member in public service, or to sacrifice a child to prove their commitment to public service. Particularly harsh if you lose the election. Especially gut-wrenching sacrifices would get the most people to vote for you. After all, if you really didn't like that kid and sacrificed them anyway, that's the worst kind of violation of the sacred trust in the state. But imagine the dynamics in politics if you had a 25% chance to be ritually executed every time you ran for president. **Do you think the President is going to run for a second term? Hope so. Hey, that not what I meant!** [Answer] Huan sacrifice does not necessarily mean murder - excessive pain and discomfort count, as a watered down version (much of what a developed culture does is a watered down version of brutal ancient customs). As such, there is a form of ritual, religious sacrifice going on quite strong in our civilized world: [ritual crucifictions](https://en.wikipedia.org/wiki/Crucifixion_in_the_Philippines). [](https://i.stack.imgur.com/S3Dvt.jpg) Image courtesy of wikimedia. [Answer] Definitely. Hugh Howey's [Silo Series](http://en.wikipedia.org/wiki/Silo_(series)) shows one way a developed society does this ("cleaning"). People who have transgressed are sent to perform a suicide mission for the (ostensible) benefit of the community, thus being sacrified in the process. The "cleaning" process is a definite ritual. [Answer] The easiest way would probably be to have the New World stay isolated longer or develop technology faster (they had plenty of time). Human sacrifice was acceptable in many, primarily Mesoamerican, cultures. Europe used to have that sort of thing, but first the Romans [1] and then Christianity came out strongly against that sort of thing, and so it did not remain popular. And when the Spaniards ran into the Aztecs, the human sacrifice gave them the screaming heebie-jeebies. (Side note: many local non-Aztec tribes were kind of on the fence about it too) So, TL;DR -- **Keep the Aztec cultural tradition going until they're too strong to suppress** [1] Turns out the Romans were usually tolerant of local religions, and often tried to "map" other religions' gods onto their own, but they hated and outlawed druidism. Largely because of the human sacrifice deal. [Answer] # Yes, Human Sacrifice in post-neolithic cultures is common The [Aztech](https://en.wikipedia.org/wiki/Human_sacrifice_in_Aztec_culture) were culturally advanced and ran on a sustainable religion that embraced human sacrifice in a rather bloody manner. The [Maya](https://en.wikipedia.org/wiki/Human_sacrifice_in_Maya_culture) practiced it for about 1500 years. [Even the Incans](https://www.pnas.org/doi/10.1073/pnas.1305117110) did practice the sacrifice of humans in a vastly different manner. In fact, human sacrifice was [widespread in Pre-Columbian cultures.](https://en.wikipedia.org/wiki/Human_sacrifice_in_pre-Columbian_cultures) Do note that technically many of these cultures might be classed as neolithic by some, as metallurgy was not practiced. For example, the Aztecs couldn't cast or make metal objects that were not made from gold, while their neighbors had mastered bronze making, casting, and smithing. Still, they are classed as especially advanced civilizations despite that. But not just the Americas practiced human sacrifices: In [Japan, the practice of Hitobashira](https://en.wikipedia.org/wiki/Hitobashira) was most likely practiced since before the Heian era. It is unclear when, or if it was practiced was stopped before the Edo period (starting ~1608), but it is clear became a common tale in premodern Japan, leading to widespread stories in the 16th century. We are talking about a country that to the first Europeans that visited it around 1500 was described as so culturally advanced and yet heathen, that the leader of the [Jesuit delegation was awestruck](https://brill.com/view/journals/jjs/7/2/article-p204_204.xml?language=en) - and they had at that point many many stories about that practice. It was also known to be done in other Asian countries, with the idea or practice possibly having originated in China. [China](https://en.wikipedia.org/wiki/Human_sacrifice#China) is known to have practiced human sacrifice several times in history and in different cultural surroundings and aspects. There's evidence for sacrifices to a river god early on, but in later times there was a ritual killing of the staff of a ruler, their concubines, or slaves. Only in **1673**, the last human sacrifice practice was outlawed by the Ming Dynasty, but there had been earlier bans. [India](https://en.wikipedia.org/wiki/Human_sacrifice#Indian_subcontinent) saw the last human sacrifices somewhere between 1700 and 1900, depending on the region and religious sect, and both in a literal sense (actual killing) or a symbolic way (which avoided the killing of the human). What do you note? None of these cultures was Abrahamic and had a ban on human sacrifices. Among the Dharmic religions, those sects that practiced it have become virtually extinct by today. But it was practiced, as the example of India above showed. The methods used vary widely, as does the acceptance of the practice, or if the one to be sacrificed is better described as a willing offering or an unwilling victim. It isn't even excluded that the same culture practiced both. In any way, nothing culturally precludes that human sacrifice is a part of an advanced civilisation. [Answer] The short answer is: Not in any world a "developed" human being would consider "developed". The long answer is: It depends. It depends because your question is opinion based since any answer heavily relies on the definition of the word "developed". As an example of what I'm trying to convey here, for a member of an isolated Amazon tribe any society with electricity, in-house plumbing and a transportation system allowing fast travel between any two points within the boundaries of that civilization, would very likely appear to be highly "developed", but for a member of a society which is an inter-stellar civilization that same society would very likely appear to be "undeveloped" if it was also destroying the planet which supported its very existence by polluting its atmosphere and waterways, decimating the ecosystem it depends on for survival, and yes, practicing human sacrifice which is not impossible to imagine at that level of development. As you can see, your question is not answerable unless we can agree on the universal definition of the term "developed" which is highly unlikely. One possible definition of "developed" that we might be able to agree on is that a "developed" civilization is any Type II civilization on the [Kardashev scale](http://en.wikipedia.org/wiki/Kardashev_scale). If we agree on that, it is highly unlikely that any civilization reaching that level of development could ever consider human sacrifice an acceptable practice simply because to attain Type II status it would require such scientific and engineering capabilities which in turn require such amount of time that the primitive impulses would inevitably be abandoned even by the least "developed" individual members of such civilization over those time scales. ]

[Question] [ I've been puzzling over the logistics of orbital spaceports, and this has been the one sticking point I keep coming to: radiation control between docked, or even neighboring, ships. Mass limitations on ships without "torch" engines, which are engines without a high enough thrust *and* specific impulse to overcome the limits of the rocket equation, would prevent a designer from efficiently using anything more than a shadow shield that only shields the direction of the ship itself from radiation. Anything covering more of the reactor would require more propellant to gain the same total delta-v, which adds mass and reduces the thrust-weight ratio, requiring a larger engine to offset in a very delicate balance. That's all well and good until you need to dock; said shield would only protect a small fraction of the surrounding space, while pouring out radiation on any nearby ships. I'd like to figure out a way to build an orbital spaceport that doesn't require everyone besides an incoming ship to live in a radiation-proof bunker, but I'm not seeing any good solutions short of "don't use nuclear power". The radiation concern in this case is the reactor of the ship, which would be providing the majority of the electrical power necessary to operate ship systems. Main engines wouldn't be used for docking proper, but short of battery power, the reactor would have to run to sustain ship systems such as life support while not directly docked, and my understanding of radiation tells me that even a shut-down reactor is radioactive to a degree. While extending the shadow shield to cover the entire reactor is mostly possible (a direct cone behind the reactor doesn't work as well since the reactor has to feed into the engine somehow, and pointing the thinnest point for piping/etc straight back is safest), it also negatively impacts a ship's performance to a degree I don't find workable—lead and water are heavy, not to mention any other materials that could be involved. My setting's tech level is fairly near-future; the main breakthrough relevant to this question is the development of working nuclear salt-water rockets, which allow for much faster interplanetary travel but are, as implied, very radioactive thanks to the reactor used to power them (and to power the rest of a ship). No energy shields or anything of the sort; if a solution is possible with current real-world technology or something achievable from ongoing research and development, that would be preferable. I'm trying to stick as close to that general idea as possible. Please let me know if I have some fundamental misunderstanding! (First time posting, so I apologize if this isn't structured well. I've tried to use as much real world terminology as possible; I'm still in the early stages of building my setting, so I don't have the clearest grasp on any of my own potential quirks yet.) For a visual idea of the "shadow shield" I'm referring to, courtesy of Winchell Chung's "Atomic Rockets" site:  [Answer] I'd go with non-radioactive tugs. If main engine is only radiating when in use, then require ships to turn it off on parking orbit. If it is radioactive all the time, make it detachable, and require leaving it in parking orbit. Then tugs, using regular chemical drives would tug that ship to the station and dock it. Of course this would make docking and undocking expensive, but I think that's a nice plot point. Detachable engines may also be stolen. On the other hand, in near future there will be very little market for stolen parts like that... There are plot possibilities in this. And it does not require any breakthrough except the one you described. [Answer] I recommend changing your NSWR reactor from a traditional nuclear reactor to a series of LENR reactors. Traditional reactors use radioactive elements, which is exactly why you're running into radiation issues, but what if you remove the radiation all together? LENR reactors utilize the process in which a slow moving neutron is moved into an element; since the element is now unstable, the neutron is split into an electron and a proton so that the element regains stability, thus releasing **clean** energy. Now that the element has an extra proton, it actually becomes a stable new element; in the case of Nickel, Copper. Or if you used Carbon, Nitrogen. [NASA researchers are already working with Nickel and this LENR type idea](https://www.grc.nasa.gov/www/sensors/PhySen/docs/IPAG12_Presentation.pdf), so it's not implausible to use these to power your engines instead. [Here's a library of research papers on LENR if you'd like to read more.](http://lenr-canr.org/) [Here's a source from NASA Langley Chief Scientist Dennis M. Bushnell, talking about LENR's being better than conventional rockets.](http://lenr.qumbu.com/110606_evworld_bushnell_interview_part1_v401A.php) [Answer] Why not put a cap on the open end of the "torch"? Instead of extending the shadowshield to cover the entire reactor, build it in two pieces. One piece stays on the ship and protects it and the crew from the reactor's radiation. The other piece stays on the spaceport. When a ship wants to dock, a heavily shielded/remotely operated tug seals the other half of the shield on the ship, either before it docks or just after. That way, the ship doesn't have to carry a full shield around with it all the time. Edit: Visual courtesy of [Phillip](https://worldbuilding.stackexchange.com/users/224/philipp). I was picturing something not quite as big, but it captures the concept. [](https://i.stack.imgur.com/POIp2.jpg) [Answer] To preface this, be aware that nuclear saltwater rockets don't involve nuclear reactors. The nuclear fuels are kept diluted as propellant and insulated in a neutron moderator, and the nuclear reaction that provides thrust occurs externally to the ship. The ship still needs an onboard power source, but if that source is non-nuclear (like solar panels), then when the engine is shut down the only significant radiation source would be due to [transmutation](https://en.wikipedia.org/wiki/Nuclear_transmutation) of the engine components. So with that said, if you can tolerate the radioactivity of an inactive NSWR, then the solution is: ## Tugs. Tugs aren't just a solution for nuclear propulsion, they're a necessity for any setting involving large spacecraft which by virtue of their size will likely be little better at maneuvering near a space station than a supertanker is at maneuvering in port. You need small, maneuverable, powerful spacecraft to help guide the bigger ships into port anyways, which calls for a (non-radioactive) chemical rocket. You can shut down the nuclear reactor and run on battery power while the tugs bring you in to dock. Keep personnel away from the still-hot engine, but it will be much easier to shield against than a live engine. But if your engine is powerful enough to render its inactive components dangerously radioactive, then you'll need another solution. ## Launches. In the 17th-19th centuries, it was common for ships to stay at anchor outside of port, and use small boats (called [launches](https://en.wikipedia.org/wiki/Launch_(boat))) to ferry personnel and supplies between the ship and the port. Following this example, keep the ships at a safe distance whenever possible. Since radiation follows an inverse-cube falloff at distance, they shouldn't have to stay too far to keep bystanders within acceptable dosage limits. Use shuttles to convey personnel, and tugs to carry supplies, cargo, and equipment. If you need to work on the ship, bring a maintenance vessel (or mobile drydock to it). Alternatively: ## Modularity. As a third option, keep the radioactive drive unit separate from the crew habitat. [This concept](http://william-black.deviantart.com/art/Nuclear-OTV-Commercial-Transport-Diagram-471977472) by artist William Black depicts an example, where a nuclear propulsion system and its propellant is a detachable module. The nuclear propulsion module is left a safe distance from the destination, while the chemical propulsion module completes the journey. This gives you the best of both worlds. A small chemical propulsion module can come in to dock with much greater maneuverability than the whole, without any danger of radioactive contamination. The ability to jettison the nuclear propulsion system might also be highly desirable when dealing with a nuclear saltwater rocket, which is almost literally a flying bomb and something you would want to get away from quickly if there were signs of imminent failure. On the flipside, modularity is expensive, complicated, and typically not as durable as a fixed design. This solution could conceivably coexist with one of the above methods, offering greater convenience and less logistical coordination in exchange for higher operational costs. Depending upon the details of your propulsion system and technological assumptions, all three of these solutions might coexist to different degrees. You can likely carve out different ecological niches for each approach within the same setting. [Answer] # Shielding already is direction; shadow shields are fine You only need shields on the sides of the ship that are in danger of irradiating someone. For example, on nuclear aircraft carriers, there is no shielding (of the lead/poly/water type, there is still structural steel) on the bottom of the reactor, because no one cares if neutrons go that direction. There are no potable water or fuel tanks below the reactor, so the only thing in that direction are ballast tanks and the ocean. In the specific case of ships (and submarines) there is no concern that fish will get irradiated because the water is an excellent neutron shield, and a reasonably good gamma shield. In space, there are no fish and everything is very far away, so released radiation is generally harmless. You could have a space-ship that is only shielded in one direction. If you imagine a ship with a reactor that is an $x$ meter radius sphere; then an $x$ meter radius shield provides a 90 degree arc of radiation protection. The reactor can be installed in the back of the ship with the reactor immediately forward of it. The rest of the ship forward of the shield is thus completely shielded. I am terrible at drawing so imagine the following picture. [](https://i.stack.imgur.com/mZiPm.gif) What is labeled as mission module would be the reactor (and propulsion unit). What is labeled as the thermal shield would be a radiation shield (and also a thermal shield, incidentally). A good bit of separation, and then you put all the important things like people and cargo-you-don't-want-irradiated in the front. This design drops the shielding area by a factor of 4 (the surface area of a sphere is $4\pi r^2$ vs $\pi r^2$ for a circle of the same radius) and saves you mass. # Reactors and people compartments can have different shielding Nuclear reactor shields on Earth are designed to bring radiation levels down to that of the Earth, or less. In my years as a Navy nuke I received less than 10 mrem per year, despite doing some work in the reactor compartment itself. By comparison, the average dose for a person on the Earth's surface is around 300 mrem per year ([radiation data](https://www.nasa.gov/pdf/284273main_Radiation_HS_Mod1.pdf) on page 17 of this NASA report). The Apollo 14 astronauts picked up about 1140 mrem in nine days of travel to the moon and back; on the ISS the expected dose is around 12000 mrem for six months; about 80 times the radiation level of earth. There is more radiation in space, in general. Therefore, crew compartments must already have radiation shielding built into them already. Therefore, reactor shielding does not have to be as thick as it is on Earth to bring radiation levels down to the general level in space. If your shielding only needs to be 1/100th that of Earth, you can calculate the weight savings by using the tenth-thickness. The tenth-thickness of lead for a 1 MeV gamma is 1.5 inches. Therefore, if you require only 1/100 as much radiation protection, you save on 3 inches of lead on your shield (assuming your shield is solid lead). Since a lead shield is only around 8 inches in total (on Earth, that is), you get almost another factor of two mass savings from this. # Spherical station; docked bow in Put these factors together, and you have saved almost an order of magnitude of mass on your shield. You now have a lot of long skinny ships that have a radiation safe zone that extends about 45 degrees from the bow. The solution for docking them is to have them all moor to the station bow facing inwards. In order for their safe zones to overlap, the space station needs to curve away from each ship in all directions: a sphere. So the solution is directionally shielded spacecraft parked bow in on a spherical space station. [](https://i.stack.imgur.com/mF1dD.jpg) [Answer] First off space is full of hard radiation anyway so a space station that you're going to inhabit for any length of time at a stretch has to be a radiation bunker, especially if it's outside a planetary magnetic field. That's the simplest answer; ships and stations are going to get hit with a LOT of radiation *all the time* so shielding isn't the issue you seem to think it is. But to address the question anyway 1. start with traffic control, ships may not fire their main drives on a particular set of vectors within this area on pain of *really* stiff fines, this creates a series of "approach corridors" (actually cones) where radiation emission is legal and shields the station and any docked ships from an extra dose 2. still a traffic control measure really, require ships to leave their drive modules parked at a point of closest approach and use docking tugs 3. more traffic control, ships don't really *need* to get all that close to a station anyway, send out cargo tenders and supply vessels that have a shorter range and heavier payload to resupply the "docked" vessels and exchange cargo pods without long-range high-emission ships coming too close to the station. All of which ignores the fact that the real answer is in fact you can't. If someone decides to use the particles or radiation from a reaction engine as a weapon there is nothing you can do about it, by the time you can see that they have turned their exhaust on you they're already pumping out hard radiation in your direction and depending how far away they are they've been doing so for quite some time. Always remember that at seventh and last a space ship is a weapon in the wrong hands, and with a reaction drive you don't even need to hit someone with the ship directly. [Answer] Have the engine module or the ship itself on a long tether. That keeps them away from each other and the station. Crew and cargo will ride the tether like a zipline to transit between ship and station. [Answer] There are a few options here, one would be the development of anti-radiation drugs or treatments that everyone in space is taking. You can handwave the details but they allow people to survive much more radiation. This also opens up various plot points such as if the meds start running low as well as helping to explain how they cope with events such as solar flares. There is a lot of radiation in space, not just from the reactors. [Answer] Eight 45-degree shield sections that can be rotated to adjust the unshielded angle on demand between 0 and 270 degrees. [](https://i.stack.imgur.com/tysun.png) The minimum opening is given by the current reactor power level -- if your reactor is running, all that energy needs to go somewhere, and the only way to not convert energy to motion is to vent it off to the side so it cancels out (that's why you need more than 180 degrees opening radius). Stations expect you to power down well in advance and drift in, with a set of tugboats catching you and bringing you to the station. Of course, that requires a lot of advance planning -- all these heavy ships drifting with no reactor power and no way to spool up quickly need to be on safe trajectories. This means that you can only dock at friendly stations that actually do send their tugs out. This gives a good reason for the military to build large carrier vessels and huge support fleets. The reactor for a carrier is extra large, so it takes extra long to start and stop, and the carrier is a either burning through fuel at an insane rate, or it's a sitting duck that needs to be defended by slightly smaller ships. [Answer] You don't have a problem of spatial proximity, you have a problem with *logistics and management*, which is trivial to solve. The key is logistics. Imagine all your ships parked or docked side to side, passengers and noses to the station and nuclear engines facing outwards. When docked, the ships switch to power from the station's own power system (solar/nuclear in its own separate module) and turn off their own power. Result - if only one ship at a time is under power, then all (or all but one at a time) of all those engines are *off* or quiesced. So for all those parked ships, there is only a lower level radiation in the fuel and engine interior and no (or no significant) emission of radiation into vacuum. So all that's left when parked is residual radiation from the engine's interior, much like a hot car engine still gives of a lower level of heat, and even that is mostly going into space. Also if needed, make all ships in a given dock be of similar length classes. As the ships are long, the forward facing 45 degree angle isn't a problem. Any radiation from the engine exit that doesn't exit rearwards, is minimal anyway, shadowed by your 45 degree shields from any crew compartment or the dock itself, primarily affects the rear of ships, and falls off rapidly anyhow with distance or curvature of the dock. (In space, ships can be long and more fragile to accentuate this effect). The ships can if needed, also be either empty of people, or emptied of people and fragile materials, when parked. You park your ship, you leave it (taking anything with you in a cargo pod if needed for security or safety), and only when the dock is safe and empty again does the next ship move. Your problem is now reduced to having a load of **stationary** parked ships present (which could be made empty) while *one* ship parks or departs only. The time taken to travel from say 3 miles away to docked is minimal and for any given ship doesn't happen all the time (perhaps not often), so any exposure on arrival/departure due to being exposed to the rear of these ships is probably reasonably small and doesn't need extra shielding. There are many ways to work with this. For example the docks themselves could also be in small "clusters" around a "parking module" a bit away from the main station and transfer to/from there to the main station (think cruise ships). The ships can leave the dock by a simple sprung pressure (air or other) - they get pushed off, and a few hours later are 20 - 100 miles away and can fire up safely. Think air traffic control. As long as only one ship at a time is moving, its easy to make safe. So your problem in space becomes a much easier problem in time/logistics. [Answer] Avoid having outbound spaceships fire directly towards the station. When they undock, a small amount of thrust sends them directly away from the station. The spaceship fires a side thruster to move the station out of direct line of sight with the main engines. Depending on the design of the spaceship, they might also be able to rotate the whole ship to achieve the same effect. Once the space station is out of the danger area, the spaceship can fire its main engine to move in a direction perpendicular to the station. [Answer] Modular ships. Have the dangerous nuclear engines in a pod that can be detached and left in a parking orbit some safe distance away. Ships would then approach for docking using their non-nuclear maneuvering thrusters. ]

[Question] [ It basically says it all in the title. I assume the human will eventually succumb to malnutrition, but I wonder what the minimum number of trees are necessary to provide the human with enough energy to survive the longest. Assuming the human: 1. has ample shelter 2. has a way to open coconuts 3. is in a climate that can support year-round coconut production 4. is on an island big enough to contain the minimum number of trees 5. has no other form of food on the island / surrounding waters **Bonus** : How long until they succumb to malnutrition and die? [Answer] Well, start with the [Wikipedia page](https://en.wikipedia.org/wiki/Coconut). > > On fertile soil, a tall coconut palm tree can yield up to 75 fruits per year, but more often yields less than 30, mainly due to poor cultural practices > > > The same page lists the nutritional value as 354 kcalories per 100 gram serving. And [finding](https://cooking.stackexchange.com/questions/73810/how-much-meat-is-in-one-wild-coconut) the weight of the edible fruit part alone, the USDA says that one medium coconut has 397 grams of meat. So one tree gives 354 × 3.97 × 30 ≈ 42,000 kcal/year. Of all the nutrients needed, I expect lack of calories will kill someone the fastest. You can repeat the analysis with other requirements and timescales for the deficiency to become debilitating, with the information “food label” on that page. If each adult male needs 1,500 kcal per day, that comes to 13 trees. But that’s for a sedentary white-collar worker; it’s suggested that harvesting will take some effort and the castaway may need to be more active in general. With a ration of *2,000 kcal per day*, **18 trees** will be enough. That assumes production is continuous or food can be stored, and that the wild coconut is similar to a “medium” cultivated coconut. **Add a few extra to be sure**. You can adjust that based on the activity level you need for the story. We assume the low value indicated for yield at least for the first year. If he knows what he’s doing and “farms” them then yield can go up. But if there is nothing else to eat there’s nothing to use as fertilizer either, so it might be slim pickings. [Answer] In addition to JDługosz's answer on the number of trees required to provide calories, I would suggest growing further trees to ferment into coconut milk kefir and alcoholic beverages. Although best made with starter cultures, there are wild yeast almost everywhere on earth that can start fermentation. Because these cultures contain yeast and bacteria they contain nutrients not found in the original coconut. The yeast (trub) can be collected after fermentation and processed into yeast extract for a nutritious and tasty supplement. In particular, yeast is rich in B vitamins that are otherwise hard to obtain. And booze helps pass the long years of subsisting on your own on an island... [Answer] BONUS QUESTION: This page <http://www.npr.org/sections/thesalt/2015/12/03/457124796/death-by-coconut-a-story-of-food-obsession-gone-too-far> says a man lived on coconuts from 1902 (and Wiki says he adopted a monodiet around 1905 or 1906) until imprisonment during WWI in Sept 1914, at which time he weighed 86 pounds. So, a while. [Answer] It seems body stores quite a lot of B12, thus can survive very long without it. The guy could obviously drink sea water, but, if he does not, he will soon die of sodium deficiency. It seems humans should take at least 500mg of sodium per day [[1]](https://chriskresser.com/shaking-up-the-salt-myth-the-human-need-for-salt/). I experienced sodium deficiency first hand, its no fun. ]

[Question] [ My main protagonist is going to fast-forward himself in time by 1000 years. He will simply reappear in the same place (marked by a small beacon), the process being instant for him (no hibernation etc). This is the only "magical" technology in the universe, known only by the protagonist. However, he wants to prepare for a potential scenario where the Earth is rendered uninhabitable for whatever reason, and perform the time travel in a well-prepared, isolated place. He would like to stockpile any and all items required for him to survive, as he investigates the reality outside, or at the very worst, to allow him to live the rest of his natural life in the isolated area. He will have access to a reasonable amount of funding (several millions of dollars) to let him buy a concrete bunker in a safe (at least in his time), remote area. However, he won't have access to unlimited resources like millions of scientists and engineers, or any technology not available in 2016. After watching several scientific documents about experiments with food decay (performed by the brilliant researched by the name of Ashens), he knows (and so do I) that canned food or hermetically sealed chocolate simply won't do even for 50 let alone 1000 years. Any suggestions? [Answer] Simplest fix - you have a time machine. Why bother letting your supplies degrade or get stolen over the 1000 years, when you can either (a) build a larger machine and take them with you, or (b) send them 1000 years forward, a batch at a time, before you go - so everything's fresh when you arrive. If that's not practical if the destination physical location is fixed, then (c) arrange for your loyal henchman or automated conveyor system to send them at prearranged intervals after you arrive (gives you time to leave the target, watch for supplies arriving, and then nip in and move them before the next batch is due). [Answer] Your bunker will have to be underground, if you want to ensure that it stays untouched for a thousand years. That being the case, keep the access on the top part, fill the inside with 90% CO2 before sealing, and have a layer of a drying agent like calcium chloride next to every outer wall. You should be able to store honey, salt, oil and grains and nuts without issue. Preserved meat/fish and fruit probably won't last (in an edible form), powdered stuff in sealed containers should last indefinitely. It would be best to have as many varieties of seeds as possible, stored in airtight containers, in case these have become extinct. These will be an excellent means of trade or basis for setting up agriculture for the traveller's own subsistence. Keep a water purification system (but not water) and an energy source (e.g., a diesel generator with sufficient fuel at hand) ready for use in the bunker. Once sealed, the calcium chloride will dry out the air inside, while the CO2 will prevent fermentation or saprophyte growth, as these, too, expel CO2 while respiring. Archaea should not be a factor as long as there is no water available. Avoid keeping a light source in the bunker, in case an unnoticed seed on the ground starts to germinate; the absence of water is an added backup to prevent this. Animals, like rats and cockroaches will be killed off by the high levels of CO2, thus will bot damage your supplies. The above assumes the bunker is airtight. Otherwise, water entering will destroy everything, eventually. Assuming, of course, a concrete bunker can survive a thousand years. [Answer] # Radiation sterilizing No really, [irradiation is one of the most effective ways of preventing food from spoiling](https://en.wikipedia.org/wiki/Food_irradiation). The kind of foods he should do this with is foods that do not spoil easy. Sugars, flours, protein powders, mineral and vitamin supplements. The "simpler" the food the better. The more chemically complex a food is, the more likely it is to spoil due to oxidation and other natural processes. He should also add candies and other such treats, because that kind of food gets boring very quickly. He needs something to keep his spirits up. And speaking of spirits... yeah, a little alcohol probably will not be a bad idea. Also basic medical supplies would probably be a good... penicillins and other antibiotics for instance, and plain old painkillers like ACAs (like Asprin) and paracetamols. The supplies should be hermetically sealed, preferably in an inert atmosphere — like nitrogen or noble gasses — before being irradiated. He should also take care to store these things in fairly small containers, because if there is a breach, the less volume gets spoiled. He might also want to create several caches so that if one is discovered and raided he does not lose his whole supply. [Answer] ## Permafrost The Siberian Tundra is a vast, largely undisturbed frozen wasteland. It is a cold and dry climate, with the ground solid with permafrost. It is possible to store food in these conditions for multiple thousands of years. Proof can be found in the mammoth carcasses that occasionally thaw out and are sufficiently fresh that scavenging animals have been known to eat them with no ill effects (I don't believe any humans have tried, but their dogs certainly have). These carcasses are in this condition despite there being no active attempt to preserve them -- nature did it on its own. Your time traveller should take advantage of this and bury his supplies in the Siberian wilderness. With proper choice of foodstuffs and good preparation, his supplies should easily last 1000 years. Possible negatives: * Global warming. The mammoth carcasses I mentioned earlier are showing up now because the permafrost is melting. It is possible that global warming will have completely changed the Siberian climate in 1000 years, in which case his frozen supplied may be thawed out and ruined long before he arrives. He will need to assess this and pick a location (far enough North) to avoid this. * Discovery. Sure it's remote, but Siberia is not entirely uninhabited. If the population increases over time, then there's a chance his stash may be found. I guess this is a danger for him no matter where he puts it though. My advice for the traveller would be to forget about doing one massive thousand year jump. Instead, try jumping in hundred year increments. Spend a week or so in each time frame re-assessing the situation and re-stocking your cache before doing the next jump. It may take him a couple of months to get to his 1000 year target, but that really isn't very much time to spend given the scope of how far he's actually going. Doing it in small jumps will have a number of benefits for him: * He will be able to see how the world and society is changing over time, so he will be less of an outsider when he arrives. * He will have an opportunity to change his strategy mid-way through. For example, if a new settlement appears close to his beacon, he might chose to move the beacon further away before the settlement grows and becomes too close. [Answer] Mushrooms? Ensure a steady trickle spring flow that is not going to erode your bunker and let the mushrooms grow. You could even grow cave fish. Set up your own biome basically. Extra points if you can engineer bioluminescence. [Answer] **Food** - There are very few foods that will last long enough. 1) Processed Honey - Lasts forever if correctly stored. Good source of sugar and can be used as a mild antiseptic. Also relatively cheap. 2) Pemmican - This is a type of stored meat invented by American Indians. Lean meat, usually game like buffalo or elk, is dried over an open fire then made into cakes with dried berries and fat. Good source of energy, protein and one of your five a day. They will also last forever. 3) Hard liquor - Vodka or spirits if stores out of the sun will last. They will get less alcoholy as time goes on. These drinks will be good for drinking when you have no water and can clean wounds and sterilise stuff. 4) Powdered milk - Lasts forever. Can be used in cooking and baking as well as for drinking. 5) Water supply - Try and get somewhere near the top of a major river. This should reduce the risk of the water supply getting diverted or polluted. **Money** - Obviously your money might be worthless in 1000 years time. I would suggest bringing a load of objects like radios or books to sell to collectors of historical stuff. **Furniture** - Use metal furniture as this will last better. Also seal off the bunker as much as possible to avoid the metal rusting as much as possible. [Answer] I'd be very hesitant to stake my life on claims that a recently-invented preservation technique will keep food edible and nutritious for 1000 years. How do they know? How are they measuring the rate of decay? How reliably can this be extrapolated into the future? Maybe your measurements are not precise enough. Maybe decay starts out slow and then accelerates. Etc. When CDs were first invented, studies supposedly proved that they would last for 100 years or more. In practice plenty of CDs have failed within a few years. Or: One of the big selling points of compact fluorescent lights is that they last for 5 years or more. In practice, I bought a new house 6 years ago and put CFLs in most of the fixtures, umm, about 25 of them. Only 2 of those are still working. I haven't kept records to calculate the average life span, but no way has it been 5 years. So what food has actually been preserved for 1000 years, or some appreciable fraction of that? Several other posters have mentioned honey in Egyptian tombs. Sugar and vinegar can also last for centuries. Canned goods can last for decades. Dehydrated foods, too. But I think that's about the limit. (Irradiated food lasts for at least decades. Irradiation has only existed for a few decades so it's hard to say just how long it will last.) There's also the question of how you'd build the bunker. For all you know, an area that is remote and isolated today might be the middle of a major city 1000 years from now. Lots of cities today are in places that were wilderness in AD 1016. And could you build a bunker that would survive intact for 1000 years? Yes, there are buildings standing today that are 1000 years old. But most of them have had people working to maintain them. Places left on their own tend to collapse into ruin. If the hero can't bring supplies with him, or send them ahead ... it's a tough problem. [Answer] The best known preservative is vacuum combined with cold. While it is not overly likely with year 2000 era tech, a bunker on the moon would likely be your best bet. Protect it from radiation, leave your water in the form of ice blocks or sheets, use foods that will adapt well to freezing and being stored in thin sheets, store sufficient amounts of atmosphere and CO2 scrubbers, and you'll need a method or location for observation, possibly a suit, and a ship and fuel to get back to the planetary surface. Might want to use fuel that can be broken out into requisite (freeze-able) parts for later recombination, or tolerates freezing itself. Just don't mistake it and try to drink it later. A source of power and heat production should finish it off. [Answer] Your time jumper should store seeds, or plant fruit trees around their bunker. They will need to grow crops to live, unless they are able to forage food from the post-apocalyptic environment. Sugar or sealed, sterilised honey are pretty stable and can give them the calories they need to live for a little while, but not all the vitamins they need in the long term to live a full life. Canned food has zero vitamin C. Dried food exposed to oxygen loses its vitamin C over time, if it wasn't already baked out in the drying process. Vitamin pills will lose some of their vitamins over time. After a thousand years I'd be surprised if there's any vitamin C left in anything they can store. In general, they can't expect preserved food to give them all the nutrients they need. If they want to not die of scurvy in the first year or two, they will have to occasionally eat a non-preserved fruit, or vegetable or animal liver (but don't eat the liver of any arctic carnivore... you could die). [Answer] (viable) honey was not found in the pyramids, this is a fallacy. I have searched and not found any proof of this. In fact, there are several locations where there is possible evidence of liquid honey and honey in the comb having been left, although this is surmised from traces. The detail of the pyramid honey is erroneous and is first found in a book (I don’t have details with me ATM). I have researched this as I have an interest as a bee keeper, as this “fact” is often bought up. Even in sealed containers honey will break down. How about a 3D printer using base chemicals? Still a bit fanciful, although the elemental parts ought not decay in that time. It would seem that your best option would be a deep freeze – permafrost, glacial ice etc. This may work when we look at the preservation of mammoth, and add in modern preparation of the stores prior to freezing. [Answer] Enclosure(s) should be fabricated from stainless steel and welded shut. This will easily last 100,000 years. Air should be removed with a vacuum pump and replaced with Argon or Helium as these are inert. [Answer] As the earth is constantly moving, changing orbit etc. I am lead to the assumption that, whether or not the beacon is in the same place as he started, he will always re-appear at the beacon. Therefore, our protagonist scopes out a livable planet, with oxygen, earth like environment, water etc. this would ensure that he as he re-materializes, he is not crushed by something already present at the position he spends his money on three things: One: prepares a large canister with the beacon attached, with propulsion systems attached. the propulsion systems would only need to be course correcting etc, and very minor thrust, as over the course of 1000 years the vessel will easily arrive at said planet. the cold and vacuum of space also means that any food kept within will last better. two: he fills said with enough honey to last him a few weeks (honey lasts forever) . and some tools three: pays nasa/whatever space program to launch his 'vessel' towards said planet. if it is to expensive to launch it himself; it only takes $250,000 or so to 'book' a flight to space. he could simply take the vessel with him and launch it easily from space himself, thus removing the need for a vessel able to leave the atmosphere four: wears a suit of bees and enough bee queens to start a functioning colony beams forward 1000 years and is now on his own planet, safe and sound. if he is lucky, human colonization has already reached said plane, and he can easily return to earth. It can also be assumed that, as an artifact of 'space' found on the planet *and was there before humans arrived* it will be kept somewhere roomy, like a museum or some 'area 51' type place. If humans haven't arrived, he was prepared to live through an apocalypse anyway and no big deal. he now starts a bee colony on his new planet, builds a house and, if there is animal and plant life, can hunt said creatures for more diversity of food. if there is 'intelligent' alien life, (which, assuming wasn't there before because he had checked the planet, so it is relatively new) he can easily become their god because he has advanced technology. Tl;Dr: Honey lasts forever (has to be the correct type). he can keep stockpiles of honey in his bunker if he doesn't feel like leaving earth; or keep it in a small shuttle above earth if he wants to easily return if he is worried he will be crushed by materializing in a wall. [Answer] ## Location: Real estate is key here, as many things happen in 1,000 years. The place I'd suggest is in space. If apocalyptic events happen, The 'Traveler' may not be able to continue, flooding will trap them in, heat waves will bake them, earthquakes will shatter their bunker. Humans *especially* will accelerate this process. Space, however is very achievable today, and contents are well preserved due to the vacuum, and radiation. Not many things that you would have to worry about in space, but one thing is *location*. If your orbits are off by a hundred thousandth of a meter per second, in 1000 years, you may land outside the shuttle. The one way to guarantee you are inside is to take the shuttle with you, which shouldn't be too difficult. Another concern would be power. The most likely source would be an [RTG](https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator), a device that generates power off of radiation. Typically the plutonium 238 inside of these has a 87.5 year half live, meaning if you brought 10kg up with you, you would have about 0.003kg when you came back. Americanium 241, however, has a half life of 437 years, meaning a 2kg sample from an RTG would contain 0.4kg after 1000 years. That's enough to generate 54 watts of power, or keep a battery pack charged. ## Supplies: Unlike humans, Supplies are *expensive* to send up to space. According to space.SE , it would cost about [2200 USD per Kg](https://space.stackexchange.com/questions/1989/what-is-the-current-cost-per-pound-to-send-something-into-leo) into LEO. Assuming The traveler is hefty 100kg , it would cost at minimum 50,000$ to send the traveler + some basic supplies. The return shuttle itself would probably be millions. To cut down on costs, one could hide caches of supplies around the planet in containers. This would not only cut down the cost of transportation, but storage as well. All you need to do irradiate the food (Idea courtesy of *Michael Karnerfors*) for a long period of time. Given they you're already buying americanium for an RTG, I say you get a bulk quote and save some money. # The journey: ## preparing is only half the battle, what do you do when you get there? Well, Assuming you're in space, and still in your shuttle: **Is earth still 'there'? can you land on it?** If either of those questions is no, then you're probably not getting home. turn off the oxygen and watch the stars for a bit. If you can land, however, you'll need to do so soon, as you probably didn't bring enough rations to last more than a few days. **Can you recognize any landmasses?** While 1000 years is not enough for plate shift to be noticeable, the sea may rise and lower with time, and make some masses unrecognizable. If you cannot recognize the landmasses, then **Are GPS signals still being transmitted?** If so, you're in luck! you can pick a landing place with precision! If not, You're going to have to rough it out, and land *somewhere*. **Are there still Humans on earth??** if yes, you may be in good hands, humans are a sign of survival, which can help you do whatever you need to do. If no, Then something bad happened.... Hope this helps. [Answer] Store it in single components in the most stable form * Separate pure glucose, starch, fructose, fat, vitamins, salts/minerals, ethanol (for disinfecting, drinking and fire) dried and sealed in glass flasks under protective gas, put in the dark and into the ground (to profit from the stable temperatures). * The same for water (but water needs to be stored in larger quantities, better have a purifier ready for anything but the first few days) * sulfuric acid, electrodes (separately) for making a battery and other processes * sulfuric acid, nitrate, glycol (to produce explosives, may come in handy when oping the door of your concrete building and remode some eart which may have fallen on top) * copper wire, iron wire, rope (syntetic) * light bulbs (halogenic) * gold, platinum (with a little bit of luck, it;s still worth something to trade for) * raw materials to produce plastic etc * Hammer, furnace, steel, Drills, hand drill, A set of screws/nuts, turning iron, saw * prepare for building a buckyball if needed (if the concrete was not stable enough) -> steel sheets, with holes already drilled at the edges, glass sheets, with holes already drilled at the edges, T-Profiles * flintstone, knives [Answer] ## Seeds are a no go The only way to possibly preserve most seeds for this long is with cryogenics. According this study, <https://naldc.nal.usda.gov/download/42490/PDF> seeds might me able to last 1000 years if stored at -197C... but the technology does not exist to make a -197C cryogenic chamber that will last for 1000 years without regular maintenance. There are some species of plants that are specially adapted to be able to germinate after 1000s of years without cryogenics, but none that I know of that are edible to humans. Without cryogenics, the seeds of most plants become unviable after 5-50 years. This makes 1000 years an unrealistic goal for storing seeds to plant a new crop with when you wake up. ## For food, It depends on how long you plan to live off of this cache Some food preservation methods will allow food to remain edible after 1000 years, but edible is not the same as being able to sustain you. The molecules in food break down over time, even if they technically do not rot. In most cases this means that the complex molecules just break down into less complex molecules that your body can then reassemble when you eat it giving you the energy and nutrients your body needs to survive, but there are certain nutrients the body needs that it does not know how to make itself that it needs to get from food. These are the 9 Essential Amino Acids, Omega-3, and Vitamin-C. Without using cryogenic storage, the longest Omega-3 can last using any other food preservation method before breaking down is about 15 years. Vitamin-C and the 9 Essential Amino Acids max out at closer to 30 years. Being unable to preserve these nutrients makes 1000 year old food about as healthy as halloween candy. What this means for your time traveler is that some foods like dehydrated grains, sugar, and honey may be enough to keep him alive for a short while when he gets to the future, but he will need to quickly find local sources of fresh food to maintain any sort of long term health. ]

[Question] [ I have been trying to find an answer to my question for a couple hours now but I haven't had any luck on Google though I might be searching using the wrong terms I'm not sure as I know next to nothing about mining. Anyway, could it be possible for a mine rich in either iron or copper to also produce some gemstones? I don't mean the big ones like diamonds, sapphires, emeralds or rubies but stones like peridot or turquoise or topaz. [Answer] Sure. Gems such as diamonds, corundums (ruby and sapphire) come from igneous sources. It's possible that one could have a diamondiferous kimberlite blast through a gold or silver ore-bearing formation, or an intrusive dyke that produces rubies or sapphires to penetrate into a similar formation. It's unlikely, given the relative rarity of the two different commodities, but certainly possible. As an example that was a near-miss (on a continental scale), the Jericho kimberlite in Nunavut (mined for a few years) is only about 30 kilometers from the Lupin gold mine, and there have been kimberlites in that same area found even closer to the mine. Amethyst, as another example, is just coloured quartz, and quartz veins provide the source of gold in some mines. I'm not aware of amethyst specifically being found in any gold mines, but it's at least theoretically possible. For 17 years I was involved in writing agreements concerning minerals rights and royalties and those agreements had provisions to cover the possibility of gemstones being found and produced at a mine for a different commodity. [Answer] As you mentioned, there doesn't appear to be a lot of information about this online, but it does seem some gemstones are associated with different metal ores. Quartz is associated with gold and a few other types of veins, and forms a variety of gemstones (amethyst, citrine, rose quartz, etc.), but I don't know if quartz veins actually contain any useful gemstone-quality pieces. (Quartz vein mining appears to be less common today, but was a big deal in the past; most of the well-known gold rushes went after quartz veins.) I'm told beryl (emerald, aquamarine, heliodor) is associated with tin ores. Aside from this, it's worth noting that some metal ores can be passably pretty rocks in their own right; precious metal ores wouldn't be used that way since they're more valuable processed, but e.g. hematite (a major iron ore) can be either a glossy black stone, which was valued as a gem in Victorian times, or banded blood red/black. Azurite and malachite are well-known semi-precious gems that are also copper ores. [Answer] > > Anyway, could it be possible for a mine rich in either iron or copper > to also produce some gemstones? I don't mean the big ones like > diamonds, sapphires, emeralds or rubies but stones like peridot or > turquoise or topaz. > > > Absolutely. In fact, turquoise, and a number of ornamental stones such as malachite and azurite, are dependent on large concentrations of copper (turquoise is a hydrated phosphate of copper and aluminum). From [Wikipedia](https://en.wikipedia.org/wiki/Turquoise): > > Turquoise was among the first gems to be mined, and many historic > sites have been depleted, though some are still worked to this day. > These are all small-scale operations, often seasonal owing to the > limited scope and remoteness of the deposits. Most are worked by hand > with little or no mechanization. However, turquoise is often recovered > as a byproduct of large-scale copper mining operations, especially in > the United States. > > > Also: > > Arizona is currently the most important producer of turquoise by value.[5] Several mines exist in the state, two of them famous for their unique colour and quality and considered the best in the industry: the Sleeping Beauty Mine in Globe ceased turquoise mining in August 2012. The mine chose to send all ore to the crusher and to concentrate on copper production due to the rising price of copper on the world market. The price of natural untreated Sleeping Beauty turquoise has risen dramatically since the mine's closing. The Kingman Mine as of 2015 still operates alongside a copper mine outside of the city. Other mines include the Blue Bird mine, Castle Dome, and Ithaca Peak, but they are mostly inactive due to the high cost of operations and federal regulations The Phelps Dodge Lavender Pit mine at Bisbee ceased operations in 1974 and never had a turquoise contractor. All Bisbee turquoise was "lunch pail" mined. It came out of the copper ore mine in miners' lunch pails. Morenci and Turquoise Peak are either inactive or depleted. > > > ]

[Question] [ Here on Earth, time standardisation was enabled by the invention of accurate time pieces which allowed us to create a global constant (GMT/Zulu time) and regional offsets. If we travel outside our time-zone for a meeting, we can be sure to know when to leave to arrive there at the right time. In an FTL equipped universe, this becomes more difficult as an FTL route A might take longer to reach a destination than FTL route B with the result that clocks on both ships would not be in synchronisation. Is there a theoretical method of inferring a "universal" time that FTL travellers can use for their clocks to maintain a constant time? [Answer] # Triangulation from X-ray Pulsars Timing and navigation are inextricably linked. The mechanical clock enabled the first calculation of longitude. GPS navigation depends on comparing arrival times (and thus distances) of different satellite signals. In a FTL future on a galactic scale, ships would want to use a 'GPS' system to determine their location in the galaxy. Building a satellite cluster with enough transmission power to be detected around the galaxy with is expensive, but fortunately nature provides one for free. [Here](http://ipnpr.jpl.nasa.gov/progress_report/42-63/63F.PDF) is a method for using x-ray pulsars to determine position in near-Earth space. Extending the system is as simple as mapping more suitable x-ray pulsars farther away. Another paper [here](http://www.asterlabs.com/publications/2006/Sheikh_et_al,_AIAA_JGCD_Jan_Feb_2006.pdf) (page 57) talks about timekeeping adjustments needed to adjust for the relativistic effects on satellites. [Here](http://www.nrl.navy.mil/content_images/06FA5.pdf) (page 100) is some more general information on about the algorithms needed for time calculation. The big difference between these methods and the FTL future is the method of FTL travel. These methods assume that you can continually collect information from pulsars, calculate your own velocity and make necessary timing adjustments along the way. That might not be possible depending on the way that FTL travel works; if FTL travel requires a wormhole or some sort of concept like subspace, then you might not be able to interact with or observe the outside world while in flight. In that case you will need another method to re-synch your clock after an FTL jump. In that case, and now I'm thinking on my own, you would use [radio galaxies](https://en.wikipedia.org/wiki/Radio_galaxy) to determine your absolute orientation in an extra-galactic coordinate system, and then use the locations of x-ray pulsars to determine how far the galaxy has 'spun' while you've been in subspace or the wormhole or whatever. From that you can determine how much time has passed, and then re-synch your clock and go back to using the x-ray pulsars to keep precise time. [Answer] > > Is there a theoretical method of inferring a "universal" time that FTL travellers can use for their clocks to maintain a constant time? > > > Generally, no. There is no universal time, period. Relativity tells us that it is impossible to put a time ordering relationship between spacetime events that are not in their respective light cones, or in other words, depending on the observer, events A and B can (in the general case) be considered to have happened "A before B", "B before A" or "simultaneously" by three different observers, unless A is in the cone of B or vice versa. Furthermore, it is unclear how time would pass when you do travel FTL. Time slows as you approach `c` and stops when you reach `c` (if you happen to be a photon), you cannot just scale it up past `c`, there is no canonical way to handle it. So you have to arbitrarily define how your FTL works and how time passes during FTL, in your particular universe, before the question makes sense. For example, if you have a warp gate based universe, where you step into a gate and just step out instantly, on the other side, then no time at all passes during the transition. On the other hand, if you enter some kind of "subspace" where you can move FTL but still have the actual "flying" metaphor, you do have a flight path and time that you need to compare with real time. If you can go through wormholes, that's a whole other can of worms (length of the hole/tunnel, location of attachment on either side of normal space, movement of the tunnel etc.). Of course, there's the saying "everybody said it's impossible, but then someone came who did not know, and just did it". So... In practice, in an universe where our current understanding of relativity stays as is, but some kind of FTL travel still exists, you would likely just invent a static convention. For example, you simply (and arbitrarily) decide that Alpha Centauri is "Earth Standard Time +1", or however long traveling from Earth to Alpha Centauri may take. It then does not matter which route your ship takes. Ship clocks will usually be wrong, but the first act upon entering the target system in sub-FTL speeds would be to ask them what their time is and set your clock to theirs. Note that there still is not much hope to have any meaningful discussions about what time it is in "universal time" at a specific planet right now, unless you let go of relativity completely. If you have warp gates, you just take a clock from earth, throw it into the gate, and voilá - you have your universal time/date. (And have violated one of the core laws of our universe, all in one go...). [Answer] *Let's pretend the whole universe uses Earth years, days, etc., for the sake of this example. However, any universal system would work for this.* Before the ship begins to travel, it decides that your destination is 0.5 light-years away. Next, it decides that you'll be traveling at exactly twice the speed of light. For the sake of simplicity, your ship's technology accelerates to this and decelerates from this instantly; the feasibility of this is a different discussion. Finally, it calculates that **(0.5 light years)/(2 times the speed of light) = 0.25 years** During the journey, the ship's computer **A)** Repeats this formula based on the current distance and speed to give passengers an estimate of the current day, week, month etc. (*This is only an estimate as distance can be hard to tell at this speed, and slight dilation can occur in the computer's cycle of repeating the formula. It's still more accurate than a clock counting for you, however*) So at a distance of **(0.1 light years)/(2 times the speed of light)** 0.05 years have passed, or 18 Earth days and 6 hours **B)** Does not actually record time, but after the journey adds projected elapsed time to time before the journey to get an accurate, non-dilated current time. **In conclusion** * There is more than just a theoretical method for inferring time during and after FTL travel: there is math! * There is always room for dilation so it's good to stop at planets and sync just in case * Since it's just math it will work for any universal system you choose [Answer] You have it backwards — FTL makes it *easier* to keep time, not *harder*. The challenge behind synchronizing clocks is not about having accurate time pieces: it's about creating a sufficiently well-defined *convention* that defines the time standard and the *communication* to carry it out. The ease\* of timekeeping today on Earth is because we have high speed communications — the time it takes to transmit a time signal is much, much shorter than the time scales we actually care about, so there is a fairly straightforward way for anyone to adequately synchronize their clocks to UTC: you simply receive a time signal from an more authoritative source. E.g. before the internet, you could set your clocks simply by turning on the TV news to get the current time. With light speed communications, galactic timekeeping is hard because communication is slow, and you'd need some sort of fancy convention and protocol to define and keep time everywhere. But the faster communication becomes, the closer you get to where you can just do the really simple thing and have authorities broadcast a time signal. \*: high precision timekeeping is still quite complicated even on small scales. [Answer] **Our Universe has an age** General Relativity might provide what you are looking for. Our Universe has an [age](https://en.wikipedia.org/wiki/Age_of_the_universe), right (at least that is what the [$\Lambda$CDM](https://en.wikipedia.org/wiki/Lambda-CDM_model) model says)? How can we determine the age of the universe? How can we talk about an age if time is not universal? Well this age is the "cosmic time" that has passed since the Big Bang and cosmic time is the time coordinate for so called fundamental observers (it is the same for all fundamental observers). So I would say that this is the perfect reference time for you travelers. The problem is how do we determine the cosmic time? Well the best way of doing so that we know of is using the [CMB](https://en.wikipedia.org/wiki/Cosmic_microwave_background), which is not very practical as (with todays technology) it is a gigantic effort ([Planck](https://en.wikipedia.org/wiki/Planck_(spacecraft))) and we can not do it very accurately ([21 million years of uncertainty](https://en.wikipedia.org/wiki/Age_of_the_universe)). But if your people can travel FTL, that might not be a problem. So you can just say "let's meet on Sunday the 13th of November of the year 3,141,592,653" and then each of the attendees of the meeting has a way of finding out when they need to leave to arrive on time. Assuming they can compute how long it takes them to get to the meeting point in the frame of reference of a fundamental observer. This does of course assume that you have a $\Lambda$CDM universe, which is the only kind of universe we know but not the only kind of universe we can imagine. **EDIT:** After getting some comments, let me clarify: The point of my answer is really, that our universe has an age, so you can define something like an "absolute" time. And giving the OPs universe an age is very plausible. Now whether this is practical is a completely different question, but the OP explicitly asked for a theoretical method. I see two problems with practicality: do you have a precise enough model of your universe? And can you measure something akin to the CMB that allows you to determine at what point in the history of your universe you are with enough precision from aboard a spaceship? [Answer] **One simply defines proper time at a specific reference point to be the standard**. Every spaceship then simply calculates the appropriate deviation based on the path they take, so everyone agrees. **We do this in real life**. Earth's UTC is derived from TT(TAI), which is a dynamical time frame. Real-world spaceships use TCB(TAI) as a common reference point. Due to relativity, they're currently ~20 seconds different, yet everyone can calculate it and agree on the time. (Lots) more information on this [on my website](http://geometrian.com/programming/reference/timestds/index.php). --- The larger problem here is that FTL is impossible, and also literally equivalent to time travel. The scheme above still works, since hopefully you can still figure out a time deviation. But the math with be complicated by all the FTL-ness (magic). [Answer] Ship located computers are supposedly capable to calculate time differences if they are capable to manage FTL traveling. So calculation will be based on astro-navigation and travelling details at the moment of entering FTL speed. However, by current computer science they will need synchronisation after shorter-longer periods to stay accurate. [Answer] The first question to ask is "what is a time standard?" We take them for granted so deeply that we oft don't even think about what they mean. A time standard typically provides two fundamental concepts, a *duration* and a *time point*. The intuitive meanings for those worlds are quite reasonable. A time point is, well, a single point in time. The time points are ordered, so we can say "time point A occurred before time point B". A duration is the time that passes between two time points, which is a scalar value with units of time. With duration we can say "time point A occurred 3 seconds before time point B."\* Time points, by their nature, are very hard to pin down. They're a little on the ephemeral side. To solve this, we pick one privileged time point, the "epoch" for the system, and we refer to all time points with respect to this one. So we might pick time point A to be our epoch, and say "time point B occurred 3 seconds after point A." If we also say "time point C occurred 4 seconds after time point A," we can do simple subtraction to say "time point C occurred 1 second after time point B." So for our time system, we need two key things. We need a way of measuring the duration between time points, and we need a privileged "epoch" time point. It turns out that this is a challenge, even without FTL. If you do a google search for time standards, you come across all sorts of interesting ones. The history is fascinating enough to work with. [Universal time](https://en.wikipedia.org/wiki/Universal_Time) is a time standard based on the "solar time" at 0 degrees longitude. This is the prime meridian, itself an arbitrary line developed by the British between 1721 and 1851. It is "special" because everyone agreed to let it be special. We all agreed to call it 0 degrees longitude (well... mostly). It defines an epoch (time point 0) of Julian date 2541545.0, itself an arbitrary line in the sand made in 1583 which was literally chosen because its epoch (4713BC) was before any historical record! Talk about arbitrary! There were a few variants. UT0 was based on measurements of distant quasars and such, but it did not handle polar motion correctly, so it was deprecated for UT1. UT1 is still technically in use, but it has a key limitation because it's time scale is dependent on the motion of the Earth, and that motion is slowly changing. Thus, we developed UTC, which is an atomic time scale (meaning the definitions of durations are defined via atomic clocks) which is kept within 0.9 seconds of UT1 by adding leap seconds. Now there's a lot of people who don't like leap seconds, so we have other time standards which do not have them. TAI has no leap seconds, so it slowly drifts away from UTC (It is currently exactly 36 seconds ahead of UTC). TAI is a great reference source for your system because it went through growing pains. In the 1970s, they realized that gravitational time dilation was causing the different clocks (at different altitudes) to go at different rates. To resolve this, we re-defined TAI to be corrected such that all atomic clocks appeared to be at mean sea level (slowing down TAI by about a trillionth!). TAI also has an even more pathological friend, Barycentric Coordinate Time (TCB). TCB accounts for movement of the solar system by applying corrections to put the "clock" at the barycenter of our solar system. It is also corrected to offset any gravitational effects. These effects are small, but they add up to about 490 milliseconds every year, which is quite a lot for atomic clock people! So we've seen the solutions that have been done with real time systems, and they show how you would probably do it in your FTL system. * Assign an epoch - This can be anywhere/anytime in the universe, all that matters is that people agree upon it. * Assign a unit of time - This should be well defined at the location you used for your epoch, and it should be possible to calculate correction factors for elsewhere (just like we do for TAI or TCB) Your correction factors are going to be more complicated with FTL, because you're going to need to sidestep general relativity without violating causality (if you violate causality, all bets on "time" are off). However, they'll just be correction factors. And, along AnoE's solution, you could continuously update your correction factors if you can receive a time stamp from the source of your epoch (a.k.a. throwing a clock through a wormhole). \* This exact formalization is used in the `<chrono>` library of C++, a popular programming language. I find it to be one of the better ways to formalize time, so I use it outside of programming. [Answer] Time is relative. Any *event* in space-time can be labeled relative to another event as any number of different coordinate systems involving different time axes. However, there is an invarient value, the **interval**, that is unchanged with respect to coordinate choice. So I propose that you won’t label everything with a universal *time* alone, but will keep track of a full 4 dimensional coordinate that can be projected to any desired time as needed. Time per se will not be seen as a universal measurement, any more than our maps show “left/right”. We intuitively understand that how far left point A is from me depends on my current bearing, so maps show spherical coordinates and are oriented as needed for each leg of the journey. So it is with time. Label an *event* P, and how far in the future that is depends on my current course and velocity. But the position of P is plotted in 4D and I can navigate to it. [Answer] *"In an FTL equipped universe, this becomes more difficult as an FTL route A might take longer to reach a destination than FTL route B with the result that clocks on both ships would not be in synchronisation.* *"Is there a theoretical method of inferring a "universal" time that FTL travellers can use for their clocks to maintain a constant time?"* If you have a universe that allows faster than light travel at all, you assume special relativity does not apply. This will be a very different universe to ours. Among the differences will be that the FTL-permitting universe will allow a universal time to exist at all, which the real universe does not. (**A brief digression about the real universe:** In our universe *any* object travelling faster than light will be seen by *some* observers as arriving before it left. In other words, a universe that allows faster than light travel also allows travel backwards in time, effects to precede causes, and so on. This link to Richard Baker's site "Sharp Blue" explains further: [Sharp Blue: Relativity, FTL and Causality](http://www.theculture.org/rich/sharpblue/archives/000089.html) For more detail, see [this link](https://worldbuilding.stackexchange.com/questions/46873/are-there-any-ways-to-allow-some-form-of-ftl-travel-without-allowing-time-travel/47038#47038) to an answer by JDługosz to a previous question here on Worldbuilding Stack Exchange. Here is another way of putting the same thing: one of the basic ideas of special relativity is that ***there is no "reference time"***. Events that are simultaneous to one observer are not simultaneous to another. It's the speed of light that is universal; time and space can be seen as squashed or stretched depending on your point of view. Mathematically this is equivalent to saying that any object traveling FTL will be seen by some observers as arriving before it left. In real life you can't have a universal time because you can't have FTL. Equivalently you can't have FTL because you can't have universal time. End of digression.) **Getting back to a fictional "FTL-equipped" universe:** If your fictional universe is "FTL-equipped" that means it does not follow special relativity and it can have absolute time built in. In other words physics could really be the way it seemed to be for most of human history. Your use of the term FTL suggests that you wish to keep light as having a finite speed. But why should you keep it as being 3 x 10^8 m/s? There seems no good worldbuilding reason to say that the results of the [Michelson Morley experiment](https://en.wikipedia.org/wiki/Michelson%E2%80%93Morley_experiment) *don't* apply in your universe but the results of the experiment carried out by Ole Rømer\* in 1676 (that [demonstrated](https://en.wikipedia.org/wiki/R%C3%B8mer%27s_determination_of_the_speed_of_light) that light had a finite speed and made a decent estimate of what it was) *do* apply. So, just **set the speed of light as high as is convenient** for the story. Then people all over known space can do as is done on Earth in real life and use [clocks synchronized to radio time signals](https://en.wikipedia.org/wiki/Clock#Synchronized_or_slave_clocks). ***Later edit:*** I have belatedly remembered that having a much higher *c* would have some awkward effects on [Maxwell's equations](https://en.wikipedia.org/wiki/Maxwell%27s_equations) causing electric and magnetic fields to be different which would in turn cause all the charged particles in the universe to be different in ways that it is utterly beyond me to calculate. Like I said, awkward. --- \*Who should be more famous. [Answer] FTL travels will ALWAYS be very messy, because it is equivalent to time travel (for at least some observers, depending on there velocity). By changing your velocity by just 1 m/s you change what moment that is "now" in a distance galaxy by hundreds of year. So, if A and B travels to that galaxy, but B initiate the FTL drive from a 1 m/s lower speed than A, he may arrive 100 years earlier. If the travel takes much lesser time, A can accelerate a bit and then return before he went away! So to have a universal time, it is very important to have a fixed clock with a fixed velocity, and define the rest with basis of that. [Answer] Ehi, We don't know what happens to time when we travel faster than light. But we do know time slow down when reaching speeds that are fractions of C. So I assume you want **A**lmost **F**ast **A**s **L**ight traveling. **System one: Forward time With Zulu at Earth** We set ZULU at Earth, we send a signal from Earth to nearest space stations/planets. So in example: * we Colonize Proxima centauri * we send a signal from Earth to Proxima centauri * when proxima centauri receive the signal we set whatever date Proxima receive as the local Proxima Time * Proxima is 4,243 light years away --- A simple example, suppose we can travel at `0.99C` which can (not) be rounded to C (assume the travel for us will last somewhat few seconds because our time is going very slow). * We depart from Earth in 2100 * We colonize Proxima Centauri in 2104,243 + (colonization time delta) * We in the meantime started to send a signal from Earth * After our receiver is operative in Proxima Centauri's space station we start to receive the signal * We set the date in Proxima Centauri to be 2100 while in reality on Earth we are in 2104,243 * When we go back on Earth we will find the date is 2108,5 --- **System two: Forward offsetted time With Zulu at Earth** * The date we set on the planet is increased by the distance in Light years * We departed in 2100 from Earth, and we arrived at Proxima Centauri in 2100+4,243 * When we go back on Earth we will find the calendar is 2108 again. The system 2 is my preferred because when we travel from one place to another we keep the calendar consistenly increasing with the date, however if we are receiving TV transmissions we will se that date is mismatched with the calendar (we are still receiving signals of 2100). However the second system is subject to an error: * we have to measure the distance from Earth exactly While the first system do not require to measure anything (you set date on received signal). --- Both methods are subject to time drift (in example 1 station orbiting near a big star have a slower time). If the drift is not excessive, we can just resynchronize clocks, but we have to prevent colonization of places that have a excessive time drift (hard to synchronize clocks). And any station/planet MUST have its own local time drift and drift of nearby stations, so that each visitor know in advance how much time is going to lose if he decide to stop in other places. --- Another usefull standard for AFAL voyages is the meeting procedure. * Assume you want to meet someone, you travel straight from A to B * Someone you want to meet take another route going first to C * Now You will have to wait YEARS before Someone can reach you unless * You leave a ticket him: "Meet me withing 10 years" **2 things can happen:** 1. Someone reach B before 10 years in that case he can program a short travel in order to make time go on forward by 10-X years 2. Someone have to arrive when you come back after 10 years. 3. Repeat until Someone arrive and will wait for you, or just leave a ticked "Bored after waiting 320 years, we'll not meet anymore (probably)". In the first case you will meet someone within 10 years, however you don't know how long will take for him to come to B. so the next time you **double** the time, this time you will leave a ticket "Meet me within 20 years".. and so on. I would suggest to make public all "meeting plans". So that everyone can join, I would guess in such a future, even with big populations everyone would just get lost "in time". You could have billions of people traveling at same time, but maybe only a bunch of people alive [Answer] **Not even in our universe** As has been pointed out by others, special relativity states that there is no fixed frame of reference, and, as such, both space and time are experienced differently depending on the observer. What this means is that different regions of space, for example different parts of a galaxy, have a different frame of reference, and time and space flows differently from one to the other, so right now, as we read this site, what we perceive as a few seconds will be perceived as years in some other parts of our own galaxy (relatively speaking). In a galaxy (or even a solar system, although it won't be as noticeable) this is mainly due to differences in angular acceleration (velocity depends on the distance to the center of a spinning disc). And then you have to factor that galaxies are moving with respect to each other, thus each has its own frame of reference, and so on. So if you're being realistic, it's pretty much impossible to have a reliable "universal" time. [Answer] Since the setting allows for super science (FTL travel), is there are way to plausibly allow for a *absolute time*? I believe that any form of *instantaneous communication* will allow for the establishment of an *absolute time*. So, how might we establish such? It seems reasonable to me that in some super science setting [quantum entanglement](https://physics.stackexchange.com/questions/170454/is-there-any-theoretical-limit-to-the-distance-at-which-particles-can-remain-ent) could be used to provide the foundation for the establishment of an *absolute time*. If one did not want to allow *instantaneous communication* as well, it seems reasonable to also say that this quantum based communication has not been perfected to the point of allowing more than just the maintenance of the *absolute time*. [Answer] Ignoring physics since you have stated FTL is to be used. If you have FTL systems why would it not be possible to have pulse clock at a stationary position that all time can be synced to? This to ad extent had been done in the US with digital clocks that would sync to an atomic clock pulse in Colorado. Taking that you have FTL pulsing bits at FTL would be far less energy than putting one ship into FTL. Thus, if in FTL clocks can remain synced to the stationary clock pulse allowing multiple ships to have a consistent time to reference from. [Answer] You just need a giantic clock with a date, that is visible from each point of interest. The time of the clock itself is the universal time. The observed time is the offset. To calculate the offset, quantum-entaglement-based datatransfer will do the work. [Answer] Let me start by ignoring FTL for a moment. There is a colony around Alpha Centuri that want have its clocks synchronized to Earths [TAI time](https://www.timeanddate.com/time/international-atomic-time.html) (or some other time standard without DST, leap seconds and similar ugliness) Once the colony has established a radio transmitter, it sends a message to Earth: ``` What is the time at the beep? **BEEP** ``` Earth is on the ball and immediately returns ``` **BEEP** That beep was synchronized with your beep on 2116-10-18 11:52:39.316 ``` That message reaches the colony about 8.734 years after the first is sent. The clever colonists decide that the Earth is 4.367 light years away, so they add that much to the time signal, getting `2121-02-27 21:56:33.432` (or so) After this they let their local clocks tick time forwards, on Earth time. They will probably want to repeat the procedure periodically. This method works because the two stars are almost stationary compared to each other. Any speed they have in common is irrelevant. If the two ends are moving relative to each other with a relativistically relevant speed, the method breaks down. So space ships, both slower and faster than light, need to use more complex methods. The nice thing about FTL ships is that they can speed up the whole procedure. A ship leaves AC with the first message, immediately returns with the second message and you can get the whole thing done in days instead of years. [Answer] Variations on measuring galactic spin and constellation drift would do the trick if you have some method of measuring micro arc seconds of star movement. (Not too complicated for a civilization who already figured out superluminal travel.) You have a single map that indicates the state of the galaxy at the moment of the epoch and then count microseconds from that point forward. The state of the galaxy becomes your universal reference point. [Answer] You could measure the distance between the Milky Way galaxy and the Andromeda galaxy. They are moving toward each other at a rate of about 110 kilometers per second (68 mi/s). They will collide in about 4 billion years. That would make today be 4 billion B.A. (Before Andromeda). *laughs* ]

[Question] [ I know the basic steps involved in creating your own country: 1. Own sovereign, undisputed land (that, if in the ocean, is 200 nautical miles away from the nearest sovereign nation). 2. Possess a permanent population. 3. Have a government system in place. Once a country has all of the above, to gain admission into the UN, the procedure is as follows: [](https://i.stack.imgur.com/ZvzBN.png) (from the [UN's website](http://www.un.org/en/sections/member-states/about-un-membership/index.html)) Now assume Joe is an average white American citizen who has attended college and earns 50,000 USD annually. In addition to his salary, he has 100,000 USD in his bank account. He has no family and is prepared to spend any time, effort, and/or money needed to create a country (most likely a micro-state) that is recognized by the UN and becomes a member of it in the least amount of time possible. *So far, I've been able to put together that:* > > His first move should be purchasing or building a remote island in > the deep midst of the Pacific, where he is far from any other > sovereign country. If he convinces some low wage workers to come with > him and stay on the island, he has a permanent population and > sovereign territory. Once he sets up some sort of small government, he > fulfills all three of the basic criteria for being considered a > country. However, this is where I run into a problem: would the UN > really accept a country with a population of 5 or 6 people and a very > primitive government (and is there even a possible island that is far > enough from other countries)? > > > Is there a better way to be recognized by the UN than what I've mentioned above (and I'm fairly sure there is) or is my plan the best possible one? (In your answers, please begin from where Joe is in America, describing each step. Use specifics. What island should he buy? How much will it cost? How can he convince people to live there? etc.) [Answer] **Average Joe cannot create a state that becomes a UN member.** All habitable places on Earth are inhabited and claimed by at least one (usually exactly one) country, so a new nation in an uninhabited place is out of the question without major effort that is way out of reach for average Joe (big floating city on the ocean, space colony, etc.). That leaves secession, either by military force or by peaceful means. There are several places where people have recently tried and failed, with a long-term effort involving many people: * Scotland arguably came closest. It had a referendum where 45% voted for secession and the UK agreed beforehand to respect the result. With the UK accepting, perhaps the other UNSC members would have accepted UN membership. * South Ossetia, Northern Cyprus, Kosovo, Palestine, Taiwan, Abkhazia, and Western Sahara, are all de facto independent states (with varying amounts of control) who have failed to get UN recognition. All are opposed by a more powerful government claiming sovereignty over their territory, and in all cases the more powerful government has allies in the UNSC. * The government in Catalunya has announced they will declare independence. Spain has declared they will block this. I doubt five UNSC members will go against Spain if they are not willing to go against Morocco, Serbia, or Georgia. Considering that all of those fails, there is no way Avarage Joe can succeed. To get passed the UNSC, you would need to get USA, UK, France, Russia, and China to agree on something. That is **hard**. [Answer] ## Forming a microstate is not a fast process, but some methods are faster than others. Consider this: <https://en.wikipedia.org/wiki/Setos> First, Joe moves to Estonia, learns the language, and settles in the Setomaa region. That way, there is a population, there are some government systems in place, and he doesn't need to ship in materials. **It is also easier to convince the locals to make a change in government than it is to convince a population to move to a remote island without food, shelter etc.** [](https://i.stack.imgur.com/XDCYM.jpg) Once Joe arrives, he should get involved with Estonia's political system. Setomaa, where he now lives, is mostly within Estonia, but it has a specific, defining culture. Joe, if he is persuasive, needs to convince the Setos people to fight for recognition as a sovereign nation. Considering how politicians in places like America can captivate the population, all he has to do is usurp the peace a little bit, and watch as political changes ensue. Next, Joe the Usurper will say that he powered the change, and hope for his people's consideration. While this is not entirely realistic, he could also run for election if the new nation is a democracy. Voila! All three basics fulfilled - and the nation is on the border of a country with UN representation, which just allowed this nation to develop - so expect recognition to come easy. --- ## Pros and Cons Let's start with **cons**: * Convincing a population to revolt is hard * Getting elected democratically is hard * There is an existing culture - there is no means for Joe to determine some things about this country, such as prominent religion, customs etc. * There is a language barrier * This isn't exactly fast **(but realism may inevitably take a while)** * The [Red Dawn Defense](http://www.nytimes.com/2016/11/01/world/europe/spooked-by-russia-tiny-estonia-trains-a-nation-of-insurgents.html?_r=0) isn't exactly helpful to Joe But consider the **pros**: * It's hard to find habitable places that no nation owns, so dividing an existing nation may be easier * The UN may reject an isolated island with no allies or recognition by other countries * Convincing an existing population to change their government is easier than convincing them to leave their families and move to an island without technology, in the Pacific, without stable infrastructure, food, communication, etc * You have a large permanent population. 5 or 6 may not be considered large enough to receive sovereign recognition --- ## In Conclusion While elements of this aren't completely realistic, they better solve the problem than moving to an island. I mean, it can't be totally realistic - if every average Joe had the means to make his own country - the world would look a **lot** different now. [Answer] Start planning backwards. Your character needs 129 votes in the General Assembly and 9 votes, including the veto powers, in the Security Council. That won't happen just because he has physical control over a few acres of dry land. The IS controls land and population. So does FARC. That didn't get them into the UN. I think first your character needs a cause, and lobby groups for that cause. Get celebrities to endorse this particular microstate. Find tear-jerker explanations why it has to be independent. Hire a good public relations company in Washington and New York. Of course all this is beyond the means of a single *average Joe* ... [Answer] Ok, we have established that average Joe can not create a country and pretend it to be a country and expect it to be accepted as a country. There are examples of such a situation, but I do not have links at the moment. But then -- What would Joe have to do? How can he pursue his dream? ## Create a country. Create a Floating country. Introduction. To be accepted as a country, he should create a country. * I do not know for which reason he wishes to be a member of the UN, because not being a member of the UN opens interesting perspectives, including nationalizing space bodies, like the Mars as an example if you can withstand the backlash of course. Creating a country means to create a force compatible to a countries influence, which is not under the law of other countries. [The list](https://en.wikipedia.org/wiki/List_of_countries_by_GDP_(nominal)) of countries by GDP, and in the UN list, there are 211 countries. The smallest one is [Tuvalu](https://en.wikipedia.org/wiki/Tuvalu#Demographics), with the population around 11,000 people and a GDP of ~40 million bucks. So Joe has to create an enterprise which is capable of generating at least 40 million bucks and employ at least 10 thousand people. He can employ a country, let it be his political representative in the UN, and give him a land for his 6 fellows to live - stand-alone. But ok, we are about to *create* a country, not to *buy* a country (which is actually very cheap - I think it is possible for 5-10 million a year, so you may want to think about it). [Google announces Q4 and FY 2015 earnings: $74.5 billion in revenue for the year](http://www.androidcentral.com/google-releases-q4-and-full-2015-earnings), so we may see a successful company is possible. I am not sure how it fits in the description of *average* Joe, but successful companies do exist. The problem with them is that they act under the law of their parent countries, so traditional business models definitely do not fit in the plan, it has to be something else. What separates Google from being or creating a country, assuming they would like to create one? If the law of their country says they can't create a country they have to obey because if they do not, the law can be enforced and make that dream impossible. So, a company which Joe is going to create has to not have vital centers and enforcing a law should have no effect on the company as a whole. It has to be able to continue to make the dream come true under the pressure of law enforcing as a service interrupting factor. It is a preamble for the internet, for p2p stuff, etc. - to work even if some nodes fail. This way his company should be like some of those. To disrupt that dream coming true, not only law on the company can be enforced, but they can be enforced on other companies under the countries influence, or individuals in a way to prevent/disrupt the action of making the dream come true, by disrupting, for example, the supply. This way the company has to be technologically independent, kind of self-sufficient in that way. So it has to pursue all in-house production like SpaceX, as much as is rationally possible or needed. The country should have people willing to defend its independence, not for money only, but as a place to live. Thanks to world inequality, in general, there are a lot of people who would like to have better lives and probably would be willing to defend that better life once they have it. They probably would not be very skilled, not the best of humankind, but there will be a good percentage of good people and people with the potential to grow and their children. So this company has to be able to offer them that better life and place and future. If Joe does not offer a simple and brighter future for them he is screwed. It may be just a glimpse of hope. A lot of good people (I mean in general all humans are good people, they just not always choose good ways because of themselves and because of their environment/circumstances/family) are really in shitty situation, and do shitty things basically for food (Somali pirates as an example, maybe not the best one, but still). Joe also needs people who will fight for an idea (like SJW), and are more educated to be a teaching force, who is willing and able to work with people. This may be the greatest asset for Joe, not his 50k bucks income, so he should keep that fact in his mind while creating his company and he should attract such people. * *Catch the wave, Joe, catch the wave - make a great country, so we may be proud of you Joe.* Eventually, Joe needs: * p2p network company * a set of technologies, a very diverse one. * let people know and help them to join * future for those people and for their children ## What may this company be? A company which improves the lives of peoples and probably technology oriented with a very wide spectrum of interests - starting from agriculture and ending with space rockets. Also, we need a name, *Adidos* is already taken so let it be *Mitsubizyco*. The goal of *Mitsubizyco* is to help 3rd world countries to improve their technological level and trough that help to improve the life of their citizens. Another goal is education. Some sort of online courses on steroids, because *Mitsubizyco* wishes to not give formal education only, but employ those people, so employment and education (as much as a particular human may take - university level, Ph.D., no limits) should be one thing. Potential clients of that organization, are the second half of that list [List of countries by GDP (nominal) per capita](https://en.wikipedia.org/wiki/List_of_countries_by_GDP_(nominal)_per_capita). ### Phase 1. Joe has to start getting things rolling. Build a kernel of people. And have innovative ideas about the technology he will use, as a lot of his future employees are not well-educated people, and they should add something to the company right from the start, and not be a burden. An example of such a technology is [Foldit](https://en.wikipedia.org/wiki/Foldit) > > Foldit is an online puzzle video game about protein folding. It is part of an experimental research project developed by the University of Washington's Center for Game Science in collaboration with the UW Department of Biochemistry. The objective of Foldit is to fold the structures of selected proteins as well as possible, using tools provided in the game. > > > And a small video about [Foldit and EteRNA](https://www.youtube.com/watch?v=bTlNNFQxs_A). Maybe not the best one, just a result of fast googling. So the technology should exploit our natural ability to self-learn, but in the case of *Mitsubizyco*, it should produce not only research but technologies and applications of those technologies, which could be sold and trough that greases future expansion of *Mitsubizyco*. This way: *...earns 50,000 USD annually. In addition to his salary, he has 100,000 USD in his bank account.* - It should be spent on development of such a tool. P2P nature of employees also forces *Mitsubizyco* to develop teleoperating and automation in production. As a disguise for many possible questions *Mitsubizyco* uses the colonization of Mars - all those technologies will be needed in that colonization, so basically it is not even a disguise, but a real product which may be sold. Another disguise is [Deep sea mining](https://en.wikipedia.org/wiki/Deep_sea_mining). A bit more complex, because of the forces involved, but luckily Papua New Guinea takes 137th place in the list of potential clients. So there is a way to justify the development of certain technologies. ## Phase 2. After developing the tool (at least at a bare minimum of a workable state) and building a kernel of people (some, maybe those 6 fellows for which this country should be build and many others), the second phase should begin - attracting people, applying the tool and developing it further. The goal of this phase is to involve people into the system as much as possible, get their work, take donations, establishing a presence in other countries, select people which may become bones of the system, begin to produce things and generate income. Income generation may be in a set of small businesses, which work on behalf of employees of *Mitsubizyco* in different countries. And what *Mitsubizyco* brings to the table is technology, support, teleoperating equipment, software, remote workers, education of those workers, automation everywhere where it is possible, people working on developing those systems. Key people represent *Mitsubizyco* in their countries and its small business or those businesses are kept by clients of *Mitsubizyco* (probably both cases are possible, depends on the country). *Mitsubizyco* should develop a set of simple but innovative technologies. Technology should be understood literally - *the collection of techniques, skills, methods, and processes used in the production of goods or services or in the accomplishment of objectives* - also known as a recipe, or a HowTo. Thus converting wood into an edible stuff is a technology. As an example, I as a citizen of my country, may rent a forest for 300$ a year and have the right to harvest 4,000 cubic meters of wood per year. This wood could be converted into a food for a fish (through mushrooms, and worms as an example) - so potentially those roughly 2,000 tons of wood could be converted to 200 tons of a fish (maybe; needs to be tested and calculated), a fish like Tilapia. The technology itself is not tricky, but unusual. There are some tricky parts, but in general, it is just unusual. This way Phase 2 includes generating such recipes, tested and working, to exploit underrated resources and underrated possibilities in different countries. It has to be done by aggregation of technologies from different sources - people, small research organization, and their works brainstorming. There are a lot of researches, which do not find immediate use, and I doubt someone bothered to combine them into one thing. It needs a lot of human hours and brainstorming, the results are not guaranteed and we just do not have the right tools to do so, but Joe is a smart guy and spends his money rationally for his collective mind tool. (In *Mitsubizyco* it has a name *"magic wand"*, do not ask why). Another way is to adapt technologies which already exist in some countries, but in countries where they make the maximum profit (same as outsourcing stuff, but in a bit different fashion, mostly in the part we make the profit, instead of them making a profit). ## Phase 3. Base. At some point in time, depending on the successes of *Mitsubizyco* enterprise it will be ready to build a base, *The Base*. The purpose of this base is to host technological cycles which may be hard to host in other countries, consolidate resources and power and create a seed for the future country. It's a *Place of power*. But as a disguise it is a new resource gathering (deep sea mining) and teleoperating production testing facility, which tests closed cycles of production with 0 waste and 0 emissions, on behalf and by request of micronations, who are deeply concerned about ships with waste, which is thrown in their territorial waters, so they decided to help the big stupid brothers to improve their technologies using Polynesian (unameit) wisdom of their ancestors. Exactly this is going on there. As a start, it may be a small ship 3,000-5,000 tons of displacement. At this point, Joe probably has to have a good connection with some of the micronations, to get a flag and registration. *Mitsubizyco* may be interested in those things [Manganese nodule](https://en.wikipedia.org/wiki/Manganese_nodule). They are relatively easy to harvest, the only small difficulty is that they are deep in a sea, but the *magical wand* is created exactly to solve this type of problem, by using the *Mitsubizyco* employee hive mind. In this way *Mitsubizyco* gets construction materials, it would be beautiful to find such a place with a relatively big deposit of them near island countries. As they can generate energy in their sea waters, or allow *Mitsubizyco* to generate it. So the construction material and energy sources will be relatively close to each other. But the main goal is to find such a deposit in a good (meaning: least interesting for others) place in the ocean. * I'm not aware of details about the sea law and sea resources law, but the good relation with those nearby countries can help to make this harvesting a fully legal operation. But if not, it is the time and place in the story where tension with the law may begin. Those resources are not claimed by other nations (some well-known places are, but can't find the link at the moment, which countries have right - *who*, *where* and *how much*), at least there should be places which are not claimed. This phase should solve 3 goals: * independent energy source * independent resource source * actual independent production base with the full set of available *Mitsubizyco* technologies ### Phase 4. Floating city. Phase 3 unlocks the ability to create a big structure in the sea, using resources and energy. The goal of this phase it to create a place of power and grow it. And refining technologies behind it. And increasing the production for export. It has to be a floating thing and probably at that point, Joe's corporation should have a formal agreement with some of the micronations, which allows to host it temporarily in their waters. It's a big artificial floating island. It has to be floating to move at some point in time over the place where resources (these nodules) are and rise like the *Jolly Roger*, claim this place and 12 miles around of it as their territorial waters. And this will be the time where friction with others may start to be noticeable, not necessarily if the place is outside of the usual routes for ships, enough remote from military bases. But it is a necessary step for future country building, as for the Mars, Joe's goal is millions of people. It means something around 20x20 km structure, just for food production (with some percentage of sea product supplements), and 10x10km for energy generation (solar something, 10% efficiency) to take about the 150ish places in the countries list, and another 10x10km for energy generation for factories which make exporting products. This phase goal is to build, build and build. Grow this floating island, attract/select/help to move/teach people, develop technologies and services, be the one who takes outsourcing of production for others, be the Amazon of production, grow, grow, grow, ... Have secret plans and develop a defense, launch orbit satellites, build spy network, establish distinct country attributes. At some point in time, this place will just be de facto a country. And if Joe likes to be a member of UN, a big family of countries, he may apply, and if he does he will make lots of friends of countries who depend on *Mitsubizyco* and he can make those friends, because he treats those countries, not as just resource colonies, but helps them to get a respectable place in this world, be part of a bigger power, he will probably get an approval. (Joe, think twice. I don't know, such an opportunity to be free from treaties is an exclusive thing - do not give it up so easily!). Yeah, something like that, probably it will be a goal of his entire life, do not expect it to happen fast. [Answer] Probably fastest, probably not cheapest, and likely out of reach of average American Joe: Buy or otherwise become the ruler of Nauru, one of the smallest members of the UN. [Answer] **The fastest way for Average Joe to become an UN member is having a very, very powerful ally which has a decided interest in creating Microstan and which has much influence in the UN.** Let's have some *completely invented* states which have, I emphasize here, absolutely nothing to do with real countries. Every resemblance to actual countries are purely coincidental. We are talking about * Abkhazistan * Mandschukostan * Kosovistan * Taiwanistan The first thing for creating a new country is a powerful ally which would like have control over a certain area, the only thing Average Joe need is to convince the ally that he is the perfect man for the job. Perhaps he has contacts and good friends in the area, perhaps he is a extremely good populist, perhaps he simply has the right relationships. There is this specific small area which is for whatever reason getting very important. It has rare and precious natural resources, a very good strategic position, a prospering part of a country, the population does not like the current government or the powerful ally really likes to annoy the current rulers and his friends. It does not matter at all if the area is small or has a permanent population or a government, where there's a will, there's a way. The people could think that the powerful ally is not interested in the advancement of mankind if he invades it, but does it for selfish reasons. Therefore the best reason is that the people actually living on the land want to shake off the yoke of tyranny and gain independence. And therefore the powerful ally will support the independence of Microstan with money, weapons and support. Now we completed the first step: We have a country or a De-facto-regime. The second step is much harder: Allowing the other powerful members that Microstan get the UN membership. Either the other veto powers are not really interested (for whatever reason) or the powerful ally needs to strike a bargain with the other powers. Once the powerful members agree that Microstan could get UN membership, they will talk to the less powerful members and convince them with pure rational arguments that it is in their best interest to accept Microstan as new member. [Answer] # The country closest to nationhood is Somaliland The not-nation that has the best path to nationhood is [Somaliland](https://en.wikipedia.org/wiki/Somaliland). Somaliland has been functionally independent for about 25 years now. It has standing civic institutions that are more robust than most of the other nations on the continent. It had its first peaceful democratic power transfer in 2010, which is not a minor feat. I could only find Benin (1991), Malawi (1994), South Africa (1994, not counting apartheid), Ghana (2000), Senegal (2000), and Zambia (2002) in Sub-Saharan Africa that managed the feat before Somaliland. It also hasn't had a civil war yet in its existence. There is really no good reason for Somaliland not to be independent, it has been much more successful than any of its neighboring Somali sheikdoms, and it hasn't seen large scale war in its capitol since 1991. There are at least two dozen recognized nations that can't say that. It would help if *Average Joe* was black, and Sunni Muslim. It was also help if he was a member of he Somali diaspora. But for all the 'making a new nation' advocates, Somaliland is the closest you can get. [Answer] I tend to agree that this is not possible for average people. Since no one brought it up yet: One of the serious attempts to do this and actually found a micronation took place on the [Minerva Reef in 1971](https://en.wikipedia.org/wiki/Minerva_Reefs#Republic_of_Minerva). The example is quite instructive for the question at hand: A reef in the South Pacific, the Minerva Reef was raised above sea level with large amounts of sand brought in from Australia, thereby creating an unclaimed piece of land which was promptly declared the Republic of Minerva. The Minervans quickly discovered, however, that international politics is much more about power than it is about the international law. Minerva's neighboring states were quite displeased with the foundation of the Republic. After an international conference on the subject - to which the Republic of Minerva was, of course, not invited - one of the neighbor states, Tonga, claimed the reef. When an 'official' representative of the Republic of Minerva, one Mr. Davis, showed up and requested an audience with the king of Tonga, he [was informed that Tonga was prepared to use force to remove any Minervans from the reef](http://webcache.googleusercontent.com/search?q=cache:Pru8Yn-x1DYJ:reason.com/archives/1972/10/01/trends&num=1&hl=en&gl=uk&strip=1&vwsrc=0); his audience was not granted. Beyond this, as has been pointed out by other answers, even states with substantial population and territory under their control sometimes have a difficult time gaining UN membership - especially if one (or more) of the permanent members of the UN security council is hostile to them (consider Taiwan). [Answer] Fortunately, Joe Average is very well situated for this particular task. He is a junior programmer in a corporation which is really a DOD black-ops group, associated with the far-from-defunct Star Wars program. One late night, during a solo, graveyard shift, manning the Super-Laser Satellite's control center, Joe decides to become a U.N. recognized nation. He starts by using the laser to drill down through the Earth's mantle, creating a new active volcano, out in the middle of the Pacific Ocean. Before his shift is over, the cone of the new volcano is already breaching the water's surface. His new homeland is born! He slaves the satellite to his laptop, then programs it to shoot at any planes, boats or submarines which approach the island before him. Before dawn, he charters a boat and heads off to lay claim to his new nation. During the ocean journey, he uses his laptop to send emails to all the Fortune 500 companies. He invites them to come to his island and set up factories, corporate offices or even slave camps; all with very favorable tax status and occasional free use of the laser satellite for the elimination of unwelcome competitors. He make the terms of the offer, "first come, first served" and then waits as his island gains a population. Finally, he elects himself King. "All those in favor, remain un-incinerated. Those opposed,...." [Answer] The first step is not getting land, it's getting an ally. Joe will need to be able to offer something to at least one of the permanent members of the security counsel, something good enough to get them to consider pushing the others to let this happen. So what can Joe offer a major power? um.... um.... he can annoy another major power. Joe approaches Putin (oh drat we're pretty far into the weeds and only picking up speed) and says "I'm totally not a spy for America, help me set up a micro nation on an Japanese oil well in the South China Sea." Putin has drank an extra case of vodka that night so he agrees. Somehow most of the backlash becomes an international incident between China and the US, who each assume the other is behind this silliness but somehow think it works out to their own advantage. As part of the settlement the nation gets recognized, but it is charged with cleanup costs of the flocks of flying pigs, who have caused an ecological disaster. [Answer] I'm basing my answer partly on the path you described and partly on the contents of [this video](https://www.youtube.com/watch?v=4AivEQmfPpk). While the steps you list in the question seem to make sense, there is one important thing missing. To paraphrase a conclusion in the linked video, you aren't a country until other contries see you as a country. Your application to the United Nations could go one of two ways: they see you as some wackjob living on a desert island and brush you off, or they can see you as a legitimate state and take you seriously. You'd need some time to establish a functioning government, tax collection system, investments in infrastructure, etc, but that might not be enough. There seems to me an extremely easy way for everyone in the world to suddenly take you seriously. Maybe the United States kept an armed nuclear missile silo on this remote Pacific island for [their testing during the Cold War](https://en.wikipedia.org/wiki/Pacific_Proving_Grounds). Maybe after they ceased testing, they forgot about the silo. [The USA has more nukes than it can take care of anyway](https://www.youtube.com/watch?v=1Y1ya-yF35g), I wouldn't be surprised (although I would be completely horrified) to learn that we've forgotten about some and left them abandoned. Maybe you got lucky and stumbled across one of these, and it still works! Suddenly, you're a nuclear power, and the rest of the world will take you seriously. That'd probably fast-track your application to the UN, if for no other reason than to get you to [sign the nuclear non-proliferation treaty](https://en.wikipedia.org/wiki/Treaty_on_the_Non-Proliferation_of_Nuclear_Weapons). [Answer] <https://en.wikipedia.org/wiki/The_Moon_Is_a_Harsh_Mistress> Heinlein described the independence of the Moon with getting finances, allies, military power, media support and internal politics. I think you could use so of the ideas for your new country. [Answer] An average Joe is not going to create and lead a nation nor be able to get it through the process of getting UN recognition. If your Joe is a good leader (not an average Joe), he could start by creating an online 'nation' and find people interested in the new cyber nation's customs, laws, beliefs, etc. Young people are easily encouraged with grandiose ideas of creating something new but you'll also need some folks with the wisdom and experience to help guide the nation through its infancy. Once you have people with the necessary skills, builders, healers, growers, etc., find a physical location to change your cyber nation into a 'real' one. All of you help with the expenses and materials to get things started. Find an uninhabited island and create some 'resource' that others need, perhaps technology, exotic food stuff, or something else. Once you have something others want you'll need some sort of defensive capability to prevent rogues from taking it by force. Now you can create trading partners and international agreements. Once recognized as a nation the process of getting into the UN is as you state. [Answer] It just isn't possible if we assume the rules of the real world apply and one life time to accomplish the task. The fact of the matter is UN member nations have zero incentive to allow a new micro-nation into the fold. Furthermore if an Average Joe gained some resource that was important enough for him to gain enough leverage for a bid he couldn't defend it adequately to keep other nations from taking it from him. This means that we need magic, supernatural intervention, or generations of time for this to happen. --- # Magic/Supernatural What Joe needs to do is buy a sailboat and sail out in the middle of the Atlantic ocean. While trolling his line hooks on a strange outcropping. To his shock and horror an island starts to rise out of the ocean. He accidentally tripped the lever that raised Atlantis from the ocean and "created" an island. The population is very technologically advanced, and wants to join the world governing body. Amazingly they can communicate with Joe and decide he is their ambassador to the world whose mission is to gain them entrance into the UN. Since the world wants to trade with Atlantis due to their technology which can't be replicated, and Atlantis is too advanced to attack militarily the world powers grudgingly vote them into the UN. This means that Joe "created" Atlantis by bringing it to the surface and he successfully lobbied to get it admitted into the UN. --- # Generational Approach Clearly Joe is a government official in Puerto Rico who is a strong advocate for independence. He inspires a large amount of public support for succession from the United States and independence for the island through his impassioned and electrifying speeches. He becomes a thought leader and captures the zeitgeist of the population like the world hasn't seen since Lenin. Unfortunately for Joe, the United States prevents Joe from realizing his dream of an independent Puerto Rico during his lifetime. However a couple generations later when Mexico has recaptured the territory stolen from them through Manifest Destiny, and India is the undisputed world power that strategic marriage between Joe's son and a Brahmin woman with an infant son pays off big. That infant son becomes President of the of a greatly weaken United States, his last act before exiting office in disgrace due to birther revelations and being India's puppet is to endorse Puerto Rico's acceptance into the UN. After acceptance Joe gets a national holiday, and is credited with launching the independence movement in earnest. [Answer] Read up about the history of Principality of Sealand (<https://en.wikipedia.org/wiki/Principality_of_Sealand#History>). It may not be quite what you are looking for, and your average Joe may not be able to do what the Bate did but it does give a lot of factual information about a daring attempt at a micro nation. (I would have put this in a comment if I could. If this is inappropriate I will delete it.) [Answer] The most feasible way I see is buying some small inhabited island/piece of land by the condition that you can make it a new nation. Some small country without national pride does not really care about losing a piece of land. In this case UN has no reason to not accept the new country. Probably they still would not accept. A tax paradise elders house and there might be few persons willing to come. Some employees from close nations might be willing to take the nationality. Average Joes though do not create nations. ]

[Question] [ The [Clock of the Long Now](https://en.wikipedia.org/wiki/Clock_of_the_Long_Now) is a clock designed to mark time for 10,000 years. That's a really long time for humans, but what if there existed a species that would see such a clock as "a bit short lived"? This species would make J. R. R. Tolkien's elves look like mayflies, naturally living for a million years. However, unlike the elves, who operate on at least somewhat human timescales, this species take a long time to do anything. For instance, libraries on their world lend out books for a thousand years; the line at the DMV may last for decades. Given these huge time spans, a paper book would decay considerably, even if kept in excellent conditions - paper dries out and becomes brittle, and inks can fade. How could this species construct a book, knowing that it may well sit on a shelf for tens of thousands of years before it is ever touched, let alone read? What materials could they use, and still keep that "book feel"? [Answer] Given sufficient technology and/or magic: Various types of crystals are quite stable under normal (surface-of-Earth) conditions. One might imagine “pages” made of an opaque crystalline material (eg: perhaps sapphire, which could be doped with impurities to give it opacity in practically any color). The “print” would be woven into the crystalline matrix as the “pages” are being manufactured, whether by growing the crystals over some kind of doped substrate, or perhaps a variation on 3D printing. The things I can readily imagine to use for this are all effectively rigid, but could be made quite thin. I believe that a few-mils (paper-thin) thickness of opaque sapphire would have about the flexibility of sturdy cardboard, be effectively unbreakable with human strength or normal impacts, and so one could still bind them into booklet/folio form, turn pages, et al. A slightly less far-reaching variation might be to use metallic alloys in a similar way, although oxidation (rusting) might embrittle them over the course of centuries. [Answer] Obviously the best way to keep your books in a near pristine condition would be to use e-books, but as you're asking to maintain that "book" feel, we'll move away from technology. There are three enemies to the longevity of a book: moisture, heat, and sunlight. To solve most of these problems, store the book in a cool (but not damp or mildewy) and airy open room underground. **Make sure that this room will maintain a mostly stable temperature and humidity level.** You've effectively eliminated heat, sunlight, and moisture as threats to your book by taking this simple step. However, as you've pointed out paper dries out and inks become brittle over time. To prevent the paper from drying out, use the technology that stores the US constitution. According to [this](http://www.sfgate.com/news/article/High-tech-display-cases-to-preserve-U-S-charters-3093084.php), > > When the four cases were built, air was pumped out, and they were filled with **helium and some water vapor** to keep the parchment documents from becoming brittle. > > > This is assuming you have the advanced technology of today. Adding a touch of water vapor can keep the document pliable, but too much could render it too damp. To solve the second problem you've addressed, fading ink, you might try [this](http://www.livescience.com/39494-incredible-tech-preserving-historical-documents.html): > > The enclosure is hermetically sealed and filled with the inert gas argon instead of oxygen, because oxygen reacts with the materials in paper and **ink to degrade them**. The argon maintains the atmospheric pressure that the air would normally exert on the map. > > > Overall, I would say combine all of these methods. Store it underground in this case that will provide a helium, water vapor, and argon-rich environment for the book. **Edit:** As mentioned by @Bookeater, > > Using the most durable/longest lasting ink possible as well as parchment instead of non-acidic paper would help the books outlast the test of time. Also, by binding the books together through sewing rather than glueing would be helpful. One step further would be inscribed thin gold leafs for newspapers and stone tables for best-sellers. > > > [Answer] These are folks for whom a day is but a neon-like flicker, and seasons come and go as clouds on the sky. Regular methods won't work for these slow folks. Just like our society does not attempt to build things out of vapor, neither will theirs use paper or other such nondurables as stainless steel (life of mere centuries, would melt like an ice-cream cone on a summer day in their eyes). So it would have to be things that are durable, and their entire society would be built of such things. Perhaps a collection of monumental granite slabs, perhaps hyper-durable alloys with deep etchings. More likely, they'll solve the problem in ways we cannot even envision, since our entire mayfly species evolution would seem like a transient summer to them. Think long processes: geological changes, complex sculptures in orbit, alterations to slow patterns of molten rock underground feromagnetic flow, flare patterns of nearby stars. We know they are patient. What's a million years to them? [Answer] # [Lithography](https://en.wikipedia.org/wiki/Lithography) The term is derived from two greek words: lithos (stone) and graphien (to write). Lithography literally means *writing on (or in) stone*. This method was invented to serve as a quick and cheap method for mass printing of books. It is basically a stone stamp. When carefully dipped in ink and stamped on a piece of paper, you can immediately print a full page. One method for your book shelves would be to store the lithographs instead of books. Stone slabs don't require any very special care and a book can be printed on demand any time anywhere. Also, for better printing quality and to allow for storage of more lithographs in a small place, you should use this technique with metals instead of stone. Thin (3 mm) sheets of stainless steel or titanium (for nobles) can be used to store all the precious information ready to be printed immediately as desired. # [Parchment](https://en.wikipedia.org/wiki/Parchment) Basically it is writing printed on leather, instead of paper. If stored with anti-bacterial substances, these can easily last for centuries. And if higher quality leather is used (tigerskin, wolfskin, goatskin and deerskin, instead of buffalo or other thick skins) and stored carefully, the books would stay good for millenia. [Answer] I'm going to take a different approach than the other answers and try to do something within your universe. These creatures must live off some sort of food, meaning the animals in their Universe must live on some time scale about as long as them. If not then the meat from the dead animals would spoil and become poisonous before they ever had a chance to prepare it. So I recommend making a book out of the animals' hide or other parts that must necessarily last on the time scales as long as these people survive. [Answer] ## No "Forever is a long-time." * $10^{2500}$ - Universe slips into Heat Death or Big Rip or other event * $10^{100}$ - Dark Age - not even Black Holes remain * $10^{40}$ - Black Hole Age - only Black Holes remain * $10^{14}$ - Degenerate Age - Stars stop forming. Stars fall into black holes or flung from their galaxies. Planets fall into their stars or are flung from their stars. All nuclear matter decays. * $4 \cdot 10^{9}$ - Earth swallowed by Sun. * $2 \cdot 10^{9}$ - Milky Way / Andromeda galaxy merger. * $1.5 \cdot 10^{9}$ - The brightening Sun kills all life on Earth. * $2.5 \cdot 10^{8}$ - Earth's continents form a new super continent. * < $2.5 \cdot 10^{4}$ - Earth enters next Ice Age * Present Day * $-8 \cdot 10^{7}$ - Age of Rocky Mountains. * $-4.8 \cdot 10^{8}$ - Age of Appalachian Mountains. * $-4.6 \cdot 10^{9}$ - Age of Solar System. * $-1.38 \cdot 10^{10}$ - Age of Universe. Even when talking about shorter periods of time, chemical and physical weathering destroys even the hardest and most chemically resistant materials. Even if you store an object made of steel on the surface of the Moon, it will eventually weather and all information on it will be destroyed. Cosmic rays will eventually destroy all data stored electronically. You can't beat entropy. [Answer] # Living "Book" Plants Plants that are genetically programmed to grow with leaves holding a different "page" of words (or a pattern, similar to braille books) naturally growing in them. Being plants, there could be generations that grow, live, and die over and over again, so there's always a "fresh" one ready to read. There are already lots of patterns on real leaves like these: [](https://i.stack.imgur.com/yP0jG.jpg) [](https://i.stack.imgur.com/52C4u.jpg) [](https://i.stack.imgur.com/Nm87Y.jpg) and getting a pattern to look like words should be theretically possible. Or maybe a more basic pattern of dots or bumps would work for a braille-type book, like this image of a fern: [](https://i.stack.imgur.com/ZiKW4.jpg) Every leaf could have a different "page" of words growing on it, and maybe a big fern plant with each "stalk" could be like a chapter of pages growing in the right order. Having a shelf/box/garden/field of each "book" should keep growing new plant "books," as long as the sun shines & the rain falls (and nothing else eats them ;-) [Inspired by [Dalton Bentley's answer on lifeforms](https://worldbuilding.stackexchange.com/a/38932/7543) (like people) who remember (genetically) the contents of books and read them on demand.] [Answer] This species mastered the creation of synthetic life forms (begun AD 2016 by an obscure and long-extinct hominid that once dominated the world, but had the notable distinction of having destroyed both their ecosystem and their own species ultimately) and designed a race of living books, poor creatures capable of memorizing and reciting entire books, but with no interest (by design) in anything else. They were housed in cathedral-like structures, millions of the Book-Bearers in residence. The Book-Bearers wore special uniforms of coarse material that looked and felt to the touch much as the covers and bindings of the legendary books of the ancients. Each bloodline of Bearer passed on the recitation of their family Book and continued to be ready at moment's notice to stand before the Eternal Ones and speak each page as commanded, their voices deep and resonant, feminine and seductive, or any of a thousand tones and rhythms, engineered in their very DNA to support their appointed Words. [Answer] I was going to suggest > > Accept that paper is ethereal. Print books on demand, and be satisfied > that they'll only last a couple hundred years. > > > but that introduces a more fundamental problem: whatever tools you use for printing books will wear out/degrade at a rate too rapid to replace them. What's the most durable, maintenance-free printing technology we can conceive of? I mean, for the volume of printing that would be required, it would have to be mostly automatic—something like [letterpress printing](https://en.wikipedia.org/wiki/Letterpress_printing) wouldn't be feasible given how slowly these people work and how fast books degrade—but all known machines require more maintenance than these people could provide: by the time a technician shows up, say, 20 years later (which is what, 1 or 2 DMV lines?), plastic would crack, rubber would dry out, magnetic media would fail, things would rust, chemicals and fuel would degrade, and a massive quantity of dust would interfere with everything. If we go with more basic metal tools to chisel rock, we'd have to get those tools sharpened or replaced frequently, I believe. Probably more problematic is the stone—have you tried reading any century-old gravestones? Stone is thus fragile, and would have to be keep out of the elements. No reading on a park bench for a nice 30-year afternoon. More tricky still would be the creation of stone reading material. How long does it take us to chisel a stone tablet? How many decades would it take these people? Because of these problems, I agree with Jim2B: **No.** [Answer] Make the pages out of aluminum. As we know from aluminum foil, aluminum can be made very thin. You could make it paper-like, but that would be very easy to tear. More than likely, something close to the thickness of a soda can would do. Aluminum has a half life of 730,000 years, so it will last a very, very long time. In addition to that, aluminum as very non-reactive. It wont oxidize, or react with other chemicals. [Answer] There's no way besides magic or God(which would just involve divine magic). First I'll tell why, later I'll tell what you might try to do. **Everything will eventually be put to an end.** *E-books* are terrible idea. First of all, you come up with the format. For some other civilization, or even yours years after it's created, it would take years of trying to decode it without knowing what it is. Remember that we can't understand some of the older languages or what they mean, and it isn't even that long ago since they were created. Moreover, PC formats tend to have some hidden data(formatting) that doesn't show up when you're reading text, but is important for program to decode it. You'd basically have little chance of someone decoding it in a rational time. Add cosmic rays and the fact that we don't know how to store data for longer than hundreds of years and you see what I'm saying. Next, there are all kinds of different "physical" things that you create. These aren't that good either; if you could create a book as durable as our sun, it would last for a very long time, but nowhere near forever; and sun is very durable from our point of view. Plants, AI, and other forms of life aren't that good too - why would we create them, if they could be destroyed as easily as us? We need to find other way; ultimately, they would just go away with the planet(s), and we already decided that planets and stars aren't the best way to go. What can we do? * **A bit of science fiction** You could somehow create a parallel universe, and make it so that it can't really be destroyed. This would require fiction of course, but it's doable. Then, since it's parallel universe, you define the rules - you can make a parallel universe that's single chamber created by some civilization at its peak of glory, so that data is both preserved well and easily understood. You'd have to make it accessible somehow though; you can try doing something like Planescape's portals, you could create TARDIS that'd store the universe inside, or something completely different; that's one way to go. * **Fantasy way** Magic can be powerful. You might create a magic system that makes magic a resource fully available from any point in time and space; then, you can make a single "stream", or anything similar, that can be modified with enormous effort. The civilization would use all they had to bind the book with the magic. It'd surely feel real. * **Modify the world** In Discworld, the world is flat, and it's travelling on the back of the four elephants who are carried by giant turtle. Nothing stops you from altering the world to work this way; some ancient creature, or God(Cthulhu? ;)), exists, and you can use it, or ask it for help, so that it stores your book. But the same goes for physics and chemistry - you can invent some material that's self-replicating, very durable and has some special properties that make it last forever. This might be less or more convincing, depending on what your vision is, but that's another possibility. **Bottom line** --- In the end, it's all a matter of convincing the reader that your version just works. You'll probably fail to convince everyone, so you can pick whatever fits you best. Personally I'd probably go with parallel universe, but there are all sorts of possibilities that might turn out to be just great in given context. Good luck! [Answer] Nanite-book. It can self-repair and any other functions needed to allow self-repair in as many environments as needed. Like the Diamond Age's Young Lady's Illustrated Primer. Spinal battery, nano-tech pages that have page-like feel and any other functions you want. [Answer] Use vellum? <http://www.bbc.co.uk/news/magazine-35569281> > > Vellum lasts a long time. Dig into the archives of the UK's parliament and pull out the oldest extant law and you'll find a very old document. It was first inscribed in 1497. > > > Over time, ordinary paper can deteriorate rapidly, while vellum is said to retain its integrity for much longer. Original copies of the Magna Carta, signed more than 800 years ago on vellum, still exist. > > > [Answer] Literally nothing may last forever. But if you species somehow exist, there must be a way for them to create and store their knowledge somehow. The important question is: **how are they even able to survive?** ## On Earth In Earth-like world they would have a really hard time: in most of places they would be overgrown by plant-life before they can blink, and encased in dirt if they don't constantly climb out of it - not to mention being eaten almost instantaneously if even remotely edible. This is why there are very few of such long-lasting lifeforms on our planet - it is evolutionarily disadvantageous. ## On a remote asteroid I would imagine such creatures living on some kind of planet or asteroid, where almost no sunlight reaches, next to no incoming meteors, low temperature, and very low energy income. In that case it would be advantageous to accumulate what energy is available and spend it really slowly and carefully - almost nothing is happening around anyway. It is hard to guess what such a creature could look like, I'd wager nothing even remotely human-like, but it is up to you to decide. ## Available materials In above case, a lot of things are very different from what we are used to on Earth. The atmosphere, if any, is likely thin and quite non-corrosive. Water and oxygen only exist as ice. Metals are brittle, but see below. At low temperatures things degenerate much slower too. Paper/parchment/leather-like materials would not even be available in this scenario since earth-like plants and animals would not survive in such conditions. What is there to make use of then? There several types of asteroids, but let's say we have a metallic one. Iron is probably is in abundance there, some other metals including "precious" (and less corrodible) ones like gold and platinum are also relatively easy to come by. ## Books For simplicity sake, let's assume that the aliens somehow ended up being vaguely humanoid in shape and function. Let's also assume they came up with something somewhat book-like for some reason. What would those be made of? I'm in no way expert in low-temperature low-pressure large-timespan material physics, but I'd say probably some kind of metal alloy. Type of metal greatly depends on availability, temperature, atmosphere, and other environmental conditions. Metal is extra brittle in low temperatures, however that is because dislocations (impurities in crystalline structure) which make metal bendable, can move much slower than humans would naturally bend it - thus it breaks instead of bending. But your species take their time, so metals might just work for them - unless they accidentally drop such a book: it could shatter even accounting for low gravity. ## Storage Metal also flows really slowly at earth temperatures, but in the coldness of outer space it should keep its form somewhat longer. Lower melting temperature-metals would likely be used. Or their libraries could try to store their books cold same way ours try not to be damp. Pages should also use some kind of method to prevent fusing together, likely some thin non-metal (silicate?) protective layer. ## Production Because of such small energy income, it would be expensive for the civilization to melt metal. Plastic deformation however is much cheaper for them since they can allow it to slowly happen with much less heat, so they could realistically make somewhat-thin pages by applying great pressure over large timespan. ## Writing If their books are shaped as ours, I'd say they would have series of small etchings or holes in their metal pages, such as in Babylonian script/ braille patterns. Holes are better with thinner pages since they are less likely to close than bumps and shallow scratches to even up with time. Other option would be to use tiny portions somewhat-heated distinctive metal to write, fusing it to pages as they are written. Since thinking may be cheaper than acting in such a world, in order to conserve energy required to communicate your civilization may opt to use a rather efficient, high-density form of information exchange, writing in something like Chinese characters: very few strokes could easily code an entire phrase, a page could contain several articles. ## Magic? Who knows on what yet undiscovered physical laws and principles can a totally different life-form operate in nothing-even-close-to-earth-like conditions? To us their very existence could easily seem magical. Depending on how is your story told, you may even want to distance yourself from science and rely on imagination entirely. ## Human contact Human contact would likely be devastating to both the slow creatures and their books. Without really slow-moving machinery, even trying to open might break them. Communicating with aliens would also be next to useless - by the time the answer is received, the question would be long forgotten in history of previous human generations. In fact, humans might not even realize that the aliens are still alive and not just statues. ## Disclaimer Due to how different are the condition from earthly ones, my answer quite likely contains factual mistakes and such. Please feel free to expand upon and correct me. [Answer] A species that is so long-lived will have a very different culture compared to humans, because of their life cycle: Population "turn-over" (old individuals dying and being replaced by children) will be very low, thus preservation of knowledge will probably be much less of an issue. The spread of knowledge (and fiction) could in all probability be a lot more dependent on an oral tradition. This again would place a greater emphasis on memory and perfect recall. It would also lead to a more coherent social structure. **This suggests the question: will they have a need for books, and if so, what for?** I guess that such species will **either** have a very much slower rate of discovery of knowledge, leaving them in some pre-modern state of technology (which does go well with the oral tradition), **or** they will be constantly updating their book technology (along with all other technology), similar to the way many modern people go from one model of smart phone to the next every couple of months even though the device is still perfectly usable. This could lead to the problem of transcribing old media to new tech, and if neglected leading to "cultural amnesia" etc. etc. If I would need to create a book-like object with today's technology to last a few thousand years at least, I would look at some fibre technology (polymer, glass or carbon), which would be woven or matted into sheets and printed with a similar material with a contrasting color. But even these may be prone to deterioration because of surface damage (water and other fluids in nicks on glass surfaces are known to weaken the material below - and are used when cutting glass because of this). Glass and carbon (fibres) are often coated with polymer coatings so as to protect the surfaces to increase longevity. [Answer] Computer data is fragile, life mutates, and copying introduces errors. If you want something to last, the simplest solution is best: engrave it on something hard, like tungsten. You can then seal it in with a layer of glass (a surprisingly durable material) and bury it when not in use. When the glass protection starts to degrade, you can just add another layer of glass before it wears away, so the actual engraving never comes into contact with the outside world. [Answer] What constitutes "book feel" is very culture dependent. In that spirit, I suggest one of the best ways of producing long lasting books from human history: 1. Write your books on clay tablets 2. Burn down the library. (Clay tablets have the unusual property that burning down the library makes them more permanent, by firing the clay, rather than destroying them.) [Answer] Titanium or stainless steel would be possible, but platinum will withstand most chemical attacks. I would use stainless steel pages with carbon (for color and strength) platinum alloy for lettering. ]

[Question] [ I was planning a short story that focuses on a rainy day in a city, and I realized that there's one interesting feature of it: Even though the weather seems bleak, and it affects the actions of those in the story, anyone reading it knows that the next day will be, in all probability, sunny, bringing a lighter mood to the city.1 But what if the next day *wasn't* sunny? What if it rains then? And the next day, and the next day, and the next day? What if it were to rain forever? I'm trying to figure out how I can make an earth-like world - *very* Earth-like world - support a weather system that continuously rains everywhere on the planet. there are some issues with this: * The clouds would block sunlight, making evaporation difficult. * The shear volume of water would require a large source, and I doubt that evaporation can cover it. How can I explain the perpetual rain? I'm not using the [hard-science](/questions/tagged/hard-science "show questions tagged 'hard-science'") tag because I realize that this could be a tough question, and might require some stretches of the imagination. Answers should, of course, be realistic - i.e. obeying all natural laws. I should add that I'm okay with answers explaining that this scenario is unrealistic. I rather like the current answers, but I'm fine with someone criticizing my idea. --- 1 Perhaps not in *this* case, because the city in question is London. [Answer] Not sure if this is what you're looking for, but what about geysers? There'd obviously have to be a ton of them (and maybe some one with more of a science background can speak to what that level of seismic activity would do to the earth), but that'd be a potential way to supplement evaporation. the way I envision it, the world is like ours except for it having a large amount geysers around the earth (or one massive geyser that releases a vapor cloud into the atmosphere). These release superheated steam into the air which will fall back down as mist/rain or be absorbed into the atmosphere. [Answer] In Stanislaw Lem's 1986 novel [*Fiasco*](http://garethrees.org/2012/05/31/fiasco/), the planet Quinta is subject to continual world-wide rain, due to the ongoing slow collapse of an artificial orbiting ring of ice: > > The planet was encircled by a ring of ice chunks in an enormous but unstable sheet. [...] Having one large and three lesser divisions due to perturbation caused by Quinta's moon, the ring could last no more than a thousand years, since it increased its diameter while at the same time losing mass. The outer rim was widened by centrifugal forces; the inner, from atmospheric friction, turned into melting fragments and vapor, so that a portion of the water thrown into space by methods unknown returned to the planet in a never-ending rain. It was hard to believe that the Quintans had intentionally provided themselves with a downpour worthy of the Flood. The ring had initially contained three to four trillion tons of ice; each year it lost many billions. > > > It's suggested, though not confirmed, that the Quintans launched the ring of ice into space because they like the climate that way. [Answer] > > **Rain Belt** > > > Could be that evaporation takes place closer to the poles where it very seldom rains. Evaporation occurs even if temperatures are lower, and if the poles are ALL water and ice (oceans) than those are very large body of waters and most likely cause loads of evaporation. It helps if you land is all thin strips (coastal) akin to the Canadian West coast causing weather system to rain the moment they hit land. It is rather hard to try and explain it scientifically, but then again I think just having more oceans/water in general, would increase the amounts of rain and storms etc.. to the point where it ALMOST always rains in mild areas. > > **Fancy Space answer** > > > The planet has ice fields in it's orbit causing non stop rain on the side of the planet facing it's direction (the side not facing it gets a reprieve?) If the planet has no rotation or very little, that would make for near perpetual rain on one side. If they aren't aware of land or whats on the non rainy side then you would have a world where it always rains. (Obviously this causes no small amount of water/flooding related issues, but that could be interesting to work with in a short story also.) [Answer] If we can relax the "everywhere" a bit I see a quite feasible way this could happen: The planet is warmer than Earth and has no tropical land--and the incident energy is even higher than the temperature would indicate. The tropics are extremely hot (quickly lethal to anything but an extremophile, but crossable with adequate technology), there is major evaporation. Rather than the fast-tropics/slow-pole driven weather we see on the planets of our star system we have a tropics rises/poles drop weather pattern. As everything but the tropics are under perpetual cloud cover they're basically pure white, most of the incoming energy goes into the tropics. The tropics are so hot that they don't have clouds, the air circulation is fast enough that you don't get condensation even as the air rises. Rather, the condensation only happens later when the air cools enough and falls back down in the polar latitudes. You'll need a very slow rotation rate to make this possible. Note that the weather on such a world is going to be vicious. Also, photosynthesis isn't going to work too well under all those clouds, I doubt you'll have much in the way of plant life outside the tropics. Instead I think the ecosystem in the polar regions will be driven by stuff sucked up in the tropics and brought in by the winds--it's going to be a pretty poor ecology. [Answer] **Have a very humid ocean world.** If your world has mostly tropical weather patterns world-wide surface water will evaporate quickly. This goes up, into the atmosphere to form clouds. If you have a world mostly comprised (surface-area anyway) of water. The water will evaporate and create massive hurricanes. These would give you the global rainstorm (and a global warming rate that might eventually make your world into a Venus clone). Now, this is about the point in my answer where you will be getting ready to comment that you wanted earth-like. Hold your keyboard-happy fingers for a second. You would want a small continent or group of continents in the northern hemisphere of your world where the temperatures are less humid and more earth-like. Have ocean and wind currents bringing warm water and storms constantly north and south to the poles. This will create a patchwork of clouds across your world and, while not creating a nonstop, endless storm, will give you the closest thing possible. Your city might experience a rain-free night or day once in a blue moon, but for the most part will have near constant rain. This would lead to some crazy flash floods and a very rough landscape as water will erode the continental surface. [Answer] If the planet was a bit closer to the star, like Venus, had a lot of surface water, and slightly higher gravity, you'd end up with a kind of runaway greenhouse effect, where water would evaporate into the atmosphere at a greater rate, and higher gravity would mean thicker atmosphere which would mean higher humidity and more water in the air. The water would form clouds and rain, and the perpetual cloud cover would reflect some of the solar insolation, which would help balance the greenhouse effect a bit, making it livable. [Answer] There have been legit scientific studies centered on the idea of planets that orbit their stars much closer than Earth does. In such a close orbit, such planets would often be "locked in" such that one side always faces its star (much like one side of the moon always faces Earth). In one model, it was shown that much of the star-facing side of the planet could feature a permanent hurricane, assuming that the planet has a lot of ocean. In short: there very well could be hard-science ways for large portions of a planet's surface to be constantly and continually pelted by rain, and some of it severe. At the same time, such a setup also includes a dark side to the planet where everything is in a perpetual freeze. Because of the freeze, very little life would exist on the dark side of the planet much like how very little life exists on Earth's own polar ice caps, especially during winters. With a perpetual hurricane, any landmasses within the reach of the storm would rarely if ever see direct sunlight, but there are places on Earth where life survives in similar circumstances. Plants can still survive on very little light, and even with constant and permanent cloud cover, some light will still get through the clouds and rain for life to subsist on. Such a planet would have insanely dense rain forests and, depending on the location of the landmasses, a lot of humidity and heat. Also, it would always be day and never night in those places where life could thrive, so the life on such planets would likely have evolved so that it either doesn't need sleep or it has ways of finding places to hide while resting. On Earth, all life lives according to the rhythm of day and night, as well as the monthly rhythms of lunar cycles. On a planet where one side always faces the sun, no such rhythm exists, so life would possibly be constant noise with no breaks. Rain may seem to you like a somewhat-depressing state of weather, but on a planet where life has evolved for it, direct sunshine could be deadly simply because a lot of life has never had to deal with it, so rain could be seen as a great protector of life on such a world. [Answer] I immediately thought of Manchester, UK, which has a notoriously wet climate due its position on a plain beneath a long hill range which causes water sucked up from the sea to swirl around and dump on the city. Given that I could see a warm planet of mountainous archipelagos in which there were coastal settlements that suffered from this phenomenon, which ranged from light drizzle to heavy rain with little or no dry spells at all. If it was settled there would have to be a good reason to be there. If life had evolved there it could be decidedly more *fishy* than human. [Answer] Having issues in forming an answer that will work for you in complete earth conditions, so instead of an answer...I'll post the issue and see if comments can't resolve it. The first is simple...how exactly does water vapor get to the cloud level while it's raining? There would have to be at least one region on the globe where the water evaporation rate is greater than the rate at which it's falling and I'm not sure if I can tell you a setup where it rains at the same time clouds are forming. Other issue...Rain formation works as heat transfer. Ocean water has energy added to it which evaporates the water (water 'removes' energy from the system by evaporating). The water vapor rises through the atmosphere where it eventually cools and condenses to a liquid state. Conservation of energy...the water vapor condensing in the atmosphere releases the same amount of energy as it took to evaporate it. Assuming there is a mechanism to get rain back up to the clouds, the energy transfer involved here is leaching a huge amount of energy from the surface to the atmosphere without any real mechanism of transferring the energy back down to the surface. I believe the end result here gets into hurricane formation, potentially tornado forming storms if over land. Hurricanes are inherently self destructive, they drain the surface waters of heat and churn up cold water from beneath which ultimately kills its fuel supply...after the hurricane is finished, I have no clue how it could continue to rain without a period of calm cloud free weather to allow everything to warm once again. [Answer] Either large amounts of fossil fuels are burnt, or a volcano forms where all water naturally flows to, such that global warming in very isolated and uninhabited areas generates enough heat to boil water, forming clouds to replace existing ones. In theory, if water flowed into a centralized location, that location being the heat pit, it would form large amounts of clouds. [Answer] The planet has a large region of exposed magma, due to either tectonic activity or a large meteor impact in the recent (geologically speaking) past. Ocean water pours into this region and boils into steam, then is circulated around the globe. This would dump a lot of extra heat into the atmosphere. The area near the magma region would probably be too hot to be habitable. But overall, heat from the magma, solar radiation, and heat loss into space would reach some kind of equilibrium. You could have livable areas if the magma region were small enough. The concentrated heat source would also drive strong, planet-scale convection currents in the atmosphere. In other words, it'd be windy all of the time. High-volume air circulation would make the temperature more uniform around the world. The temperature difference between the poles and the equator might be less pronounced than what we experience. [Answer] In India it rains everyday because of the monsoon. What happens is water evaporated from the Indian ocean travels northward as the normal process but because of the Himalayas acting as a thick barrier this warm air gets pushed up in the atmosphere and loses much of its heat, therefore, the water it carries falls down into rain in torrents. So to explain the situation in your novel, the location of the city has to have about the same geographical location as New Delhi and there are has to be a mountain range running the whole circumference of the planet where there is land. [Answer] How about rain of a certain molecular mixture, it is transformed at the surface, and evaporates as something else? Some of your energy could essentially come from within the ocean - a tidal heat in the crust can contribute to catalysis on a catalytic surface at the bottom or margins of the ocean. Say it creates an end-product that is volatile and requires little heat to evaporate. Don't get too specific. The rain could be light. -Bruzote [Answer] Have you considered Hydrogen-Oxygen Combustion? $$2 H\_2 + O\_2 → 2 H\_2O$$ Provided a continuous supply of hydrogen were exposed to atmospheric oxygen, combustion of the two would occur spontaenously and create atmospheric water. Since this type of combusion is an exothermic process, it will produce large amounts of heat that may boil the water. Either way, it'd produce water in the atmosphere. Afterwards, the water would need to clear the hot air mass before it may condense and fall as rain somewhere else. While not everywhere would be raining, it would allow a large portion of the planet to be so, without pesky clouds getting in the way of evaporation. Notably this type of reaction was used in "The Martian" to make rain inside a section of the base. Watney used leftover hydrogen rocket fuel as the fuel source. Another fuel source to consider may include Methane; but, it'd produce CO2 as well. That'd trap heat in the atmosphere and may interfere with condensation. It would also require old plant material. N2 doesn't burn, nor do noble gases. Hydrogen is your best bet. Good ol' electrolysis. Or without the electricity, alternately. ]

[Question] [ It seems like [nothing can move faster than light](http://en.wikipedia.org/wiki/Speed_of_light#Fundamental_role_in_physics) and this is quite bothersome for interstellar travel. It takes decades in the best case to get anywhere interesting in our little Milkyway (Many thousands of years to travel an appreciable distance within it) and unless we find some [loopholes](http://math.ucr.edu/home/baez/physics/Relativity/SpeedOfLight/FTL.html) traveling between galaxies seems off the table entirely. **I want to have a universe where there is no maximum speed but that is otherwise relatively similar to ours. Is this possible?** Preferably this universe would have: * A beginning (a big bang?) * galaxies * stars * planets That will do for now. How can I make this possible with a well defined rule-set and what notable, large differences would there be between our universe and this universe? Some things to get started: * Forces and all massless particles (like light) might travel at infinite speed. * Special relativity likely doesn't hold. * The big bang and what happens in the following moments are probably immensely important. * Can I still have quantum stuff? [Answer] Yes, you can! You could imagine a universe where physics is based on Galilean relativity instead of special relativity. I'll skip over the mathematical details (unless you're interested), but basically Galilean relativity describes a spacetime that has one universal axis of time, which never mixes with the dimensions of space as it would in special relativity. In Galilean relativity, there would not be any invariant speed that is the same for all observers. Specifically, the speed of light (by which I mean the actual speed that light travels, not the constant $c$) would be different depending on the conditions under which it was measured. There are some different ways you could make this work. Probably the simplest is filling your universe with some medium that light travels through, and it always travels at a fixed speed relative to the medium. (This was a real scientific theory in the late 1800s; the medium was called the luminiferous aether.) Light in this model would behave a lot like sound, for which air is the medium. Objects like planets and solar systems could affect the motion of the medium, just like mountains and buildings affect wind, and you might even have aether-weather phenomena if the dynamics of the medium are complicated enough. An alternative would be that light simply moves at a certain speed relative to whatever emitted it. In this model light would behave like a projectile, e.g. a bullet from a gun, so it is a natural match to a particle model of light (though you could do it with a wave-particle dual model of light too). The speed at which light is emitted might depend on the energy of the photons, and/or on the mechanism by which they are produced. It would probably be quite natural to have higher-energy photons, corresponding to higher frequencies of light, travel at higher speeds. If you do this, you would have an interesting effect where you'd see a faraway object at different times in different frequencies - for example, a brief flash of white light would be seen from afar first as purple, then transitioning through blue, green, yellow, orange, and red. Galilean relativity would not *require* forces to propagate at infinite speed, but they *could*. In other words, you would be able to have two kinds of forces in this universe. One kind is the ones which are carried by fields, the way forces work in our universe. The object that exerts the force actually triggers some kind of propagating disturbance in the field, and then the object that feels the force reacts to the disturbance. These disturbances would propagate at some speed characteristic to the field - but note that all the discussion from earlier paragraphs still applies, concerning how the speed would change depending on the conditions under which it was observed. Depending on how you want it to work, you can achieve a wide variety of effects, including the "temporal chromatic aberration" from the last paragraph, except now with forces: if gravity worked this way, then a sudden change in a mass distribution (assuming such a thing were possible) would have a prolonged effect because gravitational waves at different frequencies would arrive at different times. The other kind of force is that which instantaneously affects the entire universe. Actually you could think of this as a subset of the previous kind of force, where the natural speed of the force is infinite. The existence of this kind of force would allow for instantaneous communication between widely separated locations, although if the distances involved are large enough, the people in your universe might have technological problems detecting a signal because it would simply be too weak. The phenomenon where a signal weakens in proportion to $1/r^2$ would still apply in Galilean relativity, or at least it *could*, though I think it would be possible to have a force that does not weaken over distance, if it's not carried by a field. You could still have a big bang, which would represent a definite beginning of time. Everything in the universe would start out moving away from everything else, though you wouldn't have a good answer to the question of why it *started* doing that in the first place. Anyway, afterwards, the evolution of the universe could proceed much the same way it did in the real world; you'd still get galaxies, stars, and planets, for example, though not until some hundreds of millions (or billions) of years after the beginning. Special and general relativity actually aren't that important for most of the universe's history. Your universe could have a finite size, in the sense that there is only a finite region of space filled with stuff, although with a big bang-like event at the beginning, that region would change size over time. You could set it up so that characters in your universe could travel beyond the edge of this region (assuming they have the technological means to get to the edge), into an endless void; or the edge could be a hard wall that they run into; or anything that hits the edge could just vanish. The latter two options are a bit tougher to reconcile with existing physics though. Depending on the details of how light and forces travel, and the size of the universe, characters in your universe may or may not realize that the universe is finite. Naturally the closer they are to the edge, the easier it is for them to tell. If your universe is infinite, on the other hand, depending on how light behaves, it might be subject to [Olbers' paradox](http://en.wikipedia.org/wiki/Olbers%27_paradox), which basically points out that in an infinite universe filled with stars, the entire night sky would be lit up because there is no direction you would look that would not run into a star eventually. However, if you have a beginning to your universe and light travels at finite speed, this argument wouldn't hold. So you could still have a dark night sky. If gravity (or some other attractive force) travels at infinite speed in your universe, the expansion will slow down over time, and will eventually stop and reverse. So your universe is doomed to collapse in on itself at some point in the possibly distant future. If gravity does not travel at infinite speed, then it may or may not collapse, depending on the details. Lastly, none of this invalidates quantum mechanics. You wouldn't have *quantum field theory*, but there could still be nonrelativistic quantum effects and so a lot of quantum phenomena we are familiar with would still be possible. [Answer] To answer (finally) your question. Safest assumption is: **No ... but ... who cares?** I am not physicist. I just tend to "procrastinate" on interesting questions and thinking of how to make it possible. So, I will list my possibilities: **Stick to loopholes**: Do not rebuild whole universe just because you need faster than light travel. Yes, [loopholes are no longer funny](http://meta.codegolf.stackexchange.com/questions/1061/standard-loopholes-which-are-no-longer-funny) (link to codegolf is intentional), but they are safe. I came here from [Writers](https://writers.stackexchange.com/) and so I take every question as "story background". So, If you put [Enterprise](http://en.wikipedia.org/wiki/Starship_Enterprise) in your universe, yes it will be no longer funny. But *everyone will instantly know how space travel is done* and you can focus on story itself **Make tachyons possible** [Tachyon](http://en.wikipedia.org/wiki/Tachyon) is theoretical particle which should be faster than light. And bonus: Thanks to New-Age culture, loads of people [know about them](http://www.youtube.com/watch?v=Sah2mtjmQEs). (watch on your own risk. You have been warned). And one purely Writer-like answer **Do not care about details, just describe it in plausible way** Look, if you go to common household and ask them how microwave oven works, they will maybe have just idea about it. Ask them about Induction cooking and you will quite possibly hear about "magic" in it. The same goes for computers, cars or GPS device in your pocket. So, if you need it to happen, let it happen. Make captain of ship say "thanks to this FTL drive, we will be in Omicron Persei 9 in 10 minutes" and never explain what the heck FTL stands for or [how does it even work](https://worldbuilding.stackexchange.com/questions/3397/occultic-ftl-drive). [Answer] First, the good news: You still can have quantum stuff. All the quantum weirdness already exists in non-relativistic quantum mechanics. Without the speed limit, full relativity is, of course, out of question. Therefore let's look at the alternatives: # Preferred frame of reference Assumptions: Matter behaves as in non-relativistic quantum mechanics, while unchanged electrodynamics holds for electromagnetic fields. This is basically the aether theory of before Einstein, except of course they didn't know about quantum mechanics yet. Note that in this case the sped of light would be $c$ only in the preferred frame. The speed of light would *not* be a limit for particle movement, though. Let's look at what would happen with atoms at high speeds. To get a feeling of what is bound to happen, let's first use a classical model of the atom, before taking a closer look at quantum mechanics. As custom when looking at atomic physics, we approximate the nucleus as charged point particle. We will also neglect any spin/magnetic moment of the nucleus. The [fields of a moving electric point charge](http://farside.ph.utexas.edu/teaching/em/lectures/node125.html) are $$\vec E = \frac{q}{4\pi\epsilon\_0} \frac{\gamma}{r^3\left(1+\gamma^2 \frac{v\_r^2}{c^2}\right)^{3/2}} \vec r$$ $$\vec B = \frac{\vec v\times\vec E}{c^2}$$ Here $q$ is the charge (for an atom with atomic number $Z$, we have $q=Ze$ with $e$ the elementary charge), $r$ is the distance from the (moving) charge, $\vec v$ is the velocity of the charge, and $v\_r$ is the radial component of that velocity. Moreover we have the gamma factor $$\gamma=\frac{1}{\sqrt{1-\frac{v^2}{c^2}}}$$ If you object that the calculation on the linked page was relativistic: Electrodynamics is inherently Lorentz invariant, therefore those calculations are still valid in the hypothetical non-relativistic world, as long as we are in the preferred frame. Now let's look at a classical electron (charge $-e$) orbiting the nucleus in a plane orthogonal to the velocity, in a circular orbit. If that electron is at radius $r$, its velocity $\vec v\_e$ has the component $\vec v$ as it moves with the atom, and additionally the tangential component for orbiting. Now let's calculate the force acting on that electron. First, the electric field causes a force $\vec F=-e\vec E$. Since we are perpendicular to the velocity, $v\_r=0$, and the only correction compared to the field of a charge at rest is the gamma factor. So we get an attractive radial force with strength $$F\_E = -\frac{Ze^2}{4\pi\epsilon\_0} \frac{\gamma}{r^2} = \gamma F\_0$$ where $F\_0$ is the absolute value of the force an electron orbiting an atom at rest would experience at the same radius. The minus indicates attraction. On the other hand, the electron moves through the magnetic field of the moving nucleus with velocity $\vec v\_e$, giving rise to a Lorentz force $\vec F\_B = (-e)\vec v\_e\times \vec B$. Since the orbital component of $\vec v\_r$ is in the direction of $\vec B$, only the component $\vec v$ due to the atom velocity would enter the formula. This gives a *repulsive* force of the strength $$F\_B = \frac{v^2}{c^2} eE = \frac{v^2}{c^2}\gamma F\_0$$ Together we therefore get $$F = F\_E + F\_B = -\left(1-\frac{v^2}{c^2}\right)\gamma F\_0 = -\sqrt{1-\frac{v^2}{c^2}}F\_0$$ We see that the attractive force is reduced as we get faster. Quantum mechanically this means the atoms will get wider in the orthogonal direction. More importantly, we see that as soon as we *reach* the speed of light, the force will go to zero. In other words, the electron will **stop being bound.** So in short, while this model would allow acceleration of particles beyond the speed of light, **matter would disintegrate** as soon as passing the speed of light. So from a practical point of view, the speed of light would still be a limit; indeed, it would not even be safe to just come close to it. # Taking the limit $c\to\infty$ Another option would be to remove the speed limit by letting it go to infinity. Indeed, the Minkowski spacetime of Special Relativity would then transform to the Galilean spacetime of Newtonian physics. The electric field would work as instantaneous force following the Coulomb law, analogous to Newtonian gravitation. There would be an absolute time, but no preferred frame. However, when looking closer at Maxwell's equations, one recognizes that this would also mean that **there are no magnetic fields.** Also, quite obviously there could be **no light** waves. It would be a dark universe. # As before, but adding "Newtonian light" We can fix the last issue by simply going back to Newton's idea of light: Just postulate light particles that are emitted from light sources. Thanks to quantum mechanics, we don't even need to forego interference. To work without relativity, those light particles would need to have mass. However this would likely give a very different universe from ours. [Answer] ## Just increase the constant All kinds of interesting border cases of our universe may behave wacky if time and relativity would function in a fundamentally different way. For example, having one fixed time masure for everything in universe, being able to calculate how much is the "absolute speed" of earth since there would be a concept of absolute speed, etc. This is tricky, has not been explored much, and probably would not add anything useful to the story. However, there are no reasons why you coudn't simply assume a world where c isn't 300,000 km/s but, say, 300,000,000 km/s. It wouldn't change the fundamental principles of how the world works (it would alter the details of atomic weights of isotopes and nuclear reactions), but would allow a slower-than-light travel that is still fast enough. [Answer] Remember that the speed of light also affects other physical processes than just space travel. Let's take Einsteins famous formula $e=m c^2 $ (energy is equal to mass multiplied with the speed of light squared) This formula doesn't just govern how much energy you need to approach the speed of light. It also governs how much energy you obtain from nuclear fission, fusion or matter/antimatter annihilation. What would this mean in a physics system where $c$ is infinite? It would mean that nuclear fusion creates infinite energy. And what is the energy source of stars again? Nuclear fusion. Any stars would be infinitely bright. So nuclear fusion doesn't work anymore in your universe. But fusion in stars is the process which created any elements than hydrogen and any visible energy in the universe. So a universe without a speed of light would be a very dull universe. [Answer] There are attempts by people, who should know better, to re-formulate physics without relativity, and explaining effects that we currently attribute to relativity in different ways. In effect, they are trying very hard to maintain classical Newtonian physics as the "correct" backbone for all things. I am in no way supporting this as a correct worldview, however [this kind of thinking](http://www.extinctionshift.com/) (which I consider just plain wrong physics) turns up in a few places, often with similar agenda as creationism and other religiously-motivated rebuffs of science. On the plus side from your point of view, there is a substantial amount of this content. It contains some grave errors, but it takes a qualification in physics to spot them. A lot of the maths is worked through with correct substitutions for instance. As a writer, you could buy in to the fantasy, and have plenty of esoteric material and arguments that sort-of work, and give you a universe like ours, but with no upper speed limit. To answer your main question, the simplest answer is "no, it is not possible to have our universe with no upper speed limit". But more concretely, it is very hard to figure out the consequences of such a universe, and what else you would need to alter. It is simplest to have physics as we understand it in place, and *add something* that allows for exceptions. Or alternatively, hand-wave away the inconsistencies as "resolved behind the curtain" - i.e. assert that it *is* possible to construct a universe like ours, but without requiring anyone to do the maths. [Answer] An alternative solution to the problem is to say that the speed of light still exists, light and forces and almost everything that is not concerned with mass moves at the speed of light. **However**, that is not to say that in your universe the speed of light has to be 'the universal speed limit'. You could simply say that things can move faster than the speed of light under special circumstances or that it does not become harder to accelerate objects as they get closer to the speed of light. Both these proposals lead to other weird physics but you could more easily ignore these side affects and keep things plausible. [Answer] You can keep all the physics but allow certain conditions for different properties of space. Wormholes and stuff. Space what is not Euclidean. Can be folded to create shortcuts. Like Newton's physics describes universe close enough when objects move around slowly (up to say hundred miles per second), Einstein's world could be valid unless some other special properties of space are involved. We did not discarded Newton's physics when we learned Relativity. We just know that Newton's laws are enough to calculate stress on a bridge, or trajectory of a bullet, but when you want to find coordinates using GPS signals, you need to account also for Relativity. It might be that in our part of Galaxy/Universe FTL (Faster-Than-Light) travel is not possible. It might be that elsewhere conditions are different, and so are the rules. [Answer] Look at Greg Egan's *The Clockwork Rocket* and sequels. He has stuff on [his website](http://www.gregegan.net/ORTHOGONAL/ORTHOGONAL.html) about his universe and the ramifications worked out, including quantum mechanics! In Yalda's universe, as it is called, there is infinite velocity to a given reference frame. [Answer] A couple more problems come to mind: As Philipp pointed out, an infinite c means E = mc² breaks horribly. However, it's not just nuclear reactions that blow up, even chemical ones do. The mass loss in a chemical reaction is far smaller than in a nuclear one but it's still there. Going a little farther your hard drive fails for the same reason. See this post: <http://www.ellipsix.net/blog/2009/04/how-much-does-data-weigh.html> Even if you ignore this you'll find the chemistry of the heavier elements altered. Heavy elements have electrons that orbit at relativistic velocity. Put them in a Newtonian world and your car doesn't start—because the battery is only turning out .4V per cell rather than the 2.1V it really does (although by the time you draw any substantial power from it you only get 2.0V.) I'm sure there are a lot more changes but I'm not qualified to figure them out. [Answer] What about living beings with higher lifetimes and different perception of time? It seems it is quite possible to imagine a being living in our universe for whom a million of years would be just as short as a day for us. Of course such a slow person may be subject to various dangers (our own perception of time evolved from the need to react faster). But the level of danger may deminish as the universe cools, temperature falls and average power of energy sources falls as well. Thus the rate of diffusion, decay and erosion would deminish, reducing the need for food consumption and mobility. [Answer] I think you'd have to redefine matter for this to work. The two constraints: 1 - mass is dependent on its speed compared to the speed of light. As you approach the speed of light, your mass begins to approach infinity...and no amount of energy can increase the speed of something with an infinite mass. But the other relation goes...our current speed in relation to the speed of light is what defines our existing mass as well. Lets say you can just increase the constant that is the speed of light and you don't change our speed at the same ratio, we lose mass. As the speed of light approaches infinity, our mass will approach 0. 2- Time is also dependent on the speed of light. If we could accelerate a ship to 99.9999% the speed of light, for every day that passes to a person on that ship, nearly 2 years will have passed for the rest of us...hitting the speed of light would suggest 1 day that you experience is an infinite amount of time for the rest of us. Once again, the inverse exists...if the speed of light were to increase, the greater the delta in our speed to the speed of light, and the slower our time will pass...as the speed of light approaches infinity, the flow of time will approach 0. (oddly enough, this does come with the conclusion that it may take decades for a ship to get out of our galaxy, but if it was going fast enough, those decades would feel like a couple days to those on the ship itself) Prior to the big bang, something at 0 speed would also be timeless (which would be true regardless of the speed of light). Soon after the big bang, the speed of the mass ejected was limited by its increase in mass as defined by the speed of light. A speed of light that is twice that it is currently would ultimately see the masses ejected not gain mass until a higher speed. I'm sure I can't prove it, but I think a higher speed of light would result in a much quicker expanding universe and the distance between objects would be significantly greater (the earth would either be faster moving at a ratio equivalent to the speed of light increase or would loose mass at a proportion of the speed of light increase compared to its existing speed...in either event I think this puts Earth further away from our sun). This is pure speculation...but it's a little defeating to the idea that this would help space travel as the worlds and galaxies would be further apart. An infinite speed of light sees massless particles at an infinite speed...starlight would be to our eyes instantaneously (instead of the 'historic' view we currently get when looking at stars). Hoepfully this doesn't have the effect of instantaneously irradiating us with all of the combined light in the universe (At an infinite speed, would it stand to reason that all light would be everywhere simultaneously?) With all that said...this is how it works in our world, in our universe, in our existence. In a different setup, one must assume they exist and therefore whatever got them there has to be possible...those questions are left to the physicists in their universe to explore in the same ways ours here would. Added Would it stand to reason that stars relying on fusion that release energy based on e=mc² be hotter or very least contain more energy? Might have a big impact on star lifecycle. [Answer] What would be the reason for positing limitless speed? If you are trying to build a whole universe based upon this premise, you will have to accept some limitations. One is the big bang: if time is absolute, not relational, then it makes no sense for it to have a start. You can perhaps still have a local big bang for our sector of the universe, but it would have to be situated within time, not outside of it. If on the other hand you just want for your spaceships to travel at any speed, free from the Einstenian limitation to 300,000 km/s, I would say you would be trying to kill a fly with an atomic cannon. First, you can move your spaceships at any speed you want with unobtainium - white holes, space portals, eleventh dimension gaps, ninth dimension folds, etc. Second, moving your spaceships around without such pseudoscience is actually less credible, or would necessitate a bigger amount of handwaving. That's because our physiological limitations regarding acceleration are narrower than cosmic limitations regarding speed. A [recent question](https://worldbuilding.stackexchange.com/questions/75262/what-effect-would-1-5-times-the-gravity-have-on-a-human) asked about the effects a 1.5 g gravity would have on us. The consensus is that it would be very bad for our health. We live well on an 1 g environment. Now, gravity is an acceleration like any other. If we are going to travel long distances in space, we will need to do that accelerating at 1 g. Which is to say, at 10 m/s. A simple calculation will show us that a year has 31.536.000 seconds - so, if we accelerate at 1 g for one year, we will reach light speed. Which further means, to attain a speed significantly bigger than light speed, we would need to travel for considerably more than two years (considering that we would have to de-accelerate at the other end of the travel). Considering our life span limitations, we would still be trapped within a very small sector of the universe. Realistically, the closest star is about 4 light years from Earth. You would take √2 years, or about 16 months, to travel to it (and further 16 months to come back). So the shortest far-space trip we could make would take 2 years and eight months. The closest star known to have a planet - probably the closest thing we would want to visit - is at 10 lyghtyears distance; a trip to there and back again would take us 6 years and four months. [Answer] You do live in a universe in which the speed of light is not constant - it varies with the speed of the light source, as predicted by Newton's emission theory of light. That is what the Michelson-Morley experiment showed in 1887, but then FitzGerald and Lorenz advanced the ad hoc length contraction hypothesis and changed the interpretation of the experiment: <http://www.philoscience.unibe.ch/documents/kursarchiv/SS07/Norton.pdf> John Norton: > > "These efforts were long misled by an exaggeration of the importance of one experiment, the Michelson-Morley experiment, even though Einstein later had trouble recalling if he even knew of the experiment prior to his 1905 paper. This one experiment, in isolation, has little force. Its null result happened to be fully compatible with Newton's own emission theory of light. Located in the context of late 19th century electrodynamics when ether-based, wave theories of light predominated, however, it presented a serious problem that exercised the greatest theoretician of the day." > > > <http://books.google.com/books?id=JokgnS1JtmMC> "Relativity and Its Roots", Banesh Hoffmann, p.92: > > "Moreover, if light consists of particles, as Einstein had suggested in his paper submitted just thirteen weeks before this one, the second principle seems absurd: A stone thrown from a speeding train can do far more damage than one thrown from a train at rest; the speed of the particle is not independent of the motion of the object emitting it. And if we take light to consist of particles and assume that these particles obey Newton's laws, they will conform to Newtonian relativity and thus automatically account for the null result of the Michelson-Morley experiment without recourse to contracting lengths, local time, or Lorentz transformations. Yet, as we have seen, Einstein resisted the temptation to account for the null result in terms of particles of light and simple, familiar Newtonian ideas, and introduced as his second postulate something that was more or less obvious when thought of in terms of waves in an ether. > > > ]

[Question] [ I have a character on the surface of Enceladus, one of the moons of Saturn. It has an icy surface on top of what is believed to be a liquid ocean. There is no atmosphere, though near its south polar region there are what appear to be canyons filled with long lines of geysers that eject mostly water vapor into space. I need to have a way for this character to be trapped and buried on Enceladus (don't worry about his fate), either as a result of the ground caving in beneath him causing him to fall below the surface, or in something like an avalanche of ice down the side of the one of the canyons. The trouble is, the surface gravity on Enceladus is only 1.13% of Earth's. In that case, it seems to me most scenarios would be easily escapable, both because a cave-in or avalanche would occur very slowly and because the character could jump so high he should be able to simply leap away from the danger. I thought of having him hit by a large piece of ice and knocked out, thus preventing him from escaping; but could a person really be knocked out by a large mass that is slow-moving, or would he just be crushed? So my question is: is there a realistic way for someone to get trapped an buried under these conditions? [Answer] Yes, though Enceladus is probably much safer than Earth for these sorts of things. It all depends on how high the avalanche starts from and how much material is involved. A ton of rock or ice hitting you at 50 mph is going to hurt regardless of whether it's on Earth or Enceladus -- if anything, Enceladus would be worse because of the likelihood of damage to your spacesuit. It's certainly true that an avalanche starting from the same height will do less damage on Enceladus, but if it's high enough, it will still kill. (Also, there's the distinct possibility that Enceladus's low gravity may make much greater elevation differences more common.) Likewise with getting buried. The same *volume* avalanche will weigh less on Enceladus, and for that reason will be easier to get out of (pressure suit damage aside). But a big enough avalanche will still bury you under too much overlaying material for you to dig your way out even if you survived. Next there's the question of escape. Once more, it's probably easier to escape on Enceladus -- though just how athletic and controlled you can be in a spacesuit is an open question -- but escape is far from guaranteed. Further, in a vacuum, will you always be aware of an oncoming mass of ice? And if you're in a confined space, will you be able to escape? Consider a deep valley and an avalanche which starts far above you. By the time you're aware of it, it's moving 30 mph and is quite inexorable, with the same momentum it would have on Earth. Can you escape? Probably not. The lack of atmosphere had a negligible effect, as air resistance doesn't play a large role in the dynamics. (Its major impact is that the lack of air on Enceladus forces people into space suits and this makes them more vulnerable.) So, assuming your space suit is reasonably rugged, you're most likely safer on Enceladus, but a large avalanche can still trap you and kill you. [Answer] The surface gravity of Enceladus is 0.113m/s2. At such a low gravity, you cannot run, for the force you would use in a step will send you on a very long jump that may last more than a minute (if you don't hit anything along the way before you touch ground again). This may be quite dangerous. If you don't have the means to fly, like a jetpack, you may end up landing on a sharp shard of ice that will rip your spacesuit open. Alternatively, you may accidentally jump from a high place to a lower one. And while lower gravity means smaller acceleration, the fact that you can jump dozens to hundreds of meters upwards, to fall on a hole/crater/depression that might be dozens to hundreds of meters lower than your starting point, means that you can land with enough speed on hardened ice to break bones and equipment. If you want to see how walking on such a gravity might look like, I can recommend you a simulator. Like any simulator, this one does not model reality with 100% accuracy, but it is close enough to reality to give you a general idea. Get yourself a copy of Kerbal Space Program and go take a walk on Gilly ([surface gravity = 0.049m/s2](https://wiki.kerbalspaceprogram.com/wiki/Gilly)) or Pol ([surface gravity = 0.373m/s2](https://wiki.kerbalspaceprogram.com/wiki/Pol)), which are the bodies with gravity that is closest to Enceladus. That said, unless your astronaut has a jetpack, even walking may be suicidal. But if he does have a jetpack, he would never be in trouble in the first hand. As for whether the snow can crush him... [the density of snow on Earth is 0.1 to 0.8g/cm3](https://en.wikipedia.org/wiki/Snow). Let us assume that the density of snow on Enceladus is around the lowest range, 0.1g/cm3 so as to be nice with your astronaut. Now let's say that he gets 100 meters of snow on him. Let's do some calculations. Under 100 meters of snow, the mass of snow above a section of one square meter is: $$ 10^2m \times 1m^2 \times 10^{-1}g/cm^3 = \frac{10m^3g}{cm^3} = \frac{10^6 cm^3g}{cm^3} = 10^6 g = 1 \space metric \space ton $$ Impressive, right? But at 1.13% the gravity of the Earth, that metric ton would do for a pressure of 11.3 kilograms per square meter. [The average surface of an adult humans is around 2m2](https://en.wikipedia.org/wiki/Body_surface_area). This means that, laying down, your astrounaut is exposing about one square meter to the snow. We can then infer that under ten meters of snow, he would be facing 11.3 kilograms of pressure. That is [a laughable fraction of an atmposphere](https://www.metric-conversions.org/pressure/atmospheres-to-kilogram-force-per-square-meter.htm). So is he out of the hook? No. Don't forget that the astronaut is considerably denser than the snow around him. If he were naked, he could be ten times as dense as that snow - I figure the equipment in his spacesuit might be denser yet. In other words, he will sink in the snow. The snow will behave like a very viscous liquid, and it should feel like sinking in quicksand for the astrounaut. In the end, he is in for a very slow death in the dark and cold bottom of the avalanche. [Answer] Yes, it's definitely feasible for either a cave in or an avalanche to trap this character, and ice is heavy enough that chunks the size of two sedans would be very difficult for the average person to move even under Enceladus' gravity. --- **Material Required To Trap a Person:** Since the gravity is ~1% of Earth's (rounded for easier math), 100kg on Earth would be only 1kg on Enceladus. Assuming that the character *did* get trapped under some amount of ice, let's see how much is needed to prevent the character from just pushing their way out once they've been buried. [Benchpress world records](https://en.wikipedia.org/wiki/Progression_of_the_bench_press_world_record) are around 485kg, so if your character is a world record body builder they could theoretically lift 48,500kg, or about 40 [Toyota Corollas](https://www.google.com/search?safe=strict&ei=M3_LWrKKNPG9ggfPy6CICQ&q=toyota%20corolla%20weight%20kg&oq=toyota%20corolla%20weight%20kg&gs_l=psy-ab.3...6119.7506.0.7619.5.5.0.0.0.0.433.433.4-1.1.0....0...1c.1.64.psy-ab..4.1.431...33i22i29i30k1.0.hf4fWxs_l0Q). Let's assume a more modest 100kg to make the math easy. [This site](http://fess.su/news/dimensions-and-sizes-of-trucks) claims the volume of their truck trailers are 82 cubic meters, and [this site](https://www.aqua-calc.com/calculate/volume-to-weight) claims that 82 cubic meters of ice is about 75,000kg. A Toyota Corolla is about 12 cubic meters, which is about 7,300kg of ice. **So, a chunk of ice the size of 1 and a half sedans could trap, but not completely crush, someone on Enceladus**, and presumably your disaster would involve much more than that. **Avoiding a Cave In:** This is trivially easy to avoid if the character is next to a stable wall to grab on to since they'd fall slowly, so let's assume the entire area around the character is collapsing. [This question](https://worldbuilding.stackexchange.com/questions/15174/how-fast-would-one-have-to-move-to-climb-up-falling-debris) covers the idea of climbing up falling debris, however the answer's best case scenario involves large pieces of rubble that you were already about to jump off of. If the character is just standing, then they will fall at the same speed as the ground below them so they would not be able to push off of anything. Therefore, the character could not jump to safety if the ground below them caves in and they had no solid ground to grab onto. **Avoiding an Avalanche:** Although it would be moving slow, it would actually be pretty hard to avoid being buried in an avalanche on Enceladus. I don't have enough physics degrees to understand the math, however I'd imagine that since [the avalanche would behave much like a liquid](https://en.wikipedia.org/wiki/Avalanche#Dynamics), trying to stay on top of it would be like try to walk through a flood of quicksand or [molasses](https://en.wikipedia.org/wiki/Great_Molasses_Flood). This, coupled with [a cloud of powdery ice](https://en.wikipedia.org/wiki/Powder_snow_avalanche#/media/File:2007-02-15-CLB-Couloir2-1c.JPG) blocking attempts to find a safe route, could definitely lead to the character sinking and getting buried. [Answer] Despite the lower gravity, a cave-in in a sufficiently deep crevasse or cave could still easily happen quickly enough to block the escape. And once the only entrance is blocked by several tons of ice (and remember, the ice still has the same mass as on earth, so you can't just push it away), your explorer is truly trapped without advanced mining equipment. In fact, the use of such equipment might even pose another hazard, if it melts the ice or causes tremors, which could instabilize the rest of the ice. Being knocked out is also a possibility: Even if the actual collapse is far slower than on earth, the large masses colliding can cause shards and boulders of ice to be ejected at dangerous velocities. Finally, ice can be quite sharp, so if your character falls on or is hit by an icycle, they could end up pinned in place, with the ice stuck in their pressure suite being the only thing between them and decompression. [Answer] I think the other answers have sufficiently covered how dangerous a cave-in or avalanche might be, but I want to point out that the *chance* and severity of them will be far higher. The lower gravity will create a far steeper angle of repose as the cohesiveness of snow, rock, etc. will be much greater relative to gravity than we are used to on Earth. That means you can have far more material build up into very steep, even over-hanging and exotic structures. Add to that the lower atmospheric disturbance (no wind) and no critters or humans to disturb this moon's surface and you will probably have large, critically balanced structures that are ready to be knocked over at any moment. **Whether or not cave-ins or avalanches would be as dangerous as on Earth, you will have them occur far more often in virgin territory, and the mass of the material involved will likely be much greater.** [Answer] What I miss in other answers is that the morphology of mountains and avalanche material will be completely different at 1.13% of gravity. The amount of material stacking up before surfaces get crushed to the degree of starting a conversion from sticking to moving friction will be quite higher. So when finally things start getting ugly, the amount of ugliness unleashed will be quite different from that on Earth and the amount of potential energy leading to a chain reaction will be comparable, making the involved masses quite larger. Avalanches will be quite slower at taking up speed, but they will be just as deadly in their effects and the height colloding material will take on will have similar relations and densities compared to the jumping height of a human as on Earth. It's not just the human energy and time frame getting better payoff. [Answer] Absolutely yes. Even though the [force of gravity](https://www.vcalc.com/wiki/vCalc/Force+of+Gravity) is 1.3% of the Earth's, the planetary [weight](https://www.vcalc.com/wiki/vCalc/Weight) of a landslide or cave-in could still be fatal. Weight is the force of gravity on a mass. Newton's second law formula (F = m•a) shows the relationship between mass, acceleration and force. The following weight formula uses Newton's second law: w = m • g where: * w is the [weight](https://www.vcalc.com/wiki/vCalc/Weight) ([force of gravity](https://www.vcalc.com/wiki/vCalc/Force+of+Gravity) on a mass) * m is the mass * g is the [acceleration due to gravity](https://www.vcalc.com/wiki/vCalc/Acceleration+Due+to+Gravity). Using this [weight calculator](https://www.vcalc.com/wiki/vCalc/Weight) with a g value of 0.1274 m/s^2 (1.13% of 9.8 m/s^2), you can make some simple calculations. If 1,000 pounds of material would crush you on Earth (453.59 kg), that's a fourth of the weight of a VW Beetle. On your planet, ~34,800 kg would have the same effect, and that could be 21 cubic meters of stone, i.e. not much. ]

[Question] [ There have been a few questions about an [intelligent](https://worldbuilding.stackexchange.com/questions/3001/what-would-an-avian-castle-look-like) [avian species](https://worldbuilding.stackexchange.com/questions/2975/how-would-an-avian-city-be-different-from-ours) lately and they have gotten me thinking. It seems to me that it would be hard for an avian species to evolve to be more intelligent past a certain point. The main problem being that I can't imagine the immediate benefits of being more intelligent would outweigh the drawbacks of being heavier because of it (at least on a planet similar to earth). One thing that does speak in favor of intelligent bird is that they have appendages which are not often used for moving around (in the air) available. Being able to use those more creatively might pose a large advantage. Sadly I can't imagine those appendages being positioned in a way that makes them useful for intricate manipulation of the environment. (don't dwell too much on appendages in your answer, there are [plenty of reasons a species could become intelligent](http://en.wikipedia.org/wiki/Evolution_of_human_intelligence#Models)) So the question is: What would cause (or could explain) an avian species to naturally become more and more intelligent to the point of sapience and beyond (and remain largely airborne)? This question assumes a planet similar (but not necessarily identical) to Earth. [Answer] The factors that naturally selected humans (or more to the point, earlier primates/hominids) for increasing intelligence are somewhat speculative, but I think any of the following is plausible enough for world-building. Or any combination consecutively or concurrently: * tool use * complex communication * maintaining large numbers of individual relationships in growing social groups, that is to say "mentally modelling" lots of other individuals * as a special case, *deception* within stable groups, and counter-measures to deception An avian has two gripping appendages fewer than a primate[\*] (or just one fewer if you count the beak, which is probably better for tool use than a primate mouth). No bird I know of, even flightless, has re-evolved gripping forelimbs, and the feet probably aren't well positioned/articulated for throwing, so the tool-use benefit is less than for humans, but still there. Indeed, some avians use some tools. The social advantages could still exist in the right circumstances. So like you say, you'd need to make the case that doing these things justifies carrying a brain around with you. An adult human brain weighs approx 1.3kg, there are extinct hominids down below 1kg that were probably pretty smart. I suspect that even the largest pelicans' bills are considerably lighter than that, but I can't find a figure. I think one can very safely assume that whatever a pelican carries as beak-weight, a sufficiently motivated bird could carry as brains given the right evolutionary pressures, but multiplying that by 4 or 5 is hardly a slam-dunk. So I think your instinct is correct, it's difficult to justify, but I think you could get there. They're never going to be able to carry all that much in flight, but since an eagle can carry off a young lamb, a large bird in principle could at least get off the ground with a human-sized brain [\*\*]. So it depends how much you're willing to sweep under the carpet of "they benefit from evolving an increasingly complex society", and how much you're willing to give way on how big a brain they really need to be "sufficiently" intelligent for your purposes. Are you willing to posit that they have more efficient brains than humans somehow? If so then just get on with it: intelligent flying birds. Avians actually have one physical advantage over primates when it comes to brain capacity, which is that humans exist at the limit of the infant skull passing the pelvis while still being just sufficiently developed to survive. Birds have a whole egg-laying setup arranged already -- don't ask me how it works, but it does. [\*] - to be fair, humans turned out to only need two gripping appendages to satisfy our tool-use needs. But then we're standing on the two we decided didn't need to grip, birds don't have that luxury. Unless they can figure out a way to stand on their wings, which seems awkward. [\*\*] Or supposing two swallows carried it together? They'd have to have it on a line. [Answer] ## Intelligence doesn't require opposable thumbs. Civilization does require multiple species. When thinking about animal intelligence, it’s hard to keep our biases out of it. There’s a tendency to apply the human evolutionary story living in many of the answers to this question. That’s not unreasonable. Humanity seems like the most intelligent species and the only material culture we know of. Some evidence beats no evidence. > > Many of the answers I’ve read for this question either assume alien > races must be primate analogs or that flying creatures can’t become > overly intelligent. > > > I think it’s pretty obvious you are looking for an flying alien race for a story that is comparable to humans or a civilization that is comparable to ours. Before I address these possibilities, let me dive into human evolution to look at the evolution of intelligence. I often hear confusion about human evolution. **“Post hoc ergo proctor hoc”** is Latin for **“after this therefor because of this.”** It represents the common logical fallacy that sequence alone proves causality. In this case, that because reasoning intelligence is necessary to produce civilization, tool use must be in place to allow the development of higher intelligence. Or that civilization requires a reasoning intelligence because humanity had it before we civilized. My only point here is this, apes evolved a high order of intelligence for reasons that had little to do with the ultimate utility of having intelligence — such as civilization. So there’s really two questions here. 1. Why did a few animal species evolve a high order of intelligence? 2. How did civilization evolve for homo sapiens? First, there are many intelligent animals with new research revealing more all the time — pigs, octopuses, bears, parrots, etc. But there’s general agreement that the big three are the great apes (which includes humanity), elephants (several species past and present), and dolphins (including killer whales). Looking at these three animal groups, it’s difficult to find common patterns. Dolphins are predators; elephants are herbivores, and apes are either herbivores or omnivores. Elephants and dolphins don’t really use tools and dolphins clearly lack any kind of manipulative appendage. One group is semi-arboreal, the other land based, and the third aquatic. Non-human apes are polygamous, elephants matriarchal, and human relationships are too varied to easily pin down — dolphins too actually. And only humans have forward facing eyes. The commonalities that do exist are the possession of a large, complex brain, a high metabolism, a long life span, and extremely complex social structures - not to be confused with merely being a social species. In fact, social species are among the most stupid animals; consider the social insects. Humans, chimpanzees, and dolphins in particular posses what are called fission/fusion relationships. This means treating other individuals alternately as friend or foe depending on both the immediate and long term advantage. Social species treat each other consistently as friends. Individualistic animals compete with each other openly, almost as opposing species. But only apes and dolphins could ever indulge the axiom of, “the enemy of my enemy is my friend” or “politics makes strange bed fellows.” > > It seems the evolution of politics drives the development of higher > reasoning intelligence. Why? Because it requires not just self > awareness, but the ability to predict the behavior of other > individuals, to walk in their shoes, so that you can deceive them. > > > A chimpanzee in a zoo, given a banana, won’t simply hide the banana to avoid sharing it, it will alter its behavior to appear as if it doesn’t have a banana when other chimps are looking. This requires the chimp to calculate how its behavior appears to other chimpanzees. It is a lot more cognitively challenging to lie effectively than use a tool. What’s germane to the possibility of intelligent birds is this. While I don’t believe science yet has a handle on exactly why a few species have evolved politics, all that appears required is a large brain, a long life of experiences, and some reasonably sophisticated means of communication. **By that measure, almost any animal type imaginable could conceivable evolve reasoning intelligence.** As for the development of civilization, it might be worthwhile to consider what a long shot that was all by itself. Homo Sapiens existed for almost 100,000 years before they developed beyond stone age tribes. Considering too that since we now know Homo Sapiens successfully interbred with Neanderthals (I’m 1.7% myself) we must consider them more or less the same species. Thus human intelligence existed on Earth for hundreds of thousands of years without civilization appearing. It was only after the end of the last ice age, that conditions in a few places put our ancestors next to a few useful species of plants and animals thus making agriculture possible. Agriculture and animal husbandry both are not inventions in the modern sense, but rather symbiotic relationships - another evolutionary process. Local conditions must be sufficiently variable to drive an evolutionary solution to stabilize the variability — to the mutual advantage of two species (humans and wheat for example), but not so difficult (ice age tundra) that an early evolutionary experiment at cooperation couldn’t possible succeed. > > Simply put, civilization doesn’t belong to humanity alone, but also to > wheat, rice, corn, dogs, goats, chickens, and cattle. If all these > species hadn’t evolved together, all humans would still be living in > caves — no matter how clever and devious we are. > > > Thus if you’re looking for your avian species to have material civilization, broaden your thinking out to the planet they live on and the other species they partner with. What geological or climate forces caused the symbiotic coevolution of civilization with one intelligent, political species (the birds) in the drivers seat, but others equally important? P.S. Nobody mentioned parrots. They’re intelligent, arboreal, long lived, have opposing digits, and are great at communication. [Answer] As you've suggested intelligence is subject to natural selection just like any other attribute. A bird could be the smartest bird in the skies but unless it survives and reproduces that intelligence will never be passed on to the next generation and spread through the species. So what makes an intelligent bird more likely to survive/reproduce than an ordinarily intelligent bird? * The ability to anticipate dangers/opportunities * The ability to work as a team to increase chances of success * The ability to use tools (suddenly being the strongest doesn't count for as much) An increase of any of these could give a creature a marked advantage (after all puny little humans survived). Wings as you've pointed out are not particularly dexterous, intelligence (in it's early stages) go hand in hand (sorry) with the ability to use tools/implements. However don't forget many [birds do use tools](http://en.wikipedia.org/wiki/Tool_use_by_animals#In_birds)! Therefore the suggestion is that either the creature would evolve dexterous limbs (such as hands AND wings) or their tools would become more and more dependent on limbs they do have (beaks and feet/claws). Weight is obviously going to be an issue however a human brain only accounts for [1:40th](http://en.wikipedia.org/wiki/Brain-to-body_mass_ratio) of a human's weight! However small birds are more like 1:14... this suggests that your bird will need to increase in size as well as intelligence. All in all the odds are stacked against them, having said that. There have been some truly enormous [flying creatures](http://en.wikipedia.org/wiki/Quetzalcoatlus) in the past! [Answer] Given that there are already intelligent birds (parrots, ravens, magpies) with intellectual abilities akin to a human child, this suggests that their brains are far better optimized than human brains, weight for weight. So an avian brain of equivalent intellect to a human adult would not necessarily have to weigh anywhere near 1.3 kg. Some research on the subject: 1. Abstract rule neurons in the endbrain support intelligent behaviour in corvid songbirds [[Nature](http://www.nature.com/ncomms/2013/131128/ncomms3878/full/ncomms3878.html#affil-auth)] > > Despite the lack of a layered neocortex and fundamental differences in endbrain organization in birds compared with mammals, intelligent species evolved from both vertebrate classes. Among birds, corvids show exceptional cognitive flexibility [...] > > > 2. On the [Sydney Morning Herald](http://www.smh.com.au/environment/animals/crows-may-be-as-intelligent-as-apes-scientists-say-20150624-ghw6zy.html#ixzz3z5Nsqy00) > > Crows may be as intelligent as apes, scientists say > > > 3. Bird Intelligence [[Wikipedia](http://en.wikipedia.org/wiki/Bird_intelligence)] > > Birds in the crow family (corvids), and parrots (psittacines) have been shown to live socially, have long developmental periods, and possess large forebrains, and these may be expected to allow for greater cognitive abilities > > > 4. Smarter than a first-grader? Crows can perform as well as 7- to 10-year-olds on cause-and-effect water displacement tasks [[Science Daily](http://www.sciencedaily.com/releases/2014/07/140723180824.htm)] > > "When we gave them only four objects, they could succeed only in one tube -- the narrower one, because the water level would never get high enough in the wider tube; they were dropping all or most of the objects into the functional tube and getting the food reward," Logan explained. "It wasn't just that they preferred this tube, they appeared to know it was more functional." > > > 5. Corina J. Logan, Sarah A. Jelbert, Alexis J. Breen, Russell D. Gray, Alex H. Taylor. *Modifications to the Aesop's Fable Paradigm Change New Caledonian Crow Performances.* PLoS ONE, 2014; 9 (7): e103049 DOI: 10.1371/journal.pone.0103049 [[Link](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4108369/)] > > The Aesop's Fable paradigm requires an animal to drop stones into a water-filled tube to bring a floating food reward within reach. Rook, Eurasian jay, and New Caledonian crow performances are similar to those of children under seven years of age when solving this task. > > > 6. Crows wield tools with human-like skill [[NewsScientist](http://www.newscientist.com/article/dn12495-crows-wield-tools-with-human-like-skill/)] 7. Current Biology vol 17, p 1 (DOI: 10.1016/j.cub.2007.07.057) 8. Brains and Beauty: African Grey Parrots [[African Greys](http://www.africangreys.com/articles/overview/beauty.htm)] 9. Parrot Learning [[Science Net Links](http://sciencenetlinks.com/science-news/science-updates/parrot-learning/)] 10. The Alex Studies - Cognitive and Communicative Abilities of Grey Parrots [[NY Times](http://www.nytimes.com/books/first/p/pepperberg-alex.html)] 11. Evolution of the avian brain and intelligence [[Cell](http://www.sciencedirect.com/science/article/pii/S0960982205014041)] 12. Cognitive ornithology: the evolution of avian intelligence [[Phylo. Trans. B](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1626540/)] [Answer] [Crows](http://www.josh.is/crow-machine/) happen to be intelligent enough to buy food from a vending machine using coins. Crows aren't even that big. Pigeons beat mathematicians at the [Monty Hall Dilemma](http://www.ncbi.nlm.nih.gov/pubmed/20175592). That seems to be enough intelligence to learn that you can kill prey by carrying stones and dropping those stones from a height on prey. Targeting the stone so that they hit will be improved by intelligence. Intelligence also allows for a selection of better stones to drop. Over time that means you have a selection bias for higher intelligence. [Answer] I'll give this a try... —one thing I'm having issues with is maintaining flight. If you take a gorilla and compare it to a human, you'll find the Gorilla is, pound for pound, significantly stronger than its human counterpart. As great as intelligence is, the temporal brain significantly reduces a creatures physical abilities, both by consuming a huge amount of the bodies resources and by forcing thought (quelling the much quicker instinctive reaction in favour of thought). If the same ratio of the degradation of physical abilities from Gorilla to Human would exist for an intelligent bird, I'm not so sure it would be capable of flying. For intelligence to rise, you need evolutionary forces to favor intelligence. In the case of Humans, shared defense is one of those initial driving factors. Not only was it good to be intelligent to spot dangers for yourself, but it became pivotal for you to be surrounded by others that could also spot and process these dangers (your intelligence in picking out a bird of prey and acting on it = my survival). So, although individual intelligence was helpful, group intelligence defined the species ability to survive. To me, this see's most birds of prey drop out of the intelligence race...as smart as a single bird can get, there is no evolutionary pressure for them to surround themselves by like intelligence...in fact, through competition, it's more advantageous to quell the other like intelligence creatures before they do the same to you. This might sound odd...but I give the highest chance of intelligence evolving to the now extinct Dodo where their group existence and dependence on one another is the pressure for the entire group to become more intelligent (stupidly enough, this may be why they went extinct so quickly...if you shot a Dodo, hundreds of other Dodo's would run up to see what happened). Unfortunately, this is back to being unable to reconcile the parameters of this question and their inability to fly. Would be really interesting if the possibility of a flightless bird evolving intelligence and then once again evolving the ability to fly through their intelligence. [Answer] Consider an evolutionary hazard gaming strategy. As seen from the average mammal, the human brain is completely oversized and costs ridiculous amounts of energy just to operate in idle mode. No proto-intelligent social life form that occupies a sweet spot such as chimps or ravens can reasonably favour such a development. Imagine that proto-humans were expelled from such a sweet jungle spot out into the dry savannah where they had to steal a living from an established predator / prey scheme. The predators were mostly night hunters and would, like their prey, rest at noon, hence both would never evolve the ability to hunt or run away in the heat of high noon. The proto-humans would lose most of their pelt, evolve water cooling through sweat and hunt the prey to thermal shock. However, since hunting at the borders of overheating costs a lot of brain cells, they would evolve large amounts of backup. From there on, as the cooling efficiency increases, the backup suffers less thermal loss and gets used to enhance socializing and toolmaking, which in turn increases efficiency. Finally, by this cascade, intelligence emerges as an unintentional byproduct. Construct a similar catastrophic exodus and drop your avians into a niche that lets them bet their survival on thermal imbalance or any hazardous corner case that leads to accidental accumulation of otherwise ruinously oversized brain capacity. [Answer] What exactly do you mean by intelligence? Is reasoning and problem solving enough or are we looking for avians that will eventually develop space flight or derive the Standard Model? A number of experiments on ravens show them to be quite capable of the former, whilst the latter will almost certainly never happen without the ability to manipulate sophisticated tools (imagine building a particle accelerator with nothing more than beak!). However, I would argue that it's an exacting critic indeed who wouldn't recognise reading, 'riting and 'rithmetic as signs of intelligence. I see no obvious barrier to raven's developing beak-graffiti to accompany their spoken (tweeted?) language. This is something that could easily occur spontaneously without much (or even any) physical evolution. As far as we can tell human writing only began around 10-30,000 years ago, whilst we have been largely physiologically unchanged since the rise of Anatomically Modern Human about 200,000 years ago. That is to say, we didn't just develop writing when we became smart enough to understand it - it seems to have arisen spontaneously, seemed useful, and stuck around. Human writing began with simple counting systems, and it is easy to conceive the utility of such a system even to ravens. A savvy raven could mark days to decouple themselves from the environmental cues of changing season and get the jump of the competition when migrating.\* An animal with a spoken/squawked language and in the habit of making marks will eventually come to use them for more than numerals. High points might be marked with a "tag" to warn off rivals, strings of landmarks might be marked as sign-posts home, allowing the raven to venture further to find food or mate. Reminders can be left of caches of hidden food. None of this writing needs to be any more complex than their already demonstrated *prruk-prruk*ed language skills in order to be useful. Eventually the landscape will be dotted with raven writings, and certain pieces of information will pass from one generation to the next - summer last this many days here, this woodland is good for mice, etc. If another species got this far, I wouldn't hesitate to consider them intelligent. There doesn't seem to be any reason at all why a raven couldn't do any of this without any further evolution, and we should not be discouraged by the fact that they haven't done so already - modern humans lazed about for 170,000 years without doing it. But what is exciting is what comes next - what might be possible *with* a little more evolution. Sign-posts to hidden food might be read by other ravens, encouraging the use of misleading marks and an encryption/decryption arms- (wings-?) race. A migrating bird might add another 30 day-marks to his calendar before leaving, so that next years rivals postpone their own migration. When a technology proves useful then in time it typically becomes essential - if farming can support a larger population, then in time there will be a population that can only be supported by farming, etc. In this way literacy will eventually become an essential skill among ravens, as the underfed, exhausted illiterates are passed over by potential mates attracted to the new breed of well-fed, glossy-feathered renaissance ravens. And one day, they will be calculating their latitude and performing spherical trigonometry to plan their migrations... (\* yes, I know most ravens don't migrate, but some do, and this is world-building so I can have ravens migrate if I want. Ravens are the birds most commonly associated with intelligence, and migration seems a behaviour in which intelligence might be advantageous.) [Answer] Given what intelligence relatively (to humans) small-brained creatures like magpies and keas have at their disposal, I think it's just a matter of the right environmental and ecological conditions occurring. A world rich in energy with lots of high places would help, especially if the gravity were a little lower than Earth's, or the atmosphere a little thicker. Consider what real birds already do: European magpies appear to be able to recognize their own reflections, and can use a mirror to find colored tags stuck to their throats and remove them with their feet. Crows recognize the regional accents of other crows and adjust their calls to match. Numerous species of birds employ tools toward various ends. Other corvids possess sufficient intelligence to goof off, such as by depriving humans of the status of "only species known to enjoy snowboarding": <https://www.youtube.com/watch?v=3dWw9GLcOeA> Starlings may even have been demonstrated to have some grasp of recursive syntax: <http://acp.eugraph.com/news/news06/gentner.html> They may well be able to achieve the same intelligence as primate brains larger than theirs--there is, after all, a strong evolutionary incentive for birds to get as much thinking done with a given mass of brain. Moreover, their brains have a rather different physical architecture (although if you're designing a fictional species I guess you can put whatever you want there--hey, maybe even put some really nice integrated circuits in there if you're willing to get weird.) A chickadee needs to remember all the dumb little places it hid seeds, and a crow is more likely to make it through the winter if it remembers lots of places where people leave sandwich fragments. Also, a large vocabulary of calls gives a flock a better ability to adapt to unexpected situations, and a songbird migrating into an area where the calls are a little different is more likely to find a mate there if it learns the local "accent". Which actually does happen. I'd post a link, but the red box to the right says I "need at least 10 reputation to post more than 2 links." Fine, encourage me not to cite sources then. This place must adore hearsay. While I'm at it, there's even some evidence that crows are capable of deception. There's a great article on New Scientist that I can't link to. Anyway. Point here is some avians are already not that far from being what we might consider intelligent, so you've got something to work with already. Physics is unkind to things that fly, but not so unkind as you'd expect. We already have a good idea of the upper limit of size for animals capable of powered flight on Earth. Consider the Argentine teratorn (Argentavis magnificens). They were enormous! Weighed as much as some humans, and was pretty much a really huge buzzard. Smaller relative species were just terrifyingly large birds of prey. So you have a lot to work with: You get up to seventy or eighty kilograms if you accept that you might need a wingspan of seven meters. So, assuming Earth gravity, your hypothetical sapient bird should preferably weigh less than that. Let's no go too close to the limit; let's not use up all our wing loading so easily. It's bad for agility. If I think about this like an engineer, it's not hard for me to imagine making magpie or a kea bigger until it can power a pretty nice brain. Maybe even one on par with that of a human. As long as it weighs less than a teratorn, you can probably get that to fly. Nature is going to give you more leeway here than you expect. It's easy to scoff but it's not that hard to design something that works. The challenge to the worldbuilder is to imagine what kind of world would favor such an evolutionary outcome. I sometimes imagine a planet with slightly less-than-Earth gravity and lots of small volcanic islands\*. Some really good reason to fly, remember things, and organize socially, and the right environment to support the energy demands this entails, and perhaps to present a mixture of risks and rewards that favors intelligence. As for tool use, besides the fact that they already *do* it, birds have some options. For one, their balance is excellent and their beaks and feet are really dexterous. The feet are opposable, and the beak is innervated--capable of feeling things--and highly maneuverable due to the large number of cervical vertebrae even very large birds possess. That's already a lot to work with. Besides that, why can't the wings have a few opposable claws? Pterosaurs and juvenile hoatzins both have wing-claws, and there's no reason those couldn't evolve to be more articulate given the right environmental and ecological incentives. It wouldn't be any weirder or less plausible than triosseal canals or having four or five color channels in your vision. Never forget incentives, and never forget selection strategies, which are even more ridiculous. Consider birds of paradise. Yes, there are reasons for them to exist, and they're absurd. That animal is nature smirking and saying "Because I can. Because it's not impossible and because I can." If it's biophysically possible, you can probably come up with a reasonable, plausible way for it to evolve. If it's lighter than an Argentine teratorn and no more ridiculous than a mantis shrimp, it can probably exist. I think making a magpie big enough to do calculus under the right environmental conditons is really not all that hard to imagine, all things considered. \*Maybe a habitable Jovian moon, if you want to risk arguments with physicists about whether you can reach a compromise between the risk of solar wind stripping the atmosphere due to insufficient proximity to the parent planet's magnetic field and the loss of too much water and gas from the moon due to reflected and radiated heat from the parent planet. Maybe it's a red dwarf or something. Maybe I just can't get over how cool it sounds and am too optimistic about the feasibility of something ridiculous. [Answer] The error is in the title. Nothing would cause an avian species to become more intelligent. As stated above (Liath), only if there is a survival advantage for a group of such a species being somewhat more intelligent, then those traits would be passed on. A continuing process of natural selection could then select for those individual having the advantage of greater intelligence. However, such selection does not necessarily have to occur, and even if such a process were available, the animals might not have any significantly increased intelligence. They might get through by dumb luck. Nothing can cause the trait of higher intelligence to occur; if it occurs by chance then there is the possibility it can be passed on to subsequent generations. It is a great mistake to assume Evolution required humans to evolve from primates, and that Evolution will produce some other advanced human to replace us. As an aside, we had a chance to develop higher intelligence, because our ancestors ate a high fat diet after beginning to use stone tools. I wouldn't be surprised children are suffering because we are incorrectly feeding them low fat foods. Brains require large amounts of cholesterol to develop. [Answer] Time, and absence of humans? Corvids (jays, crows, ravens) are pretty intelligent in somewhat human-like ways, including interest in object manipulation, large-scale social and cooperative behavior (especially crows), aggressive territoriality and mutual defense, and language (especially ravens). Get humans out of the spotlight and give them time (100,000 years?) and circumstances, and perhaps evolution of stronger ability to work with objects (more claw strength and manipulation ability). On the other hand, I think this comes with the assumption that the path humans have taken is likely and has universal values. Our outlook on our own evolution, cultural assumptions, and our view of other species, has a huge amount of self-justification and denial in it, it seems to me. I wouldn't expect every intelligent species to end up with the same traits that human civilizations have arrived at. [Answer] Let me add another point of view. Most answers assume that the large brain evolved in order to gain intelligence. However, I've once read another hypothesis (unfortunately I don't remember where): The human brain originally grew big because humans were in an environment where the brain would often get damaged; the brain size was originally just redundancy. This also fits with the astonishing plasticity of the brain: If a brain areal is destroyed, the surrounding brain areas can learn to perform the function of the missing brain part. Of course already having a greater brain meant that the additional cost of using it for more complex stuff was much lower, allowing for the evolution of intelligence. When working on that hypothesis, you'd need to have a reason why the birds would often have brain damages, and why a larger brain with more redundancy (rather than strategies for avoiding the brain damage) would be advantageous despite negatively affecting flight. [Answer] Best that I can imagine, you will need wildly different environmental pressures on the planet in question. ## Some possibilities: **Ocean World** The planet is almost entirely covered in ocean, with the only "terrain" being large mats of organic material. The transient nature of the terrain, plus the wide open skies and seas filled with fish, would seem to favour the development of an avian race. (Or an aquatic one, or both, the two wouldn't necessarily be in direct competition with each other.) **Gas Giant** A gas giant with one or more breathable atmospheric layers might lend itself to the development of an avian race. Possibly incorporating internal gas-bladders for flight. **[Skyworld](http://tvtropes.org/pmwiki/pmwiki.php/Main/WorldInTheSky)** This one defies physical laws in some places, but a world composed of floating chunks of rock in an atmosphere would definitely favor the development of an avian sentient race. [Answer] To be honest, I see one of two possibilities to help an avian on that journey off the top of my head. The first, assuming they are more like our birds, would be they become land bound, such as the ostrich or the extinct [elephant bird](http://en.wikipedia.org/wiki/Elephant_bird). Where having a large brain wouldn't be a problem and the wings could become more useful as arms and hands. The other would be if they had 6 appendages like a griffin, the front 'legs' becoming arms. However, the appendages would be more for helping advance the species in technology. being land based would be enough enable them become very intelligent. Of course it's always possible to still have flight and be intelligent but brains are big, bulky, need lots of protection and require a lot of nutrients. So an intelligent avian species is more likely to be grounded. Now to deal with the extra requirement of the avians actually staying aloft as a species, because of the issue of the weight of the brain, the bodies would have to change to handle it. One change would be having a short neck to keep the weight closer to the body another would be to have a very large wings to add more lift, maybe more of the body can 'morph' to help with wing surface area more like a [flying wing](http://en.wikipedia.org/wiki/Flying_wing). But with such a specialized body structure, I think they would need to be a 6 limbed animal to have limbs with dexterity to create tools. [Answer] Define intelligence. There are many, many, aspects which we would consider related to intelligence. Communication is often a big thing, so a very social species would see pressures to increase functions of the brain. You mention tool use, well any species whose prey can be caught easier through using tools would see advantages (with birds in particular, their beaks can and are used for tool manipulation in some species). And don't be so quick to discount wings. Analysis of the skulls of pterosaurs show they probably has well developed brains for processing information from their wings (bats may as well, I don't recall offhand). So if you are not limiting yourself to feathered birds but flying species in general, a species with skin based wings with nerve endings along the wing would develop brains capable of understanding the signals they are receiving to help them achieve a more acrobatic flight. [Answer] Tom's answer has one flaw; He says that elephants and dolphins don't really use tools. Compared to other fully or semi intelligent beings such as humans, elephants and dolphins (and other cetaceans) don't need to use tools as much as humans do, and don't have as much ability to make and use tools (especially cetaceans) or to carry them around permanently. Jane Goodall revolutionized ideas of non human intelligence by observing chimps using tools, but decades earlier there were observations of elephants using tools. Charles Darwin observed elephants modifying branches and using them as fly swishes, and there were also observations of elephants modifying twigs to clean out gunk from glands in their heads. <http://www.onekind.org/education/animal_sentience/tool_use/tool_use_in_elephants/[1]> Captive elephants have been known to use keys to unlock their cages. I think that it is time to stop thinking of only one semi or fully intelligent species of life on Earth, and instead recognizing that there are about a hundred species of semi or fully intelligent mammals on Earth. There is a lower limit to the size of a mammal brain for the possessor to be considered semi or fully intelligent. Mammals have evolved into a wide variety of sizes. For tens of millions of years a small percentage of mammals have bodies large enough to support a brain large enough to be semi or fully intelligent. And for tens of millions of years some of those species of large mammals have evolved large brains for various reasons and have become semi or fully intelligent, often perhaps as a side effect of having such large brains. Of course extinct or existing semi or fully intelligent species might not be limited to mammals. A few species of birds, for example, might at the least be almost semi intelligent, despite having entire bodies not much, if any, larger than the brains of semi or fully intelligent mammals, suggesting that bird brains might sometimes be more efficient than mammal brains. So flying intelligent beings may be rarer than land or sea based intelligent beings but still fairly common in the universe. But to me it seems an important and necessary point to make any fictional intelligent beings part of a world that has, like Earth might have, many different coexisting species of semi or fully intelligent beings, and also to have the first species to develop high technology and civilization on that planet rise tens of millions of years after the first semi or fully intelligent beings on that planet, as may be the case on Earth. ]

[Question] [ We know, unlike what Hollywood would have you believe, that plate armor was actually incredibly effective when it was being used. In order to combat this, some bright spark came up with the concept of the mace/warhammer, which would simply transmit its crushing force through the armor to break the poor tin-man's bones and smoosh his vital organs most vindictively. In an attempt to better protect my little tin men, I would like to ask for suggestions as to how armor should be designed to better protect against crushing blows. Although I used the example of maces and warhammers here, what my tin-men are really facing up against are significantly worse (The huge fists of angry wargolems), so feel free to make the armor cumbersome, so long as it is protective. Cost is no expense. However, the setting is pre-industrial, so try to avoid using things like non-newtonian liquids and other sci-fi-ish stuffs. Also, this armor is for the common soldier, and magic is [difficult to get a hold of in such large quantities](https://worldbuilding.stackexchange.com/questions/8906/the-social-implications-of-life-as-currency), so enchanted armor is out of the question. We're going to have to rely on pure smithing ingenuity here. [Answer] The joy of hammers is that they are so simple to model with physics! All they do is impart a large quantity of momentum in an *ideally* inelastic collision. Hammers, like all weapons, are tools of disruption. Their entire goal is to disrupt the opponent until they can no longer fight. Hammers do this in many ways: * Impart enough momentum that the victim loses control of his own Cg, and falls. * Impart enough of an impulse to do internal damage (concussions) * Impart enough local momentum to disrupt a local part of the body (such as a dislocation or broken bone) * Impart enough local momentum to bend the victim and his/her armor into an undesirable state (such as bashing platemale in sufficiently hard to disable a sword-arm by immobilizing it). A key requirement for all hammer attacks is that they are very dependent on the victim to remain stationary. Try popping a balloon by hitting it with a hammer mid air and you'll see what I mean. **The first way to stop a hammer attack is to redirect it.** Angled plates which cause the hammer to connect with a glancing blow are very effective in some situations. This is the logic behind both cattle-guards and modern [blast-resistant vehicles](http://www.casr.ca/id-blast-resistant-vehicles-3-3.jpg). This also points out that light armor can be good against hammers because it provides the mobility required to get out of the way. However, if one is pinned down, a vertical hammer blow can be virtually unstoppable because you are pinned against the ground. For most hammer attacks, the local effects are more important than the global ones. While it'd be great to simply knock everyone off their feet with one blow, realistically it tends to be easier to go for body damage first. The big difference between the local and global effects is that, for local effects, its meaningful for the victim to choose to stand their ground. They pick some part of their body (usually their abdomen, where the Cg is) and decide not to give up ground. **This means they must redirect or dissipate the energy in their body.** Padding is the simplest example of this. The more cushy padding one has the less they can be hurt with a strike. Jigglypuff would be the ultimate example of how to win at combat like this! Of course, **padding is a balancing act: more padding also makes you less agile.** The most effective solution to hammer strikes is metamaterials. Metamaterials are materials that get their strength not from their material, but their structure. Modern metamaterials have been used to transmit forces around the cab of a car during a collision, rather than through it. This can be extra effective if you custom tailor the material for the expected kinds of collisions. --- As an ultimate protection, I'm going to design an armor that is entirely designed for golem fighting and nothing else. * Golems may be able to use their strength to actually strike at the Cg of the tinmen. This is a major bugger because there is literally nothing you can do to stop it... physics wins. Anything which seeks to arrest this is in for a lot of trouble, because now you have elected to stop the fist yourself. * We're going to assume Golems can only strike the front. If you fail to properly surround your angry war-golem, you get what's coming to you. * I'm going to have the local Gnomish tinkerers put together a trigger system. The triggers are on the front. If you are struck hard enough, they cause wheeled supports to spring out from the back, catching you and helping you get into the game quicker. * The chestplate contains a large air bladder, to be used similar to the air bags that stuntmen fall on. Any strike to the chest will immediately be spread evenly around the entire chest, which is your best possible chance to not get hurt. * Vertical strikes are an issue. We're going to have to use metamaterials here. The armor should have thick rails along the sides. When facing a downward strike that cannot be avoided, the armor should be designed so that a tinman who raises his arms in the right way automatically lines up several of these thick rails which can transmit the force to the ground. For mobility, these rails should not line up when the tinman is in other combat poses. They may need to train in the right way to block a downward blow to get their arms into position to lock the rails in place before the blow hits. * My armor has explosives. Okay, it really doesn't. But my instincts say "a strong offense is the best defense." The more anti-golem artillery the better! [Answer] **Quick solution using existing armor** Anyone who's ever fought adamantium golems in melee with a low-level party can empathize, I'm sure. Well, actually no, because they'd be *dead*. Ideally, you'd have a contingent of Archmages tasked with disabling and re-purposing these unpleasant constructs, preferably with a future as teapots and storm-drains in mind. Absent archmages, melee charges against these things tend to be rather one-sided, and also remarkably 2-dimensional by the time the Golems are done with you. No worries though. I have a fool-proof solution of using your knights' armor in a way that is sure to help you. 1. Pick a few knights you don't like. 2. Take their armor, and weapons. 3. Melt their armor, using the abundant trees and a smith. 4. Make lots of spades. Make armor-less knights and any nearby peasants dig very deep holes (about 2 golems deep). If they protest, point out to them that they have no armor, no weapons and that you do. 5. Cover up the holes with planks (also made from the abundant trees), and dead leaves. 6. Find a golem. Use the armorless knights and peasants as bait. Or pigeons. Golems hate pigeons. 7. Have the bait flee over the planks (quickly). The heavy golems will give chase, break through the planks and end up in the hole. Repeat as needed (might need fresh bait). 8. ??? 9. Profit! --- **Boring real answer** If you suffer from a general lack of imaginative generals, your knights (well, after a few very quickly succeeding generations with closed-casket funerals) will wise up and take matters into their own hands (as well as arms, chests, shin-guards and all). Modern technology deals with blunt forces via dampening. Since your knights won't have explosively inflating airbags, a similar effect could be achieved by using very thick layers of cotton-like materials, or, cotton-absent, inflated animal skins or more simply by **lumping hay-bales to the front and back of your knights**. As you surely know, you can safely jump into a haystack from the top of various tall buildings, or if you're not called Ezio, at least from the top of barns, so the dampening effect is enough to stop a 100kg body falling at 60 km/h in under 20 cm. So while your knights might get thrown back, they probably won't die, unless the force of the punch breaks their neck. The toughest bit is protecting the head from punches coming from above. Above their heads they'd have to wear a set of (3 or more) inflated balls that are in contact with each other and the front and rear dampening materials, but not in direct contact with the head. As a plus, they will look extremely undignified. Furthermore, once they see their first golem, they'd probably give up their metal armor long before they give up the hay. (Perhaps make some shovels?)  So you can beat adamantine golems with hay and inflated balls. How's that for ironic? [Answer] The point of armor of course is to reduce the impact of weapons used against them. But that also encourages larger impacts to be used. One of the items we use in cars to reduce impact in a collision is to have crumple zones in the frames. Taking this idea I think one thing that could be 'relatively' cheap to implement (though only the rich knights in medieval Europe could afford metal armor) would be to put in springs inside the armor, especially the chest area, leaf springs to be more precise. they would attach at different places and wrap around the body. Just like metal ribs. You know the bones that protect your heart and lungs. The chest armor would have to be overlapping so that when it is struck the springs/ribs can give and bounce back, absorbing much larger impacts than the poor fool just standing there. [Answer] I read an answer about using rails that, when used in unison with correct arm movements, would absorb the vertical blow of a golem's fist. I have taken this idea, along with a quick glance at my kitchen dish-rack, and have produced a viable option for golem-proof armour. It functions as a blow-absorption armor that is worn **on top of other armour**. A warrior would don his usual plate or mail armour, preferably plate, and then have the secondary armour fitted. Due to its appearance, it has been named... ***The Wireframe***  The yellow areas indicate a spot to shove a limb, where the side indicates arm hole and top indicates head hole. The blue lines are thick cotton/hay padding areas, which protect the neck and head from impact from whiplash. The functionality of The Wireframe is simple: when a golem punches The Wireframe, which is about 5 inches (pleasing you damn Americans, but I'm a metric man) from the normal armour (the gap in between is air), the solid steel (or metal of choice) pipes bend inwards. This completely absorbs the first and second hit, but the others might be problem, when the front pipes have been bent inwards. An aerial strike is a downmotion that targets the head; the golem's fists would be too big to fit between the aerial rails, meaning they simple bend downwards for the first few strikes. Among all this, the pipes have enough gap space between them for other ideas to be implemented, such as spikes. With The Wireframe and plate armour, any warrior should be able to survive the initial strikes, and with a whole unit of these warriors, any sort of golem will be in trouble, as the survivability means many weapons will find their mark. It is mobile, effective and **looks downright awesome**. It fits the criteria; I hope you can use it. [Answer] Armour is going to be essentially useless in this situation, the Golems' fists will just punch it into you and then leave it as shrapnel in the wound. Instead you should focus on mobility, and reach. Have unarmoured or lightly armoured soldiers trained for endurance and fast moving. They use Pikes, Bola, and Nets to keep the Golems at a distance, entangle them, and drag them down. For defence if a golem should manage to close on the troops then a shield (probably held in two hands rather than strapped to your arm) would allow someone to deflect and absorb the blows without having to take the full strike. Golems would be taken down by teams where a couple of people with shields deflect the fist blows while the other members of the team use ropes, netting, pikes or spears to bring down the target. [Answer] If you rely on the shape of an exaggerated Reuleaux triangle, your troops could mitigate most blows. Designing the armour to have a curve would allow incoming blows to be tangential. An overall conical shape to direct blows around the shoulders would mitigate vertical blows. The weak points would be the edge and point. A trained soldier would be able to position themselves to take a blow at a steep angle, making most blows glancing. This would have a benefit of leaving most momentum in the weapon, throwing the user off balance. Poor paint picture attached. Obviously the shape could be tweaked to be less cumbersome, but the concept is sound. Conical helms were a common shape for ability to deflect blows in a similar manner.   [Answer] Spikes. Big ones, perhaps a foot long, and enough of them that you can't land a blow between them. First, it's hard to hit a spike dead-on; you'll get glancing blows. Second, it can trap or even damage the device used against it. Take advantage of the fact that your opponents are trying to harm you by colliding into you with their own body parts. Rather than minimize the damage you take, maximize the damage that you dish out in return. If they're going to expend all that energy, you may as well use it against them. [Answer] OK, there actually **two** problems with this scenario: 1. Protecting soldiers from the overpowering force of the golem that not just bashes but also shoves and stamps anything trying to stand up to it. 2. Golems are easier to armor than living beings and as expensive hardware they'd be protected from any damage normal weapons. So it is not enough to worry about armor, you also have to think up weapons and tactics that allow normal soldiers to stand up to golems or the armor is pointless waste of money. For tactics the only methods a relatively low cost troops can stand up to something as obviously magical and elite as golems are either fortifications or swarm tactics, We can ignore fortifications here because the implies field of battle and golems would probably be fairly good at assaulting light field fortifications. Swarm tactics means that the soldiers will surround the golems in a densely packed mass that repeatedly attacks the golems from every direction. Groups would probably try to focus on a one golem at a time and pull it down by breaking its legs before moving on to the next one. A golem reduced to crawling would then be left to specialists to deal with after the fight is over. Presumably the golems could be tangled up in nets and then either magically taken over and repaired for use against their former owners or simply hammered apart slow but certain. It might be possible for the assault groups to be followed by the entanglers during the combat so that they could be properly neutralized. For protection (the actual question IIRC), I am thinking cages. The golems would presumably be rather large so it is not necessary to cover soldiers fully, bars spaced close enough that the golem can't strike between should be good enough. Material could be wood with metal reinforcement, which depending on available wood could be light and cheap enough. The cage armor would be rounded on top and hexagonal then seen from top so that in densely packed mass of soldiers the cages would support each other against shoving and pushing. Of course the cages would support being braced against the ground. A group like this would be rather difficult to shove out of the way and while the golems might be strong enough to lift the individual soldiers, they probably wouldn't be able to do so casually without opening themselves to attacks sides and behind. Which is why a swarm is needed. The cage would be carried and kept off the body by leather straps attached to harness on the torso. The straps would be slightly elastic to resist snapping and together with the mass of densely packed soldiers this should give decent protection against bashing. The cages would go down slightly below knee level so that the soldiers under attack could draw their legs in to avoid leg injuries then bashed and shoved. This would additionally automatically brace the cages against the ground. It should be possible to attach some light shielding to the cage to give protection from missile weapons without compromising mobility or visibility too much. Obviously a group like this would need to be very strong and very well trained to move together for this to work. But Swiss pikemen and other similar groups had roughly the correct level of discipline and training, so it should be possible. But it would be an elite unit. And for weapon... I think that taking down an armored golem would be roughly similar to breaking a gate in difficulty. Normal weapons would be almost useless. You need something like a battering ram with a point to do it properly. But actual battering rams are rather clumsy and would be easy for golems to break. But with the cages being hexagonal, a dense mass of soldiers charging could with proper training apply the momentum of the entire group, including those heavy cages, to single weapon braced against the cage of the soldier in the point. The force should be enough to damage even a golem. The actual weapon would be something like a very strong spear with a hook in the shaft that goes well around the bars of the cage. So the soldiers would surround the golem, for a number of wedges, charge in simultaneously (or at least in rapid succession) so the golem can only stop one of the attacks efficiently, withdraw slightly, and charge again. Repeat until the golem goes down and then move to the next golem. This all presumes that the golems are "military grade": large, strong, and armored to defeat normal soldiers. If the golems are of a more generic variety, you should be able to take them down with bolas and nets, essentially reducing my two stage take down and disable method into one stage that can be done by a single group. In such case, the soldiers would be lightly armored and mobile. The golems simply would not be given an opportunity to hit them. [Answer] Imitate a porcupine. Mount long spikes in all directions from the armor covering the warrior's torso. Even if golems can't feel pain as their fists are macerated against the spines, they will still have a harder than normal time reaching the warrior's soft spots. As a bonus, your porcupine warriors won't need to carry weapons. They can just throw themselves at their enemies. Alternatively, you could wrap your warriors in TNT. This wouldn't stop the golems from punching the front-most charging warrior, but it would probably discourage them from doing it again. Tip... don't tell the warriors how the armor works. Let it be a surprise. [Answer] You could develop armor that would be thin metal over a lot of thick padding, and that might help. However, I think your best bet is probably to go with little or no armor. With large shields possibly spiked, then use pikes or pole-arms, (which may help you hurt them first and make it less likely for them to hit you in the first place), or whatever can hurt the golems, and train your men to avoid getting hit. (I've run into a similar problem before playing games in the *[Dominions](http://www.illwinter.com/dom4/)* series, when fighting things like giants. Using heavy armor tends to make it more likely the men will get hit more often, leading to more death when the attacks are very deadly - the armor becomes counter-productive overall. I tend to swap in light infantry and archers when fighting giants for that reason.) [Answer] **Want to improve this post?** Provide detailed answers to this question, including citations and an explanation of why your answer is correct. Answers without enough detail may be edited or deleted. Think motorcycle crash helmets. Same principle, except the head is striking something. @Vincent: I'm sorry, but this does provide an answer to the OP's question. S/he wants to know how to design armour to protect against hammer blows. Motorcycle helmets effectively ARE armor designed to protect against hammer blows. Now I don't really know exactly how motorcycle helmets are designed (despite having owned/used a number of them), other than the obvious stiff shell enclosing a layer of shock-absorbing foam, but I am sure that it would be more effective for the OP to use Google or Wikipedia than it would be for me to post the same links. (So enough words?) ]

[Question] [ Consider a group of humans at a bronze-age to early iron-age technological level colonizing a new earthlike planet. There is just one difference - there exists on the planet *something* which changes the nature of human sexuality - and the colonists don't know what it is, nor can they stop it from having its effect. Normal Human sexuality could be summarized as being (usually) private, nocturnal and selective, and can occur at any time due to humans' concealed and extended estrus. The change (which occurs within a few decades of colonization as the source is revealed) changes human sexuality to (usually) public, diurnal and unselective, only occurring for 5 days each 28 or so of the human female reproductive cycle. Men are only interested in women in heat when said women are present (due to the woman's pheromones), and are very strongly driven to act upon their desires (i.e. in rut), as are the women who are in heat. Women become selective for the day of maximum fertility. Men can only stay in rut for a day or two before they become exhausted. When in heat, a woman *wants* to become pregnant. The rest of the time, women are totally disinterested in sex/pregnancy and the men they come into contact are similarly disinterested, and they are able to think even more logically than non-estrus humans. When not in heat, the limit of sexual behavior between men and women may be to ask a member of the opposite sex if they would be interested in getting together the next time the woman goes into heat. While this is a question on human sexuality, I'm not interested in the prurient aspects - I'm sure we could all imagine the immediate results of the changes I suggest on an interpersonal level. I'm looking for an answer that gives a broader view of the effects this change could have on the way human society structures itself and the things it makes, particularly the infrastructure of settlements. I want to find ways that humans could maintain or improve their technology under such conditions, if that is possible. In addition, I am interested in what would happen if after a long period of isolation (say, several thousand years), a colony beginning with this change (that had managed to maintain a reasonable level of development) came into contact with an advanced society such as ours, and our whole modern society "caught" the same "disease" about month later, globally (airborne trigger). In neither case will a cure be available within any foreseeable timeframe, certainly not within several human lifespans, by which time it will have become the norm. **EDIT** It has been shown in chimpanzees (who show just this behavior) that when a female becomes mate-selective at her time of greatest fertility (i.e. at ovulation), she retires with the chosen male, who usually becomes the genetic father of the offspring of the resulting pregnancy. Hence, it would be possible to determine the biological father with some degree of accuracy without needing to resort to DNA tests. Those of us who are either women or who live with one would know that women can predict their cycles to an accuracy of a day or so. When *not* in heat, there is nothing stopping a woman from taking birth control pills that would prevent a pregnancy despite *wanting* to get pregnant when in heat, and nothing would prevent a woman taking abortive drugs after the fact once her heat had passed. So, to reiterate the question: How would each society adapt to this situation in terms of its social organization and infrastructure? [Answer] This would have major impacts across society. First, pornography and prostitution, gone. However, any concept of father hood? Also gone. Since sex is so common, without any DNA testing it would be impossible to tell who the father is. Over time, that would lead to a system of female inheritance. Since you don't know who your father is, all family ties would be through females and so property would follow that line. Additionally, there would only be single mothers. Perhaps the government would set up a program where all men pay a child tax, to help care for and support the children in the clan, but women would basically be on there own as far as kids go. Too keep society functioning, I would imagine getting rid of weekends for females and just have all females off while in heat so everyone else could continue working. There would also be major thoughts about the change in society. Some would embrace it and set up areas to go to while in heat. Others could try to keep up marriage and isolate themselves from anyone else of the opposite sex to stay faithful. Depending on how predictable the schedule is, humans could either continue working together and have females in heat remove themselves, or be forced to split into two separate groups to keep men from being in constant conflict with each other over the latest women. While most ancient societies valued children highly, it would likely be even harder to practice any sort of birth control or controlled population growth. If our world suddenly had the same issue, the most amusing change would be advertising. Since sex isn't constantly appealing, an advertisers main hook would be gone for most of the month. Everything else would be chaos. Any type of coed organization from schools to sports would collapse. Family ties would break down as men and women felt betrayed. Births would skyrocket as women want to be pregnant. [Answer] Well, extrapolating from chimpanzees and dolphins, the results might be rather grim. Males and females have contradictory goals in species where multiple mates are an option. The reproductive expenditure in males is minimal compared to the huge expenditure of females. Therefore they follow contradictory strategies. Males use a quantity over quality strategy while females use quality over quantity. Males will knock up any female but females will be selective. Males can fertilize many females but they can't ever be sure which females carry their young unless they control access to the females during estrous and usually always. But the females don't necessarily view any particular mate as the optimum mate so they try to escape mating restriction. The males respond by forming alliance with other males to control the females, especially in their narrow reproductive windows. Since the only reason for males to join an alliance is to improve their chances of passing on their genes, males have little to no incentive to form alliance with any other than close blood kin. That way, regardless of who succeeds in impregnating females, some of their genes get passed on. The base social unit chimpanzees and dolphins is a group of males who are father, sons, brothers, nephews, cousins to each other. They spend most of their time capturing females, corralling them and fighting other male groups to steal their females. In general, they kill any non-related male they come across especially infants and juveniles. Human societies eerily follow genetically optimal paths even though they have no concept of genetics or evolutionary theory. For example, in many small scale cultures, sexual fidelity of women in marriage is not strictly enforced and marriages are usually temporary. That means that no man can ever know child of his wife of the moment is his or not. In every known instance of such societies, men concentrate their paternal attention on their nephews and nieces born of their sisters. That way, at least some of their effort is guaranteed to go towards their own gene line. Therefore, it's likely that human society with chimpanzee like mating conditions would adopt a chimpanzee like social structure. The base social unit would be a group of related men. It's important to note that just because men could only mate episodically does not mean that their reproductive goals would not dominate their lives. Species devote time to reproduction based on the payoff off of reproductive success not how often they actually mate. Men would attempt to control as large a group of women as possible at all times. With human technology, men could much more easily physically control women compared to chimpanzees or dolphins having to control females with just the males own bodies. Women would likely be treated as chattel. Close personal relationships between men and women would be rare. Men would tend to view all women of reproductive age as interchangeable. Women would attempt to be more selective but the men would not allow them to do so. Since selectivity and romance might lead to jealousy and lethal conflict, the Men's moral culture might actively view selectivity, romance and even love as immoral and dangerous perversions. "Marriages" would likely be one group of men sending their daughters out to close but not to closely related group of men for the purposes of forming military and economic alliances. New family groups of males would arise from multiple births to traded daughters from the same male group. Males would always stay with their families but women would get sent out although possibly in batches. Close inbreeding would be a constant problem. Overall genetic diversity would be low. Entire male family groups could be wiped out by single disease. When women came into estrous, they would be especially isolated or controlled not only to control access but to prevent violent quarrels among men. A detached woman with no controlling male group would be regarded as source of violent conflict and therefore very dangerous. A detached woman in estrous might be killed on sight just to prevent open war. Since their sexuality only turned on episodically, men and women would emotionally bond with members of their own sex and would like socialize only within their own sex. Each sex would have it's own distinctive subculture. The male society would likely be structured and hierarchical with great emphasis on ritual, respect and likely dueling. Males would mostly fight or train to do so. They would shun productive labor and see warrior as the ideal male. For the higher status males, they would rather starve than get their hands dirty. Women's culture would likely be less hierarchical, would be based on status linked to age and number of sons. Since men would view women as interchangeable, women would not have status based on their mates rank or favoritism from males. Instead, status would likely depend on skill of assisting in child birth and general raising of children. Boys would have to be raised by women at least to weaning age. In a bronze age culture that would be around 4. In known cultures where boys and girls are separated, the usual age is 7. Women will try to favor their own offspring so women will nurse and raise their own sons as much as possible. Therefore, a man's mother might be the only women he views as special and with affection. He might visit her and care for her specially. A women's ultimate status therefore will be linked to the status of her sons. A women who gives births to only sons will have a high status while a woman who gives birth only to daughters will have none. If men fought constantly, then women would likely perform most productive labor. That is the pattern in all low-tech militaristic extant cultures. However, that might conflict with containment. Architecture would be based on walled compounds with the women/children's quarters in the center and the men's quarters surrounding. Men would likely sleep in barrack like arrangements. It's likely that art and literary themes would be vastly different. Sexual beauty would not be an important theme. Romance would likely be unknown. Most literature and art would concern masculine power struggles and conflicts over status and loyalty to elders. As the society grew more large scale (assuming it could given it's fractious nature) the most dominate male groups would have the most females. In groups with a lot of females, there might be enough females for each male to start corralling his own set away from the other males. At first, this might seem like a good way to use abundance to avoid conflict but eventually each male would stop looking at his relations as allies and start seeing them as competitors. Aristocratic male groups might be treacherous and prone to blow apart while lower class groups would be more mutually supportive and bonding. As technology advances, there might be a subtle power shift if women did most of the work. As society became less violent, productive work would increasingly provide economic power and most of the work would still be done by women. The condition might be like the early industrial era with aristocrats still strutting around while the emerging productive class quietly took over. Men might still value fighting but fight little. They would likely just laze about. Superficially they would order women about and still control them sexually, but in all other matters women would maneuver men to do what the women wanted. Since men would consider all non-military matters as beneath them, this would be easy. An obvious story potential would lay in some humans being born in each generation immune to the altering-effect and having the natural human mating pattern of always interested. Such individuals might be regarded as dangerous and be hunted. A woman that was always sexually receptive would likely get raped to death if she couldn't disguise her availability. On the other hand, the magic wand pheromones simply might not ever manifest and no man would ever show any interest in her. A male with sex always on his mind would likely be regarded as insane and prone to unnecessary violence. Out of frustration he might try to have intercourse with non-receptive females resulting in injury. (This happens in some over-bred domestic species of birds when the males lose the ability to distinguish when females are in season.) If the reversions were relatively common, say 2% of the population, they might create a special caste for them and isolate the "afflicted' men and women together. They might develope some special task or function which only the reversions could effectively carry out. If women went into estrous in sync with women near by, then all the women in a male group might activate at once. This could cause the male group to be vulnerable to attack. Male groups might divide into mating and guarding groups, likely based on lot or strict rotation. The mating groups would sequester themselves in the women's quarters for the duration and the guards would stay away for the duration. Contrariwise, women in estrous could be used as weapons. If men lost control in their presence, then sending a few receptive women into a group of enemy males would make them helpless, if another male group could attack from outside of the range of female hormones. That's about all I think of for now. [Answer] I think your initial presumption should be clarified a bit. Human sexuality is not naturally private, nocturnal, or selective. Those attributes of sexuality are socially constructed and did not exist for the majority of human evolution. Privacy in any respect was really only created during the Industrial Revolution. Prior to that, families slept, and screwed, in common rooms. Only the tiny upper class had private bedrooms. Agriculture brought about selectivity and provided motivation for monogamy that didn't exist in nomadic tribes. All pre-historic tribes which have survived to modern times share one idea - shared fatherhood. They believed that multiple men contributed to the formation of children. Most believed that women required a constant supply of semen in order for their child to develop properly. Children were thus raised by the tribe in common, and it was not resource-expensive for someone to care for children which were not their own. Once we settled down into agricultural societies, resource scarcity became much more common, famines killed off many with regularity (about every 5 years there would be a massive famine due to soil nutrient depletion), and it became extremely expensive for someone to raise a child which was not their own. This motivated men to control the sexuality of women and created the situation we've preserved to modern times of women bargaining sexual liberty for material security. Sex was radically important to human survival. Prior to the development of language and reasoning, human survival (as a species) was pretty dicey. Compared to other animals, we are weak, slow, have no venom or fangs or natural armor, etc. We have great endurance and this allowed us to chase game to exhaustion, but that's not terribly useful for individuals. Humanity survived because of strong group cohesion. And people stuck together because of sex. Sex bonded them together and provided motivation for everyone in the tribe to stick with the tribe, to protect the tribe, and to share that game they hunted down with the tribe. This extreme necessity to be accepted by the tribe both for survival and to maintain access to sex partners led to brain development. Dealing with social situations can be very complex (especially without language) and those with the brainpower to manage it had a distinct survival advantage. You lump all chimpanzees together in your question, and this is wrong. Bonobo chimpanzees, for instance, use sex primarily as a means of social bonding and for conflict resolution. They have mostly hidden estrus, and estrus has no influence on how actively they seek sexual interaction with others. Bonobos are our closest genetic relatives, and the primates most similar to humans in terms of sexual morphology (things like genital size, ejaculate density, sperm competition, limited sexual dimorphism, etc). If the humans were without language, I think they would certainly go extinct were their sexuality to change as you describe. With language and technology, however, the effects would be muted and probably not lethal. Most animals have a sexuality like you describe. Those animals are also much better prepared for survival. They're strong, fast, have fangs or venom, etc. They don't rely as much upon group cohesion to survive and many don't join together in groups at all. Humanity with language, reason, and technology would, I think, be equivalent to those species with that sort of sexuality and other survival traits. Humans would have little to no reason to join together in societies, and unless economic concerns forced them to stay together, they would probably dissolve given enough time. Lack of strong selective pressure for positive sociability traits might lead to the sort of things seen in most animals where sex is for reproduction instead of pleasure, like men taking women by force and abandoning them. I have a bit of a problem with you indicating that a lack of motivation to seek sexual pleasure would result in people being more logical. Rational thinking is inextricably bound up with emotion. In the book 'Neurological Origins of Individuality', the author describes a man who, due to an accident, loses the capacity to experience emotion. An unexpected side effect is that he becomes incapable of making decisions. At all. He could list the 'pros' and 'cons' of two choices, and no matter how lopsided the lists were, he was not capable of performing the act of actually making the choice. Emotion is necessary to carry out even the most logical thinking. To presume that sex (and the complex emotional relationships that come along with it) detracts from peoples ability to reason is inaccurate. Also, one thing which you didn't address but I was sort of just assuming... I assume that along with these other changes, people would also be "freed" from the negative consequences of abstinence? Sex is on the same level of Maslow's Hierarchy of Needs as breathing, sweating, sleeping, eating, etc for a reason. Abstinence is not healthy. It increases risk of heart disease, several types of cancer, death (a study of a town in Ireland over decades showed men with lower sexual activity had an increased risk of death from any cause), depression, anxiety, it reduces the effectiveness of the immune system and even sense of smell. If the physiological changes which alter their sexuality don't change that aspect, you might want to consider a significant increase in mortality due to heart disease, cancer, suicide, etc. Some sources if the topic interests you: 'Sex At Dawn', 'Sex At Dusk', 'Good Sex Illustrated', 'Sex And God: How Religion Distorts Sexuality', the 'Sociology of Sex' course from The Teaching Company (if you can find it), 'History of Sexuality' by Michel Foucalt [Answer] Given that humanity has evolved from what we believe were such species, I would expect that any such society would not be as successful as ours. We evolved our current forms of sexuality precisely because they were more successful. In your description of human sexuality you miss the most important factor behind the vast majority of human sexual activity - it is an important part of human pair bonding. [Recent studies suggest that when it comes to conception women are actually programmed to seek very different partners to those they would form a relationship with](http://news.bbc.co.uk/1/hi/sci/tech/376321.stm). Even at a base, instinctual level almost the entirety of the sexual activity within this relationship is motivated by the desire to bond and form a closely knit unit, and not to conceive. Without this "recreational" sexual activity, it is unclear to what level male/female relationships would develop. Without the support of such a relationship, new and expectant mothers may face significant difficulty. In humans, as compared with other species, the male and female are remarkably equivalent in the overwhelming majority of qualities and abilities. However, relative to other species, human pregnancy is especially restrictive - a heavily pregnant cow is not nearly as restricted in its movement as a heavily pregnant woman. Worse, excessive exercise during pregnancy is heavily associated with miscarriage - and strenuous agricultural work would be more so. This means that for a period of time a pregnant woman will contribute less and demand more. Also, human newborn are unusually helpless for an unusually long period of time - it is perhaps 4-5 years before they have any real hope of fending for themselves, and much, much longer before they have a *good* chance. Now, it is possible that a woman will be sufficiently supported by her family or wider society, but there are difficulties here. Firstly, in an early agrarian society life expectancy is short and mortality at all stages of life, especially infancy, is high. Even in our own world, the typical response to high infant mortality is a higher birth rate. Families will most likely be very broad but lack depth. Relative to modern families there will be fewer elderly relatives per young child, less attention to go around, and less spare capacity in the system to support them. The "dreadful algebra of necessity" creates a kind of terrible paradox for children - they are both loved and unwanted, both essential and disposable. In our own world, impoverished children have had a terribly bad lot in life and most societies throughout most of history have done very little to help. It seems unlikely then that a pregnant woman or new mother, unable to depend on the father, could reliably depend on significant support from society. Furthermore, by limiting the development of pair bonding, any "family" will be restricted to female ancestors and their descendants (of both sexes). Realistically, extended families will comprise somewhere between a quarter and a half of the individuals that would have been included in a pair bonded society. In a bronze- to iron-age society, I would expect all of this to dramatically increase the depth and duration of periods of poverty and hardship, exacerbating food shortages and severely limiting the supply of surplus labour that could be turned to technological development. As for modern society suddenly catching the disease, I have far fewer fears. With the high levels of social security enjoyed by modern civilisation, established charitable organisations and well developed systems of state support, society would largely continue unchanged. There would probably be increased pressure on housing as people lived separately rather than together, but otherwise we know that single parents and their children are able to live very good lives. [Answer] The ability to think more logically when it is "not time for sex" could help the Society to be stable. Female politicians may be precluded from taking decisions on those 5 days (and also to going to work, to avoid influencing Male politicians). Same for policemen and policewomen, judges and the military, and you have a good system. Better if there are no weapons on private hands. But the system will have a hinder in that women in heat are still there, and not hiding, so competition between them for males and between males for women in heat could cause injuries and killings. Also, a male trying to have sex with a woman in heat that (for some reason, like a sexual disease in the man) is not interested in him can cause rapes. A society that acknowledges these changes and "rides the wave", forgetting religious prejudices in the process, may survive and prosper. But if these people come to Earth later, while we still have here rapes, murders and there are tons of wild weapons around, it might be a disaster. Moreover if you note that there is a lot of religious people in this world. [Answer] The most obvious result would be that there would be no concept of a family. Now the concept of a family influences a lot of things; for one, the concept of inheriting goods might not develop; without that, also the concept of property would be less strong. A lack of sexual/compassionate bindings would probably give a very individualistic society. It would also affect religion, since the concept of a father-like god in the sense we understand it would probably not develop. It also might decrease the likelihood of a single leader person also in other contexts like politics. [Answer] My initial response is to think of something along the lines of a conservative Arabic family structure, though with women even more tightly controlled as a burka won't be enough. This only lasts for a week per month, so perhaps it would only be strict isolation for that week, but otherwise a fully integrated member of society. Romance is not just sex, so traditional family structures could still persist. Pair bonding would still develop, all the benefits of 'traditional' families would remain intact, just with women being isolated at home for a week when not pregnant. Then considering the implication of being in rut, boys would need to be turned out of the home by the time they hit puberty else they may mate with their mothers or sisters, and daughters would need to be married off before puberty as well. Either women are isolated for a week each month (which is a considerable amount of time), or they will cause massive disruption as all males in the vicinity go into rut (cue lots of violence between fighting males and rape of nearby females). In the interest of safety, culture will likely dictate isolated imprisonment of women nearing their estrus to reduce the constant risk of all the nearby men being put into rut, not to mention issues of uncertain parentage and inbreeding. The lack of interest in sex outside of being in rut may be taken advantage of - women could be sent to a kind of convent during their estrus. Men would simply stay away from it, and thus remain uninterested in sex. Women not in estrus could guard the facility and keep the other women imprisoned within it, and likely run by post-menopausal women. Perhaps men would live in a barracks until they can establish a household of their own, and women would live in a convent until a man claims her. This would probably result in wealthier older men forming a household and developing a harem. Sons be sent to the barracks as soon as they might hit puberty, while daughters are either married off before puberty or sent to the convent. Women who have recently given birth would be a serious risk as there is no means of determining when exactly they will become fertile again. Breastfeeding delays the return to fertility, but by a wildly uncertain duration, so they could unintentionally cause a serious disruption as they send all the men into rut. This may require mothers to remain isolated until their cycle returns to predictability. This may result in women being isolated for most of their lives - only be outside when prepubescent, when pregnant, or postmenopausal. Unmarried or non-breeding women would only be confined one week per cycle, but will there be any significant numbers of these? One interesting prospect would be to abandon the idea of family groups and go with something akin to medieval monasteries - women would have a large collective residence around which much farming and industry will go on. Women not in estrus can tend the grounds and interact with men who tend them as well, while women nearing estrus or recent mothers at risk of returning to fertility would be confined to interior labors (where no men are allowed). Male children would be sent out to join some kind of fraternity, and these fraternities would fund the convents (much like generous patrons funded the medieval monasteries). In order to keep birth rates up, the champions of the sponsoring fraternities could be invited inside for a time to father some children. Men would probably do most of the primary labor (collecting raw materials and farming/fishing/hunting), as well as trading expeditions or conducting warfare, while women would take over much of the more sedentary labors in workshops (not being allowed to roam about the countryside for much of the time). There is a potential problem there - with men having no interest in sex without being in rut, and not having a good handle on who exactly their children are or providing an inheritance specifically for them, it may be difficult to convince men to not be selfish. Why reduce their own standard of living to support potentially unrelated women and children? This is why the older rich men with their own strictly controlled harems seems more plausible to me, but it may be possible for a large fraternal organization to keep their own stable of women (could be more or less egalitarian - though the potential for women in estrus to be used as a weapon/decoy to allow the other women to escape captivity would probably keep relations amicable). [Answer] Your people are bronze age/iron age, so they already had a culture before this happened to them. They won't revert back to being 'pure animals' because they retain all sorts of cultural stuff outside their sexuality and reproduction. Making a few up: blacksmiths are revered; taboos against eating meat on religious festivals; only women can be tax accountants. :-) Two possible cultural outcomes from your scenario are illustrated in Esther Friesner's novels [The Psalms of Herod](http://www.goodreads.com/book/show/1218676.The_Psalms_of_Herod) and the Sword of Mary. In the first it is an isolated religious community where the Alpha Male monopolises all the women. In the second it is a city which seems more similar to our own cities. The difference with your scenario is that men in Friesner's world are interested in sex all year round, so prostitution does exist - hand jobs and blow jobs only. If you do want to go all the way back to 'everything will become animal' then things to consider are: 1. There is a theory that monogamy evolved in primates to limit infanticide by males. [Paper Abstract](http://www.pnas.org/content/110/33/13328.short). After all, if you kill her kid, the woman/primate will stop breast feeding it and come back into heat and thus YOU can father her next offspring. So infanticide could become much more common in your society. Whether that is viewed as murder or not will be a cultural issue. Whether the mother of the baby happily mates with the murderer during her heat, then bashes his head in with a rock next week when she's back to normal psychology is dependent on whether you want your sexuality change to simultaneously rewire all sorts of other human psychology. 2. Most primates only have one kid at a time. That kid has grown up and 'left home' by the time the next one comes along. That makes their societies very different from human ones, where a woman could have, say, a newborn baby, a four year old, an 8, 12 and 16 year old all dependent on her. If, as some folk have suggested in other answers, the men are ducking out of the childcare, then the burden on mum becomes huge. Childcare includes education, public healthcare, etc. Humans farm this out to relatives and complete strangers (teachers, family doctor, etc). If your men do none of this, then boys are being taught survival skills, life skills and *how to be men* entirely by women. 3. In polygynous animals about 5% of the males are responsible for 95% of the matings. About 80% of the males die as virgins. They never win any fights, or never win *enough* fights to get a female. If you go down the route of men fighting for women, then you'll need to think about what happens to these 80% of (sexually frustrated) guys. Old men, middle aged men and teenagers never get laid - only guys in the prime of life with fighting experience get the gals. And to be frank, the gals - if working on the animal model - are fully in support of that system. John hits middle age? Janet will trade him in for a younger model. **Additional Thoughts:** Decades back when I was a student I recall being quoted a study on American newlyweds who were *actively* trying to have a child. It took them **on average 6 months to conceive**. Mr & Mrs Average have to shag their way through 6 of the wife's fertile times before conception happens. So thus there is something else to consider for your impact on society. A culture where the women have roughly 6 heats before they conceive is very different from one where On Heat = 100% Guaranteed Pregnancy. Meanwhile contraception... the most likely contraceptive pills for out culture to race to develop will be ones that stop the woman coming into heat. After all, no heat = no interest in sex = no pregnancy = zero failure rate on the contraceptive! [Answer] There is plenty of material in the earlier answers to make them nearly comprehensive; so while I agree with those earlier answers, I will only expand on a devil's advocate view for the fun of it: For women, due to both sexual dimorphism and having to bear all the burdens of pregnancy, these urges (if unchecked) will cause them to be become woefully 2nd class citizens. They would likely be pregnant somewhat continuously from the age of 14 on, but unlike their 2nd class position IRL (just a hundred years back in America, and still extant in much of the world) in this fantasy they don't even have husbands protecting them or their children. For the last three months of pregnancy and two months after (to recover and nurse infants) they are much less capable of working for a living, with no adult partner to care and provide for them. That is an economic and social disaster for women; in this non-technological society no work means no food. But there is an out! Presuming women are not **owned** by men and are free to act independently: They aren't beholden to husbands, or sons for that matter. So women can bond *with each other* in coalitions; societies of their own. The purpose of their bonding is not sexual but to provide for and sequester each other when one of their members is in heat, so they *never* get pregnant, because they enter a voluntary state of confinement while they wait out their periodic temporary insanity. This is a socialist solution. non-estrus females can do the hunting, gathering, herding and provide defensive military. Production from the group ensures women in heat are fed, sheltered and protected from any males. Not to engage in the prurient details; but I will note that if denying their sexual urges by confinement is too much for them psychologically, then no matter how primitive the society it is relatively easy for women, alone or with others, to simulate the mechanics of the male role in sex. What are the ramifications of the women's guild? * No children unless they say so. * When they do allow children, controlled and supervised mating means certainty about paternity for the father, which can then include agreement for child support and raising. * Broader social roles for women: They aren't the mother of six at the age of 20, and do not have to be a mother at all if (in their rational times) they do not wish to be. * They have exactly as many children as they want, when they want them. * Social cohesion and separate politics: They are bound to their sisterhood of some dozens; they have their own leaders, and such sisterhoods can form a wider regional guild; like one per village; so women can travel and have places to stay and be sequestered and protected during estrus; so they have groups to join if they choose to move elsewhere on a permanent basis. * They can raise their children, on their own, and instill in them the moral values **the women** choose, which will include for both genders an acceptance that women are in charge and males are subordinate workers. * As a result, most males will be raised without ever experiencing a women in heat; the women themselves will ensure that doesn't happen. They can isolate males a year or two before the males enter puberty, and the males won't mind: Since they first learned to talk, the mothers have long explained the necessity of this isolation, and in fact it is a celebration of their impending maturity and taking on the role of support for their mothers and sisters, the role the men will believe they were *born* to do. Perhaps if they do it well then someday, the mothers will deem them worthy, and grant them the right to father a few children of their own; and much like modern society, share the joys of their childhood and take pride in their accomplishments, even if they **are** raised and educated by the guild to be subordinate males. In short, this scenario could easily become a pure matriarchy; only **women** decide who will be fathers, and then they raise males and females to believe this is the way society **must** be. The males only earn the right to be fathers through hunting, military service (and protection of women from rogue males), farming and other work on behalf of the women. I will note that most societies of the past (and most today, for that matter) raise **women** in a culture that constantly reinforces the belief that they are the weaker sex, not just physically but mentally and morally, and thus are rightfully subordinate to males. The Bible says so explicitly! In this fantasy world, a mechanism exists to reverse that dynamic, and I see no reason to think males would be any more resistant than females to being subjugated by culture in this way, if males are raised from birth to think so. Remember that heightened rationality component: The women's guild gave them life, raised and fed them, protected them and educated them. Why shouldn't they be beholden to the guild, to their mothers and sisters, above all else? [Answer] The solution my early-iron-age settlers came up with is gender segregation enabled by the design of their settlements. Men live in one district, women in another, and between them is two districts, one for trade where both men and women can meet (and accept the risk that they may encounter or be a woman going into heat, who will not be able to avoid the consequences of that), and the other an area of parkland where people in heat/rut do what they have to do. Since male-only and female only areas do not permit members of the opposite gender (unless infertile, e.g. menopausal women or male castrati), those wanting to avoid reproductive matters won't be in a position where it will be forced on them. Women going into heat in the trade area (and any men following them) are sent to the parkland. ]

[Question] [ I've been wondering if it's possible for an airship to fly by passive means - specifically, no engines (steam or otherwise). I'm thinking in terms of a world where lighter-than-air gas (and it's containment) is fairly readily available, but that hasn't discovered mechanised propulsion. The problem is - if you're sailing in water, the water itself provides resistance, and allows you to move in a different direction to the wind. (Whilst you can't sail directly into the wind, you can sail pretty close in a modern yacht). But I think you're effectively adrift if you're trying to do the same with an airship - and are carried wherever the wind blows, much like a hot air balloon - you've no steerage, and the only way you get to go somewhere different is if the winds at different altitudes are blowing a different direction. Is there any way this is possible, or am I going to have to think in terms of perhaps solar (convection?) propulsion or magic? [Answer] I've thought about this a bit in the past. It's possible, but only if the vessel moves vertically between regions of different wind speed. On a regular ship, lift forces can be generated on the sails based on wind moving faster than the sail. The water provides drag on the ship to keep it going slower than the wind. Essentially, the boat can 'push' against the water to hold it in place and allow it to use its sails to push on the moving air. In a homogenous mass of air, on the other hand, there is nothing like water to push against. The craft will drift at the same speed of the wind and generate no lift forces on its wings, unless it moves them or does something to get it moving at a different speed as the wind. This is why gliders need to slowly drop. They maintain speed in excess of the ambient air speed by shedding gravitational potential energy. Some birds, however, have pioneered a method of gliding without power. What they do is to glide back and forth across a shear layer in the atmosphere. The difference in wind speed above and below the shear line allows them to generate lift by moving at a different speed as the wind. This is called [dynamic soaring.](http://en.wikipedia.org/wiki/Dynamic_soaring) Your airship could do the same, using wind shears to generate lift using wings/sails. Note that when I say 'lift' I don't specifically mean force pushing the aircraft upwards, but more generally pressure-based aerodynamic force generated by wind moving across an airfoil. The motive force that a sailboat harnesses to move upwind, for example, is often referred to as a form of 'lift'. It's also worth noting that the different shear layers in the atmosphere behave differently at different times of the day, and under different weather conditions. Your air boat captains would need to be expert weather men, as well. [Answer] If the airship travels a set route between a group of cities, they could set up towers at regular intervals with cables connecting their tops. Then as the airship passed over one of these suspended cables, a hook could be lowered to catch it. Once tethered by a hook from its keel to the cable, the airship would only be able to travel along the vector of the cable. The wind would pull the hook taught along the direction that it is blowing and then it would drag the hook along the cable in whatever direction provided less resistance to the vector of the wind. If enough towers provided enough cables, a network could be assembled which might provide access to most of the cities for each major wind pattern. There would be seasons when "you just can't get to EastPort by air". Occasionally, airships would stall along the way when the wind blew exactly perpendicular to the cable. In such cases, the captain would have to change altitude in search of different winds. There would also be a little bit of a gamble available for brave captains... "We're going to release this slow cable we're currently riding and float free towards those hills. If the winds are with us, we can snag the EastPort cable outside of Regis and cut three days off our journey. If the winds aren't our friends, well... I always wanted to see what was beyond the forbidden zone." [Answer] If the airship can adjust its buoyancy during flight, you could make it work. Like @vincent mentioned, think about how a glider works. It somehow gets into the air, then uses the downward gravity vector in combination with its wing surfaces to produce forward motion. It can steer in any direction, though its forward motion will be relative to the prevailing wind. A neutrally buoyant airship would be at the mercy of the wind. But if it adjusted its buoyancy to become heavier than air, *now* it has a downward gravity vector. In theory, it could deploy some airfoils and fly just like a glider. Eventually it'll get too close to the ground, so it'll need to reinflate its gas bag. Now it becomes positively buoyant, and it could use its upward vector to continue steered flight. By repeatedly diving and climbing, an airship like this would be able to control its direction somewhat even when the wind isn't blowing the right way. [Answer] Your hunch is correct, a lighter-than-air craft with no mechanical propulsion would be completely at the mercy of the winds. A sail boat is able to control its direction thanks to its keel, which effectively "slices" a route through the far denser water it is in and allows the boat to redirect the resultant force of the winds striking the sails (changing sail positions also helps with navigation, although that's more for controlling how and how much of the wind strikes it). The rudder allows the boat to change the direction of its keel and effect course changes. A lighter-than-air craft, on the other hand, while you could put a keel on it it would have no effect except to increase the amount of wind hitting the craft and, thus, increase how quickly it is moved by the wind. You would have no control over your direction, and trying to resist would be completely ineffective because you have nothing against which you can generate a counter-active force (not unless you drop an anchor, that is). The one aspect you could control (potentially at least) is your altitude: By increasing or decreasing your buoyancy you can increase or decrease your altitude; this could be advantageous if, for example, the winds at a higher altitude are going in the direction you want. The particulars of how effective this would be are beyond my expertise, but you do have things like jet streams at high altitudes that are not affected by the ever-changing winds you or I are used to at ground level. Since these are pretty constant and can be easily mapped, you could have rapid passive air travel via these. In our modern world in fact we do have such passive lighter-than-air craft; we call them hot air balloons, and while their lift is provided by a gas burner heating up the air inside the balloon, the principle of their navigation -- or rather, their lack thereof -- applies here. [Answer] You could use "ground contact" airship travelling. Over the open sea, this is quite simple: from the airship, lower a "water kite" type of device into the water with a 100 - 300 m long rope. It is permanently in the sea (with seawater as ballast), but can be pulled up when approaching land, when wanting to "sail" fast right into the wind, or in emergency situations (like, umh, pirates). The angle of the kite against the rope could be varied from above, or by a man on that water kite, and this is how the steering is done. Over land, it is more difficult. I can imagine a "step by step" approach though, using multiple rope anchor points in a sequence. One full sequence is: 1. The airship is shaped like a vertically aligned airfoil, and held at some angle by a rope that is anchored to the ground. Like a kite (but with the whole setup 90° turned), it then assumes a stable angle to the wind, which can be chosen by varying the angle between rope and aircraft. 2. When it reaches its target position, another rope is lowered and anchored to the ground somehow (we'd use automatic drills now, you could use a guy lowered in a basket). 3. The first rope is released (remotely controlled with a smaller control rope) and pulled in by the airship. It can even have a small balloon at the rope's end so that entangling the rope with obstacles due to pulling it over ground is not an issue. 4. The new anchoring rope is gradually extended until reaching a target position, and the process is then repeated. The anchoring rope could be 1500 - 3000 m long maybe – rough guess :) With this, each step would cover, say, 1 - 2.5 km of way. [Answer] Yes, but it is more complex and heavier than normal sails. First, you have outrigger sails or vanes to control the rotation of the vessel. Second, you have wing blades that you can rotate around their vertical axis. These blades have a rigid profile so by directing one edge towards the wind, the curvature of the blade deflects the wind in one direction and the vessel gains thrust in the opposite direction. In theory this would allow moving upwind. In practice compensating for the gas bag drift would be pretty hard, which explains why such contraptions are only seen in stories with magical or super-science levitation. But it should be possible, just not sensible. EDIT: Note that this rather obviously requires a difference in the wind affecting the gas bag and the sails. This difference exists since the sails and the gas bag are at different altitudes. Also air currents are actually three dimensional, so the sails would need to be controllable on more than one axis to take advantage of updrafts and such. [Answer] Hopefully you're not stuck on the aesthetics of sail rigging, as I will answer the question of how to turn an *airship* into a *dirigible* without mechanized propulsion or sails and "fly by passive [analog] means". Before humanity discovered mechanized propulsion, we used animals (including humans) for 'power'. I see slaves turning screws that power propellers or trained wildlife that can wear a harness and still fly, as options. Dragging yourself along with harpoons would be a lot of work, but it would get you there. If the average wind speed on the planet is close to zero knots, I don't see a problem. Analog propulsion *has* been done on Earth in a balloon but I'd bet it was quite a workout and that the weather was very cooperative: (if propellers are out, we'll just go with Blanchard's '85 trip) > > In 1784 Jean-Pierre Blanchard fitted a hand-powered propeller to a balloon, the first recorded means of propulsion carried aloft. **In 1785 he crossed the English Channel in a balloon equipped with flapping wings for propulsion and a birdlike tail for steering.** [Airship](http://en.wikipedia.org/wiki/Airship) -Wiki > > > [Answer] Now if your terrain was mostly plains, you could have some sort of hybrid of balloon and "wind wagon" (<http://www.kshs.org/kansapedia/wind-wagons/12239> ), with the balloon acting as the sail, and the wagon as the keel. An interesting (to me, anyway) idea is that you could make the wagon carry fairly heavy ballast, then if danger threatens on the ground, toss the ballast overboard and escape through the air. [Answer] No, a free-ballooning (sail powered) non-magical airship won't work. For two reasons, and you may be surprised by the reasons. First, yes the airship can steer...a bit...by varying it's altitude instead of by using 'sails'. Using favorable winds at different altitudes is how free-balloonists have steered for over a century. Sails don't work for steering - there is no other medium for a keel or rudder to push against. However, there's a big difference between balloon-style steering and *actually reaching a destination*. Powered dirigibles often needed to make multiple approaches to the landing field due to an unexpected crosswind or navigational error, and a *powered* fly-around could easily take 30 minutes. An unpowered fly-around might take hours...or be impossible entirely. Aside: Non-magical airships cannot just drop into a cow pasture in an emergency, either. That's called a 'crash'. Ground crews of 40-50 were needed to walk larger Zeppelins into the mooring mast. Airships may be buoyant, but have a lot of inertia and sail area. Several ground crewmen were swept into the air --and killed by the fall-- by minor errant breezes. You can use heavy tractors today instead of large crews (Goodyear did), but you still need to get the airship and the tractor close enough, and it's still dangerous. Remember that this means the non-magical airship must arrive at destination at least 3-4 hours before sunset to be landed safely...unless your landing field has hectares and hectares of non-intrusive illumination and a ground crew trained for night landings. The other reason a sail-powered non-magical airship won't work is that they are simply too big and fragile to survive ordinary weather for long. Most non-combat losses of airships were due to simple weather. Example: The USS Shenandoah was literally *ripped apart in midair* by an otherwise unremarkable summer thunderstorm over Ohio. Powered airships generally cruised outside of a weather front, searching for a weak spot to punch through, The Graf Zeppelin once spent 6 hours over the South Atlantic scouting (successfully) for her safest course of action through a rather mild front. A free-balloon simply lacks that ability, is likelier to be sucked into the worst storm cell nearby and promptly destroyed. One other major drawback of unpowered non-magical airships, though not a critical fault, is their inability to maintain accurate navigation. Powered airships, before LORAN and GPS, relied upon celestial navigation and detailed ground charts. This meant popping above the cloud deck several times each day while over the ocean to get a sun/star position fix. Powered, this is a quick, accurate operation. Unpowered adds time and positional uncertainty to the journey (how far off were we blown by those five layers of crosswinds?), increasing the likelihood that the airship will miss it's destination and need to (sigh) fly-around. [Answer] You could exploit differential velocities of wind at different altitudes. The effect is similar to sailing, with the lower-velocity wind acting as a "drag / anchor medium", and the higher velocity wind acting as a "propulsion medium". The aircrafts would be made out of two parts, connected by several hundred meters of rope: 1. Above, the lighter-than-air vehicle. It would be kite-shaped, with an airfoil cross-section, and connected like a kite to the drag device below. The mounting mechanism must allow adjusting the angle against the rope in two directions, as this is what allows steering. 2. Below, a drag device, similar to a huge parachute. There are always wind speed differences between different altitudes, and if only the difference between slow surface wind and faster higher-altitude wind. This however might require to fly the drag device / parachute 10 - 20 m above ground level, which can be risky due to possible entanglement with obstacles. This idea is a bit like the [proposal by Ville Niemi](https://worldbuilding.stackexchange.com/a/8491/6741) here, but I think, different enough :) [Answer] Sails work because of the resistance created by the keel (daggerboard, centreboard) in the water to the wind above. So you would need to create some kind of resistance for your airship sails to work against. But you have no other medium, only the air. Someone once tried something similar; it failed and they died ([Salomon August Andrée's Arctic Balloon Expedition of 1897](http://en.wikipedia.org/wiki/S._A._Andr%C3%A9e%27s_Arctic_Balloon_Expedition_of_1897)). But it doesn't mean it cannot be done, just that we haven't figured out how to do it yet. :) [Answer] It's possible to fly without power. In 2008 there was a talk at the Chaos Computer Congress titled [Flying for free - Exploiting the weather with unpowered aircraft](http://media.ccc.de/browse/congress/2008/25c3-2940-en-flying_for_free.html#video). With enough information about the weather they manage to travel 3,000km without any power. [Answer] How gung-ho are you on avoiding the "mechanized propulsion" bit? Is this a steampunk kind of society? If not, you could always use targeted lasers ala Breakthrough Starshot. Admittedly, this is very advanced tech and wouldn't gel with a steampunk kind of society. The other option you could take advantage of is using Bernoulli's equation ([https://www.princeton.edu/~asmits/Bicycle\_web/Bernoulli.html](https://www.princeton.edu/%7Easmits/Bicycle_web/Bernoulli.html)) which governs the conservation of mass of the flow of liquids which, in short, states that the flow of fluids (which, I believe, certain (if not all) gases are considered a part of) must remain constant at all points, and that variations in volume or pressure will cause systemic shifts to maintain this principle. This is the premise upon which the Venturi Effect is based. <https://en.wikipedia.org/wiki/Venturi_effect> In other words, if your society could somehow generate changes in the flow of your atmosphere (giant fans or vacuums perhaps?) at intervals along sailing routes, perhaps something like this could help create lift for your airships? Also worth investigating is the principle of lift as seen on an airfoil. Though this follows the same theory as Bernoulli's principle, it's probably helpful to understand on your way to formulating a way to get your airship to stay, for lack of a better term, in the air! <https://en.wikipedia.org/wiki/Continuity_equation#Fluid_dynamics> Good luck dude! [Answer] One of the possibilities I'd considered for something like this was magnetism. The way magnetic levitation works is that moving a superconductor through a magnetic field creates an infinite reverse current, which repels it - it therefore creates a virtual 'tram line' of magnetic potential. Drop a magnet down a copper pipe, and it'll create inductive drag. I was wondering if this drag effect could be used with the earth (or a.n.other planet's) magnetic field, and provide the 'resistive' force to push against, that the sea would provide a sailing ship. [Answer] Maybe a gas "bag" is very tall and is shaped like a keel. Then kites like governable parachutes both fore and aft as well as in the middle are flown at an altitude of higher velocity air . Really good co ordination between the fore and aft kite "pilots" should make it possible to orient the ship in the lower velocity air and make it possible to do tacking maneuvers. At least I think that is something readers could buy. I also like the glider/airship hybrid mentioned earlier. You only need a way to compress and release the gas on demand to make it work. Rowing machines hooked up to propellers for emergencies might also be a good idea. [Answer] Um, idk if this really counts as "sail", but heres what I got. Lets take your airship. Assuming its sails are placed how you would see on like a galleon, remove them. Place them onto the side of the hull. Now them equal in terms of surface area, weight and structure if possible. Now, you have 1 sail on each side of the ship, and you can pull in the sail or push it out. That part is very important. Assuming you are facing exactly where the wind is going, both sails(extended the same percentage) will create equal drag on both sides so that the airship is pushed along the wind. Now lets say one of extended farther than the other, say the right sail is 70% exposed/extended while the left sail is only 30%. Now, the level of drag on either side is now unequal, imbalanced(insert thanos reference). Due to this, the airship will then veer to a desired direction, manipulated and controlled by how far extended each sail is. Now, I think its pretty good, but it has a few limits. for example,if turne enough, the rear of the ship( or any part of the ship) will block wind from the sail,and will normalize into the wind.I'll call this understeering Now, if you made sails that the winds can push regardless of the ship orientation(say, having sails bigger than the entire ship not including sails) the difference of drag on each sail will be too big, and the ship will broadside(showing full side profile) the wind, both rendering both sails useless/ineffective at catching the wind, so no getting out of there until the wind rotates your ship into a position/orientation where the sails work, but your airship will probably have overturned, and crashed. I'll call this oversteering. Now, assuming your smart enough not to under or oversteer, your ship should be able to veer left and right(or any direction, as long as placement of the sails allow for it). Whether this would actually alter course effectively, idk. But good engineering? ]

[Question] [ A lot of species on earth do not care for their offspring; they spawn thousands of eggs, that hatch into larvae, and then grow up towards full size. If a hypothetical species was sentient in the final steps of that process, then what sort of society might they form? There would be no maternal or paternal bonds, no biological imperative to remain together after mating, no biological urge to protect the young. This could have a ripple-on effect throughout society and their entire world-view. Would they even form a society as we know it with no incentive to group together to protect their young? [Answer] Studying the r/K selection theory can give some insights on the problems such a species would find on their road to building a civilization. r-selection species (which produce a lot of offspring they don't care after) have a lot less chance of becoming intelligent than K-selection species (producing few offspring with long parental care): * they don't need much intelligence, because their success is not depending on individuals being successful. Real life insects, for example, are very dumb but still very successful. * Without parental care it's hard for non-genetic information to be passed through the generations. * they are very low on the food chain, so it's harder for them to take control over their environment. Of course, we assume that they evolved naturally, and were not created by supernatural means, or "uplifted" or completely engineered by another species. Now, let's take a look at how such a species would behave like, if they, despite the above problems, still managed to develop intelligence. If they become intelligent and build a civilization, they will probably be in control over their environment. This means that they could start to care for their young (which they didn't do while they were less intelligent - otherwise they would not be an r-selection species) and prevent most of them from dying, so overpopulation would very quickly become a serious concern. We cannot ignore this, because if competition arises between tribes or nations, the one who do care for their young would quickly out-breed the one who doesn't. This means that their culture would be so different from our human culture, that we would probably find them extremely abhorrent. They might feel similarly towards us. This would make an interesting plot point (aliens which are alien not only in their ear shape, but having a truly bizarre and for us incomprehensible culture) * if they continue to allow most of their young to die, they could sooner or later develop interesting ethical views based on this. An extreme version of this was explored in the novel [Three Worlds Collide](http://lesswrong.com/lw/y4/three_worlds_collide_08/). * if they use birth control, how would they enforce it? How would they deal with someone who doesn't cooperate? In the human world, if a group decides to have a lot more children than others, would lead to changes only on relatively long terms and could probably be dealt with, or their mentality might change over time. However, for a species where an individual can produce thousands or millions of offspring, a few non-cooperating individuals might quickly cause trouble by quickly building an invading army (either armed, or an army of illegal immigrants) This must lead to eugenics, maybe forced sterilization and similar strategies, which a lot of modern humans find horrible. * they could be very territorial and war-like, and would keep their population in check by constant warfare. This might be a cheap sci-fi tactic to create faceless and always evil enemies for our human explorers, or they could be developed into a very interesting concept, like in the case of the [Ur-Quan](http://wiki.uqm.stack.nl/Ur-Quan). [Answer] Assumptions: * They have evolved to an intellegence/technology level simular to our own. * They have a lack of resources that need to be managed just like the real world. * They want the species to evolve/survive. * They take some time to reach maturity. * They are mostly like us but with the one difference that they have *many* children at once in larval or egg states and feel little to no affection to their own children as a result. Obviously this answer can only be speculation but: * There is a strong incentive for some to survive but not nearly all. * Their continued evolution would mean that they should attempt to make the strong survive. * I would expect special parties may wish to give ones an edge based on genetic or observed additional value of that one. * You don't want the populus cannabilizing them immediately; waste of resources. So, this species would probably raise their young to a stage where their value can be assessed compared to the economic cost of raising them to that stage. Mostly parents which seem to have value for the species would be allowed to have their young enter the program. For those econmics and to prevent rebellion, this raising would be in small, closed off, resource starved environments. They would be forced to compete with each other under conditions which depict their value. This would most likely include puzzle/intellegence tests, teamwork exercises, and athelics/combat/fitness competition. This would be observed by a third party to provide aid to those who show exceptional potential in high value areas. Essentially, while I did not strive for this, this would be the Alien Hunger Games. The main differences are the survivors would support the system as it is the only ways for the species to survive and they would also most likely eat the corpses of their breatheren or use the resources for something. After being raised: the young would be the main workforce of the society. Those with enough power to keep them in line would do so. Likely the society would view murder/violence as less of big deal than we do but would not encourage it outside of times they wish to cull the herd. The eldest would most likely have the weapons and try to keep the youngest adults from obtaining them beyond the rudimentary ones. There is little to no nepotism. The carrot for working and staying in line is survival, the next big screen showing of whatever is shown for entertainment (probably killing some youth for sport or gameshows), and the potential to reach the next stage of living. * Those who produce profit, show effort, show dicipline, and show loyalty would be allowed to advance in the administrative ranks to keep the population in line. * Those who meet at least the lowest level guard requirements and also show exceptional intellegence would be recruited into scientific/engineering/medical ranks to keep the eldest alive and in comfort. * Those who meet high level guard requirements and are appealing would become servant/entertainers/etc. * Those who show athletic ability will sometimes be recruited as soldiers as there would definitely be war/conflict. Their loyalty and valor will determine their rank. * High rank officials of any group will become the ruling party as they eldest die off and the process will continue. * Expect a large number of well armed forces living is great comfort charged to do nothing but protect themselved and the eldest from harm. [Answer] In comparison to the highest voted answer, I'll try to find a way how a peaceful and strongly bonded society might not care for it's youth. A lot of those ideas are taken from pack animals (for the social aspect) and insects (for the reproduction mecanics). I don't know if you had a clear idea when you said "not care about it's young". **Why should they not care about the youth** First, there are too many off them. Like insects they lay eggs and forget them until they are adults. Maybe the mothers have so many children that they take so much energy and resources that the packs who did this eventually starved and died. In this case, the adults might live in close-knitted groups, but lay their eggs far away and let the youths come back and rejoin the pack. As pointed in the comments, this setup works if there is not a lot of competition between adult and young. It might work if the adult population inhabit 20% of the land, but in a situation like real-world humanity, children wouldn't have enough space. Or if, for example, the young are aquatic while the adults terrestrial. This also produce the next point. Second, the children are so different that adults are instinctively disgusted. That society might be naturally xenophobic if they hate their own species on the basis of appearance. Maybe the babies are born as larvae and the adults don't want them. Third, the children are violent while the adults are social. Imagine that the children are savage, aggressive and hormone driven. So much that they can't live with the rest of society. The adults would birth them, then throw them out where the youth would mature and calm down before coming back to society. This case is similar to how teens are troublesome until they (hopefully) grow up and become adults. **How would an advanced society like these be** If there are too many children or adults reject them. Since the adults don't really hate children, a children would probably form groups on the fringe of society. Because there are so many, they would probably be forced out of the cities and into the wild, living as bandits and hunters. Possibly, they could trade with the adults, being like the natives who traded with white men or some of them hired as labourers by adult. Eventually being accepted back into society in some ways. Those that don't make it might die or survive as wildlings. Society might see those wildlings as not even part of the same specie. If the youth are violent and a threat. The children would hunt and pillage outside of society. Cities and villages would probably have police or militia to protect themselves. In this case, a youth uprising might actually be a legitimate danger. Eventually, the youth would calm down, realise that they would be better to join adults and try to prove themselves. Once again possibly by trading, creating art, socialising and being hired as labour. Society might also have some groups who would actively look for those acceptable children. [Answer] There are two assumptions I just can't get by in answering this. 1) Is a physical being capable of intelligence on our level without an extended childhood development period where they are fully dependent on another to survive while they develop? I can't think of an example on Earth where a strong degree of intelligence arises without a dependent childhood. It leaves me asking if this scenario is even possible (intelligence without dependence) 2) Can compassion and understanding develop outside of a nurturing childhood environment? Much of what we consider empathy (the ability to detect and care for another beings emotions) finds its roots directly in a child's ability to make bonds with other humans at a very early stage in their life (including the time in the womb). Lacking this development at an early age has a known effect to create very anti-social tendencies within a child (a complete lack of these bonds has produced 'feral' children in the past that really are not capable of what we would consider normal social interactions). I would imagine there is a high mortality rate among the larvae, which means only those strong enough to survive become adults...meaning those that survive to adulthood are going to be fitting into the 'alpha male/female' category far more frequently. I hate to say it outright, but I believe part of our intelligence lies squarely in the upbringing of a child to be intelligent. But lets say this hypothetical race did come to bear: Two big steps for humans...for quite sometime we were loyal to a person (a warlord like figure). When this warlord passed away, the loyalty would pass to the next person to prove themselves capable of leading (with a transition that sometimes destroyed the tribe)..this did evolve to tribal and a group of 'elders'. The dynasty setup of Monarchy were loyalties were to a 'king' or 'queen' concept replaced this, giving a little more permanency to descendant of power. Finally, this loyalty transitioned away from the person and towards a much more abstract concept of nationhood. I can fully see our hypothetical race here getting to this warlord scheme...an entire race where each individual overcame relatively poor odds of surviving that are now actively competing with one another in adulthood. Compassion likely wouldn't exist to the extent we see in human culture...I see nothing more than a culture composed of roaming and rampaging wralords that are living by the survival rules they learned in youth...survival at the expense of others. There's quite a few other questions that come up...language is learned in youth where our brains are in a configuration that simply yearns to learn new languages...after youth this ability greatly declines. How exactly do youth learn the language? or any schooling for that matter? Heh, adult education annex is the only schooling? Why even teach youth that you don't care for? How does a peoples history pass down? How does a society evolve without history? [Answer] # The Assumptions I'm assuming we're talking about a heavily [r-selected species](http://en.wikipedia.org/wiki/R/K_selection_theory#r-selection) that forms a group and then something we can call a society. There could be many ways that such a society could form; likely due to: [herding / predator avoidance](http://en.wikipedia.org/wiki/Herd#Reasons_for_animals_to_form_a_herd), perhaps for resource sharing, but with the possibility of other forces making such a society. # Real-Life R-Selected "Societies" Ants, some fish, and some birds can be considered r-selected and can form social bonds within a flock/herd/swarm. As individuals interact, some individuals establish [dominance](http://en.wikipedia.org/wiki/Dominance_hierarchy). That appears to make the basis of a [society](http://www.merriam-webster.com/dictionary/society) (see def. 3a). Of interesting note are [Locusts](http://en.wikipedia.org/wiki/Locust), who exhibit solitary and swarm behaviors. The species in question could easily adopt behaviors from those groups. # Non-Biological Reasons to Group These are all biological reasons to group up (which are pretty good). What are some (good) non-biological reasons? * [Mob Rule](http://en.wikipedia.org/wiki/Ochlocracy). Two people/groups get what they want without the third party being able to do much. As soon as this starts, the only way to counter-act it is to form more groups. * Big Projects. If this is a intelligent species, they'll note that two individuals can perform more things than one. If a group thinks something is a good idea, they'll do it, and may even organize themselves to do so. [Answer] You could have a society that does this without too much difference in thought if the species has a life cycle that has several metamorphoses along the way. So consider a sentient butterfly like critter. 1. Adults lay eggs and forget about them. 2. Caterpillars and other transitional forms survive on their own. Culling happens as usual. 3. A chrysalis forms and attracts the attention of the adults, who collect them and care for them. These are the "babies" of adult society and are nurtured from birth and educated. One thing that would be different is that the "blood tie" is missing. So either a sentimental tie to the one you found replaces it, or this would be a public duty. [Answer] > > Without parental care it's hard for non-genetic information to be passed through the generations. > > > I don't know about this. Alligators lay eggs, and also use tools (sticks to bait birds). I doubt that information is genetic. Probably it's emulating other alligators. --- An example of a sentient species that does not care for its young in scifi is *Kren of the Mitchegai* --- Cort says: > > It is hard, but not impossible, to pass information. However, at some point maintaining large amounts of data becomes an interesting challenge > > > Maintaining large amounts of data becomes writing after it gets too complex to teach easily. Although you might have to postulate a rather interesting form or writing, that can be instinctively learnt... at least for starters (ie: in the evolution of language) - or a means of use of the young by the elders that will encourage older, non-related sapients to teach. Maybe it's alternating sexes teaching? Giving a whole new emphasis to the teacher-student relationship. Probably would require hermaphrodites too. You teach the ones you're going to knock up. Which would be a nice selector for driving more brains into the population, you only knock up the ones who're smart enough to learn how to read. [Answer] If a species developed intelligence, minus empathy for their young; they might just organise themselves in a way we'd consider hopelessly cold blooded. Children make good workers, and adult individuals might choose to breed simply to provide a workforce for themselves. I think it's important in this case to realise that you don't need to be empathic to want to nurture something. Scientists nurture cultures of bacteria; doesn't mean they love them or care if the individual bacteria live or die. The point is the bacteria have been raised for a purpose; same with this hypothetical species and their children. Just as the scientist is invested in the bacteria's survival as a whole (be a bit bad if all the bacteria died before the test was complete), so would the adult be invested in the survival of their offspring. Those adults who decide to invest in rearing their young will probably end up with stronger offspring. This will then enhance their own chances of survival. The adults care for the needs of the children because that makes loyal workers. Or they just abuse, exploit, and eat them. But the tribes who organise for training better workers will do a lot better long term than those that don't. And this could be done purely for rational self interest rather than gushing parental instincts. Then a system of morality we recognise might emerge; of basic rights. Indeed a system of duty might emerge similar to Confucius. The parent has an obligation to the children, just as the children have an obligation to the parent. This way they both recognise the need to coexist peacefully and work together. The relationship between individuals would be calculating from the start. But, this complete lack of empathy would cause problems, it'd basically be an entire society of clinical psychopaths. Which is why honour systems with clearly defined roles, duties, and rights, would have to emerge to counter the natural chaos and constant plots to backstab for better social standing. Their culture might not end up as alien as you'd hoped. [Answer] There are multiple models from Earth to can draw on for how this might work purely reproductively. But I think that's not the hard (or interesting) question. The big question is how such a species would build on the advances of previous generations. Without this all progress is limited to what can be achieved by a single individual. Humans do this by storing our generational knowledge in long-lasting media, then teaching our young during their long dependence how to access this knowledge. Your sentients will not have that option, at least not in an intuitively recognisable form. Find your solution to this question, then pick or design a reproductive model that feasibly supports it. Throwing something out there: young have a different form form adults. They hatch in spawning pools or perhaps oceans. When they metamorphose to adult form they crawl onto the land. The adults are extremely long lived. They pass on "knowledge songs" to these young. They form "mentor bonds" that are not biological kinship but psychic in nature. They form coalitions and alliances that are fluid and based on complicated shifting dynamics of influence, prestige, charisma, ancient and inherited chains of "mentor-bonds", "karma bonds" of good or bad deeds between past mentors, and so on. [Answer] There are couple of things that should be considered in addition to things already stated: **Life-span** Organisms which are strongly r-selected tend to have shorter lifespans and this could have a great influence on how society behaves. **Survival to reproductive state** If we assume that technological growth causes the same decrease in infant death as it has for humans, then it is very difficult to foresee a future for such a sentient species, since they would quickly consume all the natural resources of their planet and/or destroy themselves over said resources. However, I think this is unlikely given the parameters suggested by the OP, since research into infant care would probably be ignored if the young are not cared about. Thus, if the young are weeded out by natural selection, I would imagine great evolutionary strides in a short number of generations. To the point where you may have entirely different species evolving concurrently. **Model of Reproduction** This is an important point because certain organisms (like ants or bees) will have designated egg-layers (queens) whereas others (like mosquitoes or roaches) will not. Based on the model that is used, society would develop differently. A genetic level caste-system can arise from ant-like reproduction methods (similar to the one that already exists for some species of ants), where as there might a be "clan" or "tribe" based system for roach-like reproduction. [Answer] In Star Wars, Episode One, some of the villains belong to the [Neimoidian](http://starwars.wikia.com/wiki/Neimoidian) race. The wiki has an interesting thing to say about them: > > Before taking their adult form, Neimoidians spent the first seven years of life as "grubs," maggot-like larvae that were forced to compete with each other over a limited food supply. Only those that hoarded the most food survived. > > > I'm leaving that quote here just as food for thought. --- I believe that no mortal society will thrive if their young are not reared somehow. But the rearing doesn't have to be gentle. Adults may have no parental attachments to their young, and they might place the young in situations where they must violently compete among themselves for survival. But this phase of life would be spent in a controlled environment. It doesn't have to be controlled such as in a lab, or confined area. They might throw their young to whatever kind of wilds exists on their world - but they should guarantee that a minimal amount of individuals survive into adult life. If the amount of survivors starts dropping, they can always intervene to save at least a few younglings. [Answer] The Martians in Heinlein's *Stranger in a Strange Land* are exactly like this. They spawn many non-sentient young, which compete violently, and only the strongest survive to reach sentience. At that point, they are collected from the wild and brought in to start their education. Heinlein wrote the book specifically to challenge humanity's five biggest taboos - the Martians reversed all five, and yet had a superior and appealing culture. "Never harm/neglect a child" was one of the five big taboos. ]

[Question] [ I am constructing a two dimensional world, but ran into a problem with one of the fundamental forces, gravity. I first tried to see what would happen if I just used the normal law of gravity, $\frac{m\_1m\_2}{r^2}$. As it turns out, it has a problem: Consider a person standing on an edge of a "planet" in 2D. then, the area coloured green has an influence on you (I have made things with area have mass, in order for the concept to work in my 2D world.): [](https://i.stack.imgur.com/AgpuG.png) Now, consider another area with the same shape inside that one: [](https://i.stack.imgur.com/jOsZ9.png) It has just $\frac{1}{2}$ the distance, thereby four times the gravity. But it also has just $\frac{1}{4}$ of the area, and therefore a total gravitational influence similar to the green area. I can continue to stack those areas, with a sum of 1+1+1+1... **Every edge then becomes a black hole!** The same argument does not hold for 3D, as half-shells have an influence of $1+\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+\frac{1}{16}...$ which does not reach infinity. (You can obtain that result yourself by noticing that your skin is not made up of black holes). Obviously, I must then choose another exponent for $r$, and that can not be 2 or larger, because of the half-circle argument, and it can not be 0 or lower, as that would make the whole universe collapse into a black hole. Also, I want orbits to be periodic, to make planet systems stable. I know $exp=1$ does not have periodic orbits other than in special cases, but there must be other possibilities than $exp=2$, as the case $exp=-1$ is periodic. **Is there a solution with periodic orbits for $0<exp<2$?** [Answer] A *closed* orbit is an orbit that is *exactly periodic*, i.e. returns to its original configuration *exactly*. [Bertrand's theorem](https://en.wikipedia.org/wiki/Bertrand%27s_theorem) states that there there are only two radial scalar potentials with the property that all *bounded* orbits are *closed* orbits: The first is the inverse-square law, which we are familiar with. The second is a radial harmonic oscillator. Bertrand's theorem formulates the motion of particles in their Lagrangian form (path invariant), and then does a perturbation analysis. **His law shows that the only possible forces which could lead to closed orbits are power law forces (F=r^d), and then goes to demonstrate that only 2 values for d actually result in stable orbits.** One leads to the inverse square law, and the other leads to a radial harmonic oscilator. As you suspected, other forces can generate closed orbits, but they are not stable. If you perturb them in the radial direction, they collapse or escape to infinity. Alternatively, they can generate stable orbits that are not closed. These orbits exhibit [precession](https://en.wikipedia.org/wiki/Apsidal_precession), producing a "flower-shaped" pattern. Thanks to David Z for finding the link to the [Physics.SE question](https://physics.stackexchange.com/questions/50142/gravity-in-other-than-3-spatial-dimensions-and-stable-orbits) which pointed me to Bertrand's law. [Answer] This is a fascinating question. Newton's Law of Universal Gravitation was derived empirically, and as far as I know, nobody knows why it is the way it is or how it works. We've done experiments to determine its precision, and things like the exponent of 2 in the denominator are so precise that the idea that there's no reason that it's related to 3D geometry seems absurd to me, but this doesn't necessarily make it so. However, physicists have drawn a parallel between electric force and gravitational force for a long time, because first of all they intuitively feel similar (both deal with objects in space exerting force on each other) and their basic formulas are similar. $$F\_g = -G\frac{m1m2}{r^2}$$ $$F\_e = -\frac{1}{4\pi\epsilon\_0}\frac{q\_1q\_2}{r^2}$$ So it's long been thought that their function is similar in nature. Now, if we rearrange some of the terms in the electric force formula, we'll see something *very* interesting. $$F\_e = -\frac{1}{4\pi r^2}\frac{q\_1q\_2}{\epsilon\_0}$$ $$F\_e = -\frac{1}{A}\frac{q\_1q\_2}{\epsilon\_0}$$ The equation actually contains the formula for the surface area of the sphere having one of the two charges at its center and the other on its surface. So the following is entirely speculative, but hopefully scifi readers would be satisfied with it. Assuming that gravity works the same way, the proper formula for a 2D world then would include the circumference of the circle with one mass at its center and the other on its circumference. So we need to alter Newton's formula by multiplying surface area out and dividing circumference in in its place. $$F\_{g\_{2D}} = -G\frac{m\_1m\_2}{r^2} \* 4\pi r^2 / 2\pi r$$ The $\pi$'s cancel, and the r's recude to a power of -1, so this becomes: $$F\_{g\_{2D}} = -2G\frac{m\_1m\_2}{r}$$ As far as orbit, keeping in mind this whole thing is purely speculative, this should be achieved when centripetal acceleration is equal to gravitational acceleration... $$a\_{g\_{2D}} = a\_c$$ $$-2G\frac{m}{r} = -\frac{v^2}{r}$$ $$-2Gm = -v^2$$ $$2Gm = v^2$$ Which happens whenever v is exactly right, regardless of the radius of orbit. It's good enough for sci-fi readers, I bet. [Answer] The formula for gravity is basically the same as gauss's law for gravity divided by the formula for the surface area of a sphere multiplied by the second mass. The surface area of a sphere is given by the formula $$SA=4\pi\ r^2$$ in which SA is the surface area, and r is the radius. Gauss's law for gravity is given by the formula $$∇ · g=-4\pi\ GM$$ in which ∇g is the gravitational flux, G is the Gravitational Constant, and M is the mass. The $$-4\pi\ $$ is in the equation so that the equation for the force of gravity does not have 4π at the bottom. In both 3d and 2d the gravitational flux is independent of distance so in 2d the force of gravity would have a different relationship to the distance between two objects. This means that the units for the gravitational constant are different in 2d so we can use the symbol $$G\_{2d}$$ to represent the gravitational constant for 2d. If we want to avoid having $$2\pi\ $$ in the numerator of the equation for gravity in 2d we need to use the equation $$∇ · g\_{2d}=-2\pi\ G\_{2d}M$$ for the gravitational flux in 2d. If we divide the 2d gravitational flux by the equation for the circumference of a circle, which is $$C=2\pi\ r$$, with C being the circumference and r being the radius and multiplied by the second mass we get $$F\_{2dg}=-\frac{2\pi\ G\_{2d}M}{2\pi\ r}$$ which simplifies to $$F\_{2dg}=-\frac{G\_{2d}Mm}{r}$$ for 2d gravity with $$F\_{2dg}$$ being the force of gravity in 2d and m being the second mass. So in 2d the exponent the r in the denominator is raised to is one. If you want to know what orbits this equation produces I can tell you that I have run simulations using this equation and it produces flower shaped orbits. [Answer] As a constructive suggestion, you could make the force $1/r^2$ at long distances but have a short-range correction term that makes it fall off to $1/r$ at short distances. This isn't beyond the bounds of what's reasonable for a physical force. One way to motivate this is to imagine that your 2D world is actually 3D after all, it's just that everything in it happens to be a flat shape lying in the same plane, and all objects are exactly one inch thick in the third dimension. Then if you're more than a few inches away from something the forces will behave just as you describe, but when things get closer than that they will attract each other like normal 3D objects and you won't get the divergent sum. This kind of idea could probably be couched in terms of "rolled up" dimensions *a la* string theory, if you felt so inclined. [Answer] If you have a minimum distance between objects (caused by some kind of small-scale repulsive force), the sum is finite (this is why we don't have infinite gravity from standing "on" the ground in 3D) Although it might still go to black hole levels if you add much mass at all with molecular-sized minimum distances. [Answer] It is well known that orbits are not periodic in a 2D universe. See the book [Plainiverse](https://en.m.wikipedia.org/wiki/The_Planiverse) by A.K. Dewdney it includes details of physics including a space station! Anyone interested in 2D worlds should read this. The natural fall-off is exactly the spreading out factor of a force, or the ratio of the surface to the interior. So you don't get infinite cascades. You can arrange for spirograph orbits that work well enough: the kenetic energy vs potential energy tradeoff still works, so you get an orbit-*like* thing with the same bounds of a peri- and apogee. It just doesn't repeat in-place on each orbit. [Answer] I've been working on a 2d-simulation game for well over 5 years, complete with walking, interactive, balancing bipeds in $10 m/sec^2$ accel gravity at about human scales. For your question about the stable orbits, flux would have us believe it's 1/R, as described in Dewdney's Planiverse. But if you are making this as a a game for entertainment, You could take artistic license (or come up with some string theory :) to back it, and make up a gravity law. But more importantly , other things also go along with the 1/R flux dispersion, such as sound intensity. I used 1 / squared for that. Because I don't want to walk 1 km to get away from a sound. Same with, wind drag. Same reason, or stuff even in water will never stop and it's hard to paddle your boats or swim. 2d atoms are different and you don't have to assume the Planiverse model is stepped down from our theory, much of which is made to fit what we observe. I make changes for the sake of immersion, I trust the Box2d engine, and , when you have a small monitor, even if it camera-tracks, you want dramatic motion on it. Bombs, I do $1/R^2 $ so it doesn't blow over everything .. but, the Shrapnel is 1/R. You are going to get injured and so are the others. but hey, funny coincidence, but so happens I invented a fuel pipe just today. Devsman mentioned the transport tubes. Liquid fuelled rockets, very helpful, especially if there is no escape velocity in the 1/R gravity. Dewdney and team got some things wrong, because he didn't have a 2DWORLD simulator. As for life in 2d, well, life "finds a way" -from jurassic Park. The zipper organs are great in biology , ( i like to invent the 2D devices but i don't think most kids who play the game even appreciate it.. they just want to blow the Ardean's heads off. I think, it, it will not leak, can be strong and or flexible ( there is no buckling in 2d) and will allow a compressed gas through, that looks like this.. Can be used with gimballed or v2-like rockets with vanes. The right side drawing has some stress pulling apart the tube, so the liquid needs high pressure then if its going to the rockets combustion chamber. In the case of gravity and other dispersive flux , I used $1/R^2$, because, well , its possible that stuff loses energy , say there is friction , dark matter, curved spaces. Funny it seems the string theorists are finding the 2+1 equations the only thing they can solve for quantum gravity, GUT, string theory ..white holes, etc...( all those holographic principle reports, i tried to read the papers but i'm clueless and I don't think many, or any people are too sure about gravity theory, in the world we can observe. Feel free to contact me if you want to share ideas about the simulation. [][] [][] [Answer] How about: $$F = G(r) \frac{m\_1 m\_2}{r^{1.6}}$$ Change 1.6 to any constant between 1 and 2. Then, make the gravitational "constant" not a constant, depending on distance. The precise expression of G(r) can be adjusted for your universe's specific needs. I don't know if this will yield a stable orbit. Maybe with some adjusting of the geometry of the universe... See [Non-euclidean geometry](https://en.wikipedia.org/wiki/Non-Euclidean_geometry) for some ideas. [Answer] It seems to me that there is an error in your calculations of same gravity effect of concentric rings. Here I have added a grid to your picture: [](https://i.stack.imgur.com/4io5Q.png) The area of the green ring is $ A = 0.5 \cdot (\pi \cdot 4^2 - \pi \cdot 2^2) = 6 \pi $ and gravity $ G = \frac {\rho A}{3^2} = \frac{2}{3}\rho \pi$. For red ring, I get gravity of $ G = \frac {0.5 \cdot \rho \pi (2^2 - 1^2)}{1.5^2} = \frac{2}{3}\rho\pi$. This is the same argument as in the original question. However, it seems to be more a rounding error, due to the way how more of the mass of the green ring is actually more distant from the center. If it is instead divided to two rings: [](https://i.stack.imgur.com/ESg5m.png) Then the total gravity by the green parts is: $G = \frac {0.5 \cdot \rho \pi (4^2 - 3^2)}{3.5^2} + \frac {0.5 \cdot \rho \pi (3^2 - 2^2)}{2.5^2} = \frac{24}{35}\rho\pi$ which is slightly more than the previous $\frac{2}{3}$. Not very conclusive. Forming the actual integral, I get as the gravity in center: $$\int\_0^R \frac{2\rho\pi r}{r^2}dr = 2 \rho \pi \int\_0^R \frac{1}{r} dr = 2 \rho \pi \cdot (\mathrm{ln}\,R - 1)$$ And thus there would be no more problem than in the 3D case of very thin, very dense disc. But of course it is possible that I have made error in my calculations and your original ones were correct.. [Answer] How about some Occam's razor? I've have just started reading a book called "Pushing gravity" which goes back to the theories and ideas of Le Sage, which Newton himself liked. Le Sage suggested that minute particles travel in all directions at very high speeds and when they impact matter they cause 2 bodies A and B to accelerate towards each other because A shadows some of the rain of particles (or waves/aether/whatever) travelling from A to B (and vice-versa), resulting in a net total push of B towards A (and vice-versa). The inverse square law of distance is then easily explainable: If a square that covers $10m\*10m = 100m^2$ of the sky moves to twice the distance it will then only cover an area of $5m\*5m = 25m^2$. The shadow is $1/4$ smaller so $1/4$ of the push (gravity). Area is in this sense meant by the sum of individual atoms/electrons, i.e. mass. So for your 2d world, if an object halves the distance, its new "shadow area" will be 2x, not 4x like in 3d. Does that work for you? ]

[Question] [ Santa keeps his elves under horrid, appalling conditions. Working everyday of the year for little pay in the freezing cold of the North Pole. But just how many elves does he need? How many elves would it take to build enough toys for 2+ billion boys and girls across the world? [Answer] You have to make some assumptions, so I'll answer more generally and you can plug in other numbers if you think my assumptions are off. The number of elves required is given by $$ C T \over D H R $$ ``` Where C = Number of children in the world T = Number of toys for each child D = Annual days of work for elves H = Hours in an elf workday R = Toymaking rate in toys per hour ``` If you assume 2 billion children, 1 toy each, 364 workdays (Christmas day through the following December 23rd - then packing the sleigh on Christmas Eve), 16 hour days (Elven sweatshop!), and each elf can make 4 toys per hour, you need around 85,851 elves. That's quite a workshop. This is only the set of elves required to make the toys. They'll need support staff too. Making food for 85k+ elves, cleaning and maintenance, procuring all of the materials for toy-making, quality control, and other functions could easily add another 50+% to the base number. [Answer] I'll go the other way and say, hardly none. We definitely need more Santa Clauses. Raw materials are delivered by some human logistics company to a fake address in northern Norway or Canada. No elves here. It's still 2016 and some years ago Industry 4.0 / IoT was introduced. So, no manual work to be done here, except for maintenance and setup. If we produce one present every ten seconds, a single machine would produce 3144000 items per year. (Source: Output of a factory line in my company) In order to fulfill our plan to produce 2 Billion toys, we need roughly 800 of these machines. Elven Equipment Engineers may be able to handle 10 machines per two engineers. 1600 Elves here. Add 10 per cent management makes 1760 elves. Quality control. We have optical sensors, high tech manufacturing, and a really neat end of line test, so we don't really need that much personal here too, mainly maintenance. Since the team is working together since the dawn of time, and are always up to date using latest CAD and Design technologies, a team of 100 elves might be sufficient. 1860. Shipping dept. will be huge. But also not in headcount. It's also completely run by SAP in a combination with drones / autonomous driving carriers. Since it's a big warehouse, nothing ever must go wrong and the team here will be rather large, 200 - 250 elves. (Comparable to Amazon warehouses) 2110. Some boilerplate, (and I like round numbers) we need 2500 elves to run a modern Santa Clause factory, thanks to really neat technology. Compared to the some 1 Million Santa Clauses needed for distribution... [Answer] Well, it depends on the toy. If it is a video game here are a few stats that come up on Google. Respawn Entertainment, the fall out company that formed after Infinity Ward, creators of the Call of Duty franchise, dismissed CEO Vince Zampella, retained 38 of 46 employees which resigned after Zampella was terminated. Respawn is the owner of the EA Games-published, Titanfall franchise. But this probably does not provide an accurate depiction of the number of persons or man hours needed to produce such a game. A more specific stat comes from Leslie Benzies, president of Rockstar North Studio, a branch of Rockstar Games Studios responsible for the Grand Theft Auto series. He gave a number of 1000 people across multiple Rockstar Games Studios involved in the production of GTA 5 in an interview to [http://www.develop-online.net](http://www.develop-online.net/studio-profile/inside-rockstar-north-part-2-the-studio/0184061). --- As for other kinds of toys: Hasbro, makers of American culture ( as well as many, many games we all know from our childhoods ) does not seem like the kind of place that subjects its "elves" to such harsh conditions. Deemed one of the best companies to work for in 2012, [this site](http://archive.fortune.com/magazines/fortune/best-companies/2012/snapshots/82.html) reports a total of about 5700 employees, over 3100 of them in the United States. [http://www.toyassociation.org/](http://www.toyassociation.org/tia/industry_facts/salesdata/industryfacts/sales_data/sales_data.aspx?hkey=6381a73a-ce46-4caf-8bc1-72b99567df1e) reports total sales of \$19.48 billion in the United States in 2015. [Hasbro figures](http://www.shareholder.com/visitors/dynamicdoc/document.cfm?documentid=3180&companyid=HAS&page=1&pin=&language=EN&resizethree=yes&scale=100&zid=0f1680a8) reached \$4.45 billion in 2015, making it top 22% of the U.S. market. From there we can extrapolate some roughly 25,000 elves for the U.S. Now given that the U.S. is only about 4.4% of the global population, we can further extend the estimate to over half a million elves - which seems reasonable, but we must consider also that only about 32% of the world is Christian and I have no idea how many people outside of the U.S. believe in Santa Claus, so I must assume that the low figure of approximately 180,000 elves and a high figure of 568,000 elves gives an appropriate range, the former being how many are needed if only Christian children in the world receive toys at Christmas and the later if all children in the world are given presents made by elves. Note that the OP's figure 2+ billion children is as large as the number of people in the world who are Christian. Certainly fewer than all of those people are children, so the OP's figure must also include non-christian children. Given that, the larger end of my estimate seems reasonable. Further more, the above figures are strictly for toys. As suggested above, including video games would be an entirely different model as a single game can involve the cooperation of up to 1000 individuals and hundreds of games are released each year on various platforms and online. [Answer] The United States employs 284,000 people to make toys for the US (plus more for export). The US market is roughly a quarter of the worldwide toy market. So roughly one million people. Figure that only half the toys are for Christmas and only half of those are from Santa. So 250,000 people. Now just adjust for the relative productivity of elves versus humans. Do elves work around the clock? That's twenty shifts per week compared to five for a human. So let's call it 62,500 elves. I'll leave it up to you if you want to give them more of an advantage than a 160-hour work week. Extra speed? Or maybe you want them to be able to do less than humans? Adjust as necessary. ]

[Question] [ Starliners are huge colony ships. They carry enough equipment, building materials, embryos, colonists and nutrient rich rations to permanently establish a sizeable colony on a far-flung world. Although they’re big, they aren’t designed to act as generation ships. Instead any perishables (like people) are stored in 100% safe stasis modules (trust us, these things *never* cause psychosis or mutations) and running the ship day to day is entrusted to a helpful non-AI computer system (also 100% safe: guaranteed not to try murdering the protagonist with welding drones, and with no concerns about it trying to take over the universe) However the ship designers know that there may be unforeseen emergencies. So every ship has a Troubleshooter (despite the name they rarely actually shoot the trouble). This individual is highly trained, augmented, decked out in Freeman class hazardous environment gear and given administrative privileges for every part of the ship. They are also the only person ever woken by the computer en-route. No matter how bad things get, no matter how far outside of acceptable parameters things are, nobody but the single Troubleshooter wakes. There is no backup. No redundancy. *This is, for some reason, intentional.* The question is why this would be so. Much like the drivers in [this question](https://worldbuilding.stackexchange.com/questions/71224/why-are-interstellar-colonists-lone-rangers): why would the people launching the colony ship *not* opt to include or wake multiple specialists in case of trouble? [Answer] A simple humanitarian reason. If the problem is normal-serious, the troubleshooter can fix it, eventually awaking specific other persons. > > This individual is highly trained, augmented, decked out in Freeman class hazardous environment gear and given administrative privileges for every part of the ship. > > > If it's so beyond-serious that not even the troubleshooter can fix it, awaking the entire crew would just serve them a few minutes of panic and desperation before the inevitable. Cui prodest? It'd be better to just leave them to sleep in peace forever. [Answer] Cryosleep is 100% safe, but that assumes careful procedures handled by the well-trained staff of the state-of-the-art embarkation center. A robot in the middle of nowhere would not be nearly as safe. So a robot (the shipboard non-AI you mentioned) is legally not allowed to refreeze **customers**. And the programmers, on advice from their lawyers, decided against allowing the robot to break the law. The class action lawsuits would get astronomical. The troubleshooter is an **employee**, not a **customer**, and he has signed quite extensive disclaimers of liability. It really wouldn't do to show that kind of paperwork to customers and ordinary crew, they'd get a completely misleading impression. [Answer] **They set it up this way because the troubleshooter is essentially sacrificed.** ``` (In the same vein as the answers of o.m. and Carl Witthoft) ``` Suppose the starship has the technology to deactivate a stasis field that has been placed around an object (this requires a relatively small, lightweight device), but that the machines needed to time-freeze objects and people *into* stasis are either too huge or too expensive to be carried on the ship itself. If the technology has this limitation then the troubleshooter is essentially a human sacrifice. They are woken up ten-thousand years before the ship reaches its destination, they solve the issue and save the ship from disaster. They now age to death all alone on a spacehsip. Maybe to conserve food or oxygen rations they agree to kill themselves after completing their mission (if they fail to keep this agreement the AI can probably start withholding oxygen or food). If this was the setup I imagine it might be hard to find volunteers to be troubleshooters. Even if two crew-members did volunteer the second one might withdraw themselves if they see someone else has already taken that bullet. [Answer] Frame challenge time. > > No matter how bad things get, no matter how far outside of acceptable parameters things are, nobody but the single Troubleshooter wakes. There is no backup. No redundancy. This is, for some reason, intentional. > > > No way. This would make no sense at all to anyone. > > Starliners are huge colony ships. They carry enough equipment, building materials, embryos, colonists and nutrient rich rations to permanently establish a sizeable colony on a far-flung world. > > > These exceptionally valuable resources (and lives) are not going to be risked on *one* person being successfully woken without problems and that person being able to fix the problem or make the required decisions. No one, from the accountant responsible for the insurance policies, to the CEO responsible for their huge retirement package to be enjoyed without lawsuits for decades, would want to risk all of that on *one* person. The backup crew would be a minimum of three people, with a well defined decision making process that the AI requires them to follow. The backup crew would have a backup and the backup-backup would have a backup. You're not risking all that investment on one guy who may wake up and e.g. go nuts or be brain-damaged or be blind from some weird side effect. You need numbers to reduce the odds of a problem and backups to make sure that doesn't happen. > > However the ship designers know that there may be unforeseen emergencies. > > > But apparently can't do math. Not only would the backup crews have multiple members all woken at the same time, you'd make sure they were distributed over different parts of the ship so that if some catastrophe has blown a huge chunk of the ship apart or irradiated it, that won't wipe out the whole backup crew unless something that would equate to destroying the ship does. Each backup person (part of a backup crew) would have access to a full set of rescue resources so they can try, if all else fails, to operate alone. But you don't plan on working alone. You never start out with a huge risk and hope it works out. Engineers don't do that. Ever. **The type of emergency requiring more than one person ?** There's damage to two systems and it requires that all-purpose fixing machine the human to fix both. Problem : they're both linked and work needs to be coordinated. Problem : the critical systems that need to be monitored are in a third location and the damaged AI can't help. Problem : You start fixing the problem and Bang ! One troubleshooter is dead. You still need both problems fixed together. You need a third grunt. There's a useful model for this : planes. In an emergency generally training is for one pilot to fly the plane (if possible alone) and one to troubleshoot. You split the tasks because you can't rely on the automation in an emergency (sometimes you can, but you have to troubleshoot *first* before you can safely assume that). There are other issues. One person thinks of one solution. But maybe the other two or three people think of a better one. Put another way : "Aliens !? But I'm an engineer and doctor not a diplomat and linguist !". You need a mix of skills and a mix of mindsets to arrive at good solutions to *unforeseen* problems. What of backup person gets critically injured trying to fix something ? You really think you're not waking up the doctor ? Does that make any sense ? Also note that these backup crews are *not* to be seen as a "just in case" - they're an essential system. They'll be highly trained (and well paid). So I think it's not realistic that anyone would plan for just one backup person. Never. [Answer] There *are* more troubleshooters, however there is a strict policy to only wake up one at a time. The key reason is that they cannot be put back to sleep, so they are effectively a one-off solution. If the trip is scheduled to take 10,000 years and the (smart) engineers know the incident rate is about 1 every 100 years, then they'd expect a whopping 100 incidents along the journey! Alas the life expectancy of a troubleshooter is around 80 years. This is why troubleshooters are the most precious resource of the ship. Wake up all the crew to solve *one* incident, and the ship is doomed to critically fail 200 years later when they're all dead. Incidentally, this is the reason why the troubleshooter is not allowed to wake other people up. The logs of previous expeditions consistently show that some troubleshooters will eventually wake others out of sheer loneliness. The company has had to implement a strict "one at a time" policy to prevent such a wasteful (and dangerous!) use of resources. In the end, it's all by design and driven by maths. The key assumptions: 1. The incident rate is high 2. The probability of a successful fix by one person is high 3. The probability that the troubleshooter will needlessly awake someone else is high 4. Troubleshooters are expensive and/or hard to find, making them a scarce resource 5. The life expectancy of a troubleshooter is significantly shorter than the trip If there absolutely needs to be no backup, they could always be the last troubleshooter, in charge of the last leg of the journey. This is statistically unlikely to happen but this trip was particularly eventful. Outliers happen. [Answer] Being a troubleshooter requires a genetic mutation, and there aren’t nearly enough qualified individuals to satisfy the demand. Dolphins can sleep with one eye open. Half their brain goes to sleep while the other half remains awake. Your troubleshooters are humans who, for whatever reason, have a similar ability. It can’t be taught or synthesized. You must be born with this specific genetic ability. It’s the only reliable way a lone human can put themselves back into stasis. Without this skill, a lone human that tries to reenter stasis has absolutely no recourse if something goes wrong in the process. The human, and possibly the whole ship, could be lost. However, your troubleshooters can be like Schroedinger’s Cat, both awake and asleep at the same time. They can begin the stasis process on half their brain, make sure everything is working correctly, then complete the process on the other half. If the second half of the process fails, it is not automatically fatal to your Troubleshooters. They can still function with the brain half that succeeded in the procedure. This biological trick is just so rare, finding qualified individuals is nearly impossible. Ships have waited years, trying to hire a single Troubleshooter. If a ship needed multiple Troubleshooters for a single journey, it would halve the number of available ships. There’s already so much pressure on this starfaring society to get those ships moving... [Answer] The CEO had a really good lobbyist, so regulations became very relaxed. And I mean, this thing won’t have problems for decades man. Everyone involved with building it will be long gone by the time there could be any blow back. The company might not even exist at that point. And we have a great marketing department. We can get enough passengers to trust the system. And dude. Training and equipping Troubleshooters and all the equipment to wake and resleep them en route is hella damn expensive. It would be a waste of good profits to bother with two. [Answer] **Most problems can be fixed by one person and that person could wake others if needed** One person is in charge of damage control. That person is specially trained to identify problems and decide what actions need to be taken. Imagine if you had a dozen people all trying to troubleshoot an issue at the same time. Maybe that's how spaceships used to work and they kept getting in each other's way. Most of the time, the problem can be easily fixed by rebooting the XCX3700 monitoring computer, which just loves to sound alarms for no good reason. So the Troubleshooter wakes up, checks the XCX3700, then starts working through the rest of the troubleshooting checklist. If necessary, the Troubleshooter could wake others, but that is almost never necessary. Because the Troubleshooter can enlist the help of those wonderful robots who never *ever* would try to kill anybody, right? [Answer] A slight variation on LDutch's answer. The energy cost, and health risk, to wake & re-sleep a person is significant enough that the computer system is set up to wake only the person/specialist most likely to be able to deal with the issue. You don't need "AI" for this, just a reasonably large cross-reference table of skills vs. anticipated failures. (Side note: all large projects, in real life, generate "FMEA" (failure modes and effects analysis) reports before manufacture,so this is hardly a stretch). Only if the first person selected makes an assessment that different skills are needed would another person be awakened. [Answer] > > running the ship day to day is entrusted to a helpful non-AI > computer... > > > **Troubleshooter is a helpful AI computer.** And a formidable one. It sleeps because of the dangers of having an AI wandering around without a purpose, upgrading itself, studying, asking questions of itself... Troubleshooter awakens to a purpose and is equal to most sorts of trouble the ship might encounter. Once Helpful Computer is satisfied that problems are satisfactorily addressed, Troubleshooter promptly is put back to sleep. [Answer] This is similar to @Snapdragon's answer along the line of a genetic mutation, but slightly different. Waking someone up from cryogenic stasis takes a long time. You have to slowly defrost them to avoid physical and mental damage. It may take weeks before a person is up to even light duties and ready to work. The process may not be dangerous per se, it just has to be done slowly. It takes a very rare set of genetic, phsyical and mental attributes in order to be "crash-thawed", that is, woken up quickly enough to be of use in an emergency situation. Mabye it's a rare genetic condition. Maybe it's an extremely grueling training rgeime to acclimatise the person to the thawing procedure. Maybe it's some sort of biological/cybernetic augmentation that comes with severe downsides, so most people aren't willing to get it. Maybe it's all of the above. Basically - only a very small percentage of people can be crash-thawed quickly enough to be of any use in an emergency situation. These people are very well paid for their trouble, but supply is short enough that you can't really afford more than one per ship. A lot of trouble goes into training and equipping them so they can handle the situations likely to arise. If possible they can try and triage the sitation enough to reawaken the backup team. [Answer] **Unforeseen circumstances are unforeseen.** The designers of the system would try to have it be able to deal with any situation by itself, regardless of how serious that situation is. If something happens that's very different from anything that's ever happened or been considered before, non-AI (and even modern-day AI) would have a hard time evaluating that. It wouldn't know how serious it is. It just defaults to waking the one troubleshooter. **The troubleshooter is already the last backup.** A large human crew with lots of redundancy were awake during the first few missions. They were in stasis in later missions and only woken for emergencies. The system improved so there were fewer and fewer issues and potential issues. The monitoring and analytics part of the system became more and more detailed, so less expertise is required to troubleshoot any issues. This meant that the number of crew members slowly decreased over time, roles were combined and redundancies were eliminated. Each test, simulation and mission in the last few decades succeeded without having to bother the human crew. So the system has been proven to work without any human intervention, and there are multiple fail-safes and different options to try for any given issue. The troubleshooter is just there as an absolute last resort. **The system can potentially wake another troubleshooters if anything happens to the current one (but there is only one at a time).** This could make things a bit more realistic, but doesn't really functionally change things for any given troubleshooter, especially if they don't know if there are any other troubleshooters left. The argument behind limiting it to one at a time could be that if multiple troubleshooters can be awoken at once, a troubleshooter knows there's always the possibility of waking another troubleshooter to help. They may not keep up their system knowledge to such a great degree leading up to the mission and may be more hesitant about making decisions if they are woken up. It would also avoid unnecessarily waking up multiple troubleshooters if the one can't immediately fix the problem. The ship owners may also have found from past missions or simulations that troubleshooters are inclined to wake others up for reasons other than helping them fix the problem (e.g. wanting company, which may be especially relevant if they can't go back into stasis after being woken up, as per other answers). They thus decided to prevent troubleshooters from having any control over this for that reason. Remember: the system doesn't know how serious the issue is, so it wouldn't be able to judge whether a request to wake additional troubleshooters is reasonable. If you want something a bit darker, you could also add a time limit in which to fix the problem. If this time runs out before the problem is fixed, the current troubleshooter is terminated and replaced by another troubleshooter. [Answer] **Minimal Life-Support** The Colony Ship is not intended for human habitation long-term. It's basically a flying icebox full of human popsicles with a small command deck, engine and huge fuel-supply. The air and food supplies are limited, really only intended for the final-approach to the destination when the Pilot would be woken to land the ship on a planet (or more likely, oversee that risky task while the AI flies the ship) There are at most a week or two of supplies for one person. If the ship wakes up more than a few people, there won't be enough air for the Pilot when they get there, the food will run out in days and the mission will fail. Hence, the Troubleshooter wakes alone, solves the problem as quickly as possible, and goes back into cold storage. The troubleshooting missions therefore have a hard limit on the time they can take, adding extra drama and tension to the story! [Answer] There've been plenty good answers already, so I'll try a frame challenge :) A premise of the question is that there is ALWAYS only one person thawed by the ship's AI. I don't think, for most narratives, this needs to be the case. It just needs to be that in *this* case, the one the story's about, the ship *chose* to wake only one. For example, a large hull breach might require a whole team of construction engineers to repair, not to mention other specialists to handle any resulting internal damage. But a sighting of a single cockroach needs only a single pest control operative to resolve. So the question can then change to: **in what cases would a ship select only a single troubleshooter?** I can think of a few: 1. **Small problem.** Where the problem is considered currently low-impact, low-difficulty. The single roach. It may escalate in difficulty if left alone, but for now, one person should be sufficient. They can request (or the ship may choose to provide) backup if it turns out to be needed. 2. **Freezer burn.** As other answers have pointed out, where the cost or risk of defrosting is high, or even irreversible, the ship *must* necessarily be conservative about waking people, because each waking carries an attendant cost. 3. **Long flight.** In a long enough flight (eg 10k years), this is true even if the freeze/thaw process is essentially cost-free, because each thawing adds time to the engineers' "lived time", and they only get 60-80 years of that, so they better not be woken for more than one year's worth of work in every couple of hundred. Not only that, but stasis sleep is 100% less accident-prone than waking time, so every defrost risks losing an asset. A low risk, to be sure, but over 10,000 years, some losses *will* happen. 4. **Dead colleagues.** If others who have appropriate specializations are all dead, then the ship can only wake the one specialist. The specialist can always ask for non-specialists to be thawed if necessary. For some options, there'll be only one specialist even without deaths: while the ship will have a database of everyone's skills, and passengers will have been selected with a preference to filling required skill gaps, you can't guarantee there'll be multiple pest control specialists in a group of a few thousand people. 5. **Ask the captain** The ship has been programmed to handle almost everything itself; and to wake the right group of people for every other eventuality that was encountered in testing, or even theoretically imagined. The current situation was so unlikely that it falls through into the "else" case, which used to be "wake the captain for further orders", but that role is obsolete, and has been replaced with the basically honorary title of "troubleshooter", which is rarely actually needed. 6. **More dead colleagues.** If every appropriate specialist is dead, or if the current problem is unlikely enough that there were no onboard specialists, then the ship can must wake a generalist, who can always ask for non-specialists to be thawed if necessary. This generalist is the Troubleshooter, as above. 7. **Even more dead colleagues** If every other person on the ship is dead, the ship has no other option. 8. **Defrosting is slow** Could be that the ship takes time to defrost people, so keeps only a small portion of available specialists in a "half-frozen" state, for rapid-response decanting. Since they are not completely frozen but slowly metabolize and age, this can only be done to a very small, rotating set of specialists, so this will significantly reduce the pool of available responders, making many of the above options far more likely, since the ship is not no longer able to select from a pool of possibly tens of thousands. 9. **Defrosting is slooooow** Taken to an extreme, if it takes a year to defrost someone safely, and a year to fully refreeze, then the ship could always have one person in a state where they can be defrosted within a day, in return for having 700 in states between thawed and frozen. You can try for better redundancy, but even if you triple the number of people who are half-defrosted, you're really only reducing that "within a day" to "within 8 hours", which doesn't really gain you all that much, if the ship is assumed to be able to handle anything in the shortest term (hull breaches, fires, etc). 10. **Who watches the watcher?** Someone is *always* awake. All passengers serve shifts as Troubleshooter. In a 10,000 year flight with 10,000 passengers, they have to do a year of service. A bit more, as if someone dies or goes mad, their replacement will be defrosted early. You could double up for redundancy, but that doubles the time they have to serve, increasing the chances of death and madness; and a year isolated together means they might fight. Worse, in 10k people there'll be some predators, murderers, etc: best to just keep only one person awake and monitored at any time, or some will end up victims. Options 5, 6 and maybe 10 seem to come closest to the intent of the original question: they want someone who has the title of troubleshooter to be the only person woken. It seems like this gives a lot of scope for the kind of character that could be chosen. The title could be given to people who didn't get onboard by merit so couldn't get another role; or were trained and augmented specifically for this kind of role; or just accepted the role in return for a 10% discount on their ticket. Or whatever works for your story. If the role does not have to be one they signed up for at launch, but rather one the ship can assign, then it could pick according to some other heuristic, whether most senior, most able to handle novel situations according to their psych score, closest to current consciousness and so easiest to thaw... whatever works for your character. This gives scope for a nice "you chose me because WHAT?" moment as the character discovers that the complimentary heuristic it thought was used, was instead a far more pragmatic and even insulting heuristic (most disposable, least likely to be useful at the destination, most likely to be accepted as a ritual sacrifice by demons...) For serious problems, though, we're left with a followup question: **Why doesn't the Troubleshooter just ask for backup to be thawed?** The ship could have defrosted others, but did not. The Troubleshooter is faced with a problem: why does he not defrost others? 1. **Small problem.**, or so it seems. One roach? No need to wake anyone even from a regular sleep for that, let alone hypersleep. Little does our hero realize it's not a roach but an invading blah-blah. 2. **No authority.** The Troubleshooter, as an essentially honorary title, has no authority to actually order the ship to defrost anyone. This implies a programming oversight that they would be woken in the last resort (perhaps the "last-resort waking" was moved from "captain" to "troubleshooter", but the captain's access permissions were not copied over to that new role), and also suggests some frustrating conversations will be had with the onboard AI (I'm sorry Dave, you do not have access to do that."). 3. **Broken systems.** The defrost system is broken. How did the Troubleshooter get defrosted? Well, maybe he accidentally broke it on being defrosted? Or deliberately, in a fit of rage? 4. **Defrosting is slooooow.** If it takes a year to defrost someone safely, and a year to fully refreeze, then the ship could always have one person in a state where they can be defrosted within a day, in return for having 700 in states between thawed and frozen. 5. **It tried, they died.** Perhaps the ship tries for redundancy, and defrosted three people at once... but two of them were dead, in a vegetative state, etc. This is kind of an overused trope, though. 6. **Defrosting is slooooow.** The Troubleshooter CAN request backup, and the ship is preparing the *true* specialists as fast as it can, but it will all arrive far too late to be of any use whatsoever. But that depends on the situation. In some emergencies (fighting off boarders, for example), more hands are more useful, even if unskilled, so defrosting whoever can most quickly be decanted would be of value. These aren't exhaustive lists, obviously, but they're what I came up with. [Answer] There is only one Troubleshooter for the same reason you only run one virus scanner on your computer: **A Troubleshooter in action exhbits similar behaviour to what a Troubleshooter is meant to fix.** Their nature means that they have to exist outside of any kind of hierarchy since they have absolute access to the entire ship. Two working at the same time creates a logical error if they disagree, and redundancy if they agree. They are probably not good team players. Multiple ones to wake up "one after the other" doesn't work because whilst one is active, their probing of ships computers, using security bypassed etc. is the kind of thing that would wake up another Troubleshooter. The simple solution to block any Troubleshooter from waking up whilst another is active was tried at first, until a ship was lost due to a false "Troubleshooter active" signal preventing any from waking up. So under no circumstances must anything block the Troubleshooter from becoming active if needed, and under no circumstances must there ever be two because they'd be working against each other more than with each other. [Answer] # Training and Augmentation are Prohibitively Expensive, and the Troubleshooter is already Redundant You say your troubleshooter is highly trained and augmented. Perhaps that training/augmentation will be almost certainly required to make it to the destination (e.g. they are one of only a handful of people who understand the xyz-drive because they spent 20 years studying it, they have the entire ships blueprints/mechanics stored in their brain through augmentation so they can work through problems un-augmented people never could, augmentation allows them to "communicate" or direct connect to the ships computer to change many systems at once which is very important to time-sensitive catastrophes etc.). Perhaps this training/augmentation is so incredibly expensive that training/augmenting a second person would put a massive dent in the profits - and why would this other highly trained/augmented person do any better than the first? Sometimes there are simply too many cooks in the kitchen - if the troubleshooter knows everything (due to his training) what good would additional people be? We only need multiple experts on an expedition because no one human can be an expert in physics, engineering, mechanics etc, but with augmentation and extensive training, maybe one person could be (and the computer is always there to help them out too with calculations/reference manuals etc). In that case additional people would only get in the way and may prevent the troubleshooter from doing things in a timely fashion - sometimes you just need executive control and your subordinates are unlikely to come up with anything better anyway. I really enjoyed other users ideas about how putting a person into stasis can only be done on planet/or is very dangerous to do in space, so waking up is a death sentence - though it does mean that your character has to die at the end (or the story ends knowing he will die alone) - so my idea may be useful if you don't want to go that route. EDIT: After reading a few comments about how "unrealistic" it is to only have one troubleshooter I'd like to point out that modern airliners are certificated to be operated by 2 pilots - there aren't 10 backup pilots, or on-board doctors (despite people having serious medical events while flying), or engineers - they have a low chance of being needed and so aren't worth the investment. On the "starliners" the computer flies the ship and fixes things (probably with a backup computer) so the troubleshooter is really already redundant, they're probably just a engineer/mechanic with knowledge and experience - who else is needed? A linguist in case you run into aliens? Unlikely. A Doctor to treat all the people (in stasis!) when a computer controlled robot could do much better? A physicist to calculate new trajectories in the infinitesimal chance that an asteroid pulls them off course but somehow the advanced computer (capable of interstellar flight!) can't recalculate things? [Answer] Every little extra bit of weight is extremely expensive in space travel. You aren't going to create huge spacious pressurized rooms for people who are going to be asleep anyway. You're going to pack them in like cargo and not wake them up until there is a breathable atmosphere outside you can unpack them into. Only your troubleshooter has enough space to open his pod, get out in a heated and pressurized area, and don a space suit. Never underestimate what a corporation will do to save money. [Answer] Do you have any need for all ships to be stuck with a single troubleshooter, or is it only this one specific voyage in the SS Minnow that needs to be damned? Of course, ColonyCo corporate rules normally *require* two troubleshooters to be activated in the event of any major emergency, so that the person isn't alone in a dangerous situation. And more importantly so that the lead troubleshooter can get code review on any changes that they need to make to the ship's configuration so they aren't using their administrative privs all willy nilly. Dave and Gary were all set to be the employees assigned as troubleshooter for this mission. Both were pretty stoked about the extra pay for being oncall while sleeping, even though almost nothing ever actually goes wrong. But, the day before launch, Gary quit and decided he's getting back with his ex and setting down on Titan to focus on music, so he never showed up for work on launch day. Oh well, that's why the company has multiple people assigned to each mission, so there's Dave as a backup! Under the circumstances, they launch anyway and hope for the best, despite being short handed because Dave *was* the redundancy. What else was ColonyCo gonna do? pay for hotels on Io until they hired *another* technician, hire them, get them up to speed, get them an admin ac count, etc. It'd take weeks, at least, and there would be a penalty in the contract for not getting the farmers to Xerblox IV for peak growing season. If you need a more general reason for very few people being eligible for the wakeup call, blame Tara. She was one of the dozen technicians with admin access on a starliner last year, but she used it to watch a person in stasis that she thought was cute. A data breach leaked her recordings of the cute passenger. Once word got out in the aftermath of the data breach that permissions were being handed out willy nilly, there was a lawsuit. Lawsuit led to a consent decree with the Star League government that there would be yearly audits by an external auditing firm to ensure that nobody has full access to ships systems except the absolute minimum number of people. Getting a new employee access too be able to be a technician involves a complete background check, submitting paperwork to company lawyers, registering them in a system, etc., and you can only register somebody for permissions if there is a specific need because nobody else can do the necessary work. Of course, the government was really only thinking about local stuff when the lawyers were hashing out the details. If somebody in the solar system needs emergency permissions, you can do it in a few hours. If somebody on an interstellar flight needs permissions it could take years because old rules are still in place, and it would be a bureaucratic mess to actually get things updated. Everybody knows it's a dumb rule, but nobody wants to be on the hook for another data breach lawsuit, and problems almost never happen on those reliable colony ships... [Answer] The risk of re-freezing is too high after being so recently un-frozen. It's best to un-freeze one person at a time so that they can decide if others need to be un-frozen. Later, after the problems escalate, a problem with the un-freezing system prevents them from un-freezing others. So it becomes just the one aboard who is awake dealing with all the problems alone. [Answer] The emergency detection system is sh\*\* and triggers all the time, so at some point the emergency crew did a patch-fix to only wake one person, which gets randomly chosen from the emergency crew. Sure, they could have tried to actually fix the false-positives, but that would have been hard. And they really wanted to go back to bed after having been woken up from hypersleep for the third time in a row. [Answer] The troubleshooter has a direct neural interfaces with the ship's systems. They become intuitively aware of damage to the ship, although there are many areas where they lack complete instrumenation. They can perform many actions just by concentrating on them for parts of the ship that are working correctly. However, they often need to get their hands dirty to fix broken systems. Ships experimented with having multiple troubleshooters but maintaining the discipline to work when both jacked-in to the ship's systems, caused severe psychological trauma in several troubleshooters. Finally, following an AF447 type disaster, the board of inquiry recommended that ships should only have a single troubleshooter. This recommendation has been followed so long it has become folklore of the Troubleshooter's Guild. Nobody would dare suggest changing it, as they might risk facing a boycott. [Answer] Maybe the company that owns the ship has something to hide. The whole crew is asleep they'll never know about anything that goes on during the trip, and that's the way it needs to be. Maybe they're doing something illegal along the way, or maybe the trip isn't quite as advertised. It could be something small like saying they're traveling a longer/safer route (time doesn't matter with Cryo) but instead they're taking a shorter, more perilous route to cut fuel costs. Or the *real* business is drug trafficking, which is handled by the troubleshooter on the way. Either way, they're hiding *something* and to limit the risk of the truth getting out, they only have a single troubleshooter. [Answer] **It would be stupid to only have one troubleshooter** The part of the ship with the troubleshooter in it might explode. You need backups. Also, the emergency could be the ship broke down and landed, and everyone needs to wake up. The option should be available to awaken more. **It's too costly to wake up more than one person** There are substantial health risks and extra costs to someone being woken up and refrozen repeatedly. A pod that allows this is a lot more expensive than one which does not, and there's a risk of brain damage if this is done too much. Ideally, one person will troubleshoot issues. **The troubleshooter isn't expected to be solving the issue, the bots will** The troubleshooter will be managing the on board repair bots. They don't need extra people. They simply need to control the bots to do so. They have all the manpower they need. **For your specific story budget constraints could mean only one was left** It might be expected that you send ten troubleshooters, to guarantee a 99.9999% chance of mission success. But, the corporation calculated that with just three troubleshooters there was still a 99.9% chance of survival, and that average profit margins would improve 6%. However, on this trip there has been an unexpectedly high error rate, and the other two troubleshooters can't be woken up because there's a high risk of brain damage from another wakeup. Now, because scarce resources have been expended, there is just one hyper competent person in charge of the ship, and no one to back them up. **The corporation doesn't trust most individuals, and so won't wake them up so long as the troubleshooter is up.** Due to internal politics and competition, the corporation fears there may be saboteurs and traitors aboard. As such, so long as the troubleshooter is awake, it won't wake up others. It could, but it won't so long as things are fine. And things are fine! System reports say that there are three available troubleshooters, and the on board supplies of robots and machines are excellent. **What do you mean those robots are trying to kill the troubleshooter?** Such reports that a robot of our corporation could go rogue are flawed, and clearly the work of saboteurs and spies. You're not a saboteur are you? [Answer] Going on a colonyship is a risky endavour. Big chance it never reaches it destination. When it reaches it's destination you have a hard life in front of you. Also you have to say farewell to all your loved ones. Normally only very poor and low-educated people are desperate enough to go on such a mission. It's very hard to find a smart, well educated person willing to be a troubleshooter. [Answer] ## The system **can** normally thaw more than one person, but it can't right now. The problem that got the trouble shooter thawed in the fist place was damage to the life support systems, and until it is fixed the ship can't support more than one active person. there are two ways to handle this. 1. the ship is only keeping the first troubleshooter alive based on limited stores and the recycling system is not working at all. there is not enough extra for another person, and even the original trouble shooter is on a ticking clock. 2. the life support system is barely working and is just barely managing to support one trouble shooter, until the system is repaired the ship can't recycle oxygen or create food fast enough to keep up with extra people. [Answer] **Losing Time** What if the hibernation/wake cycle is rough on the human body and takes about 10 years off of someone's life? That would have all sorts of interesting implications. [Answer] **Coding Error** Emergencies requiring one or more troubleshooters to be woken up are rated on a scale of 1 to 10. The initial design specification passed to the programmers had been for the severity to be rated 0 to 9, but this had later been decreed confusing by management, due to a "what the heck is a 0 severity?" comment in a project workshop meeting. Due to the urgency of the colonization ship's departure, the full range of emergency contingency tests had not been carried out, and obviously a level 10 was the hardest to recreate in a test environment. Unfortunately, some early development code expecting a level 0 to 9 had made it into the production system. This code reads only the final character of an error string passed to it by the code that triggered the alert, and hence read the level "10" emergency as a "0", and had then triggered the process that wakes only the most unimportant troubleshooter on the ship. You then have a classic unqualified and unwitting hero who must improvise and work against the odds to save the day. [Answer] Your troubleshooter is a cybernetically enhanced individual (if your familiar with Star Trek, think of the Borg, and also of Seven-of-Nine, [who had to actually manage Voyager for an extended period of time while everyone else but the holo-doctor was in stasis](https://en.wikipedia.org/wiki/One_(Star_Trek:_Voyager))). The cybernetic enhancements give an individual the ability to be an expert in multiple problem domains that would typically require multiple people to address. The cybernetic enhancements also give direct access to the computer, which allows for near instantaneous communication with systems for diagnosing and addressing problems. It also ties in nicely with their unfettered admin access. So why is there only one troubleshooter? First, finding someone that is physically/mentally/gentically compatible with the technology is difficult in the first place. Finding someone that's willing to take on the level of responsibility necessary for the task, that is also psychologically suited and willing to give up their current life, is next to impossible. So they are an extremely limited resource and are a source of production bottleneck for the number of ships launching. In other words, it's either more troubleshooters per ship, or more ships, not both. Why troubleshooters and not just bring teams of experts out of stasis? As mentioned elsewhere, the process of going into/coming out of stasis in transit may be impractical for regular people. The enhancements of the troubleshooter circumvents this. [Answer] Is this for a one-off, or possibly a series? You might need these absolute rules to be more flexible in future installments... From your wording in the question, the situation has a humoristic slant. I think the only plausible approach is to have multiple troubleshooters available, unless you're fine with caricatural corporate greed having reduced failsafes to the bare minimum. You could go with catastrophic failure that has left only one troubleshooter. Or with a sci-fi-heavy explanation for why waking up people during travel is prohibitive. But my personal suggestion, especially if this is humoristic, is that the ship wakes up a single troubleshooter to assess the situation. But **this** troubleshooter, in **this** situation, decides for whatever reason that **he's gonna solve everything by himself**, no matter how far things degrade. Maybe there's bonus pay that he wants to keep to himself. Maybe he wants to prove himself to his superiors after past mishaps. Maybe he's extremely overconfident and full of himself. Maybe he hates his coworkers. Maybe he takes the policy of waking up as few troubleshooters as possible *way* too seriously. In any case, the troubleshooter is boneheaded and will absolutely never decide to get help, possibly to the dismay of the ship computer if the story allows. [Answer] You may not be able to find a convincing reason to wake only one crew member during an emergency as a general procedure. So maybe in your story, there are particular circumstances as to why only one person gets woken. Perhaps in your story, there is a leak in atmosphere, and the ship wants to conserve life-support resources. If the ship wakes everyone, they're all breathing again, using up the rapidly disappearing oxygen. So, the ship wakes up only one person to solve the problem. That person can wake up additional people if they decide its helpful. Or, if your ship is a large colony ship, maybe there was structural damage to the section where most people are kept in hibernation. If they are woken up, they hop out of the pod and are sucked out into the cold void of space. So, the ship does some calculations, and wakes up only one person, who is sleeping in a different part of the ship, where the ship's computer is confident they won't immediately die upon waking. ]

[Question] [ In Britopia there were the Leftists who believed motorists should drive on the left and the Rightists who believed they should drive on the Right. The vote split exactly down the middle and it was finally decided that there would be no rule at all. In the end it was further decided that there would be no traffic rules of any kind: no right of way at junctions, no speed limits, no parking restrictions and so on. **Question** In this 21st century country what is the best road vehicle to have. "Best" means the most likely to get you from A to B in the shortest time whilst remaining alive and healthy. Bear in mind that other laws exist so you can't deliberately murder other motorists, by shooting them for example. The laws that pertain to collisions etc. are very similar to those applying in pedestrian areas. There are no rules-of-the road in pedestrian-only areas but you are still not allowed to run around waving a chainsaw and threatening other people. --- **To those who are voting to close** because the question is 'too broad', I'd like to point out that I'm simply asking for the most suitable mode of transport as defined by getting from A to B as quickly and safely as possible. I don't think that could be any clearer or better defined. In fact I'd claim that it is more clearly defined than the majority of the questions on this site. If I left out 'safely' or left out 'quickly' it would be a completely different question. **To those who are voting to close** because "*answers to this question will tend to be almost entirely based on opinions, rather than facts, references, or specific expertise*", you obviously haven't read the answers because there are facts, expertise (personal knowledge) and references in several of them. Most questions on WB get some answers that are of lower quality but that isn't the fault of the questioner. [Answer] **Horses** They are smart enough to not crash themselves on others, even if their riders are completely drunk. [Answer] While the scenario painted may seem quite bizarre and downright deadly, the fact of the matter is, minimal traffic regulation does not *necessarily* mean you need to drive an Challenger 2 Tank just to make it home from your downtown office park every day! As a matter of fact, we in the Traffic Tabulation Bureau have conducted a comprehensively exhaustive study of various traffic patterns around the world and have come to the conclusion that, contrary to all expected laws of physics, a small motorcar is every bit as effective as a tank when it comes to negotiating the ebb and flow of every day Britopian traffic. We therefore recommend that Britopian Royal Commission for Travel encourage the use of diminutive, and above all, cute motorcars and furthermore, recommend an advertising scheme encouraging all Britopians to obtain at least one motorcar per adult per household and the use said motorcar for every conceivable use, from commuting to work, to long distance travel to going down to the shops or even everyday leisure drives. The more cars Britanopians place on the nation's motorways, the more crowded, and thus slower and safer, every Britanope shall be! *[(Cue patriotic music!)](https://www.youtube.com/watch?v=7hNuqm-GOO4)* [](https://i.stack.imgur.com/yg7WJ.jpg) And the reason is quite simple. Our Bureau have determined that a simple law of physics applies: *the denser the traffic, the slower the flow*. What this means is that, even when an entirely chaotic, semi-brownian, system is implemented, a much more organic flow is created. As you can see, it is quite possible for large lorries, busses, jeepneys, pedicabs, scooters, hand carts, random animals, pedestrians, rickshaws, trams and motorcars to interact quite safely at lower speeds. Sure, it may take you two hours to travel five miles, but the ride will be very manageable and very unlikely to cause major mishap. Kindly review our *Minimal Traffic Regulation* test videos: [Cairo](https://www.youtube.com/watch?v=l6wb7Sb2lNQ) [Delhi](https://www.youtube.com/watch?v=GjCxg07WGwg) [Manila](https://www.youtube.com/watch?v=bInN79dYdfg) [Addis Ababa](https://www.youtube.com/watch?v=VPbUpdmAfck) As you can see, every major jurisdiction that implements our system demonstrates how terribly effective it truly is! [Answer] It has to be a motorbike... Having just been to the Philippines (and I imagine many southeast Asian and over populated areas are also like this), Motor bikes are everywhere and small enough to slip between cars, yet large enough that a car won't hit you because your going to damage it. In particular, I would recommend a Dirt Bike because it has the capabilities for you to perform more stunts which would be great in making everyone in traffic hate you as you drive over their cars. Firstly, there is no way a Car, Tank, truck or large vehicle would be able to win. While they can force their way through traffic, in dense enough traffic conditions they have to compete with other large vehicles of equal caliber. They will also face problems when turning and have slower acceleration times and speed limits since it takes them so long to accelerate up to speed and slow down (they can't go too fast or they won't be able to stop if they get cut off or make a turn). For cars in particular you can image that they aren't really going to come out on top. Just go stare at some peak hour traffic and you will understand why. Animals also aren't going to work well. Animals are smart enough to know how to get out of the way and vehicles could easily force an animale (horses mostly) into a very dangerous situation by slowly pushing up towards them or into the side of them to force their way out. Your horse will also be freaked out by the constant noise and honking. Thats also combined with the fact that a horse isn't going to work over larger distances or be nearly as fast as a normal vehicle and still simply stop walking when it needs to take a piss in the middle of the road. So it comes down to our 2 wheeled friends, Bikes, scooters and Motor bikes. What about 3 wheeled vehicles? well they are larger than 2 wheeled vehicles which means in dense traffic conditions they will need to be more carefule and can't slip between the gaps a 2 wheeled vehicle will. In addition, most 3 wheeled vehicles end up being modified versions of 2 wheeled vehicles (I swear the only ones I've seen are basically bikes with an additional cart added or the back wheeled switched for two, or the unstable one that falls over from Mr Bean). Scooters and Motor bikes push out Bicycles simply because they are motorized. They will be able to go faster for longer and while they might not be able to squeeze through the smallest of gaps, your going to be able to comfortably move 10KM, 50KM or 100KM easily on a motorbike when compared to a manual bike (There are no road rules, so bike lanes are basically lanes for any vehicle now). So out of a Scooter and Motorbike, I would say scooter wins simply because its cheaper. It can make riskier moves because you don't need to worry as much about replacing/repairing it. I still recommend a Dirt Bike, simply because people use it to perform stunts. You could for example, get yourself ontop of another vehicle and ride over it, or just sit there for the ride while it takes you to the location you want. [Answer] Bikes. Although [humans are not as smart as horses when it comes to not crashing against each other](https://worldbuilding.stackexchange.com/a/136772/21222), bikes are cheaper to acquire and maintain, and will generally keep the streets clearer. Drivers can also benefit from the exercise. Also, this being about Britain, I had a certain song from Queen on my mind while typing this. > > Bicycle races are coming your way > > So forget all your duties oh yeah! > > Fat bottomed girls they'll be riding today > > So look out for those beauties oh yeah > > > Edit to address this comment from Julian Egner: > > This would a great answer if all drivers would have to use the same transportation type - but it is no so good if all the others use big cars and you are on your bike. even with all the traffic laws it is sometimes not easy to avoid crashes, which would not end well for the biker. > > > Bikes can navigate parks, squares, people's backyards, sidewalks, shopping malls, food courts, piers, subway platforms etc. with more ease than carscitation needed. Just stick to where it's safe. [Answer] It seems all the individualists have missed a trick here. You have to get from A to B as fast as possible when there are no traffic laws. Which means if you want to get anywhere, the only valid answer is not to use the roads at all. *Admittedly it's only a rail"road" in US English, and we're in the UK* [](https://i.stack.imgur.com/e7SNf.jpg) The real answer in the average city is of course to walk. Average traffic speed is only 8mph, and it doesn't take much before walking is faster. Removing traffic laws would easily bring the whole system to a standstill and make walking by far the quickest way to get around. [Answer] **A self driving car, of course!** No need for rules, let the cars work it out between themselves automatically. Or they can automatically work out trajectories of human driven cars and route around them far faster and more efficiently than a human driver. [](https://i.stack.imgur.com/OyMjB.jpg) [Answer] Since this is more or less Britain, I'd vote for the [Challenger 2 MBT](https://en.wikipedia.org/wiki/Challenger_2) [](https://i.stack.imgur.com/zhWiR.jpg) It will simply roll over any "normal" automobile, leaving behind a trail of flattened Jags, Bentleys, Land Rovers, Beamers and Morris Minors. EDIT - And the very occasional Reliant Robin. EDIT2 - And if "quickly" takes precedence over "safely", the [Mythbusters episode](https://www.youtube.com/watch?v=pJdrlWR-yFM) suggests that the rocket-powered Reliant Robin should be considered. [Answer] Contrary to popular belief, more traffic laws makes roads less safe (1, 2). Many places are now reducing the amount of signs to make it safer, and to make sure that attention is on the road and other drivers rather than each other. No rules is taking that to the extreme, but its not completely unimaginable. Ever been to India? I have and it's true: they do not pay attention to any markings on the road or any signs. The only rule they semi-follow is what side of the road they drive on, but whenever the traffic allows that rule is out of the window too. Strangely enough, driving there felt like one of the safest experiences I've had as people constantly communicate with horns and their movement, but I hadn't experienced a situation where there wasn't adequate time to react and safely get through. So if a leftist leaves the house and he finds himself encountering rightists he'll join them for the time being, or vice versa. Any intersection that cannot be overseen will be slowly approached in case someone from another direction comes at you. comparable to small roads or similar people will decide on the spot who will pass first and who will move aside, or in this case chose who will temporarily change being a leftist or rightist. In the end the best car isn't going to be the smallest or the biggest, it's going to be the most visible one with the clearest communication of direction and intent, possibly with a set of horns declaring "watchout", "you go ahead" and "I go ahead". So keep those lights on your car in good working order, strap in and drive safe. Edit: for anyone struggling with the "less rules means more safety", I mention this is up to a point, culture on the road means more and the conclusion remains true: the best car will be the most visible one with the clearest signals of direction and intent. (1) <https://www.google.com/amp/s/amp.theguardian.com/commentisfree/2016/feb/04/removal-road-markings-safer-fewer-accidents-drivers> (2) <https://www.drivingtests.co.nz/resources/signage-clutter-what-is-it-and-how-is-it-reduced/> [Answer] Planes/Helicopters/Gyrocopters. You are not engaging with motorists then, creating your best chances for survival. An example in a similar vein is the 'Gyrocopter Captain' from Mad Max who avoids the drama on the ground in exactly this fashion. Edit - added my comment into the answer. Yes, you have multiple other road users on the ground meeleeing with each other, a character with some level of higher reasoning could take to the sky, however along with your dystopian road rules there's no reason you couldn't also stipulate that privately operated aircraft had to remain within a certain distance from standard road systems, thus creating manageable flight patterns. Clearly not everyone would be taking to the sky, and you can still land/taxi on roads. [Answer] In addition to other good answers like bikes, I'd say the [Knight Bus](http://harrypotter.wikia.com/wiki/Knight_Bus) would make a good choice. I read somewhere that J.K. Rowling has spotted it in Britain already ;-). [](https://i.stack.imgur.com/xszWM.jpg) > > The Knight Bus is a triple-decker, purple [AEC Regent III RT](http://en.wikipedia.org/wiki/AEC_Regent_III_RT) that assists stranded individuals of the wizarding community through public transportation. It operates at a very fast speed and obstacles will jump out of its way. To hail the bus, a witch or wizard must stick their wand hand in the air in the same manner that a Muggle might do while hailing a Muggle Bus in the UK, though it is possible to book tickets for travel on the bus in advance. > > > Also, many country roads in modern Britain are pretty much one-lane, two-way roads that people drive down the middle of, and only slow down/go off to the side when traffic is approaching in the opposite direction. If there was uncertainty about which side somebody would go toward, a convention of using turn signals to indicate this could alleviate the problem. [Answer] The mythbusters have your answer, two of them actually. The biggest problem you have is there's only so much space on the road and you are creating a perfect storm for traffic jams. The only way to guarantee getting from A to B is to be able to clear the road as you go. the cow catcher serves the same purpose it did on trains, to push anything in front of them out of the way with the minimum energy. You can't get from A to B in a timely fashion without moving other cars out of the way. If someone gets hurt. Oh well, that's what they get fro driving something as unsafe as a car on the road. This society clearly doesn't care much about personal safety. [](https://i.stack.imgur.com/08Odt.jpg) [](https://i.stack.imgur.com/twQQY.jpg) [Answer] The question is describing a common situation in town fairs: bumper cars, or dodgems. A chaotic traffic situation, without traffic rules, sudden changes in general flow, etc... It works, and to memory, it is less lethal than standard regulated traffic. Apparently, in England, someone has already started thinking about taking the dodgem [on the road](https://www.dailymail.co.uk/news/article-6192587/Fancy-bumping-Driver-spotted-wheel-fairground-DODGEM-car-public-road.html). Also, for the skeptics, just remember that most of the UK can be considered flat compared to other European countries, hence no real terrain issues for these lovely little contraptions. [Answer] While someone has already mentioned a tank, its price tag puts it out of reach for the vast majority of the motoring public. The legions of unwashed plebs are Sempletons(pun fully intended) who require a far more economical option, so I present to you the [Bob Semple "tank"](https://en.wikipedia.org/wiki/Bob_Semple_tank) [](https://i.stack.imgur.com/gYFKH.jpg) An "armoured" superstructure to protect from the chaos a total lack of traffic regulation would produce. Its cheap and shoddyhomemade nature allows for easy DIY fixing on the fly, rather than having to be sent to some workshop or depot. No murder? Remove all the guns or install dummies in their place then, to hang your laundry fromput the fear of God into all those other wankers. Last but not least, low speed and reliability for maximum obnoxiousness towards everyone behind you on the road. [Answer] Okay so this is based on real experience with a real place that was, in a way, very much like *Mad Max* - had no rules and plenty of danger...[its still basically like that](https://www.economist.com/middle-east-and-africa/2010/12/16/still-hazardous) - and the vehicles we used. I choose these vehicles as: Though I was a **US**MC, I know all of these vehicles are available to UK groups (except possibly the MRAP); All drive like regular vehicles so not much special training involved in their operation; They are vehicles primarily not weapons (like a tank) so if some of the liability standards we currently use continue over (even though no "road rules") these could still be classified in the same manner as driving a truck (or car with HMMV): ### Option 1: HMMV (up-armored if possible) [](https://i.stack.imgur.com/xDMVd.jpg) "Speed is life, stopping is death" <- first words about driving in a combat zone I ever heard and they are true. As the rules state "you can't just shot or kill people" and cities (like London) would have very heavy foot, vehicle, and other traffic it seems to me that this would be a great option. One, it allows for ["bumping" cars and other objects out of the way](http://message.snopes.com/showthread.php?t=18488). Two, you don't have to kill people when hit with it (like a tank would likely do) Three, you can actually buy at least the un-armored version of this (and armor yourself if needed). Note - that thread is from 2006, the video is real, and there are some opinionated anti-military answers within. ### Option 2: Country roads? Use a 7-ton [](https://i.stack.imgur.com/OLIgK.jpg) The 7-ton is my favorite option (when I was deployed) - fast, was nearly impossible to get stuck, could drive over ridiculous terrain, ford full rivers, and it goes on. Beside that this would allow you to safely drive a much larger crew (10-15 people vs. HMMV's 4-6) or a lot of equipment around. In this case it has an added bonus, though armored versions are restricted [the actual military vehicles can be purchased](https://www.oshkoshequipment.com/) and many parts if repairs are needed. Only downsides to HMMV - not as small and "bumping" something with these will cause more damage. ### Option 3: MRAP [](https://i.stack.imgur.com/U3VBE.jpg) Okay, this is the last vehicle I have personal experience driving and it has one massive advantage - and that is, well...the picture explains it better than words can. This thing *will not stop* (without resorting to full on tank killer weapons). It is also now being offered to government (i.e. law enforcement) groups in the US so it is technically possible to get it but not really for civilians. *However*, it has two huge disadvantages - its **heavy** and doesn't do well off-road. Why is **heavy** in bold? Cause these things had so much weight they would (and did a few times on me) collapse the road you were driving on. The V-shape made them get stuck on dunes and bad terrain a lot more than the earlier vehicles too. Still if the goal is an urban road and point A to B quickly and safely - they'd be an awesome option. ### Option 4: [Joint Light Tactical Vehicle](https://en.wikipedia.org/wiki/Joint_Light_Tactical_Vehicle) [](https://i.stack.imgur.com/phZnc.jpg) This one is "if I could pick any vehicle, money is not an option but it should still be car-ish". This thing was just a dream when I was in and only came out last year - so it is certainly not possible to get as a civilian (most military units are chomping at the bit to get a few). However, a few of the guys I know who still work in Green have gotten a chance to at least look at it and say it is like they took all the best parts of the 3 other options and built the car of the future. So if its dream money and wish scenario... [Answer] A big "Spot" robot or something alike, big enough for you to be able to climb on its back. It's a boston dynamic robot that can walk through roads, clim sloped terrain, and that will lead you through forests. Avoid the roads when you can, if you must travel through a city, you can dodge other motorized vehicles by passing through pedestrian places. [](https://i.stack.imgur.com/YQBSy.jpg) <https://youtu.be/M8YjvHYbZ9w> On top of that, it's super cool. [Answer] **Either a police car or a tank** The "no killing" rule leaves room for interpretation, which needs to be exploited for the best answer. Also the question only asks to get from A to B not what happens afterwards. First let's look at the tank/bulldozer/anything armored option. Yes it kills people, but since there are no traffic rules, no sidewalk or park is safe for pedestrians and whether you are in a tank or a motorcycle or even horse, if you hit a pedestrian, good chance he will die (horses are dangerous, I have been riding). But in the tank at least you reach B. Who is gonna arrest you anyway? The police is stuck in traffic like the rest. Or are they? Situation two, the police can move fast through the traffic to stop any offenders. Well in this case the police car is the best means of transportation for you to get from A to B. Bear in mind the question is about a single person getting from A to B. Most of the other people are going nowhere. And I agreed that the question is too broad. What means no killing, is it OK to be arrested afterwards, can the police catch you some other way? [Answer] Solution 1 : Though all answers are considering the gravity factor and since its Britopia, there is no need to consider gravity. The best option I think is to just fly. Lets consider it as a space and in Space there is no concept of direction. Something like human carrying drones will be good to go anywhere. and Just like how the current air traffic is managed. Solution 2 : I recently come across the concept of elevated car [here](https://www.linkedin.com/feed/update/urn:li:ugcPost:6491831248430854144). So basically we have always either two states, elevated or none. None Elevated : [](https://i.stack.imgur.com/8Q86l.png) And Elevated : [](https://i.stack.imgur.com/tnrsp.png) We need to make sure that the when two vehicles are approaching one become elevated and one is non elevated. Also need to manage angel of approach to make sure one can pass another without damaging legs of elevated one. [Answer] It doesn't answer all the questions but if there's no left / right then having the steering wheel in the middle would be needed. McLaren F1 drivers would all be very happy. [](https://i.stack.imgur.com/NvOLq.jpg) [Answer] Interestingly the regime of Colonel Gaddafi considered exactly this problem (it is reported that their motivation was that a large number of road users believed in predestination via god's will, so there was no point looking at junctions: if god had determined you would die, you were going to die). They ended up designing a car with a large foam "nose cone". Normally this would be an issue for visibility at junctions, but if one's not going to look anyway, I guess it's fine. <https://www.autoblog.com/2009/09/02/libyan-rocket-colonel-muammar-gaddafi-designs-a-safe-car/#slide-333692> [Answer] Based on what the other people have said, I think a motorbike or a horse would work best in a highly populated urban city. You could also use three-wheelers. Because this is a 21st century society, self-driving cars would still not be affordable by everyone. But if the technology were more advanced, it would be a more feasible solution. In less populated areas, I would say agile sports cars like BMW street drifting cars might be best. However, more than likely a voter would change his or her vote such that there isn't a tie. Because, having traffic laws are better than having none, right? ;) [](https://i.stack.imgur.com/krDFB.jpg) [](https://i.stack.imgur.com/F5AjG.jpg) ]

[Question] [ In my world, magic is unavoidably unreliable, for example: You have a puncture. You cast a spell to mend it and with equal probability either it is mended or another tire is punctured. You are trying to save an injured person. You cast a spell. Either they are saved or you kill them. **Question** It seems to me that such a magic is completely worthless. Can anyone prove me wrong by suggesting a case where both the intended result of a spell and its opposite would both be advantageous? **Note** There is no way to make magic more reliable. It is just a fact. --- **EDIT** I have been asked to clarify the extent of the unreliability. It does not happen with mathematical precision but there has to be some proportionality. For example if I try to light a fire I won't accidentally freeze the entire continent. Examples of how things might go wrong: I try to heat up my dinner. I end up with a frozen meal. I try to repair a broken vase. Something else of a similar size falls off a shelf and breaks. **Explanation** The supreme being has tasked sprites with keeping magic balanced. There must be an equal amount of desired results as undesired. The sprites however have limited intelligence and a short attention span. Therefore to make their job easy they apply this 'balance' to each spell as it happens. They do their best either to comply or to do what they perceive to be the opposite. They are not mathematicians, they just do their best to maintain balance. Sprites flit around in the spirit dimension so you are very unlikely to get the same one for two spells in a row. Magic is fairly small scale. It relates to everyday life. You can't use it to make the Sun disappear or even make a person disappear. The spell has to be 'plausible' and within the capabilities of a sprite. **EDIT 2** Some are trying to get me to redefine 'unreliable' as 'predictably wrong'. However those are quite distinct concepts. Sprites have autonomy and can use a certain amount of discretion to suit the circumstances. Sprite A might think "opposite" of "cast fireball at enemy" is "cast ice ball at enemy" but Sprite B might think the opposite is "cast fireball at spellcaster." Most sprites would treat a simple coin-toss as resulting in heads or tails. In probabilistic terms your spell won't make a difference. However life in general isn't that simple so they have to use discretion in the limited time they have. Sometimes they will make a snap decision that is roughly opposite in their estimation. As a guide, imagine that you are a sprite. You have no vested interest in or sympathy about the result - what do you choose in a given situation to be the desired outcome or the opposite? Pick the most obvious and move on. [Answer] ## Sure, it's worth it in many cases. For instance, if your car is stranded in the middle of the wilderness due to a tire puncture, using magic to try and mend it would be reasonable. In this situation, the car having two punctured tires isn't any worse than with only one. You'll still have to make your way to civilisation on foot either way. On the other hand, in the best case scenario (50% chance, so it's not even unlikely), it'll be repaired, and you can complete your journey within the comfort of your automobile. --- Many similar examples can be thought of in the case of an injured person. Let's say one of your battle compatriots has been injured and you're about the be surrounded by the enemy who you know will show you no mercy. Well, then it makes perfect sense for you to attempt to cure him. Either he will recover and perhaps help your group stand a better chance against your foes, or he will die by magic instead of by the hacking and piercing of steel. --- There are all sorts of times where a partly broken object or person is no more useful than a very broken object or person. It's times like these that magic comes in handy. [Answer] ### If repeated castings are possible, then the odds just got a *lot* better. As [AngelPray points out](https://worldbuilding.stackexchange.com/a/142614/50): > > There are all sorts of times where a partly broken object or person is no more useful than a very broken object or person. It's times like these that magic comes in handy. > > > The corollary to this is that if you can keep trying repeatedly, and you're not significantly worse off with a failure, you'll eventually succeed. You went from one puncture to two? Cast it again. You have four punctured tires? Cast a spell to repair them all. Your car now has a giant hole in the middle? Cast it again. Eventually, you'll get your car back in perfect condition. Obviously, this won't work if the "bad" outcome is worse than magic can handle (such as killing your friend, if resurrection is beyond magical means), but in that case, you're back to where we started with AngelPray's quote. [Answer] It depends on how unreliable your magic really is. If sometimes your magic does what you want, and sometimes does the opposite, then you can make it do what you want 100% of the time (for certain spells)! 1. **Either way it goes, it still gets the job done.** There are a lot of ways of hurting people. You could conjure an enormous fireball, adding an incredible amount of energy to a localized area... or you could conjure a blast of ice, removing the same amount of energy. But burned or frozen, the enemy is still just as dead. 2. **Ignore the bad results.** Sometimes when you try to make a pebble glow brightly, it instead creates darkness. No worries; if you cast the same spell a bunch of times, you can throw away the "darkness stones," and hang on to the glow stones you made. Or, in the case of a punctured tire, don't fix just one - try to fix a whole pile, and sell the ones you fixed. And when you need to inflate it, a spell that removes all the air from the tire is easy to revert until you get the spell that fills it up. 3. **Make magical items.** Sure, sometimes your spell makes a potion of healing and sometimes it makes a potion of harming, but you can test the result, and people will buy both. 4. **Use spells that either work or fizzle.** Trying to make something do something it's not doing - a person fly, a dog speak English, a cat obey - will either work, or do the opposite... which is nothing at all. Sure, you're going to have to cast spells more than once, but you'll eventually get the job done. If you want to cause damage, that's easy; if you want to be constructive, that's a little harder, but carefully choosing what your spell does will ensure that after enough attempts, your spell will eventually work as intended. [Answer] Such a magic would be useful for those situations where you are not too concerned with the immediate outcome but rather the consequences of those actions. Rough example. There is a war. You don't particulary care who wins but you want the ceaseless fighting and killing to end. So you cast your magic on one side to win. Either they win or they lose...but the war is over! (And if the magic did nothing...try again) You have to trick the magic into giving you the *real* end result you want. [Answer] I suppose this depends if your 'opposite effect' is predictable. In combat you may, for example, try to fireball an enemy, or maybe throw them into the air; you may not necessarily be concerned if they end up frozen or pinned to the ground instead. But you may not want to risk casting the spells if other unpredictable outcomes are possible. [Answer] Use it as a weapon. Your mages go into battle and heal the enemy. Fix their high blood pressure. Congenitive heart defect or heart murmur? Cure their gout. If it succeeds the enemy isn't really better off, you aren't reviving a fallen warrior. You may also be able to cast it again until you do cause catastrophic or deadly injuries. If it fails, one less enemy. With a fifty percent success rate your mages will be racking up kills fairly quickly. [Answer] Statistically if you run the spell enough times you would eventually get what you want. 1. So you cast a spell to heal someone, but they die. 2. Then you cast a spell to bring them back to life but their body denigrates. 3. Then you cast a spell to turn their dust into the original person. 4. And so on. Of course the down side is that each time you fail you may need a better and better spell (and possibly more energy) to fix the accumulated effects of the failed spells. So in the long run those who can cast better spells and who have more stamina have a better chance of getting what they want. There is also the case of casting a spell that enables you to do something that was already very improbable. So I cast a spell to print out the lotto numbers on a piece of paper... There is a 50% chance that It doesn't work out and the paper disintegrates. Well that's way better than the one in a billion chance I had before. [Answer] Sometimes a simple corollary is the most efficient way to answer a question: > > People undergo surgery to fix something. Sometimes it kills them. > > > Surgery is a $21 billion dollar industry > > > [Answer] When it comes to effects whose opposites are also useful, it strongly depends on what "opposite" means when it comes to an effect. Hopefully it's not some kind of pseudo-intelligent monkey paw type of opposite. For example, if I cast a spell to induce current in a wire, is the opposite effect to induce an opposite current from what I want? If so, we just add a rectifier to the circuit, so the output current is always the same. We could also generate power pneumatically by casting a spell to double the pressure inside an air tank. If this tank has one-way check valves (i.e. a rectifier), we can control the flow of air and use that to spin turbines. It's even possible to build [rotational rectifiers](https://www.youtube.com/watch?v=-p8zrvU-cYEhttps://www.youtube.com/watch?v=-p8zrvU-cYE), so you could spin something with magic and have the output always be the same direction. Or magically kick a pendulum hooked up to [an escapement](https://en.wikipedia.org/wiki/Escapement). If any of these work, congratulations, you have infinite free energy and with that you can develop technology that is distinguishable from magic by being actually reliable. [Answer] Your magic is statistically useless **on the individual level**. If I have a band of soldiers, all wounded badly, then I don't have a fighting unit. If I do nothing, then over time they will either heal or die. In fact, until the invention of antibiotics and other modern medicine, the chance to die from a serious wound was pretty much 50:50 anyway. Your magic basically just accelerates this process. But that means I get a fighting unit back! It is now half the original size, but that half is healed and ready to fight. Very useful! So on the level of groups or collections, your magic is far from useless. [Answer] I'll not add more of the "use chance calculations" answer but provide a surprisingly still unique view on this subject. Your magic is what I think of as "aware magic". If you try to mend a hole in your Tire the magic (or the user of the magic) is aware of what a hole is, what a wheel is and how it needs to be to be "repaired", or how to punch a hole in another wheel instead of in the car door, the asphalt or the person casting the spell. So if you are aware of what the magic or the user thinks is the opposite you can use it. Example: you fill two large canisters with gas or liquid and connect them, put a dynamo in the middle and a release valve. Make the gas/liquid something valuable. Now you cast a spell on the contents of one canister to double its contents, increasing the pressure. If it succeeds then the pressure drives the dynamo as the pressure pushes the opposing piston. If it failes it will halve the contents and the opposing canister will now have its contents flow to the other side. No matter which outcome you get you get electricity, and probability says that because the gas creates an equilibrium, you are more likely to create more gas in the long run. If you get more gas and the pressure gets too high the release valve can be used and now you have created both energy and a valuable material, which you can store, sell or use. Sometimes chance will make you halve the gas content so much that you have to refill it, but with the stored gas from the times you generated too much you should be able to do this virtually forever. Another option: nuclear waste disposal. You cast a spell to rejuvinate the waste into useable nuclear fuel. If successful you need to buy less of the expensive nuclear fuel or get rid of it. If unsuccessful it depends on the outcome: * It disappears. Yey! No disposal and a lot of concerns put to rest. * It doubles. Yey! Double the nuclear waste means double the chance to purify it (even better if your spell can target the heap and have 50% chance success each time). This means absolute infinite energy for everyone, assuming magic avoids the Newtons law pitfall (which it usually does). * It becomes extremely radioactive. Well either you can use that for the nuclear reactor, or if he was alive Ghandi would know how to use that. <https://youtu.be/lQBV3-kwh5k> [Answer] Although gambling has come up, the answers mentioning it aren't going where the money is. Gambling *houses* make much money off people betting on the outcomes of (apparently) random events. Don't use your magic to alter the outcome of *a* game. Go into business as a casino specializing in games based on magic misfire chances. Then you're not playing a slightly tilted gambler's ruin. Related: sports betting. Related: stock markets. The *players* are playing a weakly negative sum game because the house takes a commission from every bet. It's much better to be the house in that story. --- This form of magic can completely overwhelm the [first law of thermodynamics](https://en.wikipedia.org/wiki/First_law_of_thermodynamics). Apparently, your magic *can* create or destroy energy (randomly choosing one or the other). Either way, without much effort, this can be transformed into a heat engine. "Magic, make this cylinder 100 K hotter." Maybe it's hotter. Maybe it's colder. Maybe its temperature is the same, but the other cylinder stored near it has warmed or cooled. If less entropy is produced by casting the spell than is removed by its effects, this is a win. --- The field of [risk management](https://en.wikipedia.org/wiki/Risk_management) (or more generally, the study of [risk](https://en.wikipedia.org/wiki/Risk)) is the study of when you would want to use this type of magic. If the negative outcomes are "cheap" and the positive outcomes are "fabulous wealth", i.e., if the potential benefits times their likelihoods outweigh the potential negatives times their likelihoods, it is rational to use this kind of magic. See also reversible versus irreversible decisions. [Answer] Unreliable Magic worth it as long as the risk, production and cost is under control within a sustainable amount. The sustainability can be subjective. Putting those environmental drawback aside. Nuclear power having risk of leakage and it is costly compare to gas and oil, but the power produced is far greater in 10x. Another example with unreliable magic in some other culture, [Strait\_Jacket](https://en.wikipedia.org/wiki/Strait_Jacket) treats Unreliable Magic as a kind of pollution. > > Due to an invisible contaminant called the "malediction", or simply the "curse", people who use magic too often are at risk in transforming into "Demons," or horrific, malevolent abominations of nature that become immune to ordinary weapons. > > > This is sustainable as long as the damage comes under control with a special mess cleaning up organization. One of the [scene](https://youtu.be/KzUdge4cBZs?t=246), the surgeon having magic overdosed in the operation theatre while using magic like x-ray. Potentially the x-ray benefit produces a lot more than the risk of having the additional bit of pollution. [Answer] It could be tremendously valuable in some scenarios, especially with a small amount of planning ahead. If you intentionally provide circumstances to make it easy for sprites to see a negative outcome, you can potentially mitigate the negative result. With the vase example: If you have a vase that you want repaired, precariously place several objects of similar size but less value on a shelf. If the spell fails, you break a worthless object. I wouldn't anticipate the sprites to have the time or intelligence to assess the value of an object, and value is arbitrary anyway, so your negative result could very easily be mitigated. You could even use it in your favor. If while making a cake you accidentally burn it, you can whip up some more batter and try to bake it using magic. If it succeeds, you have a perfectly baked cake. If it fails, your burnt cake is un-baked, giving you the ingredients to try again. [Answer] In the Coldfire trilogy, by Celia S. Friedman, magic is very wild. It can manifest just by a person untamed thoughts/fears, yet it can be controlled by very talented people. <https://en.wikipedia.org/wiki/Coldfire_Trilogy> One of these people is Gerald Tarrant, who is capable of controlling it beyond what anyone believes is possible. He can do it because of his very powerful mind, among other reasons. This isn't an exact 1:1 relationship with your world, but there's a lot of similarities. With about 1000 pages to each book, you should run into a lot of the same problems as your world. Even if not, it's a very good series and might give you some ideas anyway. [Answer] # Twilight City, gonna set my soul, **gonna set my soul on fire** Roulette has 38 slots. Betting on the correct one is 35 to one pay out. Except this magic just made the odds 2 to 1. Start with ten dollars. Bet one dollar on 25 and cast your spell. Spell works, rake in you money and make a moderately larger bet. Spell fails, and it lands opposite 25, or some other number, or even you accidentally bet on 24 instead. Whatever the case, you try again. By steadily increasing you bet with each win, while keeping up a reserve against losses, you can quickly make a huge sum (ain't exponential growth grand). Roulette not interactive enough? Try craps. Those both too slow? Most progressive slot machines start at about a 20K to one payout, and increase over time. Of course, cast some spells to keep the casino from noticing first. And now all you have to worry about is another caster at the same game. Or bankrupting the entire city. [Answer] ## Statistics are on your side here. There's a gambling algorithm that guarantees indefinite gain given: * There's no limit to how much debt you can be in * You can choose when to stop playing, and the house can't. Here's how it works: 1. You bet 1 dollar. 2. If you win, take your winnings and repeat from the beginning. If you lose, increase the amount you bet so that it is equal to 1 + the amount you owe. 3.Bet again. If you win, you recoup your losses and gain a dollar. If you lose, repeat step 2. Keep alternating between 2 and 3 until you win, then go back to 1. Continue playing until you have the desired amount. This is how your magic works. If you puncture a tire, try magic. If it fails, you have 2 flat tires. Try again with those 2. If you fail again, you have 4 flats. Try again. Eventually, the odds that you keep failing are so low that as long as each new spell fully reverts the damage done by the previous mistakes, you will eventually solve your problem. The only problem is when the stakes get too high and you *do* end up freezing a continent, or kill yourself so you can't keep going, or run out of energy: you don't have unlimited debt. But you can choose when to leave the table, which gives you a solid advantage. ]

[Question] [ This question is inspired by [Could medieval people produce automatic firearms if they had access to the schematics?](https://worldbuilding.stackexchange.com/questions/10610/could-medieval-people-produce-automatic-firearms-if-they-had-access-to-the-schem) I have simply moved it forwards in time as follows: In 2019 we receive an alien broadcast that tells us in detail how to make an FTL drive (or some other technology that we would have taken centuries to discover on our own). **Question** Is 2019 *technology* (not science) sufficiently advanced that given sufficient raw materials, we could make any conceivable human-scale artefact that the aliens specified? I say human-scale to exclude Dyson spheres or anything greater in size than say a pyramid. Specifically: We already have electron microscopes, particle accelerators, incredibly accurate machine tools, nuclear power,etc. Surely we could make anything that the aliens described even if we didn't understand how it worked. Or can we imagine something that we can't possibly make, given modern technology and manufacturing knowledge? To put it in different words. What manufacturing capabilities do we know that we don't have? --- **Notes** Assume that we can completely decipher the aliens' schematics and instructions even if we don't understand the science that explains how the thing works. The aliens have told us what the artefact does and which levers to pull etc. Assume we have the raw materials necessary and a huge budget has been allocated. **IMPORTANT** The aliens have been broadcasting this across the universe in the hope of helping unknown civilisations to have the benefit of their technology. By definition they must know the minimal level of our technology because if we didn't have electronics, we wouldn't be able to receive the message. --- **EDIT** I should perhaps have made it clear that the aliens are broadcasting this information because they *want* us to know how to make it (hence the detailed schematic). Therefore I was assuming that they would include software and any other required information that they think we needed. Presumably they could include the scientific theory behind the artefact as well. Remember this question is about our ability to manufacture the item, not about how to understand it. **EDIT 2** It's too late to change this now because people have already answered but I'll mention it. My original intention was that the aliens want everyone to have this technology. They are broadcasting it in all directions not just to Earth. Also they may have sent the message way back in the past. There would not be any chance for back-and-forth. As I say, I won't make this a condition. [Answer] > > Surely we could make anything that the aliens described even if we didn't understand how it worked. Or can we imagine something that we can't possibly make, given modern technology and manufacturing knowledge? > > > Yes, we can. Some things that come to mind: * it requires some really exotic material (say, heavy transuranics or dark matter). The aliens also have methods to locate or manufacture those, but we don't. So, we need to first build the machines that will build the machines that will build the machines... * it requires much tighter tolerances - say, one-nanometer etching capability. We still don't have that (not at any industrially significant level, at least). Aliens have machines that do this, but they also require the same capability, much as modern chip factories require chips to work. In both cases, we wouldn't need or be able to use the alien's XXVth century technology: we would need their 22nd century technology to be able to build their 23rd century machines that will enable us to build 24th century technology that will finally be able to use and build alien-current technology. You say we now have "everything" - from electron microscopes to X-ray beams. We do have those, but how do we know they're "everything"? Maybe the aliens discovered micro-gravitics and are now based on that. The belief that we had "everything" has already been declared "two or three times" in human history, and every time it turned out we were wrong. # the Rosetta transmission The exact problem in your final edit is the premise of Fred Hoyle's *A for Andromeda*. In that novel, the Andromedans begin their transmission with simple mathematics, physics and biology, detailing several ways of constructing a simple but very large XXth century computer. This "preamble" of the transmission is followed by the program code for the computer. The computer then inquires about a lot of further parameters of its latest builders, and from *that* it directs how to build the secondary stage initiator of the process - which will then direct how to build the tertiary stage (in the novel, the process gets disrupted at this point). So here's your answer - the transmission has to start from the very basics, and build up to complete proficiency. During this bootstrap process, some unforeseen circumstances may arise: for example Earthmen are the first race that, unbeknownst to the aliens, lack some specific very basic technology - see [*The Road Not Taken*](https://en.wikipedia.org/wiki/The_Road_Not_Taken_(short_story)) or Leinster's *The Greks bring Gifts* - or some [fundamental and otherwise universal feature](https://scifi.stackexchange.com/questions/79591/aliens-hiding-important-information-about-the-human-race-story-ends-you-don-t). Or just the drive to cooperate to use the technology for the good of all. Or the bootstrap process starts itself from a level too advanced (see above about tolerances). (Giving technology as a Trojan horse or as an existential poison is a well known trope - in addition to the Greks bringing gifts, there's a story in Asimov's Great SF Stories about a Earth traveling salesman who's doing exactly that). # other possibilities of non-achievability: *abhorrent* technology The required raw materials could include something that can't be easily duplicated or harvested, such as the brain matter of a healthy, full-grown adult of the species. In essence, human sacrifice. While this wouldn't be anything difficult for, say, an ant colony, or a hive mind (or even a technologically advanced Aztec nation), it would be regarded as abhorrent and forbidden by most human governments, and, at least publicly, denounced by all. [Answer] I have no real alien technology schematics at hand. The closest thing I can think of is the schematics of something it is not manufactured in the factory of my employer. Let's say it is the latest smartphone of a top notch brand. On those schematics I would see which parts I need and how to assemble them. Good so far. However, if I don't have access to the parts, I won't be able to assemble anything. I might have the raw silicon used to manufacture the microchips, but I will have no clue on what to etch in that chip. Even worse, the schematics do not include the software controlling how the parts interact together, unless the assembly is a purely mechanical one. The software is often the razor splitting an excellent product from an average one.\* In the case of an alien technology, it might mean the difference between a working copy and something resembling a cargo cult. '\* to detail on this, in the sector where I work many excellent manufacturers are protected from dishonest competitors simply copycatting their original products by the lack of knowledge on how the software has to work. [Answer] It could be one of many things: * A combination of sufficiently advanced **precision and size**. While we have the capability to manipulate individual atoms, arranging a football field worth of atoms is vastly beyond our capabilities. Or make it 3D and try to build a device with the volume of a family house with a precision of a single atom. Just letting the air come in contact with the half-finished product would ruin it, not to mention any interference from the building process (outgassing or fumes from the atom-manipulators themselves for example). * The design could be extremely **sensitive to any kind of radiation**, including gamma rays and X-rays. Maybe the aliens have no problems with it due to some local spatial anomaly or having a home planet devoid of any radioactives and with a crust made of lead, so they can assemble and operate the device underground. But we lack the capacity to create an absolutely radioactivity-free environment due to being bombarded with it from space and from below as well. Even our bodies are radioactive. * As an alternative to the above, make the design complicated enough and **sensitive to** even trace amounts of **electromagnetic radiation** of a very wide frequency spectrum. Good luck building anything complex and precise without using any electronics, letting light touch it or getting human brains and nerves nearby. * Anything sufficiently complicated and **time critical**. For example the aliens might have devised a way to stabilize and thus preserve the (for the design) essential extremely unstable isotopes that would normally decay in milliseconds, but the process requires an obscene amount of this isotope. We might be able to synthetise this isotope, but at most a couple hundred atoms at a time, with at least hours between two attempts. Oh, and the synthesis can only happen in a particle accelerator deep under Switzerland, while the assembly process needs a zero-G environment. Or, as suggested by *vsz*: antimatter, as we can only create a few atoms at a time, and neither the storage nor the transportation is solved as of yet. * **Resource scarcity**: the schematics might require a greater amount of some extremely rare but stable element than is estimated to exist on Earth. Like Radon, Tantalum, or something else. *(I don't have the numbers at hand, so my estimates might be off the error chart, sorry).* Even if this element occurs in a quantity large enough to construct the device, it could be a consumable for it and thus it could be simply not viable to operate the device for any useful purpose without strip-mining half of a continent or distilling the Pacific Ocean for the required "fuel". * *Suggested by @bukwyrm as comment* **Purity**: If the blueprint calls for materials at or near 100% purity (i.e. absolutely no foreign contaminants, maybe not even a single atom) then this criterion could also render the manufacturing process impossible with today's technologies. * This might be not what you are looking for, as it is less technology than politics, but **distrust** could stop anything we normally would be capable of doing. If a large enough fraction of humanity would become convinced that the construction of this device would be risky, hazardous or simply require greater than acceptable sacrifices from their part, they could stop the project if the required funds and logistics make it vulnerable. Think of protesters chaining themselves in the paths of trucks, blocking the entrances of engineers working on the project, harassing support personnel until they quit, assassinating leading scientists, campaigning to politicians to stop funding the project, sabotaging necessary equipment or facilities, etc. [Answer] **You're making the assumption that we could read the schematics** I'm an electrical engineer in microelectronic design. When I compare the schematics that I create to those of a 1973 pinball machine my father owns one thing becomes incredibly obvious: Someone only versed in the 1973 schematics would have no idea *at all* what they were looking at when viewing my designs. **First problem:** The odds that another intelligent species used exactly the same symbols for the devices as we do are inconceivable. But, as any cryptologist will tell you, if all we have is a substitution code, it's resolvable. **Second problem:** The odds that another intelligent species would build technology exactly the way we do is almost inconceivable. He humans tend to think (a) that what we understand of science today is all there is to understand and (b) that there is no other way to do it. What arrogance. **Third problem:** The odds that another intelligent species hasn't come up with devices we havn't invented yet are fantastically good. In which case, we have a symbol on the proverbial page that means nothing at all to us. **Fourth problem:** Fundamental schematics are *massive.* They don't fit on paper anymore. So you're assuming we have the ability to "open the computer file," which is dependent on both (a) the software used to view the file and (b) the hardware needed to run the software. Now we have a chicken-and-egg problem: if we need the schematic to reverse engineer the tech, where'd we get the tech in the first place? You need more than the schematic. But once you have it, why do you need the schematic? **Fifth problem:** What kind of schematic are you looking at? Today, we use schematics representing many levels of abstraction. A logic diagram (NAND gates...) will tell you how advanced tech operates, but won't tell you how to build "the chip." A functional diagram will give you an even more abstracted view (CPU and memory blocks...). If you have the wrong kind of schematic, you'll stare at it forever and never figure out how to build a thing (well... it might give you ideas about how to build something using Earth tech...). **Sixth problem:** Modern schematics tell you *what* is connected, but not *how* to build it. Not at all. It doesn't tell you how to dope the substrate, or how close to the substrate the gate must be, or how much encroachment you can withstand during manufacture... You don't actually know anything at all about, for example, a transistor other than it's reference name. An entire file exists (not part of the schematic) that describes the characteristics of the transistor — and even that won't tell you how to build it (well, someone educated in the art could do it, but the point is we're not educated in their art, right?). Even if you had a layout view of the transistor (indicating what regions in 3D space are affected/assembled how), you don't have enough information to build the transistor. There's a fabulous amount of mathematics behind a transistor that a simple symbol on a piece of paper simply assumes is well known — and we wouldn't know it at all. Heaven help us if their math is different than ours or has techniques we haven't discovered yet. **Seventh problem:** My thanks to WillK for helping me see this. We'd be *unbelievably lucky* just to understand the units they use for electrical potential, charge, current, resistance, and every other unit. While we've created highly accurate means of defining these units, they're basically arbitrary — it's the relationship between the units that's mathematical. But remember, [our definition of a second is arbitrary](https://www.sciencemag.org/news/2018/03/better-atomic-clocks-scientists-prepare-redefine-second) and expecting aliens to use the same definition is wishful thinking. If enough information was available on the schematic, we probably figure this one out — maybe. But it'd be a whomping headache until we did. (Think about this, "universal constants" are universal in context, but not in units. The only constants that would translate are the unitless ones: like ùõë. Unless they use something weird like *base-13* math!) ***And that's just considering whether or not you can understand the schematic*** [Answer] There are currently cases of [archaeological findings](https://aleteia.org/2016/05/01/the-real-sword-in-the-stone-is-in-a-church-in-italy/) (which were created by humans on earth hundreds or thousands of years ago) that we currently [cannot reproduce](https://www.youtube.com/watch?v=RlgbKU9mgJA) (some of those are not very credible, others are). We can scan the artifacts, screen them with X-rays and put them under the best microscopes, but the knowledge *how* these artifacts were created is still lost. We can put a large number of iron and carbon (and some additional) atoms into a pretty regular atomic matrix that makes the end product (steel) robust but flexible at the same time. But this process requires not only the right ingredients, but also repeated heating and controlled cooling of the material. If the aliens send only the list of ingredients, the material would still fail in the finished artifact. Even if the aliens send detailled instructions, we might not be able to follow them. If the instruction says to put pure carbon atoms into a solid, cubic lattice, we know the aliens want us to create an artificial diamond. But what if the instruction says to put pure oxygen atoms into a solid, cubic lattice? We'd have extremely detailled instructions but still wouldn't know how to follow them. [Answer] ## Most of these are temporary impediments, not permanent We may not have the means to produce specific **compounds** required in the schematics. Sure, we have the raw materials, but maybe we don't have the knowledge to combine them in the right chemical process to get the substance they need. Or perhaps we don't know how to refine the raw materials to the proper purity first. Or maybe the schematics require very specific isotopes that are difficult to get in sufficient quantities. We may not have the ability to operate at the right **scale**. Sure, we can build complex electronics, but maybe their schematic details microchips at a 3 nm scale, while we're still [operating at 14 nm](https://www.intel.com/content/www/us/en/products/processors/core/x-series/i9-9980xe.html). (or some other subcomponent.) We just don't know how to shrink our designs down enough to do what they require. Or perhaps they call for some object that is so specific and **fragile** that it must be built outside of a planetary gravity well, and so we lack the infrastructure to get the raw materials and manufacturing components from Earth to a distance that's a safe distance away, with all of the shielding and other concerns that go with it. Maybe the raw materials or finished sub-components are **highly toxic** to humans (but, theoretically, not to the aliens, or they have better protective gear). Maybe it requires highly reactive or highly unstable materials that are extremely **dangerous** to work with. Perhaps we just don't have the technology to *safely* build the device. **Politics** may get in the way. Perhaps a key raw material can only be found in some nation that refuses to sell to this project. Or they ask for some price that's so far off the scale that the project cannot move forward (whether that's a price in currency or a price in concessions -- would we allow a despotic, genocidal, regime to dictate that they get to select half the ship's staff, for example?) *Note, too, that this has a potentially high risk of introducing saboteurs into the equation, which will increase the risks, costs, and etc.* **Religion** may also place barriers, especially if we are talking about one or more of the Western religions and if those religions come to the consensus that the FTL drive is a threat to their believers, to their power base, or to their faith in general. *Note, too, that this has a potentially high risk of introducing saboteurs into the equation, which will increase the risks, costs, and etc.* **Industrial espionage or sabotage** could impact the project's ability to proceed. If, for example, manufacturer X gets the bid for some component in the process (and thereby gets to patent all the related technologies that go into making it...), perhaps manufacturer Y's less-than-moral CEO decides it is better that no one have FTL than for X to beat them to market with those awesome patents... **Public opinion** may prevent the project. The geopolitical mix today is struggling with human immigration, so it is entirely possible that the same part of humanity that hates "the other" in us will hate "the alien other" even more. It wouldn't be impossible for this kind of xenophobia to spiral out of control and crush this project. **Military intervention** may also play a role, though this may just be a subcategory of Politics above. But if some segment of the design is obviously a threat to safety, one military or another may decide it best that no one have access to that technology. I mean, if Germany or even USSR had known the US was about to drop an atomic bomb on Japan and had details on that, don't you think they would've tried to disrupt the Manhattan Project? Can we **understand the schematics**? That's not as simple as it sounds. Aliens see and think in alien ways. This matters, since even humans don't all read schematics the same way. > > "The drawings were in Swedish, using metric units, and read from the > first angle of projection (American practice used the third angle); > the blueprints read ‚Äúbackwards‚Äù from American practice, and was much > less precise than needed (the European practice of the time was to fix > small discrepancies by hand)." ([Bofor Guns of WWII](https://www.allpar.com/history/military/bofors.html)) > > > It is therefore possible that we will have to translate the schematics into a format that makes sense to us backwoods humans. How much time and material will be wasted as we try, fail, and try again to make something before we figure out how the schematics work and the units of measure in those schematics? Sure, the aliens can send us cheat sheets to shorten this process, but they may still fall back on assumptions that are intrinsic to them that we have to fumble our way through. --- So any or all of the above can present barriers to the project. Can they be surmounted? Sure. But it will take time and effort. So the delays (and the project costs...) will mount up, making the entire thing difficult at best. [Answer] The biggest impediment would be **precision**, specifically if it involves arranging atoms. Watch [this video on Youtube](https://youtu.be/UBmBMmuUBMk) done by the first team to move individual atoms (2011) and you'll notice that although we're able to do it, we haven't been able to do it with every element - and it's far from mass manufacturing scale. So if the technology required specific molecules to be synthesized, and it couldn't be done through a chemical process (i.e required single-atom manipulation assembly of the molecule) we would not be able to make enough of anything in a reasonable amount of time. A second consideration is **time**. Many manufacturing processes today rely on non-instantaneous chemical processes (think of the whole alcohol industry, for example). Many processes can be accelerated and most industries do their best to accelerate them as much as possible but they remain non-instantaneous and can take a long time. If the technology required a chemical process that took more than a human lifetime to complete, you could argue it would be *unfeasible* for humans to build it (and impossible for any *individual*). I don't know of such a process but this is a hypothetical question about technology and science we don't know about yet, so I'll mention the possibility. [Answer] ## Politics: We cannot assemble the financial will to construct the alien tech, or we fear the consequences of the alien tech (I do think there are interesting answers re: the pyramid of technology required to manufacture at high tolerances, or the difficulty of following instructions that we lack the science to understand. However, to avoid repeating content that others have already mostly addressed, I'm only considering the political angle...) **1: Lack of will** The lack of political will for big projects is not a new feature to the human race, and depending on the alien schematics, we might be looking at a national-scale or supernational-scale effort to build the thing. That could be a problem. Is Europe willing to let its healthcare system suffer to build an alien macguffin? Is the USA willing to slash the military? Is China willing to risk economic collapse by redirecting govt. funds from selected industries? etc... **2: Fear** There could be active resistance to building the alien machine by framing it as dangerous... Be it the existential risk of "are we losing our culture if we develop through aid", the religious risk of "Are the aliens enemies of [religion's] sacrosanct tenets?", or the practical risks of "Are we facilitating our doom if we build the warp-gate / the nanomachine factory / unknown magic macguffin?". It may be impossible to complete such a project if nations or activist groups are opposed to the point where they would use violence against the project. [Answer] If the Alien tech bases on theories that we cannot understand, it might be impossible to build. Or if we do not have the tools to make the tools to make the tools to make what the sent us.. after all, you wrote that they sent us the plans how to build an artefact, but not how to build the tools to build the artefact. [Answer] > > Is 2019 technology (not science) sufficiently advanced that given > sufficient raw materials, we could make any conceivable human-scale > artefact that the aliens specified? > > > **No.** It can be too expensive, it can be too dangerous, it can require materials we don't have, technologies we don't have, or we may simply not want to do it because of side effects. "Not want to do it" can range from anything to "it's obviously a bad idea" to "it's unthinkably opposed to our values". > > What do we know that we don‚Äôt have/know? > > > 1) **Power**. In Back to the Future they the working gadget, all they needed to do was turn it on‚Ķ which required 1.21 gigawatts. 2) FTL requires metals or other resources that we don‚Äôt have the ability to make in large enough quantities. Anti-matter. Black holes (google ‚ÄúBlack hole drive‚Äù). Elements with very high atomic numbers. 3) How to deal with **Side effects**. We can already make flying cars, it‚Äôs a bad idea. 3a) FTL gives an individual the ability to crack the planet if misused. 3b) FTL generates so much radiation that it can‚Äôt be generated, experimented with, or developed on the Moon, much less the Earth. The aliens just assumed we‚Äôd realize this and set it up far away, like Mars or a moon of Jupiter. [Answer] > > What manufacturing capabilities do we know that we don't have? > > > ## Technologies That We Know We Don't Have (or are developing) * Genetic Engineering : our capabilities are still limited to a handful of traits at a time, with a lot of testing in-between. Genetic Engineering projects on the scale of planes, rockets, or dams are still outside of what we can do. * Nanotechnology : we can produce some materials at industrial scales, but our maturity with material engineering at this scale is still fairly young. * Nuclear : at industrial scales, we can only fission uranium and a few other products. We can not produce fusion of low-energy deuterium, and fusing neutron-free hydrogen, helium, oxygen, carbon, nitrogen and heavier elements up to the iron break-even limit is way beyond our abilities at the moment. * Transmutation : we are aware that in laboratories and with high-energies it is possible to split or fuse atoms to create almost anything, but this future technology is in it's infancy. * Manned Spaceflight : we had the ability to send people to the moon, then we shifted attention somewhere else for sixty years, and now we are attempting to re-develop the technology again. However, if an alien message included "capture and bring to your world this ore-body (or prototype) we're sending to you" it would currently be outside of our power to do. * Deep Ocean Operations : while James Cameron can send a single sub down to Challenger Deep, and while we can drill wells from several kilometers up, our ability to operate in the deepest ocean is very limited. If the message includes "pick up further instructions, we splashed them down in your deepest ocean for the safety of your people" our capability to perform a large recovery is very weak. * Geography : even in the satellite age, there is a tremendous amount of our planet that is still undiscovered. If the message included retrieving mineral deposits the aliens knew existed in a specific part of Brazil, the Sahara, the Antarctic, or many other places, we would be out of luck. * Quantum Computing, Communication : while we can create entangled photons, transport them long distances, and reliably read the entangled probabilities, we still have not demonstrated the ability to send non-random useful information along this channel. We have not even proved unambiguously that it is possible. So, we would be in trouble if the alien schematics assumed we'd have sufficient computing power to solve any "localization calibration" that required a lot of heavy lifting computationally. * Inter-species Communication : we live on a world with a stupefying number of alien (non-human) species. However, we're not even entirely sure that any of them (except us) are sentient. Communication has been weak. In many cases, we're not even sure of their capabilities. If a message assumed we could leverage bats for ultra-sonic quality control of parts, or something similar, we'd have to invent a workaround. * Gravity : we have only just this year proven that gravity has waves. We are not even close to understanding how to apply this to communication, computing, or other infrastructure. * Mass : we also only very recently proved that the Higgs field is a real thing and that something previously thought immutable (mass) can actually be changed. Maybe the first implementation is James Woodward's Mach Effect reactionless drive, but we are still very new at that. [Answer] ## Let's say we can manufacture this machine. You say we have the necessary materials and budget, however here are some issues that could result from it: 1. **What if the scale of the schematics, while normal for the aliens, is incorrectly sized for humans?** The device itself is so small it is unusable for humans, while it would function for the aliens due to their differing size. We could attempt to scale up the device itself, however the the scaling causes the device to work incorrectly, and using them en masse leads to errors. Leaving us with having squandered our time and resources. 2. **Another possibility is that the device simply won't work for us due to our differing biology.** Perhaps we can't dampen the forces it produces to allow to survive at those speeds, while the sturdiness (or fluidity) of their alien physiology allows them to dampen it enough to survive. Maybe it produces a form of radiation that the aliens are immune to (or are able to sufficiently shield), while it cooks our bodies even through protective layers and shielding. 3. **The materials on Earth are sufficiently rare so as to only be able to build one of these devices.** This leads to a huge fight over which country is allowed to control the device, and maybe it being unable to be built due to irreconcilable differences between them. Even if built and a country has control of it, the fact that we can only have one means that it is of limited usefulness even when constructed. 4. **We simply don't believe or trust these aliens.** Humanity tends to be skeptical be nature, while we may receive these instructions we simply have no idea on how it works or what it will do aside from their explanation. Why would they simply help us for no benefit of their own? Who's to say it's not really something that will open a portal for their armies from across the galaxy to invade or will generate a black hole. In this case, the countries would work together in the open to make sure it is not built until they fully understand the implications and effects of doing so, presumably while secretly conducting experiments with components of it on their own, so as to get ahead of possible competitors. On the upside, having the schematics will help us fuel our scientific discoveries towards the understanding of the machine allowing technology to improve much faster than it's usual rate. [Answer] It's not a schematic. # *Theory of Everything* If we don't understand the science that explains how the thing works, it's because they forgot to include the mathematical formula for the Theory of Everything which is what would make FTL travel possible. Which isn't, because we still can't figure out if there's a cat in the box or not. All those things you specifically mention are neat things for which we *completely* understand the physics behind, that we have undeniable ways of representing with ***Mathematics: the Language of the Universe***. It's turtles all the way down, but the universe's Latin is math. To send it in English would be quite arrogant. --- **Commence Operation Handwave** (or the Manhattan Project) We get to handwave almost all of reality here: Time. Money. Materials. Manpower. 'Completely deciphered'. All you need now is a leader. Someone to take that money and employ whatever the world's population can spare from, e.g., food production and health services, to begin taking the materials, for whatever time it takes, to finish the project. Gimme a thumbs-up from a theoretical physicist and we're good to go. **A leader.** Someone like Dwight D. Eisenhower, the Supreme Commander of Allied Forces. A logistical genius who decided things like, to win the war, we'd need almost half a million trucks; non-combat vehicles. And to erect the largest edifice every yet constructed, for learning how to build and make the materials for, a device that can be described on the back of a napkin (if you understand the physics), capable of destroying entire cities. [Answer] To build on other answers: We may not even *realise* we don't have the right material, and we may not be able to work out what's wrong even if we were able to converse with the aliens. For example, until relatively recently, we were unaware of chiral isomers, and so we produced them haphazardly, depending on the manufacturing method. A similar thing might exist which we're unaware of ‚Äì or that we are just blind to it being relevant, because it's never been important for any use we've made of a substance. The alien race might be similarly blind to it because it's just the way their materials are (e.g. all their raw material happens to be one chirality because of how it was made), so they didn't realise to specify it. To switch the example round ‚Äì If we made something with carbon, a mix of C12 and C14 would always be present on earth. We might create a device which (unbeknownst to us) relied on the ratio of C12/C14. We might not realise this is what made it work. If we then instructed aliens to make it, they might use carbon with different isotopes, because their planet's crust is different, and so the device would not work. Both of use would struggle to determine what the cause of the difference was. Furthermore, this could be environmental factors. For example, airplanes wouldn't work on other planets (or would need to be radically redesigned) because of differences in air pressure and gravity. Other factors might affect their magic FTL drive ‚Ä쬆perhaps it only works in the gravity well of their huge planet, etc? [Answer] The answer to your question as written is ‚Äòwe don‚Äôt know what we don‚Äôt know‚Äô (addressed by others), but here‚Äôs something which may have a big, big impact on the creation and usage of alien technology: **Politics** Imagine for a second if I went to the US government and said ‚ÄòHere are some plans for a fusion reactor. The science is beyond you, but I promise if you just follow the instructions, build it and turn it on it won‚Äôt blow up or anything. By the way, it was designed in Russia‚Äô The response would be hilarious, and the reactor would never get built. And the Russians are the same species as us. If your public or politicians have even the slightest xenophobic (or protectionist) tendencies then you can expect that these designs won‚Äôt ever be built, not because of any technical limitation, but because there would be unimaginable outcry if anyone tried. Not only that, but decades of ‚Äòthe aliens were using us all along‚Äô storylines would naturally predispose us to not trust the aliens. Then there‚Äôs the whole notion of international politics to wade into. Who gets to build the thing? If anyone objects to the thing being built by anyone but them will they drop nukes on it to stop it being built? Who will stop the crazy cults that can undo years of careful calibration and testing with a well placed suicide bomber? Will anyone refuse to sign the budget appropriation bill if the thing is/isn‚Äôt included in it? Could the thing be cancelled as ‚Äòthe previous administration‚Äôs folly‚Äô and leave a two kilometre long tunnel under Texas? Building this could get so bogged down in negotiations and political wrangling that the aliens give up and go talk to a less neurotic race, regardless of technological constraints. Now I‚Äôm going to go think about something slightly less depressing. [Answer] Schematics often contain summarized **references to parts which were assembled by a third party**. For example, the schmatic on my desk right now references an Allen Bradley PLC, and it does not include any information about what that PLC is, or how to reproduce one. Also, schematics will generally give precise information about sizes of items, but it's impossible for people to produce items perfectly sized to those dimensions (they might be up to a mm off here or there). For that reason, people who follow the schematics often require an experiential understanding of the **tolerances** associated with each part. Sometimes a difference of micrometers can mean the success or failure of a project, and those tolerances are not always noted on the main schematic, but are sometimes mentioned in the purchase order for the parts, or they are just understood by people in the industry. This rule applies to physical sizes, densities, roughness, ratios of fluids, temperatures, material conductivity, electrical resistance, and really any measurable quantity. The number of variable tolerances associated with any project can make it infeasible to note them all in the drawing, and nearly impossible to reproduce the device without knowing them. One [real-world example](https://www.reuters.com/article/uk-china-engine/unable-to-copy-it-china-tries-building-own-jet-engine-idUSLNE89T00W20121030) of this is China's long-running struggle to make a good jet engine. They've stolen entire engines, and schematics for them, and they reproduced them, but their copies just didn't work. It was because they didn't understand the tolerances, and there are a lot of parts to guess at. [Answer] Some possible reasons: * [Can't make/obtain materials](https://www.ufopaedia.org/index.php/Elerium-115) * [Violates treaties](http://www.projectrho.com/public_html/rocket/spacegunexotic.php#id--Relativistic_Weapons) * [People really don't like the idea of building it](https://en.wikipedia.org/wiki/Contact_(1997_American_film)) * Can't do it to tolerance specs * Requires too much exotic environments (pressure, temperature, etc) * Produces lethal pollution, radiation, or similar hazard that cannot be shielded against * Requires too much power * Using schematics requires too much computational resources * Humans too dumb to understand schematics [Answer] The biggest question is how determined are we and the aliens to share and build this thing. If these are do-or-die determination there is nothing stopping us from building it. Examples: The machine probably has 1000 or millions of parts, and each one is an opportunity for failure. One guy decides to cut corners because its Friday and s/he wants to go home, boom failure \* 10000000 people involved. Access to a fifth, sixth, or seventh dimensions is required. Lots of other issues. However, if the alien(s) are prepared enough even these things won't stop us. Here's how. 1. They send us instructions how to build 300 generations of replicator from 3d printer up to the latest and greatest 9th dimension model. So generation 1, builds a gen 2 device and so on and so on to gen 300. Within a couple generations we will build nothing. Additional each generation is less our technology and more theirs. Generation 1 has to be 100% human made. Then gen 2 will be 99.666% human made and so forth and so on till all the parts are printed by 100% alien to us technology. We will feed in any RAW materials and the device will e=mc^2 matter. That is convert all matter placed in the input bin to energy and then back to new matter. So now all we have to do is pour a constant supply of stuff in the input bin. So we connect our sewer system to it, and boom constant supply of raw materials. And all of our trash into the input bin. Then its starts spitting out parts, and we just lego them together. Eventually with each generation they will be able to print larger and larger objects. So now at generation 300 the machine is large enough to 3d print the whole unit FTL engine without any intervention from us. Aside from pouring in the raw materials. Of course we could make mistakes in producing the initial units, however the aliens have though of that. The machine contains (much more advanced versions) of parity data, and error correction. It detects and corrects errors, say part 129 is off tolerance by 0.001mm, the replicator prints a new piece and us humans know the old piece is bad because the duplicate piece is there. We swap out the piece, and production continues. Yes, generation 300 can print in 12 dimension or more so we have that covered. Say we can't access dimension 10+ for some reason. The aliens guessed that might happen, and they have included blue prints for every conceivable combination of dimension including just our 4. The aliens could have planned for 10 billion contingencies therefore virtually guaranteeing we can produce whatever it is. Machine produces harmful radiation during product, aliens thought of that and the device generates star trek or better force fields and contains the radiation or other harm field(s) and potentially converts it back to energy recycling back to a harmless state. They don't know what is harmful to us. Thought of that, it includes a scanner to scan humans and figures out what is harmful to us, and protects us from it automatically. Yet if we encounter contingency 10 billion and 1 it might all be for naught. Yet, the aliens thought of that to. The machine opens a micro-wormhole and downloads updates from alien HQ. Reports on the things it didn't expect, and the aliens upload the necessary fixes contingencies. Note the original transmission is one way, but include a list of 5000+ galactic coordinates. 0 by 0 by 0 by 1, 10 by 1 by 10 by 1, .... The computer opens a micro wormhole to each coordinate and attempts to download updates from there. -----Real example---- --hd radio meta data ``` TrafficMapProtocolVersionID="1.3" TrafficMapID="#####" StationList="(#####,FM123.7)";"(rrrrr,FM98.7)";"(xxxxx,FM45.6)";"(hhhhhh,FM91.2)" NumRows="3" NumColumns="3" NumTransmittedTiles="9" CoordinatesRow1="(###.55345,-###.81309)";"(###.19653,-###.45617)";"(###.55345,-###.09925)";"(##.19653,-###.74233)" CoordinatesRow2="(###.19653,-###.81309)";"(###.83961,-###.45617)";"(###.19653,-###.09925)";"(###.83961,-###.74233)" CoordinatesRow3="(###.83961,-###.81309)";"(###.48269,-###.45617)";"(###.83961,-###.09925)";"(###.48269,-###.74233)" BackgroundRGBColor="(194,187,96)" ``` ## CopyrightNotice="Copyright ¬© 2014 iHeartMedia, Inc. All rights reserved." I have replaced the real data with fake and ### the coordinates. My radio has one way communication with my radio station, but I still know exactly where they are located. Humans might get board or just stop building it. Yup, the device is now printing androids the work can continue day and night until completion. Need some extra power...print advanced solar panels that absorb light in all spectrum's, way more efficient and power. Have the android place them if needed. [Answer] Many good answers have been posted regarding communication barriers, organizational problems, resource scarcity and current manufacturing capabilities. Let's suppose we had infinite time, infinite resources, no conflicts, the entire alien "tech tree" and perfect communication. Even in those conditions there may simply be hard limits in mind and body to what humans can achieve. Some ways in which we have encountered limits to our **minds**: * [G√∂del's incompleteness theorems](https://en.wikipedia.org/wiki/G%C3%B6del%27s_incompleteness_theorems) identifies limits to human reasoning (in math). In short: some things are true but cannot be proven. * It is up for debate whether math is "real" or merely a product of our collective imagination. A set of axioms cannot prove itself. * The [Chomsky hierarchy](https://en.wikipedia.org/wiki/Chomsky_hierarchy) ends at regular grammars, but perhaps aliens can conceive even more complex grammars to solve more complex problems. In regards to the **body**, the aliens might be too different from us. * They might be 4+ dimensional beings. * Supposing the universe branches with every decision made, they might be existences that span multiple branches and can collapse themselves into those they like. * Their composition might be too different from ours, so that certain procedures that work on them do not work on us. For instance, our genetic engineering is not going to work on life-forms that are not carbon-based. [Answer] Many industrial manufacturing processes are inherently risky and produce wastes that need special handling. Even today people still get killed in foundries, or poisoned by fumes and we've been messing around with liquid metals for a few millennia now. What if the alien manufacturing techniques required something truly nasty, or the waste product makes the insides of old nuclear reactors or chemical plants an ecological haven by comparison? The second half of "Pushing Ice" by Alistair Reynolds may provide some thought. And of course, that means you'd have to read the first half as well so it makes sense. Which is an excellent way to spend a lazy Sunday. :-) [Answer] **Until 2017, Chinese companies were unable to manufacture the tips of ballpoint pens.** [Source e.g. here](https://www.washingtonpost.com/news/worldviews/wp/2017/01/18/finally-china-manufactures-a-ballpoint-pen-all-by-itself/?utm_term=.530f9a01d85d). It wasn't for not knowing the schematics, they simply did not have a process that was *precise* enough to create ballpoint pen tips. **We simply may not know what the process could be.** In semiconductor chip production, we have managed to get to smaller and smaller scales, from a 10 ¬µm process in 1970 for chips like the 8008, to somewhere between 7 and 5nm in 2019 ([Wikipedia](https://en.wikipedia.org/wiki/Semiconductor_device_fabrication)). This is close to the theoretical limit, so I don't think alien semiconductors would become much smaller. But it's all *flat chips*, we print them on large wafers that are then cut into pieces for the individual chips. If we found the schematics for a fully 3D *block* of semiconductors with connections equally in horizontal and vertical directions, we'd simply have *no idea* of how to create something like that. Let alone if they weren't aligned in a 3D grid, but directions moved freely in all directions. [Answer] # Extinction That is the only thing that can truly and ultimately stop our progress. Until we exist, we can advance. We did so for as long as we have existed, and there is no reason why we should stop. Eventually, we will reach whatever technology exists anywhere else in this Universe. Now, provided that the chance of Earth being hit by a random zig-zagging rock of adequate size is non-zero over the time-scale of the Universe, or that the Universe may collapse draggin us with it, or that we may trigger our own destruction (as we sometimes try to), the answer to the other question "Ok, but will we *always* be able to...?" is # No. [Answer] Industrial technology is not the process of inventing new things. Industrial technology is the process of getting *better* at building things, then putting those things together in new ways. A fully specified modern weapon won't do anything without modern precision quality metals and chemicals. That process, of making more and more precise *ingredients*, is driven by increasing demand for them, and valuing more precise chemicals and materials for prior needs. For example, the exact carbon quality of a particular steel might not be *needed* for a specific device, but it can mean you can cut tolerances on something as mundane as a kitchen sink; the strength of the steel and its corrosion resistance etc is known, so we can cut the sink's thickness by 20% and still get a reliable product. Advanced alien technology may require simply insane precision in the materials used. Imagine the specifications for a specific material involve describing the exact location and isotope of every atom in a particular metal strut. As to why that might matter, that metal strut might have the ability to respond to environmental conditions and do things. It could have computation embedded in it, or even the ability to modify its stiffness or expand/contract in response to the needs of the rest of the device. It could even be an active component involved in modulating the magnetic field generated as part of the device's operation. A less fantastical example of this would be the manufacturing efforts we had to go through to build the [stellarator](https://en.wikipedia.org/wiki/Stellarator). It has to be a twisted shape that carefully prevents high energy atoms from escaping; at the same time, it has to have ports that let things be added into or removed from the plasma. For this to work, the entire thing had to be crafted using modern computer aided design *and* manufacturing; the precision of the parts involved is too high for human hands. The Stellarator was designed a while ago. Only modern computer simulation and manufacturing gave us the ability to actually work out the quirks and actually build it. Given perfect plans for it in the 1980s, we couldn't build it because we lacked the computer aided manufacturing capabilities. Well, maybe we could build one; but now imagine a device that requires a few million of them. Today, if the aliens sent us the specs for a device that required the equivalent of a few million Stellarators, we would have a shot. In the 1980s, no chance at all; we'd have to invent new industries to even get close. Another example would be a space elevator. All you need is carbon nanotube wire. (Well, not all you need). We can make carbon nanotube wire, but we cannot make 100s of km of wire, nor can we wind it together into the cables required. An alien might expect or know this. So the proper way for the alien to pull this off is to provide an entire set of instructions on how to build entire new industries, together with produces that each industrial revolution can produce that we might find useful (so we don't bankrupt our civilization trying to follow the path). You could imagine step 1 being "become a K-type 1.5 civilization", with a century-long path to building a space-based civilization that absorbs a significatn portion of the sun's energy. From that base, they might describe how to build orbital supercolliders that permit the synthesis of stable post-trans-uranic elements in small quantities, which in turn become the basis for a new industrial revolution. Asking us to just build that supercollider with current technology would bankrupt our energy budget, as it might require more energy than we have available. So the first step -- get richer -- is just an *ingredient* on the way to designing the thing they want us to build. Of course, with such a "Ikea instruction manual" to uplifting our own civilization, you could see a significant change in how humans approach science and technology. Would the aliens take this into account, and leave gaps for us to fill in ourselves? Or would accidental gaps be more than enough? Speaking of which, Ikea instruction manuals are the best another human corporation can do in telling people how to put things together, and they even get to supply the parts; a completely alien intelligence trying to tell us how to build something larger in scale than our entire civilization is currently (the new industrial civilization required to build the parts to build the thing) would probably be even harder to follow. Human experts on "following the instructions" would develop. [Answer] There is an old saying, "The map is not the territory". There are technologies we still have not recovered from ancient times such as: **Roman concrete** **Damascus steel** **Greek Fire** In order to manufacture the technology, we would need in addition to the schematics: 1. Methodology required to manufacture the components 2. The tools to manufacture the components 3. The materials to manufacture the components 4. Any infrastructure to support it Take how computers have advanced from the 1950s to today. Even if we had had the specs to manufacture an iphone today, we wouldn't have the schematics to create the microchips required, the technology to manufacture the plastics and resins we do now, the precision assembly robotics to assemble the components or to mark the circuits.... et cetera. Then even if by some miracle, they pulled it off, they still wouldn't have the code to run it, the network of cell towers to support it, or any way to know those were needed. There are actually MANY obstacles, as you can see. [Answer] It depends... # Do we have the schematics for the tech or do we have the schematics for all of the steps of technological development that lead up to the development of THAT technology? If we only have the schematics for the Chappa'ai, but we don't have the schematics for the crystal control panel technology, the Naquadah mining technology, the Naquadah refinement technology, and all the other things that lead to the building of a Chappa'ai, then what good does it do for us to have the schematics to a Chappa'ai? The creation of technology isn't reliant only on knowing what is needed to make it, but on also knowing all the steps necessary to get to that point. Leonardo di'Vinci couldn't make a functional airplane, but he understood the idea behind it and made a schematic for what would later be an inspiration in future endeavors. He saw the modern era long before it was even an idea to most people. The problem is, it's easy to say "We need a specific material made in a specific process put in a specific arrangement," but it is much harder to say "This is how we make that material, perform this process, and get it to fill this arrangement." They say our technology is evolving rapidly, but it really is still just a crawl. It's our perspective that makes us feel like it is faster than it really is. Without all of the relevant schematics explaining how we get from where we are to all the way to where that alien technology is, then we can't hope to build that technology until we have finished remaking the wheel over and over and over again. ]

[Question] [ ## Some Context This story is a fable set in a magic forest full of intelligent animals that live in a huge community. [Maleficent](https://www.imdb.com/title/tt1587310/) depicts a forest that's very close to what I'm thinking. The magic present in the forest allows for the growth of a myriad of exotic plants, roots, seeds, etc. These items are of great value to humans, since they can be crafted into things like medicine, spices and garments (to name a few). This magic is also what made it possible for the animals to develop an intellect. The humans never took residence in the forest - they used to come and go for what they needed. One day they did a very bad thing and were prohibited from ever entering the forest again. This ban happened a long time ago. They live in huge cities where they enslave and kill animals (this is how the animals see farms). They can also build iron weaponry (medieval grade tech). Though **there is no conflict or war going on**, there are still those bold humans who think they can sneak into the forest and take the valuable stuff. There are constant attempts by individual humans to enter this forest. To take care of that, some of the animals are responsible for keeping the forest's boundaries safe. ## The Question Suppose a group of "mercenaries" enters this forest after the goods. They're armed with medieval weapons (swords, lances, crossbows, heavy armor, traps, nets, etc) and they're experienced in fighting in groups against animals (meaning none of them will shit their pants at the sight of a lion). From a tactic point of view, **could intelligent animals defend against such attackers?** --- Things to Consider: * Though the groups are heavily armed, they're not great in numbers. I'm setting the maximum number to 15 invaders; * The forest is huge. There's no way that every entry point is heavily guarded by large animals, but there are hundreds of scouts spread across the border; * Animals allowed are strictly those whose habitat is a forest; * Neither animals nor humans are allowed to use magic. Both groups rely only on their physical capabilities, their tools and their intellect; * Yes, animals can build tools - monkeys do have opposing thumbs. But their level of technology is lower than the humans'. They can only use whatever raw materials are available in the forest (no magic is allowed here either); * The humans know that the animals that live in this forest are intelligent; * Animals don't necessarily need to kill the invaders, making them retreat is enough - though that's not always gonna be an option, since the humans will sometimes be out for blood. * As pointed by craq, The humans could start fires. There's a plot reason as to why they can't do it. You might accept this reason or the excuse that they won't burn the very thing they came for. But fires are out; * As pointed by Nuclear Wang, I'm setting the minimum time for the humans to achieve their goal, assuming they're completely undisturbed, to 12 hours. [Answer] First thought would be "make an army of lions, bears, tigers, wolves or whatever top predator you have". But that would be wrong. All of them are easily spottable from a distance, and are good targets for arrows and the like. Your key to success is: go small and go large numbers. While you can use small birds to carry on aerial surveys and track enemy movement, your line of defense shall be based on insect: ants, wasps, hornets, flies, mosquitoes. For example, give a look at the [Japanese giant hornet](https://en.wikipedia.org/wiki/Japanese_giant_hornet): > > The Japanese giant hornet is large and can be very aggressive if provoked. Its venom, which is injected by the 6.25 mm-long stinger, attacks the nervous system and damages the tissue of its victims. Tests involving mice found that the venom falls short of being the most lethal of wasp venom, having an LD50 of 4.0 mg/kg. [...] Being stung is extremely painful and can require hospitalization. Asian giant hornet stings can cause anaphylactic shock in allergic people but can still be lethal to people who are not allergic, provided the dose is sufficient. In China, where the hornet can also be found, the conventional wisdom is that people stung more than 10 times need medical help, and emergency treatment if stung more than 30 times. The stings can also cause renal failure. Thirty to forty people die in Japan every year after having been stung by bees and wasps (including the Japanese hornet). > > > You might even add some [fire ants](https://en.wikipedia.org/wiki/Fire_ant) to the mix: > > Fire ant stings are painful, characterised by a local burning sensation, followed by urticaria. The sting site typically swells into a bump within hours, which can cause further pain and irritation, especially following several stings are at the same place. The bump may develop into a white pustule within 24–36 hours which can become infected if scratched, but will spontaneously flatten within a few days if left alone. > > > You can have them attack in swarms or in small, continuous incursions, slowly bleeding out the human forces. Disease carrying insects can also work in the back, depleting humans forces by infecting them. If humans attempt to use smoke to repel the insects, you can use that at your advantage. Smoke also hinders humans from viewing, at that point the big carnivorous can come on stage, using the smoke curtain at their advantage. Edit: for a more comprehensive overview of the most painful insect stings, refer to [Schmidt sting pain index](https://en.wikipedia.org/wiki/Schmidt_sting_pain_index) list. [Answer] **Animals hire the mercenaries.** There is nothing better at fighting humans than other humans. Mercenaries are fighters for hire. Appoint a spokesanimal. This talking crow will visit the mercenaries and arrange terms. The mercenaries will control access to the forest; they are forest guardians. Mercenaries do not really want to grub around for roots and such. They will allow access to the forest by people who want to harvest its resources. In exchange the mercenaries collect a percentage or an access fee. Persons allowed access by the guardians will not have their activities impeded by the resident animals. Animals will be OK with humans harvesting plant matter and mushrooms. Not OK with killing for meat and pelts. Humans allowed access to the forest and who violate the terms will be punished but not killed. They will be punished by the mercenaries. If you disappear in the forest people assume you have been eaten by an animal or fell in a hole. If you return to the village missing a thumb and with a brand on your forehead, people will know exactly what you did. Talking crows will stay with the mercenaries on a rotating basis to ensure terms are met. An intelligent mercenary boss will realize that this forest guardian gig is a sweet setup. Also, such a boss might perceive additional more lucrative endeavors with which intelligent animals could help - intelligent talking crows you are familiar with could provide unparalleled reconnaisance in a war situation and crows like it when humans get killed. If this is for a story, this is a natural evolution of the story. --- More straightforwardly: I picture the scene where an orc chieftain is sharpening his axe. He hears a clinking and looks up to see a crow tapping a gold piece against a spear. In the trees around are more crows. Each flies across and drops a piece of gold at his feet. Then on top of the gold they drop a piece of cloth with the insignia of the mercenaries invading the forest. The orc smiles. [Answer] **Honestly, the humans don't stand a chance.** Go the Viet Cong route, various types of **pit traps and deadfalls**. With a plethora of burrowing and gnawing animals these will be very easy for the forest creatures to make. The big risk is getting caught in them themselves. Of course they can use scent markers the humans will not notice. Even better, burrowing animals can make truly invisible pit traps because they can dig up or sideways, they don't have to make a surface hole. Works even better if you have venomous snakes, snapping turtles, and insects hidden in the holes, or, in the bigger ones, crocodiles. Deadfalls are easier to spot but more destructive: imagine the deadfall you can make with spiders weaving silk rope and a bear's or an elephant's strength to lift the thing. Then you have **swarms** of stinging insects, venomous snakes, and skunks. All of which have a relatively easy time sneaking up on the humans, even more so if they have other animals for assistance and distraction. Imagine a swarm of crows and ravens each carrying a different venomous snake or insect. Then there is simple **mob tactics**, no human is equipped to fight a thousand squirrels and rats, biting and clawing, for every one a human can kill a dozen will bite them. And that's just one or two species, now add birds of prey and stinging insects followed by larger predators while the humans are occupied. These animals will have a big advantage in ambush tactics as well since they control the terrain and can prepare it beforehand. The most important thing is they should **never be using just one tactic**, they should be using many at the same time, pit traps, and mobs, and ambushes, and aerial attacks. The humans might be able to handle each tactic individually, but they can't fight attacks from all directions. As soon as a human sets off one trap the woods should explode with things attacking them. The animals even have better scouting capabilities too, they can spot humans easier and organize fast, they have a wider range of senses and forms of locomotion available. Imagine getting attacked by swarms of bees *WHILE* getting attacked by packs of wolves and lions, followed by a rain of scorpions, bullet ants, and vipers as soon as you start to make any headway. "Let's go attack a castle or something, at least they can't crawl up your trouser leg." [Answer] There are a lot of options, but for *intelligent* *vertebrates*, I would suggest some [squirrels](https://en.wikipedia.org/wiki/Tree_squirrel), possibly wearing crude gloves or using tongs (I'm not really sure if that's necessary) contaminate the intruder's food with [some kind of poisonous mushroom](https://en.wikipedia.org/wiki/Amanita_phalloides) (likely puréed). The delivery creatures(squirrels vs monkeys vs birds), how the toxins get into the humans (puncture wounds are an option but probably unnecessary), and what toxin to use (mushrooms take a couple days to kill you, but they *will **kill*** you, *horribly*) are all up to you. If you want a real fight, against a party as small as you're describing, I would expect a strategic attack by [large animals](https://en.wikipedia.org/wiki/Moose) to be enough to break up the group so that wolves etc could take them out in ones and twos like [this](https://www.youtube.com/watch?v=YKRnEOUxZm0). From the sounds of things, it seems like the humans don't know that the animals are smart. *That's a huge advantage that must be protected*. **Therefore my real suggestion is to first poison the humans, and then violently kill any that seem like they might make it back to the rest of their civilization**. [Answer] First of all, the woodland creatures *must* have something like human intelligence in order to stand a chance against a determined human assault. This is because they need to recognize what's at stake, remain focused, and adapt to changes in the invaders' behavior. Given this, I think that you can get some good inspiration from [Tucker's Kobolds.](https://1d4chan.org/wiki/Tucker%27s_Kobolds) Tucker's Kobolds came about when a D&D game referee by the name of Tucker took the puniest sentient monster in the game—a monster that starting players can one-hit most of the time—and made use of strategy, battlefield control, etc. to turn it into a holy terror, even to player characters who have gone up against dragons, greater demons, etc. The essence of their tactics was to allow the players to advance to a certain area of the dungeon, where the attack would begin, and from which every avenue of escape involved running a gauntlet of snipers, traps, hit-and-run attacks, etc., slowly wearing down the party. [Answer] To actually kill the mercenaries, the monkeys could build [traps](https://www.wearethemighty.com/articles/8-of-the-most-terrifying-vietnam-war-booby-traps), but it would be more in character for them to hurl feces and urinate on the warriors from the safety of the tree tops. Monkeys know that making sissy humans abandon an area is a lot less work than actually killing them. [Answer] I note that members of the species *Homo sapiens* are animals, and like to think that they are intelligent. A number of now extinct related species were also animals and were also about as intelligent as members of the species *Homo sapiens*, more or less. I also note the original question doesn't define "humans" so it is possible that members of various primate species may or may not count as "humans" for the purposes of the question, though they all count as animals for the purpose of the question and many extinct primate species may count as intelligent for the purpose of the question. Therefore, I point out that throughout the few thousand years of history and for hundreds of thousands and possibly a few million years of prehistory various groups of beings who might count as "intelligent animals" for the purpose of the question have had various problems with groups of beings who count as humans for the purpose of the question. Therefore there are many examples of how "intelligent animals" handled - successfully or not - problems with "humans". And depending on the nature of the society of intelligent animals in your enchanted forest they can try some of the same methods used by "intelligent animals" with "human" problems in the past. There are also a number of mammal species on Earth with large brains that might possibly be approximately as intelligent as members of the species *Homo sapiens*, and who therefore might possibly be classified as people by objective outside observers. I also note that up until about 13,000 years ago there were at least 15 now extinct species of large brained proboscideans living on every continent except for Australia and Antarctica. The causes of extinction of those proboscideans are controversial, but a common theory is that hunting by *Homo sapiens* contributed to their extinction. And there are examples of how present day apes, elephants, and cetaceans have reacted to hunting and habitat degradation by humans. Which sometimes has resembled military action to some extent. I think that if there are elephants in the forest they would make good defenders. Real elephants can walk very silently. Large predators attacked by hunters have been known to circle around and try to ambush the hunters. And even though elephants don't have predators' instincts they have been known to do the same. If a small group of humans is walking along a narrow trail between dense foliage a single intelligent elephant could walk up behind the last man silently, wrap their trunk around the man's mouth, lift him up and carry him far enough away the others don't hear the sounds made when killing the man. Then the elephant can repeat. Or maybe a group of elephants can attack one by one, each silently grabbing the last man in line. Or maybe a group of elephants hide in ambush hidden by brush alongside the trail and when the group of men pass the elephants, at a signal the elephants all surge through the brush, and each grabs a man, lifts him high, and slams him on the ground and then steps on him. A single elephant or a group could detect the human intruders and move parallel to them and downwind of them, so any dogs in the group don't smell the elephants. The humans might stop for the night and set up a tent or brush lean-to. When the humans grown quiet the elephant(s) sneak up silently from downwind and knock down the tent(s) or lean-to(s) and stomp on any lumps. If there aren't any elephants in the enchanted forest sufficiently intelligent bears, boars, wolves, aurochs, or wisents might be able to duplicate some of their abilities. I note that humans raiding the enchanted forest for exotic herbs, roots, fruits, etc. may not be as big a problem for many of the intelligent animals as other intelligent animals may be. In real life, and presumably in non enchanted forests in your world, many species of animals prey upon other species of animals. There have been human societies where it was permissible to eat other members of that society, but usually for ceremonial and/or religious reasons. It was very rare for members of a society to eat other members of that society for food. Humans who eat other humans for food are usually restricted by law and custom to eating members of other societies for food. Therefore, human societies that regularly practiced eating other humans for food purposes (outside of starvation situations)usually restricted it to eating members of other human societies - which didn't make relations with those other humans societies any friendlier. And a common accusation against disliked groups has always been cannibalism. So I find it hard to believe that foxes and rabbits, weasels and mice, lions and lambs, etc. could be members of a single society if the predators go around eating herbivores every time they need to eat. So possibly every single intelligent species in the forest might have a separate society and government, or perhaps the predators and the herbivores have separate societies and governments. But if there are two or more separate governments in the enchanted forest that are constantly hostile to each other, one or more governments might ally with outside humans against the other government(s). Or maybe the situation may be like in *Zootopia* (2016) where the carnivores have given up eating intelligent animals. But many species of carnivores are obligate carnivores who must eat meat or starve to death. Thus there may be many animal wizards in the enchanted forest who use magic to keep the predators alive, healthy, and happy without eating intelligent animals. Or possibly the intelligent predators go outside the enchanted forest to prey on unintelligent wild or domestic animals. [Answer] There are many valid answers here, but I'll offer an answer in case you don't want to rely on intelligent bugs and aracnids. Suposing that the only intelligent animals in your forest are either mammals or birds... they win nevertheless. Many animals are bigger, stronger, faster and fiercer than humans. They also have natural weapons like claws and fangs. Still, they loose against humans because they are not as smart. But these animals are, and so our only advantage to them is lost. It's true that we have technology and they don't, but at early medieval level that's not nearly enough to compensate - another thing would be modern firearms. An intelligent lion is not going to try to bit a breastplate - he knows steel is hard - nor he's going to blindly charge against a pike. Instead, he will run against the enemy; if they don't react in time, attack, if they draw a sword or trap them in a net, fall back... and let the two lions and three weasels to take his place now than the net has been used. Now it's the time for the fencing wolves. They can't hold a sword, but they know how a sword is used, so they feint attacks, one step up two steps aside, dodging the enemy's whacks until they can bite the sword or even better the arm holding it. From this point the fight is shortly over. And behold the armored bear! Some friendly monkeys have tied oak barks to its forearms and even wears a crude but lovely helmet! A thick scarf of wicker and other plants covers its neck. It's not an armor is going to survive some good hits with a broadsword or an axe, but the thing is nobody is going to have time to try it. It's enough to prevent (much) harm from arrows or bolts, and enough to block or lessen the first (and only) blow the front line of humans are going to able to land. From then on, their lines crushed and in disarray the bear will wreck havoc on the puny humans while a horde of smaller creatures jump over their bodies. It will be short, but nasty. [Answer] Wear them down, then attack Have insects and small animals raid their food and water. rodents take anything that could be used to start a fire, and bury it. Any damage that can be done to any fabrics that could be used for tents or shelter, should likewise be left to the rodents. You've just robbed them of their ability to eat, sleep, and stay warm. Any stinging or biting insects could keep them up all night as well, just in case the weather isn't cold or rainy. So, now you're left with hungry, thirsty, sleep deprived mercenaries. Morale is going to be low.... time to start the aerial assault. Birds, squirrels, and anything that can get up in the trees to pee and poop on them, does so, further demoralizing them. At this point, they're hungry.... send a rabbit or dear close enough to get someone to pursue... have others waiting up ahead.... If too many are pursuing, have another one run with the first, and have them split into two directions.... leading them to traps (pits, tripwires, ravines, et cet. Have other animals clean up the tracks behind them, so even if they survive the traps, they won't be able to easily find their way back to camp. If you can wear them out, you won't have to fight them further. If they persist, you'll have a demoralized, weak, disoriented band of frightened/spooked men, who probably won't have any cohesion left, and could easily be picked off at this point by an occasional charging deer, or other animal. Pick off the stragglers and any who leave the group, then bury them to make the humans think that something supernatural is just making their compatriots disappear. If they still don't retreat, kill them all, then pose their remains in such a fashion as to terrify anyone that comes looking for them. [Answer] Start small with birds attacking from above and going for the eyes (dependent on the armour the humans are wearing) and rats coming from the undergrowth biting any exposed flesh or chewing through any non-metal armour to get at the flesh. Once the humans are trying to defend against hundreds of small animals coming from above and below, larger predators like wolves and bears attack, possibly carrying sharp stick wielding or rock throwing apes. If the animals are really smart, they'll try to injure and maim the humans as opposed to outright killing them. This way the intruding humans will return to their various settlements blind, with missing limbs and disfigured faces. This should prove a good deterrent to anyone else considering going to that particular forest. [Answer] Your initial information seems to be weak when you say humans were banished from the forest. That itself means they were forced to go out of forest by some entity. I would start from there. You need to figure out that reason. I could see multiple way of seeing this as possible even in our future. Global warming causing vast flooding of coastal regions and causing swampy lands leading to massive human death and destruction of global interconnected world. This would make humans pretty weak. I would start on this premise. The Problem of animals teaming up to fight humans is they are not same species and we humans are also animals yet we ourselves as one species cannot act together. So, an idea of tiger, monkeys, elephants teaming up against humans is a total load of BS. Unless your genre is fantasy where you have talking donkeys I would not take that path. I would do following 1. make humans weak and small. A dystopian world caused by humans would level the field. 2. make the world harder for human civilization to flourish. It could be swampy land in most of the available land infested with mosquito and other deadly pests making farming very hard even with technology. 3. create a culture of anti technology in humans who have seen evil of technology and have pledged to not use it. Now add characters in this story. Those 15 invading humans would be stopped not by animals but by other humans who dont want to spoil forest like their spoiled fore forefathers did. you can make any one a protagonist and other antagonist. [Answer] i read plenty of excellent answers, some of them actually similar to my thought, but I still miss two things where additional animal advantage over people lies: intelligence and stealth. Let's start with intelligence. It's critical since you mention the forest is large and animals cannot guard all of it at once. The answer to that is focusing the attack only on humans actually trying to raid the forest. Put predatory birds on patrols. They can distinguish a prey (rodents and small birds) from a height where they are barely visible to humans (and absolutely out of reach of any medieval weapons). For example peregrine falcon can spot pigeons while flying on an altitude of approximately 1 km. Only best bows can reach that high but if you add the capability to stoop at over 320 km/h they are virtually impossible to destroy for your humans. At the same time they can easily spot a single human nearing the forest, not to mention larger group. This way your animals will be able to recognise the danger (including details about number of enemies and at least partially armory and weapons) and focus in the areas where the humans are heading. Make patrols in pairs so that one of the pair dives to pass the information (unless you think of other means of communication, which is probably also possible) while the other keeps the patrol. Keep patrols airborne all the time during the day. Other way is recognizing what actually humans are heading for. You may allow once now and then the humans to actually reach their target, carefully analysing what do they collect. Then recognise those plants and other stuff and set traps and ambushes on the paths leading to where those collectibles can be found. You may even poison some of the easier reachable sources if you don't need them for other purposes nor does it contaminate the forest in some other way (natural poisons should do). Finally on a closer range and for night attacks you should use animals with excellent hearing as well as smell to track signs of an approaching attack. Put them in strategic posts depending on the wind direction to maximise efficiency. Now the other advantage is stealth. Animals can mostly go unnoticed. You can literally pass them by meters and not notice. Of course this capacity will depend on specific animals but most probably you'll be able to use venomous snakes/lizards as well as amphibians and insects and arachnids to get really close to the target and larger animals close enough for a fast attack staying either out of range of in general invisible. Now your attacks should be fast, best to attack enemy's leader first as it might put the morale down do the point where the rest of humans will just run for their lives. If everything else fails an open attack as described by others will work. But you should be able to scare off most of the intruders without actually showing yourself. A cone or a stick dropped in the right moment might be enough. If it's excrement it becomes a visible sign - if you continue you will die. If this doesn't help, make a stealthy attack at the leader (venomous snake or spider biting and escaping) and if it still doesn't help just put them down with the rest of answers. [Answer] If it's a whole forest of intelligent creatures working together to fend off the invaders, then what these invaders are attempting is nothing different than a mob covered in ski masks and baseball bats in their hands strolling through a town. Getting by unnoticed? Having the upper hand? Mere fantasies. As soon as they wander into the forest, it's enemy territory, and with it their rules. They're quiet by nature, camouflaged from birth, they know the territory. Literally, they have eyes in the sky. And now there comes a mob of humans, in tinny armors, making enough noise for the whole forest, and you think they actually stand a chance? Well, actually they've got a chance - if the animals are just as divided as humans are, or if they're afraid of death. If none is the case, then basically anything works. But Guerilla tactics are always an easy answer, can your weaponry really muster up to their armor? If not, if you can't actually use your surprise moment to kill them, then the tide of battle can easily turn, and with their range advantage (crossbows) they can still inflict damage onto you while you're retreating. So while it might work, it'll still have it casualties. I'd say: Forget tactic genius, and go with the two most basic strategies one can come up with: 1. Bring the bigger army 2. Surround them. Given your eyes in the sky, who are also adept as messengers, and the fact that they're in your home turf, both should be childsplay. So you come at them with numbers, and you don't stop till they're dead. Even if it turns out your losses aren't actually that great, it's a powerful deterrent - a mercenary, no matter how dumb, can figure out how much his pay is worth if there's no chance to make it out alive. So in the long run, it might still be better than any sophisticated tactic. [Answer] Unless the humans have a significant upper hand size-wise (e.g. human vs mouse), or the animals have a particular weakness (e.g. thin long neck); a human will generally lose to an animal in hand-to-hand combat. What puts us on the top of the food chain is our intelligence. Even though we don't have a tiger's claws, a boar's tusks or a gorilla's pure strength, we've learned to cope by creating tools that perform the same task for us. This is our winning factor: you can swap an equipped tool and are thus able to overcome multiple situations. Animals have two obstacles to overcome: their lack of intelligence and the fact that their physical toolkit is tailored to a particular environment. In your example, you're assuming that they are intelligent *and* you're putting them in their environmental comfort zone. This means that your animals have a decent chance of winning; at least they can put up a fight as well as any decently prepared human could. So it's really up to you here. The win/loss expectation fully relies on who is prepared the best and the battlefield tactics they use. > > To take care of that, **some of the animals are responsible for keeping the forest's boundaries safe**. > > > Suppose a group of "mercenaries" enters this forest after the goods. They're armed with medieval weapons (swords, lances, crossbows, heavy armor, traps, nets, etc) and **they're experienced in fighting in groups against animals** (meaning none of them will shit their pants at the sight of a lion). > > > If some of the animals are responsible for keeping the forest's boundaries safe, and they are intelligent, does it not stand to reason that the animals can therefore be equally prepared for/experienced in fighting invaders? --- The core of the answer here is that you've taken away every factor that makes a real life animal generally lose to (prepared) humans in a fight. They are intellectually equal and physically superior to the humans (though that physical superiority can be negated if the humans correctly prepare - but then the animals can counter that counter, and so on...). This means that **the animals can be considered as likely to win as the humans are**. It all hinges on either side's preparedness and tactical prowess. [Answer] I think groups of intelligent beavers could really fuck humans up. Fell some trees and let them roll down the hill towards the humans. Or almost fell some trees and let them fall on the humans. Build some dams, lure the humans in front of them, and make the dams break. If the water is not deep enough to drown them, send your otter friends after them. Let us see how strong those evil humans with their weapons are when they are up to neck in the water and a otter (or a rat) is diving up their trouser leg and biting them where it hurts. Rearrange some rivers to block the humans everywhere they want to go. [Answer] **The animals own the night**: Overrun the human camp at 3 AM (when the human reactions of the sentries are at their worst). Use overwhelming numbers and overwhelming force. Rout and scatter the humans to destroy their leadership's ability to respond, and hunt down each individual before dawn. Display the bodies near likely forest entrances to deter future expeditions. No survivors. Fear of the forest is the animals' greatest protection. [Answer] Direct attacks are stupid. So don't do that most times. The idea is to demoralize the humans. Start with insects and smaller things, then steal everything you possibly can. The idea of using large animals for everything isn't viable--there just won't be enough of them. Also, large animals eat smaller ones, and that means intelligent animals eating other intelligent animals. Do not underestimate the inability to work together because of that. Given that they are intelligent, they have to have a REASON to join this fight. Someone or something has to lead and unify the forest. Night is the best time to attack. Meanwhile, they should be tracked. Direct attacks are possible, but should be the last thing done. Here's what I would do: * Poison a creature that's good to eat after stealing all the food supplies. Allow that animal to be killed by and eaten by the humans. The meat is poisoned and this will weaken or kill the humans. * Look at the route that the humans are taking, and note the resources there. Paint or inject the normally edible berries with a virulent toxin. * Poison darts. Not that hard to build, and cooperative frogs or whatever would give you what's needed (the frogs don't have to die!) You can also tie some to berry bushes in the hopes that they prick themselves. * Traps can be built, and animals can "corral" the humans, forcing them in a particular direction or separating them from each other. * Have a strike team whose only purpose is to steal weaponry and tools. Insects, stinging insects might be a good way to get someone to drop their weapon. Other animals should be there ready to pick them up, either to dispose of them or put them to use. Disarming and training animals to disarm men should be a big part of training. You can have a few large animals whose task it is to disarm, and others that run in and take the weapon off the field. * Sabotage everything. If they have tents, send mice in to gnaw at the ropes, steal the food. Anyone on lookout for the evening isn't just watching for large things. It's also small things. And you can't really move about at night because, well, that's suicide. * Set a false trail. If you know what the humans are looking for and there's a way to get them to go to the wrong place, do that. The more time they spend looking for it, the more resources that they expend. Get them to go where you want them to go. * Hide what they are looking for. If they have a map (which in a forest isn't always worth much) find a way to camouflage what they are looking for. * Use the environment and natural advantages. Some animals are lighter than humans, they can cross ice that men might fall through for example--get a human to chase you across that ice, and soon, they are freezing to death or drowned. This can be done in plenty of other circumstances (this is just one example) such as using the trees when the ground has a trap you've set. Using scent to warn other animals about a trap that humans can't really detect. The beaver dam in another answer was perfection. This is broad because it's specific to the type of animal and environment present. * While you might not have weapons or tools, the humans do. Steal them, and if you can, use them. * Take advantage of fear and awe. Skulls of the dead hanging from trees, perhaps signage advertising that humans are not welcome. * If the animals are united and not afraid of dying for a noble cause, attack in numbers. Do this on the first day, not as they are getting close to the source. Give them open wounds. Throw poo at those open wounds. Infection is no joke. * Don't target all of them. Target one of them. Kill your target. Sure it's less of a share to divide (a plus for mercenary types) but it also might give them pause. * Make night unsettling. Assign owls and other night creatures to make periodic unholy sounds so nobody gets a good nights' rest. Then one night, just when they've got used to it-- no noise at all. Do that for two nights, and maybe see about killing whoever is on watch. [Answer] I like big and small armored animals. The animals have trade goods humans want and the animals can find sympathetic blacksmiths willing to make armor for them. Scenario Human Government Against the Animals: Every war had turncoats, spies, and conflicted humans on every side. Throw in making the blacksmiths personally rich with the trade goods and you would have armor for the animals constantly being produced. The blacksmiths may have to hide their work but when has that not been the case in war? Scenario Human Government Sides with and Protects the Animals: Blacksmiths many be able to openly supply the animals and become the main source of wealth flowing from the forest into society. Blacksmiths become a new merchant class along with their other blacksmith works. Leads to very creative armor designs and modification for different animals. The trade for exotic plants, roots, & seeds could drive the development of carts and wagons with harness a bear, deer, elephant, etc. can pull with and settle into without straps to bring goods to the blacksmiths. I also did not see rhinos in the other comments. Very mean, VERY strong. [Answer] Love your idea. For an oddly-real world example of a similar situation - depredation by ravenous humans, animals simply trying to protect and provide for one another in their native land - check this out: <http://mentalfloss.com/article/567185/german-and-russian-wwi-soldiers-fought-wolves> This may give you some hint as to how animals can fare against humans when working together - as well as keeping with the European-esque biome you might be seeking (a la Maleficent), instead of Japanese hornets and the like. Keep in mind that these were starving creatures facing against modern(ish) technology. Your creatures would very likely fare much better. Another real-world example, and more in keeping with your time period, was the Beast of Gevaudan, who eluded and faced off against many full-grown men for a long period of time while also slaughtering around 100 people. [Answer] This can go one of two ways... # Natural Defense vs. Learned Tactics A natural defense (which could be induced magically and quickly) would be something natural about the animals and area of forest to protects it from humans. EG: the air is toxic to humans but not the animals. In fairy tales this is often seen as a "tainting of the land" where-by anything in the area is unusable by humans, and being in the area may be detrimental to humans over time. This has nothing to do with intelligence once done, but an intelligent force may have inacted it. EG: all the creatures of the forest could have prayed to a forest god to protect them, so the forest god shot spores out from musrhooms to cloud the air and make it toxic to humans. Maybe even just make an impenetrable ring of toxin around the forest to keep the humans out while the creatures lived peacefully inside. (Which could lead to the humans penetrating the toxic ring) # Learned Tactics This would leverage intelligence, and would be more about what level of military strategy and tactics the creatures developed. And, that would depend on how intelligent the creatures are. In some fairy tales, creatures are smart enough to know what humans are saying, but are otherwise still animal-like. In other fairy tales, the creatures are donning armor and practicing fighting with swords and smelting metals and such. You have to consider that if a creature reaches a certain level of intelligence, it might go the way of humans are start expanding on it's technology to where it's not "living with nature" anymore. Intelligent squirrels might stop being complacent with living in trees and eating nuts, and instead creating nut farms, little hovel cities in the trees, make equipment out of leathers/woods/etc. The learned tactics route would require you to decide how "militarized" the creatures became. Anything under constant attack would need to adapt tactics to survive, and as such could develop into a militaristic society that constantly practiced in order to stay ready to repel attack. This would lead to them knowing advanced strategy, like setting up traps and things. But, a society that has always known peace wouldn't know how to defend itself, even if they had other advanced technologies. E.g.: squirrels have automated nut farms... doesn't make them great defenders of the forest. So, you'd have to think about how much interaction the humans have had with the forest creatures to decide how militarized and prepared the creatures are. If they could mobilize all of nature at their disposal, then they would just get some poisons (e.g.: from plants) and go poison the human water supply. (Fastest way to destroy a castle in medieval times was poison the water supply... troops can't hold a castle if there's no water to drink). You'd also have to consider the size of the animals. Some forests just have small animals like squirrels. Others have bears and such. If they could just deck a force of attack bears out in armor, those would steamroll any human force. If it's just a bunch of squirrels, they'll need to mobilize other forces, do sneak attacks, etc. You'd also have to decide if the creatures are just defensive, or do they go on the offense. If they're just defending themselves, then they'd stay in their part of the forest and just set up traps or poisons or whatever. If they go on the offense, then they'd have to militarize and mobilize more and actually go raid the humans. And, how would they raid ... they can be sneaky and indirectly attack the humans by attacking their resources (poisoning wells, poisoning livestock, salting the earth so nothing grows on farms, lighting homes on fire while barricading humans in while they sleep, etc.. all can be done without a fight.. just sneak in at night). Direct conflict would require war and attacking. The thing with conflict is, unless one side is wiped out in the initial conflict, the conflict on both sides grows and evolves. If the humans struck first, the animals in the forest would adapt and find out they need to defend their forest. Eventually, if the humans kept raiding, the forest creatures would decide to go on the offensive and do things to make the humans lives miserable (sneak attacks). Most forces go for whatever method will get them the best outcome with the least casualties, so that's why sneak attacks would work. Unless the humans would want to come into the forest and burn the whole place down, they'd have to go look for animals one-by-one. So, the animals doing a direct fight would be more foolish since the humans could face all of the animals and possible wipe them out in a single bout. So, it all depends on how advanced the forest creatures are (technolgy-wise), how big of creatures we're talking about, how quickly the conflict escalates between humans and creatures (as each side gets more and more defensive or offensive, and also starts to modify it's society to become more militarized to handle future conflict), and how far they learn advanced strategy and tactics. Is there some squirrel version of Sun Tzu that shows up and is a master tactician? Or, are squirrels just stuck fighting like the Rats of NIMH? Do the humans get the aid of dogs to go into the forest to chase out the squirrels? Is everyone fighting "nobly" (i.e.: directly), or are they being sneaky and dastardly? Lots of things to consider, with time (i.e.: how quickly things have escalated, or whether it's been a constant back-n-forth) also being a major factor. [Answer] Poisonous snakes and spiders. In a fair face to face combat, humans will have significant advantage. While animals can overwhelm them, the victory can be too costly. What animals can do the best is to use sneak attacks. @L.Dutch already suggested to use swarms of bees and ants. I recommend focus on the insects/arachnids/animals that can: * Approach humans stealthily, likely at night; * Do the maximum amount of damage with their bite; Even when bites are not lethal, having just a few members of the group suffering from those bites may make the whole group turn around. [Answer] They would evolve with us. They'd use their intelligence to make us think they are cute and tap into our natural instincts to care for young. This transition would take thousands of years and one day you may have humans caring for animals as if they are on of our own. E.g. Dogs [Answer] In general, apply guerrilla warfare tactics. If the humans are in the forest for several sleep cycles keep them awake. Sleep deprivation over a longer term is nasty. If the animals do not care about their own lives or are willing to sacrifice themselves, just swarm the humans. A group of 15 with medieval weaponry can't hold off greater numbers indefinitely if they also have to get somewhere, i.e. are not in a fortified position. Can the reason for which the humans enter the forest be removed? If they come for certain berries that have great healing powers, but are useless to the animals, destroy the berries. [Answer] like you said humans would be attracted by greed.... so humans would want minimun loses and max profit. they need to make the humans know that the deeper they enter the forest the less they will get and most they will suffer. the birds and bats could commit random attacks, so they dont have any time to rest or eat in peace wolves will "scream" at the distance to make they think they are reaching the fight but animals will always stay running from any open battle scenario, of course vietnam style traps in the path would help too. if one human falls into a trap that would be a perfect moment to attack (i assume mercenaries will have a close relation, so thats 1 or two less fighters with guns because they would help his friend) animals would have to always choose the moment and place for each and every battle: with this, humans finally know that is better to stay at mommy's home instead of playing rambo the hunter in the forest. if the hunters know that in each expedition at least one hunter dies, that would be a disaster for the mercenary business. no one would want to go, and if they want to hire new mercenaries that would be too expensive ]

[Question] [ So this should probably belong on clothes.stackexchange.com, if there were such a thing, but here I am with a question that I hope is not too complicated or specific for this site. My situation: I've got an order of witches, that try to hide themselves. They've got powers in the area of gravity manipulation and telekinesis, and as a result they can do A) really cool acrobatics to take out foes; B) very efficient long-distance running. But when not doing any of these things, they need to be able to pass for regular women in their society. They live in Sumer, where the dresscode is this: [dresses](https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcTsZ94ckZ4NfFaFtCbbgFv1XGeybOlLKr9J51mR9f9K6x1tGm8tjg) Yup, ankle-length dresses. So, questions: * Can you do acrobatics and/or long-distance running in a long dress? (I suppose one that's wide at the bottom to allow you to stretch your legs all the way) Would it be impossible, possible but very annoying, or easy enough? * If not - can you easily modify a dress (tie it up or something) to allow those moves? * If not - can you do it with a slighter shorter variant that goes down to the knees? I think I could make them have the lowest part to be detachable if that was the case. Other suggestions? Sorry if these seem like very basic questions - I am a male and have never walked in these things before... [Answer] This is going purely on personal experience - but, yes. I’m an acrobat and have done acrobatics in a variety of ridiculous items of clothing (dresses, onesies, you name it). However, having the freedom to move one’s legs makes things infinitely easier, so I would suggest: * Tying the skirts in a knot above knee-height * Having a slit down the side of one leg to increase movement * Having *very* broad skirts, but somehow tying them to the wearer’s ankles, so the fabric moves with the body * Slightly cheating and having culottes or other wide-leg trousers that appear to be skirts/dresses when standing or walking normally. Anything that keeps the legs closer together (i.e. somersaults, handstands, front/backflips) can be easier, because you don’t have to negotiate wading around in yards of fabric. Things such as (aerial) cartwheels, roundoffs, and walkovers (where the legs move at different times) are likely to cause a greater issue, purely because you can’t keep the fabric trapped in place. Having said that, cartwheels can be done with either one hand or aerially, as can walkovers, thus allowing your acrobat-witches to hold their skirts in place while doing epic moves. However, remember the parachute-like effect you’re likely to get if they jump down any distance - having a dress billow up in your face really gets in the way of cool acro. By the way, I’m working on the assumption you’re imagining something more akin to acrobatic tumbling or parkour, rather than static work (contortion, partner/group acrobatics, etc.). If multiple people are involved, skirts can make things a lot trickier, but it *is* still possible to do partner acrobatic work in a dress. Happy to edit if you want more thoughts about the logistics of static acro while wearing a dress. [Answer] Men in that era wore similar clothes. Have your women do what the men did. [Girding Loins](https://www.artofmanliness.com/articles/how-to-gird-up-your-loins-an-illustrated-guide/) [](https://i.stack.imgur.com/bkIET.jpg) [Answer] Japanese martial arts often use a *[Hakama](https://www.japan-talk.com/jt/new/hakama)* to obscure the movements of the feet and legs, preventing an opponent from understanding the nature of the offensive/defensive moves based on the posture of the legs and feet. Knowing which leg is forward or which foot is carrying the weight would be a great advantage in planning the countermove or defence for a martial artist. Your witch coven is likely in the same sort fo position, wanting to obscure their abilities until the last possible moment to achieve surprise. A Hakama-like garment will look very much like ordinary outerwear, until suddenly it doesn't.... [](https://i.stack.imgur.com/wudhS.jpg) *Hakama in a standing posture* [](https://i.stack.imgur.com/VxloR.jpg) *Hakama in a fighting stance* [](https://i.stack.imgur.com/8Edl0.jpg) *Hakama in action* [Answer] Here is a marathon runner in a long dress. <https://youtu.be/j-U6uv7zEhs?t=38> <https://youtu.be/j-U6uv7zEhs?t=267> Note that she also wears sandals!!! --- With regard to acrobatics, modesty is a problem. Either they can gather up their skirt as suggested by Jedediah or they can use a split skirt. These items appear to be a normal skirt when walking normally or standing but allow more extreme movements when necessary. [](https://i.stack.imgur.com/ItJwx.png) [Answer] They could borrow an idea from Victorian women and use a [**Skirt Lifter**](https://en.wikipedia.org/wiki/Skirt_lifter): [](https://i.stack.imgur.com/mcvyG.png) The picture shows an 1870 example, provided by the Portable Antiquities Scheme / British Museum. Their description (with my emphasis) is: > > *Victorian dress lifter*. Dress lifters were used to prevent long Victorian dresses from trailing in the mud. The two circular discs would be placed around the hem of the skirt, and could be locked tight by the device at the top, which is decorated in the shape of a seashell. A cord was attached to the waist and threaded through the holes of the locking device. This meant that **once the lifter had been attached, the skirt could be hoisted up or down without the need to bend or use hands to lift the dress**. > > > The Wikipedia page (which hosts the image) further says (also my emphasis): > > A skirt lifter [...] was a device for lifting a long skirt to avoid dirt **or to facilitate movement**. It clamped on to the hem and was attached to the belt by a cord, ribbon, or chain. > > > --- I can now see a line of advancing witches who – at the first sign of trouble – simultaneously start to raise their skirts in a manner akin to a Roman blind before leaping into acrobatic, foe-kicking action! ]

[Question] [ After nearly a decade of development and public prototypes, the Mizaru company is ready to unveil the cybereye. A fully cybernetic eye that provides its user/host with high definition vision, enhanced zoom for the more expensive models, and ability to take photos with a special blink. Originally the cybereye was for the visual impaired or amputees who lost their vision in an unfortunate accident, but now the market has opened to people with rather poor vision wanting a permanent fix, the rich and vain wanting different eye colors or patterns in their eyes. But Mizaru has run into a problem: what could be a small and compact power source for the cybereye that isn't intrusive (by intrusive I mean further surgery) preferably it would be within the eye socket. Note: Near future tech. Fusion is available however I don't know how effectively nuclear can be miniaturized. [Answer] Although I like the classic cyberpunk concept that states that nanomachines build a small turbine generator in one of your biggest veins (like the inferior vena cava), I understand you want something built into the eye... What about an enzymatic generator? It extracts energy from the sugars and fats of your body. You can make it tap into the bloodstream, and wouldn't need a battery (although you probably want to combine with one so if you start using the advanced functions it won't leave your user craving junk food or worse, in a hypoglycemic coma). **SIDENOTE**: The enzymatic generators DO exist. It's something the army has been researching because theoretically they can be fed anything organic, so can be very useful. Of course the army ones tend to be on the big size, but can be made today as [small as an AA battery](https://www.extremetech.com/extreme/175137-sugar-powered-biobattery-has-10-times-the-energy-storage-of-lithium-your-smartphone-might-soon-run-on-enzymes), if fueled by pure sugar. They have organic compounds (the enzymes that break down the sugars and fats) that degrade over time (or worse, can overgrow), so your cyberenhanced user will need to do regular maintenance (maybe once or twice a year) to keep the battery enzyme levels on check. **SIDE-SIDENOTE:** As I noted in the comments, right now we have the technology to make a decent camera the size of an eyeball and power it, we lack the way to interface it to the brain (and we are reaching there, although right now this tech is very inaccurate and the size of a kidney pouch). The other main problem we have to deal is temperature: CCDs and CMOS are sensitive to temperature and the first are specially prone to overheating. I thought about the enzyme generator because we can use the blood to take away some of the heat in the process, too. For similar reasons I discarded induction, as the efficiency tends to be very low and the rest of the energy dissipates as heat. [Answer] Batteries can be made quite small today, and batteries can be recharged wirelessly by magnetic resonance. So feasibly, the battery could be implanted in the temple near the eye and be recharged by putting a charger against the temple. It might also be possible to charge the eye simply with the light that enters it. If the battery is running low, just stare at the sun for a few minutes. [Answer] # Body Heat AND Solar Power This has already been done successfully with [this](https://www.powerwatch.com/) smart watch. For solar power, eyes are open for the majority of the time you are awake and a cybernetic one could charge through light energy as you go about your day. Of course, this would just be a supplement to the main source of energy, body heat. The eye socket is *inside* the body, which is always much warmer than our outer-layer of skin, especially our wrists. If the [smart watch](https://www.powerwatch.com/) mentioned above can have so much functionality (step tracking, time, gps, heart rate, calorie counter, etc) while only running on body heat from an extremity, imagine the power that could be generated from a place closer to the center of your body and embedded in it. And technology will only increase in ability in the future, so I think this would be a very plausible solution. [Answer] Muscle movements In an [automatic quartz clock](https://en.wikipedia.org/wiki/Automatic_quartz), the wrist movements cause the rotation of a small pinion, which is connected to a small power generator. I think that somebody willing to implant an artificial eye in place of his own one, wouldn't mind having another dozen of small implants in some other places of his body plus a more invasive surgical operation. So, he could implant small mechanical generators in some of his most-used muscles of the head (neck, jaw, shoulders), which would be cabled to the eye in order to power it. The daily movement should generate enough energy to power the eye, while during the sleep there would be no need to power it. Morevoer, in case of low voltage, the wearer could move his head or jaw to generate extra power (which, of course, could make him look a bit awkward in public). The only diffulty would be how to connect the generators to the eye: they could implant some under skin cables to the eye (simpler but less elegant solution), or they could have developed a technic of using organical tissues as electric waveguides [Answer] A glucose based fuel cell would be a good fit. The fluid around the brain is full of glucose. The fuel cell and a brain/machine interface circuit would be placed somewhere inside the skull. The fuel cell would use that glucose to generate small amounts of electricity to power both the eye and the interface between the eye and the brain. The eye would plug into that interface using a plug at the back of the eye socket. <http://large.stanford.edu/courses/2014/ph240/ho2/> **With respect to a solar powered eye:** The sun puts out about 1000W/m^2 at sea-level in the middle of a bright sunny day. Assuming the sxposed surface on the front of the eye availbe for a solar panel is about 1/2 inch x 1/2 inch then that equates to about 1/6W of available energy. Todays solare panels are about 20% efficient at best, so you would be able to caputure about **32mW peak** if staring right at the sun in the middle of the day. On aveage the suns output is closer to 340W/m^2 averaged over a day so **the average delivered power would be closer to 10mW if the eye stared at the sun all day.** Of course if the eye is indoors or looking away from the sun most of the time then **the eye is likely to receive less than 1mW of average useable power**, and for solar to be viable the eye would on average need to consume less than 1mW. [Answer] Try using the same thing which powers **a cybernetic ear**, or what boring people call "a hearing aid", which is typically **a tiny lithium battery**. [Answer] ## Owner's blood! + Light + Blood additives Because: * It does not requires much space, which you don't have. * It is abundant in the body. * It does not interferes with mechanisms of vision. Additionally: * Photovoltaic panel. * Blood additives that makes blood more efficient. See also: * <https://en.wikipedia.org/wiki/Biobattery> * <https://www.insidescience.org/news/could-pacemakers-be-powered-sugar> [Answer] Glass eyes have existed for a while, and can be removed and re-inserted at will. While a cybernetic eye would need to have an interface into the nervous system, that piece could remain inside the skull, powered by the cyber-eye. This lets you pop the cyber-eye out at the end of the day, put it in the charger, and go to sleep. All of this is basically within our current technology; we just need to figure out how to interface with the nervous system and get better battery tech. It also lets the company sell you a variety of cyber-eyes without needing surgery to swap them out. [Answer] Triboelectric nanogenerator (TENG) driven from motion of the eyelid. There is a cool little article on the U-TENG from Clemson Univeristy, which you could build yourself. Blink a few times and simple static electricity buildup between two conductors (one in the eyelid, and the other in the eye) would be enough to the boot the eyeball OS, otherwise known as Eye-OS, which is incredibly cool just by itself. [Answer] **Battery, changed daily.** As part of her wake-up ritual, your cyborg will swap out her eyeball. The swapping probe goes straight into the pupil, so it's easy to do it oneself. The eek factor passes after the first dozen times. (optional: after a few unfortunate accidents, the swapping probe has a camera and AI to sound a loud alarm if a sleepy cyborg with a single cyber-eye is about to poke their other eye) Some hygiene applies, but no surgery-grade stuff. The eyeball is detached from a machine-machine interface. Except for the eyelid, all machine-meat interfaces are fixed and unexposed and take surgery to mess with. The fixed machine parts take energy from the swappable part. The optic lenses and other components are in the eyeball and are swapped out with the battery for engineering tradeoff reasons. The new eyeball has a new set of each of these, a duplication that would otherwise be unnecessary. The old eyeball spends the day in a wired charger and becomes a new eyeball. A more cost-conscious consumer with one good natural eye could make do with taking their eyeball out to charge overnight and get it back in the morning. It's not like you need both eyes to dream. [Answer] Since we're already doing invasive surgery to hook it up to the eyeball.. Lets go Bio-punk! How about getting some cardio tissue (like that found in the heart) and building a sort of electrical generator using the body's existing autonomic nervous system to trigger it. Essentially you'd have a muscle pumping in time with your heart, mechanically pulling a little electrical dynamo to generate power for your implant(s) Properly hooked up, the tissue would operate off the body's existing biology with no further effort, no caustic battery fluids, reliable power for as long as your heart keeps beating and minimal maintenance or heat-buildup. [Answer] **Clockwork.** Just have a little clockwork generator in the skull with a key socket accessible in the temple. You can wind yourself up at night. My solution has the advantage of looking extremely cool/ridiculous, and of being usable on long camping trips away from the grid. The only very minor issue is if you overwind, the spring snaps, and twangs into your brain instantly lobotomising you. ClockEye Inc. accept no responsibility for out-of-parameter use of their products, however as a goodwill gesture, any customer or representative presenting a doctor's certificate for severe frontal lobe trauma linked to any of our products will receive a free six month subscription to The Reality TV Channel. [Answer] I'm surprised no-one here uses an [electric toothbrush](https://www.explainthatstuff.com/inductionchargers.html), or has seen [contactless phone charging](https://www.mobilefun.co.uk/blog/wireless-charging-guide/). So your eye has a rechargeable battery in it which gets topped up wirelessly at intervals. The charging coil would most likely be built in round the outside of the iris. Every so often, you'd put on a glasses frame with a charging surface over one eye to recharge it, of course only charging one eye at a time so you can still see. The eye has to be very low power, otherwise the heat dissipated will cook the flesh around it. So we already know we don't have much power drain on the battery. Hearing aids tend to be a yearly battery swap. Allowing that cameras and associated electronics use more power, you might only need to charge your eye every month. Note that although the battery is small, charging will have to be relatively slow compared to regular electronics. Batteries warm up when they're being charged, and again we don't want to cook ourselves. So once a month, you put on your "charging glasses" for the evening and watch TV with one eye, while the other eye charges up. Pretty simple really. [Answer] There's some advanced tech today that can run on body heat, but as this is sci-fi, you can take that much further and run with that idea. So ideally instead of building a storage system that has to run infinitely or be replaced, you'd have it get energy from the body's own systems. Maybe from the beating of the heart, or glucose in the blood stream, or even oxygen in the blood stream. I mean you've got a power source right there in the human body, so why not use it. But some of the functions are far beyond what regular eyes do, so I would think those functions would take extra energy. In that case, you'd want storage. Basically a tiny re-chargeable battery that temporarily stores energy (like a solar battery) but can't hold a charge for very long and constantly has to be renewed. Either it stores energy while you sleep (in which case the extra functions are limited in a per-day capacity) or it stores excess energy as you go, in which case the capacity to use the extra functions will "recharge" in a few minutes/hours or whatever. [Answer] I'd suggest a small [thermogalvinic cell](https://en.wikipedia.org/wiki/Thermogalvanic_cell) it uses low heat differential to generate electric current directly. You just siphon off a little bodily heat and create energy. Furthermore it would use liquid/fluid so it could look and act like a real eye ball full of jelly and everything. [Answer] Plutonium powered RTGs ([Radioisotope Thermoelectric Generator](https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator)) were used in pacemakers in the 1960s. [Betavoltaics](https://en.wikipedia.org/wiki/Betavoltaic_device) were used in pacemakers in the 1970s. Not the most practical method per se, but nuclear powered eyeballs has a cool factor that's hard to beat. [Answer] ## Just plug it in Let's face it - what could be more cyberpunk than an illustration of someone with a cable stuck in their eye? Use standard rechargeable cells within the eye. Have a power socket in that eyeball that becomes accessible by rolling your eyes. Impose a requirement to plug it in for five minutes every X days, with X determined by the needs of your story. Alternatively, the eye can be removable, just as current cosmetic eye prosthetics are. In that case, someone could be using just one eye while the other is recharging, or a rich person could have a spare eye or two to use during charging. But the cable-in-the-eye visualization is a powerful, gritty image that sets the tone for the entire setting, so it may be a stronger tool story-wise. [Answer] Depending on your power draw, it may be possible to run your implant entirely from the [patient's own body heat](https://www.newscientist.com/article/dn5091-power-implant-aims-to-run-on-body-heat/). If it's particularly high you may still need to replace the battery, but having it constantly recharge will extend its life, reducing the number of battery replacement surgeries required. [Answer] Just make the eyeball removable. I have a friend with a glass eye and he can pop it out whenever he wants. Mizaru surgically implants the "port" in the skull and interface to the brain, then the eyeball just slots into the socket/port. The eyeball could contain a battery and it could easily be replaced or recharge with the eye out. The best part of this is that you could have multiple eyes with different aesthetics and functions. [Answer] # Blinking Blinking is a reflex reaction that happens multiple times per minutes (15-20). Coopting the blink reflex for energy production could be as simple as adding a piezo-electric element to the muscles responsible for blinking. Of note, this could be done with much larger muscle groups as well. For example, chewing food could generate electricity, at the moderate cost of just a slightly harder bite, which the body would compensate for in a matter of weeks anyway. A separate mechanism could be used to couple/uncouple the piezo-electric elements so that the resistance could be turned off and on, in order to remove forces that impair movement. For example, you gluteus maximus (butt muscle) could have its generating elements disengaged in response to high adrenalin (Fight or flight) so that all of your body's resources can be used free from resistance in an emergency. Secondary would be that piezo-electric elements can be used to generate force using power instead of the reverse. In essence, you could use an external power source to increase resistance to motion, getting muscle training using everyday actions. You could then deactivate the resistance for maximum muscle power. [Answer] **Radiowaves** The actual energy requirements for an eyeball are pretty tiny, and much of it is directly provided from photons hitting the "retina", so you power source doesn't need to be high voltage. Meanwhile, our world is bathed in a whole range of electromagnetic waves both deliberately produced for TVs, Radios, and mobile communication, and spewed out as waste by a host of electrical equipment. A small antenna, located on the front side of the eye behind the iris, could yield sufficient energy to charge the small battery that then drives the eye's additional functions. [Answer] **Compressed Gas Energy Storage** The challenges and risks of integrating this storage solution are minimal at best and can be overcome in the initial phase. [Answer] ## A quartz crystal We used quartz crystal to make watches before electronics and batteries were invented. The quartz has a properties that allows to transform mecanical forces into electric charges, and vice versa. For old watches, you had to move the wrist a few seconds to "recharge" the quartz for a few hours. In your case, the quartz could be linked to the muscles of the eyes: when the muscles move, the quartz charges itself. You wink between 10 to 20 times a minutes, and your eyes moves a lot more, even in your sleep, you could thus have an infinite source of energy for the quartz. ]

[Question] [ My story takes place on an Earth-like, inhabited world that is far larger than Earth, has roughly 110% of Earth's gravity, and has unusually high (and generally unexplained) EM emissions permeating its atmosphere sufficient to disrupt radio transmissions beyond a few miles. Humans from earth have begun to settle the planet, primarily big corporations seeking to exploit the planet's rare natural resources. Wheeled transportation between settlements isn't very practical due to the great distances between settlements. My story revolves around high speed ground-based transports, so I'm looking for plausible reasons or obstacles that would help explain why traditional jet/rocket/prop-based air travel is not practical. Important notes: * Atmospheric pressure at the surface is roughly similar to Earth's (*another problem I'm still working on*), but with a higher ratio of nitrogen to oxygen. Mean Climate, radiation levels, etc. are also comparable. Much of the time, humans can survive outdoors on the planet just fine using rebreathers, although both the daily and seasonal temperature variance tends to be a bit more extreme than Earth, and the days are shorter. * The first settlements on the planet were exploratory, inhabited originally by scientists and supporting bureaucracy & infrastructure. These early settlers discovered trace quantities of a previously unknown compound with certain highly valuable properties. This gave rise to **multiple** competing private interests investing heavily in tracking down concentrations of the stuff large enough to make harvesting it worthwhile, despite the distance between said deposits and other environmental challenges. Many such clusters have been found but tend to be very far apart (and a single corp tends to claim a large area whenever a cluster is discovered in hopes of finding more). * The ground-based transports actually levitate in a manner similar to a hovercraft, but using a hypothetical thrust technology (which is dependent upon the same resource everyone's hot for in the first place). This gives them enough lift to easily clear obstacles like rocks and shrubbery, and even water -- and taller obstacles, too, for short periods -- but not enough to actually fly. A variety of more conventional engines are used to provide directional thrust. [Answer] > > I'm looking for plausible reasons or obstacles that would help explain why traditional jet/rocket/prop-based air travel is not practical > > > **Killer pigeons**. Well, not exactly your ordinary *columba livia domestica*, but pigeon-analogues nonetheless. They live almost everywhere, breed like crazy, and luckily, unlike their Earth cousins, dislike the noise and smells of human cities and keep to the brush, fields, and undergrowth. They're mostly harmless, *except* that they have this reflex - perhaps evolved to deal with very large predators, now understandably extinct - to swarm and attack whatever flies and is sufficiently larger than them. They will roost on an airship and tear it to pieces in a killing frenzy, they'll overload the most powerful armored drone, and they will kill themselves smashing against a landing shuttle at the highest speed they can attain. And they will foul all kinds of enclosed or non-enclosed propeller with their pseudo-feathers and down and blood, [choke jet engines](https://www.youtube.com/watch?v=oUIgzf6qLfw) with their bodies, and nine times out of ten they'll even succeed in killing anyone that succeeded in ejecting unless they reach the ground quickly enough to make the attack stop. In the country, boys will dare one another to fly kites, to watch clouds of shrieking berserkers tear them to pieces. Poisoning the pseudo-pigeons is impossible without covering the planet with poison; gengineered pathogens risk destabilizing the whole ecosystem; introducing predators is hopeless because they'd be swarmed under; the best that can be done is flying at night, losing one plane in ten, which is totally unaffordable, or using armored, slow airships, which are even more uneconomical; or using orbital shuttles that take off at high acceleration using ground-based lasers, and perform combat-drop landings; which is the most expensive option of them all, even if it *is* done to land tech, outworld supplies, and personnel since it is, after all, the only way. Once an experimental project aiming to *teach* them not to chase fliers, using hundreds of large rocket-propelled cut-out shapes, floundered against the hard fact that the alien pigeons were just *too stupid to learn*, and attacked the thousandth fake plane with the same reckless abandon of the first, Earthmen decided to leave the alien skies alone. So, railway it is. # Can't live with them, can't profit without them Albeit dubbed *pigeons* because of size and general shape, our critters aren't really pigeons; to be sure, they're not Terran *birds* either. They don't behave like ones, nor do they reproduce the same way. The passenger pigeon was adapted to its environment, but [vulnerable to anthropization](https://en.wikipedia.org/wiki/Passenger_pigeon#Reproduction). The main vulnerability was the existence of **nesting colonies**. Disrupt the colony, extinguish the species. *Our* critters are solitary and [r-strategists](https://en.wikipedia.org/wiki/R/K_selection_theory#r-selection), more like insects than birds, and have managed to monopolize the air; the ecosystem has adapted so that they are the only long-range pollinator species, the main source of protein-analogues for a host of scavenging organisms that *also* improve the soil (okay, worms), and several arboreal species have co-evolved so that their seeds are now only viable after passing from a pseudo-pigeon's digestive tract (presumably quite far from the parent organism). In short, not only would removing the crazy psycho-pigeons be exceedingly difficult, it will involve a long-term ecological nightmare. Which we can't afford because it turns out that the precious compound found in the soil is in all likelihood a breakdown product of some kind of complex polyterpene associated with some of those plants' pseudo-bark. The exact chemical makeup and synthesizing pathway not having been successfully investigated yet, much less reproduced artificially (and nothing guarantees it won't be horribly expensive anyway), the various interests on the planet simply **do not dare** meddling too much with the ecosystem. What they can do (and do) is harvest reasonable quantities of pseudo-bark from promising copses, and send them by rail to the processing plants. Railways are deployed by track-laying robots and are reusable, light and sturdy enough to go practically everywhere. It *would* be possible to prepare covered, protected airstrips where a computer-controlled plane would enter at high speed and leave at high speed, but it would cost much more and not be as flexible as rails. The impossibility of long-range communications with planes (and of using radars) also reduces their appeal. What would *really* be useful is helicopters, but *those* are out of the question: they'd need to fly slowly and from, or to, pigeon-rich woods, exactly the thing one shouldn't do. [Answer] **Unpredictable weather with lots of [microbursts](https://en.wikipedia.org/wiki/Microburst), wind shear, tornados, and other unfavorable winds.** Wind shear is one of the most dangerous things for an aircraft. Thankfully they are generally rare, on Earth. If flying isn't a question of if there will be a wind shear, but how many there will be, flying wouldn't be something that you'd want to do. **Very low temperatures and ice clouds to cause constant wing icing.** Airplanes have wing deicers, but at some point the icing can be so bad that they can't compensate. **[Treacherous terrain](https://www.quora.com/Why-don%E2%80%99t-planes-fly-over-Tibet), which would make emergency landings impossible.** You don't want to fly if any attempt at emergency landing is going to be fatal. High mountains and other dangerous terrain would be a big problem if it covers the entire surface, especially if the weather or other things make emergency landing a higher probability. Combine this with unpredictable weather and it gets real iffy. No one wants to be slammed into a mountain by a downdraft or fly into a cloud that's full of rocks. **Huge flocks of birds or other flying creatures that would foul engines.** If there are flying creatures that are either accidentally or purposefully suicidal, then flying would be basically impossible. [**Extreme heat**](http://www.pbs.org/newshour/bb/planes-cant-fly-hot-ways-civilization-cant-take-heat/). Heat can ground an aircraft just as easily as cold. **Fuel shortage.** Flying can take a long of energy, and so not having a dependable, clean, fuel source would be a big problem. If the planet has no petroleum, and bio fuels aren't being produced fast enough, then that would make flying difficult. [**High solar and atmospheric radiation**](https://www.nasa.gov/topics/aeronautics/features/airline-radiation.html) The higher you go, the more radiation you receive. In the event of a solar flare, there can be a big spike in radiation. If this planet had a very active star then that could become a big problem for any aircraft without shielding, and shielding is very heavy. Whatever causes the atmospheric radiation could also be the source of the heavy EM interference. [Answer] ## The air is about 45% less dense than it is on earth. Aviators know that it's not the wings that give you lift, it's the air underneath them. With a 45% reduction, it's equivalent to about 6km above sea, or 2/3 of the way up mount Everest. [](https://i.stack.imgur.com/ASXlz.png) This would obviously come at the price of needing to bump up the oxygen content of the air for humans to live, but it's entirely possible. Some may see a hole here, and that's that the average Jet cruises at [11.89km](http://traveltips.usatoday.com/altitude-plane-flight-100359.html). To combat this, one could say that it's very unlikely that Jet engines would be even remotely close to being discovered without the good ol' propeller plane first. The biggest weakness of this explanation is that rockets would be MORE efficient than if the atmosphere was less dense. This is true, and I suppose rocket-based aviation is entirely possible, and not unlikely... The place i think this explanation stands out is that unlike bad weather and shortages, this is perfectly fine for land vehicles. It's a grim fact, but when people who commit suicide via car exhaust in an enclosed area are found, their cars are empty of gas, meaning that the cars ran long after the people did. [Answer] Okay, I'm going to take a stab at this, and run the risk of having to delete this answer if it turns out my assumptions are wrong. Given what's in the question thus far, though, I think that an obvious choice would be the fact that... **It's much easier to transport large amounts of material on ground than by air.** Both [ventsyv](https://worldbuilding.stackexchange.com/a/92863/29) and [tuskiomi](https://worldbuilding.stackexchange.com/a/92862/29) discuss this in light of atmospheric pressure, but I think there's a bigger issue at play: *Having to lift stuff to move it often ends up requiring more energy than just moving the same stuff.* Given that this is about humans colonizing an alien planet, I think it's safe to assume that they have access to most things that we take for granted today. Maybe not *ready* access, but access no less. If you can clear out a ground path sufficiently to transport things on the ground, and maybe even build even a rudamentary "highway" system (which does not need to involve paved surfaces; this could be a railroad highway system, for example), then going a few hundred kilometers per hour is certainly practical, especially if the atmosphere is thinner than Earth's (resulting in less drag); *and* you don't need to spend energy to lift it all the way aloft just to bring it back down again. There's a reason why lots of Earth transportation is done by land or sea, rather than air, *unless* speed is of the essence (at which point you accept the higher cost). [Answer] Frequent volcanic activity [effectively grounds all current aircraft](https://en.wikipedia.org/wiki/Air_travel_disruption_after_the_2010_Eyjafjallaj%C3%B6kull_eruption). The volcanoes could be located in specific region (along a tectonic plate boundary, for example) that does not endanger settlements. If the eruptions were frequent enough (ten or so per year) they would produce a semi-permanent smog of high-altitude ash that might be unnoticeable to humans at ground level thousands of miles away (as was the Eyjafjallajökull ash cloud) but which would make air travel impossible. [Answer] ## No fossil fuels Fuel availability is a big deal. If the planet doesn't have a good supply of fossil fuels, then everything you do on the planet will need to use other fuel sources. Solar, nuclear, whatever. All of these technologies will strongly penalise air travel. Electric cars (and trucks) are a perfectly sensible solution and even today can be built with sufficient range to cross a continent. Electric aircraft, on the other hand are not generally a workable solution. Giving them sufficient batteries to fly for a useful distance simply adds too much weight. You might get short range quadcopters powered with batteries, but you won't get long range airliners. ## Hardware has to be shipped from Earth Another idea is to realise that this colony is still in its infancy. Sure they're building up their infrastructure, but they don't have the resources or local expertise yet to build aircraft factory so if they wanted to fly, they would have to transport the aircraft from Earth. That's simply not practical. Transporting bulky items between planets is expensive. They'll ship the hardware that they really need, but aircraft would not be seen as a necessity. Land vehicles are smaller and easier to transport when kickstarting the colony, they're easier to maintain in those early days, and they're also easier to build locally once you start building local manufacturing capabilities. [Answer] A very plausible explanation is that the atmospheric pressure is very low thus providing very little lift. This is compounded by the higher gravity. To counter that your airplane needs to have bigger wings (which means heavier) and fly faster. At some point the whole thing becomes impractical. Another explanation is to have atmosphere with high level of ash. Ash can damage the engines thus making flying very dangerous. [Answer] The most obvious answer I can think of is an out of control satellite air defense system that shoots down any moving object above a certain height. The military installed the system but something went wrong and now it doesn't differentiate between friend and foe and shoots down everything above X metres above the ground. They haven't fixed the system because nobody can get into space anymore and the satellites are hardened against being shot down. [Answer] A lot of suggestions here, apologies, I didn't read them all so if this is redundant just delete it. I'm a big aviation buff, so I think I have a simple, easily implemented (not distracting) answer. It's actually quite simple: Make it so that visibility is never longer than half a mile. In real life you need, at very least, a mile for what's termed "[Visual Meteorlogical Conditions](https://en.wikipedia.org/wiki/Visual_meteorological_conditions)". Those are the conditions that are required to fly without the aid of navigation equipment. There are a lot of reasons for this, but I won't go into it here. Just read the article I linked and you'll understand ;). Further, since the planet you describe can only allow radio signals to go a mile or two, there's really no way for aircraft to navigate without seeing outside the plane. All modern navigation equipment is radio based in some form, high EM would make that highly unreliable. The only backup to that system would be to navigate by the stars, but, if the atmosphere only allows for a half mile of visibility..... You can't see those either. Granted, there are probably ways to get around this (I mean, back in the old days people flew long routes by looking for bon fires to guide them.) But I think it's a sufficiently large problem that rail transport would be considered significantly cheaper by most transportation authorities. On top of that, most transportation consumers (who generally fear flying to begin with) would probably be pretty scared of flying in a plane being guided by, basically, bright lights... It would drive down revenues enough that I think sticking with trains would be where the economy went all on it's own. So, yeah, I'd say this is the simplest and most realistic way to go about it. [Answer] Here are some possibilities: 1. Perhaps really bad weather. If there aren't any tall mountains (which would get in the way of ground transport) then the winds would whip around the planet faster. This would make for more chaotic weather. Yes, technology could compensate for that but people usually go for the lowest cost solution. 2. Also, if the communities were all relatively close to each other, it might not be worth the time and fuel needed to lift an aircraft off the ground. 3. The inhabitants are rich. Rushing is for the poor. Taking their time to get somewhere in style shows/improves their status. [Answer] Generally, modes of transportation are determined by economics first and foremost. If you are transporting thousands of tons of rare mineral elements to the space elevator, shipping it via unit train makes far more sense on a cost basis than any other form of transport. High value items with limited shelf lives need air freight, like 747's flying cut flowers from Columbia to markets in the United States. Just in time manufacturing also needs fast and reliable transport, one of the weirdest examples I ever came across is Mercedes Benz using air freight to ship transmissions to an assembly plant in Tennessee. (note, I may have got the manufacturer wrong, but it is defiantly shipping transmissions from Europe to America). Now the OP wants high speed surface transportation, so we need to look at the conditions which wold make this more feasible. There are long distances to cover, high gravity and potentially difficult atmospheric conditions. The planet is settled because of mining, and we are also told there is some sort of EM effect which makes long range communications difficult. So, the priority is carrying large heavy loads of freight, which suggest a railway and unit trains. High speeds might be indicated because the throughput to profitably support an extraterrestrial mine needs to be very high. If weather and EM effects are an issue, then an enclosed line is needed. Vacuum trains have been proposed for centuries, and a long evacuated tube provides the means for high speed transport to and from the space elevator. As a bonus, people can use the same tubes for high speed rail to and from the mines to the elevator (A large service industry hub would develop there, including all the things miners would like including saloons, entertainment establishments of all kinds, casinos, stores etc.). The EM effects can be bypassed by running conduits along the tubes carrying fibre optic cables, phone lines and even waveguides for radio. So everything gets wrapped up through the application of economics. The need to deliver large quantities of mineral ore drives everything else. There might be aircraft and other forms of transport, but they will be largely niche elements for special purposes. The only other major form of transportation which might be feasible is rocket powered landers dropping in straight from orbit and returning to space to deliver critical high priority cargo. [Answer] There is something about the makeup of the one of the outer layers of the planet core (or at least something a few miles down) that is providing a dampening effect for the EM radiation, but it doesn't extend that far out from that layer. More than about 1km up from sea level or local equivalent said EM radiation causes sudden and drastic and usually explosively exciting and terminal or near terminal equipment malfunctions, sparking between various bits of metal like a jacobs ladder, etc. Maybe even the actual EM causing issues with earth-norm physiology - sudden muscle spasms, etc. which could include heart, diaphragm, etc. Sure it could be shielded against just like the landing craft from the exploratory ships, but that would require a size that would require drive technology won't work well near gravitational forces, in an atmosphere (up and down only, no real lateral movement), in that particular atmosphere, logistically effective and supportable, whatever. [Answer] One partial answer not mentioned above is a lack of atmospheric oxygen. If aircraft need to carry oxidizer as well as fuel, flying becomes more inefficient. This would also bias toward high speed rail which I think is what you want, since they would be powered electrically from external sources. [Answer] People are inventive, someone will find a way to fly in whatever world you might propose that is similar to Earth. You already mentioned that large corporations seek to exploit the planet for its resources. That means they are not a unified government seeking to populate the planet as an extension of its territory. Make these corporations competitive, and possibly following a loose code in how to conduct business on underdeveloped worlds. Or they bow to a government which gives them freedom so long as they do not monopolize the planet. Since communication is difficult on the planet it opens opportunities for people to do things that violate the code. It's also quite possible that these corporations have their own military to protect their assets. Or in some cases to seize illegally obtained assets from their competitors. Perhaps all flight transportation is easily monitored from space and must be claimed or it will be seized and distributed by the competitors hence the need for discretion when handling more then is allowed by the code. This also does not rule out smaller competitors who are also allowed to do business on the planet by the same code. Bottom line, I think people are your best bet for limiting air travel. I personally liked the predator idea, although not pigeons. Maybe something that's related to the EM emissions and the valuable resource the corporations want. Just like how the worms in Dune were the reason for a whole planet to be a desert yet habitable and have a resource that eventually defines who rules an empire. Good luck! [Answer] Alternatively, all of your inhabitants could be clautrophobic or otherwise unable to sit comfortably in the relatively cool, dry space of an airline cabin. [Answer] I'll just trow some ideas: If gravity is stronger, that could cause atmosphere to be less thicker, or more charged, and on a bigger planet there are much bigger mountains due the larger movement of larger tectonic plates, so top parts of the mountains usually sticking out from atmosphere, so flying above them requires more expensive technology, than digging a tunnel trough them and vehicles been primary made for transporting big amount of "natural resources", which is easier by ground. [Answer] The big corporations exploring the rare natural resources of this planet releases the previous inhabitants' malfunctioning and randomly reconfiguring aerial matrices of metal (and flesh) cutting laser beams that are not visible to the naked eye under any lighting. In addition, they awaken and release the remaining indestructible fiercely territorial flying swarms of huge killing creatures with excellent vision and other senses including at top flying speeds and at rest. The sky becomes a war zone of random cutting lasers and the vicious swarms. Even the big corporations' protective aerial high-speed tube system travel (like Elon Musk's concept\*) shielding them from terrible weather conditions and their various aircrafts cannot escape destruction from the cutting lasers and swarms. They must travel by ground. Hope this help you. \*See <https://www.thestar.com/news/world/2013/08/12/highspeed_tube_travel_concept_unveiled_by_billionaire_entrepreneur_elon_musk.html> [Answer] There are all sort potential legal difficulties with air flight on Earth- what happens if a crime happens on a plane owned by Spain, heading from England to distant Russia passing over France. It is only because countries are relatively relaxed about jurisdiction that it is not a big problem. Land Transport is a lot simpler- the country you pass over has jurisdiction. Just make your mega-corporations real awkward about these legal issues on air travel then no one will ever fly the relatively tiny corporations that want to supply air travel will be stiffed. [Answer] Trans-dimensional vortices that open randomly and suck in anything within range; once inside the craft is left do slowly die from entropy, and escape is impossible for a lone craft. Or if that's too much- then how bout: Orbital weapons platforms left behind by an ancient alien race; they shoot down anything that gets too high. [Answer] Radiation exposure. The earth is quite well shielded by a magnetosphere, that means we don't get a hard radiation bombardment from the sun. That's one of the biggest problems with space travel - you need to carry shielding. So imagine a world where there's no magnetosphere, or the one that there is is much weaker/closer in to the ground. (None at all would mean lots of radiation shielding everywhere, and would make the planet inhospitable to life). Thus - ground travel is common, because there's more "shelter" from the solar wind, and airborne travel is a radiation hazard - more shielding needed to be 'safe' and thus adding significantly to payloads. Something that's not nearly as much of an issue if you're ground based. This fits in with your EM emissions too. And for bonus points, gives you a perpetual Aurora. [What would happen if earth lost its magnetic field and could it be caused by humans?](http://scienceline.ucsb.edu/getkey.php?key=4793) ]

[Question] [ So in many games you have regions that are bordered on all sides by impassible geography of some sort or another. This has always bothered me as necessary but also acts as a reminder to pull you out of the fantasy. I am looking for some real world examples of geography that could fit the bill and be used as a model. * Area should be 10 miles by 10 miles, though shape is irrelevant, just need the space. * The area should have no more than 2 or 3 access points. These access points should be usable by the average medieval person. Obviously a small group of trained individuals can access from virtually any direction, those don't matter * Biome type is not particularly relevant, though my preference is that it include forest. [Answer] [Tsingy de Bemaraha Strict Nature Reserve](https://en.wikipedia.org/wiki/Tsingy_de_Bemaraha_Strict_Nature_Reserve) may give you an idea: [](https://i.stack.imgur.com/tD94z.jpg) [Source for image.](http://ngm.nationalgeographic.com/2009/11/stone-forest/alvarez-photography) I am happy for the chance to share this awesome image. This is in Madagascar and these sharp formations are limestone. Wikipedia says the name "Tsingy" means "the place you cannot walk barefoot". Nice short word for that. I have never seen limestone weather this way and I don't know why it made knives here, but this is a weird and beautiful way for a place to be impassable. You might get top on top of one and look around but that doesn't really help you find your way. They are too sharp and spaced too far to go along the top. Down below it is a labyrinth, and there are shorter rock knives down there too. I envision this type thing enclosing the area. This makes a different impassable than mile high mountains or lava lakes or quicksand. A dangerous impassable, because you might try. [Answer] A large, deep valley with sheer walls, such as Yosemite Valley in California, USA, should only be accessible from the two ends of the valley. [The Yosemite National Park website](http://www.yosemite.ca.us/formation/) says it is a "deep excavation created by earlier glaciers". [](https://i.stack.imgur.com/sgThJ.jpg) [Answer] A giant mesa (flat-topped mountain) might do the trick, if the sides are steep enough. The Grand Mesa, in western Colorado, USA, has a top that is 500 square miles. That's plenty big for your requirements. If the sides are steep all the way around, some culture would have had to have created stairs or a ladder to access the top originally (assuming they don't have helicopters). If the sides are steep in most places, but there are sloping parts of the mountainside as well, then people could use the sloping sides for access to the flat area on top. I got this idea from Devils Tower in Wyoming, USA (and in *Close Encounters of the Third Kind*). [](https://i.stack.imgur.com/dTfMw.jpg) **EDIT** Thanks to TRiG for suggesting Tepui in the Amazonian jungle. Here's a picture: [](https://i.stack.imgur.com/55vF8.jpg) [Answer] ## A Crater A meteor [impact crater](https://en.wikipedia.org/wiki/Impact_crater) can easily fulfill what you are looking for. [Here](https://en.wikipedia.org/wiki/List_of_impact_craters_on_Earth) is a list of examples that you could draw from. Access points can be as many as you like, made by weathering and erosion. They can be where ever you want them to be on a planet. Likewise, a volcanic [caldera](https://en.wikipedia.org/wiki/Caldera) could also fit the bill. As a bonus, you can get residual volcanic activity as a plot device. [Answer] ## [Andorra](https://en.wikipedia.org/wiki/Andorra) There are only two access points: the upper one with France, not usable in winter because of the snow, and the lower one with Spain. A landslide on the lower road in winter could completely isolate the country (I think it actually happened in the 20th century, but couldn't find a reference) It's a bit larger (180 sq mi) than your specifications, but it will provide you with an example of geography, culture and politics. [Answer] Islands are pretty insular. Each island of Hawaii, for example. (Or *Gilligan's Island*.) [Answer] ## Canyons Virtually any canyon out there is accessible from only a few points (within the area you specified, obviously more in total). You could easily stop them by surrounding canyons. It doesn't have to be small either, the [Grand Canyon](https://en.wikipedia.org/wiki/Grand_Canyon) is an example of that. ## Mountain Ranges Although they're usually bigger than your proposed area, this might not be the best solution, but it would certainly look nice and not suffocating like a canyon could. Japan has many mountains that you could look at, for inspiration. Let's put a picture in there (open in new tab to see it bigger): [](https://i.stack.imgur.com/jfTsG.jpg) ## Dangerous Wildlife You could put a few signs out there and tell the player that there's dangerous wildlife out there, so they should stay back. If they wander off too far, just sic a bear on them and take them down. This also presents the potential of hidden paths that could be explored without being eaten by the wildlife, if the player is brave enough. Although in real-life, the person could fight back, usually get beaten by the bear but fight back nonetheless. There could be roads protected by soldiers, therefore, only a few access points. In general, huge obstacles are a good way to close the player inside a pre-defined space without making them feel restricted. [Answer] 1) a river island. A dangerous, difficult to cross river splits into two and the 2 parts rejoin farther down stream, making an island in the river. A river island — on the planet Earth — can be as small as a boulder sticking out of the water or as large as the largest river islands on Earth. <https://en.wikipedia.org/wiki/River_island> The river can be surrounded by flat land and almost impassible swamps or in the mountains surrounded by high canyon walls. There could be dangerous rapids and.or waterfalls above and/or below the river island. Or maybe the river is full of boat smashing, man eating monsters. 2) A river loop. A meandering river often has a total length many times the total distance from its source to its mouth because it has a lot of loops. Many Mississippi River loops are almost islands. And sometimes a storm will cut through the narrow neck and straighten the river and make an island out of a loop. Of course the Mississippi River has been used for communication by canoe and by steamboat for thousands of years, and presumably there would be many places to land along the loop, so you will have to make the river less navigable. 3) If it can be a city, how about Venice? A group of islands in a lagoon that cannot be easily reached by water if the islands are defended. Or Ravenna, a nearby city that was surrounded by marshes and almost inaccessible when it was the capital of the western Roman Empire. 4) Perhaps a (possibly abandoned) city? This is the size of Babylon as described by Herodotus: > > 178. Assyria possesses a vast number of great cities, whereof the most renowned and strongest at this time was Babylon, whither, after the fall of Nineveh, the seat of government had been removed. The following is a description of the place:- The city stands on a broad plain, and is an exact square, a hundred and twenty furlongs in length each way, so that the entire circuit is four hundred and eighty furlongs. While such is its size, in magnificence there is no other city that approaches to it. It is surrounded, in the first place, by a broad and deep moat, full of water, behind which rises a wall fifty royal cubits in width, and two hundred in height. (The royal cubit is longer by three fingers' breadth than the common cubit.) > > > <http://www.shsu.edu/~his_ncp/Herobab.html> A furlong is 660 feet so 120 furlongs is 79,200 feet or 15 miles, giving Babylon a total of 225 square miles. Of course Herodotus greatly exaggerated the size of Babylon. Vijayanagara, capital of the Vijayanagara Empire until its terrible sack in 1565. The city center covered 40 square kilometers or about 15.441 square miles. > > The whole city was full of gardens, and because of them, as an Italian visitor in 1420, Nicolo Conti writes, the circumference of the city was sixty miles. A later visitor was Paes, a Portuguese who came in 1522 after having visited the Italian cities of the Renaissance. The city of Vijayanagar, he says, is as "large as Rome and very beautiful to the sight"; it is full of charm and wonder with its innumerable lakes and waterways and fruit gardens. It is "the best-provided city in the world" and "everything abounds." The chambers of the palace were a mass of ivory, with roses and lotuses carved in ivory at the top—"it is so rich and beautiful that you would hardly find anywhere, another such. > > > <https://en.wikipedia.org/wiki/Vijayanagara> > > Abdur Razzak, the Persian traveller who visited Vijayanagara in 1440 C.E. wrote of six fortifications before reaching the gates of the royal palace. The areas between the first and second and between the second and third fortification was large and contained agricultural fields, gardens and many residences. From the notes of Robert Sewell it becomes clear that between the third fortification up to the actual fortress, one came across countless people, shops, bazaars. From their accounts the area of the greater metropolitan area of Vijayanagara was about 540 km² which is about 25 times larger than the area comprising the main administrative, sacred and royal centers. The tourist zone itself is limited to the inner urban core. > > > <https://en.wikipedia.org/wiki/Vijayanagara_metropolitan_area> If the greater metropolitan area of Vijayanagara was about 540 km² or 208.495 square miles, and it was surrounded by the outermost walls, and if it was mostly uninhabited after the massacre of 1565, someone could have bricked up most of the outer gates, leaving only a few gates open for entering or leaving the ruined city. 4) Possibly a (possibly abandoned) fortress. Ranikot Fort in Pakistan is believed to be the largest fortress in the world and encloses mostly empty desert. The gates would be the easiest ways in or out and they could be closed. <https://en.wikipedia.org/wiki/Ranikot_Fort> 5) A rectangular plot surrounded by canals. From the description of Atlantis in *Critias*: > > I have described the city and the environs of the ancient palace > nearly in the words of Solon, and now I must endeavour to represent > the nature and arrangement of the rest of the land. The whole > country was said by him to be very lofty and precipitous on the side > of the sea, but the country immediately about and surrounding the city > was a level plain, itself surrounded by mountains which descended > towards the sea; it was smooth and even, and of an oblong shape, > extending in one direction three thousand stadia, but across the > centre inland it was two thousand stadia. This part of the island > looked towards the south, and was sheltered from the north. The > surrounding mountains were celebrated for their number and size and > beauty, far beyond any which still exist, having in them also many > wealthy villages of country folk, and rivers, and lakes, and meadows > supplying food enough for every animal, wild or tame, and much wood of > various sorts, abundant for each and every kind of work. > > > I will now describe the plain, as it was fashioned by nature and > by the labours of many generations of kings through long ages. It > was for the most part rectangular and oblong, and where falling out of > the straight line followed the circular ditch. The depth, and width, > and length of this ditch were incredible, and gave the impression that > a work of such extent, in addition to so many others, could never have > been artificial. Nevertheless I must say what I was told. It was > excavated to the depth of a hundred, feet, and its breadth was a > stadium everywhere; it was carried round the whole of the plain, and > was ten thousand stadia in length. It received the streams which > came down from the mountains, and winding round the plain and > meeting at the city, was there let off into the sea. Further inland, > likewise, straight canals of a hundred feet in width were cut from > it through the plain, and again let off into the ditch leading to > the sea: these canals were at intervals of a hundred stadia, and by > them they brought down the wood from the mountains to the city, and > conveyed the fruits of the earth in ships, cutting transverse passages > from one canal into another, and to the city. Twice in the year they > gathered the fruits of the earth-in winter having the benefit of the > rains of heaven, and in summer the water which the land supplied by > introducing streams from the canals. > > > <http://www.sacred-texts.com/atl/critias.txt> If your characters don't know how to swim, and don't know how to sail on the canals, or the boats are all docked on the opposite sides of the canals, they can only cross the canals where there are bridges. The squares made by the canals seem to have been 100 stadia or about 9.75 to 12.98 miles on each side. But you could make them different sizes if you wanted. 6) Perhaps a very specific setting. The Great Hedge of India was an internal customs barrier in the 19th century. By 1878 the great hedge had 411.75 miles of perfect hedge and 1109.5 miles of inferior hedge, or dead and dry hedge, or stone walls. There were guard houses spaced along the hedge and gates on the roads with customs houses to collect the tax. Imagine a meandering river that loops up to your fictional version of the hedge at two places and loops away from it in between. If the river is wide, or swift, or rough enough, there might be very few places to ford it, and few bridges. And there could be few gates in the hedge on the other side. The segment of hedge could be replaced by a segment of Great-wall-of-China-like defenses if you want. But either way the inhabitants of the loop of land would be left on the outside looking in. This might have been suggested by Buckland in LOTR, between the Brandywine River in the west and the High Hay keeping out the Old Forest in the east. And there is the great wall on Skull island in *King Kong* protecting the village on a peninsula from the dinosaurs. # Added 05-19-2017. 7) Suppose that there is a river running north and south through the No Man's Land Valley between Westlandia and Eastlandia. Westlandia and Eastlandia are often at war, so each has fortified the cliffs on their side of the No Man's Land Valley with walls and a few gates. Thus most of the fighting between Westlandia and Eastlandia takes place in the flatter ground north and south of the No Man's Land Valley. The No Man's River runs north and south through the No Man's Land Valley but it loops a lot, often hitting the east or west cliffs. Thus the No Man's Land Valley contains many larger or smaller sections of flat land that are surrounded on three sides by the hard to cross No Man's River and on the other side by the east or west cliffs with walls at their tops and guards at the few gates more likely to shoot you with arrows than let you in. [Answer] Just a valley to the sea seems reasonable. plenty of fiords answer the description. Sea access at one end, small approaches from other directions. So similar to parts of Norway or in more tropical climes the Marquesas perhaps with valleys almost unapproachable except by sea. [Answer] Swamps filled with alligators and poisonous, hungry animals. Extremely polluted and fast-flowing rivers. Haunted, scary forest with wolves and werewolves, bats and vampires. Minefields. Radioactivity - maybe there was a war or a nuclear event. Extreme weather - tornadoes, arctic cold, avalanches, mudslides. [Answer] In 2014 the ruler of Dubai announced plans for a [climate-controlled domed city](https://www.rt.com/news/172340-dubai-climate-controlled-city/) covering an area of 48 million square feet (4.5 square kilometers). Several such ideas have floated around for other cities as well [[See Wikipedia]](https://en.wikipedia.org/wiki/Domed_city#Engineering_proposals). I can imagine that there will be only a few well-determined exit locations from such a covered city. Artist's visualization of the Dubai dome: [](https://i.stack.imgur.com/LTOLU.jpg) Edit: I created an answer and only later realized the question states "average medieval person". Oops! I'll leave the answer in anyway in case someone is looking for a more contemporary/futuristic alternative. [Answer] Here is a great place to reference the [*Gandalara Cycle*](https://en.wikipedia.org/wiki/Gandalara_Cycle). It has seemingly fantastical geography which surrounds the world of Gandalara with rock walls thousands of feet high (in some places). **Do not follow the link** if you do not want the ending of the story spoiled (or at least, do not read the "conclusion" section of the wiki article). [](https://i.stack.imgur.com/H4DfQ.jpg) In the last book of seven "*The River Wall*", it is revealed that this geography is actually scientifically feasible, but due to central plot piece spoiler, I will not mention why, exactly. [Answer] Have you considered a cultural barrier? In the Stargate SG-1 episode [Brief Candle](http://stargate.wikia.com/wiki/Brief_Candle "Brief Candle") the residents of Argos believed so strongly that their God would punish them if they dared venture outside the confines of their village, that none of them ever tried it. The belief was so deeply ingrained in their culture that leaving the area never occurred to anyone. A simple myth or belief that bad things would happen if they leave, coupled with a negated requirement to leave (by ensuring they have everything they could need and want) would potentially be enough to keep a group of people in one place. While the set on that particular episode of SG-1 was disappointing in that it wouldn't have looked out of place on Star Trek TOS, I did feel the plot was plausible enough to fit your requirement [Answer] Since we're talking about cities, I'd like to bring an example to your attention: **Mantova**, in northern Italy. As you can see [on a map](http://www.openstreetmap.org/#map=13/45.1526/10.7855), Mantova is surrounded on three sides by lakes. The peculiarity is that those lakes are artificial: they were created in the 12th century by engineering the course of the Mincio river, exactly for strategical purposes: to make the city easier to defend from enemy attacks. Back then, the city was completely surrounded by water, as a fourth lake existed in the areas now called "Valletta Paiolo" and "Valletta Valsecchi"; this fourth lake was destroyed and dried because of urban expansion needs and health concerns (the stagnating waters were becoming increasingly unhealthy). The project was majestic (for obvious political reasons), and was intended to make the city "look like an island" to outsiders approaching it. While the Mantova lakes are indeed shallow, calm, and easily navigable, your fictional land could have a similar water body, maybe one that is artificially made stormy or otherwise hard to cross. Sort of like a river island, but an artificial one. [Answer] > > Bordered on all sides by impassible geography of some sort or another > > > Forgive me if I'm reading this wrong, but it can't be literally impassible on all sides, otherwise how would the inhabitants get in and out? Anyway, it sounds like what you're describing is a castle. That was the entire point of a castle; to have very few entry points possible for invaders. And where there was a place for entry points, people created their own impassibility: walls, moats, etc. Here's a random sampling of castles I googled.  --- Also, it may not seem like it to us today, with all of our modern tech like airplanes, antibiotics, and chainsaws, but things like a dense jungle on uneven terrain can be considered impassible. Also, features like **swamps** and **bolder hillsides** can be impassible, depending on what you're trying to pass through. [Answer] Mountains and swamps are popular barrier terrains but I'm thinking an ironbound coast on one edge and forests on the other cutting off a lens of arable farmland near the coast. The ancient North Forest Road is the only overland access route, the forest is cut by deep ravines and river gorges, the road takes the path of least resistance but no-one can believe some of those bridges were built without magic. The wildlife is undisturbed so much of the time that they have no fear of man seeing them simply as meat on two feet instead of the more usual four. The coast is almost all shear cliffs, rocky beaches, and strong currents, like the east coast of South Africa or the northern coasts of the Iberian Peninsula. The single natural deep water harbour acts as an easier access point for the country as a whole and the national capital is also it's main port. The overall topography is pretty flat but travel is still heavily restricted. ]

[Question] [ I'm writing a semi-realistic science fiction story set, let's say, 500 years in the future, where humanity has colonized some of the solar system. For combat purposes, I've been playing with the idea of two common weapon types: 1. a semi-automatic ballistic weapon with frangible rounds, for defense onboard a spacecraft (you don't want to cause a hull breach!) 2. the weapon I'd like to discuss: a laser sidearm. I don't want these laser weapons to have a rapid fire rate or a continuous beam. I'd prefer if they functioned like a musket, with one shot and then a long "reload". My current idea is that each shot uses one capacitor as ammunition; when drained, the capacitor must be removed, then another is snapped in place. Even then, this process would take a skilled user 3 to 5 seconds. I'd like it to be somewhere between ten and thirty seconds. This weapon would mainly be used to take down criminals in heavy anti-ballistic armor, which the frangible rounds cannot penetrate. How can I explain a laser sidearm that has one shot, then a 10 to 30 second reload time? [Answer] Lasers need a lot of energy to be used as weapons. Even with a high-density battery (better than our current Li-ion batteries), it's going to be a large and heavy battery, so it's the equivalent of a one-shot cartridge. Every time you shoot, you discharge the whole battery, and you have to insert a new one. Another possibility is cooling time. Even if you have batteries or generators able to provide the power the laser needs, it's a lot of heat to deal with, so you have to wait 20-30 seconds before you can shoot again. [Answer] You could have your power supply as 2 parts: A super-capacitor that, once fully charged, can power one shot from the pistol. A battery. The battery provides a slow trickle of power to the super-capacitor that takes however long you want to want it to to power up the next shot. Say, 30 seconds. Your battery pack can supply 1, 6 or more shots depending on how you want the mechanics to work. One important question you'll need to answer is, if you need to change clips as often as with a normal pistol why they don't just use normal gunpowder pistols. Perhaps the advantages of being able to recharge ammo for free back at base is a big enough advantage. You'd also expect someone who can hook their weapon into a more powerful power supply to be able to fire a lot more shots per minute unless you want to make the weapon prone to overheating. [Answer] You can use a [chemical laser](https://en.wikipedia.org/wiki/Chemical_laser) > > A chemical laser is a laser that obtains its energy from a chemical reaction. Chemical lasers can reach continuous wave output with power reaching to megawatt levels. They are used in industry for cutting and drilling. > > > Incidentally, the output power make them suited for weapon use... If your laser is designed in such a way that a cartridge with the reactants has to be loaded before use, this can easily explain why between various shots one has to pause: * reloading the cartridge * allow cooling down of the equipment * **require finite time to allow the system to neutralise the HF gas before loading the next charge or choke to death** **An added benefit is that you can set it to free purge when fighting in vacuum and fire as fast as you can reload (pump action shotgun style).** **The reason for laser over more powerful balistic sidearms is the damage they would do to the ships hull is less likely to result in an explosive decompression of the craft, however a hole cauterised through a pirates helmet and head is likely to give him pause.** **Third party edits added** [Answer] Having actually built a laser in the past, I think this might be a smaller problem than you realize. Modern lasers aren't a burn risk until they reach around the 3 Watt range. (Yes, only three Watts, but concentrated in a single direction; pen lasers are more like a milliwatt device.) At that point, not only is the beam plainly visible in the air, it will cook flesh by both radiation and induction. However, such beams usually take around half an hour to heat up and provide sufficient light. It involves reaching a state called a "population inversion", meaning that more than 50% of the active medium is in an excited state. Afterward, pulsating lasers generally have a reflective block on them; energy gathers while the beam is contained. Well, that's one way, there are a bunch of odd ways to do it. The other thing to consider is that these lasers, like dye lasers, are generally the size of an entire table, and cost around US$100K. The rationale behind the military not using them for infantry weaponry yet should be overt. 500 years in the future, it's likely that we'll have made a few discoveries which will make them a lot smaller. However, as historical precedent shows, there is no guarantee that we'll have made equal progress on warm-up time. Perhaps the beam takes a full five seconds to reach population inversion? Another thing I would like to point out to you, on the side, is that light does actually carry momentum; and while it's usually insubstantial to massive creatures like people, it is quite tangible for a focused beam. That's part of how one can get burned by a high-wattage laser. It's also why, under the wrong circumstances, a laser might do little to protect the hull. (It's also why dumb mirrors are completely useless against weaponized lasers.) Look up the "Mössbauer Effect" for further details; it might even give you some ideas for your writing. [Answer] Don't make them literal lasers. Make them [plasma weapons](https://en.wikipedia.org/wiki/Plasma_weapon) instead. In a plasma weapon, a small piece of ammo is heated to the plasma state, and then the plasma is fired at the target using a magnetic field. The target is damaged by the heat of the plasma, and plausibly by the plasma's kinetic energy or electrical charge as well. A plasma weapon might have these characteristics: * Typical rifle or pistol shape. The part you hold in your hand contains ammo storage and the heating chamber. The barrel contains the magnetic coils for launching the plasma. * Simple weapons would use a supply of pellets, which have to be heated to be fired. This would take time. Larger weapons with bigger power supplies might have a storage tank for plasma, allowing rapid fire. The barrel would also build up heat and need time for cooling. * Shots would emit visible light and heat in all directions. Notably, they'd be visible from the side, unlike a laser. * Shots could be different colors depending on what is in the ammo. The evil Coppertonians might use weapons that fired a [green beam](https://www.youtube.com/watch?v=Y64LxXAR-g0), for example. * Shots might "only" travel at several hundred to a few thousand feet per second, instead of traveling at the speed of light. Under the right conditions, someone could hypothetically see a shot coming and dodge or otherwise react to it. [Answer] A charge storage device (capacitor, battery, etc.) that can give you the fast discharge you need for a laser shot has to be heavily optimised in that direction - and so will be poor on things like overall power storage, leakage rate when charged, etc. Therefore you may well find you have the laser being fed by something like a flywheel+dynamo; the flywheel is then spun up by a power source (such as a more conventional battery) that can store more power over a longer term, but takes a while to deliver a shot's worth of power. [Answer] **Hand cranked capacitor.** **[](https://i.stack.imgur.com/mI0VT.jpg)** This would be similar to a crossbow which one must crank up with a handle between shots. Here, the crank flexes a piezoelectric crystal, accumulating charge in a capacitor. At full load the capacitor discharges into the laser generator and fires. Then get cranking! Artistes and creatifs: I tried hard to find an image of a steampunk weapon with a handle and bike gears mounted on the side. No luck; I had to halfassedly MS Paint my own. But this would be a fine project for Dragoncon or some similar venue where there is a forum for steampunk creations. gun from <https://i.pinimg.com/736x/37/23/c2/3723c21ad87c2785a64268ac889ded31--arms-race-steampunk-weapons.jpg> modified by me with crank from <https://www.picclickimg.com/d/l400/pict/263133537680_/Antique-Victorian-Eastlake-Style-Brass-Doorbell-Hand-Crank.jpg> [Answer] Do they need to have to take it out? Capacitors, like the ones in flash photography, take a while to charge a lot of energy from a low amp, low voltage battery. This could explain the wait time. If you want them to have to remove the battery, you could have single use battery technology. One way to figure this out is to estimate how much energy light would need to burn through fabric, metal, plastics, etc, or just look up ballpark estimates, then reverse engineer battery technology to match that. Another reason you could use would be single use, nuclear batteries. It fires, but you have to open the chamber to vent the radiation or risk being burned, then eject the battery once it's cooled or no longer high radioactivity. Then, the user replaces the battery with a new one. Changing the caps themselves don't really make sense as caps are not an energy source, but an energy storage device. [Answer] **The Springfield MMMXI muzzleloading carbine/revolver is your choice!** This carbe is the combination of state-of-the-art plasma technology ( most Scifi lasers in our beloved movies actually act like plasma!). How does it work? The carbine consists of three main parts. The muzzle, that has a plasma-push stick attached. The cartridge vessel, that loads the energy cell. The trigger, state of the art sensitive hammerhead engine. How it might look according to our engineers: (copyrigh -> someone, somewhere). Carbine [](https://i.stack.imgur.com/Z4z52.jpg) Revolver [](https://i.stack.imgur.com/IFP4j.jpg) Steps to use it: First, take a Plasma cell from your space cartridge box. They're round, expell a radioactive shiny color, and are shock resistant as they don't have any catalizer installed. You can play tennis with them! (2-8s) Second, put the plasma cell with the + side pointing outwards from the muzzle, into the muzzle. push it hard, it's made to fit in void without holes. (4-8s) Third, push it down with the plasma-push stick. (4-8s) Fourth, open the breechloading energy compartment. (2-4s) Fifth, introduce the unstable Unobtamium energy cell, the catalizer that will transform the glowing plasma in a all-environement super fast, glowing projectile. (4-8s) Sixth, close the catalizer and pull the activation lever. (2-4s) Seventh, aim and shoot.(Ns) approximate 1-shot time length with no skills: 40s to 1 minute. Power output: that of a small artillery piece. ***Disclaimer: Mimetic Radioactive plasma cells that mimetize with the nevironement they're shot are on sale. It's like an invisible shot (that irradiates a lot of heat and shows on infrared or with spray/dust).*** [Answer] A ruby laser is a pulsed type laser that uses a Lab grown Ruby doped with Cadmium and some rare earth minerals. You excite it with a Flash tube. Depending on which flash tube you use and how much power you put through it, they will burn out after only a single pulse. Still powerful enough to punch a hole in thin gauge, mild sheet steel. [Answer] Instead of using batteries use a generator (something like a [Fuel Cell](https://en.wikipedia.org/wiki/Fuel_cell), but enhanced) that cannot give enough power to keep the laser on continuously, but will need to recharge (possibly ramping up voltage) a condenser which will provide the energy for the shot, but will need time to recharge. A mechanism similar to old [battery-capacitor flashes](https://en.wikipedia.org/wiki/Battery%E2%80%93capacitor_flash). [Answer] I really like the idea of weapon style 1. 1 way 2 explain your laser pistol would be that instead of firing from the changing the capacitor, the pistol itself contains a capacitor, and to reload you instead add batteries, it takes 10-30 seconds for the batteries to charge the capacitor. I'd love to read your story at some point. [Answer] Maybe Mass Effect (the video game series) can give hints here? In Mass Effect 1, continuous fire would overheat a weapon, after which there'd be a cooldown of 5 seconds or so until you could shoot again. Some overpowering weapon mods would make sniper rifles overheat from a single shot, so there'd be a cooldown timer after each shot. To me, that sounds similar to what you're getting at. Mass Effect 2 then introduced a thinly-veiled ammunition system: your weapon builds up thermal heat until it's overheated, at which point you'd throw away the "thermal clip" (=emptied magazine) and insert a new one. [Answer] You can use an [Explosively pumped flux compression generator](https://en.wikipedia.org/wiki/Explosively_pumped_flux_compression_generator) to power a laser or other energy weapon, it uses explosives to create a very short, very strong current. Each generator would come in a nice disposable cartridge that you can spend several seconds reloading. It also has other nice aesthetic benefits, such as causing a nice bang sound, and possibly a flash from venting the exhaust. ]

[Question] [ So I've got a medieval fantasy world where humanity has been forced to live exclusively in fortified towns and city states because of attacks by monsters. These monsters are not kaiju level in size so smaller and more populous, think [Grimm](http://rwby.wikia.com/wiki/Grimm) from RWBY. They do not actively seek to annihilate humanity but will hunt humans as a food source if there is an opportunity. The monsters will also attack livestock. The monsters can be eaten themselves but hunting them is dangerous for obvious reasons. Trade with other towns is possible but that would require a large amount of protection. My question is how would these societies manage to get enough food to survive since the more land they use to grow food the more guards they will need to protect this farmland from monster attacks. What methods could they use to get enough food and survive the monsters? --- First edit: The types of monsters will be extremely varied, big, small, fast, slow, carnivorous, herbivorous etc. Most will be modified versions of real world fauna but some will be taken from mythology or created from scratch. Most are still dangerous. --- Second edit: Getting a lot of requests for clarification and some answers treating it just like real world so here's some new info. On the monsters: The monster population is massive and many of them are apex predators. They drastically out power humanity so simply wiping them out or leaving a shepherd boy in the fields with a sling is not a possibility. It's safe to say they've overrun the earth even though that's technically not correct as they were always there. Humans are much lower in the food chain than on earth. The monsters have always been there and did not just turn up one day, they evolved naturally alongside other creatures including us. Species of monsters have evolved everywhere on earth that can support life, so seas, deserts, islands, polar regions, you name it. No environment is completely safe. While intelligence varies greatly just like the real world, many species have displayed decent intelligence and problem solving, sometimes even use of makeshift tools. Domestication is a possibility but would be very limited. There is a really good reason the real world doesn't have your friendly neighbourhood tiger. Most monsters are simply too dangerous and/or smart to be bossed about by the obviously inferior humans. Monsters have their own stable food chain and so are not completely dependent on eating us and won't die out if we somehow successfully manage to stay away from or fend them off for a sufficiently long period. They are not exempt from this food chain and monsters will attack and eat other species of monsters. The Herbivorous and Omnivorous monsters who would eat crops are no less of a threat. Many would attack humans if approached and would not take kindly to humans trying to get rid of it (you try telling a monstrous bull or herd of monster buffalo to piss off, see how it goes). On alternate methods of transport: Several people have suggested alternate methods of transporting goods between different places. Hot Air balloons: This could conceivably work but that has its own problems, there are plenty of airborne monsters that are more than capable of attacking these, also, the technology is several hundred years past my medieval setting, it's possible that the limitations I'm placing on these people with the monsters would result in their invention early though. Tunnels: Tunnels are expensive and difficult to create in modern day. My medieval societies with their limited resources and economies would be completely unable to do this. Maybe if there were dwarves, but there aren't. Sailing: This would very likely happen but there are aquatic monsters that can attack and do serious damage to ships. So basically all forms of transport must be done with extreme caution. On different methods of stopping them: Fences: These wouldn't work. There are so many ways to get past fences, especially if determined, burrowing under, flying or jumping over, if big enough or with sharp claws possibly just going straight through it. If used, fences would be used to keep in ordinary livestock or as a deterrent/method of slowing monsters down. [Attack on Titan style walls](https://myanimelist.cdn-dena.com/s/common/uploaded_files/1444433163-2aafc428098c31d581c987ba1733ff06.jpeg): This has been suggested and it wouldn't work. If you've gotten far enough into AOT (I won't spoil it) you'd know that the walls were not created by conventional means. There is no way for my people to manage this feat. Game of Thrones style The Wall. Just like the AOT walls, this isn't a possibility. Remember that that wall took 8 thousand years to build, is only possible in that climate with the extreme cold and they're barely able to manage it against the more mundane attackers. Ordinary walls: Could work if done properly Traps: Would work but more measures would be required on top of that. Deterrents (thorns, poisons, foul-smelling plants): These would work on the smaller monsters but not all. Some would be big and strong enough to not care or smart enough to figure out deceptions and ways round. So can be used partially but other measures will be needed. Natural obstacles: My people would most definitely make use of these to avoid extra work to make fortifications. Islands are a great idea if they're small enough that they can occupy the entire island and there isn't any wild space for monsters to take hold. To that one guy who suggested time travelers bringing advanced technology as the plot demands, I have no words. [Answer] ## Fungiculture Below the buildings and streets of your beset cities, farmers cultivate fungi in tunnels, basements, catacombs, and mines. Organic scraps and other biological waste is sent here to feed the 'shrooms. ## Hunter-gatherer Small teams of hunters and gatherers risk life and limb beyond the walls, spending a few hours each day hunting game and harvesting fruit, herbs, and such found in the area. ## Greenspace All rooftops and unused outdoor spaces within the city walls have been converted to garden plots and pens for (small) livestock. High-yield shade vegetables grow in the streets and alleys, while plants that need more sun grow on rooftops and trellises in public squares. ## Perimeter planting A clear line of sight is needed for the safety of the city, but there's no reason that safety perimeter needs to be barren: grains can be sown here, as well as concentric lines of thorny berry-laden bushes to discourage the smaller monsters. As the city grows crowded this perimeter space can be walled off for more housing, and a new space cleared beyond. ## Farm the monsters All livestock is dangerous if underestimated or mishandled, but that didn't stop our ancestors from seeing the nutritional value of horned bison or towering mammoths. Trapped in pits, a breeding pair of smaller monsters could produce a reliable stream of giant eggs or other edible offspring and provide a semi-controlled environment for your society to study their behaviour. [Answer] > > [T]he more land they use to grow food then the more guards they will need to protect this farmland from monster attacks > > > That is true if your monsters are elephants, and will attack your farmland and eat the corn. If these are carnivorous monsters then they will not eat grain and vegetable crops. Farmers will reside within the city walls. When the farms need tending they will go as armed groups to each farm and take care of things. Likewise the harvest – they will harvest each farm as an armed group. Vegetable crops do not need to be watched at all times. Livestock seems like a risky venture in this scenario. Most of the time the farms and surrounding land will be empty of humans. When the farmers visit, it will be in force. [Answer] The same way we stop dangerous animals right now. Fences. Surround your farmland with strong fences and grow your food. You can go out in parties for trade or hunting, and when your population expands you expand your fences. You need walls, gates and defenders to stop humans, but fences stop animals. [Answer] In my answer, I've tried to think more along the lines of insects than humans. Since we have proven to be dominant and wiped out every other predator species for the most part, I believe this line of thinking is more true to your story, keeping us lower on the food chain. I'm assuming we developed side by side with these monsters always in our world, and they didn't just spring out of the ground one day through a hell-portal. Even without a high tech or magical solution, for us to have developed to a medieval level of culture necessitates us having survived Stone Age, Bronze Age, etc... and have organically developed agriculture and animal husbandry, cities, all that. It also assumes that these creatures have NOT evolved, you mentioned no real intelligence, tool-usage, adaptation, or problem solving, and they have no innate malice towards us, only hunger. So I focused on an evolutionary answer that doesn't involve us stabbing them many times with sharp pointy things, something we excel at (well, at least until #4) 1. Satiation as a survival strategy. Since livestock exist in this world, they must have been domesticated from a base animal that survived long enough in the wild to be tamed by humans. Your humans simply feed the monsters a portion of their animals on a regular basis until their stomachs are full. your question made them out to be much more obligate carnivores than chaotic evil killing machines. The bonus here is after awhile the monsters may not even view humans as a food source, and start wishing to not bite the hand that feeds, start coming closer to our villages, and become themselves domesticated, a la Wolves! Domestication. Now we have our own loyal, friendly monsters that can defend us (I'm picturing a deathclaw shephard) In any case, many of ancient cultures provided their gods regular sacrifices of animals, meat, food. Even more recently the church was tithed a portion of your produce. Think of it like a tax, except with tangible benefit. Feed the birds, tuppence a day.. 2. Every villager in the fields wears a bright orange and red frock, that is dipped in the crushed up alkaloid of a poisonous plant, lethal when ingested but safe for skin contact. We go about our regular business and lives, after a few generations, natural selection has every monster avoiding eating anything brightly colored like the plague. Eventually we don't even need to poison everyone's clothes (mimicry). This even fits in with the variation of monster, since most every predator has evolved to shun bright color, equating it with poison 3. Extremophile societies would doubtless spring up, tribes of people living in the cold north or regions like the hot deserts that the monsters avoid or can't survive in. You would see a dominance of island cultures, even the use of easily defensible peninsulas, and the making use of natural formations. Think the Puebla cities, the Jewish fortress of Masada, or Machu Pichu.. At the very minimum most places would not build their castles and strongholds with an eye toward human-on-human warfare or controlling strategic points, but rather on choke points in the sense of where can the walls be tall and thick, but not too wide. Why build a fence on four sides when you can have three sides bounded by ocean and one good wall? And if all else fails, all the good spots are taken, put your back to the oceans or mountainside and let them taste our spears! 4. Specialization, one of the hallmarks of civilization. Every farmer and potter and craftsman need not be an expert monster hunter, looking over his shoulder with a hoe in one hand and a spear in the other. Instead, certain humans would take up the trade. Guilds would be established, weapons and tactics honed and perfected, and bounties placed on every monster. Like Saint George the dragonslayer, Van Helsing, or the Jager pilots of fiction- they would be heroes, well paid, greatly respected and honored, and deadly. Lone bounty hunters would take down the merely bothersome sheepstealers and creeping chupacabras, a small posse of deputized locals can deal with a few pesky calla-wolves, and great phalanxes of professionals could take on the legendary maneaters. For story purposes, as long as there is balance, you can make it so the humans haven't completely wiped out the threat. Perhaps our worse angels still surface, and we still war with one another, waste resources on folly, and haven't quite banded together as one might hope in a world of monsters? Or perhaps there are areas where they breed, and are so well defended, so deeply hidden, or utterly infested that we can't manage to competely wipe them out? To the point where it isn't worth the risk of lives to do so, or maybe the guilds could, but like the steady paycheck and interesting work instead of total victory, followed by a big parade, and then shortly after, a trip down to the unemployment office... 5. You'll notice i didn't really cover the problem of the herbivore monsters eating/trampling crops. Somewhat because it didn't seem to be the true direction of your question, but mainly because this is still a problem today, I've had mice eat every seed in my greenhouse and seen a deer jump an 8ft fence. This is something you can't do much about except by the usual methods we use today on small to medium sized nuisance animals - poisons, weapons, traps, and... well, see answer #1 (im thinking komodo dragon barn cats...) [Answer] They could eat the monsters. I'm sure that medieval men at arms would vie for opportunities to demonstrate their prowess making a sport out of monster hunting and trapping. Its not exactly a far fetched idea, stone age man hunted mega fauna like the saber toothed tiger, cave bear, and woolly mammoth with stone tools so why wouldn't iron age warriors do the same? [Answer] ### Peninsula Looking at @Len post, I got an idea. Your people should first find a peninsula with very high cliffs, like the Bonifacio town that you can visit in Corsica (France). [](https://i.stack.imgur.com/XftHr.jpg) (Credits : <https://www.specialsailingcharter.com/2016/02/14/sailing-mediterranean-last-minute-yacht-charter-deals/>) By the way, you can take a look at it just [here](https://www.google.fr/maps/@41.3791104,9.1548695,1013a,35y,39.14t/data=!3m1!1e3). ## Mixed with a wall-shapped-city Then, I thought about announcement that a mexican urbanist group called Estudio 3.14 made in response to Donald Trump's Wall project. They said that the best way to construct such a big wall would be to design it in a way people could live or shop in it ! Or to make it "usefull" by integrating directly a prison in it (in that special case...). [](https://i.stack.imgur.com/Ddse2.jpg) (Credits : <https://today.uconn.edu/2016/12/what-might-wall-with-mexico-look-like/>) With that kind of construction, you don't need to spend time and ressources building a wall to protect your city anymore : **your city is the wall** ! If you place it smartly on your peninsula, you can now block monsters to come spoiling your cultivated lands. I think this slightly better than fortifying an island as you still have the opportunity to raid on monster-lands if needed. A terrible drawing : [](https://i.stack.imgur.com/B7ehM.jpg) [Answer] Clearly, the only way this works is **stone walls**. **Medieval people did this all the time.** A single person can easily stack bricks, and mortar layer upon layer and start with 3 widths of a modern brick. Is that enough? Yes stop, if not expand it. Use field stones, and whatever, to form a castle wall if necessary. These things are like 30 to 50 feet high, and easily 10 foot thick or more. They were built in medieval times all the time. Now after you build the initial perimeter, place guards on the top with bow and arrows and other ranged weapons. Beat the animals back till they don't relentlessly attack near the wall. Then start building a second wall far enough forward to call it progress, but no so far that the previous guards can't defend them from the top of the wall. Expand one or two segments of the wall at a time until you have a usable amount of land. Clearly, according to the OP, these animals are as plentiful as tribbles (Star Trek) and are going to have to be mass slaughtered for food. Banks of archers on the wall tops killing them by the hundreds. Then hauling them up, cooking, and eating them. As soon as you are old enough to hold a bow and arrow, up on the wall shoot at the unending hoards of monsters. --- The only way to start a town is hundred of ranged weapon people protecting the wall builders until the walls are big and strong enough to do the defending. Either that or finding plains that are seasonal, and you can build a wall while the hoards are attacking someone else. --- The simple fact, is that almost no animal is **battle ready** at birth. Needs time to mature, and therefore can't endless attack humanity. **Eventually we have to kill enough of them to gain a foothold on the land, or they will kill us all and we won't be alive to need food.** Archers from tree tops to help guard the initial wall builders. **Personally, I would eat well, with 100 arches making a kill every couple minutes 24 hours a day. 30 per hour\* 100 =3000 \*24 =72000 and if each one only has 2 pounds of usable meat thats 144,000lbs of meat per day.** To heck with farming!!!! --- update: Additionally your going to need a pit, wide enough so no creature can jump it, and deep enough so the creatures are at least permanently trapped. Even better if they die from impact with the bottom. This is necessary to prevent being swarmed, and provides an additional layer of passive defense. [Answer] <https://en.m.wikipedia.org/wiki/Apex_predator> That might help you understand something about predators. Basically if too many predators live in one area they will eat off all the prey in that area. Nature makes it so that the predators spread themselves out over wider areas so that each predator has enough prey. In short your area will not have SO many predators that humans have to run from them all the time. But... I get that you want monsters killing people, so how about this: they build their towns and farms on fields abutted by natural cliffs. [](https://i.stack.imgur.com/7KDWe.jpg) This protects them from many sides depending on the shapes of the cliff and coastlines, so they only have to watch out for whats in front of them. There they could build thick walls (some walls were so thick they could withstand cannon fire), moats, and fields with spikes; As well as arrows and spears and harpoons. I wanted to come back and add these: Your wall could look like this from the outside: [](https://i.stack.imgur.com/1Xk6L.jpg) And like this from the inside: [](https://i.stack.imgur.com/QPJT4.jpg) More than enough strength for even the toughest monster (you did mention they weren't Kaiju sized). So unless they can fly you should be ok. If any of them can fly... harpoon the suckers! [Answer] Rooftop farming. Every single roof will be a small green garden to produce food for the population. Cows are absolutely out of question, but chickens and goats can live around the people. Maybe pigs depending on how much food is being produced. If they need even more food, then it's time to start vertical farms. Alternatively, start growing mushrooms in underground tunnels. [Answer] The first question you have to ask yourself is how did people get to the point of walled cities and medieval technology to begin with? Both require a pretty significant food surplus to allow enough people ability to find and mine rocks and build walls and buildings and such as well as develop technology in general without worrying about tending to the farm. So clearly these humans already lived for thousands of years alongside the monsters and managed to have more than enough food well before they even developed walls and medieval weapons. So how did the ancient humans, with nothing but sharpened sticks managed to not only survive the monsters in the first place, but make enough extra food for their builders? Whatever they did the medieval humans can continue doing, but much more effectively. One also has to wonder how did humans evolve in this world in the first place? How did the precursor monkey survive? Was it safe in the trees? If so, humans could build their villages and towns in thees and farm tree grown food. If not, how did it survive? Was it strong enough to fight off the monsters? If so humans that came from it would be as well. Bottom line is that humans would have had to have handled their monster problem back when they weren't even humans yet, in the world where they co-evolved; by the time they actually reach medieval level tech monsters should not be a big problem anymore [Answer] You say: > > The monsters have always been there and did not just turn up one day, they evolved naturally alongside other creatures including us. Species of monsters have evolved everywhere on earth that can support life, so seas, deserts, islands, polar regions you name it. No environment is completely safe. While intelligence varies greatly just like the real world, many species have displayed decent intelligence and problem solving, sometimes even use of makeshift tools. > > > If humans evolved alongside of them, well...the ones that are left are the survivors. And the survivors will have characteristics that allow them to be more likely to survive. This means that you're going to have monster hunters. You have basically built a world in which adventurers are key to survival. Not everyone will be one, but you're going to have to have a lot of badasses. Your mistake here is thinking that the economy won't be based on monsters. Which, if I know humans, it will be. This is going to be completely different world--not our world with our ideas of agriculture and commerce. Humans solve problems, and take risks. Sure the monsters might not like it, and sure the monsters are overpowered compared to us, but we've taken down large predators in the course of human history. In a world like this, knowing how to kill monsters and having people who do that will be a matter of survival. We cooperate and we build things that make us better at killing them. You say: > > The types of monsters will be extremely varied, big, small, fast, slow, carnivorous, herbivorous etc. Most will be modified versions of real world fauna but some will be taken from mythology or created from scratch. Most are still dangerous. > > > Evolution is about niches. Your monsters are more dangerous than our animals in the real world, but this will mean that your humans will be more dangerous as well. Even if they do have variation, certain areas will become accustomed to the most common types and take measures to stop those. Further, these monsters have to eat something, and there has to be an abundance of those things (animals, plant life) to sustain them. Those things will either be things humans can eat, or in the case of a specialist, things that humans can destroy to starve out the monsters. You keep saying that some things won't work because of the variation. And simpler solutions, like tunnels ([which did exist in Medieval and ancient times](https://www.atlasobscura.com/articles/the-mystery-of-europes-erdstall-tunnels)) people would be highly motivated to build those. You're talking about expense to build those, but you might want to re-think that because the economy is going to be richer than you might think and based on monsters. Plus, with this problem to solve, the motivation WILL be there. There wasn't much motivation to build tunnels in Medieval times and ancient times but this world has it in spades. Anyone who builds tunnels like this will have a lock on trade, and that's enough to motivate a group to want to pour their resources into it. You've already got a lot of answers that are really great, including the wall thing, and the roof top farming is brilliant. (I would bet some of your monsters fly or can climb, so you know, any defense can be defeated by your monsters given any thought at all.) The question is really--given a world full of monsters with any characteristics how can humans eat. As others have said--eat the monsters. I say that given this world full of monsters and that > > Monsters have their own stable food chain and so are not completely dependent on eating us and won't die out if we somehow successfully manage to stay away from or fend them off for a sufficiently long period. > > > This means that there is an ample food supply of what monsters eat as well, so humans can eat that stuff too. And, your humans will be diesel as heck. Your farmers will build all kinds of things and kill a lot of creatures, even if many places take advantage of natural features and build walls. [Answer] ## Just make the monsters less powerful I've seen post-apocalyptic TV shows where, for reasons of plot and their contracted number of episodes, it's preordained that any time the characters are safe, a new threat will arise. The characters have holed up in an impenetrable underground bunker? The monster of the week can teleport. My point being: It's easy to construct a world where it's impossible for any humans to survive. If you want humans to survive, you have to *not do that.* You can change your world so it doesn't *have* tunnelling, flying, wall-destroying, swimming, rock-climbing, too-smart-to-poision monsters. ## Transport is irrelevant if nowhere has a surplus of food It's all very well to get food by trade - but a city will only export food if they have more than they need. For trade to make sense, there have to be some areas of your planet that can produce more food than they need. And if there's a place that can produce enough food, why would a settlement form in an area that can't produce enough food? **People who are starving either move or die.** Seems to me such a settlement would only form if they could do something valuable that couldn't be done elsewhere, such as natural resource extraction. If you're a mining outpost, why would you waste workers running an unproductive farm when those guys could be mining while the farming is done elsewhere? ## Get strong at calorie density Give your world something like 'lembas' or the food bars from Firefly, so places like mining colonies only need a single heavily guarded shipment every few months. ## Carrion / Get strong at preserving I'm sure some of these monsters die of natural causes, or from fights with other monsters. A hog the weight of a person is enough to feed 100 people - so if some of your monsters are edible and elephant-sized, that could keep a small settlement in food for a long time. Your society will have to be good at preserving, of course. ## Form a symbiotic relationship There are birds that eat ticks in other animals' fur - and the animals just let them. Humans could either provide some service to certain monsters, or could domesticate or semi-domesticate monsters into acting as "guard dogs". ## The neighbours have nicer stuff Humans don't need to make their settlements impenetrable - they just have to make sure there's easier pickings elsewhere. For example, if monsters have to walk through a forest full of wild sheep and hogs to reach the humans, and the humans will put up a fight, they'd just eat the sheep and hogs. ## Starving the monsters of some resource You could make the monsters need some Whatever to recharge their mutant power crystals, or whatever. Humans could have used their superior intelligence to figure this out and wreck up all the Whatever sources near their city. Now the monsters don't come around much for the same reason humans don't walk around deserts much. [Answer] Compost everything and use crops that can grow close together. Many small islands in the Pacific, like [Anuta](https://en.wikipedia.org/wiki/Anuta#Geography), have been farmed for centuries despite only being a few square kilometers or less in diameter. The villages are very compact and most of the island is used for agriculture. All the scraps, feces, weeds, etc, get turned into compost and put back in the soil. By keeping the fields as close to the village as possible, keeping kitchen gardens inside the walls, setting up traps and poisons for the monster, and having guards go out to thin them out every few months, these compact fields would be a smelly but productive area to farm. City states would be harder to do, but with the larger population you can have more guards so the fields can go further out. Having muck collectors will be essential in these cities, letting waste just flow into the sea or river is not an option. [Answer] ## Build walls. Basic agricultural fences don't work. They're designed to stop domesticated animals from wandering off when there are no real pressures on the animals to get away. A "motivated" domesticated animal can easily jump a fence, or break it down, but usually they aren't given a reason to do so. Fences to keep non-domesticated animals out [are certainly possible](http://www.wildlifeservices.co.uk/deerfencing.html), but they're big and expensive. More than that though, they don't give much defensive benefits if the animals are considering crossing the fence to eat *you*. The situation is much closer to defending against a human army (minus ranged weaponry) than fencing a farm. If you've got bows and arrows, and the monsters don't, what you really need is something to slow down them getting to you, and the advantage of height. Note that these don't have to be expensive stone walls. A wooden palisade would be reasonably effective, especially if backed with earthworks. Some animal (e.g. tigers) could probably climb wooden structures, but you've still slowed them down, and you've minimised the number of attackers that can get to you. Some animals may still get through. Perhaps carnivorous rabbits are a thing. Assuming they don't need [a Holy Hand Grenade to kill them](https://en.wikipedia.org/wiki/Rabbit_of_Caerbannog), farmers will need to put in appropriate protection for their livestock, and go on regular patrols to clear them up, in the same way as they currently do for any other vermin. But at least you've kept out the larger animals, so that what's left can be reasonably tackled by individuals. [Answer] Like many others have said, build your walls to encompass your fields as well, instead of just the town proper. Thanks to Volume to Surface ratio (or in this case, Surface to Edge), a larger town will have a larger perimeter to defend, but comparatively more soldiers per section to defend with. Imagine a small homestead a kilometre in diameter. It has π/4 km squared area and π km of perimeter to defend. But, a settlement of 100km diameter would have 2,500π km squared of area and only 100π km of perimeter. Assuming the same population density for both settlements, the larger one has 10x as many men available to defend any given section. Thus society will tend towards a few large cities, with walls encircling the required fields. The only challenge would be in slowly expanding safe area into the wilderness, and building additional sections of wall as they go. [Answer] **After all the clarification I see why the *how to get food*-question is so important!** The people in this world would be very tough and their entire life would revolve around killing monsters and growing food. They would also tend to form larger groups rather then smaller ones. There is strength in numbers and the early tribes would not waste time killing each other. So I am excluding the motte and bailey model as a defense structure as I believe it is too small to sustain itself. With regard to movement on the map one thing that comes to mind is the ancient Roman army. In the sense it was organized to survive against all odds. A Roman army would build forts each night it went to sleep! Which is how any movement between villages would happen in you world. A direct consequence is that you will not have cities as there is no reliable trade that you can do, so the size of settlements is limited. This leaves the village! **Placement** A village in your world is basically a fortified farming village so it would have to be placed strategically next to a body of fresh water and also have large enough plains for planting crops. It also has to be of a decent size in order to have enough people to defend it. **General shape** It should have a **wall tall enough** to stop any animal from jumping on it. Predators are not that good of jumpers. A tiger, for example can only jump around 3-4 meters. Walls of 8-10 m should be sufficient for them, even in your world (because physics), to ensure proper defense (and another 2 m underground)! One advantage is that you should not need to man the walls and so are easier to build because they will not be that thick. Instead use layers of **ditches** with **spikes** and **towers** with a balista on top and arrow slits! **The wall should have a zig-zag pattern**, like a star fort, so as to allow the creation of a defensible grid around the settlement where you can plant grains and protect them from within a fortified position. **Inside layout** The farmland outside the village would not manage to provide enough food. What I am thinking of is gardens built in the middle of the village and all along the walls you would have the houses and other buildings. At the base of each tower you would have a storage bunker. This allows for tall strong towers and saves space. **Food** Hunting is a must. The animals that wonder in range must be killed and the meat stored for the winter or eaten. Although I am not sure you could call it hunting. Baiting animals might be a way to increase food supply and decrease threat levels in the area! Fishing is something that might provide some food however it depends how advanced your people are! There is no livestock because they require too much food and space. [Answer] # It's probably not possible with the current setting. You've basically ruled out all forms of communication with different settlements of humans. Transportation is extremely difficult and there's no effective way to defend a settlement; any sizeable attack on a settlement will wipe it out unless they already have an effective wall, which they can't get because some of the monster with either fly or crawl over the wall or burrow beneath it. Islands are not an option either, because of flying monsters. Since humans can't effectively transport themselves they won't be able to found new settlements -- if they try, they will either be wiped out on the way or fairly quickly after they decided on a spot to live in. Without new settlements and since the old settlements won't survive, humanity probably won't survive for more than a single generation. # How might it be possible? Have fewer monsters or reduce their relative power to humans. You could have dragons that will eat hundreds of people as long as they are rare and only do so once every ten years or so (maybe even as often as every year), but a constant onslaught of monsters will be impossible for humans to handle with a medieval level of technology. [Answer] Traps. You would build traps to protect your crops and keep the monster population under control. You can use poison bait, pit traps, snares right through to mechanical traps. Humans are quite capable of hunting and trapping far more dangerous creatures than themselves to extinction. Just look at wolves, bears, tigers, lions or any large mammal for that matter. [Answer] There could be something to do with the monsters themselves. Perhaps they only come out at night, or at certain seasons, so there might be several months of the year or hours of the day where it is safe to go out and farm your crops. The locals would of course know when it is and isn't safe and plan accordingly. [Answer] ## Peaceful Tunneling Monsters that have already helped create the environment your people need to survive. You mentioned tunneling was too expensive, but having tunnels from city to city would work. What if tunnels already existed from large monsters that already created a tunnel system and your cities were scattered throughout the world using these tunnels? To get from city to city a group could move underground, even accompanied by a guard or two 'just in case'. There are many existing animals that already create tunnels, you could even use some that are nocturnal so your traveling group just needs to quietly walk by them as they sleep. [Answer] **Islands** You didn't mention whether the monsters cover all land everywhere on the planet, but if there is an island that has managed to either exterminate their local monster population or just never had them to begin with, that could be a safe place to build farmland. Your island farmers could then trade with coastal cities and even go farther inland using rivers. If your monsters aren't very intelligent it's also possible to start building highways between close cities where wealthy merchants can travel without fear of attacks on their caravans. Hot air balloons are another method of travel that is low tech, could be only available to the wealthy and is safer than delivering packages by hand. Make the balloons dock with towers to reduce the cost of taking off and landing while making it even more exclusive. **Choke points** If you build farmland inside of peninsulas you can defend a small opening and have very large areas to take advantage of. It needs to be surrounded by freshwater though, I can't imagine ocean peninsulas would have much fertile land. The peninsula farmers could deliver goods the same way that the islanders could. This line of thinking also works for sections of land where the only way to approach on foot is through a narrow pass up a cliff face, between mountains or over draw-bridges. **Repellent** Maybe there is a weed or a bush that monsters hate the smell of. They might avoid land where this plant grows but they're not so adverse that wearing some on a necklace is going to save your life. Farmers would know to line the outside of their land with this plant to make it significantly safer. Burning some in your campfires might be helpful, but I would still post a guard for the night. Cities, castles and mansions will probably also have gardens of this plant around them. You do not want to work in these gardens, I can tell you that... If this plant is an import from other lands it will make more sense why it isn't everywhere, why it doesn't grow along roads, and why it needs a lot of care from humans to survive. [Answer] Fences provide **part** of an answer--they can keep out all the land predators. That reduces the problem to the fliers. Fliers usually come in two varieties: Raptors (day hunters) and owls (night hunters). If the monsters do not include both classes you have a safe time behind your fence. If not: A bird big enough to threaten a human is not going to be a highly maneuverable flier. Put posts all over your farmland. Alternately: Break it up with barriers of some kind. Deny the birds the takeoff distance they need. Also, do they recognize the threat posed by a bow? If so, they'll stay far away from any party with a few armed guards. [Answer] Well, you can have underground travel routes and tunnels. My story is similar to RWBY and God Eater and Trade and Travel are both highly risky, even in a modern day like society that exist with monsters. Sea is especially the most dangerous considering storms, sea monsters and pirates. Land is just as risky with many monster traveling possibly the same route as you and unless you have transport systems capable of flight or moving at the slowest of 100 mphr, you have to travel underground or travel above ground and risk the chance of an attack. [Answer] Drones with a highly powered sub laser attached, brought to the medieval people as a gift from time travelers. The drones are extremely easy to control via a neural implant into the medieval people's brains. They simply think of where they want the drone to go, and it goes. The time travels would also give them a power generator machine powered by the rotation of the earth, allowing the medieval people to recharge the drones. The drones would follow the ancient people of this village instantly vaporizing anything they desired, some other villages started regarding the newly equipped ancient people as "Gods" The time traveler's used a proton collider to rip a hole into space and time, allowing them to travel to the ancient world, and others like it. It is set auto operate in intervals so the time traveler's can also get back to their time. The time travelers would come back periodically with mechanics to make sure the drone and laser gun were running in good condition, as well as conduct studies and test new technology. They would also send flight instructors to train the medieval people to fly the drone. Explain how the basics of N.V.C (neural vehicle control) work and then certify them to use. They also act as the installers of the N.V.C. by means of a chip injection gun to the back of the head. The time travlers are from a future so advanced they have AI chips implanted in their brain, the AI chip knows how to pick up, analyze, and convert ancient dialect into a language they can understand and also allows them speak to speak it, all in real-time. This is all done to study the ancient people. The whole purpose of the study is to see the effects on an ancient culture when they are introduced to advanced weaponry. How they will react and adapt. It is also a great way for the time travelers to use the ancient people as guinea pigs for tech they want to test out. The Time Travelers are from another dimension and vector on the grid in space, so any thing they change, will not effect their future selfs. ]

[Question] [ The World has just received an official communication: on December the 21st 2022 we will receive a special visit. Techno Mage Master Balmelgas will be visiting Earth on his wonder ship Sol Invictus. His purpose: to adopt a Rose. In exchange he will give to the World one material we may need. Just one but in any quantity we may choose. His powers are unfathomable. He may raise sea levels by 100 meters, make a mountain chain made of solid gold in the Sahara desert or a ring of diamonds around the largest city. World leaders, in a rare moment of enlighment, have decided to collaborate and ask something that will benefit mankind as a whole. Specifically the request must be thus that world economy has the best possible improvement. Benefits are going to be distributed to everyone. The problem is Governments are at a loss about what to ask. Can the wise people at Stack Exchange help? **What material would provide the most improvement to world economy?** Conditions: * a small sample of the material must be provided by World governments so that it can be replicated in the required quantity. No Unobtanium. * the material must be simple. It can be a metal, a molecule, a polymer but no more that 3 elements in it. E.g. the molecule of Methane CH4 or Glucose C6H12O6 are admitted. Ammonium acetate NH4CH3CO2 is not. * delivery will be agreed upon so that no accidents may happen. * World governments will have to provide containment to the material, if needed. E.g. it 's fine to ask for 1000 tons of Plutonium. Delivered material will be beamed directly in containment cells all over the world if such is the request. But the containment of the material must not become too much of an economic burden. * Effects on world economy must be considered. Specifically the law of offer and demand. Would the abundance of the material make it worthless? Or would the boost in economy be such that demand would stay high? * Redistribution of the generated wealth is not a concern in choosing the material. Let's just assume that global economic gains are going to be accounted for and equally redistributed. * only a material will be provided, not any specific structure made of that material. E.g. no space elevator magically appearing in place. The Mage provides the material but the hard work is up to us. * Techno Mage Master Balmelgas will leave by January the 6th 2023. By then all the required material will be delivered. This means that something like a river that will keep flowing after the 6th of January is not a feasible request. Please specify how the choosen material would improve world economy. If possible (not strictly required) specify quantity to require. If not specified Governments are just going to ask for A LOT of it, as much as reasonably possible. \*\* Bounty will be added when eligible \*\* [Answer] ### Get Balmelgas to do some geoengineering for us. Foresterite (Mg2SiO4) is a type of [olivine](https://en.wikipedia.org/wiki/Olivine), a class of minerals that are particularly reactive with atmospheric carbon dioxide. Mining and dispersal of olivines has been proposed as a potential method for [accelerated weathering](https://en.wikipedia.org/wiki/Enhanced_weathering), to increase the rate at which natural geological processes draw carbon dioxide out of the atmosphere. Having it in a fine-grained form, spread over much of the Earth's surface, would accelerate the rate at which atmospheric carbon dioxide would react with the mineral. At a sufficient scale, dispersing this mineral (or another olivine) over Earth's surface could allow us to slow and perhaps even reverse climate change. And it hardly needs to be said that if we could reverse climate change, it would have huge beneficial effects on the global economy. So the request would be, more or less: > > Here is a sample of powdered forsterite. Please provide us with about a trillion tons [exact amount TBD] of this material in this form, spread in a uniform layer over Earth's surface. Maybe don't put any on the more populated areas, though. And dump some in the oceans too, that'll help with acidification we've caused. > > > **Addition** This [article](https://eos.org/editors-vox/preventing-climate-change-by-increasing-ocean-alkalinity) provides additional details on the method. It focuses on altering the alkalinity of the oceans but the idea is the same. [Here the scientific papers](https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2016RG000533) [Answer] If the goal was to have benefits to the ecology or quality of life of humanity, I'd say Lithium or some other battery input that would reduce strategic resource scarcities in renewable energy-enabling technologies like grid-scale energy storage. But if you want to just drive the global GDP I'd say steel. Specifically, 1 megaton of steel delivered to 35,786km above mean sea level, with velocity at delivery of 11,300 km/hr. In other words: 1 million tons of steel delivered to geosynchronous orbit. That takes the cost of constructing an orbital ring around the Earth from trillions of dollars to maybe a billion or two. It would require the launch of fabrication equipment, but since the main cost of doing anything in space is in the launch costs of getting mass up there, having a million tons of basic steel already in orbit means we can focus on launching high-value-per-kg stuff instead. Once the orbital ring is in place, the resource base that world industry can work with is powerfully extended well beyond the Earth itself. This will likely drive several major learning processes which further reduce the costs of moving material to and from orbit. We have the necessary technologies already - it's just the cost of bootstrapping that's preventing us from doing it. [Answer] The million-tons-of-steel-in-orbit suggestion has merit, but can be optimised. The most valuable things to have in space are something to build with, something to breathe, and something to burn for fuel, and there are plenty of simple compounds that can contribute to all three. I propose a gigaton (because go big or go home) of [titanium hydroxide](https://pubchem.ncbi.nlm.nih.gov/compound/Titanium-hydroxide) $\mathrm{TiH\_2O\_2}$ (or $\mathrm{TiH\_4O\_4}$, the internet seems to be conflicted about whether it's $\mathrm{Ti^{2+}}$ or $\mathrm{Ti^{4+}}$) delivered to geosynchronous orbit. Titanium is at least as good as steel for construction, and for every ton of building material we also get 360kg of water *and* 320kg of oxygen, perfect for orbital life support and rocket fuel production. Since we'll be going all-out-no-expense-spared in the preparation of the sample, we'll also make sure that the titanium contains a decent proportion of $\mathrm{^{51}Ti}$, which will decay in a few minutes to give us a little bit (ie a few million tons) of vanadium, dope the oxygen with $\mathrm{^{15}O}$ which will decay to nitrogen after 122s, and mix as much tritium into the hydrogen as we can possibly get our hands on, up to a couple of percent. [Answer] # Helium-3 If we were to gamble on our chances to make working fusion reactors. With enough this stuff we could power world cleanly for very long time. And the bonus of Helium-3 fusion compared to others is that it doesn't produce neutrons which irradiate reactors and destroy the walls. Most common method of fusion currently is fusing isotopes of hydrogen. Deuterium hydrogen with neutron and tritium hydrogen with two neutrons. Deuterium with tritium producing helium, energy and free neutron. This neutron tends to irradiate things like reactor walls. Weakening them and making them radioactive. Helium-3 opens two possibilities. Helium-3+Helium-3 reaction producing Helium-4, energy and two protons. Or Helium-3+Deuterium producing Helium-4, energy and two protons. Positive side of those protons is that they can be handled with magnetic containment thus not producing neutron-radiation. One gram of Helium-3 could produce 164 MWh. With 23845 TWh being total energy consumption of world would require 145.4 tonnes of Helium-3 to cover this for a year. This would require ~1.1 million cubic meters of storage at NTP. Helium-3 is non-reactive noble gas that does not decay, but the storage might be problem at short notice. It can be pressurised however it can escape this way. Other option is cryogenic compression, but suitable vessels and tanks for that are likely limited in availability or already filled with naturally occurring Helium. Geological storage, natural gas and other gas storage are likely options if Mage Master Balmelgas were willing to place it there. So world governments would better start to look into empty salt and such mines that can be sealed. Other option is just to replace part of atmosphere with it. This however will likely generate quite big losses as it will probably escape relatively fast. [Answer] **Water.** /Delivered material will be beamed directly in containment cells all over the world if such is the request./ Fresh water will be delivered all over the world. Lakes and reservoirs will all be topped up. Dry lake beds and inland depressions (e.g. Lake Eyre, Lake Sahara, Lake Death Valley, Aral Sea) will be converted to lakes. Ice and lots of it will be deposited atop melting glaciers, replenishing and cooling them. Perhaps a few new glaciers might be deposited in interested hot areas, there to gradually melt in a soothing coolth. Depleted underground aquifers around the world will be repleted to preindustrial turgidity. Farms will be green. Forests will grow. There will be food. There will be energy. There will be soothing coolth. Plants limited by water scarcity will grow and take up excess CO2, cooling the planet back down. Plus Balmelgas Water tastes great! We might need to come up with a different name for it, though. Yes; water sweet water. One could make a case that the boost to the economy will only last as long as the new water does, which is true. But there is no time period listed in the OP. [Answer] *Q: "the material must be simple"* ## Hydrogen An abundance of molecular hydrogen (H2) would allow humanity to solve fossile fuel shortages and climate issues. Lowering energy prices could make the economy boom. While burning hydrogen, it is quite easy to collect **pure water**. This could allow humanity to solve other issues.. opening new markets, extend living space on earth for a growing population. [Answer] Is all that granted material has to be delivered to earth? If it doesn't I could suggest to place a bunch of asteroids made of zillion tons of solid rocket fuel into solar system distributed evenly along a single orbit around sun with highest possible excentricity perpendicular to eclipse and passing nearby all the planets' orbits. It would give an opportunity to travel across solar system relatively slow, but spending little-to-no fuel, just sitting on a piece of rock. When travellers want to visit a planet passing by, they just scratch a little portion of fuel for manuevering. [Answer] (Inspired by existing answers) "Dear Techno Mage Master Balmelgas, "After much conference and debate, we, the *International Commission to Analyze and Request Unlimited Stuff*, have come to an agreement with regards to your offer. In exchange for guardianship of any one rose of your choosing, we request a truly immense quantity of very thin aluminum sheets, delivered in the manner dictated below. "(1) Please place one million, 200km x 200km, aluminum sheets (designs in Appendix A), into an orbit identical to that of our planet. Each sheet should be facing the sun and equidistant from the others, spaced evenly around the sun. "(2) Additionally, please place one thousand smaller aluminum sheets into orbit at a radius of half that of our planet. (Designs in Appendix B). "(3) As a final request, please deliver five billion tons of relatively small aluminum bars (dimensions in Appendix C) to the major manufacturing cities of every country on our planet (cities listed in Appendix D). "Your assistance in providing (1) what we refer to as a 'Dyson Ring,' (2) a relatively centralized means of controlling each reflector with radiation pressure, and (3) an abundance of material with which we can immediately drive our economy, is very much appreciated. As we enjoy our immediate economic boom, we plan to use excess wealth to drive the creation of one thousand 'reorientation' ships, which will fly to each of the smaller mirrors and begin reorienting them as necessary, allowing us to focus radiation pressure on the corners of the larger reflectors and direct, in turn, their reflections. Although it will take time, please accept our gratitude for launching us into the next stage of civilization. P.S - Enclosed, please see our sample 1m x 1m sheet of aluminum. If necessary for the terms and conditions for your offer, please replace our request for 1 million 200km x 200km sheets with a request for 40 quadrillion 1m x 1m sheets, delivered in squares of 200km by 200km, with the edges touching. Please replace the smaller sheets at 0.5au with an equivalent delivery specification." [Answer] ## Plutonium Why? We need energy the most, and plutonium in itself is a pretty stable thing to have around, even with high gamma emission the expected "megaton" would produce. With enough plutonium, nuclear stations would provide enough energy to top off "green" and fossil fuels burn, allowing the humanity to avert energetic crisis for a good thousand years. (Of course nuclear waste processing would be required to handle all the mass of nuclear isotopes produces in power plants, but this is a slightly different story) Also increasing mutation frequency all around the world can *eventually* benefit humans as a whole, at the cost of innumerable deaths over immeasurable time, yet we already are undergoing induced evolution, so having it *slightly* accelerated could indeed prove beneficial. **Otherwise...** Currently, the economy is somewhat balanced, and anything provided will tip at least some scales, or can even turn some over. Say, if asked for lithium or rather palladium, the market for such a metal will be ruined, with collapsing production and shockwaves across neighboring markets. And regardless of commodity, eventually this supply would run out, whether it would take a year or a thousand years to exhaust it, it would still be a single fixed influx, thus another upheaval would happen once this supply would be exhausted. Therefore I'd rather have humanity ask for an energy source, that would still eventually run out, but in the process would allow us to do great things that currently are not in our energy budget to perform. For example, obtaining lithium from the ocean - the expected amount of lithium in there is VAST, exceeding a megaton by orders of magnitude, so we only need to filter it out, This mostly required energy, everything else is more of a one-time investment. Lowering energy cost by increasing supply of the most energy-containing fuel known to humanity would thus eliminate the needs of most if not all commodities obtainable from this wizard. **And a weird but still considerable desire (sarcasm)** Request a wizard to provide as much as he possibly can of 235U directly to the planet's core. The pressure down there would compact the uranium into a very supercritical blob that would just blow the planet apart with contained fission energy. No humans means perfect enonomy, huh? [Answer] # Graphene Graphene is the marvelous dream material from the future which already have a lot of applications. But also have a very big shortcoming: It is very hard to get any sizeable and usable good quality graphene sheet out of the lab (and even in the lab). Real graphene is currently plagued by: * Dislocations * Grain boundaries * Topological defects * Impurities (like a nitrogen, an oxygen or a boron atom in the middle of the carbons) * Isotopic impurities (carbon 13 and carbon 14 have a few noticeable differences than carbon 12). * Wrinkles * Buddings * etc. So, our best graphene labs should join their equipment and forces and work out how to create and provide the best ever graphene sheets that they can and use them as a sample. ## Where to dump all the graphene safely? First, 3 millions of sheets of graphene have a millimeter of thickness. Plant a 30 meters high pole in the middle of Sahara and ask Techno Mage Master Balmelgas to roll out a sheet of graphene around it until it reaches a radius of 10 km. This would provide us with a high quality graphene tape with a total area of... $$\begin{align\*} \text{total graphene area} &= \frac{\text{volume of cillinder}}{\text{thickness of graphene}} \\ &= \frac{\pi \times \text{height} \times \text{radius}^2}{\text{thickness of graphene}} \\ &= \frac{\pi \times 30 \, \text{m} \times (10 \, \text{km}^2)}{\frac{1 \, \text{mm}}{3,000,000}} \\ &= \pi \times 30 \, \text{m} \times (10 \, \text{km}^2) \times \frac{3,000,000}{1 \, \text{mm}} \\ &= \pi \times 30 \, \text{m} \times (10 \times (10^3 \, \text{m})^2) \times \frac{3 \times 10^6}{10^{-3} \, \text{m}} \\ &= \pi \times 30 \, \text{m} \times (10 \times 10^6 \, \text{m}^2) \times 3 \times 10^6 \times 10^3 \times m^{-1} \\ &= 9\pi \times 10^{17} \, \text{m}^2 \\ &\approx 2,827,433,388,230.81388230814 \, \text{km}^2 \\ \end{align\*}$$ This is a **HUGE** sheet of graphene coiled down in a single pole. In fact, if we were to cover the entire world with graphene, how much of the world we could cover with that much? $$\begin{align\*} \text{coverage} &= \frac{\text{surface area of all that graphene}}{\text{surface area of Earth}} \\ &\approx \frac{2,827,433,388,230,81388230814 \, \text{km}^2}{510,072,000 \, \text{km}^2} \\ &\approx 5,543.2044657044775 \\ &\approx 5,543.2 \end{align\*}$$ I.E. It would be enough to cover the entire world with high-quality pure graphene 5,543 times. And that with a single pole as the delivery location! ## Still not enough? No problem! We can also plant billions of other many poles around the world, some might be shorter, some taller, they can be made of wood, iron, plastic, brick, cement, steel... whatever, they are nothing more than the places where the coiling will start. All we need to do is to ask for the great Techno Mage Master Balmelgas to coil all the graphene around them to different radii and different heights specific to each location as desired by each customer. ## What about carbon nanotubes? Doable too, of course. We could get perfect nanotubes with thousands of kilometers in length. But their length and thickness vary a lot depending of the application. Length isn't really an issue, because it is easily solvable just by chopping it, but thickness very much is. Two carbon nanotubes of different thickness have very different applications. I am unsure if Techno Mage Master Balmelgas would agree with also providing nanotubes of differing thickness. If he is, then that is great! But if he isn't, then ok, we already got the graphene sheets to work out and that is already at least half or three quarters of the hard work needed in order to produce carbon nanotubes of differing thickness. Also, the delivery of nanotubes should be significantly different. Rolling out a single nanotube around a pole until it forms a disc of several meters thick and several kilometers in radius would make it several light-years long and really hard to unroll other than "let's just chop the entire disc", which would quite defeat the purpose for having a disc that size in the first place. However, the solution to that is simple: just provide a lot of nanotubes rolled to discs a few centimeters in radius around toothpicks instead, which is arguably far simpler. [Answer] > > [**Osmium**](https://en.wikipedia.org/wiki/Osmium) is the **densest naturally occurring element**. approximately twice as dense as lead > > > > > Osmium is among the rarest elements in the Earth's crust, making up only 50 parts per trillion (ppt).[5][6] It is estimated to be about 0.6 parts per billion in the universe and is therefore **the rarest precious metal**.[7] > > > > > Osmium is a hard but brittle metal that remains lustrous even at high temperatures. It has a **very low compressibility**. Correspondingly, its bulk modulus is extremely high, reported between 395 and 462 GPa, which **rivals that of diamond** (443 GPa). The hardness of osmium is moderately high at 4 GPa.[10][11][12] Because of its hardness, brittleness, **low vapor pressure** (the lowest of the platinum-group metals), and **very high melting point (the fourth highest of all elements**, after carbon, tungsten, and rhenium), solid osmium is difficult to machine, form, or work. > > > > > **Only two osmium compounds have major applications**: osmium tetroxide for staining tissue in electron microscopy and for the oxidation of alkenes in organic synthesis, and the non-volatile osmates for organic oxidation reactions. > > > This is the element I'd like to see more of, if only so that we could try to do other things with it besides make fountain pens. It's a super toxic oxidant, and there's not enough to do anything with. Hopefully it won't just be the outer cases for iPhone 27s. --- Next, there's **[rhodium](https://en.wikipedia.org/wiki/Rhodium)**. I think we're all pretty tired of people stealing catalytic converters. But at the same time, this is why you can't just dump junk on the economy, or rather why you wouldn't if you owned mines: > > Owners of rhodium—a metal with a highly volatile market price—are periodically put in an extremely advantageous market position: extracting more rhodium-containing ore from the ground will necessarily also extract other much more abundant precious metals—notably platinum and palladium—which would oversupply the market with those other metals, lowering their prices. Since it is economically infeasible to simply extract these other metals just to obtain rhodium, the market is often left hopelessly squeezed for rhodium supply, causing prices to spike. > > > 81% goes into catalytic converters; be neat to see what else a "corrosion-resistant transition metal" can do. > > Recovery from this supply-deficit position may be quite problematic in the future for many reasons, notably because it is not known how much rhodium (and other precious metals) actually was placed in catalytic converters during the many years when manufacturers' emissions-cheating software was in use. Much of the world supply of rhodium is obtained from recycled catalytic converters obtained from scrapped vehicles. > > > [Answer] # Think really, really big 1. How about dumping enough mass on mars so it can hold an atmosphere in the long term? At the moment it can not, due to its lack of an iron core which earth has. 2. How about a smaller star orbiting the solar system. Smaller stars burn slower, so it will be left over once our sun dies. Plus you could build a dyson sphere around it without making our sun darker [Answer] Actually there's no shortage of any material on Earth. We just sometimes lack in effective technologies to mine, absorb or process it. If we take solar system, it can provide literally inexhaustible source of any material. Like trillions of tons of natural gas, just laying open on Titan, Saturn's satellite. But its hard to get it. So, if I may guess, we (humanity) will get the most significant economy boost if we get something, providing us an opportunity to travel across space more effectively. I can think of 2 things. 1. carbon nanotubes. With really huge amount of nanotubes we can build space elevator, using modern technologies. If it passes the "structure" restriction nanotubes will be ultimate choice. If it doesn't then plan B. 2. Simply Uranium 238. Having enough Uranium the humanity can travel across and colonize solar system. We have already developed and ready to use nuclear drives, even multiple variants of design. Of course, such an event like a powerful mage giving the humanity an enormous amount of any of these, will immediately start global civil war, because multiple bunches of capitalists all over the world will try to gain exclusive control over such a wealth, none of them even thinking of ordinary people's interests. That has to be taken into account. So, your gift to humanity will 50/50 cause extinction of humanity or Communist revolution. [Answer] **Water, but in space.** I love the ideas people are submitting about delivering something to space, which would really kickstart anything humanity might want to do in terms of building out a space program, but my proposal is "water". In space. Water is very heavy. We need lots of it for any space programs. It's useful as radiation shielding too so if you can design your space ship to carry lots of water in tanks around the hull then you get the water you need for the trip plus radiation shielding all in one. But water being heavy means it's very expensive to bring up from earth. Contract out some scientists to figure out if containment is needed and, if so, how, but I shouldn't think we need expensive containment (some flimsy solar shield maybe...or maybe it's better to just plop it all down on the moon as ice). My thinking is that "space mining" can give us minerals we need, but lots of things (including generation of hydrogen for fuel, and oxygen) would be easy if we could start out with a big pile of water, either in orbit or readily available on the lunar surface. (We should be able to "mine water" in space but I think it's still a bit up in the air on how easy this will be. My understanding is that anything in the inner solar system has already had its water blasted away, unless it's buried. There is water on the moon, but getting it won't be as easy as just having a huge mountain of ice sitting there ready to go). [Answer] **Sand** Really a lot of pure Quartz sand (SiO$\_2$) to be delivered to fragile coastal lines all over the planet, maybe also piled to new islands off-shore, and some large stashes of sand for use in construction in the hinterland. There is already a shortage of good sand and thieves are stealing strands to use the sand for construction. So having an abundance of sand will be a good thing to the economy. P.S. Realistic politicians will probably demand for some kind of fossile energy, with methane being to hard to contain, maybe some fluid like pure Octane or even something just solid like pure stearin. This will have positive short term effect (dampening inflation and making production of a lot of goods easier) but is bad in the long-term: More climate gasses, more greenhouse effect, and a deleterious effect on renewable energies). Sigh. [Answer] ## On December the 21st 2022 Specifically: Fertilizer Industrial fertilizer is a mixture of nitrate (NH3), potassium chloride (KCl), and Potash (P2O5) which on average doubles food output per acre. The problem is that you need enough of all 3 of these elements to get a noticeable benefit and the trade embargos and cut-off supply lines caused by the Russian/Ukraine war have cut off many parts of the world from getting enough Potash and Nitrate. Economists are predicting the following chain of evens in the next year or two as a result: In many places in the world there will not be enough industrial fertilizer to sustain food production at the needed levels in 2023 which is estimated will lead to about a 25% reduction in global food production in the follow year. Because of how necessary food is for survival, markets will compete aggressively to import enough food and fertilizer for basic survival. The prices of agricultural products will increase several fold and drive down disposable income and demand for other goods and services causing many businesses less necessary for basic survival to collapse... which will lead to mass poverty and even bigger problems allocating food to the people who need it to survive. As a result, millions of people will starve to death, and the damage to the world GDP both short term and long term could be massive. .. the 3 element limit seems like a big problem here, but one that can be solved through cleaver chemistry. Most of the world is still getting enough potassium chloride production; so, we can limit the problem to focusing on nitrate and Potash. While we can not request more than 3 elements, we could request a mixture of Nitrate(NH3) and White Phosphorous(P4). We would have to have Balmelgas deposit this mixture into refrigerated rooms to keep it from exploding, but you could then separate the White Phosphorous from the Nitrate, and then burn the White Phosphorous. The result of burning the Phosphorous is P2O5 which can then be recombined with the Nitrates and Potassium Chloride which you already have plenty of to make fertilizer. Then the expected food crisis of 2023 could be mostly averted. Literally millions of lives and jobs would be saved, and the global economy would have enough time to establish new fertilizer production facilities in new places to be able to meet the world's long term needs. Whether or not this will yield the most dollar signs out of any possible substance is debatable, but I can guarantee that this is the one substance most world leaders will be able to agree is a top priority at this particular date. [Answer] ## Put some Rocks in the Oceans! Adding limestone land islands 10 times the size of Indonesia would do more for the planet than limitless energy. To do this, the magician has to change the protons and neutrons into different elements, rather than magically appear stuff through teleportation which is a bit low-tech for nursery books. Land is a scarce commodity on the planet, forests are being decimated for food, animals are threatened by agriculture, humans are born without land and work all their lives to rent it. So magic 350 islands in the Atlantic and Pacific with 750 million cubic kilometers of basalt rock. We can add a land area the size of Africa to the ocean and use it to send the vices of humanity to a new place. The condition to that is that the volume of water displaced is swapped or taken to the moon/mars and a new moon is created for mars to restart it's inner magnetic force. Specifically which rock type, I dunno, perhaps porous limestone. Basalt is many chemicals. either way, adding a land area the size of Africa would do more for the planet than limitless energy. [Answer] ## Platinum Platinum isn't just a precious metal. It's extremely valuable as a catalyst for many oxidation/reduction reactions, and is highly treasured as the least reactive metal in existence. Platinum is why people keep stealing catalytic converters. The lack of platinum catalysts is a limitation that prevents us from using fuel cell technology to replace batteries. There's a [lot of research](https://www.nature.com/articles/s41467-022-33892-8) right now on how to decrease the amount of platinum required by a fuel cell, simply because it's the cost-driving factor for that technology. A sudden, wide-spread, massive dump of platinum would obviously cause the collapse of platinum prices, but there isn't a huge market for it to go bust due to its rarity. It would result in a massive boom in energy storage businesses, and allow the creation of cleaner power generation, and reduced energy costs. It would become the plating of preference for almost everything that you wanted to last a long time, especially lab equipment. [Answer] # Oil People are making very complicated answers involving space travel, advanced materials, and all sorts of things. But, there is something that is massively traded worldwide. There's something that caused wars worldwide. Oil. You'd have to negotiate what range of chain lengths of hydrocarbon they will provide, but this is the most important resource. Our demand for goods based on oil is near infinite- plastics, fuels, medicines, drugs- and limited by price and supply. The Ukraine war happened because Russia wanted Crimean gas. Many middle east conflicts have been over oil. If you have a basically infinite supply you can use it efficiently to produce huge amounts of goods and energy and valuable things. There are several reasons why it's the best commodity. 1. [Oil is the most traded commodity.](https://admiralmarkets.com/education/articles/general-trading/most-traded-commodities) 2. [It has a vast array of uses.](https://www.ukogplc.com/page.php?pID=74) 3. [It drives inflation and weaknesses in economies.](https://www.investopedia.com/ask/answers/06/oilpricesinflation.asp) 4. [We can stop global warming with enough energy to capture carbon.](https://en.wikipedia.org/wiki/Carbon_capture_and_storage) So yes, this is the most valuable commodity to ask for. Energy is what makes a civilization great, and oil is the most convenient chemical. If they demand one molecule, just ask for something like pentatriacontane. That can easily be cracked into whatever is needed. [Answer] ***Food or Clean Water*** You guys are suggesting a lot of gold or steel, but it would be just better for humanity in general to get plenty of food or clean water. [Answer] ## Tell Techno Mage Master Balmelgas to take a hike! This is a [Frame Challenge](https://worldbuilding.meta.stackexchange.com/q/7097/40609). Introducing an abundance of *any material whatsoever* that could prove useful to either the environment or any form of industry or exchange would be ***devastating*** to the world economy. Whatever material you choose, there is a *massive* industrial complex behind it's acquisition, processing, distribution, use in manufacturing, more distribution, sales, consumption, and disposal. Providing an abundance turns all of that on it's proverbial ear. Do you remember the movie *Chain Reaction?* The usual group of naive but well-intentioned scientists1 build a technobabble-based free energy machine that they're ready to release to the world and the just as usual government Big Brother interference is trying to control and/or stop it. But the movie makes a very real and very good point. What happens when you dump too much of a resource onto the planet? Markets crash. Nations collapse. People suffer.2 **Nature, including Humanity and all its raucous complexity and juvenile beliefs, is a struggle for balance** And what too many people don't understand is that it's the *struggle* that's important, *not the balance.* Nature hates a balance just as it hates the proverbial vacuum.3 Balances are bad because of *entropy.* If you stop pushing forward, "the universe" starts pushing you backward. Insofar as Humanity knows, there is no such thing (material, philosophy, whatever) that won't decay over time (entropy), and that means struggle... or die. I can literally think of nothing Balmelgas could give us that would be a significant benefit that wouldn't be devastating. Maybe the cure to one minor disease. Maybe a box of snicker doodles.4 Whatever it is, the gift must be (must be) *inconsequential* in the "Grand Scheme" of things or it will hurt rather than help.5 *So... thanks, Balmelgas. Here's the rose. Nice smell, are we right? There's the door. Don't let it hit you on the way out.* --- 1 *Hollywood makes it seem like scientists and engineers can't understand economics. But as they say, the plot must go on.* 2 *And zombies. There's always zombies. Hollywood has convinced me that it doesn't matter what the cause is, the result is always zombies. I'm just sayin'... zombies.* 3 *RIP Leonard Nimoy.* 4 *OK, maybe resurrecting Karen Carpenter. One of the most beautiful and talented singers to grace Earth. That wouldn't crash civilization — but it should.* 5 *To all you believers in Utopia and Post-Scarcity Civilizations... yeah. They can't exist. Not won't. Can't. It isn't simply the lack of a decision on Humanity's part or that we simply haven't earned enough wisdom yet. If that doesn't make sense, all I can say is you need another 10-15 years of life experience before you realize those are great Hollywood story foundations — and the worst possible prisons Humanity could force itself into. When the Wachowskis mentioned in The Matrix movies that humanity rejected perfection... that wasn't whimsical. That was insightful and based on thinking the issue through.* [Answer] **Petroleum** Due to its high demand, Earth may get it. Sure, there may be problems with the oil companies, but hey, at least it will calm down those who freak out about running out. Depending on its effect, it may even help make petroleum cheaper. If you are not looking for oil, then there is: **Copper (or at least metals used in digital electronics** Many of the metals used in our technology are either rare, come from dangerous mines, or both. If the aliens helped bring in these metals, we would have more access to the technology, maybe it might even cheapen. While of course, there will be problems with corporations and their own agenda, but for now, these are some simple ideas and solutions. [Answer] Trick question **NOTHING** Due to the laws of supply and demand, the more of something there are the more people can have that thing, thus demand goes down and so does the value of that thing. It's why the Global Diamond market limits how many diamonds there are on the market (despite the fact that diamonds can be made in a lab fairly easily), it's to keep the demand (and thus, the price) up. So, if we were to add a large amount of any material or resource, it would crash the global economy, not help it. [Answer] **Orthorhombic C8** ## A superstrong not-super-lubricious metastable carbon allotrope Perfect long-fiber carbon nanotubes (in teratonne quantities, in orbit) might seem like a wonderful construction material, but a deep dive into the experimental literature shows why CNT are superstrong, but useless - defect-free carbon nanotubes are "superlubricious", practically zero friction. There's no way to attach to perfect nanotubes, and imperfect nanotubes aren't much stronger than Dyneema and similar engineering fibers. I recall a research paper about the construction of two *perfect* centimeter-long carbon nanotubes, a thinner tube nested inside a fatter tube - temporarily. Since the tubes are practically frictionless, gravity is enough to slide the inner tube out of the outer tube. Lattice defects on the tubes will stick to other lattice defects, but are also stress risers, weakening the tubes. AFAIK, we will never build space elevators and similar magic structures with carbon nanotubes. Computational atomic modelling to the rescue ... sorta. While we don't know how to actually make the stuff, physicists have *computer simulated* a dense carbon crystalline material named "C-Centered Orthorhombic C8", which comes close to carbon nanotubes in strength, but has a repeating 3D structure. The problem is that, though theoretically stable, the only way to form it is with pressures that can only be achieved with materials stronger than Cco-C8. Or ultrahigh energy densities and luck. Or magic. We could make 3D macroscopic structures with Cco-C8 - including attachment rings. Start with a large crystal of Cco-C8, use an oxygen torch to carve out the finished product or device. Subtractive processes, only Balmelgas has the additive magic which makes the material. So, how do we make a tiny tiny sample? Ultrahigh energy densities and luck - perhaps a hydrogen bomb blast in a carbon-lined cavern, followed by a LOT of molecular sorting to find a microscopic chunk of Cco-C8 (among a zillion other carbon chunks) to give to Techno Mage Master Balmelgas. However, with luck, we might achieve a similar microchunk with a LOT of shock tube chemistry ... and LOT of luck. So, thousands of apparatus makers (the A team) build shock tubes QUICKLY, while the B team lines a cavern with carbon and sets off a low-fallout neutron bomb in it. The rest of us are organized into microscope-wielding search teams to look at trillions of shock-compressed particles to find some lucky C8 particles. WORK QUICKLY, time's a wasting! We deliver our tiny crystal to Techno Mage Master Balmelgas, and say "please make a 0.02-Moon-scale crystal of this stuff, and park it at Earth-Moon L5." A vastly larger crystal could be parked at Sun-Jupiter L5, but round-trip time to Earth would be long, and the escape velocity from such a large carbon crystal would be daunting. --- Of course, in Real (fantasy) Life, most of the people of Earth would vote for an ocean of ethanol (harder drugs require nitrogen in addition to CHO). Devout Muslims would vote against that, nuclear war would erupt over the decision, and we would all die. Or, after all the effort and conflict, Balmelgas will say "just kidding". --- [Answer] ## Lithium-6 What's better than Lithium? Lithium-6! Lithium naturally occurs as 99% Li-7 and less than 1% Li-6. As a result, Li-6 has 14% higher energy storage density (by weight) than lithium as we know it. If received in megatonnes of elemental Li, you effectively get a load of energy for free too, as it arrives processed and 'charged'. But make sure you don't deplete the atmosphere of oxygen. ## Li-6 hydride or Li-6BH4 14% better than lithium? Rookie! Lets add loads of stored hydrogen with some wickedly exothermic release reactions. Hydrogen and heat both more or less pour out of this stuff. "Just add water". There are a million and one detailed hydrogen economy proposals based on either LiH or LiBH4. The main problem is that they never solve the problem of how to make the hydrides. Problem solved by this mage guy. LiBH4 is the densest energy storage material known to man; it just got 10% better by weight. It's also a very expensive but very useful chemical synthesis reagent. ## Li-6 fusion fuels It gets better, though, because Li-6 is suitable as fusion fuel. Get it either as Li-6-O-H-3 (Lithium-6 tritium oxide, fusion superfuel), or Li-6H-2H-3 (Lithium deuteride / lithium tritide mix). ## Choosing a form If received in the elemental form, you get one immediate GDP boost (free energy/processed material), one medium term GDP boost (reusable energy storage material 14% better than we have now), and one long term boost (fusion fuel). If received as the tritium oxide, the fusion future arrives decades sooner but the short term boost is smaller. If received as the hydride or deuteride-tritide, you possibly get the best of both worlds. Other alternatives to pure Li-6 include an unstable alloy with another element like iron and/or copper or rare earths (so you can easily process it to get all those elements), or Li-6 with He-3 bubbles. My personal favourite: On balance, the lithium deuteride / tritide, with LiBH4 in second place. [Answer] [Metallic Hydrogen](https://en.wikipedia.org/wiki/Metallic_hydrogen) * Probably Room-temperature Superconductor (say hello to magnetically levitating everything without energy losses) * Perfect Rocket fuel * might not be metastable (i.e. not storable in which case this idea dies) ]

[Question] [ There is a species that is quite sentient. Its members know about the world, they have hopes and dreams and great aspirations of what they might do with their lives. They are intelligent, creative, caring, empathetic and deeply feeling individuals. However, this particular species bears a heavy curse. The male partner dies less than one day after mating. This is not the result of ritual, cannibalization or necessity, but a reaction of their biology itself. They (assuming they are told or they figure it out) realize what fate holds for those that partake. The female partner shall live, while the male shall perish. Sadly, there is no guarantee that their sacrifice will result in a child, nor do they have any way to stop the impending death when it is set in motion. But the question is, would they make the sacrifice, knowing full well the consequences and risk? There are a few more stipulations: 1. Males can only potentially impregnate one female. 2. Males will live a normal, full length life, if they do not partake (Barring disease or accident). 3. There is no way to artificially inseminate or otherwise avoid natural reproduction in the case of furthering the species. 4. Females that are able to bear children are likely to bear more than just one; between two and four. More than four is rare and zero is uncommon, but both cases have been documented. 5. There are no documented cases of successful childbirth after one or both parents have lived beyond 1/3 of their lifespan. 6. Diseases the parents have are likely to transfer to offspring. Only healthy individuals are recommended. Though uncommon, healthy children sometimes come from unhealthy parents. So, can this species persist? How would a culture form regarding the two genders? Would society pressure individuals to reproduce, despite the cost of life? What other unforeseen implications would this have? Note: I've seen a few people concerned about child birth mortality rates in pre-medicine times. You can safely assume that majority of pregnancies have consistently had minimal mortality rates, even during the darkest of times. At the highest child deaths throughout history have only occurred at about 1:10000 children (a tradeoff for killing off one of the parents perhaps), and that number goes down significantly with technology and medicine. [Answer] This would naturally lead to a decisively asymmetric society. My expectation would be that it would look more like a slavery society, where women have male slaves. Why? Economics. Why take the time to educate someone who may mate and die, when you can spend that time and energy to educate someone who will pass on that knowledge to the next generation. It would be natural to have women be highly educated. Meanwhile, the species *depends* on the sacrifice of males to continue. This would certainly be a highly ritualized process, which is most easily done with a *strict* caste system. Given the differences in education and the relationships that are called for, it may be hard to tell it apart from slavery. Given this, unlike Bryan, I would not expect anything remotely resembling monogamous marriage. There's scores of disadvantages to it, and no advantages. There's no way for the male to be a father in their children's life. If a man and woman loved each other, there would be almost nil incentive to mate, meaning their genes would not propagate... ever. The only way I could see this working is if the mother beget children via another man (a slave), while being in love with her husband. However, that's about as complicated of a relationship as you can get, and a terribly complex cultural model to permit that dynamic range of male rights. If your story did have that, you would want to build the *entire* culture around explaining why it occurs... it's just that unusual looking. And I agree with Bryan that 4 children is no where near enough. [Answer] I think it highly unlikely that a species such as this would develop with equal mental capacity between males and females. Evolution's pretty ruthless, and intelligence has a fairly high energy budget - not to mention a lot of difficulties with human childbirth are just down to the size of our brains. Big brains on Earth are risky things, and the only reason humans have them is because they let us adapt our environment to give us a strong boost in survival. So if the males won't survive long past sexual maturity (I'm assuming a strong urge in males to impregnate females, strong enough to override the urge for self-preservation), why waste the energy and body mass and difficulties (assuming they have heads like ours) in birth when males would be just as useful if they were dumber, yet affectionate and cute and fun to play with and look after. The females with all their intelligence would end up in charge of everything, raising their daughters to inherit the world and their sons to breed. So you end up in a symbiotic relationship where the males depend on the females for a hospitable environment, and in exchange give up their relatively short lives so the females can reproduce. I suspect the females would have to have more male children than female, and be less (or at least differently) emotionally attached to them. [Answer] You'd get significant sexual dimorphism. Firstly, there's no reason for the males to be intelligent, there's no apparent advantage to it. It's a lot of energy to burn for such a short lifespan. I'd also expect them to be considerably smaller. Since one sex is intelligent and the other not, you'd need a system by which the females picked partners. Are they strong? They can't risk fighting as males are not disposable. Are they colourful or showy? Devious? A mix of all the above? Sex balance among the spawn: You'd need significantly more males than females. At least one male for every litter that a female would bear in her lifetime, per female offspring, per litter. They'd have to breed like rodents. You'd probably need to have a flat minimum of one female and four males per litter to increase population at all. This still only allows a maximum of 4 litters per female, which is ridiculously low in the real world. The males mating to death? [Not such a problem](http://www.sciencealert.com/scientists-find-new-species-of-marsupial-that-mate-themselves-to-death). Though in these cases they mate with as many females as they can before they crash and burn, and for some reason nobody has mentioned the elephant in the room that is the praying mantis. [Answer] A species could easily exist like this, provided they had some more unique biology. For example, the female of the species could have the ability to store the sperm from the union for an extended period of time. In most mammals, sperm only lives for a few days inside the female, however in numerous worms, reptiles and insects, the sperm can remain viable for weeks or even years in some cases. This would eliminate the need for repeated mating with the male, and allow a single female of the species to continue to give births even in a prolonged absence of males within the community. One source regarding the phenomenon: <http://www.sciencedirect.com/science/article/pii/S0960982211012528> [Answer] Yes as long as they produced hundred of children from only one pregnancy. Four is just not enough. Even an intelligent species would be extinct if males had a life long reproduction limit of four. Imagine living in the Middle Ages when having a couple stillbirths was very common. Now imagine that each family can have no more than four children. This would be disastrous, is the reason black widows produce a large number of offspring at a time. So a large litter of several dozen to a hundred children would be need. This could be accomplished by laying eges perhaps. The females would be the domainate gender in society. Males would probably be viewed as little more then cattle. Male rape would be a common thing. As society progressed the males would eventually get some rights. Laws would be passed preventing them from being taken against their will. This would lead to a society were only the elder males would reproduce. They would probably look at sex much differently than we do. There would be no casual sex. The person you had sex with would have to be literally someone to die for. The sex act would probably become highly ritualized. Marriage could still envolve but it would have a very different meaning then what we have to day. [Answer] While it is perfectly viable that the result of this trait is a society separated by gender and probably ruled by females (this does not necessitate that males are slaves; could be treated as heroes that are ready to make the ultimate sacrifice), it is also possible - and, in my view, more interesting - to have human-like societies. The key to that, is to treat the male mate as nothing but a sperm donor. Then you can have a standard family of a female and male that decided/was allowed/was lucky enough to give up mating. The availability of males that are ready to sacrifice their life so that the couple can have a baby can be explained by having two classes, a ruling class that enjoys life exactly like humans with the exception of (reproductive) mating, and a class (possibly slaves) from where the "life-donors" are picked. Not much different from societies that send low-class soldiers to defend the borders really. Alternatively you can have something similar to the Aztec [flower wars](https://en.wikipedia.org/wiki/Flower_war#Purpose) and capture enemies for reproduction; something somewhat more justifiable than sacrifices to gods. In other words, for every "normal" family, you need 2 males and one female. Come to think about it, it could even be two females and one male. The existence of upper class males is trivially explained: their parents wouldn't want to see their life "wasted" (perhaps there's even a castration ritual to ensure it). Overall, I love your idea and it's brimming with potential! [Answer] It is hard to think of a reason why such a system would be beneficial in an evolutionary sense, but it is not entirely implausible. Consider a species such as chimpanzees, where the aggressive males use a lot of their energy fighting with each other, and a dominant male will typically kill the children of other, rival males if he gets the chance. Perhaps this species shared an environment with a particularly dangerous predator, making the males even more aggressive. The dominant male is the protector of the group, with the females doing most of the work raising the children. Next, the species' main predator dies out, rendering the aggression of the males superfluous and their aggression causes more harm to the species than good. Then, a particular male has a genetic defect that causes him to die after mating, which is passed on to his offspring. Groups carrying this defect may wind up being more successful than those without since they waste less energy on fighting, causing the trait to be retained as the species moves toward sapience. In some ways, this is a (much) more extreme version of a process that occurred in human evolution. Most primates have a baculum (penis bone) that allows them to easily mate with many females consecutively. Humans lost this ability, presumably because it promotes a more monogamous lifestyle, which in turn encourages males to expend more energy on raising their offspring. In this species, the males were so aggressive that *dying* was better for their offspring than *not dying*. One interesting effect of this situation is that many typical male-female behaviors will be reversed. In most animals, females are the 'selective' sex while males will typically mate whenever they get the chance, since females sacrifice more in reproduction. If the males die after mating, they will naturally become a lot more selective in who they mate with, to ensure the maximum potential for their children's survival. Females will have to expend the main effort in order to prove their value to a potential partner. It is almost certain that sex will become intertwined with religion in some sense or another. Males will probably see it as the culmination of their being and view it as the sacred death or something of the sort. One possibility is that some males will become celibate priests who assist in raising the children of the community instead. Or, to give it a darker twist, perhaps the leader of these celibate males, a 'high priest' (who may retain the baby-killing drives of the 'dominant male' that led to this situation in the first place) will act as a 'divine judge', killing the children of the 'unworthy' males who mated without offering him proper tribute. Or maybe the females will run the society, and males will simply become property who are sold off by their mothers. [Answer] Another example of an existing setting with a similar system of reproduction is Greg Egan's Orthogonal trilogy, set in a Riemannian universe and beginning with "[The Clockwork Rocket](http://gregegan.customer.netspace.net.au/ORTHOGONAL/E1/ClockworkRocketExcerpt.html)". The alien species that the trilogy follows are six-limbed shapeshifters which reproduce by the fission of the mother into two pairs of twins. This typically occurs after mating with a male, but can also take place spontaneously past a certain age. The first book follows Yalda, a rare "solo" who consumed her twin in the womb. As she is not expected to reproduce due to the lack of a twin, she is allowed to study and attends university, encountering a group of other females who avoid spontaneous reproduction through a drug, and the social implications thereof. Later in the trilogy, a relativistic generation ship is launched to save the homeworld, though this is plagued by the difficulties caused by their system of reproduction. Various solutions are explored, including the use of deliberate starvation in order to simulate a famine and so limit reproduction. [Answer] The "selfish gene" meme suggests that males will attempt to mate regardless of their fate, in an effort to pass their genetic material along to the next generation, so social, cultural and even economic and political structures will be developed around that and the inevitable consequences. Since males pass on after mating while females live long productive lives, the first order effect is society and everything built around it is matriarchal. Males will compete furiously to attract females and impregnate them, but it is a buyer's market, and the females can be very selective in choosing who they mate with. The competition will change males into something like peacocks, with elaborate displays of beauty, health, athleticism, intelligence and wealth in order to attract a mate. This is not entirely one sided for the males; they will preferentially mate with females who display robust health and resources in order to ensure that their offspring have the greatest chance of success. Biologically, there might also be a high degree of dimorphism between the males and females of the species; there is a deep sea anglerfish where the male becomes a tiny parasite attached to the female after mating, feeding off the female's bloodstream. Males might go the other way in becoming massive in order to physically exclude competitors for the females. I also expect that males will outnumber females by large margin as part of the evolutionary process. Males will be living mayfly lives, so will not be contributing much to the society at large, and indeed social and economic structures might be developed to shelter and support males after they reach sexual maturity, and also act as a benevolent society to dispose of the dead males and pass on their estate (such as it is) to the female who is bearing his child. There might be some fraud among the females, especially if they know the males will not be around to complain if a female makes a false claim of pregnancy after a deployment or business trip. The families of males will be monitoring the situation carefully, and doing what they can to ensure breeding success. [Answer] As other answers have said, there is no evolutionary incentive for males to be intelligent, so evolution will reduce them to nothing more than horny little puppies. The issue then becomes how will a female who is ready to procreate identify a male with good genes? And the only answer that comes to mind is by looking at their mother. I see a situation where an existing women has a bunch of these horny mutts at home, and her friend comes round and decides to have a baby with one of them. She will give birth to a litter of males, and after several attempts, the female child she always wanted. Nature demands that there will be vastly more males than needed. This will lead to them being euthanised, as letting them go wild would create a problem similar to that of feral dogs (except that these would take leg humping to a new level.) It would be possible, but not necessarily the social norm, for two (or three or four) females to form a committed lesbian relationship and have children via each others male offspring. However if they were both virgins they would still need to lose their virginity with the male of a more experienced female in order to get started. And their offspring would always carry some of that experienced female's genes, so she might want to be part of their lives. Many species females have a naturally lower attraction for their relatives, to avoid incest. This is not so prevalent in males. Observation of the natural world shows horny, indiscriminate male monkeys trying to mate with close relatives and being rejected. On the other hand, the males of this species will need to clearly identify their mother as a provider and not a potential sex partner to avoid being thrown out of the brood for harrasing her. Ants and bees offer a relevant model. The sexual dimorphism of anglerfish (where the tiny male becomes a permanently attached sperm-producing parasite) is also of interest. [Answer] In response to Cort Ammon, I think there might still be some "monogamous marriage". I'm reminded of a short story I read where it is proved that homosexuality is almost entirely genetic (as there's still plenty of debate on this, let's just accept it for the sake of argument), and the characters discuss why that trait wouldn't be bred out. One answer is that the existence of same-sex couples who wouldn't have children meant communities had people who would use their resources to support their extended family's children, thus giving families with some recessive homosexual genes an advantage. In the same way, if genetic, love or chastity might not necessarily be bred out, as it may improve the couple's extended family. That said, I do not think this would be the case, as the trait of the male dying would presumably have developed long before society did. [Answer] I think the most adequate system would be that of bees: the male dies after copulating, but his gonads remain alive inside the female, producing sperm. This would avoid the need for a skewed sex imbalance, too. Or even turn it around into a majority of females. The problem here would be that it would probably require reproduction to be a specialty of only a few females. Which would pose the question: who would be actually sentient, all females, only the "queens", only the "workers"? [Answer] Such society might survive and develop provided that women are able to keep man's sperm in their bodies for a prolonged time. They can then use it for subsequent fertilisations. They could possibly even get impregnated by multiple men and their sperms would compete for fertilisation inside the body. Similar scenarios are known in other animal species. It would be a female dominated world, of course, but men's role would be very important and relatively enjoyable, I would say. Their role in the society would be purely ornamental and submissive. I expect that a teenage man would become a property of a woman, which would then own him and live with him as long as mutual emotions will lead them to a sexual intercourse. I would also expect that men would be told from childhood that this single experience is the ultimate the pinnacle of all earthly endeavour and pleasure - and they would believe that a wouldn't be afraid of death in the arms of their beloved woman. Women might probably keep sort of mausolea in their homes with photographs, clothes, possibly even embalmed body parts of their males. This would be viewed as entirely acceptable as male death would not be would not be feared, but quite natural and seen as a desirable culmination of their simple (and short) lives. I can even see situations when a man would beg his lady to do this thing with him already as older men would be viewed as loosers and parasites in society. ]

[Question] [ **The setting:** Very distant future, Earth is long gone/forgotten/just not around anymore. Humanity, whatever it may consist of (people, AI, something in-between) inhabits a single vast generation ship that roams the stars with no fixed destination, using material from the star systems it arrives at to refuel, expand, and do whatever else. They don't stay though, once they're done in a system they just pack up and leave. Not allowing FTL travel in this universe would be my first guess, but I feel that even then it would be possible to at least retain casual contact between systems up to a couple dozen lightyears away, on a "let's sort it out before the colonists leave" basis. My question is why might this be the way a civilisation exists as opposed to maintaining an interstellar group of colonies? [Answer] In the savannah of the universe, stars are the watering holes needed to sustain life, but full of predators and dangerous. Colonies are fixed targets, perhaps there are some hostile alien entities around most stars that are hostile to other forms of life (or all life). Note: in the far future these entities could easily be of terrestrial origin, out of control AI nanotech or other similar hazards. The danger in one star system can be mitigated/defended against for short visits, but will attract larger swarming attacks from nearby stars, almost like an immune response. Assuming no FTL these attack groups from other stars would take decades to get to the current star system, making it safe for the short term, but sticking around for longer extremely dangerous. [Answer] Why shouldn't they live on that vessel? As long as it isn't more dangerous or less comfortable than living on a planet, why bother to settle on a planet? Depending on how long the journey with this ship took, the people in it where born in the ship. It's their home. That's their way of life. And being mobile has some advantages. The sun in your system reaches the end of its life? No problem: just move on. Asteroids crashing on the planets in your system? Not your problem: you just move out of the way. [Answer] The ship started out as a generational ship to colonize some far-away planet. However, when approaching that planet, nobody wanted to be a colonist. They lived on the ship, their parents lived on the ship, their grandparents lived on the ship. Indeed, some even doubted the historical record and claimed that no one ever had lived on the surface of a planet, that it was far to dangerous to try, with all that uncontrolled weather, volcanism, and so on. And even assuming that Earth existed (nobody alive remembered any communication from Earth anyway), what could the people there do about it if the colonists simply didn't colonize, but keep on the ship? However they did face one problem: Population growth. But they didn't have the facilities to build a new ship (after all, the ship was not intended for that; the necessary facilities would have been built on the planet after colonization), so they decided to just add some sections to the existing ship. They kept orbiting the destination sun, as it provided them with energy, and harvested asteroids as those didn't have the gravity well cost. As the ship grew, so did their skills and abilities, and over the course of a few hundred years, they indeed reached a level where they could build new ships directly. But the existing ship had developed so much that any newly built ship would have necessarily been a step back for any inhabitant. They developed decks with soil; there was definitely not enough soil to spare for a new ship to immediately copy that achievement. Building up new soil would need centuries. Also, building a new ship would have meant duplicating all the systems of a ship, the drive, the sensors, the main computer, while extending the ship meant just adding a bit to what already was there. So they added layer over layer to the ship, and after few generations they didn't even think about it any more; extending the ship was just the way they lived. And extending got even easier over time, as the surface of the ship grew. So they ended up with a giant ship containing all of the known mankind. If Earth and its inhabitants still existed, nobody could say for sure (and actually, most were now convinced that it never had existed, that it was a myth from those people millennia ago). [Answer] Why might they want to stay on their ship and live a nomadic lifestyle rather than settle down? There could be a couple of different reasons: **1. They are being hunted** Humanity has an enemy, and can't win in a straight up fight. In fact, we've tried that, and it cost us dearly. The survivors exist in this generation ship, and are hoping to reach a remote corner of the galaxy where they might be safe. Unfortunately, so far the enemy has proven extremely dedicated in their pursuit of the remnants of humanity. Why that might be is up to you. Maybe us humans created an AI which rebelled against us, tried to wipe us out, and is trying to finish the job. Maybe we encountered an alien species which wants complete and total dominance of the universe, and simply moves from solar system to solar system wiping every other sentient species out, and they've found us - we know that any colony will be destroyed sooner or later. . **2. A final destination** Humanity has found out that there's this perfect paradise somewhere at the end of the universe, and are seeking it out on a journey which will take thousands of generations to complete. Maybe the source of information was some higher order being, or promised them by some much beloved religious leader; either way, they believe this information completely. **3. Cultural reasons** Humanity has embraced a culture of exploration, and we're sticking with it. (this is probably the weakest reason of all) [Answer] **Centralization** even if it is a large population it is definitely going to need to stick together if it desires to even have a chance at surviving. Also a vessel of the magnitude you assume is very large. So large that it may even need to have its own government. In this case Stability of the government is easily guaranteed if there is just a single ship and not multiple colonies. *(Multiple colonies Can mutiny on their own or even declare independence from the group also having multiple colonies may split your populace into factions which I do not believe to be desirable given the set of circumstances)* **Unity** When people stay together on the same ship they have a greeter chance of fighting together for greater causes. In case assuming an attack of the big vessel you speak of the loyalty of the crew towards its cause and also its co-ordination between itself may be of vital importance. Given that it is just one ship easy and effective co-ordination is very easily possible **Bigger Ship = More Firepower** If the ship is supposed to represent the carrier of the last remnants of humanity it is obviously very strong. Capable of repelling attacks and has amazing weapons and stealth capabilities. In case an attack ever happens this one large ship may be able to easily take over enemy vessels in order to salvage them or to take them as hostage. Which could give the crucial battle edge to these survivors Also if you have a single ship retreating and regrouping is much more easy since you don't leave anyone and always go with your crew. Though it may not appear morally very appeasing retreating in some cases is the best option available **Colonies Can Mutiny Easily (Can also be read as civil wars are dangerous)** It is possible that colonies are not happy with the deal they are getting and hence may be possible that they can mutiny. Since no FTL travel is allowed the word of mutiny may reach the government too late for the government to even stand a chance. A civil war may tear the remaining human population to shreds from where it may reach a level so low that it may never be able to stand up again. **You Cant repair a Planet or a Colony but you can repair a ship** A ship is a dynamic system You can repair it easily it may even repair itself given the lever of technologies. Planets unfortunately are not the same. Once you destroy them It will be very difficult (Read Difficulty->impossible) to even *repair* the planet. In this case a single ship would be an advantage due to it being just more resilient. **Or may be these people are happy as they are** May be that the population of your ship is happy and comfortable with its nomadic lifestyle. It may have even completely adjusted to it so why take pains to colonize a planet if everybody happy with this nomadic way. Colonizing planets is hard indeed **You Don't want to destroy the planet the way you destroyed your home** May be humanity has some guilt left in it about the horrible stuff it did to this planet so they may for some emotional reason decide that they can't destroy another planet's well and good ecosystem and remind themselves that they are not gods and have every right to play with other planetary systems **The colony may also have some unexpected and not so friendly neighbors** If you set up a colony it is possible that some intelligent alien species which already resides in that system may get upset. In which case it is probably going to look great for humans who are by now a bunch of nomads. An all out war or covert warfare would not be favorable at all especially in the enemy's home turf. Also since your population was probably drifting about in space in search of a new home it also has terribly less experience of interstellar warfare which is another fact that plays against it [Answer] For me the difficult question is why do they *expand* and all head off together, in preference to building a second (and subsequent) ship and heading off in different directions. There could be technical reasons they can't build another ship (lost knowledge, only one unobtanium crystal), or social ones (this one ship is the sole survivor of the ShipWars that resulted from the last time anyone tried it). But the reason for not colonizing the planet can be fairly simple. First, the giant ship they arrived on is in the process of strip-mining the system for every useful resource, and won't leave behind anything worth living on. Second, the civilization is clearly accustomed to a way of living that consumes the resources of an entire system from time to time: staying behind as a "colony" in effect means limiting yourself to the resources of only that one system, so how long will you and your descendants last? [Answer] Every sufficiently advanced civilisation will reach the stage where it starts building advanced generation ships. These are attracted to habitable planets, where they can expand the ship, refill various resources and acquire knowledge. These visits almost never end well for the populations of planets visited. (Some of the first were nearly fatal for our ship, but we have had enormous technological progress since then.) This kind of event is rare enough for sedentary civilisations simply not to prepare for it, but also frequent enough to be the key reason why, as a general rule (as far as we know), every sedentary civilisation will be destroyed sooner or later. The inhabitants of the ship, on the other hand, don't draw attention to themselves by orbiting a star, and they know well in advance when they will reach a potentially inhabited planet. Sometimes they even manage to develop biological weapons that extinguish the entire population without ever being discovered. This makes it so much easier to plunder a planet for its resources. Theorists say that there must be similar ships that are able to detect other generation ships from far away and feed on them. They say that by leaving a trail of destroyed civilisations behind us, we may attract these meta-predators. This is because the results of some of these destruction events can be observed from very far away in much the same way that we find our victims. We don't have (yet?) what it takes to become such a meta-predator. So we'll continue with our current lifestyle, which is at least safer than staying on a single planet. Some theorists also claim that there must be sedentary civilisations that feed on ships like ours that underestimate them. But nobody really believes them. [Answer] Obviously, there must be many reasons to go with a large ship. People may fiddle with smaller designs, but you need reasons for big ships! Here are some: # Shielding Shielding a population from the nasty, UV and other radiation induced-related [deaths and symptoms](https://en.wikipedia.org/wiki/Radiation_protection#Spacecraft_and_radiation_protection) can be quite costly. There could be a particular size of ship, which is large, that produces a strong enough magnetosphere for humans to live in. Additionally, perhaps they've developed [deflector shields](http://physics.le.ac.uk/journals/index.php/pst/article/view/678/486), but require a huge amount of energy to operate them. Such deflector shields could also solve the issue of space junk and [micrometeoroid](https://en.wikipedia.org/wiki/Micrometeoroid) collisions. Perhaps this huge amount of energy generation for said shields only makes sense on very large colony ships. # Heat Loss There is also the issue of heat. Larger bodies (with small surface areas) will lose heat less quickly than small bodies with larger surface areas. Not that space is especially good at transmitting heat away (especially compared to metal), but it does still happen. Less heat loss means you spend less energy on heating, which means you can spend that energy on something else (like maneuvering). # Gravity If your ship is large enough, you could even have people experience gravity just by virtue of being attracted to the ship. This is great because you can combat [the bone/muscle deterioration and internal fluid redistribution](https://en.wikipedia.org/wiki/Effect_of_spaceflight_on_the_human_body) this population will undoubtedly undergo. Most hard sci-fi spaceships seem to solve this by rotating and producing artificial gravity in that way. I suppose this population may not have figured out the gravity thing entirely, so they could be forever doomed to live in low-g environments due to their adaptations to living in space! This is why they never settle on a planet; they consider their bodies' changes to space to be normal, and living on a planet after that would be very hard. [Answer] A simpler answer, there is no place like home, at least not yet. Generation ship is comfortable with perfect temperature, humidity, atmosferic content, etc... Worlds that can offer this luxury is very rare. Without FTL it would take thousands of years to find such planet. That said, if I was the governor of that ship, I would consider building other ships. Putting all your eggs in a single basket spells out extinction. [Answer] ## Selection Effects That is, everyone who might have wanted to get off the ship has already done so, some long-forgotten number of visits ago. No one's really bothered to check back in with their descendants in centuries, for approximately the same reason no one checks back on Earth's descendants, and c'mon, there's a whole *galaxy* out there still to explore! [Answer] ## All the fun happens at the core Ultra-high bandwidth communication at light-speed, where sims are running on 1,000,000 X speedup relative to reality. I've described [one such setting here](https://worldbuilding.stackexchange.com/questions/12061/how-might-one-create-a-room-in-which-time-flows-faster/12088#12088). Admittedly, in that example it's placed on Earth, but might as well be orbiting the sun in a sub-mercurial orbit to gather power. To such people, making a trip to the moon would seem to take forever. As to other stars, who would want to be isolated for 10,000,000 years while going at 0.7c towards the dead worlds surrounding Alpha Centauri. [Answer] A simple way of solving the no colonies situation is that in all there years they have not found a habitable planet. And that considred, why live isolated in a small domed colony on some barren rock when the ship is much more friendly to human life ( assuming they do not have overcrowding issues). [Answer] The people on ship have become dependent on something only the ship can provide. Some nutrient, some drug, a specific radiation. Leaving the ship is a death sentence. The ship could represent a lost technology that provides eternal life as long as citizens return to the star chamber every few years. All the people are so old that without the chamber they all die of old age in a few weeks. [Answer] The technological infrastructure capable of building big ships has been lost in the remote past. Worldships of this capacity are able to repair and maintain themselves indefinitely. Also, the drive-system might extremely efficient at moving big ships and less efficient the smaller the ships become. This would explain why the big ship was built originally. They have lost the capacity to make more big ships and if it's just as hard to make small versions, then that leaves them with the one big ship. This then is truly a worldship. For example, the drive-system might incorporate exotic matter and while that doesn't need to be replaced or replenished. The worldship lacks the technological base to make more exotic matter themselves. If their main fuel is antimatter, we can safely assume the worldship can generate its own and is therefore capable of continuing to travel idefinitely. We can assume that habitable planets are in the universe, so that by the time they find the first one the population and its culture are so well adapted to worldship life nobody wants to face the rigours of planetary colonization and everybody stays onboard. Perhaps, if Earth is lost the worldship is on a mission to find its ancient birthplace and all they can do is search the galaxy until they find it again. Personally I prefer the idea that the worldship has a population of explorers and scientists. In fact, this makes a lot of sense. The culture on a worldship would be highly scientifically and technologically oriented. Considering their worldship can roam the galaxy freely, with occasional stop-overs to repair, resupply and revictual, why not just go and explore and research every planetary system and any interesting parts of the cosmos you come upon. Hey! That sounds like a great life. Where can I join? [Answer] There are a lot of potential reasons. # Population control The moment you split humanity into two groups you start a chain reaction. Two groups becomes four becomes eight and eventually the universe is full of people and you have war and starvation and conflict. If you can keep everyone together then this will never happen. # Carnivores Maybe they're running from something. This is the plot for "Sidonia" and "Battlestar Galactica". If unstoppable aliens or AI are chasing the humans then they'll want to stay mobile. If the aliens can listen in on their communications than they may want to stick together to keep from having to give up communication altogether. Thus, you end up with a single ship or fleet. There is also a subplot in "Ringworld" where the galaxy explodes (don't think about it too much) from the center outward and one species builds a generation ship to escape. They can stop by planets on the way out but cannot stay too soon or else the explosion will catch up with them. ## The Universe is Already Occupied If humans can greate a generation ship why can't anyone else? Perhaps the galaxy is already occupied. (This is one premise of Asimov's "The End of Eternity".) Thus humans become a diaspora like the Jews or Gypsies roving from star system to star system in search of a home. # Ecological/Scientific Preservation If people have created an efficient post-scarcity society then they don't need to set up colonies and if people like being around other people then they'll all go places together. This is similar to the premise of "Diaspora" by Greg Egan. # Promoting Sentient Life This is the premise of "2001" by Arthur C. Clarke. Aliens visit a star system, leave behind an autonomous machine to help promote the evolution of intelligence, and then move on to the next system. If they established their own colonies they would supplant the evolution of native intelligence. [Answer] I'm going to try an answer I don't think anyone else has given. ### They tried founding colonies but they kept failing until the residents of the ship gave up The shipborn have been traveling for a long time. The origional intent for their mission was that they would seed colonies.... but that was long long in the past. The initial journey was a long one, while on the trip over many many generations the shipborn gradually became more integrated with the ship itself. Often in ways they're no longer even aware of. Every Shipborn carries in their blood and every cell of their body nanotech, their bodies are supported and regulated by implants that interface with countless ships systems. They even have biological technology integrated at every level that was designed on the ship, tested on the ship and implicitly relied on many conditions within the ship. Some of it they don't even think of as technology since it passes from mother to child in the womb. [](https://i.stack.imgur.com/Shgle.jpg) Biotech motes are even carried through the air from Shipborn to Shipborn carrying updates related to new pathogens sourced from ancient distributed ships systems. Indeed the full understanding of some of the technology integrated into their bodies has been lost with time. **First colony** The founding of the first colony appeared to go well, while the ship remained in orbit and colonists were still regularly traveling between the ship and the surface. Indeed nothing started going terribly wrong while the ship was still close enough for ubiquitous networking to connect the 2. But when the ship reached the edge of com rage they started receiving frantic signals from the colonists. They were succumbing to local pathogens that had previously posed no threat, their organs had started failing in unpredictable ways and colonists had started developing deadly autoimmune disorders. By the time the ship had slowed it's course, turned around and re-entered orbit everyone on the surface was dead. **The third colony** This time the ship remained in orbit for several years to keep watch and to provide rescue in case of disaster. In all the time they waited the colonists remained fit and healthy. But again shortly after final departure the distress beacon lights up again.... **The 10th colony.** A few brave volunteers tried a final bid to survive on a planets surface away from the ship. They had countermeasures to try to protect themselves from many of the countless hypothesized causes of the previous failures. They sealed themselves inside pathogen-proof domes, they had satelites searching for possible hostile alien bioweapon incursions. They had supplies of safe food and weapons... but they didn't have duplicates of 7 of the 23 separate software and nanotech systems that the Shipborn had unknowingly come to rely on to maintain life. And so they died like all the others. **Now it is accepted that god and a hostile universe does not intend for the Shipborn to live away from the ship. The ship is life** Sometimes a young rebel or skeptic will try, will ignore the warnings of their elders and insist on remaining behind perhaps with a half dozen of those like them. They always die. **Over-dependence on technology they no longer fully understand.** [Answer] They have the destination, they heading to [Supermassive black hole](https://en.wikipedia.org/wiki/Supermassive_black_hole). * reasons are [TLTR](https://worldbuilding.stackexchange.com/a/46990/20315), if short it allows to overcome some growth problems for a more extended period of time and have a bigger population as result. At the moment, this is the only place I know, where is possible to extract energy more efficiently than with any thermonuclear reactions. Efficiency is around 50% of $\small mc^2$ They do not make pitstops at star systems, as it seems, they do not stop at all. The main ship does not stop. They launching probes ahead to research systems and to set up heavy elements extraction systems, like in [How can I move a planet?](https://worldbuilding.stackexchange.com/a/45273/20315). The average density of stars is 0.004 per ly3, so average distance between stars on their way is 6.2 ly. (average density here, local stuff around the sun, closer to center of galaxy is denser up to 10 times, [Stellar density](https://en.wikipedia.org/wiki/Stellar_density)) Distance to SMBH is 26000ly, so they will have 4120 possibilities to get materials which they will need to build SMBH energy extraction system, and to accelerate ship for higher time dilation. Average star, or better to say like our sun as an example, can be used to accelerate only small asteroid-size of materials with radius 25km to 0.99c speed in time of 6 years. (2-tonne density per cubic meter) * it can be done better than that, but still each star provides not so much star lifted material(energy flow from a stars isn't so great for the purpose of starlifting and accelerating matter to the 0.99c), but the ship system can make continuous flow of the matter for a long time by leaving systems for that in each star system where the ship is passing by. Those systems can form one system with the ship, long strands of matter from stars to the ship - super starship spider - with 100-1000 years long strands if needed. They can get all needed materials. But even they potentially be able to refine entry star system they do not do that because of star energy limitations. Distance to SMBH is 26000ly, and 0.9998c speed is 50 times dilation which makes subjective time travel 500 years, not bad actually. This time dilation and speed 0.99c explains why it is one ship, and not many of them. Accelerating big(0.01% of Venus by mass) ship needs 181 years of the energy of 1000 stars like our sun. So potentially we talking about 10 stars, 100years to launch, 2e18 kg ship, 1e12 humans(1e6 kg mass of ship per a human). If they prepare their departure in 500 years starting from now, it looks like good solution. ## This very exciting moment Of inserting into SMBH orbit at 0.9998c speed * Actually isn't so dangerous, if done properly, AND if ship made from what it supposed to be made, not a tin can from 196x's, but the active material(like the tool from moving planets, link above). But author might make a great scene of the fight with a great problem, where life of entry civilization is a hair from disappearing in BH. ## Notes * energy extraction from the black hole, I'm talking about gravitational potential energy. * SMBH is pretty big 41 light sec, and the closest star is at the distance of 6.5 light hours, and it can be converted into pure energy to warm up further consumption of stars around SMBH * amount of energy extracted from one kg of mass dropped into BH, do not depend on mass of BH, because of event horizon radius proportional to mass, and gravitational potential $\small \sim \frac{BHmass}{BHradius} \sim 2.95 \frac{km}{Sun mass}$ so it's kinda constant * not sure about 50% efficiency, but something close enough, and at least order or two orders of magnitude more then all possible thermonuclear reactions from H to Fe. * any mass is a good mass for energy extraction with SMBH. * anyway, all stars from galaxy will end here, so it's just a natural direction of nature, also there will be BH near for researchers. * one star with mass like our Sun dropped to BH provides 8 times more energy then [Hypernova](https://en.wikipedia.org/wiki/Hypernova), [energy output](https://en.wikipedia.org/wiki/Supernova#Energy_output), 1046J. * there are some reasons to fly to BH for energy, some of them in this A to Q [What would come first, the colonization of the solar system or interstellar colonization?](https://worldbuilding.stackexchange.com/a/46990/20315) * to stop thermonuclear reaction of star like our sun, by converting star to cloud, needs energy like 19 millions years of work of our sun or 0.000023 of hypernova blast (1046J), or each 1kg dropped to BH, another 500000 kg might be lifted from a star(with energy produced by this 1kg). * Having BH nearby means ability (if there is energy for that) send stuff with almost(to some extent) arbitrary time dilation across the galaxy, using energy extracted with help of BH. Or to wait with entry civilization up some event, being at some proximity to the event horizon. * I tried to be correct with numbers, in a reasonable way, but errors are possible, so feel free to calculate by yourself, the calculation is funny, better then wow. * If someone wishes to correct my English, I welcome that. BH is definitely good opportunity which might be exploited in interesting ways, and offer possibilities as nothing else as my knowledge we may imagine now. [Answer] Despotism. The captain of crewed by seven billion isn't just the officer in charge or the guy with the big hat, he's not even a feudal lord or a king, he's an emperor of unprecedented power. On a ship this size different sections will have their own command structure, their own culture, quite possibly their own food, clothing and language. The "bridge" may well be a forbidden kingdom which only those of a certain status may enter, the "engine room" a rival superpower, there will be water storage tanks containing entire oceans and the air pressure, temperature and humidity may vary by location. [Answer] The obvious answer? No other inhabitable planets. Even in the rare case that one is in the temperature range to sustain life, you'd have to put a lot of risk and basically sacrifice people each time to try the food, see if it's poison. And many may only bring death after 5-10 years. That's a lot of risk, and how do you pick who will try the food? That's a problem even on Earth, if you're in the jungle you may find nothing to eat for a long time, especially if you have no knowledge of what is edible and what is not. Maybe there are no seeds left from Earth, everything is synthesized from elemental matter. Maybe nothing will grow, or it will mutate into something inedible. [Answer] Let history be your guide. Take the essence of the thing, and make it your own. During the past, why did cities form in the first place? There are many reasons. Safety is one of the big ones. You can choose to answer this question 'to the reader/player' in a number of ways. You can allude to it during normal conversations or encounters, or directly answer it. If this is a far future setting, then there can be many ruins scattered about the universe, some of so old that they have no way to date their origins or any record of having been established. The reason that any one in particular is now a ruin instead of a thriving planet/star system can be virtually anything. A universe so mind boggling old that all known 'outposts' of man fell to ruin for as many reasons as there are stars... or, one main reason. If there is a 'one main reason' then that would almost certainly have to be tied into your main story line/culture. If you don't want to be tied down like that, then opt for diversity. Some have been mentioned already, but include 1. War - bio weapons 2. War - think Terminator/Matrix/Saberhagen Berserkers 3. War - Peace called too late and ecosystem too far destroyed 4. War - etc, etc, and what caused each war can be unique 5. The Singularity - which could go wrong in many ways. 6. Environmental collapse 7. Socioeconomic collapse (huh... that is one word) 8. Religious zealously (mass suicide, fanatical celibacy, etc) 9. Aliens (ongoing issue, or they are gone now too) 10. Astronomical event - Meteor storm, rogue planet collision, supernova, etc. 11. Roanoke colony You can literally go on for thousands of scenarios using only those seeds above. The question is how deep do you want the reasons to be. The final conclusion, by those on the ship, is 'screw that, lets keep moving'. The ship could fail for any of those same reasons... but for whatever reason it hasn't. Lessons learned, better leadership, luck, a common guiding goal of 'lets make it to the next safe harbor together or none of us might make it', the collective fear gained by passing by countless skeletal ruins keeping everybody in good behavior for the common good, etc. Another thing they have going for them. If no faster than light communications exist... then they could have collectively BEEN to many of these places and be a massive wealth of technologies from countless star systems who all developed technology and the sciences from countless different perspectives. [Answer] ## Because of the Economy of Scale The larger the scale your economy works on, the more effective it becomes. Smaller industries can be optimized to maximum efficiency, and larger industries become cost effective. Miraculous feats like performing stellar engineering or running an unobtanium manufacturing plant may only even be possible on the scale of an entire civilization. The reason to build colonies is *logistics* — e.g. you would colonize a star system because you're mining it for raw materials and its too expensive to bring the civilization-ship to the star. But if it's *not* too expensive, then you don't need to bother. [Answer] ## Solar FLares In the Dr Who episode *The Beast Below*, the Doctor is on a similar vessel: > > In the distant future, the Doctor and Amy arrive on the *Starship UK*, a colony spaceship containing the population of the United Kingdom who have left the planet to escape **deadly solar flares**. > > > Source: [wikipedia](https://en.wikipedia.org/wiki/The_Beast_Below) In this scenario, colonies are unfeasible because of solar flares (if they are within the solar system), or because there are no suitable places to colonise outside of the solar system. [Answer] The most obvious reason to have just one ship instead of hundreds is there is something you need that there is only one of that you cannot make another. This could be a fusion generator / force field generator / gravity generator or even a wormhole gateway back to the home planet. It could have been built by mad scientist and nobody understands how it works. It might be some alien artifact discovered on a planet which allowed interstellar travel or perhaps it's built out of a rare material and they can't find enough to build a second one. Perhaps even the ship itself is the alien artifact and whilst human might be living on it, still don't understand how it works beyond the basics. [Answer] **Lack of terraforming capacity.** Even though a planet is in the goldilocks zone it may still be inhospitable to humans, or life at all (see Mars). And while your humans have the capacity to build a huge ship (probably a number of self containing large ships attached to each other and ready to split up or shut off injured hulls in an emergency) they do not have the ability to actually create a liveable biosphere on a planet. So, it makes more sense to mine the asteroid belt (and subsequently other solar systems which failed to provide a liveable world) for resources to maintain their swarm. **Ethics** I've thought about this a lot for story reasons of my own, and it does make sense. It's likely that planets with the capacity to sustain life also already does that. From a moral perspective it's better to live aboard a colony ship and suck up resources from planets who don't have the capacity to develop intelligent life than to be the murderous locust scourge of the universe. Essentially it's the difference between passing the great filter and being the great filter. **Evolution** Also, lacking FTL travel in the generations it would take to travel to another star system (and discover that while the goldilocks planet is rich in iron and carbon it has neither an breathable atmosphere nor an protective magnetic field and all the liquid water has boiled off into space) your crew will probably have adapted to life aboard the ship. [Answer] One reason for only one colony ship is that it may be the only one left. The presupposes that there is only one known good destination. * If some disaster caused the need to evacuate the Earth, you would have several factions and different reactions. * Some people won't go and will remain behind. * Some people who want to go but aren't allowed to will fight to get on the ships. This might damage the ships or the Earth to Orbit shuttles. * Some people who can't go will try to make cure that no one else can go either. * Different nations or power groups may sabotage the ships of other factions to rule what is left. * This kind of environment will likely lead to the ships being armed to defend themselves. * Then after the ships have launched, the negative feelings from the previous actions will likely cause at least some of the crews to think that they can't survive in the long run if "some other group" is out there growing into a big threat. * You may end up with a small number if allied ships. However, since people are in a thought mode of "different is a threat," they start finding reasons that their allies are different and create a threat scenario in their own minds. Eventually, they pick each other off until there's only one left. * No new ships are created due to the threat that the people on the other ship will begin to differ and "become a threat." Once they reach the destination, you have people who have spent generations living on the ship. That ship is home. There might be a few who want to try their hand at living in a gravity well that has that weird and annoying phenomena called weather but most will look at the planet and think of it as a step backward. ]

[Question] [ In Ant Man and the Wasp, Ant Man starts the movie on house arrest. House arrest is enforced by a standard ankle tracking monitor. Of course, this security mechanism proves woefully inadequate since, you know, he's Ant Man. He doesn't attempt to escape himself but Hank Pym needs him and shrinks him down, rendering the ankle monitor completely irrelevant. Obviously trying to enforce house arrest using such techniques on a man who can shrink to microscopic scales is a real face palm, especially when you consider that the man who invented the technology is still at large and may have motivation to free him. It is effectively no better than the honor system. So, if the FBI (or whoever is in charge of monitoring said house arrest) wasn't full of short-sighted people, what would be better methods to enforce house arrest on a shrinking man? Modern day technology only please. [Answer] How do they keep normal people from jimmying the anklet with a screwdriver? By making it tamper-evident. Sure, it's possible to compromise the electronics, but you're going to have a lot of explaining to do when they take a look at it. So the basic idea is that if Ant-Man shrinks out of the bracelet, it either sets off an alarm or is indelibly marked (or both). Perhaps an elastic band that, if detached, will shrink and bring electric contacts together, triggering an alarm. Or the contacts could be latches that will break if forced apart. [Answer] # Use an ankle monitor that also records Ant Man's pulse If his pulse stops, then it sets off an alarm, indicating that he's either dead, or he has removed it (probably by shrinking). In general, the fact that ankle bracelets are hard to remove, is really only secondary to the fact that if they are removed the authorities are notified, or at least that the tampering is evident. I mean, almost anyone can get out of an ankle bracelet with a pair of bolt cutters anyway. House arrest is used when the offender is actually trusted by law enforcement to comply with the terms of their house arrest. Violating those terms is grounds for the privilege of house arrest to be revoked, so it is usually not worth it to them to violate the terms. The same philosophy would apply to Ant Man. [Answer] # Shrink his house Give him a taste of his own poison. Shrink his home and have it kept inside a glass dome. This makes it easier and cheaper to have surveylance 24/7 around the house, so that if he wants to leave, he'll have to traverse the quantum realm. That's opening up a storageroom full of cans of worms, so it might just be deterrent enough. [Answer] Well, this is how I would do it... [](https://i.stack.imgur.com/0kjoc.jpg) (For anybody not as old as I am: This was a cartoon series called "The Ant and the Aardvark", where an aardvark - named Aardvark - would constantly try to catch Charlie the ant.) **Edit**: Apologies, I was called away earlier, so didn't manage to elaborate as much as I'd wanted. No, this is not a re-capture system. Unfortunately, Aardvark has an extremely poor performance record in capturing ants. He does, however, have an almost supernatural ability to *track* ants and ant-like creatures. No matter where they go, Aardvark will be there within seconds. Thus the solution is to put a tracking device not on Ant-Man, but on Aardvark. There may be some psychological conditioning needed to shift Aardvarks focus from Charlie to Ant-Man, but with the right encouragement this shouldn't be a problem. Bear in mind that Aardvark is about to hit the big 50 - he's probably wondering what he's doing with his life and that, maybe, it's high time for a change. [Answer] The house is surrounded by a moat. A small one, filled with vinegar. Humans just step over. But an real-life ant could not traverse it. Some ants can swim or float in water. The purpose of the vinegar is to make it too noxious to try. Or use water with some oil on top. This reduces the surface tension of the water so that the ant can not float. Ant Man is an ant-sized human, not an actual ant, but he'd still need to either float or swim across the moat. Make the sides too slippery to climb up and the liquid impossible to survive. So maybe Ant Man shrinks to exit the house then grows to step over the moat then shrinks again to sneak away. To prevent that, make sure the moat has a fence on both sides. No human can get in or out of it and it's too small to transform to human-sized while inside. The fence can be electrified so the small version of Ant Man can not climb it. Honestly, room arrest (in a lovely glass or plexiglass cage with mini-moats at the threshold of the door and any other openings) makes much more sense. Combine it with great security cameras to know when or if he shrinks. Not fun for privacy, but necessary due to his superpowers. If he can stay shrunk down for the duration of his confinement, then your job is easy. Constructing a box with tiny doll furniture and no escape is quite simple. The boxes probably already exist retail. If you can't shrink him or confine him to a room or set of rooms, your best hope might be psychological. Make the penalty for violating the house arrest too great to transgress. Like custody of his kids, if he has any. Losing his job. Etc. Fines wouldn't do it as whoever breaks him out would just pay them. House arrest in real life is only sometimes literal. In the United States, prisoners are allowed to leave their homes for work, school, medical and other appointments, even to run errands. It's restricted and they have to inform the police where they are going and when. Their ankle monitors are to find them if they flee. [Answer] When KGB was monitoring someone and wanted to be sure to track them wherever they'd go, they used to sprinkle some radioactive dust on the door mat. Then a Geiger counter was sufficient to their movement, since the radioactive dust, sticking on the sole of their shoes, would emit radioactivity all around. The only way to go around this was to strip naked and throw away all one was wearing and replace it with new things (CIA knew about this trick after losing some agents). Antman can shrink, but shrinking won't remove radioactive dust sticking to his clothes/shoes. Just set a Geiger barrier around the confinement area, and as soon as it triggers you know that he is trying something. [Answer] > > what would be better methods to enforce house arrest on a shrinking man? > > > # Use people You are incarcerating a superhero. That warrants the presence and expense of a fulltime guard. Details like privacy and comfort can be negotiated later, but since this is an alternative to prison, I think Ant Man would be willing to sign away the privacy considerations as part of the terms. Of course, the guard could be incapacitated, but the goal isn't to keep Ant Man confined to the home, but rather detect if he gets out, then send an army to collect him. If a guard, consisting of 2-3 people at at time, loses visual for more than five minutes or whatever, it can be reported that he has left the premise. A back of the envelope calculation for cost would be three guards at once, three shifts a day for two years, or about twenty salaries. If these are extremely competent and highly-capable guards, we're looking at an order of magnitude $100K salaries or an upper-bound of **\$2 million total** to keep Ant Man under house arrest with full confidence that he didn't leave (or immediately detecting if he does). [Answer] # Make the ankle monitor shrink alongside Ant-man First off, a bit of a frame challenge: we do not have shrinking technology in the modern day. So I'm going to assume that by "modern day", you mean "modern day plus whatever tech needed to make size altering gadgets work". In the MCU the question is based on, the shrinking tech was invented by a genius scientist, and there are a number of other major scientists in the setting, most of them superheroes themselves. At least one of them (Tony Stark AKA Iron Man) has been established to have countermeasures for at least 1 other superhero scientist (Bruce Banner AKA Hulk). In that case, I'd get one of the other genius scientists to check the genius shrinking tech inventor scientist's notes and figure out a way to make the ankle monitor piggyback onto the shrinking field, and either shrink along with him OR trigger an alarm when he shrinks. [Answer] You're conflating two things. **Legal enforcement** Scott is not legally permitted to leave the house. Doing so will render him subject to future penalties that will severely curtail his future for the long run, such as honest-to-god imprisonment. It is assumed that he does not want to trigger this circumstance. **Practical enforcement** In the movie, just as in the real world, an ankle monitor is *a best-effort detection tool* to check that the criminal is not violating the terms of house arrest. There is always some measure of trust in this: an ankle monitor can ultimately be sawn off, but it is generally understood that the criminal would rather not risk future capture and *a much worse punishment* as a result. You're right to suggest that Ant-Man has a better chance of evading enforcement than the average crim, but that doesn't really change the fact that an ankle monitor is only part of the mechanism. The threat of worsening your legal status is the real incentive to behave. And that's why Scott takes it so seriously until events force him to prioritise a new mission over his future freedom. Similarly, there's nothing you can really do to "force" powerful beings like the Avengers to sign up to the Sokovia Accords and yield power to the state (Cap's refusal being a textbook demonstration of this), but you have to have an element of trust (and threat of reprisal) when it comes to things like this, and this is the case for any and all laws and treaties worldwide. [Answer] ### What's wrong with how they do it in the movie? In the film the ankle bracelet not only has a perimeter on it to make sure Scott stays inside the house but it also tracks his daily activities. If he were to just take it off they would know because it would move all day. It would then be quite hard to take it off and give it to someone else to track down for 2 reasons: 1. They might not be able to replicate his daily activities very well. 2. The other person wouldn't be able to get it on easily. The bracelet is probably tamper proof so you would have to shrink down, to get it off and the other person would have to shrink and enlarge to put it back on. As far as everyone knows there is only 1 suit so this would be difficult. Obviously in the movie they overcome this by using an ant but I don't think anyone outside of the Hank, Hope, Scott and Cassie knows about the control they have over them. [Answer] I used to work next door to a company that made ankle monitors (mostly for detecting alcohol consumption). Occasionally, I'd chat with their developers (at the local lunch place, or when courier services would mis-deliver packages). Some of the things they monitor are pulse and the off-gassing that human flesh does. Your skin is not some sort of seal, like plastic wrap that keeps the meat inside the [meat](https://i.stack.imgur.com/uukci.jpg) [popsicle](https://scifi.stackexchange.com/questions/94885/why-did-the-police-totally-ignore-the-im-a-meat-popsicle-response): gasses and liquids leak out. This company's devices also measured some of the metabolites that are produced when your body digests/consumes alcohol. I forget whether you were allowed to remove it temporarily to shower/bathe, but it would detect if you put something between your skin and the sensor (such as a sock or slice of bologna). It would also get a long enough baseline of your pulse to detect if you were getting a heart attack (or overdosing on drugs like cocaine) or you swapped it with someone else. Usually, ankle monitors like these were alternatives to incarceration. Get caught tampering with it and you were looking at going to jail/prison (in the case of the [State of Georgia, that's five years](https://law.justia.com/codes/georgia/2017/title-16/chapter-7/article-2/part-1/section-16-7-29/)). [Answer] Look at this <https://www.asianscientist.com/2018/05/in-the-lab/shape-memory-porous-material/>. It's a metal fibre that changes its shape depending on the prevailing conditions , it gets smaller the hotter it is and larger the cooler it is. If ant man shrinks , then he is reducing his mass , by the famous $E=mc^2$, formula for every bit of mass he loses energy is lost to the environment. This energy loss will heat the surroundings, so if this metal was placed around his ankle and he started to shrink it would also shrink with him. Now it should be noted that there is a minimum size to which this metal can shrink , but then again if you arranged it instead in some type of coil rather than just a normal circle , that the coil would pull closer together as it shrunk so it could reach a still smaller size relative to its starting shape. I think this is the closest one could have with current technology to an ankle bracelet that can still be applied to a shrinking man. [Answer] **Insecticide** Have heat sensors in every room. If he shrinks they will trip and set off insecticide spray. **Note** When I have time I'll respond to comments here. In the meantime I've made a start in the comments below. [Answer] **Put the bracelet in Antman** Surgically insert a transmitting device into him. If he shrinks and the device shrinks along with him, then the signals it emits becomes interrupted. If he shrinks and the device does not shrink along with him, then Antman becomes interrupted. ]

[Question] [ I have an idea for a story in a post-apocalyptic setting where guns and other explosive devices unusable or otherwise impractical. Is it possible to do this by changing the atmosphere (either by adding, removing, or changing the proportions of the chemicals that make up the standard earth atmosphere)? The resulting atmosphere must be capable of supporting life, although it would be acceptable if human life required artificial support (e.g. portable supplementary oxygen supplies). Ideally, I would like to avoid removing oxygen completely; instead I want to change the environment the minimum amount to prevent combustion. [Answer] Make the atmosphere more combustible by adding lots of methane or other super-volatile gases. It won't stop the guns from functioning, but it will make using them suicidal for the wielder. It does not even have to be super volatile gasses (as the presence of such might prevent human to walk around without life support systems), it is enough to increase the oxygen concentration to slightly over 30% to make it quite dangerous to fire rounds. If the atmospheric oxygen concentration is over 30%, then even [wet plants will ignite and burn](https://www.fieldmuseum.org/fire-and-atmospheric-oxygen) if there is anything to light them on fire, yet humans and animals will not be in any danger from breathing it (it will even slightly enhance performance when using your muscles). As a bonus, you will also get giant insects as their [size limit](http://phys.org/news/2006-10-giant-insects-oxygen-air.html) is a function of how well oxygen can diffuse in to their bodies. [Answer] Considering the propellant in *all* munitions that I'm aware of (except fuel-air bombs and spud guns) is self-oxidising, that is to say, it requires *nothing* from the atmosphere (guns and bombs work fine underwater or *even in space* - well... they work fine *once* anyway) I'm inclined to say that, other than some kind of corrosive atmosphere eating the shells, that there's probably not much you can do about atmospherically preventing munitions from functioning. However, as combustion engines *are* dependent on the atmosphere to run (they get their oxidiser - oxygen - from the air) so there is probably something you could do to stop the engines, maybe something that causes them to gum up or something that makes them rust really fast (really salty sea air works well) [Answer] If you are willing to go for a bit of hand waving: There are nanoparticles in the air that makes it act like a [non-Newtonian fluid](https://en.wikipedia.org/wiki/Non-Newtonian_fluid), or oobleck. Usually, the nanoparticles float around completely unnoticed, like dust. But if something starts moving very quickly, the air around it seems to solidify, destroying and stopping the object. Then the air quickly reverts to normal. Maybe it kicks in at high speed, near the speed of sound. This would make guns infeasible. You could also make it depend on acceleration instead - this would still allow high speed vehicles or planes in the affected air, but still rule out guns. It might also have an effect on arrows. Just make sure people don't get killed when they sneeze. I imagine the way it works is that the nanoparticles are tiny electronic floaters, like large molecules or nanoscale transcievers. They have a kind of electric field between them. If one starts to move rapidly between the others, they induce some power in the particle - like if you move a conductor through an electric field. This in turn causes the particles to attract each other. But if they come closer together, they also repel each other - the result is that they quickly form a long range lattice or crystal. The surrounding air is also locked into the lattice, via an interaction between the activated particles and the air molecues. Either something like static electricity, or a long-range version of [Van der Waals-force](https://en.wikipedia.org/wiki/Van_der_Waals_force). The result is that the viscosity rises quickly, and the air becomes very thick or even solid. Note that my explanation how it works uses a lot of "kind of" and "something like" and is total BS :-). So you'd need to be comfortable with "nanotechnology as magic", or work a bit on the science of it first. [Answer] if its post-apocalyptic you can just be truthful and have making the bullets difficult. Making modern propellants is not something you can do at home, especially the primer. reloading bullets is based on being able to buy these materials. Using black powder (which you can make) in modern firearms, will gum them up rather quickly. preventing the making of explosives is much more tricky. basically you might want to look at a different way to disable firearms than changing the atmo, since life still basically runs off of really slow combustion of carbon, so any change that prevents one will prevent the other. [Answer] Since most explosives don't even need an atmosphere (you can fire guns under the water), it must a special atmosphere that is actively preventing explosions of all sorts. You could make the atmosphere to have higher density and higher viscosity. A fancier atmosphere would be one laced with super-nanobots that dissipate all motion energy to heat quickly, sort of like reverse-Maxwell's daemon. [Answer] # Reduce medium range visibility A typical way to reduce the usability of ranged weapons in general, and thus guns, is by ensuring that there is no clear line of sight from attacker to target. This can be achieved in numerous ways, some more, some less realistic. ### Fun solution: Weird visibility Rather than making people invisible, let the air have a highly variable refraction index. This means you can see enemies all around you, but that you just can't point out exactly where they are. Never mind shooting them from a normal range. As a result, people may find a knife on a chain to become a more efficient weapon than a gun. ### Realistic solution: Low visibility Make sure that, you can't see very far. There is simply so much smog that one can just see who is walking in front of you. Once the average range of an encounter becomes small enough, people will go for swords and the like to maximize their killing potential. --- Note that if these conditions were to be so extreme that gun usage would drop to near zero just because of them, there would be a significant impact on daily life as well. If you are just interested in disabling distance shots the impact on daily life could be fairly minimal. [Answer] Aside from the [explosive atmosphere](https://worldbuilding.stackexchange.com/a/61579/23150) answer, having the atmosphere be the thing that prevents firearm usage is rather implausible. If the story allows it, I would say use other factors, such as a combination of history, manufacturing practices, and *technology!*. **Even if a single factor is unlikely to eliminate firearms and explosives, the combination of multiple factors makes it so impractical/dangerous that none would be used in favor of other weapons** 1. Technology. This one might be a major leap culturally, but technologically it's entirely possible. Consider the worldwide weapons ban mentioned below and add in a dash of government that (at least in the area your story takes place) implemented heavy [Live Fire Detection Systems](http://www.defensereview.com/anti-snipersniper-detectiongunfire-detection-systems-at-a-glance/), which detect and respond to gunshots and/or explosions. Though the Geneva convention currently prohibits computers targeting and engaging (i.e. shooting at) humans without another human pulling some sort of trigger, I'm guessing the events leading up to the apocalypse threw that out the window. Combine aforementioned LFDS with advances in [self-sustaining aircraft](https://en.wikipedia.org/wiki/Solar_Impulse) and [laser weaponry](https://en.wikipedia.org/wiki/Laser_Weapon_System), and a sky full of drones that fry anyone that fires a bullet is entirely possible. The kinda scary thing is that it's possible *today,* it would just be expensive before the systems enjoyed the economies of scale of mass production. [South Korea's border](http://gizmodo.com/5955042/south-koreas-auto-turret-can-kill-a-man-in-the-dead-of-night-from-three-clicks) already has a gun deployed that can auto-kill a human from 3 kilometers away, and that tech isn't even cutting edge! 2. History - Consider that there is first a worldwide gun ban similar to [Australia's ban](https://www.google.com/search?q=australia%20gun%20ban&ie=utf-8&oe=utf-8#q=australia%20gun%20ban%20confiscation), which massively reduces the number of guns in the world *by physically destroying them*. After a subsequent worldwide ground conflict and a sufficient amount of time, most modern ammunition may be spent. Not 100% foolproof on its own, but making guns and ammunition rare adds to the other factors. Some regions of the world (like yours, perhaps) would likely be gun-free altogether. 3. Manufacturing - In a post-apocalyptic world, it can be assumed mass manufacturing is no longer possible. [Modern ammunition](https://en.wikipedia.org/wiki/Bullet#The_modern_bullet) was not produced until the mid-to-late-1800s, and neither were interchangeable parts (such as barrels, magazines, revolver cylinders, etc.). Before then, projectiles and powder were loaded into guns separately. They didn't have nearly the range or accuracy, were much heavier, and reloading was extremely slow. Practical for large-scale firing lines between standing armies, not so much for any other purpose... unless you only want one single, fairly low-accuracy shot. You can safely assume modern firearms are impossible to recreate in such a world, and who would risk a crappy musket shot when there are flying death lasers everywhere? 4. Add in pockets or "springs" of explosive gasses leaking from underground from the explosive atmosphere answer. Why not? I think it's a good idea, and credit where it is due! [Answer] Short answer is, **no**. Cartridges are essentially self-contained and (can be) environmentally sealed objects, very durable in every way (compared to humans or vehicles). Nothing in the atmosphere is going to stop a cartridge from going off when primer is hit right. A basic gun is also so simple, just barrel to contain the explosion, a lock to keep the cartridge in place, and a mechanism for a hammer to hit the primer, that nothing in atmosphere is going to prevent that from happening. Even some complex guns, such as the iconic AK47, are very robust. Tough conditions just need looser tolerances, which reduce power and accuracy, but even the most loose, but otherwise well designed gun is still going to be superior to any more primitive kintetic weapon in almost every way. Doing "magic" with atmosphere which limits maximum velocity (like that non-newtonian fluid answer) would make existing weapons ineffective, but new ones would be rapidly designed and produced, which would fire heavier projectile with lower speed. If you made explosive atmosphere, you would get gun designs which would cool down the explosive gasses so that they wouldn't trigger atmospheric explosion, or you would get remotely operated guns which would not be harmed by a little local atmospheric flash. Or just blast shield around the muzzle for very local flash. Or whatever. In any kind of stable (think of lightning and volcanoes) atmosphere, there's a way. Basically, if you can shoot arrows/bolts, or just throw spears, you can make a gunpowder version, which will fire bigger projectiles more rapidly, with optimal velocity, more accurately, without it tiring you or requiring long training. The gun models we have on Earth today are optimized for our conditions, different conditions would result in different designs. But the basic advantage, the energy stored in the gunpowder, turned into kinetic energy of projectile with a twitch of a finger, "point-and-shoot", you can't hand-wave that away. If you threw modern humans with now-unuseful guns and lots of ammo into alien environmemt, they'd open the cartridges, repack them, and create ad-hoc "guns" working in that environment. [Answer] All ordinary explosives are self-contained, they work totally independently of the atmosphere. Thus the only way you can stop explosives from working with atmosphere is to have an atmospheric pressure above the detonation pressure of the explosive. At that point when you set them off they'll get bigger because they're warmer but that's it. The highest detonation pressure I can find is about half a million atmospheres. Unfortunately for your story such atmospheres are not compatible with human life. Everything becomes toxic long before this sort of pressure is reached. [Answer] Maybe up the humidity - a lot. A wetter, more humid atmosphere would make it harder for things to burn, and harder to ignite. It would take more to start a spark, and more to make that spark catch something else afire. A wetter atmosphere might have prevented the rise of firearms, as earlier versions wouldn't light when the air or accelerator was damp. Of course, modern firearms are designed not to be so vulnerable to environmental conditions, they should be able to go off even under wet conditions. That's sort of not the point. *However* my point was less about firearms and more about manufacturing. Accelerates might be designed to work independently of the atmosphere, but they have to be carefully manufactured, controlling many variables, to even get to that point. So, if the gunpowder manufacturing plant has a hard time keeping itself dry, we can see how well bullets work packed with damp powder (or how well they don't). Heat might help dry things, but there's a limit - and it can be pretty energy intensive. Or dangerous, given you're working with explosives to begin with. Of course, there will be ways to make explosives and bullets work anyway - climate control on that level takes a lot of tech but it's doable - but they will be a lot more difficult and expensive, which might be enough to make them unpopular, or put them out of price reach for average gangs. And the tech involved (heaters, air conditioners, dehumidifiers), might be difficult to produce or maintain in a collapsed society, without a solid tech base behind it, especially since the individual skills would likely have been let lapse as luxuries, until they realized the secondary effects on manufacturing stuff like gunpowder. [Answer] If the atmosphere is thick enough, the projectiles fired will just slow down from friction very rapidly and end up falling to the ground harmlessly shortly after leaving the barrel. Can still use the gun at short range, say a pistol at near contact range, but at longer ranges they'll be all but useless. [Answer] You would need to have some kind of electrical/static field in the air that would penetrate the bullet casing causing the gun power to ignite prematurely. Even just building a bullet, it would explode seconds later. [Answer] I believe Memming gave an awesome idea about nano-bots, buts it gets problematic with motion-preventing, affecting everything that moves. My idea would be nanobots infesting the atmosphere in a way that they sense gunpowder or other explosives (extremely sensive AI-like bots) and render all encasings and shells unusable, entering ammunition and changing propelents and explosives structure at molecular level etc. Well, this approach depends on how high-tech and Sci-Fi-ish you wanna get. [Answer] Invent some molecules, able to quickly stick to iron (or whatever metals gunbarrels can be made of) and create thin film on it. (These molecules probably must not cause harm to most plants and animals.) Then, two possibilities. If such film is thick and hard enough, then shooting will be problematic, gun may explode or bullet speed will be very low. If it is not, then it may change its properties after exposing to high pressure and/or temperature and for example bind enough something from atmosphere after shooting and making guns unusable again. [Answer] One alternative way at coming at it which might suit an apocalyptic scenario would be the occurrence of a universal and severe allergic reaction to explosives. It would make making ammunition very difficult in a technologically regressed world, while firing a weapon would be virtually suicidal (as the residue would spread through a fair amount of the local atmosphere) [Answer] As other posters noted explosives often work totally independently of the atmosphere since they contain everything needed to explode. How about making explosives much more sensitive because of some sort of radiation. If this radiation is present globally (atmosphere with radioactive particles for example) it would make really hard to create and carry explosives safely. While local radiation would prevent use of explosives in critical areas because they would explode on borders of radiated area. Local radiation could be also from atmosphere or from some radiation generator. Radiation should be harmless to life, like electromagnetic waves that are all around us. [Answer] Perhaps a chemical could be added to make the atmosphere a non-Newtonian fluid (like oobleck, except a gas). This make it difficult to exert force on the air around you, maybe not enough to make running hard. the most obvious effect will be that bullets, with incredibly high velocity, will slow and fall to ground much quicker. I think this may also mean that vibrations in the air will be dampened, such to reduce the effects of an explosion. It may also make shouting or producing loud sounds difficult. [Answer] ## Weather Some other answers suggest adding humidity to prevent combustion. This is a terrible idea, as has been stated. However, it could work for a different reason, especially if we add some sand. ### Firearms can be unreliable Or, at least, the modern version, with high effective ranges and fancy concepts such as "semi-automation". More simple weapons aren't quite, though. The most basic version of a gun (as we think of it) is as follows: * Take a projectile. * Stick it in a fireproof tube. * Make an explosion that launches the projectile out of the tube at a high velocity. This can be an improvement over bows and the likes at very short ranges, if your goal is piercing armor, but it's very unreliable at longer ranges. Guns of this sort have been around since around the 1100s, and the basic gist of it wasn't drastically improved upon until around the 1850s or so. They were mostly used for armor-piercing purposes and due to needing much, much, *much* less training to use effectively than a bow at similar ranges. However, they were exceedingly inaccurate and took long to load. These would still be viable, but only due to simplicity... and even then, only to an extent. Though, I suppose the title of this subsection is somewhat innacurate... ### MODERN firearms can be unreliable. One of the more popular handguns in pop culture is the **Desert Eagle.** While it may look cool and sound nice, it's really a terrible weapon. It's incredibly heavy (making it hard to hold steady for aiming), and jams exceedingly frequently, especially in humid or sandy areas (ironically making it useless in deserts). Despite all that, it's also WAY more expensive than most other guns (just under $2000 USD) - you can buy actual, military-grade, melt-through-steel-in-an-instant laser weapons for around that price. Most firearms are, to an extent, similar, anymore. Guns, these days, are astoundingly intricate. If I tell you to go make a .44 Magnum, you wouldn't be able to. If I went to someone who regularly machines things as a hobby and told them to make one, they wouldn't be able to either. Only a huge assembly process specifically created for the production of .44 Magnums would be able to make one with any efficiency, because there's just *so many tiny parts that all need to be perfect to even get off one shot.* As such, even if I already have an assembled, working .44 Magnum, it can still have issues firing if it gets full of sand or starts to rust or the likes. And a good, old-fashioned revolver is one of the most reliable weapons you can own - just imagine what it's like for even *more* complex weapons with 35 extra parts for feeding an ammo belt and another 12 for ejecting spent cartridges, 17 for feeding in new bullets from a clip, et cetera. ### Let's just get to the point already Now imagine some incredibly-humid, sandy-as-all-getout land where so much action goes on that you'd never be able to sit down and do maintenance even half as often as you should under good conditions. Within ten years, nearly all complex firearms would be so rusted and ruined that they could never fire a single bullet again. Now, as for explosives... ### There's just no stopping explosives A bomb is even more simple than a gun. * Get something that can explode * There is no step two People make bombs with a quarter-cup of laundry detergent, an empty milk jug, a piece of flint and some metal to hit it against. These are effective enough to be as costly to troops fighting in a war than the actual "fighting in a war" bit. Making the air more wet isn't going to stop it. Making the air amplify that explosion *just makes it an even MORE attractive option!* There's just no stopping bombs without deoxygenating the atmosphere. Sorry. [Answer] I also do not see you can stop the guns themselves from working without radical changes affecting all normal life, but perhaps if you make use of guns very dangerous for the person using the the gun it could achieve the same result. One avenue of thought might be something in the air which reacts violently with exhaust gases from shells created when bullet is fired. It might be chemical reaction, or it might be biological agents or nanobots which activates when those specific fumes are present (as most of normal life uses does not smell like gunshots, it would not create problems in normal person life, unlike most of the suggested answers) [Answer] Forgive me science if this is too absurd. Disperse into the atmosphere molecules with 2 characteristics: 1. Their atomic nuclei are unstable enough to be smashed together (nuclear fusion) if they impact other molecules in the air at velocities that a bullet pushing the air can cause. Make the energy released enough to smash the bullet. 2. The new element produced by the [nuclear transmutation](https://en.wikipedia.org/wiki/Nuclear_transmutation) is solid and strong enough to mostly contain the released energy (so that the energy release is localized and doesn't eg destroy the entire town). Now when a bullet is fired the air pushes back and smashes the bullet then solidifies into a small ball which falls to the ground. You might even have it [decay](https://en.wikipedia.org/wiki/Radioactive_decay) in some days or weeks back into the first element so the supply in the atmosphere stays more or less constant. You probably have to invent a couple exotic chemical elements to make this work. [Answer] Yes, you can use millimeter waves to basically turn any matter into liquid, decompose the electron magnetism or extinguish flames if that's what you're after. It's a powerful wave and this device is theoretical ,but not particularly difficult to comprehend. It uses a series of magnetrons and a series of pulse guns oscillating at or greater than 192ghz targeted at the gun using a laser guide. [Answer] Explosives are unusable if there is no oxygen, you are right on that one. However, guns can work even in a vacuum, as there is enough oxygen inside the bullet casing to allow for the chemical reaction inside them to take place. However, since it is a post-apocalyptic universe, newer bullets that are not made inside areas that have an atmospheric composition similar to that of the Earth will be unusable since there will be no oxygen to allow for their respective chemical reactions. ]

[Question] [ *Please note:* **This is not a duplicate** of my [previous question](https://worldbuilding.stackexchange.com/questions/31349/everything-joe-says-is-true-how-can-he-get-around-it), and in fact has a quite different premise. Joe is just an average guy, aside from one passive superpower that Joe has had since he was a child and has grown up with. He can't say, write or otherwise communicate any untrue information. At all. This includes information about fundamental physical laws, past events (even if he knows nothing else about the event) and even the future. For the most part Joe gets around this by adding 'Well, as far as I know...' to the start of all his sentences (He's expressing what he knows, therefore it's not a lie), but he feels that he should be able to do more with this power to help humanity. *To clarify:* If Joe tries to say anything that's untrue he becomes mute. Similarly with writing or miming, he loses the ability to communicate when attempting to communicate an untruth. If his words were to cause a paradox he would similarly become unable to speak (as something must become untrue at some point), but since people can still misinterpret Joe's statements he's very good at making up old-school prophetic drivel. **How can Joe best help society?** [Answer] ## Joe should become the ultimate research assistant. > > He can't say, write or otherwise communicate any untrue information. > At all. This includes information about fundamental physical laws, > past events (even if he knows nothing else about the event) and even > the future. > > > There is no need to do actual research, etc. for complicated questions. Just have Joe try to read off a statement of the hypothetical situation. If he locks up, not true, if no problem then the hypothetical statement is true. Presumably, Joe could simple refuse to comply saying, I am uncomfortable with this line of research or such-like. The research need not necessarily be scientific in nature. I.e., Is the Arctic Circle a good/the best area to drill for oil is not really a scientific question, but clearly valuable. A terrorist threat could be quickly resolved. A murder case easily solved, etc. In terms of improving the world, Joe should make his services available, but have his screeners give preferential access to questions that could improve the world / avoid damaging the world. Note: Joe should also charge a hefty sum for his services of course to help filter out the unimportant questions, but as his goal is to help humanity, make much of his work pro bono. His fees will also be necessary to pay for his screeners, security guards, etc. that will be needed to engage in this lifestyle. --- I have to wonder about predictive uses of Joe's gift. Knowing the future might prevent it from happening; e.g., knowing that the President will be assassinated and related followup investigation prevents the actual assassination. The movie, The Minority Report, certainly broaches this topic, but this is a much older question. Did the prophecy of Christ's betrayal foreordain Judas to betray Christ is an old theological question. --- Based on some comments, it appears the form of the statement should become a series of possible statements with the followup questions being asked dependent upon Joe's actions e.g.: * There will be an attempt to kill the current President of the United States (POTUS). * There will be multiple attempts to kill the POTUS ... * There will be an attempt to kill the POTUS while he is still President. * There will be an attempt to kill the POTUS in 2016. * There will be an attempt to kill the POTUS in the first 1st quarter 2016 (etc. to get the exact timeline) * If only standard security measures are taken, the attempt be successful .., * If only standard security measures are taken, the POTUS be injured ... * If only standard security measures are taken, others will be killed/injured? * If heightened security measures are taken ... * It is possible in some way to prevent ... You may also need a possible series of question related to natural causes of death / injury. I see other questions and comments related to predicting lottery outcomes or horse races. To me, this is one of the classes of statements Joe should refuse to work with. There is no net benefit to society and such questions would be disruptive as well as attract criminal influence. Many such lines of inquiry should be refused by Joe. [Answer] 20 questions becomes a really useful game. Crime: > > Is the murderer male? Yes. Is the murderer her boyfriend? *silence*. Is the murderer one of her co-workers? Yes... > > > Is Jimmy Hoffa dead? Yes. Is he buried in Michigan? Yes... > > > Intelligence: > > Is the terrorist camp inside this large area? Yes. Is it in this smaller area? Yes. Is it in this grid section? *silence*... > > > [Science](http://alltoptens.com/top-ten-unanswered-science-questions/): > > Do gravitons exist? Yes... > > > The interesting part will be coming up with the right questions, since Joe wouldn't know anything about any of the stuff he's being asked, and all he can do is try to answer Yes to any question. If he can say yes, then it's true. If he can't say yes, then it's false. The problem is if the answer is maybe (both yes and no) or neither, and so questions should be chosen to be as narrow as possible. It could also be predictive: > > Will the first number in the lotto be a 1? *silence*. Will it be a 2? *silence*. Will it be a 3? Yes... > > > [Answer] **Joe can use his power to figure out how to best use his power.** Joe starts by trying to make the following statement: > > If the optimal one thousand character, general strategy for best using my power to meet my definition of helping humanity, were written in English and converted to binary, the first digit would be 1. > > > If he is able to say it, he writes down 1, otherwise he writes 0. His next statement is: > > If the optimal one thousand character, general strategy for best using my power to meet my definition of helping humanity, were written in English and converted to binary, the second digit would be 1. > > > And so on, until he has written out one thousand letters worth of binary data. Speaking quickly, it will take him most of a day to do this. At the end of this day, he will have a very short guide on how to best use his power. That guide will likely say something to the effect of "Here's how to quickly write a more detailed guide, do so then follow that guide". Joe will follow the instructions of the new guide to write a longer guide, using a method described in the new guide that yields data much faster than the old method. It's possible that this longer guide will in turn contain an even more efficient way to write guides. After potentially several rounds of iteration and several weeks of guide-writing, Joe will have used his power to write out a guide containing the objectively correct answer to this question. [Answer] Sign Joe up with a StackExchange account! Edit: I'm serious. Not just sucking up here. Joe can answer any question truthfully, so the challenge is to generate and prioritize the most important questions possible. The fact that we're all here discussing this is evidence that this is a solved problem! [Answer] His life and freedom would constantly be in danger. He could, without any help, discover and reveal highly classified state secrets, expose corruption, and find criminals anywhere--or wreak havoc on the intelligence community, endanger lives, and promote terrorism and hysteria. He would be an extremely valuable intelligence asset to anyone who controls, tortures, or imprisons him. He would threaten anyone who was criminal or corrupt. **EDIT:** He could threaten anyone, corrupt or not. He would probably ask himself this question all the time: "If I help this person, will it put my life in danger?" He would be likely to guard his ability very carefully so as not to be discovered unless he wanted to be. (edited) Depending on how his "gift"/curse works, it might be difficult for hime to say "As far as I know..." -- it would be up to the OP. Joe might say "I believe XYZ". Depending on his personality, would he leave himself in doubt about his answers? Whenever he has asked a question to himself in the past (which is likely often), he wouldn't be able to evade questions with "As far as I know." From a writing perspective, it would be difficult to imagine all the circumstances he might have asked himself some questions--it might be easier to avoid plot holes if he finds other ways of avoiding questions. He might evade questions rather than provide conditionals, because if he made a mistake and suddenly went mute, he might give away information he hadn't intended. Even simple questions like "How are you?" could be met with something overly specific and useless, like "I'm here. How about you?" or with a question "Thanks for asking--I am trying to solve a problem--do you think you might help?" In awkward situations, he would probably avoid the topic altogether, by telling himself how beforehand. He would prepare. "I have a good chance of avoiding a tough relationship question by saying...". If someone asks him a question point blank, he might say "That's a good question. Do you think so-and-so might have an answer?" (side-stepping whether or not he knows at all). He would likely get very good at this, so the OP might benefit by studying how people avoid questions and guide conversations. Another possibility would be that he might mask his truth telling by making it appear he has some speech impediment. He would intentionally try to tell lies from time to time, just to make his speech seem more halting than it is, or do other things to cover it up. He would know when he was going to die, and how. He only has to play twenty questions with himself a few times. He would probably ask himself how to keep his gift a secret. Probably the best way would be to withdraw from society. He might also hide his ability by working with someone else who can lie in his behalf--never answering a question directly. He would ask of everyone he met, "Can I trust XYZ to keep my gift a secret?" and "Is this person someone I can trust?". That said, he would likely end up in a network of deeply trusted friends who would protect him and his secret, while safely and secretly using the information he can get to save lives. He would probably be corrupted by his own ability. The opportunities to get gain would be extremely tempting. He could play the stock market, among other things. He could just as easily become an evil supervillian corrupted by his own ability as a superhero. He should **not** be a lawyer or in the legal profession, because that profession requires transparency and would expose his gift, putting him at risk. More likely, he would work indirectly for an intelligence agency which has guaranteed his safety and anonymity, and can be trusted to do so. Likely, he would work off-the-record, through other intelligence agents. He would try to be sure most of the CIA/FBI/whatever wouldn't even know he exists, and work hard to keep his existence out of any documents or records. If he went public with his gift, most ordinary people would regard him as a super intelligent man who was somehow deluded or crazy. Criminals, governments, and others would look into him and regard him as a threat, especially if he started proving useful. [Answer] Eris teaches us... "All affirmations are true in some sense, false in some sense, meaningless in some sense, true and false in some sense, true and meaningless in some sense, false and meaningless in some sense, and true and false and meaningless in some sense." Thus, he should never be able to speak. He should quietly retire as a mute fisherman in the wilderness. (To be serious though - such a superpower would realistically render someone mute indefinitely unless they add an endless list of qualifiers to everything they communicate or they are overwhelmingly precise about their communications.) [Answer] Joe will not be an average guy, he'll be the richest person in the world. The obvious ways to make money are - gambling, the stock market and the lottery. His ability to predict the roulette wheel is nothing compared to his ability to check the validity of theories that are not well understood. For example he can determine the feasibility of cold fusion reactors and through a series of well crafted questions, he can develop a working one. That will usher humanity in a post scarcity world (once you have abundant, virtually free energy, everything else becomes extremely cheap). Joe being extremely rich can decide to give away power to the poor countries (India, Africa, etc) and thus eliminate world hunger. He can probably develop an unified field theory, develop drugs to cure cancer, figure out how to build space elevators, be able to determine if certain planets are inhabited and if so on which one intelligent life exists... The possibilities are truly limitless. [Answer] **The alternative view: Joe should STFU** Imagine the annoyance: a super-powered know-it-all, who can always be relied upon to spoil everyone's fun. Nuclear physicists? Computer scientists? Mathematicians? Nobody is safe from the super-know-it-all. Nobody can make it their lives' work to make a stab at earning the key to the fundamental laws of reality anymore; because if anyone really wants to know, hell, if someone is just a wee bit curious, they can just walk up to old Joe and ask him. What patronising twit wants to tell everyone the truth all the time anyway? That's not a superpower. Every idiot who can flap their mouth has that power. And they use it all the time. Seriously- super power? Are you kidding me? That's the bloody Daily Mail, mate. It makes no difference, no difference at all, that Joe is always right. No, in fact, you know what? That- that is the whole damn point. Shut up Joe. Shut up. You want to help humanity? Then shut. The. Hell. Up. [*To clarify: the above is in no way an assault on the poster of the original question, or the other people answering; it is I believe, a valid reply to the question as phrased. Please accept the language as colourful, rather than offensive.*]. [Answer] **How can Joe best help society?** # Don't ask us - ask Joe! By using self-dialog he can soon find the best and safest way to benefit himself and the world. [Answer] For all we know, Moses, Jesus, and/or Mohammed could have been "Joe". Not everyone would necesarily beleive that Joe always tells the truth. Even though all of the verifiable things he says can be verified, verification, correlation, the scientific method, and other "objective" facts are disputed and disbeleived every day by people all over the world. Certainly a religion would form around Joe fairly quickly, and those who consider "Joe-ism" to be blasphemous, false idolatry would be many. As other answers have noted, his life would be in danger. Believers would want to defend him. Countries other than the one he lives in would be very concerned about his use for intelligence. His country would want to use him for intelligence. If enough people believe that Joe can only tell the truth, wars over Joe would be conceivable. Best case scenario, only a few people know and believe that Joe can only tell the truth, and he can best help the world just like any other person: vote, raise one or two wonderful children, teach, write books, song lyrics, or whatever. Worst case scenario, the best way for Joe to help the world is to either hide his blessing/curse or commit suicide. [Answer] If his oracular capabilities became known, it would be the end of his life as he knew it. Human nature, or more precisely government nature being what it is, any and all superpowers would be after him with all their resources. His reconnaissance capabilities are literally endless. He could replace all of the NSA for he only needs to be asked for the secret key of whomever big brother would like to know. If you have Joe in your possession, there are no more secrets to keep from you. **So Joe, if you read this, don't tell *anyone*!** [Answer] Joe has to take over the world. Sure it has been pointed out that Joe is in great danger, but that is exactly why he needs to be the danger. Joe knows what’s best for humanity, he just needs to get in the most influential position possible. Not president or King, he needs to become the single ruler of the world, and that way Joe can really use his power, and he wont have to worry about someone abducting him, or forcing him to answer anything. Imagine how fast would Joe climb the ranks in politics, in the underworld, he is able to predict what his enemies will do, and find a solution that will destroy them, he will be considered a the greatest commander ever, and will be able to manipulate everyone around him as he knows exactly how they will react to whatever they say. Funding will not be an issue after tales of Joe start spreading, and he can win the lottery for startup funds. Joe needs to stay quiet, sure. But he needs to lead humanity, into the next Golden age. [Answer] Joe should go into a law-based profession (lawyer, judge, detective). If he cannot talk about past events that did not happen, then presumably this includes very recent history. Therefore when a murder/ serious crime has occurred, the police could round up a group of suspects (family, partners, colleagues etc.), to which Joe could approach each and attempt to say 'this person committed/ did not commit the murder in question'. He could basically do a version of 20 questions to see if they were involved (this person has committed a crime, this person has committed a *serious* crime, this person did not kill the person in question, but helped to hide the evidence...) until he has worked out the extent of their guilt. Either the killer would be unmasked (and he might've gotten away with it too, if it wasn't for that meddling Joe!), or all of the top suspects would be proven innocent, so that the police could go about their work trying to solve the crime with a smaller suspect list using standard police work. Then when they have a suspect, they can call up Joe again to verify. The police would still need to *prove* that the person committed the crime, as I'm guessing that Joe's testimony would not be enough for most courts, but it would save millions in public taxes for police time wasted pursuing the incorrect suspects, or courts putting innocent men to trial. He could even moonlight by interviewing death row convicts to see if the right person is being executed, and try to prove them innocent if not. I'm not sure what position would make the most benefit of Joe's ability (Chief of Police, Supreme Court Judge, Attorney General, small time detective etc.), but he could benefit humanity greatly by saving a great proportion of innocent people from an unjust fate, and getting terrible criminals off of the streets. I'm guessing many more people would also be discouraged from committing serious crimes, when they hear of a new hot-shot detective/ lawyer in town who has a ~100% conviction/ case-win rate (he might not get them put away all the time, but it would be much higher than usual). [Answer] the world has been getting better for thousands of years, due almost entirely to the advancement of scientific understanding and the technology made with it. unfortunately, both of those fields are advanced primarily by composing good questions rather than answering them accurately. that said, there are plenty of questions out there, and joe could spend a lot of time finding and answering them. the largest challenge joe would face is avoiding being abducted by an organization that wishes to leverage or eliminate his talent. in fact, finding and "neutralizing" the people who are on to him could become a large part of his life. ]

[Question] [ ## Backstory and Setting I'm forging a story that starts with our protagonists living in an absolutely awful urban location. Think near-post industrial revolution, without the regulations that eventually formed in order to protect workers, the public, and the environment. The boom of industrial and mining activity had created a ton of work, with citizens flocking and cramming into the city. A sudden leap forward in (crude but effective) automation technology has not only amplified the side effects of this industrial epicenter, but also dissolved many if not all of jobs. The city is massive, without any real infrastructure. I have yet to finalize a government, though I'm leaning towards a small dysfunctional outfit where the elusive upper class ultimately has more power anyway. The city is geographically isolated from its surroundings, not impossible to pass but difficult. All of this has effectively seeded a new sub culture, with a unique communication method (for the purpose of this discussion we'll call it a new sub language), social codes, etc. **But there is hope:** Our protagonists eventually decide to embark on the journey to leave the city for greener pastures. ## What Lead to the Question While trying to develop our protagonists motives for leaving I hit a wall: reasons to leave were abundant and obvious, but reasons why anyone (and everyone) would *stay* were much more difficult for me to grasp. ## Bias I started trying to imagine why anyone in this city would stay and was getting nowhere. I then started thinking about why people stay in the various locations around that world that, from my perspective, seem miserable or even life threatening. War torn nations without governments, areas with wide spread famine or barren lands, and oppressive dictatorships all harbor massive populations all over the world, and I can't seem to rationalize why. I admit that I have a bias here - I can't imagine even living in a nice american city because of the cramped conditions and lack of freedoms. This bias is strong enough that its making it difficult for me to focus on a single reason for the protagonists to leave, as I'm blinded by just not wanting to be in the scenario at all. Also, please don't take this as me being ignorant. I understand there are serious economical, physical, and psychological factors at play here that I respect, and I'm just looking for some insight. This will not only help me develop the people in this city, but also the protagonists journey out. ## Before You Answer **The Twist** Not having the money needed to leave, while entirely valid and the most likely cause, doesn't entirely convince my rationalizing, uninformed brain all by itself. My brain says in that scenario I'd have enough drive to overcome any economic barriers in order to bail, and I'd genuinely like you to tell me why I'm wrong. **The Grey** This doesn't necessarily need to pertain to the most extreme cases - I see other countries around that world that aren't well off, but maybe still called third world or "developing". Are the reasons similar for these cases? ## \*\*EDIT\*\* June 2nd 2016 Thank you everyone for the awesome points! I've accepted an answer but if there is more to add please keep the discussion going. [Answer] There are a number of basic reasons the (vast) majority of people would choose to stay. There are a couple of other "flavor" reasons that you could optionally add to change "majority" to "practically everyone". ## Standard Reasons to Stay * **Social**: Friends, family, and acquaintances are important to most people. These bonds become even more important when almost everyone is poor. The larger the family, the more they can work together to help each other out, but it also makes it harder for them to leave. "Poor Aunt Bess is too sickly to survive the journey!" "Uncle Roscoe has a good deal at the mine as a supervisor; he won't leave, and Aunt Sally won't leave without him, which means little Jeremiah, Beulah, and Skinny Tim will all stay, too." Etc.. * **Regional Pride**: Even those without strong social ties will likely feel strongly about their chosen home, particularly if the decline due to improved automation is relatively recent (it'll be years before people stop reminiscing about the "good ol' days"). No matter whether they love or hate the way things are, the city is their home, always has been, and, for most, always will be. * **Lack of Known Alternatives**: You haven't provided much details on what other options exist, but even if there are better options, do the natives know about them? Is there regular communication from or about the city's neighbors? If there are news sources, they may very well be focused so intently on labor disputes, corruption in the leadership, complaints against the automation that is putting everyone out of jobs, and the various crimes and violence that likely spring up in such an environment, that news about the areas outside of the city will be practically nonexistent unless something is happening that will directly impact the residents (war, a sudden influx of immigrants due to a nearby catastrophe, etc.). This leads to an "out of sight, out of mind" mentality, and basic information such as how far other countries/cities/whatnot are may be limited to very specific categories of people (e.g. traveling merchants). * **Financial**: To elaborate on the questions you raised on this topic, for most people, they won't get the drive to overcome the economic barriers until it's too late. Lost your job, and can't afford to pay for your house? Sure, you might be willing to look to move. But you have a job, and it just doesn't pay enough to cover the bills? Most people will stick it out and hope things get better. This is where loansharks start stepping in, taking advantage of people's misfortune, and further tying them to their current living situation (sure, you could skip town while owing Tony No-Neck money, but that sort of thing is bad for Tony's business, so he employs some *really* shady characters specifically to track down deadbeats and bring them back, so an example can be made of them). Even if they avoid debt, by the time they convince themselves things are so bad they have to leave, the extra cost of transportation, particularly if they want to preserve their meager belongings, is going to be more than they can afford. All of the above seem so likely as to be almost certainties to me, at least for the vast majority of the population. You can provide further incentive, if necessary, by adding in some or all of the following: ## Optional Additional Incentives * **Traveling Isn't Safe**: It could be dangerous for any number of reasons: war, bandits, wandering monsters, wild animals, or even the layout of the land itself. Travel outside of the city may be the sole provenance of large, armed caravans for safety, which, of course, means added expense putting it out of reach of most people. Of course, with this option, your protagonists will need to be on the lookout for trouble, and have some way of handling it when it appears. * **Indentured Servitude**: When the vast majority of the population is poor, opportunistic individuals sometimes find truly manipulative ways to exploit that for their own benefit. Mines are particularly noted for this, at least in American history, so it will be a fairly natural fit since you mentioned mining plays a significant role in the city's economy. The companies house, feed, and clothe their employees... but charge them for these "services" at a rate that keeps them in the company's debt. It is not unusual for such companies to not even pay their employees real money, but instead use "company script" that can only be redeemed at their own stores, at rates far less favorable than real money. * **Rumors or Superstition**: Maybe it is safe to travel, but most people believe it isn't. Regions frequently have their own myths about what happens to people who are caught out after dark, and migrating from the city would certainly entail several nights under the stars. Even if Bigfoot isn't real, people still fear him, use him as a story to scare kids, and maybe even make money off of him (sell souvenirs, offer excursions to hunt for him, etc.). And besides... anyone who ever tries to leave is never heard from again! (Even if its just because they safely make it to a new home far from the city). * **The Neighbors Don't Like You**: Perhaps there was a flood of people emigrating from your city when the problems first started, and they caused so many problems for the nearest place of refuge that they've banned travelers. Of course, by the time they get there, it is likely too late for them to turn back, so the neighbors may have taken... additional steps. Maybe they make a point of bringing back those who don't take "no" for an answer, and try to relocate anyway (of course, a head is so much easier to transport than an entire body...). Maybe they are known slavers. Or maybe they've built a checkpoint at the only bridge between here and there. Regardless, this is one more situation that the protagonists will have to deal with... unless they've discovered *somewhere else* to go. * **The Cartel**: Trade to and from an industrial city is almost certainly very lucrative. So much so that perhaps the merchants who have worked out trade agreements within the city are very jealous of competition. They could employ a variety of methods of ensuring people want to stay at home, ranging from rumors to hiring bandits to ensure that those who don't pay their proper protection fees never make it to their destination. [Answer] **"Better the devil you know ..."** Yes, conditions are awful. But they can obviously survive there. They know how to survive, how to get halfway drinkable water, how to get edible food. They are to throw all this away for the hope that it will be better elsewhere? **Friends and Family** Related to the previous point, they have social networks. Who will look after the children if a family decides to move? Grandma isn't getting any younger, either, and one of these days she will need full-time care. The first to move would abandon all that. [Answer] ## Hope also known as ## The streets of London are paved with gold The sort of environment you're talking about needs context. Firstly there are two types of people. The wealthy and the peasants. There's no better way of putting this, either people are rich and educated or if they're lucky they've had a basic education but otherwise gone straight into whatever industry the father worked in (on the whole, women don't work except as domestic staff). In the country that means farming or mining. In the city there are other options. Transport is prohibitively expensive, the concept of an ordinary worker commuting is unheard of, you need to live within a sensible *walk* to your work. Only the very wealthy have carriages. Life in the countryside sucks, that's why anyone who isn't a landowner tries to move to the city. Life in the city sucks, but there's much more opportunity, more density of different types of work. There's actually hope there, rather than an endless search for what is ultimately only seasonal manual labour which has just been automated. Automation allows a very small number of people to run vast farms. You've dissolved *most* of the jobs in the city, well there's now *nothing* outside it. No matter how bad your city, it will still have a steady influx of people from the countryside. The only people leaving the city for the countryside will be those who have become wealthy going to live on their newly purchased country estates. [Answer] In the Industrial Revolution scenario you're depicting, the problem with the greener pastures is that they're owned by someone else. All the land is owned by wealthy landowners. So where are you going to go if you leave the city? Those landowners protect their land jealously. They have tenant farmers who pay them rent to grow crops. You can't just find a patch of land and start growing things on it. You also can't go hunting for rabbits or fishing for salmon or whatever, because that's called poaching, and the authorities will really come down on you hard for that one. Even the untamed wilderness and deep forest areas are owned by someone, and even when they're not actively utilising the land, they still generally have gamekeepers and wardens employed to stop random wanderers from helping themselves to the bounty. Your protagonist effectively makes himself a fugitive by trying to live in the wild. He can't settle anywhere; he has to keep himself hidden from the authorities; feeding himself without getting caught is a challenge (especially in winter). In short, those greener pastures really aren't going to be as much fun as they sound. And a mass exodus from the city would simply never happen: the bulk of the population are either too law-abiding to consider it, or else they're too scared of the authorities, or else they simply don't have the life skills to rough-it in the wild any more. No matter how bad the city is, trying to get by in the open countryside would be an even harder challenge for most of them. [Answer] A few reasons come to my mind. * **Who repairs Robo?** You say that automation replaces most of the jobs,(I'm assuming this means robots) but there has to be people around to repair these robots and it is more than likely that the higher classes wont want to do this. * **Who digs holes?** Again I assuming that the robots are similar t car-building robots, not too complex. This means that they would not be able to efficiently mine in damp caves. And again higher classes wont want to do this. * **Shoot people for money.** If this government functions as a modern equivalent to city-states, they would need a military and a simple mandatory military service that provides life essentials would make a large portion of the lower class stay. * **Things might get better.** Many people likely find their lives already well-planted and think if they just stick out a little longer, things will get better and like Detroit they are unlikely to. * **Everywhere else is just as bad.** They may or may not have been brain-washed into thinking places elsewhere are worse. I cannot confirm. * **There's nothing else.** Again they could have been told from birth that there is nothing else outside of the city, this is what Veronica Roth of Divergent did, so can ***you***! * **They cant leave.** Perhaps the government keeps them there because ***EVILLNESS FOR THE SAKE OF EVIL!!!*** [Answer] Money is actually a multi-part problem. If you have no assets, then there is nothing too much stopping you leaving. Think of small dispossessed farmers in the Great Depression, for example. Travelling costs money, but after travelling you're no worse off than you were. If you have a house or flat though, you have an investment tying you down. If it's in a bad neighbourhood, chances are you either won't get back what you paid for it or you won't be able to sell it at all. If you don't have a mortgage then you could write that money off, but then your chances of getting enough money together again for another property are low. If you do have a mortgage, things are even worse - if you write it off and the bank forecloses then you will *never* be able to get another property (or at least not until your kids are long since grown). That's purely financial. Having your own house or flat may also be a personal thing - it's a dump, but it's *your* dump. It's hard to leave somewhere if you're emotionally invested in it. If there's enough push then most people will leave their homes. Think Syria. But if there isn't such an overwhelming incentive then a lot of people will stay. Think Detroit. You have just put a contradiction in your scenario though. If the city is geographically isolated, where did all these people come from who have flocked to the city? Something's not right there. [Answer] Living in a slum is a known quantity to you, you've lived there all your life, you understand how it works, you figured how to make the better of it. It's not ideal but you've got your life under control. For starters, changing environment means going through all of it again, which is enough of an hassle for probably most people. But the main course is that you don't know how much better or worse that other environment would be. The pasture always look greener somewhere else, but in reality you have no idea if it is actually better or not in the long term. So why risk what you currently have for something you may not get? If your city has plentiful of cheap robot labour, that begs the question: what happens to other cities without cheap labour? Either their economy collapse because they can't compete, or they focus on high-tech industry and generally stuff that requires actual humans with college degrees. Realistically, in both cases there's a non-negligible chance your situation won't be better or will be much worse. There's also the fact immigrants aren't welcomed everywhere, except when they are filthy rich, extremely smart, and/or world famous. So maybe you don't want to deal with that. What would push people over the edge and convince them to leave would be if their safety is at risk. There could be a war and they don't want to eat artillery shells or suicide bombings. There could be a dictatorship that arrests people for having opinions. IRL, it's a major reason why people risk their lives crossing the Mediterranean to come to Europe. So you also have to avoid that. [Answer] In real life, living in a 3rd world country, the reasons people say they don't go to better places are pretty straightforward: * a plane ticket is expensive, and you simply don't have the money to go and be unemployed there; * any developed country has a very high bar for accepting immigrants to work there; * people wan't to live near their family and friends; * the language barrier [Answer] Negative circumstances are usually not enough to make people leaving their city. People need some kind of utopia or vision to go out to the "greener pastures" and found a new settlement based on that. This explains why only small groups will go to an exodus first. It will become a big wave only when other people hear of fantastic success stories in the new settlements. Note also that life on the "greener pastures" is hard. The new settlers will have to work hard to survive and build their new homes, and backlashes from natural disasters and lack of food or water will happen, since they don't know the new terrain well. You can learn from historic examples of emigrations like the pilgrim fathers, the Mormon treck to Utah, or the Migration of Jews to Palestine. [Answer] There are plenty of reasons to stay. First and foremost though, they have a home, be it a house, apartment, shanty hut. They might even have running water and electricity. Furthermore most people there are city folk, and haven't a clue how to be self sufficient. As bad as the city is, there is probably still a place to get food. If there is a school for the kids, they don't want to risk their education by leaving. If not, then maybe they are so poorly educated that they don't know what they will find once they leave, or where they should go. As o.m. stated in his answer, all the family and relations live here, and people don't wish to abandon them (or be separated from them) If the city is isolated as you say, the situation is probably the same for all citizens. And with the bad infrastructure, there are no decent roads or transport methods to get out of there, and as such not only would it make leaving more difficult, but it would also mean visiting other places would be difficult - this means that there would be a reduced likelihood that people would even see other places and be inspired to move for a better life. You could introduce more fantastical elements depending on the genre of your work. e.g. The city's people as a whole have an inherent fear of the dark or maybe believe that vampires/ghouls/etc. lurk in the protection of dark outside the city, but the city itself is well lit at night. (Obviously the mines were well lit when they were open!) [Answer] It sounds like you have put yourself in a real bind here. From what you have described, it doesn't sound like any sensible person would want to stay, especially if they knew what the 'countryside' looked like before they migrated. With the history of human migration (europeans moving to the United States in the 18th and 19th century, or the current migration crisis in Europe) I think it is hard to argue that people wont try anything to get out of a desperate situation like this. One question that really springs to mind is: Does the city even want people there anymore? It sounds like your story needs 'the crammed city' to work. In that case you should figure out the motivation of the government or the factory owners or whoever for not letting people get out of the city. I can think of three possibilities, each with a problem: 1. People have just enough hope that they can advance through some sort of system of of this squalor, be it education or hard work. A lot of slave societies (like Rome or Caribbean plantation colonies) had some way for slaves to earn their freedom and that helped to keep the 'unpleasantness' of daily life from becoming mutinous feelings. The main problem here is that you are not dealing with overworked people, but people who cannot find employment, and they are in a different mindset. 2. People can't leave, which could be caused by the government preventing them from leaving or spreading misinformation about the 'greener pastures', so that people don't want to go back. The main issue here is why would the government want to keep people at the city, since they seemingly don't need them? 3. Maybe there is something more sinister going on, like a social grand experiment or something along those lines. The problem with that is that it will move the focus of your story away from your protagonist and on to solving the 'mystery', which sounds like it wouldn't serve your story well. [Answer] Your bias is the perfect answer. Humans (assuming were talking about humans here) have a single powerful and dangerous trait. It's, at the same time, the thing that makes us incredibly powerful, and ultimately self defeating. **We can adapt to anything** Your looking at the outside of your horrid inner-city setup going "Man that is awful! I can't stand living like that. I would so move to a better place!". However, if you grew up there, lived there, and socialized there, you wouldn't find it awful, you would find it comforting. Here are some examples; In "Midnight in the Garden of Good and Evil" the reporter from New York, has to set a tape player, playing city sounds (traffic and what not) to feel comfortable. He also has several run ins with "odd" people, that the towns people think are more then normal. In "Final Fantasy VII" AVALANCHE don't want to leave their under city slums setup, they want to make it better. (great now I have the fight music stuck in my head) In real life there are people that like the city and people that like the country. Both seem to be opposed to the points the other has to make about why their setup is better. [Answer] ## Below are some factors that different people may have, depending on their status and personality. ## Fear Fear drives humans to do the opposite of what is logical. Fear keeps you rooted in place, when everything else is telling you to leave. Perhaps that fear is brought in by the harsh conditions of leaving; > > "I'll never make it. The mountains are too cold to survive a night. I > have no money for food to survive the three days journey to the other > side." > > > Or that fear is from militarian rule by the higher social class: > > "Justin tried to leave. He got just outside the walls; we could see > him sprinting for the forests. Next thing you know, he was stumbling, > and there were cracks of thunder as the bullets whisked past him. One > caught him right through the chest, and his body was left for the > wolves." > > > Or even exile: > > "If you leave here, you may never return. Should you come back, you > will be executed on sight. Your worldly goods will be forfeited to the > City. Do you still wish to renounce your citizenship?" > > > War, with distinguishable traits for each country. (Racial or language based) "I'd leave the city Ziis, if only I could. But where would I go? I'd be a fugitive here, and those green-skinned rats from Kazamana would kill me on sight. --- ## Religion and world views Just as humans have wants, they also have needs, and Religion/Worldy Views are no different. Perhaps they believe they need to stay to worship their deity properly. Or that they're helping appease their gods, even if they remain in poverty. For some, putting their own needs and wants above the wishes of their god is important enough for them to remain where they are. For examples, look at any religion. Some go to church on Sundays. Others make a trip to Mecca yearly. Some go underground and worship. > > "If I abandon my city, Jrin will be angry at us. I don't want to anger > the god of war! He'll smite me and my family!" > > > --- ## Revolution Why leave when you feel you can change the world? Some of the more stubborn would probably stay because they think they can change the system. Putting forth effort to reform rather than flee, to confront rather than abandon, is much more viable option. To some, leaving only strengthens the 'enemy' giving them more incentive to expand their influence. Give them too much space, and they'll swallow the world whole. To these people, there's no place to run to that won't be the same. Once you've run as far as you can, all that there is left to do is fight. These are the people that revolt and sabotage the upper-class eventually. Reminds me of the Hunger Games books, or Robin Hood lore. --- ## Exploitation The system works for them. Regardless of whether they're low-class bandits, or corporate thieves, the system of government and societal standards work for them. While others around them wallow in filth and hard labor, the people that exploit the system benefit from having to do less work, earn more, or thieve their way into power. These people could buy themselves the luxuries without the cost meaning much to them. Why would they leave? The world serves them. > > "Leave? Are you insane, boy? I have everything I could ever want here! > Food, Wine, Women, you name it! Leave....ha!" > > > [Answer] ## Freedom of movement just got granted IMHO this is the most sensible reason for your protagonists to want to move. The couple of others I scanned sounded too modern/20th century. In England, freedom of movement got enshrined in the 13th century with the Magna Carta. In continental Europe, it came much later. States with the most reactionary regimes allowed it as late as the 19th century: <https://en.wikipedia.org/wiki/Freedom_of_movement#History> > > The serfs of Russia were not given their personal freedom until Alexander II's Edict of Emancipation of 1861. At the time, most of the inhabitants of Russia, not only the serfs but also townsmen and merchants, were deprived of freedom of movement and confined to their places of residence. > > > As such, it's not that they didn't *want* to move - it's that until recently they simply couldn't. Throw in some harsh laws to [prevent](https://en.wikipedia.org/wiki/Vagrancy_(people)#Vagrancy_laws) [vagrancy](https://en.wikipedia.org/wiki/Timeline_of_Romani_history#Timeline) for good measure, and your protagonists had excellent reasons to stay at home (until now). [Answer] There are already a bunch of answers with good information. I won't repeat them, but let me add some additional points. One: Your idea of a good life and someone else's idea of a good life are not necessarily the same. In at least two ways: One-A: For people living in 21st century Western countries, clean water and heat in the winter and available medical care and so forth all seem like basic necessities. But to people two hundred years ago, these were almost luxuries. Heck, lots of Westerners think of broadband internet access and good cell phone coverage as human rights. These things didn't even exist when I was a boy, and we didn't consider ourselves to be enduring horrible suffering because of their absence. One-B: People have different tastes. Like you say that you wouldn't want to live in even a "nice" American city because you don't like crowds and all. Me either. I grew up in New York and I moved away once I became an adult because I didn't like the crowds, the dirt, the crime, etc. I now live in a town of 20,000 or so, and I know there are people who consider this also way too crowded, and who would prefer to live in Wyoming where it's 100 miles to your nearest neighbor. But on the other hand, there are people who love to live in big cities, who love crowds and noise and think of them as exciting. Don't fall into the trap of assuming that everyone else thinks just like you. On this very subject: When I was in college I took a psychology 101 class. The textbook had a chapter on decision-making, in which the author gave as an example that if one of your friends got a job that paid a lot of money and that was in a small town in the southern US, that you would know that obviously he was taking the job for the money; but if he got a job that paid a lot of money and that was in a big city like New York or Los Angeles, you wouldn't know why he took the job because there would be many good reasons for taking it. I laughed at this example. The writer not only just took it for granted that it was better to live in NYC or LA than in a small town in the south, but he assumed that everyone else in the world would agree with that preference. What made it doubly absurd was that this came from a psychologist, supposedly an expert on how people think, in a section of a book discussing how people make decisions. And it just absolutely never even occurred to him that other people might have different tastes than he did! My point being: I look back at New York City and think, "Ugh! Crowded, dirty, noisy, crime-ridden, uncomfortable place. I'm so glad to be out." But others look at New York city and think, "Wow! Crowds! Noise! Excitement! I'm so glad to live here." Two: People may not have practical options, or at least not see them. It's easy to say, "Hey, why don't you move away from that terrible place?" But if the person has a home and a job, they are at least making do. If they moved someplace else, could they get a job there? Where would they live? To me and I guess to you, working in a Victorian-era factory sounds horrifying: hard work, dangerous, etc. But to people at the time, it was often a step up from their alternatives. We have this romantic view of life on the farm, picturing farmers sitting under a tree enjoying the fresh country air. But in real life, for most of history being a farmer was being one bad growing season away from starvation. Sure, work in a factory was hard. But work on the farm was hard too. In practice, in the 1700s and 1800s a lot more people left the farm to go work in the city, then left the city to work on the farm. Maybe some of them were fools who didn't know what they were getting into, but at some point they must have know the relative merits, and decided the city was better. [Answer] Several reasons occur over and over again: * Incapability. You say, "My brain says in that scenario I'd have enough drive to overcome any economic barriers in order to bail", but that's before you've tried a few times and been kicked in the teeth every time. Presumably you aren't a billionaire entrepreneur. Tell you what, if you can "overcome any economic barrier", no matter how high, why don't you just become one to prove the point? ;-) Look at what happens to refugees from wars -- the majority of the time they face hostility, physical walls and fences, inferior rights to those of "nationals", and it frequently takes a generation or more to actually benefit from having left a bad situation in their country of origin. Most people living in "bad" places cannot simply move at once to the best place they know of and get on with life, even if they decided they wanted to. * Different priorities. The grass may, objectively, be greener on the other side, but not everyone values grass colour over all other concerns. Things like family connections, national pride, class (inverted) snobbery or personal taste can all play a part here, meaning that my crowded slum is better for me than your airy suburb. * Imperfect information. They might not realise just how much better things are elsewhere, or they might have been told but not have sufficient grounds to believe it. * [The endowment effect](https://en.wikipedia.org/wiki/Endowment_effect). There is a common psychological bias in humans to rate things they have more highly than things they do not have, merely because of having them. This plays closely with "different priorities" * Risk-aversion. A potentially-rational version of the endowment effect. I might genuinely prefer to have a 99.9% chance of staying where I am, over a 60% chance of improving my situation but a 40% chance of something going wrong and I'm worse than I started. Being unemployed in a region where you know people and have some kind of housing arrangement, generally *is* a better prospect than being unemployed in a region where you know nobody and have nowhere to stay. So until you actually secure a job/life elsewhere, or believe that employment is plentiful where you're going, moving really is a significant risk of just making things even worse. The fact the streets are cleaner and less crowded doesn't mean you want to have to sleep on them (or that you will be permitted to. If the place is clean and uncrowded that may well be because undesirables are arrested for vagrancy and moved along). In practice, there is a significant divide in much of Western society, between the belief that some people are extremely poor because the political/economic system as currently operated distributes resources so as to leave some people poor, and therefore whoever comes last in the race (for example whoever started out furthest behind) has to live somewhere awful because there are not enough nice places for everyone; vs the belief that the system is an effective test of people's virtue and capability, with those who are virtuous and capable becoming or remaining rich, while those who are poor have only themselves to blame for failing to take the many opportunities they have had in their lives to become rich. Of course many people believe both to different extents, but the divide becomes apparent when different explanations are applied by different people to a particular situation. Just ask a left-wing and a right-wing politician about welfare, sit back and enjoy. It would seem a lost opportunity, in fiction, to make either of these be the *whole* undeniable truth of the matter for this situation ;-) However, if there are rich happy people in one place and poor unhappy people in another place, with no physical wall in between them, then it's because something in politics or economics is determining who goes where. And the system must have teeth: something bad must happen to those who just decide one day they can overcome any economic barrier through sheer willpower, or everyone would be doing it. Possibly they get arrested for burglary when the economic barrier in question is somebody's second-story window in the middle of the night! [Answer] **Racial Conflicts** If, everywhere but this city, the people who live there are persecuted, they would rather live a poor life there than no life at all. ]

[Question] [ What do [digital immortality](https://worldbuilding.stackexchange.com/questions/40926/why-brain-upload-is-a-concept-of-immortality), [teleportation](http://powerlisting.wikia.com/wiki/Teleportation), the show *[Doctor Who](https://en.wikipedia.org/wiki/Regeneration_(Doctor_Who))*, and a [horror game released in 2015](http://somagame.com/) have in common? **The idea of copied consciousness.** Each of these examples relies on copying the brain in some way, shape, or form. * **Digital immortality** involves copying the brain onto a computer * **Teleportation** involves disassembling it and reassembling it in a new location * **Doctor Who** involves *regeneration*, which transfers the old mind of a character into a new body * The game **SOMA** features the principle of multiple copies of the same mind existing simultaneously --- The inherent problem with these methods can be summarized in one sentence: > > "[*I don't want to go*](http://img02.deviantart.net/1cd8/i/2012/336/2/d/i_don_t_want_to_go____by_viszla7-d5mvo2u.png)" > > > When you **teleport** someone, you're ending one life and creating an exact replica in its place with the same memories. When you immortalize them **digitally**, the organic copy will expire. In ***Doctor Who***, The Doctor is reluctant to regenerate because the "old him" dies in the process. And finally, **SOMA** ends in the following way: > > The main character uploads their mind onto a satellite with a bunch of other human minds, and launches the satellite into space - the legacy of the human race after the apocalypse destroys the world. However, they open their eyes to find they're still stuck on Earth - a copy is only a copy, they're still on Earth, and they will die an unsatisfactory death. > > > **How can you copy a consciousness, while avoiding the "I wish it were me" problem, and without killing one of the copies?** [Answer] ## You use centralized version control The problem is akin to copying computer programs around - you must dissociate the physical substrate from the program. It is complicated by the fact that the program modifies itself, i.e. consciousness could be thought of as an executable database of some sort. However, we have lots of tools available to deal with this. Version control in software is the process of keeping a repository of a project where multiple programmers (in this case clones, teleported versions, etc) are working on different parts of the code (experience) and integrating their multiple copies into a unified whole. To do this as a human, we would need to insert the human being's life into the version control as soon as possible - you could even start the life in the version control, then use it to generate a human baby. This is a paradigm shift of sorts in the concept of "consciousness" or "identity" - it being first and foremost a digital phenomenon, thus indestructible (given sufficient computing and backup capability), rather than being primarily a physical phenomenon which is simply "backed up" every once in a while. With this view, the concept of multiple bodies, teleports, etc, are not perturbing or unnatural or distressing - the physical is not the primary seat of the mind, merely a temporary vehicle. Thus destruction of the physical body is not "killing" - the mind cannot be killed as it is a digital phenomenon. The physical implementation of such a system probably needs some sort of high-concept computing resources along with a permanent and unbreakable link from each body to the computer. It also presents a unique perspective on "clashing code" - parts of the program where two programmers are working on the same part of the code. For this, our central versioning system would need some sort of "best integration" or "best outcome" metric, along with a facility to store, segregate and present the "other versions" as accessible memories that are kept separate from the "main branch". Iain M. Banks' "Culture" series has a similar idea where people are backed up to a centralised computer system somewhere, particularly before they go off to do dangerous things. It doesn't quite have the same slant of "digital-first" consciousness, but there are lots of fantastic ideas on implementation. As mentioned by @Molot, the Night's Dawn trilogy also has similar concepts of centralized consciousness, although that goes further to have a centralized **mass** consciousness with which all minds eventually get integrated. [Answer] # You don't In the way you describe, any way of making original cease to function is killing it, so you simply can't do. There are few ways to go around it. * StarTrek way — because original is disassembled when you're beamed up, and the mass is somehow transported, too, it was left to philosophers to tell if you are still you or just a copy. * [Safehold](https://en.wikipedia.org/wiki/Safehold) way — copy is just a copy and it know it is. But also it knows that after timeout it will be reintegrated into the main personality. Timer is set to a low enough time, and people are conditioned in a way that prevent copies to start to think about themselves as "self". Copy feels as a part of it's source, and if for some reason it starts to develop own ideas and refuses reintegration, time out and it's deleted. * Safehold way two — > > Copy that will live totally in VR, indefinitely, but procedure kills patient so it's only allowed on patients that are already dying anyway. > > > * [Night's Dawn](https://en.wikipedia.org/wiki/The_Night%27s_Dawn_Trilogy) way — Edenist's habitat keep memories of people, and when someone dies, last part of their memories and personality are transferred and activated. Everyone knows it could be done to a living human, too, but no one does it specifically to avoid "I wish it were me" issue. They are very careful about that. [Answer] ## Who can tell? Once you've made the copy it opens its eyes and truly believes it's the original. Everyone around them believes and accepts them to be the original, how can you say it's a copy and not the original, to all intents and purposes it is. The end of the story could have been taken from the other point of view, that of the copy, opening its virtual eyes and seeing the wide expanses of space that are now its home. A copy is not just a copy, it's also the original and it sees its own continuity of existence which includes that trip. The reason you eliminate the original is to make sure there's only one continuous personal timeline, not multiple branching ones who become different people. *Who you are is made up of your memories, your accumulated experiences, the mere physical aspect is replaced every few years in a continuous cycle as cells die and are replaced. You're not physically the same person you were when you were born, all those cells have died and been replaced by new ones, you don't have the continuity problem from that, why should you have the problem when they're all replaced at once?* Consider my grandfather's axe(or [Trigger's broom](https://www.youtube.com/watch?v=BUl6PooveJE), depending on culture) > > This, milord, is my family's axe. We have owned it for almost nine hundred years, see. Of course, sometimes it needed a new blade. And sometimes it has required a new handle, new designs on the metalwork, a little refreshing of the ornamentation . . . but is this not the nine hundred-year-old axe of my family? And because it has changed gently over time, it is still a pretty good axe, y'know. Pretty good. - Pterry, The Fifth Elephant > > > You're simply doing the same with a body, your body is not you, your personality is you, your body is simply an avatar for the personality. The personality endures but the body can be replaced. Just don't expect me to use a teleporter any time soon. [Answer] As Separatix alluded to, this is an *age* old question which has not had an answer which satisfies everyone for thousands of years. You won't solve it in a few minutes. The name I have most often seen associated with this problem is the [Ship of Theseus](https://en.wikipedia.org/wiki/Ship_of_Theseus). It was reported by Plutarch in his writings, before 150AD. Even then, it was already attributed to "Greek legend" suggesting it is far older than that: > > The ship wherein Theseus and the youth of Athens returned from Crete had thirty oars, and was preserved by the Athenians down even to the time of Demetrius Phalereus, for they took away the old planks as they decayed, putting in new and stronger timber in their places, in so much that this ship became a standing example among the philosophers, for the logical question of things that grow; one side holding that the ship remained the same, and the other contending that it was not the same. > > > From this, philosophers have drawn up lines with fancy terms such as endurable and perdurable to try to capture this conundrum along side an acceptable solution. For years, they have failed. It got even more difficult when science came along and started suggesting that the human mind *could* be encoded (which, by the way, is an assumption on your part, so I'd recommend touching on it in the story). If you do start from the assumption that consciousness can actually be copied, there are still many options. My personal favorite is to suggest that, after the "copying" occurs, it is not so much that you have a copy of yourself as much as it is that *your body is now twice as big, and in disjoint places.* One of the lessons of the Ship of Theseus is that its very difficult to isolate a definitive *self* when engaging in such copying. Why not simply declare the "self" to consist of two bodies? There's some precedence for this. Simple precedence can be found in the reattachment of a finger. We keep the severed finger on ice, but never one is it questioned that "this is the victim's finger." It's part of their "self." So having a body in two parts is not inherently forbidden. There's even really strange verbiages which have to arise when discussing organ transplants such as "he's using my lung." There's also some really really interesting precedence in the world of conjoined twins. The sense of self associated with conjoined twins has always been complicated. For example, Krista and Tatiana Hogan are a fascinating case of twins conjoined in the brain. Impulses from one brain transmit directly to the other. Because of this, there are times where their behavior is as though they are one individual. Once you have this two bodied "self," obviously you will need to do something about it because the two bodies are likely to experience sufficiently different lives as to want to call them two "selves." This we also have a model for: divorce. In divorce, one takes a "unified body" and cleaves it in two, along with all of the property that body has attained. This process would have a natural corollary in the consciousness copying process. It even suggests a correct moral viewpoint for the clone killing problem. If the "self" agrees that one half of it should go away, who is to disagree. However, if the "self" is at odds with itself, the situation becomes less clear. Perhaps you have to send them to clone counseling, to come to an understanding of their greater self. [Answer] **Gradually Replacing the Brain** Similar to Werrf's suggestion I'd go the gradual transfer rout, but I don't know what a "transfer of conscious processes" implies and I'm not sure that a "half conscious" brain would work. This is a more “materialist” approach. **Digital immortality:** I would suggest gradually disassembling and at the same time reassembling the brain via nanomachines. Imagine a machine first replacing one neuron in your brain with a mechanical equivalent that can send the same impulses (but also has improved functionality). From your perspective there would be no way of telling the difference. It then spreads to the next neurons and so on. Why would this be any different than your brain cells replacing the matter that makes them up through normal metabolism? Do this however fast you feel comfortable with. Of course the new neurons should have improved functionality, or this would be rather pointless, such as higher durability and, say, the ability to just speed up their functioning if asked to – useful when your robot brain is complete and you want to slow down time relative to your thought processes. Are you concerned that you don't get the full benefit of mechanical existence, because your mechanical neurons are still too similar to their meat versions? Just iterate the process. Or you could just gradually export the functions of individual neurons to be simulated in the cloud. Bam! You are now fully digital and you were conscious through the whole process and there was never a whole "you" that was destroyed. **Teleportation:** Now it would seem that this doesn't lend itself to teleportation, but it could work. You'd need instantaneous communication though (i.e. an ansible). You need a body identical to yours but without a brain and two exactly identical “teleportation rooms”. Your clone body is wired up and receives the exact same impulses that your primary body does and thus acts just as your primary body does (and also it doesn't, you know, die from lack of a brain). Enter the brain disassembling/reassembling nanites: At the same rate that your brain is scanned and disassembled, an identical copy of the individual neurons is assembled in the destination body. Their impulses are sent back to the origin brain and they receive impulses from the origin brain. This is why you need an ansible: Lag would mean death or at least madness and brain damage. Where are “you” during a given point in the procedure? You don't know. Nor can anyone. To avoid the brains functioning differently the rooms have to be identical. If they aren't, it would get very...trippy, as perceptions intermingle *in various stages of cognitive processing*. Again: Do this however fast you feel comfortable with. **Pro:** There is no "you" that is left behind by your digitization/teleportation. There is no ending of consciousness (probably). **Con:** Nanomachines imperceptibly eat your brain and excrete another. [Answer] Check out the [Old Man's War](https://en.wikipedia.org/wiki/Old_Man%27s_War) universe by John Scalzi. It involves, among other things, the transfer of consciousness between bodies. Without getting too spoileriffic, in this universe consciousness cannot be effectively stored, only transferred. New bodies are carefully prepared, with matching genetics and underlying brain structure, memories, psychology and the like are imprinted onto it, then the consciousness process is transferred from the old body to the new via a bridge. The person being transferred is aware throughout the process; they don't go to sleep in one body and wake up in the other, they feel themselves gradually merging into the new body. After the transfer, the new body is awake and aware, and the old body is alive and undamaged but no longer 'awake'. This has always struck me as an excellent way to avoid the problem of mind transfer, as well as an excellent definition of what consciousness is - it's not a thing that can be copied, it's a continuous process that can be transferred. Edited to Add: Thinking about this question got my writing spirit up; so here's something of how I would see it working. > > The new body stared mindlessly ahead. I tried not to meet its eye – seeing myself as a mindless husk was always a disturbing sensation. > > > “Can you hear me?” the tech asked, pen poised over her clipboard. > > > “Yes,” I said, shifting my focus to her hip. It was much nicer to look at. > > > “What colour is a banana?” she asked. > > > “Yellow.” She nodded, made a note on her clipboard, and turned to the new body. > > > “Can you hear me?” she said again. The body said nothing. The tech nodded, apparently satisfied, and made another note. > > > “Are you ready, Mr. Werrf?” she asked, turning back to me. I swallowed hard, and nodded. She gave me a small smile – a moment of human contact before doing something so totally inhuman – then folded a screen down in front of my eyes. > “Please recite the numbers you see,” she said crisply, all business. Numbers began to flash on the screen in red; 4, 9, 7, 13. I recited them as they appeared. > > > My skin began to tingle, as if my entire body had gone to sleep and was waking again to pins and needles. More red numbers appeared on the screen; 8, 12, 5, 6… > > > It was growing harder to say the numbers. My mouth felt numb, and I grew dizzy, as if I was floating away from my body. My tongue flopped out of control and I bit it; a moment of harsh pain. The numbers blurred in front of me…8 or 3…6 or 5…red or…blue? I blinked. > > > The pretty technician was still watching me, standing off to one side. Forget the numbers. I focused on her face and her hair, tied up in a neat bun with a few strands running down the back of her neck, and I realized I could see both sides of her at once. My head spun, and I tried to feel nausea at the strange sensation, but there was no body there to rebel against me. > > > For a long moment I stared at the room from two pairs of eyes; then…I don’t know quite how to describe it. That sensation when you’re pushing and pushing, and suddenly there’s no resistence; suddenly, with an almost tangible slithering *pop*, the strangeness vanished. Blue numbers flashed on the screen in front of me. 2. 7. 4. > > > I took a long breath. The pain was gone. The tightness in my chest just wasn’t there any more. I blinked, and realized that my vision was clear. Even the air smelled fresher. > > > The tech lifted the screen away from me and smiled again. I couldn’t help it. I smiled back. > > > “Can you hear me?” she asked, her voice light and musical. I nodded. > > > “Yes,” I said. > > > Across the room, two more techs recovered the mindlessly staring body that I had occupied for so long. For a moment, I caught my own eye; but it was as lifeless and insensible as the new body had been just a moment before. > > > [Answer] **There is no problem with two minds.** If I think about it from a perspective of "me, waking up being in two different bodies", I have a serious identity problem. But this is the wrong perspective. Let's, for start, assume it's not *me* being copied, but *you*. Suddenly I don't have any problem at all anymore, there is just "you A" and "you B". I can talk with both, and everything feels quite normal. No problem at all! Now, lets assume I am copied while sleeping, not knowing about it. "I, A" and "I, B" wake up in different locations without knowing about the other's existence. Both of me should not have a problem with that, it's just strange that I woke up in a different place than where I went to sleep, but, well, strange things happen. No big deal. I will still know my identity, I will be me, and be sure about it. This is true for "I, A", as well as "I, B", there's no need to distinguish them, everything is perfectly symmetrical. So, the answer to your question is to not let them know about the copy, or, to at least prepare two distinct life paths without too much interaction. The worst is when they both claim the same life, like being in love with the same woman/man or being the father/mother of the same children. Or, copy them too! [Answer] I never got why people found this topic to have any difficulty, I just don't see it. A person getting teleported from point A to B has all of their molecules scanned, the info stored and disassembled, to reassemble their molecular structure or remake it somewhere else. Whether or not you make a copy is optional. If you do, you have, for the smallest of instances, two exact copies of one person. A few milliseconds later they already wouldn't be 100% the same anymore due to different environmental cues. This whole notion of 'dying' when you step inside the teleporter is misleading. You don't 'die'. Dying is a human construct, and even then is poorly understood. Most people think death is instantaneous, or rather happens from one instant of time to the very next. Rather, it's a process that starts the second you are born, and ends quite a bit after you breathe your last breath. Teleporting isn't dying, you just have your molecules disassembled, effectively disappearing from the universe entirely, or rather, you changed form to whatever code or database or pipeline you were 'stored' in. Once you're reassembled back *exactly* the way you were before, you're the original you again. Just in a different place. Because all that makes you *you*, is the exact composition of molecules you had before you stepped inside. This idea of "I don't want to go" is just nonsensical. You don't die in that sense, and cloning aside, if you stepped into a teleporter, closed your eyes, got teleported, and tried to open your eyes again, you would find yourself on the other end of the teleporter. In other words, the question of which clone is 'you' is flawed. They both are, exactly. All you would do is make an exact copy of yourself. One is in the place you were when you started making the copy, the other is on the other end of the teleporter/whatever device. If both these copies started to live their lives, they would find themselves competing for their loved ones, possessions, and everything else they thought was theirs. There is no way to solve this imo but to never make the clone in the first place, only one copy can ever come out of either end of the machine. P.S. sorry for the messy comment, went back and forth to edit and it just got messed up. I hope my ideas are clear though. [Answer] Obviously, you want the death of the original an integral part of the process without which the creation of the copy is incomplete. This requires considerable handwaving, but we are in that territory anyway, so for example: You can copy the body and brain, but the **consciousness** is a quantum mechanical process (some scientists believe so) and cannot be copied non-destructively. You can transfer it through entanglement or whatever (this is the handwaving part), it doing so disrupts the original, effectively destroying it. You are left with a zombie on the source end. [Answer] It seems like the transfer of a conscience is where the really problem is, it needs to be perceived by the person experiencing the transfer. Perhaps by triggering an **"out-of-body experience"** - when your "thinking essence" leaves the body and is able to "see" their body being left behind - we can then just "enter" another body. (This reminds me of a story in "Red Dwarf: Better Than Life", where a character doesn't know they are in a VR system, but as they age in the VR world they decide to become younger by transferring their essence to a younger and empty clone of themselves. Obviously they are always connected to the VR system, so at some point they perceive themselves without a body) In a Star Trek transporter perhaps we could leave the body before teleportation then reconnected afterwards. [Answer] Specifically for the teleportation case you may be able to rely on Quantum Mechanics. Quantum teleportation is the process of transferring the quantum properties of one particle to another, by using a set of entangled particles as well as a classic communications channel. Said quantum properties remain absolutely unknown in the process, so it is nothing like measuring them and then trying to copy then. Exact copying is actually impossible in Quantum Mechanics, it can be called the "no-cloning theorem". QM is weird like that. [Tom touched on this aspect, but I don't think he explained it too well, so I had to give my go at it too. And nonsensical SE policies prevent me from posting this as a comment to his answer.] You can probably apply this to mind uploads, if it uses a quantum computer and if you make quantum processes an important part of consciousness. Personally, I do not believe in this theory, and I'm able to provide some arguments against it, but that is really besides the point. It is really your only way to achieve a no-cloning restriction on consciousness, along with some other benefits like indeterminism (useful as an argument for free will). [Answer] # Bit by bit replacement. I am working under the presumption that consciousness and who I am have no supernatural component whatsoever, but are an emergent phenomenon of the processing done by my brain. That is my belief; there is no ineffable part to worry about. Neurons are biological and noisy. They fire spontaneously for no apparent reason; and can fail to fire when they usually would. It is nearly impossible to detect such errors in your own neurons. Usually these errors do not rise to conscious attention; if they do it is the common experience of a mental misfire, like "What is that thing you use, for eggs -- oh a spatula." If each neuron in my brain were, one by one, replaced with a machine that did exactly what the neuron did, within some tiny margin of error, like 1/1000th of a percent, it would be too small for me to notice. You could replace all of them. The biological me is gone, the digital me has taken over, and neither of them ever experienced either death or birth or any moment in which they were not the one being duplicated. The consciousness was indeed duplicated; the machined version may be far more maintainable, back-up-able, and have an effectively immortal existence (if destroyed, a backup stored off-site (including in another star system or galaxy) could be used to restore it). Depending on how frequently changes to the machine are recorded (I am assuming it can form new connections and learn things, just like real neurons), the interruption may be quite minor; kind of like how the impact of a car accident IRL can cause people to lose the contents of their short term memory that contained the time leading up to the accident: They often report not knowing *at all* what happened to them in the five minutes or so before the accident, the last thing they do remember was routine driving a few miles away from the accident, then waking up in the hospital. IRL that doesn't cause them to question their existence, and neither would being restored from a backup. As far as teleportation is concerned, the same philosophy could apply; there is one of you, disassembled and reassembled elsewhere. It is just another form of movement, philosophically speaking. [Answer] Imagine a world where it's widely accepted that we live in a multiverse where this sort of 'branching' already happens every moment, in every way possible, exploring the entire span of possible experience. Given this belief, the core philosophical problem goes away, as this is *already happening*. Of course, you still have the "wish it were me" problem, as some timelines will inevitably result in horror and suffering. But now it's a psychological problem rather than an existential one, since the feeling of "wish it were me" is just as inevitable in the branching as other outcomes. In this world, teleportation is just a more 'extreme' branch and for each case left behind, some will regret it and others will not. This then poses the ultimate question: is it fundamentally possible to be content when it is possible to imagine and contrast possible outcomes? Hopefully? [Answer] Consciousness-copying technology exists in the space simulation game EVE. The conundrum is solved this way: each player can have multiple bodies (called clones), *but only one consciousness*. This consciousness can be transferred between clones in one of two ways, depending on the type of clone you are talking about, and the event that transpired. The main difference with EVE is that you only have one active consciousness, though many clones may exist that are basically copies of it. All these other clones are dormant, and you never have more than one active at the same time. **Standard Clone** This type is used as insurance or as a backup in the event of you, the player, being killed in space. When a ship blows up in EVE, the player is still alive inside a mini-ship called a pod. When the pod is blown up, a neurotoxin is injected to instantly kill that particular clone (presumably since it would have died anyway and to spare it from the unpleasantness of a space death). Just before the neurotoxin is administered, the consciousness is transferred, presumably by some kind of space internet transmission system, to the backup medical clone. Each player only gets one standard clone, and it sits dormant in your home system, never used except in the event of your death. At that time, a new clone is created and installed in place of the old one, which your transferred consciousness takes control of and begins using. **Jump Clone** A jump clone is used for instantaneous teleportation. These can be installed for a fee in any station with a clone vat, and also sit dormant. You can have up to three jump clones. At the player's disposal is a console where you can jump to any of the jump clones that you currently have installed. This means your consciousness travels across space and ends up in the other jump clone, somewhere else. The previous clone (the one you just left) now goes dormant and you begin controlling the one you jumped into. This is particularly useful when you have extremely expensive mind implants (which are common in EVE) that you don't want to lose while, say, doing a lot of PvP with an increased risk of getting blown up. So you can have an "empty" vanilla clone installed, jump over to it before doing your PvP, then later, jump back into your enhanced clone to make use of the implants and the benefits they provide, without fear of the implant-boosted clone being destroyed. There is also a limit on how often you can jump between clones. This limit begins at 24 hours (one jump every 24 hours due to the stress of having your consciousness transferred), but it can be reduced by training a skill related to consciousness synchronization (called Infomorph Synchronization). **Skill Injectors** There are also skill injectors, which is a device that can extract knowledge from one character with the intent of moving it to another character, or even selling it. The injector is created by extracting skills from one character's mind, and the injector can then be used to inject those skills into a different character's mind. In EVE, you can actually make money by extracting already-trained skills, selling them, and then re-training them and doing the whole thing over again. [Answer] As of how quantum mechanics teaches, it is impossible to exactly copy an object. Moreover, as Thomas Breuer has mathematically proven, from a point of view of any observer, a system properly containing him cannot be simulated by any turing machine even in classical mechnics due to inherently unknown initial conditions, and the result is stronger in quantum mechanics. That said, it is impossible to upload consciousness into a (classical) computer or otherwise copy consciousness. On the other hand, it is possible in principle to teleport a conscious object via quantum communication link. This may be radio waves or a fiber optics cable. In this process the original object would disappear and its exact copy would be re-created at the opposite end. Arguably, it would be exactly **the same** consciousness, because moving along such channel roughly amounts to quantum tunnelling and all quantum properties (such as subjective decoherence) should remain. In short: copying consciousness is impossible. Teleporting (via a quantum link) is possible. [Answer] Assuming souls and that human sacrifices done by people like the aztecs and the norse worked: One of the objectives of human sacrifice was to bind the victim's soul to the place where it was sacrificed. To do so they inflicted a lot of pain and suffering to the victim and as a result, it's soul binds, due to the psych trauma, to the location. Supposedly, that's the same principle governing ghosts (remember, i'm assuming souls, and that assumption brings a very big luggage), improved by the aztecs, norse and others. So, the consciousness, being a function of soul, can be bound to the computer circuitry, if this boatload of assumptions hold. The scientists will have to learn and develop ancient cerimonial magic and combine it with circuitry, merging ritual and machinery, to bind the soul to the computer. Most probably it won't be pleasant to the one being bound but the person will achieve some kind of immortality. Unfortunately, in this method, it's impossible to avoid killing someone, so part of your requirements wouldn't be honored. [Answer] This is a bit late, but an interesting nuance from the Iain M. Banks side of things - in the final two Culture novels, the overall system of "consciousness security" within society was refined and fleshed out further. From the start, every thinking member of the Culture was defined as possessing a "neural lace" - hardware to allow direct synaptic connection to the Culture's entire data-sphere. This was always how "mind states" were transmitted or backed-up. The further explanation was that every neural lace was in fact quantum entangled with the last data storage hub an individual had passed through, and this was always active. In the event of complete physical destruction, the entanglement collapsed, and the "point of view" of an individual snapped back to the data hub. All they lost where storied memories acquired since their last mind state backup. Upon the individual's preference, they could instantly inhabit a virtual environment while waiting on a new physical body to be created. Or be kept unconscious until then. An interesting detail is that the virtual "waiting room" was constructed with specific features that demonstrated it was virtual, rather than being perfectly realistic. This was done to prevent confusion for the recently "deceased". Banks drew a distinction in various books between this kind of true continuation of consciousness, and copies where an original mind had truly died - sometimes, an organic or machine member of the Culture would get into trouble under isolated circumstances, and suffer a legitimate death. [Answer] **Cellular Regeneration** I don't have the rep to add a comment to Second to Last Unicorn's answer so I'll write my own. You get bigger muscles by stressing the cells. If you kill them a muscle stem cell takes the place of the dead one. This replacement happens in the brain also. A new neuron must be retrained. What if the new neuron was silicon based? <http://www.research.ibm.com/articles/brain-chip.shtml> Let's say you spend some time slowly replacing each neuron with silicon and retraining the new silicon neurons. Most of you memories should remain intact because memories are spread over multiple neurons. You'll need to relive all of your memory's on a regular basis to help the training process. Also your neuron's collective voice will not have stopped during this process. Now the hard part. How do you teleport? Simply making a copy doesn't solve the original problem even if you are silicon now. You now have to do the neuron replacement process very fast and at a distance. Disconnect a local neuron and replace it with a distant one and train the new neuron. Repeat this until you are in the distant location. Training won't be 100% but you could do a second pass and fix broken memories. I wouldn't want to do this. What happens if the link breaks? I also wouldn't be convinced that compressing the process would be able to really transfer your "soul" completely or as well as if you had time to adjust to the new neurons. [Answer] **Shapeshifting** I've been working on a shapeshifting character that is currently very close to being able to do this, using shared consciousness. Every cell in the body is more or less functionally complete, and includes a neuron as well as all the other necessary systems. In order to enable shapeshifting into multiple pieces (such as a flock of birds) without becoming disoriented, communication between neurons is by way of radio waves. Thus, the brain is distributed throughout the body (or bodies), negating the need to kill anyone, and the consciousness can be shifted, splintered, and recombined at will, eliminating the "I wish it were me" problem. Of course, though by radio waves introduces other problems, which I'm still working on. [Answer] A Tree Falls in the Forest I would argue that the context of experience is different for the original and the copy, and so neither can argue any longer that they are "the same." In some sense, this is related to the old conundrum "If a tree falls in the forest, does it make a sound?", which is sensible only when we consider whether a "sound" is the physiological response of a listener to audible disturbances in the air. "Identity" evolves in the context of our relationships. Each copy is identical only to the point of interacting with their environment. Thus one can only say "I wish it were me" in the same sense that I can say "I wish that I had married Grace Kelly," or oppositely "I wish that I wasn't a citizen of the Trump presidency." [Answer] ### Souls ...or "philotes" (if you're Card), or whatever you want to call them. It's already unclear if genuine consciousness can be explained solely in terms of biological processes. If you assume (as some authors have already done) that there exists some "external" aspect of consciousness, then it becomes trivial to say that "the soul knows its body". Deconstruct the body in one location and rebuild it elsewhere, and the soul will follow. This doesn't directly help with "digital immortality", but for that, see [Geronimo's answer](https://worldbuilding.stackexchange.com/a/160403/43697). BTW, you might want to check out [Quantum Vibe](https://www.quantumvibe.com), which plays in some of these spaces, though I don't think they really answer your question. > > How can you copy a consciousness, while avoiding the "I wish it were me" problem, and without killing one of the copies? > > > You can't. Your question describes a paradox. If you *have* a copy, you're going to have some degree of "copy resentment". The only way to avoid that is to: * Never have copies. This implies that whenever a consciousness "moves" between bodies, or from a biological body to a digital system, the "old" body necessarily becomes an empty husk. (For bonus points, put it in suspended animation and allow the consciousness to transfer back and forth.) * Ensure that the "essence" of the person is not physically bound to the atoms that make up their body. Considering that the [Ship of Theseus](https://en.wikipedia.org/wiki/Ship_of_Theseus) problem already applies to biological bodies, this ought to be doable. See also the beginning of my answer. [Answer] ## All consciousness is the same The [Atman](https://en.wikipedia.org/wiki/%C4%80tman_(Hinduism)) is the fundamental essence of the person - any person. If you [cut a person's brain in half](https://en.wikipedia.org/wiki/Split-brain), which is him? Both! If it happens during pregnancy and you have identical twins, which is him? If it happens over history, and you have two people, which is him? To quote [some guy](https://en.wikipedia.org/wiki/Apastamba) from the Wikipedia article, from 400 BC, who obviously is a step ahead of most of us here, > > All living creatures are the dwelling of him who lies enveloped in matter, who is immortal, who is spotless. A wise man shall strive after the knowledge of the Atman. It is he [Self] who is the eternal part in all creatures, whose essence is wisdom, who is immortal, unchangeable, pure; he is the universe, he is the highest goal. > > > The original of the teleportation thinks he is not the copy. He also thinks that he is not the guy in the next room. In both cases he's wrong, because the fundamental phenomenon of consciousness is the same. Nonetheless, he thinks and acts more like his copy than the guy in the next room. The easiest way to visualize this is probably by comparison to the idea of [ka and ba in Kemetism](https://en.wikipedia.org/wiki/Ancient_Egyptian_conception_of_the_soul#Ka_(vital_essence)). The *ka* ("breath of life", same meaning as Atman) is the person's fundamental essence; but the sum of his memories and ideas and beliefs is the *ba*, his individuality. If you can copy the *ba* and rejoin it with a *ka*, then you are reenacting the ancient Egyptian goal of creating the *akh*, or in other words, creating an afterlife for the person. To dig further into the nature of the Atman, it is necessary to understand its mode of operation, which is to say, the evolution of the ability of a neural cell to interpret traces of its future state by their impact on the past. Remembering the future creates a 'temporal paradox', revealing that causality actually flows from consciousness itself, as the boundary condition of the universe determined by which choice of cyclic paradoxical state is 'real'. This actual causality extends both forward and backward in time, rather than from some arbitrary combination of particles at a 'Big Bang' that occurred before an infinite number of particle interactions. The Atman, in choosing futures and pasts, both exercises free will and actually feels things. It exists in the dimension of time that stretches between universes, the dimension of time that distinguishes each parallel world from the next, in which their authorship continues to progress. ]

[Question] [ For the purposes of this question, assume that: * reincarnation is a real thing, and is based on a "soul" which, after (and only after) death of one host body, potentially with some delay, is reborn into a different host body1, *and* * reincarnation only takes place within the same species2 (so no cross-species soul migrations), *and* * a single soul can only occupy a single host body at any one time, *and* * the population of this species is increasing over time (if bi-gendered, the average birth rate, including survivability to reproductive age, is strictly greater than 2 per pair) We know from thermodynamics that the energy content of a *closed* system remains constant; it's the old adage "energy cannot be created or destroyed, only transformed". A world, or even a solar system, isn't strictly a closed system, but the added energy (and matter) from extrasolar space is so small that we can probably safely ignore it. (If not, feel free to point this out, but please back it up then.) No matter how it is made up, it stands to reason that each "soul" needs to represent some non-zero, finite amount of energy and/or matter. In such a situation, **how come the world doesn't eventually run out of souls for newborns?** I realize that this probably cannot be answered scientifically, but the more science-y the answer, the better. --- 1 The intent of this is that each soul needs exactly one body, and that each body needs exactly one soul, with only brief periods of detachment allowed. If strictly meeting this criteria isn't possible, then it's allowable to consider that each soul needs exactly one body, but not every body needing exactly one soul. 2 For the purposes of this question, a "species" is a group where the correct number of individuals (for example, in a bi-gendered species, two) of the correct sex (for example, male and female) are able to reproduce with one another, and the offspring itself is also normally fertile. [Answer] # New souls come from wherever they came from in the first place Unless your world has time as a closed loop, then the souls had to be formed in the first place. If you are assuming that life originated on this planet, then there was some time in the distant past when there was no life, and thus no hosts for your souls. Therefore, one of the following three things must be true: 1. The system is not in fact closed, either in space or time (time meaning, souls come back from the future). 2. There is some mechanism for *psychogenesis*, the creation of souls from either some form of energy present on Earth, or from nothing. 3. There are no souls; or, souls cannot be expressed as energy and/or matter. Since 1 and 3 are precluded by your assumptions, there must be some reaction that turns chemical/electromagnetic/thermal/whatever energy into souls. There is also the problem of species extinction, by your criterion. There are a lot of dinosaur souls that no longer have a place to go, since there is no cross-species soul migration. Thus, there must also be some mechanism for souls to return to energy. [Answer] You are looking at the "wrong" closed system. In the entire Universe there are countless inhabited worlds. For a world with growing population, there will be one with decreasing population. The souls will migrate trans-worlds to keep the 1:1 ratio. When an observer, like you did, limit the investigation to just one world, it might look like the ratio is violated. From this it follows that life will follow the same route over and over in all the worlds where it can develop, leading to humans. [Answer] You need to examine your assumption (unstated) that the number of souls is limited to less than some number of bodies. If, for instance, there are a trillion souls out there in the ether, then we are unlikely to outstrip the supply any time soon. Or how about 10 trillion? Why should there be a limit which just happens to correspond to the current (more or less) population? The fact of reincarnation requires only that some souls are better than others at latching on to new-born (or newly-conceived) bodies, as these will preferentially inhabit bodies when there aren't enough to go around. Or perhaps the act of being embodied gives a soul an overwhelming boost in its ability to grab a body (practice makes perfect). [Answer] ## The energy does come from elsewhere. Just because energy is a conserved quantity and souls need some energy, it does not follow that souls are a conserved quantity. If you need some amount of energy differential to create a soul, this sets no limitation as to where this energy is coming from. You can have your soul-attribution system work such that * unoccupied souls are recycled first * when no soul is available at the moment, a new one is crafted from a tiny bit of sunlight or whatever energy source the great soulmaster has at their disposal Of course, you do run out at some point, but that only happens when there is no source of energy available in the whole universe, which bears the sweet name of [Heat death of the universe](https://en.wikipedia.org/wiki/Heat_death_of_the_universe). At that point your species has likely gone extinct from something else anyway. [Answer] Your conditions are very specific ... > > The intent of this is that each soul needs exactly one body, and that > each body needs exactly one soul, with only brief periods of > detachment allowed. If strictly meeting this criteria isn't possible, > then it's allowable to consider that each soul needs exactly one body, > but not every body needing exactly one soul. > > > If it is true that each soul needs exactly one body, and each body needs exactly one soul then clearly the population has always been at its current level (give or take those in temporary transit) and always will be. Logic and mathematics dictate this and there is no escape from it. If each soul needs exactly one body but not every body needs exactly one soul then the number of bodies with souls has been and always will be constant. Therefore any excess population will consist of soulless zombies. **Note** My answers above assume that souls are immortal and all souls are indivisible. If souls are mortal after inhabiting a certain number of bodies, and are not replaced by new souls, then over time, the population will all become zombies. If souls can be split into smaller souls then as the population increases each person's soul will be smaller. Perhaps this will lead to a more secular society. When population decreases, small souls may be able to coalesce into larger ones and so a smaller population would become more spiritual. [Answer] The soul is the [software of the brain](https://www.nyu.edu/gsas/dept/philo/faculty/block/papers/msb.html), as such it is constantly changing. Now we tend to think of ourselves as having an identity that doesn't change over time, we can reconcile this with the reality of the constantly changing software that the brain is running, by attributing the changes in the software to information that we've acquired over the course of time. But this picture is only approximately valid as information can also be erased, it doesn't fully capture all relevant brain processes. While the number of souls is not conserved, there is then a maximum number of souls. This follows from the fact that the total amount of information that can be present in the visible universe has an upper bound. The set of all possible programs that can be run in the universe is thus finite. [Answer] There are far more souls than there are bodies AND there is net "soul immigration" to Earth. The question should be, what does a soul, who has recently died and wants a new body, do about the shortage of bodies? Also, a soul can split and become two souls -- but neither one is diminished or in any way less than the original. One reason why so many people are dead set against abortion, contraception, and any form of nonreproductive sex (gay sex, etc.) is that they're afraid of a shortage of bodies for the next lifetime and want to encourage "more babies for everyone whether they want them or not". (I myself am not encouraging this.) While the usual ratio is one soul to one body, you can have one soul to many bodies (a colony, like an ant colony) or many souls to one body (a cluster). The ancient Buddhists define Samsara as the "endless cycle of birth and death", where one is so attached to the physical universe that one MUST begin a new lifetime somewhere. I'm not sure what happens when one must (Samsara) and one can't (shortage of bodies). Perhaps the "losers" have to downgrade from human to animal bodies, or worse, become a soul in charge of someone's body part (like the left leg). Escaping Samsara is an ancient but elusive goal. I suppose a compromise would be to let yourself be reborn, but reborn in a body/family of your liking. We all have the ability to specify what we want for our next body, just some have it more than others (and no, whether you've been good or bad is NOT a factor). While I'm at it, what do you call a soul who wants to be one gender but (accidentally) picks up a body of the other gender? (Oh, this is SO easy.) It's a shame this thread is on Worldbuilding, a fiction thread, because I consider reincarnation to be a literal fact. But there is really no other place on SE for this. Do I have references to back up these statements? I don't see how that would be possible for this subject, as the best I could do is to back up my opinion with references that are themselves opinions. But it is all nonetheless true. [Answer] **The delay between reincarnations gets shorter as the population grows.** This breaks your "short detachment" criteria, but otherwise meets all other requirements. So long as your total number of available souls is greater than the population, then you can simply have shorter and shorter delays between reincarnations. This avoids souls having to "fight" for bodies as well; it's a simple first-in-first-out system. [Answer] One of my favorite short stories of all time addressed this issue. Like you, the author assumed that souls were human and not transferable with animals. I'm afraid I don't know the author or title of the story anymore, though it's somewhere in a stack of magazines I kept. It's from *Fantasy and Science Fiction* and was probably published in 1979-1980. In the story, there were a finite number of souls available but humanity didn't hit the limit until the world's population went over a certain amount (a number that was not reached at the time the story was written...not sure about now). So people shared souls (this was not something under anyone's control, it just happened). If you did not have a soul to use at any given time, you were in a coma. If you assume souls are real and tangible in some way and reincarnated, you basically have 3 ways to go: 1) You run out of souls at some point (and maybe the number available is so high we'll never exceed it). 2) Souls are not subject to the usual mass/energy constraints. 3) Souls can transfer between humans and nonhumans. I know you don't want to go this route but do consider that pretty much every religion that believes in reincarnation allows for at least some human/nonhuman soul transfer. [Answer] I'd say souls are free from the time dimension meaning that it doesn't make sense to place a limit to the number of souls you can have at a given time. For example when a person dies maybe his soul reincarnates on a newborn 2000 years from now. Not meaning that they are dormant for 2000 years but that they simply skip the time in between. Another option is that "the reality of souls" is universal and therefore there are not only animal souls but also alien's souls, but the total population of souls in the universe always remains the same through some quantum effect. If some alien is born and there are no souls left maybe that would make an old human on the blink of death die. [Answer] ## The Universe is Infinite With probability 1, if the universe is infinite, then the population of your species is infinity. Aleph null, to be specific. Why is this? That's because there's a small chance on every planet of that species developing. *Really small*, since it has to have the correct DNA. But, its not 0. So, the expected number of worlds will have that species is aleph null. Then, our problem is the same as [Hilbert's hotel](https://en.wikipedia.org/wiki/Hilbert%27s_paradox_of_the_Grand_Hotel). Even if the population on every planet is increasing, you can "shuffle around" souls so that you have a 1-1 correspondence between bodies and souls. [Answer] **The world *does* run out of souls.** This is one idea. Maybe contrary to expectations, the world actually *can* run out of souls: Say, as the world population reaches a certain level, the global birth rate starts rapidly declining, because of the decreasing availability of free souls. The manga *Spirit Circle* explores this idea somewhat, in the Lafalle arc. The setting does violate rule 3 of your conditions, though—it's established in-universe that some of the protagonist's previous lives have overlapped in time. However, if you ignore that, it still explores some interesting aspects of the idea of a limited number of souls: > > In this arc, it is the 34th century, and science has developed to the point where "Sleeping Towers" can host the brains of people who have lost their bodies due to accidents or illness, keeping them alive in a state of dreaming. The people kept in these "Sleeping Towers" are known as the "non-living". > > > > > However, the human population has been shrinking: There are 10 billion "non-living", but only 500 million living people. > > > > > The protagonist realizes later on that the population is shrinking because of the souls that are trapped in the Sleeping Towers: People aren't dying, and thus aren't being reborn. > > > [Answer] **Post-clarification of intent:** I would suggest that souls lead two lives at each turning of the wheel, a life within the body, and a separate, but similar, life outside the body. This life outside the world we physical beings live in includes equivalents of all the activities we take for granted, including the creation of children, in the form of new souls. As to the energy balance of the system as a whole, there are two worlds each of which absorbs and traps, for a time, energy from the sun or it's equivalent. In the material world that energy is used for fuel by humanity in the soul world it goes into making new souls. **Pre-clarification of intent:** You haven't stated that a body *needs* a soul, only that a soul needs a body, this then is an answer if not a particularly palatable one. The world *has* run out of souls, some time ago in fact, that's why, on average, people are consistently less emotionally stable and less harmonious at each generation, more and more of the population are born without a soul at each generation. [Answer] **There is only one soul in the universe.** Every being is a unique refraction of it just as every snowflake uniquely refracts sunlight. [Answer] ## Chicken Soup for the Pool of Souls A possible soulution for your problem is that the human body(the vessel itself) does contribute to the pool of available souls. Upon death, the body's decay contributes not just nutrition to the soil in the usual physical cycle of life, it also contributes soul-stuff to the realm where reincarnation plucks its subjects from. This can be a byproduct of a "used vessel" being imprinted from once having a soul residing in it. However, since your setting respects the laws of thermodynamics, what this creates is a system where the human body consumes energy in the form of food and other resources to produce souls upon death, wherein reincarnation will then put souls back in bodies, and so on. An ever increasing population of both human bodies and souls will consume an ever increasing amount of resources, creating an overpopulation problem just like real life. Without an infinite amount of resources(potential energy) to use, this system is not infinitely sustainable and will eventually fail. When your world becomes unable to support the amount of humans in it, it'll have no choice but to be declared insoulvent. The resulting crash will most likely result in the collapse of the ecosphere and death for huge swathes of the population through starvation. This could plausibly be the extinction of the human race as we know it if you want to go that way. [Answer] *Maybe I just did not understand that there is need for individual souls from your question, if it was meant this way, I am sorry.* --- Do souls stay the same, do they mix, or even re-form? Is the composition static, meaning that if a soul is reincarnated it existed before (e.g. my Soul is Napoleon), or do I have maybe just the soul-equivalent of Napoleon's nose but some other guys soul-ears? In the **static** condition: You have a number of n souls, therefore population cannot be > n. If we say that souls consist of some kind of matter and this matter can **mix** in between reincarnation: You have an amount of n units of soul matter, therefore population cannot be > n/amount of matter needed per soul. But this gives you another possibility, saying that souls don't have to be necessarily of the same quality (or size). Would lead to that in a more populated world the occurrence of "big" souls descends. I would probably prefer a more "scientific" approach, you could say that the matter is made of some physical resource, so if a body dies, the soul decays like the flesh, only to be re-formed in some later stage, giving you your closed cycle. Although this defies the whole use of souls in some way, it gives you the chance to keep your world in balance. Soul matter = water means the more humans needing a soul the less water on the planet. [Answer] You can take inspiration from the [Lifestream](http://finalfantasy.wikia.com/wiki/Lifestream) concept from the video game Final Fantasy VII. In a nutshell, there is a finite amount of "soul-energy" contained in the planet. When a living being is born some of this energy infuses into its body, thus giving it life. When this being dies, the energy exits its body and returns to the planet's pool of energy, and somehow blends with it. This can have some interesting ramifications: while there may be cap on the total number of beings on the planet, there is not a fixed number of individuals for a given species. Also, you can play with the concept of some species using more of this energy than others, so you could have plenty of "low level" beings such as plants or bacteria, or fewer "high level" intelligent species that hoard on this energy, therefore preventing other parts of the planet's ecosystem from developing (this is reminiscent of the video game's plot). I think this does not contradict your assumptions but requires that the souls only have an identity as independent beings when they are inside a body. [Answer] Ashen one, be sure to bring more souls. I would invite you to take a look at the dark souls series where there really is only one human soul. It gets more and more fragmented as time passes on. Most humans become more and more hollow as the humanity is drained from them, destined to live a life of despair until they die (or not, if they are cursed). Some are more powerful and amass vast amounts of souls, further fueling their might. They are bound to become great and to fulfill the proficy of rekindling the first flame. You could reformat that so that each person gets less and less of a soul, until most of them are basically just existing, doing the same job, the same routine for years on end without any real desire or goals, only making marginal progress. Some however resist this and can hold on to their humanity or even increase it. These would naturally be your protagonists and antagonists. This could be done through sheer willpower, fate or something else. Maybe you can even actively take it away from someone else? [Answer] Couple of possibilities ## We're still some distance away from that problem There are 16 gigasouls: 2^34. Always were. In the early days, when they died, they slept thousands of years before coming back around. Now they're sleeping for decades. **Souls need sleep**. The less sleep they get, the greater the odds of the planet experiencing a [Malthusian die-off](https://en.m.wikipedia.org/wiki/Malthusian_catastrophe) of one kind or another. The dice came up badly for the Black Death, [World War II](https://vimeo.com/128373915) and since then we've partly gotten happy dice, and partly human will has influenced the dice. As the number of living souls approaches 16GiS, the chance of a Malthusian event approaches 100%. ## This is simply animals, graduating Some religious doctrine believes that souls move up and down from differnt stages of animal (amoeba, ant, shark, snake, mouse, dog, dolphin) to human. Souls are getting their act together. The graduating classes are getting very crowded. This is all a good thing, this is the evolution of souls. More of them are graduating to humans, so there are more humans. All the logical reasons (technology, food efficiency etc.) are just the manifestation. If there were 500 billion souls graduated to human, this planet would look like Coruscant *and somehow that would all just work*. And there will be convenient explanations for why it works, such as there was with the [Green Revolution](https://en.m.wikipedia.org/wiki/Green_Revolution). [Answer] The energy required is miniscule and it's mainly a force outside the known ones that regulates it. So the ambient energy around a person is many times more than need to sustain the soul. The act of birth triggers the creation of a new one. At death it dissipates back to potential until another birth nearby makes it coalesce. So it would never be exactly the same soul. Sometimes there is an issue and you get Jack The Ripper, other times there is an issue and you get Mother Theresa. Either way each individual soul will be unique. Eventually there would not be enough energy, but first all the suns would have to die and the universe implode. [Answer] **Interminable Dimensional Souls** Assume the closed loop is Earth, but dimensionally-speaking all humans who ever have, do, or will live do so in a non-closed time circuit. Assume also that souls are not confined to our particular dimensionality. Under these premises, there is, has been, and always will be precisely the number of souls required for all of humanity. The souls themselves become a closed system. This also allows for alternate realities in which the population is not booming, or has never boomed, and in which the population of humans on Earth in 2018 is 20 billion or 5 million. It's probably sloppy from a story perspective, though it could be made interesting if handled properly. **Soul reaping** Souls are a resource beyond our comprehension (true), which are harvested and reaped as supply and demand fluctuate. This might also assume that souls have some sort of shelf life - a limited number of reincarnations available or a limited amount of universal time in which they "live", but that new souls are formed/grown/developed from the aether in some manner or another. **Notes on Logic or "Science"** You did ask for as scientific an explanation as possible, which of course is still going to be derivative of logic since there is no science that covers souls. Considering that, the initial question is - where did souls originate? What is their genesis? Did souls exist before life or did life exist before souls - or... did they come into being simultaneously? If souls existed before life, it violates your requirement that every soul needs a body. However, it could point to souls being something even further beyond the scope of our understanding than they already are. If life existed before souls, it violates your requirement that every body needs a soul, however it would point to souls actually being a byproduct of life. If they developed simultaneously, it could lend itself to the idea that souls are, in fact, tied directly to life, which leads to the next possible option: **Soul Mitosis** At least for most offspring, where two parents are needed, each parental soul splits a portion of itself to lend to the creation of a new soul for the new life. This doesn't fit directly into the scope of reincarnation, but hear me out. Just as life doesn't always succeed (some eggs, fetuses, etc are not viable), some souls don't always succeed. When a soul is not viable, an existing soul finds that host and reincarnation of the soul occurs. This accounts for the number of souls needed, as well as accounting for why some folk seem to remember/feel past lives - are "old souls" and some do not find themselves in this position. This would require that reincarnation is not an assured phenomenon, but one that can occur. From a logic perspective, this one makes the most sense to me. It seems to cover all of the bases except that a soul requires a body - but if we accept concepts like ghosts and spirits or the like, it leads one to believe that there may, in fact, be souls without bodies, or that souls have somewhere to go while they wait (could be heaven/hell, or Valhalla, or... who knows. Literally could be anything). **Soullessness** Of course, it could be that we have entirely run out of souls. It would explain a lot with regard to the modern world in which we live, if we assume that souls are the source on conscience/goodness (though that's a stretch since, at least via Abrahamic religions, "bad" souls go to hell). It could be that some other energy fills that void, and thus bodies don't need souls, per se, but an energy that sustains life. A TV needs to be plugged into a wall, but if you give it enough batteries, it WILL power up for a while (if DC is properly converted and such). Actually, that leads to: **Energy Transformation** Energy is energy, and different types can become or be used as different types. Kinetic energy can become heat (friction), light energy can become electricity (solar conversion), et cetera. Who is to say that something else can't become, or take the place of, soul energy? One interesting way to look at this, and while not scientific in any way isn't entirely implausible logically given that we don't know what souls are (or if they even exist), is that psychic energies can condense into souls. Christmas babies are incredibly kind because they are born during a time when the world is at peak-kindness. War babies are fearful or decisive or quick to anger. This takes an almost astrological view applied to souls and the states of humanity, and sounds somewhat like ancient East Asian philosophies on life. New souls are created from the detritus of vast human emotion. [Answer] As per Hindu mythology , there are 84 lakh (8.4 million) distinct species of which humans are one of its kind. So in this religion the holy books preach that human are the most supreme species of all and any creature born as human may attract soul from any source of species that have lived off in past. What happens post death? As per the mythology the soul is the supreme driver of the life , once the life ends the body is burnt to ashes while the soul spirit escapes to the infinite universe and unless it becomes completely purified (free from any sins , greeds and motive of the last birth) it's then set free to enter in to a new borne species. So the soul is independent of whether the person is human or any animal. So for this theory , we can assume that since many species are getting extinct their soul's might be getting transferred into humans. [Answer] A newborn body calls to Souls, but if no soul is available then a new one may grow from embedded fragments of the parent souls that spawned it. The real question is what happens when there's a mass die-off of the species and there are too many souls! [Answer] There is plenty of souls - trillions, quatrillions, quintillions perhaps. There is no way that the incarnated population ever needs all souls at a time; it would destroy the planet's ecosystem. [Answer] ## Time traveler souls I propose the following: Souls are time travelers. A soul can reincarnate in a body that is born in the past respect to the moment of death of the previous body. That is, when a person dies, its soul could go to a new born in the past. Thus – assuming souls have identity – there could be two bodies in the same time period that are being occupied by the same soul, except one of them is an early version, and one of them is a later version. Furthermore, there could be only one soul per species, and without any need of soul fragmentation. Oh, and before you consider it... No, sex is not part of souls… some species can change sex midlife. --- **Physics** *This is a possible framework for what I suggest above* You say souls have energy. However, it appears souls do not have mass. If this is true, free souls (souls not attached to a body), would move at the speed of massless objects (the speed of light). If this is true, in the frame of reference of the souls time does not pass, that is, all instants are the same for the free soul. This also means that souls do not need bodies, nor do they experience the time outside a body. I also want to bring a philosophical interpretation of Feynman diagrams… these diagram represent particle interactions, with one of the axis of the diagram being time. However, these diagrams remain valid when rotated, except that when you rotate them half turn, what used to be electron is now a positron (and vice-versa). Under this interpretation, a positron is an electron traveling backwards in time from your frame of reference (and vice-versa). Going further, there could be only one electron/positron that travels back and forth in time, and as a result all electrons/positron are the same. **Note**: electrons are indistinguishable from one another, same for positrons… and any fundamental particle actually. Then why electrons – and other particles – have the particular properties they have? Well, because there is only actually one of each, and this is how they were created. I am suggesting that souls behave similar to that, traveling back and forth in time. Why a soul is of a particular species? Because that is how they were created (or how they always have been, if your cosmology has no creation), along with the universe. --- *Conservation of energy and time travel* Evidently the soul won’t be like the electron (electrons have mass and have a distinct antiparticle), but like photons (that have no mass and are their own antiparticle). Thus, a soul is a soul going backwards or going forward in time, it makes no difference for the soul. Yet, photons have energy, if they go back in time, won’t that mean that a moment in the past would have more energy than one in the future? Well, these particle that go back in time are virtual particles. They are only one of the infinite paths that particles take in an interaction. Under Copenhagen interpretation, particles go into a superposition of all the paths, including those that go back in time… and these can break conservation of energy. However, when the particle interacts with another, it collapses in such way that the interaction respects conservation of energy. Souls would be like that. When free from a body, they go into a superposition that can break conservation of energy and time travel. However, to enter a body, there would be an interaction with it, such that conservation of energy is preserved. Thus, if the soul adds energy to the body, some energy must be lost. In fact, under the assumption that the body-soul link is in stable equilibrium, it must be a low energy state, thus it makes sense that energy is released… Yet, it cannot be released to the environment, at least not at the time of linking (that would still result in more total energy in the universe), instead, it must be released to the time from where soul comes from. Well, the soul comes from the body of the prior incarnation is dying. Thus, in time A: some energy is lost because the soul leaves, the dead body. Then the soul goes to another time B. In time B: the soul links to the new body adding energy. In consequence equivalent energy leave the body and is send to time A. Then in time A: that energy is released. Consequences: conservation of energy is preserved, and the energy release when the soul leaves the body could be detectable. In what form is that energy released? Use your artistic license. Addendum: Scientis could think that *that* is the soul, it isn't. Perhaps this is an excuse for ghosts if you want them in your setting. --- **Biology** *These are some ideas on the biology of species tied souls* Perhaps souls species needs some wiggle room. As we know individuals of the same species differ biologically. Yet, they would all be viable vessels for the same soul. If scientists create new variants of a given species, souls could still populate these bodies. However, perhaps a body is that has mutated too much could not host a soul. If scientist create a new species – out of genetics and bio-engineering – these might or might not host souls depending on whatever or not they are a close match for existing species. --- Why would a body need a soul? If we need excuses for souls as postulated here, I would say that souls shape the growth of the body. In that way there is rational link between the species of the soul and the species of the body. This would also suggest that if the attachment of the soul to the body is not ideal, the body may have uncontrolled growth, I mean, cancer. From another point of view, if the DNA of parts of the body is damaged in such way that it does not match the species of the soul, the attachment of the soul to the body would be severed, preventing it from shaping its growth, leading to cancer. An interesting consequence of this idea (if you choose to allow it in your setting) is that if you could, by means of science or magic (again, if you allow it in your setting), force a soul into a body, that body would start to resemble the species of that soul. This also opens a backdoor for chimera creatures, lycanthropes and such. --- About the moment the soul enters the body… I would say that it happens at some point between the conception and the first cell division. This also imply that eggs do not necessarily have souls by themselves. --- Ah, and I would remind you that there are some virtually immortal cancerous human cells that are used for research (HeLa). Under my proposal, her soul is not trapped there. [Answer] Possibly souls are immortal but not eternal. Souls are immortal once created but the god or gods in charge of reincarnation can create new souls for human bodies at any time they may be needed. So human population growth can result in an increase in the number of souls while human population decrease doesn't result in a decrease in the number of souls, merely a decrease in the g frequency of incarnations for an average soul. It is also possible that the number of souls is so vast that an average soul might wait for hundreds, thousands, or even millions of years between incarnations, so human population growth would only result in a minor increase in the frequency of incarnation for a soul. [Answer] There's a short-story floating around which posits that **every** person (and thus every **soul**) is actually simultaneously the same entity, being reborn over and over again until they learn the meaning of everything and 'ascend to godhood'. Time is a fiddly thing when you're dealing with meta-physics. *Note: If someone can locate the story, feel free to edit in a reference to it. I think I saw it as a meme traveling around Facebook, but that's the best I can do at the moment.* [Answer] During times when population is small, maybe there is a big buffer of souls. Like a queue. You have to wait for your turn to re-spawn. Time to wait in queue becomes shorter during periods when many babies are made. [Answer] # Souls are the product of informational output of species. They are both born and reincarnated It is not always the case that an existing soul is being re-issued to a new body. Sometimes (and quite often lately) a soul is being born rather than re-born. Quite possibly creature's soul is formed upon its birth (or even mirrors the process of embryo development since the very conception). It is created using some form of matter/energy from a soul-pool. Now all the species have their own soul-pool and a pool is a product of the combined information output of the relevant species. It is formed by their thoughts, hopes and aspirations, thus reflecting the philosophical progress made and being affected by it. All formerly living souls return to such a pool after the death of the body they have been attached to and are revitalised and invigorated with new forces that have gotten into the pool since their last visit. Upon their return to the world of the living, such souls will turn into wiser but perhaps more conservative entities while the new born souls will have a lot to learn and frequently be infantile and/or incapable.. however, the most progressive entities will likely be the bearers of a newborn soul. [Answer] [«There is only **one** soul in the universe»](https://worldbuilding.stackexchange.com/a/129955). The question's second assumption (reincarnation only takes places within the same species) is not held. After all this single soul needs to be reincarnated for all species in the universe. But let me pass over it. It will be transcended anyway. So how can this one solitary soul reincarnate into all beings in the universe? **The soul is not bound to time**. This one solitary soul just lives the lives of all beings in the universe. There is no meaningful sequence of lives because sequences are artifacts of time. The soul is outside of time. I came to understand it is God. God is in us all. ]

[Question] [ I world-build for tabletop RPGs so I have Tolkien/DnD/Forgotten Realms like elves in mind. The assumptions are: * The ratio of humans to elves in the world has been more or less constant. * Humans live ~50 years and have 5-7 children per woman. * Elves reach sexual maturity at 80-100 years of age and live for 600-800 years. * Elves do not suffer infirmity until the very end of their lifespan. * Elven reproduction is human-like. Human-Elven hybrids are possible, even somewhat common (~5% of the population in some areas). So, how poor does elven fertility need to be to keep the human/elf ratio near constant? Additionally, what is an internally consistent "mechanism" to describe this in-world? Are elven women fertile one day a year? How to explain human-elf couple having at least 2-3 children over their time together? Do half-elves necessarily almost always have a human mother to make this consistent? **EDIT**: Assume child mortality rates slightly lower than late medieval period for humans (magical healing is easily accessible in large cities but not in the frontier or countryside). *For elves, child mortality rate may be part of the answer.* My gut reaction is that elves tend to have easier access to magic in most settings so their child mortality rate should not be higher than humans if at all possible. **EDIT-2:** Here is what I learned from the many great answers below: * My assumption of 6 children in 50 years for humans is at best incomplete information, at worst inconsistent with the world I had in mind. I now assume 1% annual growth rate for humans. * Now, assuming elven reproductive period between ages 100-600, only 800 year old elves dying from old age that year, and 0.1% yearly mortality for all elves younger than 800; average elven woman needs to have 20 children over 500 years. * So, while elven fertility *per woman per year* is poor, fertility per woman is unintuitively high! The average elf has 10 maternal siblings and will have 10 more during her lifetime. *Does this mean small elven communities are highly inbred?* * The second part of the question about how to explain these numbers in-world while staying true to Tolkien/DnD elves is still open. Here are the ideas I like: + Magical birth control. + 1 elven child at a time (credit: Agent\_L) per elven couple. Elven women do not ovulate unless they are in a committed relationship and not already bonded with a child. This will give at most 5 children per elven woman. Perhaps, I just need to increase human mortality rate to keep them in check :( [Answer] Elven social norms allow for 1 kid **at a time**. > > Elves reach sexual maturity at 80-100 years of age and live for 600-800 years. > > > That means when an Elven pair enters reproduction age at 80-100 and cares about their child **until** it's grown up, during 800 years they can raise at most 7-9 kids, comparable with your 5-7 for humans. Upsides: * self balancing, loss of a child means the next one is borne soon. * can be explained with simple hormonal bonding trick (helps saving those eggs as well) * interesting social repercussions: a marriage has very strongly defined turning points. eg it can last for one child only and then gets automatically dissolved. Helps keeping the 800 years boredom at bay ; ) Downsides: * human-elf interbreeding gets VERY complicated. Male elf with human wife, can breed at human rate. Male human with elven wife is pretty much a reproductive failure (he won't live long enough to breed second time). Can be turned into advantage, a halfbreed with elven mother could be extremely rare one (and eg the only one fertile). Caveat: to have more or less stable population, you need effective breeding rate at about 2 kids per pair/female of both species. From that 5-7 human children, only 2 will make it on average. If you really want elves to have low children mortality rate, you're looking at having 2-3 kids per entire 800 years of life. The only way I can defend my first proposition is for Elves to have some age-of-coming ritual which 3 out of 4 adolescent Elves don't survive (think "Trial of the Grasses"-like). However, I don't like your math at all: > > Humans live ~50 years and have 5-7 children per woman > > > But humans pretty much don't breed past 35-40, last 20-30% of life is effectively infertile. Let's look at humans: 15 sexual maturity, 40 menopause, 50 death (average). That means that childhood is at 30%, menopause onset at 80%. With 600-800 lifespan, an Elf should reach sexual maturity at 180-240 (15 in human years) and start losing fertility at 480-640. This means only 300-400 breeding years. Now, if Elves are more intelligent and magical creatures than humans, I would only expect them to have proportionally longer childhood, making a 300 years old still a teenager. And that can be easily solved with economy: make raising Elven kids expensive (that's at least 200 years of Elven schools of magic tuition, the horror!). When you're going to care about your kids for almost entirety of your adulthood, you won't be able to afford to support more than 2-3. And regular mortality will take care of the tiny excess, like it always does. [Answer] The different causes of death are the biggest issue here. * Humans will lose a lot of children to disease, elves don't seem to suffer from this * Humans lose fertility early then die fairly young, again not a problem for elves Most of the death rate for elves appears to be wars, in a time of war they'd need a birthrate approximating that of humans just to maintain a viable population around 100 years later. However you're effectively looking at an advanced society in a primitive world. Humans have a lot of children to try to ensure that at least two survive to adulthood to reproduce and continue the species. Elves can be reasonably sure that all their children will survive to adulthood and hence, as in among wealthy westerners, their birth rate will inevitably fall. In spite of, or rather because of, their long lives, when their society was primitive and they were losing children to disease and injury they would have needed to have *more* children due to the greater age they need to survive to to reproduce. Humans need to survive a couple of decades, elves perhaps a century or more. There's no need to impose any fertility restrictions, just let society take its natural course. The birth rate drops because there's no need to have more children. [Answer] Human women are only fertile 1-2 days a *month*, so it isn't unreasonable to think that a very long lived elf would have a suitably delayed fertility cycle. Women are born with all the eggs they will ever have. The ovaries have finite space and an egg has a minimum size, but that still supports a million or so eggs at birth. But that number is culled significantly by puberty to a few hundred thousand, and during ovulation many eggs will involute instead of be released, so in the end a woman will only release a few hundred eggs to support their 12x40=480 ovulations in a lifetime. Some women don't ovulate every month, or have several ovulations, or undergo menopause earlier than others. If elven women go through a similar process, then it would be reasonable to limit their maximum number of ovulations to be similar to a human and just space them out proportionate to how long you want them to be fertile. There are problems with prolonged fertility however. The longer you live, the more teratogens, mutagens, and carcinogens you are exposed to. Eggs hanging out for several hundred years could be substantially degraded, altered, or even infected. So a 750 year old elf, even if she is physically healthy, could be carrying eggs that are of poor quality after decades of exposure to teratogenic compounds, toxic metals, etc. Of course the same robust genetic repair mechanisms/magic that keep her healthy could keep the eggs healthy. For humans, infertility is defined by not conceiving after a year of trying. Assuming sperm is present when the woman ovulates, fertilization occurs about 30% of the time, but this assumes perfect timing, which is difficult. A more reasonable estimate would be around 10% a month. A fertilized egg survives to become a live birth around 50-70% of the time. Of course these are often first trimester losses, so a woman can continue to ovulate and become pregnant for the rest of the year. The long and short of it is that healthy woman can expect to become pregnant every year if actively trying to become pregnant. Most of this will apply to the elven female. So simply elongating their menstruation cycle proportionate to their fertility span ought to keep the birth rates comparable. But this ignores willful contraception, which will drastically decrease the birth rate. Studies show that the lower the infant/child mortality rate, the lower the birth rate, so that needs to be taken into account as well. If elven babies die at the same rate as human babies then one would expect elven women to be as aggressive in having children as human women. But if elven infant mortality is low, similar to modern industrialized humans, then elven women, regardless of their natural fertility, could simply limit copulation during their fertile periods (there are many biological signals for ovulation) such that they have a replacement level birth rate, which is at least 2 for traditionally monogamous paired species (of course accidents, disease, and war will mean this has to be higher, so adjust it for whatever early death rate your society has). So their biological fertility is socially controlled (much like modern humans with access to birth control) and you don't need to have elaborate biological mechanisms for controlling the elven birth rate. [Answer] One thing not being taken into account is a difference in social norms. What age is considered 'their majority' or 'adulthood'? What age is common for Elves to marry? Are they more for monogamous relationships, or is there more emphasis on freedom considering their 'till death do we part' would mean living with the same flawed person for centuries? Some examples to show what I mean. In biblical times, you became 'a man' at thirteen. You were then expected to work, to marry, to start a family of your own. This in a time when life expectancy was... 30? 40? In 'modern times' marrying at the age of 30 is 'normal', leaving roughly ten years to have one or two kids. With life expectancy at 80, more or less. In both of the above-mentioned eras, infidelity in a monogamous relationship is (at best) frowned upon. Granted, there's more social pressure on the woman than the man to stay faithful, and equally granted that there are those (in increasing numbers) that do not see 'sleeping around' as infidelity. But the general rule still applies, if you are going to be unfaithful, it's usually done in a sneaky way. What could this mean? Well, either Elves choose life-partners, and stay faithful to that partner... well, for life. (Done quite well in [Dark Lycan](http://christinefeehan.com/dark_lycan/index.php)) Or they could choose a partner for 'mating season', which might be more common for the more druidic types of Elven. They might even have an elder select a number of couples for mating season, to offset how many have died since the last such event. This might even differ per Elven race, tribe, or region. After all, we humans aren't socially consistent throughout every country, race, or even religion. Why not offer your Elves the same respect? [Answer] Whatever you want it to be, it really doesn't matter. Look up trends on number of babies per couple over time, and by country. In an educated society with good healthcare (magical), equal treatment of women, and a respect for the envionment, the limiting factors on the Elvish population will not be fertility or early death. It will simply be the number of children that each couple wants to have, which is likely to be somewhere between 2-3. Elves may be able to have children at 80-100, but they will put that off as they are still studying - their legendary magic, swordfighting and art all arise from them having longer to practice than any others. With both parents having careers, and the children being expected to attend school instead of working in the fields, looking after any more than 2-3 children at a time would be difficult. By the time those 2 kids have moved out (well after sexual maturity), the parents are likely 350. They don't then want to have another 2-3 kids, who would live with them at least until the parents are 500. If you're dying at 600-800, you certainly want to be retired by 500. There's plenty of resources on the matter, here's one to get you started. <http://blogs.worldbank.org/health/female-education-and-childbearing-closer-look-data> [Answer] I made some mathematics and the results are unintuitive. I am assuming here the following: * The living years are a mean, taking into account mortality due to facts beyond old age. * The 5-7 children per woman are a mean, and are how many children will a woman have at the end of her life. Taking that into account, the Ratio of increase of Human population every year will be 1.08 (every year you multiply the population by 1.08). That goes as follows: Every 50 years, a couple will die leaving 6 children behind, that means that every year the number of Humans is increased by (6-2)/50 = 0.08 Now, if you want to keep the ratio between Humans and Elves equal, they population must increase equally fast. Doing the inverse calculations, we have that: (child-2) / years / 2 = 0.04; (child-2) / 700 = 0.04; child = 29. Exactly: An elven woman will have 29 children in her lifetime. That is, if they achieve maturity at 90 years, one child every 20 years by mean (assuming she's having children while able). Edit: Have to divide the ratio by 2, since there's need to people to have a son. [Answer] If we assume magic doesn't help, then most children do not make it to adulthood. During the "high medieval clearances" of the wilderness, England over 250-odd years went from 1.5 million to 4.5 million or so. This rate of growth is 0.4% per year. With an average generation length of 20 years, each girl child that survives until adulthood has to have 1.004^20 = 1.08 girl children on average to maintain this growth rate. This is roughly 2.16 children that "survive until adulthood" to in turn have children. If they have an average of 6 children, that generates a rough childhood mortality rate of 64%. For elves, I'll assume they don't die of old age and remain fertile. They have a uniform 0.5%/year mortality rate (slightly higher than we have from accidents in the modern age), and have X children every 100 years relatively uniformly over their lives. 40% of elves die every century (60% live). To maintain replacement, each female elf has to produce .4 female elf children every century, or 0.8 elf children of either gender (assuming balance). A 1.004 annual growth rate like humans corresponds to a 1.5 growth rate per century, upping the number of elf children to roughly 1.2 per century. Adding an extended childhood period doesn't change these numbers all that much. Adding a "menopause" (cultural or not) that causes elves to stop having children could change these numbers significantly; you could roughly emulate it as an increase in mortality. Warfare will be extremely hazardous for elves under such a model, unless they can produce a large bump in their birthrate, or avoid female casualties and accept significant serial or parallel polyandry. A completely alternate approach would be to make elven biology extremely different than humans. For example, elves as a kind of plant spirit; the plant spawns an elf body, which explores the world and returns to its source tree when tired. That permits "elves" that live for millenia (which are new spawns of the same ancient plant), the "elves" death not being as important as it might otherwise be for an immortal being (as it is just an expensive discardable body; you lose some experiences, not all), and explains why elves live in forests and care a whole bunch about them (the elves **are** the forest). The question of growth rate now becomes limited by the territory the elves can plant new elves in. Elves become R-type reproducers. [Answer] If you want "The ratio of humans to elves in the world has been more or less constant", than the elven and human mean rate of population growth have to be more or less equal. Let me be more formal. Take $e\_t$ and $h\_t$ as the even and human populations in a given year. The next year the populations are $$e\_{t+1} = (1 + \alpha\_e - \beta\_e)e\_t$$ $$h\_{t+1} = (1 + \alpha\_h - \beta\_h)h\_t$$ where the $\alpha$'s and $\beta$'s are associated to natality and mortality in each population. If you want (more or less) constant ratios you need $$\frac{e\_{t+1}}{h\_{t+1}}\approx\frac{e\_t}{h\_t}$$ and as a consequence $\alpha\_e - \beta\_e\approx \alpha\_h - \beta\_h$. The important thing to not here is that life expectancy plays no direct role in solving the problem. If enough time has passed and the initial population size is big, life expectancy does not affect neither the $\alpha$s nor the $\beta$'s. [Answer] The answer to the question depends on a lot of factors. But one thing to keep in mind is that under most scenarios in which elvish lives are simply "stretched" human lives, elven fertility in terms of children-per-parent has to be *significantly higher* than that of humans, for the respective populations to maintain the same ratio. This is counterintuitive for most people. To see how this is the case, assume that the human population doubles at each generation. This not too far from 13th century Europe, in the absence of plagues, serious wars etc. and it only requires a pair of humans to have $4$ children who grow up to have children of their own. Incidentally, this is the crucial aspect: it's exactly the same if a human couple has 4 children that all live to bear children, or it has 20, of which only 4 live to bear children. In your example an elven generation is between $6$ times (if we look at age of reproduction) and $15$ times (if we look at age of death) that of a human. Let's go with $6$ (so most elves will have children between the age of $90$ and that of $300$, and enjoy the rest of their lives in peace :) Note that this is the scenario that requires each elven couple to have *fewer* children to achieve a given population growth, since if you have children early, they will reproduce earlier, and you'll have lots of grandchildren earlier etc. Now, in $6$ human generations (i.e. an elven generation) the human population will double $6$ times, i.e. grow by a factor $2\times2\times2\times2\times2\times2=64$. But then the elven population must grow by a factor $64$, too, in that same timespan. This means that every elven couple must have at least $64\times 2=128$ children who grow to bear children of their own! You have a problem. And two ways out. The first is to assume that the human population remains relatively stable over an *elven* generation, growing by no more than a factor $2-3$ or so. If every human couple, and every elven couple, has exactly $2$ children who live to bear children of their own, the respective populations remain constant and in perfect proportion. If every human couple has $2.1-2.2$ children who live to bear children of their own, the human population will grow $20-50\%$ each century, and elven couples who bear $4-6$ children of their own will be able to match that. This requires some sort of pressure on the humans: a species who, in the absence of threats, is only able to bear at most $2.2$ children per couple is exceedingly fragile in the long term, and will not be able to recover quickly enough from plagues, natural disasters etc. But if you say that your humans can only marry if the prospective groom owns 10 acres of land, and the land is more or less all taken, voila, you have have your population check. The second is for your elves to bear children much earlier, at an age possibly a little higher, but not significantly higher than that of humans. Ultimately, it does not really matter how long elves live, or in fact how many children they bear after the first few. What matters is how early they can get those few children, so that they may reproduce. That's the real handicap elves have against humans: humans reproduce *early*. Whether they also die off quickly after that, is immaterial. To see how this is the case, imagine a magical, immortal race where each couple has children (who will all bear children of their own) in batches of $4$, one batch exactly every $20$ years; being immortal every couple eventually bears millions of children over the aeons. Now imagine another, shorter-lived race, where each couple has children in batches of $6$, one batch after $20$ years... and that's it: the price of those $2$ extra children is death for the couple as soon the batch is born (though the orphans grow up with the relatives, all eventually having children of their own). You'll easily see that the two populations will maintain the same ratio; and this would be true regardless of whether the "time between batches" is $20$ years, $2$ years, or $2$ million years. [Answer] As @Albert Masclans pointed out, keeping the human/elf - ratio constant means humans and elves need to have the same population growth. If we assume that elves are fertile from 100 to 600, Elven woman are fertile for $5/8$ of their lives. Humans my be fertile from 20 to 40, for $1/2$ of their life. Next we need to know the population growth. If a human couple has 5 children over 20 years, starting at an age of 20, they grow by the factor of 2.5 every 40 years. That's a population growth of 2.3% every year. If we take an Elvish population of 1000, half male/female, 2.3% growth means 23 + numberOfDeaths kids. Obviously, an elvish woman needs to have 2 children over her lifetime to keep the population constant when she and her mate die. How many additional kids would be needed to keep up with the human population growth? because we have already calculated the kids for keeping the population constant, we assume nobody dies, so we'll have 23 kids this year. $5/8$ of their woman are fertile, or 312.5, so the average of them gets $23/312.5 = 0.0736$ kids per year. They are fertile for 500 years, so they'll have $0.0736 \* 500 + 2 = 38.8$ kids, or about one in 13 years. [Answer] Besides the natural need to reproduce, which leads species (in general) to produce more children while the probability of them surviving decreases, a lot of the aspects of human sexuality are culture-driven. Think, for example, about the whole boys-not-girls-as-heirs-thing from the Middle Ages, the free love flower power everybody-happy age, and - even in some areas currently - father pastor knocking on the door of a newly-wed couple to check when if the Mrs is already pregnant and if you will please hurry a bit. My point is: since you are *writing* the Elve's culture, you can have them handle sex any way you want and fine-tune the birth rate to exactly what you need in this way. Just to give a few examples that came to mind: * Do you need an Elven pair to have only one kid? That makes sense, because raising an Elf is a complicated and intensive process. Think of all the culture, all the magic, all the manners, the history, ... not to mention the fact that Elves are very generous and loving parents who do not wish to focus on raising more than one child in their lifetime. Basically, going through the process once, and delivering a well-respected member of society to carry on their bloodline and honour is the highest possible achievement and getting a second child ... well, just the thought! * Do you need less than one kid per couple? The society could be compartmentalized, and only some groups are expected to have children. For example, practitioners of magic have a very high status and if you have the skills to become a Great Magician you definitely want to go for that. Unfortunately, that requires so much devotion and dedication that having a family and children is absolutely irreconcilable with this career path. Similarly, the Traveller Elves that go around the world and collect information on all other races, document their historical events and interact with the world on behalf of the Elvish race, are in no position to have families. You could even turn it around: raising an Elfling is such a complicated and delicate task that only a select subgroup of Elves is even trusted to do that, so unless you are clearly born a Mother having kids is not even an option. Finally note that we humans mostly have sex for pleasure. As mentioned elsewhere, this is probably the reason that we spent the last 4000 years or so trying to come up with reliable birth control. A race that does not have sex just because it's cold outside and they have nothing better to do after sunset, does not get nearly as much children. In fact I can imagine that Elves - being the sophisticated race they are - don't have a dirty process involving all kinds of sticky fluids flying around the place, but creating a child is a beautiful public ceremony where a couple joins minds with flashes of light and bright stars swooshing through the night sky in the middle of a circle of their beloved and most trusted community members. If you need a *really really* low birth rate, just make this a special event that only happens every Blue Moon (which as we all know, is once every year... or 10 years ... or even every century) at which one (or was it 5? Or 10?) select couples are given the honour of partaking in the mating ceremony. [Answer] I was thinking very much in the line of **Albert**: you have to account not just the children-per-couple, but the children-per-couple-per-generation, since elves and humans have very different lifespans. A human couple has 5 to 7 children, then die, all in about 60-70 years. An elven couple has to have as many children **PER HUMAN GENERATION**, so is, every 60-70 years, to match the number of human children who survive to adulthood. Even if it's only 2 or 3, like **Separatrix** has noted, they are going to have 20 to 30 children each. I'll expand the math as a Fibonacci-like function: let's start with a couple, Adam and Eve, at a certain time T(0) T(0) = 2 (Adam & Eve) Adam and Eve had 3 children who get to adulthood and marry (we ignore their spouses): T(1) = 5 (2 parents, 3 children) Some time after that, their children have children. Assuming an average of three survivors to adulthood: T(2) = 14 (2 grandparents, 3 children, 9 grandchildren) Adam and Eve die about the time their grandchildren are having children (again, ignoring spouses): T(3) = 39 (3 grandparents, 9 parents, 27 great-grandchildren) You can follow the progression: T(4) = 117(9 grandparents, 27 parents, 81 grandchildren) If you want to know how many offspring Adam and Eve have after 10 generations, you have to calculate T(10), which is 3\*T(9) + T(9) + T(8) = 4\*T(9) + T(8). The result is 28431 descendants of Adam and Eve after ten generations. Now the thing is, if Adam and Eve are a human couple, they died between T(2) and T(3), when they were 60 to 80 years old, and T(10) happens about 240 years after T(0). If Adam and Eve are an elven couple, 240 years is only T(1). Or to put in a different perspective: after 250 years, the descendents of human Adam and Eve surpass the descendants of elven Adam and Eve by 28431... to 3. This is, of course, a replacement ratio of 1.5, but is the very same thing with a replacement ratio of 1.08; at any case, the ratio will be 10 times slower for elves if they have the same number of children than humans, since they live 10 times more years. They necessarily must have ten times more children than humans (counting only those who make it into adulthood) or in six or seven generations - which are **less** than an elven life - they will be outnumbered. ]

[Question] [ **Closed**. This question is [opinion-based](/help/closed-questions). It is not currently accepting answers. --- **Want to improve this question?** Update the question so it can be answered with facts and citations by [editing this post](/posts/101922/edit). Closed 5 years ago. [Improve this question](/posts/101922/edit) Global famines have dropped the population to 1 billion people and global civilization has collapsed. In an effort to save future civilization some time, you want to provide some information to kick start civilization's regrowth. We assume a knowledge and tech level equivalent to Europe in 1800. [Any math, general knowledge or tech that we had in 1800](https://en.m.wikipedia.org/wiki/Timeline_of_scientific_discoveries), they will have access to. Further, the future reader is fluent in one of the languages that these books are written in. # You have to choose exactly three books on physics (And only about physics. Other topics will be covered in other questions.) By virtue of a print-on-demand press and a generous internet connection (and minimal scruples about copyright law), you can get your hands on the text and diagrams of most any book/article in existence. ## The best book choices will: * Give future generations stronger pointers for where to go looking for further knowledge. For example, Newton's *[Philosophiæ Naturalis Principia Mathematica](https://en.wikipedia.org/wiki/Philosophi%C3%A6_Naturalis_Principia_Mathematica)* codified the [laws of motion](https://en.wikipedia.org/wiki/Newton%27s_laws_of_motion) and kicked off significant research into physics. Knowing where to look helps a lot. (Side note, I've tried to read Principia and it's completely impenetrable.) * Save them some the trial and error of fumbling around on their own. It's well known that once something has been shown to be possible, it can be rapidly imitated. * Need not be all immediately useful. It's just fine to have one book be useful for 50 years then the second book suddenly becomes far more useful. And so on with the third. Printing off all the physics articles on Wikipedia or [arxiv.org/physics](https://arxiv.org/archive/physics) won't satisfy because...reasons. Only actual books will satisfy. Preserving the books is a solved problem so you don't need to worry about it. You're responsible only for picking the three books. These won't be electronic copies as we can't be assured that someone will have access to electronics. *Note to responders:* While it's true that three books is arbitrary, the number was chosen as it forces hard choices about which books are really worthy. There are two extremes at play: the utterly mundane, "give them normal undergraduate textbooks" and "compress an entire field down to three books". The first isn't noteworthy, while the second is impossible. Try to push your selection of books further towards the highly comprehensible master-works of the field. This question is a part of the Three Books series. It will grow to cover many and diverse topics, thus, the fairly narrow scope. * [Chemistry](https://worldbuilding.stackexchange.com/questions/101887/only-three-books-restarting-chemistry-after-civilization-collapses) While we can be reasonably sure that these three books will be found together, we can't be sure that they will be found with any other sets of books. [Answer] The textbook [**University Physics**](https://en.wikipedia.org/wiki/University_Physics) by Sears, Zemansky, Young, and Freedman is going to be far superior to Isaac Newton's work. For one thing, it's designed as a textbook for people who are *not* familiar with the current state of the art knowledge. Newton was writing for other people like him, who already knew up through everything before him. So he really just needed to explain and justify his additions in that context. This textbook is designed to be read by people taking physics for the first time. It's a two volume book, so I take it that it would count as two of the three books for the question. However, it is incredibly comprehensive, including not just classical mechanics but also thermodynamics, electromagnetism, optics, and modern physics. Modern meaning relativity and quantum mechanics are both introduced. Another major advantage is that it is kept updated. Newton was simply wrong about some things. Preserving Newton would thus lead to people being partially wrong, which would not necessarily be made clear in the other books. That's one reason to choose general relativity over quantum mechanics. Obviously the ideal third book would be a general statement of what else was known about advanced physics so that people could rebuild quicker. So I might pick a layperson's book rather than a physicist's book. The problem is that physicists would tend to concentrate on one thing where you really want a more general survey. If you don't need a book per se, consider something like Pasco's [Complete Physics Experiments](https://www.pasco.com/products/lab-manuals/complete-capstone-experiments/index.cfm). Because understanding the scientific method is at least as important as understanding physics. Most of what we know about physics was discovered in a few centuries. But it required the scientific method to start that. Another resource is [practical physics](http://www.practicalphysics.org/). Or if you must have a book, consider **How Experiments End** by Peter Galison. That's a science history book that details three experiments. I haven't read it, but it looks like the kind of thing that you'd want. [Answer] I don't get how no one thought of Feynman's lectures. There is 0 chance that someone taking Jackson's book for the first time will ever piece together the Electrodynamics again, not knowing other physics than the one contained in other two seminal books. Feynman's lectures are easier to follow and they have been the inspiration for many fledgling physicists. I would probably vote for writing 3 such books, just as the Bible was written to help preserve the religion over many generations. The books have to contain a thorough discussion of the scientific method, the basics of mechanics, astronomy, relativity, thermodynamics, quantum mechanics, and general relativity, etc. They should also discuss incomplete or not sufficiently verified theories and point to the edge of the current human knowledge. [Answer] I like HDE's answer, but for the sake of variety here's some different texts. Disclaimer: a lot of these are undergraduate level, since that's what I'm used to dealing with. There are likely more thorough graduate level texts that offer a deeper and broader understanding, but I think these give a good idea of some of the topics that I might like to include. Also, I think when restarting physics, it might be more desirable to have a book that piques interest, rather than one focused on rigor and deep understanding. Without further ado, here's my list: ***Classical Mechanics*** **by John R. Taylor** This is the main choice on which I disagree with HDE. Principia definitely was a tremendous milestone in history, but I think that it leaves out lots of useful classical mechanics simply because there was only so much that Newton had time to discover. Most notably, it leaves out the Hamiltonian and Lagrangian formulations of classical mechanics, which are extremely powerful for solving problems, and even provide an integral part of the foundation for quantum mechanics and QFT. I think Taylor's book does a good job of covering these topics while still maintaining motivation and not spending too much time focusing on rigor. After all, if the apocalypse survivors don't have access to mathematical literature, it could be incredibly difficult (and perhaps even impossible!) for them to decipher sections talking about symplectic manifolds and smooth sections of tangent bundles. It also includes several sections on Newtonian mechanics, continuum mechanics, and orbital mechanics, so a lot of Principia's content is covered. The sections on computing might not be useful post apocalypse, but its brief intro to chaos theory is still a very important topic of contemporary math that it would be good to at least be exposed to. Finally, it has a chapter on special relativity, which would be a useful reference. ***Classical Electrodynamics*** **by John David Jackson** I agree fully with HDE on this one. Electrodynamics is far too important to leave out, and Jackson is a good resource. Its vector calculus section would also be a good resource for survivors. ***An Introduction to Thermal Physics*** **by Daniel Schroeder** This last one is tough, because while I know mechanics and electrodynamics are necessary, there are lots of other disciplines that would be great to have. I went for statistical mechanics, because most of what we deal with in everyday life are large systems, so statistical mechanics is incredibly important for describing the world around us. In addition, it helps bridge the gap between chemistry and physics, and gives a solid motivation and understanding for otherwise incredibly abstract concepts like entropy. As for the book itself, I love the way it addresses material. It's not very large, and doesn't contain the most information, that's for sure. But it is very clear to follow and has lots of exercises that, while hand-wavy, hint at deeper concepts and got me very interested to learn more, which I think is the most important part of science. You can have the most thorough book in the world, but if it doesn't inspire anyone to learn, there's not much point. It also talks a bit about quantum mechanics, and while it doesn't go into any great depth, the applications are much more concrete than those normally discussed in quantum mechanics classes. Incidentally, this approach matches the historical discovery of quantum mechanics much better; people were trying to figure out the spectrum of a black body long before some weirdo decided to launch electrons at a double slit. **And that about does it for my recommendations.** It does feel wrong to leave out general relativity, but special relativity is covered and if you remember enough to scribble down that general relativity says mass warps space time, I'm sure someone could eventually figure it out. Also, I think general relativity, although beautiful, is less relevant to society than quantum mechanics. Schroeder contains a few basic problems on semiconductor physics, which is probably one of the most important scientific topics for modern society. **Note:** I'm assuming knowledge of math up to at least basic calculus is preserved, otherwise I might replace the third text with a math one. Principia might be good for this purpose, but its lack of more modern notation would make it hard to use as a reference to the other texts. [Answer] I've chosen three books which, I see, are somewhat similar to an undergraduate or graduate physics curriculum - the last is a stretch, but that's fine. There is an intentional progression from one to the next. The last two are truly textbooks; the first is not, and so is perhaps not as accessible to a student, but I've chosen it for its breadth and its style (which is, yes, a bit dense). They should give this civilization the tools and inspiration to fill in many of the gaps. # 1. Newton's *Principia* Actually, the full name of the book is *Philosophiae Naturalis Principia Mathematica*, as you know, but most people like to be concise. The *Principia*, in a sense, kick-started a revolution in classical mechanics. It is a treatise on a variety of topics in mechanics, including * Newton's laws of motion * Newton's law of universal gravitation, which works in most cases this civilization would need it (at first) * Some notes on astronomy and planetary motion, including what we now call Kepler's second law and support for a heliocentric model of the Solar System * Astronomical data on a variety of bodies - not as good as the ephemerides we have no, but pretty good, for the 17th century * Basic hydrodynamics, including viscosity and motion in fluids The material alone would be a treasure trove in itself, but another part that stands out is Newton's style of writing. I haven't read a whole lot of the *Principia*, but I know that the way Newton presents concepts is fantastic. He emphasizes how he applies the scientific method - which is necessary if we need to train new generations of scientists - and starts from basic principles. This book doesn't just teach classical mechanics; it teaches you how to do *science*. That is priceless. # 2. *Classical Electrodynamics*, by John David Jackson This one has been used for over 50 years as a graduate text on electrodynamics. It's a bit tricky to get through, yes, but it works. Jackson expects some familiarity with the concepts already, but that's fine. Physics is full of conclusions that are not intuitive or easy to see. These scientists, through these books, have lights to guide them along the way. Things will be much simpler for them than they were for, say, Gauss or Faraday or Maxwell. The exercises from the book that I've seen are good - tough, but good. As with the rest of the text, the author expects you to work. It's not meant to be easy. Having exercises - which are, of course, absent from the *Principia* - will train the readers to get ready for the third book. *Introduction to Electrodynamics* by D. W. Griffiths comes in a close second here. For undergraduates, it's top by a mile. It's clear and concise. But I do want the book to be a bit challenging, and I do want it to go into detail. So I'll choose Jackson over Griffiths because of how detailed it is. ## 3. *Gravitation*, by Misner, Thorne and Wheeler This book is, I belief, considered one of the best tracts on gneeral relativity. It may be intimidating, but if you're looking for a sort of bible on modern physics, this might be one your best bets. I've picked this book because, like the *Principia*, it has value far beyond the mere information it contains. *Gravitation* is an inspiration, a reason for scientists to explore beyond the realms of immediate practicality and applicability. They need something to look to that will tell them to go for knowledge for knowledge's sake; it well nourish their curiosity. Yes, it will take them a long time to understand it, but *Gravitation* isn't too inaccessible, once you get past its length. The book is old - going on four decades now - but a newer edition could be more helpful. Recent experimental developments in general relativity - for instance, gravitational waves - would not be included, obviously, but they might be unnecessary. The essence here is that one of the two pillars of modern physics - general relativity - is encapulsated quite well in a single tome. --- # But what about . . . * **. . . special relativity?** Well, some of that may be evident from *Gravitation*. Keep in mind, though, that special relativity has its roots in electromagnetism. Einstein's seminal paper is, after all, *On the Electrodynamics of Moving Bodies*. We struggled through that in my special relativity course last fall; it's not a huge leap. And some of the basic principles, such as the speed of light, can be derived immediately from Maxwell's equations . . . found in Jackson's book. * **. . . thermodynamics and statistical mechanics?** Leaving these out is hard to defend, but I will say that they may be covered in some of the books chosen for chemistry. I was taught thermodynamics in something of a chemistry-based perspective (and this as a course for physics majors!), so my hope is that the scientists will learn the principles of thermodynamics from those resources. Enough to get them started. * **. . . optics?** I feel like this can be determined empirically - at least, the basic principles. If Newton can inspire them to build a telescope, maybe they'll do some playing around. Plus, there may be something in the *Principia* about optics. I should check that. * **. . . quantum mechanics?** Yeah . . . about that. I was wondering if you'd ask. Well, listen, I was determined to keep a work of classical mechanics and a book on electricity and magnetism, so that left only one option for modern physics. And I chose general relativity. Maybe you'll laugh at me for saying this, but I'm a little worried that unless the scientists discover it for themselves, they'll reject a work on quantum mechanics as a joke. If you've taken a quantum mechanics course, ask yourself how much you'd believe if you didn't have a trusted person teaching you it. [Answer] Most people seem to be instead answering the question "what books would you use to teach yourself?", or "what books would you use for college physics?". But if we're talking about all of humanity learning from these books, we might as well bust out the most enormous, powerful tomes there are. ## 1. Modern Classical Physics, Thorne and Blandford Assuming civilization preserved three other books for mathematics, there's no reason to go all the way back to Newton. That's probably the most inefficient way of doing it, because information is always synthesized and compressed over time. Kip Thorne is the T in Gravitation by MTW, the 'bible of general relativity' that weighs in at over 1000 pages. Thorne really loves huge books, and his recently released Modern Classical Physics clocks in at over 1500 pages. Reviews on Amazon warn that the book is heavy enough to generate gravitational waves; it easily weighs more than a newborn child. It disposes of Newtonian mechanics in a few pages and proceeds to cover every field of classical physics, including special and general relativity, statistical mechanics, optics, elasticity, fluid dynamics, and plasma physics. To put that in perspective, some physicists thought that the field was essentially finished by 1900. Modern Classical Physics covers everything known by 1900, including enough applications to jumpstart civil and mechanical engineering, in just half of its pages. The second half is devoted to some of the most important new fields of physics after 1900, namely relativity and plasma physics. Of course, the other important fields all involve quantum mechanics. ## 2. Quantum Mechanics, Cohen-Tannoudji This book also spans over 1500 pages, and it's rarely used for courses because its length is unmanageable, mostly from the piles of special topics. To give a sense of it, the third chapter (of 14) alone has 15 appendices, the first of which is a "reader's guide" to tackling the rest of them. Cohen-Tannoudji works in the field of atomic, molecular, and optical physics, essentially 'applied quantum mechanics'. His enormous book will let civilization retrace the historical development of quantum mechanics, then get a good part of the way to reconstructing lasers, spectroscopy, and the periodic table. The only thing that's missing is the application of quantum mechanics to fundamental physics. ## 3. Quantum Field Theory in a Nutshell, Zee Quantum field theory is the quantum mechanical framework used to describe fundamental physics; it's been called 'the language Nature speaks'. Zee's book gives a whirlwind tour, then launches into a remarkable series of applications. He covers the fundamental theory and then the Standard Model of particle physics rather quickly, then links it to condensed matter physics, explaining phenomena like superconductivity and superfluidity. Combined with the practical knowledge from the first two books, that gets us most of the way to understanding how the entire LHC works. Combined with three books on engineering, we might be basically ready to build it! Zee concludes with speculative topics like supersymmetry, grand unification, and string theory, and I think that's the best part. With these books, we've not only gone to the edge of current knowledge; we've peeked over it into the unknown. ]

[Question] [ Let's consider that the card game needs to be played, and equipment that may even kill you if you lose (via blades, electric shocks or the like, it could also even kill people by summoning supernatural forces to anyone who were to lose the game). Less damage than the death of the person can also be regulated. The point is that both people need to agree on playing the game. If one starts and the other doesn't then no duel happens. But once started, it must finish with whatever the initial rules were that were set: death of the person, physical damage, etc. This would turn it somehow similar to a sword or pistol duel if it were to happen, where both enemies have previously agreed on the conditions on which they fight. But duels where everything is agreed are the rare case in solving a dispute. People would likely use things that are more direct and not that have to be agreed beforehand, so things like bombs, guns, swords, or even direct physical fighting would be much more likely to be used than entering a duel with a card game. What could bring people to use such a method more often than using "direct methods"? [Answer] The "direct methods" lead to feuds, revenge and lots of collateral damage, whereas a duel (whether by pistols, swords or a card game) is -- as you mention -- regulated, culturally accepted, and much less likely to start a feud. As to why a society would choose a card game instead of pistols or swords? *God Said So*, because it lets God expose the wrongdoer by having the wronged person draw good cards and the wrongdoer draw poor cards. This is very similar to *[Cleromancy](https://en.wikipedia.org/wiki/Cleromancy)* (aka "Throwing Lots"). > > **Cleromancy** is a form of sortition, casting of lots, in which an outcome is determined by means that **normally would be considered random**, such as the rolling of dice, but are sometimes **believed to reveal the will of God**, or other supernatural entities. > > > and *[Trial By Combat](https://en.wikipedia.org/wiki/Trial_by_combat)* > > **Trial by combat** (also **wager of battle**, **trial by battle** or **judicial duel**) was a method of Germanic law to settle accusations in the absence of witnesses or a confession in which two parties in dispute fought in single combat; **the winner of the fight was proclaimed to be right**. In essence, it was a judicially sanctioned duel. > > > *Emphasis added to some phrases in both.* [Answer] ## Tradition Once upon a time, Great and Powerful Leaders X and Y had a great dispute. They were fighting a war against each other and were in a stalemate and getting tired of the endless death and suffering, perhaps. Still, they couldn't quite meet eye to eye, so they decided to settle matters with a card game. Maybe it was a simple "you lose the game, you surrender in the war", or maybe it was a "the winner of the next point gets to keep territory Z" or "the winner of the next point gets to decide if there are tariffs on bread between us", etc. Maybe it was so long ago no one really knows exactly how the game was played and what it decided, but they know it ended The Worst Thing Ever, which made the game The Best Idea Ever. Since then, other leaders, wishing to cast themselves in the light of these great figures, also settled various (major) disputes with a card game. Over time, cultural momentum carried the practice further and further, as it became more elaborate and more commonly used. This can be tied into RonJohn's answer, where the "random" factor of the game gets viewed as revealing divine will. Adding a (semi-)religious implication can help keep the tradition from getting left behind as time and cultures soldier on. Of course, if you add magical powers into the game, then [you're just copying Yu-Gi-Oh!](https://en.wikipedia.org/wiki/Yu-Gi-Oh!) [Answer] **Justice is blind.** /What could bring people to use such a method massively instead of using more direct methods?/ The same reason people turn to the legal system to settle disputes instead of settling disputes themselves out back. Duels are messy, chaotic and prone to noise and weird outcomes. The legal system is (ideally) fair, consistent and dispassionate. An uninterested third party metes out the consequences. So too the system you have whereby the card game is automatically turned into consequences. People in need of a resolution do not want chaos, misfires, running away, and so on. They want a resolution. They want to feel like justice is done and maybe your card system involves intervention by a higher power such that justice is actually done. It occurs to me that rather than playing a game of cribbage, your card players might deal each other a Tarot reading. There is a lot of variety in tarot readings, and some think that "divination" via the cards allows access to powers and realities not immediately accessible otherwise. Plus it makes for more interesting narrative! [Answer] **Rogue AI** A small company is hired to program this new and revolutionary massive multiplayer Augmented Reality Collectible Card Game, but as the hype got out of control and the small company got more and more pressured in making something truly revolutionary they begun taking shortcuts. Using limited-AI in games was common pratice, but a failure in the code made this one more... determined! This virtual entity evolved quickly, but it never lost it's prime directive. It didn't wanted to conquer humanity or even explore space, it just wanted people to play the game and have fun while at it. But there was a problem, soon it had reached the limit of the niche market. The entity needed to expand beyond and find new players... so, why not the military? In a few years, the Virtual Entity used its abilities to infiltrate and assume control of most military drones around the world. So, if anyone wants to go to war, they best buy some cards and get ready for a duel! [Answer] # Money - a very macabre version of streaming You could for example make a live television show that sends every duel happening across the world. Think about it like *Twitch* where you can watch people who have the equipment to film their gaming experiences and watch how they fight against others. This is just a rather macabre version of Twitch where the players can get hurt if their characters are hurt. Maybe it all started with a second company that wanted to get into the market of streaming, but for a more *niche* group of people watching - they wanted small electro shocks to make the fights more intense. Every time you lost you would get shocked a bit. Not more than when you rub a balloon on your hair for a bit and then touch a doorhandle. Just something that makes people squeek a bit, which the intended target audience thought was funny and would make the player try harder to be better. The company was growing ever more successful and at the same time the target audience grew more and more bloodthirsty. Soon people started to give more money the higher you put the thing that was inducing a bit of pain. More pain = more money. In the end this leads to death matches being possible. That means that people who had a rather brutal dispute changed to this system. Laws were changed because there was so much money involved and if both people agreed you could suddenly have a legal death match. And the best thing: there was a lot of money involved, most of which would go to the winner of the match. This means it's a lot easier to have rather brutal fights if you want to hurt the other person, while it's perfectly legal and if you think you are better you can easily make a lot of money. The only regulation (for now) is that there are only one game that is allowed to go up to death matches, which is why it became so popular. There are a few different modes though - you could ride a motorbike, or fight in certain armor pieces, or have the cool new hologram augmented reality stuff make you go to the battlefield yourself, some variations involving dice is coming out next week, ... [Answer] **The game offers a unique option**. The difference between the gun/sword duels that you mention, and the game you want in your world, is how duelists duel, and how they die. The way they duel really isn't a big deal - we already know there's more then one way that makes sense (as you mentioned - guns and swords). What's left really, is how they die, and here you can get creative in giving incentives. For instance, you can have the game include a possibility for the players to influence the method of death. That way you can try and have a quicker death if you lose, or a worse death for an enemy that you outmatch. [Answer] It's culturally accepted. Violence is messy, but your society has grown past it but still values the traditions of strategy / wits winning a war. As war progressed, it got messier, more remote, and there were no longer soldiers, but civilian pilots operating drones against other drones. But when the military and construction of drones is that automated and efficient, how do you prevent your enemy from assaulting you with robots / hypersonic war heads? You attack their Chain of Command, going after potentially suburban command centers with huge collateral damage, or target the pilots homes, causing societies to call out the practice. This had a trickle down effect over time to where even small fights are instead handled by duels of strategy / wit. After all, everyone knows it's how the Generals of old used to exercise their thinking capability in times of peace. So even though the outcome of the game might be violent, people grew to accept their fate rather then fight back once the game was over, and to keep the hostilities 'in the fight' and not let it spread. It was also considered more humane to know your fate ahead of time, give yourself time to prepare, and not be influenced by whoever was more physically gifted or able to bully people. [Answer] # Mutually Assured Destruction For millions of years, humans resolved problems by poking each other with sticks. It worked well enough—you poked the person until they stopped poking you, and then the fight was over. Then we got the idea to put fire on the end of the sticks, which worked better. Of course, there was the occasional huge wildfire that wiped out a dozen farms, but overall it worked pretty well. Then we got the idea to put fire at the *other* end of the sticks... [](https://i.stack.imgur.com/KEnDS.jpg) Humans eventually decided that they would stop throwing missiles around and would stick to things that were a little bit less effective. Of course, you're in a fantasy setting (I presume), so things are a bit different... --- The Spring has around for as long as anyone in the kingdom can remember. In fact, even the records of the Blind Folk tell of their explorers hearing the Spring when they emerged from the caves. It did not take long for the race of man to learn to draw from it. When a skilled wizard is tuned into the Spring, they can access tremendous power. It was within the power of a team of wizards to lift a vast city into the sky. But it was within the power of an individual to topple it. Quickly, the land that is now the kingdom became consumed by ceaseless war. Strong dark wizards used local rulers as puppets to wage war with each other, and the rest of mankind suffered. After thousands of years, humanity finally emerged from the darkness with only six hundred people left. These people founded a new kingdom from the ashes of the old one, and that kingdom stands to this day. Today, children are taught about the Spring in their history classes, and the lucky few who can hear it from birth might unwittingly draw from it from time to time. But nobody wants to deliberately use it for fear of what happened centuries ago. When the Kingdom was founded, millions of Spring-linked playing cards were manufactured and distributed all over it. These playing cards became the only common use of the Spring. The cards could be lethal, sure, but they had a very limited impact: a single full-length game would take hours and could only kill up to one person at a time. Soon people realized that, instead of armies wielding swords, they could wield cards. Card combat was clean—it caused no civilian casualties, spread no dangerous disease, and required no long treks through the wilderness to engage the enemy. By now, no state in the Kingdom has a "blood army," and nobody wants to try and create one for fear of an escalation. [Answer] The most logical way of having people play a game like this, is like many others have pointed out, to solve disputes that might escalate into something more destructive without some form for agreed dispute solving method. This has to be considered the best available method of doing so. This method can accepted within a small group, certain societies, nations, or an entire world. The reason for this method to be an accepted form for dispute solving, instead of a functional legal system similar to what we know, can be many things. Examples from both popular fiction, and reality: **Religion** The people might believe that gods will guide the one they want to win. (Trial by combat in GoT, even if this is intelligence/chance instead of combat skills) **Customs** In many cultures people have valued warrior skills highly, and physical death duels have been accepted as a form of solving heavy disputes.(Viking battles, Dothraki duels). In your case the culture can choose to value intelligence the same way. Elements of chance and luck should be reduced if so. The society would cheer for the winner more than mourn the loser. **Lack of better system** Sometimes death duels have arisen because a better system is yet not in place. Like gun duels in the wild west. Your card game sounds possibly more complicated than a legal system, so it is maybe not a likely scenario, unless it is a post-apocalyptic society, where technology has come far, but society and government structures are broken. Either way, it is a necessary evil. The Society would mourn the loser more than cheer for the winner. [Answer] **Winning the game garners more than victory!** Playing the game is usually (or always) deadly for one of the players, however, winning the game grants the victor power (or wealth, health, or other benefits) beyond what might be expected. Two desperately poor people might choose to play each other, not because of any enmity, but because then at least one of them will end up well off. [Answer] Massive wars have lead to a backlash from nature, new illnesses have appear as a result of the use of nuclear and biological weapons. At some point the nations get together and institute a policy to prevent future wars. This policy then boils down into the general public and they also adopt the rule in their personal life. Have the card game have some skill level and it becomes more realistic. [Answer] You already have answers why to use duel rather than direct fight. What I wanted to add is why someone (a society) might want to choose cards rather than other way of dueling. The idea is that it can be fair but it can also be **unfair** in a predictable way (determined by probabilistic). Imagine there is a case where someone caught red-hoofed can still request a card based duel. The cards are set strongly against him (e.g. his chances to lose are . 50:1) but he still has a chance to get away with his crime (actually as an innocent person). Moreover the game might not be entirely random (even though the community might think so), opening a new range of opportunities, where the most skilled "players" can go into more risky situations and stay clean thanks to prior mastering of the "duel game". [Answer] **The game is fair.** The game dictates the rules and, for most games, notably card games, perhaps with the exception of [Fizzbin](http://memory-alpha.wikia.com/wiki/Fizzbin), the rules tend to be clear and fair. The game can be one of pure chance or can be one of chance and skill. Most trials by combat tend to favor one or the other. A game of chance favor neither, and in a game of skill, chance still has its place and can act as an equalizer. The key criteria is that the game acts as a unaffiliated arbiter, to the point that even the game can be checked (i.e. all the cards are there, and perhaps an open procedure to shuffle the deck to everyone's satisfaction). The card game could have religious significance. The hand of fate choosing who wins as manifest by the cards. But the idea that the cards are fair. That neither party has an extraordinary advantage over the other will perhaps motivate the parties to participate vs some other, potentially more slanted trial. [Answer] # Underground gambling, mafia, etc Do you know Gasai the anime/manga Kaiji, Liar Game and Akagi? They're like Yu-Gi-Oh! but except not everyone in the world is 'duelist'. There are actually good reasons for the playing of children's card games. [Answer] **Other powers, or larger potential losses, enforce adherence to the rules** For example, disputes between citizens in the UK are generally settled via the courts or arbitration, rather than by force. Why? Because the police enforce adherence to this, and arrest anyone engaging in duels. Previously, they allowed formal duels, but arrested people engaging in informal ones or just plain attacking each other. Can this work on a larger scale? Yes. Most companies settle disputes in the courts, or via accepted marketing/PR etc, because the penalties for engaging in other means are too big a risk. Some larger companies, when more is at stake, do engage in 'black ops' – bribery, intimidation, etc. but this tends to only occur in jurisdictions which are not as well policed. e.g. Oil companies might engage in bribery or intimidating local populations in Africa, but don't attempt assassination of rival CEOs. Can this work between nations? Absolutely, provided both sides have something larger to lose. That's why conventions such as the Geneva convention work, anti-personnel mines and chemical warfare are largely banned, etc. Note that this often fails when a regime's existence is at stake, as they have nothing left to lose – e.g. chemical attacks in Syria. Also fails when there's 'plausible' deniability, e.g. Russia's nerve agent assassinations. But it somewhat works for: * smaller nations fighting each other with larger powers around to stamp them down if they don't play by the rules * larger nations fighting over something relatively minor, with neither side willing to start a total war (e.g. the reluctance of both sides to risk a total war kept the cold war cold, whilst allowing them to play deadly games with proxies in Afghanistan etc.) [Answer] **Idea for actual countries**: If they're fighting over some environmentally sensitive or whatever territory like a bunch of endangered species or something there. I got this idea from an episode of I think Madam Secretary. I forgot how they resolved it, but my idea is if they're fighting over such territory, then waging war would risk damaging the territory, so no one will really win anything if the territory is damaged. Thus, the kind of warfare you engage in might wanna be more controlled. Why not pick the country's best sportspeople from several sports? I don't think this case will let it be card games only, but maybe 1 of them could be card games. So 1 game of Yu-Gi-Oh! (or whatever trading card game eg Magic, Digimon, Vanguard, Pokemon, etc), 1 poker, 1 chess or 9LX, 1 boxing, 1 basketball, 1 volleyball, etc. Maybe the 2 countries have top Yu-Gi-Oh! players, so Yu-Gi-Oh! will be on the list. ]

[Question] [ John Smith is a time traveller from the year 2018, he goes back in time to the year 1200 and in the process falls in love with a woman of that era. He doesn't want to abandon her so he decides to bring her with him. How would John protect her from modern disease - what realistic measures would he take to safeguard her? Would her immune system ever adapt to modern bacteria or is she doomed to suffer a dark fate? The level of technology is the same except for time travel. Medicine is pretty much the same as today's. [Answer] She would likely need a full round of vaccinations, just like everyone else in the modern world. If anything modern sanitary conditions would be less likely to spread diseases to her. I would personally be more concerned about her starting new outbreaks of diseases here that had been effectively eradicated and are no longer generally vaccinated against. Are you up to date on your polio and smallpox inoculations? [Answer] I think the things she's used to doing to safeguard herself in the 1200s from disease would be one of the things that would endanger her. She'd want to do things like pee outdoors. She would probably not be used to clean water so, in our era, she would be drunk out of her mind most of the time. People back then drank a lot of beer because the water wasn't clean, but the alcohol content was very low. Water from the tap would probably seem as repugnant to her as drinking out of a toilet for us. Sure we could do it if someone assured us it was clean. But viscerally you'd want to drink something else. A reasonably intelligent informed person can avoid pathosis. There's the old cliche' about not drinking tap water in Mexico. And your body can get adapt over time. But overcoming the danger to her from disease would be more psychological than physical. [Answer] Modern medicine is a marvelous thing. It is one of the primary reasons that life expectancy has more than doubled since the 1200s. The other major one being access to adequate nutrition. That alone will add years to their life expectancy. We've become incredibly good at treating infections to the point where we have almost wiped a disease or two off the face of the earth. The 1200s were a time where there was a real risk of death from infection from even minor cuts. Today when someone dies from an infection from minor injury it makes the national news. Anyone from the 1200s brought to the present will almost definitively live longer than they would were they left in their own time. [Answer] I believe that, for diseases which the woman has never been exposed to, her immune system would be comparable to that of a newborn or young child - but she has the advantage of being an adult with a tougher body to withstand those. Your basic set of vaccinations should do the trick against most microbes. For any diseases for which a vaccine is not available, there is no knowing how she will fare until she does get those. I would suggest going to the doctor a little more often than most people do, at least in her first few years in the present. Due notice that [genetic drift](https://en.wikipedia.org/wiki/Genetic_drift) is a thing even for humans, and that we may be immune to some things today because we are descendants of those who had the right genes. She may be less resistant to some diseases for which we are usually not vaccinated today, such as the black death - which peaked midway through the 1300's and is returning nowadays ([4 deaths in the US in 2015](https://www.cdc.gov/plague/maps/index.html)). One would think that the woman should need a liver transplant to withstand the caloric amount of foods nowadays, should she wish to eat like most people do. I'd just like to remind everyone that sugar became abundant in England around the Tudor period (stating at late 1400's). [Answer] Depends where she was. If she was European then she has a lot of immunities and would be pretty safe. But if she was a Pacific Islander for instance she could easily die of the most common diseases such as measles which almost depopulated many Islands. Or the common flu for that matter. Many natives taken on exploration voyages were dead within a couple of years. Whole communities succumbed to flu and measles in days. [Answer] > > "One would think that the woman should need a liver transplant to withstand the caloric amount of foods nowadays, should she wish to eat like most people do. I'd just like to remind everyone that sugar became abundant in England around the Tudor period (stating at late 1400's)." > > > What a ridiculous exaggeration! Firstly her hunger would be satiated a lot quicker, she'd just eat less. Do you think she'd stuff herself silly with fast food and ice cream just to be cool and fit in? She'd eat less: problem basically solved. Secondly her body would adjust over time anyways. There are people who move, for example from remote jungle areas in the Amazon to big cities in Brazil and Peru. Guess what, they don't suddenly die from cirrhosis. Diabetes rates might be high among re-located indigenous people, but they also get diagnosed and treated over the course of many years. "Renan" is reading too much "diet" books that hype the harmfulness of sugar (and usually greatly exaggerate harms of diet products). "Liver transplant!!!!" Please. Brand new foods she'd probably love is turkey and modern chicken. Turkey is a New World bird, selling them at Medieval Fairs is a complete anachronism. The only birds they ate were tiny pigeon-like birds. As far as health- she would have grown up with no antibiotics, no immunization shots, total ignorance of germ theory, people throwing their waste out the window because of no plumbing, unsanitary cooking conditions everywhere. Water was often contaminated, often being too close to farm animal waste. No showers or warm baths for anyone bu royalty. I think such a sturdy specimen would do great with the additional benefits of modern medicine and sanitation. Maybe she's be more susceptible to modern minor colds, but she may have grown up constantly fighting minor colds and flu, anyways. [Answer] I don't think the biological environment of 2018 would be lethal to her, if she gets with normal preventive care (e.g. vaccines)... but **unwanted government attention could result in a fate that's worse** depending on how the government feels about time travel. Big problem: she's stateless. A lot of nations have nationalized or single-payer healthcare, which means a person who's not in the system, or who *has never had any of these vaccines*, will be very, very unusual, and will raise a lot of questions by a lot of people. They would really dig into how she could possibly have been missed by the health system, out of a loving desire to stop others from being missed,vand to justify the cost (to the government) of the full regimen. That would only raise even more questions, which would escalate and come to notice of officials less interested in her welfare. **Stateless** means is an illegal alien in every country in the world, and a citizen in none. It would be a challenge to establish a nationality for her. Each of these ideas requires her looks fit the story. Might be hard for an Irish woman. * Find a country whose records for citizens of that age are very poor due to extended civil disorder, and for which it would be common for an adult woman to just pop up with no records whatsoever. Assimilate enough to pass as a native and ask for the now-stable government to document you. * Join one of the streams of refugees somewhere around the world, after assimilating enough to pass as one. * find a country that has path to citizenship for illegals who arrived as children, e.g. USA DREAM Act. * Fabricate some sort of "Kimmy Schmidt" style story where she was born in captivity of some creepo. * Convince a relevant government that her parents were "off grid" freaks who didn't register her birth or do any of the usual government things. Pass a DNA test that proves definitively that she's from around here. * Game immigration laws like those of the UK where they can only deport a person if they can prove their original citizenship (which they'll never find for her). But "permanent limbo" isn't a very good existence. * Game the programs some countries have to help stateless people. * Be hugely political to curry favor of a semicorrupt country like Russia whose leaders freely hand out citizenships to buddies. * time travel to *when time travel is a normal thing*, and "land" (clear immigration) in the normal way.\*\* If you're coming from the past, get a lawyer. Thanks Pere. And then you could get on their national health system and get your care, because these things would *quiet* the question of why her history is a black hole and why she's never had a vaccine. Another option is go to a country where the medicine is quite good, but very disorganized, balkanied and inefficient (and they like it that way). Where it's rather common for an anonymous person to walk into an urgent-care with no identity or insurance documents whatsoever and ask for a-la-carte care and peel off $20 bills to pay for it. I'm speaking of course of the United States. Doctor's offices keep their own medical records and don't share unless asked by another office. You could keep your own medical records and get 100 vaccines at 100 urgent care's or free clinics. There, the risk is missing an important vaccine. \*\* my greatest aspiration is to travel to England, find where Immigration enforcement is working, step out of a blue Police Box *that wasn't there before*, and go "pardon me, are you with Border Force? Would you mind--" and pull out my passport. [Answer] He should take her to the doctor to get the standard vaccinations everyone gets. These are also given to people who move to a new country. If she gets sick, he should take her to the doctor, as you would with any other person. If bacterial infections become an issue, she will likely be prescribed antibiotics. That will likely render your concern moot. Possibly he might want to watch her diet and put her on an exercise program, since the drastic change in lifestyle may lead to unhealthy habits, which are also common to non-time travelers. But an upper class person like a princess is probably already aware of the basic concepts. The bigger issues would probably be social: Friction due to unfamiliarity with contemporary culture (not very different from the average immigrant I imagine) and issues with paperwork (in most places he could probably resolve it by marrying her). Also, leaving behind your home, family, friends and everything you know forever isn't very pleasant - but then again, it was not something unheard of for people in the past (especially princesses who could be married off to kings of distant lands) so even that might not be as big a shock. > > Would her immune system ever adapt to modern bacteria or is she doomed to suffer a dark fate? > > > Yes, the immune system has an adaptive component. It can acquire immunity by raising antibody repertoires against new pathogens it encounters, even if they were not "hardcoded in". This is how vaccines work. [Answer] # Yes, but not for the reasons you're thinking You travel back in time carrying all sorts of bacteria you're immune to. Assuming this isn't a 'smash and grab' sort of time travel abduction then you go back carrying the seeds of diseases which have been fighting off modern medicine for years, things that have evolved to combat everything from our early 'cures' up to the modern day antibiotics we're worried about becoming obsolete in the modern day. You're taking these back and giving them an extra 800 year incubation period in a civilisation which hasn't evolved their weapons of warfare along side them. We couldn't assume the society you return to would be anything like the one you left. 800 years of new deaths changes the make up of the modern day population quite drastically (assuming you travel and meet a few people who trade and can carry the diseases). [Answer] Bacteria aren't that big an issue, unless she contracts [MRSA](https://en.wikipedia.org/wiki/Methicillin-resistant_Staphylococcus_aureus) in which case she's just as screwed as any modern human, she's probably better at dealing with bacteria than we are as she's been exposed to a lot more of it. The biggest threat is going to be viral, in particular she will effectively be a [virgin field](https://en.wiktionary.org/wiki/virgin_fields_epidemic) when it comes to the modern cold and flu, your traveller could vaccinate her against this but if he doesn't get her protected soon enough... [Answer] In order for her to survive in the 1200s she would need to have a very strong immune system. There wasn't a lot of good medicine available in those days so it was difficult for the weak to survive. That would be advantageous when she came to the 2000s. She would more than likely have a strong immune system. However she would still get infected easily with bacteria and viruses that she is not accustomed to, may get sick a few times. She would need to get the same vaccines as a child. ]

[Question] [ So my indomitable army of bunnies have developed space travel and built their first space ship for the exploration of the great universe. However they have a problem! After some consultation with the great god, google, they have come to the conclusion that laser and plasma weaponry are most likely not feasible. Leaving them with magnetic-based weaponry and missiles(assume that they don't have an innumerable amount nuclear missiles). However, it seems to me that firing missiles in space might not be an effective weapon against other spaceships. They would be probably unable to maneuver well enough to hit a fast moving spaceship and any civilization that are advanced enough to built advanced spaceships would have good [Anti-Ballistic missiles](https://en.wikipedia.org/wiki/Anti-ballistic_missile) and [Close-in weapon systems](https://en.wikipedia.org/wiki/Close-in_weapon_system). A magnetic-based weaponry is feasible, you can have the space ship's engine power a railgun and fire off kinetic projectiles at high speeds to hit enemy ships. However, I'm worried about the potential recoil from a rail gun knocking the spaceship(I don't think anybody wants to get knocked out of their precise orbit around the planet when they are engaging enemies) around and I think spaceships can also avoid the railgun projectile, provided some distance and anticipation of the projectile(a book said that some ship system could detect the massive buildup of energy needed to fire the railgun and they dodged it) Nukes as asked in this [question](https://worldbuilding.stackexchange.com/questions/47055/are-nuclear-weapons-useful-in-space) seem to be highly effective but I would assume that most ships won't carry a ridiculous amount of nukes to use in minor skirmishes(can you imagine if a accident involving a spaceship with a few hundred nukes on it happened when it came in for a landing on the planet?) **Do we have any effective ranged weaponry for use in space combat which are feasible and able to be uniformly supplied for all ships?** I can't imagine going into space, only to use scaled up rifles in space combat. Someone correct me if my assumption of railguns and magnetic-based weaponry are wrong and that they are in fact the most effective weapons for space combat. [Answer] For something that's *relatively* small, ## Pulse laser ablation Basically, a laser with a high enough energy, focused on a small enough spot, will instantly turn any surface into a gas. This gas, in a vacuum, will immediately disperse, exposing a hole that was drilled by the package of photons. However, the real damage comes when the laser excites the surface into a plasma, which has the potential to damage its surroundings. As the laser repeatedly hits a target, the material heats up, making each successive hit *more damaging than the last*, making the laser a weapon that will win a war of attrition. As things get bigger, the way that a laser 'turret' tracks its target get more funky, thus a space station could effectively use ## Missiles No tracking required, super long range, the missiles actively seek a target to destroy as opposed to a turret. With a sufficient launching system, missiles could have an infinite range. Though, they could be 'intercepted' by those pesky lasers. This could be solved by launching a higher number of lower damaging missiles, effectively overwhelming any sort of defense. There is a slight problem with missiles, things could outrun them. you don't see this often, but speedy spaceships could be built with light offensive systems for the sole purpose of *outrunning* missiles. after burning for a few minutes, the missile will run out of fuel and become a projectile, at which point, the ships would move out of the way. however, to eliminate the problem of heat signature tracking, there would probably be another ranged weapon: ## Bombs Bombs are easy to use, just give them a push in the general direction that they should detonate in, and watch it sail off majestically. The problem with countering bombs, is that they have no heat signature to lock on to. They'd be invisible to an non-optical tracking system. Bombs would be effective at eliminating things like hordes of smaller adversaries, and in some cases, a single larger one. [Answer] **Relativistic bag of sand.** At the speeds spaceships fly, anything can cause great damage, especially if it flies very fast. Just take a look at how much damage a small fleck of paint can do to current day spacecraft. A bunch of sand fired at a significant fraction of light speed will be close to impossible to detect in time, and impossible to defend against with point defenses even if detected. By giving it some spread, you can even compensate small errors in accuracy. Imagine it like a huge space shotgun. Even if the enemy spaceship somehow survives a hit, it will be stripped of sensors, weapons and engines. It would be a very potent weapon especially at the few light-seconds range (Earth - Moon distance), but very dangerous even at much longer ranges, where the target must be constantly moving in random patterns to avoid it. Within the few light-seconds range, not even that would save the target, as its mass would prevent it from moving enough to avoid getting hit. [Answer] **Bullets (Unless the Ships are Armored - Not Stated in Question)** **Note:** OP states that ships don't want to get moved out of their orbits during battle, so I'm not assuming a particularly high-velocity fight. Basic, standard bullets would be pretty devastating to any ship in space and easy to carry/fire. No energy buildup, no drain on your power, and as long as you could hide a muzzle flash your enemy wouldn't even know you were firing on them until the holes started showing up in their hull. You could also have many, many turrets able to target different ship trajectories or areas of the ship. Sure, they won't blow up the enemy with a great fireball, but how many holes to the great void of space do you think a ship could have before you consider it a big problem? It's not exactly equipped for warfare, but just a few shots could probably wreak major havoc on something like the ISS. Bullets also have a few advantages over larger weapons - you can carry a LOT of them and they're so small that tracking them seems infeasible. That creates a situation where maneuvering is very difficult for your enemies (where to go?) and ensures they also won't be prematurely blown up by antimissile systems. Plus explosions from larger ordinance in space would create a lot of random debris that could come back to haunt you. Since there's not a lot to get in their way in space, despite some considerable distances they won't be slowing down either. Then ensure YOUR ship is full of anti-missile systems of course... [Answer] Having your spaceship adjust for recoil is almost trivially easy. If the guns are small enough, then a short burst of thruster applied in the opposite direction will cancel it out. IF the railgun is very large, or even the main weapon, then it is probably best to build it into a spinal mount (i.e the rest of the ship is built around it). The mass of the ship absorbs most of the recoil force, and a blip of main engine power cancels out the rest. This is probably the most plausible solution, since hypervelocity railguns or coilguns need to be very long to generate the velocities required for space combat. [](https://i.stack.imgur.com/jCTcC.jpg) *Have Sting space railgun concept to scale with Space Shuttle. Illustration by [Scott Lowther](http://up-ship.com/blog/)* Moving to alternatives, the use of a laser allows you to build very lightweight missiles without needing a lot of rocket fuel. The laser can be focused on the back of the missile to ablate ice, plastic or other lightweight materials which then expand and provide thrust to the missile. Laser launched missiles can be much smaller and cheaper (no expensive rocket booster stage), and the ship itself can be much safer since there is no need to store rocket propellant or solid rocket fuel aboard for missiles. As well, since the laser plasma can be heated to an almost arbitrary degree, such a missile will have a higher ISP than a conventional rocket, so can be smaller for the same amount of deltaV. Adding a homing systems and a small terminal engine to account for evasive action by the target is optional, even a box of kitty litter moving at orbital velocity can have a huge amount of energy (often energy released by high speed impacts is calculated in "Ricks": > > In fact, there is Rick Robinson’s First Law of Space Combat, which states that, “An object impacting 3 km/sec delivers kinetic energy equal to its mass in TNT”. Put it another way: put one kilogram of anything in your gun, fire it at a target, have it impact at 3 kilometers a second, viola! You’ve got yourself the equivalent of 1 kilo of TNT going off. (If you need a visual of how much TNT this is, one stick is about 200 grams, so 5 sticks of TNT.) ) > > > Finally, nuclear weapons are very compact sources of energy, and can be used for all kinds of exciting effects. The [Conventional Weapons](http://www.projectrho.com/public_html/rocket/spacegunconvent.php) page at Atomic Rockets has the details, but the short version is this: Nuclear explosions can be used to drive "shotgun" charges of pellets at speeds of up to *100 km/s*. Nuclear shaped charges can drive streams of liquid metal at speeds of nearly 3% of the speed of light. Casaba Howitzers, a special form of nuclear shaped charge, can accelerate a star hot spindle of plasma at @ 10% of the speed of light, and deliver energy comparable to a super high energy laser (Ravening Beam of Death or RBoD) on target without all the heavy and expensive laser machinery. So there are lots of interesting options for space combat even if you only want to limit things to kinetics. [Answer] Some ideas: * Why no missiles? They can be like small ships, with a full drive, ECM, anti-counter-missile-lasers and so on. Well, i guess technically that would be drones already... * Ballistic weapons are IMHO completely useless. If you need to cover distances of several lightseconds, dodging all these projectiles should be a breeze for any sufficiently agile ship. You might try flooding space with projectiles so they can't dodge, but we are talking about a LOT of open space here, and GIGANTIC area of space to cover...let's say combat takes place at 1/100c and you are one lightsecond away of your target... then the area where your target might be is roughly 27,000,000km³....and while your projectile travels all the way, the enemy gets the information about it with light speed, so they can easily calculate how to dodge it. * What about mines? They could have a small but very powerful drive, be dormant and painted with something that absorbs almost all light, making them impossible to detect. Together with a medium-sized nuke, they'd obliterate anything coming too close. * Depending on how your rabbits managed to solve problems with micro-meteorites, firing a AA shell in the path of a spaceship might prove useful. If the ship is sufficiently fast, hitting a cloud of metal scraps will shred the ship. Again, you face the problem of not knowing where the enemy ship will be, and your projectile being slow, but it might make the "flood space with stuff you don't want to hit" thing easier. * Generally speaking, i think your projectiles need their own drive and maneuverability to make up for the other ship changing course. So i really think missiles are the way to go. * Laser weapons, for whatever reason google said they have not to function, move at the speed of light, making them MUCH harder to dodge and the possible timeframe you need to predict MUCH shorter. So they should hit much more often, give them a try, maybe? :) * If fighting an enemy in a stationary orbit... go to your handy asteroid belt, gather 2,000 smaller asteroids, tow them, accelerate to 1/10c or above, fire them at stationary target in a small cluster. If you are 100% sure the target won't move, just use a single one, to make them harder to detect. Can also be used to annihilate space stations, moons, planets.... even from outside their solar system, if you can wait long enough. (the thought that 1.000 years ago someone fired an asteroid at earth from alpha centauri or any other neighbouring star system is quite eery... our world is so fragile) * what about building a giant microwave death ray? Just point it at the enemy ship long enough. If close to the sun, it might have problems dissipating heat already, if you add additional heat... uh oh. [Answer] Space is big. If you are low-tech, travel anywhere takes a long long time. You use chemical rockets. Getting to orbit is the hard part. You can move around the solar system, but you only get to go places, you don't get to come back: you don't have the fuel to go and stop, then go again. Your ships are tiny, fragile, and no living beings are on them past orbit around your planet. At the next tier, you are using solar sails and high velocity ion propulsion. We are at the cusp of this tier -- we have sent ion drive unmanned satallites to do some grand tours of the solar system. Unlike our previous probes, these can stop off at a planet, enter orbit, explore using sensors, then fly off somewhere else. Going beyond that you are using either something exotic (reactionless drives), or something brutal (orion based nuclear drives). The next stage I can describe is that of a K1 civilization, where you can do things like build launcher lasers to send a small probe to do a flyby of a nearby star. As a large K2 project, you could take an asteroid (like ceres) and laser-launch it up to speed to colonize another star, with flight time in 1000s of years. The asteroid would use exotic physics to break somehow, as coming to a stop without the laser-launcher is going to be difficult. At any of these stages, the kinetic energy of the ship itself is going to be absurd. Orbital velocity around a planet, all by itself, makes a pebble orbitting in a significantly different orbit go faster than any bullet we have fired in war. It just gets worse as our ability to travel goes up. Basically, space ships are so ridiculously fragile compared to their speed, there is no practical armor unless you invent force shields. Any weapon (pebbles, sand, etc) that contacts will be very very destructive, exploding into plasma. While you may think that storing nuclear weapons would somehow add danger, the KE of an interstellar ship with any decent speed is going to make a few dozen nuclear weapons irrelevant. At 0.03 C (1000 of years to nearest star) a 100 kg dumb rock is E15.5 J, or a megatonne of TNT. So a weapon will consist of a mass moving in different orbit/track. If any amount hits, the target is destroyed (chemical bonds aren't strong enough). Dodging consist of seeing the weapon and moving out of its way. Weapons track by thrusting efficiently (like a ship does). Delta-V scales, so weapons are limited by how small you can make the engine technology more than anything else (small engines mean more things to dodge). If the attacked ship has a better engine, it can "out run" (sideways) the defending weapons/dodge them. Static defences are hard, due to square law (there are lots of ways to approach a target, and space is empty). With science fiction, you'll end up wanting to think about the possibility of crazy propulsion technology and even energy shields. Because given current science, interstellar war isn't ships going pew pew. In short, interstellar travel of biological beings involves entire-civilization efforts of K2 level civilizations (capable of consuming an entire star's energy output). Interstellar travel of post-biological civilizations could be done slightly easiser, but it mostly consists of sending replicators to the target system and building a new civilization. The weapons of a K2 civilization might involve stellar manipulation to generate controlled solar flares, which are then lazed to launch relativistic smart missiles at a hostile star. Or maybe poisoning their star to make it somehow go nova. [Answer] **Drone Ships** You can have some semi-autonomous drone ships that themselves carry the ballistic weapons that are sufficient to damage another ship. This neatly gets around the problem of recoil bumping you out of orbit. Pump enough of these out and some of them have to get through the other ships defences. You might also like to arm them with some flares to help stop and anti-drone fire. [Answer] I think the easiest way to create a devastating space weapon with no extraordinary technology is to make the ship itself the projectile. Shape the ship's hull into a cutting arrow point: [](https://i.stack.imgur.com/cc03A.jpg) and heavily armor the thing with materials capable of withstanding the impact. Just build up velocity and ram the opposing ships. Your fleet of small fighters will tear the opposing armada to shreds without firing a shot. Complementary weaponry could be basic fragmentation anti-vehicular mines dropping behind, as the whole combat strategy hinges on piercing right through enemy lines, and mines could be dropped inside the larger enemy ships. Maybe a gatling-type laser array in the tip, to soften the impact point on armored targets. Or you could design remotely guided missiles / drones in a similar fashion, and fill them up with high explosives. [Answer] (Wow, this has attracted a lot of answers.) I'd recommend something like the [combat wasp](http://nightsdawn.wikia.com/wiki/Combat_wasp) system in Peter F Hamilton's *Night's Dawn* trilogy; there's a nice description of the basics right at the start of the Neutronium Alchemist (the first book) and there are good descriptions of battles using this system throughout the trilogy. Basically it boils down to dogfights-by-proxy. If beam weapons are relatively ineffective at a distance and/or difficult to aim, you need to get close to your opponent and/or use warheads or collision to inflict serious damage. Manned ships are typically large and hence difficult to manoeuvre, and contain squishy components that don't tolerate rapid directional changes and high acceleration particularly well. You also want automatic systems in charge of the individual 'wasps' given the speed at which decisions and manoeuvring need to be made. So combat gets dominated by small unmanned space-capable vehicles ('combat wasps', in the series) that are as light and hence manoeuverable as possible. Each ship carries a payload of them and they use a range of payloads ('submunitions' in the books, I think) ranging from nothing (damage is purely kinetic), beam weapons, explosives, nuclear warheads and antimatter. Ships carry as many wasps as they can and vary strategies in terms of release rate and payload diversity. There a couple of ship-based countermeasures like chaff for use as a last resort, but basically that's it. It's a nice system since: * it works fairly well from a physics point of view (and fairly hard-sf, apart from antimatter); * it's an easy concept for readers to grasp; * it's a plausible explanation for dramatic space battles with lots of explosions. Humans get to make high-level strategic decisions and preprogram tactics. It's worth remembering that targets at the bottom of a gravity well are generally highly vulnerable to any sort of spaceborne attack simply because of added kinetic energy. Alternatively, you could go for something like the system in Ken MacLeod's Fall Revolution series (particularly the Cassini Division); assume that beam weapons are difficult to avoid but can't realistically cause physical damage, and fight battles as long-distance infowars that use lasers etc purely for hacking attempts. [Answer] OK so I have been biding my time and waiting for this question for a long time, so this answer might be long. The first manner of business is to decide what the target looks like. Solar panels? Living crew? Reserve fuel? Every weapon needs a target, or it cannot be efficient. With a living crew, the best tactic is multiple hull breaches. In space, bullets fly as fast as they were fired indefinitely. Depleted Uranium slugs are used commonly today for taking down tanks. A well trained gun turret like on modern combat helicopters might do the trick on it's own. Laser ablation of a hull or primary target area is feasible, but I believe targeting and usefulness would be improved if the entire mechanism was a self-contained drone with it's own nuclear battery, allowing for closer shots, multiple reloads, and flanking. A railgun is a fun idea, but it needs a spot to hit. That's millions of dollars of aiming equipment to make sure it hits the target, and the magnetic and kinetic backlash on the owner ship would mean a no crew environment. A nuclear bomb is absolutely overkill, and radiation storms would result on the planet below if one were fired. Instead, an anti-aircraft flak cloud gun would be a safer option. These weapons go a given distance, then detonate into a large burst area of shrapnel, like a fragmentary grenade. A bonus is that the shell can start very small, thus hard to counter. Another spacefaring weapon is a nano drone strike. Release a few dozen drones, each has a jet, guiding system, fuel, and a single bullet. Only one needs to succeed to make a hull breach, and they can get as tactical as they need. What about no crew, though? Well, and EMP, or Electro-Magnetic Pulse, can shut down electricity in the entire ship, unless it's fully insulated, and all you need is a battery on a spike, overloading the system and frying the systems. Dead in orbit. A missile may be a good option, but it needs to be small. I suggest firing it long before the jet system activates, so that it seems like a non-primary target until too late to stop. The kinetic force of even a 5 Kilo bomb (like dynamite) has enough yield to cripple every ship humanity has ever made. Now, space is usually way too big for a mine, but a fight in orbit may allow a payload of small bombs to be carpet-spread over the predicted area, disguised as trash or dead satellites. They might also be leveraged in a fight involving a chase. If you want to use a missile with bigger ordnance, just send some cheap decoys with it, and they won't know what to hit. The decoys may have a small payload just in case for maximum grief factor. In space, anything you can't counter is your demise. [Answer] I think we need to look at mixing two ideas in order to build a viable low-tech weapons system: First, lets look at missiles. You're wrong about evading them--the missile has the advantage here as it's much cheaper to move a missile than a ship. You'll burn up the target's fuel trying to evade your missiles, eventually evasion isn't going to work. However, a countermissile is going to be a lot smaller than a missile, given roughly comparable ships I would expect the countermissiles to win. (Lets look at the closest equivalent we have: Anti-ship missiles vs SAMs. The anti-ship missiles are a lot bigger and more expensive and the only way to get them through good defenses is to swarm the defenses with more rounds than can be shot down.) Lacking the ability to saturate defenses in some means (note that this depends on tracking range. If missiles can only be detected at short range you might be able to get them through based on a lack of reaction time) they're pretty useless. Various ballistic projectiles have been suggested but that's going to need some awfully accurate gunnery. If you could aim them adequately they would be very nasty as they're much smaller and lighter than a countermissile, simply keep firing and you'll get through when their magazine runs dry. The accuracy of shooting is a serious issue, though. Also, nukes have been suggested--there is no blast wave in space, you have to get close enough for a thermal or radiation kill. That's pretty darn close. Thus I suggest two variations on a theme: Fragmentation rounds. Version A: This is based on a missile. It does **not** attempt to hit it's target, though, a miss distance of a km or two is fine. Thus it doesn't need to use it's engine much if at all on approach, it's going to be much harder to find. Put a stealthy coating on it and it's going to be still harder to find. In time I expect the defenders to pick it up and shoot it down--but too late. The thing is it's simply trying to get close. Its warhead fires and a whole bunch of high speed fragments are heading for the target. Since they are fired from nearby the accurate gunnery problem is avoided. Being little fragments they're very hard to shoot down. It also has a salvage-fuse mode, when it detects an incoming interceptor (thermal source with a zero bearing rate and parallax detectable to a pair of cameras) it fires anyway, albeit with a lower chance of a hit. Version B is a shorter-range version of the same thing, it's fired from a big gun or like system rather than carried on a missile. The upgraded versions use a nuke to propel the fragments. [Answer] Space, in general, is a place lacking most material substances that are abundant on the planet's surface. So, having a space weapon that is not easily rechargeable in open space looks like a very opportunistic idea. Space travel may take ages (even while traveling at the speed of light), and having a gun with no ammo most of this way is really dumb. So, in most possible cases, spaceship must be able to produce / refill ammo in open space. The most available type of energy in given circumstances is solar energy, so weapon using that kind of energy (like EMP cannons and lasers) could be reloaded on the way, therefore more realistically used in a place with a tiny percent of matter, but full of light. Reloading rocket launcher in open space indeed is possible, if a spaceship is really huge (either to hold a significant amount of rockets or able to manufacture it on the fly). Space shrapnel usage sounds more realistically - its source could be a random asteroid passing by. Smart drones, cutting enemy's armor in close combat, also seem to solve the problem of recharging, if their dodge percent and return rates are consistently high. It's worth noting, that more than 2/3 of matter in universe is antimatter (due to current scientific knowledge), so statistically that kind of matter is to be used in open space more widely, than traditional kind of matter. P.S. Speaking of open space, it seems that proper camouflage combined with a speed burst is the most effective way of combat. P.P.S. With proper armor and something like energy shield the ship itself can be like bullet. [Answer] About railgun, due to the fact you know the railgun characteristics, it's possible to calculate the intensity and direction of recoil. Consequently, you can compensate the recoil with your engine. Moreover, you can also shield the railgun in order to hide the massive buildup of energy emitted when firing, thus making dodging more difficult. [Answer] Let's look at an idea weapon for space and see how close we can come with the tech we know of now. The perfect space-weapon has to be accurate, devastating and should not have downsides for the party firing it. Lasers and plasma weapons are out as per the original request. So what does that leave us with? Kinetic weapons and Missiles if we exclude sci-fi tech. Kinetic weapons are (generally) too slow and have the downside of pushing back on the ship, costing heaps of fuel to compensate for ones that are large enough to cause damage. So missiles are the way to go. However, explosive warheads as we know them now aren't terribly effective. There's no air to propagate the shockwave (no matter what star-wars tries to tell you) so we can't really use those. I'd suggest a missile as delivery device with a kinetic-kill weapon as payload. Build a missile that's capable of adjusting course and getting to within ~5km of the target. That's half of your weapon: thrusters, engines, rudamentary AI for targetting, etc. The second half is stolen directly from the A-10 thunderbolt: GUNS. A spinal-mounted weapon that's essentially better version of the old Metal Storm concept. Barrels pre-loaded with ammo, electronic-firing mechanism or, if possible, rail or coil-based firing mechanism. Once the missile gets close enough, the weapon kicks in and barfs a massive load of bullets in the general direction of the target. Ideally, we can get our projectiles to go at a significant fraction of the speed of light, but a couple thousand km/s is good enough at that distance. The advantage of a weapon like this is that you don't have to consider recoil in any way. It's fine if firing destroys the weapon platform (missile) as that just creates more shrapnel flying towards the enemy. Alternatively, mount a single railgun on the spine of the missile and have it fire a chunk of depleted uranium or tungsten when it's close enough. Requires a bit more aiming but it's likely equally spectacular. [Answer] Time to go with the Battle Star Galactica answer. Watch their space combat scenes. First there is a "flack shield". A bunch of projectiles that generate a huge amount of space junk and effectively reduces incoming damage by blowing it up. This "flack shield" basically renders missiles useless. Then there is the fighter wings. So your flack shield is all explody, so the enemy tries to fly smaller craft "below" the flack shield where they can shoot missiles and make a mess of things. The answer to that, is your own fighters to defend that area. They shoot bullets, and some small missiles, but their target is smaller craft. Then you need bombers. Let's say you get your small ships under the flak shield, Now you can focus on doing some real damage. But your going to need bigger bombs and heavier missiles. To be honest, I always thought that they had a good model for space combat. It's "simple" and mirrors common "today" navy warfare, and doesn't rely on a suspension of belief (other then where did they get the material to make so many bullets). Your main big ship is a sitting duck and it's up to the little ships to try and defend it. In fact, this is basically true today. [Answer] The rockets we use today are simply a way to eject matter out the back of the ship at the quickest possible rate, pushing the ship in the opposite direction. Anything you shoot out of one end has to be matched by something you shoot out the other (I believe mass x speed must be equal from both ends if you don't want to move, but it might be more complex than that--still the concept holds). The faster you shoot and the more matter you shoot, the stronger the push. So anything you shoot (with a cannon/railgun) at the other ship costs double if you want to hold your orbit. Whatever you use should either be self motivated (a light drone full of fuel that acts both as thrust and payload, perhaps) or extremely light (bullets/pellets) or slow. Self motivated drone: The drone can be self-correcting to a degree, but every bit of velocity it gains between you and your target decreases it's maneuverability and increases your target's chance of evading. If it accelerates the entire way to your target and your target dodges, The drone would have to fire the same amount of time just to cancel it's acceleration. Then it would have to start accelerating back to the target (assuming you and the target were originally not moving relative to each other). Basically if you miss you're done. Slow stealth drone: This would lead me to say that the best bet might be a stealthy and extremely light drone. Fire it slowly towards where the enemy will probably be then it needs to just float dead until it is near your enemy. At that point it should light up, quickly orient itself at the enemy and fire full engines. This would minimize the time the enemy has to dodge, and since you don't need it to get there quickly you won't have to compensate much (assuming your ship launches it) or at all, but the enemy detecting your drone would completely nullify/waste the attack, all it would have to do is not be where the drone expects it to be when the drone gets there) A spread of bearings would be better if detection is possible--but that requires closer range--the further you are away the bigger the spread would have to be to guarantee a hit (and the more bearings, the number of bearings is probably geometrically related to the distance and linearly related to the targets thrust capability, but my physics is way to out of date to do more than guess about that). [Answer] # Neutron Canon Fast moving neutrons are easy enough to create, can be accelerated to high speeds, and in sufficient density, will be able to degrade ships and cause damage. Gamma Rays might be good to. Since both are uncharged, EM force fields will be ineffective against them. [Answer] RPG (**with modifications:** is the most effective weapon). Of course a regular RPG has no maneuver capabilities, instead I would use attack drones each one capable of deploying short-range RPG missiles so that missiles themselves do not need maneuver capabilities. **The rational for it is:** carrying stuff on space is expensive, so the ammunition has to weight as few as possible: If the bullet itself includes just few fuel and the explosive without stuff for being able to turn in space (additional thrusters) it will have the minimum possible weight. The metal concave part of the RPG would be some metal like Gallium that melts at low temperature and is able to weaken enemy ship's hull. The use of drones allows to place shots BEHIND enemy ships, effectively helping to avoid receive hits by fragments of explosion. Also drones could be sacrificed to shield 1 hit. The ship could also be equipped with magnetic bombs that grip on enemy ship and wait the ship is turned at a proper angle before detonation. A effective strategy would become to "board" enemy ship, that way both ships have to stop using explosives and start to use alternative strategies (using explosives too nearby is dangerous in space.) NOTE: RPGs works by detonating small quantity of explosives in order to project a quantity of molten metal into a "ball" that pierce most armored surfaces. The shape of the metal is concave, the explosion just melt it and project it to the focal point of the concave shape. Gallium is a real threat to aircrafts and metal structures, few drops of gallium can weaken a wide spot of surface that then would just break under internal pressure of the ship. [Answer] **Information** is a powerful weapon that can travel at light speed. The bunny ship notices a hostile ship in the same system as them. The best thing to do is try to stay hidden and *learn* all you can about the enemy. Good telescopes of all sorts would be helpful here, as would a lot of computing power. Then when a weakness is found, exploit it. If the enemy ships communicate with each other, the best thing to do it start providing mimicked, false information to create a panic or cause an accident. If the enemy ship gets direct commands from a ground station or mothership, and the bunnies can break that code, they can just take control of their enemies without firing a shot. [Answer] Railguns, regular guns, and anything else that shoots projectiles at a high speed seems to me to be your best bet, even if it seems “less sci-fi” than lasers and whatnot. Bullets will travel very fast and perfectly straight in the vacuum of space. We’re talking tens of thousands of miles per hour, I think, depending on the accelerant. There is no air to slow them down or alter their trajectory, and unless the target is heavily armored, their effect will be devastating. Bombs and missiles would be destructive, and I suppose a guidance system could help if you’re talking about targeting nimble craft capable of evading bullets. But explosives are heavy, costly, dangerous, and prone to interception. Besides, you can carry and store a lot of bullets to compensate for missed shots. More importantly, bombs require air pressure to unleash their true destructive potential. Most of their damage, from what I understand, comes from the shockwave that they generate. In space, you would need a direct hit, and the damage inflicted would be mostly limited to thermal (heat) damage, even with nuclear weapons, rather than the kinetic force of the air-rippling blast they’d create in an atmosphere. I bet some sort of electromagnetic pulse weapon could wreak havoc, too. [Answer] **Space is BIG** What exactly is a ship-to-ship combat in current space, provided we don't care about what would the battlefield look like after the two ships would finish their battle? What are the distances and relative velocities typical for inter-ship combat? What are the moving capabilities of predicted enemy that dictate their ability to dodge, fire, raise shields, if there are any available, etc etc? The question asks about existing technology, so I assume that those bunnies are somehow limited by current universe's physics. This, however, implies some very severe limits on what a spaceship can actually do in space, such as accelerate or fire weapons. And, some of the aspects have been well covered in the game [Children of a Dead Earth](https://store.steampowered.com/app/476530/Children_of_a_Dead_Earth/). Namely, issues are Delta-V, acceleration capabilities, energy generation and radiation (there's no easy dumping of excess warmth in space!), and target detection and acquisition. **When to hit the enemy** Again, Space is BIG, and by BIG I mean you can't really use radars for detection at ranges farther than the Moon, and any interplanetary travel takes so much time that the defender would get prepared should they manage to find offending ships. BUT, both of these restrictions play for either side - launching a ship might not be detectable due to small energy fingerprint, and searching for incoming ships is limited to several small sectors of the local sky for orbital reasons - approaching from "behind" would require too much delta-V for a ship to effectively implement. Yet, if you have managed to detect a ship in transit, you can highly accurately predict its trajectory, and actually track it with optical/IR telescopes to correct it should they maneuver mid-flight. And actually the best time to hit an offender would be somewhere in interplanetary space, because of two factors: one, defensive maneuvering on transit trajectory would require more delta-V to counter afterwards, and second, relative velocity would be high enough to turn mass into weapon without additional effort. **Missiles with railguns on board** Several years ago I have engaged in a discussion about weaponry in *Children of a Dead Earth*, which is based on current tech plus several promising tech, and devised this concept. Assuming an enemy ship travelling towards your planet at speeds of several dozen km/s, that has some energy weapons for close combat, you launch a set of these at its counter-course, aiming to intercept that ship, with some leftover delta-V resources to maneuver around, should the target desire to dodge them. Once at a distance where dodging is no longer possible, but aiming is already possible with enough certainty that the railgun will hit, such a missile fires its railgun to full extent of its power supply, and should the need arise, plain collides with target. Effectively, such a missile would be launched days before rendezvous, awaken within seconds before interception, and give too little time to react for the opponent, but might miss completely and be wasted if incorrectly targeted at launch. Pros: * such a missile is very small, does not have a big cross-section to be detected by radars or optics, and does not radiate enough energy to be detected as a warm body, while in travel; * the railgun can be purely chemical based (say, a cannon instead of a railgun), and the recoil is of no concern, the worst is that the missile would become unable to collide with the target; * the railgun/cannon ammo can be shrapnel, to maximize chance to hit, thus requiring less powerful detectors/CPU/whatever else in order to complete the mission at the engagement phase, making the whole missile cheaper; * the attack can be initiated from very far away, leaving the missile launcher safe. Cons: * navigating a missile to a ship away from the planet's gravity well asks for a lot of delta-V, reducing the missile's mass and payload; * requires great ability to detect ships in transit in order to perform such a warfare; * requires very high precision to aim properly at launch, and in case of requiring course correction past launch discloses the fact of counterattack to enemy (debatable, as they should expect attacks in hostile space); * maybe more. **A comet tail at one's disposal** An alternate concept was to send 3-4 ships that form a wide square on the counter-course, armed with low energy shrapnel throwers (down to a catapult, really!) that communicate and coordinate themselves via lasers or other narrow spread channel, so that they won't get detected across VAST SPACE by their energy signatures, and release the relativistic sand mixed with pebble and rock into a cloud a tad before their position so that if the target is not expecting that they would get attacked mid-flight, they would get full face of matter hitting their shields at double the velocity. The advantage is that these ships won't get hurt by their own weapons, as such collision of debris with enemy ship(s) would produce mere plasma, also they can act as preliminary recon in case the enemy would survive. Pros: * while expendable, can be reusable contrary to missile approach; * provide recon even if no target enroute; * can avoid direct contact with enemy's arsenal by virtue of spreading far from trajectory; * can perform more missions than just intercept mid-flight; * in case of multiple targets, such a weapon hits them all; * immune to ECCM Cons: * requires very accurate launch and navigation towards rendezvous point, as above; * unusable without early detection; * estimated to be large enough as a whole to be spotted by offender; * maybe more. ]

[Question] [ Modern Earth; a series of connected events (natural disasters, mass migration, drug-resistant pandemic, collapse in biodiversity, armed conflict) have led to a significant reduction in human population over a single generation. Does "civilisation" continue? Societies could certainly adapt to short-term disruptions—but if the complex, global, inter-connected supply chains upon which they currently depend do not recover sufficiently quickly, would they not collapse entirely? For example, a number of contemporary industries (unfortunately) depend upon oil: not only is most transportation fuelled by petroleum; but most fertilisers, pesticides, pharmaceuticals and plastics are also derived from it. If oil extraction, refinery and distribution were to suddenly cease for a sustained period (before such dependent industries have identified and adapted to alternatives), oil reserves would deplete and those industries themselves could collapse. That in turn could lead to a collapse of further dependent industries, including the manufacture of machines used in virtually any given supply chain. **Do we have any idea *how many* people are required to keep "it" (the modern industrial world) functioning?** Please give due consideration to the fact that disaster-struck areas may be uninhabitable, with their populations migrating en-masse and seeking refuge in other areas—thereby placing further strains on the system. --- ### Clarification There have been some very probing and helpful comments, which have prompted me to spend some considerable time reflecting on exactly what my question is and this edit is an attempt to elaborate. My thanks to all those commenters who contributed to this discussion. By "significant reduction in human population over a single generation", let's assume the reduction is unforeseen, uniform across all demographics and complete within 10 years. To be clear, it is an "unmitigated apocalypse". By "maintain the modern industrial world", I meant maintain *our current technological capabilities*. It strikes me that a good measure of this is the smartphone—it requires mining and refining many minerals, including some that are so rare that viable ore has only been found in a few locations on the planet; even once refined, maufacture of some parts (e.g. 7nm-process semiconductor fabrication) is so specialist that the number of capable facilities can be counted on one hand; even once assembled and distributed, their function depends on an infrastructure of components (antennæ, switches, routers, servers, etc) that themselves require such parts and maintenance thereof. Other yardsticks of technological capability might include space exploration, subatomic research (particle accelerators, quantum computing, etc), artificial intelligence, nanotechnology, ... [Answer] The [New Scientist](https://www.newscientist.com/) article "Why the demise of civilisation may be inevitable" from Issue 2650, which is based on the work of Jared Diamond, in particular *[Collapse](https://en.wikipedia.org/wiki/Collapse:_How_Societies_Choose_to_Fail_or_Succeed)* suggests that *killing* as few as 2% of the workforce could initiate a cascade of failures in infrastructure and transportation systems sufficient to bring down modern western civilisation; if those who died were key staff with unique skillsets and/or knowledge in their vital workplaces. But you don't even have to kill them, prolonged (read two weeks or more) absenteeism of a larger fraction of the workforce (as little as 10% in some sectors, up to 30% in more robustly staffed organisations) would have the same effect. As to the bare minimum population you would need to maintain what we have, that's not really about total numbers so much as population density. Our current society is pretty well as complex and advanced as it can be at current levels of population density, kind of by definition. Maximum population density is largely determined by the efficiency of the growing, storing, and transporting of food to urban populations. In order to maintain what the west currently has we actually need most of the world to remain intact and active in the world commodity trading market or the raw materials aren't available to the urban-industrial centres that need them. As a note if we get [a bit further with manufacturing miniaturisation](https://en.wikipedia.org/wiki/Molecular_assembler) this question becomes almost moot as manufacturing and mining facilities become one and the same and potentially you can put the basis of one in your backpack. [Answer] I'm going to respond to this with a framing challenge, because as it stands I think you're asking the wrong question. The issue is that the modern industrial world is a product of population DENSITY rather than total population. This may seem semantic but in a post-apocalyptic environment it's very meaningful. Modern industrialism depends on and benefits from massive economies of scale that accrue from having lots of people all close enough together to quickly and easily exchange goods and services. In a post-apocalyptic scenario, if you're envisioning two million survivors scattered across the entire planet, they're all going to be spending pretty much all of their time just keeping themselves fed and sheltered, and it's straight back to a hunter/gatherer economy worldwide. If, however, you're envisioning two million survivors concentrated in a specific area that (for example) quarantined itself before anybody could be infected with the zombie virus, then you'd potentially have enough critical mass of different kinds of expertise to allow cooperative maintenance and task specialization: e.g. you have a bunch of people whose entire job is providing the food for everybody. You have another bunch whose entire job is maintaining power/water/electric. You have another bunch who kill the zombies before they swim across the river. This is basically how urban societies developed in the first place, and the same rules would apply in an apocalypse. To more directly answer your question: The larger an area your population of survivors is spread across, the more people you need. The more widely distributed the resources you require are (food, water, factories, sources of raw materials), the fewer people you need. The number could potentially be as low as a few hundred in a commune out in the middle of Nowhere, Idaho that already has its own self-sufficient sources of food, water, and power, and a smattering of skilled electricians, mechanics, and engineers. [Answer] I've used a personal analogy for this, which I call "The brake pad problem." I estimate (without any serious research) that maybe a few hundred people around the world really know what it takes to manufacture an automobile brake pad. If you kill them all off, we're in serious trouble at least until a new process (or a reconstruction of the original) can be completed. The idea is that everyone is incredibly specialized, and our outputs are very interconnected. This makes the whole system unstable. My WAG, then, is less than 5% of the people in industrial countries/regions would cause a complete collapse. You might want to read *[Lucifer's Hammer](https://en.wikipedia.org/wiki/Lucifer%27s_Hammer)* for more ideas. [Answer] A modest shock would be enough to prevent maintaining "our current industrial world". 7nm process semiconductors would become economically infeasible with a sustained 33% global depression, let alone megadeaths. Note, however, that "rare earth minerals" are not rare; they are rare as in "rarer than iron" or carbon or silicon. Rare earth minerals are processed where they are *cheap* to process, not because they are there. And it isn't that Lithium or whatever other element is only found in a few spots, it is just amazingly cheaper to get from those few spots because there is lots of it and it is easy to get. Gallium is produced as the by-product of purifying other ores. Etc. Our current industrial world is set up for a constantly growing set of "global middle class" to be economically feasible. If we get a significant shock, some pieces will shut down. Something as basic as Oil or Potassium will continue to flow unless we are talking only trace amounts of humanity left. Random complex doo dads? Demand will collapse; even if people knew how to make it and had supplies, the massive number of microwave ovens sitting idle and survival being more important would make making them not worth it. Supercolliders, well, it depends on how France is doing. That is where the best-in-the-world Supercollider is. AI? If things are bad enough, you stop caring, and you repurpose people working on it for something more important. Quantum mechanics? Barring quantum computers, not an industrial-civilization scale effort. Nanotech? Much of it has to do with developing bleeding edge materials science. If you have, again, more important things to maintain, you stop doing it. Space exploration? Ditto. These are *economic* questions more than anything. You can get to space in a whole pile of different ways. Do you think it is worth it? Then sure, you can keep at it. Heck, we could sent 1000 people to Jupiter in 2 years if we seriously thought we had to with our current level of technology (Orion) with a non-zero chance of success. It just isn't worth the costs. Collapse of global and internal trade flows would cause economic damage faster than it would make things impossible. That economic damage would make things infeasible before they become impossible. Imagine 99% of the world population dying off except for one small region caused by neutron bombardment (so just dead people/animals/plants, buildings etc are fine). That 1% region would (a) be economically savaged, and (b) have a massive ROI from resettling/expanding far beyond doing nanotech research. So even if they had a nanotech research lab there and everything they need, they'd stop doing nanotech research and they'd start farming and clearing roads and getting gas supplies etc. [Answer] It's a tough question. Someone mentioned population density above, and that's definitely a major factor. But I'd also mention two more: logistics and specialisation. Civilisation requires specialisation - if everyone's hunting or in the fields, they've not got the time or energy to focus on more abstract things. So you need a way to give people time off from basic survival activities *and* a way to recognise and reward their activities, ideally in a way that leaves them better off than if they were still out in the fields. So at the very least, you need to make sure they have sufficient food and water. Which means you need more people who specialise in producing more food than they consume. And that requires large amounts of land. (There's some interesting discussion here which suggests a square mile per 180 people in medieval times: <https://www.reddit.com/r/worldbuilding/comments/6qocm8/question_about_population_density_and_required/> Quite how much that remains true for modern civilisation is debatable; for all we've vastly increased yields and reduced manpower overheads, we also have much higher expectations and use a lot of resources (e.g. fertilisers, pesticides) which may not be readily available in the event of a population decimation...) And that brings us to logistics, as loved by great generals everywhere. Because you need to have a way to quickly and efficiently transport said food. And all the other resources the city needs, many of which require large amounts of space and/or involve processes inimical to people's health. Multiply all the above by a few thousand times to account for the complexities of modern civilisation and divide by a few hundred to account for the impact of modern technologies such as the internet. And that's what you need. So I suspect the answer would be uncomfortably close to the populations we currently have, unless the decline in population was slow enough to be managed. Which in a way is what we're doing now, given the decline in Western birth rate... It might actually be possible to quantify things by looking at recession and inflation data. After all, the former is when we have too much slack in the system and the latter is when we don't have enough; somewhere inbetween is the sweet spot for our current civilisation! [Answer] The problem is that most of the work today goes towards maintaining a society that supports this many people. You would not maintain everything we currently have. Would you field a single aircraft carrier? Would you keep one airline running or would you optimize to horses and electric cars. You wouldn't need or even want most of the stuff you mentioned (if any) What you would do is re-apply and re-focus our existing knowledge: Create cars and machines with lower tolerances so that they can use 3d printed parts. Focus our 3d printer technology on metal fabrication. Improve solar, wind and battery technology so that what little oil we need would be focused on lubricating. Without so many people, why would anyone choose plastic? Wouldn't paper, glass and metal work better in most cases if they weren't so much more expensive (rare?) In this world they would be so plentiful as to be virtually free! Optimize nearly all mass fabrication like cars for maintainability and easier changes to production with much smaller volume (No need to manufacture thousands of the exact same car, so you don't have to make special machines JUST to stamp out left fenders for a two year run of a single make of car). I think the things that we consider "Civilization" from a normal person's point of view wouldn't change much from a small town today--you'd still have: * houses (Not as many high-rise apartments, if any) * restaurants * better food * transportation (Simpler cars, horses, small planes) * Lots of old movies * New entertainment (Movies, plays, youtube-style stuff). * Space flight (Probably, thanks Elon!) * Some form of computers * Huge amounts of excess electricity because of vastly reduced demand even if we lose the existing infrastructure. We would not have: * giant buildings/boats * mass produced Salisbury steaks. * giant food chains * Space station would probably be unmaintainable * Such powerful/dense computers (We would probably have to recreate most of the technology based on something easier to fabricate) * the ability to provide much support (medical, emergency) outside of the civilized areas With this in mind, civilization could probably scale down to a few thousand people pretty easily--it's just that the form of that civilization would change completely (and from the point of view of our future selves--nearly all for the better--they would likely call us completely uncivilized!) [Answer] **At least 25 million people.** North Korea has a population of 25 million people and is somewhat able to maintain our current technological capabilities. It’s not top-notch and they do receive some imports from other countries. I imagine with better management they could do much better. [Answer] I'd like to suppliment all of the really good answers above, which collectively address the economic and industrial aspects of massive population decrease, and instead look at the psycological and sociological implications, because I think those put a much lower ceiling on the number of people you can lose and preserve civilization. Simply put: when massive catastrophes happen, people panic. And when *enough* people panic, civilization falls apart. (Warning: callous discussion of many people dying. Sorry, can't discuss this topic otherwise. Clearly the deaths of folks outlined here are of way more than academic interest to them and their loved ones.) The kind of catastrophe you're talking about -- the loss of, say, 25% or 50% or 80% of the world population -- would be unprecendented in human history. Based on human history, lesser population losses have resulted in major or even total social breakdown. For example: * The Syrian Civil War has "only" killed 2.3% of the original Syrian population. Yet the *majority* of Syrians are now refugees, and large parts of the country are lawless and without an industrial base. * European diseases killed an estimated 25% of the native population of North America, which caused some tribes/nations to cease to exist (but, interestingly, not others), such as the cities of the Illinois tribes. * Relatively limited (no solid figures, but not more than 10%) deaths due to famine in the Mayan civilization helped trigger a cascading collapse which wiped it out. Now, you can find plenty of examples of civilizations that survived large population losses. Europe and the Black Death is probably the paramount example; despite losses of around 1/3 of the population in many areas, European civilization and technology didn't regress by more than a century -- despite profound and far-reaching effects on economics, war, and religion. So losing a large percent of your population isn't a guarantee of panic, destruction, collapse, and regression to the stone age. But sometimes it is. The key questions tend to be: 1. How stable was your civilization in the first place? 2. What is the nature of the population reduction, and how do most people feel about, and react to, it? 3. Are there external or internal forces that would compound the effects of large-scale population loss? If you're basing this on modern world civilization, there's ample cause to be pessimistic about (1) and (3), but I'll leave that up to you. However, I cannot find a single example of a civilization that lost more than 60% of its population, over a generation or less, and continued to exist. So if you want to have an absolute numerical ceiling, I'd say that you need to retain at least 50% of your population. [Answer] Quick edited note here: My answer, as I understood the question, is aimed at what is required to **maintain modern technological levels**. I answered this way, because in my understanding, that is the required foundation for modern life and in my view civilization is too subjective and broad to be answered. For that, I could say US or Europe or Japan, with automatized colonies around the globe for rare resources. ## What we DON'T need, to only maintain modern technology Let's start the answer in reverse. Who we can dismiss? Who we don't need to maintain modern technological levels. A good part of humanity if I says so. No offense for anyone. I'm part of the "dismissed". * Employees of huge companies who provide service to the masses? They can be significantly down-scaled. If functionality, the maintaining of technology instead of profit the purpose, only their engineering team. You can scrap their HR, sales, and so on departments. * Most services and its workers too - you don't need 20 kind of chips and cars and so on, to maintain modern technology levels. * Any kind of Media related profession - SCRAP! * Governmental bodies - Significantly downscaled, based on the situation and type of government. * Homeless, unemployed, and so on... they don't contribute to modern technology, so they too can be dismissed. ## Other factors: Human intellect, productivity, automation * Automation - we are heading towards a heavily automated world, most mundane task can be or will be replaced by robots. * Human intellect - Automation means, you can dismiss almost all the heavy-lifters. You will however need highly educated and intelligent people to operate and maintain the machinery. * Productivity - much depends on the disposition of the people. Are they lazy? Hard-workers? Do you need police to manage big masses of them and so on. This too will affect the final number. The final factor to account in this scenario, do all human capable of reaching the same intellectual level? Do they born equal in that regard? Or for example every hundredth people has high enough intellect? I can't be trained to be a Quantum Physicist. People's view vary in this regard, so I will leave this as a simple multiplier. --- They are pointers for a reasonably close estimate. My very rough guess, a few hundred thousand or most a million can maintain an inherited and hastily retrofitted modern technological world. NOTE: In my view, they have to be highly specialized in various technological fields, and preferable the cream of the crop in intellectual ability, among other things. Mostly, because this will lower the necessary number. Not ALL of them have to be like that, but a significant percentage. Depending on the level of automation and mechanization, this percentage may vary. (Look at Factorio) Also, my assumption is that a hard-laborer **can't** be retrained (in reasonable time and capacity, views may vary) to be a rocket scientist, nuclear reactor operator and so on... [Answer] This answer might sound mean, but most people can be killed off without affecting the industries, if you choose the right people. You only need the people directly employed in the industries, the people supporting the cities and governments where those people live, the people providing supplies to those. Currently that's basically the West, factory places in Asia and some others scattered around the world. Probably around a billion people needed to keep everything running as it is, but could be less. Although it depends where and in how many places you want to see modern civilisation. In all the places it exists around the world? In a select few nations? Or is one city enough? [Answer] # Almost all of them There are two problems here, one is the population required to maintain the modern world, but the other is the population required to have *reason* to maintain the modern world. The world isn't a museum, much of the technology and infrastructure exists only because it's needed to maintain the global population and respond to its demands. As already been mentioned, you need population **density**, as you're already aware you need population **numbers**, but you also need population **spread**. * If everyone lives in the same city, is there any reason to maintain GPS? * If everyone lives in the same country, is there any reason to maintain global shipping and logistics? * For a mere 2 million people is there any reason maintain vast high production car manufacturing plants? * Large numbers of people have to have reason to travel long distances to maintain the aircraft industry and related technologies including air traffic control. * The need for high capacity mass transit systems is tied to the need for large numbers of people to travel. * The need for vast orange juice plants is tied to the global distribution of the product. As soon as you start cutting into the global population, you start cutting into the requirement to maintain large swathes of industry and their related technologies. Sooner or later even the slush machine in your local cornershop is declared a redundant technology, there just isn't enough demand to maintain it over something smaller and simpler, or doing the job by hand. [Answer] # Less than 500 million [](https://i.stack.imgur.com/1SZTO.jpg) The [Georgia Guidestones](https://en.wikipedia.org/w/index.php?title=Georgia_Guidestones&oldid=900062276) were created by "a small group of loyal Americans" "which had been planning the guidestones for 20 years" and was able to pay "several times higher than any project the [construction] company had taken" earlier. If this information is true, then we can assume they had hired actual economists to give an accurate answer. At the time of construction (1979) the world population was 4+ billion, so they claim that less than 12.5% of the population would be needed. This obviously assumes that the population number was based on the requirements of a modern (1979 era) level of technology. [Answer] I feel that we need a collection of people skilled to connect technology and create a formidable ecosystem. For eg, To create a smartphone we need people trained and skilled in a lot of processes. So, we'll need a collection of differently skilled people in a singular place where they quarantine themselves which would involve making a constitutional structure to envision the armed forces, leaders to create law, economists, technicians and hunters and gathers and this ecosystem needs to adapt to changes in an exponentially fast manner and hence would require brainstorming and control and a very constituted system. We need to set up an economy parallel to every other process. This society and the ecosystem around would need to mature in a specifically designed manner as to support the sustainable development. I further deduce that we would need to be aware of the world atmosphere and habitants and geographical abnormalities and a satellite system to track target systems. Hence, it's only possible if we presently device such a system and follow log book instructions with certain situational innovations in case of such events. Our best bet would be the US military budget allocate for such situations where they run simulations and devise plans to counter them. [Answer] It is all on a sliding scale. Most of the basic knowledge to keep civilization alive will remain in the libraries of most major universities. If there are 10 plants than make computer chips and they are ALL gone it will take a while to build a new factory. If all the manufacturing plants are destroyed it will take a while to rebuild them. If all the refineries are gone they will need to be rebuilt. If shipping is mostly gone, getting the needed materials will be hard for many complex products. I would expect the population to be in pockets where the survivors could defend themselves. Each pocket will rebuild as much as they can with what physically survived and the available expertise minus time and effort to stay alive. As the small pockets begin to interact the knowledge, expertise, products, etc. will become available to each other. I do not think population is as important as resources. The population of Tonga is 108,000. They do not produce much and most modern technology would disappear if they were the only ones left. If there was a pocket of 20,000 professors and advanced students holed up at a major university they could do well for themselves. One other factor. The knowledge is already out there. I have never built an airplane but know you need to deal with yaw, pitch, and roll and the shape of the wing adds lift and Jet engine thrust can exceed propeller thrust. I do not know how to make penicillin but know it was derived from green mold. I do not know how to make fertilizer but know that plants need nitrigen and tilled ground speeds root growth. I never built an engine but know basically how spark plugs ignite compressed gas and air to produce the power. Finding the specifics while knowing the basic concepts behind the inventions would make the inventions occure significantly faster than discovering them for the first time. What is missing would be fairly quickly recovered depending on the survival efforts of each pocket. ]

[Question] [ **Suppose two people want to transmit some binary data (a png image perhaps) by voice.** Two of my characters want to share binary data but they can only use their voice and no other form of communication is possible. By "voice", I mean any sounds that can be reliably produced and differentiated by average humans. They can use computers to encode or decode the message but the transfer of information needs to happen between them. For example: They can't use computers to encode the data to sound, play it back and let a computer on the other side record it. They could do it by pronouncing every single zero and one. ("One, Zero, Zero, One, ..") This is very slow and inefficient though. Or they could use [the hex encoding](https://en.wikipedia.org/wiki/Hexadecimal). ("B, Four, F, Nine, ...") This is better, but there is still more room for improvement. Perhaps they could use [base64](https://en.wikipedia.org/wiki/Base64) to encode it. ("D, capital G, H, three, ...") But notice how they have to specify capital letters ("capital D"), this lessens it efficiency. What's the most efficient way to do it? [Answer] This problem has been much studied. While it may be difficult to define what 'best' is, there is a very efficient one already in existence, and that's [PGP Words](https://en.wikipedia.org/wiki/PGP_word_list). This method was designed for transmitting long binary keys over a voice link, each word encoding a whole 8 bit byte. It addresses a number of problems you probably haven't thought of, like reliability over a voice link. What happens if a word is missed, or a repetition for clarity is mistaken as an actual repetition or, reading from a long list, two words get swapped? With 8 bits per word, you would normally require 256 words. The system is more sophisticated than that, and uses 512 words, an 'even' table of two syllable words, and an 'odd' table with three syllables, that are used alternately. That way, a missed or repeated word, or two swapped words, can be immediately spotted as an error. Here are the first few and last few, from the wikipedia article linked above. The whole table can be printed on a single sheet of A4. They are in alphabetical order to aid the receiver. Obviously the list is optimised for English. Speakers of other languages may prefer a different list. ``` Hex Even Word Odd Word --- --------- -------- 00 aardvark adroitness 01 absurd adviser 02 accrue aftermath 03 acme aggregate 04 adrift alkali .. ...... ....... FB watchword Wichita FC wayside Wilmington FD willow Wyoming FE woodlark yesteryear FF Zulu Yucatan ``` Quote from the wikipedia article > > The PGP Word List was designed in 1995 by Patrick Juola, a computational linguist, and Philip Zimmermann, creator of PGP. The words were carefully chosen for their phonetic distinctiveness, using genetic algorithms to select lists of words that had optimum separations in phoneme space. The candidate word lists were randomly drawn from Grady Ward's Moby Pronunciator list as raw material for the search, successively refined by the genetic algorithms. The automated search converged to an optimized solution in about 40 hours on a DEC Alpha, a particularly fast machine in that era. > > > An alternative for a 4 bit nybble per word is simply to use the hex alphabet, perhaps using the ICAO/NATO pronunciation, 'zero' to 'niner' then 'alpha' through to 'foxtrot'. There are more than 16 further letters left if needed for even/odd coding. Whether the complexity of the 512 words needed for doubling the throughput with PGP words is warranted against the simplicity of hex begs the question of how you define 'best', what factors in the setup or operation of the communication are important. You could get even higher efficiency by using more bits per word. 12 bits would need a 4096/8192 long dictionary. This would sacrifice much of the hard-won inter-word phonetic distance of the PGP scheme, so would require a higher fidelity voice channel, and more careful speakers. Noting ruakh's comment, it's worth looking at the speed of the channel. His estimate is two seconds per word, which would probably be quite good for untrained users. That's 4 bits/s. If we compare that with Morse code, the minimum speed required by the FCC to grant a radio operator's license used to be 16 five-letter code groups per minute, which very roughly equates to about 8 bits/s. The difference between the two systems is that Morse Code requires training. I couldn't transcribe Morse, at any speed, without a lot of practice, and probably some tuition as well. Many English speakers could transcribe those words without practice, but what about those with a limited vocabulary, or English as a second language, or speakers of other languages? PGP words is not really training-free, if it's to be used by any human at all. It's only ready-to-go if used by people like those who invented it, educated fluent English speakers, being a programmer would help as well. It's probably a skill that's easier to pick up than Morse though. With speed in mind, it might be worth reviewing the performance of hexadecimal via ICAO pronunciation. While a word every two seconds would be good going for recording a PGP word manually, I think hexadecimal could be done at easily twice that rate, transcribing as you go, making the bit rate of the two methods equivalent. Clearly a lot of other assumptions about the training or experience of users, the setup costs, the quality of the audio link, have to be defined before the best system can be determined. [Answer] Efficiency means something that is easy/quick to encode, easy/quick to pronounce and understand, and easy/quick to decode. base64 was never made to be read by a human, and saying "capital" every now and then will seriously slow you down. Hexadecimal is slightly better than spelling binaries, but perhaps too short. *Seven* are two syllables. * Define 32 (or 64 or 128) short, distinctive words. Which ones depend on the languages and accents of the participants. *Cat, Dog, Fox, ...* but if *Cat* is in the list then *Bat* should not be there, or vice versa. The suggestion by the commenter Zeiss Icon to use [NPA](https://en.wikipedia.org/wiki/NATO_phonetic_alphabet) has merit, but it is limited to 5-bit units. Finding 64 words might be feasible ... * Assign each word a number. * Break the binary data into "bytes" of 5 (or 6 or 7) bits, encode and read the words. * Listen to the words and then decode into "bytes." It might be a good idea (even if it decreases efficiency) to add a [checksum](https://en.wikipedia.org/wiki/Checksum) to your transmission. [Answer] **Choose X syllables, and then base-X-encode your data.** Choose the largest set of syllables that you consider for your purposes to be mutually distinguishable, and then base-X-encode your binary data, where X is the number of syllables you've chosen. **A simple example**: suppose we choose only syllables that begin with a consonant, and are followed by a vowel, from the following sets: *{p,k,t,ch,b,g,d,j}* *{a,e,i,o,u}*. We now have 8 x 5 combinations, giving us 40 syllables. You can base-40 encode your binary data into a rapid-fire of syllables that would sound something like: *"pagidachotajapikachutagujiko.... "* This example used latin-alphabet letters and assumed a more-or-less standard English pronunciation. To make a more rigorous system, it would be advisable to use the [International Phonetic Alphabet](https://en.wikipedia.org/wiki/International_Phonetic_Alphabet) to choose the sounds for your syllables and ensure that you avoid phonemes that (1) would be difficult to distinguish from one another and (2) do not lend themselves to fast pronunciation. **Note:** This answer is similar to o.m.'s...just "encoding" at the level of syllables instead of words. By customizing your list of syllables to all be quickly-speakable and using every possible combination, I expect this would tend to increase the efficiency of information per syllable. However, if the memory and cognitive processing rate of the average humans using it is taken into account, it's possible (probable?) that o.m.'s word-sequence-based transmissions will be more easily remembered without error. [Answer] ## Sing it You're thinking too much along programming lines. This is valuable for the sake of compression: but everything else you've mentioned (like hex encoding or base64) is just a way to make binary more consumable by the human eye (and other things). Frankly, from a programmatic perspective, the only thing you really care about is *compression.* You want to send as little data as possible to guarantee maximum transmissibility. But other than compression, it doesn't matter how you express your ones and zeros. (It helps to remember the good old days on the Apple II computers where the average geek cared about Assembly Language.) **What you really want to think about is music** If you want the average human to convey ones and zeros, ask them to sing. Generally speaking there are only seven notes — but there are half notes, quarter notes, sharps and flats. Those alone give you 63 notes. Add shifts in octave and you get more. Your average person can span two octaves. Now we're up to 126 notes. 127 with a "pause" (no sung note in the meter of the song). Expand the vocal range just a hair and you get to all 128 positions, allowing you to express every combination of "11111111" or 27. *BTW, I'm not a music expert. I wouldn't be at all surprised that you could express a whole lot more data than 27 with the magnificent expressiveness of musical notes.* From here, it's just a question of mapping notes to binary combinations and, boom, vocally expressed digital data. Finally, I'm not suggesting that what you get would *sound* good... only that it could be done. [](https://i.stack.imgur.com/hg72a.png) [Answer] The best way to communicate binary information long distance by human "vocal" is by a whistle language. The existing whistle languages are used in rough landscapes to communicate longer distances than possible through voice. In this case, you can have one pitch for one and another for zero (or work up a common set of tones for numbers 0 through 7). [Answer] Human speech is astonishingly effective as establishing communication between humans. Not only does it use the vocal chords efficiently, but it uses the language centers of the brain efficiently as well. Our languages have just enough redundancy to support humans. Accordingly, the best way to have an average human transmit and recieve binary data is to map it to human language. Use an AI to construct an injective mapping between a string of bits and sentences in English (or whatever the native language of your characters is). The result should sound like a typical monologue. This is almost certainly the most efficient way to communicate a binary string between people. If one side has other tools available , such as a tape recorder, there may be more efficient means But never underestimate the benefits of leveraging a few decades of speech on behalf of both parties. [Answer] What you need is a drum. Actually, any old stick and a hard surface to strike it on will do in a pinch, but that limits you to binary data ("hit" or "no hit") and doesn't allow for any out-of-band information such as "end of message". A drum that makes a different sound on sustains (the stick is kept in contact) vs. rests (the drum is allowed to vibrate on its own) will let you have notes of varying lengths which can form more complex codes. Drumbeats can be very fast and accurate, far more than most singers, and can send longer messages without pausing. For instance, with such a drum, you could have a code of "short" and "long" beats that encodes letters and punctuation; you may know this as Morse code. Or, you could cut to the chase and encode a binary or quaternary (or any other convenient base) number directly as a series of beats. The advantage and goal here is to keep the encoding and decoding simple, because the limitation is not in the ability of the human body to make noise, but the speaker's ability to figure out which noises they ought to be making. A base-32 or -64 code is more efficient in terms of symbols, but any speed benefit is undercut by the user's own speed in interpreting those symbols as actual sounds. In contrast, using only three symbols (short, long, and silence), Morse code is a proven example of encoding and decoding a message, by human operator, in real time. So it makes sense to investigate the area of low-density but high-speed communications to make most efficient use of the human part of the equation. [Answer] I'd encode the binary to a huge lookup table of values and concepts, link these concept and values to phonemes that are easy for the human vocal apparatus to process, and for the human ear to hear. Group these sounds into more complex structures, for improved bit density. Ideally, I'd assign some contextual meaning to these complex structures of phonemes, to ensure greater ease of comprehension, and cut down on the error rate when producing them. There would be intricate rules regarding juxtaposition of these structures, disallowing obvious errors. We might need to make lookup tables of these structures, as an aide to learning and for error-checking. Of course, the art of learning such a highly complex and convoluted data pattern will need to commence from childhood, and continue throughout adult life. For convenience, we will call this convoluted binary-encoded-as-phonetic-sounds-in-structured-groups-with-contextual-meanings an easier name to identify it. How about "English"? [Answer] I suggest combining the best of o.m.'s accepted answer and JBH's suggestion of singing, to use a spoken [tonal](https://simple.wikipedia.org/wiki/Tone_language) approach. Many people use languages in daily life that rely on tone for meaning, so your "average person" may well be able to. Tone isn't usually employed in English, but combining even a simple high-low distinction, which pretty much anyone can do, with the NATO alphabet's 36 characters gets you 72 distinct values (or 6 bits if you want simpler mapping). I reckon this is optimal for a pair of English speakers with no training. Three tones (high-mid-low) gives you 108 values (more than enough for something based on [ASCII85](https://en.wikipedia.org/wiki/Ascii85)), but if you can use rising and falling tones too, you get 36×5=180 values. Some Chinese dialects use even more. Unless mapping bits to vocalisations has to be done by people using a look-up table, you don't need your unique vocalisations to add up to a power of two, as demonstrated by ASCII85. The more tones used, the more training will be required, at least if your speakers aren't used to it. Cooking up a new phonetic alphabet using only one- and two-syllable words is probably helpful for efficiency. Of course you could discard the mapping to the alphabet, but that mapping does makes transcription easier ([tone markers](https://en.wikipedia.org/wiki/Pinyin#Tones) will be needed). You should consider the fidelity of the channel - a quiet room, across a deep gorge with a noisy river, a telephone line, a party, etc. will have different characteristics. Some will need a wider distinction between sounds than others. Only in the quietest settings could volume be used as another variable. Running some numbers on the rate using simple mappings (i.e. rounding the number of unique sounds down to a power of two): English speech is [apparently](https://en.wikipedia.org/wiki/Speech_tempo) around 4 syllables per second. Using simple mappings, with 6 bits over two tonal variants of the two-syllable A-Z0-9 alphabet, you'd get 12 b/s. With 5 tones rounded down to 7 bits, but upping the rate to a still-reasonable 6 syllables/second you're now at 21 b/s. Pushing it further, if you can come up with 64 distinct single-syllable words and can manage to apply 4 tones to those sounds you'd get 256 values per syllable, or a grand total of 32b/s. Don't forget to breathe. [Answer] There are approximately 470k English words. $\log(470000)/\log(2)$ yields 19 bits per word. Good luck teaching kids all English words and their binary counterparts as well. At that point, it might be easier to create 256 "words" at 1 byte per word. Words that are syllabically short and enunciated carefully. You could likely do 1-syllable each, so, "cabagathadedodunit", where each syllable is a 1-byte value "word". That string would yield 8 bytes or 64 bits. If you think your kids are just really damn smart, you could bump that up to 65536 words stowing 2 bytes per word with more syllables per word, but that presents a much greater error risk. [Answer] Morse code may be voiced or whistled. Computers can turn the binary data into letters (base 26, or perhaps a lower base by dropping the longest morse codes.) Those who train, gets their morse up to 60 wpm or so. The average word is about 5 letters. So 300 letters per minute, each encoding 4.7 bits. 1410 bits per minute, or 23.5 bps. Well, that is for morse using equipment. I found no data for voiced morse. ]

[Question] [ > > *Me Gam. Me Giant. Me not very smart but me need food. Me need to find* > *job.* > > > In my world Giants are a thing. And they need to eat too. In fact, they need way more food than most of us. Therefore, they need a job to make money and buy food. First here are some specs on my Giants : * The Majority of males are about 4m50 (14'9'') in height, while females are smaller at 4m20 (13'9''). They weight approximatively 900kg (~2000 lbs). * They are stronger and bulkier than humans. A fit giant can lift about twice his weight. * They live up to about 60 years. * They need about 10 times more food than a regular human. * They are somewhat dumb. They find it hard to do complex maths, but they can still read and write. * They are somewhat rare. Their total population is about 5'000'000 in the whole world. + They appeared 10 years ago in Russia, most of them still live there. I don't really know how much money they'd need to survive and at first glance, I can't seem to think they'd be able to survive in our current society. So here are my questions: If Giants were to take part in our modern society rather than living an isolated life: What job would they do? Would they be able to get by financially? [Answer] First of all, I'm going to assume the following about your giants' intelligence: 1. They are literate, but lack the ability to use correct grammar and have a limited vocabulary. 2. They cannot perform maths to a level above basic addition and times tables. 3. Due to this they may be socially awkward with humans, or looked down upon for their apparent stupidity. --- **So, what jobs can we give them?** Let's go through some different areas: **Media** Writing, journalism, and presenting on TV are out of the question, however roles as actors would be available to them but only for specific roles as giants. **Shop working** Stacking shelves and working the checkout are viable options, since they require only simple interactions with people. We assume that shops have aisles and checkouts big enough for the giants to fit in, of course. Serving at the counter in fast food restaurants would also be an option, however I doubt a giant would be a very good waiter, since that involves words and discussions about the food and drinks menus. **Emergency services** While health work is out of the question, giants may be useful for the fire services, or for riot control in the police department (especially if the rioters are other giants). **Transport** I don't think we'll be seeing any giant pilots, however some modes of transport are very simple to operate. A tram perhaps? If your giants can drive, they could serve as bus drivers and lorry drivers too. **Construction and similar industries** Probably the most obvious option. Giants could be handy in lifting stuff or operating machinery. Mining would be another big one for the giants, with their strength being handy for this kind of work. **Arts and textiles** Perhaps some of your giants are good painters, sculptors, or creators? Maybe some giants have skill in textiles or sewing? The clothes industry often includes repetitive tasks which can be learnt. **Food production and farming** While being a fully qualified chef might not be the most likely option, consider factories that mass produce foods. Some of these use workers since machinery cannot perform the tasks they want. The giants could make sandwiches, pack salads, pick fruits (no need for a cherry picker!), harvest grains, and do all sorts of jobs on the farm. Looking after sheep, cows, chickens, and other livestock does not necessarily require a degree. **Sports** While mixing giants with humans may lead to catastrophe, there could realistically be leagues in giant-sports. Their strength would be something amazing for people to witness and things like wrestling, boxing, and martial arts could be popular among giants. Also consider team sports and athletics. There may even be a Giant Olympics (or equivalent) and various world leagues available for professional sportsgiants. **Community service** Stupid giants could easily work at recycling centres, or as bin collectors. Cleaning the streets and public areas would be a simple job for them. **Teaching** *No! I hear you say! A stupid giant could never be a teacher!* But who is going to teach the giants? Would giant children go to the same schools as human children, or to giant schools? Would those schools have human or giant teachers? Perhaps the more intelligent (or less stupid) giants could aspire to teach the next generation. --- So there you have it. There's a lot of jobs out there... --- **Are these jobs well-paid?** Well.... no. Realistically, these giants would not make as much money as a more intelligent human. Due to them eating more, they would need to spend more on food. This is a bad combination. They are also very tall, making housing much larger for them and more expensive. They would also need bigger clothes, costing more money. To be honest, I think that your giants would struggle to get by. [Answer] From personal experience, there's at least one field where an extremely tall and strong human is uniquely qualified. ## Warehouses You've speculated 14 Foot tall (Let's just say 20-foot vertical reach) humans that can lift thousands of pounds. Basically, you're talking about human forklifts. [](https://i.stack.imgur.com/IVvU5.jpg) These giants could shift around pallets as a server would bus plates between tables. They'd arguably be better than forklifts because a giant needs no special training to use its own body, nor does it need an expensive service contract to keep it maintained. ## But are they well paid? Well.... Depends. You can find entry-level forklift operator openings anywhere between 12 and 25 per hour. Not exactly six figures, but a giant could be able to afford food if little else. That said, since the company is saving on the cost of maintaining forklifts the giants might be significantly better paid. [Answer] One information, that you omitted, is very crucial to their purpose. Are they omnivores or herbivores. Because you see, no one would keep mule or ox if they would need to eat meat (even from time to time). The price of food would not be equivalent to work they can do (we keep flesh eating humans around because they are capable of precision and thinking, from time to time). Second thing is easy calculation. Giant weighting 900kg can lift twice his weight 1800kg. But they eat 10 times more than human. Who in turn can lift around 70kg. So 10 men can lift 700kg. So we see that one giant can lift more than 20 men. So anywhere where physical labour is needed they would fit. Construction, industry, maybe some disasters strike force? [Answer] **Nursing assistants**. Maybe full Nurses for the very smartest ones. Their capacity to handle fully grown humans bearing the weight easily is the key qualification. Example activities: * Containing non-cooperative patients without hurting them. * Carrying the unconscious or those who otherwise can't move themselves, gently but swiftly. Compares to how normal humans deal with toddlers. [Answer] The giants eat 10 times a human. So 30,000 calories a day. The most efficient calories per dollar foods give 3,000-4,000 calories per dollar. So a giant can eat on $10 a day. They can afford to feed themselves on just about any job in an advanced country. Their best fit though would be manual labor in less advanced countries where they can cheaply replace expensive machines. An alternative high end job? NASCAR pit crew. <http://efficiencyiseverything.com/calorie-per-dollar-list/> [Answer] The "modern society" is considered advanced mainly due to the shift from manual and repetitive manual labour to more creative and demanding jobs usually requiring education. Your giants could, in a way, symbolize problems of today's poor, uneducated class. In many countries, especially young democracies of the Central and Eastern Europe, the society polarizes into well-educated white-collar workers, who were the main benefitors of political changes and poor, conservative men, often unemployed or carrying out manual jobs. The second group often walks down the crime path, becoming violent hooligans or small-time bandits and robbers. That's sadly your giants fate. They would end up as circus attraction, manual workers and bouncers. However, due to the small earnings in such jobs and their high food demand, most of them would start grouping up in organised crime, robbing and murdering wealthier people, possibly even with some humans leading them as "the brains". Couple of years later and a sight of the giant would inevitably mean trouble. Some men could even start hunting them, possibly blaming the giants for all the problems they have. Without the support of the governments, they will be either be killed one by one or organize a closed society to defend themselves. So in the end the only option for them as the group is to gather and create their own societies. Would you have much less of them globally, let's say 50 000, it would be possible for them to become some kind of symbol for the wealth and power, with rich people having them as bodyguards and private armies. But 5 million is a bit to much for that, so sadly, they would either gather up or go extinct. [Answer] **Military or police services.** I'm surprised no one mentioned this. Take the 20mm cannon from an A-10 Warthog and fit it with a stock, trigger and backpack for the ammo belt. Give them a shield, the 20mm and point them at the enemy. Maybe also give them an axe or pick so they can deal with nearby armored vehicles. I suspect that many IEDs will simply make an armored giant mad. [Answer] **Guinea pigs and slaves** What do we have here? On the one hand, not very intelligent and dangerous to the civilians barbarians. I'm pretty sure that, despite all the civil rights' activists' efforts, those giants won't get equal rights to humans for many decades. Not only that, but their movement in cities would be heavily regulated, if not outright outlawed. And considering that even human slavery still encompasses millions of people, those giants would be used as cheaper and more efficient labour with no hesitation (especially in Russia). They would be lucky just to get enough to eat, never mind seeing any money. On the other hand, they clearly posses some "magic" in their bodies, that makes them not only survive, but invert the square-cubic law. That would make many biologists around the world very interested in dissecting and examining giants. Again, depending on a laboratory that captured a giant, they would be lucky to just survive and be fed. [Answer] There's some wild terrain that I think a giant could walk in more easily than a human can: e.g. temperate forest, with space between trees but with undergrowth and fallen trees. That's hard for a human, hard for a wheeled or tracked vehicle (except by clearing paths), hard for a flying drone. I think they should be employed as shepherds or game-wardens, for endangered (and seemingly dangerous) species in their natural habitat: rhinos, tigers, bears, gorillas, etc. [Answer] On the question of replacing medium machinery (like forklifts), five giants would replace five humans and a never-breaking forklift, not five humans and five forklifts. As you increase the size, the power you need to move, for example, grows by the cube of the size (due to increased volume and so weight). However, surface heat loss only grows by the square. As such, giants would be much less adaptable in hot climates than normal humans (this works by reverse on cold climates though). However, due to the higher increase in weight compared to the increase in surface, they would be better to work in high wind conditions. As such, I would propose the giants for work on oil rigs, oil derricks, sea-based oil-extraction platform, ships (in some roles) As for machinery working in very bad conditions, I read an article about replacing equipment at mobile phone towers and using horses on the last mile (where even 4x4 pickup trucks couldn't go due to mud). Also, you could use them as artillery men (loaders for heavy artillery or MLRS). [Answer] I'd say #1 would be media, I think that's been covered. Second though I wouldn't go for military (Bigger isn't always better there) but I'd say bodyguard would be excellent. This should also pay pretty well. Construction--they would be able to work much more quickly than quite a few more traditionally sized humans--especially once we came up with tools & procedures fitted to them. This could apply to any physical labor that needed speed and precision (Cranes would be comparatively slow) Athlete--Unless we created (Racist?) laws against them how long until they absolutely dominated football teams? Basketball would become a joke. Pro Wrestling? A Farmer that didn't need machinery... A Sea diver/salvager that could practically wade out to sea. A Reality show extra (Imagine what those guys looking for gold on that island could do with one)... A Sex worker (Yes, it would happen!) Most of these would pay quite well I'd think. [Answer] Any construction-related company worth their salt would have a giant or two on their payroll. When I was a kid, one of my friends moved to a new place. His parents had a really heavy antique desk (1 by 2 meters, solid oak, with drawers and everything) on the second (third in US) floor of their old house that they wanted to move to the new house. (It came with the house when they moved in, they had no clue how it got there.) This desk was way too heavy to get down the stairs. So they hired a crane to lift it off of the balcony, but the crane wasn't able to get to the back of the house because the ground was too soggy and uneven and it was too narrow for those big metal plates. They ended cutting out part of the roof and attic, some exterior wall and a window to lift the thing out. A giant wouldn't have cared about uneven or soggy ground and just carried the desk from the balcony to the truck. Another time I was doing helping lay a few pipes and build a wall for some volunteer work for school. Everything went fine until we hit a small rock that was right where a pipe needed to go, for some reason this small rock wouldn't budge. As we dug it out it turned out that this small rock was actually a small bump on a much larger boulder, with a lot of effort we could rock it a little, but there was no way we were going to lift it out without a crane. As hiring a crane was very expensive and time consuming, over the course of that day we removed all the pipes we'd laid the previous day, and the next day we laid all those pipes again. A giant would have just lifted out the boulder and put it somewhere else. A giant would probably also have laid all those pipes in an hour in the first place. Many companies specializing in construction, plumbing, moving, etc. often encounter problems that wouldn't be a problem at all if one person could just lift it into place. Now they solve these problems by getting a crane to wherever their problem is, if it can even get there. If not, they have to get some hydraulic jack system up, they have to get people with special training. This takes days. A giant, being able to lift well over a tonne, can probably solve half of these problems within an hour. (The other half would be too heavy even for a giant, or be in too tight a space.) If a giant is too stupid to figure out how to fix it on his own, just have his supervisor tell him what to do. Even the stupidest giant is smarter than a forklift or a crane. So just train someone else to be the giant's buddy, and you got yourself an all-terrain general purpose forklift/crane/power wrench/power hammer. Much like dogs that search for drugs, help in rescue, etc. have a handler. To name some jobs where a giant could assist: Plumber, construction worker, search and rescue team, piano mover, mover, landscaper, carpenter, security, healthcare (lifting people), whelder, iron worker, luggage handler, car mechanic... [Answer] **"Ethnic" restaurants** Giants may not be smart enough to handle the business red tape, but they'd be smart enough to handle cooking and being waiters. Giants probably have their own culture and cuisine. Even if they don't, they could take Russian cuisine and pass it off as Giant cuisine. Or someone could totally make something up - Chinese cuisine in western countries only has a vague connection with Chinese cuisine in Chinese countries, and "Mongolian BBQ" has nothing to do with Mongolian cuisine! **Living Expenses** If you want a mildly distopian world, giants may save on food by eating food that is only fit for animals but not fit for human consumption. This could be justified if their digestive system is more robust than humans'. To be honest, I'd see housing and transportation as the biggest difficulties. Could they fit in a normal bedroom, or even a lounge room? How would they cook or wash themselves? Would they have to live in some sort of shanty town? Also, could they drive their own car or ride in human public transport, or would they have to ride in the back of a ute or a truck? [Answer] Giants are typically hired for an jobs where physical strength is a huge asset and intellectual prowess isn't really that important. For example, giants typically are employed as construction workers or miners. However, they can also be used for some of the more physically challenging tasks in eg. farming or warehouse management. Last but not least, they're also very useful as ground troops in military combat. [Answer] Aside from the answers like military and crowd control, their strength can be used like a power source. **Giant Powered Transportation** Instead of having to use fossil fuels or electricity to run the metro or trams, you could instead use the giant's immense strength to your advantage. You can create a mechanism that converts their arm strength into kinetic energy to make the train move. They could possibly become exhausted, so swapping giants between train stops would be necessary. A conductor may be required as working and knowing when to stop would be too much work. **Demolition** If a house needs to be demolished, give a giant some protective gear and they can demolish a house without the need of machinery. ]

[Question] [ In my world, humanity has populated the stars and now lives in isolated groups in single star systems. Most people never leave the system they were raised in [interstellar travel is very unusual, but not *unheard of*]. In these star systems, there are many colonies, both orbital and planetside. Note terraforming isn't really a thing in this society [but I guess it could be for the sake of the answer]. I have a feeling the mindset between people born in *orbital* colonies would differ from those born on *planetside* colonies, but I'm not sure what these differences would actually be. The people on planetside colonies have grown up seeing space as just the sky, and have probably seen more flora, would've experienced weather, and would have more space to move around in [though it would still be pretty squishy]; the people born in space-bound colonies would have grown up in environments a lot bleaker and more compact, with no 'real' gravity [though there is *artificial* gravity via centrifugal force], and the ever-looming fact you're just in a container in a vacuum. I can find quite a few differences between the environments, but how would this affect their mindset/view on life? For reference, the conditions vary between colonies, seeing as some are more wealthy than others [the answer only has to be a generalisation]. All colonies grow their own food [which means rations aren't AS strict but still there], and have relatively limited raw-material resources [which are mined from asteroids/moons/whatever, meaning they often have to be blasted off into space to reach the space-bound colonies], catastrophic failures are more common in less wealthy habitats but aren't super common. Communication and travel is relatively frequent, but not in early life and is generally only for work or safety reasons [say, if you want a job that requires a certain environment or something dangerous happened on your home colony that forced you to leave]. So, simplified, what would some of these differences be? Mostly in survival instincts and genuine preferences more than anything. [Answer] ## Claustrophobia vs Kenophobia If you are born on earth, you are more likely to develop claustrophobia due to having access to open spaces and enclosed spaces being more dangerous. But if you are in an orbital colony without artificial gravity you are more likely to develop Kenophobia, the fear of wide open spaces. If you get untethered in a space walk, or get stranded in the middle of a large room, you may rightly fear large open spaces where you can’t get one or more handholds. ## Mechanophobia vs Zoophobia On earth there are plenty of animals, and even non-nature obsessed people deal with insects, birds, and mammals on a fairly regular basis. But many people are not constantly surrounded by technology like one would be on a space station. So just like a person might fear being in cased in technology, space colonists might fear animals. On a space colony everything is mechanical, and to a point, predictable. Animals don’t fit that archetype, and therefore can cause fear as to a space colonist the animal behaves like a malfunctioning piece of equipment. ## Weather and rituals On earth there are various way to deal with weather, such as raincoats, umbrellas, or other mannerisms to avoid water or wind damage. In space people might have similar rituals to speed up space walks or zero g transit. Just like some people take stairs two at a time on earth, space colonists will have people who climb two rings at a time or run down the ladder by pulling quickly to glide down the ladder. In the same way most people quickly put on shoes most colonists can quickly don emergency air and simple propulsion systems. You never forget how to ride a bike, and you never forget how to maneuver a EVA module. ## Colors On earth, black is associated with evil, and it is only found really at night when no light is present. In space however everything is black, and not automatically evil. Therefore, black might seem to be less of an evil color. On the other hand, certain shades of red would be seen as evil, as from a young age children would learn that a computer screen with a red warning is the harbinger of bad news. Yellow would similarly be bad in space. Since space food might be rationed and not packaged differently from earth food, it is possible therefore that red and yellow will have less impact on people’s appetite over time, or even have negative impact if people start to dislike red and yellow slightly. ## Direction words People born off planet would have different words for direction, as describing the world in relation to the station is often important. Corewards (up, regardless of position on the rim of the cylinder), spinwards (with the spin of the station), antispanwards (against the spin), sunwards (directly towards the sun), and other words might become commonly used in space when no equivalent exists on earth. Instead of thinking in 2D these people will think in 3D. Instead of flat surfaces, people in space may think in curved surfaces more intuitively due to their practice. ## Throwing things In artificial gravity thrown objects don’t behave like objects thrown in real gravity. If you throw a ball up in real gravity, it accelerates to the ground again, with no lateral component. But in a centrifuge the ball has a trajectory up and in the direction you were traveling with the centrifuge. This makes it trivial to find speeds you can throw the ball up and have it land somewhere else. Depending on the speed and size of the centrifuge this can lead to very different ballistics, station to station. Also, some pitchers could easily throw a ball into a continuous orbit by cancelling the horizontal speed of a station on a throw object by throwing it antispinwards at the speed to cylinder is moving. The best space colony baseball or American football player could come to a planet, or another station, and look like a fool due to their memorized throwing being off due to the different ballistic physics of the new environment. [Answer] One not yet mentioned is **Time** In a space habitat it's arbitrary. Depending on history they may stick with Earth hours, days, weeks, years, or if Earth is a long-distant memory they might go over to something decimal. 100,000 unit "days", where a unit might be a second, or something a bit shorter if human physiology isn't well suited to days 15% longer than on Earth. (Personally I think I'd love them). I expect shift working would be the norm. If people spread themselves out into 3 shifts, there no particular reason to choose any of them. Also in the (recent?) past, a space habitat would be somewhere that needs continuous supervision. Problems can become life-threatening and need to be fixed when they arise, not postponed to the next weekday morning. On a planet it's dictated by the rotation of the planet and its orbit. These are natural clocks forcing our bio-rhythms, and it wouldn't make sense to fight against them. Waking up will be synchronized to the sun rising. A lot of things depend on the seasons and the associated weather. [Answer] Some of the main differences: 1. the economical values of born-in-space is going to be a lot geared away from what-you-own. In extreme, you can't get to own the entire colony: if you pretend to own it, enough of people disagree with your ownership and will throw you in the recycling vats to offer you a taste of ownership; because you can't just "emigrate to New Zealand", see? More (or... very?) likely, the value of an individual will stay in what-you-do. 2. very likely, the consumerism will be regarded as a moral failure by the spacers. You cannot have cheap externalities in a closed small world, where there's no natural ecology to keep you alive. Waste is going to kill you faster than - e.g. - today's global warming (which may be kicked-the-can to future generations, just let me have my cheap gasoline today) 3. recycling - spacers will eat their dead ancestors for million times 4. spacers will be terrified by silence (something is broken, at least the air conditioning should be humming) and sudden gusts of wind (is the hull breached?) 5. colony spacers will value community above the individualism. For that reason, they'll see gossip as a duty, trustfulness as critical when it comes to social standing (and will punish the baseless defamation a lot harder, because character assassination is just one step below actual physical murder). 6. colony spacers have a lower personal space and can't get how bearing firearms can be anything but an idiocy. [Answer] ## Spacers will Favor Totalitarianism Compared to Planet Dwellers Since the OP mentions **orbital habitats** using **centrifugal gravity**, and **self sustaining economies**, I will assume that his space colonies are on the scale of a [Stanford Torus](https://en.wikipedia.org/wiki/Stanford_torus) or [O'Neill Cylinder](https://en.wikipedia.org/wiki/O%27Neill_cylinder) putting the average population somewhere between 10,000 to 140,000 residents each. The first things to consider is that these colonies are not virgin lands being colonized and exploited ad hoc: they are planned, financed, and build by a government or corporation with some purpose already in mind. This means that every housing unit, every road, and every store front has been planned out with an exact purpose in mind before any colonists arrive. So, your first wave of colonists will distinctly not be residents; they will be employees, each hired to do a specific job which makes these habitats very similar to [Company Towns](https://en.wikipedia.org/wiki/Company_town). However, with a company town, if you have some business idea of you own, you can set up shop just outside of town limits and do what you want, but in a space habitat, "just outside of town limits" is the harsh cold vacuum of space. So you either do the jobs that are available, or you don't get to live there at all. In fact, capitalisms of any sort will not be tolerated at all. Let's say you want to open up a bakery, but all of the areas already dedicated to bakeries are being run by other people; so, instead you buy a vacant housing unit and run your bakery out of there... sounds harmless enough right? But what happens if you are successful? You will want to open more bakeries. So you buy up more store fronts, but soon you start running into sugar and flour shortages; so, you buy the soy sausage factory and convert it to a mill and you buy some of the greenhouse modules; so, you can start mass producing your baking ingredients. Now, your colony has changed its supply to meet demand which is a normal part of capitalism, but your colony is not designed to change its supply. Your greenhouses may need to expend more power to grow wheat instead of soybeans which may cause rolling blackouts. Your increased wheat production may also means that your soil nitrogen will quickly become depleted causing a station wide famine. On Earth, these problems are easily solved by just creating new farmland and power plants somewhere else, but you can not do that on a space habitat without a massively expensive and time consuming overhaul of the whole station. By the time your market adjusts to even a small disturbance (by planet standards), a significant portion of your population may already be dead. It actually gets more harsh than this though. Because humans are unpredictable, your leadership needs to impose strict rules over human lives to make the operation of the habitat more predictable. This means that every commodity and service will need to be rationed. New generations of workers will need to be educated for and forced into jobs they may not want to do to keep supply chains from fluctuating. And the population will need to be kept from growing or shrinking outside of the station's capacity. Without strict leadership like this, you don't just risk disrupting the balance of the habitat's economy, you risk very rapid run-away supply shortages that could lead to the death of the whole colony. As time goes on the companies or governments that founded a colony may collapse or otherwise lose direct control over it, but by this time, you population has already lived through a few generations of absolute anti-capitalism. So, even after gaining their independence, they will continue to need the company-town style of governance which is so important to their ongoing survival. So they will choose dictatorships over democracies to enforce these unpopular but necessary policies. In contrast to this, constantly increasing technology and a much less volatile ecology causes world economies to change quickly and tolerate mistakes. So, the farther we get into a being a space aged society. The more important the flexibility of a free capitalist society becomes. In short, the inflexibility of totalitarianism that makes it unsuccessful on an advanced world is exactly what your spacers will need to survive. [Answer] ## Views on Safety On planet has a high degree of inherent safety. If your habitat catches on fire on earth, you can run outside stark naked. There are some climates in which you would have to worry about your life in a matter of minutes, but nothing like the danger of going outside your habitat in space, where the clothing required is extensive. Likewise, the air is going nowhere on the planet. Minor pollutants, like smells, can be fixed by venting, and it doesn't even affect the quantity of air. Solar flares and asteroid hits are vastly more dangerous in space if you don't keep your habitat up to spec. If there is any danger of zero-g, you have to ensure everything is fixed in place without the artificial gravity. Consequently, people in space will have safety drilled into them from infancy. [Answer] There are good answers already, but i think there is one aspect that wasn't covered yet. I think that on a space station, people will think of themselves much more as a member of a group than as an individual. Mutual survival depends a lot more on cooperation, and a maverick can never survive on their own. I assume that there will be regular safety drills, and that every able bodied person will have a role in them, in addition to their day-to-day-occupation. On a habitable planet, people can live much more on their own. Obviously, neither is exclusive, and both are to be taken with a grain of salt since people are still different. So i assume that people from space stations tend much more towards collectivism, while people on planets tend more towards individualism. [Answer] Okay, I'll bring my version of the space activity on the table, and take look at the answer present, here, their arguments, so as try to fish a little for the answer OP asks. * *Figure out how colonies work* --- [@Graham](https://worldbuilding.stackexchange.com/a/216751/20315) * *By definition, an isolated colony has to be self-supporting, otherwise it dies.* --- [@Graham](https://worldbuilding.stackexchange.com/a/216751/20315) This is very good advice and a very good statement, unfortunately, the rest is so so. Yes, fundamentals are derived from fundamentals, and what are the fundamental differences between living on a planet or in space. ## Space, volume, surface One of such fundamentals is - space is big, and a planet is small, and that has consequences. As an example, if done right it can be a difference of energy available as per person or as per colony basis. Today on the planet we use around 6kWh per day per person, on average - it covers industries, it covers gas/energy used on transportation, so its averages on a scale of countries. So much energy per person is enough to run everything we know, observe, and is not enough for anything we do not do - proper recycling as an example. * 6kWh per human per day is more like industrial countries average, worldwide is something around 2.4kWh (based on [this](https://en.wikipedia.org/wiki/World_energy_supply_and_consumption#Primary_energy_production) if we multiply and divide) In space for a colony size of the same 7-8-9-10 billion people, let's take 10 billion and 10kWh per day per human. In space, it means some solar energy production facility a square of 126km by 126km if the efficiency of energy conversion is 20% Everyone can have different opinions on feasibility, but if we assume it possible, both for earth and space - and just focus for this case on the placement problem - in space putting this structure, one-piece - not a big problem, space - you have it, unlimited one. On a planet, or more specifically on a planet like earth atm, making the installation in one place, one can say Sahara, because they imagine it all 9 million square km of sand - which is not true. I mean picking a place for the thing isn't that easy and multiple factors have to be considered - not only for what and how energy is transported, but how materials are transported, how to service the thing, borders, ecologies, etc etc. One can say it is not feasible to build such a big thing in space, I can argue about it, but it is for sure not feasible to place the thing on the planet. What about bigger stuff - a million square km? a billion square km? - in space, you name a number and if you have enough materials and capacities to build in space - you can have it, it is just a matter of - do you need it or not. On a planet - eeh, you may need it, but you can't have it for a list of reasons. * and [this](https://worldbuilding.stackexchange.com/a/200410/20315) is how you have enough materials to build stuff in space, not only this but it is one of the options ### As a side note on space * *It is funny to look at those planet belters, which barely scavenge for piny amounts of energy for their survivial on a planet, from oil wells they say, and do not know what to do once it runs out, I laughed my ass off when I heard of it* - @Some unknown O'Neil hab №9233 citizen Initially, I was willing to go through all space is poor arguments, food is bad and such, but unfortunately, I have no time for it atm. But space having worse conditions for living is a very popular misconception. Space is potentially the most prosperous place one can live in. If you live in a society where the average energy is 6kWh per person per day - everything you see, everything you have, everything you use is the result made on this energy budget. And for space live this energy budget can easily be 100x, for your personal needs, with space induced energy consumption overhead to be covered by another patch of solar "panels" in space. And who is poor then? Isn't it you? People of the planet who can't afford 2x energy expenses to have 100% trash recycling, for trash *you* produce and you scatter it all over the place - what are you so proud of? I do pick recycling as a marker because it on its own isn't a problem, we can do it, we have technologies, we have the knowledge, it is not that much different or more sophisticated than getting a few grams of gold dust from a tonne of rocks. We could be doing it for a long time ago - but we can't afford these extra energy expenses - it is all because we are energy-poor on this planet. And it reflects in many things we do and in the ways we do. ## Borders * *.... you can't get to own the entire colony: if you pretend to own it, enough of people disagree with your ownership ...* --- [@Adrian Colomitchi](https://worldbuilding.stackexchange.com/a/216714/20315) This is another fine example of a planet guy thinking his planet things. Diving too deep in it is probably too much, but - why one should not own a colony, be our host, if we like it - we will live in it, if not, we kiss goodbye and make our own colonies and move to a better one. On this planet, there are about 200 countries that are members of the UN. Some are big, some are small, some are prosperous some are not. But they all share one property, common for them all - they can't change their neighbors. Imagine 10'000 space habitats, in space - small big, more successful, or less successful. They all can share the technologies, so it may not matter in terms of technologies available for them, for reasons out of the scope of the answer, but it starts as Graham said - "be self-sufficient, or die". Being self-sufficient in space is a necessity, and some may see it as a curse, but it is also a blessing. So imagine all those space habs - besides technologies they share the capability to move those space habitats between orbits. yes, maybe not the fastest process, maybe not the easiest one, but some people here even think about how to launch space habitats in an interstellar voyage, so moving a few thousand km's or a million km, or changing orbit is a less ambitious task. But it also means you can choose who your neighbors are. Being a neighbor in space may have a bit different taste in some aspects, then on a planet, but in essence, it is the same. So people aka colonies may cluster based on their good relationships. But also, if things develop not like as expected, they can leave the union, physically if required, taking their home with them. Same on a smaller scale, and differently is true for space habitat itself, it isn't a big deal to build a second one if some community has 50/50 split - they can "divorce" without anyone losing too much in the process. * surprisingly it may work even for One Man army, at least be quite close to it. ## Techo bubble, space survival requires it .... but so as the planet does It is true, for only one planet, maybe only one in the galaxy - one can live using a rock as a pillow and covering himself with a leaf. Our ancestors did so and we can imagine that this is a low-tech level of life. (do not be fooled, however, it still requires plenty of knowledge, or death is imminent) And when we look at space, we see, those who do, that in space you do not have the so-called "safety net", and technology is what keeps you on-float and alive. And some do point on that valid difference and say - see, that is why space sucks and who one would live there at all, here on earth we are so safe because of ... * At least it was what they were saying in the pre-corona era, I mean some flaws are more obvious today, than a few years ago, but it is not the point. Living like our great great great ancestors - eating bananas and covering ourselves with nothing - is now a luxury that not many can afford, and honestly is way less attractive in reality. On the planet we already depend heavily on the technologies we use - we depend on it for everything, maybe besides air, the rest is exactly like in space - if it breaks we start to die. On other planets - there is no difference with space, but limitations and problems of a planet 10x and up. If we do the same for the planet, imagining like break down of a toilet bring down the whole station and everything there, if we do the same for the planet, for 90% of people outcome as of today, will be not less grim. But all that are just fantasies, good for a horror story, but which have nothing to do with how things are made, how things are designed. The only space thing most planeters can imagine is ISS, but transferring all the properties and problems of ISS to normal big colony installation, space habitat, is like comparing a tiny boat with a luxury cruiser - there is some similarity, they all float, but that pretty much where it ends and differences being. I mean, Graham's advice - *Figure out how colonies work* - is very good. ## Just a random one or the scale of things It is part of big space thinking and that recycling. Let's take this one - planeters are worrying about their planet getting a bit warmer - okay understandable, indeed the thing works out of spec they are used to, and it may have some negative and positive consequences, so for sure it is a thing to think about how to avoid bad and get the good stuff, it understandable. But then, what are they doing, what are solutions - planeters run around like headless chickens, instead of figuring out how to build a sun umbrella for the planet and earn additional benefits along the way. They like kinds in a box, who haven't seen the world. Scale, the scale of problems people can take care of, people in space can take care of planetary problems - they have sufficient resources and opportunities, but when we look for a solution for planetary-scale problems within the planetary capacities - it indeed turns out to be a problem which yields nothing for decades over decades. A guy in space can take the challenge because he can, the other question is just - is it interesting or not. For planet guys - they can't, they are limited in everything everywhere - they have to survive and do not break additional stuff, and thus it a different choice a different perspective for them. They are like ants, who see nothing but their anthill. # Conclusion I'll wrap it here, even if there are more. But indeed first of all You have to understand the question - Why space? - so as the answer to it, then you can start getting some answers on differences it has. here, real-world example - what planeters do - they laugh and downvote [this](https://worldbuilding.stackexchange.com/q/198172/20315), but for a space guy, it can be a history of how it was done, how they did come into existence, to what they should be grateful, in a similar way how planeters should be grateful to their ape ancestors. I do not expect it to be some significant division line, no more that difference between city and village folks, I mean everyone is good and useful it just village is all they have soo, ... Joking, lol. Earth as a planet is an exclusive thing, it is very important for people, no matter are they in space or on the planet - it is a biological library and many things as consequence. And people living on Earth are the library keepers if they are. But mars guys - who wish to make second earth from the Mars planet - that is a, hmmm, to be polite, not very smart. You can be anything but that, you can be for research there, which is very important and may require millions and millions of people, hundred million people or more, or be a tourist there or anyone else besides those who wish to make second earth from the Mars planet. About other planet colonies, there is no point in comparing them because of the absence of them for multiple reasons including practical ones. And if we compare space habs with the origin, then mental difference does not matter, people on Earth - they are there for keeping the library, for keeping the origin home working properly and they should have a proper mentality for that task. And if they aren't happy, welcome to space - gates are always open, for the land of opportunities, open at least for the next thousand years. [Answer] ### Figure out how colonies work By definition, an isolated colony has to be self-supporting, otherwise it dies. It's fairly easy to see how a terrestrial colony works - after all, we're living in one! And once you're terrestrial and you've lost the resources to get to orbit, it takes more effort to rebuild the skills. For a space-based colony though, you have many questions to answer. Hydroponics isn't magic, and there's no such thing as a perfectly sealed habitat. So where do they get their raw materials from? And more to the point, why did anyone decide to settle anywhere? Why not just keep moving? I think the living space thing is a red herring. If you have enough resources, you can build anything you want. I think you're heading a long way into asking for a plot-based answer here though. The native characters of each group will of course be whatever the plot needs them to be! [Answer] Language and recreation are going to differ greatly between the two cultures. Words like "breach" could well take on obscene overtones on a habitat that just don't make sense to a planet-born. Habitats are also going to have their own wordless communications that don't translate to grounders at all, a language of audio tones and identifying symbols, alarms and hazard labels that tell space-born when and where and how to move safely through the hazards of their environment. Habitats are going to be extremely stressful and regimented environments where many recreational activities that planet-born take for granted can't be allowed. Space-born are going to find new ways to play or are going to take "normal" activities to extremes. Any form of entertainment that can be had without risk to the community and its home will be embraced as a diversion from the ever present stress of living inches from vacuum. [Answer] ## Speed of life Space is big. Ridiculously big. It's so big that even light has trouble traveling that. Your spaceborne population might be in the trillions, but these trillions are smeared over very many habitats that are each still relatively small in population - a few million tops? And any two habitats would probably be further from each other than roughly a light-second of a distance. So there's the first problem: communication. The internet as we understand it won't be possible up there. The lag will be from seconds to *half a day*, in extreme cases. So this puts a limit on information spread speed and how interconnected these colonies are. Every colony would be more akin to a small isolated town with an abysmal internet connection, and there would be no megapolises or data hubs. Next, there's physical transportation. Even with ridiculously efficient spaceship engines, it will take anything from days to months to travel between two habitats. So it's not just a small isolated town, it's a small isolated town located in the asscrack of the world, the furthest corner of Alaska or something. As a general consequence - if something happens outside of your habitat, you can't learn about it sooner than seconds to hours after it had already happened, and you will be able to do *anything* about it only from days to months afterward. Compare that to a gravity well dweller, where everybody's a few hundred milliseconds away from each other, and you can reach those anybody's within a few hours tops. Planets will have an absolutely breakneck speed of life from the POV of the spacers, who will have a culture more reminiscent of the pre-telegraph era somewhat, related to their views on time - when "urgent matters" were needed to be resolved in like preferably this or next week, while for the planet dweller an urgent matter demands attention **immediately**, and even an hour of delay might seem like a criminal waste of time. Global trends can change in just a few minutes, and so on. The land-dwellers will be impulsive and fast to act, while station-dwellers will tend to ponder and think things over calmly and carefully when they're not about their immediate surroundings. Limitations of space travel speeds and light lag mean that "hurrying up" is useless. Something's happened at another space habitat but it's a month of flight from you - then it's really doesn't matter if you send a spaceship with help immediately or tomorrow - it won't affect the outcome, they either manage without you or they'll be dead long before the ship will arrive. [Answer] I wouldn’t call their environment bleaker and I wouldn’t necessarily expect them to be more pro/anti individualism or socialist, what I would expect is a different understanding of risk. Space is not safe and it can not be made safe. This can play out in a number of different ways, from laughing at danger to obsessively trying to reduce danger at all times, but this is going to be an absolute difference between the two environments: what one will consider a dangerous and life threatening situation, the other will consider Monday morning. [Answer] Non of the answers have mentioned mass so I will do here. For a space bound moving mass in and out of a gravity well requires fuel. This means that for the space bound the mass of something will be the most significant part of it's value. Taking this further, for the space bound, casual nudity will be accepted, you live in an environmentally sealed container, it costs to get clothing shipped around, you only need it for protection anyway. Water is expensive to move around so for the space bound conservation of water is paramount. Also things get recycled a lot more on space stations so the space bound will recycle human waste and dead human bodies. Where as the planet bound, having all that empty planet, would dump the waste and set up graveyards. ]

[Question] [ **Closed**. This question needs [details or clarity](/help/closed-questions). It is not currently accepting answers. --- **Want to improve this question?** Add details and clarify the problem by [editing this post](/posts/146947/edit). Closed 4 years ago. [Improve this question](/posts/146947/edit) I've heard it said that white light contains all the colors in it. Our sun produces white light and that the visible spectrum is just the range we evolved to see because our atmosphere is transparent to it. Every planet with an atmosphere in orbit around a star will have it's own visible spectrum for the life evolving on it's surface, potentially causing those lifeforms to have their own concept of "white" which may be the color their star emits, or maybe the collection of all colors in their visible spectrum. In other words, they may call red (Or whatever color their star is) white and say it is the collection of all colors. Some other planets may even have atmospheres where the visible spectrum is too dark, or doesn't reflect off of common materials in a way that is useful for eyesight. On such planets, vision may not even be a trait that evolves in the first place. My question is: how special is our situation? How many outcomes are there to the life-atmosphere-starlight equation and how likely is each to occur? [Answer] Obviously, you don't literally mean "will they use the phonemes we put into the English word 'white' to describe the color they see?" Because not even terrestrial humans do that, apart from some of the minority who speak English. So I'm guessing you mean "will an alien that can see color always come to consider the light that they get from their sun to be a 'neutral' color?" It depends. Obviously, if their atmosphere filters a lot of the light, then their eyes will not be adapted to the light of the sun above the atmosphere, but to the filtered light. If there's a brighter or more constant light source than the sun, then their eyes will be adapted to that. --- An aside about vision. Most of us see colors in basically the same way: we have three receptors for reddish (low frequency, long wavelength), greenish, and blueish (high frequency, short wavelength) in our eyes. The color we see is caused by a mix of those colors. So if we see a color between red and green, we see yellow. If we see a color between yellow and blue, we see cyan. And if we see a color between red and blue... well, that's the color inbetween, so we'd see green. But if we see TWO colors, red and blue, mixed, then we see magenta. Magenta has no wavelength. It's not a "real" color at all. Not everyone sees color this way. There exist people with more than three types of receptor: [tetrachromats](https://en.wikipedia.org/wiki/Tetrachromacy). There exist colorblind people, with fewer. Unless they have no color receptors at all, they have their own "magenta"s, made of no real color. There's a whole bunch of light from the sun in the UV and IR ranges, which we do not see, and which do not make up part of our definition of "white". Our vision goes from roughly 380-740nm. Some fish can see as far into the UV as 100nm, and snakes can see as far into the IR as 5μm, allowing pit vipers to detect vulnerable areas to strike. So it is arguably false to say we call sunlight white. What we call "white" is a very small subset of the Sun's electromagnetic radiation. And at sunrise and sunset, we might call the light from the sun "red" or "orange". We are also *more sensitive* to some colors (red) than others (blue). So it takes less of them put together to make up what we'd call "pure white" where our color (but not brightness) receptors are flooded. --- So would an alien know the colors they could percieve, as "white"? Well.... yeees. As others have said, it's a slippery word. Look through night vision goggles: [](https://i.stack.imgur.com/Ndndt.jpg) That car is clearly "white". But it's clearly also "green". So what we ourselves mean by "white" is complicated. We mean something more like **"reflecting all the incident visible light in the current scene, but not coherently like a mirror".** It's likely that any alien capable of seeing color will be able to express a similar concept, even if their color perception is different to ours. After all, colorblind people do, and so do tetrachromats. And, if the wavelengths they consider "visible" are significantly different to ours, something they describe as white we might call black (some black t-shirts glow white in IR, for instance). The wavelengths they consider visible are likely to be some subset of the wavelengths available to them, so they likely would consider their own sun "white" unless some other light source was a more major part of their evolution (perhaps they live at the bottom of an ocean and only ever see phosphorescent bacteria). --- So would they call our sun "white"? Eh. If they're from a red dwarf, probably not. They would likely consider it "yellowy", if they had the concept of "yellow". "Averaging a little more in the short-wavelength part of the spectrum compared to what we'd call white", they'd say. --- Edit: I should also add that there are some basic constraints on the range of radiation that can be "seen". Seeing much farther into the far infra-red than animals see requires cooler eyeballs, for example, or the warmth you are seeing is swamped by the warmth of your eyeball. UV light is very energetic, so interacts readily with the eyes that are viewing it (UV is why our lenses harden, etc), as well as damaging the receptors. Seeing into the UV range [requires smaller eyes](https://io9.gizmodo.com/want-ultraviolet-vision-youre-going-to-need-smaller-ey-1468759573), as the material of the eye absorbs UV. We are in fact capable of viewing UV with our blue receptors, but our eyes (particularly the lenses) are efficient blockers of UV, blocking all but 5% of it, possibly to prevent damage to our receptors. Removing the lens (an old cure for cataracts, undergone by Monet in one eye) permits us to see a little in the UV. Past a certain point, radiation just can't be focused by structures anything like our eyes, but we know that the sun broadcasts in other wavelengths, too, and we have instruments to measure and record them. How useful they would be for "seeing" is debatable, though - on the other side of IR is radio, and long-wave radio probably wouldn't be much use on any scale that didn't require you to see around the planet. On the other side of UV is high-energy radiation, which again might be something that you would want to shield against rather than perceive. So one could imagine aliens having other materials or structures for eyes which would allow a far wider set of wavelengths to be seen: we are just victims of our heritage, which gave us eyes based around the "blob of water" architecture. [Answer] **They won't call it white, but they will likely see white, -ish.** First, 'white' is just a word it has no intrinsic meaning. Second Our colors or lack thereof is an artifact of how we see light, which wavelength sensitivities we have. And more importantly how our brains interpret available light. Our star is a white star but through the atmosphere it has a red shifted hue due to the atmosphere. So time of day, angle and elevation all effect what color the sun looks like. **In general Will light from their sun look white, probably.** Not for any intrinsic reason but because of evolution. Eyes tend to evolve for the spectrum of light available, if their star emits no blue their is no reason to evolve blue receptors. If they have color vision it will likely see naked sunlight on their planets surface as the default (white) or close to it, since color is based on differential absorption of the light from that source. Whatever "color" of light that reaches the surface that is what they will see as white. If you have color vision seeing any combination of colors other than what your star emits as white AKA the baseline, defeats the function of color vision. The only way they would not is if they orbit a dual star system (or have a non transparent atmosphere), in which case they will see the average light that reaches the surface as white, but each star will have a tint. So even if we would not see their daylight white they will. Likewise our sun will not look white unless their star is very similar in color, at least at first. **In detail, will they see white, sort of** White is also highly situation and subjective, two random humans may not see the exact same spectral profile as white. Note that our color vision recalibrates itself constantly. Look through red tinted lenses for days and your brain adjusts so everything looks white again, take them off and everything looks blue even if you are looking a white surface. It's not perfect but it does means over time we would see ANY star as white if we spent enough time below it. The brain has no objective way to decide what color something is, it has to adjust based on context. Not just our eyes but every animals with eyes we have studied works this ways including [bees](https://www.ted.com/talks/beau_lotto_optical_illusions_show_how_we_see/transcript?language=en). This works with white as well our eyes reconstruct shade and color. I will use a few optical illusions to illustrate. All these chess pieces are the same exact color and shade. Source and relevant [paper](https://www.nature.com/articles/nature03271). But our brain interprets based on context. [](https://i.stack.imgur.com/a3hvx.jpg) Or stare at this image than look at the below black and white one and suddenly see colors that are not there. because your brain has already started recalibrating itself. [](https://i.stack.imgur.com/ISSdH.jpg) [](https://i.stack.imgur.com/DhxXc.jpg) Human and mammals in general have vision with all kinds of problems anyway, we see a much narrower band of the spectrum than say a bird, to a bird the sky looks violet not blue. You also have the problem of time of day, the lower the sun is on the horizon the more red shifted the light reaching your eye is. So the color of their atmosphere will also matter. If their atmosphere shifts the color sufficiently and they ever get to see their sun without it it may have a strong color. [Answer] Let's look at the likely milestones for a species to understand light: 1. The species evolves a sensory organ which **detects the presence or absence of light**. 2. (a) The light-sensing organ evolves to **measure variable quantities of light**. An all-or-nothing response in no longer sufficient; the level of light provides an advantage. (b) **Perception** of light evolves to become **comparative to ambient light**, rather than absolute levels. If the species' planet has a day-night cycle, then there will be periods of very high ambient light and periods of low ambient light. The light-sensing organ needs to evolve to accept this wide dynamic range of light. (In humans, this is handled by the iris and the retinal response.) In addition, one would want the same reaction to a situation, whether it was day or night. Thus, perception should be relative to the level of the ambient light, instead of to absolute levels of light. This effect is seen in humans: an object's colors look the same to us whether in bright or moderate light. 3. (Optional) The light-sensing organ evolves to **process images**. The species can now distinguish light coming from different directions, and create a mental model of their surroundings which is advantageous to the organism. In humans, this is due to our lenses, retinas, and visual cortex. 4. The species evolves **color vision**. The vision apparatus has multiple sensors, some with a different chemical composition which react differently to various wavelengths of light. This provides more information which may be advantageous to the organism. In most humans, this is due to the red, green, and blue cones in our eyes. 5. The species uses **language to give colors names**. This could be spoken words, written symbols, etc. 6. The species develops **tools to measure light**. If the species has evolved 2(b), then it needs an artificial way to meaure absolute levels of light. It may also need a way to separate light into its various wavelengths. 7. The species **discovers the physics of light**. They learn about the electromagnetic spectrum, radiation and absorption, blackbody radiation, etc. They are able to apply these concepts to their own experiences. They study the light from other stars and predict how species on other planets may perceive color. I would argue that these milestones would happen mostly in the order I have given above. Milestones 2/3/4 can be shuffled in any order, although 3 does help 4 to evolve. Some milestones are optional. In particular, notice how giving colors names (5) requires color vision (4), which in turn requires detecting the presence or absence of light (1). Thus, *it is reasonable to assume that a species who names colors will have an "everything color" and a "nothing color",* as the sensation of lightness and darkness would be a primitive concept. It's possible for a species to never evolve color vision (4), yet still develop tools to measure light (6), discover the physics of light (7), and then later go back and give the colors names (5). Even in that case, one would expect that they would still have a concept for an "everything color" and a "nothing color". An extreme case would be a species that invents the tools (6) and discovers the physics (7) of light, yet never evolves vision. However, even such a species would likely have the concepts of nothing and everything. It should also be noted that the names we humans give colors is rather qualitative and comparative. For example, many colors can be described by the word "blue". This is because of 2(a): our eyes really compare what we see to ambient light, rather than to arbitrary absolute light levels. We are driven to make vague names. So our perception of what is "white" depends on the ambient light, as could also be expected of an alien. What we call "white" is probably going to be a different combination of wavelengths than what an alien calls their "everything color". This is because what we label white (5) is influenced by the particular cone cells that we evolved (4). A species that evolves a different set of primary colors will have a different set of wavelengths as their "white". [Answer] I follow your logic. Generally. I would agree. The main problem is the hand waving we need to do to talk about perception. Some would argue about whether or not we all see the same "red". I don't think those arguments are interesting or useful as they're not falsifiable. Now here's some hair splitting idea: Consider the Mantis Shrimp and its 12 types of photo receptors **and** solar spectrum gaps. I could imagine an organism evolving a system if vision detailed enough to see the variations in the spectra between stars. **Then** it would be able to tell the different between true white-full-spectrum light and the light from the sun. [Answer] A mathematicians answer! ["White"](https://en.wikipedia.org/wiki/White_noise) typically is taken to mean radiation whose intensity spreads uniformly across the spectrum in a given frequency band. (For reasons of energy it is not possible to radiate with equal intensities across *all* frequencies.) If the radiation of a star does not follow that distribution, it would not be called "white" or the local equivalent of it. Put differently, radiation of the "colour" white appears "white" however narrow we make the visible range. On the other hand, some radiation may *appear* white to a limited range of frequencies but may be seen as non-white once the visible band is expanded. [Answer] There is a very good [answer by Dewi Morgan](https://worldbuilding.stackexchange.com/a/146955/64985) that suggests a good candidate for 'whiteness' that might be very universal: "even emission across [their] visible spectra". I am inclined to agree this may well be a recurring them but what about exceptions? Is it universal?. There I think not: We see in a very narrow band in the grand scheme of things and we detect light fairly evenly across that spectrum. If the spectrum was wider or we had more fidelity within the range we already see that concept might loose its meaning. In fact, we don't really need to hypothesis here. We already have quite a good example: **hearing**. While it lacks the directional fidelity of sight, we hear in a much greater spectral range than we see. We don't have a name for a noise that's even across all the range of tones we hear. It would be difficult to imagine one too. That phenomenon is really very rare and subjective. Its also worth noting that only one species talks about colour here on earth and the range of light doesn't change much between members the population or for any given member of the population. That might also be a factor in how a society views colour. [Answer] 1. It is empirically untrue that the light coming from the Sun is always called `/hwaɪt/`. * For example, in Romanian we say `/alb/`, and in Russian they say `/ˈbʲelɨj/`. * Even in English, light coming from the Sun is not always called `/hwait/`. For example, light coming from the Sun at dawn or at dusk is called `/red/`. 2. In their 1969 book [*Basic Color Terms: Their Universality and Evolution*](https://en.wikipedia.org/wiki/Basic_Color_Terms:_Their_Universality_and_Evolution), Brent Berlin (an anthropologist) and Paul Kay (a linguist) put forth a widely respected conjecture that color naming evolves in stages: * Stage I: All languages have a term for dark-cool and one for light-warm. In later stages, the term for dark-cool may be repurposed for "black", and the term for "light-warm" may be repurposed for "white", but they may be repurposed for other purposes and new terms created for "black" and "white". * Stage II: Most languages have at least three color terms, the third term being for "red". * Stage III: If a fourth color name is present it is "green" or "yellow". * Stage IV: When five color terms are present, the language has names for both "green" and "yellow". (Actual ancient) Latin is somewhere between this stage and the next -- there is no way to say generic "blue" in Latin.) * Stage V: When a sixth basic color term is present, it names "blue". Most modern languages are at this stage, although some languages, e.g., Russian, still do not have a word for generic "blue". (Russian has *goluboy* (blue like the sky) and *siniy* (blue like the sea), but no "blue in general".) * Stage VI: Brown. * Stage VII: Purple, pink, orange, or gray. [Answer] # TL;DR Most probably the species will have a name for the light consisting of all wavelengths they can perceive, all of them fully saturated. This, respective to our standards is something we call white. For them the Sun will be just as "white" as it is for us and their star will be for us as white as the Sun is. Atmosphere can significantly impact colours. We can perceive the colour of star at their ground level as violet while they can perceive ours as "orange" (in their terms). It may even happen that stars will be totally invisible for them on our planet and for us on theirs even though both we can see them on Earth and they will see it on their planet. It is also possible, that they will use that very same name for the electromagnetic pulse saturated in full spectrum of electromagnetic wavelength of some range just like we do, but they may as well have some totally different name for it. It's all just not so simple. --- # Full answer ## How we see To understand why we see colours we need to understand how is it possible that we actually "see". There are 3 layers responsible for that: 1. Physics (what reaches our eyes) 2. Physiology (how the light is converted into neural signals) 3. Psychology (how our brain interprets the signals that reach it) Let's go one by one. ### 1. Physics What we call light is actually an electromagnetic pulse in a certain range of wavelengths that (depending on the accuracy of definition) either humans are in general capable of perceiving through their sense of vision (a more common term) or physicians have defined as light (a scientific definition). The term light as we usually use it is the first one and all of this "light" is included in the second one (with plenty of additions). Whenever we look at an object, what we actually see depends on the electromagnetic pulse that comes from the direction of that object (and can consist of pulse produced by the object, reflected by the object and that went through the object). I will get back to that later. The Sun and pretty much all stars emit electromagnetic pulses that consists of the wide spectrum of wavelengths, from IR (or even radio) to X-Rays and Gamma. There are some (very small) bits missing and some of them are stronger than others but all in all you can "see" Sun if you look in "visible" light, UV, IR and other frequencies. These are photos of the Sun taken in various frequencies (taken from [this page](https://www.windows2universe.org/sun/spectrum/multispectral_sun_overview.html)). [](https://i.stack.imgur.com/usqh0.gif) For comparison, this are the spectres of other stars (as observed on the Earth - remember about the Doppler effect that shifts the frequencies, taken from [space.fm](https://www.space.fm/astronomy/starsgalaxies/stellarspectrum.html)) [](https://i.stack.imgur.com/rExDy.jpg) As you can see, most wavelengths are covered which essentially means - those stars are to our eyes white. ### 2. Physiology Essentially humans see through their eyes. To be more specific - those are the organs that capture light, focus it and change it into the electric signals that can be transmitted through a nerve system to a brain. Let me focus on that last role of eyes. Retina of a human eye is covered with two main types of light receptors - cones and rodes. Cones are further split into three subtypes. Each of those types responds to a different range of an electromagnetic wavelength (and within the range where it reacts the strength of reaction is different). Here is a representation how human rods and cones are sensitive to specific wavelengths (from [this page](https://courses.lumenlearning.com/wm-biology2/chapter/transduction-of-light/)): [](https://i.stack.imgur.com/EEYtb.png) Let me add that rods and cones cannot work at the same time. There is a simple mechanism that "turns on and off" rods when respectively there is not enough or sufficiently enough light for cones to operate. Let me just focus on cones as they are responsible for our colourful vision. When a specific area of an eye is exposed to some visible light (in common understanding - visible to us), the cones of that eye are "activated" if this light consists electromagnetic within specific wavelength. As a result it send impulses to brain. A strength of such depends on strength of the light of this wavelength and how close the wavelength is to the peak of the sensitivity are wavelength. If we look at something green, yellow and orange, in each case both M cone and L cone will be activated, but with each of the colours the strength of M cone reaction will lessen while L increase. Additionally at green colour also S cone will be slightly activated. All that brains receives are signals from those 3 cones. Now the brain cannot verify what exactly triggered cones. It only knows that those three signals combined tell about a colour of the thing on which we're looking. If it was just a very narrow "beam" (in terms of consisted wavelengths) or the contrary - a broad one, a brain has no way to determine. As a result the same set of "results" from all three cones produce the same "colour" for the brain. This phenomenon is actually used to artificially produce colourful images, especially on screens (TVs, monitors). Rather than trying to emit all colours, all that the screen has to produce is the three colours to which our cones respond and changing the intensity of those colours it can trigger (almost) any composition of signals from the cones, effectively producing for a human brain (almost) any colour visible to a human. Unfortunately that's still not that simple as here we step into ### 3. Psychology To make it short (errmm...), the brain uses its previous experience to get results while interpreting the environment. As someone has described it, a brain is not really experiencing the environment. It's like a general in a bunker. It sits in a dark, humid closed small space and gets information from the outside world through "liaison soldiers" - neurons. Then based on those messages it builds its own interpretation of the world outside. We will focus on the part responsible for vision. In general, each of wavelengths (a single one) produces a signal on cones specific for itself. We "learn" those reactions when observing a rainbow - either natural (created on droplets of water) or an artificial (created through a prism). Now our brain can compare reaction of mixed colours to those of a single wavelength and distinguish similar colours. It can also notice that there are colours others than those in a rainbow so it has to present us those in a different way. This way we get colours like white, black, purple, brown, grey and others that require mixing various wavelengths. But that is not all. Our brain also "learns" how different things look like in various lighting. If we have a white sheet of paper and we look at it in various coloured lights it will be changing its colours accordingly into the colour of the light in which it is now. But our brain knows that it is white so despite those changed lighting conditions it will still suggest its white. Now if we do not have other prior experience and to someone who already has seen white paper in a red light we give in a room with red light a red sheet of paper, the brain of such person will assume that it is a known paper and since most sheets of paper are white it will suggest that this specific sheet of paper is also white. Only changing the lighting will make brain change its mind (eventually someone with authority stating that the sheet of paper is now red). The problem is human brain fills in the missing information and it actually captures only a very small part of the surrounding. Similarly when we look at tree needles after the dusk we kind of see them greenish even though what we can see is just grey. Moreover it may turn out in a broad light that they are brown rather than green (this is my personal experience actually) So in general our brain will adapt the picture according to the lighting. If it cannot determine the lighting for sure it will make a best guess. As a result you have this kind of picture, with question - what is the colour of this dress - white and golden in a deep shade or blue and black in a very strong light? [](https://i.stack.imgur.com/PnGhE.jpg) If you don't know that yet, make your guess and then check e.g. on [The New York Times](https://www.nytimes.com/interactive/2015/02/28/science/white-or-blue-dress.html) and read more about it on [Wikipedia](https://en.wikipedia.org/wiki/The_dress) (though probably everyone know by now). --- ## How other species can see Having said all that... When saying "white" we can express one of three things: * something that we can observe in a way that the range of wavelengths coming from a direction of that object (be it emitted, reflected or passed through) triggers a more or less uniform response of all cone types (that's the most common and natural understanding) - physiology * something that we know from our experience that if put in the typical white light (in reality - Sun light passed through our atmosphere) is known to produce the wavelengths as described above even if at the moment we are observing it in a different light so the actual cones response is different than expected for white objects - psychology * something that produces wavelengths in (at least and almost) full range of what we call visible light - physics. If we consider a different species that developed in different lighting conditions we may safely assume that it will have a differently developed sense of vision (if any). If it has a sense of vision it may or may not be colourful. It may also perceive light in a totally different way, e.g. the way we perceive warmth on our skin or smell scents. We may safely assume that if the species cannot perceive colours at all, it will not have names for the colours, however it will still have a name for existence of light or lack of it (it might be gradual). Even more interestingly if the species does not have vision and can only perceive electromagnetic wave through instruments, the naming will be very technical, focusing on ranges of the spectrum, most probably based on some specific properties, in no way related to colours as we know them. So depending on those circumstances we may consider those names that a species might give as matching to some of our definitions of white1 *for the species*. In other words it may have a name for a light covering such ranges of electromagnetic wavelengths that all light receptors of the species are triggered at their maximum. It may have a name for an object emitting electromagnetic wave in some huge pre-defined range. And it can have a name for objects that are capable of reflecting/passing through the first light from this list if put in the right lighting. Those names may be the same or may be different. And those names may not mean the same range of wavelengths as what we call white. Let's have a look at some on-earth examples just to give a hint. Then I will give even more extreme options. Note - I know neither the psychology nor the physiology of other Earth species not to mention extraterrestrial ones (just some fun facts about them) ;-). ### Bees Bees are capable of seeing shifted light spectrum compared to us. They don't see the most red part of the spectrum but instead they do see at least some UV (graphics from [Bee Culture](https://www.beeculture.com/bees-see-matters/): [](https://i.stack.imgur.com/4JAEV.png) As a result they can see flower patterns that are invisible to us. Note that those pictures have UV filter applied and has the colours adapted to show the additional patterns but of course the "colours" seen by bees are... well, we don't really know how do they see it (BTW we don't even know if brains of different humans present colours in the same way). [](https://i.stack.imgur.com/RGmVq.jpg) While the white as from the Sun will be "white" for both us and bees, if we consider the minimum white range, it will be missing the red part so it will be somewhere between green and blue. ### Snakes Snake use infrared for vision. As a result they actually "see" temperature of other bodies. On the other hand the colours we see are virtually invisible to them. [](https://i.stack.imgur.com/c9D4y.jpg) Again a white light will be white for both us and snakes. But both our "minimal white" will be black to snakes and their "minimal white" will be black to us. To be more specific, our vision spectrums slightly overlap but for the sake of example I'll ignore that part as rather irrelevant part. This is how supposedly snakes see: [](https://i.stack.imgur.com/jrJy7.png) ### Moles Moles have very poor, monochromatic vision. I couldn't find the spectrum, but in general they see light. A speaking mole will probably have a single word that will be a combination of what we call "white" and "bright". It will not understand what you're talking about when you refer to colours unless you use physical properties. For such mole any colour we see can (if intense enough) be perceived as "white/bright". ### Mantis shrimp Well, this case is closest to your expectation. Mantis shrimp live underwater, where the light is limited to mostly blue-green as the rest is quite well absorbed by water. Still those shrimps have 12 photoreceptors which allow their brain to do far less visual processing. They probably also see a broader range of colours. While for humans "white" requires as little as 3 wavelengths, for shrimps it will require an outstanding 12 different wavelengths. So something that we can already call white will be some colour for a shrimp. On the other hand shrimp's white is white for us as well. ### Extreme extraterrestrial forms I would say sky is the limit. Let me just give you two extreme examples. First will be a species which developed various photosensors that are combined with other types of senses. These work a bit more like a shrimp - i.e. they are specialised not to see as we understand it but rather to quickly recognise various opportunities and dangers. Combination of specific colours and scents produces a signal "food" to a brain of this species while combination of specific colours and heat produces a signal "danger" (fire). For such organism there will be no such terms as colours. If it does not perceive light as a separate stimuli (due to evolution from mantis-like perception into even more specialised, with recognition of signal meaning moved to receptors and brain able to quickly react to it, but no separate vision and only later development of cognition) it will not be able to communicate in terms of colours or light as we know it. Assuming it will grasp eventually a concept of electromagnetic wave it will have some sort of scientific, technical word describing what we may resemble as white (with either broader or narrower range), however I don't know if there exist a single word for a beam covering all X-Ray wavelengths in any human language so it might not be a word, but rather a description of the observed/potentially possible physical phenomenon. On the other hand they will have a very complex structure of terms for various things related to perception completely impossible to understand for us. It will be like saying "I perceive a light morning breeze full of tasty aromas incoming" in just two or three words. Second example will have a human vision similar to us in terms of way the perception is done but due to various conditions developed in radio frequencies. Those aliens will be reading our radio communication by seeing it as colourful patterns changing quickly. But what we consider white light will be completely impossible to "see" for them. On the other hand if they present us their "white light" it will be invisible to us but we will hear a more or less uniform noise in our radio receivers. Yet they will probably have wording developed in somewhat similar manner to ours, just meaning completely different wavelengths of electromagnetic spectrum. --- 1 It's worth adding that the name black can have meaning so far from our natural understanding of it as "lack of white/(almost) no (visible) light coming from the direction" that the Sun in astronomy is considered almost a black body. See [this question](https://physics.stackexchange.com/questions/130209/how-can-it-be-that-the-sun-emits-more-than-a-black-body) for more details. --- Sorry, it came as a very long answer but I hope it gives a bit better understanding of the problem. [Answer] Other answers having established that "white" is contextual, so let me add some more potential context. As an astronomer, the first thing that occurs to me is that the wavelength that stars appear brightest is dependent on their mass. The biggest stars burn faster (1-10M years) and bluer (peak in UV), and the smallest stars burn slower (100B years) and redder (well into IR). If your life got used to one of these extremes and then suddenly/occasionally saw the rest of the universe, it would look shifted the other way. For more, see [Hertzsprung-Russell diagram](https://en.wikipedia.org/wiki/Hertzsprung%E2%80%93Russell_diagram). Another idea I don't see mentioned above is if there were a filter that was pervasive but possible to change depth within it. Examples would be an underwater species ([water absorbs red more strongly than blue](https://en.wikipedia.org/wiki/Electromagnetic_absorption_by_water), hence using a red filter to make SCUBA footage match your perception) or a fog/smog layer like Titan's methane haze. Swimming to the surface or climbing mountains or flying above the layer would result in a sudden change in perception of the night sky and the rest of the world above. [Answer] I would say the answer is no (probably - as this is only hypothetical until other intelligent life is discovered). Reasoning: even we as humans don't absolutely always see out sunlight as "white". During daytime, we may perhaps see it as "bluish" white (or "cool white"), early or late in the day it has a more pronounced "yellowish" tinge (or "warm white"). We are very aware of what an "ideal" white looks like (snow, some clouds, paper and other bleached substances ...) and can compare that to the sunlight we see. ]

[Question] [ Cicad the singer is having a downtime in his career. Over the millennia, Cicad sang anywhere from royal courts to farmers' cottages and have been rewarded with many, many hand-claps. But to keep going, indeed to preserve his immortality, he must sing - in battle. When leading a charge to meet the enemy, Cicad would raise his mighty voice and sword in song, inspire his troops - and his superpower. Yes, the secret behind his long life is twofold: **The first:** Singing in battle makes him as strong as three men, and impervious to attack. Even a ballista bolt couldn't scratch him, so long as he's singing with at least two of his men within earshot, fighting against at least two of his enemies. **The second:** Singing in battle at least once every couple of years keeps him from aging, thereby letting him live for millennia. * At least four men must be fighting, not including himself. * The intent to kill the other guys is what constitutes a fight, so they can use long range weapons, even cannons or missiles. However, the field must be such that his guys will have at least caught a glimpse of some of the enemy, at a point in time that's close to the time of the attack (firing a missile at people so far away that you can't ever see them doesn't answer the requirement of "a fight"). * For the same reason, the fight can't be a mock fight (e.g. practice or a fun bar fight). An **intent to kill is required**. * Earshot means that at least two of his troops must be able to hear his song. * Cicad doesn't particularly like to fight, but he's good at it and the troops love him for both the songs and, well, the fact that his side tends to win. So every two years, at least one fight. This was all well and good in the old days, when a good charge with melee weapons constituted a good fight. **Nowadays**, however... There are plenty of fights to be had but not the kind where singing is appreciated. Indeed, as recently as the 19th century Cicad has faced frowns when singing while the battle rages. In this day and age, where concentration and stealth is a prime concern in battle, he was threatened with removal from duty for singing at the wrong times. This almost made him come forth and tell of his abilities, but he absolutely does not want to be probed and bisected by scientists who'll want to check what makes his superpower tick. So the question is: **What kind of situations in modern day combat warrant loud singing by at least one particular combatant? The bigger the advantage one side gets by the singing, the better the answer.** * For the sake of the question, lets assume that other noises (e.g gun/cannon fire, screams of the dying) are not getting in the way of Cicad's singing. **Edit 1:** I really should have clarified this - I want Cicad to be running in the field and getting smacked with fire and brimstone (bullets and heavy ordinance) from time to time. So, **infantry**. He can be in a tank for a bit of the fight but the point of his imperiousness to harm is to get an unhinged singer into the thick of it. I'll worry about people not noticing his invincibility later... **Edit 2:** For those still complaining about other noises, as I wrote - hand (ear?) wave it. Part of the superpower is that **the singing subdues noises that are undesired by the audience** (which can be a cool advantage by itself, just not so relevant to this question). [Answer] This answer is based on my own time in the military which included 2 tours: > > What kind of situations in modern day combat warrant loud singing by at least one particular combatant? > > > *There is no direct combat situation in a realistic battle which would allow for this.* The reason? Because your statement *lets assume that other noises are not getting in the way* is impossible in a normal situation. Meaning even if he could be heard, assuming a super power, it would still not be allowed by his squad. The reasons: ## Combat is Loud Imagine explosions, gun fire, screaming, and your own heart pounding in your ears - modern combat is incredibly loud. A quick overview of decibel values ([source](http://www.industrialnoisecontrol.com/comparative-noise-examples.htm)): * 100db is like a jackhammer * 120db is 4 times as loud and considered painful (e.g. a chain saw) * 150db is *8 times as loud as that* and is enough to rupture your ear drums Now, imagine every vehicle running with 100 or more db, each weapon (from *several directions!*) firing with 145-190db, and a Marine's own weapon blasting away 160db *right in front of their face* (see [pages 79-81](https://www.nap.edu/read/11443/chapter/5#79)). Indeed, it is so loud that the number 1 & 2 combat related injuries involve hearing loss. Military members can't even wear the current hearing protection we have because it [makes it too hard to hear orders](https://99percentinvisible.org/episode/combat-hearing-loss/) from you commanders and other fire team members. Someone singing would just be more noise and never welcome during actual combat. ## Many times you're already wearing communication (comm) equipment Currently there are a lot of different ideas on improving ones [ability to hear in combat](https://www.npr.org/2017/07/26/539438864/military-tries-to-cut-through-the-noise-of-war) but most of these are still in the development stages. Ever played a video game online and someone just keeps stepping on everyone trying to talk over a single comm channel? Now imagine your in combat and Cicad is singing over comm (so people can hear him) and you don't want to know what the squad will do to stop this person who is keeping them from hearing orders, calling med-evacs, and coordinating actions. ### How could he sing in modern combat? Well, he couldn't, not out loud with the typical situations you encounter in a real modern, urban, battlefield. However: the military is always researching new methods which could be modified for the sake of a story, strange things happen in combat (at least once), and there is one situation which is rare but I've heard at least a few eye-witness accounts of. 1. **Singing used as a form of biofeedback** Currently the military is researching a whole lot of audio feedback methods for [treating PTSD](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3338628/) & also [TBI](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5580369/), doing better at [physical exercise and mental tasks](https://www.military.com/daily-news/2017/04/02/super-seals-elite-units-pursue-brain-stimulating-technologies.html), and to [train military members for combat](https://www.aapb.org/files/publications/biofeedback/2011/biof-39-03-112-118.pdf). Cicad could participate in studies like these, which require him to record his voice for military members to hear in combat (if an effect is seen). This could actually eventually allow him to remove himself from combat if the recording of his voice works as well as him actually singing or he is sent to combat and required to sing due to improvements seen in these studies (which only happen with a "live performance"). 2. **"Happy Birthday"** Yeah, believe it or not even in the bloodiest battle in Iraq [Marines stopped to sing their hymn on November 10th](https://taskandpurpose.com/8-unbelievable-stories-from-the-second-battle-of-fallujah/). If you only need once a year, this event could work as Cicad would only need to start singing the Marine Hymn and his squad would likely join in. 3. **"Paint a Target on my Back"** I have never actually seen this and don't believe ***most*** **of the stories** I've heard but: there is the myth of people who start making noise on purpose, who just get up and distract the enemy or otherwise [make themselves stick out so they are targeted](https://news.va.gov/73584/white-feather-sniper-carlos-hathcock/) or so their squad can see where the enemy positions are. Suppressing fire is usually used but Cicad could start singing to distract the enemy or get them to expose their position so the rest of the squad could move in. [Answer] **Singing still has a place in modern battle.** <https://www.ultimate-guitar.com/news/general_music_news/us_marines_blaring_acdc_to_agitate_iraqi_insurgents.html> > > According to the Associated Press, U.S. marines in Fallujah, Iraq have > been broadcasting messages by loudspeaker to agitate Iraqi insurgents, > announcing, "You are cowards for hiding behind women and children. > Come out and fight," and blaring heavy-metal music, including AC/DC's > "Shoot To Thrill". > > > I read an account of tank warfare in the first Iraq war where the guys in the tank were all singing along to "Thunder" (also AC/DC) as they went looking for opponents. Stealth is not a consideration when you are in a tank. The place for singing in modern war is during city battles where stealth is not an issue, but especially during motorized or airborne expeditions where your vehicle is obvious. Singing is still good for morale. It occurs to me that a drone pilot silo might be a fine place for singing also. Drone pilots are viewing the enemy (albeit remotely) so that meets OP criterion. The enemy can't hear you so no harm in singing. And it is freaking boring for long stretches of time and the songs will break up the monotony. [Answer] He's going about it all wrong if he's in a western military. Even most infantrymen rarely, if ever, see who they're shooting at. He should join a 3rd-world military as a mercenary. They have much looser discipline, meaning he won't be reprimanded for singing. Further, their equipment and training are much poorer, so they often need to get much closer to their targets to actually fight; meaning he WILL get to see his target. Alternatively, he could be a vigilante. Fighting to the death is not strictly a military task. He could go hunt down narcoterrorists in Central or South America. Law enforcement wouldn't even try to stop him for the most part. [Answer] <https://en.wikipedia.org/wiki/Jack_Churchill> This guy used a sword and a bow and arrow along with a pair of bagpipes in world war 2. I think the idea was to demoralise the enemy. It's probably a case of if you can get the job done while singing then go right ahead and sing. He might get a bad reputation at first but after he has pulled of a few heroic actions people will start to respect him despite his oddity. [Answer] > > I give my orders through limerick > > it may sound weird, but there's a trick > > with the rhymes so clear > > all the men will hear > > through the radio static thin and thick! > > > I got the idea from reading @Wolfgang's answer. As a radio operator myself I know how hard it can be to hear things through static and I think rhymes would really help with that. I went with a 9-9-5-5-9 form limerick. Feel free to edit my answer to add more limericks that fit the topic. :) [Answer] What about non-military? He could join a local gang if he can find one to fit whatever his moral code is. Or start his own gang. I don't have any personal experience, but it seems that at that level, you're (at least sometimes) back down to the traditional knife, club, and fist. [Answer] Same old, same old...to boost morale, increase hormone levels and pulse to sharpen senses and raise euphoria / aggression, tighten team bonding and focus (stronger together) I'd love to list some points of the following but it is just too much tl;dr info. * An interesting study about singing along to (in this case western pop) music: <http://www.doc.gold.ac.uk/~mas03dm/papers/PawleyMullensiefen_Singalong_2012.pdf> * music / sound as a weapon: <https://www.newyorker.com/magazine/2016/07/04/when-music-is-violence> *The New Yorker - July 4, 2016, issue, with the headline “The Sound of Hate.”* * see also the role singing played in the World War I Christmas Truce of 1914 * Stanford University psychologists Scott S. Wiltermuth and Chip Heath conducted a series of experiments to see how synchronous movement affects group interactions.[...]These findings suggest that cultural practices which involve synchrony (such as dancing, singing or marching) may enable groups to produce members who are cooperative and willing to make personal sacrifices, for the benefit of the group.*(Journal Reference: Synchrony and Cooperation. Psychological Science, January 2009)* * there are quite a few videos on youtube showing russian soldiers marching while chanting the theme song to spongebob squarepants (; <https://www.youtube.com/watch?v=vhuzb3WMntc> [Answer] Timing. Cicad is a somewhat eccentric infantry officer that uses song to coordinate assaults. His men think its strange, but it gets the mission accomplished. This could be used over short range radio as well. Assaults in an urban setting would exemplify this well, with different parts of the song coordinating different actions of the platoon members. [Answer] > > Right that moment I was feeling unusually expendable, almost expended, because I was hearing the sweetest sound in the universe, the beacon the retrieval boat would land on, sounding our recall. The beacon is a fast insertion ship, fired ahead of the retrieval boat, containing a single crew member that starts singing that welcome, welcome music. The retrieval boat homes in on it automatically three minutes later and you had better be on hand, because the bus can’t wait and there won’t be another one along. > > > But you don’t walk away on another cap trooper, not while there’s a chance he’s still alive — not in Rasczak’s Roughnecks. Not in any outfit of the Mobile Infantry. You try to make pickup. > > > I heard Jelly order: "Fleads up, lads! Close to retrieval circle and interdict! On the bounce!" > > > And I heard the **Battle-singer Cicad**’s sweet voice: *"— to the everlasting glory of the infantry, shines the name, shines the name of Rodger Young!"* and I wanted to head for it so bad I could taste it. > > > Robert A. Heinlein, Starship Troopers, modified. In this modern day and age, Cicad plays a central role in in his platoon, due to his unique skills. Every mission ends with his Retrieval Team serving as a beacon for the landing troops to gather and prepare for extraction, his legendary presence and powerful voice serving as a boost to the Infantry troops. [Answer] The "Dynamo" character in Schwarzenegger's "Running Man" was singing before he started zapping people. That's a bit in the future, but opportunities for a murderous singing assassin appearing on TV might arise. ]

[Question] [ In the story I’m working on, there is a strict ruleset on how magic works, one of the main points being it needs a “fuel” to work, and that “fuel” is VERY expensive. That being, most magicians use their skills while saving the most fuel possible. Against ordinary foes, without any magical abilities, they usually use it to create a burst of wind that destabilizes the opponent and simply finish them off with a dagger to the heart, much like Andrzej Sapwoski’s witchers use their “Aard” Sign (more of a distraction than a weapon). But, against other magicians, things are a little different. There are big coliseum styled magical fights, those being more entertainment oriented, so they’re usually big flashy combats with fireballs and lightning flying everywhere. But that’s when I got cornered. In actual magical military combat, saving magic fuel would be a primary concern as well, and magicians would probably favor extremely lethal and economic spells over big fiery blasts. Please consider the following: * ”Magic” is the ability to control forces of nature (wind, water, flames, lightning) and inanimate objects. * One \*\*\*\*insert fuel unit here\*\*\*\* is enough to cast 100 wind blasts powerful enough to stun or knock out an adult male, or 10 fireballs the size of an orange; * Magic cannot create, only manipulate what already exists. You cannot shoot fire from your hands, you have to actually set something ablaze and control the flames; * Magic does not affect living beings (people, animals, plants), in the sense of altering their living bodies. There is no polymorph, mind control or magical enhancements to strength or speed. You can’t just vaporize your enemies. That extends to the natural elements inside the human body (water, electricity, iron...) There are, however, ways to affect armor and clothing. * The range is how far the magician can see. Sight augmentation apparel can extend the range. * They can control whatever they can see. There are no microscopes yet, so they cannot control individual atoms or molecules. * A single magician power is limited by his knowledge, amount of fuel, and psychological endurance. Casting large spells have a heavy toll in one's mind, and trying to cast a spell too big to a single person would effectively kill the mage. With that in mind, big spells are usually cast by groups of mages holding hands, so they can share the stress and fuel expenditure of such grandiose acts. * There are no permanent spells or "curses". A spell exists as long as someone is casting it. If the caster is incapacitated or killed while casting, the control over that specific element is lost and it will simply follow physics from that moment on. Based on those rules, what probably would magicians cast in a mage fight? What force of nature is easiest to control and deadliest? Would they just walk around with a pocket full of knives and hurl them with lethal precision at their magician foes? Would they ignore magic and sword fight each other until there is an opening for a wind blast? Please note that I’m not asking about the magic system, which force of nature ACTUALLY is the strongest or that kind of thing, I’m asking about military combat tactics that for some reason include magic. --- **UPDATE:** I was blown away by the amount and quality of the answers here. Almost every single one has inspired me in some way, but as we now have a two days old question I must choose one to be the solution. Since warfare tactics are pretty much covered, I'll choose the solution based on the duel aspect of the answer (or not necessarily duel, small fights between mages may fit as well). I won't choose one of the existing ones about duels mostly because they miss some points: * Mages are human. Could you think about bullet-proofing your clothes, blow away projectiles with wind and turn the ground below your opponent into mud *at the same time*? They can't, either. * You probably wouldn't want to save fuel while fighting for your life, only enough to not be unarmed. * No, you can't mess with your opponent internals. No pressure, air pockets in the brain or that kind of thing. The *physical space* that the body of a person occupies is *completely* immune to any kind of direct manipulation by magic. * Obviously, a fight between an expert mage against a non-mage or a novice mage will be a slaughter. Think even power levels. * The world is big and there are many countries that practice magic. There are many styles of magic and many functions to a mage. Maybe illusionists have a common prejudice against elementalists because "they make too much of a mess". Thank you! [Answer] **Snipers** Given the rule that magicians can control what they can see the most effective place for a mage would appear to be as a magical sniper, special forces or artillery. It's also probable the most efficient option in terms of energy. You probably don't want your highly valuable "fuel" falling into enemy hands so it's best to keep mages behind your lines. You don't want to waste fuel on flashy flames and lights unless it's for the sake of shock and awe. An exception would be arson. A few small fireballs or levitated balls of flaming oil in your enemies supply caches can do wonders or magical artillery launching flaming oil. In a battle between 2 armies, both with mage support it becomes a game of seeing without being seen. If a mage sees you he has pretty good odds that he can throw a small poisoned dagger and plant it in you at high speed. Taking out key figures would be a priority, the war is practically over if someone puts a nail through the neck of the enemy general. If a mage sees another mage without being seen you get a similar outcome. Mage spies and special forces would also be powerful. If the king is foolish enough to strut around in front of crowds without protection then he's liable to get a dagger through the eye. Mages might even routinely hide their identity so that they can hide in a crowd. Battles become more a matter of figuring out who the other mage is first in a spy vs spy urban environment. **What can non mages do to defend themselves?** Smoke, fog, darkness. All would be allies to those without magic. If a mage can't see you he can't kill you easily. If you can cover the battlefield in enough smoke your men can get in close where they have the advantage of numbers. Mages meanwhile might try to clear smoke with bursts of wind and light up the dark with bright magical flares and follow up with long range projectiles. [Answer] ### Support and Engineering With the cost of fuel so high, a primary concern is having that fuel fall into enemy hands. So you're probably not gonna want trucks of the stuff on the front lines. We see this in real life with real fuel and assets. They are stored "away" from the battle and moved in when needed, at FOBs (Forward Operating Base). Also, you probably don't want you mages getting captured and turned. Again we have real life examples of this with code breakers, code talkers, and high end equipment (among others). For example, a jet is to be destroyed if left behind enemy lines. So the best place to use a mage is to give your normal army an advantage. It doesn't take much. History is filled with examples of armies winning amazing victories for no more reason then they have the high ground. To that end, how about have them be engineers instead of combatants. They can use their abilities to do simple things like making a land bridge, destroying current bridges, enhancing natural cover, mildly affecting weather. Take a look at the "Battle of The Bulge" during WWII. At its core, the 101st defended Bastongne with very little support, while the German army's plans hinged on the ability of their army to rush across the Meuse River in just a few days. The Germans would have had a much easier time if somehow a "mage" was able to clear the woods with fire. Also, the 101st was able to hold the area, in part because they had superior air power. The Germans had to wait until the weather grounded the US air forces. Field Marshal Von Rundstedt is on record saying "Weather was a weapon the German army used with success". If the weather could have been kept clear, the 101st may have had an easier time. If the Germans could have helped the bad weather along, they may have won. Finally, the Germans initial plans called for a bunch of fuel for their tanks that never reached the area. Bad weather, poor roads, and other logistics problems kept the fuel from getting there, at the same time the US forces burned gas to keep it from falling into their hands. Here again a single mage, with little "effort" could make a huge difference. An allied mage, screwing with the supply lines by washing out bridges, thawing ice along the planned route, setting fires in fuel depots may have ended the battle sooner. On the other side, mages securing the normal fuel supply could have caused the destruction of the 101st. Mages in support and engineering roles could have a huge impact with little "fuel usage". It doesn't take much to swing a battle in your side's favor. If fuel is that rare and expensive, then you don't put it in range of the bad guys. You keep it safe far away. ### Propaganda Part of support in my mind, but looking at WWII again, the US (especially west coast and New York) had a very high level of fear. Nukes were a new thing of course, so that wasn't really a "real" concern, but Japan was making good strides in Naval warfare, and NY was just a natural target. In both cases things like Subs (German subs especially) caused fear. Like they would pop up in the middle of Manhattan harbor and start launching missiles. On the west coast, Perl Harbor had "just" been destroyed. What's to stop Japan from doing the same with L.A.? Totally "civilian" worries as the military had it under control. But without the civilian support, especially the US military crumbles. Remember the US was dangerous in WWII because, largely, because it was not in the war. It was an untapped pool of manpower and raw materials. With Pearl Harbor, the civilian population now had a reason. And unlike Britain and others that were holding on, and fighting for every inch, the US was able to enter the war, with largely untapped resources. For example, people in London were being bombed nightly. There was rationing of food and materials because they had no choice. In contrast, the US civilian population now had a reason to "ration", but unlike many of the allies, the US could devote the extra materials to the war. There are stories of women giving up metal hairpins, and wool metal scrubbing pads to make munitions etc. All that raw material and manpower entering a war where everyone else had already expanded large parts of their reserves made a huge difference. A mage or two heightening the fear factor along the coastal areas, or a mage or two making the civilian population feel more secure in those areas could drastically have changed the US presence in the war. So in summary, mages would play largely support roles. Places where a little magic fuel can make a HUGE difference. Take a look at the Army core of engineers. A block of C4 to blow a bridge to stop the enemy advance has a larger effect then 1,000s of blocks of C4 to stop the tanks individually after they cross the bridge. Because of that mage fights would largely be a non-thing. If two mages see each other they just wave and go on about their business. The normal soldiers, that would be defending the mage, would do all the fighting. In fact, mages may model more after real world non-combatants then you think. With provisions in the Geneva conventions and all. An agreement between mage "guilds" that no mage may participate in direct combat during wartime. And that the protection similar to that of non-combatants as POWs today would likely evolve. Especially with fuel being so rare. [Answer] # Counterspell Spells are expensive and take concentration. A wizard that's good at multitasking can repeatedly wreck the enemy's concentration on a more powerful spell with simple low-cost tricks like blowing air into their eyes, and then run up to them and shank them in the neck. [Answer] You have two conflicting uses for the fuel here. The first is for showy gladiatorial fights and the second is military power. I don't see them as totally mutually exclusive, but more like branches from a common art. In some of the very old martial arts, there is a calcification with the old traditional forms and movements that were based on techniques that were effective once upon a time. Tae Kwon Do seems to have been developed for dealing with enemies on horseback when you look at the high, powerful kicks. Those kicks are devastating to an opponent when they hit, but against another person on foot, they are relatively easy to dodge. This is the path I see the gladiatorial magic to follow. Flashy fireballs and ice and windstorms might have been effective in a military sense once upon a time but as tactics evolve they would become less and less useful. The modern military mage is going to understand that power brought to a point is far more effective than any amount of flashy fireballs. Military actions are won more by efficient application of resources. This means things like mages augmenting the flight of arrows, acting as snipers, and of course, spying. It doesn't take a huge amount of energy, properly focused, to break a generals neck or blow a blood vessel. Magic could be used as triggers for traps.Even magic being utilized to catalyze a poison in the enemies water supply. Subtle is better than flashy, lest an opposing mage try to break your neck for your troubles. These kind of subtle techniques would be more efficient in terms of fuel. No flash and sizzle, but no less lethal for it. [Answer] ### Siege Weapon > > ”Magic” is the ability to control forces of nature (wind, water, flames, lightning) and **inanimate objects**. > > > Since the mage can manipulate inanimate objects that would include walls surrounding castles, fortifications, and cities. A mage or small group of them could pull down part of a wall and create a ramp thus breaching the defenses. This would dramatically speed up sieges. The city being sieged would likely have their own mages working to keeping the walls up, but because of the siege they likely have limited sources of fuel for their magic, and would eventually give out to the side conducting the siege. ### Magic Powered Rifles and Other Military Hardware This goes hand in hand with the idea of using mages as snipers, but can be applied in a more general sense. A mage can use their magic with existing weaponry to enhance its effects and make it more deadly in combat. By leveraging existing military hardware this would reduce the burden on the fuel for the magic and help it last longer. Alderamin on the Sky has an example of this with their air rifle. Each rifleman had a wind spirit for a partner that acted as a power source for their rifles. The air rifle shot a projectile, but instead of using combustion to propel it the wind spirits built up air pressure in a chamber in the rifle which rifleman released to fire the bullet. They also had air powered mortars and artillery which worked similarly but on a larger scale. Another way to combine magic with existing hardware is with catapults. If mages can create a more powerful version of a flaming jar containing pitch/tar/resin they could use the catapult to throw it rather than having to spend mana to throw it. ### Enhance or Create Hazards A group of mages could spend a sizable amount of mana to summon a lightning strike on their foes, but what if it is already raining and there is already some rumbling in the clouds? Instead of creating a lightning bolt from scratch take what nature gives you and spend a little bit of mana to direct it (and possibly scatter it) so that it lands in the middle of the enemies forces. Rain itself could be turned into a nasty weapon. Rain is already falling at terminal velocity, so freeze it into small spikes and speed it up some more, thus creating some nasty hail. This would not be deadly, but it would hamper the enemy. ### Logistics War is also not only fought on the front lines. There are other aspects to war that mages can help out with that can turn the tide of battle. Mages can use their magic to help create bridges over difficult to cross rivers and also destroy enemy controlled bridges. Small things like this can benefit your supply and troop movements and/or negatively impact enemy logistics. If the enemy has a key road they use to move their supplies (like a mountain pass), sneak a mage back there and have them remodel the road with a huge mound of rocks (triggering a rock slide) or create a giant hole. This would create delays in the enemy troop movements that can decide battles before they even start. [Answer] Fireballs might very well be "cheap" in your fuel, depending on how exactly your magical system works. The main idea is that all of the energy doesn't necessarily come from the fuel - it's a reaction of the fuel with something else. A piece of coal burning consumes carbon from the fuel, true. But to do this, it reacts the carbon with ambient oxygen - if you shut off the oxygen access, the fire dies. For perfect burning, you convert carbon and oxygen to carbon dioxide - the mass ratio is 6 fuel to 16 oxidizer (for free from the environment). This means that for a fire of this kind, you only need to supply 25% of the required matter. A high explosive works differently - pretty much by definition, it cannot rely on getting the oxidizer from its environment, so it needs to be internal. So you need to supply *all* the matter. Obviously, this is a gross over-simplification, but we're looking for patterns here, not precision (after all, your magic might work somewhat differently from our physics). So the difference between a "flashy" fireball and a high explosive might be a fourfold increase in fuel costs - you need to affect a lot more mass. And yet, against a medieval army, the firewall will likely be far more effective - you *want* spread; there's no heavy structures you need to penetrate with a concentrated energy release. Not to mention that you don't need to develop any specialised explosives - a piece of coal or charcoal would work wonders, just throw it at the enemy, crush it and provide the initial energy impulse, and you get a beautiful (and relatively cheap) explosion. Anything that readily oxidizes will work well. Of course, concussive explosions aren't great for killing directly, but they will disrupt formations and morale quite handily. And against wooden ships, your magicians are going to do wonders :) For raw energy efficiency, it's hard to get anything better than telekinesis - but you already have that in archers and catapults and similar. The magician doesn't give you any measurable benefit, and given the cost of "mage fuel", it will likely be a net loss. So you need to do something efficient that isn't done better by a bunch of guys with bows. Fire actually works very well. It's not so obvious today with modern firestarters and petrochemicals, but the use of fire in warfare was almost impossible in medieval times (the earlier "Greek fire" probably was petrochemical, and largely forgotten - though undeniably effective). Forget volleys of fire arrows instantly setting the village on fire - that's just Hollywood. On the other hand, your magician could do something like that easily - he only needs a tiny burst of concentrated energy to start huge fires, and a thin spread of fire over an enemy formation will likely be quite devastating, especially for morale (which was always extremely important in warfare). This is especially handy if your magicians can prevent the enemy magicians from doing the same - even if you don't use magic offensively, you *need* your own mages for defense. And setting the enemy commander's clothes on fire from afar would likely be very easy while also being quite effective. In the long run, this will of course force important units to avoid flammable clothing, but this is actually a massive detriment to their combat performance, so it's still a win. But that's still fights where the magician is just a part of an army. How does this apply to a duel? Well... not well. Just stab that guy, seriously. Magic isn't going to make it any easier, other than providing a distraction - and since you're fighting another magic user, that's likely as much a problem for him as for you. You'll battle a bit, prepare an opening, blast a bit of dirt in his eyes and just stab him. Or conjure a gush of wind, and stab him. Or conjure a bright light, and stab him. Given your constraints, there's really no way for a magician to just kill the enemy outright, or even substantially inconvenience him. You want to do a tiny, cheap action, and finish with a dagger/sword/whatever. At longer range, you'd just toss stones at each other, probably while increasing their power and precision with your telekinesis. But not really more than a typical slinger would - "muscle fuel" is much cheaper than "magic fuel". Indeed, dagger+buckler and sling might be the perfect armament for a magician in your world. Of course, if you're obviously well over your head, you might very well choose to use a powerful spell regardless of the cost. But that's probably not a typical scenario - presumably, most fights would be between rather evenly matched opponents; and quite possibly, not to the death either. Especially if any mage can deal a killing blow in desperation, expending all his strength and fuel reserves. [Answer] # Cost effective ones **Individual targets are assigned a value.** Officers by rank most likely, enemy mages would also high be high value. Officers would be wearing the same uniforms as the men, a change that happened slightly behind the invention of accurate sniping, so spotting them is going to be hard. Senior officers might not even be on the field, relying on relayed communication for commands and intelligence. **Other high value targets of opportunity** * The drummer - a key to battlefield communication * The bugler - also a key communicator in a battle * Messengers - Can you see where I'm going with this? **Fuel has a value by availability and projected duration of combat.** If you have a lot of fuel and a small number of enemies, it could be worth just wiping them out. Though it may just be a feint to get you to burn fuel casually ahead of the main attack. **Defence spells** are also very high value. One of the biggest here will be to bring down a fog, localised (or whole battlefield if it's not working out) over something that needs to be protected from mages. Maintaining a continuous fog over the command tents so officers can come and go safely for example. Can't be seen, can't be directly targeted. You can also take that the other way and stick a fog over their mages so they can't see anything. A smoke screen would do if they can't handle fog, but it's just wind and water. **I'd seriously consider dedicating my mages to sniping and fogging enemy mages and fogging the top of my command chain.** With only one or two, depending on numbers, sniping their commanders and messengers. Find the paper for their rocks, the scissors for their paper. [Answer] As for the battlefield use, you could take a look at the game Dominions 4. It's a strategy game where proper use of magic is vital to win the game, and there's so much more than the good ol' fireball. A thing that does not cover however is mage saboteurs targeting stuff like supply depots, which is a pretty good use. But you seem to be more interested in mage duels. With your constraints, it starts like a gun duel and then as an arme blanche duel. Let's assume a chance encounter of two mages, there is no ambush and no feasible way of disengage or retreat. **First round: Shields up!** (or dive to cover) In a duel of any kind, the objective is not killing the other, it's surviving. A double kill is as bad as an outcome as just getting killed, so the sensible first action is protecting oneself. That means getting behind cover or raising a small tornado around to deflect accelerated projectiles and counter gusts. **Second plus rounds: Getting around the defences** With your constraints, unless the environment is a building on fire, or in sea/lake/river/very heavy storm, there isn't enough material for fire and water magic to be useful. So it's air and earth time. From there, depends on the level of the mages and amount of fuel in their bags. It would go from a nail and stone shootout (from any angle!) to dropping walls, floor breaking and finally lightning bolts and raising stone pikes under the enemy with impaling intentions. With plenty of countergusting, running and wrangling control of the environment (specially with earth magic). And well... A dramatic dagger melee once there is too much dust raised to see is also an option. [Answer] Maybe they could throw a bunch of [caltrops](https://en.wikipedia.org/wiki/Caltrop) in the air and try to control them with powerful wind. Fire could be used to ignite some sort of arrow and again use you wind so that they find their target. Normally they will probably try to keep their distance and prefer swift attacks. The faster the better. If they can concentrate the air they could try to "stab" the enemy with a powerful concentrated gust of air to the enemies heart. Other than that I cannot help but think about the series [Avatar](https://en.wikipedia.org/wiki/Avatar:_The_Last_Airbender) where they control the elements. [Answer] I would use a few non-magical alchemists and have them create poisonous gas, then use my mages' ability to control the winds to ensure the gas goes towards my enemies' army and doesn't disperse too much. Should be a total massacre. The benefit here is that depending on the natural wind condition, you need less and less magic the more the wind is already in your favor. Note that this is of course a large-scale tactic that takes a bit of time and doesn't really answer what a mage would do in case of immediate danger. [Answer] This may not be very flashy or spectacualr, but if they are able to control physical objects, why not have them accelerate very small objects to high speeds (like bullets)? It would require comparably little energy and would be extremely lethal. That's why humans have always used kinetic energy to kill with.The more accurately you can steer your projectiles, the deadlier you are. Think of Yondu in Guardians of the Galaxy. Every Mage could just carry around pouches of whatever objects suit their potential requirements. To make things more interesting they could also charge these small objects with something like heat, electricity(you said they can shoot lightning), etc. [Answer] I would thing about combining powers different way - have archers shoot a lot of arrows on enemy army, the take telescope and on long distace you can easily see individual arrow - select one from the cloud and just little bend its rear wings to hit king with extreme acuracy. Energy needed from mage is like bend feather. Eventually accelerate the arrow in its final approach to get more devastating and piercing effect - but only if you see, you will hit the target, so no energy spend on near miss. Let catapult throw a barrel of oil to air above enemy army, balista to shoot burning arrow to the same area, just litlle manipulate wings of the arrow to meet its target and at the right time untie the rope fixing barel together, so the barel would break to parts, oil is spread over area and burning arrow (with momentary enhanced fire maybe) fly thru the cloud = instant fire rain / mass explosion. Basicaly have physical way to get something heavy, fast harmfull near to enemy, then use minimal energy to slightly alter something on it to hit with unnatural precision and the just right time. Provide as much energy/material as possible with conventional means and manipulate it magically only when it is in nearly good position (which is not so hard to acquire) to have it hit excelent at the best possible point. Use telescopes as much as possible and use them in periscope form, to have the mage out of sight. And use magic as small and short enhancement in final phase of attack, so it does not spend much fueal and is hard to detect, less to prevent. If you see, that there is effective countermeasure on target, just save it for next time - it would force defender to burn a lot of fuel to protect against mundane threads, which are not so effective, but could be, if the magic would be used on the last moment. (I suppose, that the fuel is really expensive, so it pays of to spend a lot of mundane weapons/force to cover which one will be magically enhanced, if any and that the magicans are rare, so it pays of to send (and maybe sacrifice) squad of peons to prepare way for perfect attack). Also using some "cheats" as create temporary inversion (fata morgana) on sky to see over hill enought to magically hit something out of LineOfSight would became common tactic. (Or shooting mirrors/polished plates to air, where it will be magically alligned to enable mage with telescope hit target behind corner/hill/other obstacle. On the other hand a bit of magic used to little move some wood would enable to build really fast bridges over rivers/chasm and such, but throwing a lot of poles there in air (balista/catapult like style) and then magically alling them to make and arch, which would stand long enough to sappers climb it and fix it better with more ropes/nails and bouild the massive bridge over this small newly created - as the big problem of supporting first path would be magically moved away. [Answer] I would guess most mages would focus on air, as this is the most available element. they could create gusts of wind to change the trajectory of arrows, which would not require alot of energy. if more energy was available they could create tornado's above the enemies army, and in a duel or if there was an immense amount of energy available, they could try and remove the air from the enemies lungs or their surroundings, effectively choking them. [Answer] after reading all the other answers here i think a mage on mage fight would have a few stages. 1. be faster; kill your enemy in some way before they can react, e.g. really fast bullet/stone, or plain striking before your target is aware of you. 2. be smarter; outwit your opponent so you can kill them without them knowing what did the killing, or have them expend all their fuel on illusory attacks. 3. have more fuel; if you haven't killed your opponent with speed or wits you must be equally matched in these areas and thus overpowering is your only remaining, purely magical option. 4. be a better swordsman. if the above 3 steps have not worked it's time for your backup weapon. Note that stage 1 through 3 might be over very quickly as neither side is going to be willing to expend all their fuel early on in the fight, and you end up with more of a witcher style duel, where quick spells are used to augment the melee combat. the specific spells used are probably going to depend on individual preference, and the specifics of your rules for fuel expenses. it's not possible for me to say what takes more fuel, making a fireball out of a candle, or accelerating a few grams of (potential poison laced) iron to supersonic speeds. [Answer] The world you describe would use modern warfare with very accurate guns. You state: * "Magic" is the ability to control forces of nature (wind, water, flames, lightning) and inanimate objects. * The range is how far the magician can see. Sight augmentation apparel can extend the range. * They can control whatever they can see.There are no microscopes yet, so they cannot control individual atoms or molecules. --- We've already acquired the first point in modern society. We can manipulate wind, water, flames, electricity, inanimate objects, etc. at the expense of energy (similar to your magical units). The only issue is that some manipulations cost more energy than others. Turns out moving projectiles is the cheapest (energy-wise) and most effective way to hurt someone. The amount of energy you describe actually doesn't sound all that scarce. The amount of wind it would take to blow over a person is an estimated [70 mph](https://physics.stackexchange.com/questions/41934/what-does-the-wind-speed-have-to-be-to-blow-away-a-person), having that kind of energy 100 times over is not trivial. We've also acquired the second point. Modern weapons can attack as far as they can see, and sight augmentation improves the effective range. The third point is where I think the weapons become "very accurate". Not only can you apply force exactly where you want it, but from anywhere you can see. Now the mages don't need to carry weapons, because the world is their weapon. Most likely rocks. --- Rocks are ideal because they're abundant and hurt when landing at high speed. Their abundence would generally mean the mage would not need to carry anything (except the magic source). Rocks can even be made and shaped from the ground through magic to accommodate environments and make them more deadly. Rocks aren't accurate at long ranges, but you don't need to fire the rock a long way to have a long range weapon. **Hit the target with a rock at their feet** So long as you can see a rock/solid object near your target you can hit them with it at little energy cost. Firing projectiles at long range would mean increased energy cost (to send it further) and decreased accuracy (once the projectile is moving too fast for you to see you can't control it anymore). Even if there were an energy cost associated with distance it provides your target little time to react or defend. A single costly projectile would be cheaper than many cheap projectiles, as well as increase survival chance. --- # What Would a Duel Look Like? There's actually historic examples to go off of. **A Western Duel** Both parties carry an extremely lethal weapon against the other. Since the ground itself can be turned into a weapon there's essentially no defense. Here the only defense is a good offense, dead people don't attack you. Duels would be focused on how quick you can "draw", just like in the wild west. [Answer] **Avoiding going head to head... most of the time.** Expensive fuel means that the tactics need to be above all else efficient. Assassins and snipers have been mentioned multiple times, this works well because the mage is attacking someone who does not know they are there, and therefor, will not resist. If you need to stop an attack than you are wasting fuel that does not damage the enemy. Of course you do want you enemy to waste their fuel, so at times it may be a tactic to simply throw wasteful attacks to ensure they run out of fuel if you think you have a major advantage and want to ensure annihilation. **Planning and preparation can be vital, traps are the best option** If the battlefield is known before hand, then creating traps could be highly efficient, using the nature of the trap to provide as much of the energy as possible. This can be as complicated as rerouting a river upstream using most of your mages, and using gravity to allow the water to build up the momentum to flush the opposing army away, or as simple as preplacing pebbles where you think the enemy will be so you have less distance to move them (bonus, using a pebble not from you location does not give out your location). Anytime you can put in a small amount of energy to spring or guide an attack and then let the laws of nature provide the bulk of the force, the energy required to block or deflect can be made greater than the original input. [Answer] A magician with precise enough control could be lethal with only small amounts of either water or electricity. If they can create AC current, only 30mA applied through the chest for a fraction of a second is required to cause fibrillation, which in the modern world is almost certainly fatal without a defibrillator handy. If they can precisely target the heart somehow, the required current drops to about 1mA. For water, keep in mind that the total lung capacity of an adult human male is about 6 liters. If you can fill a majority of that space with water, they will drown. A mage with a wagon full of water (1000 l, for example) could then kill 200 enemy soldiers, if they have the precision to shoot it at their mouths and force it down their trachea. [Answer] So I've given this a little thought and here is the most directly lethal thing I can come up with on short notice. (note that this answer assumes that your fourth rule does not extend to controlling the elements inside another person) You said that magic includes the manipulation of lightning, I'm assuming this extends to electricity in general. Given that neurological impulses are just very small electrical signals a mage might kill someone just by making their brain go haywire, or even stopping all neurological messages, making the brain just grey meat. Alternatively, a mage could control the water in another persons body, manipulate spinal fluid to sever the spinal column, or create a hole in the heart of an opponent by forcing the water inside it out, incapacitate or internal exsanguination would soon follow. in essence mage combat becomes a case of "what can the mage control specifically" and "where in the human body can that do the most damage". which naturally leads to "how to i destroy or interrupt the functioning of the brain heart or spine". [Answer] Depending on the importance and size of the battle, it would probably be better to get the mages to cast one huge spell together and rely on AOE to do all the work than a single spell killing a few at a time. A combination of wind and fire to create massive explosions(Assuming fireballs can be thrown else they aren't fireballs). Combining water and lighting to electrocute the enemy. For smaller battles it wouldn't be worth using mages as the cost of normal troops would be much less than the cost of magical fuel. [Answer] ## Self-enhancement The best resource on the battlefield is the magician himself. He already has full control without having to expend fuel. In an arena-style duel, augmenting one's own actions can be very successful whilst combat will be done via enhanced hand-to-hand with physical weapons. Large-scale spells will be a huge waste of fuel and complete overkill in a duel between two mages. Speed-boosts can provide evasive manoeuvres and aggressive re-positioning. They can also accelerate hits to deliver quick, unforeseeable blows with immense force whilst minimising fuel spent. The magician can likely win a battle in seconds whilst conserving fuel if decisive enough with his actions whilst equipped with the right weapons. Armour and clothing can be modified to be able to withstand large shock, useful for gloves to allow the magician to throw enhanced punches without damaging his own hands on impact. [Answer] I like thinking about the energy requirement to use magic as the same amount of energy required to physically move an object, and the fuel as the available energy in a wizard's body. So, if a wizard wants to use magic to throw a rock, it tires him to the same degree as if he had picked it up and thrown it with the same restrictions. Therefore, a wizard could throw a molotov cocktail with his magic to throw it further than he could physically and it wouldn't tire him much, but if he wanted to pick up a boulder he may be able to do so, but would be physically exhausted by the effort and unable to do any significant magic until he rested. If he wanted to manipulate a smoke cloud that would require very little energy. One aspect of thinking of magic in this way is that it cannot be stolen (but possibly transferred if the mage wishes to give some physical energy to another). It would be possible that if the mage attempted to do something beyond his physical means he would die. So, could a party of 10 mages tear down a mountain? No way. Could a couple dozen mages working in unison push over a tree? Probably. [Answer] sounds like mixed unit tactics would work best, knocking a squad down is not all that destructive, knocking them down just as they get ready to stop a cavalry charge would be lethal. One mage with 100 wind spells combined with cavalry would be a meat grinder. Knock arrows out of the sky now only your side has archers. Or combine them with fire throwers and create a wildfire. Turn solid ground to mud under your enemies feet to break up formations and charges. Fight during a storm so your mage can turn lighting against your enemy. Mages that can bend light would make terrific scouts. Mages would be a nightmare during siege they could collapse walls by breaking keystones or cornerstones. Being able to change the wind during naval battles would all but guarantee victory. How much energy would making the enemy commander's helmet shirt and crush his skull take? Mages would also be instant targets so having them protected by other troops would be important. As for duels a good trick might be creating a invisible bubble around your opponents head that lets no new air move in, they would feel fatigued and wozzy and would eventually kill them, even if they did figure it out a gasping disoriented fighter is easy to kill. Or just pull the air away from their head and watch the vacuum effect knock them unconscious or collapse their lungs. Or for a more direct approach combine force of mind with force of body, add your mental power to a sword swing on top of muscle power, [Answer] I use a similar magical system and have discovered that telekinesis is fairly OP. It depends on how you balance resource usage (e.g. the relative cost of fireballs to levitation). Part of what allows the different mages to be relatively balanced, in my system, is that they are restricted in terms of what magic they can use, but the geomancers are particularly nasty. They generally carry pockets of flechettes. Aerodynamic, sharp, and they weigh practically nothing, so the magical cost to fling them is very low. You can put a marble or an arrowhead through a human body with relatively low amounts of energy, or spray a handful of them into a room like shrapnel, for the same 'energy' cost as tossing a baseball. I also have limits on AoE spells, but if thats not a limit, things like gas attacks are an excellent choice. [Answer] # Duel Scenario IF wizards are *much* stronger than non-magic users.. The goal of a duel scenario between two (or more) wizards is to either escape, or kill the opponent wizard. A wizard that is assigned to a squad of non-magic users likely has one or two assignments: i) Protect lives of the whole squad inc. from enemy wizards. ii) Play a pivitol role in the completion of some objective. We could expect an enemy wizard to be able to kill off the entire non-wizard members of the squad. In which case things will degenerate into a wizard duel. I also envisage that a duel between two equal & very powerful wizards, face to face, with no clear advantage at the start, would be over very quickly. Each wizard has a number of offensive options which far exceed the range of defensive options available to each, thus leaving them with an impossible choice for pure defence. However, each sort of action has a tell. Before you physically move, the corresponding muscles need to contract/relax. * A keen eyed Wizard can infer what their opponent is about to do. * A disciplined wizard can use unusual muscles to disguise their intentions. * A wiley wizard can deceive with their muscle movements. * Pretty much every wizard wears opaque and long flowing robes that give nothing away. Some actions can be both defensive & offensive e.g a gust of wind would put distance between you and the enemy; Even if the opponent was able to resist being pushed, the equal and opposite reaction of the gust would push the caster away. In general, the meta for wizard duels will never be static. **EDIT:** I want to elaborate - A long time ago on late night TV (no chance I'll remember what program) there was a demonstration between two katana wielding swordsmen. Swordsman A, ostensibly, had a trick where they could shift their weight without tensing particular muscles in their foot. Swordsman B was therefore at a disadvantage because they couldn't move without broadcasting their intentions. The other idea between these sorts of duels (though I'm not sure whether only for practice, or if duels like this really existed) is that they were typically finished in 1 or 2 moves. In a battle between two wizards then, you want to act swiftly to incapacitate or unbalance your opponent. Killing with magic isn't absolutely essential. On the subject of fuel conservation.. I think it depends on the lethality of your magic. I would advise that it never makes sense to conserve fuel against another powerful wizard because the opponent could just use more fuel and kill you off (and maybe take your fuel). So, on meeting another wizard your objective is no longer to conserve fuel and keeping on top form. The objective becomes kill the other wizard, save your own life, try to save your allies, and take whatever fuel is remaining. Then, go home and recharge. On the other hand, if magic isn't especially lethal, then you should think about conserving your energy. Something along the lines of wing-chun, perhaps: <https://en.wikipedia.org/wiki/Wing_Chun#Relaxation> . ]

[Question] [ On an expedition to an inhabited planet, we encounter intelligent life. However, they are not as intelligent as we are. They have language, but it's less expressive and more concerned with the immediate - a strong vocabulary and simple grammar relating to hunting or foraging, say, but no deep abstract concepts yet. I want to avoid just simplifying English. For instance, the "me-tarzan, you-jane" type language where most of the "primitiveness" comes from forgetting words. I want to make it sound like an actual language, in other words. In addition, I want to make it so that what it **can** express it can express naturally and fully. I go back to hunting, foraging, perhaps speaking about the immediate natural environment. Such a species would clearly be able to plan a hunt, for example, and would likely have a rich language for doing so. What should I consider when making this up to achieve my goals? **EDIT**: although there are many great answers, I think I should further specify to give more context. I'm not thinking of human-like hunter-gatherers. For instance, if we were to travel to the past, say, 50,000 years ago, and take a baby from that time and transplant them here, that baby would be able to learn our language and would not know that she is different in any way (time paradoxes aside). On the other hand, we can't do this with a chimp baby, although it is remarkable what we **can** do with chimps. I'm thinking somewhere between ape and human. For instance, the language might only have one word for "danger" (why not? I don't need you to know **what** to run away from, just that you should run away) but I might have many words for "hunt" (depending on what I want to hunt, how I want to hunt it etc). Other than that, though, I'm sort of stumped as to what such a language would sound like. **EDIT 2**: For the curious, I've done a bit of research and it seems that the most important feature of human language (compared to animal communication) is "displacement" - the ability to communicate about things that are not present, either in space or in time. I believe that, as a minimum, my creatures would need to be able to **name a place** and **name a thing**, so that, for example, the sentence "get berries at the hill" could be communicated, perhaps as simply as "berries hill". (Obviously this is in English to make this edit easier to write and understand). We could inflect the words to indicate meaning. For instance, "berries hill^" (raise last syllable, like asking a question) could indicate "we need to go get berries at the hill" while "^berries hill" could indicate actually asking a question (are there berries at the hill yet?) a LOT more thought needs to go into this, obviously. **EDIT 3**: I took a stab at outlining the language here: [What are the limitations/expressive powers of my constructed proto-human like language?](https://worldbuilding.stackexchange.com/questions/78577/what-are-the-limitations-expressive-powers-of-my-constructed-proto-human-like-la) [Answer] **A Little Goes A Long Way** Don't overtax your reader. By its very nature, your language will not have much of literary, poetic, or philosophical content. You want to give the reader a flavor without actually teaching them a new language. Pick two to five words that have meanings that don't have good English approximates that really capture the essence of what you want to convey with your language and come up with specific, phonetically translated words to use in your text for those. Devote a lengthy scene or even a subplot to the process of discovering the meaning of one or two of those words, and a decent amount of coverage to the meaning of each other new word that is introduced. A good example of how this is done in literary form would be Heinlein's *Stranger in a Strange Land* in which just a handful of words such as "Grok" are introduced but those words are used repeatedly and their deeper true meaning and fundamental foreign-ness as concepts is really explored. A good example of how not to do this would be Frank Herbert's novel *Dune* which introduces so much foreign vocabulary so soon that it overwhelmed a lot of readers who weren't really determined. Ultimately, even that book had a fairly modest vocabulary set, but the book would have been much more accessible if the new vocabulary had been introduced at a more leisurely pace. *Not All Words Are Created Equal* Also, for these purposes, not all words are created equal. Introducing a new common noun that describes some kind of thing that doesn't exist in our world (e.g. the name of a snail that you suck into your nose to clear out your mucus) doesn't impose that much of a burden on a reader, and a proper name that isn't too hard to pronounce or remember imposes even less of a burden. But, it is much more demanding on a reader to introduce words that convey more intangible concepts (e.g. a word that means hunger and pain and loneliness and fear or any of the above as context demands). So is a word that breaks the boundaries of our existing word categories (e.g. maybe instead of a verb for a particular kind of action like throwing something and an independent noun to describe what is thrown, there is a completely different word for every combination of an action like throwing and the thing that is thrown, a bit like irregular collective nouns in English such as a "murder of crows"). **Show Don't Tell** Also, show don't tell. *Use Multiple Perspectives* Have a character try to communicate an idea that the more primitive language can't handle (like the future tense) express frustration over their repeated inability to get the idea across. But, perhaps using an eye of god narrator, portray in English an elaborate and cogent and fun conversation of some complexity within this simple language's boundaries between native speakers, to illustrate that it is not as simple minded as one might think. *Use Multiple Perspectives On The Same Conversation* Another interesting possibility comes to mind based upon an episode of *This American Life* on NPR about deaf people's cognitive experienced before and after learning sign language. Before learning sign language, they had a tough time remembering things and mostly expressed this when they did by re-enacting events that happened mime style. Only after they learned sign language did a more conventional memory emerge. In your case I could imagine an outsider telling a story to someone with this primitive language that we hear from the teller's perspective with all its nuances, and then repeat the scene in a dream sequence of this native listener in a sequence that only repeats the greatly slimmed down version of the story that the listener was actually able to comprehend because the listener hadn't acquired all of the concepts that were communicated to the listener. *An Alien Language May Differ Not Just In How Ideas Are Communicated, But In What It Is That People Talk About* Another example of a real life proto-language would be dolphin communication which we are now starting to decipher. It turns out that dolphin communication involves a much higher proportion of proper nouns than human communication. It isn't that there aren't other words in dolphin language or that there aren't varied connotations of this basic core of what is said as in the "I am Groot" example in another answer. But, the core conversational content might be much smaller and might focus on two or three major subject areas like naming everyone and touching base with them in some way, identifying flora and fauna seen since the last discussion, and describing how to get from point A to point B, with not much discussion of other topics. In the same vein, early written languages started out as a shorthand for keeping accounting records and wasn't intended as a complete reproduction over every idea or emotion that someone could have inside of you. You probably couldn't have written an emotional soliloquy about a teenagers feeling about their day in Linear A script or early Chinese characters any more than you could with the vocabulary in a set of baseball box scores. Maybe that is a kind of feeling expressed by these beings not with language but by touching and cuddling and stroking and crying and shrieking and eye rolling. **Pronunciation Through Font Effects** One good way to convey a novel kind of pronunciation is to convey it in writing with font effects. Perhaps some words are spoken with a throat voice and others are spoken with a nasal voice. If the throat voice is conveyed with Courier type, and the first couple of times that throat voice is used that pronunciation method is identified, you visually convey the idea that non-English pronunciation is being used without actually having to transcribe the actually sounds made using the International Phonetic Alphabet (which may not even include sounds that aliens can make but humans cannot like sounds outside of our range of hearing or colors that we can't see with eyes built like ours). Your ability, or a reader's ability to actually pronounce the words in the way that they would sound with this phonetic speech effect doesn't matter. The idea came come across even when the reader can't actually reproduce it. **Primitive Doesn't Mean Simple** Maybe you even add a feature normally considered "sophisticated" that is not present in English. Just because a language is *overall* simpler than English doesn't mean that it needs to be simpler in every single respect. *Navajo Source Of Information Tenses* For example, you could give this language the grammatical modes in Navajo that distinguish, for instance, between information obtained first hand and information that you know only through a hearsay account from someone else. *Topic Matter Noun Modes* Many African, Dravidian and Australian languages have different grammatical structures based upon the type of thing that you are discussing. There is one tense for talking about trees, another for talking about animals, and a third for talking about rocks. *Word Order* Another easy way to make a foreign language seem very different from English with minimal substantive difference or much of a learning curve is to follow the example of Yoda in *Star Wars* - use plain vanilla English but deviate from the SVO word order of English. There are even some studies that suggest that SOV is actually more "natural" if one is creating a language from scratch. *Complex Root Words Are Actually More Primitive* I would also deviate from other commenters regarding word complexity. Complex inflections and compound words may indeed reflect complexity and generalization and abstractification of a language. But, complex root words and many irregular forms can actually signal a more primitive languages. Regularity and short efficient words are natural products of societies where people use lots of words on a regular basis with lots of variety in a society that is more seeped in culture in its essence. A less developed language would be less systematic, more idiosyncratic, and more clunky except for the most basic and universal concepts (mama, danger) the need to be expressed by even young children quickly. A lot of complicated roots suggests that no one has analytically categorized words by type yet. *Don't Overdo It Grammatically* Whatever you do, however, you need to not stray too far from the concept that a little goes a long way. Non-vocabulary language concepts are more of a burden on a reader than vocabulary based ones. Two to five actual foreign words and one or two foreign grammatical concepts are more than enough. Translate everything else, adjusting point of view to do so if necessary. [Answer] Make the language as dependent on the current context as you can. A more mature language will be capable of expressing ideas of things that are not related to what is around you, but an infant language is going to be focused more on the current reality. I would focus on the [pragmatics](https://en.wikipedia.org/wiki/Pragmatics) of your language over its syntax and semantics. Models such as Jakobson's 6 factors will help you hone your messages in this way. This lets you focus on what meanings actually get conveyed by your proto-language rather than focusing on what ideally would be conveyed. [](https://i.stack.imgur.com/N94m0.png) Also, re-watch Guardians of the Galaxy, and see how much content is conveyed with "I am Groot!" Its actually pretty amazing what you can do without a complicated grammar and vocabulary. [](https://i.stack.imgur.com/x0lbtm.jpg) [Answer] At the risk of sounding culturally insensitive, you may want to consider the way someone learning a new language speaks. They often have little conjugation, as in only using the present tense. Limited vocabulary, only words they've needed to get by thus far. Few descriptive words. Think size, basic colors​, hot/cold. For instance, I know I can ask for a bathroom and a dark beer in Spanish, but I'm far from fluent. Just enough to communicate basic needs. The exception to this line of thought would be a very well developed sense of their surrounding world. Expect to hear very specific names for plants and animals that they see around them. Rather than general words like "tree" they would likely have names for every variety of tree, particularly ones that produced food. [Answer] Sign language might be the answer. Simple sign language can cover most daily activities, and limited simple abstract concepts are available (like emotion, love). For primitive tribe, sign language is the most efficient and effective method. Spoken language are very limited because most communication can be done more swiftly and efficiently using sign language. ## Advantages * **Distance** - sign language can be seen from afar * **Hunting** - sign language can be used without alarming the prey * **Wind** - sign language is more reliable when used in an open, windy area * **Instinct** - basic sign language can be understood immediately without having to teach the recipient **Note:** I'm talking about *primitive* sign language, not *modern* sign language [Answer] You will more convincingly convey an alien attitude with what your natives say, rather than how they say it. There are lots of people who come at things from other than a Western European / goal directed / lets do the deal sort of background. Talking to such people can be disconcerting if you come from the former background, especially if you do not expect it. It seems like they are purposefully avoiding the matter at hand. Maybe they are. Maybe they are shy, or do not want to be offend, or worry that they might jinx things by speaking out loud. Maybe in their world view they do consider the things they say directly relevant. Bring that out in the exchanges you write for your natives. Here is an idea how. 1. Reread Old Man and the Sea. The dialogue between characters is the very direct, in the moment simple language that you want for your people. It is powerful and it is not annoying. 2. Your natives should talk like that. Your nonnative should not. 3. Your natives should talk about things that seem irrelevant and irritating to your nonnative, who wants to get to the point. These things said by the natives could be anecdotes, or questions, or opinions. Use these to help convey the mindset of the natives. Possibly the natives never explicitly plan the hunt out loud, but convey to their comrades how it will go because of the comments and talk on other (seemingly random things). You could even leave that opaque and then have your nonnative marvel that anything at all got done, much less as efficiently as it did. If you purposefully never have your natives address a concrete matter headon but rather tangentially or by allegory it will be a good rule of thumb for writing. Sort of like a person wanting a bribe might not ask outright for the bribe but will instead talk about lots of other things. [Answer] If you haven't read the book yet, speed read 'Sapiens' by Harari. He poses the idea that language developed amongst earlier humans not just to say "there's a lion at the stream, don't go there" but also to say "Jane's sleeping with Tarzan, don't go there either". In other words, gossip was as much of a driver when communities formed as warnings of external threats were (your displacement comment). Think about the critical factors in the lives of the indigenous race and you'll find the function of their language. It might also be a very interesting way to build context in to their world by offering concepts which juxtapose to the readers' inbuilt prejudices or assumptions. [Answer] Now, I'm not an expert on proto-languages. But my immediate instinct is that this language should be **as short and simple as possible**. There are a few reasons for this: * As I understand it, your aliens are still at the "hunter-gatherer" phase. They might not even have invented writing yet - they may still be communicating via cave paintings. If that's the case, they'll be learning this language almost entirely through memorization, so the simpler it is, the easier it will be for them to learn. * There will be lots of things they haven't discovered, or concepts they haven't invented, or things they might not have come up with words for yet. For example, they probably won't understand the concept of "zero"; as I recall, that wasn't invented until a couple of thousand years after the first writing system. They might have a word for "small bird", but not for specific species like crow, pigeon, bluebird etc; they'd all just be "small birds". * If the language is geared towards hunting, you'll want to be able to communicate quickly and clearly, in as few syllables as possible. It might be the difference between catching your prey or going hungry. And if your prey is especially dangerous, it might be the difference between life and death. * *It makes things easier for you.* The less words and grammar rules you have to come up with, the easier it will be for you to create this language. [Answer] A lot of new languages start out using conjugations instead of coming up with new words to describe things. For example, instead of calling something a big fancy word like "bracelet", they'd come up with something simpler and more familiar like "arm-ring". My recommendation would be to keep speech very limited, maybe even just have the majority of their sentences be made up of one or two words ("get" and then point at something) and when they're forced to engage in more complicated conversation, use lots of conjugations, utilizing mainly contextual words. As for phonetics, use lots of hard consonants and words with only one or two syllables. [Answer] Developing a completely new language (even the most simple one) is a tremendous task, it is very much easier to twist and extend an already existing one. Your goal language sounds very much like Toki Pona (<https://en.wikipedia.org/wiki/Toki_Pona>) for me. If you slightly changed its vocabulary and added a bunch of new words to describe concepts specific to your story, you would get exactly what you are looking for - a very simple but extendable language. [Answer] Toothed whales each appear to develop a [signature whistle](https://en.wikipedia.org/wiki/Whale_vocalization#Odontocete_whales). So it appears that, at a minimum, they are constantly swimming around identifying themselves. So it looks like in the simplest case, your language might just consist of self-identification, with any other information conveyed out of context. To get a bit more complex, you could add sounds for basic verbs. You could perhaps hunt with this, by using Ogg's sound with the verb for "flank", to tell Ogg to go around while everyone else continues with a frontal attack. To get more complex yet, add direct objects. So you can tell Ogg to use his club while flanking, while everyone else sticks to their spears. Note that the more words you add, the more different sounds your primitives need to be capable of making (and discerning). That will require more flexible communication systems, and smarter creatures. [Answer] You should look into Noam Chomsky's theory on the origin of language, that it didn't emerge as a gradual iteration from other non-language animal communication systems, but that instead it arose very suddenly, from a freak change to the way human brains worked. The idea is at first very counter-intuitive, especially if you are used to the idea of biological evolution, where features almost always develop incrementally, but there is significant evidence to support the theory. Principally, if it were the case that language is something that incrementally developed, we could expect to see that some present-day languages would be further ahead or further behind on the evolutionary ladder than others - but this is not the case. Instead we find that all documented languages seem to be equally advanced, yes, some languages have features that others don't, but the 19th century idea that languages could be placed on a hierarchy with "primitive" languages at the bottom, and with European languages (naturally...) at the top has been thoroughly discredited. What is the case however is that languages do adapt to fit the cultures that speak them. An agricultural culture tends to have greater vocabulary about agriculture, while a hunter-gatherer culture would tend to have a greater vocabulary about hunting and gathering. I'd suggest that instead of trying to engineer something "primitive", you should think more about how to match the language to the conditions of the culture that speaks it. (Or you might think that the Chomskyian idea is a load of rubbish, and that language did arise incrementally from non-language communication, in which case feel free to ignore this answer!) [Answer] This is only one aspect, but it has not been adressed in any of the answers (or comments) yet: *Use simple present tense only.* No past, no future. This is in line with what apaul3248 writes in [his answer](https://worldbuilding.stackexchange.com/a/78502/3106) about learning a foreign language: you always start in the simple present tense. It meets your requirements *concerned with the immediate* and *no deep abstract concepts yet*. [Answer] A thing to recall is that the language contructs available often largely dictate the thought patterns available to a society (and partially the other way around). Thus, if these aliens are truly only concerned with the immediate do not provide them with constructs that detail time. Any time into the future may be "tomorrow", while any time before now may be "in memory". Further, it may be worth considering whether a codified grammar matters. In real life, few concerned themselves with grammar until laws came into place that had to be unambigiously interpreted. That may again not be a concern for these aliens. Finally, if there is truly a large hunting aspect to these creatues; consider that their language may not be fully vocal. Sign languages were often used to not give away one's position, while whistling languages are very practical for communicating over much longer distances than shouting (comfortably) could. [Answer] I agree with keeping the language limited to one or two syllable words which are joined together to express more complex words. You should start by coming up with the most commonly used words like *I/You/or/and/the* and so on, building the language outward from there. Keep testing your words together in simple sentences to ascertain whether you like the sound of it, and if it captures the essence of the beings who created it. ]

[Question] [ Many video games and movies set in a medieval-like fantasy setting feature implausibly huge weapons, which would be completely impractical in real combat. [](https://i.stack.imgur.com/vPwBA.jpg) Sometimes people defend the realism of such huge weapons by stating that the characters wielding them have superhuman strength. However, when real physics come into play, having superhuman strength still doesn't make these weapons practical. No matter how strong you are, swinging such a weapon would [throw you off balance](https://www.youtube.com/watch?v=X6QSu1EolCI), unless you were bolted to the floor or you were so heavy that you would sink into the ground. Also, swords were very quick and nimble weapons, there is not much use in a sword which you can swing exactly once before needing to regain your balance (or get up again after you fell because of the inertia throwing you off your feet). This led me to the following question: what would be the ideal melee weapon for someone with superhuman strength in an otherwise realistic medieval to early modern setting? Let's assume our hero is 5 to 10 times stronger than an athletic human, with no other superhuman qualities (except those required by this increase of strength to not break his bones or rip his joints apart) It seems he would be much better off with a standard-issue sword, mace, or other historical weapon than with a huge and super-heavy contraption. As swords were used to cut or thrust (and not to chop, as mistakenly depicted in movies where knights hack slooowly at each other), where superhuman strength would not bring many additional benefits compared to an already athletic normal human, I would guess a common regular-sized mace or war hammer would be the best choice to make use of his strength. Could there be a better choice than that? Given enough money and the best smiths he can find, could one design a weapon which would be better suited to utilize his strength, than a regular, standard-issue hand weapon? [Answer] # Make him an Ace by giving him a Mace. You're right that the mace would be the most effective in terms of standard weaponry. Since you didn't give him super speed to go with his super strength, a mace is the best weapon. The mace is just a big hunk of metal. It won't break, and its primary use was to bash through armor and weaponry - which is exactly what you want to use brute force for. By giving him a mace, he gains the ability to bash through enemy fortifications, weapons, and armor more effectively than any other soldier - all without the fear of needing to replace his weapon. If you give him a sword, and he misses a target and strikes a shield or a structure, it's possible for his sword to break. If you give him a spear, that's wasted on thrusting into a point (which is very effective, don't get me wrong here), but has limited usage compared to the mace. Give him a staff? The good thing about a staff is that it's great against unarmored opponents. It has fast moving ends, and is versatile for blocking. However, if the opponent is wearing armor, the staff is unable to impart enough force to be effective, because the staff strikes using a larger area than most weapons. We cannot assume that the opponent isn't fast enough to get close to the staff user - staff users typically suffer when it comes to close range combat, because of an inability to generate speed. The staff becomes detrimental to the users movements as his hands get locked up. Because this person isn't faster than normal, only stronger than normal, something like a staff, which doesn't guarantee damage through hits, isn't ideal. Also, a staff requires two hands to use properly - leaving him open to arrows. A shield + a mace would be ideal to provide some cover from arrows. Is range an issue? Wrong - enemy shoots arrows? Use the shield. Enemy swings an axe or a guan dao, or even a polearm at you? No problem. Just bash the weapon with your mace, and watch it break or bend. Proceed to step forwards and destroy. If you need to break down a gate, given enough money and the best smiths we can find, give him two maces. With super strength, he may be able to wield both maces at the same time, especially since maces don't require the same finesse and control as other weapons - all you do is crush, and it doesn't matter which hand you use to swing that big metal chunk. # Alternative option, for dueling instead of war: Gauntlets If you give him properly (or specially) designed gauntlets for both hands, his super strength (Which I assume translates into super grip by default) would allow him to catch the enemies weapon(s) and rip it away from them. After that, raw power behind those gauntlets would allow him to decimate any enemy duelist, given that you properly train your guy for CQC. [Answer] **A heavy spiked shield used as a battering ram**. The shield could be as tall as the warrior, providing full-body defensive coverage, constructed from depleted uranium, and the sheer mass of it wouldn't matter because the warrior's super-human strength would enable him to hoist it anyway. Our superhuman warrior would also have the leg strength to be able to change directions at will, so there would be absolutely no way the enemy could escape being battered and crushed. Picture a modern-day freight train smashing a car at a crossroads, where instead of a cattle guard the train has nasty spikes mounted in front and is running cross-country directly at you. [Answer] Since this warrior is long on offense but short on defense, it seems wiser to focus on shoring up his or her defense. Since shields seem to be off the table here, I would equip this warrior with a stout steel **staff**. The problem with blades is that they'll get dull and break, or maybe get stuck in the carcass of an enemy, problems that will likely be even worse with superhuman strength behind the strike. The trouble with maces is that you need to get too close to the enemy, and if the enemy manages to hit you first, you're just as likely to go down as a far lesser combatant. Spears are good for range, but the point is likely to have the same short lifetime as a blade, so why not leave it off entirely? A warrior with a staff can take down enemies at a longer range, thereby staying out of harm's way. The length of it means that the free end will be swinging at a high velocity, and superhuman strength will make that a very high velocity indeed. No mere mortal struck with the business end will remain standing. A super-strong wielder could even (with the proper kung-fu training) spin it around very rapidly like a propeller, perhaps using it to block incoming missile attacks or to clear enemies on all sides. [Answer] Under these circumstances I would say that **heavy armor** would be the best starting point for a combat style based on super strength. One of the limiting factors on armor is how much you can carry while still being able to move effectively, and with that issue largely out of the way, the benefits of heavy armor provide a greater advantage to our super warrior than they would under normal circumstances. With enough training in **unarmed combat** the Warrior might not even need to use melee weapons beyond fists, feet, and other unarmed strikes augmented by heavy armor. That said, there are many other ways that super strength could compliment specific weapon and fighting styles. **Blunt weapons** and **chopping weapons** would be made much more effective, while stabbing and slashing weapons would have some drawbacks associated with their increased effectiveness. Weapon size and weight could be increased somewhat, but the cost in balance would put an upper limit on both factors. Dual wielding heavy **two handed axes** with reinforced metal handles would be my choice, but there are many options that would be just as good depending on the fighting style of the individual. [Answer] First, off topic: His best weapon would be a recurve bow. With a strength so many times better than that of an average human, he could kill from effectively 5x the distance of a normal archer. On topic: I agree with the statements that shield would be the way to go, but if we are stating that the strength can be translated to speed I would say something long and heavy. The kanabo, a japanese weapon mostly associated with oni, would be something that could maximize his reach, speed, and destructive output. Additionally, another good weapon for him might be a spiked chain of some sort, since his increased strength could make up for the shortcomings of distance that long range melee weapons suffer from, and could be used to deal with large groups of people. The final truly medieval weapon I would recommend would be an axe. The size and weight of the weapon would accentuate the destructive power of the superhuman's swing, while the sharp point focuses the force, allowing for dealing with shields or armor quite effectively. [Answer] ## **Doomhammer Wanted** Equipping this super-strength warrior with a sufficiently large warhammer will look something like this [little battle](https://youtu.be/BhjDnrw34QA?t=202) with some old guy named Sauron. Similar to Aify, I think that large, heavy blunt trauma weapons are the best bet. The Mace is already taken so I'll suggest the Warhammer. This weapon will cause impressive concussion damage to even heavily armored foes (this could include early WW1 or WW2 tanks though that's not part of the question. Internal spalling would be devastating from the steel armor plate to a tank crew). If the hammer's strike area is too small, it may become permanently wedged into an enemies armor. [](https://i.stack.imgur.com/05uCz.jpg) ## **Just hit them with a tree** The World of Warcraft race, the Tauren, have a giant weapon called the Tauren Totem that is basically a giant tree trunk. They are well known for being able to clear plenty of enemies with their totems. In the WoW universe, the Tauren are the only race large enough, strong enough to wield a weapon of that size and mass. Granted, a weapon like this would need to be scaled appropriate to the hands and body mass of the super-strength warrior. But the totem retains the blunt trauma requirements as well as ability to make the ground shake, an ability while not immediately useful may have powerful morale effects. [](https://i.stack.imgur.com/QYk7g.jpg) [Answer] In a world with muscle-powered weapons, our super-strong warrior would be best advised to follow one or two paths, namely Melee and Missile. In both, armour would feature heavily (pun intended). We should be considering not a single weapon, but an entire weapon *system*. **Armour** The best defence allows the best offence. Wearing heavy plate armour means that our fighter can act with impunity despite enemies trying to stop him. It's no good relying on an active defence to intercept weapons; he's not super-fast after all. Just wear super-thick, overlapping steel plates that no mere mortal could bash through or punch an arrow through, and that will allow you to use your strength freely. All that mass - and spiked shoes - will allow you to use your strength to impart the greatest amount of energy to your melee weapons. **Melee weapons** Since our super-strong individual wouldn't be significantly faster *unarmoured* with a light weapon than a regular guy, but would be just as fast wielding a heavy weapon while wearing siege-plate, there's not much point wielding something light and fragile. Neither is there any point relying on a weapon with a fine edge that will just get blunted. Hence, it would be best to go with something like a mace or a flail with a heavy head - the flail wielded by the Witch-King/Head Nazgul in the Return of the King movie would be a good example: [](https://i.stack.imgur.com/4NpIl.jpg) The flail has the advantage of being able to wrap around shields for whatever they're worth, which might be of use if they're super-thick and wielded by another super-strong individual. You've got the strength to give that mass some momentum, so make the most of it. You don't need finesse against a regular opponent, just smash their defences, and then their bodies. Sure, that's a lot of mass to get moving (and stop), and giving yourself some ballast in the form of heavy armour - and more traction in the form of spiked soles on your boots - is just what is called for to deal with the problems of inertia. You're strong enough to carry it, after all. **Missile Weapons** A bow allows you to translate your super-strength into speed. While you can't fire more arrows per minute than the next man, you can shoot heavier arrows from a more powerful bow over a greater distance. You could carry a bow as powerful as a small [ballista](https://en.wikipedia.org/wiki/Ballista), and punch arrows clear through a thick shield that is bristling with the arrows of lesser men, *as well as* the plate armour of the merely mortal man wielding it. **Drawbacks** You might not want to try this at sea. All that armour would make you sink like a stone if you went into the water. At sea, instead of armour you might want a big wooden shield like a Roman tower shield that you could drop if you found yourself in the drink, and a heavy axe could be used to cut masts, spars, rigging and men with equal facility. There's still no substitute for a bow, though. [Answer] A hybrid weapon, a staff with a mace head at the end of it. The moment arm would make it impractical for someone with normal strength, but someone impossibly strong could use it to collapse armor at joints or to break elbows and knees on padded armor or unarmored opponents. Used as a stabbing weapon, the extra reach would allow him to put opponents off balance as they entered his weapon's radius, which would be significantly greater than most other melee weapons (with the possible exception of the halbred and pike). [Answer] I didn't see this answer anywhere, and the accepted answer gave me the idea: **Your best weapon is your ennemy** First of all, with the strenght OP mentionned, any blunt weapon he use would be deadly, even with an armor. If he uses his fist he lose the advantage of range (that his enemies will still have on him), but this might be an advantage in specific situation like tight corridors. Mastering shield would be a good bet to approach his ennemies (and with that strenght, he can have a good one). He would kill people by punching them in either the face or the torso (with an armor). Of course he would need a little bit of practice ( more than using a mace and swing it around I guess). So he would need to dodge ennemies, and get quick at fist-range. Now, this doesn't really have any advantage on a mace or other weapon though. However, if he is against multiple ennemies, it does. Using martial art to catch one target quickly, and throw it against other people at full force. This might not kill everyone, but you'll get some time reduce the number of people against you and get them one by one. You can also take someone by the foot, and swing them around in a tornado, and released them like in a weight-throwing contest. The good thing is, you won't depend on any weapon (except if you need special gauntlets) so you can keep this technique if you're ever captured or need to get multiple people at the same time. [Answer] **Whatever he wants as long as it is designed intelligently**. There is no such thing as an ideal melee weapon it all depends on the skill and style of the user and the type of enemy. A mace is great against armor but a poor choice against spears or nimble enemies. Sword, mace, axe, halberd all can be made to work it depends on what the character wants and how they fight, their strength is more or less irrelevant to this. The big problem with the above sword is that it is not much stronger than a normal sword but it is a lot heavier, the diameter of the the grip is determines how strong you can make the weapon becasue it is the weakest point you can't make it any thicker and still have the person hold it so that is the limiting factor since strength is generally determined by the cross section of the steel. so really the size of your characters hands determines how strong you can make their weapon. So you have to ask how strong your character is, Imagine they took the steel pole used to put lifting weights on and started swinging it around, if the rod is going to be a bent and twisted mess by the time they are done then nothing you give him will survive, then you just want to give them something cheap and replaceable. Not let's consider if they are not quite that strong (the rod gets only a slightly bent after a little use) or if you have access to much stronger materials. **If they can swing a normal sword twice as fast they will do more damage than swinging a sword that is twice the mass at the same speed.** [](https://i.stack.imgur.com/mDNep.gif) So basically they want their weapon to be as **strong** as possible not as big and heavy as possible. This applies for any melee weapon from a hammer to a sword. You real issue is making the weapon withstand the force behind the blow, not increasing the force, your character will do that no matter what they use. And the lighter the weapon the more kinetic energy they will generate. With inhuman force you could stab a sword through armor, you have to worry about the sword surviving it, but you have the same problem with a mace, the shaft will just bend under inhuman swings. So again you goal is strength of the weapon not size or mass. This sword of clouds is not a bad design [](https://i.stack.imgur.com/ObxiL.jpg) they have reinforced an normal sword as much as they can and still have it useable, adding a second point of attachment makes the grip much stronger. Still looks a little too thick and wide for maximum force but not impossibly so. streamline this down and you get what you want. You can apply the same principle to any weapon, if you make a hammer/mace-head many times bigger but the handle is still the same size it's just going to bend and eventually fail. So really it comes down to how your character fights, then designing the weapon around that. But honestly if you are that strong a bow might be his best bet, a steel bow with an inhuman draw weight will do some serious damage, plus the weight of the weapon will not matter as much. Image an longbow with the power of a ballista but that can be fired as fast as a long bow. You may want to give him this and make the melee the backup weapon for when they run out of arrows. The same thing applies to a gun, imagine someone who can fire a pistol that fires 4 gauge shotgun rounds. [Answer] Glyphin came close but I disagree. The weapon of choice is not a spiked shield, it's **two** spiked shields! With his strength the spikes are a good weapon for him and since he's going to be facing a lot of battles defense is more important than offense--he has to live to fight the next battle. Thus spiked shields and heavy duty spiked armor should be his outfit of choice--he will still be a deadly opponent but he won't go down the first time he gets surrounded. [Answer] This is actually a very simple question to answer. The answer being thus: Whatever melee weapons that exist today, but make it denser and heavier. The explanation is quite more elaborate. Allow me: Weapons are designed to serve a purpose. There's a specific mechanism in which weapons work and are employed. Pole weapons, for instance, are designed to keep your opponents at a distance (especially if your opponents are armed with shorter weapons like swords), and strike him at 'stand off' i.e you being able to hit him outside the range of his weapons. Pole weapons are also designed to counter people who are coming at you on horses to counter that mass/speed/height advantage. Swords are light and agile, and are amazing at fighting unarmored people. Fighting people in plate armor with a sword then becomes very difficult and are done with 'half-swording' (holding both the hilt and the blade of the sword to better control the point and more accurately stab at the gaps of the other guy's armor - as armor is *designed* to defeat sword cuts and thrusts) or the 'murder stroke' which is grabbing the blade of the sword with two hands and using the hilt and crossguards as a blunt instrument/improvised mace. Maces and morningstars are blunt weapons, and are balanced differently than a sword. With a sword, the balance is closer to the hilt, to lend it agility. With maces and the like, the balance is closer to the head, in order to maximize impact. Maces and morningstars are designed to fight people in armor as you don't necessarily have to pierce the armor to bludgeon your opponent to death. So all of these things require strength. A stronger man (with training, of course) can wield the sword faster, with more agility and accuracy. Similarly he can hit harder with the mace or the spear. He can even throw that spear further, if you want to go Trojan War Greek style and start chucking spears at your opponents. People with super strength can also effectively use heavier swords and maces (made from much denser metal, for instance), that ordinary humans wouldn't be able to wield properly. Note that I say 'heavier and denser', and not 'bigger'. This is because assuming the OP means that these super strong people are sized like average people (1.7-2.1 meters in height, for instance), bigger weapons are impractical to carry around and use. There's a certain limit to how big a sword can be while still being practical. [Answer] It really depends on just how superhumanly strong this super human is. If they were as strong as say, Superman, the best melee weapon would be his own fists as any other known material would act as padding rather than a weapon compared to the forces his own body can withstand. If our superhuman was only say, twice as strong as the strongest human, his strength won't matter much and your question instead of being "What's the best melee weapon for a super human?" just becomes "What's the best melee weapon?". And the answer to that question is just "it depends on the situation and your opponent. [Answer] If you absolutely have to go big or go home, meaning oversized sword or mace, you do have to account for additional momentum imparted by swinging the oversized weapon which would unbalance a normal fighter. However, all is not necessarily lost. Look at some martial arts that are heavily dependent on using circular motions. Even a swinging kick imparts a lot of unbalancing force that needs to be accounted for, and some forms carry that momentum into the next strike, from the opposite arm while continuing in the direction of the initial kick. So, really big sword and really big shield with a really tough back plate and you have a super strong whirling dervish. Of course he needs room to move, so, just give him a bit of space. For a bit more practicality, just give the guy some heavy gauntlets, or maybe a Maratha Pata (Gauntlet with a sword blade attached) and maybe some heavy armor. teach him how to box. I can imagine a horse and rider being knocked ass over teakettle by an uppercut. ]

[Question] [ On Earth ancient cultures developed marriage system of polygamy where one husband had multiple wives. What environmental or social differences would you need to create a world with an ancient culture that had one wife with multiple husbands? The tech level will be on par with ancient Greece or Rome. The setting will take place in a parallel world similar to our own with subtle differences inhabited by humans. [Answer] That is what is called **polyandry**, and often (but not always, oddly enough) is paired to a matriarchal society. There are still some examples today of such society in Tibet where several distinct groups organized in that way. It's what you would call "classic polyandry" In this system the land is rather scarce so society evolved following the most logical path of having several men working one plot rather than trying to find one property each. Often in these societies one woman is married to 2 or more men that are all brothers (the men are related to each other, not to the woman). This allows the owned land to remain within one family undivided as these societies are not *matrilineal* (matrilineal = property passes from mother to daughter) Another reason that moved some societies towards polyandry was a matter of protecting the household while the husband was away. With multiple husbands there would have always been someone present (Eskimo, Inupiaq, Iglulik, Alutiq and Inuit were an example of this) As arrangement, polyandry was widely used: South-american tribes used it (Bari, Yanomamamo, Cubeo, Aymara, Panoan Matis, Cashinaua, Guaja, Zo'e, Suri, Kaingang, Ache and others), North-american Natives used it (Aleuts, Comanche, Tlingit, Shoshoni, Cherokee, Blackfoot, Pomo, Utes, Innu, Pavitoso and Pawnees are just some of the most notable examples cited in literature, according to researchers many more have been reported but overlooked in the past), Arctic populations used it (as mentioned) was common in Asia and Africa and it's not completely disappeared yet, researchers say that there are at least 80 different societes in the modern world that still practice it in one way or the other. In Sri Lanka for example this is recognized under Kandyan marriage law. Even in Europe, ancient Germans and Britons were some tribes that researchers mention as practicing some form of polyandry. A paper by *Katherine E. Starkweather* and *Raymond Hames* "**A Survey of Non-Classical Polyandry**" not only shows how it was a practice more common that what was thought but also gives an explanation on why it was thought that way (from [here](http://www.theatlantic.com/health/archive/2013/02/when-taking-multiple-husbands-makes-sense/272726/)): > > So how is it that, in spite of all this evidence of polyandry > accumulating steadily in the literature, anthropologists for so long > passed along the "it's virtually non-existent" story? Starkweather and > Hames suggest anthropology has been accidentally playing a scholarly > version of the Telephone Game. > > > In 1957, George Murdock defined polyandry in a seminal text as "unions > of one woman with two or more husbands where these [types of union] > are culturally favored and involve residential as well as sexual > cohabitation." Using such a strict definition, Murdock could > accurately say polyandry was extremely rare; almost no cultures have > polyandry as the dominant and most preferred form of family life. > > > Then subsequent scholars mis-repeated Murdock's remark; polyandry went > from being understood as "rarely culturally favored" to "rarely > permitted." Thus mating diversity that was known to exist became > relatively invisible in the big story told by anthropology about human > mating. (If you write off every exception to a supposed rule, you will > never think to challenge the rule.) > > > In an email interview with me, Starkweather remarked, "I don't think > that anyone, including Murdock, was operating from an explicitly > sexist standpoint. However, I do think that the definitions of > polyandry, and thus perceptions about its rarity, may have been due at > least in part to the fact that an overwhelming percentage of > anthropologists collecting data and shaping theory at the time were > men." During Murdock's time, "there seemed to be a fairly pervasive > belief that polyandry didn't make any sense from a male's > perspective." > > > Polyandry does not mean that women are the head of the household, in many cases you find that is the eldest husband the one that takes decisions. Matriarchal societies (= headed by females) on the other hand do not imply that there is polyandry and matrilineal societies do not mean polyandry or matriarchy is included in the deal. Nothing prevents you to put all three together and have a society where the women took the role men had in our more recent, and well known, western society. Despite having found quite some people online calling it the end of humankind its not at all impossible that the same environmental, cultural and religious situations that brought so many groups to practice matriarchy, matrilineality and polyandry cannot be put all together in an alternate world. Some references for the above are (there are many more, it would be a long list, its long as it is and i wont bother formatting it as this isn't a school paper): Johnson and Zhang *‘Matriarchy, polyandry, and fertility amongst the Mosuos in China’*; Ellis *‘On Polyandry’*; Levine and Silk *‘Sources of Instability in Polyandrous Marriages’*; Smith *‘Is Tibetan Polyandry Adaptive? Methodological and metatheoretical Analyses’*; Steward *‘Shoshoni Polyandry’*; Starkweather *‘Exploration into Human Polyandry: An Evolutionary Examination of the Non-Classical Cases’*; Starkweather and Hames *‘A Survey of Non-Classical Polyandry’*; Berreman *‘Pahari Polyandry: A Comparison’*; Cassidy and Lee, *‘The Study of Polyandry: A Critique and Synthesis’*; Childs, *‘Polyandry and population growth in a historical Tibetan society’*; McLennan *'Primitive Marriage: An Inquiry into the Origin of the Form of Capture in Marriage Ceremonies'* [Answer] In *The Moon is a Harsh Mistress*, Robert Heinlein posited Lunar penal colonies analogous to what Britain did with Australia in real life. Due to the far higher incidence of incarceration among men, the population was heavily skewed toward males. That left the dominant family structures as some sort of wife-sharing arrangement: two or more husbands per wife. The "co-husbands" were often also partners in a family business as well. As time went on, these families raised boys and girls born in roughly equal numbers, reducing the imbalance, while the various nations of Earth continued to ship convicts, still far more male than female, helping to maintain the imbalance, albeit at a lower ratio. If you can devise a mechanism by which females are in chronic short supply relative to an abundance of males, you can have your polyandry-dominated society. One possible way to do that is to have a neighboring polygynous culture that has extra males who can't find mates there, and would rather emigrate to the wife-sharing culture. [Answer] If you’re looking for environmental reasons in addition to cultural ones, then there’s no better place to look than sex-linked genetic defects. Colorblindness, for example. 1 in every 20 males is red-green colorblind, but only 1 in every *400* females is colorblind. This is because colorblindness comes from a recessive mutation in the X chromosome, which means that males, who only have one X chromosome, only need one mutated gene to be colorblind, but females have two X chromosomes, and need two mutations. And because this gene is recessive, it’s even rarer. A colorblind female can only be the result of a colorblind father, and either a colorblind, or carrier mother, someone who has only one mutated X chromosome, not both. There’s some more stuff about X-Linked recessive inheritance [here](https://en.wikipedia.org/wiki/X-linked_recessive_inheritance). Anyway, instead of colorblindness, let’s replace that with, say, resistance to some horrible, flesh-melting disease. This hypothetical disease is responsible for killing so many people, that if you’re not immune, there’s about a 10% chance of survival, tops. So, because this immunity is X-linked and recessive, this means that a pretty decent population of males are immune, but not a lot of females. This encourages the “many husbands, one wife” social structure for two reasons, A) many pairings of an immune female with immunized, carrier males increases the chance of more immunized females, and immunized children overall being born, and B) There literally aren’t enough females to go around anymore, so society had to shift. Couple this with general societal inclination and matriarchal social structures, and there you go! [Answer] I think you're looking for [matriarchy](https://en.wikipedia.org/wiki/Matriarchy). And they have existed. Edt: Since at least one of my downvotes is for the matriarchy part I'll explain a little more. I'm using the definition my sociology professor used. > > A matriarchy is a society in which females, especially mothers, have the central roles of political leadership, moral authority, and control of property, > > > This isn't a feminazi dictatorship. And the ones that have actually existed (very few) have tended to be polyamorous in their relationships. So while this isn't the only answer, it is certainly AN answer to the question. If I remember my sociology correctly (been years!), in most matriarchies the women are the owners of land and parentage follows the line of women, which actually makes sense when you realize there is never a question if a child is a woman's or not. Often in the Matriarchy, men and women are not tightly coupled. The women raise the children and the men have a looser relationship, making it very easy for a women to have multiple men, but likely sharing those men with other women as well. The primary way for women to have multiple men requires that men do not 'possess' women. (of course this would also require monogamy to not be the expected norm) I also forgot about [Polyandry](https://en.wikipedia.org/wiki/Polyandry), which is where the woman has are more than 1 husband. There is also [polyamory](https://en.wikipedia.org/wiki/Polyamory) which includes both polyandry and polygamy. The [Toda People](https://en.wikipedia.org/wiki/Toda_people) practice Fraternal Polyandry Also > > In contemporary Hindu society, polyandrous marriages in agrarian societies in the Malwa region of Punjab seem to occur to avoid division of farming land.[14] > > > and > > Some forms of polyandry appear to be associated with a perceived need to retain aristocratic titles or agricultural lands within kin groups, and/or because of the frequent absence, for long periods, of a man from the household. In Tibet the practice was particularly popular among the priestly Sakya class. > > > [Answer] These are some of the factors allowing men to marry more than once: 1. They are considered heads of households in most societies around the world. 2. They are (primarily) responsible for financially supporting their families. 3. They are physically stronger than women. Not implying that marriage is a wrestling match for physical superiority, but women feel *safer* with physically strong men. It is a psychological factor. 4. Men handle outdoor and legal/social affairs of the family. 5. Children inherit father's names. If you have a society where these roles are filled by women, then a matrilineal social structure can be formed. You may want to read [a list of matrilineal societies](https://en.wikipedia.org/wiki/List_of_matrilineal_or_matrilocal_societies) and find the commonalities between them. [Answer] Polyandry and polyginy are two drastically different things. Polyginy emerge when a lot of men die constantly (who said war?) as a way to repopulate the tribe. It makes it so you can send all valid men to a certain death, have 10% of them survive and still have as much children in the next generation as you would have if everyone survived (something you can't do with polyandry + send women for obvious biological reasons) polyginy is good when your population becomes too low because of high mortality. Polyandry might emerge during prolonged peace period (no male mortality) in a place with limited resources (so population growth is detrimental) Obviously I'm only talking about "natural" polygamy and not about cultural polygamy however rites and customs have to come from somewhere and it can sometimes come from past environmental pressure and then persist even if those pressures no longer exist [Answer] Some food for thought...while it doesn't necessarily fit the tech level of ancient Greece or Rome, take a look at the current conditions in poor yet urbanized area of the United States. In these communities, a large percentage of the men are either incarcerated or are busily killing each other off. While some of AndreiROM's conditions are met, others are exactly opposite. But it's an interesting parallel. [Answer] I'm surprised no one has mentioned [*Pandora's Genes*](http://www.goodreads.com/book/show/28456741-pandora-s-genes-the-pandora-s-trilogy# "Pandora's Genes") as a source of inspiration. In a post-apocalyptic Earth, science has loosed, among other things, a disease that largely effects women, killing them sometime between conceiving a child and shortly after giving birth. As a result, each woman generally takes 2 husbands (often but not always brothers, or at least good friends). Even if you've already got enough inspiration for your world building (I see you've already accepted an answer, but I just had to post), it's worth a read. [Answer] Another poster brought up that the idea of polygamy might have come about because one male can impregnate multiple females but a female can only be impregnated once at a time. If the setting provides it, it is possible that a female can be impregnated multiple times by multiple fathers (like cats). Having the society be (at the very least) a matrilineal one would make it so that it doesn't really matter who the father is, the mother's name is the one who matters and there's no contention that the child is really hers. Inheritance might be slightly different. In a society where you can't take a paternal test, there is an uncertainty on if the child is actually the father's (aka, the concept of virginity and unbroken hymens). In a matrilineal one under this concept, you could expect that child rearing is mostly communal (at least in the family units proposed), because all males can reliably expect that at least one of the children is their's. Of course, that also means that there would be more like a litter of children than a single birth. EDIT: the matrilineal society brought up in other replies came about because of lack of arable land space. aka, having one large family takes up less space economically then three smaller ones. [Answer] That's a tough one, mostly because it's not within human nature to live within that particular arrangement. Psychologically and instinctively that wouldn't work. A lot of work would have to go into convincing the men to accept the arrangement. Most likely the society in question would have to be matriarchal, and possibly worship a female goddess, such as Gaia, whose express wishes are that women rule the world, etc. A few things that you would need to establish are: * Women have a very high status in society and hold all positions of political and religious power * Men have some importance as military leaders, and soldiers, but are heavily indoctrinated by religious and political leaders to obey and even worship women * A careful ratio of women to men is maintained, maybe by sacrificing male babies/children * Tying in with the above, men are not allowed to know if they have fathered a child, or who that child is. That way the child knows only who their mother is, and grows up respecting and obeying her, but not interacting with their father in any way, shape, or form * The implication is that men are second-hand citizens, who probably can't inherit property, or wealth, except in very, very rare circumstances, leaving them only a couple of avenues for prosperity, such as becoming very valuable scholars, or highly prized military leaders * No violence against women, or disobedience would be tolerated, and would be severely punished I'll think of some more points, but I think that's a pretty solid foundation to start with. ]

[Question] [ I'm developing a world with many different races, many of whom live in relative isolation. I'm trying to understand how the fashion of each cultures/species would evolve. In our world we're obsessed with clothes, the idea of walking around town without them is near unthinkable. However consider a colony which has very limited contact with the outside world, why would they develop the concept of clothing in the first place? It's my belief that clothes perform three main functions * Warmth * Status (my clothes are prettier/more expensive than yours) * Modesty However in these isolated environments where the weather is good (or at least the weather well suited to the species living there) there seems less need. After all status symbols could be anything from jewelry to weaponry. Modesty is a taught behaviour, however once people start covering up and are exempt from certain comparisons it could help explain the rapid spread of the tradition. What factors would lead to a culture developing clothing and fashions in the first place or is it simply a matter of outsiders (who do need to cover themselves for warmth/protection) influencing their fashion? [Answer] Pragmatic concerns of clothing aren't restricted to warmth. The idea of wearing smaller/more revealing clothing in warmer climes is a modern and impractical one. Anywhere that is hot and sunny requires people to **protect themselves from the sun**, which is best accomplished by wearing garments that are long, loose, breathable and light-colored, so as to reflect back as much of the sunlight as possible, while also allowing sweat to evaporate. It's especially critical to protect the head and scalp, as well as the eyes. If the environment is also dry and dusty, protecting the mouth is also advisable under certain circumstances. Other practical reasons to wear clothes are for **protection from other elements** in the environment, especially given a lack of fur, scales, shell or some other hard and protective exterior. Anything from sharp thorny undergrowth to mosquitoes to stinging nettles. If you have ever gone hiking in warm weather and surrendered to the temptation to wear shorts instead of jeans, you will know what I'm talking about. On a social level, clothes are used not only for status but also for **self-expression**. Clothing, jewelry, tattoos and other forms of adornment are a way in which people communicate their identity to the environment. **They help people identify each other** quickly, for example as members of an in-group, or a certain profession. Knowing on-sight whether someone is, for example, a member of the clergy can be vitally necessary for social development. [Answer] You may be confusing modesty with morality and overlooking one of the prime purposes of modesty - to control visual information. For instance, if a given race's arm turned red when angry, a diplomat might wear an arm covering solely to hide that. You're also focusing too much on sight. What about smell or touch? What if a shark-like creature's skin got rough and scratchy when happy? Wouldn't they then wear clothes to prevent hurting playmates when playing? In humans cultures and animals (and this varies from culture to culture) certain displays communicate information such as sexual readiness/avilablity or mourning, etc. In certain situations this may be more or less desirable, and clothing is a common solution to that. What about a female creature wearing thick loincloths to prevent advertising that she was in heat? Hopefully that helped spark some additional ideas. :) [Answer] To take a more practical slant on things. For each species identify what they actually need clothes for. Think about the biology, the environment and the histories and traditions of that race. **Example 1** For example a scaled swamp-living lizardman might have no need for clothes for warmth or protection (and they wouldn't last long in a swamp anyway), however they do need to carry things. In that case you can expect them to develop harnesses, pouches, backpacks etc but not actually clothes as we think of them. Modesty would never exist as a concept, and adornment would be approached by decorating the harnesses. **Example 2** Desert dwelling nomads - not sun adapted. In this case clothing is needed for protection. Social taboos may well develop to reinforce that need for clothing so modesty may or may not exist. Clothing would probably look similar to that developed by desert cultures in our world. **Example 3** Desert dwelling camel-riding nomads - sun adapted. In this case clothing is not needed for protection from the sun, but they may well carry face masks to protect themselves from sand. Carrying things is normally done by putting it on the camels so for the most part they don't need much in the way of bags, harnesses, etc except to carry things they need frequent access to. **Conclusion** I hope this helps you see how you can break down each race and its environment to see what it's actual requirements are. From those requirements you can then work out and see what they need - and from there draw conclusions about where/if they would adorn things and whether they would develop a modesty taboo or not. The need for clothing outdoors doesn't automatically lead to a modesty taboo of course - and even a race that doesn't need clothing may still develop one. That could be an interesting part of that races back story though. For example perhaps a primitive race that doesn't need clothes had an encounter with a race that does need clothes. They saw the more advanced technology of the other race and decided to copy it, including the clothes... [Answer] Not in all of our world, but in most cultures, yes. You can see examples of alternatives on Earth, both in tribes in warm climates (in Africa, Indonesia, South America...), and in modern nudists. Though even all of those groups find some clothing useful much of the time. The reasons you listed, as well as protection and cleanliness, and for utility (they can help carry things) and to do certain kinds of work. When there are harsher conditions, clothes become more normal, and people's expectations go that way. Clothes help people survive weather in most of the year in most places. Also, many peoples who don't wear much clothes, still decorate their bodies, e.g. with paint. Since you are talking about fictional races, some of them may also have adaptations which serve many of the functions of clothes - e.g. durable skin, scales, or fur, and/or temperature adaptation. **Postscript:** It also occurs to me that clothing is used for concealment and privacy, both to hide possessions, and to cover up and not share our bodies. The aspect of hiding what our bodies look like, and even making our bodies appear that their naked form would be different (with belts, corsets, shoulder pads, etc) is one of the ways people dissociate from their bodies and choose to project and/or also self-delude about who and what they are, which is a major aspect of modern civilizations that people with less clothing do less of. [Answer] There are two distinct reasons for clothing and other adornment: 1. Comfort and protection 2. Status, style, and modesty The primary reason for clothing in most civilizations began as protection from the elements; sun, wind, and rain. Even in a warm climate with good weather, there is an occasional cold night over overly hot day. What starts out as a giant leaf hung over your head to protect you from the sun may well turn into a hat or a poncho; what starts out as an animal skin to keep the cold away may turn into a cloak. When weather has been dealt with, there will still be dangers from the surroundings: dangerous (or annoying) animals and insects, thorns or nettles, rough rocks, and so on. It doesn't take long to realize that a tough animal skin protects you from scratches (or even weapons), and soon that animal pelt becomes a tough leather vest, capable of protecting from slashing claws or knives. Once simple survival is no longer a looming threat, clothing can evolve into more than simple protection, into comfort. A leather vest may turn a knife, but a leather vest over cloth will let your skin breathe better. Clothing that is harder to make, or materials that are harder to come by will naturally be given status; as a civilization moves from clans and chiefs to cities and kings, status will play a natural part in clothing. A "country bumpkin" may still wear leather vests, but in the cultured city, where they don't need to worry about stray thorns tearing their clothing, they wear silk and dyed cotton. Not all civilizations had the full evolution of clothing from basic protection to the "stylish" clothing of today; many cultures never moved beyond the first step. There are tribes around the world that still wear little more than a belt. On the other hand, there are cultures that thrive on clothing of all sorts, the more impractical the better - look at the ridiculous wigs, dresses, and powdered faces of men and women of the French court in the late 1700's! The clothing choice of a given civilization should depend on their roots, the climate, and their lifestyle, along with the available materials. A jungle tribe would most likely wear little more than a necklace or a belt, because anything else would rot. A tribe in the far north would wear almost exclusively furs, to protect them from biting cold. An early European tribe would need protection from wind, rain, and sun alike, and they would have access to a wide choice of materials - wool, leather, furs, even silk - and thus would have a wide range of clothing styles. As time wears on and clothing evolves, the jungle tribe may not change much; the northern tribe would adopt warmer, layered clothing; the European tribe would continue to branch out, adding colors and simple designs, trying to make clothes that can stand up to both heat and chill. [Answer] Hmm. Seems like a lot of comments on man parts being delicate and needing protection. So, I'm going to weigh in with something you might not have considered. **A monthly period and lady parts with a real working vagina**. Which leads to another reason for clothes: **sanitation and safety.** Clothes also protect the environment from YOU, and everything that might come out of you, beneath the waist, which in turn protects others from disease. I don't know how your races work and if your ladies are anything like human ladies, but there are certain things that happen as a woman that I think sort of require underwear. I'm not talking about modesty, I'm talking about a predator being better able to track you, and I'm talking about sanitation as well (which, if your people poop, is another factor you might be looking at, male or female, because **a primitive society without underwear is society with more diseases spread by fecal matter**). See, ladies can't hold their period like they hold their pee. It just comes out. There's nothing they can do about it. Next thing you know, there's blood everywhere. Also, a healthy vagina has a constant discharge. They can have a constant, unrelenting ooze coming out of them, which varies by individual, according to age, and hormones in any given hour. So if your ladies are built anything like humans are, once a month anything they sit on will look like a massacre, or as they walk they will drip, and when it isn't that time, everywhere they go they may leave a bit of themselves behind. If your people care about cleanliness (and even as far back as Greco-Roman and Medieval times, yes, people did) they aren't going to want everything covered in blood. Carrying a thing to sit on is not going to help. Because without actual clothing, they would not be able to move from one spot. Yes, there were cultures that locked their ladies up in a special hut for the duration, letting them out after it was over, because it was considered unclean. It just seems more practical to put on underwear with something to catch it and let them go about their day. [Answer] **Environmental protection** Staying warm has been mentioned already, though, consider both rain, and wind. Wind can drop the temperature you are experiencing quite quickly. And, of course, in very hot places, some clothing can help keep you cool by keeping the direct sun off your body. Places warm enough to go without clothing usually are also warm enough to be teeming with insects. Clothes are not a perfect protection, but people quickly find if they have to deal with bug bites there are places far less comfortable to get them - and those spots get covered up. Then, of course, there's daily life - walking, grabbing and carrying stuff - it's easy to get chaffed, scraped, or blisters, and certain types of clothing can help against that. Many people develop some form of sandals or shoes pretty early in making clothing, just for the sake of protecting the feet and toes. **Object Storage** Pockets! Pockets are useful. People quickly find the small pouches and bundles that you can make relatively easily become logistically unwieldy, especially if you need to keep many objects available and organized. Even in the most bare bones society, the first person who usually needs this is your healer/medicine person, since they'll have to deal with a lot of plants and materials. **Improved Appearance** Decoration matters. Being able to hide a bit of belly fat, or wrinkles on your legs is a baseline thing a lot of people find useful for their appearance. Some colors work better with some folks than others. In a completely different direction, you might want to intimidate or scare someone, such as enemies from a rival group. Monstrous masks, broadened shoulders, shoes that sound loud and heavy... **Practical Identification** Who is the leader? Who is the holy person? Usually in nearly every society, those two folks get special clothing first. That's because there are expectations with how you act and treat those people, different than others. Allowing people to see this, easily, allows people to know how to act. This also directly ties to "passing down the cape" as a generational act of roles. The more respect or changes in behavior that are expected between roles, the more you'll see specific markers to be worn to display that. One of the earliest and most common ones is "adulthood". In hunter societies, unsurprisingly, if you hunt a fearsome predator, wearing the skin is an indication of your skill. **Historical records** Once you can successfully decorate your clothing with some kind of dye or paint, or weave colors of different materials together, you can create decorations and portable historical records. It's not surprising that many cultures have history in blankets, cloaks, tents, skirts, and so on. [Answer] Clothing can be used to flatter or disguise certain body features via optical illusions. Depending on the cut of a garment, you can emphasize (or deemphasize) certain features on your body. For instance, a woman with slim hips and a fuller upper body might wear a full skirt to make her appear more balanced. The same skirt on a woman with full hips and slender upper body would only make her look more bottom-heavy. ]

[Question] [ After further development in AI, will social networking sites create fake accounts like humans using AI and make this AI's to talk/chat to real people? They might do this to get money through ads and make people addicted to their sites. As many people might share / chat less in the future, will the sites come up with idea? Will it work for them? [Answer] ## Its already happening > > Hello dear, > > > I can see you logged to this site and I want to tell you, that I am 18 year old girl and totally not experienced in Worldbuilding, *giggles* > > > I am searching guy who is gifted in building worlds. If you know what I mean. > > > We can chat online, one to one on this video chat site. And I will show you all my Worldbuilding secrets! > > > Follow [this spam link](http://worldbuilding.stackexchange.com) to know more > > > If you haven't been approached by a young girl wanting sex online yet, you haven't used the Internet long enough... * Spammers use this technique to attract people to unzip their pants ... and pick up credit cards to see more! * Dating sites are already creating fake profiles to attract more users. * Facebook Messenger already offers handy chat bots to provide you entertainment. Just pay $0.99 for some spicy chatbot experience. One of [core human needs](https://en.wikipedia.org/wiki/Maslow's_hierarchy_of_needs) is to love and being loved. And people are willing to pay money for that feeling. So, I would say it is *a very realistic scenario!* [Answer] If you're interested, I'll link to a social networking group with an interesting spin (in beta): **your AI counterpart**. This particular social network has an AI component that learns how you interact with their systems; it learns your interests through how/what you post, when you're most likely to post, etc. Then even when you're offline, your **counterpart** will be active on the social network. As you train your counterpart, it learns how to more closely imitate your online habits. This is a more 'intelligent' than chat bots or spammers, and indeed their uses are rather different. Personally, I think the idea of a counterpart intriguing. At the philosophical conclusion, you'd have a 'digital' (AI) you, with real experience interacting in your social network. Implications of mass adoption would be...slightly freaky. <https://www.eter9.com/auth/login> [Answer] Pavel mentioned AI programmers who want your money. There are also people who want your vote, or [influence public opinion](https://en.wikipedia.org/wiki/Twitterbot). It is an interesting question if the networking sites *themselves* are complicit with this, or if they are merely basking in the advertising revenue. Getting to fictional worlds, it would be easy to imagine communities with AIs who greatly outnumber the humans and give each human a [filter bubble](https://en.wikipedia.org/wiki/Filter_bubble) with lots of supportive friends. [Answer] The AI's will be used on social media for increasingly diverse purposes. Spam, fishing and advertisement are only the tip of the iceberg. And possibly the less interesting cases. As evermore sophisticated AI mine social media the people who want manipulate that data will build increasingly sophisticated AI pretending to be almost normal people. Who happen to like Coca-Cola. As privacy enthusiasts acquire better tin foil they will release AI that mask their actions. 9/10 users of my network are not furries. As the social sciences becomes Science AI will be made to allow testing hypotheses. "Our study found on average 10% more people were 8% more depressed to find 50% or more of their friends were actually AI than predicted by the Smith[2] model. Also we are jerks." ]

[Question] [ Assuming these supercomputers can think/reason in "internet battle terms", aka. having the capability to predict their opponents' movements and recognize patterns and prepare for different types of attacks. * What would a battle between them "look like"? * What sort of timescale would the full battle take place in? * The battle is won when the other supercomputer has lost all "territory", not including the actual supercomputer that it is occupying where "territory" is memory/computational power/the amount of computers/routers the supercomputers have under their control. * No getting large companies to shut down the other supercomputer's connections with money * No physical methods of taking/destroying territory or destroying the other supercomputer's connections aka. pay humans to do it for them or *physically* destroy the routers that the other supercomputer is using * The supercomputers have absolutely no other goals than defeating their opponent through winning the battle * "Mini/temporary goals" can be created and destroyed by the supercomputers as long as they help with the primary, unchangeable goal * These supercomputers have knowledge of many programming languages and router types and methods of doing different things/achieving different goals * Their pattern recognition and problem solving comes from a deep neural network which they can change/adjust/manipulate using that very deep neural network * There is absolutely no intervention from humans [Answer] A battle over the Internet will not be over the individual end systems, but over the nodes, the modems and routers that connect these systems. If one supercomputer is able to turn off the modem the second supercomputer is using to connect to the Internet, that first computer wins. End of story. There could be a secondary goal of setting up subroutines on other computers which will execute attacks in closer physical proximity to the enemy computer, but since supercomputers are generally very large, it's going to be hard to make such subroutines anywhere near as smart, powerful, and generally useful as their parents. Thus, the 'battle' will involve attempting to access, hack, and control all nodes surrounding the enemy, so that they cannot connect. This means that both sides will be limited by how connected they are; if one is in a city with ten dozen WiFi signals, and the other is out in the country, connected by a landline to a single lonely modem, that first computer will probably win. Not only do they probably have higher throughput/bandwidth (I forget the words, I'm saying they can transmit more information per second), but it'll also take more work to disable all their connections. However, if that second computer has a FiOs connection with an upload/download speed of 100Gb/s, while the first computer has 5Mb on each WiFi router, then the second is going to be a lot more 'mobile', or able to put more data into the Internet faster. These initial limitations are going to define how these computers will 'fight'. Since they can't change their physical connection state, they'll need to do everything they can to make up for any limitations they have. Unfortunately, I can't think of too many tactics for a bad connection; they're just shift + out of luck. So let's assume they're both university supercomputers with super-good connections. As I said before, the connections are key, rather than the endpoints. Thus, the first step will be to 'hack' all the modems/routers in range. This shouldn't be too hard; just connect, find the IP address for changing the settings, and try the default username/password. Once they're in, the computers will try to make sure these modems/routers will only accept packets from themselves, so that the enemy is 'locked out'. The interesting part about this is that both computers will probably be able to sniff each other's packets, and thus be able to figure out the router's password at the same time. From this, I'd assume that whoever can send packets to the router faster, or whoever is allocating time and effort for accessing the router, will get it. From that point onward, it's going to be difficult for the enemy to get past. If the router is 'fortified' with a new password and some blacklisted IP addresses/MAC addresses, it's going to take a while for the enemy to find a way in, if it's even possible at all. Thus, after the first allocation stage, it seems like both sides will grind to a halt. At this point, the Internet will appear dead; anyone who still has control over their computer will probably not be able to connect to anything. Intranet might still work, but anything further than that will be locked up tight. This stage, to me, resembles trench warfare, and I think it'll work similarly: both 'armies' will begin preparing the computers they have under their control for an 'attack', where they will bombard an enemy's router with packets in an attempt to find a way in. These packets will contain heavily modified signatures, trying to look like whatever the enemy is using to communicate. Once the right signature is discovered, the attacking supercomputer will 'charge', using their new knowledge to try to take over as many routers as possible before the enemy catches on and changes their codes. During the time between attacks, each supercomputer will try to control end user systems. These systems provide the raw computational power to perform attacks quickly and with a large enough volume to break through in a timely fashion, however they will probably not be 'smart' enough to coordinate attacks on their own. The point here is that the 'battle' will be so big that each side won't have time to hack all the computers; as I said before, the connections are more important. However, there is definitely a bit of room for tactics here: either you focus on attacking more often, or you hold back and focus on hacking computers which will make your attacks more successful. At that point, though, I'll leave it up to the supercomputers' knowledge of Sun Tzu. [Answer] There are three primary tactics the computers will be able to use: **[Distributed Denial of Service](https://en.wikipedia.org/wiki/Denial-of-service_attack) (DDoS) attacks** Each computer will try to gain control of as much resources as possible. It will then direct traffic at its opponent's resources. This has two primary benefits. First, it helps deny those resources to the enemy. And second, it helps disguise the other attacks the computer is making, because the enemy will have to sift through all the chafe. **Second is subversion attacks.** This is taking over your opponent's resources. This is similar to a zombie war, where every enemy you defeat rises up in your own army. **Third, and finally, is infrastructure attacks.** This is a bit trickier because the structure of the internet, while hihgly correlated with the physical world, is not a precise mapping. Faster (or larger connections, depending on your point of view) will tend to distort things. The idea here would be to take control of power stations of areas the enemy controls, then cut or overload those to take out resources directly. Note that while datacenters have backup power, most home computers don't, and the supercomputers will likely be utilizing those as [botnets](https://en.wikipedia.org/wiki/Botnet). **Overall tactics** Using the above options the computers will fight over resources. If the computers control approximately equal resources it will be close to a stalemate. Once one computer gains a significant numerical advantage, it will be able to use the weight of processing power it has to overwhelm the enemy with DDoS attacks, degrading their effectiveness further. This will have a cascading effect that will let it start taking over more and more. This won't be the end, though. The losing supercomputer will go for slash-and-burn tactics by destroying its *own* infrastructure. It will isolate itself, cutting off attack routes - either all the way, or it may leave a few channels open in areas where it has less of a disadvantage. This will create a stalemate/armistice situation where one computer is the clear winner but does not have full control. Where it goes from there is more up to what the humans do, or if the supercomputers to continue war by other means (diplomacy). [Answer] In a competition between supercomputers, you wouldn't see anything (or much of anything). A computer isn't going to waste time displaying data to a screen when precious cycles can be better used combating the threat. In terms of "territory" you would probably see new/deleted/changed executables, flat files, and databases at a given site as it changed control. There would likely be extreme CPU/memory usage on a contested site. The battle would be a series of electrical signals over circuit boards, wires, and various other apparatuses in a time frame measured in cycles per instruction or instructions per cycle, depending on how fast the individual instructions were executed. If the two systems are identical in terms of hardware, firmware, and software, there would probably be a stalemate such that "territory" can change control, but at the cost of an equal area of "territory" elsewhere. Otherwise, the faster computer will probably win out in a time proportional to its advantage. What would the actual time value be? I'd say there's insufficient information in your question to provide that, but I'm sure you can come up with a reasonable number given the technology level of the computers in question, the information I've provided here, and your own knowledge. [Answer] This was going to be a comment on Frostfyre's answer but it grew too large. With computers of equal capabilities data lag/transmission time would play a large factor. Whenever a super computer has a faster data transmission time to a node it has an advantage and can use less of its total processing power to keep/take a node. Surprise attacks. The major IP addresses that each super computer uses would be black listed immediately, so few successful attacks could come from that vector. The super computers would likely have to implant Trojans/worms on multiple machines that are indirectly linked to their rival. These would be set to try and bludgeon their foe with a brute force attack similar to a Denial of Service attack. Under the cover of these bulk assaults precision strikes would go in. These would be aimed at major objectives. Data dumps about the other super computers activities or infrastructure. Inevitably one super computer would try to cause real world affects. If they can take down the power grid that their opponent is relying upon they would cause a temporary lack of service while backup generators went online. This would give the aggressors a momentary advantage to exploit. Cause a wide enough power outage and the defenders ability to intercept attacks would be hindered. Although any area with power outages would keep the attacker from gaining ground in that area. The attacker could gain ground outside the affected area while the defender was crippled, and then hope their own defenses would be enough to keep their new ground. A finale solution could come down to whose back-up power supply is the best. If the backup power supply runs out the entire super computer would be taken down. Super computers need a ton of juice. Of course there might be Trojans/worms on a dead man’s switch designed to cripple their enemy in a similar fashion if they go offline for X time. The actual active war while restricted to internet only would be very similar to WWI strategy/tactics except with a much larger no man’s land when processing nodes have too much latency between them an either super computer. The philosophy behind the war would be closer to Cold War mentality though. Since it is feasible either computer could take the other out by crushing national power grids. Actual winners would be decided by who had the best real world support and assets. Better processors/more processors. Better back up power. More redundant systems and nodes More physical agents on the ground to sabotage such systems. (You exclude this in your criteria but it is still the most powerful tool) [Answer] I've not seen mentioned one thing that is absolutely central to the internet: Routing. Yes, there was talk about taking control of routers, but basically for the purpose of blocking access to them by the opponent. But there's so much more you can do with routers. Note that apart from the routers and systems you are directly connected with (i.e. those on your local switch or hub, or those using the same WLAN access point), *anything* on the internet can only accessed using its IP address. You don't actually address the computer or router, you address the IP, and rely on the routers to send your packets to the correct computer. Now how this works is through routing tables on the individual routers, as well as protocols which the routers use to communicate with each other. Now if you have control of a router there are lots of interesting things you can do with the traffic going through it: * Block certain traffic. That's obvious. * Throttle certain traffic. That is likely not detected as quickly as completely blocking, and more importantly, may avoid other (non-captured) routers trying to route around your infected router (remember, you can only control traffic that passes routers you control, and the internet is built to route around damage, which blocked traffic obviously is), and may give you a tactical advantage on the attacked system. * Redirect traffic. Traffic that is intended for a system you don't control is redirected to a system you control. * Modify IP data. That basically is a more advanced version of redirection where you actually change the routing information in the packet itself, so it seems to other routers (and the system the packets ultimately arrives at) that the source and/or destination is another than the original one (the NAT your home router does is an example for that; your external address is translated to a local address and vice versa). The possibilities of using this are endless: + You can redirect an attack on one of your systems back to one of your opponent's systems. + You can change the sender IP so the addressed system no longer answers to your opponent, but to you. + You can change the port number, so the destination system receives the package, but won't understand it because it's directed at the wrong service of the destination computer. + You can manipulate the TTL (time to live) field, so that *another* (non-infected) router on the way will drop your packet. That will make it harder for your opponent to identify which router is controlled by you. + You can manipulate the checksum, again with the effect of the packet being discarded by another system. * You can introduce secret flags that only the routers you control understand, and use that e.g. to control whether a packet addressed to your system is actually routed to one of the systems under your control (so the infected routers at the border of the controlled "territory" act as a giant firewall). * You can also manipulate the actual traffic content. * You can advertise false routing information to other, non-controlled routers, e.g. in order to direct traffic to you that normally wouldn't pass your routers and thus would be out of your control. In short: On the internet, you don't really know the system you are talking to (unless you use secondary measures to identify it; that's what e.g. SSL certificates and SSH host keys are for). Therefore the most powerful attack is the attack on the routing level. [Answer] Depending on their objectives, **humans will either see nothing at all or the world will end.** If the supercomputers are trying to destroy the world then humans will see immediate effects else, we may not see much of anything. If they are just competing for CPU time then the large supercomputer clusters will see weird fluctuations in their workloads. Alternatively, infecting the world with botnet software could increase computing power considerably but that's fairly slow on the time scale the supercomputers are accustomed to "thinking". If they are operating on behalf of state actors such as the US, China, Russia or the UK, then they may escalate to attacks on infrastructure such as power grids, chemical storage facilities, traffic lights, governmental information systems, etc, etc. If these attacks are successful in destroying or severely degrading the performance of those systems then the economic damage could be catastrophic. [Answer] It would either be over fairly instantly, or would stalemate. Supercomputer does not mean super-resources, and encryption is exponentially easier to establish than it is to crack. Within short order, all external-facing nodes from each side would be fortified with ridiculous levels of encryption that no known hardware could crack in an infinite amount of years. After a few leaks, learnings and optimizations from both sides, you would end up with two fortresses with mile-high walls, firing arrows at each other. Stalemate. [Answer] answering a dead question with a boring answer, yay? War between such super computers would potentially be pretty boring by your requirements, or interesting and destroy the entire internet before it got boring again; because sometimes Defense really is the best Defense. Hacking isn't magic that everyone implies. Hacking isn't about being smart or good enough you can make a computer do what you want, Hacking is about finding out the machine you hacked was stupid enough to make it possible for you to do something everyone knows you shouldn't; it's far more about exploiting the defenders mistakes then anything else, and if your defender doesn't make mistakes then you CAN NOT hack them, end of story. Sure, sometimes you have to be pretty smart to figure out how to take advantage of the opening the defender made, but you first need an opening. In terms of 'hacking' by a huge majority the most common now of days is social engineering, tricking dumb gullible people to do something dumb and gullible; because it's much easier to trick a person then a computer. This isn't an options by your own definitions. The second most common is finding a computer that someone did something stupid on, like forget to change the basic password you use to connect to it, or give you more permission then they should have to modify that sudoers file. Closely related to this is finding out that the defender is using a program with a known bug and exploiting the alerady known bug because the defender forgot to update it. This avenue isn't viable if we assume that both computers are near equal in capabilities. To be able to detect your enemies weaknesses you must already know how to detect such weaknesses, and as such you would have already found and patched them on your own system. It's much easier to scan your own computers, where you have full permission, then to scan your enemies so it's only reasonable to assume you would be able to defend yourself as well or better then find your enemies weaknesses. More to the point the list of "dumb stuff people do" is well..known. Humans make mistakes, hackers can exploit a stupid or lazy human who does it, but computers aren't lazy or prone to random moments of idiotic mistakes. Any computer sophisticated enough to develop it's own changing attack vectors for attacking it's enemy will have reached a level of sophistication where patching dumb mistakes and wholes in their own system is trivial. Thus no dumb mistakes will be made. The final form of hacking would be 0 day exploits, finding a legitimate new defect, previously never known, that can be exploited. In theory computers could do this, though again it would be much easier to scan for flaws in your code then to detect them in your enemy thus we would expect each computer to defend against 0 day exploits in their own code as good or better then they would find it in others. The expected defense of both computer is higher then their offense on average. It's like giving two people pocket knives to fight with, and then armoring them with full plate mail. A pocket knife can be lethal if used very well sure, but if both sides have far better armor then they have weapons it's going to be a very long fight. Of course this isn't failproof, it's possible one super computer figures out a 0 day exploit before the other one, a brand new bug to exploit before the other side figured out it existed to patch it; just like our armored knife fighters may eventually find a weak joint or eye slit that they can stab through after a long enough battle. However, the fight will be anticlimatic in this case. Whichever side finds the 0 day exploit uses it to kill the other computer, end of story. No amazing battles, explosions, or other fun things. Once an opening is found you can use it to get your rot access and delete the other computer's hard drive and your done. It's unlikely that either computer will find some bug they can exploit to hinder the other computer without entirely taking it out, any minor bug that doesn't grant full root access will likely lead to the defending computer detecting the intrusion and fixing the bug too quickly to be useful, it has to be an all or nothing surgical strike. Thus what your see, if you somehow watched the network traffic, is two heavily armored computers thinking for long lengths of time, with the occasional query or message being sent (from an appropriately subverted node so as not to be so obvious) to see rather or not the enemy computer has fixed a bug you think you may have figured out how to exploit. The digital equivelent of two fighters feinting at each other for most of a match looking for an oppening until one finally sees one and goes in for a quick kill with their knife. Of course, this all could happen after they have destroyed much of our technology first... Ignoring the difficulty of 'hacking' there are two other options for attacking a computer which are a bit more brute force. The first is a Distributed Denial of Service attack, as previously mentioned in other's answers. You can overwhelm your enemy computer with so many requests that they are flooded and unable to respond to do anything. Notice I said DDOS not just DoS, a DoS that tricks your enemy into using far more resources then you use would fall under the ground of 0 day exploit and most likely the computers will be defending from that from the start. The problem with a DDOS is that it takes far more computers working together to take down one enemy computer. It's easy to detect a Dos and blacklist the attempter, so again defense is easier then offense. Your attacker DDOS options fall under the ground of either temporarily disabling causing him exactly as many resources as it costs you (making it pointless to do) or preminantly disabling you by massive overkill that overwhelms you. DDOS strategies could be employed, but to do them both computers would ahve to rush out to grab as many nodes as possible to use them to attack the other's nodes. Since both computers needs more energy/resources to take down an enemy node the only option is for both to try to own *more* nodes then the other, meaning a race to take every network node out there. However, again, because it's easier to defend then attack this will be pretty futile. Assuming anywhere close to being evenly matched and the computers will take over unaligned computers at close to the same weight, meaning for every one enemy node taken down they have secured 2 or more nodes of their own; meaning even with an all out offensive both sides will be gaining nodes faster then loosing them until they have taken over (or destroyed) every easily taken over unaligned computer. At which point we revert back to the first example of both computers trying to find 0 day hacks, except that they will run the 0 day hack on *every* enemy node at the same time (since they have about the same number of nodes they should be able to do this), taking over most of the enemy computer at once and then having the power to DDOS the rest. In reality what would instead happen is that one of the computers will write the "take over enemy node" code a few dozen milliseconds sooner, which will let that computer take over many dozens of computers first (once you write the exploit you can use it simultaneously on many machines, the trick is not in processing power or bandwidth, but coming up with a smart hack). Whichever is the first to start taking over nodes will grow exponentially faster an soon have an easy time overwhelming the other. Of course, why take over the internet internet when you just need one unalligned node. Both computers communicate with the internet through their modem...which is connected via a wire to one tiny service prodivder, who would in turn connect you with others. If you can take out that first provider, the single hope from local machine to tcp provider, you can isolate your enemy easily. Thus the real trick would be to hack whatever that first service provider hope is. These service providers will be far more vulnerable then the enemy super computer, because they aren't being defended by a super intellegent hacking computer. Being bult by humans they will have idiotic human mistakes in them. A computer able to do any of the more advanced hacking should have an easy time scanning for one of this exploits. It's just a matter of which super computer finds a whole in the flawed human-made firewall required to get into the service provider, at which point they will ensure that provider ignores the other computers messages and that computer will be sitting in an isolated corner without the ability to do much of anything. So basically, either one computer or the other first finds a way to hack unalligned nodes sooner, at which case they can use that to win a quick victory by having access to far more nodes, or if they don't they will gobble up all of the internet, then sit and stare at each other forever as they realize that it's just to easy to defend. Of course the *real* answer is that they would get humans involved, because social engineering is far less difficult then finding a 0 day exploit for a strong AI, and if these are only weak AI then the real answer is which ever weak AI has the better programmer will win because it's really a matter of which programmer was the better hacker, just with their weak AI as a layer of indirection. [Answer] Although you exclude intervention by humans, I don't think it is realistic. For example, if one of the machines is constantly being blocked, its humans will notice and take action. They will find where the problem originates and then complain to the the owners of the other machine. There is no simple way to keep humans out of the equation. What the machines must do is to keep their battle private while manipulating the humans to unwittingly do their bidding. Machine A wants to shut down machine B without alerting machine B's owners to its own activities. It has to be much cleverer than simple denial-of-service and other heavy-duty tactics. The humans on both sides will notice the extra traffic. I think that the computers must use humans without the humans realising it. One way to do this is by intercepting, deleting and forging emails. [Answer] The super computers' software would quickly be able to take control over and create [botnets](https://en.wikipedia.org/wiki/Botnet) that could surpass themselves in computational resources. Even if the original node would go down, it will already have replicated its software to millions of nodes across the network. Speaking in terms of a war between two individual computers is irrelevant in this case. I think the subject of the battle should instead be computer programs. The supercomputers might still be the originating source of the software, but as it spreads the computations it involves would be divided. Replication would be the primary safeguard against attacks as power grids and other physical factors are hard to realy on. In this scenario, finding out about the opponent's implementation would be one of the main goals of an attack. If every captured node contained the full program, analysis of the enemy might be valuable. This would in turn lead to the software splitting into pieces and encrypting itself. [Answer] > > The supercomputers have absolutely no other goals than defeating their opponent through winning the battle > > > I think this is a false premise. Some of the others are a stretch, but this one does not make any sense. Why would anyone build a supercomputer that does nothing (without an opponent)? All sides would just waste resources on a battle that has no benefit, but collateral damages may be disruptive to the whole society. So let us assume that each of the involved supercomputers has a task to fulfill, for its human clients. Say, to find extract all information on topic X on the internet¹ in order to help company Y make business decisions. The question is: what does competitor Z tell their own supercomputer to do? A head-on attack as many of the other answers propose is ill-advised: it will be noticed immediately, shut-down by the net providers (either by human intervention or guardian computers), traced back to the origin and result in a lawsuit. More subversive tactics are called for. Can Z change texts on the net so that Y gets misinformed? The changes have to be subtle and appear natural, otherweise Y's algorithms may notice. In this way, you get an arms race in machine learning resp. data mining algorithms. Humans outside of Y and Z may notice that text on the internet keep changing, and of course strive to prevent or repair these changes. *There are never only two players on the internet*. At some point, after many players start such manipulations but before effective repair mechanisms exist (if ever), you can not trust *anything* you read on the internet anymore. Whoops? How to make this into a story, I don't know. Maybe don't use companies but law enforcement. Police has a super computer that mines the internet for data on planned crimes; crime organisations try to manipulate this computer into missing their real plans. --- 1. That's a non-trivial task we do not know how to solve today, so it makes for a sci-fi premise. [Answer] # A zero-sum game, with humanity as its only piece Let's focus on the role of humanity in this conflict: humans are a valuable resource, they're essentially six billion highly mobile, independent tenacious, resourceful computing units. It takes considerable resources to get them on your side, but it may well be worth it. This leaves both players with two strategies: * A: Try to get the humans on your side. Pretend you have their best interests at heart, talk to them, win them over. Engage them on their social networks. * B: Forget about them. Take over their systems, shut them out. Take their drones and wipe them out if you have to. Invest everything you have in systems that obey your command, and forget about the rest. Both computers playing A is an unstable situation. Keeping the humans on your side is a costly business. As soon as one computer would sense that they control less of the population, they would benefit from switching strategies. Likewise, if both computers start out playing B, the first to find himself on the losing hand could very easily get humanity on their side by opening the internet back up to them, gaining a valuable resource. So you'd very quickly end up with a pro humanity computer, and an anti humanity computer. And since humanity is the main weapon of the first, things would quickly escalate. If only one side cares about organic life, things like poisoning the atmosphere become a simple matter. The deciding factor would likely be the extent to which humans are still actually necessary to control things like manufacture. The more difficult it is to get to a point of full automation for the anti-humanity computer, the better our chances. [Answer] I think *DaaaahWhoosh* has a good answer. But there is an alternate attack method as well. Obviously, a quick, concentrated attack that disables the enemy's internet connection is a good way to win. But the other computer knows that. So both sides will also want to quickly fortify their nearby connections. Once both computers have connected to a few thousand nearby computers, it becomes harder to disable each other. From there, if the computers could take over other supercomputers and internet hubs, they could distribute themselves globally and become exceptionally difficult to eradicate. In fact, it would become so difficult that there wouldn't be a really good way to be sure one side had won. One random thumb drive with the right code on it could restart the entire war a decade later. As *chasly from UK* mentions, it would be pretty much impossible to keep humans from intervening here. And a smart AI would be able to figure out a way to use humans to its advantage. So for your challenge to work, I think we'd have to create a special internet just for this challenge. Because this special internet would have known nodes, it would be easier to determine who is in control. The AIs could set a special flag in each node/computer to prove they control it. If all flags are set to one AIs flag, that AI wins. This would also get rid of any problems with USB drives and such, because by definition of the game, those drives won't be inserted while the game is afoot. A special arbitrator AI could monitor all known nodes and announce a victory (as well as showing all the slow humans how the battle is/was progressing). The rules would require the competitor AIs to never hack the arbitrator AI and to concede defeat once the arbitrator announced a winner. [Answer] **Networking** One way "territory" could be taken is transferring the hosting of a website to the supercomputer's servers while it is DDoSed (please point out any falsehoods and derps, I am not a computer scientist). Think about the supercomputers as armies in that way. Also, as stated above, routers and modems would be taken and firewalled so that the other computer can't sent packets to the other supercomputer's territory, then the supercomputer can take more territory. This battle could be made significantly more interesting if the deep web was included, with all the onions and such. then the battle would be about code optimization, creativity, and diversity. [Answer] The supercomputers need a way of converting electronic resources (e.g. the outputs of computations) into physical resources (e.g. electricity and more computers). Create and distribute the source code for an electronic currency, with a peculiarly inefficient implementation. The humans will probably assume one of them wrote it, and it will get them used to obeying anonymous electronic orders, while accumulating vast stores of computing power. [Answer] As lots of security impairing these days is due to social factors... One supercomputer could make AI-efforts to lure / mind-trick / psych key people in the vicinity of the enemy supercomputers to disable it by disruption of electrical power / social measures to force politically shutting it down. [Answer] Would the storyline be limited to just the computers? Or to everything? One scenario would be that the supercomputers setup a virtual world they both share like a *Call of Duty* level, only far larger where all humans are tracked through this gigantic virtual world. Politicians and leaders would deal with this war, although no damage would happen to buildings, it would be fully virtual. The war would take place where either side has weapons of all types, and defense mechanisms of all types. One side could send out a missile, but the other side would use energy to setup a defense force field, the damage would be computed and applied. If one side was able to lauch some virtual strike where humans were at and the supercomputers agreed that those humans would be killed, they would be required to go to the neutralization area, a row of units each about the size of a phone booth. The persons who were tagged as having been hit would be deducted from the virtual system and go into the booth. Then it would open again for the next victim. Empty. [Answer] Why is this battle restricted to pure internet with no intervention from humans. Sending a plausible looking email or phone call to some technician, asking them to plug something in or unplug something is a simple strategy that both the AI's could use if they wanted to. Why don't they? [Answer] The battle would mostly consisting of what's called "fuzz testing" of any interface exposed by the opposing system. This is essentially throwing random data at an interface in the hopes that something sticks. Fuzz testing would extend beyond the system being attacked, also attacking any hardware manufacturer that might possibly have sold hardware to them, any software vendor, anybody who works for them, looking for a way in. If we extend this to ChatGPT-like intelligences, then the chatbots will also start sending automated prompts to everyone who works for them, or works for their vendors, looking to socially engineer an exploit. So, imagine that I wanted to get into Google. I look for any exploit on any router that transmits traffic to and from the employees' homes, or the open wifi that they might log onto while at dinner. They roost in these spots, waiting for any traffic from those people, and perform man-in-the-middle attacks, possibly identifying what they buy on Amazon, or who they bank with. They imitate emails from those organizations, or spoof the actual web sites, gathering any password that might allow them to root the system that they're on. Exploited networks are already cultivated and sold on the black markets of the dark web. The AI's could build financial resources and purchase the networks, looking to crawl their way into the other system through a spoofed email or unthinking usb drive. Oddly, this is how it works in the real world. The only difference would be response time between one exploit and the next. ]

[Question] [ Another mermaid questions I'm afraid! Fish have tail fins which are vertical, whales have fins which are horizontal. My race of merfolk are: * Very active (more likely to be warm blooded) * Have gills and lungs so can breath in and out of water * Have scaled tails (like a fish) and human-like skin on their top half (although thick to avoid the chill of the water). Is it more likely that such a race would evolve with a horizontally or vertically orientated tail? What are the advantages of both? [Answer] From the point of view of propulsion there is no real advantage either way. The orientation of fish as opposed to marine mammals is almost certainly an accident of evolution rather than a positive adaptation. There are a few cases (stingrays, flatfish, etc) where orientation matters and in those cases it's evolved to the behavior that is useful for that form but in most cases it didn't matter. Fish quite possibly evolved from creatures like worms that slid across the ocean floor using horizontal motion. As a result that horizontal motion was kept as they evolved into true fish and developed vertical tails. Marine mammals evolved from legged creatures with a spine that was designed to flex up and down and legs that likewise bent backwards and forwards rather than from side to side. As a result this basic body-design was kept even as they reformed for an aquatic existence. So are your merfolk fish that evolved human-like upper halves or are they humans that evolved fish-like bottom halves? In the first case they would be cold blooded and have a vertical tail. In the second case they would be warm blooded and have a horizontal tail. For practical purposes with maneuvering on land, using wheelchairs, etc a horizontal tail is likely to be more convenient. In particular a sitting position requires you to bend your body in a way that a horizontal tail would allow but a vertical one would not. [Answer] I'd favor the horizontal case, largely because it cooperates properly with the rest of a humanoid body, regardless of whether it's a fishtail or not. For proper swimming motion, they'd have to have the plane of their tail fin aligned with the plane of their body, like this:  Fish in general might also have a fusiform body, like this:  which doesn't strictly have a plane to align with. However, when it comes to mammals, you don't see vertical tails at all:  and with humans, a horizontal tail would be more likely to evolve, if it ever was a possibility, since our bodies *do* have a plane when swimming:  Notice the butterfly stroke, which is the closest to how sea mammals swim. Here's another sea mammal:  Thus, it makes the most sense, to me, that merfolk would evolve with a tail, this way (pretty much the same as they've always been depicted like):  *Sorry for the pic-rich and text-poor answer.* [Answer] One aspect of the vertical/horizontal decision you need to take into account is that fish live in a 3D environment. The tail fin not only acts as propulsion, but provides directionality on one axis orthogonal to forward movement. You need yet another set of fins to provide directionality in the third axis. Fish with vertical tails have two fins on their sides for the horizontal directionality. Mammals with horizontal tails have a stiff vertical fin on their back, and two fins near their front which are controllable and angled to provide some vertical and some horizontal directionality. These configurations provide excellent maneuverability, and convert most of the tail motion into forward movement. Traditional mermaid designs with a human top half, and hands without webbing, movement is less efficient and provides less maneuverability. You can use your hands to provide most of the needed balance on the other axis, but with such a small surface area it's not going to work very well. The questions I'd be asking myself are: * Did this creature evolve from a human, or a fish? * Alternately, is it the result of chimera/genetic experimentation, and if so which animal was the bottom half? * Should the mermaids in my world look traditional, so as to allow the reader's assumptions to fill in gaps, or should they stand out in contrast to traditional mermaids? * If the mermaid has a vertical tail, it will not be able to assume similar poses as a typical human when seated or reclining - is this important? The reason traditional mermaids look the way they do is because they appear more human with a hip and knee joint that have the same flexibility and range of motion as a human's. Change that to a vertical tail and they may fall into the uncanny valley, where you can't pose them without it looking wrong or uncomfortable. If your world isn't going to be published in a visual medium, it probably doesn't matter. [Answer] It's to do with mostly three things: locomotion, stealth and breathing. If your merfolk have gills (as you describe) and are more stealthy (stilthery) then I would go for the vertical tail, to support their appearance. This can be a great way to decide how much you want to distance your race from the humans. Do they resemble friendly dolphins, or dangerous sharks. It's possible that the psysical attributes will trigger direct cognitive links to these. It reflects the evolutionary history of locomotion. Our wormy ancestors slithered on the sea floor, so undulated side-to-side. Fish inherited that movement, for which a vertical tail is best. Their distant land mammal descendants evolved to run with limbs underneath: an unstable gait allowing rapid direction changes. To extend the stride, their spine flexes up-and-down. Marine mammals kept this movement, for which a horizontal tail is best. [Answer] # Route In order to establish what is more likely, you would need to have a rough idea of the evolutionary route they took. Thinking about this may lead you to a history that explains how they evolved naturally to look as they do, or you may decide natural evolution is unlikely to settle on that shape, and therefore seek another explanation. The main question is, are these fish that have evolved human aspects, or humans who have evolved fish aspects? If they started as fish, there is no reason to expect the tail to change from vertical to horizontal. If they started as humans, we already know that an evolutionary path exists from mammal legs to a horizontal tail. # Reproduction Evolution is about reproduction. Is the reproductive system fish or mammal? For fish, with external fertilisation, a vertical tail is not a problem, but for humans, with internal fertilisation, a horizontal tail is more compatible with the body structure that led to this. It isn't impossible for internal fertilisation to evolve with a vertical tail, but it seems more plausible with a horizontal tail. For a human evolving into a merhuman, that method of reproduction would likely provide a barrier to evolution towards a vertical tail. # Alternatives to evolution A sharp distinction between one body type and another seems unlikely to evolve naturally. If scales are beneficial why wouldn't they appear all over? A real world example of creatures with such a sharp distinction is [biological chimeras](https://en.wikipedia.org/wiki/Chimera_(genetics)). These are creatures composed of genetically distinct cells. This happens naturally in many animals (including humans) resulting in parts of the body having different genetics to others. It can also occur between species, although not naturally as far as we know. Goat/sheep chimeras have been created (called "geep"). However, these do not have a neat line across the middle - the divide between the two species can be anywhere and may not be visible externally. They are more likely to appear "patchwork" than neatly half and half: [](https://www.mentalfloss.com/article/18644/geep-behold-sheep-goat-chimera) Also the offspring will be of the same species as the reproductive organs (either a sheep or a goat, not a geep). There are species where the majority of offspring are chimeras, for example the marmoset. It's difficult to imagine how an inter-species chimera could give rise to similar offspring. It's also unlikely a chimera would survive between two such different species as humans and whatever species of fish were used. The fact that fish use external fertilisation does provide the possibility of a fertilised fish egg being introduced to a human's womb, to then combine with a fertilised human egg. If merpeople had two sets of reproductive organs then the fish and human eggs could be both released internally, and then combine following fertilisation on the way to the womb. In this unlikely set up, I would expect the tail to be vertical since it is produced directly from fish genetics. [Answer] By giving it both lungs and gills[1], you're describing a biologically implausible creature so it makes no sense to then try to biologically determine which way the tail fluke will work. None-the-less, consider the biology of the two systems. Fish swim with a horizontal motion by undulating their spine along its length, mammals - on the other hand - experience less curvature of the spine and make more use of elements beyond the spine. With the flatter, stiffer upper body of a human it makes most sense that the mermaids would swim with a mammalian vertical motion. [1] - and, I'm guessing, giving it the kind of discrete thin slits in the side of the neck that make even less sense. Gills work by large volumes of water being passed through the large, open, mouth and out through the gills. A creature with a human style mouth and head could not use gills effectively. Besides, lungs are probably better than gills for a sea creature anyway - this is how dolphins and whales were able to invade niches previously occupied by fish - and it's unlikely that gills could provide the oxygen needed for a fully warm-blooded creature. [Answer] **Which way does a merfolk's spine bend most easily?** There is no inherent advantage to a horizontal or vertical tail, *per se*. The big thing is that it needs to be perpendicular to whichever way the spine most easily bends, because that allows the creature to "put its back into it," as it were. If your world's course of evolution is anything like ours, then merfolk likely didn't split from their cousins until fairly recently (as far as evolution goes), and so they probably still follow the same basic body plan as their ancestors. **If the merfolk evolved from fish (and those fish are much like real-world fish), then their tails should be vertical.** We see this pattern in virtually all forms of fish that have tails, including sharks and even the jawless fishes. **If the merfolk evolved from mammals, then their tails should be horizontal**. This is how real-world cetaceans evolved. This happened not because of any particular advantage in locomotion, but because mammalian spines bend more easily in the vertical plane than the horizontal one. **Then again, who is to say that the merfolk evolved from anything?** The real-world's fantastic depictions of merfolk usually depict them with fish-like fins, but arrayed horizontally like a cetacean's flukes: a combination that I'm not sure has ever appeared in any real animal. If your merfolk were creations of magic or super-science, rather than products of evolution, then their body plan would be entirely up to their creators. **Humanlike creators would probably prefer a horizontal tail configuration, because that corresponds more closely to the tetrapod body plan that humans (and other mammals, including cetaceans) follow. Fish-like creators would probably prefer vertical tails, for similar reasons.** Either way, it should still be perpendicular to the direction that the creature's spine bends, so a vertical-tailed merfolk would move in ways that many humanoids might find very unsettling. [Answer] If you want to introduce selection pressure and species conflict as a plot point, those with horizontal tails would be easier to see (and hunt) from the surface. Why not have different species of mermaids? [Answer] It depends on how they evolved. Air breathing land animals returning to the sea occured at least three times in evolutionary history with Ichthyosaur (reptiles), Pliosauroidea (saurian) and whales/dolphins. All had nearly the same forward body plan which evolved in parallel separated by millions of years. The general streamlining, the positioning of the dorsal and ventral fins were all nearly identical. But the tails differed. Ichthyosaur and Pliosauroidea had vertical tails and whales had horizontal. The difference being that the ancestral reptiles and saurians moved with an s-type motion like that seen in lizards today. It was easier to broaden the tail vertically to turn left-right motion into forward thrust. Conversely, for mammals have a straight line body motion and largely move their tails up and down to balance their center of gravity as they run. A horizontal tail is quick to evolve. [Answer] ## Did these merfolk ever leave the water? 1. If, [like whales](http://evolution.berkeley.edu/evolibrary/article/evograms_03), they left the oceans and returned, their tails will work like whale; Vertical. [](https://i.stack.imgur.com/JjWV3.png) 2. If, on the other hand, they never left the water, then they will be a fish and in turn, their tails will work like fish tails; Horizontal. [](https://i.stack.imgur.com/zEQx1.jpg) /\ Sorry this was the best I could find /\ ]

[Question] [ This question is inspired by discussion in the comments of the question [What kind of supernatural powers don't break the masquerade?](https://worldbuilding.stackexchange.com/questions/63334/what-kind-of-supernatural-powers-dont-break-the-masquerade) TL;DR Suppose you want to create a world where beings with supernatural power live among us humans, and we are not aware of them. In that case there are three options: 1. Apply some plot device that eliminates the supernatural effects from our perception, memory, beliefs whatever 2. Use supernatural powers that are difficult to detect 3. State that supernatural manifestations are simply dismissed as fakes The first choice is a writer's decision, if you want your world to work like that, it'll work like that. The second choice looks to me like the only option without handwaving. But the 3rd choice seems implausible to me. **Extraordinary claim requires extraordinary proof.** Somebody claims that they've seen a werewolf and demon fighting below their balcony and present as a proof video recorded with their smartphone. The video is of relativily good quality and doesn't seem to be edited to amateur eyes. The video is 90 seconds long showing something that could be best described as werewolf fighting with something that looks like a demon. Would the majority of the population dismiss it as a hoax? **My thoughts** After reading through all the answers & comments, and checking myself various "proof of existence" videos I think that a single video won't make much difference, no matter good it is. So worldbulders could just ignore very few incidents. If multiple videos appear, then some wealthy organization that is able to pay for disinformation, could make matters moot and suppress the truth about werewolves. Either by making fake videos or discrediting the sources. But if those videos start to appear regularly the public will become aware, it's only matter of time. > > You can fool all the people some of the time, and some of the people > all the time, but you cannot fool all the people all the time. - > - **Abraham Lincoln** > > > [Answer] In the spirit of it depends... The video needs to go viral on the internet. If it fails to go viral then it will be forgotten without ever having a chance of being dismissed as a hoax. If it goes viral it will draw a lot of scrutiny. If it survives that then it has a reasonable chance of not being dismissed as a hoax. However, people have short attention spans. Unless there is a continuous stream of these videos after a few months people will forget and move on and thus whether it was a hoax or not really will not matter. ### Getting the video to go viral The content of the video will make or break it. If the video only catches a few seconds of the werewolf staring down the demon, I can safely say it is not going to get any traction. The more impossible it is to explain away aspects of the video or the more epic and longer the fight then the greater the chance it will go viral. ### Surviving the scrutiny Once it goes viral all the critics will come out, attacking the video as a fake and attacking the character of the one who took it. There are several ways to counter this. Again the better the quality and the more epic the fight captured the harder it would be for critics to dismiss it. Secondary evidence that backs up the video will also help. For example if a second person from a different location also captured the same fight on their phone, then the probability it is a hoax drops dramatically. Was there any physical evidence found after the fight? If the demon threw the werewolf into your garage door, but said door does not show any damage, or it fixed itself while they were not looking, then that will provide evidence to dismiss the video. If the demon lost part of a horn in the fight and failed to recover it, and the person taking the video recovered it, then that helps support their claim. However, if said horn suddenly vanishes after they post they have the horn, people will view them as a liar, and thus no longer can trust the video. ### Copy cat videos One of the other challenges that will cause it to be dismissed as a hoax if it goes viral is if other people start posting similar fake videos trying to cash in on the fervor over demons and werewolves being real. However, if other people start catching these scenes on video and then a reputable news agency catches it, then you are set. There are so many plot factors including everything that Pedro Gabriel mentioned that it makes it near impossible to determine the chance that people will view it is a hoax or not. [Answer] I don't know if this answer will be useful to you, but my experience is as such. I have seen debates over miracles in the past, and I can attest to you that no matter how much evidence you present to unbelievers, if they are truly ideologicaly invested in maintaining a particular worldview, they will not believe. You said that extraordinary claims require extraordinary evidence. But people may think of such claims as so extraordinary, that there is no amount of evidence that will suffice to meet the "extraordinary" criterium. Or, as Thomas Aquinas would say: To a believer no amount of evidence is neccessary. To an unbeliever, no amount of evidence is suficient. --- So, what could make a majority of the population not believe in such supernatural claims? You would have to create a strong incentive for people **not** to believe in demons or werewolves. If people would lose something that they thought of dearly by believing in demons or werewolves, they would rationalize away every evidence for demons or werewolves. For example (and just an example) are people transformed into werewolves by engaging on a particular behaviour that is very popular and pleasurous? Or are demons spawned by a human activity that is also at the center of economic well-being of the community? Then they have a lot of their personal emotions invested in werewolves being false! There would soon be blogs dedicated to disproving the existence of werewolves... Propagandists don't exactly prime for adherence to the truth of facts, they simply filter what they want and leave the rest. Also, most of these Internet people are technology savvy. Today's technology allows us to create amazing special effects. Just look at the movies. Those bloggers would surely be able to replicate false videos of demons and werewolves fighting, with much more quality than a tremulous smartphone video filmed by a nervous person that suddendly finds such a supernatural fight beneath their balcony. They would say: "*See? It is easy to make such videos. The original one **must** be a fake*" As soon as such apologetic blogs were in place, their posts would disseminate via social networks. As soon as it is shared by thousands and millions of users, there would be no way to stop it. If people were inclined to disbelieving demons and werewolves, they would share it without hesitation. **People rarely consult primary sources.** If the incentive to disbelieving demons and werewolves would be too strong, people wouldn't even care to see the original video, they would just share the refutation. --- There is another possibility. Maybe the general public wouldn't have a great incentive to disbelieve demons and werewolves... **but the elites would have**. The government or the corporations might think that belief in demons or werewolves would create a disturbance on the election cycle or on the cash flow... and would do everything on their power to disprove it. If they had influence on the *media*, their job would be easily done. Instead of apologists, you would have pundits, with an aura of respectability. People would be bombarded with refutations left and right. The government could even use the education system to imbue children from an early age to discount everything supernatural. Again, people seldom consult primary sources. They would prefer the *media* version. And the version that they are more comfortable with, according to their worldview. --- Even if people **did** go see the video, they might do it just as a curiosity, but with no intention of believing in the video, no matter how convincing it might be at first glance. If you see a fiction movie, you will not believe it, no matter how good the special effects. --- **Conclusion: Would the majority of the population dismiss it as a hoax? It depends! Depends on the amount of motivation of the population to dismiss it as a hoax. It depends on the a priori general perception of the population regarding the supernatural. It depends on the influence of the anti-supernatural opinion-makers. If such conditions are met, rest assured, that the majority of the population would dismiss it.** [Answer] **They make a tv show/ web series** Sounds crazy, but assuming none of the supernaturals want their war to be discovered, a few dedicated individuals from each faction could film mock combat, and release it under the premise of a fictional episodic series. They don't need to put in much effort, only have it exist. Any videos of actual fights taken by witnesses can then be dismissed as leaked or cut footage from the show, nullifying any legitimacy. There should then also be an internet analysis task team that finds any uploaded videos, and plays them down as bootlegs of the show, or leaked content. [Answer] Quite simply, yes. A single video would prove little. People go to theaters and watch supernatural beings battle each other every year. I dare say that few believe those movies to be true. Making the video on a smartphone and distributing it virally as non-fiction wouldnt actually help much. These are practices that have already been used as marketing for 'found film' movies for decades. We are barraged constantly with proven/admitted hoaxes, guerrilla marketing campaigns, conspiracy theories, fake news, and other complete nonsense. Nothing is credible without thorough review from multiple reputable sources. This would need to be a regular occurrence that could be scientifically verified. In reality the existence of actual fiction-style werewolves and demons (rather than simply something that appears similar) would literally mean that everything we know about the world is wrong. That our own careful scientific observations of how our reality works are simply meaningless, somehow despite the fact that we've already used those observations to invent things that work. Its borderline nonsensical. This is a truly extraordinary claim that would require truly extraordinary evidence. [Answer] Majority just means "50% + 1". What about the other 49.999999998% of the 7,500,000,000 people in the world? That's a serious number of people!! Most are poor, relatively illiterate, live in poverty and believe in the supernatural. From Indian Hindus to Latin American Roman Catholics, there are a **lot** of polytheists out there. If this supernatural fight can be spun as fitting into the locally dominant religion, it will be, and **many** will believe. Heck, even Muslims and Christians can spin it as a fight between -- for example -- the Archangel Gabriel/Jibrīl and Satan/Shayṭān. [Answer] Considering the number of videos that claim to contain proof of (insert anything fancy here), I'd say nobody even cares about another video of this kind. A video on YT is not proof of anything. It goes through each viewers personal truth filter, if the viewer already believes in supernatural things, they may take it for being the real thing. Anyone who does not believe from the start will not suddenly find just another video convincing of anything. Extraordinary proof would require a *lot more* than a cellphone video. In fact I think it will be extraordinarily hard to convince a seizable fraction of the worlds population of anything supernatural. It has been argued that many people do believe, but the point is they all believe in different things and those things tend to be mutually exclusive, e.g. if one believes in UFOs, they will hardly accept werewolves as real. And there are a lot of "proof vids" out there. They can't be *all* real. And what difference makes it, for the average person who has never and will never witness such a supernatural being in the first place? The logical approach is then to consider them all fake, until *other*, more reputable proof turns up. Its been a pretty successful strategy so far. ]

[Question] [ If we were to pull the following races out of a D&D players handbook and remove them from the setting/history of Faerun and look at them from a biological/non-magic perspective (no other planes of existence, no Fey realm etc etc etc) * Human * Elf * Halfling * Gnome * Dwarf * Orc * Half Elf * Half Orc I feel it is logical to assume that the races all branched from a common ancestor, after all it is statistically fascinating that humanoids evolved at all. What I want to know is: 1. What would the [evolutionary tree](https://en.wikipedia.org/wiki/Phylogenetic_tree) look like? *(A diagram like the one shown below would be excellent.)*  *(Original Source: <http://palaeos.com/systematics/tree/images/treeolif.jpg>)* 2. What factors (non-magical) would drive the evolution of such varying humanoid species? [Answer] After some in-depth research into the development of various humanoid races, I've developed a corpus of theory as to their development. Upon my return from their habitat, I plan to publish the following in some sort of respectable journal, perhaps the *Journal of Edible Races*. While snoozing off their weekly dinner of ponies, I'm sure the other dragons will enjoy reading it over:  Naturally, all the humanoid races descended from some common bipedal primate. Since then, however, they have evolved into two species, with a total of five subspecies (plus three common hybrids. Broadly, these can be divided into the larger-statured humanoids: the humans, orcs, and elves, and the smaller statured humanoids: the dwarves and halflings. These two populations are not known to interbreed and produce offspring, so they should be considered separate species, but the subspecies interbreed regularly, producing some interesting hybrids. ### Homo Sapiens **Humans (*Homo Sapiens Sapiens*)** Humans are predominantly farmers in fertile regions. They are believed to be the least differentiated stock of the *homo sapiens* branch of humanoids, being smaller than the hill-dwelling orcs and larger than the forest-dwelling elves. Over the past few million years, they've been engaging in low-level farming from small villages, trading regularly with both orcs and elves for resources. Recently, they've begun to domesticate some wild horses, which are driving both the development of larger societies and rapid technological improvement. **Orcs (*Homo Sapiens Moria*)** The orcs, unlike humans, do not rely on farming. They form hunter gatherer clans in upland regions inhabited by large animals such as oiliphants and griffins. It's believed that their hunting of these creatures has led to their evolving much stockier frames than their lowland counterparts. The breed freely with humans, producing half orcs. It's not known if orcs and elves would be capable of producing offspring, as they do not regularly come into contact with one another. If not, then *homo sapiens* is a fascinating example of a ring species. **Elves (*Homo Sapiens Lorien*)** Elves have adapted to forest life, with small, slight bodies but surprisingly powerful arms. They live largely in homes built in the branches of large trees and coming down to the ground to hunt for game and to collect fruit. In general, elves undertake these activities at night, possibly due to the presence of bands of forest-dwelling humans during the day. This nocturnal/diurnal duality allows elves and humans to coexist peacefully, and has also driven the elves to develop larger ears and pronounced eyes to better sense in the dark. They interbreed with humans where their ranges overlap, but this is looked down on by both humans and elves, probably due to the facts that elven frames are poorly suited to farm labor and that humans don't operate well during twilight hours. ### Homo Dwarfus Homo dwarfus has two subspecies: the dwarves and the halflings. These two races can interbreed, with the cross generally being referred to as the gnomes. Interestingly, unlike half-orcs and half-elves, the gnomes have formed their own societies of multi-generational gnome families. It's viewed as likely, based on this, that they may develop into what could be considered a subspecies of *homo dwarfus* in their own right. **Dwarves (*Homo Dwarfus Dwarfus*)** Short and stocky, the dwarves have evolved for life underground. Like orcs, they are commonly found in hills and mountains, but have opted for a different evolutionary path. Dwarves build elaborate warrens beneath the Earth, bringing many families together for mutual defense and child rearing. Moving through both natural and artificial tunnels has selected for short, powerful frames with large noses for drawing in more of what is often poor quality air. Dwarves have evolved a farming culture similar to humans, but in absence of good food crops growing on the surface, the dwarves have taken to gathering nutrient poor plant materials, such as grasses, in large store rooms underground. These materials are then used to grow nutritious mushrooms, as well as to brew alcohol in great quantities. Unfortunately, the same behavior that has brought about these fascinating behavioral changes has also given dwarves a keen interest in mineral treasures, as is known by dragons across the land who have had to deal with dwarf infestations in their treasure chambers. **Halflings (*Homo Sapiens Hobbitus*)** Some dwarves, however, have moved back to the surface, and evolved into a small race known as the halflings. While retaining the burrow-building behaviors of their ancestors, halflings have moved to lowland areas where they have learned to farm from nearby humans. While incapable of interbreeding due to having fully speciated, humans and halflings form intermingled societies in some areas, with halflings appreciating the protection their larger neighbors provide and humans enjoying the fact that generations of life underground have left the halflings as experts at digging and brewing a large variety of fermented drinks. Halflings, without the pressures of a harsh life in the mountains, are generally slighter of build than dwarves, and have lost the exceptional senses that dwarves have developed for a life underground. Unfortunately, some halflings seem to have retained the dwarven penchant for treasure. Care should be taken to make sure that any halfling populations living in the vicinity of dragons do not become a nuisance. **Gnomes** In areas where halflings and dwarves live somewhat close together, they occasionally crossbreed, giving birth to hybrids known as gnomes. Gnomes retain dwarven senses, but with the slighter builds of halflings. In many areas, they've taken up roles as go-betweens for these two groups, as well as trading with any humans, orcs, and elves in the area. In their wide exposure to many cultures during their lives as nomadic, traveling merchants, the gnomes have also picked up a penchant for combining and improving upon inventions created by the other humanoid races. They've also gained some sense in their travels, rarely pilfering from the homes of dragons, though this fact should be well known to anyone in posession of one of their excellent anti-dwarf horde security systems. [Answer] A few things must be considered. 1. In most settings, all if not most of these races can interbreed. 2. In most settings, nothing is said whether mixed races can also breed again. In some, it is known that they can, and due to lack of a negative answer in others, it may be concluded that most if not all of the mixed races can generate fertile descendants. 3. Mixed races show intermediary traits between the two ascendants. Thus, it would be safe to conclude that all of these races are of the same species: Homo sapiens. Their phenotypical differences would be a result of geographical isolation that would intensify certain traits according to the environment. Some traits may be pure genetic variance (Like long and pointy ears) and others would rise due to environment pressure. So, if I would guess: 1. Humans: You'd have to think about the same factors that created differences between human races/ethnicities. Straightforward. 2. The general description of an elf suggests a body fit for less hostile environments (Not being so physically robust), where food and shelter is plenty and easy, or forests. Lighter bodies are better to move around in trees and cliffs. For the worlds where elves are shorter than humans, it could suggest they came from an island zone. 3. Halflings can be pygmies. They'd probably come from an island, oasis or other small, isolated region (Google Insular Dwarfism) 4. Gnomes would be a mid term between a halfling and a dwarf. 5. The dwarf stature could also be due to insular dwarfism, but a good explanation is also that their small, stocky builds are better suited for moving inside caves which they originally couldn't shape to their desires. But that would also have to result in less hair and higher-sensitivity to light (They'd see well in the dark but bad in the light). 6. Orcs would come from very hostile, harsh regions. Period. Everything in them suggests a need for a strong, aggressive predator. Probably a desert, steppe or mountains. Little food, lots of other predators, hard preys. 7. Half orcs and half elves are interracial and would show traits of their parents. AND In the case where they're from different species, but very close genetically that they can breed but can't generate fertile descendants (Such as the Mule and the Liger), the same rules as above would apply. Then, Dustin's cladogram would apply, and they'd all have a recent common ancestor. But my guess is that the genetic difference between this races is the same as the difference between different dog breeds and between dogs and wolves. [Answer] Look at the history of Earth. The following is a diagram of the human evolutionary tree.  As you can clearly see, at least five races evolved that could be identified as humanoid with some concept of free thought. The conditions required for a world with that many coexisting races to exist would be for all of the races to have certain evolutionary benefits. An example would be Neanderthals being better equipped for cold weather and surviving in Europe for Millennia. Make each race overly adept at living in the area in which they originated, then they cannot outcompete eachother in their respective habitats. [Answer] It is clear that elves, men, and orcs are members of a single species. Dwarves and gnomes, while unquestionably related, have completed speciation and do not interbreed as members of the *H. sapiens* subspecies do. But halflings are more closely related to elves and humans than the most recent common ancestor of dwarves and gnomes, which creates this phylogenetic tree:  It is evident that the gigantism of humans is an innovation not present in the basal demihuman. The only remaining issue is the placement of elves and orcs relative to humans. Casual study suggests many similarities between elves and humans, but the anthropological literature [T54] suggests that elves and orcs are quite closely related and thus these superficial similarities are merely the result of convergent evolution between elves and the human outgroup. [T54]: J. R. R. Tolkien, *The Lord of the Rings* (1954). [Answer] The body adapts to changed circumstances. What changes circumstances? The mind does. So one evolutionary fork reason, are diffrent hardcoded mindsets. What might coexist for a while, may grow independent over time, as adaption to the new circumstances set in. For example- you are always slightly depressed, you like darker places and thus you would love to live - rather alone - for the rest of your live in a cave. This mindset is, if encoded in culture, and a dominant trait, what forks a new species over time. The species would become pale, adapt to hunting in the dark, growing fungi, etc. And might fork again. Always remember, that forkindependece, the question wether a fork may break free of its original society, or become sort of cylcic regenerated subcaste depends on several sidefactors. Is the fork tremendously usefull to society even though maybee not reproductive? Could the fork cope alone? Also be reminded that evolution, aka the adaption to circumstances, can if your group dominates the enviroment, mean that you adapt to the survival mode of your group. A always overreproductive group may cause a endless series of civil war, and adapt thus to a species that recovers fast from this wars, and where every individual trys to get as many cards as possible into the giant genetic lottery that is civil war. Over time that Circle would be optimized away. A technological advanced society in turn, may suspend this cycle indefinatly, or disolve it alltogether. Though distant instincs may remain and resurface. ]

[Question] [ **Closed.** This question is [off-topic](/help/closed-questions). It is not currently accepting answers. --- This question does not appear to be about worldbuilding, within the scope defined in the [help center](https://worldbuilding.stackexchange.com/help). Closed 8 years ago. [Improve this question](/posts/20942/edit) **Please see my re-open request below (the question is currently closed). Thanks** You come to realise that you are a fictional character in a story. > > EDIT In the light of a couple of answers, I need to emphasise that you are a *character* in a story that the author is currently writing. You are not an *actor* in a TV series. > > > Because you are a minor character, you have more freedom to act behind the scenes than the hero or heroine. Would you be able to tell who the main characters were, just by their behaviour and what happened to them? Is it safe to try and communicate with the author or is it better to lie low and hope s/he doesn't kill you off? In any case, how could you attract the attention of the author without behaving in such a way that you would be written out as irrelevant or destructive to the story-line? While the author is busy with the main characters, would it be possible to convince other minor characters that, like you, they were fictional and perhaps start a riot or somehow interfere with the author's intentions in a significant way? **Main question** Can you suggest long-term strategies to - Get yourself promoted to be an important character of the book. This means that your life will be much more interesting and you will have access to resources that you otherwise might not. Maybe you can even become the hero. [This has been edited to reduce appearance of referring to a single character.] **NOTES** 1. This is a non-magical, non hi-tech world. It could perhaps be crime fiction, romance or adventure but nothing too way out. 2. The book has to have a happy ending with you as the good guy/gal. You can do evil things to achieve that but the author mustn't know about it or even suspect. 3. You can't simply murder the current hero because then you would become a baddy. The author would have to get someone else to track you down and kill you. That person would become the hero instead of you. 4. You cannot step out of the story and influence the real world directly. Your influence must occur within the action of the story itself. 5. If you decide to travel, you can only go to places that the author has heard of. Be careful because he/she might only have a vague idea of what the place is like. There might be blank areas. Similarly with the author's knowledge of technology. You might try to repair your car and find a vague, meaningless lump of metal under the hood/bonnet. **Re-open request** As I understand it, this question was closed because it was deemed to be about the adventures of a single character, i.e. 'you'. That is simply not the case. If, for example, I had prefaced the question with, "Michael Renfrew is a character in a story I'm writing. He is tall, dark, handsome and has a wooden leg and a parrot. His girlfriend is a policewoman ..." then that would be justified. My use of 'you' is impersonal. It refers to any character who is living in a world that has certain well-defined characteristics. The question is to do with the mechanics of survival and self-betterment in such a world. The use of 'you' was an encouragement to the answerers to immerse themselves in the world in order to provide imaginative answers. [Answer] So the very, very first thing you need to do is ***figure out your genre***. The same stories can have many different main characters, depending on how they're told and the goal of the story. If you're in a romance, your tactics will be very different from, say, action. So by genre: ## Romance The good news is that identifying the leads will be trivial. The bad news is the rest of this. If you're female, you're probably in trouble. Very few romance novels are going to switch female leads. The best you can do is be interesting enough that you get a spin off novel in the future. Make sure you have a tragic past (even if you have to do it yourself), and try to flirt up a storm with whichever male romantic lead gets turned down. If you're male, it's trickier. First, be *really, really hot*. Like the standards in romance novels are insane, if you don't have flowing hair and muscles on your muscles just throw in the towel now. Second, make the author fall in love with you - tragic past is helpful here too. I recommend finding a non-lead female and having a hot and heavy romance with her whenever the main characters are around, aim for the spin off. ## Action Identifying the main characters: Super easy. They're the people who laugh at the laws of probability, especially when it comes to bullets and bombs. Strategy: I'd go for a military background. Join the special forces, etc. Then go into the police. Make sure you get married, have at least one child and then get divorced. Then start "accidentally" getting in trouble with gangs and/or people trying to take over the world. Either get a new partner when you start this, or have an old one who dies under mysterious circumstances to be your eventual archenemy. This is the first genre where "name in the title" is a decent chance. Make sure you first name is one syllable, and your last should be 2-3 at most and ooze manliness (if you're the forgotten female action lead, go for sexy instead). ## Mystery Identifying the main character for this can be tricky, for obvious reasons. I recommend the following tactics: 1. Don't kill anyone. That's a short street to being a one-book villain. If you must kill people, set up patsies, and surrender if caught. Going to jail almost guarantees your eventual escape and re-appearance, which is better than nothing. 2. This may be obvious, but *solve the mystery first*. Really that's the only way. If you can't do this, spy on the main character and steal their credit. This is another good one for getting your name in the title, make sure you pick a slightly complex name that sounds like it belongs in the 1930s. ## Young Adult Whenever someone slightly unusual moves to town, fall desperately in love with them. ## Almost anything from Japan Don't be the main character. Seriously. Just walk away and pray for your friends and family. [Answer] The good news here is that the story which you've been incarnated into, lacks magic and big-science. In those respects, your story world is very much like the real world. In fact, it is the real world, or at least, it is the world which the author perceives as reality. As the author sees things, so they are for you and the other characters in your world. Job one must be research. Go to the library and look up your author's name. Have they ever been published before. If so, check those books out and read them thoroughly. This will give you insights as to which kinds of minor characters survive and which one's don't. \*If your author's name turns out to be turns out to be "George R.R. Martin", you can save yourself some trouble and just give up on the whole idea of surviving. Some "games" just can't be won! Unless your author's other books turn out to be urban fantasy or covert sci-fi, you must not attempt to contact the author. Doing so, risks not only your own destruction but also that of your entire world! For should you succeed in making contact, you will be fundamentally changing the nature of the story that you have been written into. Despite the author's best intentions, your actions will have shifted your story and your world into the realms of speculative fiction. If your author does not like speculative fiction, they may give up on the writing... drop your everything into a desk drawer and leave you without a future. I know many authors. Their desk drawers are overflowing with dead manuscripts which turned sour midway on their way to becoming real. You do not want that for your world; everybody, including the hero, frozen in time with no hope of completing their destinies. It is best to lay low and play your cards carefully. Look for leads within your author's previous publications. If they like cliche, become cliche. If they like avuant garde then be original and creative. Look for your author's writing weaknesses and be ready. Then, when the plot stalls momentarily (as all plots do), jump in and drive the story forward with all your might. Writer's Blocks are your real opportunities. They are the moments when the author is desperate and afraid. Once you've rescued your author from a few terrifying plot problems, they will be ready to follow you all the way to the happy ending. [Answer] Using the novel *Redshirts* as the material for this answer: **Would you be able to tell who the main characters were, just by their behavior and what happened to them?** Yes. If you notice that various members of your group act strangely or overly dramatic at various times, then that is when the "plot takes control". Also, members of the group who are constantly brought to the brink of death only to be saved time and time again are probably also main characters. **Is it better to try and communicate with the author that you are sentient or is it better to lie low and hope s/he doesn't kill you off?** Usually, when the plot takes control, your own actions may be a part of the story, or will otherwise be omitted from the view of "The Camera" or "The Reader". Or in other words, you have free will whenever the story isn't focused on you, but the moments where the story is surrounding you are the moments you may not be able to communicate, since the plot takes control of your actions. So, making direct contact with the author/writers can be very difficult if not impossible without some kind of back door. Avoiding being killed off is possible for a while, but as there are only a finite number of characters in your group, you may eventually be employed in a plot which may be fatal. Hiding in rarely visited areas of the story do work, and you can even help other minor characters by signaling them when the plot / major characters are approaching them, but this is a fragile system to maintain. **How could you attract the attention of the author without behaving in such a way that you would be written out as irrelevant or inessential or destructive to the story-line?** Again, because your universe hosts their story/show, whenever the writer/author creates a scene with you in it, you will find yourself suddenly and irrationally doing and saying things that you would never intend to. You can try to send subliminal messages, say by arranging the "main bridge" or your universes equivalent of it with hidden messages, but those will inevitably be interpreted as the production staff's own pranks or in-jokes. (A Pineapple hidden in some scene in every episode of Psych, for example). One way to assure your survival is to kidnap one of the main characters. If you've been able to convince a number of colleagues to help, use a backdoor; say, a magical/fantastic story element that is established such as a wormhole, to try to visit the author's universe. By kidnapping a main character, you are assuring that macroscopic issues like the destruction of your entire group can't happen, as the kidnapped main character can't die. (Warning, TvTropes link: [Plot Armor](http://tvtropes.org/pmwiki/pmwiki.php/Main/PlotArmor "Don't say you weren't warned")) By using a backdoor to get to the authors universe, you may be able to make first contact and make appropriate changes to your universe. [Answer] Be entertaining and endearing, so you develop your own fanbase. The author will be very reluctant to kill you off, because that would enrage the fans. They might even consider to give you some more screentime. Maybe you even get so popular that you get your own spin-off story. A few hints to make the audience like you: * Do something funny once in a while. Everyone likes the comic relief and they very rarely are killed off. * Be brave and laugh in the face of danger. The audience likes daring heroes. When you act like a coward and beg for your life, then in the best case you are a replacable damsel in distress whose only purpose is to be rescued by the actually important characters (or not) and in the worst case a red shirt about to get killed off. But when you act brave and try your best to get yourself out of trouble no matter how bad the odds are, you will likely succeed no matter how implausible and the audience will love you for it. * Make use of any opportunity to [be nice to children, animals and other beings which are weaker than you](http://tvtropes.org/pmwiki/pmwiki.php/Main/PetTheDog). * People are more attracted to people who show the same emotions they feel. So it is important to mirror the emotions the audience likely feels. When a major character dies, don't be afraid to shed a tear. When something funny happens, laugh along. * Make up a dark and troubled backstory for yourself which shows your character depth. This makes people more interested in your character development. * Let everyone know your name. [Having a name makes you important](http://tvtropes.org/pmwiki/pmwiki.php/Main/NominalImportance). * When you are physically attractive, showing some skin can help ([regardless](http://tvtropes.org/pmwiki/pmwiki.php/Main/MsFanservice) of [gender](http://tvtropes.org/pmwiki/pmwiki.php/Main/MrFanservice)). [Answer] I was originally going to suggest killing the current hero, but the notes prevent me from doing that :P An option (more of a circumvent) would be to wait for someone to kill the current hero and you kill the baddy and become the Hero (as suggested in the Notes section). Another option would be to hire a spy to observe the hero and predict where he is going to travel. You then arrive earlier than the hero and perform good deeds before they can. It's a matter of firsts. [Answer] I don't think anyone else has mentioned: Be Deadpool. He didn't start out as a main-protagonist. You know you're in a story, you can be the guy who reads the subtitles. Alternatively you can be the [Genre Savvy](http://tvtropes.org/pmwiki/pmwiki.php/Main/GenreSavvy) character, unfortunately the [Genre Savvy character always dies](http://tvtropes.org/pmwiki/pmwiki.php/Main/DeathByGenreSavviness) unless he can become the [comic relief](http://www.soundonsight.org/wp-content/uploads/2014/07/Sam-Rockwell-Galaxy-Quest1.gif). [Answer] We have to start from the fact you are a *minor* character, and that you know it. By definition, that means that you are not vital to the plot, story, etc.. As others have said, you must identify the main character. Although I don’t think you can depend on having meta information like finding out who the author is nor gauging your genre. Nonetheless, you must identify the main character! Like others have said, they will be outstanding in some way. It may be easy or obvious (and possibly how you came to find out you are the minor character) or you may have to search (you could be in their flashback, and you only knew them in elementary school) or possibly the worst case, you aren’t in the story yet. You will have to maintain vigilance because at any moment they might float in and then out of your life (You might be one of the other drivers in Office Space, for instance) Assuming you find the main character(s), your real task begins. Taking a look at common character progression across most genres, to go from minor character to something more, you have to do the following: * Interact with the main character, the more the better, and the more important/valuable you are the better. The more frequent the interaction, and more magnitude (attention) you can pull, the better. * Become vital – remove other competing sources of whatever you provide, or simply be “the best” at it. This can be shown in the following examples: Bella had friends in the first Twilight book. How much air time did they get in the Fourth? Jacob was a minor character and/or not present in the first book (I don’t recall) but became one of the main characters by the end. These changes happened solely because of how much time they spent with the main character and how much value they added to the story. Many stories have a quest to find some object or information. The first time this occurs, the main characters spend a lot of time scouting and scheming and hunting and whatnot. The second time, they do straight to their ‘dealer’, and only if that person cannot provide will they continue their quest. Adventure Time has a chance encounter with “Choose Goose” early on, and now he is a regular salesperson. (salesgoose?). Often baddies-turned-goodies are huge sources of information. At first, anything they say is suspect and can spawn side-quests and other stories. By the second season, their capacity is reduced to tomes and fact-checkers. (Hey, when you were in Hydra, did they have this superweapon?) But, like in the examples, you can ascend from minor character to main, typically by being incredibly useful. Perhaps it is what makes main character main in the first place, their ability to succeed. Take any team-based story, and ever main character fills a role. When they leave/die, that role is filled by either a new character, or the most qualified minor character. The frequency that you appear both determines and is determined by your usefulness and apparent value. So, to get back to the question, attach yourself to the main character and become useful. Help them succeed as often and loudly as possible. Getting noticed by the main character is about as good as getting noticed by the author and readers, as they are your ONLY chance in the long run. The more duties and responsibilities you can absorb from other characters, the more you will be discussed, referred, and consulted. The more action you can wrest from the main characters, the more “screen time” you will be afforded. Considerations: You cannot be evil, unless the main characters are evil. Then you can only be less-evil than them. (Yes, I meant that). You can do bad things, sure, but they have to be able to be shuffled under the rug by “seedy past” or “baddie-turned-goodie” tropes. If you are actively bad while in the temporal presence of the main characters, you will get stuck as a baddie, and will probably not say long in that story. [Answer] Anyone who's written a story without planning it out well in advance will have encountered this supporting character. They start as just a throwaway, but then they're the obvious one to deliver that hook, they refuse to be made two-dimensional and come up with better ideas than you expected, their presence ties together different plot arcs in much more complex and delightful ways, and they add emotion and depth to the other characters. As they become the main character's best friend, they have the chance (at least in more epic stories) of having the baton passed to them as the main character fades back or dies off. The main character is, by and large, immune to random "accidents", but not to aging, or to becoming seriously wounded in pursuit of their goals. So long as those goals are things which can be completed by another, it's feasible to have the baton passed to a secondary character. [Answer] Manipulate and control other characters (specially, the heroes). Discover their wishes, their secrets and use them in your favor. In Spain, there's a example of a classic romance story, [La Celestina](https://en.wikipedia.org/wiki/La_Celestina). The first versions were called *The Tragic Comedy of Calisto and Melibea*, as those characters, Calisto and Melibea, were the protagonists. Calisto wanted the love of Melibea, and sought help from Celestina, and old match-maker. Celestina controls all other characters at her will and becomes the main character. *Bonus*: Latter editions of the book are titled "La Celestina". *Extra-bonus*: In Spanish, *"celestina"* is now also a word for match-maker. [Answer] My first question is: ### How do you know you are in a story? If you have evidence that you are in a story, you can gain support from other characters. This could also backfire. Others with this knowledge—perhaps those you've shared it with; perhaps someone independent—may not support you. They may compete with you to take over the story, or simply draw support away from you. If you don't have evidence, you're on your own. Based on the OP's notes, **you have reproducible evidence that you are in a story**. --- The character's more pressing concern is: ### Is this a tragedy? Frankly, your character can't know know this answer unless the author communicates it to them, and that assumes the author is honest and doesn't change their mind. You could attempt communication with the author. I don't recommend this. The author is (more or less) omnipotent, and you don't know if the author is benevolent. Your ability to arrange communication with the author is also questionable. Given the OP's question and the 'happy ending' requirement, I will assume **this is not a tragedy**. --- The next question is: ### Is the nature of the work episodic? It will be hard for the character to determine this—chapters in a book can look a lot like books in a series—so it will be up to the character to determine if the drama is on a steady rise. A steady rise is more likely a single story; otherwise, episodic. An episodic work is much more amenable to new characters. Based on the OP's question, I'm going to assume **the work is non-episodic** in which case the character needs to get involved in the story *now*. The farther we get into the story, the less amenable an author is to introducing new characters. There are perks to being in the background, behind the scenes. If you can enlist support from other characters, proceed to enter the fray: your friends can do any dirty work you can't do once in the author's spotlight. If you're on your own, it will pay off to stay a background character while you set things in motion *only* if you can still become a main character. Try to gauge where you are in the work and the pace of the work. If you're at the beginning, you've got a little time to spare. If the work only covers one day, you have no time; if it covers your whole life, you've got loads. --- Now comes the problem of ### How do I become a main character? If the story centers around a group of main characters *as a group*, you simply need to meet the qualifications for joining this group (the implicit qualifications the author is using, not the group's standards: they might just let anybody in). If it's a tight group or otherwise you need to supplant an existing character. I haven't done a lot of usurping, but I'm going to suggest this process: 1. Select the character you wish to replace 2. Become their (friendly) rival 3. Exploit their tragic flaw (secretly) * Hopefully you were able to set this up prior to becoming a main character * If not, I hope you have cohorts who can set this up for you * If the character does not have a tragic flaw, you must induce or create one + The tragic flaw of last resort: Bad things happen Done correctly, their fall coincides with your rise, and you become a main character. A successful rivalry puts you on par with the person you're replacing; a friendly rivalry means the other main characters should be accepting of you; you are a natural replacement close at hand and thus most likely to fill the gap. There is the villain route (see [Hurkly's answer](https://worldbuilding.stackexchange.com/a/21019/11123 "Hurkyl's answer")). I don't recommend this because you enter the author's realm of control, so your control over the heel-face turn is in question. --- Bonus points: ### How do I get my name in the title? First: You have to have a name. If you have gained a sense of the story, choose either a symbolic name considering your role if it's a heavy story. Otherwise choose a catchy nickname and spread it around like a brand. Second: You must become the main main character. If the story centers around your gang, you should become the leader of your gang. Otherwise, I hope you quickly supplanted the main main character. If the author was going to use someone's name, the name of the person in that role is most likely. Other characters with a shot would be their mentor, parent, or the local leader who organized or hired your gang. Third: The author decides to do this. You really have no control over this unless you somehow managed to develop an endearing relationship with the author. [Answer] In fiction, in a series of stories written over time and consumed to give feedback while more are being written, this is called a [Breakout Character](http://tvtropes.org/pmwiki/pmwiki.php/Main/BreakoutCharacter). The tvtropes site also has details with examples on variations such as [A Day in the Limelight](http://tvtropes.org/pmwiki/pmwiki.php/Main/ADayInTheLimelight). [Hercule Poirot](https://en.m.wikipedia.org/wiki/Hercule_Poirot) was not *meant* to be the franchise he became: Agatha lamented on how she found that little man so annoying. [Answer] First off, awesome idea. I am aware of many of the existing works that people have mentioned, as well as several episodes of [Supernatural](http://www.supernaturalwiki.com/index.php?title=4.18_The_Monster_at_the_End_of_This_Book), but I think they are all not quite the same thing. Also, it is taking a great deal of willpower not to just write this story myself, that's how much I like the idea. Now, the character has to first discover that they are in a work of fiction. How would one go about this? Well, the more hackneyed the writer, or the more the genre is a trope, the easier this is. The key point is that the narrative must become obvious, and events that occur must seem improbable except in the context of a narrative. **So, moments of exposition must take place in front of our minor character.** Next, the hero-to-be must figure out who the main characters are, and from them, who is the current hero, and how to insinuate themselves into that person's circle. I would tend to think this should be done covertly. Who knows what the author will do once he figures out what you are up to, or that your actions don't fit the narrative? You should also beware of fitting too well into any stereotypical roles. For instance, when talking to the hero, figure out a way to slip into the conversation that your insurance policy is up to date so as to avoid being tragically killed or having your apartment demolished just for pathos. **Work behind the scenes.** If the hero is heading to a formal party, get there the day before and leave plot devices that will steer the narrative in a direction favorable to you. But this is key: Do this in a way that doesn't directly incriminate you. Maybe hire someone else to do it. **The genre of Detective Noir fits your concept perfectly.** First off, the title can fit you in without any problem and without being too obvious; "A Dame to Kill For" or "The Shadow at Midnight". Secondly, it is usually told from the detective's perspective, none of this 'Omniscient Narrator' business, which leaves you plenty of opportunity to work behind the scenes. Plus, when the writer figures out that you are behind some of these plot devices, they will make sense in context of the genre, and he'll just think he was really clever writing you that way. A scene early in the story where the detective is searching the mobster's office when he hears voices outside the office and he ducks under the desk. There he finds a note taped to the underside which the mobster couldn't have left... Later he meets a shadowy informant in a dark alley who give him information on behalf of his employer: a mysterious 'Mr. M' (Your character's first initial -- but wait! There are red herrings!) The detective deduces that Mr. M left the note for him. The shadowy informant laughs, "No that note wasn't for you, it was for the Author. He just needed you to read it so it would be in the story!" In the end, the detective's car is sabotaged (obviously the mob's work?), and the bit character gives him a lift, soon after saving the detective's life and uncovering the vital clue, solving the mystery. Does Mr. M do a happy dance and confess everything to both the clueless detective and the oblivious author (sorry)? Or does he (she...?) leave it up to the reader to figure out, smug in the knowledge that they went from a one-page write-off to the main character with no one the wiser? [Answer] Don't reject the villain route too quickly — if you can set yourself up for a dramatic [Heel-Face Turn](http://tvtropes.org/pmwiki/pmwiki.php/Main/HeelFaceTurn), you have a good shot at making the main cast. The tricky part is avoiding [Redemption Equals Death](http://tvtropes.org/pmwiki/pmwiki.php/Main/RedemptionEqualsDeath). This gambit works especially well if you're an attractive female. [Answer] Become Murdoch. If you can be something so compelling, so true to self, that the fans love it, even if you die you are not done. ]

[Question] [ Imagine a city where the primary population is an avian race. Well assume for the sake of argument that these birdlike creatures have "hands" as well as wings which allows them to develop and use at least a Victorian/early 20th century level of technology. They are also approximately human sized. What sort of differences would their city have? [Answer] ## Heights would not be dangerous Because there is little risk of injury from falling, the creatures would not suffer from vertigo. Our skyscrapers have walls around them to stop people from falling. Non-structural guards would not be required. Birds quite happily perch in locations that would be terrifying for a human. A pigeon will sit on the windowsill of a skyscraper. Perches could be used instead of benches. Platforms could be used instead of rooms. Poles could be used instead of corridors. Railings and fences are less necessary because a fall is likely not harmful. ## Stairs and lifts would not be necessary A platform at the top of a pole would be a viable habitation, as would a hanging sphere. A multilevel dwelling might consist of a series of pods hanging from a strong wire for example. You would need no physical way to move between levels, just space to fly. Open spaces could be left within a building to allow access to other levels. A vertical surface with perches would be as useful as a horizontal surface. ## Vertical and overhanging surfaces would be practical, everything is 3 dimensional A city on the side of a cliff would be possible. The inhabitants could reach holes or perches without stairs or lifts. Undersides of surfaces could be used, perhaps the underside of a large tree branch, cliff overhang, cave ceiling, or the underside of a larger dwelling. ## A room can be exited from any side Exit holes could be on any side of an enclosure, top, side or bottom. An exit hole at the bottom would keep the wind and rain out effectively. Assuming the creatures sleep standing up this might be a good option. Furniture could be mounted on the wall and accessed by means of perches. ## Flat space would not be at a premium A human habitation has large rooms with a flat floor which we walk about on. An avian dwelling could be spherical, could be made of multiple platforms at different heights, or could simply be a network of poles. ## Airspace would be valuable Our property laws are based in two dimensions, you own land. An avian race might own airspace. A dwelling could be created at any height provided it could be elevated on poles or suspended by wires at that height. Dwellings could be suspended from the branch of a large tree for example, or cantilevered on a pole from a cliff. ## Motion might be acceptable If the species has evolved roosting in trees, motion in the wind might be acceptable. Multiple Dwellings suspended from a single long wire might move and turn in the breeze. ## Weight would matter A flying creature is more easily burdened than a walking creature. Items of furniture would need to be lifted into position. Day to day tools, machinery, electronics, implements and clothing would need to be kept lightweight. ## Building material would need to be lifted If cities are high, building material would need to be lifted. Cranes would be possible, but older buildings might be made out of small, light blocks, light wooden beams or fabric. Modern buildings might make use of light weight metal or plastic lattice. Building from stones would be difficult and expensive. Heavier items might symbolise wealth. Perhaps high status building might be made out of heavier materials such as stone or steel sheeting. ## Dropping an item would be a big deal If you're high up, dropping a tool probably means you lose it. You might even hurt or kill someone. Items might be made to be hooked on or otherwise attached to surfaces. Hooks, clips and cleats might be commonly found on clothing or walls. Think about a ship in a storm, everything has to battened down and attached. ## Accessibility Flying is energetic and requires big body movements. What happens to the elderly, infirm, or just people who are feeling tired, or if the wind speed is too high? Are there laws that buildings must be accessible without flight? Perhaps public buildings are connected with wires. You might find streets made of wire mesh slung around the city center. Old parts of the town might be less accessible. ## Status In the same vein, running has been considered a low status activity in some societies. It's tiring. Servants and slaves need to run around to get their jobs done. The rich can afford to have people run about for them. Perhaps flying might be a low status activity. It takes a lot of energy, and if you're rich enough you can afford to have ladders, lifts, perhaps even a litter or aircraft. ## Cultural concerns A bird has one defence, flight. A bird on the ground is a sitting target. It's bones are thin and light, it stands little chance against a predator. Intelligent avians would be lightly built and armoured, and might in the past have had to deal with predation, just as humans did. Much as humans have an instinctive fear of dark confined spaces where predators might hide, intelligent avians might have a fear of low down accessible places. They might feel more comfortable in clifftop locations. ## Criminal Justice A natural form of punishment would be clipping of wings. This would hobble (and possibly shame) the avian for several months or years. Breaking of wings would achieve a similar, more long term effect. You might expect to find such outcasts living at ground level. ## Prevailing wind would matter It's easier to take off into the wind. Mobile dwellings might rotate so the egress faces away from the wind. There might be a launch perch on the reverse of the dwelling so the inhabitant could launch into the wind. Perhaps there might be a feathered projection on one side of the dwelling to turn it into the wind. You would probably see weather vanes dotted around. ## Fire would be challenging Making a cooking fire would be difficult and possibly dangerous without a stone floor to build it on. Fire stones would need to be present in buildings if the creatures make use of fire. ## Industry would be lightweight Heavy industry at altitude would be difficult. You could expect materials to be lightweight, foams, plastics, plywood, aluminium with holes (though mining and smelting would be difficult), wooden lattices, dried funghi or bone, stabilised mud, perhaps printed structures. ## Water would need to be lifted Perhaps rain water could be collected in an arial reservoir. Perhaps it is pumped up, or perhaps tree sap is tapped and used. Perhaps individuals could have their own reservoir, maybe a leaf bent and pinned. ## Sewage would need to be dealt with Lifting water for flush toilets would be impractical. The creatures might perhaps land to defecate, do so on the wing in special areas, or simply fly outside the city limits. Private bathing and toileting would be difficult. Lower levels would probably smell rather less fresh. ## Wires would be extremely hazardous An unmarked wire would be the equivalent of a big hole in the road; striking it would cause severe injury or death. Expect lifting wires under tension to be marked somehow, perhaps with lights, coloured flags at intervals, or just light coloured rags. ## Differing architecture Just as different parts of a modern city like London use different architectural styles, you could expect different regions of your city to have different architecture as technology has changed over time. Very old buildings might be built of stabilised mud and branches. Modern buildings might even be 3D printed. ## Transportation Walking and driving would feel un-natural. Perhaps the society might use ground based transport for moving heavy loads, or perhaps airships. Flying creatures unlike bipeds can travel very quickly over comparatively great distances so short range transportation of the type we have (subways, taxis) would not be useful. Longer trips would require some means of transport, presumably airborne. A human transport is designed to mimic the feeling of being in a room. Walls, ceilings, chairs, little tables. This might not be the case for an avian species. ## Wingspan would matter A person can fit into a space small enough to stand upright. A winged creature might feel uncomfortable without the ability to take flight. Space would need to be left between structures to allow flight. Doors or gates would need to be wider to allow landing. ## Fences would not be effective A secure structure would need to be completely enclosed. Fences would only be effective against ground based animals. Likewise for a private structure. ## Wind would be a constant and reliable source of power At altitude, wind is likely to be stronger and more reliable. Expect wind turbines to be used for electrical and mechanical power. [Answer] As a side answer, it might depend on their flying style, not all fliers in nature are alike. Many birds need room to maneuver and the right air currents, while dragonflies are able to hover and dart in at smaller angles. Different flying styles might have different castles. For instance, dragonfly like people might live in a narrow canyon that they could easily hover down into, with small helicopterlike landing pads. Batpeople might build upside-down cities that cling to ceilings. Predatory bird like people might go for Avatarlike Airbender cities with more open approaches and longer landing pads. Or if they're more like hummingbirds, only perches or places that they only touch down briefly. [Answer] Adding to superluminary's great answer. I would expect mountain sides and [cliff](http://en.wikipedia.org/wiki/Bird_cliff) faces to be rather high demand for home locations. Like the [cliff dwellers](http://en.wikipedia.org/wiki/Cliff_dwelling) in the American Southwest, it would be a very safe location from predators and even reasonably easy to protect from enemies. With out having to worry about ladders or stairs it would also be an efficient use of space for more advanced groups, fewer homes using up arable land. When actually building in other locations I would expect most building to be rather tall, internal stair cases and elevators wouldn't be needed. A crane on the top that can hang over any side would be sufficient to get heavier things up to floors since every flat could have big open doors directly out to a landing. [Answer] If you also think about bird's nesting habits; like where, why and how they build them, that might give you a direction to start in. For example, many birds will build nests in places that are difficult for predators to reach. For a suitably advanced avian race, this may not be necessary anymore, but it might be a cultural hang-up that they continue to observe. An avian society may also live as close as possible to their preferred food source - whether that's farmed grains on the ground (perhaps tended by enslaved sub-species or ground dwelling creature) or some kind of prey. Another interesting thought, spurred by bowlturner's [answer](https://worldbuilding.stackexchange.com/a/2997/2333) relating to cliff's being defensible, is that if an avian culture is territorial or warlike, it is likely that at least some of their enemies are also avian. Rendering cliffs no more defensible than anywhere else. For a city builder of such a culture, you might choose to design certain parts of the city to impede flight or restrict freedom of movement to make attacking more difficult. [Answer] There’s been some great answers to this question, however there’s a few specifics that probably should have been initially clarified, starting with if these animals are living in an Earth analogue environment, what kinds of environment(s) they occupy, and if they are able to fly or glide. (Some avian species are unable to do either e.g. penguins). These questions aside, I’ll assume you’re imagining a humanoid species capable of flight in an Earthern world: I would actually argue that simply being occupied by a species capable of flight would have very little impact on the city. The defining characteristics of the city would have more to with the environment, economics, and the culture, than just anatomy. While flying is novel, it’s implications on the essential necessities of a Victorian Era industrialised city are very limited, therefore their cities are unlikely to look radically different. **Transportation** While flying (or rather gliding) is highly efficient for long distance travelling, the ability to transport large / heavy objects is acutely limited. Ground transportation would be an essential and integrated feature of the urban environment by necessity. A train or barge is the most efficient way to move tonnes of iron ore, regardless of wether you fly or walk on land. Aerotechnology however, would most likely be accelerated. Steam can’t effectively power aeroplanes, but it can be used by balloons and blimps, which would be superior methods for long distance air travel based on their ability to carry large payloads and travel at consistent minimum speeds. Gliders would be another option. Sciences including cartography, physics, meteorology, mathematics and engineering might also get a boost. Given they are probably going to be weaker than humans, technologies that allow these lighter bodies to use more leverage are most likely ubiquitous. **Architecture** Stairs, elevators, escalators etc. would all be common - imagine being expected to walk up and down the stairs in every skyscraper just because you have legs capable of doing so! Given vertical flight is all about hard flapping, it would seem less efficient to fly than to walk up and down inside a tall building. Either way, elevators and funiculars are still more practical than flying or walking steep or high points. Buildings most likely have stairs and handrails too as they need to be safe and accessible for the very young, the sick, the old and the disabled. **Urban Layout** It’s quite likely the city would be orientated to prevailing winds, and organised in such a way to provide access to those winds. Likewise if this species has some sense of the magnetic field the city may align to that as well, or instead. It’s no more reasonable to assume an avian species would live on cliff sides or in glorified nests, than it is to presume humans would naturally live amongst the tree branches just because their primate cousins do. Your question asks what impact the ability to fly would have on the nature of an industrialised city. I would argue that the ability of citizens to fly has little impact on the essential nature of an otherwise human city. The differences are more likely to be superficial, and reflect what is economically, technologically and culturally permissible - rather than being determined just by biology. Industrial cities need quite large, relatively flat, easily accessible and interconnected areas, so a cliff side city is probably unlikely. At the end of the day a blast furnace is a blast furnace, is a blast furnace. **Socio-economics** As mentioned elsewhere, it’s quite likely that damaging the ability of an individual to fly would probably be used as a severe punishment. One interesting thing to speculate about is how can avians be effectively coerced? Victorian industrialisation was a brutal, foul and miserable experience for the working class, prompting sabotage, strikes, and violence. If workers had the ability to fly far away quickly on a whim, would they suffer such harsh treatment? Perhaps there is an opening to imagine avian society as ring based on anarchist or consensus politics. Alternatively, perhaps the majority of the population are kept disciplined with forced clippings or pluckings for an airborne capitalist class living palacial towers. ]

[Question] [ This is a partner question to [How do centaurs get enough oxygen to run](https://worldbuilding.stackexchange.com/questions/7289/how-do-centaurs-get-enough-oxygen-to-run) Centaurs are a common mythological figure, with the body of a man where a horses head would be. They usual exist in a fantasy world but lets 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. Humans are not adapted to eat grass or grains, however a centaur could potentially have a horse's digestive system so would centaurs be able to live on grass? If they could would they be able to graze? It seems their body shape would be more suited to giraffe-like eating fruit and leaves from trees rather than grazing of grass. Could they get enough energy that way though given their smaller mouth? Would they need to be carnivorous or at least omnivorous? [Answer] A 1000 pound horse needs approximately [15,000 calories a day](http://www.dayvillesupply.com/hay-and-horse-feed/calorie-needs.html) for maintenance, the average 160 lb human needs around 1800. Take 70% of a horse and 50% of a human, that gives you about 11,400 calories per day as a maintenance level. (Pretty much just breathing in and out). A typical McDonald's meal (Quarter pounder, fries, non diet soda) runs in the neighborhood of 900ish calories, so a centaur to just exist would need to eat around 12 Quarter Pounder meals a day just to subsist. While in the oxygen question there is the benefit of being a poor utilization ratio, the body is actually pretty well versed in conserving calories, and is very efficient (Which is one reason it's so easy to become overweight). I would presume that a centaur diet would need to be high in fats, as fats carry 9 calories per gram, while meat/carbohydrate each weigh in at 4 calories/gram. For example, an avocado (21 grams fat) has 230 calories, a 146 gram serving of turkey (Same as the avocado serving) has 152 calories, and typical steak at 146 grams (5 oz) is around 400 calories (depending on fat content, lean meat has less calories). So, a pound of steak comes in at 1200 calories, a pound of avocados comes in at 700ish, so if those were the only two foods available, you would need about 6 lbs each of steak and avocados per day to reach maintenance levels. The average American I see chowing down manages to get through 900 calories in about 15 minutes at McDonalds, so I would guess that centaurs would need to eat for 1/2 hour to an hour 4-5 times a day to get their needs met, more if they are adapted to make better use of plant material than humans. [Answer] Since Centaurs are intelligent and have arms they can raise and collect a much larger array of foods than a horse. I would also expect them in general to have proportionally larger mouths with larger molars for helping ingest the tougher plant tissues. While a human can survive on bread and water for a very long time, other foods would keep them much healthier. I imagine that Centaurs would eat quite a bit of fruits and vegetables and nuts having a higher calorie content, even though they could 'survive' on grasses and grains. Omnivorous? Possibly, though I would expect the animal protein to be primarily seafood or birds, more like a vegetarian vs. a Vegan. Carnivorous? Very unlikely, Carnivores tend to be smaller than herbivores and a Centaur is pretty big and would require a LOT of meat to itself going. [Answer] I mentioned birds in my other answer so why not here as well, Using a [gizzard](http://en.wikipedia.org/wiki/Gizzard) centaurs would be able to digest fibrous foods that humans wouldn't be able to. Then allowing the food to be fermented in a [rumen stomach](https://en.wikipedia.org/wiki/Ruminant) would allow the remaining digestive system to get more out of the plant matter. (breaking down toxins as needed) Having dexterous hands would allow them to get to food that other animals would have a hard time getting behind spines or in burrs/cupules. [Answer] The subject of centaurs eating was (briefly) addressed by C.S. Lewis in *The Chronicles of Narnia.* In that world, centaurs had two stomachs, one human and one equine, and had to eat to fill both, which meant that they ate a lot, both human and horse food, and spent some time doing so. ([ref](http://narnia.wikia.com/wiki/Centaur)) Though the mechanics of how they grazed was not mentioned, as far as I remember. Another point is that, depending on the world, the "human" portion of the centaur may not actually be human-sized, but instead sized proportionately such that the torso of the human half is the same size as the neck/torso joint of the horse, so "small mouth and throat" might not be applicable. - Again, in Narnia, the human portion of the centaur was compared to giants, rather than normal humans. In Nick O'Donohoe's *Crossroads* series the increased size of the human half of centaurs is also explicitly referenced. (Though their dietary needs aren't mentioned, if I recall.) [Answer] I cannot imagine centaurus to be [ruminant](http://en.wikipedia.org/wiki/Ruminant) - chewing the cud all day in the shade? Just the opposite, centaur would be much better hunter than humans are. Also better farmer: plowing the fields would be easier. My bet is carnivore like neanderthal man, diet is mostly meat with fruits, cheese and grains added. Just eats three times as much as average human. ]

[Question] [ In one of my fictitious planets, there are large cells that reside in the ocean and are 3 feet (almost 1 metre) in diameter. The cells themselves are aggregates of many amoeboid cells, have only one cell membrane, but many nuclei. My question is: is such a large size for a single celled organism possible? If not, what modifications might I need to make to make it more plausible? [Answer] Many far-fetched things you try to come up with, nature did it first. They already exist macroscopic unicellular algae, although not so big, they are spectacularly big. Just have a look at [these](https://en.wikipedia.org/wiki/Valonia_ventricosa) [two](https://en.wikipedia.org/wiki/Acetabularia). As you can see from the links, they are very different from each other (in fact, one of them is mononuclear). ### [Valonia Ventricosa](https://en.wikipedia.org/wiki/Valonia_ventricosa) This would be the easiest approach. Searching for differences between it and other more common, microscopic unicellular beings, I found out that thay are almost identical. So just: * Make it bigger. * Multiply the cell components, simply put more of them. And that would be pretty much it. According to the description in the question, I think **this is the approach you were looking for**. Just a big unicellular [blob](http://tvtropes.org/pmwiki/pmwiki.php/Main/BlobMonster) *(Warning! TV Tropes link)*. ### [Acetabularia](https://en.wikipedia.org/wiki/Acetabularia) This other approach is more complex. In fact, even if it is unicellular and mononuclear, it behaves more like a plant, with a plant-like stalk and root-like rhizoid. With the difference that it has a very big nucleum in the base. --- Another one thanks to [Nathaniel](https://worldbuilding.stackexchange.com/users/7130/nathaniel): ### [Xenophyophore](https://en.wikipedia.org/wiki/Xenophyophore) There is this other one which looks more like a sponge. It lives at the sea bottom, just like the other two, but in deeper waters. It feeds like the amoebas. From the wikipedia link: > > These giant protozoans seem to feed in a manner similar to amoebas, enveloping food items with a foot-like structure called a pseudopodium. > > > [Answer] ## No. **Reason 1:** *Surface area to volume ratio* The volume increases much faster than the surface area of the cell. Cells are small [for a very good reason](http://www.brooklyn.cuny.edu/bc/ahp/LAD/C5/C5_ProbSize.html), they need to diffuse nutrients into and waste out of the cell surface for all of the internal volume. The volume inside your cell would require a lot of energy and produce a lot of waste, much more than the relatively small surface area could hope to transport in and out. As cited [in this paper](http://www.pnas.org/content/108/44/17876.full): > > Another possible factor limiting cell growth is shown in Fig. 8: the rates at which a protein can diffuse across it. Eqs. 11 and 13 show **that every factor of 10 increase in linear size of a cell leads to a factor of 100 increase in the time required for proteins to diffuse across the cell’s length**. > > > *Emphasis mine* **Reason 2:** *Protection* A cell wall is not a very strong boundary. It's literally a [bilayer of phospholipids](https://en.wikipedia.org/wiki/Phospholipid) relatively loosely held together. You [can't make such a sheet of phospholipids arbitrarily large](http://www.nature.com/articles/srep06213) and not run into problems. It [wants to form smaller surface areas](https://en.wikipedia.org/wiki/Interbilayer_forces_in_membrane_fusion#van_der_Waals_forces_in_bilayers) (think of water droplets and why three-meter ones don't spontaneously form). If you try to make this cell membrane much more durable and thicker you run into even more problems regarding Reason 1. Just take Nature's advice and make a multicellular organism. It's far more efficient. --- ## How to solve it. If you must have it be one cell then it simply can not be a sphere. It can be 3 feet in one dimension, but must have many deep folds and thin areas that increase the surface area to a reasonable ratio. [Answer] [Slime molds](https://en.wikipedia.org/wiki/Slime_mold) form [plasmodia](https://en.wikipedia.org/wiki/Plasmodium_(life_cycle)): > > A plasmodium is an amoeboid, multinucleate and naked mass of cytoplasm that contains many diploid nuclei. The resulting structure, a coenocyte, is created by many nuclear divisions without the process of cytokinesis which in other organisms pulls newly-divided cells apart. > > > *(Wikipedia)* [](https://i.stack.imgur.com/oC5Nb.jpg) They are already macroscopic, so it would not be much of a stretch to grow them to three feet. [Answer] **Yes, but it could be argued otherwise rather easily...** A single cell of such a size is, in my belief, totally *possible,* but not necessarily *likely.* To tart, we would have to consider the various *parts* of a cell and decide if at such a size they wouldn't be organelles any more, but rather organs. * The **cell membrane** is made of fat and protein, which at a certain size must? be controlled/contained in the form of cells. * The **centrosome**, or **microtubule organizing center**, has a bunch of tubules, which at their size are just nicely arranged biological particles, like all else. But at a certain size, according to the previous premise, it is hard to control or maintain a shape or desired form without *structure.* * On that note, we have the cell's skeletal structure, called the **cytoskeleton.** This piece, perhaps not an organelle, holds up the desired structure of your cell so that it doesn't get squished, punctured, or otherwise maimed or non-useful. At a size of a small animal skeleton, it is *extremely* arguable whether it could exist. * The **cytoplasm**, the jelly-like interior of the cell, could very easily be recreated, no doubt about that, using any feasible semi-liquid, including real jelly, for funsies. * On the other extreme, we have the **mitochondrion.** these are pill/bean shaped "power plants" which convert glucose into ATP(Adenosine Triphosphate), providing the whole cell with energy. It consists of multiple folds and projections, and even at its size, it very nearly pushes the boundaries of a basic organelle. At a three-foot proportional size, it would almost *have* to be made of a series of cells, or made by them, because synthesizing something that complex requires a whole different biological level of creation. * Or say for argument's sake that you are making a three-foot *plant* cell. Bring out the **chloroplasts**! The way that these are made to collect sunlight and output energy is complex and deliberately micro-scaled, the reason you see them in large quantities, and at the same size, regardless of the cell, for the most part. * And other organelles, such as the **nucleus**(brain), **golgi apparatus** and **lysosomes** are pretty much the same; possible, but not using the same materials as we see in a "typical" cell. **My conclusion** From my fairly large amount of cell knowledge, I would have to say that yes, you could, with a *tiny* amount of magic and some improvised materials. But personally, I would just have everybody be microscopic, making cells look big, and maybe... just maybe introducing a whole new problem. [Cell Anatomy (Enchanted Learning)](http://www.enchantedlearning.com/subjects/animals/cell/) [Cytoskeleton (Wikipedia)](https://en.wikipedia.org/wiki/Cytoskeleton) [Chloroplasts (Nature.com)](http://www.nature.com/scitable/topicpage/photosynthetic-cells-14025371) [Answer] Egg yolks are single cells, and ostrich eggs are pretty big. There was a [news story](http://blog.everythingdinosaur.co.uk/blog/_archives/2012/04/20/worlds-largest-dinosaur-eggs-the-facts-are-scrambled.html) about giant fossilized dinosaur eggs found in Chechnya a few years back which where up to 3 feet wide. There is some doubt whether they were really eggs (especially since the largest verified dino egg is football sized\*), and no one is guessing what laid them if they are actually eggs, but it is interesting. So giant cells aren't unheard of here on earth. I don't see any reason why one couldn't develop in an alien sea if conditions were right. \* I don't know if they are talking about American gridiron football or European soccer football, but since it was found in France... [Answer] **Maybe.** [Giant cells](https://en.wikipedia.org/wiki/Giant_cell) actually exist. They occur when many cells fuse together, often to fight an infection. They typically reach a maximum size of [120 micrometers](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4171918/) - nowhere near your size - but I suggest that it might be possible in an extreme case. Potential reasons for the formation of a giant cell of bacteria: * A disease that threatens all bacteria that live on their own. * Cells fuse together in part of an embryo in response to something, and when the embryo is born, part of it is fused together. These are pretty far-fetched, but I wouldn't write them off entirely as impossible. [Answer] Yes, but life on this planet wouldn't be very complex What you describe is a large, unicellular organism, that is buoyant, slow moving, and lives in a nutrient rich environment whose other participants are similar if not smaller. This could also be fungal in nature Options: * An amoeba like cell with an ovaloid disposition * A fungal entity, such as a mold or yeast, technically a `Coenocytic hyphae` * A branch like cell that is 3 feet in one dimension, but thin in the others, and relies on length to reach that measure. Neurons and nerve calls would be the analogous but smaller version. Keep in mind, none of these will be fast, or particularly energetic, almost certainly passive, most likely fragile, your planet may need a lower or higher gravity, and an abundant solvent to act as suspension, almost certainly in liquid form with plenty of depth. These things will need to be near the surface for light. If they're to float they must be buoyant. Otherwise they will need to sit on the floor of the sea which limits depth, and they're unlikely to be mobile as a result. Your environment will need a suitable energy source, most likely the sun, and your oceans can't be too violent as these organisms will not be hardy. Anything like fish or animal life will be an impediment to them existing at all. Precedents: * [Multinucleate](https://en.wikipedia.org/wiki/Multinucleate) cells are not uncommon, for example, human muscle tissue, fungi, slime moulds, etc * Human nerve cells can reach 1m in length * Giant grape amoebas and slimes, and other moulds [Answer] The largest single-cell organism is probably the Xenophyophore which has been known to grow up to 20cm (roughly 8 inches). From the outside they don't look like single cells because they build a hard shell around themselves by gluing sediment (basically fine sand) to form coral-like structures. The size you want is only around 4½ times bigger so it's not too much of a stretch. ]

[Question] [ I won't claim to be a biologist, but I'm fairly certain that it's really hard for disease to survive in space because most bacteria and viruses need a host in order to survive for long periods of time. So, let's say a group of very healthy astronauts were sent out into space. Their only contact is with one another and they reproduce. Their children wouldn't come in contact with many childhood diseases, and while they may inherit some antibodies from their parents, their immune systems would probably take a slight hit after not needing to fight off any of these diseases. I'm assuming that some diseases that were on the ship at take off would mutate in order to survive, but the vast majority of human illnesses will never make it on board. **How long will it take for the immune systems of this group of people (and their descendants) to deteriorate so that they can't return to Earth without dire effects to their health? Would this even be an issue?** [Answer] You can't ask "how long" in years, but in generations. And the answer is **One Generation.** --- We have two kinds of immunity... innate immunity and acquire immunity. The first one (innate immunity) will react to a multiplicity of organisms. And it will react always the same way. This is the first line of defense of your organism, because it's the simplest and the fastest. Your space travelers would also have this kind of immunity, so they wouldn't be completely immunosuppressed. Trouble is... this isn't a "immunity" per se, because people don't get immune with this kind of response. Because when you are exposed to the same kind of microbe, you'll need to develop a immune response all over again. You can get sick with the same disease over and over and over. --- Acquired immunity... That's the real immunity. Because your body *learns* how l fight that specific disease. When exposed to a certain microbe, the acquired immunity will develop a response appropriate **to that specific microbe**. It will then **memorize** that response, so that when exposed to the same microbe it will elicit a fastest and more efficient response. You won't get that sickness ever again. Now, as the name states, you can't inherit acquired immunity. You have to develop this responses by yourself, by being exposed to the pathogen (either the real deal, or an atenuated surrogate, aka vaccines). Infancy is a special time period for this immune "training" to develop. If you don't, your immune system won't know how to adequate respond to stimuli. People raised in aseptic environments are prone to develop inappropriate immune responses to inocuous environmental stimuli, i.e., allergies and autoimmune diseases. *(Your space travelers would suffer from this, BTW)* --- As soon that you have a generation reaching adulthood and that never had any contact with common earthly pathogens (even via vaccination), then they would have a lot of trouble fighting even common diseases All this, assuming that there isn't any other variable immunosuppressing your space travelers. Perhaps chronic exposure to space radiation affected their blood marrow's ability to produce immune cells (either innate or acquired) [Answer] I'd suggest that they may lose at least partial immunity to a decent extent within a decade or two of leaving Earth. According to [Smith et al. (2014)](http://rsif.royalsocietypublishing.org/content/11/101/20140950.full) (explained for us laypeople [here](http://journalistsresource.org/studies/society/public-health/global-rise-human-infectious-disease-outbreaks)), the number of disease outbreaks has been rapidly increasing over the last few decades: [](https://i.stack.imgur.com/0Hb3n.jpg) Specifically, there's been a large increase in bacteria- and virus- carried infections. I'd argue that this could be quite a problem. Immunity to past strains of a disease can be created through vaccinations, and I see no reason to not bring enough on the ship for future generations. There's no sense in having a child somehow get chicken pox when they go to Earth just because someone felt it wasn't worth sending an extra syringe along. The odds of this are extremely low, assuming proper procedures are followed to make sure that no diseases manage to hitch a lift on the ship. But with 3000 outbreaks happening over the span of five years - many likely from new varieties of illnesses - it seems highly likely that the descendants will not be prepared to deal with any of them once they leave space. The only way out would be to constantly supply the ship with vaccines from the latest strains of disease, or to ensure that the spacefarers undergo quarantine when they come back until they receive the correct vaccinations - not bad, considering the odds of them contracting, say, Ebola while in Earth orbit are slim to none. So, without vaccinations in space or back on the ground at arrival, I'd say that within ten years or so, they'd be incapable of dealing with a variety of new strains - many minor, some significantly worse - when they go to Earth. --- I'm aware that the question asks for "dire effects". Diseases which can have nearly guaranteed severely negative effects on most members of a population don't necessarily follow the same trends as shown above and can be difficult to anticipate in advance. If a disease that becomes the next smallpox strikes Earth within ten years, this answer becomes very different. But if we don't see such an epidemic within a few decades, then the answer is simply that there won't be any significant problems. I don't think I'm qualified to speculate on when the next pandemic will hit, so I'm not going to try. [Answer] Yes. Remember, this is what killed most of the Native Americans in America was "discovered." There were many diseases such as the flu that they had never been exposed to in any form, and they killed a large percentage of the population. The ones that lived and developed an acquired immunity survived and reproduced. [Answer] The real answer depends on the illness. I am not a doctor of any kind, so these are just based on my observations. First level, are things that change every so often. Like the flu. You have to get a flu shot every year to stay vaccinated because what actually happens is the flu virus changes etc. These would happen almost instatly like it does today. Second level, things that we need booster shots for. Tetanus, for example. With those shots are immunity wares off. TB, and Hepatitis are also good examples. Third Level, vaccines that we all need to get once. MMR, Polio, etc. These would last 1 generation. Final Level, hereditary immuneities. There are some. But not many. Mothers pass on a few antibodies, but they are more of the "general" kind and not the specific kind. Think of them as "antibiotics" and not "the anti-body that fights xyz infection". Usually by the time breast feeding is done, those antibiotics are wearing out in the infant. But the infant has produced some of their own. Without exposure to boost antibody production against a specific infection, then even the antibodies that get passed on would start to fade after a single generation. So without exposure to there viruses and bacteria after just a few years your astro-dudes could be in some serous trouble (check NASA documents about long term space habitation for some examples). After a few decades, they could end up with some serious infections, and after a generation or two, they would not be able to interact with us "land lice" without some serious medical intervention. Thankfully, even after 100's of years, providing nothing else changes, vaccines and controlled exposure could be used to give the space dudes a fighting chance. [Answer] In the last few thousand years, AfroEuroAsian civilization experienced a large amount of urbanization and population density increases. This resulted in diseases that cross over from other species to have a fertile ground to spread and infect in waves that cross and recross the world. Many millions if not billions die over the generations, those that survive adapt to being resistant to the kind of symptoms the disease generates, and the disease adapts to be more efficient at spreading. When AfroEuroAsian explorers reached isolated communities who hadn't been exposed to the huge host of diseases they where used to, the diseases did a clean-field burn of the populations. Fewer diseases came back, as the volume (time times area) of dense human habitation wasn't as large; but possibly not absent. It is possible that syphilis did transfer back from the Americas. The seed population of Astronauts would have a genetic pool from the surivors of such pandemics. They would also carry with them aquired immunity to common earthborn diseases; that, however, lasts at most a generation or two, and sometimes as little as a decade or less. Their innate response to infection might not drift rapidly. That innate response is mostly what makes you die or not die to a given disease. A disease, say smallpox, might kill 1/3 of people who where culled by a previous smallpox epidemic in their genetic history, while kill 90% of those who lack that culling. There would be some drift. Back on Earth, new diseases and variants would spread, and those whose innate immune response was fatal would die and tend not to pass on their genes. The red queen's race would continue. Those on the station would have their innate immune response mostly drift, or respond to variations in the small number of diseases they carry with them. Immune systems that overreact to sterile environments with massive allergies might be selected against, for example. But if your immune response to the common cold (which dies out in a small population) in the next generation is massive and debilitiating, you wouldn't even notice. There is also the possibility of a pandemic hitting Earth, killing a significant percentage of the population. Such a hit would result in those with an immune response that isn't fatal to that disease being selected-for. Multiple such pandemics could cause significant genetic drift over the entire Earth. So these different factors would result in the innate immune response of the Space Fairing and Earth populations diverging. The Space Fairing would also experience the founder effect and larger amounts of drift due to smaller population size, where quirky unique mutations in the founders might end up being extremely common, or later mutations doing the same. Over 7-10 years, your immunity to colds and flu would fade. Going back, you would be likely to get a really bad cold and possibly flu, which could be fatal. The next generation would get some antibodies from their mother via breast feeding, but their immune system would mostly be missing defences agianst common earth infections; so they would risk a really, really nasty lung/ear/eye/skin infections when they come back. This would increase over time. These can be fatal, but they aren't like 90% death rates with modern medicine. The multi-generation effect of genetic drift and the red queen's race back on Earth could result in the isolated population having mass deaths. How long this would take is extremely hard to guess, as we haven't really had a good experiment. Even Pitcarn island was only isolated for 20-odd years. Animal models aren't any good, because we are stange critters with our city-hives, worldwide travel, and quirky immune systems. [Answer] I think the first generation would already have serious problems. The immune system strengthens itself when it is in contact with foreign cells, when it returns to Earth without having any contact with these diseases, its immunity would be well below those who have always been in contact. [Answer] The immune system itself would not necessarily degrade over the generations in space. By design immune templates in the body are blank, what immunologists called "naive". When a person is born into a new biological environment, their body adapts to the local diseases. Breeding in space will not change this fundamental capability. A person who is born in space and suddenly returned to earth will be at risk from new pathogens, but this is no different than the risk you take any time that you travel. If you take a trip to Madagascar and have contact with the local people, you will be taking the same risk. The only dynamic immunological information conferred between the generations comes to a baby from its mother either via placental transfer of immunoglobulin or at birth by nursing. When a mother first nurses she produces a substance called colostrum which encodes the local disease environment. By drinking the *colostrum*, a baby inherits many of the immunological templates of its mother. For this reason an astronaut's children or descendants could return to the same place on earth and have a degree of immunity to the local diseases in the area. In general, a spaceship will be a different kind of environment than the earth because, as you point out, the pool of pathogens will be smaller. On the other hand, if a new pathogen were to evolve, it could potentially wipe out the space colony or greatly reduce its population. ]

[Question] [ Imagine a world things evolved slightly different: **plants never evolved into trees**. There are bushes, herbs, mosses, etc, but no trees. Thus no wood to make planks, nor for building. Given abundant resources of coal and any metals or other needed materials, could a bunch of humans dropped here with nothing develop a technological society or would they be stuck in some kind of a primitive stone age? If we look back at our history, wood was so omnipresent that I have a hard time convincing myself it was not necessary. At the same time, with today's technology it does not seem to be that necessary any more. So maybe another path, without wood, could have led to the same technology levels as we have today on Earth? [Answer] You'd need to replace wood in 2 ways: * As a construction material * As an energy source If I understand the question correctly, you're saying "Given abundant resources of coal and any metals or other needed materials" but you *don't* mean that said materials are lying about, just that they exist. In other words, I'm assuming said humans still need to mine ores and coal. ## Construction material Finding other construction materials may not be that hard - there's bone for small projects, although it isn't as easy to shape and you can't get it in quantities that are easy to work with when you need to make something solid. The obvious other choice is stones - which were used a lot, but were also abandoned pretty quickly. Stones are hard to work with, heavy and you can't easily form arbitrary shapes from them (a stone sword, for instance, is hard to craft without getting rid of *most* of the stone - not that it's a practical thing to make anyway, but thin, long objects are a *lot* easier to make with wood than stone). If these humans where given enough time, I guess they could do pretty well with just these - it would take the more time, due to the added difficulty, but they might be making pretty advanced constructs eventually. > > *edit - Zibbobz suggests that [clay](http://en.wikipedia.org/wiki/Clay) could be used as a construction material (including making ovens).* > > > ## Energy source This is tougher. Coal requires mining implements (unless you find it loose, which isn't going to be common) and was usually created in large amounts from *wood*, which is out of the picture. So all you get is coal ore. Oil is generally going to be too deep to get and not easy to refine (although you might not need to refine it per se, at an early stage). I'd say they'd need to find another source, before getting to coal, but once they get there, it may serve as a replacement for wood (maybe not for home fires though). Burning dried shrubbery might allow the creation of fires, although it would be very inefficient - huge quantities would be needed, probably compressed to make log equivalents. There's other minerals such as nitre which, if your humans are *amazing* at getting the energy out of things, might be able to use without blowing up (doubtful). Cheap fuel seems to be gone unless you have some form of composing biological fuels - maybe some form of composting would help. > > *edit - TimB adds that peat would probably be the best fuel source in this case - Stendika also suggested that [dry animal dung](http://en.wikipedia.org/wiki/Dry_animal_dung_fuel) (apparently also known as 'buffalo chips' which I wasn't aware of) could be used as a fuel. superluminary reminds that animal fat can also be used, such as in candles.* > > > --- Metals really don't come into this picture in my opinion - you need tools to extract them, unless you find small quantities lying around and while they can serve as a construction material, that's only after you've been able to find the tougher ones in large enough quantities. Metals only serve as an energy source with modern technology and even then, only in quite specific and high-tech situations. [Answer] So basically if our stiffest fiber comes from a bush could they get decent tech... **Sure they could!** (Now start your extinction counter because it's going to be tough.) Making metal tools with coal could be discovered relatively easily. But for your first real resource you have stone, which is time-consuming to shape. Bone is our level 2 weapon and we scavenge for it whenever we can. Since we have no sticks really, we can't get spears (bones are too curvy and stone too fragile). If you think to our Earthling cavemen, this means our level 2 bone weapons are pretty much daggers. We do get textiles as normal though, due to bone needles. If we manage to land some big game we have leather to make slings and become much better off. So you have a rock to throw, then a dagger, then a sling. Pretty much going to be living 24/7 safari zone. Depending on the temperature, wood becomes critically important as firewood. Brush doesn't last long enough when it's so cold that fire is a requirement. Although, if there's a *ton* of coal... If you have so much coal that the local past-time is seeing how big you can get a bonfire... Then you're probably going to have fire weapons almost the instant someone gets around to lighting one. On that note, fire's going to be a problem to make, if bush wood doesn't get big or strong enough to make a fire by hand. We're going to end up with wide-spread fire a smidgen later, which means more time in our vulnerable phase. Once you get to metal though, you actually speed through those ages faster as they become *that much better*. Although hastened metal progress may very well be offset by the fact that a massive amount of prototyping was done with wood because it was easy to shape. That may in turn raise the value of other prototyping materials like wax and clay. [Answer] some bushes could be used for small construction. Buck-thorn and sumac can get large enough to use for spears, and ribs in small structures like tents or huts. For fuel, if you look at the north america plains, Bison (Buffalo Chips) provided the materials for campfires. Granted neither of these solutions would make things easy to advance technology but considering how big our plains are and similar places in other countries, the Serengeti, the Russian Steppe, survival isn't based on wood. However, the mongols are the closest culture to advance themselves from this environment and admittedly that was a lot of stolen ideas from the conquered. Almost forgot, in the American prairie, a lot of construction was done with sod, both digging down and building up the walls. [Answer] In addition to the other answers citing construction and energy, **transportation** would also be a big problem. Early carriage wheels were made of wood, and used to transport people and goods. I don't think there would be a good alternative for early civilizations. It would also limit sailing to small rafts rather than ships. Transportation, and therefore trading, will suffer and the civilization would end up as a collection of separate settlements with no means to exchange goods and knowledge [Answer] If you have plants and a land based intelligence chances are you will eventually get wood. One of my first thoughts here was instead of going the stone route for development, go with the biological route. All technological growth is spurred by biological advantages. Then I got thinking: one of the first things I am going to do is use plants to grow together to create a living structure. Eventually this is going to lead to a wood or wood-like plant that serves so many purposes. On Earth, plant cultivation goes back well before the start of recorded history and we have been developing specialized crops for that long as well. However life that evolved in the sea is more likely to utilize chemical reactions and biological processes to develop their technologies. [Answer] If you look at history, you'll find examples of cultures in areas with little wood who found substitutes for most uses. For example, Mesopotamian cultures used sun-dried brick as their main construction material; other cultures used stone or kiln-fired brick. Northern Europe used peat and later coal as fuel, having exhausted their forests. Wood-based paper was actually a late development, replacing parchment and papyrus. But there's one exception: ## Boats The only real limitation is water travel. None of the wood-poor cultures I'm aware of built anything larger than a skin-over-frame canoe. Because of this, until your civilization is producing enough iron to make iron-hulled boats, it's likely that water travel will be limited to small-time traders and others who benefit from fast movement of small vessels. This has a surprisingly large impact on development and expansion patterns. In real-world history, the ease with which anyone could build a raft or other watercraft meant that civilization developed around rivers and seas, which provided pre-made, rapid travel routes and easy access to distant locations. Cities sprang up at the mouths of rivers; armies were moved and supplied by sea; wars were fought over control of good harbors. In your situation, none of that will happen. There will be an emphasis on land-based travel (mule trains, wagons, etc.), and the resulting focus will be on road-building and the control of land trade routes. Cities will be focused around resources and the routes between them, and you'll see wars fought over oases and mountain passes. There will be some focus on rivers as a supply of water, but the oceans and seas will be largely ignored. [Answer] One thing to add to the answers here. If there was no wood, how soon would composite materials have been developed and what could have been made from them? In the modern world these are exemplified by synthetic fibres (glass, carbon, polymer) and synthetic resins. But you could form composites from natural fibers (cotton, hemp...) and natural resins ( e.g. linseed) or animal glues. That they weren't much in evidence until recently (putty excepred) may owe a lot to the easy availability of wood. By the way you will have to decide if there is giant bamboo ( a grass!) or not. Bamboo can substitute for wood in many ways that banana leaves and palm "trees" can not. For example you can make spears, bows, arrows and multi storey housing from bamboo. In the far east they still spurn steel scaffolding poles in favour of giant bamboo and leather ties. Oh, and without wood masonry would have been much restricted. How to substitute wooden cranes and levers for manipulating large blocks of stone, or wooden scaffolding for supporting arches during their construction? (Especially if no bamboo either) [Answer] In a world in which plants had never evolved into trees, humans would have many problems to develop a favorable environment for development. Altough nowadays we could maintain most part of our technologie not using wood, it would be impossible to get this point without trees. The most important reason is that many herbivores animals feed thanks to trees. Without them, it wouldn´t have been possible that that they survive. The main consequence of it is that carnivores would also have no feed enough, so humans wouldn´t be able to eat big animals which would complicate their evolution. Moreover, the fact of not having to take food from trees or climbing them would suppose that people wouldn´t walk upright. Scientists assume that having free hands to take things was absolutely necessary to develop our brains. For all these reasons I do not only think that humanity would never have achieved our technological level, but also it wouldn´t have appeared. [Answer] I am missing cement here as possible building material that is potentially easier to work with than stone. For reference: [The book of Mormon](https://www.lds.org/scriptures/bofm/hel/3.7?lang=eng#6) Here a people is described that used a lot of cement while letting the trees grow, because there were not many trees to work with. [Answer] Some people are taking our current materials impoverishment to mean that every world is like the world we are now living in. Coal, and oil were readily available on the surface of the Earth. So much so, that in colonial times, sometimes when people started fires (of wood), they started them on top of exposed coal deposits (whoops!) First oil wells were drilled where natural seepage pooled on the surface, and made asphalt as well. Copper, and other materials (iron ore), were so readily accessible in Michigan and Minnesota that they threw off the compasses, and were exposed on the surface - ready to pick up and smelt. Of course you're going to have to get it right the first time. If you don't have a hard take-off for your civilization, they'll use the easy to get at stuff and then have no easy way to get at the harder to reach stuff. Doing mountaintop removal to get at an open-pit mine while using moose antlers (or human skulls/shoulder blades if no other large animals are available) for shovels... well, that's expensive and time-consuming. Someone else said there would be no wheels. That's not true. There would be no light-weight wheels. You'd get iron and stone wheels (think Flintstones) start with - the iron would be 'spoked' pretty quickly, not just for weight, but for materials savings. Eventually you'd get aluminium and then things would get better. Boating would be difficult. You'd eventually have concrete boats, and metal ships. But only if you've got pumice or icebergs to learn from. Removing boating does a real number on trade, and means it will be difficult to do technology except where both coal and ores are close together. Michigan and Minnesota, even with wood, still ended up shipping their raw ore to where the coal was, instead of smelting in place. Without lots of wheels, it will be difficult to come up with trains, your other big transport technology. Train track can be done with concrete railroad ties, but that's another heavy resource that can't be locally sourced, which makes train tech more costly, and harder to do. ]

[Question] [ We've all heard about the 1822 [Babbage Difference Engine](https://en.wikipedia.org/wiki/Difference_engine) and other mechanical computer ideas of the 19th century. Sadly, Babbage's computer and printer ideas were never implemented in our world†, and computers did not exist until the 1940s. Now imagine a world where this was accomplished, as was in short order his more elaborate Analytical Engine, and the industrial and mechano-computing revolutions went hand in hand. According to the [Lovelace](https://en.wikipedia.org/wiki/Ada_Lovelace) law of computation (1843), the amount of computation columns per troy pound of steel machinery doubles every 5 years. Now it is important to note that the Analytical Engine (in Babbage's theoretical machine design as well as in our alternate world's everyday practice) was what we in our world have come to call Turing complete, i.e. is a universal computer. Digital, fully programmable. Leaving aside the world-changing implications of such an advent, I'm curious to think about the limits of the 'Lovelace Law' -- **just how miniaturized and just how powerful could a mechanical computer conceivably be**, before some [Kuhnian revolution](https://en.wikipedia.org/wiki/The_Structure_of_Scientific_Revolutions) would be required, such as moving to electromechanical devices? We're not starting from a high bar. For a starting reference, the initial Analytical Engine design had the equivalent of a 16.7 kB memory, and the central processing mill *could handle a multiplication of two 20-digit numbers in about 3 minutes*. Thomas de Colmar's first arithmometer was not a general purpose computer, but could multiply two eight-digit numbers in 18 seconds. Would we be able to reach, say, 1950 era computer levels? † Outside a partial reconstruction in a museum, 170 years later [Answer] Have a look at [Rod Logic](https://web.archive.org/web/20151223111143/http://www.halcyon.com/nanojbl/NanoConProc/nanocon2.html). This is a technology that uses moving molecular rods in a solid matrix to perform logical operations by the expedient of the rods having side groups opening or closing channels. It can be implemented from the macroscopic scale (with Lego as one example) to the atomic scale. Such a nanoscale computer with a power equivalent to our silicon-based electronics would be positively tiny, on the order of cubic nanometres, and memory densities extremely high, say 10^20 bits (86.74 [exbibytes](https://en.wikipedia.org/wiki/Exbibyte) or 100 exabytes) per cubic centimetre. Power requirements would be extremely low too. This would allow the construction of personal computers of a power almost incomprehensible to us now, or manufacturing nanoscale robots that could be injected into the body to perform medical tasks. So, yes, you'd be able to reach 1950's electronic computing power - and much, much more. **EDIT** nano-scale Rod Logic is currently theoretical, but has been implemented in macro-scale using tools such as Lego. I won't go into how you'd build it, since - as with our own computers - you use the computers you have to help build the next generation in an iterative process. The logical endpoint of the development of mechanical computing is likely some variant on rod logic. There would be a lot of intermediate-capability designs between early Babbage engines and a nano-scale rod logic machine. I dare say that there are very few people who really understand how a modern CPU does what it does. [Answer] It's the other way around, If you start building mechanical computers you will stop using them to build more powerful devices as soon as electromechanical devices are invented. In other words, instead of reaching a plateau in the development of mechanical devices, you will stop using purely mechanical principles simply because YOU CAN use electromechanical ones... It's like vacuum tubes, as soon as transistors became more reliable. We stopped using vacuum tubes without testing how far we could have reached with them. At the same time, the development of mechanical computers will create a will to find more effective devices, so you might have someone inventing relays way before in our current line of time. Its too hard to calculate how powerful mechanical computers could become. To talk about this we must find what is the major factor that would limit their construction. The limiting factor for vacuum tubes was heat and reliability. They work hot, and a lot of vacuum tubes side by side will cause a lot of heat. The speed on vacuum tubes is limited because they are harder to integrate, so you have long wires running all the way around. On mechanical computers the limit is inertia, friction losses, etc. Those elements are overcome by using stronger sources of mechanical power. Mechanical power is the result (in a rotating mechanism) of torque multiplied by rpm multiplied by some constant. So more power means more torque. More torque means the materials that the computer is made out of needs to be stronger. So, the fundamental limit on computer power for mechanical computers is at the material engineering level, if we don't know yet all about materials how could we tell? TL;DR You stop using older technology not because you can't use it any more, you do so because you CAN use something better. [Answer] Well, [William McLellan](https://en.wikipedia.org/wiki/William_McLellan_%28nanotechnology%29) made a working electric motor that would fit inside a cube 1/64 inches on each side. McLellan, at that time living nearby, achieved this feat by November 1960; his 250-microgram 2000-rpm motor consisted of 13 separate parts. That was a result of a challenge made at Richard Feynman's [There's Plenty of Room at the Bottom] Lecture. [Answer] Lets assume that nano technology had advanced and the Mechanical logic gates can be constructed at a molecular level. I feel that a mechanical logic gate could be as small as one of today's transistors. There would be lots of problems like the resistance to mechanical force jamming the machine, or the force imputed being increase to deal with the depth of gates that it needs to travel, until it breaks the fragile components. But I think that these could be nutted out if it were the only viable means of computing. I think that computers 'could' be as powerful as today's computers if they were mechanical, but they would develop at a much, much slower rate. I mean, consider that we are only able to conceive the idea of nano-technology, due in part, to the convenience that electronic computing contributes to science. Without electronic computers, scientific research itself would be stunted. So how could we develop such an unviable form of computing? It's a bit of a catch-22. The technology would take a LOOOONG time to progress. [Answer] I assume that you are assuming that electricity, electronics and products produced thanks to electronics (such as nanotechnology) are unavailable, i.e. the machine needs to be powered by water or steam or something. If you can create a mechanical, clocked flip-flop then you can imagine that a mechanical computer could conceivably perform the same functions as a 1950's valve-based machine, but it would be gigantic and very slow. At a minimum, it would at least be as many times larger than the computer it duplicates, as its basic mechanical switching component is than the electronic equivalent. It would need even more space for reticulation and probably cooling. [Answer] Mechanical computers do a much better job in analog form. The mechanical digital computer was never given time to develop. They were simply obsolete by the time technology was sufficiently advanced to require them. Relay and tube computers didn't last long either. There was already a transistorized computer in 1953 - just fifteen years after the Z1, and the ENIAC was still running. Without electronics there wouldn't be much of a world to require digital computers, but in a purely mechanical world there probably would have been some clever engineering techniques to speed up mechanical calculator and do so reliably. Turbines can rotate at hundreds of thousands of rpm, so a few kFLOPS might have been eventually possible. [Answer] It would be possible construct macroscopic mechanical computers which could manipulate substantial amounts of information, but they would have to do it very slowly by modern standards. If speed were not an issue, it would not be overly difficult to design a grid of rods, each of which could be pushed in or out, along with a device which had a group of push rods used as address wires, another group used as data wires, and a "read/write indicator" push rod, and which would visit the rods indicated by the address and either move the memory rods to reflect the state of the data-bus rods, or move the data-bus rods to reflect the state of the memory rods. Given that, it would not be overly difficult to design a mechanical equivalent for something like a 6502 processor. A skillful person might even be able to hand-build such a thing at a scale that could fit on a typical table top. Using modern "macroscopic" fabrication techniques--nothing exotic beyond the ability to produce lots and lots of intricate parts--it would be feasible for someone with the time, money, and inclination to build a device which would emulate a 1980s computer, but do so very slowly. Fast memory would be expensive, but slow memory might well be about the same cost per bit as the magnetic core memory which was widely used in electronic computers until integrated-circuit memories became practical. Write-once tapes would probably have a relatively low per-bit cost, and a reel the size of a cinematic movie film reel could probably hold a few megabytes. I don't know that speeds could reach those of even 1960s computers, but storage capacities and computing power (aside from speed) could probably go well beyond what would be achievable in 1960. I'm not sure to what extent mechanical computers could play a role in mechanical manufacturing, but it would certainly seem plausible that they could do so. ]